Some engineering aspects of homoionized mixed clay minerals

Many studies have been conducted to investigate thephysicochemical behavior of pure clay minerals and predicttheir engineering performance in the field. In this study, thephysicochemical properties of an artificial mixture of differentclay minerals namely, 40-50% montmorillonite, 20-30% illite and 10-15% kaolin were investigated. The mixture was homoionized with sodium, Na⁺; calcium, Ca²⁺; andaluminum, Al³⁺. The engineering properties studied wereconsistency limits, sediment volume, compressibility behavior,and hydraulic conductivity. The results revealed that theliquid, plastic and shrinkage limits of soil increased withincreasing cation valence. The hydraulic conductivity of thesoil also increased with an increase in the valence of thecation at any given void ratio. Aluminum and sodium treatedclays had the highest and the lowest modified compressionindex values, respectively. Furthermore, trivalent cationsaturated clayey soil consolidates three times faster thanthat of monovalent and two times faster than that of divalent.These properties of the soils determined were, in general,similar to those of kaolinite rather than those ofmontmorillonite. The comparison of the results obtained withthe published data in the literature revealed that thephysicochemical behavior of the tested clay soil was, ingeneral, similar to that of kaolinite.     

Cadmium and nickel determinations in some food and water samples by the combination of carrier element-free coprecipitation and flame atomic absorption spectrometry

A procedure for separation and enrichment of Cd(II) and Ni(II) ions based upon carrier element-free coprecipitation by using an organic coprecipitant, 2-{4-[2-(1H-Indol-3-yl)ethyl]-3-(4-methylbenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl}-N′-(3-fluoro-phenylmethyliden) acetohydrazide, prior to their flame atomic absorption spectrometric detections has been developed. The effects of varied experimental conditions on the performance of the developed method such as pH, sample volume, amount of coprecipitating agent, etc. were evaluated in detail on the recovery of analyte ions, and the influences of some anions and cations were investigated. The limits of detection for Cd(II) and Ni(II) ions based on three times the standard deviation of the blanks (N: 10) were obtained as 0.70 μg L^?1 and 1.21 μg L^?1, respectively. The accuracy of the method was tested by analyzing a certified reference material and by spike tests. The method was applied to determine the levels of cadmium and nickel in stream and sea water, rice, red lentil, and wheat samples.     

Unsustainable urban development for Zonguldak metropolitan area (NW Turkey)

Since Turkey is located on a region that is prone to the risks of natural disasters like earthquake, flooding, and avalanche; a majority of the residential areas are facing these risks at various levels. Before determination of these risks, taking action in order to decrease the vulnerability levels of the residential areas will help keep the damage at the minimum level in case of a disaster. Urban planning decisions which are made in accordance with vulnerability studies aiming to determine natural disaster risks will not only help prevent loss of life but also help decrease negative social and economic effects of disasters. The Zonguldak city has been chosen as a case study area since Zonguldak metropolitan area has endured almost all kinds of threats that a city can face. In this study disaster-producing factors in the area are primarily considered which can be named as topography, destruction of forest lands, geological and karstic structure, mining activities, and misuse of the land, and later risk assessment is conducted with geographic information system (GIS). It has been assessed that more than half of the buildings within the study area were constructed in areas not suitable for housing. It is concluded that there is a need for urgent urban development plan for the city.     

A factor analysis study: Air pollution,meteorology, and hospital admissions for respiratory diseases

It is well known that air pollution exerts adverse effects on health and environment. Bal?kesir located in the Marmara region (Turkey) has serious air pollution problems produced by heating in the months of winter. In this study, the effect of exposure to air pollution on hospital admission for respiratory illnesses among children and adults was examined. Epidemiological data from records of hospitals, air pollutants and meteorological data were used. During July 2005–July 2007 period, there was a total of 280,426 hospital admissions for respiratory diseases. In a population-based analysis, 9 children were admitted for asthma, 17 children for acute bronchitis, and 20 children for lower respiratory diseases out of 100 children. There was a significant increase in the hospital admissions for respiratory diseases and air pollutants from October to March. It was concluded that children living in the city suffer from respiratory diseases such as asthma, pneumonia, and lower respiratory diseases. Three factors that account for approximately 90% of total variance of hospital admissions, air pollution, and meteorology were identified by means of principal component factor analysis.     

An empirical analysis of surface acting in intra‐organizational relationships

Prior research analyzing surface acting—employees' regulation of emotional expressions—has mostly focused on the interactions between front‐line employees and their customers in service industries and paid very little attention to intra‐organizational relationships. With an aim to shed light on this important yet relatively unexplored area, I developed a theoretical model analyzing the antecedents and outcomes of surface acting within organizations, by drawing on the sociometer theory and self‐presentation theory frameworks. To test the model, I conducted a cross‐level field study in a sample of 65 work groups and 478 employees in two organizations, located in a large city in Northern California. I have collected the data from two sources, including employees and their supervisors who rated their performance. Results indicated that employees were more likely to engage in surface acting when their affective traits and personal goals were less congruent with work environment. Surface acting was also positively related to perceived organizational politics and self‐monitoring. As for outcomes, surface acting was positively related to emotional exhaustion and negatively to performance. I discuss limitations, implications, and future research direction. Copyright © 2012 John Wiley & Sons, Ltd.     

Preparation of Chitosan with High Antibacterial Efficiency from Penicillium crustosum TZ18

Journal of Polymers and the Environment - Fungi are accepted as novel sources of chitinous materials. The present study was performed to produce chitinous material from locally isolated Penicillium...     

Environmental impact assessments of different auxiliary power units used for commercial aircraft by using global warming potential approach

Environmental Science and Pollution Research - In this paper, environmental impact analysis is applied to the various auxiliary power units (APUs) used for commercial aircraft in air transportation...