• Title, Summary, Keyword: Environmental sample

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Influence of CO2 concentration on carbon concentrating mechanisms in cyanobacteria and green algae: a proteomic approach

  • Ramanan, Rishiram;Vinayagamoorthy, Nadimuthu;Sivanesan, Saravana Devi;Kannan, Krishnamurthi;Chakrabarti, Tapan
    • ALGAE
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    • v.27 no.4
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    • pp.295-301
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    • 2012
  • Carbon concentrating mechanisms play a vital role in photosynthesis in microalgae and cyanobacteria especially in the proper functioning of Rubisco and assimilation of carbon via the Calvin cycle. This study evaluates the role of carbon dioxide on carbon concentrating mechanism (CCM) in a cynaobacteria, Spirulina platensis and a microalga, Chlorella sp. 786. The study organisms were grown in both atmospheric (control sample, 0.035%) and high (exposed sample, 10%) $CO_2$ concentrations. Second dimension (2D) electrophoresis revealed a huge difference in the protein profiles of both organisms suggesting the induction of CCM related proteins in the sample maintained at atmospheric $CO_2$ concentration and the repression of CCM related proteins in the sample maintained at 10% $CO_2$. Liquid chromatography-mass spectroscopy analysis revealed the presence of two important $C_i$ transporter proteins in the control sample of S. platensis, namely ferredoxin-$NADP^+$ reductase and ATP binding cassette (ABC) transport system protein. These proteins were only expressed in the control sample and were downregulated or not expressed at all in the exposed sample. Consequently, this study conclusively proves that CCMs are only inducted at low $CO_2$ concentrations and are not functional at high $CO_2$ concentration.

Consolidation characteristics of soft ground using huge sample (대형 sample을 이용한 해안 연약지반 압밀특성에 관한 연구)

  • Hong, Sung-Jin;Lee, Moon-Joo;Jung, Doo-Suk;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.1109-1114
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    • 2008
  • To investigate the effect of sample size on coefficient of consolidation of non-homogeneous soil, the result of a large size consolidation test using a huge undisturbed sample with $1200mm(D){\times}2000mm(H)$ in dimension is compared with that of oedometer test using undisturbed small sample. In addition, test results are compared with those of same test using remold sample. Experimental results show that, due to the lump of sand/silt was mixed in sample, the coefficient of consolidation of undisturbed samples have a difference for each tests. Whereas, the difference of coefficient of consolidation between remolded large and small samples is not found. Because sample size affects the test results, sample must be carefully selected for non-homogeneous soil.

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Studies on Morpho-pedo Milieu of Forest Wetland on Mt. Jeombong - Focused on Diatom Analysis and Grain Size Analysis (점봉산 산림습지의 지형·토양 환경분석 - 입도분석과 규조분석을 중심으로)

  • Kim, Nam-Shin;Cha, Jin-Yeol;Park, Yong-Su;Cho, Yong-Chan;Kwon, Hye-Jin;Oh, Seung-Hwan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.20 no.1
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    • pp.13-24
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    • 2017
  • This study is to provide basic data on ecology and morpho-pedo milieu by analyzing diatom and grain size of Mt. Jeombong forest wetland. Sample was collected from 6 points and named sample 943, 932, 885, 881A, 881b, 849. Sample 934 could not identify diatom, and the soil layer was colluvium deposited by mass-movement process. Layer of sample 932 was developed in the lower velocity environment, and presence frequence of complete diatom was very low. Hydrological situation of sample 855 was analysed in oligosaprobien environments. Sample 881A was meso-saprobic environments, velocity was slow area that inhabit musci bryopsida and sphaerocarpus. Sample 881B was acidic wetland in oligosaprobien environments. Sample 849 was analysed in oligosaprobien environments. The results of soil and diatom analysis are well reflect on wet environments of mountain wetlands and also it will expected to be in the help of environmental changes study of mountain wetlands.

