A novel cytosine-5 DNA methyltransferase, isolated from Chlorella virus NYs-1, and its encoded enzyme are disclosed. The methyltransferase recognizes a GpC dinucleotide in DNA. Methods of using the novel methyltransferase in high resolution chromatin mapping and related techniques are also disclosed.

The present invention relates to the field of analysis and manipulation of chromosomal DNA in situ. In particular, the invention provides a novel cytosine methyltransferase gene and encoded enzyme that recognizes the dinucleotide GpC, and its use in high resolution analysis and manipulation of protein-DNA interactions in chromatin.
Various publications or patents are referenced in this application to describe the state of the art to which the invention pertains. Each of these publications or patents is incorporated by reference herein.
In vivo methylation of DNA has been used successfully to study protein-DNA interactions in the chromatin of living cells. A high frequency of methyltransferase targets is critical for high resolution mapping of chromatin structure. Among currently available methyltransferase probes, the only de novo dinucleotide methyltransferase is M.SssI, which recognizes a CpG site (Renbaum, P., Abrahamove, D., Fainsod, A., Wilson, G., Rottem, S. and Razin, A. (1990) Nucleic Acids Res., 18, 1145-1152). Due to under-representation of the CpG dinucleotide in the genome, the resolution of chromatin structure maps using this enzyme is about 35 base pairs on average in S. cerevisiae (Dujon, B., Alexandrakl, D., Andrxc3xa9, B., Ansorge, W., Baladron, V., Ballesta, J. P. G., Banrevl, A., Bolle, P. A., Bolotin-Fukuhara, M., Bossler, P. et al). (1994) Nature, 369, 371-378.). With this moderate level of resolution, M.SssI can possibly serve to detect the presence of a positioned nucleosome, 146 bp in yeast, without the need for introduction of additional CpG sites into native DNA sequences. However, this resolution is insufficient for mapping the interactions of non-histone regulatory proteins, since the typical length of the target DNA sequence of most regulatory proteins is xcx9c20-30 base pairs or less. For example, the yeast TATA box binding protein (TBP) recognizes and binds to an 8 bp sequence (Kim, Y., Geiger, J. H., Hahn, S. and Sigler, P. B. (1993) Nature, 365, 512-520.), while the well-characterized transcriptional activator Gal4p binds to a 17 bp consensus sequence (Giniger, E., Varnum, S. M. and Ptashne, M. (1985) Cell, 40, 767-774.). Furthermore, methylation of CpG islands has been implicated as an important controlling element for gene regulation in mammalian systems, which may limit the application of M.SssI in higher organisms (Tazi, J. and Bird, A. (1990) Cell, 60, 909-920.). To address both the limitation of resolution and the possible inability to utilize M.SssI in higher organisms, cloning and expression of cytosine-5-DNA methyltransferases (5-meC MTase) with different specificities but similarly small recognition sites is essential.
A family of double-stranded DNA viruses that infect certain unicellular, eukaryotic, Chlorella-like green algae are reported to be a rich source of restriction/ modification systems (Nelson, M., Zhang, Y. and Van Etten, J. L. (1993) DNA Methylation: Molecular Biology and Biological Significance. Birkhauser-Verlag Press, Basel, Switzerland, pp. 186-211; Nelson, M., Burbank, D. E. and Van Etten, J. L. (1998) Biological Chem. 379, 423-428). Among the 37 viruses infecting Chlorella NC64A and the five viruses infecting Chlorella Pbi which have been partially characterized, 39 viral DNAs contain 5-methylcytosine, ranging in concentration from 0.1 to 47% of total cytosine (Nelson and Van Etten, 1993, supra; Nelson and Van Etten, 1998, supra)
One cytosine methyltransferase, M.CviJI, has been cloned from Chlorella virus IL-3A and shown to recognize the nucleotide sequence RGC(T/C/G) (Shields, S. L., Burbank, D. E., Grabherr, R. and Van Etten, J. L. (1990) Virology, 176, 16-24). As determined by the resistance/sensitivity of the viral DNAs to over 70 methylation-sensitive restriction endonucleases, at least five independent 5-meC modification systems are predicted to be encoded by some of the more highly modified viruses, including methyltransferases thought to recognize Cpc and RpCpY (Nelson and Van Etten, 1993, supra;Nelson and Van Etten, 1998, supra) . Based on the composition of the yeast genome as an example, on average, one Cpc site per 13.9 bp and one RpCpY site per 10.7 bp can be expected in the genome. Achieving this level of resolution would allow mapping the interactions of most non-histone, regulatory proteins. The cloning of methyltransferases from Chlorella viruses could greatly extend the resolution of chromatin mapping as well as allow extension of in vivo chromatin mapping to higher organisms.
The present invention provides a novel cytosine-5-DNA methyltransferase gene and its encoded enzyme, isolated from Chlorella virus NYs-1, that recognizes the sequence GpC. This methyltransferase having a small recognition site that occurs with a high frequency in eukaryotic genomes is of particular utility for high resolution analysis of chromatin structure and protein-DNA interactions in living cells.
According to one aspect of the invention, an isolated nucleic acid molecule is provided, which encodes a cytosine-5 DNA methyltransferase that recognizes a GpC dinucleotide in DNA. Preferably, the nucleic acid molecule is isolated from a Chlorella virus, most preferably from Chlorella virus NYs-1. In a preferred embodiment, the encoded cytosine-5 DNA methyltransferase has an amino acid sequence substantially the same as SEQ ID NO:2 and the encoded methyltransferase is catalytically active and recognizes the GpC dinucleotide. Most preferably, the encoded cytosine-5 DNA methyltransferase has amino acid SEQ ID NO:2.
The following isolated nucleic acid sequences are provided in the present invention: (a) SEQ ID NO:1; (b) natural variants of SEQ ID NO:1; (c) sequences that hybridize with part or all of an antisense strand of SEQ ID NO:1 and encode part or all of a protein having a catalytic activity and sequence recognition specificity the same as the protein having SEQ ID NO:2; and (d) a sequence encoding part or all of SEQ ID NO:2.
According to another aspect of the invention, a recombinant DNA molecule comprising one of the aforementioned cytosine methyltransferase-encoding nucleic acid molecules inserted into a vector for transforming cells, is provided. The recombinant DNA molecule is used to transform cells, which may be cultured cells or which may be cells of a living organism. Oligonucleotides of between about 10 to about 100 nucleotides in length which hybridize with portions of the methyltransferase-encoding nucleic acid molecule are also provided in accordance with the present invention, as are antibodies immunologically specific for part or all of the encoded polypeptide.
According to another aspect of the invention, an isolated cytosine-5 DNA methyltransferase that specifically recognizes a GpC dinucleotide sequence in DNA is provided. The methyltransferase preferably is isolated from a Chlorella virus, most preferably virus NYs-1. In a preferred embodiment, the cytosine-5 DNA methyltransferase has an amino acid sequence substantially the same as SEQ ID NO:2 and the methyltransferase is catalytically active and recognizes the GpC dinucleotide. In a particularly preferred embodiment, the enzyme has amino acid SEQ ID NO:2.
According to another aspect of the invention methods of mapping DNA-protein interactions with the novel cytosine methyltransferase are provided. One method comprises the steps of: (a) providing a sample of the cells transformed with a nucleic acid molecule that encodes the novel cytosine-5 methyltransferase; (b) growing a test culture of the transformed cells under conditions enabling production of the methyltransferase; (c) growing a control culture of equivalent cells that do not produce the methyltransferase; (d) isolating the DNA from the test culture and the control culture; (e) exposing the DNA from the control culture to the cytosine-5 methyltransferase; and (f) comparing the cytosine methylation of the DNA from the test culture with the cytosine methylation of the DNA from the control culture, a decrease in extent of methylation in the DNA of the test culture being proportional to the amount of DNA-protein interaction occurring in the DNA in the cell. The method may further include comparing a pattern of methylation in a selected region of the DNA from the test culture and the control culture, a change in the methylation pattern in the respective DNA being indicative of a location of a DNA-protein interaction in the DNA of the cell. In one embodiment, the aforementioned method is applied to analyzing interactions between nucleosome proteins and chromosomal DNA. In another embodiment, the method is applied to analyzing an interaction between a transcriptional regulatory protein and a transcriptional response element in the DNA. These methods are used to advantage in the high resolution mapping of sites of interest for in situ genetic manipulation, such as insertion of a foreign gene for gene therapy.


Mixing apparatus is disclosed suitable for the mixing and/or aeration of large bodies of water e.g. lakes or reservoirs. One particular use is in causing controlled destratification. Another area of use is in the aeration or oxygenation of liquid waste. The mixing apparatus has a draft tube (1) with an open interior, and gas injectors (6) to drive an upward flow of liquid through the draft tube (1). An arrangement of angled vanes (4) at the intake of the draft tube imposes swirl on the flow, which then rises unobstructed through the draft tube (1). No moving parts are involved.

