Material flow analysis as a tool for environmental sanitation planning in Viet Tri, Vietnam

New environmental sanitation approaches must be developed in response to the need for more sustainable water and nutrient management. This paper illustrates how the method of Material Flow Analysis (MFA) can be applied to assess measures aiming at optimizing nitrogen recovery through improved excreta management in Viet Tri, Vietnam. The purpose of this paper is to identify how the application of MFA could be rendered more affordable for planners and decision-makers in developing countries confronted with poor data availability and quality. The analysis of the Viet Tri case indicates that a tool containing a database and assisting MFA users in determining which parameters should be determined with which accuracy (sensitivity analysis) would enable planners to optimise their data collection plan. This would help planners with limited means apply MFA as time requirement and cost for data collection would be reduced

DEVELOPMENT OF FIBER REINFORCED POLYMER COMPOSITE LEAF SPRINGS

Bu çalışmanın amacı polimer kompozit yaprak yaylarda günümüze kadar olan gelişmeleri ele almak ve yapılacak yeni çalışmalara yol göstermektir. Kompozit malzemeler konusundaki araştırmaların ilerlemesi ile yaprak yayların fiber takviyeli polimer kompozit malzemelerden üretilmesine yönelik çalışmalar yapılmıştır. Bu çalışmalar neticesinde çelik yaprak yaylara nazaran polimer kompozit yaprak yaylar % 85'e varan hafiflik, daha yüksek yorulma ömrü, korozyona karşı yüksek direnç ve yüksek doğal frekans gibi avantajlara sahip olarak üretilebilmiştir. Bu makalede, polimer kompozit yaprak yaylar ile ilgili yapılmış olan önemli çalışmalar değerlendirilmiş ve yapılacak yeni çalışmalara yol gösterilmiştir Aim of this study to review development of composite leaf springs and to sign new investigations. Knowing the composite materials in detail by improved studies, design attempts for fiber reinforced composite leaf springs are being increased. Fiber reinforced polymeric composite leaf springs produced with advantages of 85% weight reduction, improved fatigue life, better corrosion resistance and high natural frequency than steel leaf springs. In this paper important studies on polymeric composite leaf springs are reviewed and further studies announce

Characterization of Environmental Solids and Surfaces

The characterization of the solid phase is one of the first steps in the study of any of the myriad of environmental reactions that involve solids and solid-liquid interfaces. Environmental solids range from relatively pure and crystalline phases to heterogeneous and multiphasic particle aggregates whose characterization requires a combination of a number of analytical methods and methodologies. The first section of this paper gives a cross section of general strategies used in different departments at EAWAG for the characterization of field samples of both natural and anthropogenic origin. The morphological characterization and the determination of the chemical composition is described in respect to the properties of anthropogenic solids. As an example, the long-term behavior of incinerator bottom ash is discussed in a case study. A second section gives two examples of molecular level studies on environmental solids: application of Extended X-Ray Absorption Fine Structure (EXAFS) spectroscopy for the characterization of poorly crystallized manganese lake particles in the context of the genesis of lake sediments, and in situ Atomic Force Microscopy (AFM) and Fourier Transform Infrared (FTIR) studies on synthetic goethite particles during the oxidation of FeII and the reduction of CrVI

