Methods and systems for producing hydrogen are provided. In one embodiment, a method of producing hydrogen comprises reacting a feed source with steam to produce a gas mixture containing hydrogen and a residue gas; introducing the gas mixture into a purification unit; adsorbing the residue gas; and discharging at least a portion of the hydrogen. The method further comprises depressurizing the purification unit; discharging at least a portion of the residue gas during the depressurization; recycling the residue gas to the feed source; and discharging the residue gas remaining in the purification unit. In another embodiment, the method includes discharging a portion of the residue gas during the depressurization such that the residue gas discharged has a higher hydrocarbon content than the secondary product remaining in the purification unit.

There is a variety of known processes for producing hydrogen. Some examples include the following: (1) steam reforming of natural gas or naphtha (2) catalytic reforming of hydrocarbons, e.g. gasoline and fuel oil, and (3) partial oxidation of coal, heavy oils, or natural gas. Of these processes, steam reforming of natural gas is probably the most widely used process for hydrogen production.
FIG. 1 shows a typical process for producing hydrogen. The process involves reacting methane 110 (e.g., from natural gas) with steam 120 in a steam methane reforming ("SMR") unit to produce primarily hydrogen and carbon monoxide (sometimes called synthesis gas). The steam reforming reaction proceeds as follow:CH4+H2O=>CO+3H2
This reaction usually takes place in the reforming unit 130 at high temperature and high pressure. The reaction is equilibrium limited and is highly endothermic. The heat for the reaction is provided by a furnace 137. Fuel 140 for the furnace 137 may be supplied from the methane feedstock 115. The hot exhaust gas 145 from the furnace 137 may be used to preheat feed 138, and generate or superheat the steam 120 for the reaction.
The effluent stream from the reforming unit 130 is then sent to a shift reactor 150 to obtain additional hydrogen. In the shift reactor 150, the carbon monoxide is reacted with steam to produce more hydrogen. This reaction is usually called the "water gas shift" reaction and the chemical equation for the shift reaction proceeds as follow:CO+H2O=>CO2+H2 The steam reacts with the carbon monoxide from the reforming reaction to produce carbon dioxide and additional hydrogen gas. The reaction energy is exothermic and the heat generated is normally utilized for producing additional steam or heating up other process streams.
The effluent stream from the shift reactor 150 is cooled and sent to a purification unit 160 to separate the hydrogen gas. Pressure swing adsorbers ("PSA") are often used as the purification unit 160 following steam reformation and shift reaction. Generally, in a PSA process, the gas mixture stream is passed over an adsorbent bed at elevated pressure, whereby the bed selectively adsorbs and holds the impurities. In this respect, the PSA process produces a substantially pure hydrogen product at elevated pressure. The impurities adsorbed on the PSA beds are desorbed at a substantially lower pressure. These desorbed impurities along with unrecovered hydrogen form a low pressure residue gas, which may include carbon dioxide, carbon monoxide, and unreacted methane.
To improve the overall thermal efficiency of the process, it is important to utilize the heat available in the process streams such as process effluents from the reforming unit 130 and the shift reactor 150, and exhaust gas 145 from the furnace 137. In addition to generating or superheating steam, such heat may be used to heat process feed, combustion air for the furnace, and preheat boiler-feed-water. Typically, the amount of steam that may be generated from all available heat exceeds the amount of steam required for the steam reformer 130. The excess steam is normally exported as a byproduct of the hydrogen plant.
As shown in Table 1 below, the residue gas 165 process stream, which may include CO2, CO, CH4, and H2, has a relatively low heating value (e.g., 2419 kcal/Nm3, compared to heating value of 9,090 kcal/Nm3 for natural gas) and is usually at a low pressure of about 1.3 bara. Consequently, use of the residue gas in a hydrogen plant is limited. Typically, the residue gas 165 is recycled to the reformer furnace 137 and used as fuel.
Table 1 below illustrates a typical material balance around the PSA.
TABLE 1ComponentUnitFeed to PSAPure H2Residue GasH2Nm3/h78449698208629CH4Nm3/h63396339CONm3/h44704470CO2Nm3/h1724617246N2Nm3/h38370313FlowNm3/h1068876989036997Heating ValueKcal/Nm3,2419LHVPressureBar a (psig)25.3 (350)24.3 (335)1.3 (5)
One problem encountered during the hydrogen generating process is that the amount of residue gas 165 may limit the flexibility and efficiency of the overall process. One example of the limitation imposed by the residue gas 165 is when the demand of by-product steam is low and suppression of steam production is desired without loss of thermal efficiency of the process. The by-product steam is typically produced by utilizing the heat in the gas exhaust 145 leaving the furnace 137 and the process effluents of the reforming unit 130 and the shift reactor 150. During a period of low steam demand, steam production may be suppressed by redirecting the hot exhaust gas 145 to preheat the natural gas feed 110, the combustion air for the furnace 137, or the fuel stream 140 to the furnace 137. As a result of the preheating, not as much heat is needed in the furnace 137, thereby reducing the requirement of the fuel stream 140. Typically, the residue gas 165 is a major component of the fuel stream 140, while "make-up" fuel, which is input from other sources e.g., fuel supplied from methane feedstock 110, makes up the remaining portion of the fuel stream 140. Because all of the residue gas 165 is fed to the fuel stream 140, a reduction in the fuel stream 140 is generally accomplished by controlling input from the make-up fuel. Thus, the degree of steam suppression depends on the percentage of the make-up fuel stream.
The make-up fuel stream is also used as a means to control the temperature in the furnace. Proper control of furnace temperature typically requires about 10 to 15% percent of heat to be provided by the make up fuel. This percentage of the make up fuel defines the lower limit below which reliable temperature control of the furnace is sacrificed. If the amount of make-up fuel is close to the lower limit, then the amount of make-up fuel may not be adjusted to reduce the furnace fuel firing. Consequently, the residue gas controls the minimum amount of the fuel stream 140 that must be fired to dispose all of the residue gas, thereby limiting the suppression of steam generation.
The following thermal balance example shows the amount of steam made when all PSA residue gas is used, and the net fuel import is at its minimum:
TotalFuel FromMake UP FuelMake upHydrogenFurnacePSAfor Tempfuel as %Exportproduced,FiringResidueControl,of TotalSteamNm3/hGcal/hGas, Gcal/hGcal/hFiringkg/h46000103.149013.1412.752560This thermal balance shows that the make up fuel is only 12.7% of total firing. To reduce the steam generation, the furnace firing needs to be reduced. However, because the make up fuel is close to the lower limit desired for furnace temperature control, the extent of furnace firing reduction is limited due to the fuel balance.
Furnace firing reduction may also be achieved by altering other operating parameters. One such parameter is the amount of steam added to the natural gas at the inlet to the reforming unit 130. Another such parameter is lowering of the reforming unit 130 outlet temperature. In both cases, these changes increase the methane slip at the reforming unit 130 outlet, which, in turn, will increase the amount and heat content of the PSA residue gas 165. However, as shown in the above example, the hydrogen generation process is already limited by the existing amount of residue gas 165, and therefore, cannot accommodate this increase in the residue gas.
There is a need, therefore, for a method to increase the flexibility and efficiency of the hydrogen generation process. There is also a need to reduce the amount of residue gas that must be disposed.

Apparatus and methods for gas separation

Air Liquide Process & Construction, Inc.

L'Air Liquid, Societe Anonyme a Directoire et Conseil de Surveillance pour l'Etude et l'Exploitation des Procedes Georges Claude


According to the present invention, a wastegate value is provided at the exhaust gas inlet of a supercharger of the internal combustion engine and the degree of opening of the wastegate valve is controlled by a control unit in accordance with the engine speed. The control unit stores the regions where the engine output increases sharply along with an increase of the engine speed (bootstrap operating region) as ranges of the engine speed, and sets the degree of opening of the wastegate valve in accordance with the speed in the bootstrap operating region, and thereby ensures that the supercharging pressure will rise gradually along with an increase of the engine speed. Due to this, sharp increases in the engine output in the bootstrap operating region are prevented and therefore no bootstrap occurs.

