• 제목/요약/키워드: chemical quality

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Analysis of Health-related Microbes by Capillary Electrophoresis

  • Moon, Byoung-Geoun;Kim, Yong-Seong
    • Bulletin of the Korean Chemical Society
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    • 제24권8호
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    • pp.1203-1206
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    • 2003
  • Analysis of health-related microbes called probiotics was performed by capillary electrophoresis. A rapid and easy characterization for two important probiotics, Saccharomyces cerevisiae and Enterococcus feacalis, was obtained in the running buffer containing poly(ethylene oxide). Quantitation of probiotic (Saccharomyces cerevisiae) shows a good linearity between the peak area versus the concentration of microbe. From the comparison of electropherograms of antidiarrhea, it was found that capillary electrophoresis could be employed for the quality control and quality assurance for the production of a medicine containing the probiotics.

시멘트 특성의 변화가 고강도콘크리트의 재료특성에 미치는 영향 (The Effects of Various Cement Type and Compositions on the Material Properties of high Strength Concrete)

  • 백상현;이종열;엄태선;임채용;안광원
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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    • pp.47-52
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    • 2000
  • Recently, it is very necessary the development of the manufacturing techniques for high strength concrete(HSC) for the large-scale size and good quality of civil structure. But, the manufacture and quality control of HSC of which shrinkage, heat of hydration and workability at construction filed are considered, is very difficult due to its low water-cement ratio and high quantity of unit cement content. In the present study, we tried to know and assess the influences of chemical and physical properties of cement on the material properties of HSC. We analyzed basic properties of 4 kinds of cement whose chemical and physical properties are different each other through various tests such as chemical analysis and mortal test. Also, we performed the assessment of the material properties of HSC for each dement by the test for the conditions of same mix design and similar compressive strength. From the results in the study, the assessment of the important quality factors of cement influencing the properties of HSC may be utilized to quality control of applied cement to manufacture the HSC of high quality.

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땅콩의 품질평가 현황과 전망 (Review of the Studies on the Qualities in Peanut)

  • 박장환;박희운
    • 한국작물학회지
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    • 제47권
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    • pp.163-174
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    • 2002
  • Peanut is one of the principal oil seeds in the world as a rich source of edible oil and protein. Peanut quality arises as a result of a complex interaction of genetic, physiological and biochemistry processes that produce the chemical composition of the peanut seed. The major factors influencing seed quality are degree of maturity and digging and drying, curing and storage as a series of harvesting. The end products, peanut butter, salted seed, confections, roasting stock and by-products are favored in world-wide because of their unique roasted peanut flavor, Literatures are reviewed mainly focusing on the physiological properties and nutritional quality of oil, protein and flavor in peanut. Chemical properties of protein and oil, and volatile flavor component in peanut seeds are studied. The objectives of this paper were to review and summarize the results obtained from the improving quality breeding program and evaluation of the chemical composition in peanut up to now.

Indoor exposure to hazardous air pollutants and volatile organic compounds in low-income houses in Lagos, Nigeria

  • Luqmon, Azeez;Musa, Olaogun;Mariam, Adeoye;Abdulazeez, Lawal;Babatunde, Agbaogun;Ibrahim, Abdulsalami;Adija, Majolagbe
    • Advances in environmental research
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    • 제1권4호
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    • pp.277-288
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    • 2012
  • This study investigated exposure to air pollutants in rooms in low-income houses at Shomolu (R1), Mafoluku (R2) and Mushin (R3) in Lagos state. The concentrations of most measured exceeded limits of Illinois Department of Public Health (IDPH) for indoor air quality. Air quality index (AQI) in rooms studied was unhealthy for sensitive people in terms of CO, unhealthy in terms of $SO_2$ and very unhealthy in terms of $NO_2$ while moderate air quality was obtained in terms of $PM_{10}$ in most rooms. High concentrations of carbontetrachloride, formaldehyde and xylene measured could have been responsible for some of the health complaints of the occupants. Factor analysis shows that cooking with kerosene, use of gasoline generator and insecticide were the major contributors to indoor air pollution in these rooms. Therefore, there is need to urgently tackle poverty as all affected by these pollutants were poor who live in substandard houses without kitchens.

