Numerical investigation of flexible beams for electromagnetic energy harvesting under the wakes from upstream cylinder

The paper investigates the potential of flexible cantilever beams numerically for electromagnetic (EM) energy harvesting under the wakes from upstream cylinder. A two-dimensional fully coupled fluid–structure interaction model has been presented. The flow solver based on the Vortex Particle Method and the structural solver based on coro- tational finite element formulation are coupled to accurately account for the geometrically nonlinear effects of such very flexible elements. A reference flutter-based harvester is sim- ulated initially for the validation of the solver. The coupled solver is used furthermore to model the power output from the flexible cantilever beam under the wakes from the upstream circular cylinder, particularly, at low wind speeds like 2-4 m/s. Satisfactory results are achieved while the modeled energy outputs of the proposed harvester model are compared with the reference harvester

Urban Renewal Strategy for a Commercial Area: Case Study-Agrabad Commercial Area, Chittagong

Rapid urbanization is a currently a challenging problem for any developing country. To keep pace with the current population growth and ongoing economic development the cities are need to be expanded. But for a developing country, the territorial expansion of any city would be difficult for reducing the load, because of its economic and structural limitations. So for utilizing its limited resources fully, urban renewable strategy is preferable for every developing country. Renewable strategies increase the efficiency of the whole area & bolster economic force. Agrabad Commercial Area, CBD is the main business area in CHITTAGONG. In this study Commercial Business District (CBD) of Chittagong is taken as a case study and paper focuses on finding some suitable strategic proposals for it

Development of New Metrics and a Tool for Social Quantification of Sustainable Process Design

The concept of sustainable design has emerged as a new paradigm. Sustainability combines economic, environmental and social aspects of Process design. In our research all the available metrics, tools that are being used for social quantification with good definition, description and calculation methodology is reviewed. Then a new tool is proposed which considers both the inherent safety and occupational health quantification for sustainable process design. The method is tailored for the process research and development stage by including only such chemical properties and process operating conditions which are obtainable at early design stage. The approach is demonstrated for the two alternative processes of DME production and for the base case and optimized case Acrylonitrile production using simulation engine ASPEN PLUSTM . With the help of the developed standard index scale and the retrofitted SUSTAINABILITY EVALUATOR the best socially sustainable process design is assessed.Chemical Engineerin

A promising plasma-catalytic approach towards single-step methane conversion to oxygenates at room temperature

Direct conversion of methane into chemicals and fuels under mild conditions has been considered as a 'holy grail' of chemistry and catalysis in the 21st century. Plasma-catalytic partial oxidation of methane (POM) to higher-value liquid fuels and chemicals over supported transition metal catalysts (Ni/gamma-Al2O3, Cu/gamma-Al2O3 and Fe/gamma-Al2O3) has been investigated in a co-axial dielectric barrier discharge (DBD) reactor at room temperature and atmospheric pressure. The selectivity of oxygenates was 58.3% in the plasma POM reaction without a catalyst, while the combination of DBD with the catalysts enhanced the selectivity of oxygenates up to 71.5%. Of the three catalysts, Fe/gamma-Al2O3 showed the highest methanol selectivity of 36.0% and a significant methanol yield of 4.7%, while the use of Cu/gamma-Al2O3 improved the selectivity of C-2 oxygenates to 9.4%, which can be attributed to the presence of more acid sites on the surfaces of the Cu catalyst. The possible reaction pathways in the plasmacatalytic POM reaction have been explored by combined means of plasma electrical and optical diagnostics, analysis of gas and liquid products, as well as comprehensive catalyst characterization. The plausible reaction routes for the production of major oxygenate (methanol) on the Fe/gamma-Al2O3 surfaces have been proposed. The surface CHx species are found to be critical for methanol synthesis; they can be formed through the direct adsorption of CHx radicals generated in the plasma gas-phase reactions or through the dissociation of adsorbed CH4 on the catalyst surface

Ag@Ni Core-Shell Nanowire Network for Robust Transparent Electrodes Against Oxidation and Sulfurization