1. Field of the Invention
The present invention relates to a supercharged internal combustion engine and, more particularly, to control of the output of a supercharged internal combustion engine.
2. Description of the Related Art
It is known that when mounting a reciprocating internal combustion engine equipped with a supercharger such as an exhaust gas turbocharger in an aircraft to drive a propulsion propeller, there are operating regions where a so-called "bootstrap" phenomenon occurs.
Here, a "bootstrap" phenomenon means the phenomenon when the degree of opening of the throttle valve of the engine or the speed setting of the governor is held constant during operation but, nevertheless, the engine speed becomes unstable and there are repeated sharp increases and sharp decreases in the engine speed. This bootstrap phenomenon is believed to occur due to the following reasons.
In a supercharged internal combustion engine, an upper limit is set for the engine supercharging pressure to protect the engine and supercharger. Usually, for the control of the engine supercharging pressure, use is made of a mechanical type wastegate valve (hereinafter abbreviated as WGV) arranged in the exhaust pipe at the inlet of the supercharger or a mechanical type intake relief valve or other supercharging pressure control valve provided in the air passage at the outlet of the supercharger. These supercharging pressure control valves are held in the fully closed condition until the supercharging pressure reaches a certain setting. When the supercharging pressure exceeds the setting, they open to suppress the rise of the supercharging pressure. For example, when the WGV opens, part of the exhaust gas bypasses the supercharger, so an increase of the pressure of the exhaust gas flowing into the supercharger (exhaust gas flow rate) is prevented and a rise of the supercharger speed is suppressed. Therefore, the supercharging pressure will not rise to more than the pressure setting. Further, the intake relief valve similarly opens when the supercharging pressure exceeds the setting and releases part of the supercharger outlet air into the atmosphere to suppress the rise of the supercharging pressure.
FIG. 3(A) shows the characteristic of change of the supercharging pressure PD with respect to the engine speed NE in an engine having such supercharging pressure control valve. As shown in FIG. 3(A), while the engine speed NE is low (in FIG. 3(A), region where 0<NE<NE1), since the pressure (flow rate) of the exhaust gas of the engine is low and the supercharger speed does not rise, the supercharging pressure PD is maintained at a substantially constant low value PD1. When the speed of the supercharger rises along with the engine speed and the engine speed reaches NE1 (FIG. 3(A)), the supercharging pressure PD starts to rise. In the region of NE1.ltoreq.NE<NE2 in FIG. 3(A), the supercharging pressure PD sharply rises along with the rise of the engine speed NE. Further, when the supercharging pressure PD reaches the setting PD2 of the supercharging pressure (NE=NE2), the supercharging pressure control valve opens, so the supercharging pressure PD is held at the constant value PD2 regardless of the engine speed (region of NE.gtoreq.NE2). FIG. 3(B) and FIG. 3(C) show the characteristic of the degree of opening of a supercharging pressure control valve (in this case, a WGV) and the characteristic of the engine output with respect to the speed NE, respectively. As shown in FIG. 3(B), the WGV is maintained fully closed in the region where the engine speed NE is lower than NE2. In the region where the speed NE is higher than NE2, the degree of opening of the WGV is increased along with a rise in the speed NE to hold the supercharging pressure PD at the setting PD2.
Therefore, the engine output HP rises relatively gradually in the region where the speed NE is NE<NE1, but the engine output also rises sharply in accordance with a sharp rise of the supercharging pressure PD in the region of NE1.ltoreq.NE<NE2. Further, in the region of NE.gtoreq.NE2, the supercharging pressure PD is maintained at the constant value PD2, so the increase in the engine output once again becomes gradual. Note that the rated output of an engine for an aircraft is usually set to a speed close to that shown by NER in FIG. 3(C).
However, in an aircraft engine, the engine speed NE is determined by the power consumption of the propeller and the engine output. That is, the power consumption of the propeller increases in proportion to the cube of the speed when the pitch is constant. Therefore, in actual operation, when the engine speed rises, the power consumption of the propeller also increases along with the engine output and the engine is operated at a speed where the power consumption of the propeller and the engine output are balanced. Therefore, in the region where the change in engine output with respect to a change in the engine speed is large (for example, the region of NE1.ltoreq.NE<NE2), the engine output will end up changing by a large amount even when the engine speed changes slightly due to disturbances etc., and the balance of the power consumption of the propeller and the engine output will end up being lost.
For example, in a case where the engine speed rises slightly in this operating region, the power consumption of the propeller does not change that much when the speed rises just slightly yet the engine output rises by a large margin. Therefore, the rise of the engine speed does not stop at the slight amount of rise of the speed which triggered it and rises all at once to the speed where the increase in the power consumption of propeller due to the rise in the speed and the output determined by the engine output characteristic (FIG. 3 (C)) are balanced.
The condition where the engine speed does not stabilize but repeatedly rises and falls in this way even when the degree of opening of the throttle valve is maintained constant is called a "bootstrap". A bootstrap occurs in the region where the change of the engine output is large with respect to the change of the engine speed such as the region of NE1.ltoreq.NE<NE2 in FIG. 3(C), that is, the operating region where the supercharging pressure control valve is generally fully closed. When a bootstrap occurs, the engine speed can no longer be accurately controlled and problems may arise in the operability of the aircraft. Therefore, in the past, the general practice has been to prohibit regular operation in the bootstrap operating region.
The above explanation was made for the case of a fixed pitch propeller, but generally a speed governor using a variable pitch propeller is used for an aircraft engine. A speed governor is a mechanism for adjusting the power consumption of the propeller by changing the pitch of the variable pitch propeller so as to hold a set engine speed. That is, when the propeller pitch changes, the power consumption of the propeller will change even at the same propeller speed. Therefore, when a difference arises between the engine speed during flight and the preset speed, the governor performs control to change the propeller pitch in accordance with the difference between the actual speed and the set speed and hold the engine speed at the set value. In this way, in an engine provided with a speed governor, it is possible to obtain an engine output more stable than the case of a fixed pitch propeller engine.
However, even in an engine provided with such a speed governor, there are cases where bootstrap occurs in a bootstrap operating region where the rate of change of the output with respect to the engine speed is large as mentioned above. That is, in such an engine, when the engine speed rises, the propeller pitch is increased to make the engine speed fall, but in the actual operation, there is a time delay caused by the operational delay etc. of the pitch control mechanism in the time interval from when the rise of the speed is detected to when the propeller pitch increases. Therefore, in the bootstrap operating region where the change of the output with respect to the engine speed is large, the engine speed ends up sharply rising during this delay time and cases arise where bootstrap occurs in the same way as the case of a fixed pitch propeller.
As explained above, bootstrap occurs due to the fact that the characteristic of increase of the engine output due to the rise of the supercharger speed and the characteristic of increase of the engine load (power consumption of the propeller) do not match each other.
While not relating to an aircraft engine, attempts have been made to control the supercharging pressure of the supercharger to make the characteristic of increase of the engine output and the characteristic of increase of the engine load match.
For example, this type of control apparatus is described in Japanese Unexamined Utility Model Publication (Kokai) No. 61-113936. The apparatus of this publication relates to a supercharging pressure control apparatus for a supercharged internal combustion engine used in vehicles. In this vehicular use supercharged internal combustion engine, at the time of vehicle starts and rapid acceleration, the supercharging pressure of the turbocharger rises sharply along with a rise in the engine speed, so the engine output also sharply increases. Therefore, a mismatch occurs between the characteristic of increase of the engine output and the characteristic of increase of the engine load (drive power to drive wheels). This causes slipping of the drive wheels at starts and during acceleration. The apparatus of the above publication is directed to preventing slipping of the drive wheels. The apparatus opens the wastegate valve to correct the supercharging pressure to become lower than the normal pressure setting when the rate of rise of the engine speed exceeds a predetermined value. The apparatus of this publication suppresses sharp rises in the speed of the engine by this correction so as to prevent slipping of the drive wheels from occurring.
The apparatus of the above Japanese Unexamined Utility Model Publication (Kokai) No. 61-113936 is effective in prevention of slipping of drive wheels during vehicle starts and acceleration, but if the apparatus of the publication were applied to a supercharged internal combustion engine for an aircraft, it would not be possible to prevent occurrence of bootstrap.
That is, in the apparatus of the above publication, the wastegate valve is designed to be opened after a sharp rise in the engine speed is detected. However, in an aircraft engine, when a sharp rise of the engine speed occurs, bootstrap is already occurring. Therefore, in the apparatus of this publication, while it is possible to reduce the extent of rise of the supercharging pressure (engine output) after the occurrence of bootstrap, it is not possible to prevent the occurrence of bootstrap itself.


In this invention, after a hole has been drilled or excavated, injection probe(s) are placed at appropriate depth(s), the excavated native materials are replaced with appropriately sized crushed rock or other natural or synthetic materials, and then a polymeric resin is injected through the probe(s) to encapsulate and bind the fill material, whereby upon curing the polymeric resin and fill material forms a foam friction pile. Such friction piles drilled or excavated adjacent to each other will form a foam sheet piling system. The foam piles can also be re-enforced using nylon, polypropylene, fiberglass, other synthetic or non-synthetic materials or combinations of these materials. The polymeric resin typically would comprise a high density closed cell, water resistant expanding two component polyurethane foam system.

