• Title/Summary/Keyword: sunlight

Search Result 1,032, Processing Time 0.022 seconds

A Study on Changes of Physical Properties of Rooftop Exposed Waterproofing PVC Sheet based on Longterm Outdoor Exposure Testing with Bearings (North, South) (옥상 노출방수용 PVC 방수시트의 방위별(남, 북) 장기옥외폭로에 따른 물성 변화 연구)

  • An, Ki-Won;Moon, You-Seok;Kim, Chun-Hag;Song, Je-Young;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2015.11a
    • /
    • pp.147-148
    • /
    • 2015
  • Exposed type waterproofing PVC sheets installed on structure rooftops are subject to changes in physical properties after longterm exposure to sunlight. Particularly when consideration the rotational movement of sunlight over the day through the course of the sun rising from the east and setting in the west, in the case of flat roofs the amount of UV ray the the surface of the PVC waterproofing sheet receives may be even throughout, but in cases of slanted rooftops the sunlight exposure may be uneven across the surface. In this regard, this study examines the effect uneven sunlight exposure on the exposed type waterproofing PVC sheets installed on slanted rooftops.

  • PDF

Effects of sunlight and predacious microorganisms on survival of enteric bacteria in sewage water (하수중 장내세균에 대한 태양광선 및 포식미생물의 살균효과)

  • 최경화;정혜경;김치경
    • Korean Journal of Microbiology
    • /
    • v.20 no.1
    • /
    • pp.21-26
    • /
    • 1982
  • The disinfection effects of sunlight and predacious microorganisms on enteria of Escherichia coli and Proteus vulgaris were examined in sewage water at 22 to $26^{\circ}C$. The test prganisms were disinfected by 4 to 5 logs during 6-hour a day exposure to sunlight for seven days. The effect was proportional to the light intensity and was proved to be dur to the action of the visible light of short wavelength which can transmit the soft glass of a flask glass. The predacious microorganisms decreased trhe test organisms by about 3 to 4 logs during 7 days. The complex actions of sunlight and predacious microorganisms were variable depending upon the test organisms, but the total effects of those enviromental factors were yet completely understood.

  • PDF

Effect of Sunlight on the Rancidity of Soybean Oil (대두유의 산패에 미치는 일사광선의 영향)

  • 임국이
    • Journal of the Korean Home Economics Association
    • /
    • v.19 no.1
    • /
    • pp.33-37
    • /
    • 1981
  • The accelerating effect of sunlight on the rancidity of soybean oil and the efficacies of several anti-oxidants were measured. The result is as follows: 1. The ac야 value and peroxide value of soybean oil were 0.16 and 1, 72 respectively. 2. the peroxide value of soybean oil which was exposed to sunlight nine hours a day for six days was 134.3: 21 times of that which was not exposed to sunlight. 3. The peroxide value of the soybean oil with 0.02~0.06% BHA decreased a little, but not significantly. 4. The anti-rancidity effect of BHT was a little stronger than BHA. 5. The anti-rancidity effect of ascorbic acid alone was negligible. 6 The peroxide value of soybean oil with an anti-oxidant which comprised ascorbic acid, BHA and BHT decreased to one third of that which was not treated with anti-oxidant.

  • PDF

A Possible Sunlight Effect on the Aging Characteristics of Silicone Rubber used for Outdoor Insulation (태양광 모의 열화에 의한 옥외용 실리콘 고무의 열화특성에 관한 연구)

  • Lim, C.R.;Lee, J.H.;Kim, J.T.;Koo, J.Y.;Park, W.K.
    • Proceedings of the KIEE Conference
    • /
    • 1998.07d
    • /
    • pp.1276-1278
    • /
    • 1998
  • In this paper, aging characteristics of silicone rubber used for outdoor insulation have been investigated with regards to sunlight effect. For this purpose, silicone rubbers were aged under the artificial sunlight by use of xenon arc lamp(1500W) and various tests were performed such as tracking, breakdown, contact angle, stress, strain. And then, in order to elucidate the changes of material, analysis have been followed as follows; FT-IR, SEM and EDS. Regarding the effect of the sunlight, it was obs that the surface of test samples are severely da with decreased hydrophobicity, tracking resistan breakdown strength.

