• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.6 s.165
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• pp.955-965
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• 2007

Safety helmets are used widely in various industries by workers since they are legally required to wear them. However, thermal discomfort is one of the major complaints from helmet users. To relieve this problem, frozen gelled packs can be considered for use inside the helmets. In this paper, tests were performed on humans to evaluate the physiological strains of wearing safety helmets and to investigate the effects of using frozen gelled packs inside the helmets. Experiments were conducted in a climatic chamber of WBGT $33{\pm}1^{\circ}C$ under four differed experimental conditions: 1) not wearing a safety helmet(NH); 2) wearing a safety helmet with frozen gelled pack A(HA); 3) wearing a safety helmet with frozen gelled pack B(HB); and 4) wearing only a safety helmet(OH). The results were as follows. First, when comparing NH with OH, physiological responses such as $\bar{T}_{sk},\;T_r$, HR and sweat rate were significantly higher in OH and subjective sensations were reported as less hot and more comfortable than NH(p<.05). Second, in regard to the frozen gelled packs inserted inside the safety helmets, some physiological responses in HA were different from those in HB, according to the two different types of packs. HA was hotter, more uncomfortable and less exhausted than HB. However, result from both HA and HB were lower than those from OH in terms of temperature and humidity inside safety helmet, sweat rate, $T_r$ increase, heat storage(p<.05). When wearing safety helmets with frozen gelled packs, it was shown that heat strain can be alleviated. These results are expected to help millions of workers who complain that wearing safety helmets is uncomfortable and messy.

• The Journal of Dong Guk Oriental Medicine
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• v.8 no.2
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• pp.115-129
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• 2000

The cause that the increase of animality fat intakes, under exercise, fatness, adding the stress, advanced age etc., the occurrence rate of the circulation system disease has been increased. And the thrombosis importantly came to the front as the risk factor of these circulation system's disease. Nowadays, the ischemic disease has especially discussed, for example the angina or myocardial infarction, originated in thrombosis that came from the platelet aggregation. In the western medicine, as the cure and prevention, using the aspirin or ticlopidine for platelet aggregation suppressant. But in the , the curing method must be used properly according to the pectoralgia or heartache's kind, state, grade. The platelet do not attache to the normal hemangioendothelial cell. But when it stimulated by endothelium peronia and so on, it attache to the injury endothelium or rise aggregation between the platelet. On this time, it secrete the platelet aggregation inducer as like ADP, thromboxane A2 from the inside of platelet. So it has first defensive function through the aggregation augment that prevent the celerity consumption of blood. But the activation of abnormal platelet occur the platelet grume and thrombogenesis. So it bring up the occlusive angiosis, so to speak, cardiovascular disease, cerebrovascular disease, arterial sclerosis. In oriental medicine, the thrombosis in the category of blood stasis and this blood stasis present the generalise or local blood circulation disturbance that generated by all kinds of pathological fact or blood stream retention accompanying with a series of syndrome. As the syndrome, stabbing pain fixed at certain region, squamous and dry skin, fullness and pain of the chest and hypochondrium, firmness and fullness of the lower abdomen, black stool, dark purple tongue or with ecchymoses and petechiae etc.. has been created. And it becomes the pathopoiesis cause that the convulsion and palpitation, severe palpitatiion, tympanites, the symtom complex with a mass or swelling in the abdomen, insanity, stricken by wind etc.. Moreover, it used the drugs for invigorating blood circulation and eliminating blood stasis or drugs for removing blood stasis for all kinds of syndrome through the blood stasis. And the drugs for activating the blood circulation, such as Salviae Radix, Angelicae Sinensis Radix, Persicae Semen, Achyranthis Radix, Cnidii Rhizoma, Carthami Flos are used for that. And it is used to the herbs of insects that has strong effect about the disintergrating blood stasis such as Hirudo, Scolopendrae Corpus, Buthus, Lumbricus etc.. On this study, It used Geijibokryunghwan(GBH) and the consisting herbs to investigate the influence of platelet aggregation about drugs that used to improvement various symptoms created by the thrombosis in oriental medicine. GBH formula has as formula recorded in the , action of 'eleminating the evil and not impairment of healthy energy' and 'promoting the flow of QI and cold and heat, so used for the expel blood stasis herbs from the ancient. Therefore we investigated the restraint effect of GBH and the consisting herbs about the platelet agregation induced to the ADP, AA or collagen. The conclusion is following. 1. When it added the aggregation inducer after that it added GBH and individual consisting herbs in the PRP, GBH showed the (+) inhibition effect on the platelet aggregation and it showed the (+) inhibition effect in the individual consisting herbs as like Paeoniae Radix and Moutan Cortex Radicis. 2. It showed the (+), (+,++) inhibition effect on the platelet aggregation in Paeoniae Radix Hoelen, Paeoniae Radix Moutan Cortex Radicis, Hoelen Moutan Cortex Radicis etc. 3. In the aggregation inhibition activating on the difference of density, GBH showed strong inhibition effect to the aggregation state induced to collagen, and it showed the inhibition effect in the individual consisting herbs as like Paeoniae Radix and Moutan Cortex Radicis about the aggregation induced by the collagen. 4. It showed the strong inhibition effect about the aggregation induced by the collagen in Paeoniae Radix Hoelen, Paeoniae Radix Moutan Cortex Radicis, Hoelen Moutan Cortex Radicis etc Like this, as confirm GBH and the individual consisting herb's inhibition effect of platelet aggregation, We considerated that GBH and the individual consisting herbs have practical applicational value of clinical trial in the thrombosis caused by platelet aggregation.

