Using an homogenizer operating at higher pressures (ca. 2000 bar) than those conventionally used in ice cream manufacturing, it is possible to generate smaller oil droplet sizes (ca. 0.3 xcexcm) in an ice cream premix. It allows stabilization of a larger air:water interface, leading to smaller discrete gas cells which in turn modify the organoleptic quality of the ice cream.

The invention relates to a method of preparation of an aerated frozen product such as ice cream, wherein at least part of the aerated frozen product premix is subjected to an ultra high pressure treatment. The invention also relates to an aerated frozen product obtained according to this process.
Ultra high pressure (UHP) is a known method for killing spores and has been suggested as a suitable route to food product pasteurisation. In Japan a range of pressure de-contaminated products such as jellies, preserves, purees and sauces have been launched on the market (Byrne, M. (1993) Food Engineering International, 34-38).
Furthermore isolated, native proteins have been subjected to UHP. These proteins are in their native form, they have not been treated chemically or thermally before the pressure treatment by methods which significantly modify their protein structure (van Camp, J; Huyghebaert, A (1995) Food Chemistry 54(4) 357-364; Okamoto, M; Kawamura, Y; Hayashi, R; (1990) Agric Biol Chem 54(1) 183-189). It is generally believed that there would be no advantage in subjecting proteins which have already been substantially denatured by for example an initial heat-treatment prior to UHP.
DE 42 26 255 discloses the treatment of cream with ultra high pressure in order to crystallise the fat.
It has now been discovered that the presence of a fine microstructure is critical to produce the correct texture and quality of ice cream. Organoleptic evaluation of ice cream done by the applicant of the present invention has shown that small air cells and ice crystals are associated with increased creaminess and reduced iciness, which are recognized parameters for good quality ice cream. For example, for a given ice cream formulation, a reduction in gas cell and/or ice crystal size will enhance creamy texture (and reduce ice crystal perception, nevertheless the sensory attributes are not directly influenced by the de-emulsified fat level. However, the ice cream microstructure produced in a scraped surface heat exchanger (freezer) has been found to be unstable and both ice and air structure coarsen significantly in the time taken to harden the product to typical storage temperatures of xe2x88x9225xc2x0 C. Therefore, an important step to achieve small gas cells in ice cream is to stabilize gas cells during hardening.
To retain the desired microstructure, it has now been found that it is necessary to generate a partial network of fat aggregates adsorbed onto the air interface to provide a steric barrier to gas cell coalescence. To generate this fat network, a proportion of the oil droplets need to partially coalesce as a consequence of the shear regime encountered within the ice cream freezer. It is known that the collision efficiency (the probability of two colliding droplets remaining permanently in contact) can be significantly affected by the initial droplet size and the protein surface coverage. The collision efficiency decreases as the droplet size decreases. However, small molecule surfactants can displace protein at the oil:water interface and allow a higher collision efficiency at a given droplet size.
In the processing of ice cream, an homogenization step is used to generate small oil droplets, preferably with a monomodal size distribution to allow the controlled fat destabilization under shear. For an ice cream premix, the average droplet size, d[3,2], upon homogenization is typically 0.6-1.0 xcexcm. Numerous process and product variables affect homogenization efficiency. Those which have been found to have the largest effect on the final droplet size distribution are the dispersed phase volume, the type and level of surfactant used and, in particular, the pressure applied during homogenization. It has now been found that by using an homogeniser operating at higher pressures (ca. 2000 bar) than those conventionally used (ca. 150 bar), it is possible to generate smaller oil droplet sizes (ca. 0.3xcexcm) in an ice cream premix.
Generation of significantly smaller, and therefore a higher number of, oil droplets can allow stabilization of a larger air:water interface, leading to smaller discrete gas cells which in turn alter the organoleptic quality of the ice cream. However, it has now been discovered that very small oil droplets will give inherently stable ice cream mixes which will not generate the desired microstructure unless the desired level of fat partial coalescence occurs. To achieve this, it is necessary to either increase the collisional force between the droplets or reduce the steric barrier to coalescence. This is achieved by either optimizing the applied shear stress during processing or by manipulating the interfacial composition by the appropriate selection of emulsifiers.
It has also been discovered that the sensory properties of ice cream is dependent on the size of the fat droplets. For a given air cell size, the ice cream with the smallest fat droplets scores best on creaminess when blind tested by a trained panel.
Emulsifiers
Emulsifiers are defined as in Arbuckle, W. S., Ice Cream, 4th Edition, AVI publishing, 1986, ch 6 p92-94.
Stabilizers
Stabilizers are defined as in Arbuckle, W. S., Ice Cream, 4th Edition, AVI Publishing, 1986, ch 6, p84-92. They can for example be locust bean gum, carrageenan, guar gum, gelatin, carboxy methyl cellulose gum, pectin, algin products and mixtures thereof.
Frozen Aerated Dessert
A definition of a frozen aerated dessert can be found it Arbuckle, W. S., Ice Cream, 4th Edition, AVI Publishing, 1986, ch 1, p1-3. Preferably, a frozen areated dessert accodring to the invention is a milk or fruit based frozen aerated confection such as ice cream. An ice cream is a frozen food made by freezing a pasteurized mix with agitation to incorporate air. It typically contains ice, air, fat and a matrix phase and preferably;
milk/dairy fat 3 to 15% (w/w)
milk solids non fat 2 to 15% (w/w)
sugar and other sweeteners 0.01 to 35% (w/w)
flavours 0 to 5% (w/w)
eggs 0 to 20% (w/w)
water 30 to 85% (w/w)
Overrun:
Overrun is defined as in Ice Creamxe2x80x94W. S. Arbucklexe2x80x94Avi Publishingxe2x80x941972xe2x80x94page 194.
Destabilising Emulsifier
Destabilising emulsifier means any emulsifier which gives, at a level of 0.3%, a level of extracted fat of at least 25% in an ice cream premix containing 12% butter oil, 13% skim milk powder and 15% sucrose as described in on figure 4 in xe2x80x98The stability of aerated milk protein emulsions in the presence of small molecule surfactantsxe2x80x99 1997xe2x80x94Journal of Dairy science 80:2631:2638.
Examples of such destabilising emulsifiers are unsaturated monoglyceride, polyglycerol esters, sorbitan esters, stearoyl lactylate, lactic acid esters, citric acid esters, acetyllated monoglyceride, diacetyl tartaric acid esters, polyoxyethylene sorbitan esters, lecithin and egg yolk.
Ice Cream Premix Production
In a jacketed 500 liter mix tank, water is added at 85xc2x0 C., then milk powder, sugar, stabilizers, butteroil with emulsifier dissolved are added and mixed with high shear mixer and heated to maintain a temperature of 65xc2x0 C. for standard production and 55xc2x0 C. for production according to the invention:
Standard production: the premix is heated with plate heat exchanger to 83xc2x0 C., homogenize with Crepaco single stage valve homogeniser at 140 bar. After holding at 83xc2x0 C. for 15 seconds the mix was cooled with a plate heat exchanger to 5xc2x0 C. and held at this temperature for at least two hours prior to freezing.
Invention: the premix was heated with a plate heat exchanger to 83xc2x0 C. and held at this temperature for 15 seconds to pasteurize the mix. The mix was tempered at 55xc2x0 C. (+/xe2x88x925xc2x0 C.) in a holding tank prior to homogenization and collected after a single pass through the homogeniser (Nanojet Impinging Jet, ref: Verstallen, A., Apparatus for homogenizing essentially immiscible liquids for forming an emulsion described in U.S. Pat. No. 5,366,287) at an input pressure of 1600 bar (+/xe2x88x9250 bar). During homogenization there is a temperature rise of 2-2.5xc2x0 C./100 bar. Immediately after homogenization the mix is passed through a plate heat exchanger and cooled to 8xc2x0 C. (+/xe2x88x923xc2x0 C.). The mix is held in a jacketed aging vessel at this temperature for at least two hours prior to freezing.
Ice Cream Processing
The mix was processed according to two different routes.
Standard Freezer
The mix was aged overnight and was processed through an ice cream freezer (Crepaco W104 freezer (SSHE) with a series 80 dasher operating at 4 bar barrel pressure). All ice cream was produced at a mix throughput of 120 l/hr at 60% or 100% overrun with an extrusion temperature of xe2x88x926.0xc2x0 C. and xe2x88x925xc2x0 C. respectively. Ice cream was collected in 500 ml waxed paper cartons and hardened in a blast freezer at xe2x88x9235xc2x0 C. for two hours.
Single Screw Extruder
The outlet of the SSHE was connected to a single screw extruder (SSE) (as described in WO98/09534) resulting in exit temperatures of ca. xe2x88x9214.5xc2x0 C.
Fat Composition
Fat composition analysis was carried out according to the Rose-Gottlieb method: British Standard Methods for Chemicals analysis of ice cream, Part 3. Determination of fat content (BS2472: part 3: 1989 ISO 7328-1984).