This invention relates to construction of friction piles or friction pile-like structures for supporting and under-pinning structures on stable and unstable base soils, and for construction of shoring system(s) in stable and unstable base soils as for example:
(A) preparation of foundation support systems for buildings, walks, bridge abutments, concrete roads, and other structures requiring a base support system;
(B) construction of an in-situ barrier to prevent collapse or sloughing of native soils within a delineated perimeter foot print or face where excavation is to be undertaken;
(C) construction of vertical support members in perma-frost or ice-lensed soils which bear the loading of residential, commercial, industrial buildings, pipelines, or any other structures requiring the utilization of this type of foundation support system;
(D) construction of an anchoring or pinning system to which road beds, walks, and other such structures can be anchored to prevent horizontal movement of base soils beneath these structures.
In typical construction of foundation support systems where piles are needed or where piles are needed to construct a structural floor or structural concrete slab, friction piles are employed. Friction piles are typically either of the driven or drilled type. The latter system employs the drilling of a pre-determined size of hole which is filled with concrete and left to cure and thereby forming a friction pile. This pile may or may not be re-enforced with steel re-enforcing-bar. Alternatively, steel members, wooden timbers or poles, or synthetic members are manually driven into base soils to pre-determined depths with a resultant friction pile being formed. A system or array of such piles are put in place to support and eliminate or minimize future settlement of whatever structure is to be constructed on the system of piles.
In certain construction situations barriers are required to be driven into the base soils to prevent sloughing of base soils as the soils on one side of the barrier are excavated for a foundation, installation of a pipeline, etc. Typically, these barriers are sheets of steel that are mechanically driven into the base soils and which can be joined to each other through a tongue and groove like linkage at the ends of the steel sheets. Typically this is referred to as placement of sheet piling. The sheet piling can also be constructed of sheets of synthetic materials. Alternatively, steel, wooden or synthetic members or poles may be driven into base soils adjacent to each other to prevent sloughing.
Typically in base soils where perma frost or ice lensing is a condition, vertical support members are driven or drilled into the base soils to support a building, pipeline or other structure. Typically, wooded members are driven into the base soils to provide a friction pile. Wood members are used as the thermal conductivity of wood is low. Steel members can also be used but steel has a high thermal conductivity and more susceptible to result in settlement as heat is transferred through the steel member and the perma frost degrades. Vertical support members can also be installed by firstly drilling a hole, inserting a wooden or metal member and back filling around the member with a slurry which either freezes in place or sets up and cures in the case of certain cementitious slurries.
Under certain construction circumstances, friction piles can be used to tie-in adjacent horizontal structures such as gravel, asphalt concrete or concrete roads to prevent them from moving. Movement of such structures is typically as a result of a slip face in the base soils that may be caused by perma-frost or ice lenses.
The construction of typical friction piles for use in foundation construction or the construction of structural slabs and in the construction of vertical support members have certain inherent problems or negative characteristics such as:                A) In the case of friction piles which are drilled and the drilled hole is filled with concrete, the very heavy weight of the concrete must also be taken into account in calculating the load relative to the anticipated holding strength of the friction pile. Typically the piles have to be drilled deeper to take into account the fairly considerable additional weight of the pile itself.        B) Maximum friction or holding strength is achieved when as much of the surface of the concrete pile comes into contact with the wall of the drilled hole. This "contact" is not maximized whenever there is an occlusion in the wall of the concrete pile.        C) Concrete as a cementitious material is made with water and as such is susceptible to shrinkage as the concrete cures and any shrinkage of the concrete will lessen the skin friction of the pile. Curing time can also be a mitigating factor in slowing up the next stage of construction after the friction piles have been poured in place.        D) It is not atypical for piles to have to permeate a number of different strata of base soils and wherever the pile goes through a weak strata, the skin friction in this area will be significantly less thereby reducing the overall holding capacity of the pile and requiring a deeper pile to overcome this condition.        E) Wooden vertical support members although having a relatively low coefficient of heat transference, heat will still transfer through the wood and when placed in a perma-frost or ice-lens condition, eventual degradation of the perma-frost will occur


A thermal blanket includes an inflatable covering with a head end, a foot end, two edges and an undersurface. The covering is inflated through an inlet at the foot end by a thermally-controlled inflating medium. An aperture array on the undersurface of the covering exhausts the thermally controlled inflating medium from the covering. Exhaust port openings are provided that the edges of the covering to vent the inflating medium, which enhances circulation of the thermally-controlled medium through the cover. An uninflatable section is provided at the head end, together with an absorbent bib attached to the covering, adjacent the uninflatable section. An uninflatable section may also be provided at the foot end having a pair of seams to form an erectable drape section. When inflated, the thermal blanket self-erects and provides a bath of thermally-controlled inflating medium to the interior of the erected structure. The enhanced circulation of the medium through the covers maintains a relatively high average temperature under the blanket and a relatively uniform distribution of temperature in the inflating medium which is exhausted through the apertures into the structure's interior. When the structure covers a patient, the uninflatable section at the head end provides a relatively unobstructed view of the patient's face, while the absorbent bib maintains a relatively sanitary environment in the area beneath the patient's head. The uninflatable section at the foot end retains heat from the inflating medium to warm the patient's feet and insulate the bare skin of the feet from excessive conductive heat from the hose connected to the inflation inlet. The thermal blanket may be sized to cover selected areas of a patient such as the upper body, including the chest, arms, or shoulders, or the lower body, including the pelvic and groin area and the legs.

This invention relates to thermal blankets used in a medical setting to deliver a bath of a thermally-controlled medium to a patient.
The thermal blanket prior art is best expressed in our prior U.S. Pat. No. 4,572,188 entitled "AIRFLOW COVER FOR CONTROLLING BODY TEMPERATURE." In our prior patent, a self-erecting, inflatable airflow cover is inflated by the introduction into the cover of a thermally-controlled inflating medium, such as warmed air. When inflated, the cover self-erects about a patient, thereby creating an ambient environment about the patient, the thermal characteristics of which are determined by the temperature of the inflating medium. Holes on the underside of our prior art airflow cover exhaust the thermally-controlled, inflating medium from inside the cover to the interior of the erected structure. Our airflow cover is intended for the treatment of hypothermia, as might occur postoperatively.
Evaluation of our airflow cover by skilled practitioners has resulted in general approbation: the opinion is that the airflow cover efficiently and effectively accomplishes its purpose of giving a thermally-controlled bath. We have realized, however, that, while our prior art airflow cover achieves its objective, certain improvements to it are necessary in order to realize additional clinical objectives and to enjoy further advantages in its use.


The plurality of nodes in a computer network is divided into a plurality of peer groups. The plurality of peer groups can further be divided into a plurality of upper level peer groups. Routing information for each peer group is summarized according to an algorithm. This summary routing information is then stored in nodes which are not a member of that peer group. The algorithm for summarizing the routing information, represents each peer group as a summary node where nodes of the peer group which connect to other peer groups, are considered ports of the summary node. Metric values for the characteristics of paths connecting these ports are determined. A metric average is computed for all of the port-to-port paths and this average is then halved to give a peer default metric value for a routing path entering into, or exiting from that particular peer group. An exception method can be included, if a particular port has a significantly different metric value for entering into or exiting the peer group from that port. Also a bypass metric can be included in the summarization information if a particular path between ports of the peer group has a metric value which is significantly different from the peer default metric value.

In computer networks a plurality of nodes are connected by a plurality of links. Often the connection of links and nodes is not orderly, symmetrical or follows an established pattern. Also there is often a plurality of possible routing paths between a first and second node. Methods are known to determine a plurality of routing paths in such disorganized networks. When a plurality of routing paths are available, one path needs to be selected for the actual data transmission. The choice of the actual path is often based on characteristics of the different paths. Metric values are used to represent the characteristics of a path, and each path often contains a plurality of different links and nodes which have different metric values for the characteristics that are important in selecting a routing path. A metric value is determined for each characteristic of each path by combining the metric values of each link and node in the path. This metric combining in this document will be referred to as "metrically adding". However depending on the characteristic, the combining of metric values is not always by simple mathematical addition. When the characteristic is time delay or distance, the time delay or distance for each link and node is simply added. When the characteristic is a data rate type characteristic, the metric value for the path is the lowest data rate of the links and nodes. When a characteristic is similar to a standard deviation of noise, the standard deviation of noise for a routing path is a more complicated combination or addition of the standard noise deviations of the individual links and nodes.
When the number of nodes and links in a computer network is relatively small, each node can store the metric values for all the links and nodes in the network. When a node wishes to communicate with another node, a plurality of routing paths are determined and the node calculates the metric values for the different characteristics of each routing path by metrically adding the metric values for the individual characteristics of each link and node in the path. When the number of links and nodes in a computer network is relatively large, it becomes impossible, or at least impractical, for a node to store all the metric values of all the links and nodes in the network. Instead of limiting the size of the network, it has been proposed to layer the network in a hierarchical manner.
In a layered network, a group of nodes and the links connecting those nodes are formed into a peer group. A computer network can then have a plurality of peer groups. Each node in a peer group contains actual information for the links and nodes in its own peer group. The node only contains summary information for other peer groups to which it does not belong. In this way, each node does not need to store large amounts of routing information and simplifies the routing process.
For the hierarchical layering of computer networks to operate properly, the summarization of the routing information for other peer group's must reasonably reflect the routing properties of the peer group being summarized, while substantially reducing the amount of information needed to describe that peer group. Typically summarization methods have been "and-hoc" or "heuristic" in nature.

Summarization of routing information in a hierarchical network


A power pooling apparatus uniformly distributes sector loads in a mobile communication system. The power pooling apparatus comprises a distributor for distributing signals output from a signal generator according to respective sectors; a radio signal processor for performing signal processing to provide an output of the distributor to an antenna; and an adaptive signal processor for determining a characteristic matrix of the distributor by using an output in a predetermined position on a signal processing path of the radio signal processor, and providing the characteristic matrix of the distributor to the distributor.

