Experimental and Calculated Stark Widths Within the Kr I Spectrum

On the basis of the precisely recorded 20 neutral krypton (Kr I) line shapes (in the 5s−5p and 5s−6p transitions), we have obtained the basic plasma parameters, i.e., electron temperature (T) and electron density (N) using our line deconvolution procedure in a plasma created in a linear, low-pressure, pulsed arc discharge operated in krypton. The mentioned plasma parameters have also been measured using independent experimental diagnostics techniques. Agreement has been found among the two sets of the obtained parameters. This recommends our deconvolution procedure for plasma diagnostical purposes, especially in astrophysics where direct measurements of the main plasma parameters (T and N) are not possible. On the basis of the observed asymmetry of the Stark broadened line profile, we have obtained not only its ion broadening parameter (A) which is caused by influence of the ion-microfield over the line broadening mechanism but also the influence of the ion-dynamic effect (D) over the line shape. The separate electron (We) and ion (Wi) contributions to the total Stark width, which have not been measured so far, have also been obtained. Stark widths are calculated using the semiclassical perturbation formalism for electrons, protons, and helium ions as perturbers

Finite element simulation of tensile test of composite materials manufactured by 3D printing

© 2020 Institute of Physics Publishing. All rights reserved. A principle of 3D printing is based on formation of continuous layers of materials up to a formation of the final shape. Materials for production of given components are composite materials, especially on the basis of so-termed CFRP, CRP, (carbon fibre - so-termed polymers reinforced by carbon fibres). The objective of this paper is to predict the deformation length of carbon/onyx composite laminates using Finite Element Analysis (FEA) and compare with universal testing machine INOVA FU 160 deformation results through the tensile load. Specimen were printed at raster orientation angles of 0°, 45° and 90° to test orientation effects on part strength. 16 ply CFRP specimens with various stacking sequences were analysed for their strength and displacements. A shell model has been established for simulation of the tensile test composite specimen which enables to understand the mechanical strength and strain at failure of the composite materials. The simulations of experiment are provided in FEM program ANSYS and ANSYS/Workbench

Determination analysis of temperature regimes, functional characteristics and sliding curves of a hydrodynamic clutch

Analysis of output quality of power transmitters is possible in position when characteristics are determined earlier. This is the reason why we focused on determination of these characteristics for a concrete power hydro-transmitter. This means that the investigation task primarily consisted of determination of functional characteristics, defining of the sliding curves and temperature regimes of a concrete hydrodynamic clutch. Results of velocity and pressure field investigations in the working space of this clutch, obtained by use of the same test setup, are the basis for determination and analysis of the functional characteristics, sliding curves and temperature regimes. In this work we also analyzed function of the hydrodynamic transmitter in assembly with an internal combustion engine, as well as a process of acceleration and deceleration of a vehicle with this assembly in it

THE SEXUALITY OF SEX WORKERS: SEXUAL AROUSABILITY AND THE SEXUAL PROFILE OF WOMEN ENGAGED IN PROSTITUTION IN SERBIA

Background: In a view of sex work being a sexual behavioural activity, the main objective of our research was to explore the sexuality of sex workers in Serbia regarding to intensity of their sexual arousability. Subjects and methods: The research was conducted on 30 sex workers and 30 controls of randomly selected social and demographic characteristics, without any signs of psychiatric morbidity. For the evaluation of the intensity of sexual arousability, SAI (Sexual Arousability Index) questionnaire was used. Results: The analysis of the main total scores of the SAI for the sex workers and control participants showed no statistically significant difference in the overall intensity of arousability (p>0.05). However, item by item analysis of the questionnaire showed qualitative difference in sexuality between sex workers and controls, related to certain aspects of sexuality. Conclusions: These findings allow the space for further research in the way of identifying origins of qualitative issues in the sexual profile of sex workers, in correlation to women who are not sex workers, i.e. whether they had been result of potential biological, specific psychodynamic factors, or have been formed as a result of the direct influence of the sex work

