A remote processor (RP) adapted for use with a telephone system is provided according to one embodiment of the invention. The RP includes a communication interface capable of communicating with a service control point (SCP) of the telephone system and a processing system. The processing system is configured to present a troubleshooting graphical interface and present one or more troubleshooting tools to be used in troubleshooting RP operations and in troubleshooting RP interactions with the telephone system.

1. Field of the Invention
The invention is related to the field of communications, and in particular, to a troubleshooting interface for client-routed toll free telephone calls in a telephone communication system.
2. Description of the Prior Art
Modern telephone communications systems commonly offer a toll-free call service. In a toll-free telephone call, the call recipient pays for the call, and not the caller. Toll-free call services are therefore widely used by businesses in order to encourage calls from customers and potential customers.
Another popular use for toll-free calls are customer service functions, wherein customers can use a toll-free number to obtain information, register complaints, apply for services, make purchases, etc. A large toll-free service client may possess multiple toll-free call centers, and may desire the capability to route incoming toll-free calls to specific call center locations. This may include routing such traffic in order to manage traffic flow and keep a call center from being overloaded. This may also include routing to avoid traffic problems due to transient conditions, such as telephone network problems, differences in hours between locations, to handle special events such as sales promotions, to accommodate service downtime requirements, etc.
Toll-free calls are typically routed by a service control point (SCP). The SCP is in communication with a telephone communication network and a remote processor (RP). The RP provides routing information to the SCP, including real-time routing information and routing changes. When routing is to be changed, routing data stored in the RP may be modified in order to affect the change. In operation, the SCP receives a called telephone number (i.e., a 1-800 telephone number), determines the destination using the RP (the destination is not specified by the dialed telephone number in a 1-800 call), and determines the routing of the telephone call through the telephone lines and switches of the telephone communications system.
A prior art approach to routing has been to allow toll-free service clients to route their own incoming traffic. This allows the client to be responsive to traffic, local conditions, network problems, etc. The routing control extends limited client access to the RP. The RP therefore can be employed by a toll-free service client to set routing conditions as desired. However, the toll-free service client is generally given only limited access to the remote processor, and is generally not allowed to perform operations that affect the system as a whole (as opposed to affecting just the client's routing operations), or are complex, such as troubleshooting problems that occur during routing of a toll-free call.
Although employees of a toll-free service client may be able to specify message routing, another important area is troubleshooting and fixing problems that may occur in routing. When an operational routing problem occurs, the toll-free service client according to the prior art may have to call a customer service department, wade through an automated telephone menu and/or wait in a voice queue, explain the problem to a customer service representative, and wait for the customer service representative to identify and fix the problem. This process is slow and frustrating to the client, and further incurs cost to the client due to lost time. Another drawback of this prior art approach is that many problems in computerized systems can be solved by a small set of simple troubleshooting processes, without any need for elaborate diagnostics or elaborate solutions. For example, cycling power to a computerized device will usually reset internal values and eliminate an operational problem. This drawback is compounded in that the customer service representative is not only generally busy and not immediately available, but if required to fix elementary problems, the customer service representative therefore has less time to spend on truly serious problems where the customer service representative is most needed.

Troubleshooting interface for client-routed toll-free telephone calls


A digital x-ray phase contrast soft tissue imaging and mammography system offers significant cancer detection sensitivity and a significant improvement in accurate detection and interpretation of mammograms. In addition, the proposed system produces digital mammograms and thus has the advantages of digital mammography. The system overcomes the limitation of the current approaches to mammography using phase contrast effects and offers substantially higher performance than the current mammography used in hospitals and clinics. The proposed system uses the phase contrast imaging, in a breast and other soft tissue structures, instead of absorption contrast employed in the current x-ray mammography, allowing detection of smaller disease structures with substantial reduction in radiation dose.

X-ray mammography is currently the primary method for breast cancer screening. Recent randomized clinical trials have shown that screening mammography has reduced mortality from breast cancer by 25-30% in women between the ages 50-70, and by 18% among between the ages of 40 and 50. A recent report by the Institute of Medicine has indicated much could be done to improve breast cancer screening and save even more lives. The report calls for technological improvement in the accurate interpretation of mammograms and the development of new screening technologies. With the best screening method currently available, mammograms still miss up to 17% of tumors and give about 10% false-positive result.
The current medical mammography systems use absorption contrast and the images are recorded on film. Significant improvement can be made in both the image formation mechanism and image recording, as substantial gains in imaging contrast and detector efficiency are possible with recent technological development.


Embodiments described in this application relate generally to a system, an apparatus and/or methods for manufacturing electrodes by infusion electrolyte into compacted electrode materials. In some embodiments, a working electrode materials can be produced using an infusion mixing and manufacturing process. In some embodiments, a single-sided finished electrode can be produced directly from a dry powder mixture using an infusion mixing and manufacturing process. In some embodiments, a double-sided finished electrode can be produced directly from a dry powder mixture using an infusion mixing and manufacturing process. The electrodes produced by an infusion mixing and manufacturing process generally perform better than those produced by non-infusion processes.

Electrochemical cells, including batteries based on lithium ion technology are ubiquitous in our everyday life. Batteries are typically constructed of solid electrodes, separators, electrolyte, and ancillary components such as, for example, packaging, thermal management, cell balancing, consolidation of electrical current carriers into terminals, and/or other such components. The electrodes typically include active materials, conductive materials, and other additives. Some known methods of manufacturing include coating a metallic substrate (e.g., a current collector) with slurry composed of an active material, a conductive additive, and a binding agent dissolved or dispersed in a solvent, evaporating the solvent, and calendering the dried solid matrix to a specified thickness. The electrodes are then cut, packaged with other components, infiltrated with electrolyte and the entire package is then sealed.
Current battery manufacturing methods generally involve complicated and expensive manufacturing steps in addition to the various components and steps mentioned above. For example, a manufacturing step, such as casting the electrode, produces electrodes with limited thicknesses, for example, less than 100 μm (final single sided coated thickness). Such limitations in electrode thickness inevitably lead to batteries with lower capacity, lower energy density, and a high ratio of inactive components to active materials. Therefore, there is a pressing need to develop an advanced manufacturing method—to simplify the manufacturing processes, increase production efficiency by streamlining and integrating certain manufacturing steps, while at the same time decreasing inactive components in the electrodes and finished batteries—that can potentially lead to batteries with increased energy density, charge capacity and overall performance.

Systems and methods for infusion mixing a slurry based electrode


Embodiments of a color image matching scheme are disclosed. In one embodiment, a pixel intensity count is determined for color components of color images in a database and for a query color image. A fuzzy similarity and/or a fuzzy dissimilarity between the query image and the database images is computed based at least in part on the pixel intensities counts. An image is selected from the database based at least in part on the computed fuzzy similarity and/or dissimilarity, where computing a fuzzy similarity and/or dissimilarity includes computing the matching intensity. Other embodiments are described and claimed.

This disclosure relates to image processing and, in particular, to retrieval of an image from a database of color images.
The problem of retrieval of a query image from a database of color images has received attention in recent times due at least in part to exploration of Internet usage. For example, retrieval of a query image from a database of images is a task employed in the area of digital imaging, computer vision, and many other multimedia applications. Image retrieval using similarity measures has been observed to be an elegant technique for Content Based Image Retrieval (CBIR) systems. The task of image matching involves determining the mutual correspondence between two images in a set of database images. Content-based query systems process a query image at least in part on the basis of a classification procedure that assigns the unknown query image to the closest available image in the database. The performance of the CBIR system typically depends on several factors that usually involve extracting a set of features that constitute the image and then identifying suitable similarity measures, based on image distance function.


An optical waveguide of an optical deflector comprising a planar optical waveguide or an optical fiber type optical waveguide is cut while perpendicularly pressing a blade having a blade tip with an angle of inclination against the optical waveguide at a desired location thereof to form an oblique end face serviceable as an oblique end face mirror.