Improvement in the Quality of Kimchi by Fermentation with Leuconostoc mesenteroides ATCC 8293 as Starter Culture

  • Li, Ling;Yan, Yu;Ding, Weiqi;Gong, Jinyan;Xiao, Gongnian
    • 한국미생물·생명공학회지
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    • 제48권4호
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    • pp.533-538
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    • 2020
  • To investigate the effect of the predominant microorganisms in kimchi on quality, Leuconostoc mesenteroides ATCC 8293 was used as starter culture during kimchi fermentation. A higher number of lactic acid bacteria and lower initial pH were observed in starter kimchi than in non-starter kimchi in the early stage of fermentation. The concentrations of the main metabolite, lactic acid, were 69.88 mM and 83.85 mM for the non-starter and starter fermented kimchi, respectively. The free sugar concentrations of starter kimchi decreased earlier than those of non-starter kimchi, and the levels of free sugars in both kimchi samples decreased during fermentation. At the end of fermentation, non-starter kimchi had a softer texture than starter kimchi, suggesting that L. mesenteroides is useful in extending shelf life. Sensory evaluation showed that starter kimchi had higher sourness and lower bitterness and astringency values, resulting in high sensory quality. These results suggest that the L. mesenteroides ATCC 8293 strain could be a potential starter culture in kimchi.

Chemical Water Quality of Lake Eui-Am

  • Choe, Sang;Kwak, Hi-Sang
    • 한국해양학회지
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    • 제6권2호
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    • pp.63-77
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    • 1971
  • An year-long survey of chemical water quality for Lake Eui-am in Kang-won Province, Korea, was conducted from June 1970 to May 1971 to study the water quality and seasonal variations of productivities in relation to selected physical and chemical environmental factors. A monthly series of water samples were taken at the deepest basin of 18m depth of the lake. Water quality parameters determined were water temperature, Secchi disc reading(transparency), pH, O$\_$2/, CO$\_$2/, alkalinity, acidity, Cl, hardness, Ca, Mg, total residue, total ignitious residue, COD, BOD$\_$5/, nutrients, total-Fe, soluble Fe, Mn and Cu. On the whole, the results indicate that the chemical water quality of Lake Eui-am is high, and vary with season. The lake water is characterized that higher levels of dissolved oxygen(8.6 ml/L in mean of whole water) or percent saturation of dissolved oxygen(114%), and of nitrate nitrogen (523 $\mu\textrm{g}$/L). On the other hand, CO$\_$2/(9.6ppm), chlorides(3.5ppm), Ca(7.7ppm) Mg(2.2ppm), hardness(28.5ppm), silica(2.4ppm) and BOD$\_$5/(1.08ppm) are quite low. In terms of nutrient levels, the lake water exhibit slight signs of eutrophication. The high values for nitrate nitrogen, soluble iron and Cu of the lake water suggest that there are some imputs such as domestic and industrial discharges to the lake.

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WRF-Chem 모형을 이용한 한반도 대기질 모의: 화학 초기 및 측면 경계 조건의 영향 (Simulation of Air Quality Over South Korea Using the WRF-Chem Model: Impacts of Chemical Initial and Lateral Boundary Conditions)

