scholarly journals Development and Efficiency Assessment of New Methods on Rapid Assessment of Toxicity in Environmental Monitoring

2020 ◽  
pp. 458-469
Author(s):  
E. A. Lushchay ◽  
D. E. Ivanov ◽  
E. I. Tikhomirova
Keyword(s):  
Biological Monitoring ◽  
Natural Environment ◽  
Water Samples ◽  
Elevated Temperatures ◽  
Rapid Assessment ◽  
Coli Strain ◽  
Quantitative Chemical Analysis ◽  
Environment Quality ◽  
Conventional Methods ◽  
Express Methods

The transformation of hazardous pollutants in the environment usually results in formation of hard-to-identify compounds that may have a significant impact on ecosystems. They are difficult to identify by conventional methods of quantitative chemical analysis, but their detrimental effects can be detected by biological methods. The goal of this study was to develop novel methodological approaches to the express assessment of the state of the environment as well as toxicity of its components in the process of biological monitoring at hazardous industrial facilities. The article presents the results of comprehensive toxicity assessment of environmental objects using originally developed system of express methods. The objects of research were water fleas (Daphnia magna Straus and Ceriodaphnia affinis Lilljeborg), infusoria (Paramecium caudatum), preparation of lyophilized fluorescent bacteria based on recombinant Escherichia coli strain M-17 (Ecolum), algae (Chlorella vulgaris Beijer, Scenedesmus quadricauda (Turp.) Breb.), and mammalian gonads. The original methods for determining toxicity by changing the motor activity of water fleas at elevated temperatures of the studied environment are described. The description of the following original utility models is presented: “Method of bioassay for water samples and device for its implementation”, “Device for express assessment of natural environment quality” and “Device for comprehensive assessment of natural environment quality”, confirmed by the patents of the Russian Federation. Their use may significantly reduce the cost of ecotoxicological studies in terms of time and money expenditures. The effectiveness of the system of express methods was established during a biological monitoring of a sanitary protection zone of the Balakovo NPP. Toxicity of the samples of bottom sediments, soil, as well as water samples from the cooler pond and the adjacent water area of the Saratov reservoir were identified. The bioassay results were matched by both conventional methods’ results and originally developed system of express methods.

Comparative Assessment of Sporophyte and Gametophyte Thermal Resistance of Winter Rape

2019 ◽  
pp. 15-22
Keyword(s):  
Elevated Temperatures ◽  
Rapid Assessment ◽  
Temperature Stability ◽  
Temperature Factor ◽  
Plant Genome ◽  
Limiting Factors ◽  
Initial Assessment ◽  
High Temperature Stability ◽  
Winter Rape ◽  
High Yields

The temperature factor is one of the limiting factors for obtaining high yields of crops, so one of the main tasks of selection is to search for temperature-resistant genotypes and to create on their basis the banks of crops with high temperature stability. The first step to solving this problem is to conduct a rapid assessment of the temperature plasticity of large populations and to isolate breeding-valuable genotypes from them. There are numerous methods that allow, in the short term with minimal technical and material costs, to carry out an initial assessment of a large number of genotypes at sporophytic level and differentiate them by resistance to the temperature factor. These methods include the method of estimating pollen populations. These studies have repeatedly been conducted on many cultures, their correctness is due to the expression of a large part of the plant genome, both at the diploid and haploid levels of development and demonstrated by many studies in this direction. The aim of our study was to study the stability of gametophyte and sporophyte of collecting varieties and varieties of winter rape to elevated temperatures, to study the correlation between the heat resistance of sporophyte and gametophyte.

scholarly journals ECOGEOCHEMICAL DIAGNOSTICS CONDITION OF URBAN ENVIRONMENT ON POLLUTION SNOW COVER OF VORONEZH CITY

2015 ◽  
Vol 4 (4) ◽  
pp. 121-126
Author(s):  
Tatiana Ivanovna Prozhorina ◽  
Semyon Aleksandrovitch Kurolap ◽  
Nadezhda Ivanovna Yakunina
Keyword(s):  
Comparative Analysis ◽  
Chemical Composition ◽  
Snow Cover ◽  
Urban Environment ◽  
Chemical Elements ◽  
Rapid Assessment ◽  
High Sorption ◽  
Express Methods ◽  
Functional Areas ◽  
The City

