The present invention describes a process utilized for the remediation of soils and petroleum drilling wastes contaminated with hydrocarbons, which consists in stabilization by application and mixing in specific proportions of calcium oxides and organic conditioners. It is possible to treat materials with concentrations of at least seven percent (dry weight) of hydrocarbons petroleum hydrocarbons (TPH) and reduce the concentration to 1-1.5% TPH. Furthermore, residual toxicity is completely eliminated in the treated material, vegetative growth is stimulated, the treated material does not present significant concentrations of hydrocarbons leachates and it passes all criteria to be considered not a dangerous waste (CRETI or TCLP).

In the Gulf of Mexico Region, a grand industry has been generated for the production and refining of hydrocarbons. Related to this industry are the production of oily wastes from exploration and production, typically containing residual diesel, which is used in the formulation of drilling muds.
On the other hand, this region has suffered many spills due to corroded piping. There are some oil fields older then fifty years old. Many of these are in marsh areas or in mangroves o other swamps. Since pipelines were installed to connect individual wells to separation batteries, and from there to refineries and petrochemical plants, the anaerobic corrosion was not considered to be important, and as a result, many pipelines are corroded and spilling oil. Lately, Petroleos Mexicanos has been installing pipeline with protection, or made of non-corrodible materials to take care of this problem. The kinds of soils more commonly affected are from low lying areas, this kind of soil has high concentrations of organic material and clay. Some contaminated sites are found in the recent coastal plain, in sandy soil. Although the number of these last sites is less, it is of greater concern due to the probable impact on aquifers, due to their high permeability.
In addition to the chronic spills caused by corrosion in the production fields, Petroleos Mexicanos in the refining area manages approximately 13 thousand kilometers of pipelines in the country which frequently are affected by spills due to clandestine robberies of oil from the pipelines, especially between Minatitlan, Veracruz and Puebla State.
There also exist dumps of semisolid oily waste in the region. Due to the climatic condition in the Gulf of Mexico Region (above all high precipitation), industrial landfills are not permitted, as in other parts of the republic, such as Mina N. L. (see Bremer, 1995 and the Official Mexican Norm NOM-CRP004-ECOL/1993). Due to this limitation, as well as the generation of large quantities of oily waste resulting from drilling muds, marshy vegetation and soils contaminated by spills, muds from systems for the treatment of waste water from petrochemical plants and refineries, the petroleum districts previously used oil well confinement pit. Normally, the used the main waste pit in an oil well that never produced petroleum, or an old well that does not produce and is capped. These pits were never designed to receive the quantity of waste put in them and were not constructed of impermeable materials. Many times all of the space in the pit was used up but waste was still deposited at the site, especially in the drilling platform, beside the pit. This inadequate management of wastes frequently resulted in run off and infiltrations of hydrocarbons in the nearby environment.
Besides the above mentioned sources, there exist effluents from petrochemical plants and refineries. Many of these have old API (American Petroleum Institute) type water treatment systems which separate less dense and denser fractions by gravity. Generally, they were not adequate to control the quantity of oil in the flow, resulting in the contamination of nearby areas, commonly marshes, canals, rivers and lagoons. These waters regularly contain salts from the petroleum deposit, in addition to hydrocarbons, which can adversely affect the marshes and water bodies.
In this region it is difficult to determine exactly the extension of land which is contaminated, due to political and economic interests in the region, exaggeration and the confusion which is to be found. In recent years the theme of "contamination" has been politicized and there exists an "industry of claims". Just in Tabasco State, Beltran (1993) reports that there are approximately 7,200 hectares affected, of these more than 90% are in marshes or floodable areas. More recently, Petroleos Mexicanos, with help from the Mexican Petroleum Institute has identified approximately 300 hectares contaminated in the state and 178 pits which are contaminated with oily wastes are projected to be restored (LaJous, 1997). Much of this difference is due to the definition of "contaminated areas", and the criteria used to determine it.
The levels of contamination vary much according to the sources of hydrocarbons and the age of the petroleum installations. In the extreme western part of Tabasco State, where the majority of installations are older, some around 50 years old, it is common to have hydrocarbon spills coming from corroded pipelines. In general, the extension of a spill is a stain of approximately 5 hectares, in which the concentration of hydrocarbons can reach up to 30% (Rodriguez, 1997).
En the more recent areas of petroleum activity, for example in the north and northeast of Tabasco State, the techniques used to protect the environment were bettered over the years. In this zone, the pipelines are newer, and many have a covering to reduce the corrosion. Due to this, the spills caused by corrosion of pipelines are much less. Additionally, the design, construction, and management of waste pits were improved and much fewer problems of infiltrations or runoff are to be found (Vinalay, 1998). In this part of the state it is rare to encounter zones with obvious stains of oil. Near the petroleum wells, the extension of hydrocarbons is normally less than one hectare and with concentrations less than 1000 ppm TPH (Total Petroleum Hydrocarbons, Dominguez, 1998).
It is worth mentioning that the new policy of Petroleos Mexicans is not to leave oily wastes in pits during the drilling of wells. When the phase of drilling in which inverse muds are require takes place, these are recycled in the most possible way; the spent muds and contaminated cuttings are deposited in a concrete pit with a laminate roof or in containers. Periodically, these wastes are recollected for treatment in a central site among various wells. However, there are many areas which have been contaminated by historical practices of the last century.
Besides the above mentioned activities related to exploration, production and refining of petroleum, there also exist various sites in the Mexican republic which are contaminated due to inadequate use of the products derived from petroleum. Among these include spills of fuels and lubricants in the great industrial areas dedicated to the manufacture of goods, such as can be found in Mexico City, Federal District, in Mexico State, Monterrey, N. L., Saltillo, Coahuila, Guadalajara, and various areas of the Bajio region, among others.
Furthermore, spills in thermoelectric plants in the country, bus stations and repair shops, airports and marine ports should be considered, due to the use of large volumes of lubricants and fuels.
It is important to look for appropriate technological solutions to the characteristic conditions of the country, in climatic, social and economical terms. In this context, it should be mentioned the value of developing remediation technologies as alternatives for the recovery of impacted ecosystems and agroecosystems, and to avoid problems of health risk. However, today almost all of the technologies used for remediation of contaminated soil or treatment of drilling cuttings are from abroad, which requires the importation of know-how, materials, reagents and sometimes machinery and personnel. This situation has consequences such as in the increase in costs, the creation of dependency from abroad, and many times these technologies are not implemented adequately. Various times it has been necessary to send remediation projects out to bid repeatedly due to the incompletion of contractors or due to the lack of service providers which are incompetent to realize the solicited task adequately, causing delays and increasing the administrative costs related to the remediation. On the other hand, it is common the bad management of imported technologies results in infertility in treated soils. For these reasons the effectiveness is frequently reduced, and the remediation contractors have great difficulty in meeting the established goals of their client (Petroleos Mexicanos) and the environmental authorities.
Below a description of the remediation technologies most used in the region is presented:
Confinement
This consists of the excavation of contaminated materials and the placement of these materials in a site prepared for their final deposition, said site having a series of engineering controls such as liners, leachate ponds, monitoring wells, etc., which assure that the contaminated material will never be in contact with biological receptors. It is important to select an adequate site for the location of this kind of remediation, one having low precipitation, with geological horizons that reduce possible migration, a depth to aquifer of hundreds of meters, without seismic activity and out of the paths of hurricanes and tropical storms. These conditions exist in few areas of the country, being one of the principal limitations of this technology. Currently, their is only one site (in Mina, Nuevo Leon) of this type at the national level, which means that contaminated materials must be transported large distances, practically doubling the cost.
Reuse—Recycling
In these kinds of technologies the contaminated material is neutralized and reutilized for another purpose, typically for construction. Drilling cuttings have been incorporated into raw materials on the fabrication of cement and bricks; in the process the hydrocarbons are incinerated. The principal limitation of this technology is the local market for these materials, which reduce the quantity of materials that a cement or brick plant can receive and treat. Another application of this technology has been the production of structural base for rural roads or parking areas, in Poza Rica and the Lazaro Cardenas Refinery (Minatitlan, Veracruz), using soil of other materials which are extremely contaminated with oil as raw material. This technology is appropriate only for very contaminated materials, which contain approximately 30% or more of hydrocarbons, and where the hydrocarbons are of a very viscous type. It is not applicable to the majority of spills or drilling cuttings.
Incineration
In the incineration of materials to be treated, they go by a conveyor to an oven, commonly rotary, or "rotary kiln", in which they are heated to temperatures greater than 800° C. to completely burn all of the organic contaminants. The residue is the mineral fraction of the soil and some ashes; all of the organic substances are burned. This is effective to treat soil with any kind of organic contaminant including viscous crude oil, PBCS, dioxins, chlorophenols, and many pesticides. However, the cost is high. Abroad it is approximately $100-$500 USD per ton of treated soil. The resulting material is not fertile. For use in crops, pasture, or nature refuge, it is necessary to add mulches and to realize a recovery of the soil structure which increases the technology cost even more. There has been only one remediation project with this technology in the southern part of the country (Mexico), in the Cinco Presidentes Oil Field (Tabasco). During the project there were problems with the high humidity content and organic matter in the soil to be treated, and they had to re-run several batches of material through the oven more than once, increasing costs. Furthermore, there were problems in maintaining the equipment functioning due to local labor customs, and the lack of parts and trained personnel. Due to this experience this technology was discarded as a remediation technology by PEMEX Exploration and Production, South Region.
Thermal Description
In this technology the materials to be treated go by a conveyor to an oven where they are heated, but only to volatilization temperature, not incineration. The vapors are collected in an extraction hood and are incinerated in a smaller oven at a high temperature, or they are treated by other processes such as condensation, or reuse, among others. The mass to be incinerated is reduced, this being the vapors instead of all of the material, reducing energy costs. The process is less costly than incineration and completes with other technologies in terms of costs for small volumes. It is effective for volatile and semi-volitile organic contaminants: drilling cuttings, soil contaminated with gasoline, diesel, light and medium crude petroleum. The treated material still conserves some fertility; the majority of the soil organic material is not burned. None-the-less, this technology is complicated in the Gulf of Mexico region due to the high humidity in the soil, which implies a higher energy cost to be heated. On the other hand, the equipment is imported, and for this reason represents problems with logistics to obtain parts and trained personnel for its implementation, all of which increase operation costs. Likewise, there are not mobile equipment in the region, making it necessary to transport contaminated materials to a central treatment centre and thereby increasing costs.
Chemical Oxidation
