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Found 6289 publications

Influence of cryogenic attrition ball milling on the particle size of microcrystalline cellulose at different moisture contents

Zsolt András Nánási H. Hargitai László Mészáros

Publication Name: Materials Science Forum

Publication Date: 2017-01-01

Volume: 885

Issue: Unknown

Page Range: 202-207

Description:

In this study the effect of attrition ball milling on cellulose particle size distribution was studied. The effect of moisture content of cellulose and grinding time were examined and grinding was carried out at room temperature and under cryogenic conditions, as well. The grinds obtained were studied with electron microscope, and the characteristic dimensions of ground particles were determined using image processing software. Results revealed that effective size decrease of cellulose particles was achieved at low moisture content at room temperature, while under cryogenic conditions high moisture content was necessary, i.e. frozen moisture enhances grinding efficiency in the latter case.

Open Access: Yes

DOI: 10.4028/www.scientific.net/MSF.885.202

Human urine as an efficient fertilizer product in agriculture

A. Zseni J. Nagy

Publication Name: Agronomy Research

Publication Date: 2017-01-01

Volume: 15

Issue: 2

Page Range: 490-500

Description:

Flush toilet based water infrastructure, which handles blackwater and greywater together, causes a lot of environmental problems. Among these, the loss of valuable organic material and nutrient content of human excreta (faeces and urine) is not sufficiently emphasized yet. Utilization of human excreta for agricultural purposes is based on the separate collection of greywater and human excreta. As urine contains most of the nutrients of human excreta, researches focus mainly on urine’s treatment and utilization for agricultural purposes. We reviewed the data in literature about the nutrient content of human excreta. In this paper we present the content of macro and microelements of human urine to show its potential value as a fertilizer. To confirm the necessity of urine’s utilization in agriculture instead of treated it by traditional waste water treatment methods, we have collected and compared the most important advantages and disadvantages of traditional wastewater treatment, separated handling of greywater and excreta as well as human urine’s agricultural utilization.

Open Access: Yes

DOI: DOI not available

Types of development paths and the hierarchy of the regional centres of Central and Eastern Europe

Ádám Páthy

Publication Name: Regional Statistics

Publication Date: 2017-01-01

Volume: 7

Issue: 2

Page Range: 124-147

Description:

After the rapid transformation period of the 1990s, determined predominantly by the crisis effects of a radical political-economic transition, the reshaping of the spatial structure and urban networks slowed in the post-socialist countries of Central and Eastern Europe. The spillover effects of the market economy transition are fad-ing, and cannot be generalized. Instead, other factors, such as involvement in global processes and the creation and exploitation of new types of synergies, become the main drivers of the differ-entiation and development in the urban system. This study attempts to explore the framework and specifics of this new environment by exam-ining resources for development in the Eastern and Central European regional centres.

Open Access: Yes

DOI: 10.15196/rs070202

Digital image analysis of sheet metal testing and forming

Szabolcs Szalai Imre Czinege

Publication Name: 15th Imeko Tc10 Workshop on Technical Diagnostics 2017 Technical Diagnostics in Cyber Physical Era

Publication Date: 2017-01-01

Volume: Unknown

Issue: Unknown

Page Range: 176-180

Description:

Digital image analysing methods are widely used for evaluating local deformations in sheet metal tests and forming processes. The paper is focusing on tensile tests of uniform and non-uniform width flat specimens made of aluminum alloys, which are suitable for demonstrating Löders strain, Portevin-Le Chatelier (PLC) effect and for determination of Forming Limit Curve. Tests were carried out using GOM-ARAMIS® digital image analysis hardware and software. Observation of local deformations during tensile tests showed that initiation and evolution of local strains depend on the position of specimens related to rolling direction of sheet. Using non-uniform width specimens the local deformations are concentrated on the smallest cross-section in the final stage of tensile test. The measured major and minor strains give points of FLC.

Open Access: Yes

DOI: DOI not available

Parallelization of numerical examination of nonlinear systems using maple

No authors available

Publication Name: Civil-Comp Proceedings

Publication Date: 2017-01-01

Volume: 111

Issue:

Page Range: Unknown

Description:

In this work we present possibilities of the parallelization of numerical examination and simulation of nonlinear systems, especially creating phase-plane diagrams in parallel. For construction of such diagrams Maple was used because it provides algorithms for solving differential equations and two models for parallelization. These are the Task programming model and the Grid programming model. The paper describes the development, the test and the comparison of the parallel programs created according to the two parallelization models. Even using a simple desktop with low number of processors a relative good speedup with a good efficiency could be achieved in both cases. It was also examined how the problem size affects the speedup and the efficiency.

