• Title/Summary/Keyword: Contribution rate

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Degradation of oxytetracycline by nano zero valent iron under UV-A irradiation: Chemical mechanism and kinetic

  • Hassanzadeh, Parisa;Ganjidoust, Hossein;Ayati, Bita
    • Advances in environmental research
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    • v.3 no.1
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    • pp.29-43
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    • 2014
  • Pharmaceutical wastewater effluents are well known for their difficult elimination by traditional biotreatment methods and their important contribution to environmental pollution due to its fluctuating and recalcitrant nature. OTC is one of the nonbiodegradable antibiotics that makes antibiotic-resistant, so it can make be high risk for environment. NZVI can be a good choice for removal of OTC in aqueous solution. Response surface methodology (RSM) was used to optimize the amounts of NZVI and OTC to be used at pH 3 and under 200 W, UV-A irradiation. The responses were removal percent of absorption at 290 and 348 nm, TOC and COD of OTC. In the optimum condition, Linear model was performed 155 ppm of OTC were removed by 1000 ppm NZVI after 6.5 hours and the removal efficiency of absorption at 290 and 348 nm, TOC and COD were 87, 95, 85 and 89 percent, respectively. In the similar process, there is no organic compound after 14 hours. The parameters ORP, DO and pH were investigated for 6:30 hours to study the type of NZVI reaction in process. In the beginning of reaction, oxidation was the dominant reaction after 3 hours, photocatalytic reaction was remarkable. The mechanism of OTC degradation is proposed by HPLC/ESI-MS and four by products were found. Also the rate constants (first order kinetic chain reaction model) were 0.0099, 0.0021, 0.0010, 0.0049 and $0.0074min^{-1}$, respectively.

Sustainable concrete mix design for a target strength and service life

  • Tapali, Julia G.;Demis, Sotiris;Papadakis, Vagelis G.
    • Computers and Concrete
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    • v.12 no.6
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    • pp.755-774
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    • 2013
  • Considering the well known environmental issues of cement manufacturing (direct and indirect levels of $CO_2$ emissions), clinker replacement by supplementary cementing materials (SCM) can be a very promising first step in reducing considerably the associated emissions. However, such a reduction is possible up to a particular level of SCM utilization, influenced by the rate of its pozzolanic reaction. In this study a (4-step) structured methodology is proposed in order to be able to further adjust the concrete mix design of a particular SCM, in achieving additional reduction of the associated levels of $CO_2$ emissions and being at the same time accepted from a derived concrete strength and service life point of view. On this note, the aim of this study is twofold. To evaluate the environmental contribution of each concrete component and to provide the best possible mix design configuration, balanced between the principles of sustainability (low environmental cost) and durability (accepted concrete strength and service life ). It is shown that such a balance can be achieved, by utilising SCM by-products in the concrete mix, reducing in this way the fixed environmental emissions without compromising the long-term safety and durability of the structure.

Study on the Radiocarbon Dating with Liquid Scintillation Counting (액체섬광계수법을 이용한 방사성탄소 연대측정법 연구)

  • Kim, Nak Bae;Woo, Hyung Joo;Hong, Wan;Cho, Soo Young
    • Analytical Science and Technology
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    • v.5 no.4
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    • pp.381-387
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    • 1992
  • Optimum counting condition of a low level liquid scintillation counter for radiocarbon dating has been determined to minimize the contribution of tritium activity and get the highest FOM by the variation of scintillation solutions, scintillation solution to benzene ratio, and ${\beta}$-ray spectrum counting ranges. Under the condition, background count rate has been reduced to $2.26{\pm}0.03cpm$, and the maximum measurable age reached to about 40,000 years. And the practicality of counting system has been verified by the analysis of shell and peat samples.

