• Journal of Welding and Joining
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• 제2권1호
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• pp.4-17
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• 1984

Overlaid weld metals of austenitic stainless steel in a pressure vessel of power reactor are usually post-weld heated for a long period of time after welding. The PWHT is considered as a kind of sensitizing and it is important to check the soundness of the weld metal after PWHT, especially about the precipitation of carbides. The purpose of this report is to obtain information on the relation between the change of microstructure and Post-Weld Heat Treatment in the overlaid weld metals. Metallurgical aspects of the problem on austenitic stainless steel heated at $625^{\circ}C$, $670^{\circ}C$, $720^{\circ}C$ and $760^{\circ}C$ for 3, 10, 30, 100 and 300 hours have been investigated by means of optical-micrography, micro-hardness measurement, scanning electron microscope and electron-probe micro analysis. From the results obtained, the following conclusions are drawn; 1) The PWHT above $625^{\circ}C$ for a long time causes a diffusion of carbon atoms from low alloy steel into stainless steel, and consequently carbon is highly concentrated at the boundary layer of stainless steel. 2) C in ferritic steel migrated to austenitic steel and carbides precipitated in austenitic steel along fusion line. At higher temperatures, the ferrite grains coarsened in the decarburized zone. 3) In the change of microstructure of stainless steel overlaid weld metal, the width of carbides precipitated zone and decarburized zone increased with increase of PWHT temperature and time. 4) At about $625^{\circ}C$ to $760^{\circ}C$, chromium carbides, mainly $M_{23} C_6$, precipitate very closely in the carburized layer with remarkable hardening. 5) Precipitation of delta ferrite from molten weld metal depends on solidification phenomenon. There was a small of ferrite near the bond in which the local solidification time was short, comparing with after parts of weld metal. Shape and amount of ferrite were not changed by Post-Weld Heat Treatment after solidification.

• Journal of Acupuncture Research
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• 제26권2호
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• pp.41-48
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• 2009

Objectives : The conventional direct and indirect moxibustion therapies for prostate treatment could not been applied to the acupuncture point of $CV_1$(Conception Vessel Meridian 1, 會陰) because of its boring body region. The position of $CV_1$(會陰) is the back side of hard part between the anus and the genital organ. The conventional moxibustion methods have many troubles in operating to the acupuncture point of $CV_1$(會陰). In order to get rid of these problems, we have suggested the special heat generating terminal especially for prostate. The features of the special heat generating terminal for prostate are the low temperature infrared heater and the adhesive moxa-pad. These features are no burnt, no fiery and especially suitable for the point of $CV_1$(會陰). Methods: The heat generating terminal which is a part of the moxa-extract moxibustion cauterizer is composed of a PTC(Positive Temperature Coefficients) ceramic heater and the adhesive moxa-pad We had got the experimental demonstrations by the stimulating the acupuncture points which are $CV_1$(會陰), $BL_{28}$(Bladder Meridian 28, 膀胱兪), and $CV_3$(Conception Vessel Meridian 3, 中極) with the special heat generating terminal for the prostatitis and the benign prosthetic hypertrophy. And the stimulation level was 43$^{\circ}C$ infrared heat for one hour. The type of thermography is IRIS-5000. Results : With one subject suffering the prostatitis and another subject suffering the benign prosthetic hypertrophy, we cauterized the acupuncture points $CV_1$(會陰), $BL_{28}$(膀胱兪) and $CV_3$(中極) with the special heat generating terminal for prostate. We measured the temperature variations by the thermography before and after stimulations. Finally we estimated the tendency of temperature decreasing in the region of post-stroke urinary symptoms and the improvement of nocturnal enuresis after the stimulations. Conclusions : We suggest that the special heat generating terminal of moxa-extract moxibustion cauterizer proposed herein is effective for the treatment of prostate by NIH-CPSI and IPSS.

• Asian-Australasian Journal of Animal Sciences
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• 제23권11호
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• pp.1462-1468
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• 2010

The effects of vitamin C and vitamin E with selenium on acid-base balance and some stress hormones were evaluated during heat stress in goats. Goats, 1.5 years of age, were divided into control, heat stress and antioxidant treatment groups 1, 2 and 3. Except for the control, all groups were exposed to a temperature of $40{\pm}2^{\circ}C$ with a relative humidity of 30% for 5 h/d for 21 days in a psychrometric chamber. Rectal temperature and respiratory rates were recorded daily post exposure. Blood samples were collected on every 3rd day for estimation of plasma vitamins C and E, total antioxidant activity and hormones, and separate blood samples were taken to estimate acid-base status. The rectal temperature and respiratory rates were increased (p<0.05) in the heat stress group only. Except for pH and $pO_2$, which were increased significantly (p<0.05) other parameters of acid-base balance such as $pCO_2$, $HCO_3^-$, $TCO_2$, BEb, BEcef, PCV and Hb were significantly decreased (p<0.05) in the heat stress group. An improvement in acid-base status was noted in the antioxidant supplemented groups. Prolactin and cortisol levels were significantly (p<0.05) higher and free T3 and T4 levels were significantly (p<0.05) lower in the heat stress group. Levels of prolactin and cortisol were decreased and free T3 and T4 were increased in antioxidant treatment groups. Different levels of antioxidant supplementation resulted in similar protection against heat stress.

