• Title/Summary/Keyword: Light conditions

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Effect of Light and Feed Restriction During Rearing on Production Performance of Egg Strain Layers

  • Ahsan-ul-haq, Ahsan-ul-haq;Ahmad, Nazir;Rasool, Shahid;Shah, T.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.10 no.6
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    • pp.657-664
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    • 1997
  • 432 Babcock ISA white leghorn pullets reared for 8 weeks on a standard managemental conditions were exposed to feed/nutrient and light restrictions from 9 to 20 weeks of age. Four feeding regimes i. e. 100, 85 or 70 percent of the recommended allowance and low energy (2,500 Kcal/kg) low protein (13% CP) ration were fed each in the three light regimes i. e. (A) Natural day light starting from 13.24 hr/day at 8 weeks of age and ending 10.41 hr/day at the end of 20 weeks; (B) Constant 11 hr/day light and (C) starting with 13 hr/day at 8 weeks and decreasing @ 20 min/week till 20 weeks of age. At the age of 20 weeks all the birds were shifted to separate cages under uniform lighting feeding and management. During the 21st week light was increased to 12 hr a day and thereafter with an increase of 30 min per week, increased to 16 hr a day at the age of 29 weeks. From 20 weeks onward till 72 week age, all the birds were offered commercial layer rations ad libitum, prepared according to climatic conditions. The results of the study revealed that birds reared under natural and constant light had higher weights than decreasing light, yet they could not out perform during production period. The effect of feed and nutrient restriction, on the other hand, was found significant during rearing as well as production period. The birds exposed to higher level of feed and those exposed to nutrient restriction were lighter in weight. The 100% fed birds laid their first egg at an early age. However, those reared on 85% of the recommendation excelled all other groups in terms of produced number of eggs, egg mass, hen housed and hen day production and net returns.

Degradation of Microcystins during the Decomposition Process of Cyanobacterial Cells (Cyanobacteria의 분해에 따른 Microcystins의 변화)

  • Shin, Jae-Ki;Yim, Seong-A;Choi, Il-Hwan
    • Korean Journal of Ecology and Environment
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    • v.33 no.1 s.89
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    • pp.9-22
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    • 2000
  • The decomposition processes of Microcystis aeruginosa under the light and dark conditions were investigated in relation to the change of microcystins, physicochemical and biological factors. Cyanobacterial cells from upper stream of Lake Dae-chong were collected and incubated in the matrix of raw water under the light and dark conditions without additional nutrients. The decomposition of Microcystis cells started from beginning of the experiment and most of the cells were decomposed on 12th day. Under the light condition the concentration of toxins in filtrate fractionwas increased with the increase of viscosity as the decomposition of algal cells proceed whereas no significant change was observed under the dark condition. Microcystin- RR was most labile toxin than the other two microcystins because it was identified mainly in lyophilized cells but detected at trace level in the filtratefraction.

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Correlation Conditions for Marine Microalgae Isochrysis galbana under Illumination of Light Emitting Diodes (LED를 광원으로 사용한 해양미세조류 Isochrysis galbana 상관관계 조건 도출 연구)

  • Choi, Boram;Kim, Dongsoo;Lee, Taeyoon
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.10
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    • pp.63-68
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    • 2012
  • This study was performed to determine optimum conditions of batch type cultivation of Isochrysis galbana cultivated under various wavelengths of light emitting dioes (LEDs). Among LEDs used in the cultivation, white LED was found to be the most effective light source, and light intensity of 3,000Lux resulted in the most effective for the cultivation of Isochyrysis galbana. Comparison with common light source, fluorescent light, showed less effective than that with white LED. Four different air flow rates were tested to overcome shading effects due to denser cell concentration in the solution. In results, cell growth rates and maximum cell concentrations were similar regardless of air flow rates. Three times greater cell concentrations, however, were observed when air was applied.