This technology depends on the partial oxidation of the hydrocarbons and mineral fraction using non-specific oxidants. In some methods part of the hydrocarbons are mineralized. In others the oxidized minerals and hydrocarbons are united to stabilize the material. The reagent dosification, pH, homogenization, and curing of the mix are managed. Typically, this results in a reduction in the hydrocarbon concentration of only 60-70%, being inadequate for the treatment of materials with high concentrations. Commonly, the reagents added are toxic and cause problems in the soil, including infertility. The majority of chemical oxidation technologies depend on the importation of reagents making the remediation more costly.
Chemical Stabilization
In the chemical stabilization, chemical reagents are added to the contaminated material which result in pozzolanic reactions in said material, sometimes adding other kinds of reagents which work to improve the fixation, such as polymers, ashes, silica, hydrophobilizing agents, etc. The use of chemical substances, especially calcium oxides which promote pozzolanic reactions, is also used in the construction industry to firm up bland materials, permitting the construction of roads, buildings, etc. on such materials. Internationally, this technology has been used for the stabilization of contaminated materials, but in general in low concentrations. In Mexico, this is not currently being used for remediation of waste treatment.
Microencapsulation
In the microencapsulation the different phases of free oil, water and sediment are separated with gravity separators, similar to API separators. The recovered sediment is mixed in liquid form with a cationic surfactant, forming micelles of surfactant and the organic contaminant. A solution of silicates (or carbonates) is applied that precipitate on the cationic nuclei of the micelles forming small grains of silicates with the consistency of sand. This does not work well for organic soils but it does work for mineral soils with less than 10% of total organics. The material can have problems at temperatures above 40° C. and this aspect needs to be watched. The homogenization and dosification are very important. It is effective for all kinds of organic contaminants and even materials slightly contaminated with metals. The reagents used are mostly imported. In the southern part of the country there has been difficulty implementing this technology due to the fact that it requires close attention to detail for its application. Generally, the regional population is not detail oriented and there have been problems in materials mixing, frequently having to treat a batch of material more than once to decontaminate it, reducing efficiency in the process, and increasing costs. This technology has been abandoned by PEMEX Exploration and Production, South Region due to the problems, but it still is being used in a limited way by the Marine Zone for the treatment of drilling cuttings.
Bioremediation
Bioremediation uses native and introduced microorganisms that consume organic contaminants, reducing their concentration. Conditions such as humidity, nutrition, aeration, and mixing are managed to optimize microbial activity. This technology is relatively economical but it is slow, requiring a constant mixing of the material in treatment to maintain aerobic conditions. Furthermore, it requires large area for treatment. None-the-less, due to the relatively low cost in comparison with other physical-chemical remediation technologies, it is one of the most used technologies in the southern part of the country.
Biochemical Degradation
Biochemical degradation treatment consists of the application and mixture of different reagents in waste pits to promote a series of chemical and biological reactions. Commonly, at the outset, surfactants are added to the drilling cuttings to mobilize hydrocarbons and make them more available for subsequent treatment. If a significant quantity of free phase oil is produced, this is collected on the surface. Afterward, an oxidant such as hydrogen peroxide is applied to partially oxidize the hydrocarbons. Lastly, inorganic nutrients and "organic catalyzers", such as manure are mixed into the material to promote biodegradation. All of these operations are carried out using excavators, or dredges, mixing the material sequentially in the same waste pit in which the material (such as drilling cuttings or other wastes) was originally stored. This method has an advantage over other methods because it is not necessary to construct a treatment cell, thereby reducing costs, area, and simplifying the logistics of remediation projects. Nevertheless, there are potential problems with this method due to the semisolid conditions which are created in the waste pit, and because the equipment used is not adequate to provide sufficiently aerobic conditions for the oleophilic microorganisms employed in the biological treatment phase. Because of this, the biodegradation rates are much reduced, prolonging treatment times, and increasing costs due to equipment rental, fuel, and labor. On the other hand, the waste pits in which these materials are encountered, are not impermeable, and the constant mix of materials in them, as well as the application of surfactants con provoke the mobilization and infiltration of hydrocarbons, contaminating aquifers, many of which are only a few meters below the soil surface in the southern region (from <1 m up to 5 m, in general). The other inconvenience of the technology, as with bioremediation, is the necessity to constantly mix the material during the biological treatment phase, which increases costs (machinery, fuel, labor).
Composting
It is a non-specific oxidation of vegetable tissues and organic contaminants carried out by fungi and actinomycetes. Concurrently, a spontaneous chemical polymerization of the subproducts takes place resulting in the formation of humus, a more stable form with low toxicity (humification). To implement this kind of treatment, organic conditioners are added and chemical and physical conditions (humidity, temperature, aeration, nutrition) are controlled. The application of this technology is limited due to the requirement of large quantities of organic amendments in the mixture (typically 70%) and logistic problems in obtaining the large volumes necessary. Furthermore, by adding such large volumes of material, the project costs are increased due to the need to also increase the amounts of reagents, machinery rental, fuel and labor. It has only been used in tow sites in the southern part of the county, in the Sanchez Magallanes Oil Filed, Tabasco, and in the Santa Alejandrina marsh, behind the Lazaro Cardenas Refinery in Minatitlan, Veracruz.
Phytoremediation
Phytoremediation is the use of plants to immobilize contaminants in the soil and subsequently detoxify the material by mineralization and humification processes in which plant roots as well as rhizosphere associated microbes participate. It is very slow and today it is not used in Mexico, however, there are preliminary experiments in tropical environments using above all grasses for the cleanup of soils contaminated with hydrocarbons (Zavala et al. 2002, Hernandez and Pager 2003). It does not work for contamination below the root zone, for example in a waste pit, and for certain kinds of contaminants there may be concern of contaminant migration to adjacent lands before the remediation of the site is accomplished.
Discussion on Process Function
Various physical, chemical and biological processes are involved in the functioning of this technology. During the initial treatment with calcium oxides, it is probable that a pozzolanic reaction takes place between these and clay silicates in the soil or drilling cuttings with the subsequent formation of calcium silicates, calcium aluminates and hydrated calcium aluminum silicates (LaGrega et al. 1996). This process has been used to stabilize clayey soils for use as construction material (McKennon et al. 1994), as well as for macroencapsulation of soils contaminated with hydrocarbons or other oily compounds, sometimes in combination with other additives (such as fly ash, silica, cement, polymers or hydrophobilizing agents, Shimoda et al. 1989; Masuda et al. 2001; Kao et al. 2000; Ritter 1995; Weitzman and Hamel 1989; DuPont 1986; Al-Tabbaa and Evans 2003).
Among patents of special interest are: McKennon et al. (1994), for solidification of clayey soil for construction purposes; Shimoda et al. (1989), which employs quicklime and/or dolomite in combination with a polymer (PFTE) for the stabilization of hydrocarbon contaminated soil, Masuda et al. (2001), which uses calcium oxides and derivatives thereof for the stabilization of soil contaminated with dioxins and PCBs, Kao et al. (2000), which combines a mixture of additives such as calcium oxides and a heating process in ovens which immobilizes organic and inorganic contaminants, and Ritter (1995), which adds hydrophobilizing agents with lime to render waste substances inoffensive. Nonethe-less, these methods only stabilize soil with relatively low concentrations of organic contaminants and result in only partial treatment. In none of these patents is the use of calcium oxides in combination with organic conditioners contemplated for the stabilization of materials contaminated with hydrocarbons or oily contaminants.
During the next phase of the treatment, when organic amendments are added, absorption is probably the principal process involved, at least initially. It has been shown that absorption of organic contaminants is soil is primarily due to the soil organic content (Chiou et al. 1979), especially the humic substances therein (Bogan et al. 2003), and several organic materials, mostly of vegetable origin have been used as sorbents for the treatment of waters and waste waters (Perez et al. 2002; Choi 1996; Varghese and Cleveland 1998; Deschamps et al. 2002). Among the patents of interest in this context, there is Perez et al. (2002), in which the use of sugar cane bagasse is mentioned for the treatment of petroleum contaminated water. Studies have also suggested that the type of humic materials in soil affect the sorption of these compounds (see Gauthier, 1987, for example) and have proposed the addition of refined humic substrates for remediation of xenobiotic contaminated soils (Fukushima et al. 2002).
Following the initial sorption of the hydrocarbons to the organic materials added, further biological and chemical processes are probably involved in the remediation. Some of the more available hydrocarbons are likely mineralized by oleophilic microorganisms, these kinds of hydrocarbons being readily biodegraded (Atlas 1986; Xie and Barcelona 2003). However, it is probable that a considerable portion of the hydrocarbons are sequestered by humification reactions thereby reducing the availability in the soil and the relative toxicity (Alexander 1995; Kelsey and Alexander 1997; Barr and Aust 1994; Paul and Clark 1989; Bohn et al. 2001; Ehlers and Luthy 2003; Bogan and Sullivan 2003; White et al. 1999).
Various investigators and inventors have also proposed adding organic materials to contaminated soil to stimulate microbial mediated treatment, by sorption into the organic amendment and subsequent decomposition of the vegetable organic matter and organic contaminant, either by mineralization or humification reactions (Breitenbeck and Grace 1997; Valo et al. 1991; Bradley et al. 1996; Grey et al. 2000; Gill 1996; Torstensson and Castillo 1997).
Important patents in this context are: Bradley et al. (1996), which suggest the use of sugar beet pulp enriched to increase its nitrogen content, in combination with white rot fungi for the decomposition of aromatic compounds, including polycyclic aromatic hydrocarbons (PAHs) and chlorinated aromatic compounds; Valo et al. (1991), on the treatment of soil contaminated with chorophenol, using Rhodococcus and Mycobacterium, in a process in which heat is generated by composting (to increase the biodegradation rate), and in which the bacteria are immobilized on a polyurethane support; Grey et al. (2000), which uses composting for the decomposition of the xenobiotic methoxychlor; and Gill (1996), which is about inoculating cotton waste with contaminated soil, composting the mixture, mixing the composted material with contaminated soil (a ratios of 1:1 to 1:5) plus adding chemical accelerators, and maturing the mixture at ambient temperature, as well as composting of organic material used as an absorbent for contaminants. In contrast to the chemical-biological stabilization in this proposal, these researchers have used primarily composting techniques, frequently using much greater amounts of organic amendment (on the order of 30-70% organic matter, instead of 1-10% as in this patent application), in a process that is qualitatively different; or they propose the application of modified organic amendments, instead of unmodified amendments.
During the maturation phase of the process, the role of the plant rhizosphere may also be important. Plant roots assist bioremediation in the soil by a number of processes. Initially, they are important because they assimilate organic substances, such as hydrocarbons, effectively immobilizing them among the roots. Subsequently, they stimulate microbial by exuding organic compounds that act as cosubtrates for oleophilic microorganisms. Also, when the roots grow they open up the soil, increasing aeration and improving drainage. Many of these processes also stimulate microorganisms that act in the humification of organic contaminants. For example, many rooty materials, especially lignin containing substances, can serve as food for actinomycetes and fungi, the principal microbes involved in the production of soil humus. Additionally, some plants have enzymes which initiate the breakdown of some hydrocarbons, especially the aromatic fraction (Zavala et al. 2002; Adams and Castillo 2004; Adams and Castillo 2000; Schnoor et al. 1995; Carman 1997; Carman et al. 1997; Drake 1997, Drake 1997a, Hernandez and Pager 2003). After a few months, it is common to observe a vigorous herbaceous growth, being an important aspect of this method, which demonstrates not only the detoxification of soil and drilling cuttings, but also improvements in the soil productivity as well.