• 한국분말재료학회지
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• 제29권1호
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• pp.14-21
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• 2022

In the powder bed fusion (PBF) process, a 3D shape is formed by the continuous stacking of very fine powder layers using computer-aided design (CAD) modeling data, following which laser irradiation can be used to fuse the layers forming the desired product. In this method, the main process parameters for manufacturing the desired 3D products are laser power, laser speed, powder form, powder size, laminated thickness, and laser diameter. Stainless steel (STS) 316L exhibits excellent strength at high temperatures, and is also corrosion resistant. Due to this, it is widely used in various additive manufacturing processes, and in the production of corrosion-resistant components with complicated shapes. In this study, rectangular specimens have been manufactured using STS 316L powder via the PBF process. Further, the effect of heat treatment at 800 ℃ on the microstructure and hardness has been investigated.

• 대한골관절종양학회지
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• 제3권2호
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• pp.80-88
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• 1997

저온 열처리 후 신경의 기능적 회복과정을 연구하기 위해 가토의좌골 신경을 $60^{\circ}C$로 30분간 처리한 후 2주, 4주, 8주, 12주, 16주 후에 근전도 검사 및 조직학적 검사를 실시하여 다음과 같은 결과를 얻었다. 1. 신경전도 검사에서 평균 진폭은 실험 2주째에는 5마리 중 1마리를 제외하고는 측정되지 않았으며, 4주째에는 대조군의 7.2%, 8주째에는 26.8%, 12주째에는 52.9%, 그리고 16주째에는 89.5%의 수준으로 회복되었다. 평균 잠복기는 정상 대조군에서 0.62msec였으며, 실험군에서는 4주째에 3.58msec, 8주째에 2.68msec, 12주째에 1.2msec로 시간이 경과함에 따라 회복되어, 16주째에는 0.622msec로 대조군과 차이가 없었다. 2. 침근전도 검사에서 실험 2, 4, 8주째까지는 많은 수의 세동전위 및 양성 예파가 관찰되었으나, 12주째부터는 그 수가 감소하여 16주째에는 세동전위는 관찰되지 않았고 양성 예파만 관찰되어 손상된 신경이 회복됨을 나타내었다. 3. 조직학적 검사에서 실험 2주 및 4주째에는 유수신경섬유에 상당한 공포성 변성이 있고 신경섬유의 수가 감소된 것을 관찰할 수 있었으나, 시간이 경과할수록 신경섬유의 수가 점차 회복 되었으며 16주째에는 대조군과 차이가 없었다. 이상의 성적으로 미루어 보아 저온열처리에 의해 손상된 신경은 처리후 시간이 경과하며 기능적으로나 형태적으로 회복되므로, 임상적으로 신경이 종양조직으로 둘러싸이거나 접촉된 사지에서도 사지보존술이 가능할 것으로 사료된다.

• 한국대기환경학회지
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• 제30권4호
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• pp.350-361
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• 2014

Exhaust gas containing wood tar of high concentration is discharged from charcoal production kilns. The large amount of emissions are often found by operational failure. The purpose of this study is to investigate the performance of an integrated treatment system in treating charcoal production exhaust. The system, which combined a tar collection device and a post-combustion unit, was proposed to remove moisture, wood tar, particulate matter, and other gas-phase pollutants (CO, $CH_4$, total hydrogen carbons) from exhaust gases. Heat recovery units were also applied in the system to utilize waste heat.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권4호
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• pp.173-178
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• 2003

In this paper, we studied the physical and electrical characteristics of $\textrm{WSi}_{x}$ thin film with respect to the adoption of the DCS (dichlorosiliane) post flow and the variation of deposition temperature. XRD measurements show that as deposited thin film has a hexagonal structure regardless of deposition Process. However, we find that the phase of thin film has changed to a tetragonal structure after the heat treatment at $680^{\circ}C$. Adoption of DCS post flow and increment of deposition temperature result in the increments of Si/W composition ratio. These conditions also result in the increment of sheet resistance by the amount 3.0~4.2$\Omega$/$\square$, but give the tendency in the decrement of stress by 0.27~0.3 E10dyne/$\textrm{cm}^2$. We also find that the contact resistance of word line and bit line interconnection was decreased by the amount 5.33~16.43$\mu$$\Omega$-$\textrm{cm}^2$, when applying DCS post flow and increasing deposition temperature.