1. Field of the Invention
The present invention relates to an optical deflector comprising an optical waveguide having a deflection mechanism for use in optical communication, measurement, information processing, etc., and a process for producing the same.
2. Description of the Prior Art
Optical waveguides having such a deflection mechanism include a planar optical waveguide and a fiber optical waveguide. When the term "optical waveguide" is simply mentioned in the following description of the present invention, it is intended to encompass both of a planar optical waveguide and a fiber optical waveguide. In other cases where specific mention is necessary, one type is referred to as a "planar optical waveguide", while other type is referred to as a "fiber optical waveguide" or an "optical fiber."
A 45-degree oblique end face mirror, formed by providing a planar optical waveguide or a fiber optical waveguide with a 45-degree oblique end face, is capable of compact 90-degree deflection. Accordingly, an optical deflector comprising a planar optical waveguide provided with the above-mentioned mirror and an optical deflector comprising a fiber optical waveguide provided with the above-mentioned mirror are expected to be elements effective, for example, in providing a high level of integration of an optical module and reducing the assembling cost.
Active study and development have particularly recently been made of optical transmitter and receiver with a structure wherein arrayed surface emitting (surface sensitive) optical devices are coupled with optical waveguides disposed in horizontal directions relative to the emitting (sensitive) surface of these surface emitting (sensitive) optical devices by means of 45-degree oblique end face mirrors formed at ends of the optical waveguides in order to produce compact and inexpensive parallel optical transmitter and receiver.
Reported technologies of forming a 45-degree oblique end face mirror at an end of a planar optical waveguide include (1) a method wherein an end portion thereof is mechanically cut off obliquely with a microtome (see B. L. Booth, "Polymers for integrated optical waveguides," in Polymers for Electronic and Photonic Applications, C. P. Wong, Ed., New York: Academic, 1993, pp. 549-599), (2) a method wherein such an oblique end face mirror is formed by reactive ion etching [see H. Takahara et al, Proc. of SPIE, vol. 1849, 70-78 (1993)], (3) a laser abrasion method, and (4) a method wherein a 45-degree cut is made with a thin rotary blade [see Osamu Mikami et al, "Hikari Jisso Gijutu no Tenbo (A Review of Optical Packaging Technology)," Shingaku Giho (Shingaku Bulletin), OPE95-47 (1995-08)].
FIGS. 1 and 2 are diagrams illustrating the method (1) wherein an end portion of a planar optical waveguide is mechanically cut off obliquely with a microtome. In FIGS. 1 and 2, numeral 201 refers to a waveguide film, 202 to a blade, 203 to waveguide films having respective oblique end face mirrors formed at the ends thereof by cutting-off with the blade 202. According to the method shown in FIGS. 1 and 2, the waveguide film 201 fixed oblique by 45 degrees relative to the cut-off direction is cut off with the blade 202 to form oblique micro-mirrors (face mirrors). This method (1) is simple but involves problems such as (1-i) an inapplicability thereof to an optical waveguide formed from a rigid material such as glass and to an optical waveguide supported on a rigid substrate such as a silicon or glass substrate, (1-ii) an incapability of forming oblique end face mirrors only for some of optical waveguides formed in parallel with each other in one and the same sample, though possible for all of the optical waveguides, (1-iii) a difficulty in highly accurately positioning a location where an oblique end face mirror is formed, and (1-iv) a slight increase in reflection loss because of a limited smoothness of cut-off surfaces.
On the other hand, the method (2) wherein an oblique end face mirror is formed by reactive ion etching involves problems such as (2-i) a complicated and time-consuming step, (2-ii) a difficulty in determining etching conditions and a difficulty in forming an oblique end face mirror with a good accuracy of the angle of inclination thereof.
On the other hand, the laser abrasion method (3) involves problems such as (3-i) expensive equipment and time-consuming mirror formation, and (3-ii) a difficulty in determining etching conditions and a necessity of great alterations in mirror formation equipment and conditions for every material.
FIGS. 3 and 4 are diagrams illustrating the method (4) wherein a 45-degree cut in a planar optical waveguide is made with a rotary blade to form oblique end face mirrors. In FIGS. 3 and 4, numeral 204 refers to a substrate, 205 to a lower cladding layer, 206 to a core, 207 to an upper cladding layer, 208 to a rotary blade, and 209 to a 45-degree cut. According to this method, a sample is fixed to have the optical axis of the planar optical waveguide at an angle of 45 degrees with the rotary blade, and then cut with the rotary blade 208 at an angle of 45 degrees to form the 45-degree cut 209 in a waveguide consisting of a core and a cladding. This method (4), though advantageous in that a mirror plane excellent in smoothness can be formed by selecting a suitable blade, involves problems such as, (4-i) such a difficulty in fixing a sample as to require specially devised equipment, (4-ii) a difficulty in controlling the angle, and (4-iii) a difficulty in smoothing the oblique end faces by secondary working or processing because the oblique end faces are formed in a narrow cut groove.
On the other hand, a method (5) wherein an end face of an optical fiber is polished obliquely using a polishing machine [see K. P. Jackson et al., Proc. of SPIE, vol. 994, 40-47 (1988)] was contrived as a technology of forming a 45-degree oblique end face mirror at an end of an optical fiber. This method, though widely used due to its capability of obtaining a smooth optical mirror plane, involves problems such as (5-i) a difficulty in securing an accuracy of a position where an oblique end face mirror is formed, (5-ii) a difficulty in delicately controlling the angle of inclination of a mirror plane, (5-iii) a difficulty in polishing a number of samples at once and a low productivity because of the necessity of a long polishing time, and (5-iv) a methodological incapability of localized mirror formation midway of optical paths of a fiber sheet or a fiber board having optical fibers embedded in the sheet or board with a resin.
Meanwhile, in a surface emitting laser for ordinary use in an optical transmitter and receiver module designed to be inexpensive, an oscillation wavelength is in a 0.85 .mu.m band. Thus, it is important that a waveguide material involves a low loss in this wavelength band. For example, a polyimide known as a heat-resistant polymeric material involves an electron transition absorption ranging from the ultraviolet region to the visible light region with a high loss of about 1 dB/cm in the 0.85 .mu.m band. Accordingly, an optical waveguide made of a conventional material is unsuitable for use as an optical waveguide constituting an optical deflector.
As described above, conventional optical deflectors comprising an optical path of a planar optical waveguide type are problematic in respect of the method of forming an oblique end face mirror. Specifically, the method (1) wherein oblique end face mirrors are formed by a cutting-off operation involves problems such as (1-i) an inapplicability thereof to an optical waveguide formed using a rigid material or supported on a rigid substrate, (1-ii) an incapability of forming oblique end face mirrors only for some of optical waveguides formed in parallel with each other in one and the same sample, (1-iii) a difficulty in securing an accuracy of a position where oblique end face mirrors are formed, and (1-iv) a slightly high reflection loss attributed to the roughness of cut-off surfaces.
On the other hand, the method (2) wherein an oblique end face mirror is formed by reactive ion etching involves problems such as (2-i) a complicated and time-consuming step, (2-ii) a difficulty in determining conditions and a difficulty in putting the angle of inclination of an oblique end face mirror in accurate agreement with the desired angle.
On the other hand, the laser abrasion method (3) involves problems such as (3-i) expensive equipment and time-consuming mirror formation, and (3-ii) a difficulty in determining etching conditions and a necessity of great alterations in mirror formation equipment arid conditions for every material.
On the other hand, the method (4) wherein a 45-degree cut in a planar optical waveguide is made with a rotary blade to form oblique end face mirrors involves problems such as, (4-i) such a difficulty in fixing a sample as to require specially devised equipment, (4-ii) a difficulty in controlling the angle, and (4-iii) a difficulty in smoothing the oblique end faces by secondary working or processing because the oblique end faces are formed in a narrow cut groove.
On the other hand, in a conventional optical deflector comprising an optical fiber type, an oblique end face mirror is formed by oblique polishing, but the oblique polishing method (5) involves problems such as (5-i) a difficulty in securing an accuracy of a position where an oblique end face mirror is formed, (5-ii) a difficulty in delicately controlling the angle of inclination of a mirror plane, (5-iii) a difficulty in polishing a number of samples at once and a low productivity because of the necessity of a long polishing time, and (5-iv) a methodological incapability of localized mirror formation midway of optical paths of a fiber sheet or a fiber board having optical fibers embedded in the sheet or board with a resin.

Optical deflector, process for producing the same, and blade for use in production of optical deflector

Nippon Telegraph and Telephone Corporation


Provided is a method for determining effective porosity of high clay-bearing rock core, comprising: acquiring a saturated sample NMR T2 spectrum of a high clay-bearing rock core sample, which is measured when temperature of saturated aqueous solution reaches a preset temperature after rock core sample saturated with water being immersed into the saturated aqueous solution and placed and heated in constant temperature and humidity environment; determining a nuclear magnetic total porosity of rock core sample according to the saturated sample NMR T2 spectrum; acquiring permeability and NMR T2 spectrum of the rock core sample placed in the constant temperature and humidity environment and dried until different time; generating cross-plot of permeability and nuclear magnetic porosity; determining first porosity and second porosity; and determining an effective porosity of the h rock core based on the first porosity, the second porosity, and the nuclear magnetic total porosity.

For a high clay-bearing rock, fluids in the rock include a movable fluid, a capillary bound fluid and a clay bound fluid, respectively corresponding to a movable fluid porosity, a capillary bound fluid porosity and a clay bound fluid porosity. The sum of these three fluid porosities is a total porosity, and the sum of the movable fluid porosity and the capillary bound fluid porosity is called an effective porosity.
The existing methods for determining an effective porosity of a high clay-bearing rock core (a rock core with clay content greater than 5%) mainly include a fluid (usually kerosene) saturation weighing method, a helium injection porosity method, a nuclear magnetic resonance (NMR) method, etc. Due to influence of uncertain factors such as temperature, humidity, time and etc., these methods lead to a clay-adsorbed water loss, resulting in relatively large measurement results of the effective porosity.
Regarding the above technical problem, no effective solution has been proposed yet.

Method for determining effective porosity of high clay-bearing rock core, computer device and computer readable storage medium


A process for realizing TFT devices on a substrate comprises the steps of: forming on the substrate, in cascade, an amorphous silicon layer and a heavily doped amorphous silicon layer, forming a photolithographic mask on the heavily doped amorphous silicon layer provided with an opening, removing the heavily doped amorphous silicon layer through the opening for realizing opposite portions of the heavily doped amorphous silicon layer whose cross dimensions decrease as long as they depart from the amorphous silicon layer, removing the photolithographic mask, carrying out a diffusion and activation step of the dopant contained in the portions of the heavily doped amorphous silicon layer inside the amorphous silicon layer, for realizing source/drain regions of said TFT device.

