Abstract The paper presents a comparative analysis between the surface global irradiation measured for Romania and the predicted irradiation obtained by numerical simulation. The measured data came from the Romanian National meteorological Administration. Based on a preliminary analysis that took into account several criteria among which, performance, cost, popularity and meteorological and satellite data accessibility we concluded that a combination GFS-WRF(NMM) or GFS-WRF(ARW) is most suitable for short term global solar irradiation forecasting in order to assess the performance of the photovoltaic power stations (Badescu and Dumitrescu, 2012, [1], Martin et al., 2011, [2]).
{"title":"Comparison Between Measurements and WRF Numerical Simulation of Global Solar Irradiation in Romania","authors":"D. Isvoranu, V. Badescu","doi":"10.1515/awutp-2015-0103","DOIUrl":"https://doi.org/10.1515/awutp-2015-0103","url":null,"abstract":"Abstract The paper presents a comparative analysis between the surface global irradiation measured for Romania and the predicted irradiation obtained by numerical simulation. The measured data came from the Romanian National meteorological Administration. Based on a preliminary analysis that took into account several criteria among which, performance, cost, popularity and meteorological and satellite data accessibility we concluded that a combination GFS-WRF(NMM) or GFS-WRF(ARW) is most suitable for short term global solar irradiation forecasting in order to assess the performance of the photovoltaic power stations (Badescu and Dumitrescu, 2012, [1], Martin et al., 2011, [2]).","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73220563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Pulsed laser irradiated vanadium surface morphology under different ambient has been prepared and characterized using fractal dimension analysis method on scanning electron microscopy (SEM) images. In presence of different ambient, self-periodic and self-similar surface patterns (e.g. dots, islands, and pins) were grown and appeared in different shapes. The fractal dimension (FD) of this developed vanadium nanostructure was calculated by fractal box count method (FBM). The calculated fractal dimension (FD, Df) shows dependence on the different type on ambient and the number of laser shots.
{"title":"Fractal Analysis on Morphology of Laser Irradiated Vanadium Surfaces Under Different Ambient","authors":"Zs. Szkiva, A. Balint, M. Füle, L. Nánai","doi":"10.1515/awutp-2015-0104","DOIUrl":"https://doi.org/10.1515/awutp-2015-0104","url":null,"abstract":"Abstract Pulsed laser irradiated vanadium surface morphology under different ambient has been prepared and characterized using fractal dimension analysis method on scanning electron microscopy (SEM) images. In presence of different ambient, self-periodic and self-similar surface patterns (e.g. dots, islands, and pins) were grown and appeared in different shapes. The fractal dimension (FD) of this developed vanadium nanostructure was calculated by fractal box count method (FBM). The calculated fractal dimension (FD, Df) shows dependence on the different type on ambient and the number of laser shots.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72816354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In this paper it is present a non contact method for 3D measurements on parabolic surface antenna. In order to obtain modal parameters and modal shapes of a parabolic surface antenna a Microflown USP (Ultimate Sound Probe) is used. Microflown sensors are close to antenna and can be used for the non contact measurement of the normal component of the structural velocity.
{"title":"Non Contact Vibration Measurements on Parabolic Surface Antenna","authors":"D. Simoiu, L. Bereteu","doi":"10.1515/awutp-2015-0109","DOIUrl":"https://doi.org/10.1515/awutp-2015-0109","url":null,"abstract":"Abstract In this paper it is present a non contact method for 3D measurements on parabolic surface antenna. In order to obtain modal parameters and modal shapes of a parabolic surface antenna a Microflown USP (Ultimate Sound Probe) is used. Microflown sensors are close to antenna and can be used for the non contact measurement of the normal component of the structural velocity.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79127021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Lungu, R. Giugiulan, A. Lungu, M. Bunoiu, A. Neculae
Abstract This paper investigates the possibility to improve the filtering process of flue gas by separation of suspended nanoparticle using dielectrophoresis. The study focuses on the particles having an average radius of about 50-150 nm, that cannot be filtrated by classical techniques but have a harmful effect for environment and human health. The size distribution nanoparticles collected from the flue gas filters of a hazardous waste incinerator plant were evaluated. Based on obtained experimental data and a proposed mathematical model, the concentration distribution of nanoparticle suspended in flue gas inside a microfluidic separation device was analyzed by numerical simulations, using the finite element method. The performances of the device were described in terms of three new specific quantities related to the separation process, namely Recovery, Purity and Separation Efficiency. The simulations could provide the optimal values of control parameters for separation process, and aim to be a useful tool in designing microfluidic devices for separating nanoparticle from combustion gases.