There are circumstances in which it is important to be able to mix bubbles of air or other gas into a body of liquid in order to treat it. One well-known instance is waste water treatment. Industrial effluents and sewage need aeration. Less well known but of great importance is the treatment or aid to natural regeneration of large static water supplies, such as rivers, lakes and reservoirs. Particularly where there is little or no natural flow or circulation, such large bodies of water are liable to certain difficulties which can render them unfit for use unless special measures are taken. In particular, bodies of water tend to stratify stably into layers of different temperatures, which do not mix with one another and which contain different levels of dissolved oxygen. Water from lower layers generally contains very little dissolved oxygen. It may contain high levels of dissolved metals or other pollutants. It is usually not fit for use. This is a problem in a reservoir if the level falls. Another issue is the growth of algae, particularly blue-green algae, which is an undesirable presence in reservoirs and flourishes at certain levels in still water, particularly the sunlit surface layers where it consumes oxygen ("BOD"). Chemical reactions occurring at lower or bed level may also consume oxygen ("COD"). The sea is likewise prone to stratification, despite tidal flows, e.g. there can be problems for fish farms and shellfish farms when concentrations of undesirable organisms such as algae arise near or are carried into the farm zone in a stable stratum.
Over the years there have been various proposals for dealing with these problems. One approach is to generate a line source or point source of bubbles by pumping compressed air through a series of holes in a pipe lying on the bed, or through a porous block. The rising bubbles entrain water and generate a buoyant bubble plume—a mixture of water and bubbles—which causes vertical exchange and mixing, reducing the bad effects of thermal stratification. A refinement of this is to provide an upright tube near the bottom of the body of water and pump compressed air into the bottom of this tube, in the manner of an air lift pump used in dredging. The resulting imbalance of hydrostatic pressure forces the low-density air/water mixture continually up the tube, creating a substantial upward flow into which (a secondary benefit) some extra oxygen may dissolve. The air/water mixture leaving the top of the tube entrains further near-bed water as it rises towards the surface, increasing the vertical exchange effect. The best entrainment is achieved when the bubbles are small and evenly distributed in the tube and the flow is strongly turbulent and rotational (swirling). U.S. Pat. No. 3,452,966 (Smolski) describes a device known commercially as the "Helixor" in which the cylindrical tube interior is spanned by an integrally-extruded helically-twisted strip, to cause a rotational flow when compressed air is directed into the two openings at its lower end from holes in an air line. This device has been widely used over the years. However it is difficult to make, and the air bubbles tend to be large and to follow the shortest path up the helix without mixing with the water. Also the flow resistance is high. See also EP-A-826640. Other prior proposals use a draft tube with an empty interior, either without rotation or creating rotation flow by the circumferential angling of compressed air input jet openings near the base of the column. See WO 79/00895 and U.S. Pat. No. 3,855,367. However the rotational impetus in the latter is small.
In the waste treatment field, many gasification apparatus are described using rotating impellers or paddles to drive mixing between liquid and gas, but the need for a mechanical drive in situ makes these expensive and limited in their field of use.


The invention relates to a method and a device (10) for localizing an insulation fault in an operating electrical equipment (8) connected to a power supply system (2). Fundamental function blocks of the invention are an electric monitoring device (12), which identifies an insulation fault and communicates a respective fault time to an identifying device (16) via a communication channel (14), said identifying device (16) identifying a faulty operating electrical equipment (8) by electrical equipment of a turning-on/-off signal progress characteristic to the particular operating electrical equipment (8).

The invention relates to a method and a device for localizing an insulation fault in an operating electrical equipment connected to a power supply system.
The foundation for safely supplying electrical energy is based on reliable power supply systems. The high availability of power supply demands highly complex electric installations which are provided with protective and monitoring devices in order to identify faults on time and to be able to implement a time- and cost-saving fault localization.
In a grounded power supply system, an insulation fault can manifest itself as a residual current which does not trigger a fault-current protective device but in the long term poses an insidious threat in particular to people who come into contact with electrically conductive installation parts. In ungrounded power supply systems, a decreasing insulation resistance value can pose a risk to operational safety. It is thus necessary to duly identify, locate and eliminate as quickly as possible such insulation faults.
In grounded grids, residual-current monitors (RCM) are known to be used as electric monitoring devices which identify an (elevated) residual current in the power supply system. In ungrounded power supply systems, insulation monitoring devices are used as electrical monitoring devices which continuously examine whether the insulation resistance of the entire electric installation—the power supply system including the electric operating electrical equipment connected thereto such as consumers or generators—does not fall below a predetermined minimum value.
If an insulation fault is reported by the monitoring device, the fault is then generally identified but not yet localized in most instances. As a rule, the fault localization is a time- and cost-intensive task since the fault must be eliminated as quickly as possible but the fault location is as of yet unknown.
According to the contemporary state of the art the fault is either localized manually by electrical equipment of portable localizing devices or automatically using permanently installed fault localization devices, most of the time with the aid of measuring current transformers.
Depending on the desired local resolution, a plurality of measuring current transformers is required. The more selectivity is desired, the more measuring current transformers have to be installed. With a sufficient amount of measuring current transformers, a selectivity all the way to individual sockets can be attained which, however, disadvantageously encompasses a corresponding material and installation expenditure.
The fault localization is therefore often very cumbersome in particular in faults which occur in connected operating electrical equipment, such as consumers or generators.

Method and device for localizing an insulation fault in an operating electrical equipment connected to a power supply system


A system and method for lung cancer screening is provided. The system includes a database including structured patient information for a patient population and a domain knowledge base including information about lung cancer; an individual patient record; and a processor for analyzing the patient record with data from the database to determine if a patient has indications of lung cancer. The method includes the steps of inputting patient-specific data into a patient record; performing at least one lung cancer screening procedure on a patient, wherein at least one result from the at least one procedure is inputted into the patient record in a structured format; and analyzing the patient record with a domain knowledge base to determine if the patient has indications of lung cancer.

In the United States, lung cancer is the second most common cause of cancer and the leading cause of cancer deaths for both men and women. Survival from lung cancer is dependent on the stage of the cancer. The stage is determined by the size and location of nodules (e.g., tumors), the presence of cancer in the surrounding lymph nodes, and the spread of cancer to distant sites. When lung cancer is treated in its earliest stage, the cure rate approaches 70% or greater. Therefore, early detection is crucial for increasing the survival rates for patient with lung cancer.
Traditionally, X-rays have been used to detect nodules in patients showing symptoms of lung cancer. However, the smallest nodule detectable by X-ray is approximately 1 cm, which is an indication of advance growth, and subsequently, survival rates for patients exhibiting these nodules are low. Computerized tomography (CT) scans are capable of detecting lung cancer nodules much smaller than by conventional X-rays. CT scans have a much higher resolution than X-rays and can detect a nodule at only 0.5 mm in diameter.
Although CT scans can detect very small nodules, CT screening is expensive. Determining whether detected nodules are malignant requires multiple CT examinations over several months to make sure that the nodule does not grow. Furthermore, most patients screened have some "junk" in their lungs which may show up as a nodule in a CT scan due to its high resolution. However, every nodule can not be biopsied for several reasons. First, as with multiple CT scans, a biopsy is expensive. Most importantly, a biopsy causes much anxiety in patients due to the fact it is an invasive procedure and it has a certain amount of risk associated with it. Therefore, a protocol for lung cancer screening needs to balance the costs associated with the tests to be performed and the burden placed upon the patients while maintaining a high quality of care.
In view of the above, there exists a need for improved systems and methods for screening persons for lung cancer, monitoring nodule detection, and managing patients exhibiting lung cancer indications.

Patient data mining for lung cancer screening


Embodiments disclosed herein address the need in the art for efficient management of grant, acknowledgement, and rate control channels. In one aspect, a list associated with a first station is generated or stored, the list comprising zero or more identifiers, each identifier identifying one of a plurality of second stations for sending a message to the first station. In another aspect, sets of lists for one or more first stations are generated or stored. In yet another aspect, the messages may be acknowledgements, rate control commands, or grants. In yet another aspect, messages comprising one or more identifiers in the list are generated. Various other aspects are also presented. These aspects have the benefit of reduced overhead while managing grant, acknowledgment and rate control messaging for one or more remote stations.

