bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement Approach of Mean Heat Transfer Coefficient for Packed Bed of Vegetables
Authors: Łapiński Adam , Butrymowicz Dariusz , Kołodziejczyk Mirosława 
Published: April 2017

Abstract
The non-invasive measurement approach of the mean heat transfer coefficient for the packed bed of vegetables may be thought as still open issue. There is a clear need for the assessment of heat transfer conditions for various types of fruits and vegetables in order to accurately predict the thermal load that is necessary to select refrigeration equipment for cold storage chamber. Additionally, there is significant development in numerical modelling of heat and mass transfer processes in cold storage chambers for fruits and vegetables which requires precise heat transfer prediction. The theoretical basis for the indirect measurement approach of mean heat transfer coefficient for the packed bed of vegetables that is based on single blow technique is presented and discussed in the paper. The approach based on the modified model of Liang and Yang was presented and discussed. The testing stand consisted of a dedicated experimental tunnel along with auxiliary equipment and measurement system are presented. The geometry of the tested vegetables bed were presented. Selected experimental results of heat transfer are presented and discussed for the packed bed of carrots. These results were presented as dimensionless relationship. The obtained results were compared with the existing dimensionless relationships developed for the packed bed consisting of elements of various regular shapes.
Nickel and Copper-Free Sintered Structural Steels Containing Mn, Cr, Si, and Mo Developed for High Performance Applications
Authors: Cias A. , Stoytchev M. 
Published: April 2017

AbstractIn an attempt to study the sinterability of potential high-strength nickel-free sintered structural steels containing Mn, Cr, Si and Mo compacts were prepared based on sponge and water atomised iron powders and on Astaloy prealloyed powders. To these were admixed ferromanganese, ferroslicon, and graphite. The samples were sintered at temperatures 1120 and 1250°C in laboratory tube furnaces in hydrogen, hydrogen-nitrogen atmospheres with dew points better than -60°C or in nitrogen in a semiclosed container in a local microatmosphere. After sintering the samples were slowly cooled or sinterhardened. Generally resultant microstructures were inhomogeneous, consisted of pearlite/ bainite/martensite, but were characterised by an absence of oxide networks. Sintering studies performed over a range of compositions have shown that superior strength, ranging beyond 900 MPa, along with reasonable tensile elongation, can be achieved with these new steels.
Evaluation of pore sizes in welded joints made in various constructional materials on the basis of penetrant testing by colour method
Authors: Czuchryj J. , Irek P. 
Published: April 2017

Abstract
It has been compared the dimensions of indications obtained in colour liquid-penetrant inspection. The indications arose from simulated pores drilled in test elements. The series of penetrant tests included different structural materials. On the basis of test results it has been ascertained the possibility of evaluation of the pores depth as well as it has been determined recommended development times for different constructional materials
Geometric Parameters of Cutting Tools that Can be Used for Forming Sided Surfaces with Variable Profile
Authors: Razumov M. , Grechukhin A. , Maslennikov A. 
Published: April 2017

Abstract
This article describes machining technology of polyhedral surfaces with varying profile, which is provided by planetary motion of multiblade block tools. The features of the technology and urgency of the problem is indicated. The purpose of the study is to determine the minimum value of the clearance angle of the tool. Also, the study is carried out about changing the value of the front and rear corners during the formation of polygonal surface using a planetary gear. The scheme of calculating the impact of various factors on the value of the minimum clearance angle of the tool and kinematic front and rear corners of the instrument is provided. The mathematical formula for calculating the minimum clearance angle of the tool is given. Also, given the formula for determining the front and rear corners of the tool during driving. This study can be used in the calculation of the design operations forming multifaceted external surfaces with a variable profile by using the planetary gear.
Practical Application of the Concept of Separating the Zone of Overheating and Reducing the Stress Level in Cathode Block of an Aluminium Electrolytic Cell During Formation of Connection with the Steel Pin by Cast Iron Pouring
Authors: Piekło J. , Maj M. 
Published: April 2017

Abstract
The article presents the concept of division of a carbon block into single cathode sections to reduce stresses that occur during thermal shock accompanying the operation of pouring cast iron into a shaped groove in which the current-carrying steel pin is mounted. The temperature field and the state of stress were determined by FEM. Experimental measurements were used to determine the core displacement during pouring operation. The calculations were verified by thermovision and photoelastic method. Based on the temperature field and stress field analysis, a method for the block division into sections has been proposed, resulting in a significant reduction of the stress level.
Experimental determination of the void volume fraction for S235JR steel at failure in the range of high stress triaxialities
Authors: Kossakowski P. G. 
Published: April 2017