  • 이재형;장임석;이상현
    • 대기
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    • 제25권4호
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    • pp.639-657
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    • 2015
  • There is an increasing need to improve the air quality over South Korea to protect public health from local and remote anthropogenic pollutant emissions that are in an increasing trend. Here, we evaluate the performance of the WRF-Chem (Weather Research and Forecasting-Chemistry) model in simulating near-surface air quality of major Korean cities, and investigate the impacts of time-varying chemical initial and lateral boundary conditions (IC/BCs) on the air quality simulation using a chemical downscaling technique. The model domain was configured over the East Asian region and anthropogenic MICS-Asia 2010 emissions and biogenic MEGAN-2 emissions were applied with RACM gaseous chemistry and MADE/SORGAM aerosol mechanism. Two simulations were conducted for a 30-days period on April 2010 with chemical IC/BCs from the WRF-Chem default chemical species profiles ('WRF experiment') and the MOZART-4 (Model for OZone And Related chemical Tracers version 4) ('WRF_MOZART experiment'), respectively. The WRF_MOZART experiment has showed a better performance to predict near-surface CO, $NO_2$, $SO_2$, and $O_3$ mixing ratios at 7 major Korean cities than the WRF experiment, showing lower mean bias error (MBE) and higher index of agreement (IOA). The quantitative impacts of the chemical IC/BCs have depended on atmospheric residence time of the pollutants as well as the relative difference of chemical mixing ratios between the WRF and WRF_MOZART experiments at the lateral boundaries. Specifically, the WRF_MOZART experiment has reduced MBE in CO and O3 mixing ratios by 60~80 ppb and 5~10 ppb over South Korea than those in the WRF-Chem default simulation, while it has a marginal impact on $NO_2$ and $SO_2$ mixing ratios. Without using MOZART-4 chemical IC, the WRF simulation has required approximately 6-days chemical spin-up time for the East Asian model domain. Overall, the results indicate that realistic chemical IC/BCs are prerequisite in the WRF-Chem simulation to improve a forecast skill of local air quality over South Korea, even in case the model domain is sufficiently large to represent anthropogenic emissions from China, Japan, and South Korea.

강수 분석자료의 신뢰성 검토에 관한 연구 (A Study on the Quality Assuranc of Chemical Analysis Data of Precipitation Samples)

  • 강공언
    • 환경위생공학
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    • 제10권3호
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    • pp.85-98
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    • 1995
  • In order to ensure that all major cations and anions were accurately measured, the quality assurance checks of chemical analysis data by considering ion and conductivity balance of each precipitation sample were performed. To check the quality assurance of chemical analysis data, precipitation samples were collected by wet- only precipitation sampler at Seoul site and their chemical components were analyzed. By checking the problems for the screening methods of chemical analysis data used until recently, the f value expressed as the ratio of the sum of cations and anions equivalent concentration( $\Sigma $C/$\Sigma $A ) was found to be not ap priorate for data screening. Also, the scattering plot between cation and anion equivalent concentrations in each sample was found to show the general tendency of ion balance but was proved to not quantitate the standard of data screening at a set of samples of various concentration levels.4 more appropriate value was therefore required, h value is defined as (A-C)/C for C≥A and ( A-C)/A for C<4. This value was showed to check the ion balance in a viewpoint of quantitative as well as qualitative and to be useful in applying this expression to a measurement data set. However, the standard o( data screening must vary in response to the ion concentration of sample. In this study, the quality assurance of chemical analysis data was checked by considering both the ion balance evaluating by h value and the electrical conductivity. As these quality assurance checks were applied to Seoul data serf 67 valid samples were obtained. The result of statistical summary in the analytical parameter of precipitation samples collected for a certain period was found to be computed in the precipitation volume- weighted mean( VWM) rather than the arithmetic mean( AM), but PH In the VWM of hydrogen ion concentration. The annual VWM of pH values was 5.0(4.9 ∼ 5.1).

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Comparative assessment of surface and ground water quality using geoinformatics

  • Giridhar, M.V.S.S.;Mohan, Shyama;Kumar, D. Ajay
    • Advances in environmental research
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    • 제9권3호
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    • pp.151-160
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    • 2020
  • Water quality demonstrates physical, chemical and biological characteristics of water. The quality of surface and groundwater is currently an important concern with population growth and industrialization. Over exploitation of water resources due to demand is causing the deterioration of surface water and ground water. Periodic water quality testing must be carried out to protect our water resources. The present research analyses the spatial variation of surface water and groundwater in and around the lakes of Hyderabad. Twenty-Seven lakes and their neighboring bore water samples are obtained for water quality monitoring. Samples are evaluated for specific physico-chemical parameters such as pH, Total Dissolved Solids (TDS), Cl, SO4, Na, K, Ca, Mg, and Total Hardness (TH). The spatial variation of water quality parameters for the 27 lakes and groundwater were analysed. Correlation and multiple regression analysis were carried out to determine comparative study of lake and ground water. The study found that most of the lakes were polluted and this had an impact on surrounding ground water.