1. Field
The present invention relates generally to wireless communications, and more specifically to active sets for grant, acknowledgement, and rate control channels.
2. Background
Wireless communication systems are widely deployed to provide various types of communication such as voice and data. A typical wireless data system, or network, provides multiple users access to one or more shared resources. A system may use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), and others.
Example wireless networks include cellular-based data systems. The following are several such examples: (1) the "TIA/EIA-95-B Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System" (the IS-95 standard), (2) the standard offered by a consortium named "3rd Generation Partnership Project" (3GPP) and embodied in a set of documents including Document Nos. 3G TS 25.211, 3G TS 25.212, 3G TS 25.213, and 3G TS 25.214 (the W-CDMA standard), (3) the standard offered by a consortium named "3rd Generation Partnership Project 2" (3GPP2) and embodied in "TR-45.5 Physical Layer Standard for cdma2000 Spread Spectrum Systems" (the IS-2000 standard), (4) the high data rate (HDR) system that conforms to the TIA/EIA/IS-856 standard (the IS-856 standard), and (5) Revision C of the IS-2000 standard, including C.S0001.C through C.S0006.C, and related documents (including subsequent Revision D submissions) are referred to as the 1xEV-DV proposal.
In an example system, Revision D of the IS-2000 standard (currently under development), the transmission of mobile stations on the reverse link is controlled by base stations. A base station may decide the maximum rate or Traffic-to-Pilot Ratio (TPR) at which a mobile station is allowed to transmit. Currently proposed are two types of control mechanisms: grant based and rate-control based.
In grant-based control, a mobile station feeds back to a base station information on the mobile station's transmit capability, data buffer size, and Quality of Service (QoS) level, etc. The base station monitors feedback from a plurality of mobile stations and decides which are allowed to transmit and the corresponding maximum rate allowed for each. These decisions are delivered to the mobile stations via grant messages.
In rate-control based control, a base station adjusts a mobile station's rate with limited range (i.e. one rate up, no change, or one rate down). The adjustment command is conveyed to the mobile stations using a simple binary rate control bit or multiple-valued indicator.
Under full buffer conditions, where active mobile stations have large amounts of data, grant based techniques and rate control techniques perform roughly the same. Ignoring overhead issues, the grant method may be better able to control the mobile station in situations with real traffic models. Ignoring overhead issues, the grant method may be better able to control different QoS streams. Two types of rate control may be distinguished, including a dedicated rate control approach, giving every mobile station a single bit, and common rate control, using a single bit per sector. Various hybrids of these two may assign multiple mobile stations to a rate control bit. A common rate control approach may require less overhead. However, it may offer less control over mobile stations when contrasted with a more dedicated control scheme. As the number of mobiles transmitting at any one time decreases, then the common rate control method and the dedicated rate control approach each other.
Grant based techniques can rapidly change the transmission rate of a mobile station. However, a pure grant based technique may suffer from high overhead if there are continual rate changes. Similarly, a pure rate control technique may suffer from slow ramp-up times and equal or higher overheads during the ramp-up times.
Neither approach provides both reduced overhead and large or rapid rate adjustments. An example of an approach to meet this need is disclosed in U.S. patent application Ser. No. 10/780,824, entitled "COMBINING GRANT, ACKNOWLEDGEMENT, AND RATE CONTROL COMMANDS", filed Feb. 17, 2004, assigned to the assignee of the present invention. In addition, it may be desirable to reduce the number of control channels, while maintaining desirable probability of error for the associated commands on the control channels. There is a need in the art for a system that provides the ability to control the rates of (or the allocation of resources to) both individual mobile stations as well as groups of mobile stations, without unduly increasing channel count. Furthermore, there is a need to be able to tailor the probability of error of various rate control or acknowledgement commands. An example of an approach to meet this need is disclosed in U.S. patent application Ser. No.10/781,285, entitled "EXTENDED ACKNOWLEDGEMENT AND RATE CONTROL CHANNEL", filed Feb. 17, 2004, assigned to the assignee of the present invention.
While the flexibility of control afforded with combined grant, rate controlled, and acknowledged transmission allows for tailoring of the allocation of system resources, it may be desirable to control the role of various base stations in a system with respect to which signals they transmit and in which allocation controls they may participate. An ad-hoc signaling scheme to provide control may be costly in terms of the overhead required for signaling. Failing to control the reach of some base stations may also cause system performance issues if a grant or rate control command is issued, with effects that are not apparent to the issuing base station. There is therefore a need in the art for efficient management of grant, acknowledgement, and rate control channels.

Grant, acknowledgement, and rate control active sets


An antenna structure includes a loop radiation element, a balance radiation element, a first additional radiation element, and a second additional radiation element. The loop radiation element has a first feeding point. The balance radiation element has a second feeding point. The balance radiation element is coupled to at least a first connection point on the loop radiation element. The balance radiation element is substantially surrounded by the loop radiation element. The first additional radiation element is coupled to a second connection point on the loop radiation element. The second additional radiation element is coupled to a third connection point on the loop radiation element. The loop radiation element is disposed between the first additional radiation element and the second additional radiation element.

Field of the Invention
The disclosure generally relates to an antenna structure, and more particularly, to an almost isotropic antenna structure.
Description of the Related Art
With the advancements being made in mobile communication technology, mobile devices such as portable computers, mobile phones, multimedia players, and other hybrid functional portable electronic devices have become more common. To satisfy user demand, mobile devices can usually perform wireless communication functions. Some devices cover a large wireless communication area; these include mobile phones using 2G, 3G, and LTE (Long Term Evolution) systems and using frequency bands of 700 MHz, 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, 2100 MHz, 2300 MHz, and 2500 MHz. Some devices cover a small wireless communication area; these include mobile phones using Wi-Fi and Bluetooth systems and using frequency bands of 2.4 GHz, 5.2 GHz, and 5.8 GHz.
Wireless access points are indispensable elements that allow mobile devices in a room to connect to the internet at high speeds. However, since indoor environments exhibit serious signal reflection and multipath fading, wireless access points should process signals in a variety of directions simultaneously. Accordingly, it has become a critical challenge for antenna designers to design an almost isotropic antenna in the limited space of a wireless access point.


A message sending device sends a message. A message receiving device generates reception authentication information of the message when receiving the message, and further generates reception confirmation information of the message by using the reception authentication information of the message, to send the reception confirmation information of the message to a reception confirmation information verification device. The reception confirmation information verification device verifies the received reception confirmation information. The message sending device obtains a reception confirmation of the message for the message receiving device based on the verification result. This configuration reduces a processing load in each node as much as possible for confirming whether data to large numbers of nodes under a multihop environment have been received in each node.

The present invention relates to a message reception confirmation method, a communications terminal and a message reception confirmation system. The present invention is applicable to the case, for example, in which a server broadcasts a message to sensor nodes and confirm the reception, in a system such as sensor network system configured by a server for performing concentrated control for the system and by large numbers of sensor nodes configured at low cost.

Message reception confirmation method, communications terminal and message reception confirmation system


Scrolls separable radially, to enable cleaning and polishing of the inner surfaces of the throat area, are disclosed. In one of the embodiments, an inner structure of the scroll intrudes into the throat area for selectively reducing the area, in order that flow, pump head, and speed can be matched.

This invention pertains to volutes and scrolls, and the like, such as are incorporated in fluid-working devices, namely turbines, centrifugal pumps, and compressors. Exemplary thereof are those shown in U.S. Pat. No. 4,181,466, issued on Jan. 1st, 1980, to Bruce R. Owen for a Centrifugal Compressor and Cover; U.S. Pat. No. 4,743,161, granted on May 10th, 1988, for Compressors, to Frank B. Fisher, et al; and U.S. Pat. No. 2,925,952, for a Radial-Flow Compressor, issued on Feb. 23rd, 1960, to Alexander Garve. The scrolls depicted in the aforesaid patents are of the overhung type, which are advantageous when compared to the more conventional, symmetrical volute or scroll. However, in that the overhung scroll is so difficult to cast, it is not commonly used in commercial centrifugal pumps. In addition, the overhung scroll has only a limited access to the inner, scroll passage for the purposes of cleaning and polishing. The prior art scrolls, further, offer no facility for selectively modifying the scroll throat area. What has been sought in this art, then, is an improved scroll geometry which will facilitate (a) casting, (b) cleaning and polishing of the inner scroll passage, (c) means for modifying the scroll throat area, and (d) with removal of the front cover, gives access to the impeller for cleaning and/or removal of debris from the inlet and the impeller periphery.


The present disclosure provides a semiconductor package, which includes a substrate, a passivation layer, a post-passivation interconnect (PPI) having a top surface; and a conductive structure. The top surface of the PPI includes a first region receiving the conductive structure, and a second region surrounding the first region. The second region includes metal derivative transformed from materials made of the first region. The present disclosure provide a method of manufacturing a semiconductor package, including forming a first flux layer covering a portion of a top surface of a PPI; transforming a portion of the top surface of the PPI uncovered by the first flux layer into a metal derivative layer; removing the first flux layer; forming a second flux layer on the first region of the PPI; dropping a solder ball on the flux layer; and forming electrical connection between the solder ball and the PPI.

Wafer Level Packaging (WLP) refers to the technology of packaging an integrated circuit (IC) at a wafer level, instead of the traditional process of assembling the package of each individual die on individual packages. One feature of the WLP is that the resulting integrated circuit package is practically the same size as the individual package diced. Furthermore, WLP provides a streamlining of the semiconductor manufacturing process from start to customer shipment.
Soldering structures are well-adopted in WLP for external electrical connections. These range from hand-soldering methods to machine soldering methods. It is well-known to use a flux material with the soldering material. The flux material satisfies a number of functions. Generally a main function of the flux material is to ensure that conductive material of a first component, for example a support substrate such as a printed circuit board (PCB) interconnects well with good electrical conduction across the solder interconnect to a second component such as an electronic component.
To form a successful interconnection it is often necessary to apply a flux material. A number of different alternatives have been used. It is known for example to include a solid flux material within the soldering material. Generally such a soldering material would then be provided in a wire or other such solid form which would incorporate a core of flux material running through the solder. As the solder melts upon heating, the flux is activated, and the resulting interconnect formed if the soldering process is of an acceptable standard. It is also known to use solder paste materials. Solder pastes are generally homogenous, stable suspensions of solder particles in a flux medium material.
Reflow soldering is used in the automated manufacture of PCB's, wherein electronic components are surface mounted on PCB's to which a solder paste material has previously been applied by a method such as screen or stencil printing or dispensing. The PCB is then subjected to a sufficiently high temperature, to cause the solder to liquefy and to join the components in place on the PCB. The heat can be supplied by, for example, infrared, heated conveyor belt or convective means.

Semiconductor packaging and manufacturing method thereof

TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.


A hopper system for powder material includes a hopper and a cover. The hopper has hopper sidewalls that extend downward from an upper end of the hopper with at least one of the hopper sidewalls being sloped along a portion thereof. A hopper axis extends vertically between at least some of the hopper sidewalls. The cover is disposed at the upper end of the hopper and includes an opening configured for the powder material to flow therethrough and into the hopper. The opening defines a vertical material loading axis that is offset relative to the hopper axis. A diverter member may be provided that is positioned along the material loading axis and configured to divert the powder material entering through the opening. A powder material feed system may be disposed adjacent the lower end of the hopper to feed the powder material from the hopper.