Pieces of ice cream are randomly selected to give a total mass of approximately 100 g, placed in a blender jar, covered with a lid and allowed to soften at room temperature. This mix is then blended for two minutes (up to 7 minutes for products containing particulates, e.g. nuts) to obtain a homogeneous mixture. The temperature is kept below 12 C during softening and blending. 4 to 5 g (accurately measured to 1 mg) are weighed into a fat extraction flask and water at 65 C is added to obtain a total volume of 10 ml and mixed thoroughly. Ammonia solution (2 ml, 25% (m/m) of NH3) is added and the flask immediately heated at 65 C for 15-20 minutes in a water bath and cooled to room temperature at which time ethanol (10 ml) is added. Diethyl ether (25 ml) is added and the flask shaken vigorously for 1 minute. Light petroleum (25 ml) is the added and the flask shaken for 30 seconds. The stoppered flask is allowed to stand for 30 minutes before decanting the supernatant. The solvent is then removed by evaporation or distillation. The fat content is expressed as a percentage by weight.
Gas Cell Sizing
The microstructure of all ice cream samples was visualized by Low Temperature Scanning Electron Microscopy (LTSEM). All samples were stored at xe2x88x9280xc2x0 C. prior to structural analysis using a JSM 6310F scanning electron microscope fitted with an Oxford Instruments ITC4 controlled cold stage. The samples were prepared using the Hexland CP2000 preparation equipment. A sample at xe2x88x9280xc2x0 C. of size 5xc3x975xc3x9710 mm was taken from the centre of a 500 ml block of ice cream. This sample was mounted onto an aluminium stub using OCT mountant on the point of freezing and plunged into nitrogen slush. OCT is an aqueous based embedding medium used primarily for cryotome preparation of material for light microscopy. It is also called tissue tek and is supplied by Agar Scientific. The advantage of using oct rather than water to mount the samples for electron microscopy is that when OCT changes from liquid to solid ie. freezes it changes to opaque from transparent allowing visual identification of the freezing point. Identification of this point allows the sample to be mounted using a liquid at its coldest just prior to solidifying which will give support during rapid cooling. The sample was warmed to xe2x88x9298xc2x0 C. fractured and allowed to etch for 2 minutes before cooling to xe2x88x92115xc2x0 C. The surface was coated with Au/Pd at xe2x88x92115xc2x0 C., 6 mA and 2xc3x9710-1 mBar Argon. The sample was transferred in vacuum to the LTSEM and examined under microscope conditions of xe2x88x92160xc2x0 C. and 1xc3x9710-8 Pa.
The gas structure in ice cream was quantified by measuring the gas cell size distribution from SEM images using the AnalySIS 2.11xe2x80x94package AUTO (SIS Munster, Germany) with xe2x80x98Bxe2x80x99 version software. The AnalySIS programme may be run using SEM images in two data formats, either as data direct from the JEOL microscope or as images scanned from Polaroids. All gas cell sizes were measured from SEM micrographs. The optimum magnification was such that there were less than 300 gas cells per image. The programme was used semi-automatically such that particle edges were calculated automatically (by difference in grey-scale) and refined manually (by deleting and redrawing around particle boundaries not selected correctly). Since ice crystals may also have been selected by the programme, the gas cells were then manually selected and the distribution analyzed using the maximum diameter parameter. All gas cells present on an SEM micrograph were counted and up to six SEM images were used. Generally, at least 1000 gas cells were counted. The average size was determined as the number average, d(1,0), of the individual cell sizes.
Premix Fat Droplet Sizing
Particle sizes in the premix emulsion were measured using a Malvern Mastersizer (Malvern Instruments, UK) with water as the continuous phase using the 45 mm lens and the presentation code 2 NAD. Ultrasound was applied to the Mastersizer tank for one minute before measurement. The surface weighted mean d[3,2] was calculated. The diameter by which 90% by volume of the distribution was smaller, d[0.9] was taken as the limit of individual fat droplets.
Ice Cream Fat Droplet and Fat Aggregates
Two different methods were used.
Mastersizer Method:
20 ml sample of ice cream was heated to 60xc2x0 C. for 5 minutes, added to the Malvern Mastersizer water bath, then sonicated for 2 minutes. The average droplet size, d[3,2] and size distribution were measured. The proportion of fat aggregates in the melted ice cream was calculated as the proportion of fat (expressed as % volume) with a particle size greater than the d[0.9] determined for the unaggregated premix fat droplets.
Solvent Extraction Method:
10 g sample (W1) is weighed into a measuring cylinder and left at room temperature to melt for 4 hours. 50 ml petroleum spirit is added, the cylinder stoppered and inserted into a mechanical agitator. The cylinder is inverted for one minute at a rate of one inversion per second and then allowed to stand for 5 minutes and the solvent decanted in to a pre-weighed beaker (W2 ). A further 25 ml solvent is added and the cylinders inverted 3 times by hand. After standing (2-3 minutes) the solvent layer is decanted again into the beaker. The beaker is placed in a fume cupboard overnight to evaporate the solvent and then dried in a spark proof oven at 100 C for 15-30 minutes. The beaker is then cooled in a dessicator and reweighed (W3 ). The percentage of de-emulsified fat is [(W3 xe2x88x92W2 )/(Cxc3x97W1)]xc3x97100 where C is the percentage of fat in the ice cream divided by 100.
It is a first object of the present invention to propose a process for manufacturing a frozen aerated product having an overrun of between 20% and 180%, preferably between 60% and 100%, comprising the steps of;
producing a premix a premix comprising 2 to 15% fat (w/w), up to 1% (w/w) emulsifier, and 45 to 85% (w/w) of water,
homogenizing the premix in order to produce fat droplets having a d(3,2) below 0.6 micron, preferably below 0.5 micron, even more preferably below 0.4 micron,
cooling, freezing and aerating the homegenised premix. The product can then be extruded and optionally deep frozen.
This enables the production of smaller fat droplets which in turn generate smaller air cells, preferably wherein the mean gas cell size d(1,0) is below 20 micron, more preferably below 10.5 micron. It has also been found that out of two ice creams with the same composition and the same air cell size, the one with the smallest fat droplets was found to be the preferred one when tasted by a trained panel.
In a first preferred embodiment of the invention the homogenising step takes place at a pressure of between 1000 and 2000 bar, preferably between 1400 and 1800 bar.
In a second preferred embodiment of the invention, the premix contains a destabilising emulsifier. Preferably the destabilising emulsifier is selected from the group consiting of unsaturated monoglyceride, polyglycerol esters, sorbitan esters, stearoyl lactylate, lactic acid esters, citric acid esters, acetyllated monoglyceride, diacetyl tartaric acid esters, polyoxyethylene sorbitan esters, lecithin and egg yolk. More preferably the destabilising emulsifier is unsaturated monoglyceride. Preferably also the (destabilising emulsifier/fat) weight ratio of the premix is between 10:1500 and 15:300, even more preferably between 15:1200 and 15:600.
The incorporation of destabilising emulsifier, and particularly unsaturated monoglycerides, allows for the production in a SSHE of a frozen aerated product with gas cells smaller than the one obtained by freezing a premix in a SSHE followed by cold extrusion in a SSE as disclosed in W098/09534.
In a third preferred embodiment of the invention, the homegenized premix is first frozen at a temperature of between xe2x88x924 C and xe2x88x927 C in a scrapped surface heat exchanger and then extruded in a screw extruder at a temperature of between xe2x88x9210 C and xe2x88x9218 C. Even more preferably, the screw extruder is a single screw extruder.
The combination of Ultra High Pressure homogenization together with cold extrusion, allows the production of an aerated product product with gas cells smaller than the one obtained by freezing a premix in a SSHE followed by cold extrusion in a SSE as disclosed in W098/09534.
Preferably also, the temperature of the premix prior to homogenisation is above 50 C. More preferably, the homogenisation generates a temperature rise of the premix of between 30 C and 45 C. By so doing it is no longer necessary to use a plate-pack heat exchanger for pasteurisation. Moreover, by starting with a temperature of the premix, prior to homogenization of above 50 C while having a temperature rise of below 45 C, it is posiible to reach a temperature after homogenisation which is not above 95 C, something which prevents the water from boiling, something which would generate bubbles in the premix.
Before, or after homogenization, it is possible to have a pasteurization step.
It is a second object of the present invention to provide a frozen aerated product, having an overrun of between 20% and 180%, preferably between 60% and 100%, and comprising 2 to 15% (w/w) of fat and destabilising emulsifier in a (destabilising emulsifier /fat) weight ratio of between 10:1500 and 15:300, preferably between 15:1200 and 15:600.
Preferably the destabilising emulsifier is selected within the group consiting in unsaturated monoglyceride, polyglycerol esters, sorbitan esters, stearoyl lactylate, lactic acid esters, citric acid esters, acetyllated monoglyceride, diacetyl tartaric acid esters, polyoxyethylene sorbitan esters, lecithin and egg yolk. More preferably the destabilising emulsifier is unsaturated monoglyceride.
More preferably the (destabilising emulsifier/fat) weight ratio of the frozen aerated product is between 10:1500 and 15:300, even more preferably between 15:1200 and 15:600.
It is a third object of the present invention to provide a frozen aerated product having an overrun of between 20% and 180%, preferably between 60% and 100%, and comprising 2 to 15% (w/w) of fat, wherein the mean gas cell size d(1,0) is below 10.5 micron.

