903 results about "Pulse electric field" patented technology

A gas diffusion electrode for a proton exchange membrane fuel cell is prepared by electrodeposition of a catalytic metal in nanocrystalline form on a substrate by contacting an electrically conductive substrate and a counterelectrode with a plating bath containing ions of a metal to be deposited on the substrate and passing a pulsed electric current between the substrate and counterelectrode having pulses that are cathodic with respect to the substrate and have a short on-time and/or a short duty cycle with a frequency from about 10 hertz to about 5000 hertz. In a preferred embodiment the electric current is a modulated reversing electric current having pulses that are cathodic with respect to the substrate and pulses that are anodic with respect to the substrate, the cathodic pulses having a short on-time and/or short duty cycle, the charge transfer ratio of the cathodic pulses to the anodic pulses being greater than one, and the frequency of the pulses ranging from about 10 hertz to about 5 kilohertz.

A method and apparatus are provided for delivering an agent into a cell through the application of nanosecond pulse electric fields (“nsPEF's”). The method includes circuitry for delivery of an agent into a cell via known methods followed by the application of nanosecond pulse electric fields to said cell in order to facilitate entry of the agent into the nucleus of the cell. In a preferred embodiment, the present invention is directed to a method of enhancing gene expression in a cell comprising the application of nanosecond pulse electric fields to said cell. An apparatus for generating long and short pulses according to the present invention is also provided. The apparatus includes a pulse generator capable of producing a first pulse having a long duration and low voltage amplitude and a second pulse having a short duration and high voltage amplitude.

A sub-microsecond pulsed electric field generator is disclosed. The field generator includes a controller, which generates a power supply control signal and generates a pulse generator control signal, and a power supply, which receives the power supply control signal and generates one or more power voltages based on the received power supply control signal. The field generator also includes a pulse generator which receives the power voltages and the pulse generator control signal, and generates one or more pulses based on the power voltages and based on the pulse generator control signal. The controller receives feedback signals representing a value of a characteristic of or a result of the pulses and generates at least one of the power supply control signal and the pulse generator control signal based on the received feedback signals.

The present invention is related to methods in which an electric field pulse is applied to cells and tissue. Several embodiments of the present invention relate to the application of electric field pulses to cells to regulate the physiology and biophysical properties of various cell types, including terminally differentiated and rapidly dividing cells. Methods of regulating transcription of a gene in a cell, marking a cell for diagnostic or therapeutic procedures, determining cellular tolerance to electroperturbation, selectively electroperturbing a population of cells, reducing proliferation of rapidly dividing cells in a patient, and facilitating entry of a diagnostic or therapeutic agent into a cell's intracellular structures are also provided.

The invention relates to a metal piece, the roughness concentration of the surface of the metal piece is 0.02 micron to 0.1 micron, and the reflectivity of the surface is 65 percent to 90 percent. A method for processing the surface of the metal piece is used for obtaining the metal piece by polishing a metal substrate, and the polishing comprises the following steps: polishing pretreatment is carried out to the metal substrate; the metal substrate after the polishing pretreatment is dipped in polishing liquid containing ammonium salt and an addition agent, the metal substrate is put on a positive pole, and a pulse electric field with high frequency and high voltage is applied for plasma body polishing; and the metal piece is obtained after the polished metal substrate is washed and parched. Compared with the traditional polishing method, the method for processing the surface of the metal piece has the advantages that the electrochemistry leveling of the surface of the metal substrate is greatly increased, and the roughness concentration is reduced.

A system and method for selectively treating aberrant cells such as cancer cells through administration of a train of electrical pulses is described. The pulse length and delay between successive pulses is optimized to produce effects on intracellular membrane potentials. Therapies based on the system and method produce two treatment zones: an ablation zone surrounding the electrodes within which aberrant cells are non-selectively killed and a selective treatment zone surrounding the ablation zone within which target cells are selectively killed through effects on intracellular membrane potentials. As a result, infiltrating tumor cells within a tumor margin can be effectively treated while sparing healthy tissue. The system and method are useful for treating various cancers in which solid tumors form and have a chance of recurrence from microscopic disease surrounding the tumor.