Systems for the makedown of powder material such as dry polymers may include a plurality of units or stations. These stations may include a material storage station, a material supply station in which material is supplied from the storage station, and a mixing station at which the dry polymer is mixed with a liquid such as water. In some instances, a holding station including one or more holding tanks may be provided at which the wetted solution may be held until use.
Powder material used with the makedown process may be stored within containers that are manually manipulated to fill a storage unit at the material storage station. Depending upon the weight of a container and the physical abilities of an operator, lifting and positioning the container at a loading location may be physically challenging.

Powder material hopper system with offset loading


An electronic circuit device according to the present invention includes a base substrate including a wiring layer having a connection part, at least one electronic circuit element, and a re-distribution layer including a photosensitive resin layer, the photosensitive resin layer enclosing a surface on which a connection part of the electronic circuit element is formed and a side surface of the electronic circuit element and embedding a first wiring photo via, a second wiring photo via and a wiring, the first wiring photo via directly connected to the connection part of the electronic circuit element, the second wiring photo via arranged at the outer periphery of the electronic circuit element and directly connected to a connection part of the wiring layer, the wiring electrically connected to the first wiring photo via and the second wiring photo via on a same surface.

Various types of packaging have been put into practical use for integrated circuit devices (referred to as a semiconductor chip) in which sophisticated integrated circuit is configured. For example, wafer-level package (WLP) and FOWLP have been put into practical use in recent years. This FOWLP is called a Face-Up type or a Face-Down type depending on the mounting orientation of the semiconductor chip with respect to the substrate.
Face-Up type is less susceptible to vibrations in the manufacturing process or thermal expansion of the sealing resin, and is suitable for FOWLP requiring precision since the semiconductor chips contained therein are processed after being fixed to the base substrate. In recent Face-Up type, Cu pillars bonded on the connecting terminals of the respective semiconductor chips fixed to the base substrate is molded with the sealing resin, and chemical mechanical polishing (Chemical Mechanical Polishing: CMP) is applied to stack the relocated wiring structure (re-distribution layer) so as to form an electric connection at the tip of the exposed Cu pillars.
On the other hand, in the Face-Down type, after the surface on which the connecting terminal of the semiconductor chip is provided is fixed to the support material through an adhesive layer, the entire semiconductor chip is molded with resin, and then this support material is peeled off to expose the contact points of the semiconductor chip. The re-distribution layer is laminated on this exposed surface.
In particular, the Face-Up type FOWLP is suitable for the system integration using a plurality of semiconductor chips. Since it does not require a normal printed substrate, the package is thin and the wiring length is shortened, so that the inductance and the floating capacitance are reduced, and the transmission rate of signals can be increased.

Electronic circuit device and method of manufacturing electronic circuit device


An injection mold for forming a pattern for use in investment casting having mold sections carrying two pattern-forming surfaces and a translatable third pattern-forming element movable on a mold section. The mold also includes an inner core. Parting lines are located at inconspicuous locations by sizing and shaping the mold sections. The method of use of the injection mold includes employing an arrangement for facilitating lower mold section and for raising the inner core to facilitate its removal.

Aluminum molds for making wax patterns have been in use for years. Combination aluminum and epoxy molds have also been used. Epoxy mold parts have the drawback of wearing after repeated use and of being easily damaged during the handling required to carry out repeated molding operations. Additionally, it is well known that aluminum molds have superior heat transfer relative to epoxy molds, thereby reducing dwell time for wax pattern production and overall cycle time.
Where molded parts have included an intricate interior cavity, a plurality of mold sections and cores have been required. The mold parts and cores require handling to accomplish assembly and disassembly. Further, in the molding of demanding shapes such as golf club heads parting lines have presented problems requiring trimming and reworking wax patterns. Prior wax patterns for making golf club heads are disclosed in U.S. Pat. Nos. 5,204,046 and 5,417,559.

Injection mold apparatus for producing a pattern


The purpose of the present invention is to decrease the time required to create fault injection test data when performing an ECU simulation test. An ECU simulation device according to the present invention is provided with a database in which fault modes are defined for each type of circuit element, reads out, from the database, fault modes for each circuit element provided in an ECU, and generates a test pattern for each of the fault modes.

The number of electronized control techniques relating to operation and movement of an automobile tends to be increased year after year. Several tens of in-vehicle electronic control units (ECUs) have become mounted in one automobile, and size of the entire software (hereinafter referred to as control software) mounted on the ECUs has reached one million to ten million lines (in a source code mainly written in C language).
While a development scale of the control software is increased as described above, there is demand for shortening a development period of the control software. For this reason, maintaining and improving quality of the control software in short-term development have been large problems for a manufacturer and a supplier of automobiles. In particular, design relating to safety is required to be compliant with the standard of ISO26262.
In Automotive Safety Integrity Level (ASIL) defined by ISO26262, it is strongly recommended that verification by fault injection be performed at shipment of products defined by ASIL-C or ASIL-D. The purpose of this is to provide evidence of verifying no infringement on safety with respect to a fault mode expected in a use case when an ECU product is released to the market. As described above, demand for safety design of an in-vehicle control unit is at a high level.
The ISO26262 standard recommends use of a simulation technique in the verification. In view of the above, in a recent technical trend, a technique that models an entire system including an ECU and verifies the control software and fault injection by simulation starts to be applied to mass production development.
PTL 1 below describes the technique of "building a fault circuit model for performing a fault simulation based on fault element information, performing simulation of a non-fault circuit model, extracting a state value of each terminal and element of the non-fault circuit model at the time of fault injection from a result of the simulation, estimating a state value of each terminal and element of the fault circuit model based on the extracted state value, and performing a fault circuit simulation from a fault injection time by using the estimated state value as an initial value of the fault circuit model" as a technique whose object is "to shorten a simulation execution time period of a fault simulation performed for an electric fault in a circuit simulation for the purpose of FMEA of a circuit including an analog element" (refer to the abstract).


A method and a circuit arrangement for shaping any actual a.c. voltage characteristic into any reference a.c. voltage characteristic are described, which store the excess power in voltage overshoots in the form of a current in a current storage device using power electronic switching elements, and thus they compensate for the power deficiency when there is a voltage shortfall. The power electronic switching elements are driven by a digital automatic state machine through appropriate control pulses so that there is no fixed switching rate. The preferred field of application is for active filtering of the voltage of an electric three-phase or a.c. power supply system.

In electrical engineering, the problem of converting an actual a.c. voltage into a desired reference a.c. voltage arises in many applications. Such applications may include, for example, power electronics, low-frequency electronics, communications electronics, etc.
The preferred field of application for such methods and circuit arrangements is filtering the voltage of an electric three-phase or a.c. power supply system which is strongly subject to voltage harmonics generated by power electronic equipment and arrangements due to the switching components. Conventional methods of filtering harmonics out of line voltages have involved only methods and arrangements based on passive electronic components. Active methods and circuit arrangements for shaping and filtering a.c. voltage have been used only for filtering harmonics out of line currents.
Since only filters with passive electric components have been used to suppress voltage harmonics, a method of shaping a.c. voltage and a suitable circuit arrangement for this purpose based on active electronic components are to be created so that costs and high losses in passive filters can be reduced.
This principle should theoretically be capable of converting any desired a.c. voltage form to any other a.c. voltage form at a power supply connection point. The field of application of this method and circuit arrangement should thus be expandable to a great extent into areas that are far from being limited to just electric supply systems, power electronic loads or the elimination of harmonics.

Method and circuit arrangement for shaping a.c. voltage


An electronic controller (16) controls the operation of an electrochemical oxygen generating system (14) producing a desired gas. The product gas is fed to a storage unit (12) or a regulator (28) and pulsing valve (28) controlling the gas flow to a user. A two-stage system (180) combines a low pressure 100 and a high pressure (150) gas generating subsystems. The low pressure subsystem (100) uses IMAT's (106) to pump oxygen from ambient air to generate a low-pressure. The high pressure subsystem (150) uses IMAT's (160) to pump oxygen to high-pressure oxygen storage devices (194).

