A billet includes a solid steel body and an alloy cladding. The cladding may include a square tube in which the body is inserted with an interface at which the cladding becomes bonded to the body when the billet is heated and rolled or otherwise worked into a ferrous product. At least one element composed of a mass of finely divided scavenging aluminum, titanium or magnesium, is placed in the tube adjacent the body and separate from the interface. The elements are advantageously compressed into briquettes which scavenge oxygen from residual air at the interface to prevent oxidation of the cladding at the interface. The tube may be closed to prevent gases outside the billet from penetrating to the interface. Alternatively, reliance may be placed on the briquettes to scavenge oxygen from the residual air and also from atmospheric air and furnace gases before they can penetrate to the interface.

In discussing the background of the invention, it is useful to refer to a series of inventions covered by patents applied for by Cacace et al. These patents and the processes described therein are referred to herein as the "earlier Cacace" patents and processes. The most recent of these appears to be the family of patents that include U.S. Pat. No. 6,706,416.
The earlier Cacace patents deal essentially with the production of long products such as reinforcing bars (hereinafter referred to as "rebars") comprising a core of mild steel and having a stainless steel cladding. These rebars are produced from billets comprised of a stainless steel jacket filled with briquettes of mild steel swarf. The billets can be heated and rolled into finished rebars having the desirable properties and low cost of mild steel but which have a stainless steel cladding for substantially increased corrosion resistance. On perusal of these patents it is clear that the achievement of a satisfactory metallurgical bond at the interface between the stainless steel cladding and the steel core has been problematical. The root of the problem is the occurrence of oxidation at elevated temperatures of the chrome in the stainless steel at the interface. There are several potential sources of the oxygen that causes this oxidation. One source is the residual oxygen in the air that remains in the briquettes and in the jacket after the billet is formed. A second source is atmospheric oxygen that enters the billet through its ends, particularly after the billet is heated. This can happen when the billet cools after it is removed from the furnace, causing the gas pressure inside the billet to drop below atmospheric pressure. It can also happen as the billet is heated due to the thermal gradient between the core and the much hotter cladding. As a result, a gap develops between the core and the cladding and this is further exacerbated by the thermal expansion of the stainless steel, which is greater than that of mild steel. A third potential source of oxygen is the residual oxidation (rust) that is present on the surface of the particles of mild steel swarf that make up the briquettes. In the absence of preventive measures, this oxidation reacts with carbon that, as the temperature increases, diffuses out of the mild steel to form CO (carbon monoxide) and/or CO2 (carbon dioxide). Both CO and CO2 can cause significant oxidation of the stainless steel at elevated temperatures.
In the process described in U.S. Pat. No. 6,706,416 this problem has been addressed by the use of dual additives which are mixed with the swarf particles before the briquettes are formed. The working examples of the first of these additives are powdered ammonium chloride (NH4Cl) and urea. When the billet is heated, these evidently break down into gaseous form at a temperature below which the oxidation of the stainless steel is significant. These gases are under pressure in the hot interior of the billet and act to displace the residual oxygen. This first step is employed in conjunction with the action of the second additive. This second additive, the working example of which is aluminium, becomes increasingly reactive as the temperature increases above that at which the ammonium chloride or urea has completely broken down. The aluminium reacts with oxygen in the rust to form aluminium oxide and also with any oxygen that enters the billet from the atmosphere, thus preventing oxidation of the chrome.
In U.S. Pat. No. 6,706,416 it is stated that "both NH4Cl and urea generate considerable volumes of reducing gases in the temperature range from 200° C. up to about 500° C.". A similar statement appears in U.S. Pat. No. 5,676,775 in which the use of a single additive such as NH4Cl and urea is suggested. These statements are inaccurate insofar as they suggest that NH4Cl and urea generate gases that reduce Cr oxides in the billet. In fact the named agents evolve nitrogen (N2), hydrogen (H2) and chlorine (Cl2). The Ellingham diagram for the reaction of metals to form oxides indicates that these substances should not be reducing to Cr oxides in the conditions existing in the billet. The applicant now believes that it is more likely that their evolution creates a positive gas pressure in the billet. The gases are thus carried out of the billet and, in the process, drive residual air out of the billet. So, from a temperature well below 500° C., the quantity of residual atmospheric oxygen in the billet would diminish until it is probably close to zero. The remaining sources of oxygen in the billet would be the iron oxide on the surface of the swarf and air that enters through the ends of the billet after the NH4Cl and urea are spent.
As stated in U.S. Pat. No. 6,706,416, the iron oxide from the swarf combines with carbon derived from the mild steel swarf to form, first CO2 and then, at higher temperatures, CO. This process starts to take place on a significant scale at quite a low temperature, perhaps 300° C. CO2 is oxidising to Cr and, contrary to what is stated in U.S. Pat. No. 6,706,416, the Ellingham diagram shows that CO should be reducing to Cr oxides only above about 1225° C. Temperatures in the billet at the interface between the core and jacket may not always uniformly exceed this transition temperature because it is very close to the temperatures (1260-1280° C.) at which billets clad with austenitic SS normally exit the furnace. This could be due to temperature variations inside the billet or because the soaking times in the furnace are insufficient. The reducing reaction of CO may therefore not always be strong enough to bring about complete reduction, resulting in a micrographically visible layer of Cr oxides dispersed about the surface of the SS. A more concentrated, or even continuous, oxide layer would occur if the transition temperature is not reached at all, resulting in even less bonding at the interface and possibly product failure.
In U.S. Pat. No. 6,706,416, aluminium, the second metal that is added to the billet, is therefore relied on to ensure the reduction or prevention of Cr oxides as the temperature rises after the NH4Cl or urea are spent.
Having regard to the disclosures in the earlier patents, it is clear that, in the processes described therein, each reducing agent on its own is insufficient to prevent the formation of Cr oxides that impede subsequent bonding of the SS jacket to the core.
It also seems clear that, for an open ended billet comprised of granulated mild steel briquettes, as used in the earlier process, it is essential that both additives, i.e. NH4Cl or urea, and aluminium should be well dispersed through the granules. In any case, it may be concluded that, for an adequate bond between the SS jacket and the carbon steel core, it is necessary is to avoid, as far as possible, the formation of Cr oxides at the interface from the commencement of heating until the jacket becomes bonded to the core.
There are significant potential disadvantages to using swarf as a feedstock for the core in the earlier process described above.
In a full scale manufacturing operation, it may be difficult to maintain a reliable source of swarf of a particular grade in a situation in which it is necessary that the end product comply with an international standard and specification.
Furthermore, it is self-evident that costly specialised machinery, some of which is described in U.S. Pat. No. 5,088,399, is required for preparing the swarf and the billets in the earlier process. In addition, because of their furnace design, most established rolling mills cannot roll from round billets. It is not easy to envisage machinery that will be capable of producing billets that comprise compressed swarf and have a cross sectional shape that is not round. Further, the size, and especially the length, of the billets, at least those described in the earlier patents, is quite small. There are only a limited number of existing rolling mills that are able to roll billets of such short length and even fewer that can also roll from a round billet. This is partly because existing furnaces are of the pusher type designed for handling square billets. Round billets require furnaces of the walking beam type. The use of small billets is likely to result in the rolling process being inefficient because modern rolling mills are designed to roll ever-longer billets to enhance productivity. Although in principle the size and length of billets that comprise compressed swarf could be increased, and the shape changed, the technical problems involved in achieving suitable machinery for this purpose might well be insuperable.
Another problem inherent in the earlier process described above, again self evident, is that the gases evolved by the NH4Cl and urea must necessarily be vented. Apparently the billet is open-ended for this reason. This is stated in U.S. Pat. No. 5,124,214, notwithstanding that it suggests the use of a cap to enclose the ends of the billet. However, this patent is dated prior to the use of any additives as described above. Furthermore, although this patent also contains a suggestion that the tube can be sealed by applying a graphite paste to the ends of the core, this would be unworkable.
The paste would rapidly become friable and porous with the moisture in the paste rapidly being driven off. This would cause the graphite to collapse and therefore no longer form the barrier intended. Moreover, the graphite would react with the steel in the briquettes at a temperature of about 1000° C., effectively forming molten cast iron and would be completely ineffective in reducing Cr oxides.
U.S. Pat. No. 5,676,775 discloses only an open-ended billet. In U.S. Pat. No. 6,706,416, an experimental billet is disclosed which contains only aluminium as an additive. Although this billet is described as closed, it is provided at each end with a vent hole to allow gases to escape from the billet. The vent holes were welded closed after the billet was removed from the furnace. Having regard to what has been said above, the applicant believes that that these vent holes would not prevent residual atmospheric oxygen causing oxidation of Cr in the billet at lower temperatures, before the aluminium additive becomes active.
One object of the invention is to provide a billet comprising a solid steel body and a cladding composed of stainless steel, or a nickel-chrome, nickel-copper or copper-nickel alloy in which oxidation which interferes with the bond between the cladding and the steel body in the finished product is reduced, at least to the extent of providing a commercially acceptable finished product.


An amplifier circuit with improved turn-on and turn-off transient operation includes an amplifier and a controller for controlling the amplifier output during initial and subsequent circuit turn-on and turn-off. The amplifier is biased by a positive power supply voltage and has a differential input driven by a reference voltage and a single-ended input signal. Where the output is single-ended, a single amplifier provides a single-ended output signal. Where the output is differential, the amplifier includes cascaded, differential input, single-ended output amplifiers which together provide a differential output signal. Following circuit turn-on and turn-off, the reference voltage, which drives one of each of the differential inputs, typically charges to or discharges from, respectively, a value of half of the positive power supply voltage. Following circuit turn-on and turn-off and during initial charging or discharging, respectively, of the reference voltage, the controller forces the single-ended output signal to follow the relatively slowly charging or discharging reference voltage and the differential output signal to remain at zero. When the reference voltage is fully charged, the controller releases control and both the single-ended and differential output signals become equal to the sum of the reference voltage and a multiple of the input signal. Hence, turn-on and turn-off transients in the output signal due to circuit turn-on and turn-off are avoided.

