• 품질경영학회지
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• 제46권3호
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• pp.425-440
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• 2018

Purpose: This study is aimed at developing of the flex resistance testing process at low temperature with the waterproof fabric to suit the military environment, and is designed to fit for the purpose of the waterproof materials in order to optimize the test method by finding out matters to improve from existing the test method and through previous studies. Methods: The test method, which has been applied to flex resistance of existing water-repellent materials, was improved and consequently, differentiated test results could be obtained according to the test temperature, sample size, and flexing method. Results: The testing of the total of 8 samples revealed that performance of the military requirement could hardly be met just by presenting the materials or 2~3 layers when the quality criteria for high functional water repellent fabrics were applied. PTFE(Polytetrafluoroethylene) is preferred to PU(Polyurethane) to be used in the extremely low-temperature environment, but durability under the low-temperature environment may be varied depending on film thickness or laminating technique even if the materials of waterproof films are identical. Therefore, in addition to the material or texture, the test method capable of reflecting durability under the low-temperature environment shall be suggested, and the newly designed test method proposed in this study was shown to suggest differentiated quality criteria by the material. Conclusion: The water resistance measurement and the test method following flex resistance with expanded range of flex will enable the differentiable test of the samples according to the number of repetition. This study is meaningful in that it suggests a differentiable test method capable of establishing a basis of deciding suitable material when selecting military goods made of water repellent material by properly improving the test method.

• Journal of Ecology and Environment
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• 제41권8호
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• pp.213-222
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• 2017

Background: This study was conducted to assess the physicochemical water quality and the altitudinal distribution of low-temperature and mountain epilithic diatom (LTMD) community in Buk and Hangae streams that are located in Seorak Mountain with the height of 1708 m in Korea. And the community characteristics of LTMD found in the Buk and Hangae streams were compared to that of LTMD from the Han River system. Results: The physicochemical water qualities of Buk and Hangae streams were determined to be very clean. As a result of analyzing the community composition, 135 taxa of epilithic diatoms were determined, and 22 taxa appeared including Hannaea arcus var. subarcus which are known to have low-temperature and mountain ecological characteristics in the literatures. The relative frequencies of LTMD were 37.0~0.9% range from the upper to lower regions. Although Diatoma tenuis, Eunotia minor, and Gomphonema affine are known to be ubiquitous in streams and lakes, in this research, the three taxa were added into low-temperature and mountain epilithic diatom, since D. tenuis and E. minor appeared only in altitudes above 600 m, and G. affine had the highest relative frequency during spring and fall in altitudes above 700 m, when water temperature was around $10^{\circ}C$. Conclusions: Among the 24 taxa of low-temperature and mountain epilithic diatom (LTMD) (including the 3 taxa added in this study), 14 taxa (Diatoma hyemalis, D. mesodon, D. tenuis, Hannaea arcus, H. arcus var. subarcus, Ulnaria inaequalis, Eunotia bilunaris, E. implicata, E. minor, E. muscicola, E. silvahercynia, E. septena, Delicata delicatula, and Gomphonema affine) represented the characteristics of LTMD very well; they grow best in water temperatures below $15^{\circ}C$ in Buk and Hangae streams and Han River system.

• Korean Chemical Engineering Research
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• 제50권1호
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• pp.6-10
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• 2012

본 연구의 목적은 styrene-butadiene-styrene(SBS) 블록공중합체와 폐타이어 고무분말(crumb rubber, CR)로 개질한 아스팔트의 저온접착특성에 대해 파라핀오일 가소제의 영향에 대한 것이다. SBS/CR로 개질한 아스팔트 블렌드와 파라핀오일/SBS/CR 아스팔트 블렌드의 온도 민감성을 침입도와 연화점으로 측정하였다. 형광현미경으로 파라핀오일/SBS/CR 아스팔트 블렌드에 대한 개질제들의 분산 상태와 만능시험기로 저온에서 접착성질을 각각 측정하였다. 저온접착시험에서 SBS 함량의 증가와 파라핀오일 함량 5 wt % 및 10 wt %에서 접착강도와 변형률이 증가하였다. $-20^{\circ}C$에서 측정한 접착강도와 강인성은 파라핀오일이 10 wt %와 SBS 공중합체의 양이 6 wt %인 조성에서 최대값을 얻었다. SBS/CR/아스팔트 블렌드에서 파라핀오일의 첨가는 유연성을 부여하는 효과를 나타내고, 저온에서 강인성의 증가를 가져오는 것을 확인하였다.

