Heavy metal concentrations in water, suspended matter, and sediment from Gökova Bay, Turkey

The contents of heavy metals (Fe, Mn, Pb, Cu, Cd, and Hg) dissolved in water and suspended solids of Gökova Bay—partly and fully sampled in 2005 and 2006, respectively—are quite higher than the average values encountered in uncontaminated sea water. The high concentrations are associated with terrestrial inputs from the mining zones and anthropogenic (domestic + industrial) sources. Moreover, the distribution of Fe and Cu is affected by primary production because these elements function as nutrients in biological activities. The Cr, Ni, and Fe concentrations of surface sediments are above the shale average. The Cr and Ni contents of surface sediments representative of river mouths strongly correlate with total phosphorus contents. In a sulfide-poor environment, Pb and Cu were concentrated at a higher ratio in surface sediments than Cd, probably due to higher stabilities of their surface complexes with amorphous iron oxides and clay minerals existing as major components in the sediments. The exceptional enrichment of Zn may be attributed to double oxide formation with amorphous iron oxides in sediments. The high metal values are most probably caused by terrestrial inputs from anthropogenic sources and the mining zones at the southeast part of the bay. The Al, Mn, Pb, Cu, Zn, and Hg contents are below the shale average. The low values have possibly originated from the coarse-grained sandy sediments having a low affinity for metals. There are no distinct differences in the metal distributions in water and suspended matter between the years 2005 and 2006 in the bay, probably due to low sedimentation rates.     

Assessing spatio-temporal trend of vector breeding and dengue fever incidence in association with meteorological conditions

Th aim of this study is to investigate spatio-temporal trends of dengue vector breeding and epidemic (disease incidence) influenced by climatic factors. The spatio-temporal (low-, medium-, and high-intensity periods) evaluation of entomological and epidemiological investigations along with climatic factors like rainfall (RF), temperature (T_max), relative humidity (RH), and larval indexing was conducted to develop correlations in the area of Lahore, Pakistan. The vector abundance and disease transmission trend was geo-tagged for spatial insight. The sufficient rainfall events and optimum temperature and relative humidity supported dengue vector breeding with high larval indices for water-related containers (27–37%). Among temporal analysis, the high-intensity period exponentially projected disease incidence followed by post-rainfall impacts. The high larval incidence that was observed in early high-intensity periods effected the dengue incidence. The disease incidence had a strong association with RF (r = 0.940, α = 0.01). The vector larva occurrence (r = 0.017, α = 0.05) influenced the disease incidence. Similarly, RH (r = 0.674, α = 0.05) and average T_max (r = 0.307, α = 0.05) also induced impact on the disease incidence. In this study, the vulnerability to dengue fever highly correlates with meteorological factors during high-intensity period. It provides area-specific understanding of vector behavior, key containers, and seasonal patterns of dengue vector breeding and disease transmission which is essential for preparing an effective prevention plan against the vector.     

Study of heat exposure during Hajj (pilgrimage)

Heat stress presents a main problem to Muslim Hajeej (pilgrims) during Hajj (pilgrimage) season, particularly in summer. Records of the Saudi Ministry of Health show close relation between heat casualties and climatic heat load through consequent Hajj seasons. The present study was conducted to evaluate the climatic heat load in Hajj locations during summer of 1995 as well as just before and during the Hajj season of 1997. Heat measurements including: T (a), T (w), T (g), WBGT, relative humidity and air velocity were conducted through July-September 1995, and on March/April 1997, in 10 Hajj locations at morning, noon, afternoon and night. The highest WBGTs were at Haram court, Ghazzah area and Muna housing area, followed by Arafat areas and Muzdalefah, and the lowest at Azizia area. However, all the WBGTs were considerably higher than the ACGIH-TLV for safe heat exposure, particularly during daytime; meanwhile, heat exposure considerably exceeded the ASHRAE comfort zone at all locations all times. The natural climatic condition is a major contributing factor to the overall heat load; moreover, potentiated by heat dissipated from Hajj activities, including Hajeej crowds, human activities, and the vehicles' masses exhaust. This situation is further synergized by some pilgrims' misbehavior (e.g. living in open sunny areas, using vehicles without roofs) and lack of awareness of the seriousness of heat exposure among them. An outline for a control strategy has been suggested based on planting open areas of Arafat and Muna, provision of air conditioned housing and tents in Muna, segregation of pedestrians from vehicles and their provision of shaded roads and rest areas, establishing more water spatters in Arafat and Muna, checking the performance of large vehicles before issuing their permits for operation during Hajj, providing vehicles parking isolated areas away from Hajeej tents, provision of ample amounts of quality drinking water in all Hajj locations, provision of ample optimal ambulance services, and dissemination of educational information to Hajeej for their taking advantage of Fiqh (religion rules) waivers in performing Hajj rituals to minimize their heat exposure, and for their personal protection.     

