Process,Characterization and Biodegradability of Aliphatic Aromatic Polyester/Sisal Fiber Composites

The biodegradability, morphology, and mechanical properties of composite materials made of Poly(butylene adipate-co-terephthalate) (PBAT) and sisal fiber (SF) were evaluated. Composites containing acrylic acid-grafted PBAT (PBAT-g-AA/SF) exhibited noticeably superior mechanical properties due to greater compatibility between the two components. The dispersion of SF in the PBAT-g-AA matrix was highly homogeneous as a result of ester formation between the carboxyl groups of PBAT-g-AA and hydroxyl groups in SF and the consequent creation of branched and cross-linked macromolecules. Each composite was subjected to biodegradation tests in Rhizopus oryzae compost. Morphological observations indicated severe disruption of film structure after 60 days of incubation, and both the PBAT and the PBAT-g-AA/SF composite films were eventually completely degraded. Water resistance of PBAT-g-AA/SF was higher than that of PBAT/SF, although weight loss of composites buried in Rhizopus oryzae compost indicated that both were biodegradable, even at high levels of SF substitution. The PBAT-g-AA/SF films were more biodegradable than those made of PBAT, implying a strong connection between these characteristics and biodegradability.     

Landscape ecological security assessment based on projection pursuit in Pearl River Delta

Regional landscape ecological security is an important issue for ecological security, and has a great influence on national security and social sustainable development. The Pearl River Delta (PRD) in southern China has experienced rapid economic development and intensive human activities in recent years. This study, based on landscape analysis, provides a method to discover the alteration of character among different landscape types and to understand the landscape ecological security status. Based on remotely sensed products of the Landsat 5 TM images in 1990 and the Landsat 7 ETM+ images in 2005, landscape classification maps of nine cities in the PRD were compiled by implementing Remote Sensing and Geographic Information System technology. Several indices, including aggregation, crush index, landscape shape index, Shannon’s diversity index, landscape fragile index, and landscape security adjacent index, were applied to analyze spatial–temporal characteristics of landscape patterns in the PRD. A landscape ecological security index based on these outcomes was calculated by projection pursuit using genetic algorithm. The landscape ecological security of nine cities in the PRD was thus evaluated. The main results of this research are listed as follows: (1) from 1990 to 2005, the aggregation index, crush index, landscape shape index, and Shannon’s diversity index of nine cities changed little in the PRD, while the landscape fragile index and landscape security adjacent index changed obviously. The landscape fragile index of nine cities showed a decreasing trend; however, the landscape security adjacent index has been increasing; (2) from 1990 to 2005, landscape ecology of the cities of Zhuhai and Huizhou maintained a good security situation. However, there was a relatively low value of ecological security in the cities of Dongguan and Foshan. Except for Foshan and Guangzhou, whose landscape ecological security situation were slightly improved, the cities had reduced values in landscape ecological security, with the most decreased number 0.52 in Zhaoqing. Results of this study offer important information for regional eco-construction and natural resource exploitation.     

Methyl mercury in fish—a case study on various samples collected from Ganges river at West Bengal

This study investigated the presence of total mercury (Hg) and organic mercury levels in the muscle of 19 common fresh water fish species captured from river Ganges, West Bengal, India. The total mercury level found in our study may not cause any toxic effect, but the methyl mercury (MeHg) level in some freshwater fish species was surprisingly very high and toxically unacceptable. The results of mercury analysis in various specimens indicated that some fish muscles tended to accumulate high levels of Hg, and approximately 50–84% of Hg was organic mercury. A strong positive correlation between mercury levels in muscle with food habit and fish length (age) was found. Wallago attu possessed the highest amount of organic mercury in their muscle tissues, and it was 0.93 ± 0.61 μg Hg/g of wet weight. Whereas in small-sized fishes Eutropiichthys murius, Puntius sarana, Cirrhinus mrigala, Mystus vittatus or Mystus gulio, and Tilapia mossambicus, it was below the detection limit. Contamination in Catla catla (0.32 ± 0.11), Anguilla bengalensis bengalensis (0.26 ± 0.07 μg Hg/g), Chitala chitala (0.25 ± 0.18), Rita rita (0.34 ± 0.14), and Ompok pabda (0.26 ± 0.04) was also above the 0.25 μg Hg/g of wet weight, the limit set by the PFA for the maximum level for consumption of fish exposed to MeHg. Though in Labeo rohita (0.12 ± 0.03), Mastacembelus armatus (0.17 ± 0.02), Pangasius pangasius (0.12 ± 0.16), Bagarius bagarius (0.12 ± 0.01), and Clupisoma garua (0.1 ± 0.01), concentration was below the recommended level, in Lates calcarifer (0.23 ± 0.0) and Mystus aor (0.23 ± 0.1), it was threatening. Interestingly, a low concentration of Hg was found in post-monsoon samples.     