1. Field of the Invention
The present invention relates to analog amplifier circuits, and in particular, to analog amplifier circuits for receiving AC-coupled input signals and producing DC-coupled output signals.
2. Description of the Related Art
Referring to FIG. 1, analog amplifiers, such as audio power amplifiers, are often required to operate from a single power supply. This means the AC input signal (VIN) must be AC-coupled to the input of the amplifier circuit since the internal AC reference, or "ground," for the amplifier circuit is at DC voltage between DC circuit ground and the power supply potential, e.g. at a value equal to one-half of the applied DC power supply voltage. This AC reference is established by a resistive voltage divider (R.sub.1 and R.sub.2) with a bypass capacitor (C.sub.B) for charging to and maintaining the DC reference voltage across the lower resister. (In this particular circuit, as is often the case for audio power amplifiers, two serially cascaded inverting amplifiers are used in a bridge-tied-load configuration to drive a load, e.g. a speaker, with a differential output signal.)
However, this type of circuit suffers from a problem due to the necessity of having an AC-coupled input. Upon application of DC power (V+) to this circuit, the bypass capacitor begins to charge, as does the input coupling capacitor (C.sub.C) which is grounded at the input side by the output impedance of the grounded input signal source. Since the RC time constant for the bypass capacitor and its associated charging resistance are typically different from that for the input coupling capacitor and its associated charging resistance the capacitors charge at different rates. This results in the two capacitors having, at any given points in time during their charging or discharging periods, different voltages across them. In turn, this causes a transient signal to appear across the load. For example, during initial circuit turn-on, the current for charging the input coupling capacitor flows form the output of the first amplifier through its feedback (RF.sub.F1) and input (R.sub.I1) resistors. The resulting signal at the output of the first amplifier appears at the load in the "negative" portion (VOUT-) of the differential output signal, with the "positive" portion (VOUT+) applied by the second, cascaded inverting amplifier. This initial signal across the load is a turn-on transient which in the case of an audio power amplifier produces a "click" or "pop" from the speaker. (Similarly, during circuit turn-off, a turn-off transient produced by unequal discharging of the capacitors will often produce a "click" or "pop" from the speaker as well.)
Similar turn-on and turn-off transients occur in single-ended circuits, i.e. those amplifier circuits in which a single-ended output signal is provided to a grounded load (e.g. either VOUT- or VOUT+ only) rather than a differential output signal to a load isolated from circuit ground.
Conventional amplifier circuits have been developed which address this "pop" problem in a number of different ways. One approach has been to avoid using single power supply circuits by biasing the amplifier circuit between equal positive and negative power supply voltages with the output driving a grounded load. This allows the input coupling capacitor to be eliminated, thereby eliminating the cause of the turn-on and turn-off transients. However, this requires a second power supply which increases system complexity and costs. Another approach has been to apply the single DC power supply voltage in a gradual manner to initiate the flow of DC bias currents within the amplifiers. However, this results in the amplifier circuit having an indeterminate state of operation during turn-on and turn-off. Further, turn-on and turn-off transients can still occur when power is removed and quickly reinstated as in when a system reset is performed.
Accordingly, it would be desirable to have an analog amplifier which can be operated with a single power supply and reduced turn-on and turn-off transients.

Amplifier circuit with reduced turn-on and turn-off transients


A vanity case is provided in which a first hinge piece and a second hinge piece are formed in one of the case body and the lid, and a hinge block is formed in the other one of the case body and the lid and arranged between the first and the second hinge pieces. A friction member is provided to brake the rotational speed of the lid caused by a torsion spring. A protrusion is provided for braking the rotational speed of the lid by sliding contact. A recessed circumferential portion is formed in the vanity case so as to release the sliding contact of the braking protrusion at least at the closed position of the lid.

As a technology of improving both usability and a sense of luxury by automatically opening a lid of a vanity case and controlling its opening speed, there is known a prior art disclosed in Japanese Patent Application Laid-open No. 2006-36263. In this prior art, a shaft (pin) disposed in a case body is inserted into a shaft holding portion provided at the lid, an urging means is provided for urging the lid in an opening direction, and viscous material is charged between the shaft and the shaft holding portion such that the lid is slowly opened with respect to the case body. In the above-mentioned case, the shaft holding portion provided at the lid can be rotated around the shaft in accordance with the opening operation of the lid, and at that time, the viscous material resists against the relative rotation between the shaft and the shaft holding portion, so that the speed of rotation of the lid due to the urging means is controlled.


The invention relates to a dendritic macromolecule comprising a core and branches emanating from the core wherein the branches are based on vinyl cyanide and/or fumaryl dinatrile units. The invention also relates to processes for preparing these dendritic macromolecules. The dendritic macromolecules according to the invention are not sensitive to degradation through hydrolysis reactions and are also very stable at a high temperature. The processes are very suitable for large scale production of the dendritic macromolecules without requiring purification of reaction intermediates.

Dendritic macromolecules, sometimes referred to as dendrimers, are three-dimensional, highly ordered oligomeric and polymeric molecules with a very good defined chemical structure. Some dendritic macromolecules are known and are described, for example, in Angew. Chem. Int. Ed. Engl., 29: 138-175 (1990), the disclosure of which is incorporated herein by reference. This article describes a number of different dendritic macromolecules, for example polyamidoamine (PAMAM) dendrimers, which are also described in U.S. Pat. No. 4,507,466, and polyethyleneimine (PEI) dendrimers, which are also described in U.S. Pat. No. 4,631,337.
The applications envisaged for dendritic macromolecules are as diverse as they are numerous. The aforementioned publications mention several possible applications such as, for example, electronic applications, applications for the calibration of sieves, catalysts (and catalyst supports), selective membranes and coatings, but applications as impact modifiers or as cross-linking agents in several plastics could also be considered.
A drawback of the aforementioned dendritic macromolecules, however, is that PAMAM dendrimers are very sensitive to degradation through hydrolysis reactions. In particular, these dendrimers are not stable at an elevated temperature, which means that these macromolecules degrade significantly when they are exposed to higher temperatures.
The heretofore known procedures for preparing dendritic macromolecules also suffer from drawbacks. For instance, the two procedures described in Angew. Chem. Int. Ed. Engl. 29:138-175 (1990) are incapable of being scaled-up to provide commercially useful quantities of dendritic macromolecules. During one synthesis procedure, the so-called `protected group method`, the composition of the dendritic macromolecules, i.e., polyethyleneimine (PEI) dendrimers, is very accurately controlled via the strategic use of protected groups, which prevents undesired side reactions and undesired defects in the structure of the dendritic macromolecules. During the other synthesis procedure, the so-called `excess reagent method`, with which for example polyamidoamine (PAMAM) dendrimers are prepared, a very large excess of reagents is used to statistically minimize the risk of undesired reactions and defects.
The aforementioned `protected group method` is based on the presence of protected aziridine rings. The aziridine rings are opened with the aid of primary amines, after which the deprotection is effected with the aid of a strong acid. The complex isolation procedures, the low yield of the synthesis procedure and the use of expensive reagents renders this method unsuitable for large-scale, e.g., commercially viable preparation of PEI dendrimers.
The aforementioned `excess reagent method` includes, as a reaction step, the complete Michael addition reaction of primary amine groups to methyl methacrylate, followed by amidation using ethylenediamine. However, the synthesis of the polyamidoamine dendrimers thus formed requires a very large excess of reagents to prevent undesired side reactions. The greater part of the excess amount of reagents is removed through evaporation in, for example, a rotary evaporator, after which the last residual amounts of the reagents are removed from the viscous reaction product in a precipitation step. The intermediate product between the various synthesis steps must, however, be completely pure, which means that the precipitation step has to be repeated several times. These complicating factors render this synthesis procedure for dendritic macromolecules also unsuitable for large-scale application.
The drawbacks of each of the aforementioned synthesis procedures are so great that the use of these procedures on a large--and hence commercially attractive scale--involves insurmountable problems. "The main stumbling block to most of these applications is that large-scale synthetic methods remain to be developed." Science 251:1562-1564 (March 1991).

Dendritic macromolecule and the preparation thereof


A front light unit of an embodiment comprises: a light source unit for an image display device; a light guide unit for guiding light incident from the light source unit and outputting the guided light to a display unit; and a holographic optical element unit being opposite to the display unit and disposed on the light guide unit. Therefore, the present invention can adjust the direction of light output from the light source unit and increase the quantity of light transferred to the display unit, using a pattern formed in the holographical optical element unit, thereby improving the efficiency of light supplied from the light source unit and reducing the sizes of the light unit and the display device including the same.

An image display device, which converts an image generated and supplied from a display device, such as a liquid crystal (LC) display device or an electro luminescence (EL) display device, into a virtual image using a virtual image optical system and supplies the same to an observer, is commonly known.
Such an image display device is being applied to recently widely used wearable display devices such as, for example, head-mounted displays (HMDs), smart glasses, etc.
Further, the image display device is also being applied to head-up display devices, which display a virtual image indicating various information necessary for traveling to a point on a sight line of a pilot or a driver so that the virtual image is overlaid on the field of view ahead of the pilot or the driver.
A conventional image display device employs a polarization beam splitter in order to transfer light emitted from a light source to a display unit.
In general, a polarization beam splitter divides incident light into polarized components such that a P-wave component passes therethrough and an S-wave component is reflected therefrom and travels to a display unit. At this time, the display unit generates image light using the polarized light supplied from the polarization beam splitter.
However, there is a problem in that the polarization beam splitter is an expensive optical component and in that there is a limitation in the extent to which the size of the image display device can be reduced due to the space occupied by the polarization beam splitter.

Front light unit and image display device


A temperature and humidity sensor includes a substrate, a first electrode provided on the substrate, a linear second electrode at least part of which is so provided as to extend along the first electrode, and a moisture sensitive film provided between the part of the second electrode extending along the first electrode and the first electrode. The second electrode has a section that is formed in a spiral shape when viewed from above so as to form an inductor. With this, a precise oscillation circuit can be configured so that a temperature-humidity sensor small in size and capable of being easily manufactured can be provided.

