• Asian-Australasian Journal of Animal Sciences
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• v.23 no.11
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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.

• Journal of Powder Materials
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• v.29 no.1
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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.

• The Journal of the Korean bone and joint tumor society
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• v.3 no.2
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• pp.80-88
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• 1997

Malignant tumors of extremeties involving major neurovascular structures have been treated by amputation. However recent development of diagnostic tools(CT, MRI etc.), surgical techniques, anticancer chemotherapeutic agents, and radiation techniques allow surgeons to treat malignant tumors in the limb without amputation. It has been reported that a local application of low-heat to the tissue with tumor can kill tumor cells. It is, however, not known if the attendant neural and vascular injuries may be recovered. The present study was, therefore, undertakn to address this question in rabbit sciatic nerves. A low-heat injury to the sciatic nerve was induced by perfusing the nerve with $60^{\circ}C$ saline for 30 minutes and the courses of functional and morphological recovery of the nerve were evaluated for 16 weeks. The results are summerized as follows : 1. In the electromyographic nerve conduction test the average amplitude was markedly attenuated at 4 and 8 weeks after the low-heat treatment, but it progressively increased to the level 89.5% of the control at 16 week post-treatment. The average latency in the control group was 0.62 msec. The latency in the experimental group was much longer than this at 4 and 8 week post-treatment, but it progressively reverted to the control level, showing 0.622 msec at 16 weeks. 2. In the needle EMG, many fibrillation potentials and positive sharp waves were appeared until 8 weeks post-treatment. After 16 weeks, however, no fibrillation potential was observed. 3. In the early phase of post-treatment period, the myelinated nerve fibers contained many vacuoles and the number of myelinated nerve fibers appeared to be considerably reduced. However, as time goes myelinated nerve fibers were regenerated, such that after 16 weeks the histologic appearance of the nerve was similar to that of the control group.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.4
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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.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.4
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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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• v.20 no.6
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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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• v.15 no.10
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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.

• Korean Journal of Materials Research
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• v.8 no.4
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• pp.317-322
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• 1998

The stabilization of low dielectric constant SiOF films prepared by conventional PECVD using TEOS and $C_2F_6$ was evaluated by the $N_2O$-plasma post-deposition annealing. Properties of SiOF film became unstable when it was air-exposed or heat-treated. Water absorption of SiOF films was increased as F content was increased due to the for¬mation of F -Si- F bonds. Also F content of SiOF films decreased after heat treatment. $N_2O$-plasma post-deposition annealing was proved to be effective on stabilizing SiOF films. which was mainly due to the formation of thin SiON layer near the top surface of films. However. the value of dielectric constant was greatly increased again when $N_2O$-plasma post-deposition annealing was done for a long time. To stabilize the SiOF films without an increase of dielec¬tric constant by $N_2O$- plasma post-deposition annealing. the annealing time should be kept the minimum value. to which stabilizing effects against air environment and heat treatment were preserved.

• Membrane Journal
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• v.8 no.1
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• pp.29-41
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• 1998

Thin-film composite reverse osmosis membranes of aromatic polyamides were prepared by the interfacial polymerization. Aromatic polyamides as active skin layer were made from the interfacial polymerization of MPD(m-phenylene diamine) in the aqueous and TMC(trimesoyl chloride) in HCFC(1,1-dichloro-1-fluoroethane) organic solvent. The performances of the various reverse osmosis composite membranes prepared by changing processing variables were examined. The performance of membrane manufactured by batch system was varied with organic solvent, monomer concentration, dipping time, heat treatment temperature, acid acceptor, ethanol post treatment, and acid post treatment. Ethanol post treatment was the most dominant factors in increasing permeate amount, while the monomer concentration and dipping time were the main factors in increasing selectivity. The spiral-wound module was produced with the membrane prepared at optimum condition of the continuous process. Comparing the performance of this membrane module made here with that of commercial membrane module, the permeate flux was increased by 33% while the rejection was decreased by 5%.

• Journal of the korean Society of Automotive Engineers
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• v.9 no.2
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• pp.28-33
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• 1987

This thesis is to improve the mechanical properties of carbon steel by the ion-nitriding, and post-heat treatment. The structures of ion-nitrided SM45C steel were changed to martensite by quenching from 730.deg. C and 800.deg. C. And then a few of the quenched specimens was tempered at 200.deg. C for 120 min. The emphasis in this study is focussed on Comparison of hardness and fatigue strength with the ion-nitrided steel. The results obtained are summerized as follows. 1. To improve the hardness and fatigue strength of ion-nitrided steels, it is effective to under take diffusion treatment for a short time at the austenite temperature(800.deg. C). 2. If ion-nitrided steel is heated for a long time at high temperature, de-nitriding occure. 3. The quenching treatment after nitriding on the carbon steel is necessary to improve the mechanical properties of the steels.