• Title/Summary/Keyword: Energy losses

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The Study for Practical use of Bioremediation Agent in Oil-Contaminated Area (해상유출유 오염지역에서의 미생물처리제 활용 방안 연구)

  • Chung Jin-Won;Yoon Joo-yong;Shin Jae-Rouk;Kim Han-Gyu
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.6 no.2
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    • pp.3-15
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    • 2003
  • Recently more than 450 incidents of oil spill a year have occurred in nearshore of Korea, which caused unmeasurelable losses in fisheries and severe damage in marine ecosystem. Two approaches remain paramount in any response to marine oil spill : the enhancement of natural dispersion of the oil by using dispersants, and mechanical recovery using booms and skimmers. A technique currently receiving fresh attention is the enhancement of the natural bioremediation of oil through the application of micro-organisms and/or nutrient. Oil, like many natural substances, will biodegrade over a period of time into simple compounds such as carbon dioxide, water and biomass. Bioremediation is the term used to describe a range of processes which can be used to accelerate natural biodegradation. More specifically biostimulation is the application of nutrients, and bioaugremetation or seeding is the addition of microbes specially selected to degrade oil. Bioremediation is an economically attractive method for the clean-up of oil-contaminated area. Bioremediation has been demonstrated to be an effective oil spill countermeasure for use in cobble, sand beach, salt marsh, and mud flat environment.

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Factors Affecting True Metabolizable Energy Determination of Poultry Feedingstuffs III. Effects of excreta collecting period and of feeding of soluble carbohydrates on metabolic and endogenous energy losses (양계사료의 TME 측정에 영향하는 요인에 관한 시험 III. 분채집시간과 가용성 탄수화물의 급이가 내인성 에너지 손실에 미치는 영향)

  • 이영철;강도환
    • Korean Journal of Poultry Science
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    • v.10 no.1
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    • pp.53-59
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    • 1983
  • The stuff was carried out in order to investigate the effect of level of feed input on AME (AME$\_$F/) and TME (AME$\_$FC/) values and of diet types of experiment on TME values of corn. yellow and soybean meal Experimental diet was fed as type of balanced diet instead of single ingredient at the level of 25. 50 and 75gm The results obtained were as follows : 1. The AME and AME$\_$F/ values of corn ana soybean meal were significantly different (P<.05) at each level of feed input. especially at 50gm feed input. the AME and AME$\_$F/ values of corn and soybean meal were the highest of all treatments and the AME of corn between 50gm and 75gm of feed input was not found significant difference(P>.05). 2. The TME and AME$\_$FC/ values of corn were not significantly different (P>.05) at each feed input but those of soybean meal differed greatly (P<.05) the fact that AME$\_$FC/ and TME values of soybean meal were the highest at 50gm of feed input was indicative that there were problems to measure AME$\_$FC/ and TME values of soybean meal. 3. There was not found significant difference (P>.05) according to the type of diet when fed single and balanced diet.

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Effect of Silicone Rubber Content on Thermal Stabilities of EPDM/Silicone Blends (실리콘고무 함량이 EPDM 고무의 열적 안정성에 미치는 영향)

  • Park, Soo-Jin;Kim, Jong-Hak;Joo, Hyeok-Jong;Jin, Fan-Long
    • Elastomers and Composites
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    • v.40 no.4
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    • pp.266-271
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    • 2005
  • In this work, the thermal stability factors, such as the thermal decomposition temperature, decomposition activation energy ($E_d$), and char yield, were measured to investigate the effect of silicone rubber (SR) content on the thermal stabilities of EPDM/SR blends. As a result, the thermal decomposition curve of EPDM/SR blends was similar to the neat EPDM rubber at 10 wt% SR and the thermal decomposition temperature increased above this content. The $E_d$ value of EPDM rubber initially decreased and then was constant above 20 wt% weight losses. The $E_d$ of EPDM/SR blends was higher than that of the neat EPDM rubber and then decreased with increasing the weight loss when the SR content was in the range of 10-20 wt%. Whereas the $E_d$ of the blends was lower than that of the EPDM rubber and then decreased with increasing the weight loss when 30 wt% SR was added. The char yield at $800^{\circ}C$ increased with increasing the SR content, because the decomposition of silane groups in the backbone was capable of forming a silane-rich residue after the initial stage of thermal degradation, which finally prevents further heat transfer and diffusion in the blends.

