Contactless ICT transaction model of the urban transport service

The paper examines the problem of the productive functioning of an urban passenger transport system, which has a modular structure for the generation and exploitation of the urban transport services. The research objects consist of conventional, scalable and innovative contactless transaction models of an urban transport services in the case study of the Transport Organization (TO) – Joint Stock Company for Passenger Railway Transport “Serbia Trains” (Srbija Voz a.d.). The urban transport service is defined by invoking users, user expectations and requirements, the input data provided by users to a transport provider, the mechanisms for access and delivery of the service, the resources and roles responsible for delivery, security requirements and other parameters. The communication platform for modeling urban transport services in different transaction contexts is defined by the utilitarian framework with 6W dimensions with situational mapping of the 6 Communication Dynamics Factors (6CDF). The technology-process restructuring was achieved with the scalable In-formation Technology (IT) model by implementing the elements of electronic business in the key activities of the supply of the train tickets. Using the results of the performed research, in the paper has been developed an innovative, non-contact ICT model of urban transport services on the platform for integrating the Internet service into the process-technology and behavioral-context structures. First published online 4 May 202

Symmetry of k·p Hamiltonian in pyramidal InAs/GaAs quantum dots: Application to the calculation of electronic structure

A method for the calculation of the electronic structure of pyramidal self-assembled InAs/GaAs quantum dots is presented. The method is based on exploiting the C-4 symmetry of the 8-band k·p Hamiltonian with the strain taken into account via the continuum mechanical model. The operators representing symmetry group elements were represented in the plane wave basis and the group projectors were used to find the symmetry adapted basis in which the corresponding Hamiltonian matrix is block diagonal with four blocks of approximately equal size. The quantum number of total quasiangular momentum is introduced and the states are classified according to its value. Selection rules for interaction with electromagnetic field in the dipole approximation are derived. The method was applied to calculate electron and hole quasibound states in a periodic array of vertically stacked pyramidal self-assembled InAs/GaAs quantum dots for different values of the distance between the dots and external axial magnetic field. As the distance between the dots in an array is varied, an interesting effect of simultaneous change of ground hole state symmetry, type, and the sign of miniband effective mass is predicted. This effect is explained in terms of the change of biaxial strain. It is also found that the magnetic field splitting of Kramer's double degenerate states is most prominent for the first and second excited state in the conduction band and that the magnetic field can both separate otherwise overlapping minibands and concatenate otherwise nonoverlapping minibands

Analysis of Indicators of Corporate Responsibility in Road Freight Transport: Results of Transport Companies and FMCG Retailers in Serbia

The aim of this paper is the analysis of indicators of corporate responsibility in road freight transport, with special emphasis on freight transport and delivery to Fast Moving Consumers Goods (FMCG) retailers and final consumer. The main task is to rank the importance of corporate responsibility indicators in freight transport from the perspective of the management of transport companies, as well as management of retail stores. In this context, empirical research was conducted on a sample of 124 managers of transport enterprises and 181 managers of FMCG retailers in Serbia. The results showed that the impact of indicators does not depend on the region, transport company and retail store. The indicators show a statistically significant dependence on FMCG type that is being transported. The conducted analysis and achieved results are important in practice as they show to the management of transport companies which indicators should be developed, so that customers (retailers), and thus the users of final products are satisfied. Disadvantages of the existing research and suggestions for future studies are provided in the paper

Educating youth on project sustainability : project engagement and recognition of the green deal

The European Green Deal is a blueprint for a more sustainable life throughout the European Union and its member states. It is based on environmental protection and sensible consumption. However, implementing Green Deal policies necessitates the participation of local populations who are affected by pollution. This paper presents the significance that youth hold in contributing to the implementation and development of the European Green Deal and the circular economy as well as the key role they play in local self-government in order that the aims of the European Green Deal be achieved. To do so, three pilot studies (29 youth were engaged) and one comprehensive research (201 youth were engaged) were conducted on university and secondary school students in Republic of Serbia in 2022. Based on these, youth were found to not possess environmentally friendly habits, as well as adequate education on sustainability challenges. Theoretical and practical implication has been discussed