1. Technical Field
The present invention relates to a process for manufacturing a TFT (Thin Film Transistor) device realized with source and drain regions having gradual dopant profile and corresponding device.
The invention particularly, but not exclusively, relates to a TFT device of the non-self-aligned type and the following description is made with reference to this field of application by way of illustration only.
2. Description of the Related Art
As it is well known, in the last years polycrystalline silicon Thin Film Transistors (TFTs) have raised a great interest for their applications in large area microelectronics (LAM). They have taken an important role thanks to the possibility of combining a low realization cost with high performances. In fact, these TFT transistors show neatly higher performances with respect to the transistors realized with amorphous silicon in terms of mobility and stability.
Moreover, the introduction of a re-crystallization step through exposure to excimer laser (ELC, i.e., Excimer Laser Crystallization) in the manufacturing processes of these devices has allowed in fact to considerably improve the quality of the polysilicon layer they are made of, both increasing the grains sizes and reducing the density of the defects at the edges and inside the grains themselves. The combination of more extended grains and low density of defects allows to realize TFT transistors with high mobility and field effect (μfe) suitable for realizing AMLCD, i.e., Active Matrix Liquid Crystal Displays or AMOLED, i.e., Active Matrix Organic Light Emitting Displays) to be used in laptops and in latest generation cell phones (UMTS), using the TFT transistors not only as switches of the active matrix but also for realizing the integrated elements of the addressing and control circuitry for the rows and the columns of the matrix itself.
A first known process for realizing TFT comprising source-drain regions self-aligned to the gate electrode provides the formation on a glass substrate of an amorphous silicon layer, which is followed by a crystallization step through laser for transforming the amorphous silicon layer into a polycrystalline silicon layer. On this latter layer the gate dielectric is deposited, and then the gate electrode is formed, which serves as mask for the successive dopant ionic implantation step which realizes the source-drain regions inside the polysilicon layer.
The process then requires a further annealing passage (either laser or thermal) for the removal of the defects induced by the implantation step and the dopant activation.
Since these devices are realized on glass substrates, the implantation step is not followed by a conventional diffusion step of the dopant atoms for realizing source-drain regions diffused towards the device channel (under the gate electrode) and thus these source-drain regions have a very high concentration gradient ("abrupt" junction type) originating high electric fields during the operation of the TFT device. In fact, the diffusion step of the dopant atoms implies a thermal step at high temperature which would deteriorate the glass substrate.
Although advantageous under several aspects, these TFT transistors which are formed with known "abrupt" junctions show problems linked to the high biasing voltages of the "drain" region which reduce the electric performances of the TFT transistors, such as for example the anomalous increase of the output current, also called "kink" effect, besides the degradation of the electric characteristic linked to the presence of hot carriers and to an increase of the turn-off current of the TFT transistor known as "leakage" current.
In fact, the electric field associated with the biasing voltage of the "drain" region is in turn sensitive to the dopant profile of the "drain" region next to the channel region, in particular when the dopant profile of the "drain" region, next to the channel region, has a very high concentration gradient ("abrupt" junction type).
Therefore this first known process leads to the formation of source and drain regions with high concentration gradient dopant profile and, as per what has been mentioned above, under biasing conditions of the "drain" region, imply an increase of the electric field in the channel regions with subsequent electric deterioration of the TFT transistor performances.
A second known process for realizing TFT comprising source-drain regions non-self-aligned to the gate electrode provides the formation on a glass substrate of an amorphous silicon layer which is followed by a dopant ionic implantation step for realizing the source-drain regions inside the amorphous silicon layer. A crystallization step through laser is then carried out, which activates the implanted dopant and further causes the diffusion of the dopant atoms towards the channel region comprised between the source/drain regions, with a diffusion length which depends on the number of laser pulses applied.
Due to the photolithographic tolerances, the overlapping between the gate electrode and the source-drain regions cannot be lower than about 2 μm, resulting in parasitic capacitances.
It is also known that the source/drain regions of the non-self-aligned TFT can be realized with doped silicon layers deposited through PECVD on an amorphous silicon layer, as described in the article "Thin Film Transistors Fabricated by In Situ Doped Unhydrogenated Polysilicon Films Obtained by Solid Phase Crystallization" by L Pichon, K Mourgues, F Raoult, T Mohammed-Brahim, K Kis-Sion, D Briand and O Bonnaud published on Semicond. Sci. Technol. 16 (2001) 918-924.
In this latter process, the doped layer on the channel is removed prior to the silicon crystallization step. This removal step is realized through a plasma etching of CF4+O2 (RIE) which realizes regions with vertical side walls as shown in FIG. 4. This removal process is not selective between the doped silicon layer and the underlying amorphous silicon layer, thus the etching time should be exactly calculated. Moreover, the plasma used for the etching can generate defects in the etched region, which is the active portion of the channel.
A further process for the manufacturing of the TFT transistors with gradual junctions, called lift-off, is described in the article "A Novel Fabrication Process For Polysilicon Thin film Transistors With Source/Drain Contacts Formed by Deposition and Lift-Off Of Heavily Doped Layers" by G. Fortunato et al, published on "Solid State Electronics", vol. 46 (2002) 1351-1358, and shown with reference to FIGS. 1A-1O.
In particular, on a glass substrate 1a silicon nitride layer 2, a first silicon oxide layer 3, an hydrogenated amorphous silicon layer 4 (a-Si:H), a second silicon layer 5 and a photo-lithographic mask 6 provided with first openings 7 of a first width are formed in cascade.
As shown in FIG. 1C, the second oxide layer 5 is selectively removed through the first openings 7 to form second openings 8, in this second oxide layer 5, of greater width than the first openings 7.
A first strongly doped polysilicon layer 9 is then formed on the photo-lithographic mask 6 and a second strongly doped polysilicon layer 11 on the hydrogenated amorphous silicon layer 4 inside the second openings 8.
In particular, the second polysilicon layer 11 is not in direct contact with the walls of the second openings 8 and forms the source and drain regions of the TFT transistor 10, which will be hereafter indicated with the same reference number 11. As shown in FIG. 1D, a gap region is then formed between the second oxide layer 5 and the source/drain regions 11.
The process then goes on with the removal of the photo-lithographic mask 6 and of the first polysilicon layer 9 (lift-off) as shown in FIG. 1E.
Also the second oxide layer 5 is then removed, as shown in FIG. 1F.
The presence of the gap region facilitates the removal step of the second oxide layer 5.
As shown in FIG. 1G, the process goes on with a de-hydrogenation step which is followed by a re-crystallization step through exposure to an excimer laser beam (ELC, i.e., Excimer Laser Crystallization).
At the end of this step the hydrogenated amorphous silicon layer 4 has been transformed into a polycrystalline silicon layer 4a wherein the source/drain regions 11 are integrated as shown in FIG. 1H.
A second photolithographic step is then carried out for removing the silicon layer which is outside the source/drain regions 11 and the device channel so as to delimit the active area of the TFT transistor 10. A third oxide layer 13 is then formed on the whole exposed surface, as shown in FIG. 11.
By means of a third photolithographic step which makes use of a further photolithographic mask 14 provided with third openings 15 aligned to the source/drain regions 11, the third oxide layer 13 is removed until the polysilicon layer 4a is exposed, for opening contact vias 16, as shown in FIG. 1L.
Once a metallic layer 17 is formed on the whole device, as shown in FIG. 1M by means of a fourth photolithographic step which makes use of a further photolithographic mask provided with fourth openings 19 aligned to the third openings 15 with smaller width, the metallic layer 17 is removed through the fourth openings 19, to form the contacts CT of the TFT transistor 10, as shown in FIGS. 1N and 1O.
This lift-off process of the source/drain regions 11 could be realized without needing the presence of the second oxide layer 5, however, the lift-off step of the source/drain regions 11 from the resist mask 6 does not ensure a neat definition between the active regions and the regions to be removed after the lift-off process itself. The process therefore shows a certain criticality and to overcome this problem the second silicon oxide layer 5 has been exactly introduced immediately below the resist mask 6. In this way in fact, by subjecting the second oxide layer 5 to a selective and prolonged etching, shown in FIG. 1C, it is possible to succeed in removing it far below the edge of the resist mask 6 thus creating a discontinuity that makes the lift-off process easier.
However, although this measure removes the criticality of the feasibility of the source/drain regions 11 due to the removal of the oxide layer 5 which has the function of hardmask after the lift-off process has occurred, it introduces another one which, even if not critical from a feasibility viewpoint, is instead critical from an industrial viewpoint since it is linked to the reproducibility of the openings 8.
In fact, the etching step of the oxide layer 5, after the photolithographic step, necessarily occurs though wet process and below the resist mask 6. The control of the lateral width of the openings 8 is critical and thus the width and the lateral profile of the source/drain regions 11 are not repeatable.
In fact, the lateral profile of the polysilicon layer 11 which is grown inside the openings 8 strictly depends on the width of the openings 8 below the mask 6 that, as already said, is not controllable and repeatable.
The poor controllability on the oxide layer 5 which is laterally etched, besides on the variation of the channel length, has then negative effect also on the shape of the dopant profile of the source/drain regions after the crystallization step.
In fact, this crystallization step, necessary for activating and diffusing the dopant of the polysilicon layer 11 in the polysilicon layer 4a, provides again in the polysilicon layer 4a a similar dopant profile which preserves the memory of the previous process originating source and drain regions 11 with dopant profile also being not enough repetitive from an industrial point of view, more or less of the "abrupt" type, depending on how the process tolerances associated with the photolithographic step are combined with the photolithographic step, etching step as well as with the greater or minor selectivity of the lift-off process in general associated with the resist/residual deposited material removal and residual oxide removal steps and this causes electric performances of the device with wide excursion of the control parameters.
Therefore, the lift-off process implies an intrinsic poor reproducibility of the structure of the active region of the transistor 10 which in turn implies a wide dispersion of the electric parameters, to the disadvantage of a low product performance which make the process little attractive on an industrial scale.

Process for manufacturing a TFT device with source and drain regions having gradual dopant profile


A mating extender electrically engages with a pair of complementary connectors. The mating extender comprises an insulative housing having first and second mating sections, and a number of wafers parallelly assembled into the insulative housing. Each wafer comprises an insulative frame and a plurality of contacts each formed by a pair of electrically stacked semi-contacts. Each contact has an intermediate portion retained in the insulative frame, a pair of first contact tails and a pair of second contact tails at opposite ends of the intermediate portion and received in the first and the second mating sections of the insulative housing, respectively.

