A process for the removal of liquid, gaseous and/or dissolved constituents from a process stream. The process stream is contacted with an adsorbent comprising a first porous material which has been incorporated into a second porous material at least 30 vol. % of the pores of the first and second porous materials of which are filled with an extraction liquid. The affinity between the adsorbent and the constituents to be removed exceeds the affinity between the constituents and the extraction liquid.

1. Field of the Invention
The invention pertains to the use of an adsorbent for the removal of liquid, gaseous and/or dissolved constituents from a process stream.
2. Prior Art
The above use is generally known and widely employed in chemical engineering. One well-known example is the use of a column filled with activated carbon for the removal of, say, aromatic and/or chlorinated hydrocarbons from a process stream. Once the activated carbon in the column has become saturated, it is generally replaced by fresh activated carbon, while the saturated carbon is reactivated. Meanwhile it has been found that several synthetic adsorbents can be regenerated a number of times with, say, steam.
A major drawback to the known process is that it is susceptible to certain inorganic contaminants which are commonly found in very minute concentration, in, say, groundwater to be treated, such as compounds of iron, manganese, calcium, and magnesium which in themselves are not harmful and so do not need to be removed, yet which nevertheless, in the course of time, may lead to fouling of the adsorbent because a substantial part of its surface area will be covered with said contaminants. To overcome the aforementioned problem it has been proposed in WO 94/03249 that instead of particles having adsorbent properties, particles having extracting properties be used. The extracting particles having a particle size in the range of 0.1 to 10 mm have pores with a diameter of 0.01 to 50 μm with an extraction liquid immobilised therein.
Although better results can be achieved with these particles, especially after long-term use, than with the well-known adsorbents because of the extracting particles showing no tendency to fouling or a much lower one, the adsorption capacity of adsorbing materials, especially when the overall concentration of the constituents to be removed does not exceed more than about 100 ppm, as a rule is higher than that of the extracting synthetic particles described above. Consequently, a column containing adsorbents such as activated carbon can be much smaller in size than a column filled with extracting synthetic particles to achieve the same result. For that reason there is great need for an adsorbent which combines the advantages of a higher capacity and a lower tendency to fouling, such as is present in extracting synthetic particles.
The invention provides for the use of an adsorbent for the removal of liquid, gaseous and/or dissolved constituents from a process stream which obviates wholly or for the most part the problems which occur when using the known adsorbents.

Use of an adsorbent for the removal of liquid, gaseous and/or dissolved constituents from a process stream


With the use of a voltage across a secondary winding of a transformer, a DC output voltage and a conduction time width of a current in the DC reactor on the secondary side circuit in an immediately preceding period, the turning-on time width and the turning-off time width of a synchronous rectification MOSFET in the secondary side circuit of the transformer are obtained by calculations, without receiving any signals from a primary side circuit, to thereby carry out control of a synchronous rectification circuit in a forward DC-DC converter with the time in which a current flows in a diode reduced to the minimum.

1. Field of the Invention
The present invention relates to a DC-DC converter that converts a DC power supply voltage to produce another DC voltage insulated from the DC power supply voltage and particularly to a controller of a synchronous rectifier circuit that rectifies a voltage of a secondary winding of a transformer in the DC-DC converter.
2. Background Art
In FIGS. 6A to 6C, examples of related forward type DC-DC converter circuits are shown each of which uses a synchronous rectifier circuit using related art. FIG. 6A is a circuit diagram showing a one-transistor type DC-DC converter circuit including a main (hereinafter referred to as "primary") winding n1 and a magnetic resetting (hereinafter referred to as "tertiary") winding n3 on the primary circuit side of a transformer Tr and a synchronous rectifier circuit on the secondary winding n2 side. The circuit is that described in Japanese Patent No. 4,094,727.
In the DC-DC converter circuit, a series circuit of the primary winding n1 of the transformer Tr and a semiconductor switch (here, a MOSFET) Q1, to which a diode D1 is connected in inverse parallel, is connected in parallel to a DC power supply DP. Moreover, between the other end of the tertiary winding n3, connected in series to the primary winding n1, and the negative electrode of the DC power supply DP, a diode D2 is connected. The secondary winding n2 of the transformer Tr is connected in parallel to a series circuit in which the source terminal of a synchronous rectification MOSFET Q2, to which a diode D3 is connected in inverse parallel, and the source terminal of a freewheeling MOSFET Q3, to which a diode D4 is connected in inverse parallel, are connected. In addition, across the MOSFET Q3, a smoothing filter is connected in parallel which is formed of a series circuit of a reactor L and a capacitor C. Furthermore, across the capacitor C, a DC load LD is connected in parallel. The gate terminal of the synchronous rectification MOSFET Q2 is connected to the one end of the secondary winding n2 and the gate terminal of the freewheeling MOSFET Q3 is connected to the other end of the secondary winding n2.
In such a configuration, the turning-on of the MOSFET Q1 induces a voltage across the secondary winding n2 of the transformer Tr to allow a current to flow along a path of the reactor L→the parallel circuit of the capacitor C and the load LD→the diode D3 to supply DC electric power to the load LD, by which DC electric power is supplied to the load LD. By giving a turning-on signal to the MOSFET Q2 in this mode, the current in the diode D3 is commutated to the MOSFET Q2.
Subsequent to this, the turning-off of the MOSFET Q1 allows the excitation energy of the transformer Tr to be absorbed in the DC power supply DP through the diode D2 and the resetting winding n3. Moreover, in the circuit on the secondary winding n2 side, by turning-off the rectifying MOSFET Q2 and simultaneously turning-on the freewheeling MOSFET Q3, the current in the reactor L is brought into a freewheeling condition along a path of the parallel circuit of the capacitor C and the load LD→the parallel circuit of the diode D4 and the MOSFET Q3→the reactor L and is made reduced. This, compared with the case without the use of the MOSFETs Q2 and Q3, reduces a forward voltage drop, by which a conduction loss can be therefore made reduced.
In the driving system, the rising of the gate driving signal for each of the MOSFETs Q2 and Q3 becomes slower compared with the rising of the current in each of the rectifying diode D3 and the freewheeling diode D4. This lengthens the time in which a current flows in each of the diodes to cause small effect of loss reduction. For solving the disadvantage, in the circuit described in Japanese Patent No. 4,094,727, a PLL (Phase-locked-loop) circuit is used to generate a signal with the phase thereof leading to the phase of the voltage across the secondary winding n2 of the transformer Tr for being served as the driving signal of the MOSFET.
FIG. 6B is a circuit diagram showing the circuit described in JP-A-11-206118 as an example of related art. The circuit has a configuration in which from a control circuit of a gate driving signal for the primary side MOSFET Q1, an additional signal is transmitted to the secondary winding n2 side of a transformer Tr through a signal insulating transformer Trx and a gate driving circuit GD1 to be applied as a driving signal to the gate of a MOSFET Q3 connected in inverse parallel to a freewheeling diode D4. The driving signal, compared with the rising of the voltage across the secondary winding n2 of the transformer Tr, has a rising in a leading phase. Thus, compared with the example of the related circuit shown in FIG. 6A, the time in which a current flows in the diode D4 can be reduced to reduce a conduction loss.
FIG. 6C is a circuit diagram showing the circuit described in Japanese Patent No. 3,991,785 as an example of related art. On the secondary winding n2 side of the transformer Tr, in parallel to the MOSFET Q2, a gate driving circuit GD3 is connected which detects the direction of a current to drive the MOSFET Q2 and, in parallel to the MOSFET Q3, a gate driving circuit GD2 is connected which is identical to the gate driving circuit GD3. The gate driving circuits GD2 and GD3 have the circuit configurations identical to each other. The gate driving circuits GD2 and GD3 detect that the cathode potentials of the diode D4 and D3 lower compared with the anode potentials thereof when currents begin to flow in the forward directions of the diodes D4 and D3 so as to immediately apply driving signals to the gates of the MOSFETs Q3 and Q2, respectively. The circuit has the advantage of requiring no insulating transformer to simplify the circuit configuration compared with the circuit shown in FIG. 6B.    Patent Document 1: Japanese Patent No. 4,094,727    Patent Document 2: JP-A-11-206118    Patent Document 3: Japanese Patent No. 3,991,785
As was explained in the foregoing, the synchronous rectifier circuits have various kinds of configurations in their driving systems. For improving the conversion efficiency of a synchronous rectifier circuit, it is important to shorten the time to the utmost in which a current flows in the forward direction of a diode and to interrupt a reverse current at the switching of a diode and a feedthrough current of a MOSFET. Thus, it is necessary to optimize the timing of making the MOSFETs in the synchronous rectifier circuit turned-on and -off.
In the example of the related synchronous rectifier circuit shown in Patent Document 1, the use of the PLL circuit providing phase lead of the voltage across the winding of the transformer enables synchronous rectification with high conversion efficiency. However, the PLL circuit causes a delay of more than one period in the response thereof, which makes it impossible for the PLL circuit to respond to an abrupt variation in an input voltage or in a load to result in an increase in a loss.
In the example of the related synchronous rectifier circuit shown in FIG. 6B, a transformer is required for insulating a signal in the primary side circuit from the secondary side circuit, which increases the number of parts and the area of surface mounting. In the example of the related synchronous rectifier circuit shown in FIG. 6C, when change in current with respect to time di/dt ("i" represents a current and "t" represents time) is large, delay in detection is caused which produces a flow of a reverse current or a feedthrough current to lower the conversion efficiency of the circuit.
Accordingly, it is an object of the invention to provide a forward DC-DC converter to which a driving circuit is applied that can reduce a loss in a secondary synchronous rectifier circuit without receiving any signal from a primary circuit.