1. Technical Field
The invention relates to the field of electrochemical gas generators, and more particularly to ceramic oxygen generating systems (COGS) for generating and delivering oxygen to a user.
2. Background Art
There are a variety of ways to generate and deliver substantially pure oxygen for use in medical applications and in the electronic industry, for laser cutting, and in many other applications. Two key areas of use for pure oxygen are breathing purposes in home oxygen therapy (HOT) patients and for aviation crewmembers.
Oxygen can be stored in cylinders at elevated pressures and stored as liquid oxygen in what is commonly called a Dewar. These techniques are of common knowledge and have been utilized for many years.
More recently oxygen can be concentrated or generated real-time using a variety of molecular sieves to separate and concentrate oxygen from a pressurized air source using a pressure swing adsorption process (PSA) or a vacuum pressure swing adsorption (VPSA) process. Oxygen product generated by pressure swing adsorption is low cost and readily available. However, the oxygen concentration on these products is about 90 to 95%.
Even more recently oxygen can be generated using an electrochemical process that ionizes the oxygen molecules at one surface of a ceramic membrane, transports the ions through the membrane, and reforms them as oxygen molecules on the other surface of the membrane by removing the excess electrons from the ions. This type of technology is also known as a ceramic oxygen generating system (COGS).
Oxygen conserving devices that provide a short pulse of oxygen to the user through a nasal cannula at the beginning of inhalation have been widely used for many years to reduce the quantity of supplemental oxygen delivered to patients who suffer from chronic lung disorders while still maintaining an adequate oxygen saturation level in the blood stream. This has been commonly referred to as pulse dosing of oxygen.
This type of oxygen pulse dosing technology has recently been used on aircraft to provide supplemental oxygen to pilots of general aviation aircraft that typically fly at altitudes of up to 32,000 feet. Similarly, oxygen breathing regulators have been used for many years to reduce the amount of oxygen consumed by aerospace crewmembers at various altitudes to minimize the possibility of oxygen toxicity of the user, while providing a minimum level that is a physiologically safe oxygen concentration to prevent the occurrence of hypoxia at higher altitudes. Physiologically safe concentrations of oxygen have been provided by the breathing regulators that entrain aircraft cabin air and add it to the stored or generated oxygen before delivery to the crewmember to lower the concentration to the desired level as a function of atmospheric pressure-altitude. This is most commonly accomplished using the well-known pneumatic injector device. This technique has also been used to dilute the oxygen generated from PSA oxygen concentrators in aircraft to the desired concentration.
If an aircraft is equipped with the PSA oxygen concentrator and cabin pressure of an aircraft is lost above an aircraft altitude of about 30,000 feet, then the purity of the oxygen being generated by the PSA, which is only about 95% Oxygen, does limit the time of exposure that the crewmember can safely stay at the higher altitudes. However, if the aerospace oxygen system is comprised of stored oxygen of 99.5% Oxygen or has a back-up oxygen system (BOS) that contained 99.5% oxygen, then additional aircrew safety can be provided in the event of the loss of cabin pressure at these higher altitudes. However, the use of 99.5% oxygen in either the high-pressure storage or liquid form requires periodic replenishment ranging from daily to weekly periods of time and results in a logistics burden to the user.
The implementation of the PSA oxygen concentrators into aerospace applications has solved the requirement for oxygen on a daily basis, but has had limited acceptance as a supply of oxygen for use after the loss of cabin pressure at the higher altitudes. Currently, only the F-15E aircraft uses a back-up oxygen supply that is automatically filled with 93% oxygen that is generated and stored using a PSA oxygen concentrator with an integral compressor. An emerging limitation to using PSA oxygen concentrators on next generation aircraft is the trend towards the use of more efficient engines with higher bypass ratios that result in less compressed air being available for the PSA oxygen concentrator and other air handling systems on the aircraft. This results in market pressures to minimize or eliminate the use of compressed air from the aircraft engine.
Many aerospace applications need a way to generate oxygen at a purity of greater than 99.5% and store it at an elevated pressure for emergency conditions, while providing a lower concentration for normal flying conditions when the aircraft cockpit is equivalent to a pressure-altitude of less than about 25000 feet. This system needs to be compatible with current aircraft personal equipment that includes oral-nasal masks that can deliver the oxygen at pressures up to about 70 mmHg under certain normal and emergency flying conditions.
Similarly, many home oxygen therapy patients can benefit from an oxygen generator that can deliver oxygen in the home via a pulse-dosing oxygen conserving device using a nasal cannula during, while also storing oxygen in a portable cylinder for temporary use outside the home. This reduces the logistics burden of the home health care provider by eliminating the need to replenish the portable oxygen cylinders after use. Some patients that have sleeping disorders are better served by a continuous flow from the nasal cannula in order to maintain the desired oxygen blood saturation levels while they sleep.
Certain ceramic materials, when subjected to specific conditions, will actively pass oxygen atoms through its matrix. Previous embodiments of this concept have shown that a properly designed ceramic membrane can act as both a means for concentrating 100% oxygen and for pressurizing oxygen to levels suitable for recharging conventional oxygen cylinders.
A basic ceramic oxygen generating system generally consists of one or more temperature controlled ovens which contains ceramic oxygen generating elements. In order to supply enough oxygen for the ceramic elements, air is circulated inside the oven. Since the ceramic elements operate at high temperature (about 700° C.), air has to be heated before inputting to the oven. Heat exchangers are used to preserve the heat and reduce temperature of oxygen-depleted air exhausted from the oven.
Major problems of such a basic COGS described include:                The ratio of air input flow to oxygen output flow is very high (20 to 1). This high input flow requires having heat exchangers to avoid heat loss or thermal shock to the ceramic elements.        Heat exchangers efficiency needs to be high to preserve the heat. Therefore, they are expensive.        To exchange the heat, the oven has to be pressurized to generate a return (oxygen-depleted exhaust) flow. The positive pressure generates thermal leak around openings/cracks on the oven.
Oxygen at high purity levels, high pressures, and high temperatures creates a hazardous environment because it will support vigorous combustion of many conventional materials. Thus, it is very difficult to design a cost-effective pressure vessel capable of holding pure oxygen at high pressures and high temperatures. Previous embodiments of this concept have utilized the ceramic membrane as an initial pressure vessel for the high purity oxygen, until it can be cooled enough for safe transfer to, and storage in, conventional oxygen cylinders.
Using the ceramic membrane as a pressure vessel incites a powerful conflict between maximum operating pressures and the rate of oxygen concentration. The ceramic material is relatively brittle, thereby ill suited for withstanding the tensile stresses associated with internal pressurization. Increasing the wall thickness of the module will lower the material stresses, but it will also lower the module's oxygen concentration rate and operating efficiency.
Ceramic oxygen generating modules such as the Integrated Manifold And Tubes (IMAT) described in U.S. Pat. Nos. 5,871,624; 5,985,113; 6,194,335; 6,352,624; and others have been used in oxygen generating systems. However, in most of the applications, the IMAT's outside surfaces are interfaced with air and oxygen is pumped through the ceramic to the inside cavities (circuit). This design limits the maximum oxygen generating pressure due to high tensile stresses on the ceramic.
While the above cited references introduce and disclose a number of noteworthy advances and technological improvements within the art, none completely fulfills the specific objectives achieved by this invention.

Oxygen generator with storage and conservation modes


A method and apparatus for electrostatic spray deposition (ESD) for fabricating a thin-layer yttria-stabilized zirconia (YSZ) electrolyte on a solid oxide fuel cell (SOFC) anode substrate constructed of nickel-YSZ cermet. By reducing the thickness of the electrolyte, and thereby reducing the cell internal IR drop, an intermediate temperature SOFC (ITSOFC) can operate at 600–800° C. A collar positioned at a distance from a discharge end of a spray nozzle enhances a spray pattern of a precursor including the electrolyte material and thus provides a very thin electrolyte layer.

1. Field of the Invention
This invention relates to electrostatic spray deposition techniques for applying an electrolyte material to a substrate, such as for a solid oxide fuel cell, wherein a precursor including the electrolyte material is discharged from a spray nozzle that has a collar positioned about the nozzle, for applying a relatively thin layer of the electrolyte material on the substrate surface.
2. Discussion of Related Art
Conventional electrostatic spray deposition (ESD) methods and apparatuses have been used to apply an electrolyte material to an anode structure of a solid oxide fuel cell (SOFC), but the conventional methods and apparatuses currently produce state-of-the-art electrolyte layers each having a thickness of 30–40 μm.
With conventional designs, one disadvantage is that materials and structures used to construct SOFC components cannot operate effectively at temperatures lower than 900° C.–1000° C., which is a temperature range at which conventional SOFC components operate. Yttria-stabalized zirconia (YSZ) is typically used as an electrolyte material because of its chemical stability and strength properties. However, even at a temperature of 1000° C., the specific ionic conductivity is relatively low, for example about 0.1 Ω−1.cm−1, and thus a thickness of the electrolyte layer must be relatively small. At higher operating temperatures of a conventional SOFC, a grain-boundary morphology connected with segregation, sintering, etc., can vary and thus reduce long-term and cycling stability of the conventional SOFC. In the industry, there is considerable effort to define and manufacture ceramic materials suitable for an intermediate temperature (IT) SOFC that has better stability than that of a conventional SOFC. One important requirement for improving a SOFC cell structure is to minimize an overall voltage loss of the SOFC.
Various conventional SOFC designs may be classified as electrolyte-supported, anode-supported and cathode-supported. The cathode-supported design is rarely used. In a planar cell the supporting cell component must provide sufficient mechanical strength to span a cell width, which is typically 10–20 cm. Thus the supporting cell component should be thicker than the other two components, and may even be thicker than an inter-connect (IC) layer if the IC layer is not designed for structured support, for example an IT-SOFC having a thin metallic foil for the IC layer. An electrolyte-supported SOFC usually has YSZ disks of approximately 100 μm thickness, on which relatively thin electrodes, each about 10 μm thick, are screen-printed. At an operating temperature of 1000° C. such an electrolyte layer thickness is tolerable, but at an operating temperature of 600–800° C., the electrolyte layer thickness must be much less, for reasons discussed below.
In a tubular design developed by the business entity Siemens-Westinghouse, the cathode is used as the supporting layer and thus has a cathode thickness of approximately 2 mm, which easily causes excessive polarization at relatively high current densities. The polarization is much less for an anode of comparable thickness, at least with hydrogen as a fuel. Anode-supported cells normally include a pre-fabricated relatively thick anode, on which a relatively thin electrolyte layer is deposited. The anode of an anode-supported SOFC is usually pre-sintered at a relatively low temperature to strengthen the anode, without significant shrinking. The YSZ electrolyte is then slurry-coated and sintered to the required temperature. The cathode is also slurry coated and sintered in a separate step.
Table 1 identifies properties of materials used in various cell components of a conventional tubular SOFC. The higher operating temperatures, around 1000° C., of the conventional SOFC limits the number of materials available for the cell components, because of a need to satisfy stringent criteria for chemical stability in oxidizing and reducing environments, for chemical stability of contacting materials, for conductivity, and for thermo-mechanical compatibility.
TABLE 1Specifications of SOFC Components in Tubular SOFCComponentConventional PropertiesAnodeNi/ZrO2 cermet (Y2O3 stabilized ZrO2)Electrochemical Vapor Deposition (EVD) or Slurrydeposition (EVD expected to be replaced by anodesintering)Thermal Coefficient of Expansion (TEC) 12.5 × 10−6cm/cm° C.~150 μm thickness20–40% porosityCathodeSr or Ca doped lanthanum manganite (SLM)Extrusion, sintering~2 mm thicknessTEC 11 × 10−6 cm/cm° C.Expansion from room temperature to 1000° C.30–40% porosityElectrolyteYttria (8 mol %) stabilized ZrO2 (YSZ)EVDTEC 10.5 × 10−6 cm/cm° C.Expansion from room temperature to 1000° C.30–40 μm thicknessCell InterconnectMg doped lanthanum chromitePlasma sprayTEC 10 × 10−6 cm/cm° C.~100 μm thickness
The physical limitations of current materials make apparent a need to develop cells with composition of oxides and metals that operate at intermediate temperatures in a range of 600–800° C.
Conventional SOFC designs make use of thin film concepts where films of electrode, electrolyte, and inter-connect material are deposited on one another and sintered, to form a cell structure. The state-of-the-art YSZ electrolyte in a SOFC operating at 1000° C. must be about 25–50 μm to keep the ohmic loss to a level comparable to that of the liquid electrolyte in a conventional PAFC. In manufacturing the tubular SOFC, dense YSZ layers of about 40 μm thickness are often fabricated by an Electrochemical Vapor Deposition (EVD) method, as well as by tape casting and other ceramic processing technologies.
A lower limit of the thickness of a YSZ electrolyte layer or another ceramic membrane is in part a function of the production process such as EVD, tape casting or other processes. The electrolyte layers deposited not only should be very thin and 100% dense, but should also have uniform composition and optimal microstructure. The electrolyte film should have sufficient mechanical strength to withstand the thermal stresses occurring due to start-up, shut-down, and other temperature swings during operation. As the thickness is reduced, the microstructure of the film becomes more important to adequately reduce ohmic resistance. It is believed SOFC with a thin-film electrolyte having a grain size of 100 nm or less can produce an overall electrolyte resistance at an acceptable low level.
With the IT-SOFC, whether or not using current electrolyte materials such as YSZ, there is a need to reduce resistance or ohmic losses that occur across mixed ionic-electronic conducting electrodes as well as ionic conducting electrolyte. Main ohmic losses are related to the electrolyte. Thus, there is an apparent need to reduce a thickness of the electrolyte layer. When the electrolyte layer is a relatively thin film, such as having a thickness of 5–15 μm according to this invention, its resistance at intermediate temperatures is comparable to, or less than, that of a conventional electrolyte layer having a thickness of 30–40 μm, and operating at 900–1000° C. There is a need to reduce an electrolyte layer thickness to 5–10 μm, or perhaps less, for SOFC operation at 600–800° C. To maintain IT-SOFC power densities well above those of the high-temperature SOFC, it may be necessary to reduce the thickness of the YSZ electrolyte layer to only a few micrometers.