• Journal of Ceramic Processing Research
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• 제20권6호
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• pp.655-659
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• 2019

Calcium phosphates such as HA (hydroxyapatite), β-TCP (tricalcium phosphate) and biphasic HA/β-TCP, were synthesized by wet chemical precipitation in aqueous solution combined with ball milling process. Nanosize powders of the calcium phosphates were synthesized using Ca(OH)2 and H3PO4. The effects of initial precursor Ca/P ratio (1.30, 1.50 and 1.67), ball milling process and post heat-treatment on the phase evolution behavior of the powders were investigated. The phase of resulting powder was controllable by adjusting the initial Ca/P ratio. HA was the only phase for as-prepared powders in both cases of Ca/P ratios of 1.50 and 1.67. The single HA phase without any noticeable second phase was obtained for the initial Ca/P ratio of 1.67 in the overall heat-treatment range. Pure β-TCP and biphasic calcium phosphate (HA/β-TCP) were synthesized from precursor solutions having Ca/P molar ratios of 1.30 and 1.50, respectively, after having been heat-treated above 700 ℃. The β-TCP phase has appeared on the pre-existing DCPD (dicalcium phosphate dihydrate) and/or HA phase. Dense ceramics having translucency were obtained at a considerably lower sintering temperature. The modified process offered a fast, convenient and economical route for the synthesis of calcium phosphates.

• Asian-Australasian Journal of Animal Sciences
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• 제15권10호
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• pp.1453-1457
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• 2002

The experiment was conducted to find out the effect of 4 feeding systems on growth, feed intake, eating behavior, lactation performance, gestation period, post-partum heat period, conception rate and parasitic infestation of Black Bengal goat. Twenty four does of approximately 1 year of age were randomly selected for 4 treatment (feeding systems) groups having 6 replications in each. Treatments were stall feeding ($T_1$), tethering ($T_2$), restricted grazing ($T_3$) and grazing ($T_4$). $T_1$ group was housed continuously and adequate amounts of natural grass were supplied for ad libitum feeding. $T_2$ group was tethered for grazing natural grass from 8 a.m. to 4 p.m. being moved at one hour intervals. Goats of $T_3$ group were allowed grazing from 8 a.m. to 1 p.m. $T_4$ group was grazed from 8 a. m. to 4 p.m. Concentrate supplement was given at the rate of 150 g per day per goat for all of the treatment groups. Duration of experiment was 219 days. Daily live weight gain was significantly (p<0.05) higher in case of stall fed goats than that of others. DM intake also significantly (p<0.05) differed among the treatment groups and was 3.40 3.95, 3.76 and 4.05 per cent of their live weight for stall feeding, tethering, restricted grazing and grazing groups, respectively. Rate of rumination was significantly (p<0.05) higher in case of tethering group of goats than that of others. Birth weight of kids, milk yield, lactation period and post-partum heat period were significantly higher in case of stall fed goats than others. Tethering group showed significantly (p<0.05) higher litter size than others. Infestation rate of Fasciola was significantly (p<0.05) higher in the grazing group. In conclusion, it may be stated that among these feeding groups overall performance of stall fed goats was more satisfactory, and that the tethering group showed better performance than the others.

• 한국재료학회지
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• 제8권4호
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• pp.317-322
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• 1998

플라즈마 화학기상증착법에 의해 증착된 저유전율 SiOF박막의 물성 안정화를 위하여 증착후 $N_2O$플라즈마로 열처리함으로써 그 특성을 평가하였다. SiOF박막은 대기방치 및 열처리에 불안정한 성질을 가진다. SiOF 박막은 박막내의 F-Si-F 결합의 존재 때문에 흡습현상이 발생하며, 박막내의 F함량이 증가함에 따라 수분 흡수가 증가한다. 또한 열처리를 거치면서 F이 탈착되어 박막내의 F함량이 감소한다. $N_2O$플라즈마 열처리는 표면에 얇은 SiON층을 형성시킴으로써 박막을 안정화시키는데 효과적이었다. 그러나 장시간의 N/sun 2/O플라즈마 열처리는 유전율을 크게 증가시킨다. 따라서 $N_2O$플라즈마 열처리에 의한 유전율의 증가없이 물성을 안정화 시키기 위해서는, 대기방치나 열처리에 의한 안정화 효과를 유지하면서 $N_2O$플라즈마 열처리에 의한 유전율의 증가를 최소화시킬 수 있는 공정의 확립이 필요하다.