• 한국방재안전학회논문집
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• 제17권3호
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• pp.1-11
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• 2024

본 연구에서는 저온환경의 유기질토가 다량 함유된 불량한 지반에서 장기적으로 안정적인 비전통유 파이프라인 고속설치 시공을 위한 기술을 개발하기 위하여 되메움 재료로써 특수재료와 현장토를 사용한 저온 환경에서 원활한 시공성과 장기 내구성을 만족하는 유동성 개량 되메움재를 개발하는 것이 목적이다. 이를 위하여 시멘트계 특수재료를 개발하였으며 개발된 특수재료와 현장토를 혼합한 유동성 개량 되메움재의 현장시공 품질 기준에 만족하기 위한 시공성과 내구성을 파악하기 위한 실내시험을 수행하였다. 유동성 개량 되메움재의 시공품질기준 항목은 미국 ACI(America Concrete Institute)에서 제시한 CLSM(ACI 229R-13) 기준을 만족하는 것으로 목표를 설정하였다. 또한, 저온환경에서의 적용성을 파악하기 위하여 저온에서 동일한 항목으로 시험하고 상온의 실내시험결과와 비교 평가 하였다.

• 한국축산식품학회지
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• 제24권2호
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• pp.115-120
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• 2004

도계과정에서 탕침 온도를 저온(53-55$^{\circ}C$), 중온(59-61$^{\circ}C$), 고온(65-67$^{\circ}C$)으로 변화시켰을 때 닭고기의 육질에 미치는 영향과 저장 특성을 구명하고자 실시하였다. 탕침 온도가 높을수록 피부의 황색도(b$^{*}$ )는 감소하는 경향을 나타냈으며, 물리적 변화에서 보수력은 저온(67.043%)에서 고온(69.26%)으로 온도가 높아질수록 증가하는 경향을 나타냈다. 전단력은 저온(1.70kg/0.5inch$^2$)보다 고온 (2.54kg/0.5 inch$^2$)으로 높아질수록 유의적으로(p＜0.05) 증가하였다. 저장 3일에 저온 탕침 처리 닭고기의 지방산패도(TBARS) 값은 저온 0.25, 중온 0.24, 고온 0.27mg MA/kg으로 중, 저온에서는 비슷한 경향을 나타났으나 고온에서는 약간 증가한 것으로 나타났다. 총세균수는 저온에서 4.99, 중온 4.88, 고온 4.05 log CFU/mL를 나타나 탕침 온도가 높아질수록 감소하는 경향을 나타내었으나 유의적인 차이는 없었다(p＜0.05). 도체 조사에서 깃털의 출현율은 탕침 온도가 높아지면서 큰 것(1cm 이상)은 중온(59-61$^{\circ}C$)부터 현저히 감소하는 경향을 나타냈으나 중온과 고온에서는 차이가 거의 없었다. 외상은 탕침 온도가 61$^{\circ}C$ 이하인 저온, 중온에서는 0.6cm를 나타냈으나 고온처리에서는 7 cm로 급격히 증가하여서 고온처리에 따른 피부의 손상이 심한 것으로 나타났다. 이상의 결과는 탕침 온도가 너무 낮을 경우는 육색 및 물리적 특성은 양호하나 미생물이 증가하고, 깃털이 잘 뽑히지 않는 단점이 있으며, 고온일 경우는 황색도(b$^{*}$ )가 낮아지는 경향을 나타내며, 도체에서 깃털은 잘 뽑혔으나 표피 손상으로 근육의 노출이 많았다.

• Fisheries and Aquatic Sciences
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• 제3권1호
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• pp.14-22
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• 2000

The relationship between the distribution of demersal fishes and that of the water masses was examined by using the catches data and hydrographic data in the Yellow Sea and the East China Sea on May 13-19, 1996 and May 10-17, 1997. During the study period, the dominant fish species were Cleisthenes pinetorum herzinsteini, Lophiomus setigerus and Pseudosciaena polyactis. These three low temperature water species accounted for $21-24\%$ of the total catches. The percentage of the low temperature water species was high in the Yellow Sea and the coastal area on the continental shelf of the East China Sea but was low in the vincinity of Kyushu during the study period. In the East China Sea, the isotherm of $15^{\circ}C$ at 50m, mid layer depth, was located more southeast in 1996 than in 1997. The bottom water temperature was about it lower in 1996 than in 1997. The direction of the detided current on the continental shelf of the East China Sea was southward in 1996 and northward in 1997. Yellow Sea Bottom Cold Water (YSBCW) strongly expanded to south in 1996 when the northward current was weak. But, Tsushima Warm Current (TSWC) strongly intruded into the continental shelf of the East China Sea in 1997. As YSBCW expanded strongly to south in 1996, the percentage of the low temperature water species relative to the total catches was high. But, TSWC strongly intruded and the percentage of low temperature water fishes was low in 1997.