Method and apparatus for electrostatic spray deposition for a solid oxide fuel cell


A method for forming dual damascene metallic structure that utilizes the formation of a protective photoresist layer at the bottom of a vertical window to prevent damages to a device region in the substrate when subsequent etching operation is carried out to form a horizontal trench pattern. The protective photoresist layer at the bottom of the vertical window is formed by irradiating the photoresist layer with a dose of radiation having energy level insufficient to chemically dissociate the photoactive molecules of the photoresist layer near the bottom of the vertical window.

1. Field of Invention
The present invention relates to a method for manufacturing ultra large-scale integrated (ULSI) circuits. More particularly, the present invention relates to a method for patterning interconnects on a semiconductor wafer using a dual damascene process.
2. Description of Related Art
The dual damascene process, in which metal is skillfully buried inside patterned grooves in a substrate, is frequently used these days and has become one of the best methods for fabricating integrated circuits. Conventionally, metallic interconnects are formed by depositing a metallic layer over an insulating layer, for example, a silicon dioxide layer. Then, the insulating layer is etched to form a pattern of predefined conductive lines so that a vertical contact window can be formed between conductive layers. Thereafter, metallic material similar or dissimilar to the conductive layer is deposited into the contact window to complete vertical connection between the conductive layers.
FIG. 1 is a cross-sectional view showing a metallic interconnect above a semiconductor substrate fabricated according to a conventional method. As shown in FIG. 1, the method of fabrication includes providing a substrate 10, and then patterning a device area 11. Thereafter, a first insulating layer 12 is formed above the substrate 10 followed by patterning. Next, a first metallic layer 13 is deposited over the substrate 10 so that the first metallic layer 13 is electrically coupled to the device area 11 through a contact window 14. Similarly, a second insulating layer 15 is formed over the first metallic layer 13. Then, a second metallic layer 16 is formed over the second insulating layer 15 so that the second metallic layer 16 is electrically connected to the first metallic layer 13 through a contact window 17. Finally, a third insulating layer 19 is formed over the device to protect the structure.
A slant angle is made on the sidewalls of the contact window when the dialectric windows are etched to form contact windows 14 and 17. The slant angle ensures good continuity of the metallic layer when using the method discussed above. However, if the slant angle is too steep, the metal at the corner edges of the contact window can be damaged quite easily. On the other hand, if the slant angle is too gentle, although continuity in a metallic conductive line is greatly improved, wafer area occupation tends to increase so that compact window structures are difficult to achieve. Moreover, the dielectric windows and contact windows will create a rather uneven surface such that subsequent interconnect layer fabrication becomes very difficult. Although FIG. 1 is not drawn according to scale, it is obvious that the uneven upper surface can easily lead to reliability problems. One problem that can happen at the interface location S between the first metallic layer and the second metallic layer is short-circuiting. This is because the insulating layer in the neighborhood of S is too thin. Another problem that can happen is an open-circuit condition due to the formation of a thin metallic layer near O.
A dual damascene method of fabrication is now commonly used to resolve the above problems. FIGS. 2A through 2D are cross-sectional views showing the progression of manufacturing steps in producing a dual damascene interconnect structure in a semiconductor substrate according to a conventional dual damascene method. First, as shown in FIG. 2A, a substrate 30 is provided. On this substrate 30, patterned metallic layers 31 are already formed. Next, a dielectric layer 32 is formed above the substrate 30, and then the dielectric layer 32 is planarized so that its thickness is same as the vertical height of a subsequently formed plug. Thereafter, dielectric layer 33 and dielectric layer 34 are sequentially formed above the dielectric layer 32. In the subsequent step, using conventional photolithographic and etching methods, the dielectric layers 32, 33 and 34 are patterned to form a vertical window 36 exposing a metallic layer 31 on the substrate 30. Later, a photoresist layer 38 is formed over the substrate 30. Then, using a fixed dose of light 40, patterns on a photomask 41 are transferred to the photoresist layer 38.
Next, as shown in FIG. 2B, the photoresist layer 38 is developed. Hence, a horizontal trench pattern 42 is formed exposing the vertical window 36 and the metallic layer 31 below.
Subsequently, as shown in FIG. 2C, using the photoresist layer 38 as a mask and the dielectric layer 33 as an etching stop layer, an etching operation is performed. For example, an anisotropic etching process is used such that the horizontal trench pattern 42 is transferred down to the dielectric layer 34 to form a horizontal trench 42'.
Finally, as shown in FIG. 2D, the photoresist layer 38 is removed, and metallic material 44 is deposited into the vertical window 36 and the horizontal trench 42'. Subsequently, extra metallic material 44 deposited above the dielectric layer 34 is removed using a chemical-mechanical polishing (CMP) method to complete the fabrication of a dual damascene metallic structure.
The above dual damascene process is able to reduce problems caused by windows and metallic conductive lines, and will improve the tolerance of over-coverage problems. Furthermore, even at the lowest allowed errors of design rules, the integrity of the conductive lines can still be maintained. In addition, it can avoid all the problems caused by depositing a thin layer of insulating material or metal over a window having slanting sides. However, there is still the problem that the metallic layer 31 at the bottom of the vertical window 36 is exposed and unprotected, and so will be etched by the etchant in the process of forming the horizontal trench 42. Consequently, the metallic layer 31 can be easily damaged resulting in a change in device properties, and ultimately may have to be scrapped.
In light of the foregoing, there is a need to provide an improved method of forming dual damascene structures.

Method for forming dual damascene structure


There is provided a clutch/brake unit having aligned input and output shafts, clutch disks partially immersed in oil carried by the input shaft, brake disks partially immersed in oil fixed to the housing, and two series of friction disks also partially immersed in oil each series of friction discs secured to the output shaft and each series engagable by separate DC voltage coils. A fan is provided which is rotatable with the input shaft to provide cooling air to the clutch/brake unit. The operation of the clutch/brake unit is controlled by a computer which controls the relationship of the output shafts speed in relation to time.

