• Title/Summary/Keyword: Remaining capacity

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Selection of Promising Wind Farm Sites and Prediction of Annual Energy Production of a Wind Turbine for Eight Islands in Korea (국내 8개 도서지역 대상 풍력발전 유망후보지 선정 및 발전량 예측)

  • Kim, Chan-Jong;Song, Yuan;Paek, Insu
    • Journal of the Korean Solar Energy Society
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    • v.37 no.6
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    • pp.13-24
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    • 2017
  • Finding promising wind farm sites in islands of Korea is performed in this study. Total ten islands that have been measuring wind speed and direction using automatic weather stations for at least ten years were subjects of this study. Conditions for finding suitable wind farm sites including wind resource and various exclusion factors were applied and two islands that were found not to be suitable for wind farms were excluded. Micositing of a single wind turbine for the remaining eight islands was performed to estimate the annual energy production and the capacity factor.. Based on the simulation results, the wind farm sites selected within the eight islands were found to be suitable for wind power. The capacity factors were varied between 22.3% and 33.0% for a 100 kW wind turbine having a hub height of 30 m.

Myanmar Libraries after the 'Opening Up'

  • Bradley, Fiona
    • Journal of Information Science Theory and Practice
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    • v.5 no.4
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    • pp.49-67
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    • 2017
  • This article assesses the recent development of libraries in Myanmar and efforts to build the sector's capacity leading up to and after the first democratic elections held in the country in nearly 50 years, at the end of 2015. Cyclone Nargis in 2008 is viewed as a 'framing event' (Birkland, 1998) that led to national legal and policy reforms, an increase in national and international projects to support development of Myanmar libraries, and the strengthening of local actors including the Myanmar Library Association to coordinate and lead development activities. Although in need of modernisation, networking, and professional skills, the existence of a widespread number of all library types across the country provides an important foundation for further development. The current status and readiness of libraries is explored in the broader context of the rapid leap from limited to more widely available access to information and technology. The article finds that there is great potential for libraries in Myanmar to support the continued transition to democracy as evidenced by the role of libraries and access to information in other countries that have transitioned. Remaining challenges include the potential of backsliding on national reforms, and the need for significant investments in infrastructure and skills. Libraries must be transformed to meet the changing needs of information users in a young democracy.

Effect of Hydrodemolition on Bonding Strengthof Structures Repaired or Rehabilitated with VES-LMC (VES-LMC로 보수.보강된 구조물의부착강도에 미치는 Hydrodemolition의 영향)

  • Kim, Seong-Kwon;Shim, Do-Sick;Lee, Bong-Hak;Yun, Kyung-Ku
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.397-400
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    • 2006
  • Most of the civil structures in Korea and abroad have many kinds of damages when they are facing over-loaded traffics, long-term serviceability, and severe environmental conditions. Repair, rehabilitation, and retrofit are important for maintaining the serviceability of structures. In recent year, VES-LMC has been widely used as repair material for bridge deck repair and rehabilitation, because the VES-LMC has a various benefits such as traffic opening after 3 hours of curing, higher durability and bond strength. In case of any structure repaired or rehabilitated with VES-LMC, those were influenced capacity of bond between the base layer of slab and VES-LMC as well as physical properties of each other materials. The capacity of bond depended on purity of interface, micro cracks, curing of VES-LMC and so like. A kind of popular concrete repair technique, High pressure water jetting equipment is extremely efficient at removing damaged concrete. Removing damaged or poor quality concrete from sensitive structures such as bridge, tunnels, multi-story car parking decks and runways, using the high pressure water jetting could remove damaged or poor quality concrete remaining healthy and sound concrete. Accordingly, the purpose of this study is that it was to evaluate effect of hydrodemolition on the bond strength of VES-LMC overlay compared with effects of other method such as breaker, untreated. Also, it was evaluated the effect of surface moisture.

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Analysis of RC beam with unbonded or exposed tensile steel reinforcements and defective stirrup anchorages for shear strength

  • Wang, Xiao-Hui;Liu, Xi-La
    • Computers and Concrete
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    • v.10 no.1
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    • pp.59-78
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    • 2012
  • Although the effect of corrosion of reinforcing bar on the shear behavior of the reinforced concrete (RC) beam had been simulated by tests of the beam with unbonded, half-exposed or whole-exposed tensile steel reinforcements as well as defective stirrup anchorages, theoretical methods to accurately predict remaining capacity of this kind of RC beams, especially shear capacity, are still lacking. Considering the possible position of the critical inclined crack, the actual pattern of strains in the concrete body within the partial length and the proposed compatibility condition of deformations of the RC beam, shear strength of the RC beam with unbonded or exposed tensile steel reinforcements and/or defective stirrup anchorages is predicted. Comparison between the model's predictions with the experimental results published in the literature shows the practicability of the proposed model. Influence of the length of unbonded or exposed tensile steel reinforcements and the percentage of stirrups lacked end anchorages on the shear strength of the RC beam is discussed. It is concluded that, the shear strength of the RC beam with unbonded or exposed tensile steel reinforcements and/or defective stirrup anchorages is greatly influenced by the length of unbonded or exposed tensile steel reinforcements and the percentage of stirrups lacked end anchorages, this influence can be adverse, insignificant or even favourable, dependent on the given parameters of the corresponding normal bonded RC beam.