FACTORIAL STRUCTURE OF THE RELATIONSHIP BETWEEN AGGRESSIVENESS AND PERSONALITY DIMENSIONS IN JUNIOR KARATEKAS

The goal of this study was to identify the factorial structure and the relation of aggressiveness and basic personality dimensions, as well as metric characteristics (reliability) of the applied scales and subscales. The study was conducted on a sample (N = 287) consisting of both genders, aged between 14-16 years. The following measuring instruments were used:  Buss-Perry Aggression Questionnaire (AQ), Eysenck Personality Questionnaire (EPQ), and the Big Five Plus Two Inventory (BF+2). The applied scales and subscales point to a high reliability type of internal consistency (α > .70), which confirms the appropriate psychometric characteristics, as well as validity of instruments on the athletic population. Principal Component Analysis (PCA) was performed, and with Varimax rotation, three dimensions with latent values of more than one were extracted, and they explain 60,41% of total variance. Results have shown that in the structure of the first component, factors of the second order (Psychoticism and Social desirability from the EPQ, Aggressiveness and Negative Valence from BF+2) significantly contribute to aggressive reactions. The second isolated component is saturated by personality constructs from the EPQ and BF+2 models, which can be interpreted as intrusiveness and domination. The composition of the third component – uncontrollable physical aggression – is maximally burdened by negative correlations of the dimensions Psychoticism and Social desirability from the EPQ, Conscientiousness (in a negative direction) and Negative Valence from BF+2, as well as Physical aggression from the AQ, Aggressiveness from BF+2, and Rage from AQ. In this study, theoretical and practical implications required for operationalization of these findings are discussed.Key words: karate athletes, AQ, EPQ-R, BF+

Robust digital processing of speech signals

This book focuses on speech signal phenomena, presenting a robustification of the usual speech generation models with regard to the presumed types of excitation signals, which is equivalent to the introduction of a class of nonlinear models and the corresponding criterion functions for parameter estimation. Compared to the general class of nonlinear models, such as various neural networks, these models possess good properties of controlled complexity, the option of working in “online” mode, as well as a low information volume for efficient speech encoding and transmission. Providing comprehensive insights, the book is based on the authors’ research, which has already been published, supplemented by additional texts discussing general considerations of speech modeling, linear predictive analysis and robust parameter estimation

Synthesis of tetraalkyl thiuram disulfides using different oxidants in recycling solvent mixture

A new optimized laboratory synthesis of tetraalkylthiuram disulfides, starting from dialkyl amines and carbon disulfide in presence of three oxidants (hydrogen peroxide, potassium peroxodisulfate and sodium hypochlorite) and appropriate reaction media (two mixtures of isopropyl alcohol-water used in two consecutive syntheses) was presented in this work. The first synthesis was performed in a recycled azeotropic mixture of isopropyl alcohol-water 87.7%-12.3%, and second in a filtrate obtained after first synthesis, which was a mixture of isopropyl alcohol-water 70.4%-29.6%. After the second synthesis and filtration, recycled azeotropic mixture isopropyl alcohol-water 87.7%-12.3% was regenerated from the filtrate by rectification. Considering this, the technology for beneficial use of recycling isopropyl alcohol-water mixture as a reaction medium for tetraalkylthiuram disulfides synthesis was developed. This concept could contribute to extraordinary economical benefit of implemented optimal laboratory synthesis at semi-industrial level. High yields of tetraalkylthiuram disulfides were obtained at both laboratory and semi-industrial level. Structure and purity of synthesized compounds were confirmed by elemental analysis, as well as FTIR, 1H- and 13C-NMR, and MS spectral data.U ovom radu je prikazan nov optimizovani laboratorijski postupak sinteza tetraalkiltiuramdisulfida, polazeći od dialkilamina i ugljendisulfida u prisustvu oksidacionih sredstava (vodonik-peroksid, kalijum-peroksodisulfat i natrijum-hipohlorit), u odgovarajućem reakcionom medijumu: dve smeše izopropil alkohol-voda korišćene u dve uzastopne sinteze. Prva sinteza se izvodi u reciklovanoj azeotropskoj smeši izopropil-alkohola-voda sastava 87,7%-12,3%. Izvršena je optimizacija postupka u odnosu na molarni odnos reaktanata i koncetraciju proizvoda u suspenziji. Filtrat, dobijen nakon filtriranja suspenzije tetraalkiltiuram-disulfida iz prve sinteze, koji sadrži smešu izopropil alkohol-voda 70,4%-29,6%, uspešno je korišćen za naredne sinteze tetraalkiltiuram-disulfida. Nakon druge sinteze, filtracijom suspenzije, dobija se filtrat kao smeša izopropil-alkohol-voda 57,0%-43,0%, koji se regeneriše rektifikacijom pri čemu se dobija azeotropska smeša sastava izopropil alkohol-voda 87,7%-12,3%. Primenom navedenog postupka osvojena je tehnologija koja uključuje proces reciklovanja smeše reakcionog medijuma izopropil alkohol-voda za sintezu tetraalkiltiuram-disulfida. Takav koncept doprinosi izvanrednoj ekonomičnosti implementiranog optimalnog laboratorijkog postupka sinteze na poluindustrijski nivo. Visoki prinosi tetraalkiltiuram-disulfida su dobijeni sintezama na laboratorijskom nivou, kao i primenom na poluindustrijskom nivou proizvodnje. Struktura i čistoća sintetisanih jedinjenja: tetrametiltiuram-disulfid (TMTD), tetraetiltiuram-disulfid (TETD), tetrapropiltiuram-disulfid (TPTD), tetraizopropiltiuram-disulfid (TiPTD), tetrabutiltiuramdisulfid (TBTD), tetraizobutiltiuram-disulfid (TiBTD), su potvrđene FTIR, 1H- i 13C-NMR spektroskopijom, MS spektrometrijom i elementalnom analizom. PR Projekat Ministarstva nauke Republike Srbije, br. 172013

