Utilizing waste corn-cob in biosynthesis of noble metallic nanoparticles for antibacterial effect and catalytic degradation of contaminants

Environmental Science and Pollution Research - In the present study, cost-effective, and environmentally friendly fabrication of silver and gold nanoparticles was performed by using aqueous extract...     

Mesocosm and in situ observations of the burrowing shrimp Calocaris templemani (Decapoda: Thalassinidea) and its bioturbation activities in soft sediments of the Laurentian Trough

In vivo observations in laboratory mesocosms and aquaria, accompanied with in situ photographic surveys, have shown that the burrowing shrimp Calocaris templemani has a significant impact on bottom sediment dynamics and geochemistry in the St. Lawrence Estuary. This burrowing shrimp establishes and maintains complex semi-permanent burrows made up of several interconnected, ‘U-shaped’ galleries with generally four or more openings to the sediment surface. In the Estuary, at 345 m depth, Calocaris average density was estimated at 3.4 individuals m^?2. Observed individual burrows reached a maximum volume of 0.54 L. C. templemani displaces this volume of mostly anoxic sediments from the subsurface layers (down to 15 cm) to the sediment surface, thereby obscuring some of the natural stratification patterns. With an estimated turnover rate of about 8 L m^?2 year^?1 of sediment, our calculations suggest that over a period of about 18.75 years, all the sediment to a depth of 15 cm will have been reworked by C. templemani alone.     

Recycling disposable cups into paper plastic composites

The majority of disposable cups are made from paper plastic laminates (PPL) which consist of high quality cellulose fibre with a thin internal polyethylene coating. There are limited recycling options for PPLs and this has contributed to disposable cups becoming a high profile, problematic waste. In this work disposable cups have been shredded to form PPL flakes and these have been used to reinforce polypropylene to form novel paper plastic composites (PPCs). The PPL flakes and polypropylene were mixed, extruded, pelletised and injection moulded at low temperatures to prevent degradation of the cellulose fibres. The level of PPL flake addition and the use of a maleated polyolefin coupling agent to enhance interfacial adhesion have been investigated. Samples have been characterised using tensile testing, dynamic mechanical analysis (DMA) and thermogravimetric analysis. Use of a coupling agent allows composites containing 40 wt.% of PPL flakes to increase tensile strength of PP by 50% to 30 MPa. The Young modulus also increases from 1 to 2.5 GPa and the work to fracture increases by a factor of 5. The work demonstrates that PPL disposable cups have potential to be beneficially reused as reinforcement in novel polypropylene composites.     

Influencing factors on sustainable development: a case study in Quang Tri province,Vietnam

Background Sustainable development (SD) is a common concept. Knowledge and attitudes are essential in the SD process. This study assesses the knowledge, attitudes, and practices (KAP) of local people about SD. Aim To study the factors that influence the understanding of the concept, contents, and indicators of different aspects affecting the health and environmental issues. Methods A cross-sectional study was carried out from June to July 2007 among 546 households in the Quang Tri province. Data were gathered on basis of socio-demographic variables, namely age, gender, education, occupation, income, and region. Chi square tests and multivariate analysis were performed on the obtained data. The data were cleaned and analysed using SPSS 15.0 for windows. Results Occupation is related to knowledge, attitude, or practice. Income is related to knowledge or practice. Gender related to only attitude. Lastly, region is related to attitude or practice. The proportion of wrong understanding about SD is 2.0 times (95% CI: 1.3; 3.1, p < 0.001) higher than that of the people who have good understanding about it. The rate of willingness to do any related SD programmes of the people who understanding is 2.1 times (95% CI: 1.4; 3.2, p < 0.001) higher than that of the people who have bad one. Conclusions This study shows that knowledge on sustainability of the local communities is low. Occupation and income influence understanding of SD more than region, age, gender, and education. Most of the local people who do not understand SD in general, do not want to participate or act in SD programmes.     

Optimal allocations of agricultural intensity reveal win-no loss solutions for food production and biodiversity

Regional Environmental Change - Reconciling biodiversity conservation and food production may require the fine-tuning of both agricultural intensity and its spatial allocation. Here, we explored...     

Application of GIS and modelling in health risk assessment for urban road mobility

Transport is an essential sector in modern societies. It connects economic sectors and industries. Next to its contribution to economic development and social interconnection, it also causes adverse impacts on the environment and results in health hazards. Transport is a major source of ground air pollution, especially in urban areas, and therefore contributes to the health problems, such as cardiovascular and respiratory diseases, cancer and physical injuries. This paper presents the results of a health risk assessment that quantifies the mortality and the diseases associated with particulate matter pollution resulting from urban road transport in Haiphong City, Vietnam. The focus is on the integration of modelling and geographic information system approaches in the exposure analysis to increase the accuracy of the assessment and to produce timely and consistent assessment results. The modelling was done to estimate traffic conditions and concentrations of particulate matters based on geo-referenced data. The study shows that health burdens due to particulate matter in Haiphong include 1,200 extra deaths for the situation in 2007. This figure can double by 2020 as the result of the fast economic development the city pursues. In addition, 51,000 extra hospital admissions and more than 850,000 restricted activity days are expected by 2020.     

Disaggregation of nation-wide dynamic population exposure estimates in The Netherlands: Applications of activity-based transport models

Traditional exposure studies that link concentrations with population data do not always take into account the temporal and spatial variations in both concentrations and population density. In this paper we present an integrated model chain for the determination of nation-wide exposure estimates that incorporates temporally and spatially resolved information about people's location and activities (obtained from an activity-based transport model) and about ambient pollutant concentrations (obtained from a dispersion model). To the best of our knowledge, it is the first time that such an integrated exercise was successfully carried out in a fully operational modus for all models under consideration. The evaluation of population level exposure in The Netherlands to NO₂ at different time-periods, locations, for different subpopulations (gender, socio-economic status) and during different activities (residential, work, transport, shopping) is chosen as a case-study to point out the new features of this methodology. Results demonstrate that, by neglecting people's travel behaviour, total average exposure to NO₂ will be underestimated by 4% and hourly exposure results can be underestimated by more than 30%. A more detailed exposure analysis reveals the intra-day variations in exposure estimates and the presence of large exposure differences between different activities (traffic > work > shopping > home) and between subpopulations (men > women, low socio-economic class > high socio-economic class). This kind of exposure analysis, disaggregated by activities or by subpopulations, per time of day, provides useful insight and information for scientific and policy purposes. It demonstrates that policy measures, aimed at reducing the overall (average) exposure concentration of the population may impact in a different way depending on the time of day or the subgroup considered. From a scientific point of view, this new approach can be used to reduce exposure misclassification.