• The korean journal of orthodontics
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• v.39 no.4
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• pp.213-224
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• 2009

Objective: The aim of this study was to find out whether Er:YAG laser can aid in debonding ceramic brackets, and to see what kind of method will be the most appropriate for debonding. Methods: One hundred and ninety teeth, monocrystalline brackets ($MISO^{TM}$, HT, Ansan-Si, Korea), polycrystalline brackets ($Transcend^{TM}$ series 6000, 3M Untek, Monrovia, CA, USA) and the KEY Laser3 (KavoDental, Biberach, Germany) were used. Experimental groups were classified according to the type of ceramic brackets, and the amount of laser energy (0, 140, 300, 450, 600 mJ). After applying laser on the bracket at two points at 1 pulse each, the shear bond strength was measured. The effect of heat caused by laser was measured at the enamel beneath the bracket and pulp chamber. After measuring the shear bond strength, adhesive residue was evaluated and enamel surface was investigated using SEM. Results: All ceramic bracket groups showed a significant decrease in shear bond strength as the laser energy increased. The greatest average temperature change was $3.78^{\circ}C$ on the enamel beneath the bracket and $0.9^{\circ}C$ on the pulp chamber. Through SEM, crater shape holes caused by the laser was seen on the enamel and adhesive surfaces. Conclusions: If laser is applied on ceramic brackets for debonding, 300 - 450 mJ of laser energy will be safe and efficient for monocrystalline brackets ($MISO^{TM}$), and about 450 mJ for polycrystalline brackets ($Transcend^{TM}$ series 6000).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5877-5884
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• 2014

Recently, abnormally cold weather has been reported more frequently in winter due to the climate change and abnormal weather changes. On the other hand, the heating capacity of a railcar may be not enough to warm the cabin under severe cold climatic conditions, which is one of the reasons for the passengers' complaints about heating. In this study, the effects of ambient temperature and heater power on the cabin temperature was investigated to obtain the minimum ambient temperature for the tested railcar. The test railcar was placed in a large-climatic chamber, and various ambient temperature conditions were simulated. The effects of the heater output were investigated by monitoring the cabin temperature under a range of heater output conditions. The mean cabin temperature was $14.0^{\circ}C$, which was far lower than the required minimum temperature of $18^{\circ}C$, under a $-10^{\circ}C$ ambient temperature condition with the maximum heat power. When the ambient temperature was set to $0^{\circ}C$ and $10^{\circ}C$, the maximum achievable cabin temperature was $26.1^{\circ}C$ and $34.0^{\circ}C$. Through calculations using the interpolation method, the minimum ambient temperature to maintain an $18^{\circ}C$ cabin temperature was $-6.7^{\circ}C$ for this car. The vertical temperature difference was higher with a higher power output and higher ambient temperature. The maximum vertical temperature difference was higher than $10^{\circ}C$ in some cases. However, the horizontal temperature difference vs. low temperature (< $2^{\circ}C$) was independent of the power output and ambient temperature. As a result, it is very important to reduce the vertical temperature difference to achieve good heating performance.

• Journal of Animal Science and Technology
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• v.54 no.1
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• pp.15-22
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• 2012

This study was conducted to investigate the effects of grain sources on the ruminal methane production in Hanwoo steers. Six Hanwoo steers (BW = 614.4 ${\pm}$ 8.3 kg) were fed, on a DM basis (TDN 6.91 kg), 10% rice straw and 90% barley or corn based concentrate, respectively, according to Korean Feeding Standards (Hanwoo). Each period lasted 18 days including a 14-day adaptation and a 4-day measuring period. The steers were in the ventilated hood-type respiration chamber system (one cattle per chamber) during each measuring period to measure heat and methane production for 1 day. Nutrient intake and digestibility were not affected by steer fed grain sources. Methane concentration was not affected by steer fed either barley or corn-based concentrate, respectively (0.022% vs. 0.025%). Methane production was greater by steers fed corn than those fed barley (119.3 g/day vs. 139.4 g/day). This result indicated that methane emission factor by maintenance energy requirement for the late fattening Hanwoo fed corn was higher than the steers fed barley (43.6 kg/head/year) vs. corn (50.9 kg/head/year). Methane conversion rate (Ym) was 0.04 Ym and 0.05 Ym for barley and corn, respectively.

