• KIEAE Journal
• /
• 제7권5호
• /
• pp.65-71
• /
• 2007

The purpose of this study was to analyze the difference of thermal sensation by radiant floor heating as ecological design element. The experimental investigations were carried out in climate chamber, and subjects were 34 college-age females in good health. The experimental variable was radiant heat by floor heating, and experimental controlled conditions were indoor temperature, relative humidity, and air velocity in climate chamber and clothing value and activity of subjects. The results are as follows. (1) Indoor temperature($21{\pm}0.5^{\circ}C$) in climate chamber were maintained as controlling. Clothing values of the subjects were controlled as average 0.73 clo. In the floor heating-off, globe temperature was average $23.2^{\circ}C$(22.4~24.1), but in the floor heating-on, globe temperature was average $24.8^{\circ}C$(23.0~25.5). (2) In the floor heating-off, thermal sensation rating was average -1.03(slightly cool), in the floor heating-on, thermal sensation rating was average +1.03(slightly warm). (3) There were the differences of thermal sensation by radiant floor heating although indoor temperatures were maintained in an equal state. (4) The thermal sensation rating was tending upward according as the globe temperature was getting higher.

• 한국대기환경학회지
• /
• 제26권1호
• /
• pp.77-84
• /
• 2010

The diffusion and partition coefficients of polyurethane foam (PUF) are estimated using a microbalance experiment and small chamber test. The microbalance is used to measure sorption/desorption kinetics and equilibrium data. When the diffusion condition is controlled in the chamber of the sample, interactions between volatile organic compounds (VOCs) and PUF can lead to the estimation of a relatively homogenous rate of mass transfer in the interiors and surfaces of PUF. The estimates of the material/air partition coefficient (K) and the material-phase diffusion coefficient (D) are shown to be independent of the concentrations of VOCs. This approach, if applied to a diffusion-controlled or physically-based model, can facilitate more precise prediction of their source/sink behavior. Although further research and more rigorous validation is needed, an emission model applied with the diffusion and partition coefficients from this research holds promise for the improvement of reliability in predicting the behavior of VOCs emitted from porous building materials by D and K.

• 한국음향학회지
• /
• 제31권4호
• /
• pp.225-234
• /
• 2012

The anechoic chamber is essential tool to measure the various acoustic parameters with high precision. The chamber provides the climate controlled indoor environments but requires the dedicated room at a great cost in order to isolate and absorb sound field. Provided the purpose of the chamber is specific to the experiments of sound localization, the performance requirements excluding free field can be alleviated for cost effective solution. This paper designs low cost and profile anechoic chamber based on acoustic pyramids and evaluates the performance specified by the Annex of ISO 3745. Data analysis is employed to measure the free and hemi-free field performance over five straight paths for working areas and four paths for non-working areas. The identical two measurement campaigns were conducted for free and hemi-free field chamber which is easily interchangeable by simple labor in this chamber design. In the working area with conventional speaker, the results of these analyses demonstrate that lab-designed anechoic chamber is in conformance with ISO 3745 for 250 Hz - 16 kHz one-third octave band at free field chamber and for 1 kHz - 16 kHz one-third octave band at hemi-free field chamber.

• 한국환경농학회지
• /
• 제29권4호
• /
• pp.374-380
• /
• 2010

본 연구에서는 농촌진흥청에서 개발한 LED Chamber System을 이용하여 명기시간 동안 광질과 광조사 방법 제어가 단절단엽의 국화 배양소식물체(Dendranthema grandiflorum L., cv. 'Cheonsu')의 생장에 미치는 영향을 검토하였다. 실험은 청색, 적색 및 녹색의 단일광질 또는 청색+적색, 청색+녹색 및 적색+녹색의 혼합광질 조건하에서 이들 광질을 명기 16시간 동안 연속적으로 또는 초당 50회 간격과 분당 20초간격으로 간헐적으로 제어하면서 42일간 수행하였다. 총 일장을 4시간 단축한 분당 20초 간격의 간헐조사는 관행의 형광등 연속조사에 비해 국화의 절간길이 신장에 의한 신초신장을 촉진하였으나, 배양소식물체의 양적생장은 연속광 처리에 의해 유의하게 증가하였다. 한편, 명기동안 녹색광을 초당 50회 간격으로 간헐제어한 경우 연속조사에 비해 건물중이나 엽면적 증대와 같은 양적생장은 억제되었으나 형태적인 면에서의 절간신장은 촉진되었다. 따라서, LED Chamber System을 이용한 광질이나 광조사 방법의 제어는 관행의 형광등 이용 연속조사에 비해 명기시간 단축에 의한 전력소모량 감소 및 기내 배양소식물체의 생장이나 형태제어에 효과적인 배양기술로 이용 가능할 것으로 판단된다.