An Improvement on the Analysis Techniques of Environmental Radioactivity Around Nuclear Power Plants (원전주변 환경방사능 분석기술의 개선(I))

  • Kim, Soong-Pyung;Chae, Gyung-Sun;Chung, Woon-Kwan
    • Journal of Radiation Protection and Research
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    • v.20 no.1
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    • pp.8-15
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    • 1995
  • An estimate of a change in radioactivity's circumstances around the nuclear power plant is validated with the results of the radioactivity measurements are compared. In this study, to further enhance the reliability of the results obtained from the environmental radioactivity measurements and analysis around the nuclear power plants that have been carried out up to the present. In the korea standard, there is the technical analysis guide for general stable chemical element's, but there is not the technical analysis guide for the radionuclei. therefore the environmental sample collection, the pretreatment of the sample and radionuclide analysis in the sample, the result's of the environmental radioactivity measurements by each organization, etc. are different. It is not sufficient for the database to forecasting a change in radioactivity's circumstances. A comparative study of collection and pretreatment techniques for the soil sample, the results by comparison, the method of minimizing the relative error are proposed. At one side of sample collection, there are going to considered that the surroundings of sample collection like the lay of the land, the provision of the selection standard for the area and pathway of radionuclide adhesion, the coherence of sample collection, etc.. at another side of pretreatment of the sample and measurement in the case of soil sample, how to do homogeneously the soil particle size and the standard tools, i.e. kinds of meshes, must to be selected.

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Validation of Suitability on Proficiency Testing Samples for Acute Toxicity Test with Daphnia magna (생태독성 숙련도 시료의 적절성 평가)

  • Shin, Kisik;Park, Woosang;Lee, Jungseo;Yu, Soonju;Park, Taejin;Kim, Jongmin
    • Journal of Korean Society on Water Environment
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    • v.31 no.1
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    • pp.49-54
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    • 2015
  • Acute toxicity test with Daphnia magna has a variety of factors such as incubation condition of test species, food quality and proficiency of laboratory workers. Therefore, proper proficiency testing samples were required for evaluating the competence of laboratory workers. This study aims to propose some appropriate proficiency testing samples for laboratory workers of acute toxicity test with Daphnia magna. Proposed four kinds of standard samples (Sample A, B, C, and D) for proficiency testing were selected from reference materials which were recommended from Canada and USA WET(Whole Effluent Toxicity) authorities. Proposed standard samples were tested by trial application of proficiency testing, homogeneity and stability checks using repeatability test. Sample A, C and D were estimated ad the suitable candidates for proficiency test standard samples except for Sample B. In addition, Sample A was proved to be the most suitable sample.

Significant Parameters for Assessing Soil Contaminant-Leaching to Groundwater and Determining Soil Sample Size in Field Survey

  • Jeong, Seung-Woo;An, Youn-Joo
    • Environmental Engineering Research
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    • v.13 no.2
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    • pp.73-78
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    • 2008
  • For a given soil-contaminated site, a level of soil contamination is characterized and decisions on risk may be made from the risk assessment. The study evaluated critical design factors for the determination of sample size in the sampling design plan and the assessment of soil contaminant- leaching to groundwater. Two variables, the minimum relative detectable difference (T) and coefficient of variation (CV) were evaluated for the sample size determination. The minimum number of samples can be appropriately determined by CV under a T value greater than or equal to 0.2. Soil-contaminant leaching to groundwater was evaluated by using the Soil Screening Level equation of U.S. Environmental Protection Agency and the Risk Based Screening Level equation of American Society for Testing and Materials, with the same input parameters. The groundwater concentrations estimated from soil contaminant concentrations were significantly affected by the Darcy velocity of groundwater and the organic content of soil.

Trihalomethane Formation by Chlorine Dioxide in Case of Water Containing Bromide Ion (브롬이온을 함유한 상수 원수에 이산화염소 주입시 THM생성거동에 관한 연구)

  • Lee, Yoon-Jin;Lee, Hwan;Nam, Sang-Ho
    • Journal of Environmental Health Sciences
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    • v.25 no.3
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    • pp.83-88
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    • 1999
  • This study was carried out to examine the behavior of THM formation in water treated with chlorine dioxide where humic acid was used as THM precursor. THM was not detected in bromide-free water, but formed in water containing bromide. When 10 mg/l of chlorine dioxide was added to water containing 5 mg/l of humic acid and bromide respectively, 20.46 ${\mu}$g/l of THM was formed. It is postulated that chlorine dioxide oxidize bromide to hydrobromous acid, which subsequently reacted with humic acids similar to chlorine reaction. The formation of THM could be reduced at low pH. Among THM formed, CHBr$_3$ was the predominant species in the alkaline solution, while CHCl$_3$ in the acidic solution. A sample pretreated with chlorine dioxide for 24h before addition of chlorine showed a reduction of 75.1% in THM formation, compared with a sample not pretreated with chlorine dioxide and a sample treated by chlorine for 24h prior to addition of chlorine dioxide also showed a reduction of 37.8% in THM formation, compared with a sample not added with chlorine dioxide. It may explain that chlorine dioxide oxidizes directly a fraction of THM.

