1,720,970 research outputs found
Characterization of Post-Mining Soil and Solid Waste from Silica Sand Purification
No full textPost-mining soil and solid waste from the silica sand refining industry is widespread and the potential long-term impact of toxic metals and metalloids is a significant and under-appreciated issue. This study presents the characteristics of post-mining soil and solid waste resulting from silica sand purification to observe its physical, chemical, and biological composition. Analysis of the physical properties was carried out with reference to ASTM 112-10 and the results show that post-mining soil contains 36.95% sand, 18.80% clay, and 42.74% silt, with coefficients of permeability and porosity of 0.69×10-6 cm•s-1 and 35.84%, respectively. Meanwhile, the solid waste contains 43.35% sand, 35.96% clay, and 20.68% silt with coefficients of permeability and porosity of 1.49×10-6 cm•s-1 and 51.12%. The overall mineralogy and morphology of both samples showed that they have the same chemical composition as gehlenite (Ca2Al2SiO7), spinel (MgAl2O4), akermanite (Ca2MgSi2O7), monticellite (CaMgSiO4), aluminum oxide (Al2O3), magnetite (Fe3O4), and hematite (Fe2O3) supports this data. The chemical composition of both samples is SiO2, Al2O3, CaO, and MgO, but the post-mining soil has lower heavy metal and nutrient contents compared to solid waste. Meanwhile, solid waste has a high content of heavy metals and nutrients due to washing and bonding from the silica sand purification process. The abundance of bacteria (Colony Forming Unit) for the 10-4 and 10-5 dilutions in post-mining soil was 1.59×103and not detected, while in the solid waste, 4.10×105 and 1.64×105 were found, respectively. This study can be used as base values for modifying the two samples, which can be applied in mining land reclamation
Comparing Life Cycle Assessment of Fish Preservation Method on Fishing Vessels in Indonesia
Get PDF\ua9 Published under licence by IOP Publishing Ltd.The economic benefit that the fishermen can obtain primarily depends on the quality of their catches. Therefore, it is essential to ensure that the caught fish stays fresh until entering the market. The most common fish preservation on traditional fishing boats in Indonesia is block ice, which must be carried in the fish hold from the home port. In comparison, another alternative method for fish preservation is the Flake Ice machine that can produce ice on-board. The study on Life Cycle Assessment (LCA) was conducted on these two fish preservation methods to understand the environmental impact of each technique. For undertaking the assessments, LCA software known as SimaPro was employed. The system boundary for the LCA about fish preservation applied the "well to wheels"approach and covered the whole service life of the vessel for the full consecutive 20 years of operation. The functional unit for the assessment was fish preservation of 4 tonnes during a 7-day fishing trip. The input of the evaluation was the materials and energy required to produce the amount of ice or to operate a refrigeration system for each year of the vessel\u27s operation, with a total of 30 trips per year. The paper explored the environmental impact of these two fish preservation methods in terms of Ozone Layer Depletion and Global Warming
Evaluation Of Landfill Management At Gunung Kupang Landfill, Banjarbaru City
No full textBanjarbaru City is the capital city of South Kalimantan Province with waste generation in 2023 of 67,854,410 kg/year. Based on the Banjarbaru City Waste Masterplan for 2021-2025 supported by Banjarbaru City Regulation No. 5 of 2023, one strategy to reduce the amount of waste dumped in landfills is the optimization and development of waste infrastructure including landfills. Waste management at the Gunung Kupang Landfill has not been optimal when viewed from the capacity of waste management. One strategy in the policy of 'Increasing Service Coverage and Quality of Management Systems' in the Masterplan is the rehabilitation of landfills that pollute the environment. Before the landfill was decided to be rehabilitated, an evaluation was carried out using the ARRPET (Asian Regional Research Program on Environmental Technology) method. An overall evaluation of the existing conditions at the Gunung Kupang Landfill has never been carried out so it needs to be carried out using the ARRPET method. The results of the environmental evaluation of the existing conditions of the Gunung Kupang Landfill with ARRPET produced a risk index score of 529.24. This value is included in the risk index with a moderate category so that the recommended follow-up is to rehabilitate the landfill into a sustainable landfill as soon as possible. Therefore, it is planned to build a methane gas installation and landfill mining in landfill zone 2 as a rehabilitation method so that the potential for environmental pollution can be minimized and the life of the landfill can be extended. Based on the evaluation results, the rehabilitation method is feasible to be carried out where the NPV of both rehabilitation methods is positive and the BCR is more than 1
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
EFFECT OF pH ON LIQUID-PHASE MASS TRANSFER AND DIFFUSIVITY COEFFICIENT AT LEACHATE TREATMENT OF MUNICIPAL WASTE LANDFILL IN ANAEROBIC BIOREACTOR
Get PDFLeachate is a liquid waste resulted from physical, biological and chemical decomposition of landfill waste. Leachate contains complex dissolved organic and anorganic substrate which are biodegradable and non-biodegradable. Anaerobic treatment principally utilizes anaerobic bacteria in order to degrade the dissolved organic substance into biogas. Anaerobic treatment is very sensitive towards the substrate cocentration, temperature, and pH. This research used anaerobic bioreactor with the volume of 160 L, the ratio of the leachate: biogas is 70:30. Seeding and acclimatization steps were done, respectively for 10 days, leachate treatment was done in 21 days. Seeding, acclimatization, and leachate treatment were done on the pH ambience of 7.2 and 8.0 and ambient temperature. COD and VFA analysis were done every two days. The objective of this research is to decide the pH effect on the coefficient of liquid-phase mass transfer: kL, and the diffusivity of the dissolved substace, DL. pH affects the degradation of the concentratio of dissolved organic substrate in the leachate. The higher the pH is, the higher the obtained VFA concentration is. VFA concentration is affected by pH; however, it still considers the optimal pH condition of the substrate biodegradation. pH affects the average rate of mass transfer, rkL and diffusivity of the dissolved substance, DL in the anaerobic treatment of leachate. pH affect the concentration of dissolved organic substrate which subsequently influenes the coefficient of liquid-phase mass transfer of the leachate, kL and the diffusivity of the dissolved substance, DL. The higher the pH is, the more increasing the kL is and the more decreasing the DL is
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
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