Agricultural wastes, oil palm trunk (OPT) veneer and oil palm empty fruit bunch (EFB) mat were used for the preparation of
hybridized plywood using 250 and 450 g/m2 of urea formaldehyde (UF) as gluing agent. The mechanical (flexural strength, flexural modulus, screw withdrawal, shear strength),
physical (density, water absorption, thickness swelling and delamination) and thermal (TGA) properties of the biocomposites
were studied. Images taken with a scanning electron micrograph (SEM) indicated an improvement in the fiber–matrix bonding
for the laminated panel glued with 450 g/m2 of UF. 相似文献
The fate of chlorothalonil, chlorpyrifos and profenofos in sandy loam soil under tropical condition was studied in a vegetable
plot in the Cameron Highlands, Malaysia. The plot was treated with chlorothalonil, chlorpyrifos and profenofos according to
normal agricultural practices of the Cameron Highlands. Water (runoff and lysimeter), soil and bedload sediment samples were
taken according to a sampling schedule. Residues in water, soil and bedload sediment samples were laboratory analysed to determine
amount. Chlorothalonil residues were detected in the range of < 0.01–0.08 mg/kg in the soil, < 0.01–0.02 ng/mL in the leachate,
< 0.01–0.02 ng/mL in the runoff and < 0.01–0.11mg/kg in the sediment. Field studies of chlorpyrifos showed residue levels
of < 0.01–0.06 mg/kg in the soil, < 0.01–0.07 ng/mL in the leachate, < 0.01–0.08 ng/mL in the runoff and < 0.01–0.62 mg/kg
in the sediment. Residue levels of profenofos were detected in the range of < 0.01–0.02 mg/kg in the soil, < 0.01–0.87 ng/mL
in the leachate, < 0.01–0.08 ng/mL in the runoff and < 0.01–0.35 mg/kg in the sediment. The three pesticides dissipated rapidly,
with DT50 (time for 50% loss) of less than two days. The study showed that these pesticides dissipated rapidly under the climatic
conditions of the Cameron Highlands in Malaysia. 相似文献
Objectives: Studies from different parts of the world have indicated that the impact of road traffic incidents disproportionally affects young adults. Few known studies have been forthcoming from Arabian Gulf countries. Within Oman, a high proportion of the population is under the age of 20. Coupled with the drastic increase in motorization in recent years, there is a need to understand the state of road safety among young people in Oman. The current research aimed to explore the prevalence and characteristics of road traffic injuries among young drivers aged 17–25 years.
Methods: Crash data from 2009 to 2011 were extracted from the Directorate General of Traffic, Royal Oman Police (ROP) database in Oman. The data were analyzed to explore the impact of road crashes on young people (17–25 years), the characteristics of young driver crashes, and how these differ from older drivers and to identify key predictors of fatalities in young driver crashes.
Results: Overall, young people were overrepresented in injuries and fatalities within the sample time period. Though it is true that many young people in crashes were driving at the time, it was also evident that young people were often victims in a crash caused by someone else. Thus, to reduce the impact of road crashes on young people, there is a need to generally address road safety within Oman. When young drivers were involved in crashes they were predominantly male. The types of crashes these drivers have can be broadly attributed to risk taking and inexperience. Speeding and nighttime driving were the key risk factors for fatalities.
Conclusion: The results highlight the need to address young driver safety in Oman. From these findings, the introduction of a graduated driver licensing system with nighttime driving restrictions could significantly improve young driver safety. 相似文献
Water is a scarce commodity in Kuwait. With rapid growth of population coupled with increasing urbanization and agriculture, the demand for water in Kuwait is continually on the increase. The main water source in the country is from desalination with small quantities from underground aquifers. Wastewater effluent at least for irrigation purposes, could be a valuable source to augment this dwindling water supply, and should not continue to be wasted. Reuse of wastewater effluent could both minimize the disposal of water to the environment and reduce the demand on fresh water supplies. This paper discusses the features of reuse, the processes used and standards adopted. Design data, operational results, and physical characteristics for the three wastewater treatment plants (Ardiya, Jahra, and Riqqa) in Kuwait are discussed. In addition, the paper reports on the results of a research study undertaken to determine the willingness, level of awareness and knowledge among the people of Kuwait in using wastewater effluent for different purposes. Cost and benefit analyses were conducted on wastewater effluent and reuse. The study concludes with useful recommendations to both the authorities and the citizens of Kuwait. 相似文献
In this study, the biogeochemical cycle of arsenic in the Bosporus and the Golden Horn, which have a two-layer stratified
structure, was investigated and the dominant feature in this cycle was observed to be the anthropogenic (domestic + industrial)
activities. On the contrary, in the rural areas which are far from human activities, such as İğneada, the seawater–atmosphere
interchange can be observed evidently in the periods covering the primary production. 相似文献