Method for the preparation of an aerated frozen product

Good Humor - Breyers Ice Cream, division of Conopco, Inc.


An image forming apparatus having a unit for charging the surface of an image carrier uniformly with electricity, a unit for forming an electrostatic latent image on the surface of the image carrier charged electrically, a unit for developing the electrostatic latent image formed on the surface of the image carrier to thereby form a toner image and a means for transferring and fixing the toner image to a transfer member. The developing unit includes a developing roller which is disposed so as to contact the image carrier. The developing roller is connected to a power source for charging the toner particles on the developing roller with electricity with the same polarity as the charging polarity of the the image carrier, and for applying an electric potential to the developing roller so that the toner particles remaining on the developing roller are stuck to an image portion of the image carrier and the toner particles remaining on a non-image portion of the image carrier are attracted by the developing roller. The developing roller rotates in the direction opposite to that of the image carrier and a peripheral velocity of the developing roller exceeds 1.2 times that of the image carrier. Since the collected toner particles are not necessary to be disposed of, the environment is not polluted and the efficiency of using the toner is improved.

1. Field of the Invention
The present invention relates to an apparatus for and a method of forming an electrophotographic image, and more particularly to those adapted for various business machines and instruments, especially for a storage device such as a printer.
2. Description of the Prior Art
An electrophotographic image processing apparatus has been conventionally utilized as an electrophotographic printer. Such an image processing system carries out the steps of charging an image carrier, i.e. a photoconductor drum with electricity uniformly, forming a latent image on the photoconductor drum, developing the latent image by toner, transferring the toner on the photoconductor drum to a transfer member, fixing the toner on the transfer member and removing the toner remaining on the photoconductor drum therefrom. There is a technique to remove electricity before the next charging process starts upon completion of the transferring process in order to prevent an afterimage from being formed on the photoconductor drum. The charging process and the transferring process are generally performed by utilizing corona discharge.
Since a harmful substance such as ozone produces through the corona discharge, it has been collected by a filter, etc. However, the use of the filter for a long time causes the degraded collective efficiency and the frequent filter replacement.
An ozone free process where ozone is prevented from generating by employment of a roller type transfer system or a charging roller system is proposed. (refer to Electronic Communication Institute Thesis '77/4 Vol. J60-C NO. 4 pp 213-218).
The roller type transfer system performs the steps of placing a transfer member on a toner image formed by development on the surface of a photoconductor drum, pressing a transfer roller on the transfer member and applying a voltage polarity of which is opposite to that of the toner, to the transfer roller. In this system, an electric field is generated in a gap between the transfer member and the upper layer of the toner image whereby the toner is transferred to the toner member by an electrostatic force of the electric field.
The charging roller system has the same principle as the roller type transfer system for charging the photoconductor drum with electricity. In this system, a voltage is applied to a charging roller so that an electric charge is directly applied to the photoconductor drum, which leads to no generation of ozone.
There is proposed an image forming system eliminating a cleaning process (Refer to Japan Hardcopy '89 Thesis pp 143-143). In this system, the photoconductor drum is exposed to light after the photoconductor drum is uniformly charged with electricity by the corona discharge whereby the surface potential of the exposure portion is attenuated. Toner is stuck to the attenuated portion by reversal development while toner in a thin layer which remains on the photoconductor drum is collected therefrom. That is, since the toner which remains on the nonexposure portion of the photoconductor drum after the completion of the transferring process is charged with electricity with the same polarity as that in the developing process, the toner is attracted by the developing unit owing to the electrostatic force caused by the difference between the surface potential of the photoconductor drum which is charged with electricity and the developing bias.
The employment of this cleaningless process can miniaturize the image processing apparatus and can recollect the remaining toner in the developing process. Therefore the toner is not necessary to be disposed of and can be reused with high efficiency.
However, since the ozone free process collects the remaining toner by a cleaning blade or a brush or the like, the collected toner should be disposed of. Furthermore, in the cleaningless process, since the efficiency of the filter for collecting harmful substance is gradually lowered as the time lapses, the filter has to be maintained and controlled by proper replacement, which becomes troublesome.
Accordingly, even if both the processes are combined with each other, since the photoconductor drum contacts the charging roller while the toner remains stuck to the photoconductor drum after the transferring, the toner is attracted to the charging roller with ease, whereby the remaining toner is difficult to be collected in the developing process, thus leading to deterioration of the printing quality.

Apparatus for and method of forming image


A window insertable pet door devised for removable installation in a window without tools and without altering the window by including a center frame having a U-shaped bracket on a top side thereof and a pair of side panels that slidingly extend from the center frame to engage a bottom railing and a respective one of a right railing and a left railing of a window frame. Each side panel includes an outer trim and a static barrier wall therewithin formed of a plurality of vertical popoid pleats. An annular door frame is centrally disposed in the center frame, with a gasket being disposed between the door frame and the center frame. A plurality of pliable triangular flaps, radially disposed within the door frame, converge at a center point of the door frame to simultaneously fold inwardly and outwardly for passage of a cat therethrough.

Various types of pet doors that permit a pet to enter and exit through exterior doors and windows are known in the prior art; however, a majority of these pet doors require the use of tools for installation and the alteration of the door or window into which the pet door is installed. Further, many of the known pet doors require installation near the bottom end of the door, making the pet door accessible to wild animals, rather than to only the pet or pets of a household. What is needed is a window insertable pet door for removable installation in a window without tools and without altering the window and for eliminating accessibility to wild animals. The present device accomplishes the foreoing by including a substantially planar center frame having a U-shaped bracket installed on a top side which receives a lower wall of a slider window therein thereof to assist in securing the center frame to a window. A side panel slidingly extends from each side of the center frame and is configured to removably slidingly engage a bottom railing and a respective one of a right railing and a left railing of a window frame surrounding the window. Each side panel has a continuous outer trim and a static barrier wall continuously disposed within the outer trim and being formed of a plurality of vertical popoid pleats. An annular door frame, centrally disposed through the center frame, has an inner perimeter and an outer perimeter and a plurality of triangular flaps radially disposed therein from a center point. The flaps simultaneously fold inwardly in a direction toward the rear side of the center frame from a neutral position in a same plane as the inner perimeter and alternately simultaneously fold outwardly in a direction toward the front side of the center frame from the neutral position. The door frame has a diameter configured to allow passage of the domestic cat therethrough. A gasket is continuously disposed between the outer perimeter of the door frame and the center frame. The gasket is formed of a mesh screen that permits airflow through the gasket and alternately a solid wall, such as Plexiglass® or glass. The gasket, the flaps, and the side panels prevent wild animals and insects from entering a structure through the device, in contrast to a conventional swinging pet door installed at the bottom of a door.
Thus, the present device is installable into a window with proper support, but without the use of tools and without altering a window or a door as is required by many pet doors. The present device provides a pet caretaker the freedom to be away from home without the worry of whether the pet has access to the outdoors or to the indoors for food, water, and shelter. Use of the present device allows a caretaker to leave a litter box outdoors which, in turn, eliminates odors associated with a litter box from the structure.


A mold for producing a coping used in a dental implant includes a male component having a protrusion and a female screw forming part. The mold further includes a female component having a recess and a male screw forming part having a different rotation direction from that of the female screw forming part. A cavity for producing the coping is formed by combining the male and female components. Since the mold includes a male component having a female screw forming part, and a female component having a male screw forming part with a different rotation direction than the female screw forming part, a produced coping may be easily separated from the male and female components.

When a dental implant surgery is performed, for the patient's convenience, a temporary crown is bonded to a dental implant implanted into the alveolar bone. FIG. 2 shows an exemplary case when a temporary crown 9 is mounted. In order to mount the temporary crown 9, a temporary abutment 2 is combined with an upper portion of a dental implant 1 implanted into the alveolar bone. Then, as illustrated in FIG. 1, acrylic resin is filled in a crown mold 3 for forming the temporary crown 9, the crown mold 3 is fixed to the temporary abutment 2 until the acrylic resin is cured, thereby forming the temporary crown 9.
However, in the above conventional temporary crown bonding method, a large amount of heat is generated and the generated heat lasts for a long time during curing of the acrylic resin filled in the crown mold 3.
In particular, considering that the acrylic resin filled in the crown mold 3 is cured in the mouth of a patient, the patient may experience inconvenience due to the generated heat, and the inconvenience may increase if the generated heat lasts for a long time.
Also, since the conventional temporary crown bonding method directly cures the acrylic resin filled in the crown mold 3, it is not easy to precisely bond the temporary crown 9 to the temporary abutment 2 at a desired position and angle.

Mold for dental copings and copings produced by using the mold


A dimpled heat spreader includes a central portion configured to couple to the circuit board component, an outer portion coupled to the central portion, and dimpled portions disposed within the outer portion. The outer portion is configured to extend from the central portion and support the dimpled portions beyond a footprint of the circuit board component when the central portion couples to the circuit board component. The dimpled portions of such a heat spreader provides more exposed surface area (e.g., per square inch) than conventional heat spreaders with flat end portions for improved and enhanced heat dissipation via natural convection into the ambient air. Moreover, a heat spreader with such dimpled portions is relatively easy and cost effective to make vis-à-vis more complex structures such as fins or posts thus enabling a manufacturer to produce dimpled heat spreaders using a high volume, low cost assembly process.

In general, a heatsink is a large, metallic device having (i) a base which is configured to mount on top of an integrated circuit (IC) package and (ii) fins or posts coupled to the base which extend away from the IC package and into an airstream generated by a fan assembly, i.e., forced convection airflow. Unfortunately, heatsinks are inappropriate in certain environments such as tight or narrow confined spaces in which there is only natural convection available (e.g., a substantially enclosed space with no forced convection airflow) or where forced convection airflow is minimal (e.g., constricted spaces between daughter cards which connect to a motherboard).
One conventional cooling approach for cooling an IC package within a tight space is to use a conventional heat spreader, i.e., a flat metallic device which attaches to the top of an IC package and which dissipates heat into the ambient air with minimal or no access to forced convection airflow. One conventional heat spreader model has two flat end portions and a flat middle portion all of which are substantially 0.013 inches thick. The flat middle portion has substantially the same width and length as the IC package. Each flat end portion has pre-scored bend lines (or folding scores). To install the heat spreader, a technician peals off a protecting seal of adhesive material which is stuck to the flat middle portion. The technician then presses the flat middle portion of the heat spreader onto the IC package so that the flat middle portion adheres to the top of the IC package. If the IC package sits in a restricted space between adjacent circuit board structures (e.g., other neighboring IC packages) the technician can bend each flat end portion along a pre-scored bend line so that the flat end portions do not interfere with the adjacent circuit board structures.
Another conventional heat spreader model includes a monolithic structure which is substantially 0.060 inches thick and has substantially the same width and length as the IC package. This heat spreader does not have any portions that extend beyond the footprint of the IC package. That is, this heat spreader substantially matches the footprint of the IC package along all four sides and simply adheres to the top of the IC package using adhesive in a manner similar to that for the above-described heat spreader with the flat end portions.