1. Field of the Invention
The present invention relates to a mating extender, and more particularly to a mating extender which is able to vary in height and is adapted for simultaneously and electrically connecting with a pair of headers respectively mounted on two printed circuit boards.
2. Description of Related Art
U.S. Pat. No. 6,152,747 discloses an electrical connector assembly comprising a plug and a receptacle. The plug and the receptacle both comprise a number of parallel modules. Each module comprises an insulative support, a plurality of signal contacts attached on one side of the support and a shielding plate attached on another side of the support. Each signal contact comprises a tail having a solder ball attached thereon. The shielding plate is formed with a plurality of end portions each having a solder ball attached thereon. The solder balls on the signal contacts and the shielding plate lie in a common plane. The plug is adapted for being surface mounted onto a first printed circuit board with the solder balls soldered onto corresponding pads on the first printed circuit board. The receptacle is adapted for being surface mounted onto a second printed circuit board positioned parallelly to the first printed circuit board with the solder balls soldered onto corresponding pads on the second printed circuit board.
In some applications, a large distance is required to be kept between the first and second printed circuit boards. Therefore, a high profile plug or receptacle is accordingly designed to satisfy this requirement. However, as the height of the plug or the receptacle increases, it becomes more difficult to surface solder the plug or the receptacle to the printed circuit boards.
Hence, a mating extender between the plug and the receptacle is desired to overcome the disadvantage of the prior art.

Mating extender for electrically connecting with two electrical connectors


A surface cold electron emission display device includes; a pair of an element-substrate and a transparent substrate sandwiching a vacuum space and facing to each other; plural ohmic electrodes disposed on the element-substrate parallel to each other; and plural cold electron emission elements made of semiconductor. Each cold electron emission element includes; a semiconductor layer formed on the ohmic electrode; a porous semiconductor layer formed on the semiconductor layer; and a metallic thin film electrode formed on the porous semiconductor layer to face the vacuum space. The device also includes; a plurality of bus electrodes formed on the metallic thin film electrodes for bridging and electrically connecting the adjacent metallic thin film electrodes and extending perpendicular to the ohmic electrodes; a plurality of collector electrode disposed on the transparent substrate parallel to each other for capturing emitted electrons from the metallic thin film electrode; and a fluorescent layer formed on the collector electrode.

1. Field of the Invention
The present invention relates to a cold electron emission display device comprising electron emission elements comprising a semiconductor.
2. Description of the Related Art
There is known a FED (field emission display) as a surface-light-emitting display comprising an array of cold electron emission sources without any necessity of heating the cathode. A principle of light-emission in the FED is similar to that of a CRT (cathode ray tube) except for the cathode structure of the cold electron emission source array. That is, the gate electrodes draw electrons from the separate cathodes to the vacuum space and then the electrons travel and impinge upon the fluorescent material disposed on the transparent anode, so that the fluorescent material emits light.
However, there is a problem of a low yield rate in the manufacture of FED, because the field emission source array requires complicated many processes for the manufacture in which each minute cold cathode projecting to the vacuum should be micro-machined.


There is provided a semiconductor memory device including; first and second active areas formed to extend in a first direction on a semiconductor substrate, first and second split word lines formed in a second direction on the semiconductor substrate, a common source line extending between the first and second active areas in the first direction and coupled to the first and second active areas, a first variable resistance element formed on the first active area between the first and second split word lines, a second variable resistance element formed on the second active area between the first and second split word lines, first and second bit lines extending in the first direction and respectively coupled to the first and second variable resistance elements.

1. Field of the Invention
The present invention relates to a semiconductor memory device. More particularly, the invention relates to a semiconductor memory device having resistive elements providing improving memory cell density.
2. Description of the Related Art
Resistive Random Access Memory (hereinafter, 'RRAM') stores data by varying the resistance of a resistive element. Data may be written to a selected memory cell in an RRAM by applying a predetermined current to the corresponding resistive element. The amount of applied current may be controlled by defining a voltage potential difference between a bit line and a source line associated with the selected memory cell. RRAM generally includes types of RRAM in which different data values may be written in accordance with the polarity (i.e., the directional flow) of the applied current through the resistive element. Such devices are sometimes referred to as a "bipolar RRAM." In the case of a bipolar RRAM, a bit line and source line are required for each memory cell in order to write different data values to the bipolar RRAM. As a result of this requirement, the size of a memory cell array becomes large.


A collapsible stand having a top (14) formed by two mating leaves (15, 17) and supported by legs (28, 30, 32, 34). The legs are pivotedly joined to braces (20, 22, 24, 26) underlying the leaves. The components of the stand pivot with respect to one another so to allow the stand to be easily erected and collapsed. However, due to interaction between at least one of the braces and at least one retainer (64) on the underside of one of the leaves the stand cannot be collapsed without initial planar movement of the leaves away from one another. Since such movement is rare during normal usage, the stand is strong and secure during normal usage. A pair of brackets (80, 82) for holding dimensional lumber (79) may be attached to the braces. When the lumber is placed in the brackets, the stand is further secured in its erect position.

Many individuals have the need to move a table or work stand from one location to another or to store the stand when it is not in use. Thus, stands or tables that can be easily collapsed and erected have been developed. Examples of these types of tables are disclosed in U.S. Pat. No. 3,692,358 issued Sep. 19, 1972 to A. Y. Sung and U.S. Pat. No. 4,592,287 issued Jun. 3, 1986 to L. R. Thygeson.
These stands such as shown in the Sung and Thygeson patents are generally of a type having an erect position in the top planar supporting surface formed by two meeting halves and a folded generally planar position for transportation and storage. The meeting halves are each positioned on pairs of braces which are pivotally connected to corresponding legs. The legs are then pivotally connected to the corresponding leg of the other meeting half. When the legs are opened, the braces are pivoted towards one another until the meeting halves abut to form the top planar supporting surface used as the table top. While such tables do achieve the basic purpose of being easily erected and also easily collapsed to a compact transportation or storage condition, they lack of necessary stability required in certain types of work since the two table members of the table may pivot away from one another with relative ease.


A method and an apparatus for automatically feeding slider-zipper assemblies to a station where the slider-zipper assemblies can be attached to bag material, such as thermoplastic film. The apparatus includes a slider guide having a channel running the length thereof. The channel has a cross section that allows passage therethrough of sliders slidably mounted to a tape of connected slider-zipper assemblies. A tape drive mechanism is located at the outlet of the slider guide. The tape drive mechanism includes a pair of rollers that form a nip therebetween. The zipper flanges of the tape are threaded through the nip. The rollers have respective grooves that form a space for passage of the sliders as the tape is advanced by the rollers. The zipper tape with sliders exits the tape drive mechanism and is drawn into a zipper flange sealing position by a tape transfer assembly comprising a bank of drive rollers having silicone surfaces in contact with the zipper tape. The drive rollers have peripheral grooves that oppose a longitudinal groove in a shelf, the zipper profile being captured between the opposing grooves.

The present invention relates to methods and apparatuses for automated manufacture of a reclosable plastic package having a resealable closure, especially as part of a form, fill and seal process. In particular, the invention relates to methods and apparatuses for manufacturing reclosable plastic packages and bags having a slider-zipper assembly installed in the mouth of the package.
In the use of plastic bags and packages, particularly for foodstuffs, it is important that the bag be hermetically sealed until the purchaser acquires the product, takes it home, and opens the bag or package for the first time. It is then commercially attractive and useful for the consumer that the bag or package be reclosable so that its contents may be protected. Flexible plastic zippers have proven to be excellent for reclosable bags, because they may be manufactured with high-speed equipment and are reliable for repeated reuse.
A typical zipper comprises one fastener strip or member having a groove and attached to one side of the bag mouth, and another fastener strip or member having a rib and attached to the other side of the bag mouth, which rib may interlock into the groove when the sides of the mouth of the bag are pressed together. Alternatively, a fastener strip having a plurality of ribs may be on one side of the bag mouth, while a fastener strip having a plurality of grooves or channels may be on the other side, the ribs locking into the channels when the sides of the mouth of the bag are pressed together. In the latter case, there may be no difference in appearance between the two fastener strips, as the ribs may simply be the intervals between channels on a strip that may lock into another of the same kind. In general, and in short, some form of male/female interengagement is used to join the two sides of the bag mouth together. The fastener strips or members are bonded in some manner to the material from which the bags themselves are manufactured.
In the automated manufacture of plastic reclosable packages or bags, it is known to feed a zipper assembly to a position adjacent a sheet of thermoplastic film and then attach the zipper assembly to the bag by means of heat sealing. The zipper assemblies are attached at spaced intervals along the thermoplastic sheet, one zipper assembly being attached to each section of film respectively corresponding to an individual package or bag. The zipper assembly consists of two interlocking fastener strips that, in the final package, lie inside the mouth of the package. Each fastener strip preferably has a flange that extends toward the product side of the package in a direction transverse to the line of the zipper. In accordance with one known method of feeding zipper assemblies to an automated form, fill and seal machine, the zipper assembly is in the form of a tape that is unwound from a spool for automated feeding. The tape comprises a continuous length of interlocked fastener strips. The continuous tape is feed to a cutting device that cuts the tape at regular lengths to form an individual zipper. Each individual zipper is attached to the thermoplastic film by heat sealing or other suitable means.
Prior to cutting and heat sealing, the zipper assembly must be automatically positioned correctly relative to the thermoplastic film. Moving the zipper assembly into position overlying the thermoplastic film requires a positioning device. Some prior art positioning devices comprise a channel that guides the continuous zipper tape toward its proper position relative to the thermoplastic bag making film. The zipper assembly may be positioned parallel or perpendicular to the direction of movement of the bag making film. Because the fastener strips of a zipper assembly not slider-operated have a constant profile in the lengthwise direction, it is a relatively simple matter to design a linear guide channel having a cross section which matches the profile of the interlocked fastener strips with sufficient clearance to allow the zipper tape to be pushed or pulled through the guide with minimal friction, yet not so great as to allow the zipper tape to skew, twist or move sideways in the guide channel.
Other types of reclosable plastic bags, however, contain a slider that facilitates a consumer opening and re-closing the package by disengaging and re-engaging the two sides of the zipper. However, adding a slider to the zipper assembly requires the design of guide devices different than those used when reclosable packages having zippers without sliders are being manufactured.
In the prior art it is known to feed a continuous tape of interlocked faster strips to a shaping device that crushes the strips at regular intervals in the lengthwise direction to provide restraints or stops for the slider. At the next station, a slider insertion device inserts a respective slider onto each section of zipper tape between successive slider end stops. The slider can be slid along the zipper tape between a leftmost position in abutment with the left-hand slider end stop and a rightmost position in abutment with the right-hand slider end stop. The resulting tape of slider-zipper assemblies must be fed automatically to a station where each slider-zipper assembly will be cut off the end of the tape and attached to a respective section of the thermoplastic bag material, e.g., by heat sealing, such sections of thermoplastic bag material being spaced at package intervals.
There is a need for a method and an apparatus for guiding a tape of slider-zipper assemblies to a desired position overlying the bag making film during automated feeding of the slider-zipper assemblies. The apparatus must take into account that the sliders intermittently placed along the continuous zipper tape have width and height dimensions greater than the corresponding dimensions of the interlocked profiles of the zipper halves.

