• 한국태양에너지학회 논문집
• /
• 제35권2호
• /
• pp.63-71
• /
• 2015

Soiling is the accumulation of dirt on photovoltaic (PV) modules and can reduce the performance of the PV power plant depending on the site location. Nevertheless, the reason which can not be the great interest to researchers of PV reliability is the phenomenon of performance loss caused by external environmental factors, not the internal degradation of the PV module. In this paper, we provide the phenomenon, history, research overview and mitigation method in order to help understanding of the soiling.

• Preventive Nutrition and Food Science
• /
• 제8권1호
• /
• pp.105-112
• /
• 2003

Animals possess a highly sophisticated mechanism of storing energy in adipose tissue inside their bodies. However, in humans it has been clarified that adipocyte (fat cell), which composes the body fat (adipose) tissues, development and the extent of subsequent fat accumulation are closely associated with the occurrence and advancement of various common diseases (e.g., type-2 diabetes, coronary artery disease, and hypertension) resulting from obesity. Recent exciting progress in clinical and biochemical studies of adipocytes has rapidly clarified the functions of adipocytes and adipose tissue. Interesting findings are the function of white adipocytes as "secreting cells" and the molecular mechanism undelying adipocyte differentiation at the transcriptional level in relation to nuclear receptors. Consequently, the adipose tissue is being targeted for the prevention or treatment of many common diseases. In this review, I will focus on recent information on characteristics of adipocytes and the relationship between obesity and common obesity-related diseases. diseases.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 추계학술대회 논문집
• /
• pp.65-68
• /
• 2000

Polyethylene, has long history and is widely used, was researched due to good electrical properties by many authors. But PE under stress has the critical defects of space charge accumulation and tree growth, so various methods such as catalyst, additives and blend to improve these problems have been execute, of which we selected blending method. As in our previous papers we investigated electrical conduction, dielectric and AC dielectric breakdown characteristics, we did DC dielectric breakdown characteristics in this paper. We selected pure LLDPE, pure EVA and LLDPE films mixed with EVA as specimens, which were mixed with the weight percentages of 50, 60, 70 and 80[wt%] to be thin film. DC applying voltage speed was 500[V/sec]. The relation between dielectric breakdown characteristics and the variations of super structure due to mixing was investigated, and especially trap level at amorphous region, threshold energy increment of conductive electron at free volume were considered.

• 한국안전학회지
• /
• 제20권3호
• /
• pp.42-46
• /
• 2005

The static electricity by thinner flow and discharge energy is investigated experimentally for the purpose of preventing the electrostatic discharge and damage. Test system for evaluating streaming electrification consists of a teflon pipe, a reservoir tank a pump, flowmeters and an electrometer. When dielectric liquid flows through a pipe from one vessel to another, the potential difference generated in the collecting vessel is due to the accumulation of charges. These charges result from the convection of a part of the electrical double layer existing in the tube at the contact between the liquid and the inner wall. When the fluid velocity increases, the electric current increases proportionally. The charging current and accumulated charges by streaming electrification at the thinner velocity of 40cm/s are measured a range of 5 nA and $0.27{\mu}C$ respectively. This amount of static discharge energy generated by streaming electrification is enough to ignite flammable solvent. Therefore surface electric potential should decrease by using electrostatic shielding and ground.

• Endocrinology and Metabolism
• /
• 제31권1호
• /
• pp.1-6
• /
• 2016

Immoderate energy intake, a sedentary lifestyle, and aging have contributed to the increased prevalence of obesity, sarcopenia, metabolic syndrome, type 2 diabetes, and cardiovascular disease. There is an urgent need for the development of novel pharmacological interventions that can target excessive fat accumulation and decreased muscle mass and/or strength. Adipokines, bioactive molecules derived from adipose tissue, are involved in the regulation of appetite and satiety, inflammation, energy expenditure, insulin resistance and secretion, glucose and lipid metabolism, and atherosclerosis. Recently, there is emerging evidence that skeletal muscle and the liver also function as endocrine organs that secrete myokines and hepatokines, respectively. Novel discoveries and research into these organokines (adipokines, myokines, and hepatokines) may lead to the development of promising biomarkers and therapeutics for cardiometabolic disease. In this review, I summarize recent data on these organokines and focus on the role of adipokines, myokines, and hepatokines in the regulation of insulin resistance, inflammation, and atherosclerosis.