A beam terminator for a high-power laser beam comprises a thermally conductive body including a beam-trapping chamber. A tapered spiral channel extends into the conductive body for guiding the beam. The beam is partially absorbed while propagating along the channel to the trapping chamber. What remains of the beam is absorbed in the trapping chamber.

High-power solid-state lasers that deliver very high intensity beams for laser machining operations, after being turned on can take up to 5 minutes to reach a stable operating condition. Accordingly during any relatively brief period between operations it is preferable not to turn the laser off. During this period the beam must be terminated, safely, at something other than a work-piece. The beam is terminated at what is usually termed a beam-dump, a beam-terminator or a beam-trap by practitioners of the art. A high-intensity, repetitively pulsed laser beam can reach an average power level from a few hundred (W) to several kilowatts (kW). This makes the design of a beam-terminator very challenging.
Several forms of beam terminators are described in the prior-art. By way of example, U.S. Pat. No. 4,864,098 discloses a beam dump in the form of a cone structure. When such a structure is used with a very high intensity beam, however, the tip of the cone can melt due to a large heat concentration. A simple multiple reflection beam dump arrangement is disclosed in U.S. Pat. No. 5,237,454. This structure arrangement is also susceptible to damage by a high-intensity beam as there is necessarily some beam absorption at each reflection and the first reflection is at near-normal incidence. U.S. Pat. No. 6,792,017 discloses an arrangement wherein a laser beam is trapped by a plurality of absorbing plates in an enclosure through which a cooling fluid is circulated. The beam accesses the enclosure through an optical window. While this arrangement is apparently relatively compact and effective in beam termination, the window could quickly become contaminated in an industrial environment. The contamination would absorb the laser beam which could lead to a run-away absorption condition with a risk of the window breaking and leaking cooling fluid.
It is believed that none of the prior art beam-terminating arrangements is practical for industrial or commercial use with very-high power beams. There is a need for a compact, efficient beam-terminator that has a minimum of operational components and is suitable for use in an industrial environment.

Beam dump for a very-high-intensity laser beam


A hot runner nozzle assembly includes a nozzle heater, a hot runner nozzle, a nozzle tip, a nozzle tip seal surrounding the nozzle tip and a connecting element positioned to removably couple the tip seal to the nozzle tip and to create a first contact seal between the nozzle tip and the tip seal and a second annular contact seal between the tip seal and a mold component. The nozzle tip is made or shaped via a sintering process from a metal matrix composite (MMC) material having a first coefficient of thermal expansion. The tip seal is made or shaped from a ceramic based powder material, having a second coefficient of thermal expansion that is different from the first coefficient of thermal expansion. In operation this hot runner nozzle assembly provides an improved heat profile and a reduced leakage at the tip area under a wider operating processing window.

Hot runner injection nozzles are known. These nozzles are made of several parts designed to meet injection molding operating conditions for various materials and for various applications. These parts are made of various materials that need to be manufactured with high accuracy, low tolerances and also configured to be machine-able with available manufacturing equipment. These hot runner nozzles and the associated parts need to be designed and made to be easy to assemble and service in the field.
An area at the end of the nozzle is the nozzle tip area, which is proximate to the mold gate. In this area the injection pressure is very high. Nozzle tips are known and they are in many cases attached to the body of the nozzle in the nozzle tip area.
The nozzle tips sometimes have to be made of materials having conflicting properties or characteristics. If they are made of highly conductive materials, these materials are in many cases not very wear resistant. Many of the materials that can be used for the nozzle tips used in hot runner nozzles and that have good wear resistance have low thermal conductivity.
In many hot runner nozzle applications there is a need to use nozzle tip connectors, nozzle tip seals and nozzle tip insulators that have to cooperate with the nozzle tips and operate and perform together as a unit.
Because the nozzle tips and the tip seals are made of different materials and because they have a different thermal conductivity and a different coefficient of thermal expansion at the injection molding processing temperatures, there is always a concern with the known tips and seals regarding two types of leakage caused by the injection pressure of a molten material into a mold cavity through the nozzle tips. A first leakage, that sometimes is harder to contain, can appear between an outer surface of the tip and an inner surface of the tip seal. A second more common leakage can appear between an outer surface of the tip seal and a wall of a mold component adjacent the mold gate contacting the outer surface of the tip seal. Other leakage paths can further appear between other cooperating surfaces of the nozzle tip and tip seal that have small gaps caused by manufacturing errors or thermal expansion.
There is a need to design and manufacture hot runner nozzles and hot runner nozzle tips that have improved features and good thermal and wear resistance properties.
There is a need to design and manufacture nozzle tips, nozzle tip connectors, nozzle tip seals and nozzle tip insulators that have improved features and characteristics to better cooperate with the nozzle tips and better operate and better perform together as a unit.
There is a need to design and manufacture nozzle tips, nozzle tip connectors, nozzle tip seals and nozzle tip insulators where the first leakage and the second leakage are contained for long hours of operation of the hot runner nozzle.

Injection nozzle with multi-piece tip portion


A subject for the invention is to provide a low-cost heat-resistant filter element produced from polyethylene particles which is for use in separating and collecting particles from a dust gas, can be continuously used even in a high-temperature environment of about from 70° C. to 130° C., especially from 90° C. to 110° C., is excellent in chemical resistance, and has flexibility and excellent suitability for mass production. Another subject is to provide processes by which the heat-resistant filter element can be produced at a reduced equipment cost while taking care of the environment. In the invention, a coating layer of a fluororesin was formed on a surface of a permeable porous molding obtained from particles of a resin composition containing a polyethylene as a main component of a resin ingredient and from 0.1 to 3 parts by weight of an antioxidant per 100 parts by weight of the resin ingredient by fusion-bonding the particles to one another at the surface thereof.

Techniques heretofore in use for collecting dusts generating in factories, when the dusts are products or are to be collected, for example, in order to preserve the working environment, employ a bag filter obtained by knitting glass fibers or fibers made of a heat-resistant synthetic resin to obtain a filter fabric and sewing the fabric into a bag, a felt filter fabric, or a self-supporting filter medium, i.e., a filter element, obtained by sintering a ceramic or synthetic resin powder into a permeable porous object. There also are cases where dusts are collected with an electric dust collector.
Filter elements of that type which have been proposed include one produced by sintering a synthetic resin powder into a self-supporting filter element (see JP-B-Hei. 1 (Sho. 64)-5934) and one produced by sintering a powder of polyethylene, polypropylene, or the like and coating a surface of the sinter with polytetrafluoroethylene particles together with an adhesive (see JP-B-Hei. 2-39926).
However, there are cases where the bag filter constituted of a heat-resistant filter fabric leaks dust particles because the weave texture of the fabric is course. On the other hand, the felt fabric is gradually clogged and comes to have increased air-flow resistance, resulting in the necessity of an increased power for the air blower. It further has a drawback that when the dust collected is removed by back washing, the filter fabric may be damaged by friction with the retainer (filter fabric shape retainer). The dust collection with a ceramic sinter or electric dust collector necessitates a high equipment cost because it is expensive.
Furthermore, the filter element obtained by sintering a synthetic resin powder, when the ambient temperature rises to 70 to 90° C. or higher, begins to change in material and becomes difficult to use as a filter, although it undergoes no change in material and withstands use at around ordinary temperature. The heat resistance may be improved by using a heat-resistant resin such as a polysulfone or the like as a synthetic resin powder. However, such a heat-resistant resin is not always sufficient in resistance to chemicals and mechanical strength, and use thereof results in an increased cost because the material itself is expensive.
A first object of the invention is to provide a low-cost heat-resistant filter element produced from polyethylene particles which is for use in separating and collecting particles from a dust gas, can be continuously used even in a high-temperature environment of about from 70° C. to 130° C., especially from 90° C. to 110° C., is excellent in chemical resistance, and has flexibility and excellent suitability for mass production.
A second object of the invention is to provide processes by which the heat-resistant filter element can be produced at a reduced equipment cost while taking care of the environment.

Heat-resistant filter element and method for production thereof


A method for pre-segmenting a large tree or treetable for purposes of visualization and deeper exploration of individual nodes, with the segments sized so as to allow inclusion of at least some amount of content-indicative text for each node. This invention pre-partitions a tree or treetable into segments of related nodes whose approximate maximum dimension permits significant text to be presented for each node. The segments can be visually differentiated in an outline depiction of the tree or treetable as a whole, and individual segments then extracted for deeper exploration. The segments may also be constrained to represent only nodes within the same logical grouping, which may be an identified subtopic, or collection of less-focused material, or other type of grouping. When the segments are so constrained, regions of adjacent segments associated with each such grouping can also be visually differentiated from other such regions.

