74 research outputs found
Visoko obrazovanje i privredni rast u savremenim tržišnim privredama
The aim of the doctoral dissertation is to examine the role of higher
education and emphasize the importance of strengthening its
capacities as well as the improvement of the quality of the higher
education system in order to stimulate the economic growth and
development.
The analysis contained in the work is based on the indicators from the
areas of education, economic growth and the labor market in the EU
countries from 2006 to 2017. The descriptive segment of the analysis
compares the above mentioned countries, non-EU European and some
Balkan countries. In order to estimate the position of higher education
in those countries, we analyzed the organizational models and
financing of their higher education systems, while, in order to define
their power and efficiency, we analyzed the investment in higher
education and the achievements of higher education systems. To
prove the quantitative impact of higher education on economic
growth, an econometric model with the method of multi-regression
has been developed.
The research indicates that higher education has a relatively higher
significance for the process of economic growth when compared to
the importance of lower levels of education. The analysis presented in
the paper confirms the importance of higher education for solving the
problem of unemployment and brain-drain, as the crucial problems of
labor markets of contemporary economies. The research shows that a
greater investment in higher education results in a higher quality of
higher education systems defined by the ranking of universities on the
world ranking lists. The dissertation provides an insight into the
stagnancy of the Serbian higher education system on the basis of
numerous factors compared to higher education systems of developed
economies contained in the research. The results of the applied multiregression
analysis support the theory that higher education, measured
by the number of university graduates in a population, is a significant
factor of economic growth measured by the GDP growth rate.
A set of proposals referring to the changes of higher education in
accordance with the needs of the labor market and improvement of
the contribution of this system to economic prosperity is presented in
this paper
Assessment of synergistic effect on performing the co-pyrolysis process of coal and waste blends based on thermal analysis
The preliminary thermogravimetric studies of co-pyrolyzed low rank coals (lignites Kostolac and Kolubara) with waste materials (spent coffee ground and waste rubber granulate) in a form of blends have been performed. Thermal analysis measurements of blend samples were carried out in a nitrogen, atmosphere at three different heating rates of 10, 15, and 20 K per minute. The coal-waste blends were prepared in the percentage ratios of 90:10, 80:20, and 70:30. This work analyzed the synergy analysis for considered blends shown via descriptive parameters during co-pyrolysis process. According to the performed analysis, the presence of synergistic effect was identified, where strong interactions were also observed. For lignite-spent coffee ground blends, it was found that two factors which affect the synergy effect with coal are concentration of added biomass material and the heating rate. For lignite-tire rubber granulate blends, the blending ratio take on a decisive role for positive consequences of a synergistic effect (ratios below 30% of tire rubber granulate in coals are desirable). Also, in this work the influence of micro-scale condition parameters such as heating rate (as the experimental regulatory factor) was analyzed on the magnitude response of synergism during co-pyrolysis
Multicomponent Modelling Kinetics and Simultaneous Thermal Analysis of Apricot Kernel Shell Pyrolysis
Apricot kernel shells are naturally available source of biomass with potential for conversion to clean energy through a thermo-chemical process such as pyrolysis. To facilitate further process development, an advanced mathematical model which represents the process kinetics is developed and validated on the thermal decomposition
studies using simultaneous thermal analysis, over a temperature range of 30-900 °C, at four heating rates of 5, 10, 15 and 20 °C min−1, under argon atmosphere. Model-free analysis and numerically developed methods were utilized for determination of effective
activation energies, pre-exponential factors and the fractional contribution. A novel approach is introduced in order to determine actual pseudo-components of studied biomass that are included in its composition. The comparative study of the obtained kinetic results was also presented. The results obtained strongly indicated that the
pseudo-component reaction modelling method could be employed to predict the experimental devolatilization rate and biomass composition with a high likelihood of success
Comparative pyrolysis kinetics of various biomasses based on model-free and DAEM approaches improved with numerical optimization procedure
The pyrolysis process of various types of biomass (agricultural and wood by-products) in non-isothermal conditions using simultaneous thermal analyses (STA) was investigated. Devolatilization kinetics was implemented through combined application of model-free methods and DAEM (distributed activation energy model) using Gaussian distribution functions of activation energies. Results obtained were used in the curve prediction of the rate of mass loss against temperature at various heating rates by numerical optimization. The possible calculation of biomass samples behavior under pyrolytic conditions as the summation of their pseudo-components, hemicelluloses, cellulose, and lignin is also explored. The differences between experimental and calculated data are less than 3.20% offering a quality test of applicability of proposed model on the kinetic studies of a wide range of biomass samples. It seems that the most physically realistic model is the decomposition of biomass in three reactions, depending on the composition of the biomass regarding hemicelluloses, cellulose, and lignin. Kinetic model applied here may serve as a starting point to build more complex models capable of describing the thermal behavior of plant materials during thermochemical processing
Kinetic Parameters Identification of Conductive Enhanced Hot Air Drying Process of Food Waste
The efficient utilization of waste from food industry is possible after thermal treatment of the material. This treatment should be economically feasible and compromise the energy efficient drying process. The main goal of this investigation is to determine drying characteristics of nectarine pomace as a waste from food industry. The measurements were performed in an experimental dryer by combined conductive-convective drying method with disk-shaped samples of 5, 7, and 10 mm thickness and 100 mm in diameter at the air temperatures of 30, 40, 50, 60, and 70°C, hot plate temperatures of 50, 60, and 70°C and air velocity of 1.5 m/s. The drying curves were compared to a few semi-theoretical mathematical models. The Logarithmic model showed the best correlation. On the basis of experiments, it is determined that the drying process takes place in a falling rate period and it is accepted that the main mechanism of moisture removal is diffusion. The effective coefficient of diffusion was determined using experimental results by calculating the slope of the drying curves. Drying time and equilibrium moisture are determined for each experiment. Analysis of drying curves showed that the conductive-enhanced drying method reduces drying times and increases the diffusivity coefficient. The character of drying rate curves for conductiveenhanced drying was analysed and compared with pure convective drying of nectarine pomace
Measurements of , K, p and spectra in proton-proton interactions at 20, 31, 40, 80 and 158 GeV/c with the NA61/SHINE spectrometer at the CERN SPS
Measurements of inclusive spectra and mean multiplicities of ,
K, p and produced in inelastic p+p interactions at
incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c ( 6.3,
7.7, 8.8, 12.3 and 17.3 GeV, respectively) were performed at the CERN Super
Proton Synchrotron using the large acceptance NA61/SHINE hadron spectrometer.