Method and apparatus for feeding slider-zipper tape to application station


A photodetector including a photodiode formed in a semiconductor substrate and a waveguide element formed of a block of a high-index material extending above the photodiode in a thick layer of a dielectric superposed to the substrate, the thick layer being at least as a majority formed of silicon oxide and the block being formed of a polymer of the general formula R1R2R3SiOSiR1R2R3 where R1, R2, and R3 are any carbonaceous or metal substituents and where one of R1, R2, or R3 is a carbonaceous substituent having at least four carbon atoms and/or at least one oxygen atom.

1. Field of the Invention
Embodiments of the present invention generally relate to the field of imagers made in monolithic form. More specifically, embodiments of the present invention relate to the structure of photodetectors used in such imagers.
2. Discussion of the Related Art
Fixed or mobile image acquisition devices are increasingly used in many fields. They must be inserted into smaller and smaller spaces. For example, image acquisition devices are inserted into portable phones. According to another example, in the medical field, it is desirable to have image acquisition devices of small dimensions able to be arranged on endoscopes.
It has thus been attempted to make, in monolithic form, image acquisition devices of small dimensions with an image quality at least comparable to that of known optical devices.
A monolithic image acquisition device includes photodetectors arranged at the intersection of lines and of columns of an array.
A cross-sectional view of FIG. 1 illustrates four photodetectors of a line or column of an image acquisition device. A photodetector comprises a photodiode D formed in a semiconductor substrate 1. The surface area taken up by photodiode D typically has a side or a diameter ranging between 0.2 and 1.5 μm. Substantially above the interval separating two neighboring photodiodes D, metal interconnects are formed in a dielectric 5. The metal interconnects are formed of several levels of metallization 3 and of vias. The thickness of dielectric 5 is generally greater than the total height of metallizations 3 and depends on technological constraints linked to standard technological processes and/or to the circuits formed around the image acquisition area, such as circuits for reading and processing the acquired images. The thickness of dielectric 5 typically ranges between 1.5 and 6.5 μm.
A succession of filters F of transparent resin colored in red R, green V, or blue B is formed in dielectric 5. Filters F follow one another so that, on a same line, two different colors alternate and that, on two successive lines, one color is common. For example, a first line comprises filters according to the sequence B-V-B-V and the next line comprises filters according to the illustrated sequence R-V-R-V. Filters F follow one another in a continuous fashion and the interface between two neighboring filters F is substantially above the middle of the interval separating two underlying photodiodes D. Thus, each photodetector comprises a filter F associated with a photodiode D. The filter F of each photodetector is topped with a respective converging lens L, also made of transparent resin.
It has been provided to form in each photodetector, between a filter F and its corresponding photodiode D, a waveguide G. Waveguide G is formed of a waveguide block 7 surrounded with dielectric 5. Block 7 is formed of a material with a refraction index n7 greater than that, n5, of dielectric 5 (n7>n5). Block 7 is of straight or slightly conical cylindrical shape. Block 7 is placed above lens L to receive the photons injected by lens L towards photodiode D. The high portion of block 7 is separated from filter F by a thickness of dielectric 5 negligible as to the induced light losses, typically on the order of a few nanometers. Similarly, the bottom of block 7 is placed above photodiode D and is separated therefrom by a thickness of dielectric 5 on the order of a few nanometers. The presence of waveguide G enables decreasing light intensity losses and avoiding wrong detections linked to a dispersion of the photons and/or to their refraction against the metallizations 3 which appear across the relatively significant thickness of dielectric 5.
According to one example of the waveguide G, the guide is formed of a cone of a silicon, oxygen, carbon, and nitrogen compound called silicon oxynitride, which exhibits an index n on the order of from 1.6 to 2.3 according to its stoichiometry formed in a thick silicon oxide layer (SiO2) of index n=1.43. Another example of the waveguide G uses tantalum oxide, which has an index n on the order of 2, as a high-index material.
However, the use of such materials may raise practical problems. In particular, block 7 of FIG. 1 of the present application is formed by filling a deep and narrow opening in the dielectric 5. "Deep and narrow" means in the present description an opening having a ratio between the depth (substantially equal to the thickness of dielectric 5) and the average diameter (substantially equal to that of photodiode D) greater than 2. The filling of such an opening, which is performed by chemical vapor deposition (CVD), must be homogeneous. However, on filling of a narrow and deep opening with compounds of silicon oxy-carbo-nitride type or with tantalum oxide, bubbles or cavities form. Such bubbles form traps for the received light Further, when block 7 is formed of a silicon oxy-carbo-nitride or of tantalum oxide, problems of mechanical hold with peripheral silicon oxide 5 can be observed. Moreover, some of the silicon oxy-carbo-nitrides, as well as the tantalum oxide, deteriorate during the thermal cycles implemented in the rest of the process, especially the encapsulation and packaging anneals performed at temperatures from 300 to 400° C.
In another approach, a waveguide element is formed of alumina of index 1.63 or of silicon nitride (n=1.83) formed in a thick silicon oxide layer n=1.43. According to a variation of this approach, the high-index block 7 is silicon oxide n=1.43, formed in a thick dielectric layer 5 made of a material with a lower index such as an oxysilane of index 1.39.
The use of alumina or silicon nitride in a thick silicon oxide layer may exhibit disadvantages similar to those described previously for tantalum oxide or silicon oxy-carbo-nitrides.
The use of silicon oxide in oxysilane may also raise problems. In particular, this results in a significant modification of the materials used in the optical area with respect to the material present in the neighboring non-optical areas in which it is desirable to keep silicon oxide as an interlevel dielectric 5. This complicates and increases manufacturing costs. Further, the use in a thick layer of oxysilane with a refraction index lower than that of silicon oxide raises problems of mechanical hold, of ability to be locally etched, especially to form metallization levels 3 and the vias, as well as problems of resistance to thermal stress, especially on forming of the metal levels.


A waveguide includes a waveguide body, a twist plate, and a first and second probes. The waveguide body defines a waveguide cavity therein wherein the waveguide cavity has an aperture at a first end thereof, and wherein the waveguide cavity has a waveguide axis therethrough extending from the first end to a second end. The twist plate is in the waveguide cavity at the second end of the waveguide cavity wherein the twist plate is parallel to the waveguide axis, wherein the twist plate includes a leading edge facing the aperture, and wherein the leading edge includes first and second portions with the second portion being more distant from the aperture than the first portion. The first probe is in the waveguide cavity between the aperture and the leading edge of the twist plate for receiving a first signal having a first polarization entering the aperture. The second probe is in the waveguide cavity between the first probe and the leading edge of the twist plate for receiving a second signal having a second polarization entering the aperture. Related receivers and methods are also discussed.

