The diesel engine uses the intercooler for cooling of charging air by the turbo-charger. But the cooling efficiency of the intercooler which is influenced by the vehicle speed is decreased in low vehicle speed. If the vortex tubes are substituted for the intercooler due to their many intrinsic benefits in many industrial fields as parts for refrigerating machines, the cooling efficiency could be advanced in the low speed range. In this study, a counter-flow type of vortex tube is employed to investigate the temperature separation characteristics with various geometric configurations for optimization of charging air cooling. A parametric study was conducted to evaluate the performance of the vortex tube with various geometric structures and operating inlet pressures. The results show that variation of the cold exit orifice hole diameter significantly influences the energy separation between two exits.

Bumblebees are widely used to pollinate various crops, especially tomato, in greenhouses and fields. An artificial hibernation is essential for year-round rearing of the bumblebee that undergoes one generation per year. Here, we investigated whether a cold temperature and humidity affect artificial hibernation of the bumblebee queen Bombus terrestris. In cold temperature regimes of 0℃, 2.5℃, 5℃, 7.5℃ or 12.5℃ under a constant humidity 70% over, the queens stored at 2.5℃ was the best performance in survival rate, which was 74.0% in one month, 67.0% in two months, 60.0% in three months, 46.0% in 4 months, 33.0% in 5 months, and 24.0% in 6 months and lowed in the order of 0℃, 5℃, 7.5℃ and 12.5℃. And also, the colony developmental characteristics after diapause was 1.2-1.5 fold higher than those at queens stored at 5℃. In terms of cold humidity, the queens hibernated at 70% under 2.5℃ was the best performance in survival rate, which was 93.3±3.4% in one month, 83.3±0.0% in two months, 76.7±0.0% in 3 months and 36.7±12.1% in 5 months and lowed in the order of 50% and 90%. The rates of oviposition, colony foundation and progeny-queen production of queens hibernated at 70% were 80.8%, 30.8% and 30.8%, respectively. These values correspond to 1.7-3.3 fold that at queens stored at 50%. Therefore, 2.5℃ and 70% R.H. were the favorable cold temperature and humidity conditions for diapauses-break of B. terrestirs queen.

고무제품에 근간을 둔 면진장치는 상당한 저온효과와 약간의 변형도 속도효과를 보여준다. 면진장치의 비탄성거동에 영향을 미치는 이들의 속성은 면진장치의 거동을 정확히 모델링하기 위해 반드시 고려되어져야 하기 때문에, 고무와 납 모두에 영향을 미치는 저온효과와 변형도 속도효과를 고려할 수 있는 해석모델을 제시하였다. 얼린 면진장치를 일정 수직하중에서 수평방향 반복하중을 가한 실험결과들로부터 시스템 식별(SI : system identification)을 적용하여 해석모델에 필요한 고무와 납의 매개변수들을 구하였다. 제안된 해석모델은 면진장치의 거동을 유사하게 표현할 수 있음을 보여준다.

The research of cold therapy is preceding rarely nowadays. This study was researched to measure the skin temperature of the right foot malleolus when the leg change the situation precisely speaking it was cold, elevation, cold plus elevation. Twenty young healthy volunteers(M:10, F:10)with no history of cardiopulmonary disease, peripheral artery disease were tested. This study were analyzed by one-way-repeated ANOVA. In the first we examined the within changes of the skin temperature between before and after examination for each modality. The skin temperature at all of modalities had fallen. Therefore we could know the fact that elevation plus cold modality had fallen skin temperature significantly more than elevation or cold. And there were no significant difference between male and female. We conclude that elevation and cold therapy could be better effective on edema, contusion and sprain than cold or elevation therapy independently.