The invention belongs to the quality analysis technology field and in particular relates to a method of using a plurality of ion traps for the tandem mass spectrometric analysis, including that a high frequency capturing electric field based on a quadrupole field is produced in the first ion trap for capturing ions with various mass-to-charge ratios. A dipolar excitation alternating electric field with certain frequency along the direction of a straight line for connecting the center of the first ion trap center with the center of a second ion trap center is produced in the first ion trap. Thus, the ions with a mass-to-charge ratio oscillate along the direction to reach to the large amplitude under the resonance excitation. Furthermore, a discharged pulse electric field generates in a specific phase of the first ion trap. The ions reaching to the large moving amplitude are discharged and enter the second ion trap. And the ions with other mass-to-charge ratios are still left in the first ion trap. Through a deceleration field added in the second ion trap or the gas collision, the entering ions or byproduct ions are captured and the researching analysis is further made in the second ion trap.

Compositions and methods are provided for modulating the growth, development and repair of cartilage, bone or other connective tissue. Devices and stimulus waveforms are provided to differentially modulate the behavior of chondrocytes, osteoblasts and other connective tissue cells to promote proliferation, differentiation, matrix formation or mineralization for in vitro or in vivo applications. Continuous-mode and pulse-burst-mode stimulation of cells with charge-balanced signals may be used. Cartilage, bone and other connective tissue growth is stimulated in part by nitric oxide release through electrical stimulation and may be modulated through co-administration of NO donors and NO synthase inhibitors. The methods and devices described are useful in promoting repair of bone fractures, cartilage and connective tissue repair as well as for engineering tissue for transplantation.

Pasteurization and sterilization of a flowable material such as food is performed by means of pulsed electric field. The flowable material is passed through a pair of closely spaced narrow electrodes at a high speed. The electrodes are applied with a continuous high electric potential. Because the material spends a very little time between the electrodes, it experiences a short pulse of a high electric field which electrocutes bacteria in the flowable material.

The invention discloses high-linear light transmittance fine crystalline transparent alumina ceramics and a method for making the same under the condition of a pulse electric field. The transparent alumina ceramics is sintered within a temperature range of between 1,050 and 1,400 DEG C with the time of the entire sintering process less than 30 minutes; moreover, the material has a relative density higher than 99.5 percent, average grain size of between 0.3 and 1 micron, Vickers hardness more than 20GPa, bending strength of between 700 and 900 MPa, fracture toughness of between 3 and 4 MPam<1/2> and linear light transmittance more than 50 percent; and the linear light transmittance of a better material can reach to more than 62 percent. The transparent alumina ceramics can be pure alumina with the purity more than 99.99 percent, or can be alumina ceramics in which one sort, or any two sorts, or any three sorts of addition agents including 0.01 to 0.5 percent of MgO, 0.01 to 0.5 percent of Y2O3, 0.01 to 0.5 percent of La2O3 and 0.01 to 0.5 percent of ZrO2 are added. The method for making the transparent alumina ceramics has the characteristics of low temperature and quickness; moreover, the technology has high reliability, and the deviation between the mechanical property and the optical performance of transparent alumina made in different batches is not more than 2 percent.

The treatment of effluents in which a flow of the effluents is subjected to a pulsed electric field that modifies physicochemical and biologic characteristics of the medium, this modification being used during a solid/liquid separation operation, of the settlement or membrane filtration type. The solid/liquid separation operation and the application of a pulsed electric field are operations carried out at different locations along the effluent flow. The pulsed electric field has voltage value, current value, pulse repetition frequency, and voltage front shape characteristics chosen such that the required effluent treatment can be achieved as a function of the locations at which these membrane filtration operations are carried out and a pulsed electric field is applied.