Techniques for cooling a circuit board component within an environment with little or no forced convection airflow


A method and apparatus for dicing semiconductor wafers is provided. The method comprises: forming an etch mask on the wafer, and then etching the wafer with a wet etchant, such as KOH, to form a peripheral groove around each die. Etching the wafer can be from the front side of the wafer, from the back side of the wafer or with partial etches from both sides. The etch process can be performed on a single wafer using a spray head apparatus or on batches of wafers using a recirculating dip tank apparatus.

In semiconductor manufacture, integrated circuits are formed on a wafer formed of silicon or another semiconducting material. In general, layers of various materials which are either semiconducting, conducting or insulating are utilized to form the integrated circuits. These materials are doped, deposited and etched using various well known processes. Each wafer is processed to include a large number of individual semiconductor dice or chips.
Following the wafer formation process, the wafer is diced to separate the individual dice for packaging or for use in an unpackaged form. The two main techniques for wafer dicing are scribing and sawing. With scribing, a diamond tipped scribe is moved across the surface of the wafer along pre-formed scribe lines. These scribe lines are also referred to as "streets". The diamond scribe forms shallow scratches in the wafer surface. Upon the application of pressure, such as with a roller, the wafer separates along the scribe line. The breaks in the wafer follows the crystal lattice structure of the wafer substrate. Scribing can be used for wafers that are about 10 mils or less in thickness. For thicker wafers, sawing is the preferred method for dicing.
With sawing, a diamond-tipped saw rotating at high rpms contacts and saws the wafer along the streets. Sawing can be partially or completely through the wafer. Typically with saw cutting, the wafer is mounted on a supporting member such as an elastomeric adhesive film stretched across a film frame.
One problem with either scribing or sawing is that chips and gouges can form along the severed edges of the die. In addition, cracks can form and propagate from the edges into the substrate of the die. Chipping and cracking are particularly a problem with scribing because only one side of a rectangular die can be scribed in the <110> direction. Consequently, cleaving of the other side of the die results in a jagged separation line. Because of chipping and cracking, additional spacing is required between the dice on the wafer to prevent damage to the microcircuits. As a result, not as many dice can be formed on a standard sized wafer and wafer real estate is wasted.
Another problem with conventional scribing and sawing processes is that the equipment is complicated and therefore expensive to install and maintain. Diamond tipped scribes and saw blades in particular are very expensive and require frequent replacement. In addition, with these processes the wafers must be scribed or sawed one at a time. Consequently, throughput is limited unless a large number of machines are employed.
To overcome some of the problems associated with scribing and sawing, abrasiveless methods for dicing semiconductor wafers have been proposed. For example, one proposed abrasiveless dicing mechanism can be etching with a wet etchant. However, such an abrasiveless method has not heretofore been successfully utilized for volume semiconductor manufacture. One problem with dicing a wafer using etching techniques is that wet etchants for silicon can adversely affect the exposed bond pads on the dice. Bond pads formed of aluminum are particularly susceptible to degradation by an etchant such as KOH. In addition, any residuals of the etchant on the die can be catastrophic to the die performance.
In view of the foregoing, it is an object of the present invention to provide an improved method and apparatus for dicing semiconductor wafers into singulated dice. It is yet another object of the present invention to provide an improved method and apparatus for dicing semiconductor wafers that is abrasiveless and that does not form cracks or chips in the singulated dice or adversely affect the electrical devices formed on the dice. It is a still further object of the present invention to provide an improved method of wafer dicing that does not require expensive equipment and consumable components and in which a high volume throughput can be achieved. Other objects, advantages and capabilities of the present invention will become more apparent as the description proceeds.

Method and apparatus for dicing semiconductor wafers


An entertainment system has a music storage system storing a plurality of music pieces, a playback system coupled with the music storage system, a navigation system providing current map information including a present location, wherein a current map has a plurality of zones each being assigned to one of a plurality of zone types, and a controller for controlling playback of selected music pieces, wherein the controller maintains a plurality of playlists, each having a plurality of music pieces and being assigned to at least one zone type. The controller receives information of a present location and a current zone type and selects an assigned playlist, wherein the navigation system further provides information about a distance and/or time to a next zone. The controller modifies the assigned playlist such that a transition to the next zone is timely synchronized with the ending of a music piece of the assigned playlist.

Today's music entertainment systems in vehicle are often based on digital music players that contain a variety of playlists with a plurality of different music pieces. In many cars music can be played from an external portable media player or an onboard system. A stored media or radio is often chosen at random independently of the environment the vehicle is operating in.
In other applications, conventional portable music systems are used for exercising wherein a portable player detects whether a runner drifts off their desired predetermined pace. In such a case the portable player is controlled to start choosing songs from a motivational playlist rather than the standard playlist in order to help the runner maintain their desired pace. The idea in this case is to look at a performance variable such as the pace of the runner, and choose music appropriately to help bring the runner to a predetermined pace.
Some conventional vehicle music entertainment systems affect the music based on the driving conditions such as raising and lowering the volume of the music based on the vehicle speed, or driver cognitive loads from navigation or incoming phone calls. These systems look at the immediate state of the vehicle, and once they detect a specific condition, they react without foresight. For example, U.S. Pat. No. 7,132,596 discloses an automatic music selecting system which can select a piece of music for a driver of a vehicle depending on certain parameters. It includes a music storing device that stores a plurality of music pieces and a navigation system for detecting the current position of the vehicle. Such a system uses a current position information and sensors for detecting environmental conditions, such as a location or weather, or time, to select a music piece. Thus, depending on certain parameters, a specific music piece is selected.
However, this can lead to abrupt changes and uncoordinated playlists. Hence, there is a need for a more sophisticated music selection system for vehicles. The goal is to make the driving experience more pleasurable, as if the drive were scripted to contain a soundtrack.

Predictive environment music playlist selection


An exercise system for use in a vehicle includes a frame that has a pair of spaced apart base members. Support legs extend from each base member and a crossbeam is connected to and extends between each support leg. Mounting fixtures are positioned on each support leg and on each base member. Additionally, one or more exercise devices may be removably secured to each mounting fixture. In operation a user may attach an exercise device to the frame and undertake resistance exercises for the arms, legs and torso. Various sized individuals at various strength levels can be accommodated via altering the resistance of exercise device.

1. Field of the Invention
The present invention relates to personal exercise equipment designed for, although not limited to, use within motor vehicles, particularly, semi tractors, motor homes, buses and large recreational vehicles. Both driver and passenger seats are ideal locations, but the invention is positionable and may be used anywhere in a vehicle.
2. Description of Related Art
Twentieth century mankind has, through its own inventions, made exercising of the body through daily activity almost non-existent. At the same time, medical science has proven the paramount importance of physical exercise to human longevity and quality of life. We, mankind, have therefore invented hundreds of systems and apparatus to artificially or intentionally exercise the body.
Most of this exercise equipment is available to individuals by going to a physical location such as a gym or their own in-home workout location. There is, however, a large and quickly growing group of people who are, for the most part of their lives, mobile and thus unable to go to a fixed location to obtain exercise.
People who spend most or all of their day, and sometimes night, in vehicles are in great need of exercise. The benefits from the ability to safely exercise while seated in a vehicle, stopped or moving, are immeasurable, and are one reason for the present invention.
There have been a few devices created for exercise within vehicles, but all have significant shortcomings when compared to this invention.
U.S. Pat. No. 5,141,482 discusses a seat exercise device to be used specifically and exclusively for abdominal exercise in virtually one position. It further requires the attachment of a mechanism to the body as well as the chair or seat, making the device cumbersome to use and very limited in its scope of exercise.
U.S. Pat. No. 4,013,287 discusses a device that permanently attaches under the dashboard and offers a stirrup attached to a spring device for one to insert their foot in and extend the spring device thereby exercising one or several leg muscles. This device is again very limited in scope of exercise. Further, its location seems to pose a significant safety risk in that it hangs in the area where footwork is required to operate a vehicle.
U.S. Pat. No. 6,183,403 B1 discusses a vehicle exercise system consisting of two very separate parts. Part 1 allows arm use of an elastic member with the member's other end being secured by the upper portion of a vehicle doorjamb. This allows arm exercise, but primarily in a sideways fashion; and with a one-point attachment located above and off to the side of the exerciser, a very limited range of motion is achieved. Certainly, symmetrical exercise of both arms cannot be realized from this setup without changing seats and moving the apparatus to the opposite door. Further, when not exercising, the apparatus must be removed via opening the door. If not removed, it creates an unsafe distraction while dangling in front of the side window of the vehicle. Part 2 allows arm and leg use from an elastic length whose other end is attached to a belt that is attached to the seat. Having only two attachment points offered for the elastic mechanisms again results in a very limited range of exercise motion. Further, it appears that the connection points are free to slide along the length of the seat connection belt, which would result in the elastic members pinching against the exerciser's body when extended, causing discomfort. In addition, both parts of this invention appear to cause wear and likely damage to the vehicle components.
Accordingly, there is need in the art for an exercise system that provides balanced and symmetrical bodily exercise offering a large range of movement (muscles to be exercised), utilizing equipment that is out of the way and non-hazardous when not in use. The present invention accomplishes the above-cited requirements.