In applicant's co-pending Published International Application WO92/22938 there is disclosed a dual polarisation waveguide probe system in which a waveguide is incorporated into a low-noise block receiver in which two probes are located for receiving linearly polarised energy of both orthogonal senses. The probes are located in the same longitudinal plane on opposite sides of a single cylindrical bar reflector which reflects one sense of polarisation and passes the orthogonal signal with minimal insertion loss and then reflects the rotated orthogonal signal. The probes are spaced .lambda./4 from the reflector. A reflection rotator is also formed at one end of the waveguide using a thin plate which is oriented at 45.degree. to the incident linear polarisation with a short circuit spaced approximately a quarter of a wavelength (.lambda./4) behind the leading edge of the plate. This plate splits the incident energy into two equal components in orthogonal planes, one component being reflected by the leading edge and the other component being reflected by the waveguide short circuit. The resultant 180.degree. phase shift between the reflected components causes a 90.degree. rotation in the plane of linear polarisation upon recombination so that the waveguide output signals are located in the same longitudinal plane.
The above waveguide probe system has been found to perform well for the purpose for which it was designed; to provide significant signal isolation better than 40 dBs. across the current Astra satellite bandwidth being 10.7-11.8 GHz. and across other bandwidths such as 11.7-12.2 GHz. for DBS and 12.2-12.75 GHz. However, there has been a trend to increase the frequency range transmitted by new satellite systems. In fact, the frequency bandwidth is planned to increase from 10.7-11.8 GHz. to 10.7-12.75 GHz. on the Astra system in the near future. With the aforementioned design it has hitherto been difficult to use a single LNB or waveguide to cover this wider frequency range, the frequency range being covered by two or more LNBs which are tuned to cover part of the frequency range, for example 10.7-11.8 GHz. and 11.7-12.2 GHz. The existing LNB may be frequency limited because of the bandwidth achieved by the reflection rotation of the existing design.
JP-A-02029001 discloses a waveguide system which is used to rotate and reflect a signal. One embodiment of this system uses a stepped dielectric plate, which is non-reflecting, to introduce a phase shift of 180.degree. for one component of the signal relative to the orthogonal component. This reference discloses an alternative embodiment which uses a capacitive metal rod or a dielectric rod on the diagonal line of the waveguide cross-section instead of a stepped dielectric plate. The particular solution to this problem may require a dielectric plate or rod or a capacitive metal rod.
GB 2 076 229 discloses the use of a stepped plate in apparatus for converting circularly polarised signals in a square waveguide into linearly polarised signals. It is a modified form of septum polariser which is well known in the art, and may not relate to reflection and recombination of signals to provide an increased frequency range of operation.
FR 2 615 038 discloses a waveguide with a vane which acts as a short circuit to one of the coaxial probes. The apparatus may not provide phase rotation and recombination and may not be suitable for providing an increased frequency range of operation.

Dual polarization waveguide probe system


An electroacoustic transducer of small dimensions has a cup-shaped component made of a metallizable plastic material embedded in a housing component having a housing shape and being of a non-metallizable plastic material. The cup-shaped component has an inner surface provided with a metal coating. A magnet is arranged in the cup-shaped component. A diaphragm is connected to the housing component and has an oscillation coil configured to interact with the magnet.

1. Field of the Invention
The invention relates to an electroacoustic transducer with small dimensions, in particular, transducers having a housing with an outer diameter of 15 mm or less.
2. Description of the Related Art
With increasing miniaturization of electroacoustic transducers for use in cordless telephones, cellular telephones, head sets, dictation devices, computer monitors etc., there are problems which are unknown in classic transducer technology. An important problem is trying to maintain the transducer characteristics in view of the relative tolerances which, as a result of the reduction of the dimensions, become increasingly greater while at the same time trying to keep constant or even reduce the cost per piece, because, as a result of the high production numbers, the question of cost is of much greater significance than in the case of large-volume transducers which are produced in small production numbers for special applications.
Classic electroacoustic transducers which operate according to the electro-dynamic principle are comprised essentially of a cup-shaped housing which is open at the front and into which a magnetic system is introduced from the front. The magnetic system is comprised of the actual magnet and a multi-part yoke wherein the yoke forms at the front side an annular air gap. A diaphragm, which is fastened on the housing at the front side of the magnetic system, has a oscillation coil which projects into the air gap of the yoke and can oscillate in this air gap in the axial direction. The individual yoke parts are usually the following: a cup-shaped part arranged at the bottom, having the magnet glued thereto at its center, and a circular front part whose outer circumference forms the inner circumference of the air gap.
The special problem of the miniaturization is the centricity or eccentricity between the air gap and the oscillation coil because, when any eccentricity is present, the diaphragm begins to wobble and the transducer characteristics are significantly disturbed. In the case of miniaturization of the transducer, the eccentricities, which for large-size transducers are still permissible, present a serious quality problem because the relative eccentricity for the same absolute tolerances and miniaturization of the components increases, of course, with the degree of miniaturization. For example, in the case of transducers with a diameter of the housing of approximately 15 mm it is already required to lower the eccentricity into the range of less than hundredths of millimeters in order to achieve the predetermined transducer characteristics without distortion.
When it is also taken into consideration that the tolerances of the usually employed parts, i.e., housing, magnetic system, securing rings and the like, in the normal transducer construction are in the range of tenths of millimeters, while in the case of highly precise parts as they are mandatorily required for the small transducers the tolerances are in the range of five hundredths of millimeters, it is immediately clear that even for average pairs of tolerances eccentricities can occur easily which are no longer within acceptable limits. In the case of unfavorable pairs, the permissible eccentricity is easily surpassed.

Electroacoustic transducer with small dimensions


A liquid crystal display device includes a timing controller generating a voltage compensation control pulse and a gate control signal, a voltage compensation signal generator generating a voltage compensation signal, the voltage level of which is gradually reduced during one frame period, in response to the voltage compensation control pulse, a power unit outputting a gate-on voltage to a plurality of gate lines by gradually increasing the level of the gate-on voltage in response to the voltage compensation signal, and a gate driver sequentially supplying the gate-on voltage to the plurality of gate lines in response to the gate control signal.

1. Technical Field
The present invention relates to a liquid crystal display (LCD) device and, more particularly, to an LCD device and a method of driving the same that can substantially prevent variations in brightness of an LCD panel by gradually increasing the level of a gate-on voltage.
2. Discussion of Related Art
A liquid crystal display (LCD) device displays an image by applying an electric field to a liquid crystal material having dielectric anisotropy injected between two substrates and by controlling the intensity of the electric field to control the amount of light transmitted through the liquid crystal material.
The LCD device may be classified into an active matrix type and a passive matrix type according to driving methods. An LCD device using a thin film transistor (TFT) of the active matrix type is widely used. The TFT may be formed of amorphous silicon or polysilicon. The TFT using polysilicon has low power consumption and low manufacturing costs; however, the manufacturing process is complicated. The TFT using amorphous silicon, having a less complicated manufacturing process, is widely used as an LCD element for a large screen LCD. Moreover, a gate driving circuit may be integrated into an LCD panel using the amorphous silicon TFTs. In this case, the gate driving circuit is provided on the LCD panel and thereby a separate driving integrated circuit is not required.
When such an amorphous silicon gate (ASG) is used, variations in brightness occur between the top and bottom of the panel as the panel size increases due to a gate-on voltage being lower towards the bottom of the panel. Therefore, voltages applied to pixels vary according to the position of the panel, even though the same data voltage is applied.

Liquid crystal display device and method of driving the same


A motor includes a bearing sleeve arranged with a base and having opposite opening and sealing ends; a stator coupled with the base or bearing sleeve; and a rotating member disposed in the bearing sleeve and including a shaft and a limiting portion adjacent to the sealing end. A first end of the shaft connects with the limiting portion, a second end of the shaft has a coupling portion, and the limiting portion has a first contact surface. A thrust bearing is arranged between the shaft and the bearing sleeve and has a second contact surface facing the first contact surface. At least one of the first and second contact surfaces is an uneven surface. A hub is coupled with the coupling portion of the shaft and has a permanent magnet corresponding to the stator.

1. Field of the Invention
The present invention generally relates to a motor with a thrust bearing and, more particularly, to a motor capable of steady rotation.
2. Description of the Related Art
Referring to FIG. 1, a sketch diagram of a conventional motor with a thrust bearing is shown, which is identified with a reference number of "9" and which has a seat 91, a stator 92 and a rotor 93. The seat 91 is coupled with a bearing housing 911 receiving a thrust bearing 912 and a pushing board 913 inside. The bearing housing 911 has two opposite openings for the rotor 93 to extend into the thrust bearing 912 and to couple with a lid 914 respectively. The stator 92 is coupled with an outer periphery of the seat 91. The rotor 93 includes a hub 931 integrally forming an annular wall 932 and a shaft 933. The annular wall 932 is located between the seat 91 and the bearing housing 911, to provide functions such as dust-resistance and anti-leakage of oil. The shaft 933 extends through the thrust bearing 912 and couples with the pushing board 913. Specifically, this kind of motor 9 is disclosed in patents such as a China patent application with the application number of 200410054614.4 (which is US Pat. No. 7,021,829) and title of "Fluid-Dynamic-Pressure Bearing, Spindle Motor Furnished with the Fluid-Dynamic-Pressure Bearing, Method of Manufacturing Rotor Assembly Applied in the Spindle Motor, and Recording-Disk Drive Furnished with the Spindle Motor."
With the above structure, in rotation of the rotor 93 relative to the thrust bearing 912, an upper surface of the pushing board 913 abuts against the thrust bearing 912 with a large area "F"since this upper surface contacts with a lower surface of the thrust bearing 912. As a result, in operation of the rotor 93, friction between the pushing board 913 and the thrust bearing 912 is large, which affects the rotation of the rotor 93 significantly. Therefore, it is necessary to improve the conventional motor 9.

Sunonwealth Electric Machine Industry Co., Ltd.


A size adjustable footwear includes an upper, an insole, a midsole, an outer sole, and a size adjustment mechanism. The midsole includes a heel plate and a toe plate. The upper is perimetrically connected around the midsole. The insole is adjacently connected atop the midsole and internally positioned within the upper. The outer sole is perimetrically connected around the midsole as the midsole is positioned in between the insole and the outer sole. The heel plate and the toe plate are slidably engaged to the size adjustment mechanism. The size adjustment mechanism is operatively integrated in between the heel plate and the toe plate, wherein the size adjustment mechanism elastically expands and contracts the upper, the midsole, and the outer sole.