{"title":"The Aharonov-Bohm Effect and Transport Properties in Graphene Nanostructures","authors":"M. Lungu, R. Giugiulan, A. Lungu, M. Bunoiu, A. Neculae","doi":"10.1515/awutp-2015-0110","DOIUrl":"https://doi.org/10.1515/awutp-2015-0110","url":null,"abstract":"Abstract This paper investigates the possibility to improve the filtering process of flue gas by separation of suspended nanoparticle using dielectrophoresis. The study focuses on the particles having an average radius of about 50-150 nm, that cannot be filtrated by classical techniques but have a harmful effect for environment and human health. The size distribution nanoparticles collected from the flue gas filters of a hazardous waste incinerator plant were evaluated. Based on obtained experimental data and a proposed mathematical model, the concentration distribution of nanoparticle suspended in flue gas inside a microfluidic separation device was analyzed by numerical simulations, using the finite element method. The performances of the device were described in terms of three new specific quantities related to the separation process, namely Recovery, Purity and Separation Efficiency. The simulations could provide the optimal values of control parameters for separation process, and aim to be a useful tool in designing microfluidic devices for separating nanoparticle from combustion gases.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73093746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In most of the applications involving neural networks, the main problem consists in finding an optimal procedure to reduce the real neuron to simpler models which still express the biological complexity but allow highlighting the main characteristics of the system. We effectively investigate a simple reduction procedure which leads from complex models of Hodgkin-Huxley type to very convenient binary models of Hopfield type. The reduction will allow to describe the neuron interconnections in a quite large network and to obtain information concerning its symmetry and stability. Both cases, on homogeneous voltage across the membrane and inhomogeneous voltage along the axon will be tackled out. Few numerical simulations of the neural flow based on the cable-equation will be also presented.
{"title":"Neural Flows in Hopfield Network Approach","authors":"C. Ionescu, E. Panaitescu, Mihai Stoicescu","doi":"10.1515/awutp-2015-0101","DOIUrl":"https://doi.org/10.1515/awutp-2015-0101","url":null,"abstract":"Abstract In most of the applications involving neural networks, the main problem consists in finding an optimal procedure to reduce the real neuron to simpler models which still express the biological complexity but allow highlighting the main characteristics of the system. We effectively investigate a simple reduction procedure which leads from complex models of Hodgkin-Huxley type to very convenient binary models of Hopfield type. The reduction will allow to describe the neuron interconnections in a quite large network and to obtain information concerning its symmetry and stability. Both cases, on homogeneous voltage across the membrane and inhomogeneous voltage along the axon will be tackled out. Few numerical simulations of the neural flow based on the cable-equation will be also presented.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73629704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Baník, Jozefa Lukovičová, G. Pavlendová, R. Podoba
Abstract The paper deals with the problem of decreasing level of knowledge of university students due to the changes of the school system in Slovakia. As the commonly repeated words connected with education in 21st.century are key competencies, we tried to look at the problems and challenges in teaching physics from this point of view. The role of classical experiments in our computerized world is also discussed.
{"title":"Problems in Teaching Physics at Technical Universities","authors":"I. Baník, Jozefa Lukovičová, G. Pavlendová, R. Podoba","doi":"10.1515/AWUTP-2015-0102","DOIUrl":"https://doi.org/10.1515/AWUTP-2015-0102","url":null,"abstract":"Abstract The paper deals with the problem of decreasing level of knowledge of university students due to the changes of the school system in Slovakia. As the commonly repeated words connected with education in 21st.century are key competencies, we tried to look at the problems and challenges in teaching physics from this point of view. The role of classical experiments in our computerized world is also discussed.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79936084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract This paper is focused on improving the quality of nowcasting solar irradiance by enhancing the clear sky component of the model. A simple linear correction for the average atmospheric transmittance is proposed. The correction is based on the most recent measurements recorded prior the forecasting moment. The proposed procedure was tested against data measured on the Solar Platform of the West University of Timisoara. Overall results demonstrates a notable improvement in the clear sky model accuracy.