Exercise system for use within a vehicle


In a data base processing method including a central processing unit for analyzing a plurality of queries made from a plurality of users so as to determine an internal processing procedure with respect to a data base, and for performing the internal processing procedure; a secondary storage for storing data capable of being shared by each user; and, an input/output controlling processing unit including at least one cache storage, for controlling a transfer of a plurality of records which are required for input/output processing operations between the central processing unit and secondary storage. The data base processing method is featured in that a decision is made whether or not a prefetching operation is carried out at a start of an input/output processing operation by judging the internal processing procedure which has been formed by the query; a retrieval range into which a record to be fetched has been stored is formed when the prefetching operation is performed; and, a prefetching record number is determined as an input/output processing demand unit, taking account of an access characteristic of the internal processing procedure and also a system characteristic containing a size of the cache storage, a performance, of the central processing unit, and a traffic of the input/output processing unit.

The present invention relates to an apparatus and method for processing data in a data base in a computer system.
It should be noted that a data base is arranged according to a relation viewed by a user as a two-dimensional table type, and a line of this two-dimensional table corresponds to a tuple. Also, the tuple is constructed by more than one attribute (referred to as a column).
In data base processing, for instance, a relational data base process, data to be processed is present in a secondary storage (an external memory device, such as a magnetic disk device). A large quantity of data must be read, and transferred with respect to each of a number of data base operations. When a large amount of data is required to be transferred in such a data base system, the required amount of data transfer time deteriorates the performance of the data base system.
To this end, one method has been proposed for efficiently utilizing the time period during which the data is transferred from the secondary storage. That is, the data transfer time period is overlapped with another time period during which the data base is processed. This technique is well known in the art. In general, since the capacities of both a program and data greatly exceed an extension of a main storage capacity, a concept of a current storage architecture is indispensible.
Also, in most data base management systems, in particular a relational data base management system (simply referred in as a "DBMS" hereinafter), a buffer (data base buffer) in a main storage is utilized to hold a copy of a partial data base which has been stored into a secondary storage in order that the input/output processing time is shortened. If the data to be processed, which has already been fetched into the data base buffer of the above-described main memory, still remains after the data process processing, in case the data is again needed, the input/output processing to the secondary storage with the higher access cost is no longer required, resulting in an improvement in the performance of the entire system. However, as the memory capacity of the data base buffer is restricted, a replacement of the content is required, so that the replacement algorithm produces an influence on the system performance. As a consequence, a selection basis for determining which data should be maintained in the data base buffer is important when the data is replaced therein. As one selection basis, for instance, the LRU algorithm (Least Recently Use Algorithm) has been proposed. This algorithm is based upon the assumption that the longer a time period for the data from the last access to the present access becomes, the smaller is the possibility for further access of the data. However, in the normal data base processing, since there is data sequential access processing and data random access processing, the above-described assumption may not be satisfied in all specific cases. As a result, it is not useful in the data base buffer to rely upon the simple LRU algorithm. Since the input interrogation is analized to form an internal processing procedure in the relational DBMS, it is possible to determine the data base reference characteristics. As conventional techniques to solve the above-described problems by using the characteristics information, DBMIN, HOT set model or the like have been proposed.
For example, reference is made to Chou, H., and DeWitt, D. J. "An Evaluation of Buffer Management Strategies for Relational Database Systems" Proc. of the 11th Conf. on VLDB 1985, pages 127-141, and Sacco, G. M., and Schkolnick, M. "A Technique for Managing the Buffer Pool in a Relational System Using the Hot Set Model" Proc. of the 8th Conf. on VLDB 1982, pages 257-262.
In addition, another conventional approach has been well known such that an input/output device including a cache storage is arranged between a main storage the a secondary storage so as to shorten an input/output process time. This cache storage operates to read data of a secondary storage, as a whole, which is stored closely to a record that is input/output in a plurality of record units. Then, if a processing type may be assumed in which there is a high probability to store the record just after the access demand in the cache storage, the input/output processing time can be considerably reduced. That is to say, it is very useful in the central processing unit of DBMS if predictable data can be prefetched and stored into the cache storage when accessed. As previously described, however, since the sequential access processing mode is mixed with the random access processing mode, it is found that the input/output processing time becomes long due to the various read miss operations according to the conventional control method of the cache storage.
In accordance with the above-described conventional techniques, there is no clear proposal that the cache storage is actively scheduled while utilizing the access characteristics predicable in DBMS, so as to shorten the input/output time.
Also, in a system in which a plurality of users simultaneously refer to a data base, the data predictably being referred to is input-processed in the cache storage by overlapping the data transfer time period (containing the seek time period and read time period of the secondary storage) with a time period required for data-base-processing the data in the central processing unit (CPU), whereby the input/output processing time can be essentially shortened. However there is a demand that a high-speed response is required to an interrogation from a user. In addition, in accordance with an internal processing procedure formed by this user's interrogation, since the input/output processing times for the prefetching process which is predicted by the access characteristic of the internal processing procedure are greatly different, there is another problem in the conventional method where the data is read based upon a predetermined prefetching record unit that unnecessary data is prefetched uselessly and also necessary data is not prefetched. Furthermore, it is found that the throughput of the entire system cannot be guaranteed unless the prefetching record number as the input/output process demand unit, or the page number is determined in accordance with the system characteristics representative of a size, a multiplicity and a CPU performance of the cache storage, and a traffic of each input/output processing device.
On the other hand, in a DBMS, there has been proposed a buffer management system based on QLSM (Query Locality Set Model), in which buffers are divided and managed in response to a data base query demand. In this buffer management system, a buffer having a proper size is divided from all of the buffers with respect to the data base query, a replacement algorithm suitable for the data base reference pattern of the query thereof is determined, and the input/output operations of the data are managed for each of the divided buffer groups, i.e., locality sets. If the data page in the locality set of a certain data base query is desired to refer to another data base query, this page is transferred to a locality set of another data base query other than the demanded one. Accordingly, there is a drawback that in this case, the buffer which has stored the data page in question destroys the replacement algorithm of a locality set of a certain data base query.
In the above-described conventional techniques, there are problems that in case that the same data page is referred to in response to a plurality of data base queries, the processing time required for receiving and transferring the data between the buffers of the respective locality sets is increased, the buffer search processing time within other locality sets is increased when there is no data in a locality set itself, and the system cannot depend upon the replacement algorithm of the respective locality sets.

Method apparatus for determining prefetch operating for a data base


Provided is a prepreg suffering little resin particle fall-off and little resin peeling during prepreg production and during handling in order to have excellent dielectric properties for PPE and favorable adhesiveness. A PPE-containing prepreg constituted of a base material and a curable resin composition including PPE particles, wherein the prepreg is characterized in that (1) PPE extracted from the prepreg using a mixed solvent of toluene and methanol in a mass ratio of 95:5 includes PPE particles (A) insoluble in the mixed solvent, (2) the amount of PPE contained in the PPE particles (A) is 70 mass % or higher, and (3) the number-average molecular weight of the PPE contained in the PPE particles (A) is 8,000-40,000.

In recent years, with the significant progress in information network technology and expanding services that implement information networks, there has been a demand for increased data volumes and faster processing speeds for electronic devices. Smaller signal wavelengths are effective for transferring digital signals in greater volumes and at higher speeds, and advances are being made toward achieving higher signal frequencies. Because electrical signals in the high-frequency range tend to decay in wiring circuits, there is a need for electronic circuit boards with high transmission characteristics.
Two approaches are effective for obtaining electronic circuit boards with high transmission characteristics, namely (i) reducing the dielectric loss tangent of the dielectric material (such as the insulating resin reinforced in the base material) and (ii) lowering the skin resistance of the conductor (such as metal wiring).
As a method of (i) reducing the dielectric loss tangent of the dielectric material, there is known a method using a low-dielectric resin such as polyphenylene ether (hereunder, PPE) as the insulating resin. PPE has low permittivity, a low dielectric loss tangent and an excellent high-frequency characteristic (i.e. dielectric characteristic), as well as high heat resistance, and is therefore suitable as an insulating material for electronic circuit boards of electronic devices that utilize high frequency bands.
In PTL 1 there is disclosed a technique of adding a curable monomer or polymer to PPE to form a curable resin composition. In PTL 2, there is disclosed a method of chemically modifying PPE and combining the PPE with triallyl isocyanurate and/or triallyl cyanurate as a curable monomer to form a curable resin composition. PTLs 3 and 4 disclose PPE resin compositions employing low-molecular-weight PPE. Also, PTLs 5 and 6 describe methods using opaque dispersions in which particles of a resin composition comprising a crosslinkable resin such as PPE or styrene-butadiene copolymer and a crosslinking aid such as triallyl isocyanurate (TRIC) are dispersed in a non-chlorine-based organic solvent at ordinary temperature. PTL 7 describes a resin composition comprising low molecular weight PPE and an epoxy resin. PTL 8 describes a method employing a varnish in which PPE particles are dispersed in a solvent consisting of at least 90% water.
PTL 9 describes a low-dielectric resin comprising a PPE-modified butadiene polymer, an inorganic filler and a saturated thermoplastic elastomer. PTL 10 describes a high-frequency multilayer wiring board employing PPE as a low-dielectric resin. PTL 11 describes a laminating material employing a thermosetting resin comprising a resin with a polyphenylene oxide backbone and TRIC, as a low-dielectric resin.