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A Study on Acquisition Cost of Weapon System by Sensitivity Analysis (민감도 분석을 통한 무기체계 획득 비용분석에 관한 연구: 함대공유도탄 비용분석을 중심으로)

  • Oh, Yeong-Min;Kwon, O-Sung
    • Journal of the military operations research society of Korea
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    • v.36 no.2
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    • pp.107-124
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    • 2010
  • In order to estimate the life cycle expense of the weapon system acquisition from the first demand planning phase until the last disuse phase, we apply the reliable expense analysis method to the current situation in Korea by using the sensitivity analysis. We estimate the total cost of the weapon system acquisition by focusing on the most important variables such as exchange rate, and hence by strengthening the function of the existing expense analysis method, which is used to be simply recognized as a tool of cost reduction. Therefore, this study could make a contribution to the literature in this area, in terms of deriving the most cost-efficient method of acquisition by comparing the various estimated costs that result from the different alternatives of the weapon system acquisition.

Analysis of Nursing Intensity Related to Nursing Activities in Operating Room using the Relative Value Scale For Nursing Cost (간호수가 산정을 위한 상대가치를 이용한 수술실 간호행위 간호강도 분석)

  • Ha, Ru Mee;Kwon, Kyoung Ja;Woo, Jin Ha;Kim, Jung A
    • Journal of Korean Clinical Nursing Research
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    • v.20 no.2
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    • pp.162-176
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    • 2014
  • Purpose: The purpose of this study was to perform an operating room nursing activities analysis and estimate nursing intensity of each nursing activity based on the Relative Value Scale (RVS). Methods: The methodology for this study of RVS was based on the work of Hsiao et al. The first stage was to identify nursing activities and the second to measure intensity of nursing activities including technical skill, mental effort, and stress. Results: Calculation of the RVS for 99 nursing practices showed a score range from 300.00 to 1337.78. CS operation assistant, OS operation assistant, and obtaining certification had high nursing intensity. Surgical hand washing, putting on surgical gowns, surgical gloves and surgical caps and mask had low nursing intensity. Conclusion: The activities of operating room are not compensated separately but reimbursement is usually included in physician fees. In the future, an estimation of nursing cost should show the nursing contribution rate to total operation revenue.

A Study on Bulk Deposition Flux of Dustfall and Insoluble Components in Pusan, Korea (부산지역 강하먼지와 불용성 성분의 침적량에 관한 연구)

  • 김유근;박종길;문덕환;황용식
    • Journal of Environmental Science International
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    • v.10 no.3
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    • pp.209-216
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    • 2001
  • Dustfall particles were collected by the modified American dust jar (wide inlet bottle type) at 6 sampling sites in Pusan area from March, 1999 to February, 2000. Thirteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Si, and Zn) were analyzed by AAS and ICP. The purposes of this study were to estimate qualitatively various bulk deposition flux of dustfall and insoluble components by applying regional and seasonal distribution. Dustfall amount of regional variations were found in order of coastal zone, industrial zone, commercial zone, agricultural zone and residential zone, and seasonal total dustfall had higher concentrations during spring for 6.741 ton/${km}^2$/season, lower concentrations during summer for 1.989 ton/${km}^2$/season, and annual total concentration was 17.742 ton/${km}^2$/year. The regional distributions of enrichment factor show well-defined anthropogenic metals (Cd, Cu, Pb, and Zn) at industrial and agricultural zone, and contribution rate of soil particles were found in order of summer, fall, winter and spring. Factor loading effects of chemical composition of dustfall were found in order of road traffic emission source and combustion processed source, industrial activity source, soil source and marine source.

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A study on the Prediction of Indoor Concentration due to Radon Exhalation from Domestic Building Materials (건축자재 라돈 방출에 의한 실내공기 중 라돈농도 예측에 관한 연구)

  • Lee, Cheolmin;Gwak, Yoonkyung;Lee, Donghyun;Lee, Dajeong;Cho, Yongseok
    • Journal of Environmental Science International
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    • v.24 no.9
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    • pp.1131-1138
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    • 2015
  • Radon exhalation rates have been determined for samples of concrete, gypsum board, marble, and tile among building materials that are used in domestic construction environment. Radon emanation was measured using the closed chamber method based on CR-39 nuclear track detectors. The radon concentrations in apartments of 100 households in Seoul, Busan and Gyeonggi Provinces were measured to verify the prediction model of indoor radon concentration. The results obtained by the four samples showed the largest radon exhalation rate of $0.34314Bq/m^2{\cdot}h$ for sample concrete. The radon concentration contribution to indoor radon in the house due to exhalation from the concrete was $31.006{\pm}7.529Bq/m^3$. The difference between the prediction concentration and actual measured concentration was believed to be due to the uncertainty resulting from the model implementation.

