• 대한치과기공학회지
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• 제29권1호
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• pp.49-57
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• 2007

This study was to add crushed frit with different grain sizes to 3Y-TZP so that it could determine the mechanical properties depending on sintering temperature. In this study, 3 types specimens were prepared in powder with respective additions of 20wt.% frit, which was sized through 24-, 48- and 72-hour ball milling with zirconia. Then, sintered pellets were tested in experiments under the temperature variations for different compositions. As a result, this study came to the following findings: 1. It was found that the higher sintering temperature and the longer ball milling time of frit led to the higher sintered density. 2. Bending strength tended to increase with higher sintering temperature and longer ball milling time of frit. 3. Hardness tended to increase with higher sintering temperature and longer ball milling time of frit. 4. However, it was found that fracture toughness didn't vary significantly depending on sintering temperature. From these findings, it was concluded that the smaller frit grain size and the narrower particle size distribution of frit lead to the better mechanical properties.

• 한국약용작물학회지
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• 제20권3호
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• pp.184-189
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• 2012

This study was carried out to have the basic and applied informations relating to increase the productivity and quality of ginseng. 2 years-old ginseng was cultivated under hydroponic culture with the controlled environment conditions in a greenhouse. Major growth characters and yields were investigated with two different temperatures and several growth stages. The plant height and stem diameter were higher at low temperature than those at high temperature. They were not clearly different with six different growth stages. The root length was not clearly different between two temperatures; however it was continuously grown from June until August. The root diameter was higher at low temperature than that at high temperature. It was rapidly increased from June until August. The length, width, and area of leaf were higher at low temperature than those at high temperature. The fresh and dry weights of different plant tissues were also heavier at low temperature than those at high temperature. The moisture content of ginseng root was continuously decreased from June until August. The yield of ginseng was higher at low temperature compared to that at high temperature. The cultivating conditions in hydroponic culture of ginseng, especially temperature, would be an important factor to have better growth and production.

• Fibers and Polymers
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• 제6권2호
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• pp.103-107
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• 2005

An attempt was made to correlate the polymerization temperature and rheological and thermal properties of acrylonitrile (AN)-acrylamide (AM) copolymers. The copolymers were synthesized at different polymerization temperature. The copolymer structure was characterized by gel permeation chromatography (GPC) and Infrared spectrum (IR). The rheological and thermal properties were investigated by a viscometer and differential scanning calorimeter-thermogrametric (DSC-TG) analysis, respectively. When the polymerization temperature increased from $41^{\circ}C\;to\;65^{\circ}C$, the molecular weight $(\bar{M}_w)$ of copolymers decreased from 1,090,000 to 250,000, while its conversion increased from $18\%\;to\;63\%$, and the polymer composition changed slightly. To meet the requirements of carbon fibers, the rheological and thermal properties of products were also investigated. It was found that the relationship between viscosity and $\bar{M}_w$ was nonlinear and the viscosity index (n) decreased from 3.13 to 2.69, when the solution temperature increased from $30^{\circ}C\;to\;65^{\circ}C$. This suggests the dependence of viscosity upon $\bar{M}_w$ is higher at lower solution temperature. According to the result of activation energy, the sensivity of viscosity to solution temperature is higher for AN-AM copolymers synthesized at higher polymerization temperature. The result of thermal analysis shows that the copolymers obtained at higher polymerization temperature are easier to cyclization evidenced from lower initiation temperature. The weight loss behavior changed irregularly with polymerization temperature due to irregular change of liberation heat.

• 한국식품저장유통학회지
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• 제4권1호
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• pp.33-38
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• 1997

In order to provide informations for designing packaging and storage condition of dry jujube (Zizyphus jujuba MILLER), moisture sorption isotherm was determined for temperatures of 20, 30 and 4$0^{\circ}C$, and quality changes were evaluated as function of temperature and water activity. Dry jujube at a given water activity showed higher equilibrium moisture content for lower temperature. Moisture isothem could be fitted by GAB model equation, giving higher C value, lower m0 and relatively constant k value with increase in temperature. Ascorbic acid was lost more highly at higher temperature and water activity, and showed negligible retention for whole range of water activity and temperature studied after 141 days. Browning increased with water activity up to 0.73 at 30 and 4$0^{\circ}C$. Dry jujube of high water activity had high L value in surface color, which represent brightness of surface color. Considering quality retention in the storage, dry jujube is desired to be dried to water activity of 0.42 and be stored at temperature below 3$0^{\circ}C$

• Journal of Plant Biology
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• 제8권1_2호
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• pp.19-23
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• 1965

Interaction occuring among the different Ca concentrations, pH and temperatures in the promotive effect of Ca in pollen growth was studied by using pollen from Crinum asiaticum and Cryptostegia grandiflora. Data for pollen tube elongation were found to be more indicative of representing the promotive action of Ca ion in pollen growth than those for pollen germination, and were served to evaluate the experimental results. The pollen growth increased as the concentration of Ca increase. The optimal pH range for pollen growth shifted from the lower pH to the higher as the concentration of Ca increase. The characteristic Ca effect was disappeared, and no pH effect at various ranges was observed when pollen grains were grown at the low temperature(8$^{\circ}C$). The Ca effect became quite pronounced if temperature were raised. The Ca effect became even mroe striking if the condition was in higher pH ranges (weak alkaline). Higher pH ranges were found to be more favorable for the Ca action, whereas higher temperature was required to bring about more pronounced Ca effect. Thus, the longest pollen tube was obtained with the highest pH, temperature adopted for the medium supplemented with Ca in the present experiment, and the shortest tube with the lowest temperature applied at the highest pH. Pectin synthesis in pollen tube was considered as a metabolic process, whereas Ca binding in pectin of the pollen tube wall as non-metabolic in nature. Disappearance of Ca effect at the low temperature was probably brought about by blocking the metabolic synthesis of pectin, and nonmetabolic Ca binding seems to take place more extensively with higher concentrations of Ca and at higher pH levels than the lower.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.102-104
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• 1996