The present invention relates generally to a combination clutch/brake unit. More particularly, the present invention relates to a new and improved oil shear clutch/brake unit having frictionally engagable clutch and brake plates and disks which are at least partially immersed in a bath of oil so that the kinetic energy produced in starting and stopping heavy loads is transmitted by "shearing" the oil between the various plates and disks. It has been found that this type of immersion increases the life of the friction elements over those in clutch and brake units which operate dry. The oil immersion type of clutch and brake unit also increases the maximum operating speeds.
Clutch/brake units of various types have long been employed to transmit rotational energy between a power source and equipment to be driven thereby. Such units are generally employed so as to provide means for alternately starting and stopping such driven equipment. The inclusion of the braking feature enables more rapid deceleration of the output shaft than that provided by friction alone. When it becomes necessary to accurately position a machine, machine tool or work piece, a servo has been employed. Along with the servo comes the problems associated with servos including the servo's complexity and specialized maintenance.
It is accordingly a general object of the present invention to provide a new and improved clutch/brake unit.
It is another object of the present invention to provide a new and improved clutch/brake unit that utilizes a plurality of oil submerged friction disk torque transmitting elements which will exhibit a minimal amount of wear by virtue of the fact that the torque transmitting function is achieved by the shearing of oil interjacent the disks.
It is still another object of the present invention to provide a new and improved clutch/brake unit of the above character that can be operated at high speeds and at high cycle rates as a result of a low drive inertia and an effective oil cooling medium.
It is a further object of the present invention to provide a clutch/brake unit wherein the clutch and brake functions are electronically controlled and able to emulate a servo without the servo's complexity and specialized maintenance.
It is another object of the present invention to provide a new and improved clutch/brake unit that will find universality of application.
Further important objects of the present invention are to provide a new and improved clutch/brake unit which is simple in design, economical to produce and operate, extremely rugged and maintenance-free during operation, and wherein the input and output shafts thereof are readily adapted for mounting to any associated machine, gears, sheaves, couplings, etc.
Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

Electrically actuated clutch brake apparatus


A differential assembly for a motor vehicle includes a plurality of pinion gears in meshing engagement with a plurality of side gears. At least one of the pinion gears and side gears is formed from a tubular insert and a tubular preform forged together in a forging die. A method for manufacturing a differential assembly is also provided.

As is well known in the art, the fabrication of typical differential side gears and pinion gears for an automotive differential assembly is complex and costly and as such, greatly adds to the cost of the differential assembly. A typical process for forming a differential gear includes forging, annealing, rough machining, carburizing, hardening and finish machining operations. Despite the almost universal use of such forming processes, several drawbacks have been noted.
One such drawback relates to the initial forming of the differential gear through forging. As those skilled in the art will appreciate, the differential gear is typically blanked or rough-formed in a forging operation from a solid billet of steel. This forging operation is relatively inefficient because the shape of the "in-process" forging is substantially different from the final desired gear shape. Specifically, each of the differential gears contemplated for manufacture by the present invention include relatively large apertures extending through the center of the gear. As such, many machining operations are required after forging. In addition, a relatively large proportion of the forging material is machined off and wasted.
Another drawback concerns the machining of the differential gear. The numerous machining operations that are performed on the differential gear typically account for more than 70% of the total cost of the gear. Furthermore, the protracted nature of the machining operations often results in an average cycle time that exceeds one or more days in length.
Yet another drawback concerns the material from which the differential gear is formed. Typically, the steel billet from which the gear is formed is a low carbon steel having characteristics that are particularly well suited to both forging and machining. Such steels, however, generally lack the strength that is desired for a gear and as such, a time consuming and costly carburization process is typically employed to create a layer of relatively high carbon steel on the surface of the differential gear. Carburization usually entails the placement of semi-finished gears into a heated, high-carbon environment for an extended period of time to permit carbon to migrate into the gear material to a predetermined depth. The differential gear is subsequently heat treated so that the high carbon layer provides a level of strength and durability that is commensurate with the intended application.
Accordingly, there remains a need in the art for an improved differential gear manufacturing method that permits increased flexibility in the design of the gears of the differential and the adaptation of lower cost processes for their manufacture.

Net-shaped gear and manufacturing method for forming net-shaped gear employing insert and preform


A hand-held power screwdriver includes a low-noise torque clutch (5) for transmitting torque to a tool spindle (4) and formed of claw clutch (6) and ratchet clutch (7), with the ratchet clutch (7) having a rotatably driven first ratchet member (7a) and a second ratchet member (7b) both having, respectively, oppositely oriented, circumferentially arranged, oblique cams (9), with the claw clutch (6) having a first claw member (6a) and a second claw member (6b) having oppositely oriented claws (11), respectively, the first claw member (6a) of the claw clutch (6) being fixedly connected with the second ratchet member (7b) of the ratchet clutch (7) for joint rotation therewith, and with the screwdriver further including at least one engagement member (12) for connecting the second claw member (6b) with the tool spindle (4) for joint rotation therewith and for disconnecting the claw member (6b) from the tool spindle (4) and a retaining element for connecting the second claw member (6b) of the claw clutch (6) with the tool spindle (4) in a free-running position.

1. Field of Invention
The present invention relates to a hand-held power screwdriver with a low-noise torque clutch.
2. Description of the Prior Art
In the hand-held power screwdrivers used for screwing in of screws, in order to prevent overrotation of a screw, force flow from the drive motor to the screw-driving tool is interrupted upon the torque reaching a predetermined threshold. A conventional torque clutch has two rachet clutches preloaded against each other. The ratchet members have respective, circumferentially arranged, oblique cams. The drawback of a conventional ratchet clutch is a disturbing loud grating which in addition to noise, which leads to a significant wear of the ratchet clutch.
European Patent EP990488B1 discloses a hand-held power screwdriver with a low-noise torque clutch which is formed as a combination of a ratchet clutches. To this end, oblique cams are formed on opposite sides of an axially displaceable ratchet member and are associated with two axially spaced ratchet clutches. The combination torque clutch is unnecessarily very complex and, with two ratchet clutches, the wear of the power screwdriver is unnecessarily high.
Accordingly, an object of the present invention is to provide a hand-held power screwdriver with a low-noise torque clutch having a low wear.

Hand-held power screwdriver with a low-noise torque clutch


The invention includes a mount with a knob including a shaft extending therefrom. A two piece socket housing defines a socket therebetween. The two piece socket has a portion formed as a first clamp element. A ball member is disposed in the socket and includes a slot and an attachment structure. A second clamp element has a connector, preferably an internally threaded nut captured therein. The shaft passes through a first portion of the two piece socket, the slot of the ball member, a second portion the two piece socket and terminates in the second clamp element, such that when the knob is manipulated, the two piece socket fixes the ball member in position and a clamping force is generated between the first clamp element and the second clamp element.

There are numerous mounts or clamps which use a ball and socket arrangement of parts. These devices have the advantage of permitting movement of the ball in the socket to adapt the mount to various conditions. These devices have more flexibility regarding applications and adaptations. However, they are often complex and heavy and thus, often cumbersome, and furthermore can be lacking in clamping accuracy. Furthermore, attaching one of the prior art ball and socket devices to something else often requires a complex secondary clamping arrangement.
There is a need for a simple and flexible universal mount that overcomes the above deficiencies. The invention satisfies the demand.


In a communications system, one or more remote antenna systems communicate with one another and with associated base stations using a millimeter band microwave link, such as an E-band communications link. The remote antennas may be daisy-chained together to communicate with a plurality of base stations located at a base station hotel. Remote antennas may be positioned in cells having different peak traffic times to enable load balancing between base stations that share a common backhaul communications link with a mobile switching center.

Cellular networks provide a communications path between each subscriber's mobile phone and a mobile switching center (MSW). The mobile switching center manages communications to and from mobile phones in a variety of locations. These communications travel between the mobile switching center and subscribers' mobile phones through a base station. Typically, several base stations are affiliated with each mobile switching center, and each mobile phone communicates through a base station that is nearby relative to other base stations. As the mobile phone changes location (when, for example, its user is driving in a car), it may also change the base station through which it communicates.
The area in which a mobile phone can communicate with particular base station is known as a cell. Each base station has a radio frequency (RF) antenna, through which it communicates with the mobile telephones within the cell. Each base station also has a backhaul facility, through which it communicates with the mobile switching center to carry mobile telephone conversations within the cell. The backhaul facility typically communicates with the mobile switching center through either a microwave link or a terrestrial wire, such as a T-1 line.
To provide a high quality of mobile phone service, it is desirable for these cells to be adjacent to one another, leaving no intermediate gaps in which cellular phone service is unavailable. Likewise, each cell should be arranged such that its corresponding base station has the capacity to handle all the telephone conversations carried out by users at peak times within the cell. Thus, a central business district in which many mobile telephones are used during the business day is typically provided with a higher density of base stations, each with a smaller cell, than in outlying areas.
Designing a cellular network for a high quality of service involves a number of complicating issues. For example, to avoid gaps in service areas, so-called "coverage holes," it may appear desirable to design larger cells that are served by base stations with high-power antennas. However, the larger cell would encompass more subscribers and may cause calls to be dropped if the capacity of the base station is exceeded. Another solution—increasing the number (and, accordingly, the density) of base stations—entails a great financial expense, the regulatory and architectural challenge of finding (and leasing) a desirable location for each base station, and the task of arranging for backhaul communications from each new base station to the mobile switching center.
To provide flexibility in the design of mobile telephone networks, remote antenna systems have now become available. A remote antenna system corresponds to a particular base station, but it can be positioned remotely from its corresponding base station. Several remote antennas can be associated with each base station, allowing the cell associated with the base station to extend into carefully controlled areas. For example, if the mobile telephone service provider determines that there is a coverage hole between two existing cells, it can position a remote antenna within that hole and associate that remote antenna with an existing base station.
One available remote antenna system is the Digivance Long-Range Coverage Solution (LRCS), from ADC Telecommunications, Inc., of Minneapolis, Minn. Although remote antenna systems provide additional flexibility to mobile telephone service providers, the service provider must still arrange for communications between the base station and the remote antenna system. These communications typically take place over a fiber optic line. As a result, the service provider must arrange for a terrestrial path between the remote antenna system and the base station. If the remote antenna system is located within the same building (such as a sports arena, for example) as the base station, it may be feasible to run a fiber optic line. This fiber optic tether, however, restricts a more flexible arrangement of base stations and remote antenna system, particularly as the desired separation between the two becomes greater.