Temperature and humidity sensors capable of detecting temperatures and humidity are disclosed in, for example, Japanese Unexamined Utility Model Registration Application Publication No. 7-20536 (Patent Document 1), Japanese Unexamined Patent Application Publication No. 6-148122 (Patent Document 2), and Japanese Unexamined Patent Application Publication No. 58-70153 (Patent Document 3). These temperature and humidity sensors include a moisture sensitive film for humidity measurement and detect humidity based on a change in magnitude of resistance or electrostatic capacity.
Further, detection of electrostatic capacity of a humidity sensor using an oscillation circuit is disclosed in Japanese Unexamined Patent Application Publication No. 61-14556 (Patent Document 4) and Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2012-508877 (Patent Document 5), for example.
Patent Document 1: Japanese Unexamined Utility Model Registration Application Publication No. 7-20536.
Patent Document 2: Japanese Unexamined Patent Application Publication No. 6-148122.
Patent Document 3: Japanese Unexamined Patent Application Publication No. 58-70153.
Patent Document 4: Japanese Unexamined Patent Application Publication No. 61-14556.
Patent Document 5: Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2012-508877.
It can be considered to configure an oscillation circuit as disclosed in Patent Documents 4 and 5 using capacitance and resistance of a humidity sensor based on an electrostatic capacity technique as disclosed in Patent Documents 1 through 3 as well as inductance of an inductor that is provided separate from the humidity sensor.
In the case where an oscillation circuit is a CR oscillation circuit, because, in general, the phase rotation is gentle and oscillation frequency precision is low, and the circuit is susceptible to parasitic capacitance and resistance components, electrostatic capacity of a humidity sensor is required to be large. Accordingly, in a humidity sensor in which a moisture sensitive film is provided between two electrodes like the sensors in Patent Documents 1 and 2, areas of the electrodes need to be enlarged, thickness of the moisture sensitive film needs to be thinned, and so on. However, miniaturization of the sensor becomes difficult if the areas of the electrodes are enlarged, and an amount of change in electrostatic capacitance becomes small and the manufacturing of the sensor becomes difficult if the thickness of the moisture sensitive film is thinned. In a humidity sensor provided with linear electrodes like the sensor in Patent Document 3, intervals between the electrodes need to be narrowed. However, narrowing the intervals makes it difficult to manufacture the sensor.


A method for providing state inheritance across command lists in a multi-threaded processing environment. The method includes receiving an application program that includes a plurality of parallel threads; generating a command list for each thread of the plurality of parallel threads; causing a first command list associated with a first thread of the plurality of parallel threads to be executed by a processing unit; and causing a second command list associated with a second thread of the plurality of parallel threads to be executed by the processing unit, where the second command list inherits from the first command list state associated with the processing unit.

Field of the Invention
The present invention relates to processing units and, in particular, to hardware for parallel command list generation.
Description of the Related Art
Microsoft® Direct3D 11 (DX11) is an API (Application Programming Interface) that supports tessellation and allows for improved multi-threading to assist developers in developing applications that better utilize multi-core processors.
In DX11, each core of a CPU (central processing unit) can execute threads of commands in parallel. Each core, or different threads on the same core, generates a separate command list via its own copy of a user-mode driver to increase performance of the software application. A command list is an API-level abstraction of a command buffer, which is a lower-level concept. The driver builds up a command buffer as it receives API commands from the application; a command list is manifested by a completed command buffer plus any additional implementation-defined meta information. The contents of a command list or command buffer are typically executed by a GPU (graphics processing unit). There is a single thread running on one of the CPU cores that submits command lists for execution in a particular order. The order of the command lists, and therefore the order of the command buffers, is determined by the application program. Command buffers are fed into the core via pushbuffers. The command buffers are composed of methods to be executed by the core, typically a GPU.
However, DX11 does not allow processor state inheritance across command lists. Instead, the processor state is reset at the beginning of every command list to a so-called "clean slate state." That means that each user-mode driver thread sets all the state parameters in the processor at the beginning of the command list. Not providing state inheritance across command lists provides a significant drawback since threads cannot cooperate when executing the application program. Moreover, the added processing cost of resetting the processor state to the clean slate state using dozens or hundreds of commands adds inefficiencies to the system, thereby reducing overall performance.
As the foregoing illustrates, there is a need in the art for an improved technique that addresses the limitations of current approaches set forth above.

Hardware for parallel command list generation


A method for processing an electronic document (ED) to infer columns in the ED, where the ED comprises a plurality of characters. The method includes generating a mark-up version of the ED having text-layout attributes of the characters in the ED, where the characters are grouped into paragraphs based on the text-layout attributes, and each paragraph corresponds to a paragraph bounding box surrounding a corresponding paragraph, generating border pieces by initiating a pair of left scan and right scan from each paragraph bounding box to identify any adjacent paragraph bounding box, and generating, based at least on the border pieces, column borders for use in inferring the columns in the ED, where at least one column has a vertically aligned portion of the paragraphs.

An electronic document (ED) (e.g., word processing document, spreadsheet, slide show, webpage, etc.) may include columns that are used to organize contents within the ED. A column is a vertically aligned portion of all paragraphs in the ED. Often, organizing paragraphs into columns improves readability of the ED. However, columns are not always explicitly identified (i.e., labeled and/or tagged) within the ED. Regardless, users still wish to search for the columns in the ED.

Column inferencer based on generated border pieces and column borders


A non-metallic centralizer for use with downhole operations. The centralizer is formed of a hollow, cylindrical body, a plurality of non-metallic blades protruding from the outer surface of the cylindrical body, and a plurality of wear buttons positioned on each of the plurality of blades, each of the wear buttons having a surface designed to reduce grabbing or sticking and wear of the hollow cylindrical body.

Oil and gas drilling is a complex process in which a variety of different types of equipment is used. Generally, once a well bore is drilled to a pre-set depth into the earth, a casing, typically a cylindrical tube, is run into the well bore and cemented in place. This provides structural stability to the well and permits the operator to selectively produce and treat only certain zones. To ensure that the casing is centered in the well bore, so that it does not lean against the wall of the well bore, a device called a centralizer is positioned around the casing. The purpose of centralizers is at least two-fold. First, while the casing string is being run into the hole, the centralizers reduce the torque and drag factors seen by the operator while getting the casing to depth (some are designed to allow the casing string to rotate independently to further reduce friction while running in the hole). Another purpose is to center (or centralize) the casing once it has been run to total depth, so that when the cement is pumped, it can circulate all around the casing string to provide a good cement job. Typically, this means that cement has successfully been placed 360 degrees around the casing without a noticeable "wide" or "narrow" side to the annulus. Centralizers are typically formed as hollow-cylindrical tubes, although other types of centralizer geometries are also known. Once the casing is in place and is centered in the well bore with the centralizer, cement is pumped around the outer surface of the casing, between the outer surface of the casing and the wall of the well bore, in order to seal the well bore and to structurally support the casing. Once total depth is reached and all casing strings are cemented in the hole, the well can be selectively completed to allow oil to be extracted through the casing in a controlled manner.
Use of a centralizer in this process is important because, if the casing is not centered in the well bore, the annular cement layer will not form a strong bond in the area where the casing makes contact with the wall of the well bore, thus reducing the mechanical integrity of the well and reducing the proficiency of zonal isolation between formations. Conventional centralizers come in a variety of types, including solid centralizers which are formed of a hollow, cylindrical body having longitudinal blades on an outer surface extending along a length thereof. The blades can be solid, or spring-like blades. Solid centralizers are typically formed of metal or polymer materials. The spring-like blades are typically made of a metal material. Conventional steel or aluminum centralizers work well for their intended purpose, but they are heavy, difficult to handle, and do not provide a low coefficient of friction between the centralizer and the well wall (either casing, if there is casing already set in the upper portion of the well, or formation) thus causing the centralizers to experience high torque and drag forces. Polymer-based centralizers have become an attractive alternative to metal or alloy-based centralizers to alleviate some of the problems above. Use of a polymer material greatly reduces the coefficient of friction, thus reducing the torque and drag forces to which the centralizers are objected. However, polymer-based centralizers have their own disadvantages, in that they are worn down more easily by the abrasive forces of running in hole due to their lower mechanical strength. As a result, they can be worn down completely in some cases, thereby eliminating the centralizing function and potentially causing poor cement jobs where the casing string lays directly against the formation, thus increasing the health, safety, and environmental concerns, since the zones in the formation may not be effectively isolated.
Some attempts have been made to include projections on an outer surface of the centralizer, particularly the centralizer blades, to reduce the frictional forces exerted on the centralizer. For example, metallic centralizers have been formed with Teflon™ projections on an outer surface of the centralizer in order to reduce torque and drag forces while running downhole. However, such projections are sacrificial, i.e. wear down quickly, as the mechanism to reduce frictional forces, thus reducing torque and drag on the centralizer. That can be effective when the underlying blades are made of metal so as not to be sacrificed themselves, but in the situation where the underlying blade is a polymer material, the blade itself would also be quickly sacrificed, causing the problems outlined above.
What is needed is a solution for polymer blades to reduce wear and abrasion without sacrificing the wear reducers and subsequently the polymer blades themselves.

Non-metallic centralizer for downhole drilling apparatus


A remote station for a wireless communication system including a base station is disclosed. The remote station includes a front end structure configured to receive packet data in parallel on a subset of carrier frequencies. Each packet data is preceded by a header field for identifying the remote station as the recipient of the packet data and the subset of carrier frequencies is based on a set of a corresponding number of multiple carrier frequencies.