Phylogenomics and its Growing Impact on Algal Phylogeny and Evolution

  • Adrian , Reyes-Prieto;Yoon, Hwan-Su;Bhattacharya, Debashish
    • ALGAE
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    • v.21 no.1
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    • pp.1-10
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    • 2006
  • Genomic data is accumulating in public database at an unprecedented rate. Although presently dominated by the sequences of metazoan, plant, parasitic, and picoeukaryotic taxa, both expressed sequence tag (EST) and complete genomes of free-living algae are also slowly appearing. This wealth of information offers the opportunity to clarify many long-standing issues in algal and plant evolution such as the contribution of the plastid endosymbiont to nuclear genome evolution using the tools of comparative genomics and multi-gene phylogenetics. A particularly powerful approach for the automated analysis of genome data from multiple taxa is termed phylogenomics. Phylogenomics is the convergence of genomics science (the study of the function and structure of genes and genomes) and molecular phylogenetics (the study of the hierarchical evolutionary relationships among organisms, their genes and genomes). The use of phylogenetics to drive comparative genome analyses has facilitated the reconstruction of the evolutionary history of genes, gene families, and organisms. Here we survey the available genome data, introduce phylogenomic pipelines, and review some initial results of phylogenomic analyses of algal genome data.

Matching Sourcing Destination with Fashion Brands' Business Model: Comparative Advantages of Bangladesh and Vietnam Apparel Industries

  • Jacobs, Bertha;Simpson, Leslie;Nelson, Sara;Karpova, Elena
    • Fashion, Industry and Education
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    • v.14 no.2
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    • pp.11-23
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    • 2016
  • This study investigated the comparative advantages of the Bangladeshi and Vietnamese apparel industries using Global Value Chain (GVC) framework. In this study, the GVC framework was expanded to include social and environmental sustainability issues. Secondary data, for the 2012 - 2013 period, were collected and analyzed for each component of the apparel GVC. The findings indicated that while both countries have unique comparative advantages, Vietnam clearly emerged as a leader on many GVC components. Bangladesh's comparative advantage lies in lower wages, producing high volume orders, and lean manufacturing. In spite of Vietnam's higher labor costs, it has comparative advantages in higher productivity, skilled and trained workers, manufacturing of intricate styles of high quality, agility and flexible manufacturing, more developed infrastructure and logistic services as well as greater social and environmental compliances. This study contributes towards insight into best sourcing fit for fashion brand business models. Based on the findings, fashion driven companies offering more complex styles at a faster rate will benefit from choosing Vietnam. In contrast, Bangladesh might be a better choice for high volume driven companies that offer basic apparel and better value for their consumers. From theoretical perspective, the research makes an important contribution by expanding the GVC framework.

The Evaluation of Water Quality Using a Multivariate Analysis in Changnyeong-Haman weir section (다변량 통계분석을 이용한 낙동강 창녕함안보 구간의 수질 특성 평가)

  • Gwak, Bo-ra;Kim, Il-kyu
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.6
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    • pp.625-632
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    • 2015
  • The study of water environment system using a multivariate analysis in Changnyeong-Haman weir section has been conducted. The purpose of this study is to establish better understanding related water qualities in the Changnyeong-Haman weir section which can provide useful information. The data were consisted of water quality data and algae data including WT(water temperature), pH, DO, EC, COD, SS, T-N, $NH_3-N$, T-P, $PO_4-P$, Chl-a, TOC, d-silica, t-silica, Cyanobacteria, Diatoms, and Green algae. Statistical analyses used in this study were correlation analysis, principal components, and factor analysis. According to correlation analysis on COD and TOC, it revealed that the each value of correlation coefficient was 0.843. On the other result, a negative correlation was observed between diatoms and d-silica. Furthermore, the results of principal component analysis to the overall water quality were classified into four main factors with contribution rate 81.071%.