Silver nanowire (Ag NW) based transparent electrodes are inherently unstable to moist and chemically reactive environment. A remarkable stability improvement of the Ag NW network film against oxidizing and sulfurizing environment by local electrodeposition of Ni along Ag NWs is reported. The optical transmittance and electrical resistance of the Ni deposited Ag NW network film can be easily controlled by adjusting the morphology and thickness of the Ni shell layer. The electrical conductivity of the Ag NW network film is increased by the Ni coating via welding between Ag NWs as well as additional conductive area for the electron transport by electrodeposited Ni layer. Moreover, the chemical resistance of Ag NWs against oxidation and sulfurization can be dramatically enhanced by the Ni shell layer electrodeposited along the Ag NWs, which provides the physical barrier against chemical reaction and diffusion as well as the cathodic protection from galvanic corrosion

Sustainable approach of solid waste management of small urban area: case for Habiganj municipality in Bangladesh

Existing solid waste management system of Habibganj municipality (pourashava) of Bangladesh was studied. A total of 234 households were surveyed. Solid waste generation rate was found to be 0.36 kg/cap/day. Household waste disposal was one of the main problems across the city. Among the different options of waste disposal, 21.4% and 23.9% respondents generally threw their wastes into nearby ponds and drains, respectively. About 14.5% of the sampled households discarded their wastes in their respective compound and only 12% households used bins supplied by the municipality. About 10.7% households disposed their garbage on the roadside. Lack of awareness, lack of dustbins, and improper maintenance of drainage system and lack of drainage facilities were the main reasons of the current inadequacy of the management system as reported by 183 (78%) respondents. The results indicate that for a 200 MT capacity composting plant, safe distance will be about 800 m from the disposal site in terms of odorous impact, while 500 m for health impact. In this study, a sustainable management system of solid waste disposal is suggested for the Habibganj municipal area

Monitoring antimicrobial susceptibility of Neisseria gonorrhoeae isolated from Bangladesh during 1997- 2006: Emergence and pattern of drug-resistant isolates

Gonorrhoea is one of the most common sexually transmitted infections (STIs) in developing countries, and the emergence of resistance to antimicrobial agents in Neisseria gonorrhoeae is a major obstacle in the control of gonorrhoea. Periodical monitoring of antimicrobial susceptibility of N. gonorrhoeae is essential for the early detection of emergence of drug resistance. In total, 1, 767 gonococcal strains isolated from males and females (general population and those with high-risk behaviour) from different parts of Bangla-desh were studied during 1997- 2006 . Minimum inhibitory concentrations of penicillin, tetracycline, cipro-floxacin, ceftriaxone, spectinomycin, and azithromycin for the isolates were determined by the agar dilu-tion method. Isolates resistant to three or more antimicrobial agents are considered multidrug-resistant. The prevalence of plasmid-mediated penicillinase-producing N. gonorrhoeae (PPNG) and plasmid-mediated tetracycline-resistant N. gonorrhoeae (TRNG) was determined. Nine percent of the isolates were resistant to ciprofloxacin in 1997 compared to 87% in 2006. Multidrug-resistant N. gonorrhoeae have emerged in 1997 , and 44% of the strains (n= 66) isolated during 2006 were multidrug-resistant. Forty-two percent of the isolates in 2006 were both PPNG- and TRNG-positive compared to none in 1997 . The rapidly-changing pattern of gonococcal antimicrobial susceptibility warrants the need for an antimicrobial susceptibility-monitoring programme, and periodical analysis and dissemination of susceptibility data are essential to guide clinicians and for successful STI/HIV intervention programmes

Acetylene-Based Materials in Organic Photovoltaics

Fossil fuel alternatives, such as solar energy, are moving to the forefront in a variety of research fields. Organic photovoltaic systems hold the promise of a lightweight, flexible, cost-effective solar energy conversion platform, which could benefit from simple solution-processing of the active layer. The discovery of semiconductive polyacetylene by Heeger et al. in the late 1970s was a milestone towards the use of organic materials in electronics; the development of efficient protocols for the palladium catalyzed alkynylation reactions and the new conception of steric and conformational advantages of acetylenes have been recently focused the attention on conjugated triple-bond containing systems as a promising class of semiconductors for OPVs applications. We review here the most important and representative (poly)arylacetylenes that have been used in the field. A general introduction to (poly)arylacetylenes, and the most common synthetic approaches directed toward making these materials will be firstly given. After a brief discussion on working principles and critical parameters of OPVs, we will focus on molecular arylacetylenes, (co)polymers containing triple bonds, and metallopolyyne polymers as p-type semiconductor materials. The last section will deal with hybrids in which oligomeric/polymeric structures incorporating acetylenic linkages such as phenylene ethynylenes have been attached onto C60, and their use as the active materials in photovoltaic devices