1. Field
The present invention relates generally to wireless communication, and more specifically to cellular wireless communication.
2. Background
The field of communications has many applications including, e.g., paging, wireless local loops, Internet telephony, and satellite communication systems. An exemplary application is a cellular telephone system for mobile subscribers. (As used herein, the term "cellular" system encompasses both cellular and personal communications services (PCS) system frequencies.) Modern communication systems, such as a wireless communication system, designed to allow multiple users to access a common communications medium have been developed for such cellular systems. These modern communication systems may be based on multiple access techniques such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), space division multiple access (SDMA), polarization division multiple access (PDMA), or other modulation techniques known in the art. These modulation techniques demodulate signals received from multiple users of a communication system, enabling an increase in the capacity of the communication system. In connection therewith, various wireless communication systems have been established including, e.g., Advanced Mobile Phone Service (AMPS), Global System for Mobile communication (GSM), and other wireless systems.
In FDMA systems, the total frequency spectrum is divided into a number of smaller sub-bands and each user is given its own sub-band to access the communication medium. Alternatively, in TDMA systems, the total frequency spectrum is divided into a number of smaller sub-bands, each sub-band is shared among a number of users, and each user is allowed to transmit in predetermined time slots using that sub-band. A CDMA system provides potential advantages over other types of systems, including increased system capacity. In CDMA systems, each user is given the entire frequency spectrum for all of the time, but distinguishes its transmission through the use of a unique code.
Frequency hopping is a technique employed in a number of communication systems to provide frequency diversity over time. A frequency hopping system transmits on a different (usually narrowband) carrier (also referred to herein as "carrier frequency") during every transmission unit or slot. The sequence of the carriers that are employed (hopping sequence) is usually such that hops between non-contiguous frequencies are performed, in order to better combat frequency-selective fading. An example of a system employing frequency hopping is GSM/GPRS/EDGE (also referred to as GERAN).
Channel quality estimation, which includes signal strength measurements, is one of the key characteristics of those systems employing a fast feedback scheme, which then exploits multi-user diversity. In such systems, the receivers estimate the quality of their reception from a base station according to some predefined metric (e.g. C/I strength). This is generally performed after a beacon or pilot is measured. The beacon or pilot can be non-intermittently (CDM or Code Division Multiplex) or intermittently (TDM or Time Division Multiplex) transmitted by the base station. The receivers report the measured quality to the base station with appropriate messages or indications. The base station can then exploit this information to schedule subsequent transmissions, in a fashion that is depending on the details of the scheduling algorithm employed by the network itself. In particular, the network can use this information to schedule a transmission towards the user experiencing the best channel conditions (multi-user diversity), or adapting the modulation and coding to the channel conditions of the selected user (fast link adaptation).
The mechanism described above generally relies on the fact that the system employs the same carrier. In other words, the measurement process performed by a receiver takes place on the same frequency that is used for subsequent scheduled transmissions. This is one of the requirements for the scheduling process to be able to take into account the received reports. This requirement cannot be fulfilled in most frequency hopped systems. In such systems, beacon measurements and scheduled transmissions would often be on separate, uncorrelated carriers. Even if the channel is correlated (hopping within the channel coherence bandwidth), the interference could be drastically different from one carrier to another. Therefore, the reporting-scheduling process would not be able to exploit the selectivity of fading/interference thus providing the corresponding gain. Such a limitation is illustrated in FIG. 8 in which a remote station's receiver receives data 800 on carrier 1 in frame 2 and then hops to carrier 2 in frame 2 to receive data 802.

Apparatus and method for receiving packet data on a subset of carrier frequencies in a wireless communication system


A rotating tool system attachment on the spindle of a computer numerical control (“CNC”) machine includes a rotating assembly mounted on a static assembly. The rotating assembly provides a continuous supply of a wire material for deposition on a substrate during an additive manufacturing process. The rotating assembly includes a material supply housing a feedstock of wire mounted on a rotating spindle and a wire feeder configured to draw the wire from the wire supply and provide the wire for application during the additive manufacturing process. The tool system can be attached to the spindle of CNC machine to provide additive manufacturing capabilities to the CNC machine.

This disclosure relates generally to additive manufacturing. More specifically, this disclosure relates to a tool system that can be attached to the spindle of a milling machine that can be utilized in additive manufacturing.
Additive manufacturing is a process whereby components are manufactured in a layer-by-layer fashion. Additive manufacturing allows complex design features to be incorporated into parts where those complex design features were infeasible with previous manufacturing techniques. One form of additive manufacturing, referred to as solid state additive manufacturing ("SSAM"), involves applying a deposition material to a substrate without requiring the deposition material to undergo a phase change. In friction surfacing additive manufacturing ("FSAM"), which is a form of SSAM, friction and pressure between the deposition material and the substrate cause the deposition material to heat to near its melting point, thereby causing the deposition material to plasticize but not melt. The plasticized deposition material is then applied to the substrate. The layers of deposition material can be machined into a final form.
Computer numerical control ("CNC") machines are automated machine tools controlled by computers that execute pre-programmed sequences of control commands to have the machine tools shape a workpiece. CNC machines remove material from the workpiece, such as through grinding or milling, to shape the workpiece into the final form. CNC machines can include a machine spindle that can attach to various tool attachments to machine the workpiece. The computer is pre-programmed with instructions, and the computer controls the machine spindle and the tool attachment to shape the workpiece. The machine spindle can utilize multiple tool attachments to machine a single workpiece into the final form. The machine spindle can automatically change between multiple tool attachments as the workpiece is shaped.


A principal component analysis or an independent component analysis is conducted on the living body signals, e.g., local cerebral blood amount change signals obtained by the living body optical measurement to extract and display multiple component signals thereof. Signals other than the component signals containing noise are selected from these component signals automatically or manually, and the local cerebral blood amount change signals are reconstructed by using selected signals. The reconstructed signals is displayed and further subjected to the component analysis or the reconstruction as appropriate, and used for the profiling of information necessary for the diagnosis. Consequently, high-precision target signals can be obtained by completely removing external noise included in the living body signals, particularly the noise which cannot be adequately removed by the moving average and the filtering processings.

The optical measurement apparatus can measure blood circulation, blood flow and changes of the hemoglobin amount inside the living body by irradiating visible to infrared light onto the part of an object to be examined and by measuring a light that reflects inside the living body. When the optical measurement is performed while the object is loaded with stimulation or task, changes in blood circulation, blood flow and changes in the hemoglobin amount are observed, as compared with that without such stimulation or load. Accordingly, by comparing these changes with the known change patterns, distinctive attributes and characteristics of the subject can be identified.
Since this optical measurement apparatus can obtain information of the living body non-invasively and easily without restraining the subject, the clinical applications of the optical measurement apparatus is being put into clinical use.
The clinical applications of the optical measurement apparatus include the identification of an epileptic focus, the identification of the linguistic area in the pre-examination of epileptic surgery and the diagnosis of cerebral disease. In the examination to identify the linguistic area, for example, the area is identified by measuring local cerebral blood amount change signals for the right and left temporal lobes attributable to the language stimulation load and comparing the range of thus obtained local cerebral blood amount change signals. This is a very important examination to reduce the damage of cerebral function accompanying the removal of an epileptic focus, and a technique for accurately identifying the area is demanded.
However, the superimposition of the local cerebral blood amount change signals by the signals inside the living body and various outside noise signals including apparatus noise and . . . signals attributable to body movement makes it difficult to obtain highly precise local cerebral blood amount change signals.
The moving average and the filtering, as described in Patent Document 1, have been used to remove these noises, but they often failed to remove the noise sufficiently. For example, the spike noise components which generate at CH2 of the graph in FIG. 3 are characterized by a broad frequency band. In order to remove such noises by filtering or moving average, the filter should be applicable to a broader band or the moving average should be applicable for a longer period of time. However, they have such disadvantage that necessary local cerebral blood amount change signals are also removed.    Patent document 1: Japanese Patent Application No. 2002-177281

Optical measurement apparatus for living body


The invention relates to a process for simultaneously N(2)-acylating piperazic acid or an ester thereof and forming a bicyclic ring structure. The invention also relates to the use of that process step in a method of synthesizing a bicyclic compound useful as an intermediate for the production of an inhibitor of a caspase, particularly an inhibitor of interleukin-1xcex2 converting enzyme (xe2x80x9cICExe2x80x9d).