1. Field of the Invention
The present invention relates generally to a power amplification apparatus, and in particular, to a power amplification apparatus in a mobile communication system.
2. Description of the Related Art
In general, a mobile communication system such as a code division multiple access (CDMA) communication system, has a power amplifier (PA) included in its output stage. Power amplifiers power-amplify a radio frequency (RF) signal to provide a signal having an appropriate level for transmission over a radio path via an antenna.
FIG. 1 is a diagram illustrating an example of a prior art power amplification apparatus in a 3-sector antenna system. FIG. 1 is a power amplification apparatus in a 3-sector antenna system having α, β and γ sectors. The power amplification apparatus includes power amplifiers (PAs) 100 which are independently driven in association with corresponding sectors. When many calls are concentrated in a certain sector, the power amplifier for the sector has a heavy load. In order to sufficiently provide services desired by a user to the sector having a heavy load, capacity of the corresponding power amplifier must be increased. Since such a situation may occur for all sectors in the same way, there is a necessity to set capacity of every sector's power amplifier to its maximum possible value.
However, since call distribution per sector is not uniform according to time and sector, a method of setting capacity of every sector's power amplifier to its maximum value may be inefficient in terms of utilization of the power amplifiers. In particular, the life span of a power amplifier having a heavy load is decreased compared with power amplifiers not under a heavy load.
Meanwhile, the conventional power amplification apparatus can include a redundant power amplifier to handle situations in which a service is dropped due to a failure of a certain power amplifier. However, the redundant power amplifier does not operate while the other power amplifiers are being driven, thus increasing inefficiency in terms of the overall utilization of the power amplifiers.

Adaptive power pooling apparatus and method in a mobile communication system


A symmetrical ac power system provides a balanced ac output, whose maximum voltage with respect to a reference ground potential is one-half the ac output voltage, and which is derived from a single phase ac source through the use of an isolation transformer having a center-tapped secondary winding. The center tap is connected to the output power load circuit as a ground reference potential with respect to the symmetrical ac output so as to constitute the reference ground potential for the power supply and load. Since symmetrical ac power is applied to the load by the system, reactive load currents, other power artifacts, EMI and RFI emissions and other interference and noise components ordinarily resulting from the application of conventional ac power to the load are reduced or eliminated by appearing as equal inversely phased signal elements which cancel one another. In order to maximize the performance of the symmetrical power system, the isolation transformer has a bifilar-wound secondary winding.

When electrical power distribution techniques were first being developed, little was known about the current carrying capacity of copper wire, voltage drop, line loss and many other aspects of electrical power distribution. The availability and cost of copper wire was a major consideration. Thomas Edison and his engineers developed a means of power distribution that required twenty-five percent less wire than any other then known method. Essentially, two circuits could be distributed using only three wires by using a common wire. Over 100 years later, the "Edison Circuit" remains as the standard for power distribution. Single-phase transformers with a center tap output terminal are designed for this purpose. A circuit wire originating from the center tap is used as the common wire for two circuits. For safety reasons, the center tap is also used as the reference point from which the grounding system originates. Many interference problems are attributable to the neutral-to-ground connection made at the center tap. Because of impedance in alternating current ("ac") circuits, not all of the power flows directly back to its source. Some power is changed into noise in one form or another, escapes from the neutral wire into the ground reference and causes interference or malfunction in the operation of electronic equipment. Two-wire output (noncenter tapped) 120 volt isolation transformers and 120/208 volt three-phase 4-wire systems are similarly neutral-to-ground referenced and also exhibit such noise problems.
Harmonic distortion, reactive currents, power factor, radio frequency interference ("RFI"), electromagnetic interference ("EMI") are some of the many aspects of poor power quality and interference in problem situations. Active power conditioning is the one possible way to address the most serious of these problems. Micro-processor based power factor correction, micro-processor based anti-harmonic noise, true sinewave inverters and similar sophisticated technology are proposed to solve the problems. The technology is very sophisticated and is rapidly advancing. The one underlying theory behind all of this technology is that problems manifest themselves in electronics when stray current in the neutral wire escapes from the circuit and flows into the ground wires where there is a network of paths that lead into signal circuitry. This is called an eddy current and is one of the ways noise can get into electronic signals. If the reactive power elements can be cleaned up and the power signal made more efficient, eddy currents can be avoided.
Improved grounding system designs have been developed in an attempt to reduce noise in the reference source. For example, a "Linear Signal Reference Grid" may be used to attempt to handle ground loops and balance chassis potentials. An impedance of 0.1 ohms is the recommended standard. But since reactive currents are most of the problem, lowering impedance only facilitates greater current flow. Much reactivity occurs directly between the voltage source and the ground reference itself (in normal mode) in balanced power supplies and balanced filter circuits which has little to do with neutral wires, inter-chassis potentials or how a grounding circuit is constructed. Reducing chassis-to-chassis potentials does little to prevent some reactive currents from saturating the grounding grid and gaining access into high impedance signal circuits through the reference. The high impedance path in most of these signal circuits is an inductor, a low level signal input transformer. Induction causes some of the reactive current to be realigned with its lagging voltage phase only to reappear as noise in the program signal. Hum bars on a video monitor are one manifestation of this phenomenon.
In modern electronic applications in normal mode or in the more customary "differential" mode of operation where there is a "hot" wire a "neutral" wire and a "grounding" conductor, there is a two-way relationship between the voltage signal and reference potential with the reference positioned at one extremity. In the analogous art of electronics, this is called a "single-ended" or "unbalanced" circuit. The consequences of this single-ended, two-way relationship between the voltage signal and the ground reference become clearly apparent when reactive power artifacts originating from the load appear in the neutral wire. The reference source of a reactive power artifact on the neutral is rotated one hundred and eighty degrees from the neutral at the "hot" side of the power circuit where the load is connected so as to be opposite the original reference. Not all of the reactive current on the neutral wire flows back to its source because of impedance across the power system's transformer. Some of it is left on the line. There are also other types of power artifacts and grounding system noises which originate at the load. By design, there was to be but one reference point, now there are at least two. The complexities that this situation presents where there are multiple and various types of loads are so great as to have been unsatisfactorily resolved by the above-mentioned prior art methods and devices.


A power regulating system and method are provided for regulating power in a portable computing device. The portable computing device includes microprocessing and radio communication capabilities. The power regulating system utilizes a number of power states to regulate the device's internal power source voltage. The power regulating system operates to selectively control and regulate the device's internal power consumption based on the power state of the device, and thereby extends the useful life of the device by prolonging the battery life of the device.

As society becomes increasingly mobile, mobile electronic devices are enjoying a tidal wave of popularity and growth. Cell phones, wireless PDAs, wireless laptops and other mobile communication devices are making impressive inroads with mainstream customers. Constraining this growth and limiting customer satisfaction, however, is the lack of a truly adequate high-coverage-area, inexpensive, small, battery-efficient wireless communication system. Cellular data-transmit telephony-based solutions are far from power-efficient, and impose (relative) cost and size burdens that make them unusable.
Many of these mobile electronic devices operate using an internal power source. The internal power source, generally a lithium-ion battery, provides power to the associated device. Unfortunately, due to various limitations, the power source has a limited lifetime which can adversely affect a user's experience using the device. Due to the size constraints of the mobile electronic device, it is difficult to provide a power source having a preferred capacity and an extended useful lifetime.
Furthermore, in addition to a limited power resource, since many mobile electronic devices rely on radio transmissions, it is important to manage the amount of internal noise generated by each device, otherwise the radio signal reception may be corrupt or null. Many radio receivers manage this problem by using Faraday cages, or by careful frequency planning that guarantees that there will be no interference between the on board electronics and the radio receiver. However, in some devices, the received radio frequencies are very close to the operating frequencies of the on-board electronics, so that it is not possible to alleviate the problem with frequency planning. Nor is a Faraday cage desirable due to the limited space available inside a typical mobile electronic device.

Power regulation system and method for a portable electronic device


A catalyst includes LTA zeolite including copper ions, wherein a Si/Al ratio of the LTA zeolite is 2 to 50. The catalyst is coated on a honeycomb carrier or a filter. The catalyst removes NOx from a reaction gas at 100° C. or above. The catalyst has an NOx conversion rate of 80% at 450° C. or above.

In general, carbon monoxide, hydrocarbons, and nitrogen oxides are included as harmful materials in exhaust gas of diesel vehicles. Nitrogen oxides cause environmental problems such as photochemical smog and acid rain, as well as human diseases. Therefore, there is a demand for improving engines and developing a post-treatment technology of exhaust gas.
The most effective technology for removing nitrogen oxides uses a selective catalytic reduction (SCR) method. This method has been developed according to a reducing agent such as ammonia (NH3), urea, hydrocarbon (HC), and the like, and various catalysts. Ammonia (NH3) has been known to be effective in removing nitrogen oxides from a fixed object such as a power plant and an incinerator. Since there is a problem of storage/transport and use of ammonia, in case of a moving object such as a vehicle, urea has been known to be effective as it is capable of being easily decomposed to ammonia by heat decomposition and a hydration reaction.
As the catalyst for use in the selective catalyst reduction method, zeolite-based catalysts such as copper (Cu)/zeolite having excellent functions has been developed.
In particular, high temperature activity of such a catalyst is important in treatment of high-temperature exhaust gas.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

This patent is subject to a terminal disclaimer.