Indentification of Cholesterol Oxides Formed in Butter under Varied Storage Conditions (상이한 조건에서 저장한 버터로부터 생성된 콜레스테롤 산화물의 확인)

  • Chang, Young-Sang;Yang, Joo-Hong;Shin, Hyo-Sun
    • Korean Journal of Food Science and Technology
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    • v.22 no.7
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    • pp.762-766
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    • 1990
  • The effect of storage conditions on the oxidative stability of cholesterol in butter was studied by identifing cholesterol oxides by TLC. Experimental variables for storage conditions were packaging(packaged and unpackaged), storage temperature(ambient and refrigerated), light source(dark, fluorescent and ultraviolet), and storage period(2, 4, 6, and 8 weeks). No cholesterol oxides were detected from packaged butter under all storage conditions. When unpackaged butter was stored under darkness at ambient and refrigerated temperatures, cholesterol oxides were not detected even after 6 weeks of storage, but small amounts of $7{\alpha}-and\;7{\beta}-hydroxycholesterols$ were detected after 8 weeks of storage. When unpackaged butter was stored under ultraviolet light at ambient temperature, $7{\alpha}-hydroxycholesterol,\;7{\beta}-hydroxycholesterol$ cholestane-triol, and cholesterol epoxide were detected after 2 weeks of storage, and when fluorescent light was used instead of ultraviolet light, the same species of cholesterol oxides were detected after 6 weeks of storage.

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Optimization of Cultivation Conditions on Effective Seedlings of Veronica rotunda var. subintegra (Nakai) T.Yamaz. (산꼬리풀의 효과적인 육묘를 위한 재배조건 최적화)

  • Lee, Sang In;Yeon, Soo Ho;Cho, Ju Sung;Jeong, Mi Jin;Lee, Cheol Hee
    • Journal of Bio-Environment Control
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    • v.29 no.2
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    • pp.181-188
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    • 2020
  • This study was conducted to identify the optimal conditions for seedling growth in Veronica rotunda var. subintegra (Nakai) T.Yamaz. which a endemic plant and can be development as ornamental plants. We sowed V. rotunda var. subintegra (Nakai) T.Yamaz. seeds, and exposed the seedling was different treatment conditions. We varied soil type and fertilizer concentration, shading ratio, additional fertilizer concentration, pretreatment light exposure and collection time of seeds. We found that seedling growth was good in horticultural substrate (with no additional fertilizer), but mixed soils supplemented with fertilizer inhibited growth, regardless of the fertilizer concentration. In the 55% shading treatment, seedling growth was greater than in the non-shading treatment. High concentration addition of fertilizer (Hyponex) promoted plant growth, in terms of both plant length and fresh weight. Exposure of seeds to a red light-source prior to germination had a greater effect on seedling growth than exposure to other light sources. Seedlings exhibited better growth when grown from seed collected in 2018, rather than 2017.

The Influence of Light Reduction on the Growth of Microcystis aeruginosa and Variation of Environmental and Chemical Parameters in Large-scale Cultivation System

  • Yang, Taehui;Cho, Ja-young;Kang, Ha-jin;Lee, Chang Soo;Kim, Eui-jin
    • Korean Journal of Ecology and Environment
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    • v.53 no.4
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    • pp.336-343
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    • 2020
  • Large-scale cultivation of Microcystis aeruginosa in different light conditions was conducted for verifying the cell growth in a greenhouse system. Environmental and chemical parameters of the large-scale culture medium were measured for analyzing the interaction between M. aeruginosa and its symbiotic bacteria. During cultivation, a difference in cell growth pattern was observed between control (natural light) and light-limited groups (reduction of blue, green, and blue/green light, respectively). Comparing the control group, the light reduced groups showed slow and delayed cell growth through the cultivation period. Also, there is differences in the consuming pattern of total nitrogen and total phosphorus which indicated that the possibility of interaction between M. aeruginosa and symbiotic bacteria.

Binary-phase Complex Spatial Light Modulators Driven by Mirror Symmetry

  • Choi, Minho;Choi, Jaewu
    • Current Optics and Photonics
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    • v.5 no.3
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    • pp.261-269
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    • 2021
  • Binary-phase complex spatial light modulators (BP-C-SLMs) are proposed and simulated. This study shows that bottom-top mirror-symmetrical uniaxial systems between two orthogonal polarizers allow one to construct BP-C-SLMs. BP-C-SLMs double the information-handling capacity per pixel, compared to the conventional amplitude-only spatial light modulators (A-SLMs), as well as being simply implemented with a single spatial light modulator (SLM), rather than a combination of an A-SLM and a binary-phase SLMs. Under limited conditions, BP-C-SLMs can control only the amplitude in single-phase space, and act as A-SLMs.

