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Nazli Yesiller James L. Hanson Jason T. Cox Danielle E. Noce 《Waste management (New York, N.Y.)》2014,34(5):848-858
This investigation was conducted to evaluate experimental determination of specific gravity (Gs) of municipal solid waste (MSW). Water pycnometry, typically used for testing soils was adapted for testing MSW using a large flask with 2000 mL capacity and specimens with 100–350 g masses. Tests were conducted on manufactured waste samples prepared using US waste constituent components; fresh wastes obtained prior and subsequent to compaction at an MSW landfill; and wastes obtained from various depths at the same landfill. Factors that influence specific gravity were investigated including waste particle size, compaction, and combined decomposition and stress history. The measured average specific gravities were 1.377 and 1.530 for as-prepared/uncompacted and compacted manufactured wastes, respectively; 1.072 and 1.258 for uncompacted and compacted fresh wastes, respectively; and 2.201 for old wastes. The average organic content and degree of decomposition were 77.2% and 0%, respectively for fresh wastes and 22.8% and 88.3%, respectively for old wastes. The Gs increased with decreasing particle size, compaction, and increasing waste age. For fresh wastes, reductions in particle size and compaction caused occluded intraparticle pores to be exposed and waste particles to be deformed resulting in increases in specific gravity. For old wastes, the high Gs resulted from loss of biodegradable components that have low Gs as well as potential access to previously occluded pores and deformation of particles due to both degradation processes and applied mechanical stresses. The Gs was correlated to the degree of decomposition with a linear relationship. Unlike soils, the Gs for MSW was not unique, but varied in a landfill environment due both to physical/mechanical processes and biochemical processes. Specific gravity testing is recommended to be conducted not only using representative waste composition, but also using representative compaction, stress, and degradation states. 相似文献
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The purpose of this paper is to conceptualize the hitherto separate domains of Cyberspace and International Relations into an integrated socio-technical system that we jointly call the cyber International Relations (Cyber-IR) system and to identify and analyze its emergent properties utilizing the methods common to science and engineering systems adapted here for the social sciences. Our work is an exploration in both theory and methodology. This paper (a) identifies the actors and functions in the core systems, Cyberspace, and IR, (b) disambiguates system boundary, (c) creates a design structure matrix (DSM), a matrix of the interdependencies among functions of actors, (d) analyzes DSM qualitatively to show multiple interdependent and heterogeneous Cyber-IR properties, and (e) analyzes quantitatively the differential importance of core functions as well as the impact of actor attributes on influence in Cyber-IR. This work forms a baseline for further understanding of the nature of the heterogeneous influences of the various actors and the various outcomes that could result from it. 相似文献
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Zeinab Jamalzadeh Mohammad Haghighi Nazli Asgari 《Frontiers of Environmental Science & Engineering》2013,7(3):365-381
In this work, xylene removal from waste gas streams was investigated via catalytic oxidation over Pd/carbon-zeolite and Pd/carbon-CeO2 nanocatalysts. Activated carbon was obtained from pine cone chemically activated using ZnCl2 and modified by H3PO4. Natural zeolite of clinoptilolite was modified by acid treatment with HCl, while nano-ceria was synthesized via redox method. Mixed supports of carbon-zeolite and carbonceria were prepared and palladium was dispersed over them via impregnation method. The prepared samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller surface area (BET), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric (TG) techniques. Characterization of nanocatalysts revealed a good morphology with an average particle size in a nano range, and confirmed the formation of nano-ceria with an average crystallite size below 60 nm. BET analysis indicated a considerable surface area for catalysts (~1000 m2·g?1). FTIR patterns demonstrated that the surface groups of synthesized catalysts are in good agreement with the patterns of materials applied in catalyst synthesis. The performance of catalysts was assessed in a low-pressure catalytic oxidation pilot in the temperature range of 100° C-250°C. According to the reaction data, the synthesized catalysts have been shown to be so advantageous in the removal of volatile organic compounds (VOCs), representing high catalytic performance of 98% for the abatement of xylene at 250°C. Furthermore, a reaction network is proposed for catalytic oxidation of xylene over nanocatalysts. 相似文献
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Akça I Kutluk Yilmaz ND Kizilkaya R 《Journal of environmental science and health. Part. B》2005,40(2):285-296
Beet soilborne pomovirus (BSBV) is an important soilborne virus disease in growing areas of sugar beet. BSBV was transmitted by Polymyxa betae Keskin. Effects of azadirachtin on BSBV and soil biological properties were studied under a greenhouse. The presence of BSBV was tested in soil samples using bait plant test and triple antibody sandwich-enzyme-linked immunosorbent assay (TAS-ELISA). The concentration of BSBV in sugar beet roots was significantly reduced by the application of azadirachtin to the soils. TAS-ELISA absorption values in 1.52, 3.04, and 7.60 ppm were lower than that 0.38 and 0.76 ppm of azadirachtin. Furthermore, in this study, it was determined the 0.38, 0.76, and 1.52 ppm doses of azadirachtin in soils had high amounts of soil biological properties (Cmic, BSR, DHA), while the 3.04 and 7.60 ppm doses had no statistical significance compared to the control treatments. 相似文献
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James L. Hanson Nazli Yeşiller Michael T. Onnen Wei-Lien Liu Nicolas K. Oettle Janelle A. Marinos 《Waste management (New York, N.Y.)》2013,33(10):1993-2000
A numerical modeling approach has been developed for predicting temperatures in municipal solid waste landfills. Model formulation and details of boundary conditions are described. Model performance was evaluated using field data from a landfill in Michigan, USA. The numerical approach was based on finite element analysis incorporating transient conductive heat transfer. Heat generation functions representing decomposition of wastes were empirically developed and incorporated to the formulation. Thermal properties of materials were determined using experimental testing, field observations, and data reported in literature. The boundary conditions consisted of seasonal temperature cycles at the ground surface and constant temperatures at the far-field boundary. Heat generation functions were developed sequentially using varying degrees of conceptual complexity in modeling. First a step-function was developed to represent initial (aerobic) and residual (anaerobic) conditions. Second, an exponential growth-decay function was established. Third, the function was scaled for temperature dependency. Finally, an energy-expended function was developed to simulate heat generation with waste age as a function of temperature. Results are presented and compared to field data for the temperature-dependent growth-decay functions. The formulations developed can be used for prediction of temperatures within various components of landfill systems (liner, waste mass, cover, and surrounding subgrade), determination of frost depths, and determination of heat gain due to decomposition of wastes. 相似文献
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Raguraj Sriharan Kasim Susilawati Jaafar Noraini Md Nazli Muhamad Hazim Amali Rathnasekara Kuruppu Arachchige 《Environmental science and pollution research international》2022,29(40):60631-60640
Environmental Science and Pollution Research - Emerging demand for humic substances escalated the short supply of coal-related resources from which humic substances are extracted in large... 相似文献