• Journal of Animal Science and Technology
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• v.53 no.2
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• pp.161-169
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• 2011

Methane production during anaerobic fermentation in the rumen represents an energy loss to the host animal and induces emissions of greenhouse gases in the environment. Our study focused on comparison in methane production from growing Korean native steers fed different grain sources. Six Hanwoo steers (BW = $180.6{\pm}3.1$ kg) were fed, on a DM basis (TDN 2.80 kg), 40% timothy and 60% barley concentrate (Barley) or corn concentrate (Corn), respectively, based on the Korean Feeding Standards. Each period lasted 18 days including a 14-day adaptation and a 4-day measuring times. The steers were in the head hood chamber system (one cattle per chamber) during each measuring time to measure heat and methane production per day. Different grain sources did not affect digestibilities of dry matter, crude protein, crude fiber, crude fat, NDF, ADF and nitrogen-free extract. The mean methane concentrations per day were 202.0 and 177.1 ppm for Barley and Corn, respectively. Methane emission averaged 86.8 and 77.7 g/day for Barley and Corn, respectively. Methane emission factor by maintenance energy requirement for the growing steers fed barley based concentrate was higher than the steers fed corn based concentrate (Barley vs. Corn, 31.7 kg $CH_4\;head^{-1}\;yr^{-1}$ vs. 28.4 kg $CH_4\;head^{-1}\;yr^{-1}$). Thus, methane conversion rate was 0.065 (6.5%) and 0.055 (5.5%) for Barley and Corn, respectively.

• Restorative Dentistry and Endodontics
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• v.31 no.5
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• pp.344-351
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• 2006

The purpose of this study was to evaluate the thermal expansion characteristics of injectable ther-moplasticized gutta-perchas and a Resilon. The materials investigated are Obtura gutta-percha, Diadent gutta-percha, E&Q Gutta-percha Bar and Epiphany (Resilon). The temperature at the heating chamber orifice of an Obtura II syringe and the extruded gutta-percha from the tip of both 23- and 20-gauge needle was determined using a Digital thermometer. A cylindrical ceramic mold was fabricated for thermal expansion test, which was 27 mm long, with an internal bore diameter of 3 mm and an outer diameter of 10 mm. The mold was filled with each experimental material and barrel ends were closed with two ceramic plunger. The samples in ceramic molds were heated in a dilatometer over the temperature range from $25^{\circ}C$ to $75^{\circ}C$. From the change of specimen length as a function of temperature, the coefficients of thermal expansion were deter-mined. There was no statistical difference between four materials in the thermal expansion in the range from $35^{\circ}C$ to $55^{\circ}C$ (p > 0.05). However, Obtura Gutta-percha showed smaller thermal expansion than Diadent and Metadent ones from $35^{\circ}C$ to $75^{\circ}C$ (p < 0.05). The thermal expansion of Epiphany was similar to those of the other gutta-percha groups.

• Clean Technology
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• v.26 no.4
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• pp.329-335
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• 2020

Methanol synthesized from renewable hydrogen and captured CO2 has recently attracted great interest as a sustainable energy carrier for large-scale renewable energy storage. In this study, molten carbonate fuel cell's performance was investigated with the direct conversion of methanol into syngas inside the anode chamber of the cell. The internal reforming of methanol may significantly improve system efficiency since the heat generated from the electrochemical reaction can be used directly for the endothermic reforming reaction. The porous Ni-10 wt%Cr anode was sufficient for the methanol steam reforming reaction under the fuel cell operating condition. The direct supply of methanol into the anode chamber resulted in somewhat lower cell performance, especially at high current density. Recycling of the product gas into the anode gas inlet significantly improved the cell performance. The analysis based on material balance revealed that, with increasing current density and gas recycling ratio, the methanol steam reforming reaction rate likewise increased. A methanol conversion more significant than 90% was achieved with gas recycling. The results showed the feasibility of electricity and syngas co-production using the molten carbonate fuel cell. Further research is needed to optimize the fuel cell operating conditions for simultaneous production of electricity and syngas, considering both material and energy balances in the fuel cell.