Prepreg comprising polyphenylene ether particles


A heat pipe wherein a condensable liquid phase working fluid is encapsulated in a container sealed in air-tight condition; wherein the wick composed of the porous body for refluxing the liquid phase working fluid by a capillary pressure is provided in the container; wherein a part of the container functions as an evaporating part for evaporating the working fluid by means of inputting the heat from outside; and wherein another part of the container functions as a condensing part for condensing a vapor of the working fluid by means of radiating the heat to the outside; comprises a direct reflux flow passage for flowing the liquid phase working fluid to the evaporating part, which has a flow cross-sectional area greater than that of a cavity formed in the porous body.

1. Field of the Invention
The present invention relates to a heat pipe for transporting heat as latent heat of a working fluid such as a condensable fluid, and especially to a heat pipe which is constructed to create a so-called pumping force for refluxing a liquid phase working fluid to a portion where it evaporates, by means of a capillary pressure of a porous material.
The present invention relates to the subject matter contained in Japanese Patent Application No.2003-38404, filed on Feb. 17, 2003, which is expressly incorporated herein by reference.
2. Related Art
In the customary way, a heat pipe for transporting heat in the form of latent heat of a working fluid is well known in the prior art. The heat pipe of this kind is a heat conducting element encapsulating a condensable fluid such as water in a sealed receptacle (container) after evacuating an air therefrom, and which is constructed to transport the heat as latent heat of a working fluid by evaporating the working fluid with the heat inputted from outside, and by condensing a vapor by radiating the heat after the vapor flows to a condensing part of a low temperature and a low pressure. Accordingly, since the heat is transported in the form of latent heat of the working fluid, the heat pipe has more than ten times to several hundred times of heat transporting capacity in comparison with that of copper which is known to have the highest heat conductivity.
According to the heat pipe of this kind, the heat is transported by means of flowing the evaporated vapor phase working fluid to the condensing part in the low temperature and low pressure side, and after the heat transportation, the condensed liquid phase working fluid is refluxed to the evaporating part (i.e., a heat inputting part) by a capillary pressure of a wick.
The wick is, in short, a member for creating a capillary pressure, and therefore, it is preferable to be excellent in so-called hydrophilicity with the working fluid, and it is preferable to have its effective radius of a capillary tube as small as possible at a meniscus formed on a liquid surface of the liquid phase working fluid. In this connection, a porous sintered compact or a bundle of extremely thin wires is employed as a wick generally in the customary way. Among those wick members according to the prior art, the porous sintered compact may create great capillary pressure i.e., a pumping force to the liquid phase working fluid, because the opening dimensions of its cavities are smaller than that of other wicks. Also, the porous sintered compact may be formed into a seat shape so that it may be employed easily on a flat plate type heat pipe or the like called as a vapor chamber, which has been attracting attention in recent days. Accordingly, the porous sintered compact is a preferable wick material in light of those points of view.
The heat transporting characteristics of the heat pipe including the vapor chamber is thus improved as a result of an improvement of a wick material and so on, and miniaturization is also attempted in connection with this. At the same time, how to cool a personal computer, a server, or a portable electronics device, which are enhanced in its compactness and capacity, has been becoming a problem in recent days. The heat pipe has been garnering the attention as a means for solving this problem, and it has been employed more frequently. Examples of employing such downsized and thin-shaped heat pipe are disclosed in Japanese Patent Nos. 2,794,154 and 3,067,399.
As described above, it is possible to increase the capillary pressure for refluxing the liquid phase working fluid if a porous body is employed as a wick to be built into the heat pipe. This is advantageous for downsizing the heat pipe (or the vapor chamber). If the liquid phase working fluid is refluxed by utilizing the pumping force of the capillary pressure, the liquid phase working fluid is carried inside of the wick; however, in case of the wick of a porous body, because a flow path created therein is the cavity created among the fine powders as the material of a porous body, so that the flow cross-sectional area of the flow path has to be small and as intricate as a maze. Therefore, there is a disadvantage in that the flow resistance is relatively big. Also, the liquid phase working fluid is to be contained in the cavity so that an amount of the working fluid is not always sufficient. Accordingly, if the inputted amount of heat from outside increases suddenly and drastically, for example, there will be a possibility of so-called drying out such that the wick goes into a dry state due to a shortage of the liquid phase working fluid fed to the portion where the evaporation of the working fluid takes place.
Moreover, in general, the porous body to be employed as the wick is produced by sintering the fine powder material, so that there is no particular bias on a void content and it is uniformally even. If the wick of the porous body is moistened by the working fluid, the liquid phase working fluid disperses almost uniformly over the entire part of the wick. Since this is likewise exemplified even when the heat pipe is under operation, the liquid phase working fluid is dispersed and contained even in the portion where the heat is not inputted from outside, in case of the vapor chamber wherein the sheet-shaped porous body is employed as the wick. Consequently, this causes a reduction of the reflux rate or feeding amount of the liquid phase working fluid, to the portion where the heat is inputted from outside. Accordingly, there is room for improvement from this point of view.

Heat pipe excellent in reflux characteristic

International Business Machines Corporation


The present invention pertains to field of medical technology, specifically relates to a pyridino-oxopyridazine derivative of formula (I), its pharmaceutically acceptable salts, its stereoisomers or its solvates, wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R7′, R8′, R9′, L and ring A are defined as the description; the present invention further relates to methods for preparing the compounds, a pharmaceutical composition comprising the compound, and use of the compound and the pharmaceutical composition in manufacture of a medicament for treatment and/or prophylaxis of an inflammatory disease, symptom and condition characterized in undesired inflammatory immunoreaction or associated with undesired inflammatory immunoreaction, as well as all diseases induced by oversecretion of TNF-α and PDE-4 or associated with oversecretion of TNF-α and PDE-4.

Hormones are a kind of compounds influencing cell activity in different manners. In many cases, hormones act as messengers to trigger specific cellular reactions and activities. However, many effects induced by hormones are not caused by specific effects of hormones. On the contrary, a hormone firstly combines with a receptor, thereby triggering release of a second compound, and the second compound further influences cellular activity. In this case, the hormone is called as first messenger, and the second compound is called as second messenger. Cyclic adenosine monophosphate (adenosine-3″,5′-cyclic monophosphate, cAMP or cyclic AMP) is considred as a second messenger of hormones such as adrenaline, glucagon, calcitonin, adrenocorticotrophic hormone, lipotropic hormone, luteinizing hormone, norepinephrine, parathormone, thyroid stimulating hormone and pitressin. Thus, cAMP mediates cellular reaction with hormones, and cAMP also mediates cellular reaction with various neurotransmitter.
Phosphodiesterases (PDEs) have function of hydrolyzing second messengers in cells, degrading cAMP in cells, thereby terminating biochemical action transducted by these second messengers. PDEs family has 11 enzymes, in which PDE4 enzyme is a specific cAMP hydrolase, mainly distributing in airway smooth muscle cells as well as inflammatory cells and immune cells such as lymphocytes, macrophages, neutrophile granulocytes, eosinophilic granulocytes, basophilic granulocytes, mononuclear leucocytes, epithelial cells, regulating cAMP level in these cells.
PDE4 inhibitors can inhibit activities of these immune cells and inflammatory cells, can be used for treatment of diseases caused by inflammations, such as asthma, chronic obstructive pulmonary disease (COPD), rheumatoid arthritis, multiple sclerosis, Alzheimer's disease (AD), Parkinson's disease (PD) and stroke which are central nervous system diseases resulting from neuron injury induced by potential inflammation.
Roflumilast is the first marketed PDE4 inhibitor. Patients with COPD showed a significant decrease in number of neutrophile granulocyte in phlegm after more than 4 weeks of oral administration of Roflumilast, and slight improvement in pulmonary function after more than 6-12 months of oral administration. But it could not significantly alleviate acute exacerbation of symptom or improve life quality, which reason might be the side-effects limited the application dose.
Cilomilast is a PDE4 inhibitor, and is terminated for use at phase III due to adverse reaction of emesis. One concerned problem of using PDE4 inhibitor is side-effects of inducing emesis. Studies have shown that PDE4 has 4 subtypes: PDE4A, 4B, 4C and 4D; wherein PDE4B relates to anti-inflammation, PDE4D also has anti-inflammatory function, but they also relate to central emesis reaction. Some studies have shown that Cilomilast has activity to PDE4D 10 time better than the activity of PDE4B, while Roflumilast has equivalent activity to PDE4B and PDE4D. Therefore, PDE4 inhibitors with equivalent activity to PDE4B and PDE4D would be designed to remarkably reduce side-effect of emesis, increase therapeutic window of drug, and achieve optimal therapeutic effects.
MK-0873 is a drug under study in Merck & Co., and has now entered into clinical phase II. This compound had a module different from Roflumilast and Cilomilast, and data in documents show that it has equivalent activity to various subtypes of PDE4, thereby reducing frequency of adverse effects such as emesis in some extent, increasing therapeutic window and fulfilling better therapeutic effects.

We further optimize the module of MK-0873 compound so as to find desired drug of PDE4 inhibitors to meet clinical requirements.

Substituted pyrido[2,3-c]pyridazin-4(1H)-ones as tumor necrosis factor alpha and phosphodiesterase 4 inhibitors


The present invention is directed to methods for the prophylactic and therapeutic treatment of retinal ischemia and retinal inflammation. The methods involve the administration of an inhibitor of the protein tyrosine kinase pathway to an animal, such as a mammal, in particular a human, in an amount sufficient to treat the retina for ischemia or inflammation prophylactically or therapeutically. The inhibitor of the protein tyrosine kinase pathway is preferably genistein or an analogue or prodrug thereof or a pharmaceutically acceptable salt of any of the foregoing.