{"title":"Improving The Accuracy of the Empirical Clear Sky Solar Irradiance Models","authors":"Oana Mares, D. Vizman, M. Paulescu","doi":"10.1515/awutp-2015-0111","DOIUrl":"https://doi.org/10.1515/awutp-2015-0111","url":null,"abstract":"Abstract This paper is focused on improving the quality of nowcasting solar irradiance by enhancing the clear sky component of the model. A simple linear correction for the average atmospheric transmittance is proposed. The correction is based on the most recent measurements recorded prior the forecasting moment. The proposed procedure was tested against data measured on the Solar Platform of the West University of Timisoara. Overall results demonstrates a notable improvement in the clear sky model accuracy.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85455377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In this paper we discuss interplays between the Aharonov-Bohm effect and the transport properties in mesoscopic ring structures based on graphene. The interlayer interaction leads to a change of the electronic structure of bilayer graphene ring such that the electronic energy dispersion law exhibits a gap, either by doping one of the layers or by the application of an external perpendicular electric field. Gap adjustments can be done by varying the external electric field, which provides the possibility of obtaining mesoscopic devices based on the electronic properties of bilayer graphene. This opens the way to controllable manipulations of phase-coherent mesoscopic phenomena, as well as to Aharonov-Bohm oscillations depending on the height of the potential step and on the radius of the ring. For this purpose one resorts to a tight-binding model such as used to the description of conductance.
{"title":"The Aharonov-Bohm Effect and Transport Properties in Graphene Nanostructures","authors":"D. Racolta, C. Micu","doi":"10.1515/awutp-2015-0106","DOIUrl":"https://doi.org/10.1515/awutp-2015-0106","url":null,"abstract":"Abstract In this paper we discuss interplays between the Aharonov-Bohm effect and the transport properties in mesoscopic ring structures based on graphene. The interlayer interaction leads to a change of the electronic structure of bilayer graphene ring such that the electronic energy dispersion law exhibits a gap, either by doping one of the layers or by the application of an external perpendicular electric field. Gap adjustments can be done by varying the external electric field, which provides the possibility of obtaining mesoscopic devices based on the electronic properties of bilayer graphene. This opens the way to controllable manipulations of phase-coherent mesoscopic phenomena, as well as to Aharonov-Bohm oscillations depending on the height of the potential step and on the radius of the ring. For this purpose one resorts to a tight-binding model such as used to the description of conductance.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83086028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The information-theoretical entropy, also called the “classical” entropy, was introduced by Wehrl in terms of the Glauber coherent states (CSs) | z > , i.e. the CSs corresponding to the one-dimensional harmonic oscillator (HO-1D). In the present paper, we have focused our attention on the examination of the information-theoretical entropy, i.e. the Wehrl entropy, for both the pure and the mixed (thermal) states of some quantum oscillators.
Wehrl用Glauber相干态(CSs) | z >，即与一维谐振子(HO-1D)相对应的CSs，引入了信息理论熵，也称为“经典”熵。在本文中，我们把注意力集中在对某些量子振子的纯态和混合(热)态的信息理论熵，即Wehrl熵的检验上。
{"title":"On The Information-Theoretical Entropy for Some Quantum Oscillators","authors":"D. Popov, N. Pop, Simona Șimon","doi":"10.1515/awutp-2015-0108","DOIUrl":"https://doi.org/10.1515/awutp-2015-0108","url":null,"abstract":"Abstract The information-theoretical entropy, also called the “classical” entropy, was introduced by Wehrl in terms of the Glauber coherent states (CSs) | z > , i.e. the CSs corresponding to the one-dimensional harmonic oscillator (HO-1D). In the present paper, we have focused our attention on the examination of the information-theoretical entropy, i.e. the Wehrl entropy, for both the pure and the mixed (thermal) states of some quantum oscillators.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78161551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The paper reports on the presence of various metals in soil in Timis county. A set of 18 samples were collected from different points of interest. The metal content of the samples was investigated using a handheld XRF Niton XLp 300 GOLDD analyzer. Special attention was paid to the metals with harmful potential to humans. Based on the obtained results, a set of conclusions on the environment’s health was drawn.
{"title":"Analysis of Metal Content in Soil in Timis County","authors":"N. Stefu, A. Neculae, L. Turcu, Á. Bálint","doi":"10.1515/awutp-2015-0105","DOIUrl":"https://doi.org/10.1515/awutp-2015-0105","url":null,"abstract":"Abstract The paper reports on the presence of various metals in soil in Timis county. A set of 18 samples were collected from different points of interest. The metal content of the samples was investigated using a handheld XRF Niton XLp 300 GOLDD analyzer. Special attention was paid to the metals with harmful potential to humans. Based on the obtained results, a set of conclusions on the environment’s health was drawn.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88701056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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