• 전력전자학회논문지
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• 제26권6호
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• pp.421-428
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• 2021

Lithium-ion secondary batteries exhibit advantageous characteristics such as high voltage, high energy density, and long life, allowing them to be widely used in both military and daily life. However, the lithium-ion secondary battery does have its limitation; for example, the output power and capacity are readily decreased due to the increased internal impedance during discharging at a lower temperature (-32℃, military requirement). Also, during charging at a lower temperature, lithium dendrite growth is accelerated at the anode, thereby decreasing the battery capacity and life as well. This paper describes a study that involves increasing the internal temperature of lithium-ion secondary battery by energy circulation operation in a low-temperature environment. The energy circulation operation allows the lithium-ion secondary battery to alternately charge and discharge, while the internal resistance of lithium-ion battery acts as a heating element to raise its own temperature. Therefore, the energy circulation operation method and device were newly designed based on the electrochemical impedance spectroscopy of the lithium-ion secondary battery to mediate the battery performance at a lower temperature. Through the energy circulation operation of lithium ion secondary battery, as a result of the heat generated from internal resistance in an extremely low-temperature environment, the temperature of the lithium-ion secondary battery increased by more than 20℃ within 10 minutes and showed a 75% discharging capacity compared with that at room temperature.

• 대한기계학회논문집
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• 제8권3호
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• pp.195-200
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• 1984

본 연구에서는 SUS 304강의 상온하의 평골재 표면에 발생. 성장하는 미소표면 피로균열의 거동을 파괴역학적 관점과 수법으로 정량적으로 조사하려는 연구의 일환 이다.

• 한국재료학회지
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• 제12권5호
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• pp.363-368
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• 2002

we proposed the use of $Si_2H_ 6/H_2$ chemistry for selective silicon epitaxy growth by low-pressure chemical vapor deposition(LPCVD) in the temperature range $600~710^{\circ}C$ under an ultraclean environment. As a result of ultraclean processing, an incubation period of Si deposition only on $SiO_2$ was found, and low temperature epitaxy selective deposition on Si was achieved without addition of HCI. Total gas flow rate and deposition pressure were 16.6sccm and 3.5mtorr, respectively. In this condition, we selectively obtained high-quality epitaxial Si layers of the 350~1050$\AA$ thickness. In older to extend the selectivity, we kept high pressure $H_2$ environment without $Si_2H_6$ gas for few minutes after first incubation period and then we conformed the existence of second incubation period.

• 한국수산과학회지
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• 제44권4호
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• pp.366-371
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• 2011

The sea squirt Halocynthia roretzi is mainly cultured in Tongyeong, Southern coastal area of Korea. This study presents the physiological rates of respiration, excretion, feeding and assimilation efficiency of the sea squirt Halocynthia roretzi to analyze the SFG(scope for growth) and net growth efficiency, determined during 2007. Oxygen consumption and nitrogen excretion rates increased with a rise in temperature during the summer period whereas feeding rates decreased. The O:N ratio was high during winter(October to February). Assimilation efficiency showed an annual average of 75.4% during the experimental period, except during a period of elevated temperature in July to September(average $25^{\circ}C$). Net growth efficiency($K_2$) was 8.7 to 64.2% except for May to September, when temperature increased at the aquaculture farm. SFG was negative from May to September, reflecting high temperatures and low feeding rates during this period; its highest positive values occurred during winter.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3312-3316
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• 2013

Single crystals of hexagonal graphenes were successfully grown on Cu foils using the atmospheric pressure chemical vapor deposition (CVD) method. We investigated the effects of reaction parameters, such as the growth temperature and annealing time, on the size, coverage, and density of graphene domains grown over Cu foil. The mean size of the graphene domains increased significantly with increases in both the growth temperature and annealing time, and similar phenomena were observed in graphene domains grown by low pressure CVD over Cu foil. From the comparison of micro Raman spectroscopy in the graphene films grown with different annealing times, we found that the nucleation and growth of the domains were strongly dependent on the annealing time and growth temperature. Therefore, we confirmed that when reaction time was same, the number of layers and the degree of defects in the synthesized graphene films both decreased as the annealing time increased.