Catalyst and method for preparing catalyst


The invention provides an external circulation type ball screw device comprising screw shaft and nut having first and second screw grooves. A circulation member comprises first leg, second leg and connection portion. The first leg comprises a first end surface having first inner and outer points, and the second leg comprises a second end surface having second inner and outer points; first and second entrances formed on the first and second end surfaces of circulation passage; first and second thickness respectively provided between the first entrance and the first inner and outer points thereof; the second thickness being greater than the first; the third and fourth thickness respectively provided between the second entrance and the second inner and outer points thereof; the fourth thickness being greater than the third. The groove wall of the second screw groove occupied and the occurrence of broken teeth of the nut are reduced.

1. Technical Field
The present invention is related to a ball screw device, in particular, to an external circulation type ball screw device.
2. Description of Related Art
Ball screw device plays a significant part role in the field of linear transmissions, in which the configuration of the rolling balls can reduce the friction between the screw shaft and the nut such that the screw shaft and the nut can perform relative movements with each other rapidly and precisely.
As new mechanical structures are designed and built to be smaller in size, the volumes of the ball screws need to be confined in sizes as well in order to fit into such smaller spaces. Among a great number of ball screws, the external circulation type of ball screw is particularly suited to situations where limited spaces are available. As shown in FIGS. 1 to 3, a external circulation type ball screw device comprises a screw shaft 1, having an outer periphery provided with a first screw groove 2, a nut 3, having a through-hole 4 and an inner periphery thereof provided with a second screw groove 5 opposing said first screw groove 2 of said screw shaft 1. And a rolling path form between said first screw groove 2 and said second screw groove 5. A plurality of rolling members 6 are confined to move within the rolling path. As the screw shaft 1 (or the nut 3) is rotated, the rolling members 6 are rolled to drive the nut 3 (or the screw shaft 1) to move axially. Furthermore, a circulating tube 7 inserted into the nut 3 comprises two ends connected to the first screw groove 2 and the second screw groove 5 respectively. After the rolling members 6 move along the bearing path and enter into the circulating tube 7, they would return back to the rolling path again, forming an endless circulation. It shall be noted that during the operation of the ball screw device, the rolling members are not passing through the entire second screw groove, and for the portion of the second screw groove where the rolling members pass through is called an effective thread zone (E.T.Z.). During the operation of the ball screw device, the effective thread zone is required to bear the force exerted by the rolling members. On the other hand, for the portion of the second screw groove where no rolling members pass through is called an invalid thread zone (I.T.Z) which bears no forces exerted by the rolling members.
However, as shown in FIG. 2 and in the abovementioned external circulation type ball screw device, the circulating tube 7 penetrates through the nut 3 and is connected to the bearing path such that the tube wall of the circulating tube 7 to occupies the groove wall effective thread zone of the second screw groove 5 in the nut 3, causing the groove wall to be thinner and as a result and making the effective thread zone of the second screw groove 5 vulnerable to groove wall collapsing as well as the problem of broken teeth of the nut.

External circulation type ball screw device


Rotary head recording and/or reproducing apparatus in which respective oblique tracks on a record medium are scanned, each track having an information signal area in which information data is recorded and a track following area in which a tracking control pilot signal is recorded. The track following area precedes the information signal area; and in the preferred embodiment, an additional track following area follows the information signal area. The pilot signal is recorded in only a portion of the track following area, the remainder of which has timing sync data recorded therein. In an after-recording mode the timing sync data is reproduced, detected and used as a reference to define an after-record area.

This invention relates to rotary head recording and/or reproducing apparatus of the type which records/reproduces tracks containing an information signal area and a track following area, the latter being used in a reproducing operation to control the tracking of a head as it scans a track and, more particularly, to such apparatus wherein timing sync data is recorded in the track following area for the purpose of establishing a precise afterrecord area for the after-recording of additional information in the track.
Rotary head recorders have long been used to record video signals and, more recently, to record digital audio signals, the latter being recorded on digital audio tape (DAT). In such rotary head recorders, information, such as video information, audio information or multiplexed video and audio information are recorded in an oblique track across a record tape or other record medium and such information may be recorded in analog or digital form. Digital recorders of the rotary head type generally provide superior performance characteristics because of the inherent advantages derived from digital recording techniques, namely the accuracy with which a recorded digital signal may be reproduced and the ability to rely upon digital error correction techniques, such as error correction codes, to compensate for errors that, nevertheless, may be introduced during the recording or reproducing operation. A typical digital video recorder, as an example, records at least three types of information in a track: a digital video signal, a digital audio signal and a digital subcode signal which may be used as a control signal, such as a display control signal. In such digital video recorders, the video, audio and subcode information typically are recorded in time division multiplexed form such that the video information is recorded in a video section, the audio information is recorded in one or more audio sections and the subcode information is recorded in a subcode section in a track. In addition, and to assure reliability during a reproducing operation, it is common to record a pilot signal in one or more additional areas in the track, such areas being designated automatic track following (ATF) areas.
In one proposal for a digital rotary head recorder, ATF areas are disposed in advance of the information area (i.e. an ATF area is scanned before audio, video and subcode information is scanned) and also in areas which follow the information area. As a rotary head rotates into scanning relationship with a track, the head begins its scan at a head entering end of the track and the head rotates out of its recording relation with the track at a head leaving end. ATF areas are recorded in the vicinity of the head entering end and the head leaving end, respectively. The pilot signals which are reproduced from the head entering end ATF area and from the head leaving end ATF area are used in a servo loop to adjust the speed at which the tape is transported, thereby assuring that the heads are generally centered over the respective tracks which they scan.
It often is desirable to operate rotary head recorders of the aforementioned type in an after-recording mode. An after-recording mode also is known as a dubbing mode wherein audio information, for example, is after-recorded in a track at a time subsequent to the recording of video information in that track. Such audio information may be a translation of audio signals from one language to another, thereby "dubbing" such audio information in synchronism with the movement of, for example, a subject's lips. As another example, the audio information may be in the form of a "voice over" but, nevertheless, is related to the video information. Such voice over techniques are well known and are commonly used in video production, programming and the like. In addition to after-recording audio information, as just described, it also is common to record video information or even subcode information in an after-recording mode. In these after-recording operations it is important to define with accuracy the particular area in a track in which the audio or video or subcode information is to be after-recorded. For example, if audio information is to be after-recorded, it is important that such audio information be recorded only in the allotted audio sections so as to avoid inadvertent erasure or "over-writing" of video information. Likewise, if video information is to be after-recorded, it is important that the beginning and end of the video signal area be defined accurately so that the after-recorded video information is recorded substantially only in the video area and does not erase previously recorded audio or subcode information. Likewise, if subcode data is to be after-recorded, it is important that the subcode area be defined accurately so that subcode data is recorded substantially only in that area.
Since ATF areas are recorded in preceding and following relation with respect to information areas (it will be understood that the term "information area" is intended to refer to one or more, or even all, of the audio, video and subcode areas), it had been thought that, in an after-recording mode, the pilot signal normally recorded in the ATF area can be detected and used to define the appropriate after-recording area. However, the pilot signal typically is nothing more than a burst of pilot frequency. If that burst is detected at the beginning of the ATF area and used as a reference from which the after-recording area is established, it is expected that the after-recording area will properly begin at the very beginning of the information area. But, if the pilot burst is not detected until the middle or even the end of the ATF area, then the beginning of the after-recording area may be somewhat delayed. This delay often is quite variable and unpredictable. Consequently, the after-recording area may begin too late, thus leaving previously recorded information which should have been erased (or overwritten); and the after-recording area may extend into a section of the track which should not have been erased. Thus, by relying upon the accurate detection of a pilot signal, the precise definition or establishing of the after-recording area generally cannot be carried out with a high degree of accuracy. Hence, desired signals which should not have been erased by after-recording may, in fact, be over-written. This problem is exacerbated by the fact that the frequency of the pilot signal normally recorded in the ATF area is quite low, which means that the pilot signal might not be accurately detected until a substantial portion of the ATF area has been scanned.

Recording and/or reproducing apparatus with means for establishing an after-recording area


A thermal design and method of operation of a rotary internal combustion engine having at least one housing, a rotor rotating within the housing, and a mechanism for combusting mixture of fuel air and steam supplied into the housing to drive the rotor, in which the temperature of the inner walls of the combustion region which are in contact with combusting gases attains 700xc2x0 C., and in which the temperature of the combusting gases does not exceeds 1800xc2x0 C. The thermal design includes: lining of the surface of the combustion zone with heat resistive materials such as a refractory metal; the use of material with low heat conductivity such as iron for the construction of the body of the engine in order to minimize heat loses by heat transfer to ambient; and the effective cooling of the body of the engine with boiling heat transfer by water which is circulated in cooling channels passing throughout the engines structure. Methods of operation of the engine include the feedback of steam, which is produced in the cooling channels into the combustion region where it is mixed with the fuel and thus lowers the temperature of the combusting gases while leaving the power of the engine intact, and the use of the hot gases of burnt fuel to ignite a fresh compressed mixture of fuel air and steam.

