摘要:
The present invention relates to a microbiological process for the production of citric acid by assimilation of olefins. Normal olefins of C.sub.8-40 produced from thermal cracking of petroleum wax or from polymerization of ethylene are suitable as carbon source for this fermentation process. Said process is carried out by culturing the microorganism selected from the group of Candida tropicalis, Candida intermedia and Candida brumptii, their mutants and their variants in the culture medium containing acid olefins. Citric acid is accumulated in said medium in the process of the culture.The most suitable strain utilized in the present invention is Candida tropicalis, their mutants and their variants.
摘要:
The present invention relates to a microbiological process for the production of citric acid by assimilation of .alpha.-olefins, normal paraffins and their mixture. This process is carried out by culturing the microorganisms selected from the group of Candida tropicalis, Candida lipolytica, Candida intermedia and Canida brumptii and their mutants and their variants under higher concentration of dissolved oxygen than that in ordinary aeration in the culture medium. The concentration of dissolved oxygen in the culture medium is suitable in the range of from 5 to 40 ppm, preferably from 10 to 30 ppm on the weight basis of said culture medium in this invention. There is many means of which increase the dissolved oxygen in the culture medium. For example, in case of supplying a mixture of oxygen and air in the culture medium, the mixing ratio is suitable to from 2 parts to 25 parts of oxygen per 10 parts of air, preferably from 4 parts to 17 parts of oxygen per 10 parts of air by volume under normal temperature and pressure. It is important that the period maintaining the high concentration of dissolved oxygen in said culture medium should be immediately after the logarithmic growth phase of cultivation. Consequently, the productivity of citric acid is remarkably improved at high yield of more than 150 g/l in said fermentation process. .alpha.-olefins of C.sub.8-40, normal paraffins of C.sub.8-20 and their mixture are used as carbon source in this invention.
摘要:
The present invention relates to a suppressing method of iso-citric acid formation in producing citric acid from hydrocarbons by fermentation.This process is carried out by culturing the microorganisms selected from the group belonging to Candida tropicalis, Candida lipolytica, Candida intermedia and Candida brumptii and their mutants and variants in the culture medium containing paraffinic and olefinic hydrocarbons and their mixture as carbon source under aerobic conditions, wherein specific non-ionic surface active agent is added to said culture medium.The specific non-ionic surface active agent added to said culture medium is selected from the group of sorbitan fatty acid esters and polyoxy-ethylene sorbitan fatty acid esters. The amount of specific surface active agent added to said culture medium is enough from 0.005 to 0.5 percent by weight, preferably from 0.02 to 0.2 percent on the weight basis of said culture medium.
摘要:
In an apparatus for checking patterns on printed circuit boards by comparing two patterns formed on two printed circuit boards, registration patterns each including orthogonal straight line segments and respectively formed on the two printed circuit boards are imaged by two imagers, and registration images from the imagers are matched by means of a registration unit to accurately match an image of a pattern to be checked on one printed circuit board with an image of a reference pattern on the other printed circuit board.
摘要:
A semiconductor substrate has a major surface, another major surface on the opposite side of the first major surface, a strain gauge stripe formed in the central portion of the second major surface by diffusing an impurity therein, and electrodes connected to the strain gauge stripes. These strain gauge stripes are spaced from the peripheral edge of the second major surface by a distance greater than 1/3 of the length of the same major surface. The first major surface of the semiconductor substrate is bonded to an elastic metal load plate.
摘要:
A method for fabricating an electron device on a substrate includes the steps of forming a dummy film over the substrate such that the dummy film covers a device region of the substrate and an outer region of the substrate outside the device region, forming a dummy pattern by patterning the dummy film such that the dummy patter has a first height in the device region and a second height smaller than the first height in the outer region, forming another film over the substrate such that the film covers the dummy pattern in the device region and in the outer region with a shape conformal to a cross-sectional shape of the dummy pattern, and applying an anisotropic etching process acting generally perpendicularly to the substrate such that a surface of the substrate is exposed in the device region and in the outer region.
摘要:
A non-asbestos-based friction material for brakes, clutches or the like for automobiles, large-size trucks, railway cars and various industrial machines. The friction material has excellent friction and rust preventive characteristics, and attacks the plane it faces to a limited extent. The non-asbestos-based friction material is produced by forming and then curing the non-asbestos-based friction material composition comprising a fibrous base, binder and filler as the major ingredients. The composition contains at least one type of steel fibers selected from the group consisting of iron, special dead soft steel and dead soft steel, containing carbon (C) at 0.13% or less at specific contents, in the fibrous base at 1 to 50% by volume of the whole friction material.
摘要:
A non-asbestos friction material made by molding and curing a composition comprised of a fibrous base, a binder, and a filler has a 100 Hz vibration damping factor (tan &dgr;) at 300° C. minus tan &dgr; at 50° C. value of at least −0.030. The binder may be a rubber-modified high-ortho phenolic resin, a resin mixture of a rubber-modified high-ortho phenolic resin and a rubber-modified phenolic resin, or a resin mixture of two or more rubber-modified phenolic resins. The friction material has an excellent and long-lasting noise performance, and good wear resistance, functional stability, and fade resistance. The rapid curability of the composition enables a short molding cycle.
摘要:
A pressure transducer is arranged to mount a semiconductor pressure sensor in a housing such that the pressure of a high-pressure fluid is applied to one side of the semiconductor pressure sensor through a high pressure seal diaphragm and a sealed liquid in the high pressure side, while the pressure of a low-pressure fluid is applied to the other side of the sensor through a low-pressure seal diaphragm and a sealed liquid in the low pressure side, and a protecting member is provided closer to the low-pressure seal diaphragm.
摘要:
A differential pressure transmitter has a pressure receiving portion and a sensor portion which are constituted from separate parts separably jointed with each other. The sensor portion includes a semiconductor sensor having one side formed with a resistance pattern and the other side which has a thick-walled peripheral portion and a thick-walled central portion. The semiconductor sensor is incorporated in the sensor portion as being supported at the thick-walled peripheral portion thereof. The pressure receiving portion includes seal diaphragms disposed on both sides of the pressure receiving portion and a central diaphragm disposed therein. The semiconductor sensor is arranged such that the side thereof carrying the resistance pattern faces the pressure receiving portion.