Application of Multiattribute Decision-Making Methods for the Determination of Relative Significance Factor of Impact Categories

A relative significance factor (f _i ) of an impact category is the external weight of the impact category. The objective of this study is to propose a systematic and easy-to-use method for the determination of f _i . Multiattribute decision-making (MADM) methods including the analytical hierarchy process (AHP), the rank-order centroid method, and the fuzzy method were evaluated for this purpose. The results and practical aspects of using the three methods are compared. Each method shows the same trend, with minor differences in the value of f _i . Thus, all three methods can be applied to the determination of f _i . The rank order centroid method reduces the number of pairwise comparisons by placing the alternatives in order, although it has inherent weakness over the fuzzy method in expressing the degree of vagueness associated with assigning weights to criteria and alternatives. The rank order centroid method is considered a practical method for the determination of f _i because it is easier and simpler to use compared to the AHP and the fuzzy method.     

Comparative Influence of Forest Management and Habitat Structural Factors on the Abundances of Hollow-Nesting Bird Species in Subtropical Australian Eucalypt Forest

We examined the impact of single-tree selective logging and fuel reduction burns on the abundance of hollow-nesting bird species at a regional scale in southeastern Queensland, Australia. Data were collected on species abundance and habitat structure of dry sclerophyll production forest at 36 sites with known logging and fire histories. Sixteen bird species were recorded with most being resident, territorial, obligate hollow nesters that used hollows that were either small (<10 cm diameter) or very large (>18 cm diameter). Species densities were typically low, but combinations of two forest management and three habitat structural variables influenced the abundances of eight bird species in different and sometimes conflicting ways. The results suggest that habitat tree management for biodiversity in production forests cannot depend upon habitat structural characteristics alone. Management histories appear to have independent influence (on some bird species) that are distinguishable from their impacts on habitat structure per se. Rather than managing to maximize species abundances to maintain biodiversity, we may be better off managing to avoid extinctions of populations by identifying thresholds of acceptable fluctuations in populations of not only hollow-nesting birds but other forest dependent wildlife relative to scientifically valid forest management and habitat structural surrogates.     

Chemical Treatments of Natural Fiber for Use in Natural Fiber-Reinforced Composites: A Review

Studies on the use of natural fibers as replacement to man-made fiber in fiber-reinforced composites have increased and opened up further industrial possibilities. Natural fibers have the advantages of low density, low cost, and biodegradability. However, the main disadvantages of natural fibers in composites are the poor compatibility between fiber and matrix and the relative high moisture sorption. Therefore, chemical treatments are considered in modifying the fiber surface properties. In this paper, the different chemical modifications on natural fibers for use in natural fiber-reinforced composites are reviewed. Chemical treatments including alkali, silane, acetylation, benzoylation, acrylation, maleated coupling agents, isocyanates, permanganate and others are discussed. The chemical treatment of fiber aimed at improving the adhesion between the fiber surface and the polymer matrix may not only modify the fiber surface but also increase fiber strength. Water absorption of composites is reduced and their mechanical properties are improved.     

Status of recycling end-of-life vehicles and efforts to reduce automobile shredder residues in Korea

The present end-of-life vehicle (ELV) recycle rate and management status during the dismantling stage were investigated to aid the establishment of policies for the management of ELVs by surveying information and using the results gained from questionnaires given to dismantlers. The average recycle rate at the dismantling stage was 44% of the mass of a new vehicle and the rest of the ELV was then compressed and transported to shredding companies to recover mainly the iron content, which averaged 38.7% of the mass of a new vehicle. Nonferrous metals such as copper, antimony, zinc, and aluminum accounted for only 1.5%. The automobile shredder residues (ASRs) were composed of light and heavy fluffs and soil/dust and amounted to 15.8% based on the mass of a new vehicle. The dumping of fluff and inorganic residues in landfill sites, however, will be restricted when new regulations are implemented to reduce the disposal amount to less than 5% of a new car, as has been done in European countries and in Japan. The detailed characteristics of ASR were investigated to suggest appropriate means of treatment such as volume reduction or the utilization of thermal technologies to meet future expected enforcement. Also, some concerns on hazardous pollutant release such as that of dioxins while utilizing such thermal treatment methods were considered. The present on-going research and development projects to meet such future management targets are also introduced.     