TO MINIMIZE WARPAGE IN PLASTIC INJECTION PARTS BY TAGUCHI METHOD

Bu makalenin amacı Taguchi metodu kullanılarak plastik parçaların üretiminde etkili olan; farklıürün tasarımı, giriş sayısı, giriş ölçüleri ve yolluk tasarımı parametreleri ile üründe oluşan çarpılmanınen aza indirilmesidir. Kontrol parametreleri olarak ürün tasarımı, giriş sayısı, giriş ölçüleri, yolluktasarımı kullanılmış ve deney kalıbı tasarlanıp imal edilmiştir. Kalıp imalatı sonrasında çarpılmadeğerlerinin elde edilmesi için üretilen kalıp kullanılarak plastik enjeksiyon yöntemiyle üretimyapılmıştır. Plastik malzeme olarak polipropilen (PP) Petoplen MH220 kullanılmıştır. Kalıp tasarımıaşamasında ve çarpılma değerlerinin kullanılmasında üç seviyeli deney tasarımına dayanan Taguchimetodu kullanılmıştır. Taguchi'nin ortogonal dizini, Sinyal/Gürültü (S/G) oranı ve varyans analiziçarpılmayı etkileyen kontrol parametrelerinin optimum seviyelerini bulmak için kullanılmıştır. Kontrolparametrelerinin optimum seviyeleri ile yapılan doğrulama testi sonuçları plastik enjeksiyon kalıplamaişleminde çarpılmaların azaltılmasında Taguchi Metodunun uygun bir metot olduğunu göstermiştir. The objective of this paper consist of minimization of the warpage in terms of process parametersof the plastic parts have different product design, gate numbers, gate dimensions, runner design usingTaguchi method. A mold designed and manufactured considering the control parameters such asproduct design, gate numbers, gate dimensions, runner design. After mold manufacturing, plasticparts manufactured by plastic injection molding process in this tool to exploite the warpage data. Thepolymeric material is selected polypropylene (PP) Petoplen MH 220. Taguchi method was used tomold design stage and exploiting warpage data based on three level of experimental design.Orthogonal arrays of Taguchi, the signal-to-noise (S/N) ratio, the analysis of variance (ANOVA) areutilized to find the optimal levels and the effect of control parameters on warpage. Confirmation testwith the optimal levels of control parameters are shown that the Taguchi method is very suitablemethod for minimization of warpage at plastic injection molding process.

Predicting youth participation in urban agriculture in Malaysia: insights from the theory of planned behavior and the functional approach to volunteer motivation

This study examines factors associated with the decision of Malaysian youth to participate in a voluntary urban agriculture program. Urban agriculture has generated significant interest in developing countries to address concerns over food security, growing urbanization and employment. While an abundance of data shows attracting the participation of young people in traditional agriculture has become a challenge for many countries, few empirical studies have been conducted on youth motivation to participate in urban agriculture programs, particularly in non-Western settings. Drawing on the theories of planned behavior and the functional approach to volunteer motivation, we surveyed 890 students from a public university in Malaysia about their intention to join a new urban agriculture program. Hierarchical regression findings indicated that the strongest predictor of participation was students’ attitude toward urban agriculture, followed by subjective norms, career motives and perceived barriers to participation. The findings from this study may provide useful information to the university program planners in Malaysia in identifying mechanisms for future students’ involvement in the program

Biofuel production using thermochemical conversion of heavy metal-contaminated biomass (HMCB) harvested from phytoextraction process

Over the past few decades, bioenergy production from heavy metal-contaminated biomasses (HMCBs) has been drawing increasing attention from scientists in diverse disciplines and countries owing to their potential roles in addressing both energy crisis and environmental challenges. In this review, bioenergy recovery from HMCBs, i.e. contaminated plants and energy crops, using thermochemical processes (pyrolysis, gasification, combustion, and liquefaction) has been scrutinized. Furthermore, the necessity of the implementation of practical strategies towards sustainable phytoextraction and metal-free biofuels production has been critically discussed. To meet this aim, the paper firstly delivers the fundamental concepts regarding the remediation of the brownfields using phytoremediation approach, and then, reviews recent literature on sustainable phytoextraction of heavy metals from polluted soils. Thereafter, to find out the possibility of the cost-efficient production of metal-free biofuels from HMCBs using thermochemical methods, the impacts of various influential factors, such as the type of feedstock and metals contents, the reactor type and operating conditions, and the role of probable pre-/post-treatment on the fate of heavy metals and the quality of products, have also been discussed. Finally, based on relevant empirical results and techno-economic assessment (TEA) studies, the present paper sheds light on pyrolysis as the most promising thermochemical technique for large-scale electricity and heat recovery from HMCBs