The present invention relates generally to the field of information analysis and display. More specifically, it provides methods for partitioning tree-structured textual material into topically related clusters of adjacent items, then developing digests of each cluster. The digests include both shorter overviews and arbitrarily long summaries. The tree-structured material involved could be for example, but is not limited to, trees containing the messages and postings of an archived discussion within a newsgroup, discussion list, or on-line forum. This invention also provides methods for partitioning a two-dimensional tree visualization, called a treetable, into conveniently sized segments for detailed exploration. The segments may be grouped into regions corresponding to the topically related clusters.
To establish some terminology, a "tree" or "tree structure" is a standard term denoting an abstract data structure that models information as a set of nodes connected by directed edges such that: (a) there is exactly one element having no incoming edges, called the "root"; and (b) all other nodes have exactly one incoming edge. A leaf node is a node with no outgoing edges. All nodes besides the root node and the leaf nodes can be called "interior nodes". The "parent" of a node is the source of its incoming edge, and the "children" of a node are the targets of its outgoing edges. A "subtree" of a tree is a set of nodes consisting of a "subtree root" node that has no parent in the subtree, and other nodes all having parents in the subtree.
The present invention is intended for use in connection with tree structures whose interior nodes represent substantial amounts of logically related textual information. For example, in the tree-structures formed by archived discussions, the nodes represent individual messages or contributions, and a message represented by a child node is a response to the message represented by its parent. The creation of the parent-child links in archived discussions can be established by a combination of conventional means utilizing header information, and deeper means, as described in U.S. patent application Ser. No. 09/732,024, titled "Method and System for Presenting Email Threads as Semi-connected Text by Removing Redundant Material", by Paula Newman and Michelle Baldonado, incorporated by reference hereinabove.
Tree-structured archived discussions on a particular subject are usually represented for exploration by indented lists. Each contribution is represented by some identification information, such as contributor name and date, indented under the identification information for its parent. The individual contributions may then be accessed for reading by selecting one of the list items. However, archived discussions pay varying amounts of attention to the ostensible subject and initial contribution, and often branch into several subtopics, so the reader cannot assume, based only on the ostensible subject, whether any portion of the discussion is actually of interest, and, if so, what parts of the discussion. A more informative representation of the overall content of an archived discussion is described in U.S. patent application Ser. No. 09/732,029, titled "Method and System for Display of Electronic Mail, by Paula Newman, incorporated by reference hereinabove. In that representation, initial substantive fragments of each contribution, containing actual text of the message rather than quotes or quote introduction, are embedded within a reduced-width linear tree tailored to text embedding. This representation is suitable as a level of presentation of the discussion, and also as the content of an emailed digest summarizing activity in the discussion list, or as a client side digest of such activity. Client-side accumulation of email from discussion lists, involving concatenating, or sampling, messages from all mail received in a particular period, is introduced in U.S. patent application Ser. No. 09/717,278, titled "Systems and Methods for Performing Sender-Independent Managing of Electronic Messages, by Michelle Baldonado, Paula Newman, and William Janssen, incorporated by reference hereinabove.
Yet another method of representing the overall content of an archived discussion is described in U.S. patent application Ser. No. 09/954,388, titled "Method and Apparatus for the Construction and use of Table-like visualizations of Hierarchic Material, by Paula Newman and Stuart Card, and U.S. patent application Ser. No. 09/954,530, titled "Method and Apparatus for the Viewing and Exploration of the Content of Hierarchical Information, by Paula Newman and Stuart Card, both incorporated by reference hereinabove. In this method, the conversation tree is presented in a two dimensional tabular form called a "treetable". In such a treetable, each cell represents a single node and exactly spans the cells representing its children if any, and a substantive initial fragment of the message associated with the node is displayed in the cell, to the extent that space allows. The individual columns and subtrees of the treetable may be selected for expansion (reducing other parts of the tree), to view more of the associated texts, and the full texts of each column may be selected for display in auxiliary windows or frames. (Note that a similar representation is described in an article entitled "Structured Graphs: a visualization for scalable graph-based case tools" by M. Sifer and J. Potter, in the Australian Computer Journal, Volume 28 Number 1, and also in later papers authored by M. Sifer and other colleagues, but in these references the potential of the structure is not exploited for purposes of exploring trees whose nodes have associated significant text.)
While the latter two methods (reduced-width linear trees and treetables) with embedded initial fragments are useful methods of providing overviews for smaller discussions and other tree-structured textual material, they are less useful for larger discussions. For example, for a stored conversation consisting of 93 messages, a reduced-width linear tree containing initial fragments requires over 11 standard-size display windows. Alternatively, if such a conversation is represented in a treetable that can be contained in a single window, the cells are too small to contain any indicative content, and there are too many columns to expand individually to determine if there is content of interest.
Therefore, more accessible digests of such larger discussions are needed. Current approaches to text processing address some related problems. Methods have been developed for segmenting individual documents into extents dealing with different approximate subtopics, and for identifying the topics covered by the most indicative words, as described in U.S. patent application Ser. No. 10/103,053, titled "Systems and Methods for Determining the Topic Structure of Portion of a Text" by loannis Tsochantaridis, Thorsten Brants, and Francine Chen, incorporated by reference hereinabove. Methods have also be developed for summarizing identified topic extents by collections of extracted sentences, and for associating summary elements with the text extents covered, as described, for example, in a paper by Branimir Boguraev and Mary Neff entitled "Discourse Segmentation in Aid of Document Summarization", in the Proceedings of the Hawaii International Conference on System Sciences (2000). Methods have also been developed for summarizing collections of separate documents by grouping them by topic, generally using centroid-based clustering methods, and then extracting sentences dealing with each topic. An example of such an approach is described by Dragomir Radev, Hongyan Jing, and Malgorzata Budzikowska in the paper "Centroid-based summarization of multiple documents: sentence extraction" in the Proceedings of the ANLP/NAACL 2000 Workshop on Automatic Summarization (Seattle, Wash., April 2000) pages 21-29. However, tree-structured discussions are neither single documents nor collections of independent documents, and specialized methods are needed for their segmentation and summarization.
Two limited approaches seem to have been developed, to date, relating to segmenting tree-structured discussions, but none, as far as can be ascertained at this time, to summarizing those discussions. A paper by K. Tajima, Y. Mizuuchi, M. Kitagawa, and K. Tanaka entitled "Cut as a querying unit for WWW, Netnews, and E-mail", in the Proceedings of the 9th ACM Conference on Hypertext and Hypermedia (1998) descries a method for identifying overlapping subtrees of a discussion as units of information retrieval, to put retrieved messages into a useful context. The clustering method processes the thread tree bottom-up and, at each step, combines a parent with currently open child subtrees, separately or together, if the similarity between the parent word vector and the centroid vector of the child subtree or subtrees exceeds an (unspecified) absolute input threshold. The word vectors used to represent the vectors handle quoted passages by reducing the weights of quoted words, in order to keep inter-message distances from being too small. While no results are given, if the threshold is set relatively high, this method would probably lead to shallow subtrees, suitable as query results. However, it is unlikely that the method would lead to clustering results suitable for subtopic identification or digesting. Based on our experiments, quoted words require more detailed treatment, and some trials of a similar single-link clustering method using distances between a node and the centroid of an adjacent cluster produced unsatisfactory results.
Another approach related to discussion tree segmentation is described in a paper by H. Ozaku, K. Uchimoto, M. Murata, and H. Isahara entitled "Topic Search for Intelligent Network News Reader HISHO", in the Proceedings of the 2000 ACM Symposium on Applied Computing. This paper describes a method for retrieving many discussions relating to a query topic, and then attempting to filter out discussion subtrees irrelevant to the topic. The method uses, for the most part, noun keywords to represent messages, and tries to find "topic changing articles" where the proportion of never-seen-keywords shifts, and "topic branching articles" where a message gives rise to several responses distinguished by their keyword usage and their referenced quotes. This strategy is reported as of limited success in finding topic-changing articles (recall=57%) and larger success in finding topic branching articles.
The present invention incorporates methods of dividing a tree-structured discussion into major subtopics, and of developing digests containing segments for each such subtopic. Two types of digests are developed, that may be inspected in sequence. Shorter digests, which we will call "overviews", choose a set of texts in each subtopic based on topic-relevance and potential for providing coherent sequences, and represent each such text by one or more extracted sentences. Potentially longer digests, which we will call "summaries", choose a set of extracted sentences representing a proportion of the text associated with a subtopic, by a combination of features resting on inherent properties of the sentences, and on the content of a developing summary.
The present invention also provides methods for pre-segmenting a large tree or treetable for purposes of visualization and deeper exploration of individual nodes, with the segments sized so as to allow inclusion of at least some amount of content-indicative text for each node. There have been many approaches developed to allow investigation of detailed areas of large visualizations, usually distinguished as either "fisheye" approaches, that expand part of visualization at the expense of other parts, or "focus plus context" approaches that extract and expand part of visualization into another window. Some examples of these approaches as applied to trees and treetables are: (a) in-situ expansions of nodes in the neighborhood of a selected node within a "Degree of Interest Tree", described in U.S. patent application Ser. No. 09/747,634, titled "System and Method for Browsing Node-Link Structures Based on Estimated Degree of Interest, by Stuart Card, incorporated by reference hereinabove, (b) in-situ expansion of treetable columns and complete subtrees (all nodes descended from a given node, and extraction of sets of columns and complete subtrees into another window, as described in U.S. patent application Ser. No. 09/954,388, titled "Method and Apparatus for the Construction and use of Table-like visualizations of Hierarchic Material, by Paula Newman and Stuart Card, incorporated by reference hereinabove, and (c) iterative restriction of the display to subtrees or user-defined sets of nodes, is provided in a treetable-like visualization described in the papers "The SGF metadata framework and its support for social awareness on the World Wide Web", by O. Liechti et.al. in World Wide Web (Baltzer), 1999. 2(4., and "M. Sifer and O. Liechti, "Zooming in One Dimension Can Be Better Than Two: An Interface for Placing Search Results in Context with a Restricted Sitemap" by M. Sifer and O. Liechti, In Proceedings of the 1999 IEEE Symposium on Visual Languages (Tokyo, Japan) 72–79.
These methods all have some problems when used in connection with large trees. In-situ expansion of neighborhoods, columns, or subtrees can be disorienting when the expanded nodes are to contain significant amounts of text, because the shape of the tree changes dramatically, and little space is left for unexpanded nodes. Also, for large trees, subtree extraction (or restriction of the display to a subtree) tends to be an iterative process. This may be suitable when the tree represents a generalization hierarchy, so that higher level nodes provide good cues as to the content of lower level ones, but not otherwise, for example when the trees represent discussions, or the network of linked nodes on a website, reduced to a tree by removing cyclic paths. Finally, leaving the specification of sets of nodes to be extracted to users is problematic both because it is laborious, and because successive extractions are still generally needed to make sufficient node-identification information visible to permit an intelligent selection.
For this reason, the methods provided in this invention pre-partition a tree or treetable into segments of related nodes whose approximate maximum dimension permits significant text to be presented for each node. The segments can be visually differentiated in an outline depiction of the tree or treetable as a whole, and individual segments then extracted for deeper exploration. The segments may also be constrained to represent only nodes within the same logical grouping, which may be an identified subtopic, or collection of less-focused material, or other type of grouping. When the segments are so constrained, regions of adjacent segments associated with each such grouping can also be visually differentiated from other such regions.
The method for partitioning is related to, but different from, the large body of work on partitioning graphs (collections of nodes linked by edges, but not necessarily hierarchic) into a roughly equal-size subgraphs, given either the number of subgraphs to be found or a maximum size per subgraph, and possibly some additional constraints on the subgraphs, with the purpose being to minimize the number of edges between subgraphs. Much of the work derives from an algorithm described by B. W. Kernighan and S. Lin in the paper "An efficient heuristic procedure for partitioning graphs", in The Bell System Technical Journal, 49(2) 1970, in which a greedy algorithm obtains an initial partitioning, and then nodes are iteratively moved among subgraphs to improve the quality of the partition. Such methods have applications in VLSI design, distribution of processes and data among processors, and sparse matrix representations. The problem addressed by the methods of the present invention is different, in that the permissible subgraphs are far more constrained; subgraphs must represent either subtrees or sets of subtrees whose roots have a common parent (and sometimes are part of the same logical grouping), and must largely respect a given layout dimensionality. This, in turn, permits the careful initial partitioning algorithm described in this invention to be sufficient to the purpose.
Further advantages of the invention will become apparent as the following description proceeds.