The present invention relates to internal combustion engines and, more particularly, to an internal combustion engine that is significantly more efficient than those known heretofore.
Internal combustion piston engines have been familiar and ubiquitous since the days of Otto and Diesel. These engines suffer from several widely recognized deficiencies. One is that their thermal efficiencies are far less than their theoretical efficiencies according to the second law of thermodynamics. Up to 30% of the heat released by fuel combustion is absorbed by the engine cooling systems. Another 30% is devoted to engine operation, including compressing air or an air-fuel mixture in the cylinders of these engines. From 5% to 20% of the available energy may be wasted because of incomplete combustion of hydrocarbon fuels. The net result is that these engines generally have overall efficiencies between 32% and 42%.
Another deficiency of these engines is that their exhausts tend to contain toxic substances: carbon particles and carcinogenic hydrocarbons because of incomplete combustion, and nitrogen oxides formed at the high (1800xc2x0 C. to 2000xc2x0 C.) combustion temperatures that characterize these engines. A third is that they provide power by transforming the reciprocating motion of their pistons to the rotary motion of their crankshafts. When the fuel-air mixture in a cylinder of an internal combustion engine explodes, the piston is at or near top dead center. At this position, the moment arm, across which the rod connecting the piston to the crankshaft transfers force to the crankshaft, is close to zero. Therefore, the piston exerts minimal torque on the crankshaft. As the piston moves down from top dead center, the moment arm through which the piston transfers force increases, but in the meantime the combustion gases expand somewhat, losing some of their propulsive force, so that the maximum torque exerted on the crankshaft is less than the maximum torque that could be exerted if the force of the piston could always be transferred to the crankshaft at maximum moment arm. Several attempts have been made to address some of these deficiencies.
Ferrenberg et al. (U.S. Pat. No. 4,928,658) use a heat exchanger to preheat the input fuel and air of an internal combustion engine with some of the heat of the exhaust gases. Loth et al. (U.S. Pat. No. 5,239,959) ignite the fuel-air mixture in a separate combustion chamber before introducing the burning mixture to the cylinder, in order to attain more complete combustion and inhibit the formation of nitrogen oxides.
Forster (U.S. Pat. No. 5,002,481) burns a mixture of fuel, air and steam. This mixture burns at a relatively low temperature of about 1400xc2x0 C., and nitrogen oxides are not formed. Gunnerman (U.S. Pat. No. 5,156,114 and in RE35,257) burns a mixture of hydrocarbon fuel and water, but requires a hydrogen-forming catalyst to achieve the same power with his mixture as with ordinary gasoline. Each of these prior art patents addresses only one of the defects of reciprocating internal combustion engines. None addresses the problem in its totality. U.S. Pat. No. 5,797,366, which is incorporated by reference for all purposes as if fully set forth herein, and co-pending U.S. patent application Ser. No. 09/069,545, describe an engine that further addresses the outstanding deficiencies of existing internal combustion engines. Firstly, in this engine, the axis of rotation of the power shaft of the engine is perpendicular to the plane of motion of the piston. The piston is connected to the power shaft of the engine, and the force of the piston always is applied to the power shaft at a constant moment arm perpendicular to that axis of rotation, so that maximum torque is imposed on the power shaft.
Secondly, in this engine, high pressure steam is extracted from the cooling system and returned to the combustion chambers, thus preventing severe heat loses and increasing thermal efficiency. Thirdly, ecologically it is a desirable engine in which a mixture of fuel, air and steam is burned in one or more combustion chambers, each combustion chamber being defined by a toroidal combustion chamber housing, a piston and a valve. The mixture is burned at a temperature of about 1800xc2x0 C. which is by about 200xc2x0 C. lower than the combustion temperature in existing internal combustion engines, thereby minimizing the formation of nitrogen oxides and reducing the warming up of the globe.
Yet, the toroidal engine of U.S. Pat. No. 5,797,366 and co-pending U.S. patent application Ser. No. 09/069,545 has a principle drawback; the volume of the combustion chamber increases as the burning mixture pushes the piston away from the valve. This increase in volume, before the mixture is entirely burned, tends to decrease the thermodynamic efficiency of this engine. The engine described in PCT Application US99/19315, which is incorporated by reference for all purposes as if fully set forth herein, and in U.S. application Ser. Nos. 09/146,362 and 09/250,239 is free from this drawback because the combustion stage there, takes place at a constant volume.
Thus, the thermodynamic efficiency of the combustion stage of the engine described in PCT application US99/19315 and in U.S. application Ser. Nos. 09/146,362 and 09/250,239 is superior to the efficiency of the corresponding engine which is described in U.S. Pat. No. 5,797,366 and co-pending U.S. patent application Ser. No 09/069,545, and therefore it represents a very efficient engine from the mechanical, and thermodynamical standpoints.
In order to construct and to operate this engine, its basic mechanical design has to be accompanied by a thermal design which will address the main point of its cooling and the prevention of heat loses during its operation.
Yet, even this engine has some thermal inefficiency which is related to its heat loses. It is known that rotary internal combustion engines have unique dynamic thermal control problems which are partly described in U.S. Pat. No. 3,964,445 to Ernest, et al. Summing up briefly: The inner surface of the rotor housing is subjected to higher temperatures and to much greater temperature extremes as compared to the inner surfaces of the cylinders of the reciprocating engines.
The uneven temperature distribution along the inside of the toroidal chamber and the need to dissipate large quantities of heat, dictate the use of a good heat conductor, consisting of aluminum alloy, as the housing material, even so, the Wankel engines which have a housing made of aluminum, and which are the only type of rotary engine which have achieved commercial success, can be cooled efficiently only because the large surface-to-volume ratio of their combustion and expansion chambers.
It appears that regulating and stabilizing the temperature of a rotary engine during operation and minimizing heat loses to surrounding are apparently two contradicting objects which their simultaneous fulfillment is yet an unsolved problem.
As a result most rotary internal combustion engines did not live to their expectations, and it is impossible to utilize their basic advantages.
I have discovered that: in the engine of PCT Application US99/19315, raising the temperature of the inner surface of the toroidal chamber in general, and of tile inner surface of the combustion chamber in particular, to 650xc2x0 C.-700xc2x0 C., optimizes the thermal efficiency of the engine, provided that the engine can be cooled effectively, without wasting the heat absorbed by the coolant. This leads to an improvement of the engine.
The present invention is the thermal design of a toroidal internal combustion engine, aimed to enable this temperature range of the inner walls of the combustion chamber, which includes the selection of the appropriate materials for its construction, and method of its stable operation.
According to the present invention there is provided an engine including: (a) at least one housing; (b) a rotor, rotating within the at least one housing, and (c), a mechanism for supplying fuel and air to the at least one housing, combustion of said fuel in said air then driving said rotation of the rotor; wherein, in at least one of said at least one housing, at least one component, selected from the group consisting of the rotor, and the at least one housing, is made of a material having a thermal conductivity no greater then that of iron.
According to the present invention there is provided an engine including, (a) at least one housing; (b) a rotor, rotating within said at least one housing, and (c) a mechanism for supplying fuel and air to the at least one housing, combustion of the fuel in the air then driving the rotation of the rotor; wherein the surface of at least one component selected from the group consisting of the rotor and, a portion of said housing that is in contact with combusting gases, is lined with a layer of heat resistive material.
According to the present invention there is provided an engine including, (a) at least one housing; (b) a rotor, rotating within the at least one housing, (c) a mechanism for supplying fuel and air to the at least one housing, combustion of said fuel the air then driving the rotation of the rotor, and (d) at least one cooling flow channel to carry aqueous cooling medium in the at least one component selected from the group consisting of the at least one housing, and the rotor, further comprising; a mechanism for leveling and regulating heat fluxes into the aqueous cooling medium, to ensure that the heat fluxes will be no greater then about 120 W/cm2.
According to the present invention there is provided a method for operating an engine having a combustion zone and a cooling flow channel wherein, an aqueous cooling medium is at least partially converted into steam while cooling hot gases in the combustion chamber of the engine, comprising the steps of: (a) burning a fuel-air-stream mixture in the combustion zone; (b) withdrawing at least some of the steam from the flowing cooling channel; and, (c) introducing a fuel-air mixture together with the withdrawn steam to the combustion zone.
According to the present invention there is provided a method for using gases of combusted fuel for generating mechanical power in an engine, comprising the steps of: (a) providing an engine having two housings, for each said housing, a rotor rotating within said housing, a mechanism for supplying fuel and air to at least one of said housings, combustion of said fuel in said air then driving rotation of said rotor; and, (b) delivering gases of said combusted fuel from said housing in which said combustion takes place to said other housing.
According to the present invention there is provided an engine, comprising: (a) two housings; (b) for each of the two housings: a rotor, rotatably mounted within each housing, the rotor and each housing defining between them a toroidal chamber, the rotor including at least one piston projecting into the toroidal chamber, each of the at least one piston including a leading face and a trailing face; and, (c) for each the housing, at least one valve, movably mounted within each housing; wherein a combustion region of substantially constant volume is bounded by the leading face of the at least one piston of a first of the two housings while the at least one piston approaches the at least one valve of the first housing, and by the trailing face of the at least one piston of a second of the housing while the at least one piston departs the at least one valve of the second housing.
The present invention follows the mechanical design of the engine described in PCT application US99/19315. Like the prior art engine of U.S. Pat. No. 5,797,366 and co-pending U.S. patent application Ser. No. 09/069,545, the engine of the present invention includes one or more housings with toroidal interiors. Within each housing rotates a rotor to which is attached one or more pistons that projects into the toroidal interior of the housing. The rotor and the housing define between them a toroidal chamber. One or more valves in the housing alternately seals the region between itself and an approaching or departing piston or moves to allow the piston to pass.
Like the prior art engine of U.S. Pat. No. 5,797,366 and co-pending U.S. patent application Ser. No. 09/069,545, the engine of the present invention includes provisions for engine cooling by water, superheated water steam that is produced in cooling flow channels which run throughout the engine body, and is partially injected as steam into the combustion chamber to increases the thermal efficiency of the engine and to lower the combustion temperature.
One difference between the engine of the present invention and the engine of U.S. Pat. No. 5,797,366 and co-pending U.S. patent application Ser. No. 09/069,545, is that in the preferred embodiment of the engine of U.S. Pat. No. 5,797,366 and co-pending U.S. patent application Ser. No. 09/069,545, separate toroidal chambers are used for compression, combustion and expansion, and combustion occurs there in a steadily increasing volume; whereas in the engine of the present invention, the valves, the pistons, the rotor, or some combination thereof, define a combustion region of approximately constant volume in which combustion takes place as the valve or valves move to accommodate the transit of the one or more pistons.
This allows the engine of the present invention to operate according to the more efficient Trinkler cycle: A mixture of compressed air, steam and fuel introduced into the combustion region by the cooperative motion of the pistons and the valves burns therein at approximately constant volume. The burning mixture then is released to an expansion region, where more fuel is injected to continue the burning and keep the expanding mixture at least initially at approximately constant pressure. The difference between the present invention and the invention in PCT application US99/19315, is that former applications dealt exclusively with the mechanical description of the engine, while the present invention discloses its thermal design and the materials which have to be used in order to enable its construction and subsequent steady state operation in optimal thermal conditions.
The heart of the invention is the design, construction and method of operation of an engine in which the temperature of the inner walls of the combustion and expansion chamber during steady state operation will stay uniformly distributed, constant with time at a value of 650xc2x0 C. to 700xc2x0 C. We refer to this situation as thermo-stabilization of the engine.
Thermo-stabilization is achieved by balancing apparently two contradicting effects; (a) increasing the temperature of the inner surface of the combustion and the expansion chambers, and (b); an effective heat removal from the body of the engine.
The increase of the temperature of the inner walls, which are in contact with the burning gases produced during the combustion, is aimed to diminish the rate of cooling of these gases by the walls and thus, contributes to efficiency by lowering pressure decrease inside the expansion chamber during the stroke.
The way by which this increase in the temperature of the interior walls of the chambers is achieved, is by the use of constructing materials with average lower heat conductivity than the heat conductivity of the constructing material of existing internal combustion engines, e.g. the use of iron alloys such as cast iron or steel instead of aluminum alloys.
Consequently, the engine loses less heat to surrounding, and has to be alternatively forced cooled by circulating water in cooling flow channels which are bored in the housing, in the rotor and in the valve. This forced cooling system has to be more efficient then the existing cooling system for internal combustion engines.
Here, an effective cooling method is provided, which is based on the physical effect known as xe2x80x9cboiling heat transferxe2x80x9d in which a liquid dissipates heat from its cooled object by absorbing heat because of its partial evaporation.
The liquid which is conducted in cooling flow channels bored in the body of the member to be cooled, may be driven by a pump or moves in its channels by other means, e.g. centrifugal forces. If the liquid is water moving in its channel at a speed of about 0.5-0.8 m/sec, its coefficient of boiling heat transfer is between 5 W/(cm2 degree C.) and 10 W/(cm2 degree C.), as taught in U.S. Pat. No. 5,977,714 to Adamovski.
The cooling by the mechanism of xe2x80x9cboiling heat transferxe2x80x9d requires uniform and controlled heat fluxes along the circumference of the cooling flow channel which is in contact with the water. It is necessary to limit the dissipated heat flux to about 120 W/cm2, otherwise the water in the hotter part of the channel will boil vigorously in the mechanism of xe2x80x9cfilm boilingxe2x80x9d and lose contact with the inside wall of the channel. To achieve this uniformity and control, the heat conductivity of the block of material in which the cooling channels run, is locally modified by insertions, which have heat conductivities different than that of the block material.
The water, which boils in the cooling flow channel, becomes a high-pressure hot steam (100 Kg/cm2 at 300xc2x0 C.), This steam is introduced into the compression chamber of the rotary engine together with fuel injection. Thus, the heat collected during cooling is not dissipated; instead, it produces some extra work because the injected steam expands as it is heated during the combustion.
The combustion mixture which includes air, hot steam and fuel vapor, does not degrade the power of the engine in comparison to the power produced by the steam less mixture, and it has the advantage, that the combustion temperature is lowered and hence, less poisonous nitrogen oxide is formed.
Accordingly, the scope of the invention also includes a protocol for injecting fuel, air, steam and even burned gases into the combustion chamber. The fuel is a fluid (liquid or gas) hydrocarbon or mixture of hydrocarbons, such as gasoline, diesel fuel, kerosene, an alcohol such as ethanol or methanol, propane, butane, and natural gas. If the flash point of the injected fuel is sufficiently low, it ignites spontaneously. Otherwise, the fuel is ignited by conventional ignition means such as a spark plug.
The disclosures in the present invention are applicable to internal combustion engines in general, and to rotary internal combustion engines in particular, thus it is the object of the present invention to provide an internal combustion engine with improved thermal efficiency.
It is another object of the present invention to provide an internal combustion engines with low heat loses.
It is another object of the present invention to provide an internal combustion engine, which is more economical on fuel than prior art engines.
It is another object of the present invention to provide an internal combustion engine, which is more reliable than prior art engines.
It is another object of the present invention to provide an internal combustion engine that has minimum impact on the environment.
It is another object of the present invention to provide an internal combustion engine, which contributes less nitrogen-oxide pollutants during its operation than prior art engines.
It is another object of the present invention to provide an internal combustion engine, which contributes less heat to the environment than prior art engines.
Other objects of the invention will become apparent upon reading the following description taken in conjunction with the accompanying drawings.

