Life Cycle Assessment on the Effects of Parameter Setting in Direct Recycling Hot Press Forging of Aluminum

2018 ◽  
Vol 923 ◽  
pp. 143-148 ◽  
Author(s):  
Mohd Amri Lajis ◽  
Nur Kamilah Yusuf ◽  
Azlan Ahmad

Metallic material processing plays a significant role in terms of global environmental impact which contributes to the climate change phenomena that is a serious international environmental concern and the subject of much research and debate. Thus, energy-and resource-efficient strategies in the metal shaping technology domain need to be identified urgently. A frequent theme in the debates that surround waste and resources management is the extent to which the recycling of metallic materials offers genuine benefits to the environment. Solid state recycling techniques allow the manufacture of high density aluminum alloy parts directly from production scrap. In this paper the environmental impacts associated with ‘meltless’ scrap processing routes through hot press forging process with varying parameter has been studied. A comparative analysis has been performed, with different operating temperature and holding time of direct recycling hot press forging process AA6061 aluminum chip. The importance of an environmental performance analysis that included both parameter setting was discussed and highlighted throughout the paper. Finally, the application of the proposed parameter setup has resulted in the setting up of an eco-process. Indeed, LCA study on recycling (solid-state) are recommended as well it gives a noteworthy benefit to the environment and to fill the knowledge gap.

2017 ◽  
pp. 527-537
Author(s):  
Aleksandra Ljustina

Migration is one of the oldest and most used strategies for overcoming negative social issues. Despite the fact that it is historically deeply rooted, environmental migration as a social phenomenon has only recently become the subject research of numerous scientific fields. However, the study of current environmental migration is characterized by a number of issues, such as absence of an adequate definition and multi-causality of environmental migration. In this paper, through conceptual framework, author analyzed two main questions: who are environmental migrants and what reasons cause environmental migration. Due to the destruction of the global environmental balance, as well as accumulated environmental disturbances, it is likely that environmental migration will increase in future and there is nowhere you cannot make more use of scientific and professional projection of the future than in demographic and environmental spheres of human life. There is no doubt that our future is unpredictable. However, the environmental factors influencing the pattern of human interaction with the environment must be taken into account when projecting future development of the modern society. Such is the context in which the complex relation among migration, change and the environment has to be studied. In order to establish the basis for controlling environmental migration caused by negative changes in the environment, it is necessary to adopt a consistent strategy instead of ad hoc activities that are being used. In this paper, author analyzed societal response for the challenges caused by environmental migration, specifically regarding actions related to governing environmental migrations.


2021 ◽  
pp. 0734242X2098205
Author(s):  
Katekanya Tadsuwan ◽  
Sandhya Babel

Plastic waste has become a global environmental concern. One type of plastic waste is microplastics (MPs), which can spread easily in the environment. Wastewater effluent is one of the land-based sources of MPs. This study investigates the amount of microplastic (MP) pollution in an urban wastewater treatment plant (WWTP) in Thailand. Water samples were collected and examined to find the types, morphology and sources of MPs. Wastewater was filtered through a set of sieves ranging from 5 mm to 0.05 mm. Sludge samples were also collected to find the potential risk from the application of dried sewage sludge. Fourier-transform infrared spectroscopy (FTIR) was used to confirm the types of MPs. The amount of MPs in the influent was 26.6 ± 11.8 MPs/L. More than one-third of MP particles were removed after a grit trap, followed by 14.24% removal in the secondary treatment. If the peak flow rate of the WWTP is reached, 2.32 × 109 MP particles can be released daily. The amount of MPs in a sludge sample was 8.12 ± 0.28 × 103 particles/kg dry weight. Dry sludge is one of the potential sources of MP contamination in agricultural soil. Most MPs in the liquid fraction and sludge sample were fibres. Results from FTIR analysis showed that the major types of MPs in the WWTP were polyester fibres, followed by polypropylene, polyethylene, silicone polymer and polystyrene. This finding indicates that a conventional WWTP may act as a path by which MPs enter the environment.