• 대기
• /
• 제27권4호
• /
• pp.499-509
• /
• 2017

Possible links among cosmic ray, cloud, and climate have scientific uncertainties. The reputed topics have been highly controversial during several decades. A link between the atmospheric ionization by galactic cosmic rays (GCR), which is modulated by solar activities, and global cloud cover was firstly proposed in 1997. Some researchers suggested that the GCR can stimulate the formation of cloud condensation nuclei (CCN) in the atmosphere, and then the higher CCN concentrations may lead to an increase of cloud cover, resulting in a cooling of the Earth's climate, and vise versa. The CLOUD (Cosmic leaving outdoor droplets) experiment was designed to study the effect of GCR on the formation of atmospheric aerosols and clouds under precisely controlled laboratory conditions. A state-of-the-art chamber experiment has greatly advanced our scientific understanding of the aerosol formation in early stage and its nucleation processes if the GCR effect is considered or not. Many studies on the climate-GCR (or space weather) connection including the CLOUD experiment have been carried out during the several decades. Although it may not be easy to clarify the physical connection, the recent scientific approaches such as the laboratory experiments or modeling studies give some implications that the research definitively contributed to reduce the scientific uncertainties of natural and anthropogenic aerosol radiative forcing as well as to better understand the formation processes of fine particulate matters as an important parameter of air quality forecast.

• 한국의류산업학회지
• /
• 제11권6호
• /
• pp.947-952
• /
• 2009

The purpose of this study is to analyze skin wettedness($w$) used as the rate index of thermal comfort, and to evaluate the wear comfort of outdoorwear. Skin wettedness is widely used to express the degree of thermal comfort. If skin wettedness exceeds a certain threshold, the body feels damp and discomfort. An experiment which consisted of rest(30 min), exercise(30 min) and recovery(20 min) periods was administered in a climate chamber with 10 healthy male participants. Two kinds of outdoorwears made of 100% cotton fabrics (Control) and specially engineered fabrics having feature of quick sweat absorbency and high speed drying fabric (Functional) were evaluated in the experiment. The condition of climate chamber was controlled according to the thermal insulation of 4 kinds of experimental ensembles(E1~E4). Total sweat loss, sweat loss absorbed into clothing and skin temperature were measured. Skin wettedness was calculated from the ratio of evaporative rate to the maximal evaporative capacity. Skin wettedness of 'Functional' was lower than 'Control' in the 3 kinds of ensembles(E1, E2, E4) because the materials of 'Functional' were composed of quick sweat absorbency and high speed drying fabrics, water vapour permeability and waterproof fabrics.

• 한국의류산업학회지
• /
• 제10권5호
• /
• pp.683-689
• /
• 2008

The purpose of this study was to investigate physiological responses such as rectal temperature, skin temperature, micro climate, sweat rate and subjective sensations using cold protective clothing with five different clo value. The clo value was measured by thermal manikin in windless condition. Healthy five 20's males volunteered as subjects for wearing trial experiment. The climate chamber was controlled at $50^{\circ}C$, 65% RH. The experiment consisted of repeated exercise and recovery periods. We found that the higher clo value has, the higher mean skin temperature, micro climate and sweat rate show. They felt warm and wet with higher insulation clothing. Thermal comfort increased in the last recovery period after exercise. There was significant difference between five cold protective clothing. In correlation analysis of clo value, it showed that correlation coefficient(r) values were more than 0.8. Therefore, in terms of clothing insulation, we found that correlation between thermal manikin experiment and wearing trial experiment was high. Clothing insulation could be variable according to many factors such as body movement, covering area, clothing gap, layering and design. Considering the body movement, we thought that insulation measurement need to carry out both thermal manikin experiment and wearing trial experiment.