Toroidal internal combustion engine and method for its thermo-stabilization


The present invention provides a memory system interface design, which provides access to a dual width memory bus. Specifically, a subsystem and method provides for interfacing with a 32 bit or a 64 bit bus. The 32 bit bus would be used for low end products, and the 64 bit bus would be used for high end products. A memory control unit (MCU) supports both the 32 bit and 64 bit modes. Selecting a 32 bit or 64 bit memory subsystem gives a user more room to adjust system cost and performance.

1. Field of the Invention
The present invention relates generally to the field of microprocessor memory systems, and more particularly to a system that supports a dual width memory bus.
2. Discussion of Related Art
A typical computer-based processor system (or computer system) consists of three major subsystems: a main memory, one or more central processing units (CPU) and an input-output (I/O) subsystem. In a computer system, the various subsystems must have interfaces to one another. For example, the memory and CPU need to communicate, as well as the CPU and I/O devices.
This communication is typically done via a bus. The bus serves as a shared communication link between the subsystems. Two major advantages of having a bus are low cost and versatility. By defining a single interconnection scheme, new devices and subsystems can easily be added to the computer system. Moreover, peripherals may even be ported between separate computer systems that use a common bus.
One reason bus design is so difficult is that the maximum bus speed is largely limited by physical factors: the length of the bus and the number of devices (and, hence, bus loading). These physical limits prevent arbitrary bus speedup.
The objective of designing a memory subsystem is to attempt to match processor speed with the rate of information (or bandwidth) of memory at the lowest level and most reasonable cost. For main memory, we can use a wider bus called a "memory bus" to increase the memory bandwidth or to reduce the latency of memory. In the case of a memory subsystem, the memory bandwidth is the number of memory bytes that can be transferred (either fetched or stored) between the CPU and the memory per unit time. Hence, the maximum memory bus bandwidth B is equal to B=W/Tm byte/s, where W is the width of word in bytes delivered per memory cycle Tm.
Oftentimes, a variety of different size memory buses are available to help increase performance. However, designing a system that allows access to multiple external buses having different widths presents a design problem. If, for example, a system that is currently configured to accept data from the memory bus in 32 bit blocks, a 64 bit data transfer will create a predicament for the CPU and/or cache. Consequently, a system is needed that allows memory buses with different widths to be utilized without changing the overall configuration of the computer system. For a more in depth discussion of the above, see Hennessy et al., Computer Architecture a Quantitative Approach, Morgan Kaufmann Publishers (1990).

System for supporting a buffer memory wherein data is stored in multiple data widths based upon a switch interface for detecting the different bus sizes


An arrangement is described used to throttle data in a connected computer device having a device configured to transmit and receive data from a host, the device comprising, a device controller configured to interact with at least memory array and a data transfer throttling arrangement, the data transfer throttling arrangement configured to measure a bandwidth threshold for the device controller and pass data through the device controller when a bandwidth of the device controller is one of at and below a threshold.