Currently, the most popular are the express methods of quality control of the environment, which permit a relatively rapid assessment of ecological and geochemical situation. one such method is based on the use snow cover. snow has a high sorption capacity and is informative in identifying the object of man-made pollution of the urban environment. the paper presents the results of a study of the chemical composition of snow that had fallen in Voronezh during winter 2015. snow samples were taken in the period prior to snowmelt in various functional areas of the city. in order to identify the degree of technogenic impact on the various parts of the city of Voronezh, was made a comparative analysis of the results:аccording to the actual presence of pollutants in precipitation for the study of functional areas;сalculate the rate on the concentration of chemical elements for test samples of snow.according to the degree of mineralization and dust content in snow can be seen technogenic pressure on environment.therefore, a comparative analysis of the degree of contamination of snow in the various functional areas of the city were carried out for the two indicators of the chemical composition - the total mineralization and suspended particles(dust).the results of the analysis of the chemical composition of the melt water indicate an increased level of technogenic pollution of snow cover in all investigated functional areas of Voronezh.

scholarly journals Additive manufacturing of TiAl-based alloys

2020 ◽  
Vol 7 ◽  
pp. 35 ◽  
Author(s):  
Thywill Cephas Dzogbewu
Keyword(s):  
Additive Manufacturing ◽  
Elevated Temperatures ◽  
High Rate ◽  
Widespread Application ◽  
Tial Alloys ◽  
Powder Bed ◽  
Geometrical Accuracy ◽  
Heating And Cooling ◽  
Conventional Methods ◽  
Increasing Demand

The ever-increasing demand for developing lightweight, high-temperature materials that can operate at elevated temperatures is still a subject of worldwide research and TiAl-based alloys have come to the fore. The conventional methods of manufacturing have been used successfully to manufacture the TiAl-based alloy. However, due to the inherent limitations of the conventional methods to produce large TiAl components with intricate near-net shapes has limit the widespread application and efficiency of the TiAl components produced using conventional methods. Metal additive manufacturing such as Electron Beam Melting technology could manufacture the TiAl alloys with intricate shapes but lack geometrical accuracy. Laser powder bed fusion (LPBF) technology could manufacture the TiAl-based alloys with intricate shapes with geometrical accuracy. However, the inherent high rate of heating and cooling mechanisms of the LPBF process failed to produce crack-free TiAl components. Various preheating techniques have been experimented, to reduce the high thermal gradient and residual stress during the LPBF process that causes the cracking of the TiAl components. Although these techniques have not reached industrial readiness up to now, encouraging results have been achieved.

scholarly journals PENGEMBANGAN METODE CITRA DIGITAL BERBASIS APLIKASI ANDROID UNTUK ANALISIS ION LOGAM Cr(VI)

Alotrop ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 117-124
Author(s):  
Marti Hitsmi ◽  
Mochamad Lutfi Firdaus ◽  
Nurhamidah Nurhamidah
Keyword(s):  
Metal Ions ◽  
Digital Image ◽  
Water Samples ◽  
Metal Ion ◽  
Limit Of Detection ◽  
Tap Water ◽  
Inductively Couple Plasma ◽  
Image Method ◽  
Complex Method ◽  
Conventional Methods

The presence of heavy metals in the environment can be a serious problem because it is harmful to human health. One of the heavy metal ions that pollute the environment is the Cr6+ metal ion. The usual tool used to analyze metal ions is Cr6+ is the Atomic Absorption Spectrometry (AAS) and Inductively Couple Plasma (ICP) which are very expensive and require trained personnel. The purpose of this study was to design a simple detector for Cr6+ metal ions as an alternative to conventional methods using AAS and ICP. The detection tool was developed using the android-based digital image method with SLR data analysis techniques obtained from the reaction of the metal ion complex Cr6 + with the compound dhypenilcarbazida (DPC). The parameters of the tool measured were accuracy, selectivity and sensitivity with the reaction of DPC compounds as complexes. The comparison level of this method is the complex method with DPC using a UV-Vis spectrophotometer. This research was carried out in the Chemistry Laboratory FKIP UNIB in November 2018 until March 2019. The implementation of tool parameters was tested to samples of aquatic environments in Bengkulu City, namely PDAM Kota Bengkulu water, tap water of FKIP UNIB Dean, Lake UNIB water, Sungai Hitam water and water Pantai Panjang. The results showed that the detection of Cr6+ metal ions made by the android-based digital image method had better accuracy, selectivity and sensitivity than conventional methods. The DPC is selective for Cr6 + metal ions with a change in color from clear to violet, at a wavelength of 540 nm. Accuracy was checked using a UV-Vis spectrophotometer with 99% accurate results. After that, test sensitivity to Cr6 + metal ions. using the android application method generates a Limit of Detection (LOD) of 6.7 ppb. The detector that was developed was applied to water samples in the city of Bengkulu, it turned out that all of the water samples showed that the levels of Cr6+ metal ions were still below the threshold determined by the Minister of Health Regulation, so it was still safe to use in everyday life.