Method and apparatus for segmenting hierarchical information for display purposes


A method for managing physical-to-logical address information in a memory system includes determining whether a memory fragment of a memory block is a last memory fragment of the memory block. The method also includes, in response to a determination that the memory fragment is not the last memory fragment of the memory block: performing a write operation on the memory fragment; storing, in cache associated with the memory system, physical-to-logical address information associated with the memory fragment; and, in response to a determination that the cache is full, writing, to a next memory fragment of the memory block, control metadata associated with physical-to-logical address information stored in the cache.

Non-volatile memory systems are a type of memory that retains stored information without requiring an external power source. Non-volatile memory is widely used in various electronic devices and in stand-alone memory devices. For example, non-volatile memory can be found in laptops, digital audio player, digital cameras, smart phones, video games, scientific instruments, industrial robots, medical electronics, solid-state drives, USB drives, memory cards, and the like. Non-volatile memory can be electronically programmed/reprogrammed and erased.
In such memory systems, memory management operations, such as garbage collection (e.g., compaction), are typically performed in order to reclaim memory that may include old or stale data. This may free up reclaimed memory for reprogramming and may generally improve memory performance. Memory systems use memory address information to identify and/or locate memory for garbage collection operations. Typically, such memory address information includes physical-to-logical address information, which indicates a mapping between physical addresses of the memory to logical address of the memory. Such memory address information is typically stored in a table in memory of the memory system, which may require an undesirable amount of memory.

Systems and methods for managing physical-to- logical address information


The present invention relates to the field of molecular imaging, i.e. nuclear and fluorescent imaging using metal ion radionuclides in combination with chelates highly functionalized with peptidic, nonpeptidic or protein ligands or additional signalling moieties.

Metal radionuclides are frequently used in nuclear imaging and therapy. Fluorescently labelled ligands are commonly used for optical imaging in animal models or in vivo imaging during i.e. surgical interventions. Related tracers are usually formed from a metal binding group (chelate ligand) or fluorescent units and moieties, which are bound, with or without linkers, to one or more targeting vectors.

Currently, DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) is the most frequently used compound for the purpose of nuclear imaging with radiometals. It forms stable complexes with many transition metal ions as well as lanthanide ions. Very frequently, one of the acetic acid side arms of this molecule is used to for conjugation of DOTA to the targeting vector resulting in the formation of an amide. For imaging purposes, the metal ion is finally added in the last step, thereby forming the complex which serves as the tracer or radiopharmaceutical. Particularly for complexation of lanthanide ions, the most established chelators are DOTA and derivatives of this structure, such as 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (DO3A). For smaller metal ions such as Ga(III), bifunctional chelators based on the 1,4,7-triaza-1,4,7-triacetic acid (NOTA) structural motif, such as NODAGA (1,4,7-triaza-1-glutaric acid-4,7-diacetic acid), have recently gained popularity because the resulting complexes are more thermodynamically stable and are formed more easily.
All of these chelators bind the radioactive metal ion by coordination on the nitrogen atoms of the azamacrocycle backbone and on the deprotonated carboxyl groups of the acetic acid substituents. These carboxylic acid moieties thus have to be deprotonated in order to act as coordination sites, which is why a pH value exceeding their pKa of approx. 3.5-4.5 must be maintained during the labelling procedure. Labelling at a lower pH is substantially hampered. In case of the radionuclide 68Ga(III) this is somewhat contradictory due to the fact that at pH>3, formation of colloidal Ga(OH)3 commences which is also inhibiting the complex formation. For labelling of all iminopolyacetic acid ligands, like the above mentioned ones, a careful adjustment of pH value to 3-3.5 is thus mandatory. In addition, labelling of DOTA-like structures requires either heating, usually up to 80-95° C., or comparably high ligand concentrations, in the range of for example 1 mM.
In order to prepare bioconjugates of chelators, that is, molecules consisting of a targeting vector covalently bound to a chelating unit, the use of protecting groups on either side is mandatory in most cases according to the prior art. Particularly in case of DOTA or DO3A, the carboxylate moieties intended for metal complexation are often protected during amide coupling, see for example Schottelius M, Schwaiger M, Wester H J. Rapid and high-yield solution phase synthesis of DOTA-Tyr3-octreotide and DOTA-Tyr3-octreotate using unprotected DOTA. Tetrahedron Lett. 2003, 44 (11), 2393-2396. Tris-tert-butyl esters of these compounds are thus employed for conjugation. In most cases, an additional subsequent deprotection step is necessary in order to obtain the desired fully deprotected bioconjugate.
In the context of bioconjugates, the term multimer refers to molecules which comprise more than one targeting vector of the same kind. Multimers are desirable because in comparison to monomers, they can exhibit increased affinity to the respective target, thus often resulting in higher target uptake, higher target/background ratios, and thus better images. For preparation of multimeric radiometal tracers, DOTA-like chelators are usually bound to a linker which allows more than one targeting vector to be bound. The assembly of such molecules usually involves multistep syntheses with low overall yield. In addition and especially in the case of Ga-68 labelled peptides, two carboxylic groups of DOTA have been used for the formation of dimers by amide formation.
Combination of more than one imaging modality is usually referred to as multimodal imaging. Imaging technologies that can be combined include positron emission tomography (PET), single photon emission computed tomography (SPECT), planar scintigraphy, fluorescence imaging, magnet resonance tomography (MRT), optical imaging (either fluorescence or bioluminescence imaging) and combinations thereof, i.e. PET/CT and PET/MRT. To perform multimodal imaging, tracers are required possessing more than one reporter unit, e.g. combining the presence of a chelate unit for radiometals (for e.g. PET) with a so called fluorophor (for fluorescence). For such an approach, the presence of targeting vectors in the same molecule is, however not mandatory, still necessary for functional imaging.
Recently, a novel chelating unit based on 1,4,7-triazacyclononane, PrP9 (I), has been introduced, see for example Notni J., Hermann P., Havlickova J., Kotek J., Kubicek V., Plutnar J., Loktionova N., Riss P. J., Rosch F., Lukes I., A Triazacyclononane-Based Bifunctional Phosphinate Ligand for the Preparation of Multimeric Ga-68 Tracers for Positron Emission Tomography. Chemistry—A European Journal. 2010; 16(24):7174-7185.

3PrP9 (I) is particularly suitable for complexation of smaller radiometal ions, such as 68Ga3+. In contrast to the above mentioned chelators bearing carboxylates, phosphinic acid moieties exhibit pKa values below 1. Thus, labelling can be performed at pH<2, thus circumventing formation of colloids.

Triazacyclononane-based phosphinate ligand and its use for molecular imaging


The present invention provides formulations and methods to enhance the delivery of nucleic acids to cells. Formulations comprising dextrin polymers in combination with sugars provide enhanced delivery of nucleic acids, particularly eucaryotic expression vectors, demonstrate enhanced delivery of nucleic acids to cells in vivo. The present invention also provides methods of treatment in combination with such formulations.