• Korean Journal of Agricultural Science
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• v.9 no.2
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• pp.546-555
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• 1982

To evaluate the digestibility and absorbability of proteins, and the rates of energy and nitrogen(N) metabolism of the Korean native goats, studies were carried out with open type respiration apparatus based on the nitrogen-carbon method. The results on the nitrogen retention and the metabolic rate of energy, which was obtained with one male (10-month-old) and one female (24-month-old) goats, both weighing ${\simeq}20kg$, are summarized as follows. 1. When the goats were fed ad libitum the medium quality orchard grass hay, they consumed hay about 0.66 to 0.92% of body weight per day. The hay intake was remained the same even when high quality hay was provided. This amount of hay intake was relatively lower than that of dairy goat and sheep. It was believed to be partly due to the change in feeding enviroment. When fed with hay and soybean meal together, the goats ate hay about 1.06% and soybean meal about 0.60% of body weight, corresponding to 1.66% of body weight as fed basis. 2. The $CO_2$ gas produced from the goat in the open type respiration chamber and absorbed with KOH solution was estimated to be 99~117g/day. The difference in feed intake did not influence the $CO_2$ production; however, these seems to be a linea relationship between body weight and $CO_2$ production. 3. When fed orchard grass hay only, the goats showed protein digestibility of 24~41%. The protein digestibility incresed to 58.2% when fed hay and soybean meal together. A negative nitrogen balance(-0.16g N/day) was observed with goats fed 11.53g N originated from 212g hay and 150g soybean meal. Converting that nitrogen ingested to a crude protein, the amount of crude protein intake by the goats per day was 77.9g compared to 40~45g N known to be required in a day by goat weighing 20kg, indicating that the extra protein ingested was metabolized to provide energy. 4. When the male and female goats comsumed 624 kcal gross energy and 824 kcal gross energy by consuming 158g and 213g of hay, respectively, the digestible energy intake was calculated to be 260kcal for the male and 199kcal for the female goat. The daily heat production of male and female goats were 338kcal and 334kcal, respectively, when fed hay only. However, the female goat fed 212g hay and 150g soybean meal produced about 591kcal per day. Consequently, the energy requirment of the Korean native goats weighing ${\simeq}20kg$ was concluded to be $${\geq_-}$$600kcal net energy per day. 5. The fasting heat product ion of a male goat weighing 27.7kg was 412kcal per day when fasted for 2~3 days. When fasted for 3~4 days, the value decresed to 240kcal. The enviromental temperatures during the expreimental period were ranged from 19 to $34.5^{\circ}C$. The goats seemed to be panting when the chamber temperature rose to $32^{\circ}C$ or above. 6. When fed low levels of dietary protein, serum protein levels of the goats were decresed slightly ($${\leq_-}$$10%); however, urea content in the serum was observed to decrese to a great extent (3X).

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.6
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• pp.761-773
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• 2000

Eighteen growing male Murrah buffalo (Bubalus bubalis) calves were divided into three groups consisting of six animals each and fed three urea ammoniated wheat straw (UAS) -based rations supplemented with concentrate mixtures (roughage: concentrate ratio 58:42) containing deoiled ground nut cake, GNC (8%), formaldehyde treated GNC (8%) or fish meal (8%) to undertake comparative evaluation of these rations in terms of their $CH_4$ production and growth (285 d duration) potential. A digestibility trial (10 d duration) was followed by a comparative calorimetric study in respiration chamber. Dry matter (DM) intake (84.3 to $89.3g/kg\;W^{0.75}d^{-1}$) did not differ between treatments. The digestibility coefficient of DM, organic matter (OM), crude protein (CP), neutral and acid detergent fiber did not differ significantly in different diets. Urinary energy loss as a percent of gross energy (GE) was not affected by diets. Average values of $CH_4$ production were 84.3, 77.6 and 99.1 g/d and $CH_4$ energy losses as percent of gross energy were 5.7, 5.2 and 6.1 percent on .GNC, formaldehyde treated GNC and fishmeal, respectively, and did not differ significantly. When expressed per unit of digestible OM intake, $CH_4$ production (g) was lower (p<0.05) on formaldehyde treated GNC (30.6) than on untreated GNC (30.6) and fish meal (31.9). Total ME intake and heat production were similar and hence the energy balances on different diets were similar. Nutritive value of rations in terms of digestible CP and ME were similar. Average daily gain calculated on the basis of regression of fortnights on cumulative liveweight gain in calves fed on concentrate containing unprotected GNC, protected GNC and fish meal were 437.1, 483.9 and 481.6 g, respectively. This indicated that the intake of energy was sufficient to meet the requirement of calves growing at 400 g per d. However, CP intake was around 150% of the stipulated standard (Kearl, 1982). Feed conversion ratios on unprotected GNC, protected GNC and fish meal were 11.60, 11.10 and 10.4 respectively. It was concluded that because significantly (p<0.05) low $CH_4$ is produced on protected GNC (8%), it is very good and sustainable protein source in comparison to poor quality fish meal and untreated GNC to be used in concentrate mixture for supplementing UAS-based diets.