Gas chromatographic separation and determination of chloroanthracene isomers on fly ash

An efficient, reproducible and rapid fused silica capillary column gas chromatographic method, in splitless mode, for analysing of the three chloroanthracene isomers is described. The method affords efficient separation and good linearity for each isomer in the range of 0.2 -200 μg/ml. The method can also be used in separation and determination of another thirty three aromatic and their halosubstituted compounds. This paper also presents the applications of the method in analysing of complex products mixture from reaction of the selected aromatic compounds with hydrogen chloride on fly ash surface from municipal incinerator.     

Teleworker knowledge sharing and the role of altered relational and technological interactions

Given the growing importance and complexities of telework and the challenges associated with knowledge sharing, in this study we investigate teleworkers and their propensity to share knowledge. We do so by investigating if the relational qualities of teleworkers in the form of trust, interpersonal bond, and commitment, act to impact teleworker knowledge sharing. We also investigate how telework's altered spatial and technical interactions shape knowledge sharing, by testing the contingent role of technology support, face-to-face interactions, and electronic tool use. Results using matched data from 226 teleworkers support the role of teleworker trust, interpersonal bond, and commitment in predicting knowledge sharing. Moreover, the impact of trust on knowledge sharing is found to be moderated by technology support, face-to-face interactions, and use of electronic tools, whereas the impact of commitment is contingent upon the use of electronic tools. Copyright © 2009 John Wiley & Sons, Ltd.     

Radiative effects of aerosols over Indo-Gangetic plain: environmental (urban vs. rural) and seasonal variations

Aerosol radiative effects over two environmentally distinct locations, Kanpur (urban site) and Gandhi College (rural location) in the Indo-Gangetic plain (IGP), a regional aerosol hot spot, utilizing the measured optical and physical characteristics of aerosols, an aerosol optical properties model and a radiative transfer model, are examined. Shortwave aerosol radiative forcing (ARF) at the top of the atmosphere (TOA) is 30 W m(?-?2)). Shortwave atmospheric heating due to aerosols is >0.4 K/day over IGP and peaks during premonsoon at >0.6 K/day due to lower single scattering albedo (SSA) and higher surface albedo. TOA forcing is always less negative over Kanpur when compared to Gandhi College due to lower surface albedo except in postmonsoon owing to higher SSA. This happens as TOA forcing depends on SSA and surface albedo in addition to aerosol optical depth. The magnitude of longwave forcing and atmospheric cooling in an absolute sense is significantly small and contributes only about 20% or less to the net (shortwave + longwave) forcing. Aerosol radiative effects over these two locations, despite differences in aerosol characteristics, are similar, thus confirming that aerosols and their radiative influence get transported due to circulation. ARF over Kanpur and Gandhi College is an order of magnitude higher when compared to greenhouse gas forcing. A large reduction in surface reaching solar irradiance accompanied by large atmospheric warming can have implications on precipitation and hydrological cycle, and these aerosol radiative effects should be included while performing regional-scale aerosol climate assessments.     

水稻杂交后代表观直链淀粉质量分数与蜡质基因(CT)n微卫星多态性的相关性

以来自２ 个水稻杂交组合的后代遗传群体为材料,研究了蜡质基因（ Ｗｘ） 微卫星标记（ＣＴ）ｎ 多态性与稻米表观直链淀粉质量分数（ ｗ（ＡＡ）） 之间的相关性． 第１ 个群体是浙农８０１０ 与嘉育２９３ 的杂交Ｆ６ 代育种品系,双亲均为籼稻,ｗ（ＡＡ） 分别为８ ．７％ 和２５．６ ％ ,Ｗｘ 基因型为分别为（ＣＴ）１８（ＣＴ）１８ 和（ＣＴ）１１（ＣＴ）１１ ．另一群体为ＣＭ１０１ 与ＩＧＲＡ４０９ 杂交Ｆ５ 家系,亲本ＣＭ１０１ 为一个粳型糯稻,Ｗｘ 基因型为（ＣＴ）１８（ＣＴ）１８ ;ＩＧＲＡ４０９ 为籼稻,ｗ（ＡＡ） ＝ ２７．５％ ,Ｗｘ 基因型为（ＣＴ）１１（ＣＴ）１１ ．结果发现,在２ 个杂交组合的后代群体中,高ｗ（ＡＡ） 材料Ｗｘ 基因型均为（ＣＴ）１１（ＣＴ）１１ ,低ｗ（ＡＡ） 及糯稻的均为（ＣＴ）１８（ＣＴ）１８ ,中等ｗ（ＡＡ） 材料的则为（ＣＴ）１８（ＣＴ）１１ 的杂合体．统计分析表明,Ｗｘ 基因型与ｗ（ＡＡ）之间存在显著的相关性,在浙农８０１０×嘉育２９３ 和ＣＭ１０１ ×ＩＧＲＡ４０９ 两个群体中相关系数分别达０ ．９５０９ 和０．９７０４．     

Nickel accumulation and its effect on growth,physiological and biochemical parameters in millets and oats