Determination of volatile organic compounds pollution sources in malaysian drinking water using multivariate analysis

A field investigation was conducted at all water treatment plants throughout 11 states and Federal Territory in Peninsular Malaysia. The sampling points in this study include treatment plant operation, service reservoir outlet and auxiliary outlet point at the water pipelines. Analysis was performed by solid phase micro-extraction technique with a 100 μm polydimethylsiloxane fibre using gas chromatography with mass spectrometry detection to analyse 54 volatile organic compounds (VOCs) of different chemical families in drinking water. The concentration of VOCs ranged from undetectable to 230.2 μg/l. Among all of the VOCs species, chloroform has the highest concentration and was detected in all drinking water samples. Average concentrations of total trihalomethanes (THMs) were almost similar among all states which were in the range of 28.4--33.0 μg/l. Apart from THMs, other abundant compounds detected were cis and trans-1,2-dichloroethylene, trichloroethylene, 1,2-dibromoethane, benzene, toluene, ethylbenzene, chlorobenzene, 1,4-dichlorobenzene and 1,2-dichloro - benzene. Principal component analysis (PCA) with the aid of varimax rotation, and parallel factor analysis (PARAFAC) method were used to statistically verify the correlation between VOCs and the source of pollution. The multivariate analysis pointed out that the maintenance of auxiliary pipelines in the distribution systems is vital as it can become significant point source pollution to Malaysian drinking water.     

Antibacterial and Catalytic Performance of Green Synthesized Silver Nanoparticles Embedded in Crosslinked PVA Sheet

Journal of Polymers and the Environment - In this research work, a green method of using Saussurea costus extract for the synthesis of silver nanoparticles (AgNPs) is developed. Analysis of the...     

Numerical investigation of geometrical defect in cold forging of an AUV blade pin head

The precision of cold forging parts becomes critical because the process depends on many factors such as the size and complexity of the parts. Defects negatively affect the assembly accuracy and the performance of the parts. Therefore, defects must be detected and prevented as soon as possible before the manufacturing process begins. The paper intends to investigate the geometrical defect of the cold embossing pin head, which may result in an inaccurate assembly of the blade. In this paper, defect formation was studied using DEFORM-2D based on material flow pattern and stress distribution. The defect was measured in terms of incomplete filling and geometries of the bulging. The effect of the distance to the edge (DTE) is significant to the formation of defects. The size of the bulge is reduced and the filling ability shows better performance as the DTE increases. The FE results are in good agreement with the experimental result.     

MULTIDISCIPLINARY PLANNING AND MANAGING OF WATER REUSE1

ABSTRACT: This paper examines a rapidly expanding area of water supplies, specifically water reclamation and reuse, and provides a comprehensive planning methodology for developing and evaluating water reuse alternatives. The methodology uses five phases: goal setting, identification of reuse opportunities, development and evaluation of planning alternatives, assessment of water reuse linkages, and making decisions and recommendations. A tool called “input-output modeling” is used in the third phase to present numerical data and choices. The methodology seeks to integrate the hydrologic and socio-economic aspects of water resources planning in the area of study. Water reuse may satisfy some of the increasing demands for water in the world, but water quality, economics, public attitudes, and legal and institutional constraints may impose limits on the extent to which it can be employed. The challenge in planning systems is to maximize the utilization of water reuse in the fact of these constraints. The importance of multidisciplinary collaboration cannot be overemphasized. This paper assesses the potential for water reclamation and reuse in developing countries by considering the relationships among the pertinent technical, social, economic, and environmental parameters. Generally, the planning process for water reuse has focused on specific technological processes, but in order to ensure the efficient transfer of waste water reuse technology into the society, the methodology seeks to provide a conceptual model which integrates the hydrologic and socioeconomic aspects of water resources planning and water reuse within the study area. (KEY WORDS: water reuse; water reclamation; planning; methodology; model; reuse technology; socio-hydrologic systems; socioeconomic systems.)     

Personality of young drivers in Oman: Relationship to risky driving behaviors and crash involvement among Sultan Qaboos University students

Objective: Drivers’ behaviors such as violations and errors have been demonstrated to predict crash involvement among young Omani drivers. However, there is a dearth of studies linking risky driving behaviors to the personality of young drivers. The aim of the present study was to assess such traits within a sample of young Omani drivers (as measured through the behavioral inhibition system [BIS] and the behavioral activation system [BAS]) and determine links with aberrant driving behaviors and self-reported crash involvement.

Methods: A cross-sectional study was conducted at the Sultan Qaboos University that targeted all licensed Omani's undergraduate students. A total of 529 randomly selected students completed the self-reported questionnaire that included an assessment of driving behaviors (e.g., Driver Behaviour Questionnaire, DBQ) as well as the BIS/BAS measures.

Results: A total of 237 participants (44.8%) reported involvement in at least one crash since being licensed. Young drivers with lower BIS–Anxiety scores and higher BAS–Fun Seeking tendencies as well as male drivers were more likely to report driving violations. Statistically significant gender differences were observed on all BIS and BAS subscales (except for BAS–Fun) and the DBQ subscales, because males reported higher trait scores. Though personality traits were related to aberrant driving behaviors at the bivariate level, the constructs were not predictive of engaging in violations or errors. Furthermore, consistent with previous research, a supplementary multivariate logistic regression analysis revealed that only driving experience was predictive of crash involvement.

Conclusions: The findings highlight that though personality traits influence self-reported driving styles (and differ between the genders), the relationship with crash involvement is not as clear. This article further outlines the key findings of the study in regards to understanding core psychological constructs that increase crash risk.