2012 ◽  
Vol 18 (2) ◽  
pp. 245-254 ◽  
Author(s):  
Biljana Angjusheva ◽  
Emilija Fidancevska ◽  
Vojo Jovanov

Dense ceramics are produced from fly ash from REK Bitola, Republic of Macedonia. Four types of fly ash from electro filters and one from the collected zone with particles < 0.063 mm were the subject of this research. Consolidation was achieved by pressing (P= 133 MPa) and sintering (950, 1000, 1050 and 11000C and heating rates of 3 and 100/min). Densification was realized by liquid phase sintering and solid state reaction where diopside [Ca(Mg,Al)(Si,Al)2O6] was formed. Ceramics with optimal properties (porosity 2.96?0.5%, bending strength - 47.01?2 MPa, compressive strength - 170 ?5 MPa) was produced at 1100?C using the heating rate of 10?C/min.


2015 ◽  
Vol 58 (1) ◽  
pp. 191-209 ◽  
Author(s):  
Joana Castro Pereira

Is it possible to talk about the rise of a new global (dis)order founded on the challenges posed by environmental issues? Through the review of the state of the art on the subject, this article analyzes the growing importance of the environment, and natural resources in particular, in international relations; and aims to raise awareness among International Relations scholars to the potential positive impact of the development of the discipline in integration with global environmental change studies.


2020 ◽  
Vol 217 ◽  
pp. 11004
Author(s):  
Galina Semenova

Air pollution is an environmental problem that is familiar to residents of absolutely all corners of the earth. It is especially acutely felt by residents of cities where enterprises of ferrous and non-ferrous metallurgy, energy, chemical, petrochemical, construction, pulp and paper industries operate. In some cities, the atmosphere is also severely poisoned by vehicles and boiler houses. These are all examples of anthropogenic air pollution. The subject of the study is the emissions of carbon dioxide into the environment. The purpose of the study is to solve the problem of environmental pollution by harmful substances and preserve the ecology in the world. Methodology. The main indicators characterizing the impact on the environment - CO2 emissions in the global energy sector - have been systematized; two indicators have been identified that determine the level of atmospheric pollution. Results - the scale of the influence of atmospheric air pollution on human health and the entire ecosystem as a whole was revealed.


2021 ◽  
Vol 22 (1) ◽  
pp. 117-122
Author(s):  
João Vitor Gobis Verges ◽  
Nivea Massaretto Verges

ResumoAs Alterações Ambientais Globais têm se colocado como pauta de inúmeras políticas e condicionantes culturais, econômicas e sociais em diferentes países no Mundo, sendo refletidas nas perspectivas educacionais. Dessa forma, procura-se, com este trabalho, apontar um cenário de concepção e de prática sobre as alterações ambientais globais no escopo do ensino de Geografia na educação profissional e tecnológica. Nesse sentido, o objetivo da pesquisa se assentou em desvelar os seguintes aspectos: 1) mecanismos metodológicos para as aulas desenvolvidas; 2) eixos analíticos sobre as Alterações Ambientais Globais; 3) instrumentos utilizados; 4) referenciais teóricos; 6) papel do livro didático; 7) enfoques formativos dos docentes. Para isto, foi aplicado um questionário a docentes de uma instituição da rede federal de educação profissional e tecnológica no Brasil, denominada Instituto Federal de Educação, Ciência e Tecnologia. O questionário foi empregado para 11 docentes, apresentando interrogações sobre os itens acima enumerados. Obteve-se como resultado que há o predomínio de aulas expositivas e seminários, as análises sobre o tema ocorrem, majoritariamente, pelas mudanças climáticas e desmatamento, as aulas se baseiam em maior parte nos documentários e gráficos, há a prevalência de referenciais teóricos brasileiros, ocorre a constatação ampla de que os livros didáticos são deficitários e mais de 35% dos professores consideram que suas formações não possuem enfoque para o trabalho com as Alterações Ambientais Globais. Palavras-chave: Prática Docente. Meio Ambiente. Didática. AbstractGlobal Environmental Changes have been placed on the agenda of numerous policies, cultural, economic and social conditions in different countries in the world, being reflected in educational perspectives. Thus, this work seeks to point out a scenario of conception and practice on global environmental changes in the scope of teaching Geography in professional and technological education. In this sense, the objective of the research was based on unveiling the following aspects: 1) methodological mechanisms for the developed classes; 2) analytical axes on Global Environmental Changes; 3) instruments used; 4) theoretical references; 6) the textbook role; 7) teachers training approaches. For this, a questionnaire was applied to teachers of an institution of the federal network of professional and technological education in Brazil, called Federal Institute of Education, Science and Technology. The questionnaire was answered by 11 teachers, asking questions about the items listed above. It was obtained as a result that there is a predominance of expository classes and seminars, the analyzes on the subject are mainly due to climate change and deforestation, the classes are mostly based on documentaries and graphics, there is a prevalence of Brazilian theoretical references, it occurs the widespread finding that textbooks are deficient and more than 35% of teachers consider that their training does not have a focus on working with Global Environmental Changes. Keywords: Teacher Practice. Environment. Didactic.