Power management has become a critical issue in the computer industry. Power management is a critical parameter in solid state drives since these drives are integrated in laptop computers that consume low power in order to increase the battery life. Two important parameters are defined in devices that are used in laptop computers, namely peak power usage by a connected component and average power.
Referring to FIG. 1, a graph of power usage over time of a device connected to a laptop computer is shown. Both the device and the laptop computer are conventional devices. As can be seen in the graph of power usage over time, an average power for a device connected to a laptop computer may be 2 Watts, while the peak power may be five times that amount, 10 Watts. Durations for the power consumption may also differ as also provided in FIG. 1. Typically, the time for peak power may extend for a short interval of one (1) second, while the average power for a device connected to a laptop computer may extend for greater than six (6) seconds. Power systems, therefore must provide varying power levels at varying time limits.
During operation, conventional devices have significant challenges with power consumption. In some cases, both a low speed computer interface and high speed computer interface are used and are incorporated in the same unit to be connected to a computer. Conventional systems that use a low speed computer interface and a high speed computer interface do not adequately control the power consumption properties of an arrangement that must be connected to a computer.
There is a need to provide a memory arrangement that can be connected to a computer, such as a laptop computer, that manages power consumption requirements.
There is a further need to provide a memory arrangement that can be easily connected to a computer that also has a high speed and low speed interface.
There is a further need to provide an memory arrangement that has a high speed and low speed interface that work together to optimize the flow of data to and from a host machine, such as a computer, to a connected device, such as a memory arrangement.
There is a further need to provide a memory arrangement that interfaces with a host computer that maximizes the operation of the memory arrangement which maintaining control of power requirements. There is also a need to provide a memory arrangement that may shape the power used by the memory arrangement so that a more efficient power usage is performed.

Power shaping and peak power reduction by data transfer throttling


A method for marking a semiconductor wafer 302 includes the steps of: providing a reticle 300 including liquid crystal pixels; positioning the semiconductor wafer in proximity to the reticle; directing radiation through a first plurality of the pixels onto a first location on the wafer; changing the relative positions of the semiconductor wafer and the reticle; and directing radiation through a second plurality of the pixels onto a second location on the wafer. The first plurality of pixels can be used to form a first mark and the second plurality of pixels can be used to form a second mark, wherein the second mark is different from the first mark. The marks can be made of a pattern of dots in order to save space. The pixels can be selected to form certain marks by using a computer 304 to turn on or off a transistor that may be associated with each pixel. Also described is a system for marking a semiconductor wafer. The system includes a wafer mount 301; a radiation source 306 in proximity to the wafer mount; a reticle 300 which includes liquid crystal pixels and that is positionable between the radiation source and the wafer mount; and a mechanism 303 for changing the relative positions of the reticle and the wafer mount. The radiation source can be non-coherent far-ultraviolet, near-ultraviolet, or visible sources, or a laser.

This invention is in the field of integrated circuits and in the field of marking integrated circuits for tracking purposes.
There is a need in the semiconductor industry for a reliable method of marking integrated circuit die ("chips") to facilitate tracking of these devices after they are manufactured and sent to customers worldwide. For example, in instances where a customer detects an imperfection in a particular chip, or desires more chips that behave like a particular chip, the ability to ascertain the provenance of the chip and the conditions under which it was fabricated can constitute a competitive advantage for an integrated circuit manufacturer. Whereas, in the past, the marking of the chips on a particular wafer has been possible, it has been possible to only mark chips with a gross level of identification, since all of the chips on a wafer in a given lot of wafers of a particular type of integrated circuit are made with the same set of reticles or masks. Since, for a given level in the fabrication of the chip, that same reticle is stepped across the entire wafer, it has not been possible to give each individual chip its own identifying mark during the wafer fabrication process, where it is most cost efficient to do so. Thus, a problem with a particular chip can only also be traced back as far as the level of identification on the chip allows.
In addition, the continuing demand for smaller chips has put space at a premium and has complicated the task of marking. Typically, all of the wafers in a lot bear the same mark, indicating the device design type, year and month of manufacture, and perhaps the location of manufacture. The identifying mark is also typically large enough to be visually identified with a microscope, for example. As the demand for smaller chips is increasing, the space available for placing such information on each chip has diminished accordingly. For example, for a 1.5 mm×1.5 mm device package, it is not unusual to have space sufficient on the chip for only about five identifying characters, three for the device type and two for the year and month of manufacture, for example. A defect in such a device can only be traced to the year and month in which the chip was made. In many cases, a manufacturer may have fabrication facilities all over the world and many thousands of wafers produced by each of those facilities a month, so much more detailed marking of such small chips is needed. It is clear that there is a need in the industry for better ways of marking integrated circuit die.


An operator's section construction for a work vehicle includes an operating device mounted on a vehicle body, a driver's seat mounted on the operating deck, a first operating device provided on one of right and left sides of the operating deck and a second operating device provided on the other of the right and left sides of the operating deck. On an upper face of the operating deck, there are formed a mounting portion for the driver's seat, a mounting portion for the first operating device, and a mounting portion for the second operating device; the driver's seat, the first operating device and the second operating devices being mounted on the respective mounting portions independently of each other.

With this type of conventional technique, a traveling machine includes an excavator device attached to a front portion of a swiveling deck mounted to be swivellable about a vertical axis, an operating deck fixed on the swiveling deck, a driver's seat mounted on the operating deck, an engine mounted to a rear portion of the swiveling deck, an operational oil tank mounted to a right side portion of the swiveling deck, and right and left controlling devices disposed on the right and left sides of the driver's seat. The right and left controlling devices include a main control valve operated by a control lever to allow such operations as a swiveling operation of the swivel deck, operations of a boom, an arm and a bucket of the excavator device, etc. (See JP2002-149255A).

Operators section construction for work vehicle


Disclosed herein are systems, methods and devices system for identifying a misbehaving computerized device. In some implementations, the system includes a processor to perform operations including receiving, by the system, a report about a computerized device, wherein the report comprises a pseudonym certificate from the computerized device, and wherein the pseudonym certificate comprises a linkage value. The operations also include transmitting, by the system and to a cloaking authority device, a request for a cloak index, wherein the request for the cloak index comprises the linkage value from the pseudonym certificate from the computerized device. The operations also include receiving, by the system, the cloak index from the cloaking authority device, and determining, by the system and using the cloak index, that the computerized device is the misbehaving computerized device.

As computers have become ever more miniaturized and commoditized, manufacturers are producing more and more varied devices that include one or more embedded computer or processor. The computer in a computerized device can control the device's operation; collect, store, and share data; communicate with other computers and other computerized devices; and update its own software, among other things.
The Internet of things (IoT) is the network of computerized physical devices that have embedded processor(s), electronics, software, data, sensors, actuators, and/or network connectivity, which enable these devices to connect and exchange data via digital networks, including the Internet, cellular networks, and other wireless networks. Typically, each "thing" is uniquely identifiable through its embedded computing system, and is able to communicate and inter-operate within the existing Internet infrastructure.
"Things", in the loT sense, can refer to a wide variety of computerized devices, such as consumer appliances, enterprise devices used in business and corporate settings, manufacturing machines, farming equipment, energy-consuming devices in homes and buildings (switches, power outlets, bulbs, televisions, etc.), medical and healthcare devices, infrastructure management devices, robots, drones, and transportation-related devices and vehicles, among many others.
For example, most, if not all, modern vehicles (e.g., cars, trucks, aircraft, trains, watercraft, and the like) contain several embedded processors or embedded computers in their subsystems, and are computer-controlled in at least some aspects. Similarly, a growing number of modern transportation infrastructure devices (e.g., traffic lights, traffic cameras, traffic sensors, bridge monitors, bridge control systems, and the like) contain at least one, and often many, embedded processors or embedded computer systems, and are computer-controlled in at least some aspects. These computer-controlled elements of the transportation network typically communicate with each other, passing various types of information back and forth, and they may react, respond, change their operation, or otherwise depend upon the information received/sent from/to other vehicles in Vehicle-to-Vehicle (V2V; also known as C2C, Car-to-Car) communications and/or from/to infrastructure elements in Vehicle-to-Infrastructure (V2I, also known as C2I, Car-to-Infrastructure) communications for safe, correct, efficient, and reliable operation. These elements, communications, actions, and interactions may be collectively referred to as a V2X environment, where X represents any device, including another vehicle.
The computers in computerized devices operate according to their software and/or firmware and data in conjunction with the operation of their hardware, (such as processors, memory, busses, etc.), and the input data that the computerized devices use, (such as data from other devices; for example, location data (e.g., from a GPS device), speed data, braking data, time data, temperature data, etc.). Problems with software, data, hardware, or inputs can cause a computerized device to operate in an aberrant or anomalous manner, such that the device behaves in a way that deviates from its standard, normal, or expected behavior. Such problems may be unintentional, such as a problem caused by the failure of a hardware device or an unintentional bug in software; or intentional, such as a problem caused by unauthorized persons or organizations (e.g., hackers) replacing or changing the software in a computerized device.
Accordingly, it is desirable to provide improved systems, methods and techniques for securely identifying computerized devices that are behaving in an anomalous or aberrant manner, for example, in order to reduce or stop the effects of their misbehavior on other devices and their environment.