• 반도체디스플레이기술학회지
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• 제9권4호
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• pp.71-76
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• 2010

According to recent changes in industry for semiconductor devices, a low-temperature treatment has become a necessity. These changes relate to size refinement and the development of new materials. While variation in cooling efficiency does not affect the yield when using a high-temperature treatment, uniform cooling efficiency is necessary avoid "inconsistencies/bends" in low temperature treatments. However it is difficult to increase temperature stabilization in low temperature treatments. In this paper, using CFD (Computer Fluid Dynamics), we analyze and manipulate the design and input of the low-temperature system to attempt to control for temperature variations within the quartz tube, of which airflow appears to be a predominant factor. This simulation includes variable inputs such as airflow rate, head pressure, and design manipulations in the S.C.U. (Super Cooling Unit).

• 한방재활의학과학회지
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• 제21권4호
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• pp.145-156
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• 2011

Objectives: This study was resigned to observe change of body temperature for patients with low back muscular pain after NUGA MRT-II(pulsed electromagnetic therapy) treatment. Methods: This study was a randomized, patient-assessor blind, placebo-controlled, pilot trial study. After the approval of institutional review board(IRB), we have recruited 38 patients suffering from low back muscular pain and divided them into two groups randomly: the treatment group and control group. To the treatment group, NUGA MRT-II was practiced and to the control group sham device was practiced and their low back muscles and acupuncture points three times a week for 2 weeks from February 2011 to May 2011. After 1 week of last treatment, We compared body temperature of two groups. Results: 1. There was significant decrease of body temperature on both Shinsu(BL23), Chishil(BL52), Kwanwonsu(BL26) acupunture points for the treatment group. 2. There was no difference in the decrease of body temperature between treatment group and control group except. Left Kwanwonsu(BL26). Conclusions: We found out that treatment of NUGA MRT-II on low back muscular pain can reduce the temperature of low back.

• Journal of Plant Biology
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• 제32권4호
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• pp.235-245
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• 1989

The contents and the compositions of total free amino acids were investigated in the rice(Oryza sativa L. cv. Chuncheong) seedlings under low temperatures. Activities of some enzymes associated with the markedly changed amino acid content were also investigaetd. Under low temperature, the contents of soluble protein and the total free amino acids increased, while the content of total nitrogen decreased. Although asparagine＋glycine were the most abundant amino acid speceis in the rice seedlings at the control temeprature, low temperature treatment for 3days brought about the decrease in their amount to about 60% level of the control plants. On the other hand, alanine showed the highest increase in the content among all the free amino acids, though glutamine, proline, asprtic acid, valine and tyrosine also increased after low temperature treatment. To eludicate the decrease of asparagine＋glycine level under low temperature, the activities of asparagine aminotransferase and asparaginase which metabolize asparagine were investigated in the rice seedlings under low temperature. The activity of asparaginase increased markedly, while that of asparagine aminotransferase decreased under low temperatures. Therefore, it was suggested that asparaginase metabolizes asparagine predominatly in the rice seedlings under low temperatures.

• 한국전기전자재료학회논문지
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• 제18권2호
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• pp.148-152
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• 2005

Atmospheric low-temperature plasma was produced using dielectric barrier discharge (DBD) plate-type plasma reactor and high frequency of 13.56 Hz. The surfaces of polyimide films for insulating and packaging materials were treated by the atmospheric low-temperature plasma. The contact angle of 67$^{\circ}$ was observed before the plasma treatment. The contact angle was decreased with deceasing the velocity of plasma treatment. In case of oxygen content of 0.2 %, electrode gap of 2 mm, the velocity of plasma treatment of 20 mm/sec, and input power of 400 W, the minimum contact angle of 13$^{\circ}$ was observed. The chemical characteristics of polyimide film after the plama treatment were investigated using X-ray photoelectron spectroscopy (XPS), and new carboxyl group bond was observed. The surfaces of polyimide films were changed into hydrophilic by the atmospheric low-temperature plasma. The polyimide films having hydrophilic surface will be very useful as a packaging and insulating materials in electronic devices.

• 한국생산제조학회지
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• 제20권2호
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• pp.162-168
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• 2011

In this research, nitrogen plasma source ion implantation(PSII) of non-coated tungsten carbide endmill tools was conducted with low heat treatment for increasing wear resistance. After the low heat treatment of PSIIed tools to give a homogeneity of wear resistance, the surface modification of tools was analyzed by hardness test, surface roughness and cutting forces. As for the resultant cutting forces, low heat treatment in temperature of $400^{\circ}C$ and $500^{\circ}C$ is stable because of low cutting resistance. The 20-minutes heat treated tool at spindle speed 25000rpm has superiority of surface roughness, Ra of $0.420{\mu}m$ and was found to have good wear resistance. The higher hardness value was obtained by increasing temperature from $300^{\circ}C$ to $600^{\circ}C$ for PSIIed tools with low heat treatment. As the PSIIed tools under 10minutes at temperature of $600^{\circ}C$ have the highest hardness as Hv of 2349.8, It was analyzed that temperature processing give much influences on hardness.