Retinal ischemia occurs as a result of occlusion of a retinal blood vessel, such as occlusion of the central retinal vein or artery or a branch retinal vein or artery. Occlusion of blood vessels results in low oxygen tension in adjacent tissues, which triggers a signaling cascade that culminates in neovascularization, capillary nonperfusion and macular edema (Koroma et al., J. Cell. Biochem. 59: 123-132 (1995)). Retinal vein occlusion can occur in patients suffering from hypertension and hyperlipidemia and not infrequently can occur in diabetic patients, in particular patients suffering from type II diabetes. In type I diabetic patients, retinal vein occlusion and chronic hypoxia may be related to other microvascular complications of diabetes, such as diabetic retinopathy and proteinuria, although hypertension and a trend to increased hyperlipidemia are strikingly highly prevalent in diabetic patients with retinal vein occlusion (Dodson et al., European J. Ophthalmol. 3(3): 109-113 (1993)).
Tyrosine-phosphorylated proteins, vascular endothelial growth factor, and basic fibroblast growth factor increase after occlusion of a retinal blood vessel, especially within the occluded blood vessel. In addition, two signal proteins in tyrosine kinase pathways, namely phospholipase C.sub..gamma. and mitogen-activated protein kinase, are activated (Hayashi et al., Invest. Ophthalmol. Vis. Sci. 37(11): 2146-2156 (1996)).
Tyrosine phosphorylation of cellular proteins and changes in the expression of the fibroblast growth factor receptor have been suggested to play a role in the activation of endothelial cell proliferation by short-term hypoxia, such as that resulting from retinal blood vessel occlusion (Koroma et al. (1995), supra). Endothelial response can run the gamut from increased cell proliferation and synthesis of IL-1.alpha. (Shreeniwas et al., J. Clin Invest. 90: 2333-2339 (1992)) and upregulation of TGF.beta. (Santilli et al., Ann. Vasc. Surg. 5: 429-438 (1991)) to increases in glucose transporter (Loike et al., Am. J. Physiol. 263: C326-C333 (1992)), intracellular calcium (Arnould et al., J. Cell. Physiol. 152: 215-221 (1992)), prostaglandins (Michiels et al., Am. J. Physiol. 264: C866-C874 (1993)), membrane-associated proteins (Ogawa et al., Am. J. Physiol. 262: C546-554 (1992)), enthelin-1 (Gertler et al., J. Vasc. Surg. 18: 178-182 (1993)), and platelet aggregating factor (PAF; Caplan et al., Biochim. Biophy. Acta 1128: 205-210 (1992)). The origin of the endothelial cells can affect the manner in which they respond to hypoxia (Tretyahkov et al., Am. J. Physiol. 265: C770-780 (1993)). In this regard, hypoxia-induced phosphotyrosine has been shown to be markedly blocked by the protein tyrosine kinase inhibitors herbimycin-A and methyl 2,5-dihydroxycinnamate (Koroma et al. (1995), supra) but not by the protein tyrosine kinase inhibitor genistein (Koroma et al. (1995), supra).
Retinal ischemia is currently treated by retinal destruction, primarily by laser photocoagulation. The disadvantages of such treatment are obvious, with loss of visual function dependent on the extent of the retinal destruction required.
Ocular inflammation can occur as a result of disease, bacterial or viral infection, ocular surgery, which includes cataract surgery, retinal surgery, refractive surgery, and corneal surgery, e.g., corneal transplantation, and the like. Ocular inflammation can also occur as a result of corneal transplant rejection.
Cystoid macular edema is a common ocular abnormality resulting from a vast etiology and characterized by perturbation of the integrity of the blood-retinal barrier of the perifoveal capillaries and the optic nerve head. Such perturbation is readily observable as leakage of fluoresceine dye by angiography with accumulation of fluid as microcysts in the outer plexiform layer. Causative etiology includes postcataract or laser capsulotomy (Irvine-Gass syndrome), uveitis, branch or central vein occlusion, topical epinephrine use, severe hypertension, radiation retinopathy, perifoveal telangectasia and retinitis pigmentosa.
Ocular inflammation is currently treated by corticosteroids. The disadvantages of such treatment are cataracts, increased intraocular pressure, corneal melting, systemic complications, high blood pressure, aseptic necrosis of the femoral head, cardiovascular diseases, facial hair and many others. Nonsteroidal anti-inflammatory compounds are also administered. The disadvantages of such compounds include certain blood diseases, peptic ulcers, gastric distress, and platelet dysfunction with bleeding, and others.
Therefore, there remains a need for methods for the effective prophylactic and therapeutic treatment of retinal ischemia and ocular inflammation. Accordingly, it is a principal object of the present invention to provide a method of prophylactically and therapeutically treating retinal ischemia, such as that associated with occlusion of the central vein, the central artery, a branch vein or a branch artery, or macular edema following ocular surgery, such as cataract surgery, retinal surgery, refractive surgery, and corneal surgery, e.g., corneal transplantation, and the like. It is another principal object of the present invention to provide a method of prophylactically and therapeutically treating ocular inflammation. e.g., macular edema, such as that associated with disease, bacterial or viral infection, or ocular surgery, such as cataract surgery, retinal surgery, refractive surgery, and corneal surgery. e.g., corneal transplantation, and the like, and corneal transplant rejection, among others. These and other objects of the present invention will become apparent from the detailed description provided herein.

Use of a protein tyrosine kinase pathway inhibitor in the treatment of retinal ischmemia or ocular inflammation

Johns Hopkins University, School of Medicine


A semiconductor chip is flip chip bonded on a substrate wherein the semiconductor chip has a first surface on which bumps are provided. An insulating sealing resin is provided in a space defined between the semiconductor chip and the substrate and also around the semiconductor chip. An electrically conductive resin is provided which extends over a least a part of a second surface of the semiconductor chip, a part of the sealing resin and a ground pattern provided over the substrate.

1. Field of the Invention
The present invention relates to a semiconductor mounting structure, and more particularly to a flip chip semiconductor mounting structure.
2. Description of the Related Art
A conventional flip chip semiconductor mounting structure is illustrated in FIG. 1. A semiconductor chip 1 with bumps 3 is bonded on a substrate 1. The bumps 3 are bonded and electrically connected with mounting pads 5 which have been provided on a bonding surface of the substrate 1. A solder resist 9 is further provided over the bonding surface of the substrate 6 except for the mounting pads 5. The bumps 3 form a space between the semiconductor chip 1 and the substrate 6. A sealing resin 4 is provided in the space defined between the semiconductor chip 1 and the substrate 6.
FIG. 2 is a plane view illustrative of a semiconductor chip 16 adhered via an insulation material such as a glass material on a lead frame without use of die bonding. An insulation oxide film is formed over a surface of the semiconductor chip 16. A ground aluminum wiring 13 is provided over the insulation oxide film wherein the ground aluminum wiring 13 extends over peripheral portions of the semiconductor chip 16. Namely, the ground aluminum wiring 13 extends along each sides of the semiconductor chip 16 to encompass a center portion of the semiconductor chip 16. The insulation oxide film underlying the ground aluminum wiring 13 has a large number of contact holes 15 aligned along the ground aluminum wiring 13. Electrode pads 17 are aligned along the inside of the ground aluminum wiring 13. Ground electrode pads 14 are also provided in the alignments of the electrode pads 17. The ground electrode pads 14 are connected to the ground aluminum wiring 13. It is possible that a bottom surface of the semiconductor chip 16 is adhered via an insulation material such as glass material onto the lead frame. In this case, the ground electrode pads 14 are electrically connected via bonding wiring to external leads for grounding the package so that the substrate of the semiconductor chip 16 is grounded. The ground electrode pads 14 are connected to the ground aluminum wiring 13. This ground aluminum wiring 13 is further electrically connected via the contact holes 15 to the substrate of the semiconductor chip 16. As a result, the substrate of the semiconductor chip 16 are grounded with stability.
The semiconductor chip 16 may be mounted onto the substrate by use of not only the wire bonding but also bumps, for example, the flip chip bonding.
If the flip chip bonding is used to bond the semiconductor chip via bumps onto the mounting pads of the substrate as illustrated in FIG. 1, then the substrate of the semiconductor chip is grounded only via the bumps. Since, however, the ground resistance is large, it is difficult to keep the substrate of the semiconductor chip 1 at the ground potential with stability.
On the other hand, if the semiconductor chip is mounded on the substrate as illustrated in FIG. 2, then it is necessary to provide the ground aluminum wiring on the peripheral region of the semiconductor chip. It is also necessary to further provide a large number of contact holes for contacting the ground aluminum wiring to the substrate. It is furthermore necessary to provide bonding wires for connecting the ground electrode pads 14 to the external leads. For those reasons, the semiconductor chip area is caused to be enlarged. The assembling cost and the mounting cost are caused to be increased.
In the above circumstances, it had been required to develop a novel flip chip mounting structure for allowing stable operations of a semiconductor chip.

Flip chip semiconductor mounting structure with electrically conductive resin


A soft tissue diagnostic apparatus for diagnosis of stress and injury in anatomical soft tissue by detecting the response of the soft tissue to acoustic energy and a method of detecting soft tissue damage or stress and treating the tissue. An acoustic transmitter transmits excitation acoustic energy toward a target area of soft tissue of a subject. An acoustic receiver receives responsive acoustic energy generated by the soft tissue in response to the excitation acoustic energy transmitted by the acoustic transmitter and generates an output signal representative of the response of the soft tissue to the excitation acoustic energy. An analyzer receives the output signal of the acoustic receiver and provides an indication of at least one of stress and injury in the soft tissue based on the output signal. Areas of stress are inhibited to find the origin of soft tissue pain.