Material flow indicators to measure progress toward a sound material-cycle society

This article reviews recent progress in material flow analysis and its use in providing resource productivity indicators and is based on developments in Japanese policy toward a sound material-cycle society and in international forums such as within the Organisation for Economic Development and Cooperation, covering both institutional and methodological issues. Indicators derived from economy-wide material flow accounts such as direct material inputs are useful to demonstrate the absolute size of a physical economy and to reinforce the need to both reduce consumption of natural resources and limit waste generation. Interpretation of material flows as resources and potential environmental impacts is discussed, and linkages between the size of material flows and specific environmental impacts and damage must be further elaborated for use in environmental policy. Lessons learned from the practical use of resource productivity indicators are also discussed. Additional indicators are needed that can be used to evaluate the performance of microeconomic contributors. The need for an integrated approach that links upstream resource issues and downstream waste issues through the 3Rs concept or the circular economy/society concept is attracting increasing attention. Consequently, the accumulation of reliable scientific knowledge and data in this field in a fully international context is essential.     

Study of Fatigue Life and Filler Interaction of Paper Sludge Filled Epoxidized Natural Rubber (ENR) and Maleated Natural Rubber (MNR) Composites

An investigation on the effect of epoxidation and maleated natural rubber (MNR) on fatigue and rubber-filler interaction properties of paper sludge filled natural rubber composites was elucidated. Paper sludge loading was varied from 0 to 40 phr and conventional vulcanisation system was used while compounding was carried out on a laboratory sized two roll mill. Two different types of natural rubber, SMR L and ENR 50 having 0 and 50 mole% of epoxidation were used in order to investigate the effect of epoxidation on the composites. Results indicate that, at a fixed filler loading, ENR 50 vulcanizates exhibit higher fatigue life than SMR L vulcanizates especially at filler loading below 20 phr which might be associated with better rubber-filler interaction. In the case of composites with the addition of maleated natural rubber (MNR), a higher fatigue life was observed due to presence of physical and/or chemical linkages, which increases the interfacial adhesion. Scanning electron microscopy (SEM) micrographs of fatigue fracture surfaces and rubber-filler interaction study supported the observed result on fatigue life.     

Biodegradation of Polycaprolactone Powders Proposed as Reference Test Materials for International Standard of Biodegradation Evaluation Method

Polycaprolactone (PCL) powders were prepared from PCL pellets using a rotation mechanical mixer. PCL powders were separated by sieves with 60 and 120 meshes into four classes; 0–125 μm, 125–250 μm, 0–250 μm and 250–500 μm. Biodegradation tests of PCL powders and cellulose powders in an aqueous solution at 25°C were performed using the coulometer according to ISO 14851. Biodegradation tests of PCL powders and cellulose powders in controlled compost at 58°C were performed by the Mitsui Chemical Analysis and Consulting Service, Inc. according to ISO 14855-1 and by using the Microbial Oxidative Degradation Analyzer (MODA) instrument according to ISO/DIS 14855-2. PCL powders were faster biodegraded than cellulose powders. The reproducibility of biodegradation of PCL powders is excellent. Differences in the biodegradation of PCL powders with different class were not observed by the ISO 14851 and ISO/DIS 14855-2. An enzymatic degradation test of PCL powders with different class was studied using an enzyme of Amano Lipase PS. PCL with smaller particle size was faster degraded by the enzyme. PCL powders with regulated sizes from 125 μm to 250 μm are proposed as a reference material for the biodegradation test.     

Application of magnetic field and iron in order to change medicinal products of <Emphasis Type="Italic">Ocimum basilicum</Emphasis>

In the present research, the effects of static magnetic field, with or without iron on the growth, the activity of certain enzymes (like polyphenol oxidase and phenyle alanine ammonialyase), the content of phenolic compounds and the essential oil composition of sweet basil (Ocimum basilicum) were studied. Treatment of plants with static magnetic field with or without iron led to decrease of the growth of plants as well as decrease in the activity of phenyle alanine ammonialyase and of phenolic compounds content. In addition in those plants exposed to magnetic field the amount of essential oils, notably of methyl chavicol, was increased. Exposure of plants to the magnetic field decreased the activity of polyphenol oxidase, whereas treatment of plants with iron when exposed to magnetic field increased polyphenol oxidase activity. In this group the content of essential oil was reduced.