Quantum transport in semiconductor quantum dot superlattices: electron-phonon resonances and polaron effects

Electron transport in periodic quantum dot arrays in the presence of interactions with phonons was investigated using the formalism of nonequilibrium Green's functions. The self-consistent Born approximation was used to model the self-energies. Its validity was checked by comparison with the results obtained by direct diagonalization of the Hamiltonian of interacting electrons and longitudinal optical phonons. The nature of charge transport at electron -- phonon resonances was investigated in detail and contributions from scattering and coherent tunnelling to the current were identified. It was found that at larger values of the structure period the main peak in the current -- field characteristics exhibits a doublet structure which was shown to be a transport signature of polaron effects. At smaller values of the period, electron -- phonon resonances cause multiple peaks in the characteristics. A phenomenological model for treatment of nonuniformities of a realistic quantum dot ensemble was also introduced to estimate the influence of nonuniformities on current -- field characteristics

Uticaj Bonsilage Plus i Bonsilage Forte na smanjenje mikroflore tokom siliranja lucerke

Crops at ensiling contain both aerobic and anaerobic microorganisms and a range of bacteria and fungi that affect silage quality. Typical classes of microorganisms on plants prior to ensiling are aerobic bacteria, lactic acid bacteria (LAB), enterobacteria, yeasts, molds, clostridia, bacilli, acetic acid bacteria and propionic acid bacteria. The quality of silage depends on the competition between different groups of microorganisms. LAB, which are responsible for the silage fermentation process, usually dominate the silage microflora, but undesirable microorganisms, that occur at low levels on fresh plant material, may grow during the storage of silage and lead to anaerobic or aerobic spoilage. In this study, effects of silage inoculants on reduction of microflora during ensiling of alfalfa have been investigated. The results showed that the addition of commercial silage inoculants, Bonsilage Plus and Bonsilage Forte, had significant effect in reducing total number of aerobic bacteria, enterobacteria, yeasts, moulds and sulphite reducing clostridia during ensiling of alfalfa.Biljni materijal za siliranje sadrži aerobne i anaerobne mikroorganizme i niz bakterija i gljivica koji utiču na kvalitet silaže. Tipične klase mikro-organizama na biljkama pre siliranja su aerobne bakterije, bakterije mlečne kiseline (LAB), enterobakterije, kvasaca, plesni, klostridije, bakterije sirćetne kiseline i bakterije propionske kiseline. Kvalitet silaže zavisi od dominacije različitih grupa mikroorganizama. Bakterije mlečne kiseline, koje su odgovorne za proces fermentacije silaže, obično dominiraju mikroflorom silaže, ali broj neželjenih mikroorganizama, koji se javljaju u niskom nivou u svežoj biljnoj masi, može da raste tokom skladištenja silaže i dovede do njenog kvarenja. U ovom radu je ispitivan uticaj silažnih inokulanata na smanjenje mikroflore u toku siliranja lucerke. Rezultati su pokazali da je dodavanje komercijalnih inokulanata Bonsilage Plus i Bonsilage Forte, imalo značajan efekat na smanjenje ukupnog broja aerobnih bakterija, enterobakterija, kvasaca, plesni i klostridija tokom siliranja lucerke

Density matrix theory of transport and gain in quantum cascade lasers in a magnetic field

A density matrix theory of electron transport and optical gain in quantum cascade lasers in an external magnetic field is formulated. Starting from a general quantum kinetic treatment, we describe the intraperiod and interperiod electron dynamics at the non-Markovian, Markovian, and Boltzmann approximation levels. Interactions of electrons with longitudinal optical phonons and classical light fields are included in the present description. The non-Markovian calculation for a prototype structure reveals a significantly different gain spectra in terms of linewidth and additional polaronic features in comparison to the Markovian and Boltzmann ones. Despite strongly controversial interpretations of the origin of the transport processes in the non- Markovian or Markovian and the Boltzmann approaches, they yield comparable values of the current densities