Chemical-biological stabilization process for repairing soils and cuttings contaminated with oils and petroleum derivatives


A display device able to raise a light resistance of pixel transistors without depending upon a light shielding structure and a method of production of same, wherein an average crystal grain size of a polycrystalline silicon film 111 forming an active layer of the pixel transistors is controlled to be relatively small so as to suppress a photo-leakage current. The smaller the crystal grain size, the larger the included crystal defects. Carriers excited by light irradiation are smoothly captured by a defect level, and an increase of a photo-leakage current is suppressed. On the other hand, the average crystal grain size of the polycrystalline silicon film 111 constituting the peripheral transistors is controlled so as to become relatively large. The larger the crystal grain size, the larger the mobility of the carriers, and the higher the drivability of the peripheral transistors. This is because a higher speed operation is required for the peripheral transistors than the pixel transistors due to scanning of pixels and sampling of image signals.

FIG. 1 is a schematic perspective view showing an overall configuration of a general active matrix type display device.
As shown in FIG. 1, this display device has a flat structure comprising a display panel 10 and provided with a pair of glass substrates 11 and 12 and an electrooptic material held between them. As the electrooptic material, use is made of for example a liquid crystal 13.
The glass substrate 11 is formed with a display unit 14 and a peripheral drive unit integratedly formed. The drive unit formed on the glass substrate 11 includes a vertical drive circuit 15 and a horizontal drive circuit 16. One peripheral edge of the substrate 11 is formed with terminals 17 for external connection. The terminals 17 are connected via interconnects 18 to the vertical drive circuit 15 and the horizontal drive circuit 16.
The display unit 14 is formed with pixel circuits, each including a pixel electrode 14a and a thin film transistor (TFT) 14b driving the same, in a matrix. A gate interconnect 19G is formed for every row and a signal interconnect 19S is formed for every column of the matrix array of the pixel circuits. Each pixel circuit is arranged at an intersecting portion of two interconnects, a gate electrode of the TFT 14b is connected to a corresponding gate interconnect 19G, a drain region is connected to a corresponding pixel electrode 14a, and a source region is connected to the corresponding signal interconnect 19S. The gate interconnects 19G are connected to the vertical drive circuit 15, and the signal interconnects 19S are connected to the horizontal drive circuit 16.
On the other hand, an inner surface of the glass substrate 12 facing the glass substrate 11 is formed with not shown a counter electrode. The counter electrode is arranged facing the pixel electrodes 14a. Individual pixels are formed by the pixel electrodes 14a, the counter electrode, and the liquid crystal 13 held between the two.
A TFT 14b, as explained above, is provided corresponding to each pixel and switches each pixel ON and OFF. In the present specification, a TFT for pixel switching formed in the display unit 14 will be sometimes referred to as a "pixel transistor". On the other hand, the peripheral vertical drive circuit 15 and the horizontal drive circuit 16 also include TFTs (thin film transistors) formed by integration simultaneously parallel to the pixel transistors. Below, in this specification, the TFTs configuring the peripheral drive circuits 15 and 16 will be sometimes referred to as "peripheral transistors". Both the pixel transistors and the peripheral transistors comprise TFTs (thin film transistors) formed by stacking a polycrystalline semiconductor thin film (for example, polycrystalline silicon film) and gate electrodes via gate insulating films.
FIG. 2 is a view of an example of the configuration of a projection type display (hereinafter, referred to as a "projector") using the liquid crystal display panel 10 shown in FIG. 1.
This projector 20 has, as shown in FIG. 2, a structure comprised of a light source 21, a transmission type liquid crystal display panel 10A sandwiched by a pair of polarization plates 22 and 23, and an enlargement projection optical system 24 arranged in order along the optical axis. Here, the liquid crystal display panel 10A has the flat structure shown in FIG. 1. The light source 21 is configured by an elliptical reflection mirror 25 and a lamp 26 arranged at the center thereof and radiates high intensity illumination light to an arrangement direction of the liquid crystal display panel 10A (front side). The front surface of the light source 21 is provided with a filter 27 which absorbs the unnecessary UV-ray component and infrared ray component included in the illumination light. Further in front of this is arranged a condenser lens 28 which condenses the illumination light and makes it strike the entire surface of the light incident side of the liquid crystal display panel 10A. The enlargement projection optical system 24 is arranged on the light transmission side (front) of the liquid crystal display panel 10A and enlarges and projects an image formed by a display unit 14A of the liquid crystal display panel 10A to the front. The enlarged and projected image is formed on a screen 29.
The liquid crystal display panel 10A is divided into for example a normally white mode display unit 14A and a peripheral nondisplay unit 212. The nondisplay unit 14B includes for example a peripheral drive circuit. A pair of polarization plates 22 and 23 are arranged so that their polarization axes are orthogonal. The display unit 14A of the liquid crystal display panel 10A includes a twist oriented liquid crystal and has an optical rotatory power of 90 degrees with respect to the incident light. On the other hand, the pair of polarization plates 22 and 23 are crossed-Nicol arranged. Accordingly, linearly polarized light passing through the incident side polarization plate 22 is rotated about its polarization axis 90 degrees by the liquid crystal included in the display unit 14A and passes through the emission side polarization plate 23. Accordingly, a normally white mode display is obtained, and an enlarged and projected image is formed on the screen 29.
Projection display devices (projectors) using liquid crystal display device (LCD) in this way are rapidly spreading along with the improvement of brightness since large screen displays are easily obtained.
A projector is a device having a strong light source, controlling the image by a liquid crystal display acting as a light valve, and enlarging and projecting the image information. Strong light strikes the liquid crystal display device. Due to requests for further improvement of the screen luminance or reduction of size of projectors, the amount of incident light per unit area of the liquid crystal display device is becoming increasingly larger.
On the other hand, reflection light etc. generated inside the optical system or liquid crystal display device due to strong incident light strikes the active layers of some pixel transistors, so leakage current (hereinafter referred to as a "photo-leakage current") caused by optical excitation is caused. An increase of the photo-leakage current becomes a cause of flicker and roughness of the screen, so gives a fatal defect to the image quality.
In the past, in order to cope with the increase of the amount of incident light, a light shielding structure for shielding the pixel transistors from the top and the bottom has been formed. By arranging metallic films or silicide films in a manner covering the incident side and the emission side of the pixel transistors and optimizing the shapes and dimensions thereof, it was possible to shield the pixel transistors from light and hold or improve the image quality.
However, the light shielding structure inevitably sacrifices the numerical aperture of the pixels, so runs contrary to the requests for higher luminance of the screen. Due to the necessity of improvement of the numerical aperture of the liquid crystal display panel, it has already become difficult to sufficiently secure the light shielding area.