Communications system and method using remote antennas


A heat exchanger includes one or more parts composed of a braze clad aluminum alloy having a composition defined essentially by the formula: Al 1.1% Mn 1.1% Mg 0.15 Cu and being brazed to other aluminum parts. The heat exchanger exhibits usable strength at operating temperatures ranging up to 232.degree. C. 450.degree. F!, and is especially suited for use in the charge air cooler of a diesel engine.

1. Field of the Invention
The present invention relates to aluminum heat exchangers and parts thereof having improved properties, and more specifically to such heat exchangers and parts which exhibit increased strength at elevated temperatures.
2. Description of Related Art
Several aluminum alloys are currently used in construction of heat exchangers. The 20 most common are alloys typified by an alloy bearing designation AA 3003. This alloy has low strength, and is easily formed to sheet, fins and tubes. Slightly higher strengths are obtained by heat exchanger parts constructed using alloy AA 3005. The AA 3003 alloy has good corrosion resistance and was initially employed in radiators. Thereafter it was used in construction of heat exchangers such as charge air coolers (inter-coolers) on automobiles equipped with turbochargers.
Turbochargers use the engine exhaust gas to turn a turbine which drives a compressor forcing air into engine's piston cylinder chamber, increasing combustion efficiency which improves fuel efficiency and performance. The compression of the intake air increases its temperature, somewhat reducing the beneficial effects of the air compression. For this reason, it is beneficial to cool the intake air compressed by the turbocharger prior to its injection into the cylinder chamber. This is done by employing an air to air heat exchanger (known in the automobile and truck industry as an inter-cooler or charge-air-cooler). The now cooled and compressed air results in maximum performance derived from turbocharging, lowering emission levels and improving fuel efficiencies. In North America turbochargers are generally used only on specialty automobiles, but they are employed on almost all heavy trucks and construction vehicles. Because the benefits of turbocharging increase as the pressure of the intake air increases, there is a desire to further increase the output pressure of turbochargers. Such a pressure increase is accompanied by a proportional increase in gas temperature, in accordance with Boyle's gas law. This, in turn, places increased temperature demand on the charge-air-coolers.
The new 2nd & 3rd generation alloys that have been developed for use in heat exchangers had as objectives, improved corrosion resistance, improved brazeability and increased strength. Excellent corrosion resistance was obtained by increasing the % Cu to the existing alloys. Heat exchangers constructed using the modified alloy 3190 exhibited improved strength; a similar alloy is MD 356, which also has Ti additions to further increase its corrosion resistance.
In heat exchanger and radiator construction, the alloys AA 3003, AA 3005, MD 356 and 3190 are the core alloys currently used; the compositions of these alloys are given in Table 1. These structural core alloys are joined into a component by brazing. The braze alloys are clad on one or both sides of the core alloy. The braze alloys typically have an Al--Si eutectic base, which falls between the 7% Si or 12% Si composition range. For radiator applications, the water side is clad with "pure" aluminum that further improves the corrosion resistance. Cladding thickness varies from 5 to 15% of the core alloy thickness. Because significant diffusion occurs when the braze clad Al--Si melts it is necessary that the braze clad be compatible with the core alloy. The solidus of the core alloy must also be above the braze temperature. These requirements limit the type of alloy that may be used as the core.
TABLE I __________________________________________________________________________ Mn Mg Cu Si Fe Cr Zn Ti Alloy wt %! wt %! wt %! wt %! wt %! wt %! wt %! wt %! __________________________________________________________________________ AA3003 1.0-1.5 0.1 max 0.05-0.20 0.6 max 0.7 max -- 0.1 max -- AA3005 1.0-1.5 0.20-0.60 0.3 max 0.6 max 0.7 max 0.1 max 0.25 max 0.1 max 3190 1.0-1.5 0.3-0.7 0.3 max 0.4 max 0.4 max -- -- -- MD356 0.8-1.3 0.4-0.6 0.30-0.55 0.25 max 0.4 max -- 0.1 max 0.11-0.20 __________________________________________________________________________
The 2nd & 3rd generation aluminum alloys, such as the proprietary MD356 and 3190 alloys are limited to temperatures of 177.degree. C. 350.degree. F!, as are the AA3003 & AA3005 alloys on which they are based. This temperature limitation seriously restricts the potential benefits of turbocharging systems. Metals other than aluminum could be used for charge air coolers to improve the elevated temperature strength, just as copper is used for radiators. However, the increase in weight encountered in use of those metals would offset any benefit derived from the increased power afforded by their ability to operate at higher temperatures.
A charge air cooler or intercooler is conventionally comprised of a side plate, header, tubes and fins. Hot gas is fed to the tubes by the header which is basically a manifold that is held in place by a side plate. The fins are thin sheets attached to the tubes in order to promote cooling. The cool air flows over the fins and the outside of the tubes, while the hot gas flows inside the tubes and the manifold. The tubes and manifold are therefore hotter than the fins. All of these parts are brazed together, with the result that any alloy used must be able to withstand an approximate 600.degree. C. braze cycle.
AlliedSignal Turbocharging Systems Division (ASTS) charge-air-coolers are constructed using the 3190 alloy for the header and tubes and AA3 003 for the less demanding fins. These give satisfactory service under current operating conditions. However, it has been found by ASTS that the 3190 and similar alloys tend to fail by thermal fatigue when used in charge-air-coolers designed for temperatures in excess of 177.degree. C.
ASTS have calculated the stress and temperature distribution in a charge air cooler on a Freightliner DDA-960-470 HP engine subject to the most severe conditions it would encounter during passage over the Rocky Mountains using the Loveland Pass. It was found that the first tube connection to the header would experience the maximum temperature and stress. The stress at this location is higher, because it is the location at which the header is connected to the cooler side plate, at this location the header is not only cooler, but is also firmly fixed in position. The stress experienced occurs not only during the acceleration cycle, but also during deceleration, when the temperature differential is reversed. ASTS found that the temperature reaches 405.degree. F. and the effective stress is 4.0 ksi. Comparison with fatigue curves shows that theoretically the header tube connection will fail by a low cycle failure after an unacceptable 6,000 "Loveland Pass" cycles. Such failures were found by ASTS in the new aircooler intended for operation at over 177.degree. C. Another failure mode is bending of the side plate. Analysis indicates that although the temperature of the side plate is only around 150.degree. C., the stress is high, with calculated values of 9 ksi, hence its failure mode is typical of an overloaded structure rather than a fatigue failure.
Heat exchangers constructed using the stronger AA 6000 type alloys have been proposed; but these devices have been found to over-age at temperatures above 177.degree. C., thereby causing rapid (<100 hours), deleterious loss of mechanical properties with time.
There remains a need in the art for a heat exchanger, the parts of which exhibit useable strength after long term exposure to temperatures above 177.degree. C. and after experiencing a standard braze cycle.

Heat exchanger having aluminum alloy parts exhibiting high strength at elevated temperatures


An electronic party game, comprising display cards for displaying questions to be asked to a player, and a response monitor for monitoring the player's psycho-physiological responses to the questions. The response monitor comprises a housing dimensioned to be fit into the palm of the player answering the questions, the housing having an outside top surface shaped to receive two extended fingers of the player, and a pair of electrodes extending through the top surface, each of the electrodes being positioned to contact one of the extended fingers near the tip thereof, bias means operatively coupled to an outside portion of the housing for selectively biasing the player's fingers against the electrodes, an electronic circuit located within the housing which generates an electric current from one electrode to the other through the player's fingers and a voltage signal correlatable with the change in resistance resulting from the player's response to the questions, and an indicator which generates a signal indicative of the changes in resistance. The subject monitor is capable of monitoring a user's psycho-physiological responses to hearing a pair of questions and determining whether the user's response to the first question is greater than the user's response to the second question.

This invention relates to party games, and more particularly, to electronic party games and components thereof.
Board-games, card games and other party games have provided entertainment for groups of people for many years. A number of party games require individual players to answer questions. These answers in turn entertain the group. One such game, known as Scruples (trade mark), tests individual players with moral dilemmas. A disadvantage associated with this game is that a player may lie, in answering the moral question, and often it is difficult or impossible for the other players to detect the lie.
There exist a number of lie-detector devices which have been considered to be suitable for entertainment purposes. U.S. Pat. No. 3,648,686 discloses an instrument for measuring the galvanic skin response, which utilizes a bridge amplifier and relies upon a change in the audible frequency to signal an untruth, but this device has poor resolution. U.S. Pat. No. 3,841,316 discloses an apparatus for measuring the psychogalvanic reflex, which also uses a resistance bridge circuit, but this device is not practical, since the transistor meter combination required to make the circuit practical does not exist. U.S. Pat. No. 4,331,160 discloses a lie-detector apparatus which is an improvement over that disclosed in the above patents, because it provides a constant baseline, but it also uses a resistance bridge circuit which does not create a linear output. Furthermore, these prior art devices are not very reliable lie-detectors, because they do not take into account the fact that a particular person may have a relatively high response to every question, or a relatively low response to every question, regardless of whether a person is telling the truth.
There also exist highly sophisticated polygraph machines which calculate scores corresponding to the certainty of deceit, based upon complex measurements of various factors, but these machines are very expensive, and can only be used by trained operators.
There is accordingly a need for a relatively simple, inexpensive lie-detector apparatus, adapted for use as a component of a party game.

Game apparatus and method for monitoring psycho-physiological responses to questions