A Review of Quantitative Landslide Susceptibility Analysis Methods Using Physically Based Modelling (물리사면모델을 활용한 정량적 산사태 취약성 분석기법 리뷰)

  • Park, Hyuck-Jin;Lee, Jung-Hyun
    • The Journal of Engineering Geology
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    • v.32 no.1
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    • pp.27-40
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    • 2022
  • Every year landslides cause serious casualties and property damages around the world. As the accurate prediction of landslides is important to reduce the fatalities and economic losses, various approaches have been developed to predict them. Prediction methods can be divided into landslide susceptibility analysis, landslide hazard analysis and landslide risk analysis according to the type of the conditioning factors, the predicted level of the landslide dangers, and whether the expected consequence cased by landslides were considered. Landslide susceptibility analyses are mainly based on the available landslide data and consequently, they predict the likelihood of landslide occurrence by considering factors that can induce landslides and analyzing the spatial distribution of these factors. Various qualitative and quantitative analysis techniques have been applied to landslide susceptibility analysis. Recently, quantitative susceptibility analyses have predominantly employed the physically based model due to high predictive capacity. This is because the physically based approaches use physical slope model to analyze slope stability regardless of prior landslide occurrence. This approach can also reproduce the physical processes governing landslide occurrence. This review examines physically based landslide susceptibility analysis approaches.

Nutritional Status of Continuous Ambulatory Peritoneal Dialysis Patients (지속성복막투석 환자의 영양상태에 관한 연구)

  • Park, Jin-Kyung;Son, Sook-Mee
    • Journal of Nutrition and Health
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    • v.39 no.7
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    • pp.624-640
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    • 2006
  • Dialysis patients are at risk of malnutrition not only because of losses of nutrients during peritoneal dialysis but also because of anorexia that results in inadequate nutrient intakes. The aim of this study was to estimate the nutritional status of 154 patients receiving continuous ambulatory peritoneal dialysis (CAPD), especially focused on protein-energy malnutrition and vitamin and mineral status. The mean age of the subjects was $5.12\;{\pm}\;12.4\;y$ with educational years of $12.3\;{\pm}\;0.4\;y$ for male and $9.6\;{\pm}\;0.4\;y$ for female. The mean duration of dialysis was $22.7\;{\pm}\;21.7\;mo$. The causes of renal failure included diabetes (32.7), chronic glomerulonephritis (15.0%), and hypertension (8.5%). The main complications associated with chronic renal failure were hypertension (86.1%), diabetes (35.4%) and liver disease (9.0%). The mean daily energy intake was $1216.8\;{\pm}\;457.3\;kcal$ and increased to $1509.2\;{\pm}\;457.2\;kcal$ when added with the energy from dextrose in dialysate. The latter was still much lower than estimated energy requirement but energy intake per kg of body weight (28.1 kcal/1 g) was within the range of that recommended for CAPD patients' diet therapy (25 - 30 kcal/kg). The average daily intake of protein was $49.2\;{\pm}\;25.1\;g$ with 37.6% of the patients showing their intakes less than Estimated Average Requirement. The average protein intake per kg of weight was 0.9 g/kg, which is less than that recommended for CAPD patients (1.2-1.5g/kg) with mean serum albumin level $3.2\;{\pm}\;0.5\;g/dl$. The proportion of the patients with dietary calcium intake less than EAR was 90.9%, but when added with supplementary calcium (phosphorus binder), most patients showed their total calcium intake between EAR and UL. Fifty percent of the patients were observed with dietary iron intake less than EAR, however most patients revealed their total iron intake with supplementation above UL. The addition of folic acid with supplementation increased mean total folic intake to $1126.0\;{\pm}\;152.4\;{\mu}g$ and ninety eight percent of the subjects showed their total folic acid intake above UL. The prevalence of anemia was 83.1 % assessed with hemoglobin level, even with high intakes of iron with supplementation. Thirty four percent of the patients showed their fasting blood glucose was not under control $(\geq\;126\;mg/dl)$ even with medication or insulin probably due to dextrose from dialysate. The mean blood lipid levels were within the reference levels of hyperlipidemia, but with 72.1 % of the patients showing lower HDL-C. In conclusion, Fairly large proportion of the patients were observed with protein malnutrition with low intake of protein and serum albumin level. Few patients showed their vitamins and minerals intake less than EAR with supplementation. For iron and folic acid, their intakes were increased to above UL for large proportion of he patients. However, more than eighty percent of the patients were still anemic associated with decreased renal function. The serum blood glucose and lipid level were not under control for some patients with medication. It seems that supplementation and medications that patients are taking should be considered for dietary consulting of CAPD patients.