지구/행성 내부의 다양한 지질학적 과정을 이해하기 위해서는 고온-고압 환경에서 지구 내부 구성 물질의 특성을 이해하는 것이 필수적이다. 이러한 고압환경을 생성하기 위하여 사용되는 멀티 앤빌 프레스 (multi-anvil press)는 주로 상부맨틀조건의 극한 상황을 재현하는데 사용된다. 멀티 엔빌프레스의 지질학적 사 용을 위한 필수 보정 과정 중 하나는 압력을 생성하기 위한 프레스의 유압과 실제로 시료에 가해지는 압력 사이의 관계인 압력-부하 보정(pressure-load calibration)이다. 압력-부하 보정은 일반적으로 고온-고압 조건에 서는 결정질 물질의 상전이를 이용해서 이루어지는데, 고온에서의 경우와 달리 저온(상온)의 경우 상전이 과 정이 상대적으로 비효율적이므로 압력-부하 보정의 다른 방법론이 요구된다. 본 연구에서는 파이로프 조성 (Mg3Al2Si3O12)의 비정질(비정질 파이로프)의 상온에서의 압축(cold compression)에 따라 발생하는 영구적인 고 밀도화 현상(permanent densification)과 그 기원이 되는 알루미늄 배위 환경의 변화를 고해상도의 27Al MAS 및 3QMAS NMR 분광분석을 통해 정량화하고, 이로부터 압력에 따른 알루미늄의 배위수 변화를 이용해 14/ 8 HT 조립세트(assembly set)와 1,100톤 멀티 앤빌 프레스에 대한 상온에서의 압력-부하 보정을 수행하였다. 본 연구는 NMR분광분석을 이용하여 압력보정을 수행한 최초의 연구결과이며, 비정질 파이로프의 압축-감압에 따른 원자 단위에서의 비가역적 구조 변화는 섭입대 환경과 같은 저온 고압 환경에서 비정질 물질이 겪는 변 화와 그에 따른 지질학적 현상의 이해고양에 실마리를 제공한다.

The Korean Peninsula has experienced regime shift (RS) in winter temperature since the mid-1980s. After the RS, monthly mean temperature significantly increased by 1.05°C in December with 95% confidence level, 1.36°C in January with 99% confidence level, and 1.60°C in February with 99% confidence level, respectively. Interestingly there is no RS in warm winter with 95% confidence level while there is a clear RS in cold winter with 99% confidence level, especially in December and January (DJ), indicating that the RS of winter temperature is mainly due to an abrupt temperature shift in December and January after the RS. Composite analysis suggests that abrupt shift in January after the RS is related to the reduction in sea level pressure (SLP) between Siberian high and Aleutian low, leading to anomalous southerly. However, abrupt shift in December is closely related to the propagation of Rossby wave spanning from the weakening of Ural high to negative anomaly over the North Pacific via high pressure anomaly over the Korean Peninsula, leading to adiabatic heating. Wave activity flux analysis suggests that the abrupt shift of DJ and the associated high pressure anomaly over the Korean Peninsula is induced by the propagation of Rossby wave spanning from North Atlantic Ocean to the Korean Peninsula via the Arctic, especially in cold winter.

Background: Dehisced ginseng seeds need to be stored at cold temperatures for around 3 months to break their physiological dormancy, and thus, to aid in gemination. In the presence of high moisture in such an environment, seed spoilage and pre-germination may lower seed quality and productivity. To improve seed quality during cold-stratification, the effects of seed dehydration and temperature were tested. Methods and Results: In early December, dehisced ginseng seeds were dehydrated at 4 different levels and stored at 2℃- 2℃, and –20℃ for 3 months. Germination was carried out on the filter papers moistened with distilled water; emergence of root, shoot, and seed spoilage were assessed. Seed viability was examined by the tetrazolium test. More than 90% of the seeds stored at 2℃ and –2 ℃ without drying or endocarp dehydration germinated, but seeds that were dehydrated to have a moisture content (MC) below 31% showed poor germination and lost their viability. In addition, the seeds stored at –20℃ failed to show effective germination. Conclusions: Seed storage after endocarp dehydration might help to improve seed quality and increase seedling's ability to stand during the spring-sowing of ginseng.

This purpose of this study was to determine the best enrichment medium for rejuvenating and recovering Salmonella placed in cold temperature prior to the employment of the gold biosensor combined with a light microscopic imaging system. A mixture of nalidixic-resistant Salmonella Typhimurium and Enteritidis were inoculated onto chicken (1,000 CFU/chicken). After cold injury at 4℃ for 24 hr, Salmonella on chicken was enriched for 6 hr with six non-selective media including buffered peptone water broth, lactose broth, brain heart infusion broth (BHI), universal pre-enrichment broth, nutrient broth, and tryptic soy broth, and five selective media including brilliant green broth (BG), rappaport-vassiliadis R10 broth, selenite cystine broth, selenite broth, and tetrathionate brilliant green broth (TBG) for the comparison of Salmonella growth. Various concentrations of Salmonella (10, 50, 100, 500, and 1,000 CFU/chicken) were then enriched for 6 hr in both BHI and BG media to select the best media. BHI was selected as the most effective non-selective enrichment medium, while BG was selected as the most effective selective enrichment medium. Finally, BHI medium was selected as the most efficient enrichment medium for Salmonella growth injured from cold temperature during processing or storage.