• 한국초지조사료학회지
• /
• 제6권2호
• /
• pp.111-118
• /
• 1986

본(本) 시험(試驗)은 주요북방형(主要北方型) 목초(牧草)에 있어서 기상환경(氣象環境)과 예취방법(刈取方法)이 비구조성(非構造性) 탄수화물(炭水化物)의 합성(合成) 및 축적형태(蓄積形態)에 미치는 영향(影響)을 구명(究明)코자 한국(韓國)의 Suweon, Cheju 및 Taekwalyong과 서독(西獨)의 Freising 및 Braunschweig에서 $1975{\sim}'79$년간(年間) 실시(實施)되었다. 공시초종(供試草種)은 orchardgrass, perennial ryegrass 및 meadow fescue를, 예취관리(刈取管理)는 방목기(放牧期)(년(年) $6{\sim}7$회(回)), silage 기(期)(년(年)$4{\sim}5$ 회(回)) 및 건초기이용(乾草期利用)(년(年) 3 회(回))으로 구분(區分) 분할구배치법(分割區配置法) 4반복(反復)으로 시험(試驗)을 실시(實施)하였는바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 북방형(北方型) 목초(牧草)에 있어서 비구조성탄수화물(非構造性炭水化物)의 합성(合成) 및 축적형태(蓄積形態)는 초종(草種) 및 재배지역(栽培地域)에 따라 차이(差異)가 크다. 초종별(草種別) total nonstructural carbohydrates (TNC) 함량(含量) meadow fescue가 8.01%로 가장 높았으며 다음은 perennial ryegrass 6.08% 및 orchardgrass 4.39%의 순(順)이었다. 이같은 결과(結果)는 서독지방(西獨地方)의 TNC 함량(含量) 12.73%(meadow fescue), 18.02%(perennial ryegrass) 및 10.42% (orchardgrass) 보다 낮은 수준(水準)으로 지역간(地域間)에 현저(顯著)한 차이(差異)가 있었다. 2. Orchardgrass의 비구조성(非構造性) 탄수화물(炭水化物) 함량은 fructosan .34%, mono- 및 disaccharose 3.04%로 mono- 및 disaccharose 형태(形態)로 다량(多量) 축적(蓄積)되는데 반(反)해 perennial ryegrass에서는 fructosan 3.25%, mono- 및 disaccharose 2.83%로 fructosan 함량(含量)이 약간(若干) 높은 편이었다. Meadow fescue 식물(植物)의 축적형태별(蓄積形態別) 함량(含量)은 각각(各各) fructosan 3.93%, mono- 및 disaccharose 4.08%이었다. 3. 비구조성(非構造性) 탄수화물(炭水化物)의 합성(合成) 및 축적(蓄積)은 환경온도(環境溫度)가 상승됨에 따라 감소(減少)되었다($P{\leqq}0.1%$). 이같은 원인(原因)으로 우리나라에 있어서의 계절별(季節別) mono- 및 disaccharose와 fructosan 함량(含量)은 봄철의 2.69% 및 1.34%에서 고온건조(高溫乾燥)한 여름철에는 각각(各各) 1.28% (mono- 및 disaccharose) 및 0.34% (fructosan)로 감소(減少)되었다. 그러나 여름철 기온(氣溫)이 낮은 Freising 및 Braunschweig에서는 계절간(季節間) 탄수화물(炭水化物)의 함량변화(含量變化)가 한국(韓國)에서와 같이 뚜렷하게 나타나지 않았다. 4. 비구조성(非構造性) 탄수화물(炭水化物)의 합성(合成) 및 축적(蓄積)은 목초(牧草)의 잦은 예취(刈取)에서 크게 감소(減少)되었다. 이와같은 원인(原因)으로 여름철 고온기간중(高溫期間中) 잦은 예취이용(刈取利用)은 식물체내(植物體內)의 TNC 함량(含量)을 감소(減少)시켜 예취후(刈取後)의 재생력(再生力)이 크게 약화(弱化)된다. 그러나 기온(氣溫)이 낮은 조건(條件)에서는 예취관리(刈取管理)에 따른 비구조성(非構造性) 탄수화물(炭水化物)의 함량변화(含量變化)가 크게 나타나지 않았다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권10호
• /
• pp.1587-1593
• /
• 2007

A single factorial experiment was conducted to test the effects of three dietary levels of energy on mRNA expression of fatty acid synthase (FAS-mRNA) and hormone-sensitive lipase (HSL-mRNA) and their association with intramuscular fat in finishing pigs. 72 crossbred (Large $White{\times}Rongchang$) barrows with an average initial body weight of 20.71 (s.e. 0.1) kg, were randomly allotted to three dietary treatments (11.75, 13.05 and 14.36 MJ DE/kg) and fed until slaughtered at 100 or 101 kg. The diets were iso-nitrogenous and iso-essential amino acids. The growth performances including the duration of finishing were changed linearly (p<0.05) or quadratically (p<0.05) with increased dietary energy levels. The effects of dietary energy content on the percentage of external fat, intramuscular backfat and the fat thickness were linear (p<0.05). The content of dietary energy increased FAS-mRNA linearly or quadratically, while HSL-mRNA decreased linearly or quadratically in backfat and Longissmus dorsi muscle. Meanwhile, significant positive correlations (p<0.05) were found between energy level and intramuscular fat, FAS-mRNA or the ratio of FAS-mRNA to HSL-mRNA, between the ratio of FAS-mRNA to HSL-mRNA and intramuscular fat. However, the correlations between HSL mRNA and dietary energy or intramuscular fat were negative (p<0.05). The results indicated that dietary energy level regulates lipid accumulation, especially intramuscular fat, possibly by modulating the mRNA of FAS and HSL together rather than individually.