Paradigms of rural tourism in Serbia in the function of village revitalisation

Rural regions in Serbia differ considerably in social, economic and demographic characteristics. Basic problems and trends almost all the rural regions share are migrations, poor diversification of economic activities, extensive agriculture, high level of unemployment, lack of employment possibilities, poor and underdeveloped infrastructure, low GDP per capita in comparison to the urban regions and unpolluted environment faced with potential threats . The subject of this paper is to point to the potentials of the rural tourism in Serbia with the aim of village revitalization, as well as its prevention from dying out. Also, the aim of the paper is to stress the fact that the rural tourism is a sustainable model of development and preservation of Serbian village and Serbian peasant from more aspects: economic, tourist, sociological, the spatial planning and ecological ones. Finally, the aim of the paper is to emphasize that it is possible to save village identity by its transformation into ethno village adopting the idea of European ethno villages. Rural tourism in Serbia must become `main` industry` and a generator of sleeping national economy. The main benefits belong to the rural households. Tourist agencies must be engaged in enabling a dialogue between their employees and local representatives. Clients must not only be observers but also critics in the spirit of trust and transparency. A full and true comprehension of the rural tourism role is realized through revealing habits of the host, traditional values rooted in the existing culture, establishment of relations amongst population at the local level. Serbia has favourable conditions for developing rural tourism. It has, in the first place, preserved nature, mild climate, clean air, unpolluted rivers and lakes, rich flora and fauna. At the moment, 11 regional centres (comprising 10-15 municipal offices) are engaged in collecting and spreading relevant information for respective target groups, as well as in strengthening of activities in the local communities. Serbia earns about 10 billion dinnars annually from the rural tourism or one-sixth of gross home product. With a better utilization of the potentials, the participation could be much higher. Rural tourism offers great opportunity for new work posts, but capacities should be used to a greater extent and the problem of seasonality should also be overcome. All the key aims of the rural development in Serbia must be defined by the strategy: development of sustainable and efficient agricultural sector, standard of living of the population which lives from agriculture, creation of social and economic conditions in the rural regions, all of it within the National strategy of the rural development of the Republic of Serbia

Dynamic modelling of elastic plates reinforced by strong fibres

© 2020 Institute of Physics Publishing. All rights reserved. Here are considered composite materials reinforced which strong fibres, which have an important property that they are anisotropic, and in many cases this anisotropy may be very strong, in the sense that mechanical properties are strongly dependent on direction. Such materials are highly resistant to deformation by extension in the fibre direction compared to other deformation modes. Thus material has been modelled as a transversely isotropic for which the extensional modulus in the fibre direction is much greater than that in a direction perpendicular to the fibres. Material is modelled as coordinate free and such model is employed for examination of waves propagating in an infinite plate reinforced by strong fibres. Wave propagation in layer reinforced by one family of fibres with wave direction parallel with stress free boundaries, but otherwise with angle arbitrary to fibre direction, are examined here. The dispersion relations, in specific carbon fibres - epoxy resin composites, are examined. Expressions are also obtained for the variation of displacements and stresses through the thickness of the plate