With the boom in industrialization, there is an increase in the level of heavy metals in the soil which drastically affect the growth and development of plants. Nickel is an essential micronutrient for plant growth and development, but elevated level of Ni causes stunted growth, chlorosis, nutrient imbalance, and alterations in the defense mechanism of plants in terms of accumulation of osmolytes or change in enzyme activities like guiacol peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD). Ni-induced toxic response was studied in seedlings of finger millet, pearl millet, and oats in terms of seedling growth, lipid peroxidation, total chlorophyll, proline content, and enzymatic activities. On the basis of germination and growth parameters of the seedling, finger millet was found to be the most tolerant. Nickel accumulation was markedly lower in the shoots as compared to the roots, which was the highest in finger millet and the lowest in shoots of oats. Plants treated with a high concentration of Ni showed significant reduction in chlorophyll and increase in proline content. Considerable difference in level of malondialdehyde (MDA) content and activity of antioxidative enzymes indicates generation of redox imbalance in plants due to Ni-induced stress. Elevated activities of POD and SOD were observed with high concentrations of Ni while CAT activity was found to be reduced. It was observed that finger millet has higher capability to maintain homeostasis by keeping the balance between accumulation and ROS scavenging system than pearl millet and oats. The data provide insight into the physiological and biochemical changes in plants adapted to survive in Ni-rich environment. This study will help in selecting the more suitable crop species to be grown on Ni-rich soils.

     

Arsenic contamination of the environment: a new perspective from central-east India

This paper reports a regional contamination of the environment in central-east India that does not share geology or boundary with the Bengal Delta Plain. About 30,000 people residing in 30 villages and towns are directly exposed to arsenic and more than 200,000 people are "at risk." Complete geographical extent of this contamination is being established, and this newly reported contaminated area could be quite large. This paper further reports that the mechanisms involved in arsenic mobilisation are complex and the two theories of arsenic mobilisation, i.e., pyrite oxidation and oxyhydroxides reduction, do not fully explain the high levels of arsenic contamination. This paper also proposes the "oxidation-reduction theory" for arsenic mobilisation where the arsenic originates from the arsenopyrite oxidation and the arsenic thus mobilised forms the minerals and gets reduced underground in favourable Eh conditions. The stoppage of water withdrawal from the contaminated sources did not result in lowering of arsenic levels as expected according to the heavy groundwater extraction theory (pyrite oxidation theory). Cases of arsenicosis in the region are on the rise and the switchover to less contaminated water has not reversed the arsenicosis progression in the affected persons even after 2 years. Surface water of the rivers is also being contaminated because of the probable dislocation of contaminated groundwater due to the heavy rains in monsoon season, which indicates that the river water could be a major carrier of arsenic in dissolved or adsorbed forms that may be a cause of contamination of the delta plains.     

Hair from different ethnic groups vary in elemental composition and nitrogen and phosphorus mineralisation in soil

Disposal of hair wastes at landfills causes nitrate leaching to ground water, and use of the waste as fertiliser could be a viable option. This study was to determine elemental composition of major hair types in South Africa and their nitrogen (N) and phosphorus (P) release in soil. Wastes of African, White and Indian hair were obtained from local salons and analysed for carbon (C), N and sulphur (S) with the Leco CNS analyzer, and P, bases, aluminium (Al) and micronutrients, with the ICP. We also conducted an incubation study to determine changes in mineral N and P in soil. Hair wastes were added to soil at increasing rates based on N, incubated at 25 °C with destructive sampling after 0, 28, 56 and 84 days and pH, ammonium-N, nitrate-N and extractable P measured. All data were subjected to analysis of variance. Indian and White hair had higher N than African. White hair had higher C and lower potassium (K) than those of other types. The Fe levels in hair were in the order White > African > Indian, whilst those of Al were African > Indian > White. African hair had higher calcium (Ca), manganese (Mn), zinc (Zn) and cobalt (Co) than the other types. Ammonium-N and nitrate-N releases were in the order: Indian > African > White, especially at higher rates. Ammonium-N increased in the first 28 days and declined thereafter, when nitrate-N increased and pH decreased. The findings implied that hair types differ in elemental composition and nitrogen release in soil, with implications on pollution and soil fertility.     

Tradescantia pallida cv. purpurea boom in the characterization of air pollution by accumulation of trace elements

Tradescantia pallida cv. purpurea, a plant species widely employed for ornamentation in Brazil, has been successfully used for monitoring the genotoxicity of various agents by the micronucleus assay. To amplify knowledge about its suitability as a bioindicator species, its capacity for accumulating trace elements from urban air pollution was evaluated. T. pallida was rooted using standardized soil, and the vases were distributed in two highly polluted sites of the urban area of S?o Paulo, Brazil (Cerqueira Cesar and Congonhas districts), and in one unpolluted control site situated approximately 50 km from downtown S?o Paulo (in Caucaia do Alto). Approximately six months after exposure to pollutants, adult leaves of this plant were collected monthly for 12 months. The leaves were washed with deionized water, dried, and ground for analyses. Characterization of element levels was carried out by neutron activation analysis. Powdered samples and standards were irradiated at the IEA-R1 nuclear reactor for short and long periods, and concentrations of As, Ba, Br, Ca, Ce, Cl, Cr, Co, Fe, K, La, Mn, Na, Rb, Sb, Sc, Sr, Th, and Zn were determined. Analysis of variance applied to the results indicated that samples from polluted sites present the highest concentrations of Ba, Ce, Cr, Co, Fe, La, Sb, and Sc (p < 0.05). Discriminant analysis revealed that it was possible to distinguish the two polluted areas with a precision of 97.5%, based on the amount of pollutant elements measured in the plants at each site. The results indicated the potential use of T. pallida as an accumulator plant for air pollution biomonitoring.