• Plant Resources
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• 제3권1호
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• pp.66-70
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• 2000

Umbelliferae medicinal crops have low germination under natural condition. Special objective of this study is to investigate morphological characteristics of seeds and effects of environmental factors such as light and temperature on their germination and seedling growth in Umbelliferae plants, using them as oriental medicine materials. Fruits of Umbelliferae are bi-partite type and form 2 seeds. Their oil canals and funiculus or carpaphore has apparently specific shape. Seed shape of Buplerum falcatum, Ligusticum acutilobum and Foeniculum vulgare are oblong, Ledeboutiella seseloides, Angelica dahurica, Angelica gigas elliptic, and Ostericum koreanum ovate. Color of seed coats varied from yellow to dark brown. Seed size was 3.2 to 6.9 mm in length, 1.7 to 4.9 mm in width. One thousand-seed weight of Buplerum falcatum was lowest(at 1,660 mg) and Ledebouriella seseloides and Angelica gigas were relatively highest(at 3,970 mg) having larger size than any others. Optimum temperatures for seed germination and seedling growth ranged from 20 to $25^{\circ}C$ and especially temperature at $25^{\circ}C$ improved seed germinations of Ledebouriella seseloides, Angelica dahurica and Ligusticum acutilobum regardless of light condition.

• Transactions on Electrical and Electronic Materials
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• 제15권5호
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• pp.262-264
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• 2014

Pristine ZnO, 3 wt.% Ga-doped (3GZO) and 3 wt.% Ag-doped (3SZO) ZnO nanowires (NWs) were grown using the hot-walled pulse laser deposition (HW-PLD) technique. The doping of Ga and Ag in ZnO NWs was observed by analyzing the optical and chemical properties. We optimized the synthesis conditions, including processing temperature, time, gas flow, and distance between target and substrate for the growth of pristine and doped ZnO NWs. The diameter and length of pristine and doped ZnO NWs were controlled under 200 nm and several ${\mu}m$, respectively. Low temperature photoluminescence (PL) was performed to observe the optical property of doped NWs. We clearly observed the shift of the near band edge (NBE) emission by using low temperature PL. In the case of 3GZO and 3SZO NWs, the center photon energy of the NBE emissions shifted to low energy direction using the Burstein Moss effect. A strong donor-bound exciton peak was found in 3 GZO NWs, while an acceptor-bound exciton peak was found in 3SZO NWs. X-ray photoelectron spectroscopy (XPS) also indicated that the shift of binding energy was mainly attributed to the interaction between the metal ion and ZnO NWs.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.84-84
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• 2022

The limit of crop cultivation is moving northward due to the temperature rise by climate change. There is a problem with crop growth if early sowing is performed at a time when the temperature is low. It is difficult to secure crop productivity and cultivation stability due to the low temperature and short cultivation period. Therefore, this study was conducted to analyze the change in growth characteristics and yield of corn for grain when early sowing is performed in central region of South Korea. This experiment was conducted at experimental field of Suwon in 2021. Three varieties of corn for grain such as Kwangpyeongok, Sinhwangok, and Hwangdaok were sown at intervals of 5 days from 20 March to 15 April. The planting density at this time was sown with a row interval of 70 cm and a plant interval of 25 cm. Nitrogen, phosphoric acid, and potassium fertilizers were applied at 17.4 kg, 3.0 kg, and 6.9 kg per 10a, respectively. Phosphoric acid and potassium fertilizers were all applied before sowing and nitrogen fertilizer was applied 50% before sowing and 50% in the fifth leaf period. The corn growth characteristics and yield components were investigated. The seedling establishment rate by sowing date was in the range of 68.5~88.5%, and it showed a difference depending on the variety. The range of days from sowing to tassel and silk emergence by sowing date was 79.9~98.4 and 81.0~98.9 days, respectively. As the sowing date was delayed, the days from sowing to tassel and silk emergence decreased. The growth characteristics and yield of corn by sowing date are as follows. Plant height was the highest at 241.3 cm at the sowing on 25 March, and Stalk diameter was the thickest at 25.6 mm at the sowing on 31 March. The fresh weight per plant was the highest at 728 g at the sowing on 25 March, and the dry weight per plant was the highest at 185 g at the sowing on 31 March. Corn growth characteristics did not show a certain trend depending on the sowing date, and corn growth was more vigorous at the sowing on March 25 and 31 than the others. In the case of ear weight, it was the heaviest with 344 g at the sowing on 25 March, and filled ear length ratio showed a tendency to decrease as the sowing time was delayed. The weight of 100 grains and grain yield per 10a of maize were the highest at 36.0g and 878.7kg/10a, respectively at the sowing on 25 March. Although the growth and yield of corn for grain were good during early sowing in the central region of South Korea, it is necessary to investigate the limit temperature for early sowing of corn by examining the annual variation according to weather conditions.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.274-274
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• 2017