Chemical Indices of Soil Quality: Effects of Heavy Metal Additions

  • Yang, Jae-E.;Choi, Moon-Heon;Lee, Wi-Young;Kim, Jeong-Je;Jung, Yeong-Sang
    • Applied Biological Chemistry
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    • v.41 no.8
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    • pp.587-594
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    • 1998
  • The objective of this research was to characterize effects of Cu or Cd additions on chemistry of soil quality indices, such as pH, EC, cation distribution and buffering capacity. Metals were added at rates ranging from 0 to 400 mg $kg^{-1}$ of soil. Soil solution was sequentially extracted from saturated pastes using vacuum. Concentrations of Cu or Cd remaining in soil solutions were very low as compared to those added to the soils, warranting that most of the added metals were recovered as nonavailable fractions. Adsorption of the added metals released cations into soil solution causing increases of ionic strength of soil solution. At metal additions of $200{\sim}400\;mg\;kg^{-1}$, EC of soil solution increased to as much as $2{\sim}4\;m^{-1}$; salinity levels considered high enough to cause detrimental effects on plant production. More divalent cations than monovalent cations were exchanged by Cu or Cd adsorption. The nutrient buffering capacity of soils was decreased due to the metal adsorption and release of cations. pH of soil solution decreased linearly with increasing metal loading rates, with a decrement of up to 1.3 units at 400 mg Cu $kg^{-1}$ addition. Influences of Cu on each of these soil quality parameters were consistently greater than those of Cd. These effects were of a detrimental nature and large enough in most cases to significantly impact soil productivity. It is clear that new protocols are needed for evaluating potential effects of heavy metal loading of soils.

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Chemical Assessment of Heavy Metal Contamination in Soil

  • Yang, Jae-E.;Choi, Moon-Heon
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 1997.05a
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    • pp.8-11
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    • 1997
  • Current methods of evaluating soil contamination by heavy metals rely on analyzing samples for total contents of metals or quantities recovered in various chemical extracting solutions. Results from these approaches provide only an index for evaluation because these methodologies yield values not directly related to bioavailability of soil-borne metals. In addition, even though concentrations of metals may be less than those required to cause toxic effects to biota, they may cause substantial effects on soil chemical parameters that determine soil quality and sustainable productivity. The objective of this research was to characterize effects of Cu or Cd additions on soil solution chemistry of soil quality indices, such as pH, EC, nutrient cation distribution and quantity/intensity relations (buffer capacity). Metals were added at rates ranging from 0 to 400 mg/kg of soil. Soil solution was sequentially extracted from saturated pastes using vacuum. Concentrations of Cu or Cd remaining in soil solutions were very low as compared to those added to the soils, warranting that most of the added metals were recovered as nonavailable (strongly adsorbed) fractions. Adsorption of the added metals released cations into soil solution causing increases of soluble cation contents and thus ionic strength of soil solution. At metal additions of 200~400 mg/kg, EC of soil solution increased to as much as 2~4 dS/m; salinity levels considered high enough to cause detrimental effects on plant production. More divalent cations (Ca+Mg) than monovalent cations (K+Na) were exchanged by Cu or Cd adsorption. The loss of exchangeable nutrient cations decreased long-term nutrient supplying capacity or each soil. At 100 mg/kg or metal loading, the buffering capacity was decreased by 60%. pH of soil solution decreased linearly with increasing metal loading rates, with a decrement of up to 1.3 units at 400 mg Cu/kg addition. Influences of Cu on each of these soil quality parameters were consistently greater than those of Cd. These effects were of a detrimental nature and large enough in most cases to significantly impact soil productivity. It is clear that new protocols are needed for evaluating potential effects of heavy metal loading of soils.

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Sorption Behavior of Acetic Acid onto Activated Carbons (활성탄에서의 아세트산 흡탈착 거동)

  • Lee, Chae-Young;Chung, Jin-Suk;Shin, Eun-Woo
    • Korean Chemical Engineering Research
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    • v.46 no.6
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    • pp.1130-1134
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    • 2008
  • Acetic acid has been used as a solvent in the process of manufacturing terephthalic acid. Although the used acetic acid has been mainly separated and recovered through the distillation process, adsorption process can be applied to recover a small amount of acetic acid remaining in the stream after the distillation process. In this study, activated carbon was selected as an adsorbent for acetic acid and the effects of temperature and acid treatment on adsorption capacity were investigated. The adsorption capacities of activated carbon for acetic acid were 0.176 mmol/g at 303 K and 0.118 mmol/g at 343 K, respectively. Adsorption capacity decreased with increasing temperature. The acid treatment of the activated carbon induced the increase in adsorption capacity, which was ascribed to increase in surface functional groups such as phenolic hydroxyl groups and carboxilic acid groups on the carbon surface. In the results of acetic acid desorption, 89% of adsorbed acetic acid was desorbed from activated carbon.