• 한국자동차공학회논문집
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• 제22권3호
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• pp.81-89
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• 2014

This study researched on the effect of HP/LP-EGR system to improve fuel consumption of Low Temperature Combustion Engine. Firstly, low temperature combustion engine with HP/LP-EGR system was established using 6.0L wastegate turbocharger HDDI engine. And suppliable EGR rate of the engine was proven to be enough to realize stable low temperature combustion. Then, optimum operating strategy was founded to develop fuel consumption of the engine. Control parameters were HP/LP-EGR valve and IPCV(Intake Pressure Control Valve) duty. Experiments method was that characteristics of the engine were measured and analyzed according to HP/LP-EGR strategies while EGR rate was fixed. Operating range for the strategy were divided into three parts, low load for low temperature combustion, high load for conventional diesel combustion, and transient condition. Finally, with the above strategy of this study, BSFC of the engine was improved about 2% compared to the base engine, and emission level, NOx and PM, met Tier4Final emission regulation.

• 한국환경농학회지
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• 제26권4호
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• pp.325-331
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• 2007

본 실험은 상추의 춘파재배 시 종자의 건열처리 및 저온 처리에 따른 상추품종의 반응을 조사하고자 수행하였다. 추대반응은 저온처리, 무처리 및 건열처리 순으로 빨랐다. 초장은 저온처리에 의해 5-10 cm 가량 더 커졌으나 건열처리는 몇몇 품종의 경우 오히려 생육을 억제하였다. 건열처리와 저온처리의 차이는 정식 후 시간이 경과함에 따라 점차 상쇄되었다. 생체중은 모든 처리구간의 차이가 뚜렷하지 않았다. 'Red Gyeolku'는 매우 빠른 추대성을 나타내었으며 특히 저온처리에 의해 초장의 생육이 촉진되었다. 그러나 'Cheongchima'는 다양한 종자처리 이후에도 추대율이 높지않아 만추대성 품종으로 여겨졌다.

• 원예과학기술지
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• 제29권2호
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• pp.135-143
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• 2011

In the Doritaenopsis hybrid, like most of the orchid species and hybrids, temperature is crucial for the vegetative-to-reproductive transition, and low temperature is required for bud differentiation. To understand the molecular mechanism of this process, an orchid GIGANTEA (GI) gene, DhGI1, was isolated and characterized by using the rapid amplification of cDNA ends (RACE) PCR technique. Sequence analysis showed that the full-length cDNA is 4,022 bp with a major open reading frame of 3,483 bp, and the amino acid sequence showed high similarity to GI proteins in Zea mays, Oryza sativa, Arabidopsis thaliana and other plants. Semi-quantitative RT-PCR revealed that DhGI1 was expressed throughout development and could be detected in roots, stems, leaves, peduncles and flower buds. The expression level of DhGI1 was higher when the plants were flowering at low temperature (22/$18^{\circ}C$ day/night) than the other growth stages. Further analysis indicated that the accumulation of DhGI1 transcripts was significantly increased at low temperature, and concomitantly, initiation of the peduncle was observed. However, DhGI1 levels were low under high temperature (30/$25^{\circ}C$) conditions, and flower initiation was inhibited. These results indicate that the expression of DhGI1 is regulated by low temperature and that DhGI1 may play an important role in inflorescence initiation in this Doritaenopsis hybrid at low temperatures.

• 한방재활의학과학회지
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• 제21권4호
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• pp.145-156
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• 2011

Objectives: This study was resigned to observe change of body temperature for patients with low back muscular pain after NUGA MRT-II(pulsed electromagnetic therapy) treatment. Methods: This study was a randomized, patient-assessor blind, placebo-controlled, pilot trial study. After the approval of institutional review board(IRB), we have recruited 38 patients suffering from low back muscular pain and divided them into two groups randomly: the treatment group and control group. To the treatment group, NUGA MRT-II was practiced and to the control group sham device was practiced and their low back muscles and acupuncture points three times a week for 2 weeks from February 2011 to May 2011. After 1 week of last treatment, We compared body temperature of two groups. Results: 1. There was significant decrease of body temperature on both Shinsu(BL23), Chishil(BL52), Kwanwonsu(BL26) acupunture points for the treatment group. 2. There was no difference in the decrease of body temperature between treatment group and control group except. Left Kwanwonsu(BL26). Conclusions: We found out that treatment of NUGA MRT-II on low back muscular pain can reduce the temperature of low back.