• 한국자원식물학회지
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• 제24권3호
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• pp.292-297
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• 2011

This experiment was carried out to investigate the appropriate chilling requirements for breaking dormancy by treating the dormant plant of Hanabusaya asiatica with low temperature ($4^{\circ}C$) for different time periods. The rates of sprouting and flowering were higher with longer treatment periods at low temperature. In addition, the growth and flowering of the plant were better when it was potted after treatment at a low temperature for 90 days. The abscisic acid levels and polyphenoloxidase activity of the dormant plant increased during the low temperature treatment, reached a climax 90 days and decreased thereafter. The catalase activity was the lowest after the low temperature treatment for 90 days and increased subsequently. The peroxidase activity increased and showed a sharp rise after the low temperature treatment for more than 90 days. Considering the physiological activities of the enzymes, the changes in the abscisic acid levels, and the characteristics of growth and flowering after sprouting of the plant, the appropriate cold periods required for breaking dormancy could be 90 days.

• 열처리공학회지
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• 제17권2호
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• pp.78-86
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• 2004

Effects of the annealing parameters on the formation of ferrites transformed at low temperatures were studied in cold-rolled ultra low carbon steels with niobium and/or chromium. Niobium and chromium were found to be effective in the formation of the low temperature transformation ferrites. The low temperature transformation ferrites more easily formed when both higher annealing temperature and longer annealing time, allowing substitutional alloying elements to distribute between phases, are in combination with faster cooling rate. It was found from EBSD study that the additions of niobium or chromium resulted in the increase in the numbers of high angle grain boundaries and the decrease in those of the low angle grain boundaries in the microstructures. Both granular bainitic ferrite and bainitic ferrite were characterized by the not clearly etched grain boundaries in light microscopy because of the low angle grain boundaries.

• 열처리공학회지
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• 제23권5호
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• pp.269-276
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• 2010

This study has been carried out to the low temperature plasma nitriding treatment on the mechanical properties of stainless steel at temperature range between $400^{\circ}C$ and $500^{\circ}C$. It was found that there was precipitated to free CrN matrix below $400^{\circ}C$ and there was precipitated S-phase of STS 316L, ${\varepsilon}$-phase of STS 409L and ${\alpha}N$-phase of STS 420J2. STS 316L has formed relatively abundant CrN phase and ${\gamma}^{\prime}-Fe_4N$ phase at $500^{\circ}C$, alternatively STS 409L and STS 420J2 were more deeply nitrided than STS 316L at $500^{\circ}C$.

• 한국작물학회지
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• 제43권3호
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• pp.147-151
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• 1998

The conductivity test is a measure of electrolytes leakage from plant tissue. The shorter the maturation period after heading was the greater electrical conductivity (EC) of rice seed. The polymer-coated seed was not different in EC compared with non-coated seed. As soaking time of rice seed increased, EC increased gradually. The EC varied from 9.9 to 20.7$\mu$S $cm^{-1}g^{-l}$ for control plots and from 21.3 to 41.7$\mu$S $cm^{-1}g^{-l}$ for heat-killed seeds which were produced by autoclaving seeds at 121$^{\circ}C$ for 20 minutes. The germination speed (the rate of 5th day) of rice seed was 94% at control plot, 83% at low temperature and 20% at high temperature. Besides, germination percentage was 95% for the control, 92% for the low temperature treatment and 39% for the high temperature treatment. The EC was negatively correlated (r=-0.771$^{**}$) with germination percentage at low temperature. Water uptake in seeds of 30, 40, 50 days after heading (DAH) was greater than that of 20 DAH. Plant height of seedlings was 9.84 cm for the control but 4.32 cm for the high temperature treatment, and the tallest for polymer-coated seed. Dry weight of seedlings was 0.841 g for the control and 0.287 g at high temperature. Besides, the polymer-coated seed was heavier than non-coated seed. The number of roots was largest from 40 to 50 DAH and polymer-coated seed, but was decreased from 20 to 30 DAH. The length of roots was 20.52 cm at control plot and 19.89 cm polymer-coated seed but 8.68 cm for the low temperature treatment and 7.28 cm for the high temperature treatment.

• 열처리공학회지
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• 제23권5호
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• pp.263-268
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• 2010

This investigation was focused on the low temperature tensile properties, phase change, changes in nitrogen content and corrosion resistance in the 22Cr-5Ni-3Mo duplex stainless steel after high temperature gas nitriding and solution annealing (HTGN-SA). From the HTGN-SA treatment, the duplex (ferrite + austenite) phase changed into austenite single phase. The nitrogen content of austenite single-phase steel showed a value of ~0.54%. For the HTGN-SA treated austenitic steel, tensile strength increased with lowering test temperature, on the other hand elongation showed the maximum value of 28.2% at $-100^{\circ}C$. The strain-induced martensitic transformation gave rise to lead the maximum elongation. After HTGN-SA treatment, corrosion resistance of the austenite single-phase steel increased remarkably compared with HTGN- treated steel.