• 생명과학회지
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• 제8권5호
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• pp.550-556
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• 1998

염소, 요오드, 담수처리에 의한 바이러스 병원성 약화 시험결과, 염소 5 ppm이상에서, 담수 50% 이상에서 살균효과를 나타내었으나 요오드는 효과가 없었다. Peptidoglycan, schzophyllan의 면역증강 효과를 시험한 결과, 각각 7일간 격 투여구와 2일간격 투여구에서 생존율이 대조군에 비해 높게 나타났다. 화학적, 효소적, 생물활균제를 투여하여 수질 및 저질 개선시험결과 화학적 개선제, Mg(OH)$_2$의 효과가 수질, pH, 강열감량 부분에서 효과가 가장 컸으며, 특이하게 효소적 개선제는 총 황화물의 농도를 약간 높이는 것으로 나타났다.

• 상하수도학회지
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• 제20권4호
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• pp.637-643
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• 2006

The bench-scale chlorine exposure study was performed to investigate the effect of pretreatment by free chlorine and monochloramine ($NH_2Cl$) on the performance of RO membranes made of polyamide (PA). Feed monochloramination at 2mg/L did not cause significant productivity loss compared to free chlorine. However, metal coagulants reacted with monochloramine, the PA membrane suffered from a gradual loss of membrane integrity by chlorine oxidation, which was characterized as a decrease in salt rejection. Especially, RO membranes exposed to alum coagulants with monochloramine revealed the salt rejection lower than those exposed to iron coagulants. XPS membrane surface analysis demonstrated that the chlorine uptake on the membrane surface increased and carbon peaks were shifted significantly when exposed to alum coagulants with monochloramine.

• 전자공학회논문지A
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• 제30A권4호
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• pp.1-10
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• 1993

This paper presents the designing/manufacturing scheme of the diplexer for satellite transponder which is composed of 2-channel bandpass filters, coupled with E-plane T-junction, having symmetrical waveguide E-plane step discontinuity structures. The 2-channel bandpass filters of the diplexer are designed by the scheme of connecting ${\lambda}_{g}$/2 shunt stub to the waveguide E-plane, playing the role of heat sinks without attaching a special heat sinks and to give the profitable productivity and allow the low-cost manufacturing at mass production, tuning screws are eliminated which have been used to compensate the operating characteristics of manufactured filters. The 2 channel bandpass filters of manufactured 14/12 GHz diplexer for domestic Ku-band satellite transponder have the return loss of 25 dB, insertion loss of 0.3 dB in passband, and below-50 dB of stopband characteristics (T$_{x}$ : f$_{o}{\pm}$250 MHz, R$_{x}$ : f$_{o}{\pm}$220 MHz) at room temperature.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1365-1367
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• 2003

In this paper, element technologies such as soldering. arrangement and lamination processes for photovoltaic module manufacture were examined and described as main processes. Especially solder paste and temperature condition in soldering process, loss factor in arrangement process and process conditions in lamination process are investigated to minimize the electrical loss. As a results, temperature condition in soldering process was found to be critical to contact resistance of electrode and life-time. Productivity of the process decreases dramatically by physical damage during arrangement process. Pressure level and press condition of upper chamber in lamination process were important parameters for the reliability. According to the test result of photovoltaic module, electrical properties dropped about $5{\sim}25%$ after 5 years.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.137-138
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• 2023

This study proposed the optimal mixing time for pre-mixed cement and post mixed cement using the statistical analysis method of box plots. Pre-mixed cement can prevent material seegregation, strength loss, and quality variation if mixed for at least 60 seconds, and the data median is shown to be within the box range. Post-mixed cement should be mixed for at least 180 seconds to prevent material segregation, strength loss, and quality variation, and compressive strength tends to increase with longer vibrating times. Therefore, it is suggested that using pre-mixed cement can shorten the vibrating time and increase the productivity of the concrete.

• 펄프종이기술
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• 제40권2호
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• pp.37-42
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• 2008

Defects of corrugated board were limiting factors to the corrugated industry's growth. On-line detecting systems of defects are beneficial to increase profits of the corrugated board companies by reducing base paper consumption, increasing process reliability, and increasing productivity. By replacing naked eye inspection of defects to a defects detecting system, continuous inspection without fatigue may guarantee final products quality. The system was developed, which was consisted of line scan CCD camera, lens, illuminating parts, high speed image processor, software, various input parts, and output parts. First installation location of the system was at before fluting process after base paper unwinding, and surface of liner board was inspected by the system. Second installation location was after fluting process and combining process for liner board. Production loss includes ragged appearance of edge, irregular flute shape, wrong combination of flute, score cracking, defects in base paper, and flute cracking. The production loss was analyzed before and after the system installation at a commercial domestic mill. The production loss ratio was defined as a production loss weight per total production weight. The production loss ratio before the installation was decreased a lot from 1.28%(during 3 months before installation) to 0.76%(during 12 months after the first installation) and to 0.25%(during 6 months after the second installation).