Display device, method of production of the same, and projection type display device


A Parallel Round-Robin Arbiter (PRRA) system and method for arbitrating among N requesters. A plurality of leaf nodes that correspond to the N requesters form a directed ring of a hierarchical decision tree, wherein the leaf nodes are operable to propagate requests from the requesters. Each leaf node is provided with status logic operable to transmit its priority status for resolution of requests by the decision tree. Logic associated with the decision tree's nodes is operable to hierarchically resolve the requests propagated by the leaf nodes, wherein each leaf node is operable to transmit its grant to one of its immediate leaf node neighbors coupled to it via the directed ring for influencing the neighboring leaf node's priority status logic.

1. Technical Field of the Invention
The present invention generally relates to arbitration techniques. More particularly, and not by way of any limitation, the present invention is directed to a Parallel Round-Robin Arbiter (PRRA) system and method for arbitrating among a plurality of requesters.
2. Description of Related Art
Arbitration is a widely used technique for resolving contention among a plurality of entities that generate simultaneous requests with respect to one or more common resources. For example, in a crossbar switch application where multiple data input queues need to be switched to a number of output ports, an arbitration scheme is typically employed for deciding how the input data is to be scheduled through a switching fabric disposed between the inputs and the outputs. As a basic building block of a scheduler, accordingly, design of a fast and fair arbiter is critical to the efficiency of the scheduling process, which is the key to the performance of a high-speed switching apparatus.
Known hardware-based arbiter designs involve a Round-Robin arbitration (RRA) methodology where the basic components of some of the designs comprise various circuit blocks such as encoders, multiplexers, barrel shifters, carry-look-ahead circuits, and the like. Although these designs may be adequate in some applications, they are nevertheless afflicted with certain deficiencies. For example, the conventional hardware RRA designs have a rather formidable AT complexity (the product of time and chip area), that is, the designs involve longer arbitration times while taking up an inordinate amount of circuitry.

Parallel round-robin arbiter system and method


The level shift device of the present invention comprises: a level shift circuit which converts a voltage level of a single input signal; and a duty correcting circuit which offsets a difference in the duty of an output signal of the level shift circuit with respect to the duty of the input signal.

1. Field of the Invention
The present invention relates to a technique for reducing an error generated in the duty ratio of an output signal with respect to the duty ratio of an input signal in a level shift device which outputs the input signal after shifting the level of the signal by a prescribed amount.
2. Description of the Related Art
FIG. 4 shows a structure of a conventional level shift device which outputs an input signal after shifting the level of the signal by a prescribed amount. This level shift device comprises a complementary signal generating circuit 10 having a low-potential power source VDD1 as a voltage source, and a level shift circuit 20 having a high-potential power source VDD2 as a voltage source. The level shift device shifts the level of input signal Sin of the low-potential power source VDD1 to the output signal of the high-potential power source VDD2. Reference numerals In1-In4 are inverters of the complementary signal generating circuit 10, QP1-QP4 are PMOS transistors of the level shift circuit 20, QN1-QN4 are NMOS transistors, LH is an R-S latch circuit, and In5, In6, and In8 are inverters.
The action of the level shift device shown in FIG. 4 will be described by referring to a timing chart shown in FIG. 5. The input signal Sin that is inputted to the level shift device is shown in (a) of FIG. 5. The input signal Sin is supplied first to the inverters In2 and In3 via the inverter In1. Further, the input signal Sin is supplied to the inverter In4 via the inverter In3. At that time, output signal S1 of the inverter In2 becomes a normal signal that has a delay τ1 with respect to the input signal as shown in (b) of FIG. 5. Meanwhile, output signal S2 of the inverter In4 becomes an inverted signal that has a delay τ2 with respect to the input signal as shown in (c) of FIG. 5.
The output signal S1 of the inverter In2 is supplied to the gate of the NMOS transistor QN2 of the level shift circuit 20. As shown in (b) of FIG. 5, when a high-level signal is supplied to the gate of the NMOS transistor QN2 at time T2, the NMOS transistor QN2 turns to an ON state. At that time, a feedback signal (inverted signal of a signal S5) from the inverter In5 is high-level, so that the NMOS transistor QN1 turns to an ON state, and the PMOS transistor QP1 turns to an OFF state. Further, since its gate is earthed, the PMOS transistor QP2 is always in an ON state. The on-resistance of the PMOS transistor QP2 is set as a higher resistance than those of the NMOS transistors QN2 and QN1. With this, when a high-level signal is supplied to the gate of the NMOS transistor QN2 at the time T2, input signal S3 to a NAND circuit N1 of the R-S latch circuit LH becomes low-level as shown in (d) of FIG. 5. Thus, the output signal S5 of the NAND circuit N1 gradually becomes high-level from the time T2 onward of (f) in FIG. 5 due to the gate capacity of the inverter In5. The output signal S5 is supplied to the inverter In5. Further, after its polarity is inverted, the output signal S5 is supplied to the gates of the PMOS transistor QP1 and the NMOS transistor QN1.
Through this, the fall edge of input signal S3 inputted to the NAND circuit N1 of the R-S latch circuit LH is fed back as the fall edge of the input to the gates of the PMOS transistor QP1 and the NMOS transistor QN1 after a delay of a prescribed amount of time. Due to the feedback signal, the PMOS transistor QP1 turns to an ON state, the NMOS transistor QN1 turns to an OFF state, and the input signal S3 to the NAND circuit N1 of the R-S latch circuit LH becomes high-level.
At that time, the other input signal S6 of the NAND circuit N1 is low-level, so that the output signal S5 of the NAND circuit N1 is maintained as high-level.
In the meantime, output signal S2 of the inverter In4 is supplied to the gate of the NMOS transistor QN4 of the level shift circuit 20. As shown in (c) of FIG. 5, when a high-level signal is supplied to the gate of the NMOS transistor QN4 at time T12, the NMOS transistor QN4 turns to an ON state. At that time, a feedback signal (inverted signal of a signal S6) from the inverter In6 is high-level, so that the NMOS transistor QN3 turns to an ON state, and the PMOS transistor QP4 turns to an OFF state. Further, since its gate is earthed, the PMOS transistor QP3 is always in an ON state. The on-resistance of the PMOS transistor QP3 is set as a higher resistance than those of the NMOS transistors QN4 and QN3. With this, when a high-level signal is supplied to the gate of the NMOS transistor QN4 at time T12, input signal S4 to a NAND circuit N2 of the R-S latch circuit LH becomes low-level as shown in (e) of FIG. 5. Thus, the output signal S6 of the NAND circuit N2 gradually becomes high-level from the time T12 onward in (g) of FIG. 5 due to the gate capacity of the inverter In6. The output signal S6 is supplied to the inverter In6. Further, after its polarity is inverted, the output signal S6 is supplied to the gates of the PMOS transistor QP4 and the NMOS transistor QN3.
That is, the fall edge of the input signal S4 inputted to the NAND circuit N2 of the R-S latch circuit LH is fed back as the fall edge of the input to the gates of the PMOS transistor QP4 and the NMOS transistor QN3 after a delay of a prescribed amount of time. Due to the feedback signal, the PMOS transistor QP4 turns to an ON state, the NMOS transistor QN3 turns to an OFF state, and the input signal S4 to the NAND circuit N2 of the R-S latch circuit LH becomes high-level. At that time, the other output signal S5 of the NAND circuit N2 is low-level, so that the output signal S6 of the NAND circuit N2 is maintained as high-level.
Therefore, when a high-level signal is supplied to the gates of the NMOS transistors QN2, QN4, the output signals S5, S6 of the NAND circuits N1, N2 turn to high-level after a delay of a prescribed amount. The NAND circuits N1 and N2 are in feedback connection where the output of each NAND circuit is fed back to the input of the other. Thus, when the output signal S5 of the NAND circuit N1 becomes high-level at time T3, the output signal S6 of the NAND circuit N2 turns to low-level gradually due to the gate capacity of the inverter In6 as shown in (g) of FIG. 5. Further, when the output signal S6 of the NAND circuit N2 becomes high-level at time T13, the output signal S5 of the NAND circuit N1 turns to low-level gradually due to the gate capacity of the inverter In5 as shown in (h) of FIG. 5.
The output signal S6 of the NAND circuit N2 is outputted after the polarity thereof being inverted by an inverter In8. Thus, level-shift output signal S8 that is the output of the inverter In8 becomes the one as shown in (h) of FIG. 5. The rise edge of the level-shift output signal S8 has a delay τP with respect to the fall edge of the input signal S3 of the NAND circuit N1 shown in (d) of FIG. 5. Meanwhile, the fall edge of the level-shift output signal S8 has a delay τR with respect to the fall edge of the input signal S4 of the NAND circuit N2 shown in (e) of FIG. 5.
Now, high-level period TH and low-level period TL of the level-shift output signal S8 will be investigated. Assuming that the duty ratio of the input signal Sin to the complementary signal generating circuit 10 is 50%, and the half wavelength is T0, the high-level period TH can be expressed asTH=T0−(τ1+τP)+(τ2+τR), and the low-level period TL can be expressed asTL=2×T0−TH.
Therefore, provided that TL>TH, the difference ΔT between the high-level period TH and the low-level period TL can be expressed asΔT=TL−TH=2{(τ1−τ2)+(τP−τR)}.
Assuming that τ2=2×τ1, and τP=2×τR, for example, it can be expressed asΔT=2(τR−τ1).
When the above is looked at on the basis of the output signal S2 of the inverter In4 from a different point of view, the fall edge (at time T13) of the level-shift output signal SB has a delay τR with respect to the rise edge (at time T12) of the output signal S2. The output signal S1 of the inverter In2 is retarded with respect to the input signal Sin by the amount of time τ1 that is generated by the inverter In2. The output signal S2 of the inverter In4 is retarded with respect to the input signals Sin by the amount of time τ1′ that is generated the inverters In3 and In4. It is considered that τ1′=τ1, assuming that the inverters In2, In3, and In4 have the same characteristics.
The rise edge (at time T4) of the level-shift output signal S8 is retarded from the rise edge (at time T2′) of the output signal S2 by the amount ofτP−τ1′=τP−τ1=2τR−τ1.
That is, the delay of the rise edge of the level-shift output signal S8 with respect to the output signal S2 is (2τR−τ1), while the delay of the fall edge of the level-shift output signal S8 with respect to the output signal S2 is τR as mentioned above. Therefore, the high-level period TH of the level-shift output signal S8 is the length that is obtained by shortening the half wavelength T0 of the input signal Sin by the amount of (2τR−τ1)−τR=τR−τ1. In the meantime, the low-level period TL of the level-shift output signal S8 is the length that is obtained by extending the half wavelength T0 of the input signal Sin by the amount of (τR−τ1). Thus, the difference ΔT between the high-level period TH and the low-level period TL becomes asΔT=(τR−τ1)×2=2(τR−τ1), which is consistent with the explanation provided above.
Since τR≠τ1, the difference ΔT between the high-level period TH and the low-level period TL does not take a value, 0. That is, there is an error generated in the duty ratio of the level-shift output signal S8 with respect to the duty ratio of the input signal Sin.
As described, with the conventional circuit, there is a fluctuation generated between the duty ratios of both signals, due to a delay difference between the two signals generated in the complementary signal generating circuit and a delay in propagation of the signals of the R-S latch circuit used in the level shift circuit.