The invention relates to a process for simultaneously N(2)-acylating piperazic acid or an ester thereof and forming a bicyclic ring structure. The invention also relates to the use of that process step in a method of synthesizing a bicyclic compound useful as an intermediate for the production of an inhibitor of a caspase, particularly an inhibitor of interleukin-1xcex2 converting enzyme (xe2x80x9cICExe2x80x9d).
Compounds containing a bicyclic aza-containing ring systems have been prepared as conformationally restricted dipeptide surrogates for a variety of medically important compounds. In particular, such ring systems are present in angiotensin converting enzyme (ACE) inhibitors, such as Cilazapril(copyright), and in caspase inhibitors, such as inhibitors of interleukin-1xcex2 converting enzyme (ICE).
Current methods for synthesizing compounds containing these byciclic aza-containing ring systems have many disadvantages. The typical methods of forming this ring system have been described [EP 94,095, WO 95/35308, WO 97/22619, U.S. Pat. Nos. 5,656,627, 5,716,929 and 5,756,486 and J. P. Kim, et al., Tetrahedron Letters, 38, pp. 4935-4938 (1997)].
These methods involve multiple steps wherein an N(1)-protected piperazate must be provided. An appropriately protected amino acid, usually a xcex3-ester of glutamic acid, is coupled to the piperazate. After deprotection, the bicyclic system is then formed via an acid chloride coupling at the N(1) position.
The main disadvantages to such methods are the use of expensive reagents and the number of steps required for protection and deprotection making the overall process extremely time consuming. Moreover, these methods are often useful for research purposes but are not amenable to large scale production.
In order to be more commercially feasible, it would be desirable to produce compounds containing a byciclic aza-containing ring system in an easier, less expensive manner than has been previously described.
Applicant has solved this problem by providing a new method of simultaneously N(2)-acylating an N(1)-protected piperazic acid or an ester thereof and creating a bicyclic ring structure comprising that acylated piperazic acid or ester. Until now, formation of said bicylcic compound had not been achieved via N(2)-acylation.
This method involves the formation of the desired bicyclic system in two simple steps. This method also utilizes inexpensive reagents, require no selective protection/deprotection and is amenable to large scale production. Moreover, this method produces very little contaminating by-products. And this method preserves chirality between the N(1)-protected piperazic acid or an ester thereof and the resulting byciclic aza-containing ring system.
This method is particularly useful for producing an intermediate that may be subsequently converted into a caspase inhibitor, particularly an inhibitor of ICE, through additional steps known in the art.
The following abbreviations are used throughout this application:
t-Bu=tert-butyl
Et=ethyl
Cbz=carboxybenzyl
DMF=N,N-dimethylformamide
THF=tetrahydrofuran
MTBE=methyl tert-butyl ether
DCC=dicyclohexylcarbodiimide
EDC=1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride
Ac=acetyl.
DBU=1,8-Diazabicyclo[5.4.0]undec-7-ene
Fmoc=9-Fluorenylmethoxycarbonyl
According to one embodiment, the invention provides a process for converting compound G to compound H:
wherein:
R1 is a C2-4 straight chain alkyl substituted at the carbon alpha to the COOH moiety with N(R4)(R4), NO2 or N3 and optionally substituted at any other carbon with one or more substituents independently selected from C1-6 straight or branched alkyl, C2-4 straight or branched alkenyl or alkynyl, Oxe2x80x94[C1-6 straight or branched alkyl], Oxe2x80x94[C2-6 straight or branched alkenyl or alkynyl], oxo, or halo; wherein
each R4 is independently selected from H or an amino protecting group, with the proviso that both R4 are not simultaneously hydrogen;
R2 is selected from hydrogen, C1-6 straight or branched alkyl, C2-6 straight or branched alkenyl or alkynyl, or Ar, wherein said alkyl, alkenyl or alkynyl is optionally substituted with Ar; wherein
Ar is a saturated, partially saturated or unsaturated monocyclic or bicyclic ring structure, wherein each ring contains 5 to 7 ring atoms and each ring optionally contains from 1 to 3 heteroatoms selected from O, N and S; and
Ar is optionally substituted at one or more ring atoms with one or more substituents independently selected from C1-6 straight or branched alkyl, C2-6 straight or branched alkenyl or alkynyl, Oxe2x80x94[C1-6 straight or branched alkyl], Oxe2x80x94[C2-6 straight or branched alkenyl or alkynyl], oxo, halo, NO2, N(R4)(R4), or CN;
n is 0 or 1;
any substitutable ring carbon is optionally substituted by Q1; wherein
each Q1 is independently selected from xe2x80x94Ar1, xe2x80x94T1xe2x80x94R9, or (CH2)1-3xe2x80x94T1xe2x80x94R9; provided that when xe2x80x94Ar1 is substituted with a Q1 which comprises one or more additional xe2x80x94Ar1 groups, said additional xe2x80x94Ar1 groups are not substituted with Q1; wherein
Ar1 is a saturated, partially saturated or unsaturated monocyclic or bicyclic ring structure, wherein each ring contains 5 to 7 ring atoms and each ring optionally contains from 1 to 3 heteroatoms selected from O, N and S; and
wherein each Ar1 is optionally singly or multiply substituted at any ring atom by xe2x80x94N(R9)(R9), halo, xe2x80x94NO2, xe2x80x94CN, xe2x95x90O, xe2x80x94OH, -perfluoro C1-3 alkyl,
xe2x80x83or xe2x80x94Q1;
wherein each R9 is a C1-6 straight or branched alkyl group optionally substituted with one or more substituents independently selected from xe2x80x94F, xe2x95x90O or Ar1, wherein any R9 may be substituted with a maximum of two Ar1;
T1 is selected from a valence bond, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SOxe2x80x94, xe2x80x94SO2xe2x80x94, xe2x80x94NR10xe2x80x94, xe2x80x94NR10xe2x80x94C(O)xe2x80x94, xe2x80x94C(O)xe2x80x94, xe2x80x94Oxe2x80x94C(O)xe2x80x94, xe2x80x94C(O)xe2x80x94Oxe2x80x94, xe2x80x94C(O)xe2x80x94NR10xe2x80x94, Oxe2x80x94C(O)xe2x80x94NR10xe2x80x94, xe2x80x94NR10xe2x80x94C(O)xe2x80x94Oxe2x80x94, xe2x80x94NR10xe2x80x94C(O)xe2x80x94NR10xe2x80x94, xe2x80x94S(O)2xe2x80x94NR10xe2x80x94, xe2x80x94NR10xe2x80x94S(O)2xe2x80x94, or xe2x80x94NR10xe2x80x94S(O)2xe2x80x94NR10xe2x80x94; and
each R10 is independently selected from xe2x80x94H or C1-6 straight or branched alkyl;
The term xe2x80x9camino protecting groupxe2x80x9d, as used herein, means a moiety that prevents chemical reactions from occurring on the nitrogen atom to which that protecting group is attached. An amino protecting group must also be removable by a chemical reaction. Amino protecting groups that are acid cleavable include t-butoxycarbonyl. Examples of amino protecting groups that are base cleavable include Fmoc and alkyl carbamates. Amino protecting groups that are cleaved by hydrogenolysis include Cbz and allyloxycarbonyl. The phthalimide protecting group is typically removed by treatment with hydrazine.
In a preferred embodiment, R1 is substituted at the terminal carbon (i.e., the one bound to the N(1) ring nitrogen) with oxo, making R1 an acyl-containing moiety. More preferred is when R1 contains both the protected amine substituent and the oxo substituent. One of the most preferred R1 groups is:
In another preferred embodiment, n is 1.
In yet another preferred embodiment, R2 is t-butyl.
The method of this invention comprises the steps of:
(a) combining compound G with an organic solvent selected from dichloroethane, dichloromethane, toluene, chlorobenzene, chloroform, monoglyme, diglyme, THF, or CCl4;
(b) adding less than about 0.2 equivalents of DMF;
(c) adjusting the temperature of the resulting mixture to between 20xc2x0 C. and 100xc2x0 C.;
(d) adding about 2 or more equivalents of SOCl2 to said mixture over a period of between 2 and 24 hours.
Not all organic solvents may be used in step (a). The list of solvents set forth above are known to work. Other similar organic solvents may also work in the reaction and are to be considered part of the present invention. Preferably, the organic solvent is toluene or dichloroethane.
In step (b), it is preferred to use about 0.1 equivalent of DMF. Step (c) is preferably carried out at about 60xc2x0 C. In step (d), it is preferred to use about 2 equivalents of SOCl2 as a solution in toluene or dichloroethane. It is also preferred that the solution of SOCl2 be added slowly over a period of about 2 hours. Addition of the SOCl2 solution over less than 2 hours tends to drastically reduce the efficiency of the reaction.
According to another preferred embodiment, about 5 equivalents of base are added to the reaction at step (b). Preferably, the base is selected from pyridine, collidine, lutidine, NaHCO3, imidazole, triethylamine, N-methylmorpholine, diisopropylethylamine or K2CO3. Most preferably, the base is 2,6-lutidine.
Once the SOCl2 solution has been added, the reaction is complete. At that point compound H may be isolated by standard procedures, such as diluting the reaction with an organic solvent and then washing the solution first with NaHCO3 and then with brine, followed by drying over Na2SO4 and concentrating.
The conversion of compound G to compound H requires cyclization to occur at the N(2) position. This reaction is seemingly amenable to standard conditions well known in the art for forming an acid chloride intermediate. However, we determined that treating compound G with the known acid chloride forming reagents PCl5, oxalyl chloride, and SOCl2 under conditions well known in the art formed little or no desired product H.
Such well known reaction conditions include combining the starting compound with solvent, typically dichloromethane, and adding 1 equivalent or more of the acid chloride forming reagent (e.g. SOCl2, PCl5, or oxalyl chloride) at various temperatures. The details of the conditions used for some of these reactions are set forth in the examples. Such standard conditions were ineffective in converting compound G to desired compound H. Without being bound by theory, we believe that the method of converting compound G to compound H as set forth herein does not proceed via an acid chloride intermediate.
Extensive experimentation was required to achieve the reaction conditions of this invention. The results of these experiments were highly variable and yields varied greatly depending upon the specific conditions used. Only the method of this invention achieved the conversion of compound G to compound H in high yield ( greater than 75%) and purity.
Compound G may be obtained through standard synthetic routes well-known in the art. One such route is depicted below. Scheme 1 depicts the creation of intermediate E.
In Scheme 1, xe2x80x9cHalxe2x80x9d is any halogen; n and R2 are as defined above; and each Rxe2x80x2 is an independently selected carboxyl protecting group. Examples of suitable Rxe2x80x2 include, but are not limited to, alkyl, alkenyl, aryl, and aralkyl groups. Each of these steps is well-known in the art. Specifics concerning the conditions and reagents used at each step are set forth in the Examples.
The conversion of intermediate E to compound G is set forth in Scheme 2, below. That conversion may be achieved in either one of the two ways depicted in Scheme 2, depending upon the nature of R1.
In Scheme 2, Rxe2x80x2, R1, and R2 are as defined above. Reaction 4A comprises simultaneous deprotection of E and acylation if the amine protecting groups can be removed by hydrogenolysis, e.g., if the protecting group is Cbz. If not, a deprotection step must precede the addition of the anhydride F for the acylation reaction.
In order to completely deprotect at both nitrogens under transfer hydrogenation conditions, at least 2 equivalents of a proton donor (e.g., Et3SiH) must be added. If only one equivalent of the proton donor is added, deprotection occurs selectively at the N(2) nitrogen:
The resulting N(1) protected compound, M, is also useful as an intermediate in producing medically important compounds, such as the ICE inhibitors described herein and in PCT publications WO 97/22619 and WO 95/35308. Thus, this reaction to produce an N(1) protected compound is also an embodiment of the present invention.
When compound F contains substituents and is not symmetrical, reaction 4A may produce mixtures of compounds, wherein acylation of the N(1) nitrogen may occur at either C(O) functionality. This may be avoided by using substituents that favor the formation of the desired product. For example, in reaction 4A, the use of:
as compound F directs the formation of a compound wherein acylation of the N(1) nitrogen occurs at the C(O) functionality furthest away from the phthalimide substituent [J. A. Elberling, et al, Organic Preparations and Procedures Int., pp. 67-70 (1978)].
Reaction 4B depicts the formation of G from intermediate E in a stepwise manner. The two carboxy protecting groups (Rxe2x80x2) on compound E may be different, such that the N(1) protecting group (xe2x80x94COORxe2x80x2) can be selectively removed without removing the N(2) protecting group. Compound F can then be coupled at the N(1) position to afford compound E-1. Deprotection of the carboxyl protecting group affords compound G. Each of these steps is well known in the art. Specifics concerning the conditions and reagents used at each step are set forth in the Examples.
Intermediate compound G, and its subsequent conversion to compound H, may serve as the key intermediate and synthesis step, respectively, in an improvement in the synthesis of known caspase inhibitors, particularly inhibitors of interleukin-1xcex2 converting enzyme (xe2x80x9cICExe2x80x9d), such as those described in U.S. Pat. Nos. 5,716,929, 5,656,627, and 5,756,466 and in PCT publications WO 95/35308 and WO 97/22619.
Those inhibitors have the general formula (I):
wherein:
any ring is optionally substituted at any carbon by Q1, at any nitrogen by R5, and at any atom by xe2x95x90O, xe2x80x94OH, xe2x80x94COOH, or halogen;
X1 is CH or N;
g is 0 or 1;
m and mxe2x80x2 are independently 0, 1 or 2;
n is 0 or 1;
each J is independently selected from xe2x80x94H, xe2x80x94OH, or xe2x80x94F, provided that when a first and a second J are bound to a C, and said first J is xe2x80x94OH, then said second J is xe2x80x94H;
T is xe2x80x94Ar3, xe2x80x94OH, xe2x80x94CF3, xe2x80x94C(O)xe2x80x94C(O)xe2x80x94OH, xe2x80x94C(O)xe2x80x94OH or any biosteric replacement for xe2x80x94C(O)xe2x80x94OH;
R3 is xe2x80x94CN, xe2x80x94CHxe2x95x90CHxe2x80x94R9, CHxe2x95x90Nxe2x80x94Oxe2x80x94R9, xe2x80x94(CH2)1-3xe2x80x94T1xe2x80x94R9, xe2x80x94CJ2xe2x80x94R9, xe2x80x94C(O)xe2x80x94R13, or xe2x80x94C(O)xe2x80x94C(O)xe2x80x94N(R5)(R10);
T1 is xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SOxe2x80x94, xe2x80x94SO2xe2x80x94, xe2x80x94NR10xe2x80x94, xe2x80x94NR10xe2x80x94C(O)xe2x80x94, xe2x80x94C(O)xe2x80x94, xe2x80x94Oxe2x80x94C(O)xe2x80x94, xe2x80x94C(O)xe2x80x94Oxe2x80x94, xe2x80x94C(O)xe2x80x94NR10xe2x80x94, Oxe2x80x94C(O)xe2x80x94NR10xe2x80x94, xe2x80x94NR10xe2x80x94C(O)xe2x80x94Oxe2x80x94, xe2x80x94NR10xe2x80x94C(O)xe2x80x94NR10xe2x80x94, xe2x80x94S(O)2xe2x80x94NR10xe2x80x94, xe2x80x94NR10xe2x80x94S(O)2xe2x80x94 or xe2x80x94NR10xe2x80x94S(O)2xe2x80x94NR10xe2x80x94;
each R5 is independently selected from xe2x80x94H, xe2x80x94Ar1, xe2x80x94C(O)xe2x80x94Ar1, xe2x80x94S(O)2xe2x80x94Ar1, xe2x80x94R9, xe2x80x94C(O)xe2x80x94NH2, xe2x80x94S(O)2xe2x80x94NH2, xe2x80x94C(O)xe2x80x94R9, xe2x80x94C(O)xe2x80x94Oxe2x80x94R9, xe2x80x94S(O)2xe2x80x94R9, xe2x80x94C(O)xe2x80x94N(R10)(Ar1), xe2x80x94S(O)2xe2x80x94N(R10)(Ar1), xe2x80x94C(O)xe2x80x94N(R10)(R9), or xe2x80x94S(O)2xe2x80x94N(R10)(R9);
each R9 is a C1-6 straight or branched alkyl group optionally singly or multiply substituted with xe2x80x94OH, xe2x80x94F, xe2x95x90O or Ar1, wherein any R9 may be substituted with a maximum of two Ar1;
each R10 is independently selected from xe2x80x94H or C1-6 straight or branched alkyl;
R13 is xe2x80x94H, xe2x80x94Ar1, xe2x80x94R9, xe2x80x94T1xe2x80x94R9 or xe2x80x94(CH2)1-3xe2x80x94T1xe2x80x94R9;
each Ar1 is a cyclic group independently selected from a monocyclic, bicyclic or tricyclic aryl group containing 6, 10, 12 or 14 carbon atoms; a monocyclic, bicyclic or tricyclic cycloalkyl group containing between 3 and 15 carbon atoms, said cycloalkyl group being optionally benzofused; or a monocyclic, bicyclic or tricyclic heterocycle group containing between 5 and 15 ring atoms and at least one heteroatom group selected from xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SOxe2x80x94, xe2x80x94SO2xe2x80x94, xe2x95x90Nxe2x80x94, or xe2x80x94NHxe2x80x94, wherein said heterocycle group optionally contains one or more double bonds and optionally comprises one or more aromatic rings;
Ar3 is a cyclic group selected from phenyl, a 5-membered heteroaromatic ring or a 6-membered heteroaromatic ring, wherein said heteroaromatic rings comprise from 1-3 heteroatom groups selected from xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SOxe2x80x94, xe2x80x94SO2xe2x80x94, xe2x95x90Nxe2x80x94, or xe2x80x94NHxe2x80x94;
wherein each Ar1 or Ar3 is optionally singly or multiply substituted at any ring atom by xe2x80x94NH2, xe2x80x94C(O)xe2x80x94OH, xe2x80x94Cl, xe2x80x94F, xe2x80x94Br, xe2x80x94I, xe2x80x94NO2, xe2x80x94CN, xe2x95x90O, xe2x80x94OH, -perfluoro C1-3 alkyl,
xe2x80x83or xe2x80x94Q1; and
each Q1 is independently selected from xe2x80x94Ar1, xe2x80x94R9, xe2x80x94T1xe2x80x94R9, or (CH2)1-3xe2x80x94T1xe2x80x94R9; provided that when xe2x80x94Ar1 is substituted with a Q1 which comprises one or more additional xe2x80x94Ar1 groups, said additional xe2x80x94Ar1 groups are not substituted with Q1.
Preferably, the process of this invention is used as a step in the synthesis of a compound of formula I, wherein n is 1 and m is 2.
In another preferred embodiment, the process of this invention is used as a step in the synthesis of a compound of formula I, wherein R5 is an acyl moiety selected from xe2x80x94C(O)xe2x80x94Ar1, xe2x80x94C(O)xe2x80x94NH2, xe2x80x94C(O)xe2x80x94R9, xe2x80x94C(O)xe2x80x94Oxe2x80x94R9, xe2x80x94C(O)xe2x80x94N(R10)(Ar1), or xe2x80x94C(O)xe2x80x94N(R10)(R9).
In yet another preferred embodiment, the process of this invention is used as a step in the synthesis of a compound of formula I, wherein X1 is CH; each J is H; mxe2x80x2 is 1; T is xe2x80x94COOH or a biosteric replacement for xe2x80x94COOH; g is 0; and R3 is xe2x80x94C(O)xe2x80x94R13.
In the most preferred embodiment of using the process of this invention as a step in the synthesis of a compound of formula I, said compound has the structure:
Alternatively, the process of this invention may be used as a step in the synthesis of a compound of the formula (II):
wherein:
Z is selected from
p is 1 or 2;
each R5xe2x80x2 is independently selected from xe2x80x94C(O)xe2x80x94R10xe2x80x2, xe2x80x94C(O)Oxe2x80x94R9xe2x80x2, xe2x80x94C(O)xe2x80x94N(R10xe2x80x2)(R10xe2x80x2), xe2x80x94S(O)2xe2x80x94R9xe2x80x2, xe2x80x94S(O)2xe2x80x94NHxe2x80x94R10xe2x80x2, xe2x80x94C(O)xe2x80x94CH2xe2x80x94Oxe2x80x94R9xe2x80x2, xe2x80x94C(O)C(O)xe2x80x94R10xe2x80x2, xe2x80x94R9xe2x80x2, xe2x80x94H, xe2x80x94C(O)C(O)xe2x80x94OR10xe2x80x2, or xe2x80x94C(O)C(O)xe2x80x94N(R9xe2x80x2)(R10xe2x80x2);
each R9xe2x80x2 is independently selected from xe2x80x94Ar1 or a xe2x80x94C1-6 straight or branched alkyl group optionally substituted with Ar1, wherein the xe2x80x94C1-6 alkyl group is optionally unsaturated;
each R10xe2x80x2 is independently selected from xe2x80x94H, xe2x80x94Ar1, a xe2x80x94C3-6 cycloalkyl group, or a xe2x80x94C1-6 straight or branched alkyl group optionally substituted with Ar3xe2x80x2, wherein the xe2x80x94C1-6 alkyl group is optionally unsaturated;
R13xe2x80x2 is selected from H, Ar1, or a C1-6 straight or branched alkyl group optionally substituted with Ar1, xe2x80x94CONH2, xe2x80x94OR5xe2x80x2, xe2x80x94OH, xe2x80x94OR9xe2x80x2, or xe2x80x94CO2H;
each R51 is independently selected from R9xe2x80x2, xe2x80x94C(O)xe2x80x94R9xe2x80x2, xe2x80x94C(O)xe2x80x94N(H)xe2x80x94R9xe2x80x2, or two R51 taken together form a saturated 4-8 member carbocyclic ring or heterocyclic ring containing xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, or xe2x80x94NHxe2x80x94;
each R21 is independently selected from xe2x80x94H or a xe2x80x94C1-6 straight or branched alkyl group;
Y2 is xe2x80x94H2 or xe2x95x90O
each Ar1 is a cyclic group independently selected from the set consisting of an aryl group which contains 6, 10, 12, or 14 carbon atoms and between 1 and 3 rings and an aromatic heterocycle group containing between 5 and 15 ring atoms and between 1 and 3 rings, said heterocyclic group containing at least one heteroatom group selected from xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SOxe2x80x94, SO2, xe2x95x90Nxe2x80x94, and xe2x80x94NHxe2x80x94, said heterocycle group optionally containing one or more double bonds, said heterocycle group optionally comprising one or more aromatic rings, and said cyclic group optionally being singly or multiply substituted by xe2x80x94Q1;
each Q1 is independently selected from the group consisting of xe2x80x94NH2, xe2x80x94CO2H, xe2x80x94Cl, xe2x80x94F, xe2x80x94Br, xe2x80x94I, xe2x80x94NO2, xe2x80x94CN, xe2x95x90O, xe2x80x94OH, -perfluoro C1-3 alkyl, R5xe2x80x2, xe2x80x94OR5xe2x80x2, xe2x80x94NHR5xe2x80x2, OR9xe2x80x2, xe2x80x94N(R9xe2x80x2)(R10xe2x80x2), R9xe2x80x2, xe2x80x94C(O)xe2x80x94R10xe2x80x2, and
provided that when xe2x80x94Ar1 is substituted with a Q1 group which comprises one or more additional xe2x80x94Ar1 groups, said additional xe2x80x94Ar1 groups are not substituted with another xe2x80x94Ar1.
Preferably, the process of this invention is used as a step in the synthesis of a compound of formula II, wherein Y2 is O and R21 is H.
In another preferred embodiment, the process of this invention is used as a step in the synthesis of a compound of formula II, wherein R5xe2x80x2 is selected from xe2x80x94C(O)xe2x80x94R10xe2x80x2, xe2x80x94C(O)Oxe2x80x94R9xe2x80x2, xe2x80x94C(O)xe2x80x94N(R10xe2x80x2)(R10xe2x80x2), xe2x80x94C(O)xe2x80x94CH2xe2x80x94Oxe2x80x94R9xe2x80x2, xe2x80x94C(O)C(O)xe2x80x94R10xe2x80x2, xe2x80x94C(O)C(O)xe2x80x94OR10xe2x80x2, or xe2x80x94C(O)C(O)xe2x80x94N(R9xe2x80x2)(R10xe2x80x2).
In yet another preferred embodiment, the process of this invention is used as a step in the synthesis of a compound of formula II, wherein Z is
p is 1 and R51 is selected from xe2x80x94Ar1, xe2x80x94C1-6 straight or branched alkyl or xe2x80x94C1-6 straight or branched alkyl substituted with Ar1.
In the most preferred embodiment of using the process of this invention as a step in the synthesis of a compound of formula II, said compound has the structure:
In the synthesis of these inhibitors, R1 contains an amino protecting substituent. Preferably R1
The conversion of compound G to compounds of formula I or II is set forth in Scheme 3 below.
In Scheme 3, R2-R5 C, g, J, m, mxe2x80x2, n, X1, Z, and T are as defined above. Gxe2x80x2 is optionally substituted at any ring carbon with one or more substituents selected from C1-6 straight or branched alkyl, C2-4 straight or branched alkenyl or alkynyl, Oxe2x80x94[C1-6 straight or branched alkyl], Oxe2x80x94[C2-6 straight or branched alkenyl or alkynyl], oxo, halo or Q1;
Each of these steps is well known in the art. Compounds of formula J may be readily obtained from compound Hxe2x80x2 by deprotection of the amine. When R1 is
the removal of the amine protecting substituent is typically carried out with hydrazine. Coupling of amine J to R5 is achieved with standard coupling reagents, such as EDC, DCC or acid chloride to afford compound K.
Depending upon the nature of R2, its hydrolysis may be achieved with an acid (when R2 is t-butyl), a hydroxide (when R2 is any other alkyl, alkenyl, alkynyl, or Ar) or hydrogenolysis (when R2 is an Ar-substituted alkyl, alkenyl or alkynyl). This produces the corresponding acid L from the ester K.
The acid L is then coupled using standard coupling conditions to the amine
to afford a compound of formula I or to the amine xe2x80x94NHxe2x80x94Z to afford a compound of formula II. These standard coupling conditions include, but are not limited to, EDC, DCC, or acid chloride-mediated coupling.
According to another embodiment, the invention provides a process for converting a compound of formula G to a compound of formula I or II comprising the steps of:
a) combining compound G with an organic solvent selected from dichloroethane, dichloromethane, toluene, chlorobenzene, chloroform, monoglyme, diglyme, THF, or CCl4;
b) adding less than about 0.2 equivalents of DMF;
c) adjusting the temperature of the resulting mixture to between 20xc2x0 C. and 100xc2x0 C.;
d) adding about 2 or more equivalents of SOCl2 to said mixture over a period of between 2 and 24 hours;
e) removing of the amine protecting group from compound H to form amine J;
f) coupling of R5 to amine J to form ester K;
g) deprotecting ester K to form acid L; and
h) coupling acid L to:
i)
xe2x80x83to form a compound of formula I; and
ii) xe2x80x94NHxe2x80x94Z to form a compound of formula II.