Many methods have been developed over the last 30 years to facilitate the introduction of nucleic acid into cells which have greatly assisted, inter alia, our understanding of the control of gene expression.
Conventional methods to introduce DNA into cells are well known in the art and typically involve the use of chemical reagents, cationic lipids or physical methods. Chemical methods which facilitate the uptake of DNA by cells include the use of DEAE-Dextran (Vaheri and Pagano, Science 175:434). DEAE-dextran associates with and introduces the DNA into cells. However this can result in loss of cell viability. Calcium phosphate is also a commonly used chemical agent which, when co-precipitated with DNA, introduces the DNA into cells (Graham et al Virology (1973) 52: 456).
The use of cationic lipids (e.g. liposomes (Felgner (1987) Proc.Natl.Acad.Sci USA, 84:7413) has become a common method since it does not have the degree of toxicity shown by the above described chemical methods. The cationic head of the lipid associates with the negatively charged nucleic acid backbone of the DNA to be introduced. The lipid/DNA complex associates with the cell membrane and fuses with the cell to introduce the associated DNA into the cell. Liposome mediated DNA transfer has several advantages over existing methods. For example, cells which are recalcitrant to traditional chemical methods are more easily transfected using liposome mediated transfer.
More recently still, physical methods to introduce DNA have become effective means to reproducibly transfect cells. Direct microinjection is one such method which can deliver DNA directly to the nucleus of a cell (Capecchi (1980) Cell, 22:p 479). This allows the analysis of single cell transfectants. So called "biolistic" methods physically insert DNA into cells and/or organelles using a high velocity particles coated with DNA (Neumann (1982) EMBO J, 1:841).
Electroporation is arguably the most popular method to transfect DNA. The method involves the use of a high voltage electrical charge to momentarily permeabilise cell membranes making them permeable to macromolecular complexes. However physical methods to introduce DNA do result in considerable loss of cell viability due to intracellular damage. These methods therefore require extensive optimisation and also require expensive equipment.
More recently still a method termed immunoporation has become a recognised techinque for the introduction of nucleic acid into cells, see Bildirici et al Nature (2000) 405, 298. The technique involves the use of beads coated with an antibody to a specific receptor. The transfection mixture includes nucleic acid, typically vector DNA, antibody coated beads and cells expressing a specific cell surface receptor. The coated beads bind the cell surface receptor and when a shear force is applied to the cells the beads are stripped from the cell surface. During bead removal a transient hole is created through which nucleic acid and/or other biological molecules can enter. Transfection efficiency of between 40–50% is achievable depending on the nucleic acid used.
Typically, gene therapy involves the transfer, and optionally the stable insertion, of new genetic information into cells for the therapeutic treatment of disease. Genes that have been successfully expressed in mice after transfer by retrovirus vectors include human hypoxanthine phosphoribosyl transferase (Miller A et al, 1984, Science 255:630). Bacterial genes have also been transferred into mammalian cells, in the form of bacterial drug resistance genes.
Transformation of hematopoietic progenitor cells to drug resistance by eukaryotic virus vectors has also accomplished with recombinant retrovirus based vector systems (Hock R A and Miller A D 1986, Nature 320:275–277; Joyner, et al. (1983) Nature 305:556–558; Williams D A et al 1984, Nature 310:476–480; Dick J E et al, 1985, Cell 42:71–79); Keller G et al 1985, Nature 318: 149–154; Eglitis M et al, 1985, Science 230: 1395–1398). Adeno-associated virus vectors have been used successfully to transduce mammalian cell lines to neomycin resistance (Hermonat P L and Muzyczka N, 1984, supra; Tratschin J D et al, 1985, Mol. Cell. Biol. 5:3251). Other viral vector systems that have been investigated for use in gene transfer include papovaviruses arid vaccinia viruses (See Cline, M L (1985) Pharmac. Ther. 29: 69–92).
The main issues with respect to gene therapy relate to the efficient targeting of nucleic acid to cells and the establishment of high level transgene expression in selected tissues. A number of methodologies have been developed which purport to facilitate either or both of these requirements. For example, U.S. Pat. No. 6,043,339 discloses the use of signal peptides which when fused to nucleic acid, can facilitate the translocation of the linked nucleic acid across cell membranes. U.S. Pat. No. 6,083,714 discloses a combined nucleic acid and targetting means which uses the polycation poly-lysine coupled to an integrin receptor thereby targetting cells expressing the integrin. EP1013770 discloses the use of nuclear localisation signals (NLS) coupled to oligonucleotides. The conjugate may be covalently linked to vector DNA and the complex used to transfect cells. The NLS sequence serves to facilitate the passage of the vector DNA across the nuclear membrane thereby targetting gene delivery to the nucleus.
Nucleic acid, for example vector DNA, may be introduced into an animal via a variety of routes including enterally (orally, rectally or sublingually) or parenterally (intravenously, subcutaneously, or by inhalation).
It is known that introduction of certain aqueous solutions into the peritoneal cavity can be useful in the treatment of patients suffering from renal failure. Such treatment is known as peritoneal dialysis. The solutions contain electrolytes similar to those present in plasma; they also contain an osmotic agent, normally dextrose, which is present in a concentration sufficient to create a desired degree of osmotic pressure across the peritoneal membrane. Under the influence of this osmotic pressure, an exchange takes place across the peritoneal membrane and results in withdrawal from the bloodstream of waste products, such as urea and creatinine, which have accumulated in the blood due to the lack of normal kidney function. While this exchange is taking place, there is also a net transfer of dextrose from the solution to the blood across the peritoneal membrane, which causes the osmolality of the solution to fall. Because of this, the initial osmolality of the solution must be made fairly high (by using a sufficiently high concentration of dextrose) in order that the solution continues to effect dialysis for a reasonable length of time before it has to be withdrawn and replaced by fresh solution.
Other osmotic agents have been proposed for use in peritoneal dialysis and in recent years dextrin (a starch hydrolysate polymer of glucose) has been used. When instilled in the peritoneal cavity, dextrin is slowly absorbed via the lymphatic system, eventually reaching the peripheral circulation. The structure of dextrin is such that amylases break the molecule down into oligosaccharides in the circulation. These are cleared by further metabolism into glucose.
Typically, a medium chosen to introduce gene therapy materials to a patient via a body cavity might be a buffered saline solution, for instance, phosphate buffered saline (PBS).
Dextrin solutions have been proposed as the medium for delivery of drugs to the body via the peritoneum. In GB-A-2207050, such a solution is proposed for the intraperitoneal administration of drugs for which enteral administration is unsatisfactory. Such an approach is stated to be particularly useful for the delivery of peptide drugs such as erythropoetin and growth hormones. Reference is also made to cephalosporin antibiotics. Dextrin solutions have also been described for the administration of chemotherapeutic agents in the treatment of ovarian cancers. The use of icodextrin formulations to increase the efficacy of chemotherapeutics (especially 5FU) by increasing their dwell time in the peritoneal space is well described in Dobbie J W. (1997) Adv Perit Dial. 13: 162–7 and McArdle C S, et al. (1994) Br J Cancer 70(4):762–6.
The present invention is directed to a dextrin containing solution which shows enhanced ability to deliver nucleic acid to cells resulting in high level expression of transfected genes.


A system comprises a plurality of wireless stations for exchanging data over a wireless network and a coordinator station such an access point. The coordinator station receives a request for a traffic specification from one of the wireless stations. The traffic request comprises a traffic parameter (202) representative of the traffic specification. The coordinator station runs an acceptance algorithm (226) to determine if the request can be met based on the parameter and a current traffic schedule based on other previously granted traffic requests (228). If the new request can be accommodated, a traffic scheduler thereafter generates a new traffic schedule (232, 234) using the Cyclic Executive Model (230).

1. Field of the Invention
The invention relates to the field of wireless local area networks and proposes systems and methods for scheduling traffic over a local area network. The invention is particularly relevant to wireless local area networks where traffic is categorized and where priorities are given to traffic categories based on respective associated timing constraints. The invention is further relevant to wireless systems operating according to the IEEE 802.11e specification.
2. Description of the Related Art
Personal computers (PC) and traditional consumer electronic (CE) devices such as set-top boxes, television sets, sound systems and the like are slowly converging and both PCs and CE devices now offer functionalities that tend to satisfy customers' needs in similar ways. Wireless technologies provide this link between the two areas of expertise and CE manufacturers are working on bringing the PC content to the living room and/or, vice versa, on bringing living room content such as TV programs to the user's PC. A major concern with wireless communication is however to ensure data delivery over an unreliable and crowded environment. In addition, some traditional problems, e.g. delays, interferences, losses, encountered over wireless mediums when transmitting non-multimedia data such as text files or emails are only exacerbated when dealing with multimedia content. Indeed, multimedia content does not tolerate packet losses or delays and IEEE 802.11e seeks to solve this issue by defining quality of service for data transmission over WLANs. In order to do that, IEEE 802.11e introduces traffic prioritizing, traffic negotiation and traffic scheduling.
The basic architecture in a wireless local area network as defined in IEEE 802.11 is a basic service set (BSS). A BSS is a set of stations that can communicate with one another directly as it is done in independent basic service sets, or via an access point, as done in infrastructure basic service sets. Stations can transfer data following one of several access mechanisms. A first access mechanism is known as carrier sense multiple access with collision avoidance (CSMA/CA) according to which a station senses the wireless medium before beginning a transmission. The station can either use a physical carrier sensing mechanism or, preferably, the station can use a virtual carrier sensing mechanism as provided in the IEEE 802.11 specification with the network allocation vector (NAV). Such access mechanism is also referred to as the distributed coordination function (DCF), which is a contention based channel access that all stations use when they compete for the medium. A second access mechanism is a centrally controlled one that uses a poll and response protocol to avoid collision and contention. This access mechanism is also called the Point Coordination Function and is managed by a Point Coordinator (PC) usually located in an access point (AP). Stations transmit requests to the PC that logs the requests in a polling list and polls the stations one after another for traffic while also delivering traffic to them. The PCF is the preferred access mechanism when time-sensitive multimedia content is transmitted over a crowded environment. The PCF may be used together with the distributed coordination function (DCF). To this end, the Point Coordinator has a timing advantage over other stations in the BSS in taking over the medium and, once the Point Coordinator has gained access to the medium, it may then negotiate and control the transmission of time-sensitive data, e.g. content streaming, from one station to another.
The IEEE 802.11e lays down the basis for traffic categorizing and traffic controls and how traffic is actually scheduled is left to the manufacturer's choice. There is therefore a need for a reliable and efficient scheduling scheme.