Finding the right shoe size can be a daunting task due to various reasons. The growing feet of toddlers and children changes rapidly as they develop making it problematic and tiresome for parents as they end up spending a lot of money buying shoes that their children will outgrow after a couple of months. Multiple people also often have one foot that is larger than the other forcing them to wear different shoe sizes. Furthermore, the size of one's feet may change over time due to aging, trauma, or medical conditions. The present invention addresses all the above issues adequately. The present invention allows people to extend or shorten the length of a footwear as needed to accommodate the changes in feet size over time.
The present invention provides adjustable inner and outer soles that can expand and contract simultaneously, or one at a time if necessary. The size adjustable mechanism can utilize different mechanisms powered by one or more dials, bars, rods, a set of guides, springs, flexible structure, etc. The size adjustable mechanism is preferably integrated into the inner sole and hidden from the external environment to not affect the ornamental look of the footwear. The outer sole is a casing made from rubber stretchable material to receive the inner sole and to hold/stabilize the overall structure of the inner sole during the contraction and the extension of the size adjustable mechanism. The inner sole comprises multiple sections (ex: insole and midsole) connected by the size adjustable mechanism which can be pushed away from each other or pulled together to adjust the overall size of the footwear. Further, the size adjustable mechanism is preferably manually operated and easily accessible to the user.


The present disclosure may provide a cleaning apparatus for cleaning parts. The cleaning apparatus may comprise a housing defining a washing chamber having an opening through which parts may be loaded/unloaded into the washing chamber. The cleaning apparatus may also comprise a spray system adapted to direct a washing solution to clean the part in the washing chamber. The spray system may comprise a spray array with at least one rotatable spray head. The spray head may comprise a plurality of nozzles through which the washing solution is directed to clean the part in the washing chamber. The cleaning apparatus may also comprise a closure which may provide controlled access to the washing chamber through the opening and may be movable between a closed position to sealingly close the opening and an open position so as to allow for loading and unloading of parts into the washing chamber without obstruction.

When repairing or reconditioning a machine, it may be required to clean parts of that machine. For instance, when reconditioning engines, engine parts may often be covered in grease, oil, and/or exhaust debris and thus may require cleaning to ensure the engine is able to operate as efficiently as possible once re-assembled. Generally, cleaning may be done in a chemical bath and/or in specially-designed cleaning equipment.
The use of a chemical bath, while effective, may take a long time to completely clean the part. Chemical baths may typically have a large volume of one or more chemicals contained in a vessel which is able to be agitated. The part to be cleaned may then be submerged in the chemical(s) and may sit in the bath for a significant amount of time in order to allow the chemical to clean the product. Chemical baths may be a very slow way of cleaning a part and also may present significant safety and environmental issues due to the nature of the chemical(s) (typically a caustic soda).
Cleaning equipment generally may comprise a housing having an opening at its upper face which is controlled by a closure. The interior of the housing may define a washing chamber which may accommodate a basket intended to receive machine parts and the like and which may be driven to rotate about its central axis within the housing. The washing chamber may be associated with a suitable spray system intended to direct a washing solution on to the parts being carried by the basket. Generally, the basket may be rotated while the spray system may remain fixed.
Cleaning equipment may be designed to suit particularly-sized parts. For example, a size of the housing, the design of the basket, and/or the associated spray system may be tailored to dimensions of parts the cleaning equipment may be used to clean. Current cleaning equipment may fall short for larger parts.
Due to size, cleaning equipment designed for large parts may lack portability and may take up a large area of floor space. The need for a large floor space may also be required to allow the part to be loaded into and unloaded from the cleaning equipment. Logically, in order to load and unload the part into the cleaning equipment, the opening of the cleaning equipment may need to be suitably sized. This opening may generally be closed by doors that may swing open and thus may need room to open and be positioned so as not to hinder the loading and unloading of the parts. This may increase the amount of floor space required to accommodate the cleaning equipment.
Due to the cleaning equipment's lack of portability, operators who need parts cleaned on a regular but perhaps not full-time basis may need to transport the parts to a location where there is suitable cleaning equipment. Alternatively, operators may rely on a process of cleaning which may be substandard. These delays in the repair/reconditioning of the part caused by the cleaning process may add considerable expense to the process.
Further, the position of the opening and the operation of the doors of cleaning equipment may make it difficult to load and unload a large part using an overhead crane. Such loading may require an operator to assist in manoeuvring the part into and out of the cleaning equipment, which may create an unsafe work environment.
As machinery, such as trucks and trains, become larger and more powerful, their engines and other parts may also increase in size and weight. For instance, an engine block of a V12 or V16 locomotive engine may be too large to be cleaned in current cleaning equipment. Due to the weight and shape of these parts, rotating baskets in available cleaning equipment may not readily support the load. Furthermore, the closure may make it very difficult to load and unload the part. Another difficulty may include the spray system of the cleaning equipment being unable to adequately clean the part's interior cavities.
Current cleaning techniques may not effectively clean parts of large size. In some attempts, a cleaning machine without a rotating basket may be utilized to clean the engine block, whereby the engine block may be placed vertically in the cleaning machine. However, and setting aside difficulties in loading and unloading the part, the engine part may be prone to distortion as a result of being in a vertical orientation for such a period of time. Furthermore, this method may not facilitate the cleaning of the cavities of the engine block.
In relation to chemical baths, the engine block may be required to sit in a bath for 2-3 days and may require at least 20000 liters of chemical, which may be prohibitively time consuming and expensive. Another option may be to manually clean the part. This method of cleaning not only may provide a substandard level of cleaning, but also may require a significant amount of time (e.g., at least 200 hours) as well as a large volume of solvent.
The preceding discussion of the background art may be intended to facilitate an understanding of the present disclosure only. The discussion may not be an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

Apparatus and method for cleaning machines


The inventive subject matter relates to a method for detecting the presence of a biological substance of interest in a test sample of saliva or oral fluid, comprising combining said test sample with a fluorescence-labeled ligand to said biological substance and detecting a change in the fluorescence polarization of said test sample produced by binding of said fluorescence-labeled ligand to said biological substance. In one aspect of the inventive subject matter, said method comprises additional steps for comparing the fluorescence polarization of said test sample with the fluorescence polarization of a control solution. Also provided is a miniaturized, portable apparatus for measuring the fluorescence polarization of a liquid sample.

