1,720,965 research outputs found
Investigations into the utilisation of chicken litter for power generation
Full text linkThis thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonChicken litter is commonly used as bio fertilizer or soil ameliorant due to its high content of nutritional components such as nitrogen (N), phosphorus (P) and potassium (K). Oversupply of chicken litter to land, however, may cause problems due to the built-up of excessive nitrogen which oxidises, forming nitrates and ammonia compounds. The highly concentrated nitrates can contaminate both surface water and groundwater, which are sources of drinking water. Evaporation of ammonia also causes odour problems in the surrounding areas. With fast increasing chicken production, and limits on the use of chicken litter as fertilizer on local farms an alternative utilisation approach is the use of chicken litter for energy production. Energy production from chicken litter is of particular interest in developing countries where electricity supply from the grid may not be existent or is highly unreliable.
Possible technologies for the conversion of chicken litter to energy are combustion, anaerobic digestion, gasification and pyrolysis. Literature review of these methods has indicated that considering energy conversion efficiency, economic and environmental factors, pyrolysis can be a suitable method for application in developing countries such as Indonesia. For this reason, this thesis focuses on pyrolysis and its potential to produce char, syngas and bio oil yield.
Three types of pyrolysis have been studied. These include: slow pyrolysis in the temperature range 350°C - 450°C, intermediate pyrolysis at the temperature range 500°C -700°C and fast pyrolysis in the temperature range 400oC – 600oC. The types of chicken litter used as the feedstock in slow pyrolysis were hay mix (chicken manure + hay), straw mix (chicken manure + straw), rice husk mix (chicken manure + rice husk), wood shavings mix (chicken manure + wood shavings). For the intermediate pyrolysis, fresh chicken litter (FCL) from Ireland and pelletized chicken litter (PCL) from Finland were used. For the fast pyrolysis experiments, only PCL was used.
The result of the chicken litter pyrolysis experiments showed that the dominant product was char in the slow pyrolysis, liquid (bio-oil) in the intermediate pyrolysis and gas (syngas) in the fast pyrolysis. In addition to the experiments, simulations were performed using Aspen plus, to determine the maximum amount of electric energy that can be generated from the pyrolysis of chicken litter. The simulations were based on chicken litter from a farm with a production of 400,000 birds/batch. Liquid yield was determined from the experiments to have the highest calorific value, and thus, the simulations were performed using the parameters and results from the experiment that generated the highest level of liquid yield-this was the FCL pyrolysis at temperature of 500 °C.
The simulation revealed that the heat from the combustion (burning) of all gas yield plus 35% of char yield would be sufficient to serve as the heat input for pyrolysis process. The heat from combustion of the liquid yield was then used as the energy input to an ORC system to generate electrical power. The results showed that the system with could produce electrical output of around 150 kW with an overall conversion efficiency of 6.5%. Economic analysis using the Net Present Value (NPV) methodology and investment conditions in Indonesia has shown that, assuming all the electrical energy generated and 65% of the char yield is sold, the system would produce a return on investment of 9 years. Improvements in ORC efficiency and reduction of capital cost as well as reduction in interest rates (currently 12% in Indonesia) is expected to lead to increased return on investment and improved viability of these systems for both energy security and reduction of environmental impacts in developing countries.Government of Indonesia through the Ministry of Education and Culture and Politeknik Negeri Bandung. Centre for Sustainable Energy Use in Food Chains (CSEF) through RCUK Grant No. EPSRC Grant ref EP/K011820/
Pemanfaatan Biogas sebagai Sumber Energi Penghasil Energi Pendinginan, Energi Listrik dan Energi Pemanasan - Studi Fisibilitas
Full text linkWalaupun menjadi salah satu sumber polusi yang cukup tinggi, penggunaan bahan bakar fosil sebagai sumber energi masih menjadi yang dominan jika dibandingkan dengan jenis sumber energi yang lain. Selain itu, permasalahan yang terjadi saat ini adalah produksi bahan bakar fosil tidak sebanding dengan permintaan yang terus meningkat. Guna menurunkan dampak negatif dari penggunaan bahan bakar fosil, penggunaan energi yang ramah lingkungan terus dikembangkan, salah satunya adalah yang digunakan pada penelitian saat ini, yaitu pemanfaatan biogas sebagai sumber energi pendinginan, energi listrik dan energi pemanasan atau yang dikenal dengan trigeneration energy. Metoda yang digunakan adalah dengan cara memanaskan fluida dengan bahan bakar biogas, lalu fluida panas dialirkan ke sistem refrigerasi sistem absorpsi dan sistem pembangkit listrik TEG (thermoelectric generator). Berdasarkan hasil perhitungan, pemanasan fluida menggunakan biogas membutuhkan energi sebesar 615 watt. Kemudian besaran energi ini digunakan untuk sistem pendingin absorpsi dan TEG yaitu berturut-turut 70 dan 397 watt. Sisa energi sebesar 148 watt dapat digunakan untuk energi pemanasan. Ketika energi pemanasan tidak digunakan, maka energi dari fluida panas (615 watt) dapat seluruhnya digunakan atau di maksimalkan untuk pembangkitan energi pendinginan dan energi listrik. Keywords:
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Comparison of Utilization an Absorption and Vapour Compression Chiller in Sub-Tropical Country Building – A Feasibility Study
Full text linkThe present study investigate the feasibility of absorption chiller utilization as part of trigeneration system that possibly applied in sub-tropical country building. Trigeneration is refer to the heat utilisation from electric generator (combined heat and power, CHP) to generate absorption chiller in order to produce chilled water for air conditioning system (combined cooling, heat and power, CCHP). Compare to the vapour compression system, absorption chiller that is mainly generated by heat waste, promised benefit economically and environmentally. Overall efficiency of CCHP can reach 71 % and possibly reducing emission until 146709.07 kg CO2. Economic analysis using the Payback period methodology has shown that the CCHP would produce a return on investment of 2.6 years. Improvements absorption chiller and support from government are expected to lead to increased return on investment and improved viability of the system
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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