Национална економија

Serbian. У овом одељку разматрају се опште карактеристике националне економије. У првом делу приказан је њен историјски развој, који је обухватио привреду у средњовековној српској држави Немањића, преко развоја у оквирима турске феудалне државе, изградње самосталне српске државе након српских устанака и ослобођења од Турске, па до развоја у савременим условима 20. и 21. века. Тај вишевековни развој протицао је у сталним напорима да се превазиђе наслеђена економска заосталост, да се унапреди и модернизује привреда, односно да се претежно аграрна земља претвори у земљу с модерном индустријском привредом, али и уз отпоре изражене у супротној тенденцији да се одржи аграрни, односно сељачки карактер земље. Ипак, био је то процес који се уз мање или више осцилација, али у целини успешно одвијао све до пред крај 20. века. Међутим, почев од последње деценије претходног века земља је током процеса транзиције била деиндустријализована, тако да је сада на нивоу развоја од пре неколико деценија, и стоји пред поновним захтевима за (ре)индустријализацијом. У другом делу разматрају се актуелне карактеристике привреде Србије, подељене у четири сектора. English. In this chapter the main characteristics of the national economy will be considered. In the first part there is explored its historical development. It involves the economy of the middle century Nemanjićs’ Serbian state, through the development in the framework of Turkish feudal state, the building of independent Serbian state after the Serbian uprisings and liberation from Turkey, up to development in modern circumstances of 20th and 21st centuries. This many centuries development characterize constant efforts to overcome the inherited economic backwardness, to move up and modernize the economy, i.e. to transform the predominantly agrarian state to the state with modern manufacturing economy, but also with resistances represented in opposite tendency to keep agrarian, i.e. peasant character of the state. Although, it was the process, that successfully carried out until to last decade of 20th century. But, since this decade the state was deindustrialized through the transition process, so it is now on the level of some decade before, and state is confronted with the repeated need for reindustrialization. In the second part of this chapter the actual characteristics of the Serbian economy are considered, divided in four sectors

Importance of Polaronic Effects for Charge Transport in CdSe Quantum Dot Solids

We developed an accurate model accounting for electron-phonon interaction in colloidal quantum dot supercrystals that allowed us to identify the nature of charge carriers and the electrical transport regime. We find that in experimentally analyzed CdSe nanocrystal solids the electron-phonon interaction is sufficiently strong that small polarons localized to single dots are formed. Charge-carrier transport occurs by small polaron hopping between the dots, with mobility that decreases with increasing temperature. While such a temperature dependence of mobility is usually considered as a proof of band transport, we show that the same type of dependence occurs in the system where transport is dominated by small polaron hopping

Mapping of the Business Infrastructure in Serbia with a Special View at Brownfield and Greenfield

Contemporary business dictionaries lack a precise definition of the notion of business infrastructure. Also, there is an open question as to what are all the things that comprise a business infrastructure. In Serbia, there is not a legislative framework yet which recognizes and stimulates its development by categories and geographic position. Parallel to the lack of notional and legislative frameworks, we can also observe numerous activities in the field of creation of development policies and project investments in concrete facilities and sites. During the previous several mandates (since 2007), the Government of Serbia has stimulated the development of business infrastructure throughout the country using the budget funds. During the same period, significant donor funds have been spent precisely for the projects in the sphere of enhancement of business infrastructure in Serbia. In addition to the definitions provided for a set of important notions, the paper also presents a structural analysis based on the results of the survey / mapping of business infrastructure. It also shows the methodological procedure with a special view at the socalled brownfield and greenfield potentials. Also, the results of the survey have been considered within a general socio economic context with a critical view at the effects of the implemented development policies