• 전자공학회논문지
• /
• 제50권7호
• /
• pp.3-9
• /
• 2013

본 논문에서는 IR-UWB (Ultra Wideband-Impulse Radio) 시스템을 위한 선택적 가중치를 적용한 에너지 검출기와 이에 적합한 동기 방법이 제안되었다. 구현이 용이한 에너지 검출기(ED)는 IR-UWB 시스템의 수신기로 많이 사용되나, 심볼 주기로 샘플링 된 에너지를 데이터 검출에 이용하기 때문에 수신 성능이 좋지 않은 단점이 있다. 이러한 단순한 에너지 검출기의 성능을 개선하고자 가중치를 적용한 에너지 검출기가 제안 되었다. 가중치를 적용한 에너지 검출기는 데이터 검출 이전에 동기 획득과 함께 가중치의 결정이 요구된다. 한편, 에너지를 이용한 검출 방법에서 최적의 가중치는 에너지 값이 되기 때문에 동기 획득과 가중치 획득이 동시에 이루어질 수 있다. 본 논문에서는 이러한 점을 이용하여 심볼 동기와 가중치 획득을 동시에 얻는 간단한 동기 방법을 제안한다. 또한, 제안된 알고리즘에서는 잡음 레벨 이하의 구간은 에너지 누적에서 제외함으로써 기존의 WED 보다 간단하지만 낮은 SNR에서 좀 더 향상된 성능을 가진 수신기를 얻을 수 있게 된다. 제안된 알고리즘은 IEEE 802.15.4a의 프리앰블 심볼과 채널 모델을 이용해 모의실험을 통해 검증되었다.

• Journal of Biosystems Engineering
• /
• 제8권2호
• /
• pp.39-48
• /
• 1983

This study was performed to obtain the basic data which could be used for the modification of the manual center-burner-type rice-husk furnace into a small scale automatic type for the multi-purpose use in the farm. For this purpose, first, the utilization feasibility of the rice-husk furnace in the farm was analyzed briefly in aspects of available amount of rice-husk for the fuel, annual operation time and replaceble amount of residential heating energy with rice-husk in the farm. For the experiment a prototype furnace geared with an automatic feeding device was fabricated, and feed rate, mold size and chimney height were changed to investigate the combustion efficiency of rice-husk and thermal efficiency of the furnace. Also, optimum and limiting operational factors were observed in each treatments. The results obtained are summarized as follows. 1. If the rice-husk is intensively used for residential heating in the farm for winter season, on an average 51 percent of the total heating energy can be replaced with the rice-husk. Therefore, development of a small scale automatic rice-husk furnace was recognized to be feasible. 2. The operational condition depending on husk-feed rates was very important factor for successive steady burning operation of the given furnace. When the feed-rate was 1.5 kg/hr, the top of the burning zone should be kept at the position about 55 cm from the bottom of the combustion chamber with the periodic removal of ash (termed as steady state position), which was 18 cm above the mold waist. When the feed rates were 2.4 kg/hr and 3.0 kg/hr, the steady state position was at about 4 cm above the mold waist. 3. The mold size affected inflow rate of air into the furnace and consequently CO content in the exhaust gas. The relatively bigger mold gave positive effect on the air-inflow rate. 4. When the husk-feed rates were 1.5 kg/hr, 2.4 kg/hr, 3.0 kg/hr, the combustion efficiencies of the rice-husk were 98.5%, 97.4% and 95.0%, the thermal efficiencies of the furnace were 93.4%, 93.2% and 87.6%, and CO content in the exhaust gas were 1.21%, 1.03%, and 2.43%, respectively. The air-inflow rates were decreased with the increase of feed rates. When the amount of excess air was 30-40%, the CO content in the exhaust gas was at the minimum level. 5. When the chimney height was lowered from 260 cm to 96 cm, the air-inflow rate was slightly decreased, but the average temperature in the combustion chamber, CO content in the exhaust gas and combustion and thermal efficiencies were not changed significantly. 6. The incidental problems associated with the protytype furnace were accumulation of the ash inside the mold, accumulation of the cinder between the outer-drum of the furnace and the combustion chamber wall, and accumulation of the cinder in the chimney.

• 임산에너지
• /
• 제25권1호
• /
• pp.24-30
• /
• 2006

충북 월악산 동사면(해발 300m)에서 48년생 소나무 천연림의 바이오매스와 연간 순생산량을 추정한 결과, 소나무림의 바이오매스는 줄기부 87.3 ton/ha, 가지부 41.43 ton/ha, 잎 9.41 ton/ha로서 지상부 전체가 138.14 ton/ha로 추정되었으며, 연간 순생산량은 줄기부 5.3 ton/ha/yr, 가지부 2.93 ton/ha/yr, 잎 2.62 ton/ha/yr로서 지상부 전체 10.85 ton/ha/yr로 추정되었다. 또한 소나무림 지상부의 에너지량은 2,981 GJ/ha, 연간 에너지 고정량은 239 GJ/ha/yr로 나타났다. 한편, 월악산 지역 소나무림의 엽면적지수는 6.58로 나타났다.