A Study on the Actual Conditions of Museum Environment for Old Textile Collections -Focused on university Museums- (직물류 유물의 전시 및 보관환경 실태조사-대학박물관을 중심으로-)

  • 배순화
    • Journal of the Korean Society of Costume
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    • v.34
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    • pp.109-120
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    • 1997
  • The conservation of collections in muse-ums is an important aspect for our her-itage. The control of museum environment is a vital factor in the preservation of cool-lections. Inappropriate or fluctuating envi-ronmental conditions can cause irreparable damage to works of arts. In this research we investigated the ac-tual conditions of museum environment for old testiles using questionnaire and mea-sured dye fasing of old textiles on exhibi-tion for 2 months in a university museum the major results are as follows: 1. The control of temperature and rela-tive humidity is a vital factors I the preservation of old textiles in museum generally acceptable temperature and rel-ative humidity standards for old textiles are 18-23$^{\circ}C$ and 50-65% R. H and light level for textiles on exhibition should be limited to 30-50 lux. 2, In university museums the limate control system in exhibition and storage area is in an early stage. Therefore to minimize the deterioration of old textiles the best method of controlling the envi-ronment is to have centralized climate control system in sorage area as well as in display area. 3. Conservator is needed to maintain collections scientifically. Only professional conservator by combining scientific tech-nical and artistic training has the exper-tise needed to maintain the physical in-tegrity of old textiles. In order to solve the inferior environment of museums the staff should recognize the importance of the condition of exhibition and storage. 4. Old textiles are susceptible to damage by light and associated heat. Dyed textiles which have been exhibited under the light without any UV filter were faded notice-ably within two months of exhibition. Light levels for textiles on exhibition should be limited to 30-50 lux. It is de-sirable to use special light source that can absorb UV. and UV filter is also recom-mended to reduce photodegradation of old textiles.

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Analysis of Female Windsurfers' Performance Using Global Positioning System Information During Competitions (여자 윈드서핑 선수의 경기 중 Global Positioning System 정보를 활용한 경기력 분석)

  • Chun, Sa Bin;Park, Jong Chul;Park, Sang Ha;Kim, Jin Soo
    • Korean Journal of Applied Biomechanics
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    • v.31 no.3
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    • pp.162-167
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    • 2021
  • Objective: This study aimed to identify the different wind speed categories and competitive level among windsurfers through GPS variables to provide the useful information on the development of training programs for enhancing windsurfers' performance. Method: Data from 69 female athletes who participated in 27 races during the 2018-2019 windsurfing season were used for the analysis. Average board speed, total race time, total distance, upwind race time, downwind race time, beam reach race time were collected through GPS. Unconfirmed data were excluded along with penalty point data. The wind conditions were classified as light, light to medium, medium, medium to heavy, and heavy wind, the competitive levels were classified as level 1, level 2, and level 3. Results: As for the average board speed, the level 1 or level 2 group showed higher board speed than the level 3 group in all wind conditions except for the light wind. The total race time and upwind race time showed less time in level 1 or level 2 group than level 3 group in all wind conditions. The total distance, downwind race time and beam reach race time showed less distance and time in level1 group than level 3 group under sufficient wind conditions. Conclusion: Our results show that the aerobic capacity to sustain pumping during upwind course in wind conditions below 15 kts effects performance. In wind conditions of 15 kts or more, indicated that the board control for the fast board speed and small distance required during up, down, beam reach courses had an effect on competition performance. This information can be provided to windsurfers and coaching as basic data for training programs to improve performance.

A Study on the Lighting Characteristics Appeared Architectural Space by Steven Hall and Richard Meier's works (스티븐 홀과 리차드 마이어의 건축공간에서 나타나는 빛의 표현 특성에 관한 연구)

  • Kim, Jung-Gon;Koh, Gwi-han;Bang, Moon-sun
    • Korean Institute of Interior Design Journal
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    • v.22 no.6
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    • pp.251-258
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    • 2013
  • Space and figure are formed not by themselves but by the existence of light. It is important that plays a role as an intermediary of cognition which enables the formation of space and figure through Human's recognition in the process of design. Human perceive space and identity every basic form by the contrast of light and dark. The existence of light is very inclusive concept in the space, so space and form are completed by light. The change of based on time, place, and its amount acts as an important element Which can change the form of Space. In Space light doesn't work simply as light itself, but have a very close relation with Space, Form, Structure, Material, Color elements, Space is limited by physical form but human perceive space relatively by many other conditions, So same space can be experienced differently by the characters of light. Human can recognized and observe an object in the space as he processes information collected through light. In this process light make it possible for human to see the shape in space. therefore, the shape of space can get meanings when light exists. the space recognized by light is the mean that activates human activates in space.