1. Field of Invention
The present inventive subject matter relates to novel methods for detecting the presence of a biological substance of interest in a test sample of saliva, oral or other bodily fluids. Also provided is a miniaturized, portable, hand-held apparatus for measuring the fluorescence polarization of a liquid sample.
2. Description of the Related Art
Immunoassays. Infectious disease rates and immunization strategies continue to evolve in the United States and worldwide in response to societal needs, national defense, and evolutionary changes in the organisms producing disease. Immunizations are performed to prevent many infections, while prophylactic population screening is utilized for infections lacking effective vaccines and for those diseases having a low enough incidence that mass immunization is not deemed most efficacious.
The current method for diagnosis of disease, determining exposure to biological materials such as pathogens, or monitoring immunization status varies depending on the specific assay. Some methods employ an in vivo assay. Others require a biological sample, such as blood or serum, to be obtained and tested. Tests performed usually are one of the non-homogeneous type diagnostic methods such as enzyme-linked immunosorbant assay (hereinafter "ELISA"), radioimmunoassay (hereinafter "RIA"), or agglutination. All are surface-binding, heterogeneous assays and require the antigen of interest to interact with a surface to achieve success, often at the expense of high non-specific binding and loss of specificity.
Fluorescence Polarization
Fluorescence polarization (hereinafter "FP") is the process in which visible or ultraviolet light is polarized with a filter and shines on part of a molecule, the fluorochrome, that in turn fluoresces, emitting light of longer wavelength whose signal is captured and recorded. The emitted light recorded stays more polarized in solutions when there are slower turning, large molecule-fluorochrome complexes than when there are smaller labeled molecules. Different fluorochromes can be chosen to accommodate molecules of different sizes up to 107 kDa molecular weight.
U.S. Pat. No. 4,585,862 to Wang, et al., issued Apr. 29, 1986, discloses a method and reagents for determining a ligand, particularly steroid, hormone, antiasthmatic, antineoplastic, antiarrhythmic, anticonvulsant, antibiotic, antiarthritic, antidepressant, cardiac glycoside, or a metabolite thereof, in biological fluids such as serum, plasma, spinal fluid, amnionic fluid, and urine. In particular, Wang, et al. relates to a specific class of tracer compounds required as reagents in such procedures.
U.S. Pat. No. 5,976,820 to Jolley, et al., issued Nov. 2, 1999, discloses a homogeneous immunoassay in which a fluorophore-conjugated lipopolysaccharide derived bacterial antigen is reacted with antibodies specific for the antigens in a diluted serum specimen, with quantitative detection of the formation of an immune complex obtained by measuring the change in fluorescence polarization after complex formation.
U.S. Pat. No. 6,432,632 to Nakayama, et al., issued Aug. 13, 2002, discloses a fluorescence polarization method for analyzing an assay-object in a sample, comprising the steps of: (a) providing a fluorescent-labeled protein in which a protein is covalently bound to a fluorochrome(s), wherein the protein is capable of specifically binding to the assay-object; (b) allowing the fluorescent-labeled protein to bind to the assay-object; and (c) measuring a change in the degree of fluorescence polarization which has taken place in the fluorescent-labeled protein by its binding to the assay-object.
Saliva and Oral Fluids
Saliva and oral fluids are biochemically distinct and have been increasingly recognized as acceptable alternatives to serum for use in diagnostic tests for certain hormones, drugs, antibodies and antigens. Oral fluids are collected without pain, needle sticks, or religious and social prohibitions, and their use involves minimal risk or exempt protocols for the use of human subjects. Surprisingly, diagnostic assays utilizing saliva and other oral fluids appear as entries in the National Library of Medicine MEDLARS database with a frequency of only 1 in 30 and 1 in 100, respectively, when compared to entries in which blood serum is reported.
Knowledge of the epidemiology of diseases is important in health care planning and treatment. Both are dependent upon accurate and rapid diagnosis. Using an under-utilized and elegant technology, fluorescence polarization, we have developed assays for accurate and rapid detection and diagnosis of antibodies to pathogens producing diseases of military and commercial interest. The technology is homogeneous and can accurately estimate concentrations of diagnostic markers, drugs and chemicals, or bio-hazardous agents in oral fluids and environmental samples within a few seconds to several minutes. Further, the inventive oral immunodiagnostic assay systems are robust and relatively unaffected by use with non-homogeneous samples, such as whole blood or saliva. Specificity of FP assays is generally very high, approximately 98%, with good sensitivity. The applications of FP salivary diagnostics to determination of tuberculosis exposure and of anthrax immunization status are provided as examples.
There is potential for widespread use of these assays as non-invasive tests, especially as more compact, simplified fluorescence polarimeters become available. FP tests are provided and are applicable to a wide spectrum of microorganisms. Rapid FP salivary diagnostics, have both military and civilian applications and may be used in a clinic or field setting to aid in diagnosis of disease, detection of exposure, or verification of vaccination. Particularly in those instances where rapid detection in field situations is required, these considerations and continuing improvements in standardization of collection methods make the use of saliva and oral fluids as well as bodily fluids a novel and effective diagnostic media of choice for the future.
Fluorescence Polarization Detection Instrumentation
Fluorescence polarization instruments and their use for clinical applications are described, for example, in "Design, Construction, and Two Applications for an Automated Flow-Cell Polarization Fluorometer with Digital Read Out"; R. D. Spencer, F. D. Toledo, B. T. Williams, and N. L. Yoss; Clinical Chemistry, 19/8, pages 838-344 (1973). Such instruments can rapidly analyze body fluid samples labeled with a fluorescent material.
Early instruments of such type required relatively high wattage, intense light sources, such as 200-250 watt mercury or xenon gas discharge lamps, in order to obtain the desired emission radiation from the sample at a signal to noise level ratio sufficient for detection and amplification by a low-noise photomultiplier tube and associated electronics. Such high wattage, bright lamps also require substantial cooling in order to maintain the integrity of the optical system.
An improved fluorescence polarization instrument is described in U.S. Pat. No. 4,516,856, issued to Popelka on May 14, 1985. Popelka discloses an optical system for a fluorescent polarization instrument including a low wattage, low intensity focused light source and a polarizer/liquid crystal combination in the excitation path focusing excitation light of alternate planes of perpendicular polarization onto a fluorescent liquid sample, wherein emitted light from the fluorescent sample is filtered, polarized and focused onto a photomultiplier for processing, and a series of non-reflective baffles are placed around the sample to reduce reflections; monitoring means monitor the excitation light and maintain a substantially constant intensity level focused on the sample, while the low wattage, low intensity light source is provided by a 50 watt tungsten halogen projector lamp. An exemplary prior art instrument schematic is shown in FIG. 1.
Even with these improvements, current instruments are large, bulky tabletop instruments with high voltage and high power usage, and thus substantial AC power requirements. Further, current FP instruments suffer from intrinsic background fluorescence contributed by fluorescent biological molecules such as NAD, NADH, NADP, and NADPH. In addition, current FP instruments also suffer from intrinsic AC line voltage noise. Thus, there is a need for improved fluorescence polarization instruments which are smaller, lighter, and operate using a battery pack or other low power DC power source; avoid the intrinsic background fluorescence contributed by fluorescent biological molecules such as NAD, NADH, NADP, and NADPH; and offer a simplified optics block design. In particular, with increasing prevalence of non-invasive FP tests applicable to a wide spectrum of microorganisms, to aid in diagnosis of disease, detection of exposure, or verification of vaccination, both military and civilian applications in a clinic or field setting will require portable FP instruments. The inventive apparatus satisfies this need by providing a miniaturized, portable apparatus for measuring the fluorescence polarization of a liquid sample.

Fluorescence polarization instruments and methods for detection of exposure to biological materials by fluorescence polarization immunoassay of saliva, oral or bodily fluids

The United States of America as represented by the Secretary of the Navy


A method to improve the safety and comfort of an ultra large marine floating system is provided. The ultra large marine floating system has a length of 350 to 550 m, a width of 45 to 80 m, and a depth of 25 to 35 m. The ultra large marine floating system has a tank zone and a plant zone that are visibly separated from one another. Additionally, the tank zone has LNG storage tanks, self-supporting spherical (MOSS type) tanks, a membrane tank arranged in a hold, and the plant zone includes a liquefied natural gas plant.

When LNG is burned, the LNG produces a small amount of emission of nitrogen oxide and sulfurous acid gas and hence has been increasingly demanded as clean energy year by year. The LNG is produced by cooling natural gas to approximately −162° C. to thereby liquefy the natural gas and is carried by the sea to a consumption area by an LNG carrier.
Under circumstances where the price of energy is rising worldwide, development projects of a large-scale gas field of seabed far from land are currently beginning in earnest.
In the light of this trend, the following production and transportation system has been focused: that is, a marine floating system having a liquefied natural gas plant and an LNG storage tank arranged thereon is floated on the sea; in the marine floating system, the impurities of the natural gas are removed and the natural gas is liquefied to produce LNG and the LNG is stored in the tank; and when an LNG carrier arrives at the marine floating system, the LNG is offloaded (shipped off) from the LNG storage tank.
As compared with a case where a liquefied natural gas plant is constructed on the land, the transportation system has the following advantages: pipeline facilities from a gas field of seabed and in the sea to the land can be reduced; an environmental load can be reduced because development on the coast is not required; and workers can be comparatively easily secured because an LNG-FPSO is constructed in a country or a region different from those in which a gas field is developed and is towed to the site.
The LNG-FPSO (Floating LNG Production, Storage and Off-Loading system) used for this has the functions of liquefying gas, which is produced from a gas field of seabed, on the ocean to produce LNG, storing the LNG in a tank, and loading it onto an LNG carrier.
An LNG-FSRU (Floating LNG Storage and Re-gasification Unit) has a function of gasifying LNG received from an LNG carrier delivering the LNG gas to the land.
The LNG-FPSO include a tank or tanks for storing a large amount of produced LNG, and as its tank structure, LNG tank technology, which has been fostered in the construction of a conventional LNG carrier, is expected to be adopted. However, since how the LNG storage tank is used is different between the LNG-FPSO and the LNG carrier, care is needed. In the case of the LNG carrier, a phenomenon that a liquid cargo in the tank violently sloshes (sloshing phenomenon) is unlikely to occur even during heavy weather because the LNG storage tank is used either in full load condition or in unload condition and is never in half load condition. Only during cargo handling work, a liquid level in the tank greatly changes, but since the cargo handling work has been usually performed in a port where waves and winds are quiet, it has been possible to almost disregard the sloshing.
On the other hand, in the LNG-FPSO, the sloshing phenomenon is thought to be likely to occur because it is constantly moored on the ocean where a weather condition is severe and a liquid level in its LNG storage tank changes from time to time according to a production amount of LNG and a loading amount to the LNG carrier, and half load condition daily occurs.
Another important thing about the LNG-FPSO is that loading the liquid cargo to the LNG carrier with the use of a loading arm, a special hose with a coupling system or the like, by STS (ship to ship) operation, in particular, while the LNG carrier is alongside the LNG-FPSO (side by side), is now under consideration. Considering that the cargo handling for a conventional LNG carrier has been performed while the LNG carrier is moored at a berth provided in a safe port, it is thought that the aforesaid STS cargo handling on the ocean has a high risk caused by a collision accident occurs between the LNG-FPSO and the LNG carrier trying to approach it to damage the hull, or an accident such as the damage of the hull by leakage of the liquid cargo from the loading arm. Therefore, in designing the tank and ship of the LNG-FPSO, it is necessary to take such risks into full consideration.
Following three kinds of LNG storage tanks conventionally used in LNG carriers have been adopting, a self-supporting spherical tank (MOSS type tank), a self-supporting prismatic tank (SPB type), and a membrane tank and it is expected that one of these three tank types will be adopted also in the LNG-FPSO.
Regarding the self-supporting spherical tank, it is a self-supporting tank made of an aluminum alloy and is supported in a hold of a double hull construction, via a skirt extending from its equatorial portion. A thermal insulation layer is applied on an outer surface of the tank (external thermal insulation). Due to its spherical shape, the self-supporting spherical tank has a disadvantage of low volumetric efficiency because it is not well fitted in the hold. However, in the tank of this type, owing to its external thermal insulation, the thermal insulation layer does not suffer damage even by sloshing during heavy weather.
Regarding the self-supporting prismatic tank, a main body is a prismatic tank made of an aluminum alloy and longitudinal strength members reinforcing of the tank are provided on an inner side of the tank, and a thermal insulation layer is provided on an outer surface of the tank. This type requires void space between the prismatic tank and an inner hull of the ship, which accordingly reduces volumetric efficiency of the tank. On the other hand, since the longitudinal strength members can be provided inside the tank, sloshing of a liquid cargo does not easily occur during heavy weather, and even if the sloshing occurs, the thermal insulation layer provided on the outer surface of the tank is not damaged.
In the membrane tank, on an inner surface of a hold fabricated with a double hull structure, thin sheets (membranes) made of nickel steel or stainless steel are affixed, with a thermal insulation layer there between, to form a LNG tank. This type is excellent in volumetric efficiency because almost all the volume of the hold can be used as a tank volume. On the other hand, it has a disadvantage that the membranes and the thermal insulation layer are likely to be damaged by the sloshing of a liquid cargo. It also has a problem that a thermal insulation work, in particular, the welding of the membranes is complicated and it requires a long period for the construction.