AbstractThis paper is concerned with the critical void volume fraction fFrepresenting the size of microdefects in a material at the time of failure. The parameter is one of the constants of the Gurson-Tvergaard-Needleman (GTN) material model that need to be determined while modelling material failure processes. In this paper, an original experimental method is proposed to determine the values of fF. The material studied was S235JR steel. After tensile tests, the void volume fraction was measured at the fracture surface using an advanced technique of quantitative image analysis The material was subjected to high initial stress triaxialities T0ranging from 0.556 to 1.345. The failure processes in S235JR steel were analysed taking into account the influence of the state of stress.
Impact of electro slag remelting on 14 109 steel properties
Authors: Pribulová A. , Futáš P. , Kmita A. , Márasová D. , Holtzer M. 
Published: April 2017

Abstract
The Electro Slag Remelting (ESR) is one of the remelting processes in the field of metal refinery. In this process, the slag plays various roles, such as heat generation, protection of melt, and chemical refining. The main objective of the experiments described in this article was to identify the most appropriate slag composition for the electro slag remelting of the steel in order to achieve the chemical composition compliant with the standard applicable to the given steel, minimum sulphur content, minimum contents of oxide and sulphide inclusions, as well as mechanical properties corresponding to the standard applicable to the steel STN 14 109. Ten electrodes were remelted, whereas the remelting was carried out under 8 slags. The used slags containing 70% of CaF2 and 30% of Al2O3 with different addition of CaO, the slags consisted of the same components as previous slags, whereas the ratio of individual components was 1:1:1, and with SiO2 and MgO and slag without Al2O3. With regard to all the above mentioned facts, the slag types which may be regarded as the most appropriate for the STN 14 109 steel remelting are the basic slags containing 70% of CaF2 - 30% of Al2O3 with added 30 and 45 weight % of CaO.
Identification of the steel viscosity and dynamic yield stress for the numerical modelling of casting simulations in the semi-solid state
Authors: Solek K. 
Published: April 2017

Abstract
Conditions of some casting processes cause flow of both liquid and semi-liquid metal alloys inside the die cavity. Generally, the continuous casting, squeeze casting or thixoforming could be classified as such processes. Design or optimisation of casting technology using numerical simulations requires knowledge of the rheological properties. The main objective of the experimental work, presented in this publication, is an analysis of the viscosity of 1.2080 (X210Cr12) high carbon steel in liquid and semisolid state. The secondary purpose of the experimental work was a development of the viscosity models used in continuous casting and thixoforming simulations. The significant achievement of this particular study was identification of thixotropy phenomenon which occurs not only during thixoforming, but also during magnetohydrodynamic stirring in continuous casting processes.
Quantitative analysis of stability of 9%Cr steel microstructure after long-term ageing
Authors: Golański G. , Jasak J. , Zieliński A. , Kolan C. , Urzynicok M. , Wieczorek P. 
Published: April 2017

Abstract
The paper presents the results of research on the microstructure of martensitic X10CrMoVNb9-1 (P91) and X13CrMoCo- VNbNB9-2-1 (PB2) steel subject to long-term ageing at the temperature of 620°C and holding times up to 30 000 hours. The microstructural tests of the examined steel types were performed using a scanning microscope Joel JSM - 6610LV and a transmission electron microscope TITAN 80 - 300. The stability of the microstructure of the investigated steels was analyzed using a quantitative analysis of an image, including measurements of the following: the density of dislocations inside martensite/subgrain laths, the width of martensite laths, and the mean diameter of precipitates. It has been concluded that during long-term ageing, the microaddition of boron in PB2 steel significantly influenced the slowing of the process of degradation of the martensitic steel microstructure, as a result of slowing the process of coagulation of M23C6 carbides and Laves phase. It had a favorable effect on the stabilization of lath microstructure as a result of retardation of the processes of recovery and polygonization of the matrix.
Wave propagation in a microstretch thermoelastic diffusion solid
Authors: Kumar Rajneesh 
Published: April 2017

Abstract
The present article deals with the two parts: (i) The propagation of plane waves in a microstretch thermoelastic diffusion solid of infinite extent. (ii) The reflection and transmission of plane waves at a plane interface between inviscid fluid half-space and micropolar thermoelastic diffusion solid half-space. It is found that for two-dimensional model, there exist four coupled longitudinal waves, that is, longitudinal displacement wave (LD), thermal wave (T), mass diffusion wave (MD) and longitudinal microstretch wave (LM) and two coupled transverse waves namely (CD-I and CD-II waves). The phase velocity, attenuation coefficient, specific loss and penetration depth are computed numerically and depicted graphically. In the second part, it is noticed that the amplitude ratios of various reflected and transmitted waves are functions of angle of incidence, frequency of incident wave and are influenced by the microstretch thermoelastic diffusion properties of the media. The expressions of amplitude ratios and energy ratios are obtained in closed form. The energy ratios have been computed numerically for a particular model. The variations of energy ratios with angle of incidence for thermoelastic diffusion media in the context of Lord-Shulman (L-S) [1] and Green-Lindsay (G-L) [2] theories are depicted graphically. Some particular cases are also deduced from the present investigation.
Hungarian Culture of Philosophy and Historiography of Philosophy in Transylvania
Authors: Tonk Márton 
Published: April 2017