• 자원ㆍ환경경제연구
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• 제26권2호
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• pp.139-172
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• 2017

본 연구는 국제원자력기구(International Atomic Energy Agency: IAEA)의 원자로정보시스템(Power Reactor Information System: PRIS)에서 제공하는 원자로 운전실적지표를 이용하여 원전의 안전성에 미치는 기술적 비기술적 요인의 역할을 분석한다. 이를 위해 안전성의 척도로 원전의 고장정지에 따른 발전손실률 (FLR: forced loss rate)을 사용했다. 1970년부터 2015년까지 전 세계에서 운영된 모든 원전으로 구성된 패널자료를 통해 분석한 결과, 기존 연구와 마찬가지로 원전의 전반적인 기술수준과 정비기술수준이 향상될수록 FLR이 하락하는 사실을 확인했다. 하지만 1986년 체르노빌 원전 사고 이후 기술적 요인이 통제된 FLR은 유의적으로 상승했다. 이는 원자력발전사업자가 체르노빌 사고 이후 원자력안전을 위해 보다 많은 기회비용을 지불하고 있다고 해석된다.

• ALGAE
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• 제35권3호
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• pp.237-252
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• 2020

Temperate rocky reefs dominated by the giant kelp, Macrocystis pyrifera, support diverse assemblages of benthic macroalgae that provide a suite of ecosystem services, including high rates of primary production in aquatic ecosystems. These forests and the benthic macroalgae that inhabit them are facing both short-term losses and long-term declines throughout much of their range in the eastern Pacific Ocean. Here, we quantified patterns of benthic macroalgal biomass and irradiance on rocky reefs that had intact kelp forests and nearby reefs where the benthic macroalgae had been lost due to deforestation at three sites along the California, USA and Baja California, MEX coasts during the springs and summers of 2017 and 2018. We then modeled how the loss of macroalgae from these reefs impacted net benthic productivity using species-specific, mass-dependent rates of photosynthesis and respiration that we measured in the laboratory. Our results show that the macroalgal assemblages at these sites were dominated by a few species of stipitate kelps and fleshy red algae whose relative abundances were spatially and temporally variable, and which exhibited variable rates of photosynthesis and respiration. Together, our model estimates that the dominant macroalgae on these reefs contribute 15 to 4,300 mg C m^-2 d^-1 to net benthic primary production, and that this is driven primarily by a few dominant taxa that have large biomasses and high rates of photosynthesis and / or respiration. Consequently, we propose that the loss of these macroalgae results in the loss of an important contribution to primary production and overall ecosystem function.

• 대한토목학회논문집
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• 제26권1D호
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• pp.141-147
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• 2006

강우에 의해서 발생하는 토양유실은 비옥한 표토를 유실시켜 생산성의 저하를 초래하고, 유실된 토양입자는 하천이나 호수, 댐 등에 퇴적되어 저수용량의 감소와 수질관리에 어려움을 야기 시키므로 이에 대한 대처가 필요하다. 본 연구에서는 위성 영상과 GIS 기법을 활용하여 유역내 토양침식에 영향을 미치는 토양조건, 피복조건, 지형조건들을 추출하고 이 요소들을 범용토양유실공식(USLE; Universal Soil Loss Equation)에 적용하여 유입퇴적량 및 유입 가능성이 높은 위치를 파악하였다. 또한 유입되어 하상에 쌓여 있는 퇴적량은 투과성이 강한 음향측심기를 활용하여 퇴적층과 지층의 고도 정보를 획득하여 산정하고 유실량과 퇴적량을 비교하여 퇴적되는 비율을 도출하였다.

• Journal of Plant Biology
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• 제14권4호
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• pp.19-26
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• 1971

The sample stand of Pinus rigida plantation was chosen from those at the Choongnam Forest Experiment Station, Choongnam. The diameter at breast height (D) and the height of tree (H) of each tree in the sample plot of 200$m^2$ were measured yearly a from 1967 through 1969. The stand was 12.7-13.4cm in mean diameter and had a stand density of 2,150 trees per ha. The trunk, branches and leaves of each sample tree were separately weighed according to the stratified clip technique. The allometric relation between D2H and dry weight of trunk (Ws), branches (Wb) and leaves (Wl) were approximated by $$W_s=0.05917 (D^2H)^{0.837}$$ $$W_0=0.00655 (D^2H)^{0.989 }$$ $$W_l=0.04466(D^2H)^{0.690}$$ From the above, the standing crops in the sample stand was estimated to be as much as 76.7, 81.7 and 88.2 tons of dry matter, above ground, per ha in 1967, 1968 and 1969, respectively. Annual net production, as the sum of the biomass newly produced during one year, was estimated at 4.97-5.47 tons per ha per year. The respiratory and the photosynthetic rate deduced from theoretical calculations were 0.045 and 0.74kg of dry matter per kg per year. Tentative estimate of annual respiratory loss was made and annual gross production was roughly estimated at 4.4-4.7 and 10.7-12.9 tons of dry matter per ha per year. The ratio of respiratory loss to gross production was approximately 36-41:1.