Comparison of some quality properties of soils around land-mined areas and adjacent agricultural fields

When agricultural lands are no longer used for agriculture and allowed to recover its natural vegetation, soil organic carbon can accumulate in the soil. Measurements of soil organic carbon and aggregate stability changes under various forms of land use are needed for the development of sustainable systems. Therefore, comparison of soil samples taken from both agricultural and nearby area close to land-mined fields where no agricultural practices have been done since 1956 can be a good approach to evaluate the effects of tillage and agriculture on soil quality. The objective of this study was to compare tillage, cropping and no tillage effects on some soil-quality parameters. Four different locations along the Turkey–Syria border were selected to determine effects of tillage and cropping on soil quality. Each location was evaluated separately because of different soil type and treatments. Comparisons were made between non-tilled and non-cropped fallow since 1956 and adjacent restricted lands that were tilled about every 2 years but not planted (T) or adjacent lands tilled and planted with wheat and lentil (P). Three samples were taken from the depths of 0–20 and 20–40 cm each site. Soil organic carbon (SOC), pH ,electrical conductivity, water soluble Ca⁺⁺, Mg⁺⁺, CO₃^-2{\rm CO}_{3}^{-2} and HCO₃^-{\rm HCO}_{3}^{-}, extractable potassium (K⁺) and sodium (Na⁺), soil texture, ammonium (NH₄⁺{\rm NH}_{4}^{+}–N) and nitrate (NO₃–N), extractable phosphorous and soil aggregate stability were determined. While the SOC contents of continuous tillage without cropping and continuous tillage and cropping were 2.2 and 11.6 g kg⁻¹, respectively, it was 30 g kg⁻¹ in non-tilled and non-planted site. Tillage of soil without the input of any plant material resulted in loss of carbon from the soil in all sites. Soil extractable NO₃−N contents of non-tilled and non-cropped sites were greatest among all treatments. Agricultural practices increased phosphorus and potassium contents in the soil profile. P₂O₅ contents of planted soils were approximately 20 to 39 times greater than those of non-tilled and non-cropped soils at different sites. FTIR spectra showed that never tilled sites had greater phenol, carboxylic acid, amide, aromatic compounds, polysaccharide and carbohydrates than other treatments.     

Legitimacy &; Canadian Farm Animal Welfare Standards Development: The Case of the National Farm Animal Care Council

Awareness of farm animal welfare issues is growing in Canada, as part of a larger food movement. The baseline Canadian standards for farm animal welfare—the Recommended Codes of Practice for the Care and Handling of Farm Animals—are up for revision. The success of these standards will depend in part on perceived legitimacy, which helps determine whether voluntary code systems are adopted, implemented, and accepted by target audiences. In the context of the Codes, legitimacy will also hinge on whether the standards-developers marshal narratives about farm animals that accord with their audiences’ expectations. The aim of this paper is to catalogue factors that influence legitimacy in farm animal welfare standard-setting, including which narratives of animal welfare are emphasized by standard-setters. Drawing upon the example of the baseline Canadian standards, and the National Farm Animal Care Council, the paper will present a theoretical and methodological framework for analyzing legitimacy in the context of animal welfare standards-development and discuss associated policy considerations.     

Effect of Ionizing Radiation on the Morphological,Thermal and Mechanical Properties of Polyvinyl Alcohol/Polyethylene Glycol Blends

Blends of water—soluble polymers based on Poly vinyl alcohol (PVA) and Polyethylene glycol (PEG) have been prepared by the solution casting technique. The effect of various doses of γ-radiation on the structural properties of PVA/PEG polymer blends with all its compositions has been investigated. From the visual observation of all the blend compositions, it was found that, the best compatibility of the blend is up to 40% PVA/60%PEG. The structure–Property behavior of all the prepared blends before and after γ-irradiation was investigated by IR Spectroscopy, thermogravimetric analysis (TGA), mechanical properties and Scanning electron microscope (SEM). The gel content and the swelling behavior of the PVA/PEG blends were investigated. It was found that the gel content increases with increasing irradiation dose and PVA concentration in the blend. Swelling percent increased as the composition of PEG increased in the blend. The results obtained by FTIR analysis and SEM confirm the existence of possible interaction between PVA and PEG homopolymers. TGA of PVA/PEG blend, before and after γ-irradiation, showed that the unirradiated and irradiated PVA/PEG blends are more stable against thermal decomposition than pure PVA. Improvement in tensile mechanical properties of PVA/PEG blends was occurred.     