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Concentration Characteristics of PCBs in Pine Needle and Soil at Rural Area (교외지역에서 소나무 잎과 토양 중 PCBs의 농도 특성)

  • Shin Eun-Sang;Yeo Hyun-Gu
    • Journal of environmental and Sanitary engineering
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    • v.21 no.1
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    • pp.1-11
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    • 2006
  • This study was to investigate concentration characteristics of atmospheric PCBs in soil sample and pine needle at rural area. Profiles of PCB congener detected in pine needle and soil sample have a difference that low molecular PCBs mainly existed in pine needle, whereas high molecular PCBs were mainly existed in soil sample because of their different vapor pressure and octanol-air partitioning coefficient($K_{OA}$) of each congeners. Correlation coefficients(r) of PCB congeners simultaneously detected in soil and pine needle were significant (r>0.71, p<0.01), which showed that PCB congeners patterns of atmosphere could be estimated in using pine needle and soil sample indirectly. The contributions(%) of higher molecular PCBs(>penta-CB) to total PCBs in soil sample were higher than those of pine needle and the contribution of lower molecular PCBs(

Evaluation of the Measurement Uncertainty from the Standard Operating Procedures(SOP) of the National Environmental Specimen Bank (국가환경시료은행 생태계 대표시료의 채취 및 분석 표준운영절차에 대한 단계별 측정불확도 평가 연구)

  • Lee, Jongchun;Lee, Jangho;Park, Jong-Hyouk;Lee, Eugene;Shim, Kyuyoung;Kim, Taekyu;Han, Areum;Kim, Myungjin
    • Journal of Environmental Impact Assessment
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    • v.24 no.6
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    • pp.607-618
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    • 2015
  • Five years have passed since the first set of environmental samples was taken in 2011 to represent various ecosystems which would help future generations lead back to the past environment. Those samples have been preserved cryogenically in the National Environmental Specimen Bank(NESB) at the National Institute of Environmental Research. Even though there is a strict regulation (SOP, standard operating procedure) that rules over the whole sampling procedure to ensure each sample to represent the sampling area, it has not been put to the test for the validation. The question needs to be answered to clear any doubts on the representativeness and the quality of the samples. In order to address the question and ensure the sampling practice set in the SOP, many steps to the measurement of the sample, that is, from sampling in the field and the chemical analysis in the lab are broken down to evaluate the uncertainty at each level. Of the 8 species currently taken for the cryogenic preservation in the NESB, pine tree samples from two different sites were selected for this study. Duplicate samples were taken from each site according to the sampling protocol followed by the duplicate analyses which were carried out for each discrete sample. The uncertainties were evaluated by Robust ANOVA; two levels of uncertainty, one is the uncertainty from the sampling practice, and the other from the analytical process, were then compiled to give the measurement uncertainty on a measured concentration of the measurand. As a result, it was confirmed that it is the sampling practice not the analytical process that accounts for the most of the measurement uncertainty. Based on the top-down approach for the measurement uncertainty, the efficient way to ensure the representativeness of the sample was to increase the quantity of each discrete sample for the making of a composite sample, than to increase the number of the discrete samples across the site. Furthermore, the cost-effective approach to enhance the confidence level on the measurement can be expected from the efforts to lower the sampling uncertainty, not the analytical uncertainty. To test the representativeness of a composite sample of a sampling area, the variance within the site should be less than the difference from duplicate sampling. For that, a criterion, ${i.e.s^2}_{geochem}$(across the site variance) <${s^2}_{samp}$(variance at the sampling location) was proposed. In light of the criterion, the two representative samples for the two study areas passed the requirement. In contrast, whenever the variance of among the sampling locations (i.e. across the site) is larger than the sampling variance, more sampling increments need to be added within the sampling area until the requirement for the representativeness is achieved.

Discussions about Sample Preparation Techniques for Oxygen and Hydrogen Isotope Analysis (산소와 수소 동위원소 분석을 위한 시료 전처리 기술에 대한 고찰)

  • Lee, Kwang-Sik;Lee, Insung
    • Economic and Environmental Geology
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    • v.29 no.2
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    • pp.207-214
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    • 1996
  • For many years oxygen and hydrogen isotope analysis have been used as one of the most valuable research tools to investigate many geological processes. There are many sample preparation techniques of oxygen and hydrogen isotope analysis for various geological samples. We introduce here several important sample preparation techniques for oxygen and hydrogen isotope analysis and discuss the problems of each method in detail.

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