Spectra are presented as function of rapidity and transverse momentum and are
compared to predictions of current models. The measurements serve as the
baseline in the NA61/SHINE study of the properties of the onset of
deconfinement and search for the critical point of strongly interacting matter
Measurement of negatively charged pion spectra in inelastic p+p interactions at = 20, 31, 40, 80 and 158 GeV/c
We present experimental results on inclusive spectra and mean multiplicities
of negatively charged pions produced in inelastic p+p interactions at incident
projectile momenta of 20, 31, 40, 80 and 158 GeV/c ( 6.3, 7.7,
8.8, 12.3 and 17.3 GeV, respectively). The measurements were performed using
the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton
Synchrotron.
Two-dimensional spectra are determined in terms of rapidity and transverse
momentum. Their properties such as the width of rapidity distributions and the
inverse slope parameter of transverse mass spectra are extracted and their
collision energy dependences are presented. The results on inelastic p+p
interactions are compared with the corresponding data on central Pb+Pb
collisions measured by the NA49 experiment at the CERN SPS.
The results presented in this paper are part of the NA61/SHINE ion program
devoted to the study of the properties of the onset of deconfinement and search
for the critical point of strongly interacting matter. They are required for
interpretation of results on nucleus-nucleus and proton-nucleus collisions.Comment: Numerical results available at: https://edms.cern.ch/document/1314605
Updates in v3: Updated version, as accepted for publicatio
Measurements of , , , and proton production in proton-carbon interactions at 31 GeV/ with the NA61/SHINE spectrometer at the CERN SPS
Measurements of hadron production in p+C interactions at 31 GeV/c are
performed using the NA61/ SHINE spectrometer at the CERN SPS. The analysis is
based on the full set of data collected in 2009 using a graphite target with a
thickness of 4% of a nuclear interaction length. Inelastic and production cross
sections as well as spectra of , , p, and are
measured with high precision. These measurements are essential for improved
calculations of the initial neutrino fluxes in the T2K long-baseline neutrino
oscillation experiment in Japan. A comparison of the NA61/SHINE measurements
with predictions of several hadroproduction models is presented.Comment: v1 corresponds to the preprint CERN-PH-EP-2015-278; v2 matches the
final published versio
Measurements of , , and spectra in proton-proton interactions at 20, 31, 40, 80 and 158 GeV/ with the NA61/SHINE spectrometer at the CERN SPS
Measurements of inclusive spectra and mean multiplicities of π ±
π±
, K ±
±
, p and p ¯
p¯
produced in inelastic p + p interactions at incident projectile momenta of 20, 31, 40, 80 and 158 GeV /c
GeV /c
(s √ =
s=
6.3, 7.7, 8.8, 12.3 and 17.3 GeV
GeV
, respectively) were performed at the CERN Super Proton Synchrotron using the large acceptance NA61/SHINE hadron spectrometer. Spectra are presented as function of rapidity and transverse momentum and are compared to predictions of current models. The measurements serve as the baseline in the NA61/SHINE study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter
Measurements of π± differential yields from the surface of the T2K replica target for incoming 31 GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS
Measurements of particle emission from a replica of the T2K 90 cm-long carbon target were performed in the NA61/SHINE experiment at CERN SPS, using data collected during a high-statistics run in 2009. An efficient use of the long-target measurements for neutrino flux predictions in T2K requires dedicated reconstruction and analysis techniques. Fully-corrected differential yields of π ± -mesons from the surface of the T2K replica target for incoming 31 GeV/c protons are presented. A possible strategy to implement these results into the T2K neutrino beam predictions is discussed and the propagation of the uncertainties of these results to the final neutrino flux is performed
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