A track and hold (or sample and hold) offset compensated amplifier circuit that performs offset compensation in response to a comparison of sign (or sign and value) of the current forced to the output terminal of operational amplifier in order to keep it at the potential of holding capacitor during the holding phase. Based on this comparison, the comparison circuit increases or decreases the voltage differential applied between the positive and negative input terminals of the operational amplifier depending on whether the comparison circuit detects that the current forced to the output terminal of the operational amplifier is positive or negative. During the holding phase, negative feedback is disconnected, and the positive and negative input terminals of the operational amplifier are connected.

1. The Field of the Invention
The present invention relates generally to offset compensated amplifier structures operating in track and hold or sample and hold mode (hereinafter referred to collectively as "track and hold", that perform offset compensation during the holding phase.
2. Background and Relevant Art
The track and hold circuit is a key building block for circuit designers. Track and hold circuits receive an analog signal that may vary over time. The track and hold circuit operates in two phases, a tracking phase and a holding phase. During the tracking phase, the output of the track and hold circuit approximately tracks the input signal of the circuit. During the holding phase, the circuit outputs a constant value that represents the strength of the input analog signal at a particular instant in time.
FIG. 6 illustrates a track and hold circuit 600 in accordance with the prior art. During the tracking phase, switch 603 is closed. In this closed loop configuration, each of the operational amplifiers 601 and 602 has unity gain. Thus, the output voltage VOUT tracks the voltage provided at the positive input terminal of the operational amplifier 602, which tracks the input voltage provided to the positive input terminal of the operational amplifier 601.
At the transition from the tracking phase to the holding phase, the switch 603 is opened, thereby isolating charge stored at the upper terminal of the holding capacitor 604. In this configuration, the voltage at the positive input terminal of operational amplifier 602 is held constant. The operational amplifier 602 is still in unity gain configuration and thus the held voltage is provided as the output voltage VOUT of the track and hold circuit 600.
Also during the holding phase, the held output voltage VOUT is provided to the negative input terminal of operational amplifier 601. The operational amplifier 601 is now in open loop configuration and thus has a high gain. In this open loop configuration, even if the voltage VIN is constant and identical to the held voltage VOUT, the inherent input offset of the operational amplifier 601 will result in large variances in the voltage at the output terminal of the operational amplifier 601. Often, the output voltage may even saturate to either the negative supply voltage or the positive supply voltage.
Accordingly, a large voltage differential may develop across the switch 603 during the holding phase. When the switch is closed at the transition from the holding phase to the next tracking phase, a rather significant amount of charge redistribution will occur across the switch 603. This is reflected through the unity gain operational amplifier 602 as rippling on the output voltage VOUT. This rippling degrades output signal quality and may cause unwanted Electro-Magnetic Interference (EMI), which could affect the performance of surrounding circuitry. Furthermore, in order to obtain accurate tracking, this rippling should be eliminated as much as possible. In order not to disturb the next holding phase, the rippling should settle within certain tolerances before the next holding phase begins. This settling time may result in inaccuracies and delays, thereby adversely impacting the circuit's primary function, and slowing the operation of the track and hold circuit for a given level of accuracy and resolution.
In order to increase the accuracy of the input voltage tracking and the accuracy of the voltage held during the holding phase, many conventional track and hold amplifiers employ offset compensation circuitry that compensates for the offset problems in the input operational amplifier. Typically the offset compensation of the input operational amplifier 601 is done by disconnect its negative input terminal from output node VOUT. The terminal is then connected to the input voltage node VIN, thus realizing a short between the input terminals of operational amplifier 601. The offset of this input operational amplifier is thus amplified with open loop gain of 601 to its output, where amplified offset information is processed by an analog or digital offset compensating feedback loop. Such conventional sample and hold circuits still develop large voltage differentials across the switch 603 during the holding phase, causing rippling of output voltage VOUT at the transitions between the holding and the tracking phase. To reduce this rippling, such circuits may, for example, clamp the output terminal of the input operational amplifier to a particular voltage during the holding phase. Nevertheless, there may still be some significant voltage differential across the switch 603 depending on the difference between the clamp voltage and the previously held voltage. Such a voltage differential may still result in rippling once the switch is closed.
Such conventional track and hold circuits compensate for offset of the input operational amplifier, but do not account for a varying operating points of the amplifier structure as input voltage is varying. Specifically, the input offset of the amplifier structure may depend on the input voltages. Typically, the offset value and sign is evaluated against a fixed reference level present on the output of the input operational amplifier. This would cause the operating point-dependent offset component to remain uncompensated in such structures, causing the additional distortion of output signal.
Other conventional sample and hold circuit use circuitry that requires one or more additional capacitors beyond the needed hold capacitor in order to eliminate rippling of output signal caused by voltage differential across the switch 603. Capacitors, while small in a simple circuit diagram, may occupy significant layout area in order to provide a reasonable amount of capacitance to efficiently filter the rippling. The presence of additional capacitors may thus significantly increase the size of the resulting circuit and slow down its operation.
Accordingly, what would be advantageous is a track and hold circuit that reduces rippling and compensates offset (including its operating point related component) even if the input voltage varies significantly during the holding phase, and which does not require additional capacitors.

Track and hold circuit with operating point sensitive current mode based offset compensation


The invention relates to a pulling device for providing a smooth linear pulling movement. The device comprises a shaft (8) rotatable around its longitudinal axis, a pulling nut moving linearly on the shaft and driven by the rotational movement of the shaft and arranged to have the member to be pulled to be attached to, and a motor (9) providing the rotational movement of the shaft. The linear movement of the pulling nut is advantageously provided with the aid of pulling bearings set against the shaft (8) at a pitch angle. It is essential to the invention that the rotational movement of the motor (9) is transmitted to the shaft (8) through the intermediary of a flexible O-ring (25) between mutually nested parts (8, 22) associated with the motor and the shaft. The O-ring (25) forms between said parts (8, 22) a narrow contact surface closing a circular line, the purpose of which is to keep the rotational movement of the shaft as smooth as possible. The pulling device according to the invention is well-adapted for moving, for instance, the exposed sliding plate pulled out of the RIM cassette used in X-ray photography during the reading of the information on the plate and its subsequent emptying.

The object of this invention is a pulling device for providing a smooth linear pulling movement, comprising a shaft rotatable around the longitudinal axis thereof, a pulling nut moving linearly on the shaft and propelled by the rotational movement of the shaft and to which the member to be pulled is arranged to be attached, and a motor providing the rotational movement of the shaft.
The pulling device according to the invention is intended for application objects requiring extremely smooth linear movement. An example of such an application is the withdrawal of the sliding plate of a RIM cassette used in X-ray photography for reading the information recorded on the plate.
The X-ray radiation conducted through the object of the X-ray photography and modified by the absorption in the object is focused on the layer of tunable fluorescent material on the sliding plate of the RIM cassette with the information included on the radiation being recorded on the layer. After this exposure phase, the plate in the cassette is read by a separate reading device which converts, with the aid of a laser beam, the information into an image which is then displayed on a computer screen or written out on film.
The reading of the sliding plate of the RIM cassette is in practice effected by pulling the plate out of the cassette to the reading position where the information on the plate is read while the plate is in the smoothest possible linear movement. After the reading, the plate is transferred to an emptying position where it is emptied of information with the aid of a powerful light, and finally the plate is returned back to the cassette to wait for the following time of use. Previously the sliding plate has been transferred from the cassette to a separate belt conveyor for the reading and emptying of the information, but patent application FI-903796 discloses a newer solution which uses a pulling device which propels the sliding plate and pulls the plate out of the cassette and returns it back in while the reading and emptying of the information takes place during the reciprocating movement of the plate. The pulling device comprises a shaft driven by a stepper motor and rotatable around its longitudinal axis, and a pulling nut (slide) moving linearly on the shaft and engaging the sliding plate. The pulling nut is actuated by the rotational movement of the shaft through the intermediary of pulling bearings set at a pitch angle against the shaft.
Patent application FI-903796 does not closely describe the coupling of the stepper motor with the rotatable shaft. However, the solution heretofore included the coupling of the stepper motor to a flywheel via a massive rubber vibration absorber. The end of the shaft was attached to the flywheel by a screw joint. However, the difficulty with this kind of solution is that the flywheel and the shaft must be accurately concentric in order to avoid mutual lateral deviations in the rotational movements of these members. This has been a very difficult task to achieve in practice. In addition, the potential inclining of the shaft of the stepper motor has had, in the known solution, a tendency to correspondingly incline the shaft because of the limited flexibility of the massive rubber.


The conventional two plates with beamsplitter of the Mirau interferometer are replaced with two achromatic λ/4 retarders. The upper surface of the second retarder is coated with a 50 percent reflecting film, so that it also functions as a beamsplitter. The objective is illuminated with a linearly polarized beam. As a result of this arrangement, the test and reference beam emerging from the Mirau interferometer are orthogonally polarized beams suitable for achromatic phase shifting, thereby facilitating the use of the Mirau interferometer for monochromatic to broadband phase-shifting interference microscopy. Alternatively, it can be used for equalization of beams intensity by placing a rotatable polarizer at the exit of the objective.