1. Field of the Invention
The invention relates to diagnosis and treatment of soft tissue pain. More particularly, the invention is a method and apparatus for measuring responses of soft tissue subject to acoustic stimulation, processing the response, and interpreting the response to indicate the location of stress and/or injury in soft tissue and for verifying the effectiveness of treatment of soft tissue.
2. Description of the Related Art
Existing techniques for diagnosis of the source of pain in soft tissue are relatively subjective and inaccurate. Typically, clinicians rely upon responses to patient questionnaires, medical histories, and subjective observation to diagnose the source of pain in soft tissue. These tools are inherently imprecise even when used in a meticulous manner. Several expensive technologies have been applied to diagnosis of the source of soft tissue pain. For example, magnetic resonance imaging (MRI), x-rays, and computerized tomography (CT) are known noninvasive technologies. Invasive technologies include nerve blocks, probes, and the like. Even when utilizing these technologies, results are frequently inaccurate or inconclusive. Multiple studies have shown that x-rays have little value in routine examination of the source of soft tissue pain. Even MRI is now only rarely recommended in back pain, since surgery based on such imaging has had a high failure rate. Moreover, the demonstration of abnormal scans and x-rays in people who lack back pain symptoms casts serious doubt upon the value of these technologies in soft tissue diagnosis.
Other diagnostics have little value in diagnosing the source of soft tissue pain. Nerve conduction studies and electromyography are indicated for detection of nerve damage only at advanced stages. Measurement devices for indicators of tissue mobility or tension are limited in scope and applicability. Ultrasound may image large muscle tears and can depict certain tissue, but not specifically pain or stress in tissue. Nerve blocks may identify an area of pain but are not suited for routine evaluation because skilled administration of injected anesthetic agents are required and risk factors are elevated. Blood flow analyses also have limited relevance to soft tissue pain.
Serum and saliva analyses for substances associated with pain have been used to diagnose the source of pain. However, protocols, norms, and standardization of sampling and processing techniques have yet to be established for such analyses. One theory is that visualization of chronic neck-shoulder pain can be achieved through the quantification of lowered microcirculation. However, this quantification requires the insertion of optical laser-Doppler single-fibers into two muscle sites concurrently with increased static contraction using electromyography. Of course, this method, even If proven to be accurate, is painful and has a high risk factor.
It is known to use acoustic energy to determine physical properties of various nonliving materials. Also, acoustic energy has been used In various medical applications. For example, U. S. Pat. No. 5,795,311 discloses an apparatus for treating tissue by imparting acoustic energy thereto. U.S. Pat. No. 5,458,130 discloses an apparatus which applies ultrasonic energy for measuring bone density, and strength, and for treating musculoskeletal tissue using a complex signal generator and processing system. U.S. Pat. No. 4,509,524 discloses a device for characterizing tissue based on reflected ultrasonic waves. U.S. Pat. No. 4,819,621 discloses an apparatus for detecting cavitation in tissue injuries by detection of a reflected acoustic signal. U.S. Pat. No. 4,216,766 discloses an apparatus for treating tissue by applying acoustic energy at the resonant frequency of a gas filled cavity surrounding the tissue to be treated. U.S. Pat. No. 5,115,808 discloses an apparatus for measuring the velocity of acoustic signals in tissue for determining the shear elastic properties of the tissue. U.S. Pat. No. 5,545,124 discloses a method for alleviating pain by charging tissue with acoustic shockwaves. However, the prior art does not permit reliable detection of stress in soft tissue through noninvasive measures. Accordingly, the prior art fails to provide a method or apparatus for diagnosing the source of pain due to soft tissue damage or stress.
Therefore, a vast area of difficult and often intractable syndromes of pain defy quantification and thus are difficult to treat in a reliable manner. Conventional diagnostic investigation often yields limited or equivocal findings, and involves expensive, painful and indirect methods. It follows that, therapeutic measures are compromised by this lack of resources.
The phrase "soft tissue" as used herein includes muscles, ligaments, connective tissue and fascia, nerve and blood vessel walls, and other essential structures of the body. Diagnostic designations relating to these tissues include chronic pain, strain, musculoskeletal pain and injury, myofascial pain and injury, benign, non-malignant, or idiopathic pain; myalgia, fibrositis, or fibromylalgia; repetitive strain injury (RSI) or overuse injury, including carpal tunnel syndrome (CTS), epicondylitis, tennis elbow, bursitis and tendinitis, temporomandibular joint disorder (TMD or TMJ), orofacial and neck pain, several types of headache, pelvic pain of unknown etiology, and back pain (all of which are included in the classification of "soft tissue pain" as used herein). The onset of soft tissue pain may have had an identifiable traumatic component but the duration of the pain often far exceeds the expected physiological process of recovery. Gross damage and disease processes are often absent with soft tissue pain.
The economic impact of soft tissue pain is reported by such studies as those of the annual combined cost of back pain-related medical care and disability compensation, which alone may reach $50 billion annually in the U.S. Back pain affects about 31 million Americans, is the leading cause of activity limitation in young adults, and generates annual U.S. productivity losses in the range of $28 billion. Incidence of tension-type headaches has been reported as high as 48.9%, with numerous annual lost workdays and days of decreased effectiveness at work, home, or school. Neck pain occurred at a 34% rate in one study. These statistics are representative of the magnitude of the of soft tissue pain which is severely hampered by lack of efficient diagnosis. It is frequently difficult to differentiate between specific conditions which benefit from surgery and those which do not. Despite due care in evaluation, surgery fails a significant percentage of patients who do not obtain relief and whose condition may even worsen. Conversely, surgical interventions performed for non-pain reasons are themselves a recognized cause of chronic soft tissue pain which is difficult to identify.

Soft tissue diagnostic apparatus and method


A battery assembly has a command module with a power connection interface and a battery matrix interface. A battery matrix has a plurality of battery cells, an electrically erasable programmable read only memory (EEPROM) and a command module interface. The battery matrix interface may be removably interconnected with the command module interface, enabling power delivery from the battery matrix through the command module to the power connection interface and review of the EEPROM for capacity feedback with respect to remaining electrical power of the battery matrix.

Field of the Invention
The invention relates to an electrical power storage system. More specifically, the invention relates to a multiple cell battery system with a removable and thus reusable command module, providing disposable battery cells with smart battery functionality.
Description of Related Art
Integrated communications and/or weapons gear utilized, for example, by law enforcement and/or military personnel requires increasingly high levels of power storage carried proximate the users body. A Conformable Wearable Battery (CWB) is a battery configured for integration with a users body armor, tactical vests, load bearing equipment and/or haul harness, providing mobile electrical power with reduced weight, improved user ergonomics and fail safe characteristics.
A rechargeable CWB with fail safe characteristics is disclosed in copending US Patent Application Publication No. 20130295434, owned by Applicant and hereby incorporated by reference in the entirety. Each rechargeable CWB provides electrical power with smart battery functionality including an on-battery power switch and remaining power visual feedback. The battery type and status information may also remotely queried via a data bus incorporated into the battery power connection interface.
Primary batteries (single use, non-rechargeable) are well known. Although primary battery chemistries typically enable higher energy storage density and lower cost materials, it may be difficult to accurately detect remaining power levels of primary batteries.
Competition within the mobile electrical power storage industry has focused attention upon increasing power capacity while simultaneously reducing size, weight and cost.
Therefore, it is an object of the invention to provide a mobile electrical power storage system that overcomes deficiencies in such prior art.

Conformable wearable battery with removable command module


Systems and methods are provided for charging energy sources with a rectifier using a double-ended inverter system. An apparatus is provided for an electric drive system for a vehicle. The electric drive system comprises an electric motor configured to provide traction power to the vehicle. A first inverter is coupled to the electric motor and is configured to provide alternating current to the electric motor. A first energy source is coupled to the first inverter, wherein the first inverter is configured to provide power flow between the first energy source and the electric motor. A second inverter is coupled to the electric motor and is configured to provide alternating current to the electric motor. A rectifier is coupled to the second inverter and configured to produce a direct current output. The second inverter is configured to provide power from the rectifier to the electric motor.

In recent years, advances in technology, as well as ever evolving tastes in style, have led to substantial changes in the design of automobiles. One of the changes involves the power usage and complexity of the various electrical systems within automobiles, particularly alternative fuel vehicles, such as hybrid, electric, and fuel cell vehicles. Electric and/or hybrid vehicles may be designed to use electrical energy as a primary source of traction power. However, the supply of electrical energy and thus the achievable range of operation of the vehicle are limited based on the components selected as energy sources.
Many of the electrical components, including the electric motors used in such vehicles, receive electrical power from alternating current (AC) power supplies. However, the power sources (e.g., batteries) used in such applications provide only direct current (DC) power. Thus, devices known as "power inverters" are used to convert the DC power to AC power, which often utilize several of switches, or transistors, operated at various intervals to convert the DC power to AC power.
Additionally, such vehicles, particularly fuel cell vehicles, often use two separate voltage sources (e.g., a battery and a fuel cell) to power the electric motors that drive the wheels. "Power converters," such as direct current-to-direct current (DC/DC) converters, are typically used to manage and transfer the power from the two voltage sources. Modern DC/DC converters often include transistors electrically interconnected by an inductor. By controlling the states of the various transistors, a desired average current can be impressed through the inductor and thus control the power flow between the two voltage sources.
The utilization of both a power inverter and a power converter greatly increases the complexity of the electrical system of the automobile. The additional components required for both types of devices also increase the overall cost and weight of the vehicle. Accordingly, systems and methods have been developed for operating a motor coupled to multiple power sources without a DC/DC converter while maximizing the performance of the motor by utilizing dual inverter electrical systems.

Charging energy sources with a rectifier using double-ended inverter system