The invention relates to a method for additionally adding an electric field in a ladle furnace to deoxidate and refine without pollution and a device of the method, which belong to the technical field of the refining technology. The method is characterized in that the method comprises: additionally adding the electric field between molten steel or molten metal and molten slag in the ladle furnace, taking the molten slag as a channel which transmits dissolved oxygen in the molten steel or the molten metal outwards, applying a direct current pulse electric field between the molten steel or the molten metal and the molten slag which is on the molten steel or the molten metal, controlling the transmitting direction and the speed of oxygen atoms from a system between the molten steel or the molten metal and the molten slag, simultaneously reinforcing the mass transfer process of the dissolved oxygen in the molten steel or the molten metal, and thereby realizing deoxidation of the molten steel or the molten metal without pollution. The invention has the advantages of simple technology, convenient operation, rapid and effective deoxidation and the like.

The invention relates to a method capable of improving the instant dissolving performance of soybean milk powder and belongs to the technical field of soybean product processing. The method comprises the following steps: (1) adding weak alkali water into soaked soybeans according to a certain proportion for pulping and after pulping, carrying out pulp and residue separation to obtain raw soybean milk; (2) after pulsed electric field processing is performed on the raw soybean milk, adding a proper amount of emulsifier, then carrying out high-pressure steam pulp boiling to obtain cooked soybean milk, adding a proper amount of citric acid into the cooked soybean milk, then adding protease for enzymolysis, carrying out enzyme deactivation and filtering after enzymolysis, adding a certain amount of a reducing agent into the filtered soybean milk to carry out blending and uniform mixing, carrying out vacuum concentration after the blended soybean milk is homogenized, and after concentration, carrying out spray-drying and spraying of soybean phospholipid oil to obtain the instant soybean milk powder. The method has the advantages that the requires process equipment is simple, and is safe to operate; according to the method, the pulsed electric field technology and the enzymolysis technology are utilized; by the synergistic effect of the added reducing agent and emulsifier, the instant dissolving performance of the prepared soybean milk powder is improved; meanwhile, the prepared soybean milk powder has no beany flavor and bitter taste.

A method of converting biological material into energy resources includes transmitting biological material to a pulsed electric field (PEF) station, and applying a PEF to the biological material within a treatment zone in the PEF station to generate treated biological material. The method also includes transmitting the treated biological material to a biogenerator, and processing the treated biological material in the biogenerator to produce an energy resource. A converter may carry out this process, and may include the PEF station and the biogenerator.

The invention discloses a method for repairing micro-defects inside metal materials which can repair the micro-defects inside the metal materials so as to improve the performance of the metal materials without affecting the thermal deformation of the metal materials. The method comprises the following steps: putting the metal material to be repaired in an external physical field excitation device capable of generating a pulsed magnetic field and a pulsed electric field, and selecting the appropriate field treatment process for processing according to the magnetic property of the metal material and the configuration type of the microscopic defect inside the substrate. In this way, the in-situ repair of internal defects of metal materials can be realized by pulsed magnetic field and pulsed electric field induction. Therefore, the plastic toughness of metal materials is improved, the strength of materials can be increased, the abrasion resistance of materials can be greatly improved, the initiation of microcracks can be restrained and expansion of the microcracks can be delayed, and the fatigue life of the materials can be significantly prolonged. In addition, the whole repair process will not cause significant temperature rise and thermal deformation of the metal material.

The high voltage pulse electric field processing device for food and beverage consists of two electrodes connected to two poles of high voltage pulse power supply. The two electrodes are two coaxial hollow pipes in different diameters and the same cross section shapes and are separated with insulating rings on two ends and sealed with insulating discs. The ring interval between two hollow tubular electrodes is cavity for the material to be treated, and there are material inlet and material outlet in the outer layer electrode. The high voltage pulse electric field processing device is suitable for sterilizing food and beverage at normal temperature and artificial ageing of wine, and produces no change of treated material in flavor, state and nutritive components. As wine artificially ageing device, the present invention has fast ageing speed, convenient and efficient treating process.

