摘要:
22-Dehydrohomocholenic acid and process for preparing the same. 22-dehydrohomocholenic acid finds application as an intermediate in the preparation of 22-dehydro-25-hydroxycholecalciferol and exhibits antibacterial properties.
摘要:
The hole pressure differential is measured by providing at least one hole in a wall along which the liquid is caused to flow. The wall may constitute a portion of a passage, reaction vessel or the like. A pressure transducer or sensor is recessed into the hole to measure the hole pressure therein. At least one non-hole pressure transducer is also provided to measure the non-hole pressure along the wall. The hole pressure and the non-hole pressure, as measured, are combined subtractively, or otherwise, so as to derive the difference between the non-hole pressure and the hole pressure at a particular location along the wall. The non-hole pressure sensor may be located opposite the hole at a point where the non-hole pressure is the same as it would be at the location of the hole. In another arrangement, two non-hole pressure sensors are provided upstream and downstream at intervals from the hole, in which case the hole pressure may be combined subtractively with the average of the non-hole pressures. Similarly, two holes and hole pressure sensors may be spaced upstream and downstream at intervals from the non-hole pressure sensor so that the non-hole pressure may be combined subtractively with the average of the hole pressures. Other arrangements may utilize a sequence of two non-hole pressure sensors and one hole pressure sensor with subtractive combining means to derive the differential hole pressure. Alternatively, two hole pressure sensors and one non-hole pressure sensor may be arranged in sequence. Similar arrangements may be employed to measure the protuberance or negative-hole pressure differentials, by replacing the holes and hole pressure transducers with protuberances and protuberance pressure transducers.
摘要:
A method for preparing optically active 2-substituted-4-hydroxycyclopentane-1,3-diones by subjecting 2-substituted cyclopentane1,3,4-trione or 2-substituted-3-alkoxy-2-cyclopentene-1,4-dione to the fermentative enzymatic action of microorganisms of the orders Endomycetales, Mucorales, Moliliales and Eurotiales.
摘要:
THE PREPARATION OF CASTING OF GRAY CAST IRON HAVING REDUCED CHILL AND HARD SPOTS WITHOUT INCREASED SHRINKAGE HOLES IN WHICH THE COMPOSITION IS FORMULATED TO CONTAIN A METAL COMPONENT SUCH AS TELLURIUM, SELENIUM, BISMUTH OR MISCH-METAL, PREFERABLY IN COMBINATION WITH TITANIUM, TO CARRY THE METAL TO A LIQUID PORTION BELOW THE EUTECTIC ARREST.
摘要:
The disclosed flowmeter comprises a probe or transducer utilizing a C-shaped electromagnet which includes an energizing coil and is adapted to produce a magnetic field extending across a stream of blood, flowing along a blood vessel, or a stream of some other conductive liquid. The movement of the blood across the magnetic field generates a voltage which is picked up by first and second electrodes. Normally, the coil is energized with an alternating or pulsating current. A first output lead is connected to the first electrode, while second and third output leads are connected to the second electrode. The second and third output leads are on opposite sides of a plane including the electrodes and the first output lead, such plane being parallel to the magnetic field. To minimize transformer-type coupling between the coil and the leads, a potentiometer is connected to the second and third leads. The adjustable tap of the potentiometer and the first output lead are employed as the output connections from the electrodes, the tap being adjusted for minimum error signal output. A grounded electrostatic shield is employed between the coil and the leads. Moreover, a ground electrode is positioned to engage the blood vessel at a neutral point between the first and second electrodes. A second adjustable potentiometer is connected across the supply leads for the coil. The tap of the second potentiometer is grounded and is adjusted for minimum error signal output. One or more adjustable balancing capacitors are connected between at least one of the supply leads and at least one of the output connections. Such capacitors are adjusted for minimum error signal output and are effective to neutralize the distributed capacitances between the coil and the output leads. A soft resilient material, such as silicon rubber, is employed to encapsulate the electromagnet and the output leads. Such material is adapted to be compressed by the pulsations of the blood vessel around which the flowmeter probe or pickup is mounted. Thus, the provision of such soft material prevents damage to the walls of the blood vessel.
摘要:
25,26-DIHYDROXYCHOLECALCIFEROL AND METHOD FOR PREPARING SAME. 25,26-DIHYDROXYCHOLECALCIFEROL IS CHARACTERIZED BY ITS ABILITY TO INDUCE INTESTINAL CALCIUM TRANSPORT.
摘要:
A process for separating hafnium from zirconium wherein the tetrahalides of the metals are reacted with a metal selected from the group consisting of aluminum and zirconium in finely divided form in the presence of an aluminum trihalide at a reaction temperature above the melting point temperature for the aluminum trihalide whereby the reaction is carried out in a liquid system with preferential reduction of the zirconium component over the hafnium component to enable separations therebetween.
摘要:
1,25-Dihydroxycholecalciferol. The compound is characterized by antirachitic activity (vitamin D-like activity) and by its high activity in promoting intestinal calcium absorption indicating a more rapid onset of antirachitic activity.
摘要:
An analytical spark gap is provided between the conductors of a resonant line at one end thereof. The other end of the line is connected to a radio frequency power source which can be electronically pulsed. The conductors of the line are preferably in the form of inner and outer coaxial cylinders. The spark gap is preferably between a first electrode at one end of the inner conductor and a second axial electrode connected by means of an end wall to the outer electrode. A current injection input lead is connected to an intermediate point along the line, so as to provide an effective length of one-quarter wavelength between the injection point and the spark gap. In this way, a node is produced at the injection point. Around the spark gap, the outer conductor forms a cylindrical chamber, in which acoustical resonances are set up, with resulting stabilization of the spark in that the spark is held stationary in an axial position. Optical resonance can also be produced within the chamber by providing a cylindrical mirror on the inside of the outer cylindrical conductor around the spark gap.