Study on the Mechanical Stability of Red Mud Catalysts for HFC-134a Hydrolysis Reaction (HFC-134a 가수분해를 위한 Red mud 촉매 기계적 안정성 향상에 관한 연구)

  • In-Heon Kwak;Eun-Han Lee;Sung-Chan Nam;Jung-Bae Kim;Shin-Kun Ryi
    • Clean Technology
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    • v.30 no.2
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    • pp.134-144
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    • 2024
  • In this study, the mechanical stability of red mud was improved for its commercial use as a catalyst to effectively decompose HFC-134a, one of the seven major greenhouse gases. Red mud is an industrial waste discharged from aluminum production, but it can be used for the decomposition of HFC-134a. Red mud can be manufactured into a catalyst via the crushing-preparative-compression molding-firing process, and it is possible to improve the catalyst performance and secure mechanical stability through calcination. In order to determine the optimal heat treatment conditions, pellet-shaped compressed red mud samples were calcined at 300, 600, 800 ℃ using a muffle furnace for 5 hours. The mechanical stability was confirmed by the weight loss rate before and after ultra-sonication after the catalyst was immersed in distilled water. The catalyst calcined at 800 ℃ (RM 800) was found to have the best mechanical stability as well as the most catalytic activity. The catalyst performance and durability tests that were performed for 100 hours using the RM 800 catalyst showed thatmore than 99% of 1 mol% HFC-134a was degraded at 650 ℃, and no degradation in catalytic activity was observed. XRD analysis showed tri-calcium aluminate and gehlenite crystalline phases, which enhance mechanical strength and catalytic activity due to the interaction of Ca, Si, and Al after heat treatment at 800 ℃. SEM/EDS analysis of the durability tested catalysts showed no losses in active substances or shape changes due to HFC-134a abasement. Through this research, it is expected that red mud can be commercialized as a catalyst for waste refrigerant treatment due to its high economic feasibility, high decomposition efficiency and mechanical stability.

Using the Binomial Option Pricing Model for Strategic Sales of CER's to Improve the Economic Feasibility of CDM projects (이항옵션가격 모형을 활용한 CER 판매전략 구축과 이를 통한 CDM 사업 수익성 향상 방안에 관한 연구)

  • Koo, Bonsang;Park, Jong-Ho;Kim, Cheong-Woon
    • Korean Journal of Construction Engineering and Management
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    • v.15 no.1
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    • pp.111-121
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    • 2014
  • The Clean Development Mechanism (CDM) allows New & Renewable Energy projects to make additional income by selling CER's, which represent the amount of Green House Gases(GHG) that is reduced in the project. However, forward contracts used to hedge fluctuating market prices does not allow projects to sell CER's at a premium. As an alternate approach to maximize CER revenue, CER's are modeled as a 'real option', in which CER's are sold only above the desired sales price. Using the Binomial Option Pricing model, the resultant lattices are used to determine whether to sell, defer or abandon the option at individual nodes. Overlaying Pascal's Triangle on the lattices also enabled the calculation of the annual probabilities for deferring CER sales without incurring downside losses. Application to an actual Landfill Gas project showed increased overall NPV, and that CER sales could be deferred at a maximum of 2 years. The proposed framework allows transparency in the analysis and provides valuable and strategical information when making investment decisions related to CER sales of CDM projects.

Pseudo Dynamic Test Study on Seismic Performance Evaluation of RC Columns Retrofitted by PolyUrea (내진보강용 폴리우레아로 보강된 철근콘크리트 기둥의 내진성능 평가에 대한 유사동적실험 연구)

  • Cho, Chul Min;Lee, Doo Sung;Kim, Tae Kyun;Kim, Jang-Ho Jay
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.2
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    • pp.289-301
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    • 2017
  • As earthquakes have frequently happened all over the world, huge losses of human life and property have occurred. Therefore, retrofitting and strengthen technologies of non-seismically designed structures in Korea are urgent. Also, there has been a growing interest about seismic retrofitting, where researches on the topic have been actively pursued in Korea. The study results showed that ductility inducing retrofitting method is more superior stiffness inducing method. In Japan, Super Reinforcement with Flexibility (SRF) was introduced. Therefore, in this study, seismic performance evaluation was performed through pseudo dynamic test and uniaxial compression test for RC column retrofitted by PolyUrea for ductility inducing retrofitting material. Uniaxial compression test results showed that strength of all specimens retrofitted by PolyUrea was higher than that of RC specimens. Also, all specimens retrofitted by PolyUrea also showed ductile fracture behavior. In pseudo dynamic test, by appling real earthquake record, the seismic behavior of RC column reinforced by PolyUrea was evaluated through relative displacement, reinforcement strain, displacement ductility, and dissipation energy. The results showed that PolyUrea helped to enhance seismic performance of RC columns.