Abstract
The first part of the study debates the role and the status of philosophy in the Hungarian culture in Transylvania, trying to explain why philosophy has not become an organic part of the Transylvanian culture as a whole. There are presented a few experimental and theoretical arguments, especially the theory of the so-called ‘short philosophical tradition’. The second part the paper seeks to analyse the impact of the ‘short philosophical tradition’ on the current philosophy life in Transylvania, bringing an overview of the institutional structure of Hungarian philosophy in Transylvania.
Minority Civil Society
Authors: Bodó Barna 
Published: April 2017

Abstract
Both the concept and the issue of civil society is a matter of dispute in respect of theory and practice alike. The present paper has a triple ambition: outlining the history of ideas behind the concept, providing an interpretation, and carrying out a distinct analysis of the processes characteristic of the East-Central European region. Owing to the unrealistic expectations formed around the concept, mystification poses a great danger to present-day civil society. In what follows, we will analyse the dilemmas evolved around the issue of civil society.
An Optimization of Closed Frequent Subgraph Mining Algorithm
Authors: Demetrovics J. , Quang H. M. , Anh N. V. , Thi V. D. 
Published: April 2017

Abstract
Graph mining isamajor area of interest within the field of data mining in recent years. Akey aspect of graph mining is frequent subgraph mining. Central to the entire discipline of frequent subgraph mining is the concept of subgraph isomorphism. One major issue in early subgraph isomorphism research concerns computational complexity. Normally, the subgraph isomorphism problem is NP-complete. Previous studies of frequent subgraph mining have not solved NP-complete problem in the subgraph isomorphism. In this paper, we proposeanew algorithm which can deal with this problem. The proposed algorithm can solve the subgraph isomorphism in polynomial time in some settings. Moreover, the new algorithm is proved theoretically more effective than previous studies in closed frequent subgraph mining.
Quantifying whether different demographic models produce incongruent results on population dynamics of two long-term studied rodent species
Authors: Amori Giovanni , De Silvestro Valentina , Ciucci Paolo , Luiselli Luca 
Published: April 2017

Abstract1. Population density (ind/ha) of long-term (>15 years) series of CMR populations, using distinct demographic models designed for both open and closed populations, were analysed for two sympatric species of rodents (Myodes glareolus and Apodemus flavicollis) from a mountain area in central Italy, in order to test the relative performance of various employed demographic models. In particular, the hypothesis that enumeration models systematically underestimate the population size of a given population was tested.2. Overall, we compared the performance of 7 distinct demographic models, including both closed and open models, for each study species. Although the two species revealed remarkable intrinsic differences in demography traits (for instance, a lower propensity for being recaptured in Apodemus flavicollis), the Robust Design appeared to be the best fitting model, showing that it is the most suitable model for long-term studies.3. Among the various analysed demographic models, Jolly-Seber returned the lower estimates of population density for both species. Thus, this demographic model could not be suggested for being applied for long-term studies of small mammal populations because it tends to remarkably underestimate the effective population size. Nonetheless, yearly estimates of population density by Jolly-Seber correlated positively with yearly estimates of population density by closed population models, thus showing that interannual trends in population dynamics were uncovered by both types of demographic models, although with different values in terms of true population size.
Long term changes in water areas and wetlands in an intensively farmed landscape: A case study from the Czech Republic
Authors: Šantrůčková Markéta , Demková Katarína , Weber Martin , Lipský Zdeněk , Dostálek Jiří 
Published: April 2017

Abstract
The landscape of the Czech Republic currently faces droughts that are caused by several factors. One of the reasons for drought is landscape development and land cover changes. Changes in water and wetland areas and streams were studied by comparing old military maps and the present state. Water and wetland areas in fertile lowlands significantly decreased over time; the landscape was continuously dried out with the aim of increasing agricultural and woody production. While water and wetland areas occupied nearly one-third of the study area (Nové Dvory and Žehušice micro-regions in Central Bohemia) at the end of the 18th century, the present share of these areas is only 3.5%. There was a decrease of approximately 10% in each period, and nearly all of these areas disappeared by the end of the 19th century. Water and wetland areas were changed primarily to arable land. The length of streams decreased by the end of the 19th century. Drainage and irrigation channels were built during the 20th century, and although they are only periodic or episodic streams, these channels increased the total length of streams.
Self‐Assessment Quiz Taking Behaviour Analysis in an Online Course
Authors: Ozarslan Yasin , Ozan Ozlem 
Published: April 2017