Open Access: No

DOI: DOI not available

A fuzzy information propagation algorithm for social network based recommender systems

Gergely Posfai Gabor Magyar L. T. Kóczy

Publication Name: Advances in Intelligent Systems and Computing

Publication Date: 2017-01-01

Volume: 462

Issue: Unknown

Page Range: 35-49

Description:

Web-based services that have become prevalent in people’s everyday life generate huge amounts of data, which makes it hard for the users to search and discover interesting information. Therefore, tools for selecting and delivering personalized contents for users are crucial components of modern web applications. Social recommender systems suggest items to users assuming the knowledge of the users’ social network. This new approach can alleviate the common weaknesses of traditional recommender systems, which completely ignore the users’ personal relationships in the recommendation process. In this paper, a social network based fuzzy recommendation technique is presented, which propagates information through the users’ social network and predicts how users would probably like a certain product in the future. Experimental results on a public dataset show that the proposed method can significantly outperform popular and widely used recommendation system methods in terms of recommendation coverage while maintaining prediction accuracy and performs especially well for cold start users, that have only rated a few items or no item at all previously.

Open Access: Yes

DOI: 10.1007/978-3-319-44260-0_3

The willingness and preparedness of local governments in Ap Vojvodina/Serbia to grip and use development funds of the European Union

No authors available

Publication Name: DETUROPE

Publication Date: 2017-01-01

Volume: 9

Issue: 2

Page Range: 118-128

Description:

EU funds that are available in Serbia are modest both in volume and number, since Serbia received preaccession status only in 2014. Before that, it was only a potential pre-accession country on the external border of the European Union. From the five components of IPA (2007-2013) Serbia could have utilised only the first two components in the pre-accession process: building of EU institutions (EXCHANGE IIV, Regional Socio-Economic Development Programme) and enhancing cross-border cooperation As a conclusion we can say that although substantial sums were invested from the above mentioned resources into the economy of Vojvodina for its development, the main indicator - the GDP - has been increasing only slightly, while these projects have no effects on decreasing unemployment. In the overall economic situation, unemployment is primarily decreased by emigration, in which Vojvodina Hungarians take part at a rate above the average compared to their headcount, thus decreasing the economic power of the community through emigration.

Open Access: No

DOI: DOI not available

EXPLICIT strong stability preserving multistep runge-kutta methods

Christopher Bresten Daniel Higgs Zachary Grant Adrián Németh Sigal Gottlieb David I. Ketcheson

Publication Name: Mathematics of Computation

Publication Date: 2017-01-01

Volume: 86

Issue: 304

Page Range: 747-769

Description:

High-order spatial discretizations of hyperbolic PDEs are often designed to have strong stability properties, such as monotonicity. We study explicit multistep Runge-Kutta strong stability preserving (SSP) time integration methods for use with such discretizations. We prove an upper bound on the SSP coefficient of explicit multistep Runge-Kutta methods of order two and above. Numerical optimization is used to find optimized explicit methods of up to five steps, eight stages, and tenth order. These methods are tested on the linear advection and nonlinear Buckley-Leverett equations, and the results for the observed total variation diminishing and/or positivity preserving time-step are presented.

Open Access: Yes

DOI: 10.1090/mcom/3115

Overall imperfection method for beam-columns

No authors available

Publication Name: Advances and Trends in Engineering Sciences and Technologies II - Proceedings of the 2nd International Conference on Engineering Sciences and Technologies, ESaT 2016

Publication Date: 2017-01-01

Volume:

Issue:

Page Range: 87-92

Description:

The principles and applications of the overall imperfection method for beamcolumns are presented in this paper. The buckling resistance of a beam-column member is determined by the resistance of its critical cross-section taking into account the second-order effect. The maximum amplitude of the initial imperfection, in the shape of elastic buckling mode, is determined from fundamental cases. Fundamental case: simply-supported member with uniform cross-section subjected to uniformly distributed forces. The standardized buck-ling resistance of this reference member is based on theoretical and empirical background. The proposed overall imperfection method is adequate for computer-aided design procedures which contains an advanced elastic beam-column finite element method. The accuracy of the overall imperfection method is shown by a parametric study.

Open Access: No

DOI: DOI not available