Level shift device having reduced error in the duty ratio of the output signal


A system and method is provided for chat message prioritization that uses a combination of machine-derived and user-supplied relevancy criteria to present a filtered, annotated, and/or highlighted chat stream.

1. Technical Field
The invention relates to chat messaging. More particularly, the invention relates to automatically and manually prioritizing and highlighting chat messages on a computer display device, so that the user's attention is drawn to particular content or senders.
2. Description of the Prior Art
Chat rooms have become a common form of communication, not only for social users but also to foster rapid, networked information sharing and discussion in large private and government organizations. Chat rooms have proven particularly useful for disseminating and discussing rapidly changing real-time situations, as evidenced by their widespread adoption in military command centers.
A typical chat session consists of textual messages from a sender to one or more recipients, who view both sent and received messages in a chat client that provides a "chat room" window on a computer screen. Typically, a message is composed and then sent using a mouse click or key press, after which time it becomes visible to all users logged into the particular chat room. As new messages appear and the chat window fills with text, the oldest messages are scrolled or otherwise displaced from the window.
It is not uncommon for a command center technician or operator to have several chat windows open at a given time, each monitoring a separate session with its own participants and context. The constant flow of textual information in simultaneous multiple sessions makes it difficult and time-consuming for a single user to effectively monitor incoming messages and determine which, if any, merit further thought and response. Without reading through all chat threads in their entirety, an operator may miss relevant and important incoming messages, making it likely that important information will be missed when the operator's attention is pulled away from a specific chat room to perform some other mission function.
Limited attempts have been made to alleviate this problem by highlighting specific categories or sources of information. For example, certain chat clients, such as Chocoa (Fujitsu Corporation, Tokyo, Japan) or MITRE's Dynamic Chat Manager (MITRE Corporation, Bedford, Mass. and McLean, Va.) allow users to specify keywords that are then highlighted whenever they arise in a session. The latter program also highlights chat rooms with high activity level and messages from members of a user's social network, as derived from the frequency of interaction between pairs of users.

System and method for chat message prioritization and highlighting


A reluctance machine system is provided that comprises a reluctance machine having a stator defining a plurality of stator poles, a plurality of phase windings wound around the stator poles, and a rotor defining rotor poles and inter-pole gaps. Contoured topsticks, a dust cover and an endshields are used to reduce the amount of noise in the reluctance system. A winged terminal housing is also used to allow manipulation of the terminal housing and enhance alignment while protecting critical wires.

Reluctance machines are well known in the art. In general a reluctance machine is an electric machine in which torque is produced by the tendency of a movable part to move to a position where the inductance of an excited winding is maximized (i.e. the reluctance is minimized).
In one type of reluctance machine the phase windings are energized at a controlled frequency. This type of reluctance machine is generally referred to as a synchronous reluctance machine. In another type of reluctance machine, circuitry is provided to determine the position of the machine's rotor, and the windings of a phase are energized as a function of rotor position. This type of reluctance machine is generally referred to as a switched reluctance machine. Although the description of the current invention is in the context of a switched reluctance machine, the present invention is applicable to all forms of reluctance machines, including synchronous and switched reluctance motors and to other machines that have phase winding arrangements similar to those of switched reluctance machines.
The general theory of design and operation of switched reluctance machines is well known and discussed, for example in The Characteristics, Design and Applications of Switched Reluctance Motors and Drives, by Stephenson and Blake and presented at the PCIM '93 Conference and Exhibition at Nuremberg, Germany, Jun. 21-24, 1993.
As a switched reluctance motor (or generator) operates, magnetic flux is continuously increasing and decreasing in different parts of the machine. The changing flux results in fluctuating magnetic forces being applied to the ferromagnetic parts of the machine. These forces can produce unwanted noise and vibration. One major mechanism by which these forces can create noise is the ovalizing of the stator caused by magnetic forces normal to the air-gap. Generally, as the magnetic flux increases along a given diameter of the stator, the stator is pulled into an oval shape by the magnetic forces. As the magnetic flux decreases, the stator pulls or springs back to its undistorted shape. This ovalizing and springing back of the stator will produce audible noise and can cause unwanted vibration.
In addition to the stator distortions resulting from the phenomena described above, the fluctuating magnetic forces in the motor can distort the stator in other ways, as well as distorting the rotor and other parts of the machine system. For example, distortions of the rotor can cause resonance of the rotor end-shields. These additional distortions are another potential source of unwanted vibration and noise.
Another source of undesirable noise in reluctance machines include the "siren" effect often associated with such machine. As explained above, the rotors and stators used in most reluctance machines include salient poles. The mechanical structure resulting from the placement of such a salient pole rotor within a core defined by a salient pole stator is similar in some respects to a siren and can, in some instances, produce unwanted audible noise according to the same phenomenon taken advantage by a siren to produce noise.
A still further source of unwanted noise associated with some reluctance machines is the noise that results as air is drawn into and passed through the reluctance machine during operation. During operation of many reluctance machines, the rotation of the rotor, especially at high speeds, tends to draw air into and through the cavity within which the rotor is positioned resulting in undesirable "windage" noise.
Although the problem of unwanted acoustic noise and vibration has been recognized, known control systems for reluctance motors do not adequately solve the problem. One proposed solution has been to implement complicated control techniques to carefully control the currents applied to the phase windings of the machines. Certain of such approaches are generally discussed in C. Y. Wu and C. Pollock, "Analysis and Reduction of Vibration and Acoustic Noise in the Switched Reluctance Drive," Proceedings of the IAS '93 pp. 106-113 (1993). While these current control approaches can reduce the noise produced by a reluctance machine they are often difficult and costly to implement. Moreover, these types of reduced-noise current switching schemes constitute only one possible form of noise reduction and do not necessarily remove all of the sources of potentially unwanted noise.
It is an object of the present invention to provide for a reduced noise reluctance machine that can be easily constructed and that can operate, in isolation or in combination with reduced-noise current switching schemes to reduce the noise produced by a reluctance machine.


A system for controlling exhaust emission oxides of nitrogen (NOx) during restarts of an internal combustion engine (ICE). The system includes a first sensor for determining a first level of exhaust gas oxygen at a location upstream of a catalytic converter, a second sensor for determining a second level of exhaust gas oxygen at a location mid-bed of the catalytic, and a controller for performing at least one process to reduce NOx emissions when a difference between the first level of exhaust gas oxygen and the second level of exhaust gas oxygen exceeds a predetermined amount.