This article reports for the first time the antibacterial, antifungal, antioxidant and anticancer activities of vilangin synthesised from embelin isolated from Embelia ribes berries. E. ribes is widely used as traditional herbal medicine in India. E. ribes is used as appetiser, carminative, anthelmintic, alexiteric, laxative and alterative. This plant is also used to treat tumour, ascites, bronchitis, mental diseases, dyspnoea, heart diseases, urinary discharges, jaundice, hemicrania, and worms in wounds. Here the major compound, embelin, was isolated from the fruits of E. ribes. Vilangin was synthesised by condensation of embelin with formaldehyde in acetic acid solution. The biological activity of vilangin is unknown so far. Hence, we studied antibacterial, antifungal, antioxidant and anticancer activities of vilangin. The minimum inhibitory concentration value of vilangin was 62.5 μg/mL against Staphylococcus epidermidis and Salmonella typhimurium. The radical scavenging activity was maximum at 1,000 μg/mL. Ferric reducing antioxidant power assay of vilangin showed a twofold higher value compared to the standard. Vilangin showed 61.95 % of cytotoxic activity in vitro against A549 lung adenocarcinoma cancer cell line at a dose of 500 μg/mL with half-maximal inhibitory concentration (IC50) of 400 μg/mL. Vilangin can thus be further tested as a new drug. 相似文献
Environmental Science and Pollution Research - The objective of the study is to conduct the socio-economic and environmental survey about the feasibility of Saudi Arabia-China-Pakistan Economic... 相似文献
Polymeric hydrogels are designed to serve many purposes in various fields of human endeavor. Herein, crosslinked polyacrylamide (PAM) composite hydrogels impregnated with coal fly ash (CFA) were synthesized, characterized and tested as fracture sealing agents in high water producing permeable zones in petroleum industry. The concept of utilizing CFA as an inorganic additive in the matrix of hydrogel emanates from the fact that CFA constitutes majorly alumina and silica. Both chemical oxides can induce the CFA to promote the inherent properties of hydrogel. Polyethyleneimine (PEI) was chosen as the crosslinking agent. Neat PAM/PEI hydrogel and PAM/PEI–CFA hydrogels at various CFA loadings (0.5, 1 and 2 wt%) were synthesized via a transamidation reaction pathway. The developed hydrogels were characterized by hybrid rheometer, FTIR, SEM and XRD instruments. Rheological results reveal that the PAM/PEI–CFA composite hydrogels embedded with various CFA quantities were more elastic than the neat PAM/PEI hydrogel, indicating the dispersion and reinforcing effect of CFA. The functional groups of these hydrogels were confirmed by the FTIR while SEM analysis show that the surface micrographs of neat PAM/PEI hydrogel and PAM/PEI–CFA1 hydrogel were porous in several regions. In contrast, the micrographs of PAM/PEI–CFA2 and PAM/PEI–CFA3 hydrogels demonstrated dense and “net-like” structural patterns. Further, XRD analysis revealed that CFA impregnation has a significant effect on the bulk structural properties of the fabricated hydrogels. The swelling rates of these hydrogels were determined by the gravimetric method and their diffusion parameters evaluated using Fickian diffusion and Schott-order kinetic models. Efficacy of the PAM/PEI–CFA composite hydrogel as fractures sealant in oil and gas wells was conducted at a typical reservoir temperature, 90 °C, and the outcome demonstrated considerable sealing potency. 相似文献
The development of membrane-based desalination and water purification technologies offers new alternatives to meet the global freshwater demand. Rapid advancement in carbon nanotube-based and graphene-based nanomaterials has drawn the attention of scientific investigators on various desalination technologies. These nanomaterials indeed offer advantageous structure, size, shape, porosity and mass transport behavior for membrane separation process. This article reviews theoretical and experimental investigations of carbon nanotube- and graphene-based composite materials for desalination. Special attention is given to the simulation of molecular transport through these materials. Further, recent advances in the application of functionalization of carbon nanotube- and graphene-based materials for salt rejection and hydraulic permeation properties are discussed. 相似文献
Proper identification of environment's air quality based on limited observations is an essential task to meet the goals of environmental management. Various classification methods have been used to estimate the change of air quality status and health. However, discrepancies frequently arise from the lack of clear distinction between each air quality, the uncertainty in the quality criteria employed and the vagueness or fuzziness embedded in the decision-making output values. Owing to inherent imprecision, difficulties always exist in some conventional methodologies when describing integrated air quality conditions with respect to various pollutants. Therefore, this paper presents two fuzzy multiplication synthetic techniques to establish classification of air quality. The fuzzy multiplication technique empowers the max-min operations in "or" and "and" in executing the fuzzy arithmetic operations. Based on a set of air pollutants data carbon monoxide, sulfur dioxide, nitrogen dioxide, ozone, and particulate matter (PM(10)) collected from a network of 51 stations in Klang Valley, East Malaysia, Sabah, and Sarawak were utilized in this evaluation. The two fuzzy multiplication techniques consistently classified Malaysia's air quality as "good." The findings indicated that the techniques may have successfully harmonized inherent discrepancies and interpret complex conditions. It was demonstrated that fuzzy synthetic multiplication techniques are quite appropriate techniques for air quality management. 相似文献