Fabrication and Optimization of a Fiber-optic Dosimeter for Proton Beam Therapy Dosimetry (의료용 양성자선 계측을 위한 광섬유 방사선량계의 제작 및 최적화)

  • Jang, Kyoung-Won;Cho, Dong-Hyun;Yoo, Wook-Jae;Seo, Jeong-Ki;Lee, Bong-Soo;Hwang, Eui-Jung;Shin, Dong-Ho;Park, Sung-Yong
    • Progress in Medical Physics
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    • v.21 no.1
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    • pp.29-34
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    • 2010
  • In this study, we have fabricated a fiber-optic dosimeter for a proton beam therapy dosimetry. We have measured scintillating lights with the various kinds of organic scintillators and selected the BCF-12 as a sensor-tip material due to its highest light output and peak/plateau ratio. To determine the optimum diameter of BCF-12, we have measured scintillating lights according to the energy losses of proton beams in a water phantom. Also, we determined the adequate length of organic scintillator by measuring scintillating lights according to the incident angles of proton beam. Using an optimized fiber-optic dosimeter, we have measured scintillating lights according to the dose rates and monitor units of proton accelerator.

Modelling Pasture-based Automatic Milking System Herds: The Impact of Large Herd on Milk Yield and Economics

  • Islam, M.R.;Clark, C.E.F.;Garcia, S.C.;Kerrisk, K.L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.7
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    • pp.1044-1052
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    • 2015
  • The aim of this modelling study was to investigate the effect of large herd size (and land areas) on walking distances and milking interval (MI), and their impact on milk yield and economic penalties when 50% of the total diets were provided from home grown feed either as pasture or grazeable complementary forage rotation (CFR) in an automatic milking system (AMS). Twelve scenarios consisting of 3 AMS herds (400, 600, 800 cows), 2 levels of pasture utilisation (current AMS utilisation of 15.0 t dry matter [DM]/ha, termed as 'moderate'; optimum pasture utilisation of 19.7 t DM/ha, termed as 'high') and 2 rates of incorporation of grazeable complementary forage system (CFS: 0, 30%; CFS = 65% farm is CFR and 35% of farm is pasture) were investigated. Walking distances, energy loss due to walking, MI, reduction in milk yield and income loss were calculated for each treatment based on information available in the literature. With moderate pasture utilisation and 0% CFR, increasing the herd size from 400 to 800 cows resulted in an increase in total walking distances between the parlour and the paddock from 3.5 to 6.3 km. Consequently, MI increased from 15.2 to 16.4 h with increased herd size from 400 to 800 cows. High pasture utilisation (allowing for an increased stocking density) reduced the total walking distances up to 1 km, thus reduced the MI by up to 0.5 h compared to the moderate pasture, 800 cow herd combination. The high pasture utilisation combined with 30% of the farm in CFR in the farm reduced the total walking distances by up to 1.7 km and MI by up to 0.8 h compared to the moderate pasture and 800 cow herd combination. For moderate pasture utilisation, increasing the herd size from 400 to 800 cows resulted in more dramatic milk yield penalty as yield increasing from c.f. 2.6 and 5.1 kg/cow/d respectively, which incurred a loss of up to $AU 1.9/cow/d. Milk yield losses of 0.61 kg and 0.25 kg for every km increase in total walking distance (voluntary return trip from parlour to paddock) and every one hour increase in MI, respectively. The high pasture utilisation combined with 30% of the farm in CFR in the farm increased milk yield by up to 1.5 kg/cow/d, thereby reducing loss by up to $0.5/cow/d (c.f. the moderate pasture and 800 cow herd scenario). Thus, it was concluded that the successful integration of grazeable CFS with pasture has the potential to improve financial performance compared to the pasture only, large herd, AMS.