1. Field of the Invention
The invention relates generally to a system and method for a strategy for monitoring and controlling engine NOx emissions, and more particularly to a system and method for monitoring and controlling NOx emissions during restarts of hybrid and conventional vehicles.
2. Background Art
Hybrid electric vehicles (HEVs) utilize a combination of an internal combustion engine (ICE) in connection with an electric motor. The electric motor is fed electrical energy from a battery to provide the power needed to propel a vehicle (i.e., provide power to vehicle wheels) for improved fuel economy when compared to a conventional (i.e., an internal combustion engine only) vehicle. In a hybrid vehicle, fuel economy can be improved and exhaust emissions can be reduced by shutting down (i.e., turning off) the engine, especially when the ICE operates inefficiently, and using the electric motor to provide all of the power needed to propel the vehicle. As such, hybrid electric vehicles (HEVs) typically perform engine shut off and restart operations frequently while driving.
However, when the user (e.g., driver of the vehicle) wants more power than the electric motor can provide or when the battery becomes depleted, the engine is generally restarted to provide the requested additional power. During engine shut downs and restarts, air is pumped by the engine into the exhaust system. An exhaust system catalyst adsorbs the oxygen from the air. Frequently, the volume of the adsorbed oxygen is sufficient to saturate the oxygen storage capacity of the catalyst. A three-way catalyst (TWC) that has a saturated or nearly saturated oxygen storage capacity can have diminished NOx conversion ability. When combustion is resumed (i.e., when the engine is restarted), the NOx emissions from the engine typically are not efficiently reduced or eliminated by the catalytic converter until the oxygen storage level in the catalytic converter is reduced from the saturated level.
Conventional non-hybrid vehicles (i.e., vehicles that are powered only be an internal combustion engine) operate under similar circumstances during deceleration fuel shutoff. As such, conventional vehicles can have diminished NOx conversion ability during deceleration fuel shutoff.
One example of a conventional approach to controlling exhaust emissions for ICEs is disclosed in U.S. Pat. No. 6,629,408. The exhaust emission control system includes first and second oxygen concentration sensors respectively provided upstream and downstream of the nitrogen oxide removing device for detecting an oxygen concentration in the exhaust gases. The air-fuel ratio of an air-fuel mixture to be supplied to the engine is changed from a lean region to a rich region with respect to a stoichio-metric ratio. An amount of reducing components flowing into the nitrogen oxide removing device from the time when an output value from the first oxygen concentration sensor has changed to a value indicative of a rich air-fuel ratio after enrichment of the air-fuel ratio is calculated. Deterioration of the nitrogen oxide removing device is determined according to the calculated amount of reducing components and an output value from the second oxygen concentration sensor. However, such conventional approaches generally fail to monitor and predict the effectiveness of the HEV and conventional ICE vehicle restart emissions performance, and fail to provide remedial processes.
Thus, to efficiently and effectively provide for controlling exhaust emissions for ICEs, there is a need for an improved system and method for monitoring NOx emissions during restarts of hybrid vehicles and conventional vehicles.

System for controlling NOx emissions during restarts of hybrid and conventional vehicles


A microscope having an objective lens and illumination means configured in combination such that said illumination means illuminates a specimen through a different region of the objective lens than that used for observation, and having an opaque region separating the illumination and observation regions. The basic optical design is capable of resolving optically isolated micron-sized voxels deep within tissue, without the use of a computer and when illuminated only with visible light.

1. Field of the Invention
The present invention relates generally to microscopy, and more particularly to ultraviolet and near ultraviolet microscopy, and still more particularly to a microscope having an objective lens and illumination system configured in combination such that the illumination system illuminates a specimen through a different region of the objective lens than that used for observation.
2. Background Discussion
Much of biological research, neuroscience research, artificial general intelligence research, and numerous other relatively exotic and esoteric areas of research are now substantially "hung up" on practical technological limitations; to with, the lack of suitable equipment and instrumentation. The limitation resides most particularly in the present inability to "functionally diagram" tissue, especially brain tissue. When it becomes available, functional diagramming may be as transformative to neuroscience and several other fields as were computers.
To date, the most ambitious functional diagramming project was performed manually. It involved diagramming the 302 neurons in the nematode (roundworm), Caenorhabditis elegans. The database is now on-line. Unfortunately, without the capabilities of the UV CT microscope and the method of using it, as described herein, that database does not include component values. And without component values, researchers are unable to label even the neurons with any detail beyond neuron type: "sensory", "interneuron", and "motor."
Cognition is primarily concerned with interneuron functionality, which is determined by component values, such as synaptic efficacy. The same neuron in different subjects may have different functions, as the operation of each neuron may result from self-organization. Hence, a useful analysis would have to be completed on a single subject, which precludes all but fully automated methods.
Each synapse likely has several quantitative component values. Aside from efficacy, there may be a variety of statistical accumulators that control changes (learning), nonlinearities that may be needed for certain computations, synaptic integration and/or differentiation, along with other as-yet unknown characteristics.
Many informal proposals have been made for methods of diagramming. The primary challenge in diagramming is that each method produces neuron images differently, so that gaining understanding of the operation of living tissue using one method may not be transferable to other methods for diagramming. However, when the functionality of neurons and synapses is more fully understood, diagramming methods unusable on tissue (e.g. scanning electron microscopy) might indeed become applicable and may even produce superior diagramming results.
Diagrams are needed to understand neurons, and neuronal understanding is needed to produce better diagrams. This proposition expresses the next logical step on the long path to complete neuronal understanding, leading to the production of accurate functional diagrams.
Moreover, better understanding of neuronal function is expected to lead to mathematical algorithms to "fill in" and "clean up" what the present invention "sees," to produce a result that far exceeds the imaging capabilities of the present invention.
The fundamental limitation in resolution is approximately ⅓ of the wavelength used for illumination or observation. This limitation applies to all methods, from MRI to electron microscopes. Like most tissue, brain tissue is transparent to radiation of nearly all wavelengths into the near UV region, whereupon the tissue becomes opaque. Due to this transparency to visible light, it is possible to directly observe the veins in one's wrist. Opacity to shorter wavelengths is the basis of Lasik eye surgery, as its use of short wavelength UV affects only the surface cells.
For diagramming purposes, observation must be made at near-UV wavelengths to utilize transparency at maximum possible resolution. Alternatively, methods not relying on transparency must be employed. Unfortunately, not enough is known to understand what might be seen at higher resolutions. Without transparency, there is presently no known way to observe detail in living neurons, a necessary requirement to close our present gap between form and function.
Near-UV has another advantageous feature for this application; namely, that in addition to being able to see near-UV light scattered by the interfaces between transparent structures having differing indexes of refraction, complex molecules naturally fluoresce when exposed to near-UV. Their natural fluorescence provides for a limited chemical analysis of complex molecules at points in tissue—a feature not available with other methods. Conventional subtractive staining provides fluorescence, but it hides structures beneath the stained details, making it unusable for diagramming.
The problem in using natural fluorescence is that it is extremely weak, due to the low number of fluorescing molecules present in complex tissue. It has been observed in the laboratory, e.g., observing fluorescent flashing from living neurons as they operate, but only low quality images using complex setups have been produced, and this has precluded its use in diagramming. It is the object of the present invention to bypass this historical barrier.
It would appear, then, that it would be advantageous to diagram utilizing near UV scattered light and fluorescent microscopy techniques. However, there is a residual problem. Present confocal microscopy methods fail to produce images of sufficient quality from bulk tissue to use for automated diagramming. The present invention advances a method of utilizing common focus microscopy, separated point scanning, and UV computed tomography (UV CT) to overcome those shortcomings.
In the late 1960s, Marvin Minsky of MIT's AI lab developed the first working machine vision system able to successfully parse visual scenes, thereby paving the way for the sorts of brain diagramming now contemplated. Marvin Minsky also invented the confocal microscope. Soon after there was an early effort at Carnegie Mellon University to diagram insect brains using a computer program written by Michael Everest. Researchers attempted to microtome slices of the brains and to stain them for microscopic scanning using 2D visible light methods. The effort failed because some slices were inadvertently destroyed, and staining is a subtractive process (whereas scatter and fluorescence are additive) so that it was impossible to see anything behind a stained detail. Further, large microtome slices must be >4μ thick to withstand handling, but some important parts of neurons (axons, for instance) may only be 1μ or less wide. The present invention provides more than an order of magnitude more real-world resolution than prior methods by working in 3D with ultraviolet, and uses UV CT to extract more detail than present visual methods can extract.
To date there have been no successful automated brain diagramming projects. Automated brain diagramming appears to be impossible until microscopes similar to the present invention are available. To diagram brains, such a microscope will require the largest supercomputers now available to deal with the overwhelming computational load that can produce whole-brain diagrams in months, rather than centuries.
It may prove impossible to fully diagram brains through observation alone, as the present invention seeks to do, and this would be due to structural details not microscopically observable at practical speeds by any conceivable method. It is hoped and expected, however, that other methods not based on observation will provide the missing details, e.g., by applying analytical methods to infer that which cannot be seen.
Background Technology:
Perhaps the best discussion of the technical background can be found at the Carl Zeiss Microscopy Online Campus web page, entitled, "Digital Imaging Considerations" [see http://zeiss-campus.magnet.fsu.edu/print/spinningdisk/introduction-print.html]. Therein, the best prior art methods, those utilizing lasers and Petrá{hacek over (n)} disks, are discussed for digitally imaging tissue. These methods do not utilize the methods and apparatus of the present invention. The present invention is an optical improvement independent of the scanning method.
Note that there are speed problems in performing fast real-time scanning with a single moving spot. This can be easily eliminated in systems with an intelligent pseudo-random scanning capability, because not every point must be scanned with every frame. All that must be scanned with every frame are points around various edges to identify when, and in what direction, they move, and one point within each structure to identify when its chemistry changes. Changes in these parameters would then trigger other localized scanning. This will speed up the scanning process by 100:1 or more.

Coincident focus microscope having superior resolution and contrast in three dimensions


Disclosed is a solid state detector which comprises a photo-conductive layer for generating charges upon irradiation of recording light and a substrate laminated to the photo-conductive layer, the substrate having a thermal expansion coefficient different from that of the photo-conductive layer. The solid state detector prevents deformation and breakdowns due to temperature changes of environments. Specifically, the solid state detector comprises a photo-conductive layer and a substrate laminated to the photo-conductive layer, the substrate having a thermal expansion coefficient smaller than that of the photo-conductive layer. In the solid state detector a deformation suppression layer, which has a thermal expansion coefficient smaller than that of the photo-conductive layer and suppresses deformation resulting from thermal expansion of the photo-conductive layer and the substrate, is laminated on a side of the photo-conductive layer opposite from the side of the substrate.

