scholarly journals Zeolites application in terrestrial and space industry – a review

2020 ◽  
Vol 32 ◽  
pp. 209-223
Author(s):  
Adelina Miteva ◽  
Valeria Stoyanova

This brief overview presents an attempt to systematize some of the available historical and recent data on the impact of zeolite science and engineering on the progress of various areas of Earth and Space development. The basic structural and chemical properties of natural and synthetic zeolites are presented. Valuable applications of the zeolites, such as catalysts, gas adsorbers and ion exchangers are also included. The most commonly used methods for the synthesis of zeolites from different materials are presented, as well as some Bulgarian developments for the reuse of waste materials to zeolites. The important role of zeolites as an indispensable material for improving the quality of soil, fuels, water, air, etc., required for the needs of orbiting space stations and spacecrafts has been confirmed by typical examples.

2013 ◽  
Vol 801 ◽  
pp. 35-40
Author(s):  
Marián Bujna ◽  
Miroslav Prístavka ◽  
Pavol Kaplík

Thermal spraying influences several physical and chemical properties of the coating surface. The most important of them are hardness, density, porosity, corrosion resistance and adhesion. This technology of surface treatment of material is often used for its high degree of hardness. Hardness and erosion resistance are the parameters that need to be achieved particularly in working conditions where there is excessive component wear. In this paper, we deal with the impact of purifying on the quality of molybdenum layer. Insufficient cleaning may result in a poor quality of the sprayed layer. Our aim is to measure and analyse the quality of molybdenum layer thickness applied by thermal spraying after insufficient cleaning.


Author(s):  
Marián Bujna ◽  
Miroslav Prístavka ◽  
Petr Dostál ◽  
Maroš Korenko ◽  
Milan Kadnár

In this paper we deal with the impact of roughness on the quality of molybdenum layer. Insufficient cleaning may result in a poor quality of the sprayed layer. Our aim is to analyze the influence of surface roughness on the quality of molybdenum layer thickness applied by thermal spraying. Thermal spraying influence several physical and chemical properties of the coating surface. The most important ones include: hardness, density, porosity, corrosion resistance and adhesion. This technology of surface treatment of material is often used for its high degree of hardness. Hardness and erosion resistance are the parameters that need to be achieved particularly in working conditions where there is excessive depreciation of a component.


2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.


2020 ◽  
Author(s):  
Tulin Okbinoglu ◽  
Pierre Kennepohl

Molecules containing sulfur-nitrogen bonds, like sulfonamides, have long been of interest due to their many uses and chemical properties. Understanding the factors that cause sulfonamide reactivity is important, yet their continues to be controversy regarding the relevance of S-N π bonding in describing these species. In this paper, we use sulfur K-edge x-ray absorption spectroscopy (XAS) in conjunction with density functional theory (DFT) to explore the role of S<sub>3p</sub> contributions to π-bonding in sulfonamides, sulfinamides and sulfenamides. We explore the nature of electron distribution of the sulfur atom and its nearest neighbors and extend the scope to explore the effects on rotational barriers along the sulfur-nitrogen axis. The experimental XAS data together with TD-DFT calculations confirm that sulfonamides, and the other sulfinated amides in this series, have essentially no S-N π bonding involving S<sub>3p</sub> contributions and that electron repulsion and is the dominant force that affect rotational barriers.


2020 ◽  
pp. 137-149
Author(s):  
Krzysztof Szewior

The author focuses on the manner and effects of German higher education reforms that have changed the model of university management. The point of reference is the quality of education and its role, how universities ensure it, and how it is verified through evaluation and accreditation. These elements divide the article into two parts: a part about quality and a part about evaluation and accreditation. The analysis includes the impact of global processes and Europeanization. The research approach is characteristic for public policies, sciences of management and quality. The theories used in this article: the theory of systems and neo-institutionalism, as well as perspectives: the university as an active strategic partner, entrepreneurial university, the third role of universities. The publication is based on desk research and on the analysis of processes.


2021 ◽  
pp. 1-21
Author(s):  
Davide Vittori

Abstract Scholars have long debated whether populism harms or improves the quality of democracy. This article contributes to this debate by focusing on the impact of populist parties in government. In particular, it inquires: (1) whether populists in government are more likely than non-populists to negatively affect the quality of democracies; (2) whether the role of populists in government matters; and (3) which type of populism is expected to negatively affect the quality of liberal-democratic regimes. The results find strong evidence that the role of populists in government affects several qualities of democracy. While robust, the findings related to (2) are less clear-cut than those pertaining to (1). Finally, regardless of their role in government, different types of populism have different impacts on the qualities of democracy. The results show that exclusionary populist parties in government tend to have more of a negative impact than other forms of populism.


Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 370
Author(s):  
Umair Iqbal ◽  
Ravirajsinh N. Jadeja ◽  
Harshit S. Khara ◽  
Sandeep Khurana

Hepatic encephalopathy (HE) is a common neurological consequence in patients with cirrhosis and has a healthcare burden of USD 5370 to 50,120 per patient annually. HE significantly hampers the quality of life and is a major cause of morbidity and mortality. Patients with cirrhosis are at a high risk for protein-calorie malnutrition due to altered metabolism. Current evidence has changed the old belief of protein restriction in patients with cirrhosis and now 1.2 to 1.5 g/kg/day protein intake is recommended. Case series and studies with small numbers of participants showed that a vegetarian protein diet decreases the symptoms of HE when compared to a meat-based diet, but the evidence is limited and requires further larger randomized controlled trials. However, vegetable or milk-based protein diets are good substitutes for patients averse to meat intake. Branch chain amino acids (BCAA) (leucine, isoleucine and valine) have also been shown to be effective in alleviating symptoms of HE and are recommended as an alternative therapy in patients with cirrhosis for the treatment of HE. In this review, we provide an overview of current literature evaluating the role of protein intake in the management of HE in cirrhosis.


Medicina ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 161
Author(s):  
Paolo Custurone ◽  
Laura Macca ◽  
Lucrezia Bertino ◽  
Debora Di Mauro ◽  
Fabio Trimarchi ◽  
...  

The link between psoriasis and sport is a controversial issue. The topic has been poorly investigated, and nowadays there are many unsolved questions, dealing with the role of psoriasis in influencing the sporting habits of patients and, vice versa, the impact of sport activity on course, severity and extent of the disease, with particular regard to the indirect benefits on cardiovascular risk and metabolic syndrome. Moreover, the role of physical activity on patients’ quality of life and the potential limitations on physical activity due to joint involvement have not been well elucidated until now. In this narrative review we will try to provide answers to these queries.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Nando Sigona ◽  
Jotaro Kato ◽  
Irina Kuznetsova

AbstractThe article examines the migration infrastructures and pathways through which migrants move into, through and out of irregular status in Japan and the UK and how these infrastructures uniquely shape their migrant experiences of irregularity at key stages of their migration projects.Our analysis brings together two bodies of migration scholarship, namely critical work on the social and legal production of illegality and the impact of legal violence on the lives of immigrants with precarious legal status, and on the role of migration infrastructures in shaping mobility pathways.Drawing upon in-depth qualitative interviews with irregular and precarious migrants in Japan and the UK collected over a ten-year period, this article develops a three-pronged analysis of the infrastructures of irregularity, focusing on infrastructures of entry, settlement and exit, casting a comparative light on the mechanisms that produce precarious and expendable migrant lives in relation to access to labour and labour conditions, access and quality of housing and law enforcement, and how migrants adapt, cope, resist or eventually are overpowered by them.


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