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Heavy Metals in Paddy Soils of Brunei Darussalam and Their Relationship with Selected Soil Properties
Kyi Pyar Zin,
L. H. Lim,
J. M. R. Sarath Bandara,
H. M. Thippeswamy
Issue:
Volume 5, Issue 3, June 2017
Pages:
64-72
Received:
7 March 2017
Accepted:
23 March 2017
Published:
13 April 2017
Abstract: In Brunei Darussalam, available information of heavy metals in agricultural soils is sparse and hence a baseline study was carried out on soils in rice growing areas. In this study, trace elements as well as common soil characteristics were determined from twenty six of major rice fields such as Wasan, Limau Manis, Selapon and Lot Senkuang. Al, Fe, Mn and Cd were high in these areas however; Cu, Zn, Cr, Co, Ni and Pb were below safety limit of soil while Mn and Cd were above the permissible limit according to the WHO/CCME/European Union guidelines. The variations in metal concentrations in these samples are highly correlated to the acidic condition, organic matter and CEC of the paddy soils. The distributions of Al, Fe, Cu, Mn, Cd, Cr, Co, Pb were high at low pH. Cu, Zn, Cd, Ni and Pb showed positive correlation with organic matter while the quantities of Al, Fe, Mn, Cr and Co were negatively correlated. Correlation analyses showed that the Cd, Zn and Ni were associated with CEC while most of the metals were related to Al and Fe. The soils of the studied areas are extremely acidic with pH 3.0-4.6, and low in cations, CEC and available P, while having a high OM content. Low content of P was due to high amount of Al and Fe in these areas.
Abstract: In Brunei Darussalam, available information of heavy metals in agricultural soils is sparse and hence a baseline study was carried out on soils in rice growing areas. In this study, trace elements as well as common soil characteristics were determined from twenty six of major rice fields such as Wasan, Limau Manis, Selapon and Lot Senkuang. Al, Fe,...
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Characteristics of Atmospheric Trace Gases, Particulate Matter and Heavy Metal Pollution in Karachi, Pakistan
Durdana Rais Hashmi,
Akhtar Shareef,
Razia Begum
Issue:
Volume 5, Issue 3, June 2017
Pages:
73-82
Received:
17 November 2016
Accepted:
30 November 2016
Published:
24 April 2017
Abstract: This study was carried out for determination of Aerosol particulate matter (PM10), trace gases (SO2, NO2, CO) and heavy metals (Zn, Pb, Mn, Cu, Ni and Cd) in the atmospheric air of Karachi city. Sampling has been done at thirteen locations between during the year of 2014. The total average concentrations of SO2, NO2, CO and PM10 were 65.9, 98.7, 1.49 and 202.14μg m–3, respectively. An atomic absorption spectrophotometer (AAS) was used to determine the trace metal concentrations in the PM10 size fraction. The total average concentrations of Cd, Zn, Pb, Mn, Cu and Ni in PM10 were 0.09, 2.55, 2.23, 1.92, 2.15 and 1.44μg m–3 respectively. The Pb concentration in Karachi shows a decreasing tendency, presumably due to the ban on the use of leaded fuel. The overall trace metal concentrations in Karachi are higher than those in European (e.g., Spain, Norway) and East Asian (e.g., Taiwan) locations, but lower than those measured in Southeast Asian (Kanpur, Delhi, Mumbai, India) cities.
Abstract: This study was carried out for determination of Aerosol particulate matter (PM10), trace gases (SO2, NO2, CO) and heavy metals (Zn, Pb, Mn, Cu, Ni and Cd) in the atmospheric air of Karachi city. Sampling has been done at thirteen locations between during the year of 2014. The total average concentrations of SO2, NO2, CO and PM10 were 65.9, 98.7, 1....
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Indoor and Outdoor Concentrations of Bioaerosols and Meteorological Conditions of Selected Salons in Four Areas of Ibadan North Local Government Area
Alli Abosede Sarah,
Ana Godson Rowland E. E.
Issue:
Volume 5, Issue 3, June 2017
Pages:
83-90
Received:
3 April 2017
Accepted:
18 April 2017
Published:
7 June 2017
Abstract: Microorganisms are ubiquitous in the atmosphere but their concentrations are significantly affected by specific environmental factors. Thus, the characterization of bioaerosol levels in both the indoor and outdoor environment have become an important issue due to their adverse health effects. Therefore this study assessed the indoor and outdoor concentrations of bioaerosols and the meteorological conditions in selected salons in four areas of Ibadan North Local Government Area, Oyo State, Nigeria. This comparative cross-sectional study comprised of onsite observations, meteorological measurements viz: temperature and relative humidity (RH) and microbiological assessment (fungi and bacteria load). Building characteristics and sanitary conditions of salons were assessed using a walk-through observational checklist. A TE-10-890 single stage sampler was used for viable bioaerosol sampling and isolates were identified according to standard methods. Data obtained were analysed using descriptive and inferential statistics with SPSS (version 20). Mold growth and damp roof were observed in less than 20% and 40% of salons at the study locations respectively. Mean indoor and outdoor temperature and RH across Agbowo, Mokola, Yemetu and Bashorun were significantly higher than ASHRAE guideline limits. The mean concentrations of bacteria and fungi aerosols were significantly higher indoor than outdoor (p<0.05). Staphylococcus spp, Bacillus spp, Enterobacteria spp and Flavobacterium spp. were the predominant bacteria species isolated while Aspergillus spp, Penicillium spp, Fusarium spp, and Mucor spp. were the most common fungi species detected in the samples. The study showed that both the indoor and outdoor air were contaminated with bacteria and fungi, therefore it is important to control the environmental factors that support microbial growth in order to curtail occurrence of possible adverse effects they may have on health.
Abstract: Microorganisms are ubiquitous in the atmosphere but their concentrations are significantly affected by specific environmental factors. Thus, the characterization of bioaerosol levels in both the indoor and outdoor environment have become an important issue due to their adverse health effects. Therefore this study assessed the indoor and outdoor con...
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Improved Processing Research on Arc Tooth Cylindrical Gear
Issue:
Volume 5, Issue 3, June 2017
Pages:
91-95
Received:
24 February 2017
Accepted:
23 March 2017
Published:
29 June 2017
Abstract: Based on the analysis of arc tooth cylindrical gear forming principle and on the basis of existing processing methods, also combined with the principle of ordinary milling knife plate rotating, This paper puts forward an improved double-edged milling method of the Arc tooth cylindrical gear, which include two aspects: one is the double edged sword substance milling gear, double-point tool forming tooth at a time, with the module gear form point contact transmission vice; The second is to use double tooth gear milling tool, cutting tool a tooth, the gear machining and broadsword dish of double edge milling gear transmission line contact vice. It concluded that the improved processing technology is more advanced, the method of production is more efficient.
Abstract: Based on the analysis of arc tooth cylindrical gear forming principle and on the basis of existing processing methods, also combined with the principle of ordinary milling knife plate rotating, This paper puts forward an improved double-edged milling method of the Arc tooth cylindrical gear, which include two aspects: one is the double edged sword ...
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