1. Field of the Invention
The invention relates in general to Mirau interferometry for optical testing and, in particular, to a modified Mirau interferometer producing orthogonally polarized beams suitable for achromatic phase-shifting interference microscopy.
2. Description of the Prior Art
Because of its simple configuration and corresponding relative ease of calibration, the Mirau interference objective is used widely to study the structure of surfaces requiring observation at higher magnification, typically 10× to 75×. It features a very compact interferometer incorporated in a single microscope objective, as illustrated schematically in FIG. 1. Light from an illuminator (not shown) is passed through a microscope objective 10 onto a beamsplitter consisting of a beamsplitting coating 12 between two identical transmissive plates 14 and 14′. The transmitted beam T proceeds to the test surface 16 of a sample object S, while the reflected beam R is directed to the reference surface 18, typically an aluminized spot on the front surface 20 of the microscope objective 10. The two beams T and R reflected from the test and reference surfaces, respectively, are recombined at the beamsplitter 12 and return through the objective 10 toward a detector element (not shown).
In an alternative Mirau embodiment, shown in FIG. 1B, the two plates 14,14′ are separated and the top plate 14 is positioned away from the coated beamsplitting plate 14′ in contact with the reference surface 18. As one skilled in the art would readily appreciate, the optical effect is the same because in both configurations the test and reference beams (T and R, respectively) traverse the same optical distance (due to the fact that the plates 14 and 14′ are identical).
The interference pattern formed in the image plane contours the deviations from flatness of the test surface 16. As is well understood in the art, if the beamsplitter in the Mirau interferometer (or the whole microscope objective incorporating the beamsplitter, or the object, or the reference mirror) is mounted on a piezoelectric translator (PZT), so that the optical path difference (OPD) can be changed by known amounts, very accurate measurements of surface profiles can be made using phase-shifting techniques. Mirau interferometers also provide inherent compensation for chromatic dispersion because the beamsplitting element 12 is contained within the two identical plates 14,14′. Thus, each beam (T and R) traverses the exact same optical length twice in each direction upon impinging on the beamsplitter, thereby negating any dispersive effects of the plates medium.
However, the performance of Mirau interferometers (as well as all other scanning interferometers) is affected by the fact that the algorithms used in optical scanning interferometry assume that the amplitude of interference signal modulation remains constant during the scan. In fact, that is almost never the case. In practice, the light intensity detected as a result of interference of the test and reference beams, which would be perfectly sinusoidal under ideal single-wavelength and zero-numerical-aperture conditions, as shown in FIG. 2, exhibits a modulation variation that affects the interferometric result even when narrow-band light is used (or non zero numerical aperture or both), as illustrated in FIG. 3.
Furthermore, it is well known that the use of monochromatic light is accompanied by the so-called 2π phase ambiguities that arise when the measurement range involves a change in the optical path difference (OPD) greater than a wavelength. Phase unwrapping techniques are used in the art, but they are effective only with smooth continuous surfaces and break down when the test surface exhibits a sharp step or a discontinuity.
One way of overcoming the 2π-ambiguity problem is by using white light and scanning the object along the height (z) axis. The position along the z axis yielding maximum visibility of the fringes (the coherence peak) for each pixel in the image is known to correspond to the height of the object at that point. The visibility peak can be located by shifting the phase of the reference wave by three or more known amounts at each step along the z axis and recording the corresponding values of intensity. These intensity values can then be used in conventional algorithms to evaluate the fringe visibility at that step. However, if the phase shifts are introduced by changes in the OPD, as is the case in conventional scanning interferometry, the value of the resulting phase shift varies inversely with the wavelength, thereby producing fringes with varying modulation, as shown in FIG. 3, and the calculated phase and modulation may contain errors.
This problem may be overcome by using a different technique of phase shifting involving a cycle of changes in the polarization of the light to produce the same phase shift, measured in degrees or radians, for all wavelengths. This phase shift, known in the art as the Pancharatnam phase shift (see S. Pancharatnam, "Achromatic combinations of birefringent plates," Proc. Indian Acad. Sci., A 41, 137-144, 1955), is a manifestation of the geometric phase and it can be used to generate any required wavelength-independent phase shift without changing the optical path difference. As a result, geometric phase-shifting has found many applications in interferometry.
In white-light interference, a change in the geometric phase produces a shift in the fringes under the coherence envelope, but the coherence envelope stays in place, as illustrated in FIG. 4, resulting in no change in the fringe contrast at each point. In comparison, the whole white-light interferogram is shifted during scanning phase shifting, resulting in changing fringe contrast at each point. Thus, for multi-wavelength interferometry a geometric phase-shifter is preferred because it will produce the same phase shifts for any wavelength used in the interferometer.
Achromatic phase-shifters operating on geometric phase have been developed in the art using circularly polarized light, as illustrated in FIGS. 5A and 5B, for example. Linearly polarized light can be achieved by placing first a polarizer in the path of a beam, then passing the light through a quarter-wave plate that makes it circularly polarized, and then through a rotating half-wave plate followed by a quarter-wave plate and another polarizer (FIG. 5A). In a simpler arrangement, the last three elements are substituted by a single rotating polarizer (FIG. 5B). In all cases, in order to introduce a phase shift between two interfering beams, the two beams exiting the interferometer need to be orthogonally polarized (note that then the first polarizer shown in FIG. 5A is not needed).
Based on these principles, FIG. 6 illustrates a Michelson interferometer adapted for geometric phase shifting operation by producing two orthogonally linearly polarized beams at the output of the reference and object arms of the interferometer. A geometric phase-shifter consisting of a rotating half-wave plate mounted between two quarter-wave plates with their axes set at 45° to the angles of polarization of the two beams, is placed at the exit of the interferometer. This interferometer employs the type of geometric phase-shifter shown in FIG. 5A in which the first quarter-wave plate creates left- and right-handed circularly polarized beams. The half-wave plate then changes the right-handed circularly polarized beam to a left-handed one and the left-handed circularly polarized beam to a right-handed one. Finally, the second quarter-wave plate brings the two beams back to their original orthogonal linear polarizations.
As a result of this configuration, a rotation a of the half-wave plate shifts the phase of one linearly polarized beam by +2α and the phase of the other orthogonally polarized beam by −2α, so that a net phase difference of 4α is introduced between the two beams. This phase difference is very nearly independent of the wavelength over the whole visible spectrum. The polarizer makes it possible for the two beams to interfere.
Another type of geometric phase-shifter utilizes the configuration of FIG. 5B, wherein a rotating polarizer is placed after the quarter-wave plate that changed the two orthogonally polarized beams leaving the interferometer to left- and right-circularly polarized beams. In this case, if the test beam is left-circularly polarized and the reference beam is right-circularly polarized and both beams are incident upon the linear polarizer set at an angle α with respect to the x-axis, both the test and reference beams, upon passing through the polarizer, become linearly polarized at an angle α. However, a phase offset +α is added to the test beam and a phase offset −α is added to the reference beam. A rotation of the linear polarizer by α therefore introduces a phase shift 2α between the two interfering beams. The linear polarizer acts as a phase shifting device and also makes it possible for these beams to interfere. While an achromatic quarter-wave plate could be used to extend the spectral range over which this phase-shifter operates, it turns out that the variations in the phase shift produced by this system due to variations in the retardation of the quarter-wave plate with the wavelength are quite small. (See S. S. Helen, M. P. Kothiyal and R. S. Sirohi, "Achromatic Phase-shifting using a Rotating Polarizer," Opt. Commun., 154, 249-254, 1998).
Because the measurement time can be critical in some industrial applications, it can be reduced significantly if the interferograms are collected simultaneously. This can be done using yet another form of geometric phase-shifting, a pixelated mask, as disclosed in U.S. Pat. No. 7,230,717 (Millerd et al.). As illustrated in FIG. 7, a polarizing beamsplitter is used to produce reference and test beams with orthogonal polarizations. Quarter-wave plates are placed in the reference and test beams so that each beam initially transmitted through the beamsplitter is reflected when it returns, and vice versa. These two beams pass through a quarter-wave plate, which converts the two orthogonally polarized beams to right- and left-handed circularly polarized beams, and then through a phase mask. The quarter-wave plate can be placed at the exit of the interferometer, or in front of the camera, while the phase mask is placed just in front of the CCD array in the camera.
The phase mask is a micropolarizer array built up of groups of four linear polarizer elements having their transmission axes at 0, 45, 90, and −45 degrees (or at 0, 45, −45 and 90 degrees) and is structured so that each polarizer element is placed over a detector element. These four linear polarizer elements introduce phase shifts between the test and reference beams of 0, 90, 180, and 270 degrees. Thus, four phase-shifted interferograms, obtained from each group of pixels, are recorded simultaneously using a single CCD array. As one skilled in the art would easily recognize, the phase mask works as a geometric phase-shifter, the two essential requirements being that the test and reference beams traveling through the quarter wave plate have orthogonal polarizations and that the micropolarizer array match the CCD array.
The solutions described above for effecting geometric phase shifts have been used successfully to overcome the multiple-wavelength and numerical aperture problems discussed above in various interferometer configurations, but no comparable solution has yet been found for Mirau interferometers. In order to use a phase shifter operating on the geometric (Pancharatnam) phase, the Mirau test and reference beams T and R emerging from the interferometer need to be linearly polarized in orthogonal planes. However, because of the compactness of the Mirau interferometric objective and the coaxial configuration of the test and reference arms, very little space is available for introducing additional optical elements and a workable solution has not been found to date in spite of the frequent commercial use of Mirau configurations for optical scanners. The present invention is directed at a viable solution for this problem.

Polarization mirau interference microscope


The present invention relates to a transflective thin film transistor substrate and method of fabricating the same. A liquid crystal display device according to the present invention includes: a gate line crossing a data line with a gate insulating film there between to define a pixel area; a thin film transistor connected to the gate line and the data line; an organic film on the gate line, the data line and the thin film transistor, having a transmission hole passing through the gate insulating film in the pixel area; a pixel electrode on the organic film via the transmission hole and connected to the thin film transistor; and a reflective electrode having an edge part different from an edge part of the pixel electrode on the pixel electrode and exposing the pixel electrode of the transmission hole.

