Carbon Heater Research Articles

Synthesis of Ti3SiC2 polycrystals by hot-isostatic pressing of the elemental powders

Synthesis of Ti3SiC2 polycrystals by hot-isostatic pressing of the elemental powders

Measurement of Effective Thermophysical Properties for Cryopreserved-State Evaluation in Frozen Red Blood Cells Suspension.

The purpose of this study is to estimate the viability of frozen biological materials during cryopreservation with the thermophysical properties. Human red blood cells are selected as test biological material. Propylene glycol (0, 10 and 35%w/w) was selected as cryoprotectant. The test chamber was contacted with carbon heater on a copper block immersed in liquid nitrogen, and cooled from room temperature to -196°C at a cooling rate of 1 to 300°C/min. Temperature rise of 5°C was applied to the suspension at -190°C, the effective thermal diffusivity was determined with Laplace transform method. As a result, the effective thermal diffusivity decreased with decrease of intra-and extracellular ice formation fraction in their suspension, which affects their survival after thawing. Thus assessment of cryopreserved biological materials can be achieved with the thermophysical properties.

Silicon crystal growth using a liquid-feeding Czochralski method

Silicon single crystals with uniformity along the growth direction were grown using a new continuous Czochralski (CCZ) method. Polycrystalline silicon rods used as charge materials are melted by carbon heaters over a crucible without contact between the raw material and other substances. Using this method, silicon crystals with diameters as large as 6 or 8 inch and good uniformity along the growth direction were grown.

Externally heated copper vapor laser using a carbon heater

An externally heated copper vapor laser using a carbon tubular heater is described. A recrystallized alumina tube of 20-mm inner diameter is used as the laser tube, which is located inside the tubular heater. When the heating power of the carbon heater is 3 kW, the temperature of the laser tube is 1600 °C. The average laser output power is measured to be 1.2 W at a laser tube temperature of 1500 °C when the charging voltage to the energy storage capacitor is 5 kV, the pulse repetition rate is 5 kHz, and the Ne gas fill pressure is 10 Torr.

Use of the line-shaped electron beam in silicon-on-insulator (SOI) — a new opportunity in semiconductors

A thin layer of polycrystalline Si is deposited on an insulator such as SiO 2 grown on a Si wafer (active elements may be built on it) or a glass substrate, then it is melted to regrow into a single crystalline film of device quality, on which active element are fabricated. Various energy sources are used in this process including carbon heater, spot and shaped laser or electron beams. The line-shaped electron beam with a very high energy density of over 1 MW/cm 2 seems the most promising one due to its capabilities of generating fewer crystalline defects, negligible thermal effects to the underlying substrate and a high through-put, the most desirable features for 3-dimensional integration which should resolve the difficulties encountered in the present 2-dimensional integration.

Energy Transfer from a Pulsed Thermal Source to He II below 0.3 K

Results of measurements of the angular distribution of the energy flux radiated from a pulsed heater immersed in He II at low temperatures (around 230 mK). It is shown that the energy transfer from a pulsed carbon heater at a relatively high temperature to ambient liquid helium maintained at low temperature cannot be adequately described by the phonon-coupling models. The experimental data on the velocity and angular distribution of the energy flux radiated from the plane of the heater indicate that the energy from the heater is transferred to a layer of hot helium adjacent to the surface of the heater and that this layer acts as the effective source of excitations radiated into the ambient liquid helium. The extent and shape of this source depend on the total energy flux produced by the heater.

銅および銅合金に対する硬ロウのぬれ性

The possibility of alloying can not be avoided at the interface between molten brazing filler metal and base metal in brazing, so the wettability of brazing filler metal can not be easily explained theoretically. We used the original apparatus for wettability test and investigated the relation between the wettability of brazing filler metals of Ag-P-Cu and Ag-Cu-Zn-Cd systems on copper and the silver content in brazing filler metals, one between the wettability and the test temperature, one between the wettability and the atmosphere, and the wettability of brazing filler metals of Ag-P-Cu systems on various copper alloys without flux.The conclusions are as follows:1) As to the wettability of brazing filler metals of Ag-P-Cu systems on copper, the wettability of BCuP-2, -6, -3 and -4, which contain less than 6 percent of silver, make little or no difference and that of BCuP-5, which contains about 15 percent of silver is excellent. As to the wettability of brazing filler metals of Ag-Cu-Zn-Cd systems on copper, the wettability of brazing filler metals containing from about 12 to 50 percent of silver increases with silver content in brazing filler metals and that of LAg-67Cd, which contanins more than 50 percent of silver decrease on the contrary.2) The wettability of brazing filler metals of Ag-P-Cu systems without flux in air atmosphere is less than the one and in carbon heater and in argon gas. The wettability of brazing filler metals of Ag-Cu-Zn-Cd systems with flux is not affected by the kind of atmospheres at all.3) The wettability of brazing filler metals of Ag-Cu-Zn-Cu systems on 6/4 brass in about 50 percent more than the one on copper.4) As the test temperature rises, the wettability of each brazing filler metal increases.5) Brazing filler metals of Ag-P-Cu systems wet copper, 5 percent phosphor bronze and 8 percent phosphor bronze without flux, but do not wet common copper alloys except them.

Note an experiments on the temperature and velocity in the wake of a heated cylindrical obstacle

For the experiments, the results of which are shown in fig. 3, a solid carbon cylindrical rod of diameter 5/8-inch was mounted in a 3-feet wind tunnel of the N. P. L. type. The length of the rod was 3 feet. The rod was directly heated by passing through it a current of about 70 amps/ The experiments, result of which given in fig. 4, were made with a thin walled copper cylinder having a lenticular section (2.·60 inches by 0.53 inch) mounted in the I-foot open-jet junnel. The cylinder was heated by two carbon heaters of diameter 5/16-inch. The current through the carbon rods was 19 amps.