Biohydrogen using leachate from an industrial waste landfill as inoculum

Since hydrogen is a renewable energy source, biohydrogen has been researched in recent years. However, data on hydrogen fermentation by a leachate from a waste landfill as inoculum are scarce. We investigated hydrogen production using a leachate from an industrial waste landfill in Kanagawa Prefecture. The results showed no methane gas production, and the leachate was a suitable inoculum for hydrogen fermentation. The maximum H₂ yield was 2.67 mol of H₂ per mol of carbohydrate added, obtained at 30°C and an initial pH of 7. The acetate and butyrate production was significant when the H₂ yield was higher. Oxidation–reduction potential analysis of the culture suggested that hydrogen-producing bacteria in the leachate were facultative anaerobic. Scanning electron microscope observations revealed that the hydrogen-producing bacteria comprised bacilli about 2 μm in length.     

A study on legislative and policy tools for promoting the circular economic model for waste management in China

The circular economy has been developing rapidly in recent years in China. A legislative system has been created to provide legal protection for the development of a circular economy, including a series of price and tax measures in the waste management area. These measures form the basic foundation for promoting better waste management under the circular economic model. Many challenges, however, remain. For instance, the legal system needs to incorporate more sophisticated science, and China lacks key waste treatment technology that could support the further development of a circular economy. There is also a need to educate the public about the concept of the circular economy and its benefits. Specific suggestions are made for the development and implementation of the circular economic model.     

Seawater Intrusion and Sustainable Yield of Basal Aquifers1

Liu, Clark C.K. and John J. Dai, 2012. Seawater Intrusion and Sustainable Yield of Basal Aquifers. Journal of the American Water Resources Association (JAWRA) 48(5): 861‐870. DOI: 10.1111/j.1752‐1688.2012.00659.x Abstract: Basal aquifers, in which freshwater floats on top of saltwater, are the major freshwater supply for the Hawaiian Islands, as well as many other coastal regions around the world. Under unexploited or natural conditions, freshwater and the underlying seawater are separated by a relatively sharp interface located below mean sea level at a depth of about 40 times the hydraulic head. With forced draft, the hydraulic head of a basal aquifer would decline and the sharp interface would move up. It is a serious problem of seawater intrusion as huge amounts of freshwater storage is replaced by saltwater. Also, with forced draft, the sharp interface is replaced by a transition zone in which the salinity increases downward from freshwater to saltwater. As pumping continues, the transition zone expands. The desirable source‐water salinity in Hawaii is about 2% of the seawater salinity. Therefore, the transition zone expansion is another serious problem of seawater intrusion. In this study, a robust analytical groundwater flow and salinity transport model (RAM2) was developed. RAM2 has a simple mathematical structure and its model parameters can be determined satisfactorily with the available field monitoring data. The usefulness of RAM2 as a viable management tool for coastal ground water management is demonstrated by applying it to determine the sustainable yield of the Pearl Harbor aquifer, a principal water supply source in Hawaii.     

Selecting Variables for Habitat Suitability of <Emphasis Type="Italic">Asellus</Emphasis> (Crustacea,Isopoda) by Applying Input Variable Contribution Methods to Artificial Neural Network Models

This study aimed to compare different methods to analyse the contribution of individual river characteristics to predict the abundance of Asellus (Crustacea, Isopoda). Six methods which provide the relative contribution and/or the contribution profile of the input variables of artificial neural network models were therefore compared: (1) the ‘partial derivatives’ method; (2) the ‘weights’ method; (3) the ‘perturb’ method; (4) the ‘profile’ method; (5) the ‘classical stepwise’ method; (6) the ‘improved stepwise’ method. Consequently, the key variables which affect the habitat preferences of Asellus could be identified. To evaluate the performance of the artificial neural network model, the model predictions were compared with the results of a multiple linear regression analysis. The dataset consisted of 179 samples, collected over a 3-year period in the Zwalm catchment in Flanders, Belgium. Twenty-four environmental variables as well as the log-transformed abundance of Asellus were used in this study. The different contribution methods seemed to give similar results concerning the order of importance of the input variables. Nevertheless, their diverse computation led to differences in sensitivity and stability of the methods and the derived outcomes on the habitat preferences. From an ecological point of view, the environmental variables describing the stream type (width, depth, stream order and distance to mouth) were the most significant variables for Asellus in the Zwalm catchment during the period 2000–2002 for all applied methods. Indirectly, one can conclude that the water quality is not the limiting factor for the survival of Asellus in the Zwalm catchment.