The invention relates to the technical field of the preparation of the particle reinforced metal-based composite, in particular to a method for synthesizing a particle reinforced aluminum-based composite under a high-intensity ultrasonic field and a pulsed electric field. The method is mainly characterized in that when the melt direct reaction method is adopted to perform the in-situ reaction of the particle reinforced aluminum-based composite, the high-intensity ultrasonic field and pulsed electric field are both applied on the reaction melt. The parameters of the high-intensity ultrasonic field are as follows: the frequency is 22-30kHz and the intensity is 1-10W/cm<2>. The parameters of the pulsed electric field are as follows: the peak density of current is 0.1-10A/cm<2> and the pulse frequency is 0.1-10Hz. The method has the significant advantage of the coupling of the high-intensity ultrasonic field and the pulsed electric field, thus the thermodynamics and kinetics of the in-situ particle formation reaction can be improved, the mixing of the reactant and the melt can be improved and the shape and size of particles in micron-scale/nanoscale can be controlled; and the dispersion effect of particles in the melt can be controlled, and the method is suitable for the preparation of the high performance micron-nano particle reinforced composite.

A technology for fining the solidified Al-alloy structure includes proportioning raw materials, conventional smeling, removing slags and gas, refining, casting while applying a pulse electric field, and cooling.

The invention discloses an emulsion gel in which fat-soluble vitamins are embedded and a production method based on a pulse electric field. The production method includes the following steps: dissolving octenyl succinic acid modified starch in water, heating in a water bath, stirring until the material is completely gelatinized and dissolved, and cooling to room temperature; adding edible oil in which fat-soluble vitamins are dissolved to obtain a mixed solution; using a high-speed shearing machine and a high-pressure homogenizer to shear and homogenize the obtained mixed solution so as to a coarse emulsion; adding starch into the coarse emulsion, and uniformly stirring to obtain an emulsion; adding a methylcellulose solution to the emulsion, uniformly mixing and performing pulse electricfield treatment, heating in a water bath, degassing, and cooling to obtain an emulsion gel. The pulsed electric field of the invention promotes the interaction between methylcellulose and starch molecules, has a higher elastic modulus, and is easier to form a network structure that is more favorable for embedding fat-soluble vitamins. Thereby, fat-soluble vitamins are effectively embedded, and thepurpose of slowly releasing fat-soluble vitamins is achieved.

The invention relates to a method for synchronously preparing high-stability rice bran oil and rice bran protein, and belongs to a vegetable oil and protein extraction processing technology. The method comprises the steps of (1) grinding rice bran and then carrying out extrusion processing to obtain an expanded product; (2) mixing the ground expanded product with water to obtain a mixed liquid, and treating the mixed liquid by using a pulsed electric field; (3) adding alkaline protease into the mixed liquid which is treated by using the pulsed electric field, and carrying out enzymolysis to obtain enzymatic hydrolysate; carrying out enzyme deactivation on the enzymatic hydrolysate, and then carrying out centrifugal separation to obtain free oil, an emulsion, the hydrolysate and residue; separating the free oil, and standing still to obtain the rice bran oil; (4) collecting the hydrolysate and the emulsion, adding neutral protease into the collected hydrolysate and emulsion, carrying out secondary enzymolysis and centrifugal separation, and freeze-drying to obtain the rice bran protein. The method is simple in required processing equipment, low in cost and high in rice bran oil extraction rate, and the high-quality rice bran protein can be obtained at the same time.

Systems, devices, and methods for electroporation ablation therapy are disclosed, with the device including a set of splines coupled to a catheter for medical ablation therapy. Each spline of the setof splines may include a set of electrodes formed on that spline. The set of splines may be configured for translation to transition between a first configuration and a second configuration. Each spline of the set of splines in the second configuration may be petal shaped.