Background : Upon harvest in the summer, seeds of Panax ginseng are unmatured and need further maturation, dehiscence and cold-stratification, for germination. For the cold-stratification, the seeds should be stored in the cold temperature for 90-100 days, however no further description about the storage condition have been described even though there have been many problems in emergence rate and quality of ginseng in the spring-sowed filed. Methods and Results : Thus here we tested 3 different storage temperature(2℃, -2℃, and – 20℃) in combination of 4 different seed water content(59%, 54%, 31%, and 7%) as cold-stratification condition. After 100 days of storage, seeds were placed on the filter paper after watering with distilled water in the petri dish and incubated at 10℃. Fifty percent of seeds stored at 2℃ with 59% water content had already germinated even in the storage room before germination test. Seeds with 59% and 54% water content stored at 2℃ and –2℃ germinated in a similar rate, but emergence of above ground part was higher in the seeds with 54% water content. Seeds with 31% and 7% water content stored at 2℃ and –2℃ showed low germination rate, because of fail in stratification or death. Seeds stored at –20℃ scored even lower germination rate and fail in emergence of above ground part. Conclusion : Seed water content and temperature during the cold-stratification period of ginseng seeds affected on the seed viability and germination rate, thus control of seed water content and storage temperature might improve the emergence rate of spring-sowed ginseng filed.

Because ordinary concrete cannot be hardened well under sub-zero temperatures, anti-freeze agents are typically added to prevent the frost damage and to ensure the proper hardening of concrete. With the advantage of a rapid exothermic reaction property, jet set concrete may be used as a cold weather concrete because it can reach the required strength before being damaged by cold weather. Recent studies are reported that magnesia-phosphate composites can be hardened very quickly and hydrated even in low temperature, which can be used as an alternative of severe cold weather concrete in arctic regions. This study developed the magnesia-phosphate composites that can be used in severe cold regions and suggested an appropriate mixture design from the experimental results.

본 연구는 급성염증과 비슷한 지연성 근육통이 있을 때 초기 한냉치료를 적용함에 있어 냉기에 의한 냉각통증을 최소화하면서, 근육온도를 낮출 수 있는 방법으로 냉기단독과 냉기와 적외선 조사 병용을 적용하여 피부온도에 미치는 영향을 측정하고, 냉기와 적외선 병용치료의 효율성을 평가함과 동시에 초음파를 통한 근 두께를 바탕으로 등척성 근기능을 평가해보고자 하였다. 본 연구의 결과 냉기와 적외선 병용치료 시 냉기 단독치료보다 냉각통증의 빈도가 낮게 나타났으며, 냉각통증 자각 시점도 늦게 나타났다. 또한 충분한 냉기적용 후 피부온도가 재가온되는데 있어서 냉기를 2회 적용할 때가 1회 적용할 때 보다 더 느려지며, 냉기 단독치료보다 냉기와 적외선 광선 조사 병용치료 시 더 느려짐을 나타내어 2회 이상의 반복적인 냉기 적용이 냉기의 효용이 있다고 나타났다. 또한 상완이두근 두께 변화에 있어서 병용군이 대조군보다 더 크게 나타나 이 효과를 뒷받침하게 되었다. 이러한 연구결과 자료는 향후 급성염증이 있는 환자에게 한냉치료와 관련된 치료적인 자료로써 활용될 수 있을 것이라 생각되고 근골격계 초음파 진단기를 활용하여 통증에 대한 자각도를 간접적으로 표현하는 것이 구체화되어 임상에서 널리 활용될 것으로 보여진다.

This paper is to investigate the effect of heat curing method on strength development of concrete subjected to -10℃ by preparing mock up specimen, which had slab, wall and column. As expected, the application of heat curing methods had larger strength than non heat curing specimen because of higher maturity. And within 7 days of heat curing, minimum strength to protect from early frost damage was achieved.