Method for synthesizing caspase inhibitors


A process is presented for removing the fouling problems associated with the product recovery in a methanol to olefins conversion process. The process includes passing the quenched MTO process stream to a product separator, wherein an intermediate stream is generated and includes water and heavier hydrocarbons. The intermediate stream is processed to remove the buildup of heavier hydrocarbons.

The use of plastics and rubbers are widespread in today's world. The production of these plastics and rubbers are from the polymerization of monomers which are generally produced from petroleum. The monomers are generated by the breakdown of larger molecules to smaller molecules which can be modified. The monomers are then reacted to generate larger molecules comprising chains of the monomers. An important example of these monomers is light olefins, including ethylene and propylene, which represent a large portion of the worldwide demand in the petrochemical industry. Light olefins, and other monomers, are used in the production of numerous chemical products via polymerization, oligomerization, alkylation and other well-known chemical reactions. These monomers are essential building blocks for the modern petrochemical and chemical industries.
Light olefins can be generated through the conversion of oxygenates to olefins. A common process is the methanol to olefins (MTO) conversion process. The process involves many steps and includes recycling of streams such as water generated by the MTO process. However, the MTO conversion process generates solid materials and heavy hydrocarbons that can present fouling issues in the process units. Specifically, in the MTO process, unacceptable levels of contaminants, or heavy components, if not removed, can be carried over to the oxygenate stripper. The subsequent fouling of heat exchangers and downstream devices increased costs, through subsequent energy losses, and need for increased downtime to refurbish fouled devices, in particular heat exchangers. The fouling issues have been found to be the buildup of heavy hydrocarbons including highly substituted aromatics, such as hexamethyl benzene (HMB) and pentamethyl benzene (PMB).
U.S. Pat. No. 9,452,957, the entirety of which is incorporated herein by reference, discloses a process which separates heavy hydrocarbons in an MTO conversion process. While presumably effective for its intended purpose, there is a continual desire for efficient and effective processes for separating heavy hydrocarbons from an MTO reactor effluent.

Processes for separating an MTO effluent


According to a method and apparatus for calculating thermal sensitivity, a set temperature .theta..sub.(th) is calculated on the basis of an air temperature Ta and a clothing thermal resistance Icl. Thermal energy H.theta..sub.(th) is supplied to a heater capable of adjusting a sensor temperature Tcr so as to set the sensor temperature Tcr to be equal to the set temperature .theta..sub.(th). The thermal sensitivity is calculated on the basis of the air temperature Ta, the clothing thermal resistance Icl, the set temperature .theta..sub.(th), and the thermal energy H.theta..sub.(th).

The present invention relates to a thermal sensitivity calculating apparatus for calculating thermal sensitivity, e.g., an equivalent temperature (Teq), felt by a human body.
An equivalent temperature Teq is used as an evaluation index of a thermal environment felt by a human body, i.e., thermal sensitivity.
As the first method of obtaining this equivalent temperature Teq, a method has been proposed, in which an equivalent temperature Teq.sup.* substantially equal to the equivalent temperature Teq is obtained by measuring a radiant temperature Tr, an air temperature Ta, and an air velocity Vair by using different sensors, and performing predetermined arithmetic processing of the measured values. This method requires complicated arithmetic processing, and the processing time is undesirably prolonged.
Under the circumstances, as the second method of obtaining the equivalent temperature Teq, a method is proposed, in which a heater is incorporated in a module main body, and the amount of power to be supplied to the heater is controlled to always keep a temperature (sensor temperature) T.sub.cr of the module main body to be a constant value (e.g., 36.5.degree. C.). According to this method, the equivalent temperature Teq.sup.* can be calculated by measuring the amount of power to be supplied to the heater and performing predetermined arithmetic processing of the measured value.
In the second method described above, however, since an environment measuring section constituted by the module main body and the heater is much smaller than a human body, as is apparent, the air current sensitivity of the measuring section is much larger than that of the human body.
This difference in air current sensitivity indicates that the equivalent temperatures Teq and Teq.sup.* remain substantially equal to each other at an air velocity of less than 0.1 m/s but differ from each other when the air velocity is increased to 0.1 m/s or more. More specifically, at an air velocity of 0.1 m/s or more, the equivalent temperature Teq.sup.* becomes lower than the equivalent temperature Teq. As a result, accurate measurement cannot be performed.
According to the second method described above, however, there is a critical drawback that accurate measurement cannot be performed when the air velocity Vair is high, in spite of the advantage that the radiant temperature Tr, the air temperature Ta, and the air velocity Vair can be integrally measured, i.e., the advantage that the arithmetic processing can be simplified.

Method and apparatus for calculating thermal sensitivity


Disclosed is a process for making middle distillate and lower olefins. The process includes catalytically cracking a gas oil feedstock within a riser reactor zone by contacting under suitable catalytic cracking conditions within the riser reactor zone the gas oil feedstock with a middle distillate selective cracking catalyst that comprises amorphous silica alumina and a zeolite to yield a cracked gas oil product and a spent cracking catalyst. The spent cracking catalyst is regenerated to yield a regenerated cracking catalyst. Within an intermediate cracking reactor such as a dense bed reactor zone and under suitable high severity cracking conditions a gasoline feedstock is contacted with the regenerated cracking catalyst to yield a cracked gasoline product and a used regenerated cracking catalyst. The used regenerated cracking catalyst is utilized as the middle distillate selective catalyst.

The fluidized catalytic cracking (FCC) of heavy hydrocarbons to produce lower boiling hydrocarbon products such as gasoline is well known in the art. FCC processes have been around since the 1940's. Typically, an FCC unit or process includes a riser reactor, a catalyst separator and stripper, and a regenerator. A FCC feedstock is introduced into the riser reactor wherein it is contacted with hot FCC catalyst from the regenerator. The mixture of the feedstock and FCC catalyst passes through the riser reactor and into the catalyst separator wherein the cracked product is separated from the FCC catalyst. The separated cracked product passes from the catalyst separator to a downstream separation system and the separated catalyst passes to the regenerator where the coke deposited on the FCC catalyst during the cracking reaction is burned off the catalyst to provide a regenerated catalyst. The resulting regenerated catalyst is used as the aforementioned hot FCC catalyst and is mixed with the FCC feedstock that is introduced into the riser reactor.
U.S. Pat. No. 3,928,172 discloses an arrangement of reactors that provides for the gasoline product of gas oil cracking to be re-cracked in a dense fluid catalyst bed reaction zone with freshly regenerated catalyst. The used catalyst from the gasoline re-cracking reactor is used for the gas oil cracking in a riser cracking zone; however, there is no teaching that a portion of the freshly regenerated catalyst may bypass the gasoline re-cracking reactor to be used in combination with the used catalyst from gasoline re-cracking reactor in the riser cracking zone. This patent focuses on the production of gasoline that satisfies certain quality specifications, and, thus, it is not directed to a process for converting gas oil to preferentially yield middle distillate and lower olefin products. Therefore, the patent fails to recognize numerous various means by which higher lower olefin and middle distillate yields may be achieved in the above-described process arrangement involving the re-cracking of heavy gasoline in the boiling range of 260° F. to 380° F.
U.S. Pat. No. 5,372,704 discloses a process for the cracking and re-cracking of liquid hydrocarbons. Feed to the re-cracking reactor may be FCC heavy naphtha. The re-cracking reactor uses spent catalyst from the FCC reactor with up to 100% of the catalyst used in the re-cracker reactor being spent FCC catalyst. The re-cracking catalyst activity is controlled by mixing hot regenerated FCC catalyst with the spent FCC catalyst. The re-cracking catalyst mixture includes from 50 to 95 wt % spent FCC catalyst and from 5 to 50 wt % regenerated FCC catalyst. Spent re-cracking catalyst may be used in the FCC riser reactor along with hot regenerated FCC catalyst. This patent focuses on improving the quality of FCC gasoline and generating higher yields of gasoline from refinery streams, and it is not directed to a process for converting gas oil to preferentially yield middle distillate and lower olefin products. Therefore, the patent fails to recognize numerous various means by which higher lower olefin and middle distillate yields may be achieved in its process.
As noted above, many FCC processes and systems are designed so as to provide for a high conversion of the FCC feedstock to products having boiling temperatures in the gasoline boiling range. There are situations, however, when it is desirable to provide for the high conversion of the FCC feedstock to middle distillate boiling range products, as opposed to gasoline boiling range products, and to lower olefins. However, making lower olefins requires high severity and high reaction temperature reaction conditions. These conditions normally result in low middle distillate product yield and poor middle distillate product quality. It is therefore very difficult in the conventional cracking of hydrocarbons to provide simultaneously for both a high yield of lower olefins and a high yield of middle distillate products.