1. Field of the Invention
The present invention relates to a solid state detector in which a substrate and a photo-conductive layer for generating charges upon irradiation of recording electromagnetic waves, which hold image information, are integrally laminated. The present invention relates also to a solid state detector in which a substrate and a photo-conversion layer for emitting light upon the irradiation of the recording electromagnetic waves are integrally laminated.
2. Description of the Related Art
In radiography performed for the purpose of medical diagnoses and the like, a radiation image recording/reading apparatus which uses a radiation solid state detector to detect radiation and output image signals expressing radiation image information, has been known. As the radiation solid state detector used in this apparatus, various types of detectors have been proposed and put into practical use.
In terms of charge generation processes for converting radiation into charges, there is, for example, a photo-conversion type radiation solid state detector which obtains signal charges by detecting fluorescence, which is emitted from a fluorescent substance upon irradiation of the radiation, by a photoelectric transducer thereof, where signal charges are to be stored in a charge storage portion of the photoelectric transducer, after which the storage charges are converted to an image signal and outputted (for example, U.S. Pat. No. 4,803,359 and Japanese Unexamined Patent Publication No. 2(1990)-164067, PCT International Publication No. WO92/06501, and SPIE Vol. 1443 Medical Imaging V; Image Physics (1991), pp. 108–119 etc.). There is also a direct conversion type radiation solid state detector which collects signal charges generated in a photo (radiation)-conductive layer upon irradiation of radiation by a charge collection electrode thereof, to be temporarily stored in a charge storage portion, where the storage charges are converted to an electrical signal and outputted (MATERIAL PARAMETERS IN THICK HYDROGENATED AMORPHOUS SILICON RADIATION DETECTORS, Lawrence Berkeley L. University of California, Berkeley, Calif. 94720 Xerox Parc. Palo Alto, Calif. 94304, Metal/Amorphous Silicon Multilayer Radiation Detectors, IEEE TRANSACTIONS ON NUCLEAR SCIENCE. VOL. 36. NO. 2. APRIL 1989, and Japanese Unexamined Patent Publication No. 1(1989)-216290 etc.).
Furthermore, in terms of charge reading-out processes for reading out stored charges to the outside, there is a TFT (thin film transistor) readout type solid state detector for scanning-driving TFTs coupled to a charge storage portion to read out the stored charges. There is also an optical readout solid state detector for irradiating reading light (reading electromagnetic wave) thereto to read out the charges.
In addition, there has been proposed an improved direct conversion type radiation solid state detector in U.S. Pat. Nos. 6,268,614 and 6,376,857. The improved direct conversion type radiation solid state detector adopts a direct conversion type and an optical readout type. The improved direct conversion type radiation solid state detector is constituted by sequentially laminating a first electrode layer which is transmissible by recording radiation; a photo-conductive layer for recording, which exhibits photo-conductivity (to be precise, radiation conductivity) upon irradiation of recording radiation, which transmits through the first electrode layer; a charge transport layer acting substantially as an insulative substance for charges of the same polarity as that of charges held in the first electrode layer and acting substantially as a conductive substance for charges of the opposite polarity to that of the charges; a photo-conductive layer for reading, which shows photo-conductivity (to be precise, electromagnetic wave conductivity) upon irradiation of a reading electromagnetic wave; and a second electrode layer which is transmissible by the reading electromagnetic wave. The improved direct conversion type radiation solid state detector stores signal charges (latent image charges), which hold image information, in an interface (storage portion) between the photo-conductive layer for recording and the charge transport layer.
Herein, in the above described direct conversion type and improved direct conversion type radiation solid state detectors, the photo-conductive layer is usually formed on a substrate made of glass or the like. Furthermore, also in the photo-conversion type radiation solid state detector, a photo-conversion layer containing a fluorescent substance and the like, which converts radiation to light, is formed on a substrate made of glass or the like.
However, when the photo-conductive layer or the photo-conversion layer is laminated to the substrate made of glass or the like as described above, a thermal expansion coefficient of the photo-conductive layer or the photo-conversion layer differs from that of the substrate. This leads to deformation of the photo-conductive layer or the photo-conversion layer as a result of temperature change in the environments thereof. Extreme deformation leads to the deformation of a read out radiation image, and the possibility of a breakdown of the radiation solid state detector.


A holding device is used to maintaining a push button of a spray container to be pressed to release contents without continuous press by an operator. The holding device for a spray container comprises a supporting part which is placed around the push button, an adjusting part having a pillar-shaped portion standing on the supporting part and a diving board-shaped portion connected to the pillar-shaped portion and extending over a top of the push button, on a top of the diving board-shaped portion having a recess; and an auxiliary part being pillar-shaped and standing on the supporting part, having a protrusion toward the adjusting part to be engaged with the recess.

A sprayer containing fluid under pressure releases the fluid by pressing a push button equipped with the sprayer. This spray-type container is used in various fields such as painting as it enables an operator to apply large volumes of fluid rapidly with substantial control over the fineness and density of the spray mist. In addition, this spray-type container can store the rest of the contents in a good condition for great lengths of time.
However, it is difficult for an operator to maintain a continuous or constant pressure by his finger on the push button for any great length of time due to fatigue. It may lead to failures of control over the fineness. Further, other securing devices only disclose big, heavy, or complicated structures; those structures lead to significant operator fatigue or cause high manufacturing costs.


A method and system for automated bill payment service makes use of one or more application programs, such as a bank's retail system application and a bill payment application, running on one or more servers, as well as one or more data storage devices. A customer calls, for example, an 800 number and enters identification information in response to prompts by the system. The system verifies the customer's identification and, in response to selection of a single bill payment option, prompts the customer to enter information about at least one bill payment for a payee. The system provides selection of the payee from a customer-specific bill payee list or a system-spoken payee list and various menu functions. The system automatically schedules the bill payment for the customer according to the entered bill payment information, and renders the scheduled payment to the payee for the customer. The system also provides the customer with the ability to check the status of payments that have already been scheduled, as well as to change or cancel payments.

Providing customer services, such as bill payment services, manually by customer service representatives via a telephone typically consumes an inordinate amount of personnel time in terms, for example, of customer service representative telephone traffic. Therefore, a manual bill payment service is a service-related problem for a financial institution, such as a bank. Automation of such a bill payment service would enable the bank, for example, to off-load a tremendous amount of telephone traffic from its customer representatives.
Further, off-loading telephone traffic from customer service representatives by automating such services would enable customer service representatives to provide more service to the same customer base by spending more time with individual customers. Additionally, automation of bill payment services would enable customers, for example, to schedule their payments no matter where they may be located throughout the country. The financial institution may also provide other financial services, including for example, a direct access service, which customers can access via their personal computers (PCs), and he financial institution may also want to allow its customers to utilize bill payment services aspects of such direct access service via the financial institution's automated telephone service.

System and method for automated bill payment service


Method of confirming the presence or absence of leaks in a liquid storage container, particularly in partially filled underground storage tanks, subjected to partial vacuum for the purpose of testing the tank for the presence of a leak in the area above the liquid using a hydrophone or microphone either positioned in or attached to the container to detect the sound produced by the ingress of fluid into the container as a result of the vacuum. The ingress of fluid is confirmed by recording and observing the vacuum pump on/off cycles, the on/off cycles for a leaking container being distinguishable from the on/off cycles for a non-leaking container.

The present invention relates to the detection of a perforation in the wall of a liquid storage container. More particularly, the present invention relates to an improvement to the method described in U.S. Pat. No. 4,462,249, commonly assigned to the assignee of the present invention and hereby incorporated in its entirety by this specific reference thereto, for detecting such perforations by evacuating the tank and acoustically detecting the bubbles that are formed in the liquid stored in the container as a result of the passage of air through any perforation(s) that may be present.
Although the method described in U.S. Pat. No. 4,462,249 is used successfully and extensively for the testing of such liquid storage containers as the underground gasoline tanks of a service station, there are instances in which it is useful to either confirm the result of that testing method or to increase the leak detection capability. The latter is particularly desirable in that, although at present, the applicable federal regulations prohibit leakage of gasoline from such facilities at a rate exceeding 0.1 gallons per hour, on information and belief, those regulations are soon to be changed to perhaps reduce that maximum permissible rate by half. Further, the ability to detect smaller leaks may yield useful data as to the expected life of a particular storage tank that can be used to plan the maintenance of the tank and to prevent the occurrence of an environmentally significant leak.
Such tanks also present some unique leak detection problems for which increased detection capability is useful. For instance, many such tanks do not themselves have perforations that cause the loss of gasoline therefrom; the leak is actually located in the connections and/or lines leading out of the tank. The leak may also be in the vapor recovery line. Likewise, if the tank is installed below the water table or the perforation is near the bottom of the tank and the tank is nearly filled with gasoline, the leak may be difficult to detect by the method described in U.S. Pat. No. 4,462,249.
It is therefore an object of the present invention to provide a method of confirming the presence of a leak in a liquid storage tank or other container.
Another object of the present invention is to provide a method having increased leak detection capability.
Another object of the present invention is to provide a method of detecting a leak in a liquid storage container regardless of the location of the perforation from which the liquid leaks in the tank and regardless of whether the perforation is located above or below the level of the liquid in the container.
Another object of the present invention is to provide a method having increased leak detection capabilities for use in a liquid storage container that is only partially filled with liquid.

Method of confirming the presence of a leak in a liquid storage tank


Platelet-specific, chimeric immunoglobulin and immunoglobulin fragments are described. The chimeric molecules are made up of a nonhuman antigen binding region and a human constant region. Preferred immunoglobulins are specific for glycoprotein IIb/IIIa receptor in its complexed form; they block ligand binding to the receptor and prevent platelet aggregation. The immunoglobulins are useful in anti-thrombotic therapy when administered alone or in conjunction with thrombolytic agents, as well as in thrombus imaging.