The fabrication and analytical expression for the temperature dependent capacitance characteristics of inverted staggered hydrogenerated amorphous silicon thin film transistors(a-si :H TFT) from 303k to 363k were presented. The results show that the experimental capacitance-voltage characteristics at several temperatures are easily measured. Capacitance increased exponentially by gate voltage increase and decreased by temperature increase. C/C(max) ratio decreased at higher temperature, C/C(min) ratio increased at higher temperature.

• 한국식품과학회지
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• 제21권3호
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• pp.425-429
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• 1989

고추의 건조 중 중요한 품질요소인 carotenoid 파괴 및 비효소적 갈변의 kinetics를 건조 중 품질측정을 이용한 dynamic test에 의하여 평균 수분함량과 온도의 함수관계를 결정하였다. 1차반응으로 가정된 carotenoid 파괴 속도상수는 고온 고수분에서 높았으며 수분의존성에 있어서 건조중간의 어떤 수분함량에서 최소치를 보여주고 있었다. 온도의존성에 있어서 활성화 에너지는 7.7-27.4kcal/mol로 나타났고 수분함량이 높을수록 높았다. 0차반응으로 분석된 비호소적 갈변은 온도와 수분함량이 높을수록 쉽게 일어났으며 활성화에너지는 7.5-20.2kcal/mol로서 수분함량이 높을수록 높았다.

• 복식문화연구
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• 제12권2호
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• pp.279-289
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• 2004

This study was conducted to compare the hunting reaction of finger in the cold water. Finger skin temperature is measured the left middle finger tip immersion in cold water of 5℃ for 30 minutes and measurements were made on finger skin temperature(Ts), thermal comfort, and cold pain sensations during the experiment at the spring (March) and Winter(December). Results were follows. Is before immersion was at the highest in spring and at the lowest in winter and was closely related to the indoor temperature Ts during immersion and recovery. Mean of finger skin temperature(MST), the skin temperature at the first rise(TTR) and amplitude of finger skin temperature reaction during immersion(AT) were significant higher in spring than that in winter(P＜.01). The lowest skin temperature(LST) during the cold water immersion were significantly higher in spring than that in winter (P＜.05). The frequency of the appearance of cold-Induced vase dilation(CIVD) was higher in spring than that in winter. However, time for the first temperature(TTR) and recovery time(RT) had no seasonal variation. In addition, cold pains during immersion were felt more strongly in spring than in winter. Local thermal sensation, finger thermal sensation in dynamic state during hand immersion was different from that in the Winter. Spring was slowly cold in cold water immersion.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.625-629
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• 2000

Six yearling Suffolk ewes were used to study the effect of different roughage proportion diets (30%=LR, and 70%=HR) and intake levels (0.7 M and 1.3 M) on heat production and thermoregulatory responses in sheep exposed to different ambient temperatures (20 and $30^{\circ}C$). Sheep fed HR had higher heat production (HP) and time spent eating (TSE) and lower time spent standing (TSS) than those fed LR. But effect of roughage proportion on vaginal temperature (Tv) was obvious only at high intake and at $30^{\circ}C$. Sheep fed high intake had higher Tv, HP, TSS, and TSE than those fed low intake. Roughage proportion and intake level did not have an effect on respiration rate (RR), but ambient temperature did. Ambient temperature did not have an effect on HP, TSS and TSE. At $30^{\circ}C$ sheep had higher Tv and RR than those at $20^{\circ}C$. There were interactions between intake level and ambient temperature in TSS, between intake level and roughage proportion in TSE, and between roughage proportion and ambient temperature in HP. Results indicate that high roughage diet imposes a greater potential heat load on animals than low roughage diet when given at high ambient temperature, but not at low ambient temperature. And the effects is more pronounced at high intake.

• Preventive Nutrition and Food Science
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• 제11권2호
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• pp.155-159
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• 2006

Models capable of predicting the product quality of mixed apple and carrot retentates (MACR) have been developed using response surface methodology and used to characterize the effects of processing conditions including average transmembrane pressure (ATP), temperature, and blend ratio. Color, soluble solids, total sugar, vitamin C, acidity, turbidity, and viscosity were used to assess the product quality following the ultrafiltration (UF) process. $L^*-value$ decreased with increased ATP, but the value was not affected by changes in temperature. Blend ratio also greatly influenced the $L^*-value$. Redness ($a^*-value$), on the other hand, was less affected by temperature and ATP. As the ATP and temperature increased, yellowness increased gradually. Soluble solids contents appeared to decrease gradually as the ATP increased for all blend samples, but the effect of temperature seemed to be less. Total sugar content was more affected by temperature than ATP. In general, samples containing 75% carrot had higher amounts of vitamin C regardless of processing conditions. Changes in acidity were also complex and appeared to respond to interactions among ATP, temperature, and blend ratio. Turbidity increased for all samples as both ATP and temperature increased. The higher the amount of carrot in the blend samples, the higher values for turbidity. Although the changes were small, viscosity appeared to increase as the ATP and temperature increased during UF.