1. Field of the Invention
The present invention relates to a transflective thin film transistor substrate of a liquid crystal display device, and more particularly, to a transflective thin film transistor substrate and method of fabricating the same that is adaptive for simplifying its process.
2. Discussion of the Related Art
A liquid crystal display device controls the light transmissivity of liquid crystal, which has dielectric anisotropy, using electric field, thereby displaying a picture. For this, the liquid crystal display device includes a liquid crystal display panel to display a picture through a liquid crystal cell matrix, and a drive circuit to drive the liquid crystal display panel.
Referring to FIG. 1, a related art liquid crystal display panel includes a color filter substrate 10 and a thin film transistor substrate 20 which are bonded together with each other having a liquid crystal material 24 therebetween.
The color filter substrate 10 includes a black matrix 4, a color filter 6 and a common electrode 8 which are sequentially formed on an upper glass substrate 2. The black matrix 4 is formed on the upper glass substrate 2 in a matrix shape. The black matrix 4 divides the area of the upper glass substrate 2 into a plurality of cell areas in which a color filter is to be formed, and prevents the optical interference and external light reflection between the adjacent cells. The color filter 6 is divided into red R, green G, blue B in the cell area by the black matrix 4 to transmit red, green and blue lights respectively. The common electrode 8 supplies a common voltage Vcom to a transparent conductive layer, which is spread over the entire surface of the color filter 6, wherein the common voltage Vcom becomes a reference when driving the liquid crystal 24. And, to flatten the color filter 6, an overcoat layer (not illustrated) is additionally formed between the color filter 6 and the common electrode 8.
The thin film transistor substrate 20 includes a thin film transistor 18 and a pixel electrode 22, wherein the thin film transistor 18 is formed every cell area which is defined by the cross of a gate line 14 and a data line 16 in a lower glass substrate 12. The thin film transistor 18 supplies a data signal from the data line 16 to the pixel electrode 22 in response to a gate signal from the gate line 14. The pixel electrode 22 formed of a transparent conductive layer supplies the data signal from the thin film transistor 18 to drive the liquid crystal 24.
The liquid crystal material 24 having dielectric anisotropy rotates along the electric field formed by the common voltage Vcom of the common electrode 8 and the data signal of the pixel electrode 22 to control the light transmissivity, thereby making the gray level realized. The liquid crystal display panel further includes a spacer (not illustrated) to maintain the cell gap between the color filter substrate 10 and the thin film transistor substrate 20.
The color filter substrate 10 and the thin film transistor substrate 20 of the liquid crystal display panel are formed using a plurality of mask processes. One mask process includes a plurality of processes such as a thin film deposition (coating) process, a cleaning process, a photolithography process (hereinafter, referred to as a photo process), an etching process, a photo-resist peeling process, an inspection process and so on. In particular, the thin film transistor substrate includes the semiconductor process and requires a plurality of mask processes, thus its manufacturing process is complicated so that it becomes a material cause for the increase of the liquid crystal display panel manufacturing cost.
A liquid crystal display devices is generally classified into a transmissive type having a picture displayed using the light being incident from a backlight unit, a reflective type having a picture displayed by reflecting an external light such as a natural light, and a transflective type using an advantage of both the transmissive type and the reflective type.
There is a problem that the power consumption of a backlight unit is high in the transmissive type while the reflective type depends on the external light so as not to be able to display the picture in a dark environment. On the other, the transflective liquid crystal display device operates in the reflective mode if the external light is sufficient and in the transmissive mode if the external light is not sufficient, thus it can reduce the power consumption more than the transmissive liquid crystal display device and it is not restricted by the availability external light, which is different from the reflective liquid crystal display device.
To this end, the transflective liquid crystal display panel includes each pixel divided into a reflection area and a transmission area. Accordingly, a reflection electrode, formed in the reflection area, and an insulating film for making light paths in both the reflection area and the transmission area the same should be further added in a transflective thin film transistor, as compared to the thin film transistor as illustrated in FIG. 1. As a result, because the number of mask processes must be increased, there is a problem that the manufacturing process of the related art transflective thin film transistor substrate is complex.

Transflective thin film transistor substrate of liquid crystal display device having a contact electrode connecting a data link to a data line


There is provided a culinary whisk comprising one or more wire loops for mixing foodstuffs, the or at least one of the wire loops includes an inner metallic wire portion and an outer polymeric portion enclosing the inner portion, wherein the inner portion is provided with groove(s) along substantially the length thereof for increasing frictional contact with the outer portion or means for fixedly adhering the outer portion to the inner wire portion whereby in use relative movement between the external portion and the internal portion is reduced.

There are numerous types of culinary whisk in the market. Traditional culinary whisks generally comprise a utility portion made of a number of metal wire loops at one end and the utility portion is secured to a handle at the other end. In use, a user would hold on to the handle and use the utility to mix foodstuffs in a container. Although the use of metal wires is desirable to the extent that they are flexible and durable, they are not suitable if the container in which the foodstuff to be mixed is a non-stick container having a non-stick layer or Teflon layer. This is because in a whisking motion the metal wires would inevitably scratch the non-stick layer and would not only damage the container but also cause contamination of the food to be mixed.
The present invention seeks to not only address the problem of scratching but also seek to maintain a high level of efficiency to a whisking operation and/or improve the durability of the whisk, or at least to provide an alternative to the public.

Maxpat Trading & Marketing (Far East) Limited


Compositions and methods for treating fibrotic diseases are provided.

Several publications and patent documents are cited throughout the specification in order to describe the state of the art to which this invention pertains. Each of these citations is incorporated herein by reference as though set forth in full.
Myofibroblasts are the likely cause of lens fibrotic diseases that result in loss of vision, such as posterior capsule opacification (PCO) and anterior subcapsular cataract (ASC). PCO is a common complication of cataract surgery. The origin of myofibroblasts in ASC and PCO is unknown. Presently, there is no method that can be used to effectively block the development of lens fibrotic disease, such as PCO.

Compositions and methods for the treatment and prevention of lens fibrotic diseases


In a safety coupling for a motor vehicle for transmitting a driving torque between a machine shaft of an electric machine and a wheel drive shaft driving at least one wheel of a vehicle, torque is transmitted during disturbance free normal operation between the machine shaft and the wheel drive shaft via a releasable positive coupling. If a torque exceeding a limit value occurs, the releasable positive coupling is disengaged, and therefore an elastic coupling device at least briefly takes over the transmission of torque.

The invention relates to a safety coupling for a motor vehicle.
In electric vehicles or hybrid vehicles that use an electric machine as driving engine the electric machine is often inseparably connected with the drive wheels, i.e, there is no coupling between the electric machine and the driving wheels but for example only a positive force transmission element such as a cardan shaft or a transmission. When an error occurs in the electric machine or in the power electronics in such a rigid drive connection or when the power electronics is switched to an active short circuit for generating a safe vehicle state, very high torque peaks can occur for a short time which significantly exceed the nominal torque of the motor and can vibrate with high frequency. Such a torque peak can have triple the value of the nominal motor torque, which may render the motor vehicle instable with regard to driving dynamics. The tires of the drive wheels, which are rigidly coupled with the electric machine via the drive train, may thereby lose their grip on the street.
In principle, it is possible to integrate elastic intermediate elements into the drive train in order to decrease the torque peak in case of a malfunction. This elasticity in the drive train however has adverse effects during normal operation, because the positive characteristic of the electric machine, namely a fast torque buildup, can no longer be optimally used. In addition, the elastic intermediate elements also render the drive train more prone to interfering vibration during normal operation.


A coaxial cable connector includes a standard and a mini adapter. The standard adapter includes coaxial hollow inner and outer sleeves. The mini adapter includes an inner member having a finger clamp; and a cylindrical housing having a first and a second tubular end portion. The first tubular end portion is externally formed of elastic hooking portions corresponding to the finger clamp in the mini adapter, and a plurality of long slots behind the elastic hooking portion. A contact spring is provided in the mini adapter with contact strips thereof received in the long slots. When the mini adapter is fully inserted into the standard adapter, the inner sleeve compresses the elastic hooking portions to thereby force the finger clamp to engage with a central conductor of the coaxial cable, and pushes the contact strips to mechanically and electrically engage with a foil layer of the coaxial cable.

An existing coaxial connector is used to connecting a coaxial cable to a mating connector, so that the coaxial cable may be used in cable TV signal transmission, data transmission line, etc. The coaxial cable normally includes a central conductor, an insulator surrounding the central conductor, a foil layer surrounding the insulator, at least one braided conducting sheath surrounding the foil layer, and a jacket surrounding the at least one braided conducting sheath. The currently available coaxial cables may be divided into several different specifications, including RG6, RG7, RG11, RG59, etc., and each coaxial cable of a specific specification must be installed with a corresponding connector. When a coaxial cable is connected to a mismatching connector, failures in signal transmission would occur. Moreover, a large number of connectors in different specifications must be manufactured at increased cost to match differently sized coaxial cables.
It is uneasy to determine whether a cable and a connector have the same specification. Most cable installers determine the correct matching of cable and connector simply based on personal working experiences. Before a coaxial connector can be installed onto an end of a coaxial cable, that end of the coaxial cable must be processed for associating with the connector. Then, the connector is manually pushed onto the processed cable end until the jacket and the braided conducting sheath of the coaxial cable are isolated from the insulator and the coaxial cable has been inserted into the connector by a required depth. Finally, a hexagonal clamping tool is used to compress the connector against the coaxial cable to firmly join them together. In response to the coaxial cables of different specifications, total three differently sized hexagonal clamping tools must be prepared to ensure the application of sufficient compression force on the coaxial connector. The differently sized hexagonal clamping tools require extra cost and are inconvenient for carrying. It is therefore desirable to develop a coaxial cable connector that may be used with coaxial cables of different specifications.

Phoenix Communications Technologies International