Abstract
Self-assessment is vital for online learning since it is one of the most essential skills of distance learners. In this respect, the purpose of this study was to understand learners’ self-assessment quiz taking behaviours in an undergraduate level online course. We tried to figure out whether there is a relation between self-assessment quiz taking behaviours and final exam scores or not. In addition, we investigated how self-assessment quiz taking behaviour differs with respect to learner profile. In line with this purpose, 677 students’ 6092 test events across Project Culture course on Sakai CLE LMS were analyzed. For the analysis of the quantitative data, one-way ANOVA, Chi-Square test of independence, independent-samples t-test and descriptive statistics were utilized. The results revealed that learners who attended self-assessment quizzes regularly had higher final exam scores than others who did not attend those quizzes. Also, they were more satisfied with the course than others study field. In addition, learners who attended selfassessment quizzes regularly had a higher degree of perceived learning. However, number of attempts to those quizzes does not have an effect on final exam scores. On the other hand, a statistically significant relationship was found between attempt number and gender in favour of female learners.
Open and Distance Learning: Cultural Practices in Nepal
Authors: Pangeni Shesha Kanta 
Published: April 2017

Abstract
Nepali education culture is dominated by face-to-face tutoring. It has a long history starting from the Gurukul culture to the present formal schooling. Emerging practices of using technology in education have been promoting online learning as a form of distance education and gaining popularity. This paper focuses on digging out the contextual reality of open and distance learning (ODL) practices in Nepal beginning with an analysis and the author’s personal impression of the context. Core focus is placed to explore and discuss different thematic issues such as modes of learning associated education culture/tradition, flexible learning for Nepali students, ODL as a pedagogical tool for teacher education and implementation of ODL in Nepal. The author’s personal reflection, literature review, and insights from learning theories are meaningful to enrich the discourse. The paper concludes showing the promising future of ODL in Nepal as an option to traditional mode of education. In addition, attention is drawn on the need of Open University and role of existing universities for the successful implementation of ODL in Nepal to adapt acculturation of online learning by respecting the need of the new generation of learners at the age of Internet culture.
Effectiveness of National Airlines in Europe – the DEA Approach
Authors: Żółtaszek Agata , Pisarek Renata 
Published: April 2017

AbstractNational airlines operate in a highly competitive environment. EU airlines face a challenge to compete with low cost carriers, as a result of the liberalization process in the sector. European flag airlines of non-EU member states, not benefiting from liberalization, are forced to compete internationally. This research is focused on national carriers, as they provide the majority of service to and from central and regional airports. Therefore, to establish the most efficient entities on the passenger air transport market, DEA (Data Envelopment Analysis) methodology, has been utilized. The purpose of this paper is to evaluate the effectiveness of 29 chosen national airlines in Europe in the year 2013, using the DEA approach, to pinpoint the subset of fully-efficient market leaders, as well as potential sources of inefficiency, among less effective carriers. The analysis incorporates information on inputs (e.g. fleet, number of employees, number of countries and airports served) and outputs (revenue, annual passengers carried, load factor). The results show that more than 40% (12 of 29) researched airlines are effective and the other 34% are near-efficient. Moreover, outcomes suggest that “going big” may not increase effectiveness. It is harder to achieve full efficiency for big carriers than small ones.
Income Absolute Beta-Convergence of NUTS 3 Level Regions in New EU Member States before and During a Crisis
Authors: Folfas Paweł 
Published: April 2017

Abstract
This paper is aimed at answering the question of whether absolute income (GDP per capita) beta-convergence exists in the case of regions in new EU Member States before the period of 2000–2008 and during the 2008–2011 crisis. The sample consists of 211 regions (NUTS 3-level) of Bulgaria, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovenia and Slovakia.
The research is based on econometric models, namely on the spatial lagged model (SLM), the spatial error model (SEM) and the Durbin spatial model which contrary to the ordinary least squares the (OLS) model include possible spatial dependencies. The SLM and SEM models as well as the Durbin spatial model detect the absolute income beta-convergence on the level of about 1% during the years 2000–2008. Additionally, models do not confirm the existence of absolute income beta-convergence during the crisis of 2008–2011. SLM models (which offer the most reliable findings) find a spatial correlation (measured by the rho-parameter) at a level of 0.75 during 2000–2008 and 0.35 during 2008–2011. Thus, absolute income beta-convergence in the case of NUTS 3 regions in 10 new EU Member States existed only in the pre-crisis period and this period is characterized by much stronger spatial dependencies than the period of 2008–2011.