scholarly journals Whole-Genome Sequence of Salmonella enterica subsp. enterica Serovar Typhimurium Strain WG49 and Escherichia coli Strain WG5 Used in South Africa for Phage Detection in Water Samples

2018 ◽  
Vol 6 (26) ◽  
Author(s):  
L. Bothma ◽  
D. Gonzalez-Ibeas ◽  
C. Mienie ◽  
C. C. Bezuidenhout ◽  
R. Adeleke
Keyword(s):  
Escherichia Coli ◽  
South Africa ◽  
Genome Sequence ◽  
Water Samples ◽  
Salmonella Enterica ◽  
Coli Strain ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Content Type ◽  
Serovar Typhimurium

Salmonella enterica subsp. enterica serovar Typhimurium WG49 is widely used for enumeration of F-specific RNA (F-RNA) coliphages in water.

scholarly journals Toxicity Assessment of Produced Water Using Microtox Rapid Bioassay

2018 ◽  
pp. 1-9 ◽  
Author(s):  
Chinyere Augusta Ajuzieogu ◽  
Lucky Obukowho Odokuma ◽  
Chikere, Chioma Blaise
Keyword(s):  
Biological Monitoring ◽  
Water Samples ◽  
Produced Water ◽  
Toxicity Assessment ◽  
Effective Concentration ◽  
Adequate Treatment ◽  
Monitoring Protocol ◽  
Rapid Bioassay ◽  
Microtox Test ◽  
Median Effective Concentration

Aim: The study aimed at employing the Microtox test procedure in the current biological monitoring protocol as a reliable, rapid and ecologically relevant bioassay tool for toxicity assessment in environmental compliance monitoring of produced water discharges. Study Design: Inhibition of bioluminescence by V. fischeri [median effective concentration (EC50)] was employed as the toxicity index. Place and Duration of Study: Microbiology Department of Halden Laboratories, Port Harcourt, Nigeria / one month. Methodology: Percent reduction in bioluminescence by V. fischeri after 15-min exposure to the PW samples was recorded as median effective concentration (EC50) values. Results: The 15 min EC50 values of the untreated and treated produced water samples for V. fischeri was 1.0% and 23.27% respectively. Microtox test indicated the treated and untreated produced water samples were “very toxic” and “extremely toxic” respectively, after 15 min exposure time. Conclusion: These findings emphasize the need for adequate treatment of produced water to meet standard discharge limits of regulatory agencies in Nigeria, as both physicochemical analysis and bioassay (Microtox) suggested that the treated PW was toxic to V. fischeri. This study thus supports the use of Microtox (bacterial toxicity) system as a sensitive and rapid bioassay tool for biological monitoring protocol in Nigeria's petroleum industry.

scholarly journals Temperature Sensitivity and Cell Division Defects in an Escherichia coli Strain with Mutations in yghB and yqjA, Encoding Related and Conserved Inner Membrane Proteins

2008 ◽  
Vol 190 (13) ◽  
pp. 4489-4500 ◽  
Author(s):  
Kandi Thompkins ◽  
Ballari Chattopadhyay ◽  
Ying Xiao ◽  
Margaret C. Henk ◽  
William T. Doerrler
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Membrane Proteins ◽  
Elevated Temperatures ◽  
Divalent Cations ◽  
Microscopic Analysis ◽  
Coli Strain ◽  
Temperature Sensitive ◽  
Membrane Composition ◽  
Inner Membrane

ABSTRACT Ludox density gradients were used to enrich for Escherichia coli mutants with conditional growth defects and alterations in membrane composition. A temperature-sensitive mutant named Lud135 was isolated with mutations in two related, nonessential genes: yghB and yqjA. yghB harbors a single missense mutation (G203D) and yqjA contains a nonsense mutation (W92TGA) in Lud135. Both mutations are required for the temperature-sensitive phenotype: targeted deletion of both genes in a wild-type background results in a strain with a similar phenotype and expression of either gene from a plasmid restores growth at elevated temperatures. The mutant has altered membrane phospholipid levels, with elevated levels of acidic phospholipids, when grown under permissive conditions. Growth of Lud135 under nonpermissive conditions is restored by the presence of millimolar concentrations of divalent cations Ca2+, Ba2+, Sr2+, or Mg2+ or 300 to 500 mM NaCl but not 400 mM sucrose. Microscopic analysis of Lud135 demonstrates a dramatic defect at a late stage of cell division when cells are grown under permissive conditions. yghB and yqjA belong to the conserved and widely distributed dedA gene family, for which no function has been reported. The two open reading frames encode predicted polytopic inner membrane proteins with 61% amino acid identity. It is likely that YghB and YqjA play redundant but critical roles in membrane biology that are essential for completion of cell division in E. coli.

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