Toxins ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 507 ◽  
Author(s):  
Linghui Cao ◽  
Isaac Yaw Massey ◽  
Hai Feng ◽  
Fei Yang

The mortality rate of cardiovascular diseases (CVD) in China is on the rise. The increasing burden of CVD in China has become a major public health problem. Cyanobacterial blooms have been recently considered a global environmental concern. Microcystins (MCs) are the secondary products of cyanobacteria metabolism and the most harmful cyanotoxin found in water bodies. Recent studies provide strong evidence of positive associations between MC exposure and cardiotoxicity, representing a threat to human cardiovascular health. This review focuses on the effects of MCs on the cardiovascular system and provides some evidence that CVD could be induced by MCs. We summarized the current knowledge of the cardiovascular toxicity of MCs, with regard to direct cardiovascular toxicity and indirect cardiovascular toxicity. Toxicity of MCs is mainly governed by the increasing level of reactive oxygen species (ROS), oxidative stress in mitochondria and endoplasmic reticulum, the inhibition activities of serine/threonine protein phosphatase 1 (PP1) and 2A (PP2A) and the destruction of cytoskeletons, which finally induce the occurrence of CVD. To protect human health from the threat of MCs, this paper also puts forward some directions for further research.


1795 ◽  
Vol 85 ◽  
pp. 270-289 ◽  

Having already investigated the means of producing artificial cold, and at the conclusion of my last paper (on the congelation of quicksilver) dismissed that part of the subject, the best method of making use of those means naturally becomes a desideratum ; to that therefore I have lately given my attention, and flatter myself that the following observations may be considered as an useful appendix to my former papers. The freezing point of quicksilver being now as determined a point on the scale of a thermometer, viz .— 39°, as the freezing point of water ; and as this metal, exhibited in its solid state, affords an interesting as well as curious phænomenon ; I shall apply what I have to say principally to that object. Frequent occasions having occurred to me of observing the superiority of snow, in experiments of this kind, to salts, even in their fittest state, that is, fresh crystallized, and reduced to very fine powder, I resolved upon adopting a kind of artificial snow.


1988 ◽  
Vol 9 (1-3) ◽  
pp. 155-170 ◽  
Author(s):  
Arthur J. Sedlacek ◽  
Charles A. Wight

In this article, we review recent work in the authors' laboratory on the subject of free radical chain reactions of chlorine with small hydrocarbons in amorphous solids. The solids are formed as thin films by spray deposition of the gaseous reagents onto a cryogenic window. Reactions are initiated by excimer laser photolysis at 308 nm, which dissociates a small fraction of the chlorine molecules to atoms. Product yields and branching ratios are determined by infrared absorption spectroscopy. Reactions of chlorine with cyclopropane or cyclobutane proceed by true chain reactions, as evidenced by high product quantum yields (number of product molecules formed per laser photon absorbed by the sample). Measurements of the dependence of the product yield on the relative concentrations of chlorine and hydrocarbon provide clues to the reaction mechanism in the solid state. The cyclobutane reaction appears to involve H atom transfer from cyclobutane to cyclobutyl radical as an intermediate step in the overall reaction. Reaction of chlorine with propane, n-butane, or isobutane does not appear to involve chain propagation and is dominated by radical recombination processes which result in low quantum yields. All of these results are discussed in terms of reactions which occur in a solid state environment where molecular motion is severely restricted.


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