Temperature has an adverse effect for potential growth and development of Codonopsis lanceolata. The present study examined the responses of growth, yield and mineral element contents under temperature variables in C. lanceolata. Plant height exhibited the best result as being 2 m or higher the open field culture, while the growth is the most restricted in the $30^{\circ}C$. The open field culture also had the largest number of leaves in the early stage of growth. The number of leaves and the height tended to be increased with the temperature of $20^{\circ}C$ and $25^{\circ}C$. The number of branches showed no significance as 32 branches and 26 branches in open field culture and $20^{\circ}C$, respectively. The smallest number of branches was observed in the $30^{\circ}C$ with 15 branches. The leaf color recorded the lowest value in the open field culture unlike the growth above the ground. But all other temperature had no significance with the leaf color value between 50.0 and 52.6. The elevated temperature induced the thinner and shorter diameter and length of root. However, the root diameter was not significantly changed with the change of 1.8 cm and 2.1 cm at open field culture, with $20^{\circ}C$ and $25^{\circ}C$, respectively. The fresh weights of the primary root and lateral roots were 6.3 g and 3.1 g, respectively, at the high temperature. The result showed the thickening of the lowest part under the ground as restricted. The fresh weights of the main root and lateral root were the highest on the open field culture, 20.6 g and 12.2 g, respectively. The contents of cellulose were the highest as 4.41% in the $20^{\circ}C$, followed by the open field culture, $25^{\circ}C$ and $30^{\circ}C$. The higher temperature reduced the contents of cellulose. Moreover, P showed higher ratio in the high temperature while Ca and Mg exhibited the higher ratio towards the low temperature. On the contrary, minor quantity (less than 1%) of mineral nutrients was observed towards all temperature variables.

• 한국잡초학회지
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• 제7권1호
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• pp.98-106
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• 1987

Carbofuran이 벼 생육(生育)에 미치는 영향을 알기 위해 1981년(年)부터 1986년(年)까지 영남작물시험장(嶺南作物試驗場)에서 벼종자(種子) 발아영향(發芽影響), 못자리 묘생육영향(苗生育影響), 본답(本畓) 벼생육영향(生育影響) 및 기상재해영향(氣象災害影響) 등(等)을 통(通)하여 구명(究明)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. Carbofuran 처리(處理)는 벼종자(種子) 발아(發芽)에 영향을 미쳤는데 지상부(地上部)보다 지하부(地下部)의 생육(生育)에 대한 영향이 컸다. carbofuran 농도(濃度)가 높아짐에 따라 전체종근수(全體種根數)는 감소(減少)되나 뿌리당(當) 길이는 50ppm까지 길어졌다. 2. 보온절충식(保溫折衷式)못자리에서의 carbofuran 처리(處理)는 무비구(無肥區)에서 3요소비료(要素肥料) 표준시용량(標準施用量) 정도(程度)의 생육(生育)까지 증진(增進)시켰고 또한 통일형(統一型) 품종(品種)의 적고피해(赤枯被害)를 회복(回復)시키는 효과(效果)가 있었는데 적고회복(赤枯回復) 요인(要因)으로는 파괴(破壞)된 엽록소(葉綠素) 자체(自體)의 회복(回復)이 아니라 묘생육량(苗生育量) 증대(增大)에 의한 것이었다. 그리고 carbofuran 처리시기효과(處理時期効果)에 있어서는 파종전(播種前) 처리(處理)가 가장 높고 다음으로는 vinyl 제거전(除去前), vinyl 제거후(除去後)의 순(順)이었다. 3. 본답(本畓)에서의 벼 벼생육증진효과(生育增進効果)는 이앙전(移秧前) 처리(處理)가 이앙(移秧) 25일(日) 후(後) 처리(處理) 보다 그리고 1 모작답(毛作畓)보다 2모작답(毛作畓)에서 높은 경향(傾向)이었고, 증진(增進)되는 생육형질(生育形質)로는 년차간(年次間) 및 품종간(品種間) 다소(多少) 차이(差異)가 있지만 간장(稈長), 수수(穗數), 영화수(穎花數) 및 추수력(抽穗力) 등(等)이었는데 그 중(中)에서도 수수증대(穗數增大) 요인(要因)이 가장 컸다. 4. Carbofuran 처리(處理)는 감수분열기(減數分裂期)와 출수기(出穗期)의 저온피해(低溫被害)와 침관수(浸冠水) 피해경감효과(被害輕減効果)가 있었으며 주요(主要) 생육증진요인(生育增進要因)으로는 임실비율(稔實比率), 등숙비율(登熟比率) 및 광합성능력증진(光合成能力增進)에 있었다.