Impacts of post-mortem ageing prior to freezing on technological and oxidative properties of coarse ground lamb sausage in a model system

  • Choe, Juhui;Kim, Hyun-Wook;Farouk, Mustafa M.;Kim, Yuan H. Brad
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.7
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    • pp.1021-1028
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    • 2017
  • Objective: The objective of this study was to evaluate the effects of ageing time of lamb loins prior to freezing on technological characteristics and oxidation stability of coarse ground lamb loin sausage using in a model system. Methods: Lamb loins (M. longissimus lumborum, n = 25) were aged at $-1.5^{\circ}C$ for 0, 1, 2, 3, and 8 wk and then frozen for the remaining days (a total of 30 wk). The aged/frozen/thawed lamb loins were ground, and model sausages were formulated with 75% aged/frozen/thawed lamb loin, 25% water, 1.5% sodium chloride (NaCl) and 0.3% sodium tripolyphosphate. The pH and thaw/purge loss of aged/frozen/thawed lamb loins were evaluated, and protein functionality (protein solubility and emulsifying capacity), water-holding capacity and textural properties of model sausages were determined. Cooked model sausages were vacuum-packaged in a plastic bag and displayed under continuous fluorescent natural white light ($3^{\circ}C{\pm}1^{\circ}C$). Colour and lipid oxidation of the cooked model sausages were evaluated on 0 and 21 d of display storage. Results: Ageing prior to freezing had no impact on pH and purge/thaw loss of lamb loins and the colour of cooked sausages (p>0.05) made from the loins. Lamb loins aged for at least 3 wk prior to freezing numerically improved total and myofibrillar protein solubilities (p>0.05) and emulsion activity index (p = 0.009) of meat batter, but decreased cooking loss (p = 0.003) and lipid oxidation (p<0.05) of model sausages. Conclusion: This study suggests that post-mortem ageing of raw meat prior to freezing could improve water-holding capacity and lipid oxidative stability of sausage made from the meat.

A Case Study of Bridge Scour Vulnerability Evaluation and Prioritization for National Highway Bridges in the National Capital Region (수도권 국도교량 세굴위험도 평가 및 등급화 사례 연구)

  • Park, Jae-Hyun;Kim, Jeong-Hun;An, Seong-Chul;Lee, Ju-Hyung;Chung, Moon-Kyung;Kwak, Ki-Seok
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.2
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    • pp.7-21
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    • 2008
  • Foundation failure due to bridge scour during floods is the leading cause of bridge failure. Performed were the evaluation of bridge scour vulnerability and prioritization on real bridges registered in the National Highway Bridge Inventory of the capital region. The case studies for 30 national highway bridges consist of site investigation including boring test, bridge scour analysis fur the design flood, bearing capacity evaluation of the bridge foundation before and after scour, comprehensive evaluation of bridge scour vulnerability, and prioritization. Nine of 26 spread (feting bridges showed the potential future vulnerability to scour with significant decrease in the bearing capacity of foundations due to scour and the remaining 17 spread footing bridges were expected to maintain their stability to resist the effects of scour. Three of 4 pile foundation bridges exhibited considerable decrease in the bearing capacity of foundation after scour.

A Study on the Application of Modeling to predict the Distribution of Legally Protected Species Under Climate Change - A Case Study of Rodgersia podophylla - (기후변화에 따른 법정보호종 분포 예측을 위한 종분포모델 적용 방법 검토 - Rodgersia podophylla를 중심으로 -)

  • Yoo, Youngjae;Hwang, Jinhoo;Jeon, Seong-woo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.27 no.3
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    • pp.29-43
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    • 2024
  • Legally protected species are one of the crucial considerations in the field of natural ecology when conducting environmental impact assessments (EIAs). The occurrence of legally protected species, especially 'Endangered Wildlife' designated by Ministry of Environment, significantly influences the progression of projects subject to EIA, necessitating clear investigations and presentations of their habitats. In perspective of statistics, a minimum of 30 occurrence coordinates is required for population prediction, but most of endangered wildlife has insufficient coordinates and it posing challenges for distribution prediction through modeling. Consequently, this study aims to propose modeling methodologies applicable when coordinate data are limited, focusing on Rodgersia podophylla, representing characteristics of endangered wildlife and northern plant species. For this methodology, 30 random sampling coordinates were used as input data, assuming little survey data, and modeling was performed using individual models included in BIOMOD2. After that, the modeling results were evaluated by using discrimination capacity and the reality reflection ability. An optimal modeling technique was proposed by ensemble the remaining models except for the MaxEnt model, which was found to be less reliable in the modeling results. Alongside discussions on discrimination capacity metrics(e.g. TSS and AUC) presented in modeling results, this study provides insights and suggestions for improvement, but it has limitations that it is difficult to use universally because it is not a study conducted on various species. By supporting survey site selection in EIA processes, this research is anticipated to contribute to minimizing situations where protected species are overlooked in survey results.