자두 '대석조생'의 생육단계별 수확시기 및 저온저장 온도에 따른 저온장해과 발생 양상과 품질 특성을 구명하고자 하고자, 자두 '대석조생'을 60%, 80% 그리고 90% 이상의 착색율로 구분하여 수확한 후, 1, 4, 5, 그리고 에 최대 48일간 그리고 에서 3일간 숙성시키면서 호흡 변화, 품질 특성 및 저온 장해과 발생 양상을 조사하였다. 60% 착색기에 수확한 자두를 보다 낮은 저온에 저장하였을때 경도, 색도, 중량감소율과 적정산도의 유지

농산물 저온저장고 내부의 온도분포 균일화를 수치해석적으로 분석하기 위해 3차원 CFD 시뮬레이션을 수행하였다. CFD 시뮬레이션 모델은 속도벡터 및 온도분포 측정치와 비교를 통해 검증하였으며, 온도분포 균일화 향상을 위한 적정 팬용량 및 적재방법을 설정하기 위해 몇 가지 팬풍속 및 저장물과 벽체간의 거리 등에 대해 기류패턴과 온도 분포를 분석하였다. CFD 시뮬레이션의 검증에서 속도벡터 분포는 PIV시스템에 의한 측정치와 비교했을 때 표준 k-모

저온에서 가루차를 일반포장, 일반포장+항산화제, 일반포장+방습제처리시 4개월 이후 품질관련 성분인 총질소, 총아미노산, 탄닌, 카페인, 엽록소, 지방산 함량이 상당히 저하되었으며, 일반포장 + 진공처리는 일반포장 저장에 비해 1개월 정도 저장기간의 연장이 가능하였다. 제품의 표면색상은 저온보관시 일반포장에서는 저장 1개월에 a값(녹색)이 -16.43에서 저장 5개월에는 정도 감소된 -10.11로 크게 감소되었다. 외관과 내질에 따른 관능평가시 저

Forty-four F₁ hybrids derived from crosses among eleven temperate japonica rice cultivars were grown and evaluated for traits related to cold tolerance including days to heading and spikelet fertility in the cold-water irrigated plot (17℃) and

The climatological study of temperature inversion was conducted at the Tsukuba of Japan during the cold half year, the periods of which were both from October 1981 through March 1982 and from October 1982 through March 1983. Meteorological phenomena were observed to appear both from 10m to 200m above the ground and from the surface to 300hPa. The data collected from those phenomena were analyzed in terms of statistics, and investigated from a synoptic point of view. The results are as follow. The dispersion of the surface inversion happens right after sunrise through the whole period. The higher the upper layer is, the later that happens. Up to a height of 200m, the wind speed at a height of 25m has the greatest effect on temperature, but on the other hand the wind speed at a height of 10m has the greatest effect on inversion intensity.

수도의 냉해 경감을 위하여 인산 및 붕소의 시용효과를 구명코저 인산을 10a당 10, 20kg, 붕소를 0, 3, 5, 10, 20, 30kg을 분벽기, 유수형성기 및 감수분열기에 시용하고 유수형성기 이후부터 15-18℃ 로 냉수처리한 결과를 요약하면 다음과 같다. 1. 붕소의 시용량이 많아질수록 시용후 3일경부터 염색이 황변하며 생육이 억제되었으며 생육후기에는 염색이 암갈색으로 착색되고 엽선단의 양록이 말리며 고사되었다. 한편 조립의 선단부에도 암갈색으로 착색되었다. 2. 엽록소 함량은 분벽기와 유수형성기에 10a당 5, 10kg의 붕소 시용구에서 높았으며 감수분열기 처리에서는 일정한 경향이 없었다. 3. 광합성능력과 붕소시용간에는 일정한 경향이 없었으나 분벽기 시용구에서는 붕소량이 많을수록 증가되었다. 한편 엽록소 함량이 증가되어도 이에 비례하여 광합성능력은 별로 증대되지 않았다. 4. 근활력은 대체로 무처리구에 비하여 붕소처리구가 다소높았다. 특히 분벽기에 10a당 3, 5, 10kg의 붕소처리구에서 높았다. 5. 붕소처리에 의한 출수촉진효과는 붕소의 시용시기가 빠를수록 촉진되는 경향을 보였고 붕소수준간에는 무처리구에 비하여 붕소를 10a당 3, 5, 10kg 시용구에서 3-7일의 촉진효과를 보였다. 6. 붕소처리는 등숙에 영향을 미쳐 인산수준 및 처리시기에 관계없이 붕소를 10a당 3, 5, 10kg 시용한 구에서 약간 높아졌다.