This patent is subject to a terminal disclaimer.

Method and apparatus for making a middle distillate product and lower olefins from a hydrocarbon feedstock


In order to provide a dispersion-compensating optical fiber able to be applied over a broad wavelength band, having a large effective area, and as a result, suppressing the occurrence of non-linear effects, the present invention comprises a dispersion-compensating optical fiber that compensates chromatic dispersion of a 1.3 μm single-mode optical fiber over the entire wavelength range of 1.53-1.63 μm characterized in that, chromatic dispersion at a wavelength of 1.55 μm is −50 ps/nm/km or less, the dispersion slope is negative over the entire wavelength range of 1.53-1.63 μm, a cutoff wavelength is provided at which there is substantially single-mode propagation, bending loss is 30 dB/m or less, effective area is 20 μm2 or more, and the absolute value of chromatic dispersion during compensation of the chromatic dispersion of a 1.3 μm single-mode optical fiber serving as the target of compensation is 0.5 ps/nm/km or less.

1. Field of the Invention
The present invention relates to a dispersion-compensating optical fiber and an optical transmission path. The present specification is based on patent applications filed in Japan (Japanese Patent Application No. 2000-54646, Japanese Patent Application No. 2000-159071, Japanese Patent Application No. 2000-216587, Japanese Patent Application No. 2000-241547 and Japanese Patent Application No. 2000-266169), and the contents described in said Japanese patent applications are incorporated as a part of the present specification.
2. Background Art
Optical communication systems that transmit at the 1.55 μm wavelength band (the so-called C-band: typically covering a range of about 1.53-1.57 μm) are used practically by combining single-mode optical fibers for transmission such as a "1.3 μm band dispersion single-mode optical fiber having nearly zero chromatic dispersion at a wavelength of 1.3 μm" or a "standard single-mode optical fiber", and dispersion-compensating optical fibers.
For example, since the chromatic dispersion of a 1.3 μm single-mode optical fiber is roughly +17 ps/nm/km (positive chromatic dispersion) at a wavelength of 1.55 μm, when this is used to perform optical communications in the 1.55 μm wavelength band, considerable chromatic dispersion occurs. In contrast, since dispersion-compensating optical fibers have negative chromatic dispersion in which the absolute value in the 1.55 μm wavelength band is comparatively large, by combining these in the manner described above, the chromatic dispersion that occurs in ordinary 1.3 μm single-mode optical fibers extending, for example, for several tens of kilometers, can be compensated by a dispersion-compensating optical fiber having a comparatively short used length.
In addition, since the dispersion slope of a 1.3 μm single-mode optical fiber in the 1.55 μm wavelength band is roughly +0.06 ps/nm2/km (positive value), in order to compensate according to this dispersion slope with the chromatic dispersion, it is preferable to use a dispersion-compensating optical fiber having a negative dispersion slope. If dispersion slope can be compensated, this can also be used in applications involving transmission of a plurality of pulsed light having different wavelengths as in the manner of high-density wavelength division multiplexing transmission (DWDM transmission).
On the other hand, transmission characteristics deteriorate when non-linear effects occur in optical fibers. In the case of propagating high-power signal light in the manner of optical communication systems using wavelength division multiplexing transmission and an optical amplifier that have already been used practically in particular, due to the high power density, non-linear effects tend to occur easily, resulting in the need for technology that suppress non-linear effects.
Although methods for suppressing non-linear effects have been proposed, including a method in which the non-linear refractive index of the optical fiber is decreased by reducing the amount of Ge, F or other dopant doped to the core, and a method in which Brillouin scattering, which is one of the non-linear effects, is suppressed by changing the outer diameter of the optical fiber when drawing from the fiber base material, enlargement of the effective area (which may be abbreviated as Aeff) of the optical fiber is a particularly effective method.
However, in the above-mentioned dispersion-compensating optical fibers of the prior art, although such optical fibers have been developed which attempt to improve the so-called performance index (FOM; Figure of Merit), which indicates the amount of chromatic dispersion per unit loss, while also being able to compensate the dispersion slope, it has been difficult to simultaneously realize these characteristics along with enlargement of Aeff.
In addition, a system that performs optical communication in the so-called L-band (1.57-1.63 μm), which is of a longer wavelength than the C-band that has been used in the past, has recently been examined. Wavelength bands used for optical transmission at present or in the future are reaching or will reach a broad range of 1.45-1.63 μm, which includes the so-called S-band (1.45-1.53 μm).
Thus, although a dispersion-compensating optical fiber is required that is able to compensate the chromatic dispersion and dispersion slope of single-mode optical fibers for transmission in not only the C-band, but also other wavelength bands such as the S-band and L-band, conventional dispersion-compensating optical fibers have been unable to adequately satisfy this requirement. Consequently, these optical fibers have been inadequate particularly in applications to wavelength multiplexing, high-speed, long-distance transmission and so forth.
In addition, although large Aeff is also simultaneously required in these wavelength bands, conventional dispersion-compensating optical fibers were unable to accommodate this requirement as well.
Moreover, dispersion-compensated optical fibers are required to have single-mode propagation at the used wavelength band and bending loss that is small enough to allow practical use.
In addition, these dispersion-compensating optical fibers of the dispersion slope-compensating type have conventionally been incorporated in optical communication systems in the form of modules by being housed in, for example, a suitable case. Recently however, studies have been conducted that attempt to form the dispersion-compensating optical fiber itself into a cable and insert it into the transmission path, and several of these attempts have been reported.
This is because, if a dispersion-compensating optical fiber itself was able to be used as a transmission path, since it would be possible to eliminate the arranging space of the module, while also being able to substantially shorten the length of the optical fiber through which the optical signals are transmitted, the transmission characteristics of the overall system could be improved.
However, although reports have been made regarding dispersion-compensating optical fibers of the dispersion slope-compensating type that place the emphasis on compensation of chromatic dispersion and dispersion slope as well as reduction of loss, there have been no effective studies or reports made regarding enlargement of Aeff.
Suppression of non-linear effects is essential for achieving the faster speeds, longer distances and wavelength multiplexing described above, and in the case of inserting a dispersion-compensating optical fiber of the dispersion slope-compensating type in the form of a transmission path, there are cases in which it is difficult to achieve practical use unless Aeff is provided to an extent that is able to effectively suppress non-linear effects.
In addition, dispersion-compensating optical fibers of the prior art required that, for example, the refractive index of the core center be larger than that of an ordinary single-mode optical fiber, and had the problem of increasing the amount of dopant doped to the core center.
Normally, a core center is formed from quartz glass doped with a dopant such as germanium etc. that provides the action of increasing refractive index, while the cladding provided around an outer periphery of the core is formed from pure quartz glass or fluorine-doped quartz glass, etc.
In addition, the glass transition point of the quartz glass decreases proportional to the amount of dopant doped. Thus, if the amount of dopant doped increases, since the difference in viscosities of the core and cladding increases when the fiber base material is heated and melted to draw the optical fiber, the drawing rate and drawing temperature are restricted from the viewpoint of mechanical strength, thereby resulting in the problem of being unable to obtain a dispersion-compensating optical fiber with low loss.
In addition, if the refractive index of the core center is high, Aeff tends to decrease. This results in greater susceptibility to the occurrence of non-linear effects, thereby leading to the problem of deterioration of transmission characteristics.
However, in the dispersion-compensating optical fibers of the prior art, optical fibers realizing chromatic dispersion and dispersion slope compensating effects while enabling the refractive index of the core center to be comparatively small have been unable to be obtained, resulting in problems in terms of ease of production, low loss and non-linearity, etc.
In addition, if Aeff is enlarged in an example of a dispersion-compensating optical fiber of the prior art, the absolute value of chromatic dispersion tends to become smaller, resulting in the problem of the length for compensating single-mode optical fibers for transmission becoming excessively long.

Dispersion-compensating optical fiber and hybrid transmission line


A mat perimeter system comprising a mat module, a connector, a resilient border and a resilient corner is disclosed. The mat module has upstanding studs attached on one edge and matching stud receptacles formed into another edge. The studs fit within the stud receptacles allowing the building of a modular mat system. Connectors having two spaced apart rows of studs attached to a base fit within the stud receptacles and allow the creation of another row of studs. Borders and corners fit over the studs to create a desirable perimeter. The studs have locking lips for interlocking with lip recesses formed within the stud receptacles and for interlocking with stud slot lip recesses formed into the borders and corners.

Interlocking modular mats serve a useful purpose. They allow a custom sized mat to be quickly constructed. Current interlocking modular mats have interlocking studs and stud receptacles. Modular mats can be connected to each other by inserting the studs of one mat into the stud receptacles of another mat. Once the custom sized mat is constructed there is a need for borders and corners which can be cost effectively manufactured and securely attached to the mat.
The present invention provides a mat perimeter system comprising a mat module, a connector, a resilient border and a resilient corner which can be cost effectively manufactured. The mat modules, connectors, borders and corners can be tightly secured to each other. The connection strength is further increased by the use of interlocking lips and lip recesses.