  • PDF

Exploration of a Light Shelf System for Multi-Layered Vegetable Cultivation (자연광 다층 작물재배를 위한 광선반 시스템에 관한 연구)

  • Jang, Seong-Teak;Chang, Seong-Ju
    • KIEAE Journal
    • /
    • v.13 no.2
    • /
    • pp.61-66
    • /
    • 2013
  • This study is to eliminate the need for conventional high density plant factory's artificial light source such as LED to reduce the initial investment of the light source installation as well as the operation cost. Use of solar light could enhance the quality of the vegetables similar to those grown in the natural environment. Provision of solar light into the multilayer vegetable cultivation facilities and collecting maximum and sustainable sunlight without too much loss by tracing solar path and properly distributing it through careful control during daytime are crucial for realizing the investigated rooftop light shelf system for multi-layered vegetable cultivation. In this study, we developed an innovative way of effectively allocating sunlight inside even to otherwise shaded zone of a multi-layer vegetable cultivation facility. To prove the effectiveness of the system's sunlight collection and distribution capability, both simulation and experiment in Daejeon are performed and the outcome is analyzed.

An Evaluation of High Performance Sunlighting Mirror Systems (고성능 태양광 채광시스템의 채광성능평가)

  • Kim, J.T.;Hwang, M.K.;Chung, Y.G.
    • Journal of the Korean Solar Energy Society
    • /
    • v.22 no.2
    • /
    • pp.49-59
    • /
    • 2002
  • Recently, due to high rise building by rapid urbanization, the spaces incapable of being penetrated by sunlight into interior is increasing. So, sunlighting systems are important means to be able to get sunlight into indoors and to make sure of sunshine awareness. This study aims to evaluate lighting performance of sunlighting mirror systems. As results. these are very useful for the increase of an average illuminance of indoors and the penetration of sunlight. Especially, the second reflecting mirrors can be applied to spaces lack of sunlight. And these sunlighting systems developed in the present study is validated physical and psychological performance to both building and people.

Effect of Sunlight on the Reduction of Mycelia and Aflatoxins (태양광선에 의한 Aflatoxin의 감소 효과)

  • 변영희;김종규
    • Journal of Food Hygiene and Safety
    • /
    • v.14 no.4
    • /
    • pp.428-432
    • /
    • 1999
  • This study was performed to investigate the possible effect of sunlight on the reduction or degradation of mycelia and aflatoxins. The mycelia and aflatoxins were produced by Aspergillus parasiticus ATCC 15517 in a yeast-extract sucrose broth (YES) and potato-dextrose agar (PDA) and then exposed to sunlight. The weight of mycelia was decreased to 76.8% in 8 hours and to 66.7% in 168 hours(p<0.05). The total aflatoxin level was significantly decreased to below 50% (46.3% in the YES broth and 49.6% in the PDA) in 8 hours (p<0.05). After 168 hours, a 90.4% degradation of aflatoxin in the YES broth and a 77.2% degradation of aflatoxin in the PDA was observed, respectively (p<0.01). The results showed that the degradation ratios of total aflatoxin level increased with increased exposure time to sunlight. These results indicate that sunlight could be an effective factor in aflatoxin degradation although its effect on mycelia was less pronounced.

  • PDF

Removal of $NO_x$ by using of $TiB_2$ Photocatalysis ($TiB_2$ 광촉매를 이용한 $NO_x$ 제거)

  • Lee, Yong-Hwan;Choi, Im-Ho
    • Journal of environmental and Sanitary engineering
    • /
    • v.24 no.4
    • /
    • pp.112-115
    • /
    • 2009
  • This research was performed to purify water quality through removing T-N, and T-P and to estimating rate of $NO_x$ by the response of photocatalyst using ceramics. The ceramics was a mixtures of Titanium Diboride($TiB_2$) which is used to develop armored cars with excellent protective power and lightness, Olivine, and Hwangto with water and was furnaced for an hour at $1160^{\circ}C$. Hwangto and Olivine used in the study are produced at Haenam-gun, Jeonnam, and Andong-city, Gyeongsangbuk-do, respectively. The ground Hwangto and Olivine were seived through PR $100{\times}200$, and $TiB_2$ was a product of SIGMA ALDRICH. The experiment was performed under the sunlight, Mass flow controller was used for constant flow to pass through the pyrex reactor which was fully charged with furnaced ceramics. The concentration of $NO_2$ gas passed through the pyrex reactor was measured by Multi Gas Monitor. The reaction took for 60 minutes, The material was exposed to sunlight for 40 minutes. The sunlight was interrupted before and after the exposure for 10 minutes. The result showed that the concentration of $NO_2$ gas of the ceramics with $TiB_2$ and without $TiB_2$ became reduced and then maintained the same concentration under the sunlight, and became increased when the sunlight is interrupted. The $NO_2$ removing efficiency of the ceramics mixed with $TiB_2$ was 14~43% higher than that of the ceramics without $TiB_2$ under the sunlight. The study showed that the removing rate of $NO_2$ was 80% when the mixture rate of Hwangto, Olivine, and $TiB_2$ was 68%, 30% and 2%.