• 한국생활과학회지
• /
• 제7권1호
• /
• pp.119-127
• /
• 1998

The purpose of this study was to evaluate thermal properties of pesticide protective clothing made of three different nonwoven fabrics which have barrier properties of pesticide. In order to assay the thermal properties of experimental clothing, thermal resistance measurements for clo value and thermographic assessment were conducted using a surface temperature controlled thermal manikin. The thermal manikin was dressed with underwear and experimental clothing. Air temperature in a climate chamber was kept at $28^{\circ}C$ and its humidity was 70% RH. Air velocity was controlled at less than 0.15m/s. Inner radient temperature was almost equal to the air temperature. The basic thermal insulation value(Icl) of underwear was 0.28 clo. The thermal properties of the experimental clothing were varied according to the type of material used in construction. The basic clothing insulation value for C1(spunbonded nonwoven fabric), C2(spunlaced nonwoven fabric), C3(SMS nonwoven fabric) were 0.705 clo, 0.725 clo, 0.738 clo respectively. The C3 experimental clothing made of SMS resulted in higher surface temperatures than the others with more yellowing spots being evident on the thermogram.

• 한국농림기상학회지
• /
• 제14권1호
• /
• pp.19-27
• /
• 2012

본 연구는 외국에서 이용해 왔던 기존의 상부 개방형 온실의 단점을 보완하여, 장기적인 연구가 요구되는 수목을 대상으로 설치한 상부 개방형 온실의 운영결과를 제공하고자 하는 것이다. 이 자료에는 이산화탄소의 농도 조절 능력 및 안정성을 비롯하여, 대기와 OTC 내부 간의 미세환경 차이에 대한 정보를 포함하고 있다. OTC 시설은 대조구인 OTC 외부 시험구, 대기와 동일 $CO_2$ 농도의 OTC 시험구, 대기 $CO_2$ 농도의 1.4배 증가시킨 OTC 시험구, 대기 $CO_2$ 농도의 1.8배 증가시킨 OTC 시험구로 구성되어 있다. 이시설은 온실 6기, $CO_2$ 폭로장치 6기, $CO_2$ 제어장치 6기, 액화탄산가스 탱크 1기, 제어감시실 1실로 구성되어 있다. 온실 6기는 직경 10m, 높이 7m의 10각형 구조물로 제작되었으며, 상부 개구율은 75% 이상을 유지하고 있다. $CO_2$ 폭로를 위해 16개 원통형 토출배관을 도입하였다. OTC의 평균 가동률은 2010년 6월에 94.2%로 가장 낮았으나, 7월 이후부터는 98% 이상의 가동률을 나타냈고, 2011년에는 100% 가동률을 보였다. 2010년과 2011년 모두 $CO_2$ 농도 조절 결과는 목표 값에 도달하였으며, 2011년이 보다 안정된 값을 나타냈다. 2011년 무처리 OTC의 $CO_2$ 농도는 목표 값의 106%였으며, 1.4배 OTC는 목표 값의 100%, 1.8배 OTC는 목표 값의 94%였다. 대기와 OTC 내부의 온도는 오전 10시부터 오후 2시 사이에 차이가 가장 컸는데, 편차는 $1.2{\sim}2.0^{\circ}C$를 기록했으나, OTC간 온도 차이는 크지 않았다. 대기와 OTC 내부간 상대 습도의 차이는 0.1~1% 사이로 매우 적었다. OTC를 운영하는데 사용된 $CO_2$ 가스 소비량은 2010년과 2011년 6월에 가장 많은 11.33톤과 17.04톤을 기록했다.

• 대한가정학회지
• /
• 제27권3호
• /
• pp.29-38
• /
• 1989

The purpose of this study is to investigate the physiological respones and subjective wearing sensations of the body of different materials of underwears. Experimental underwears were round neck-line shirts made of 100% cotton (60's plain stitch), 100% untreated nylon and hydrophillic finished 100% nylon (140 D. tricot). Four healthy female served as subjects. The experimental chamber was controlled at a constant temperature (23±1℃), constant relative humidity (53±3%) and air velocity of 0.25m/sec. The skin temperature, rectal temperature, pulse rate, clothing climate of temperature and humidity, and subjective wearing sensations were measured every five minutes during 75min. The results showed the level of the fiber hygroscopic properties was most relevant in the sensations of wearing: thus, cotton and treated nylon were felt by the subjects as more confortable fabrics, than untreated nylon.