Platelet aggregation is an essential event in the formation of blood clots. Under normal circumstances, blood clots serve to prevent the escape of blood cells from the vascular system. However, during certain disease states, clots can restrict or totally occlude blood flow resulting in cellular necrosis.
For example, platelet aggregation and subsequent thrombosis at the site of an atherosclerotic plaque is an important causative factor in the genesis of conditions such as angina, acute myocardial infarction, and reocculusion following successful thrombolysis and angioplasty. Heart attack patients are typically treated with thrombolytic agents such as tissue plasminogen activator or streptokinase, which dissolve the fibrin component of clots. A major complication associated with fibrinolysis is reocclusion based on platelet aggregation which can result in further heart damage. Since glycoprotein (GP)IIb/IIIa receptors are known to be responsible for platelet aggregation, reagents which block these receptors are expected to reduce or prevent reocclusion following thrombolytic therapy and to accelerate the rate of thrombolysis. Such reagents are also expected to be useful in therapy of other vaso-occlusive and throboembolic disorders.
One approach to blocking platelet aggregation involves monoclonal antibodies specific for GPIIb/IIIa receptors. A murine monoclonal antibody, designated 7E3, that inhibits platelet aggregation and appears useful in the treatment of human thrombotic diseases is described in published European Patent Application Nos. 205,207 and 206,532. It is known in the art that murine antibodies have characteristics which may severely limit their use in human therapy. As foreign proteins, murine antibodies may elicit immune reactions that reduce or destroy their therapeutic efficacy and/or evoke allergic or hypersensitivity reactions in patients. The need for readministration of such therapeutic modalities in thromboembolic disorders increases the likelihood of these types of immune reactions.
Chimeric antibodies consisting of non-human binding regions joined to human constant regions have been suggested as a means to circumvent the immunoreactivity problems of murine antibodies. See Proc. Natl. Acad. Sci. USA, 81:6851 (1984) and PCT Application No. PCT/GB85 00392. Since the constant region is largely responsible for immunoreactivity of an antibody molecule, chimeric antibodies with constant regions of human origin should be less likely to evoke an anti-murine response in humans. However, it is unpredictable whether the joining of a human constant region to a murine binding region of a desired specificity will reduce immunoreactivity and/or alter the binding capability of the resulting chimeric antibody.

DNAs encoding chimeric immunoglobulin light or heavy chains and fragments thereof having variable regions derived from monoclonal antibody 7E3, and vectors and host cells comprising same

The Research Foundation of State of New York


A method and apparatus are provided for providing route guidance to a user of a vehicle navigation system. A route is generated which corresponds to a plurality of maneuvers. A warning distance is determined from a particular geographic location associated with a particular maneuver, the warning distance being based in part on a variable parameter. A maneuver instruction corresponding to the particular maneuver is then provided at the warning distance from the particular geographic location. In some embodiments, where the particular maneuver corresponds to a first junction, and a second junction similar to the first junction is within the warning distance, the warning distance is adjusted to an adjusted warning distance.

The present invention relates to the manner in which a vehicle navigation system communicates a calculated route to a driver. More specifically, the present invention relates to the timing of warning prompts which alert the driver to upcoming maneuvers.
Vehicle navigations systems employ a variety of methods for communicating a route to a driver. One method employs warning chimes to alert the driver to an upcoming maneuver. Another employs a series of voice prompts. The timing of these chimes or voice prompts are crucial to effective route guidance. If a prompt is delayed, the driver may not be able to execute the maneuver in a safe and orderly manner. If a prompt is issued too early and a significant amount of time elapses before the vehicle arrives at the maneuver location, the driver may not be properly alert.
Currently available vehicle navigation systems which have warning chimes or voice guidance typically employ a fixed distance at which the driver is warned of an upcoming maneuver. That is, once the vehicle is determined to be within a particular distance of the geographic location at which the maneuver is to be executed, the system issues the warning chime or the voice guidance prompt. Unfortunately, this method does not account for the often widely varying characteristics of the environment in which the vehicle is operating. For example, if the fixed warning distance is set to provide adequate notice to the driver in a freeway environment where the speed limit is 65 miles per hour, it will likely be too long for a residential area where the speed limit is typically 25 miles per hour.
Moreover, a fixed warning distance may cause confusion by encompassing more than one junction at which similar maneuvers may be executed. This will almost certainly be the case where the fixed warning distance is set relative to a freeway environment. Because such a warning distance would be relatively long, it would likely encompass more than one intersection in a different environment where the average vehicle speed is considerably less such as, for example, a residential environment. Such confusion is unacceptable if a vehicle navigation system is to adequately guide the driver along a calculated route.
It is therefore evident that a more flexible approach is needed for communicating warnings of impending maneuvers to the user of a vehicle navigation system.

Voice guidance timing in a vehicle navigation system


A medical examination and treatment system comprises a radiation source that emits particle radiation, an X-ray emitter located on one side of a target volume and diametrically opposite to the radiation source, and a detector located between the target volume and the radiation source. The target volume is positioned to be exposed to the particle radiation. A radiation direction of the X-ray emitter is oriented opposite to a radiation direction of the particle radiation.

An irradiation device for heavy-ion therapy is known for example from German Patent Application DE 198 35 209 A1.
In radiation therapy, an exact aiming of a radiation beam at a target tissue to be treated is of great significance and importance. As such, radiation therapy devices are generally combined with diagnostic devices. For example, a medical irradiation system known from German Patent Application DE 35 02 776 A1 includes a simulator with an X-ray tube and an image amplifier for substantially precise positioning of a patient to be examined. In this German Patent Application, a stationary linear accelerator that emits corpuscular rays is for example provided as the radiation source. An additional X-ray emitter, which is provided for diagnostic applications, can be positioned as needed in front of the linear accelerator, or between the linear accelerator and the patient. Before the irradiation begins, the X-ray emitter is removed back out of this position. Alternatively, in the known system, both the linear accelerator and the X-ray emitter may be stationary, but the patient is moved from a diagnosis position to a therapy position. This movement of the patient, however, is a potential source of geometrical inaccuracies in irradiation therapy.

Medical examination and treatment system


A shoe outsole has a heel post extending outwardly therefrom. An outer heel cover has a hole for receiving the heel post in an assembled position. The heel post thus acts as a convenient positioning guide for the heel cover. A plurality of fluid-filled heel cushioning members at least partly surrounds the heel post between the outsole and the cover in the assembled position, for cushioning heel impacts during use of the footwear. A plurality of dividers on the outsole extend radially of the heel post, and position each cushioning member between a pair of the dividers. The dividers thus act as convenient positioning guides for the cushioning members. The cushioning members have different resistances to compression for adjustably cushioning heel impacts during use of the footwear.

1. Field of the Invention
The present invention generally relates to shoe heels and to methods of manufacturing the shoe heels.
2. Description of the Related Art
A shoe generally consists of an upper attached to a sole. The upper encloses a foot and typically includes an insole to provide initial support and cushioning to a bottom of the foot. An outsole is the ground-contacting portion of the sole and includes a heel. The outsole provides traction, stability, and protection to the remainder of the shoe. Outsoles are composed of durable materials, such as rubber, to provide high abrasion wear resistance. A midsole, if used, is composed generally of a softer, more flexible material than the outsole.
The increase in demand for shoes for sports and outdoor activities such as walking, running, hiking, and playing tennis, basketball and like sports has prompted many advances in shoe design to improve protection and comfort to the feet, ankles, legs, hips, etc., especially to improve cushioning, shock absorption, and stability at the heel. Efforts to improve cushioning at the heel, while maintaining adequate stability, have incorporated various gels in an attempt to enhance and prolong cushioning and energy return. However, soles incorporating gels are costly to manufacture and relatively unpredictable in their functional characteristics. Although the functional characteristics of the shoe are of primary importance, other factors such as the cost of manufacture and appearance of the shoe must also be taken into account for full consumer satisfaction.


A method and system is provided of controlling a pump having a pumping element configured to provide pressurized fuel to a common rail accumulator coupled to a plurality of fuel injectors configured to inject fuel into a corresponding plurality of cylinders of an engine, comprising: receiving rail pressure values indicating a current fuel pressure in the accumulator; and responding to the received at least one rail pressure value by controlling operation of the pumping element during each potential pumping event of the pumping element to generate actual pumping events during at least some of the potential pumping events to cause the rail pressure values to remain within a desired range and to at least one of increase an overall efficiency of the pump, decrease audible noise generated by the pump, increase reliability of the pump and reduce injection pressure variations at the plurality of fuel injectors.

Fueling systems, and in particular fueling systems using a common rail accumulator, are typically controlled to maintain the fuel available to the fuel injectors within a desired pressure range. To this end, conventional control methodologies for fuel pumps receive feedback representing the rail pressure and cause the pumping element(s) of the fuel pump to deliver a partial capacity quantity of fuel to the accumulator during every pumping cycle. However, fuel pumps are inherently inefficient when operated at less than full capacity. Moreover, in many system configurations a percentage of pumping cycles are not in the preferred phasing relationship with the operation of the fuel injectors. Therefore, causing fuel delivery during every pumping cycle may result in increased audible noise, vibration and harshness. Also, controlling pump operation to rail pressure alone may include operating the pumping element(s) in regions that impair reliability and durability and/or cause undesirable variability in rail pressure at or during fuel injection events. Accordingly, it is desirable to provide control methodologies for fueling systems that address these and other shortcomings of conventional approaches.

Fuel pump pressure control structure and methodology