Class concepts and stratification research in Slovenia

This article deals with the concept of class and class analysis in sociological research in the last few decades in Slovenia. It reveals the specific reasons for the relatively marginal role of this sort of analysis before and especially after 1990. First, it lists a selection of the key class and stratification studies during the communist era. Second, it describes the class and stratification studies that occurred before and around the regime change (1980-1991). Third, it describes a number of stratification research studies after 1991 (to the present), with many international components. The research efforts of a few influential research groups in Slovenia that have engaged in class and stratification studies, following special approaches, are presented and commented on: the Marxist tradition, a Bourdieuian approach focusing on symbolic discourse, and a structurally based labor process approach. In the conclusion, both a substantive and methodological account of relative achievements in the field are offered

Specializacija in integracija dela v industrijskem obratu

Productional divison of labour implies the dissemination of several fragments of a production process among particular individuals. The work fragmented in this way can be joined into a unified production process solely by way of — corresponding to the mentioned fragmentation — differentiation, concentration, and centralization of the integrative/management activity. To manage an industrial plant means to transmit partial operations — segments of the productional division of labour. Management is the point of the division of labour which stands above the productional division of labour: the counterpoint of the productional division of labour. Productional division of labour, on the one hand, and the managerial counterpoint of this division of labour, on the other, represent the poles of the quantitatively and qualitatively unequal distribution of activities within an industrial plant. Such substantially unequal distribution of activities in the production process in the matrix how the management pyramid, i. e. power in the production process is set up / established.Produkcijska delitev dela je porazdelitev različnih fragmentov nekega produkcijskega procesa na različni individue. Tako fragmentirano delo je možno povezovati v enoten produkcijski proces samo s pomočjo — tej fragmentarnosti odgovarjajoče — diferenciacije, koncentracije in centralizacije integrirajoče/upravljalske dejavnosti. Upravljanje industrijskega obrata je posredovanje delovnih operacij — segmentov produkcijske delitve dela. Upravljanje je en pol delitve dela, ki je nadprodukcijsko delitvijo dela kot drugim polom. Produkcijska delitev dela po eni strani, ter uprav-ljalski kontrapunkt te delitve dela po drugi strani, sta pola kvantitativno in kvalitativno neenake delitve dejavnosti v industrijskem obratu. Ta bistveno neenaka delitev dejavnosti v produkcijskem procesu je tista matrica, po kateri se oblikuje upravljalska piramida — oblast v produkcijskem procesu

Review of membrane contactors designs and applications of different modules in industry

Nov način primene membranskih procesa u prečišćavanju voda iz različitih industrija je korišćenje membranskih kontaktora. Tehnologija membranskih kontaktora ima primene u tretmanu otpadnih voda, farmaceutskoj industriji fermentaciji, proizvodnji poluprovodnika, ekstrakciji proteina, karbonizaciji pića, uklanjanju isparljivih organskih komponenata (VOC) iz otpadnog gasa i tako dalje. Membranski sistemi projektovani da formiraju kontakt između dve komponente (tečno / tečno, tečno/gas i gas/gas) su zajednički definisani kao membranski kontaktori. Membranski kontaktori su uređaji koji postižu prenos materije u sistemu gas/tečnost ili tečnost/tečnost bez disperzije jedne faze unutar druge. Membrana se koristi za separaciju i transport radne komponente mnogo lakše u odnosu na druge usled razlika u fizičkim i/ili hemijskim karakteristikama između membrane i komponenata. Postoji nekoliko prednosti pri korišćenju membranskih kontaktora u odnosu na konvencionalne metode. Neke od njih su: ne postoji plavljenje pri visokim protocima, zadržavanje radnih karakteristika pri niskim protocima, odsustvo emulzije, nema razlike gustina traženih fluida i velika površina. Glavni cilj ovog rada je bio pregled karakteristika i primene membranskih kontaktora, posebno primene kontaktora za izdvajanje rastvorenog kiseonika iz vodenih rastvora uz pomoć vakuuma.New way for applying membrane processes for purification water in different industries is using membrane contactors. Membrane contactor technology has applications in wastewater treatment, pharmaceuticals, fermentation semiconductor manufacturing, protein extraction, carbonation of beverages VOC removal from waste gas and so forth. Membrane systems that are designed to form an interface between two components (liquid/liquid, liquid/gas, and gas/gas) are commonly referred to as membrane contactors. The membrane contactors are devices that achieve gas/liquid or liquid/liquid mass transfer without dispersion of one phase within the other. The membrane is used to accomplish a particular separation and transport of one component more easily than another because of differences in physical and/or chemical properties between the membrane and the permeating components. There are a few advantages to using membrane contactors in contrast to conventional methods. Some of them are no flooding at high flow rates, no unloading at low flow rates, absence of emulsions, no density difference between fluids required, and high interfacial area. The main goal in this paper has been a general review of membrane contactor designs and operations, especially in applying of contactors for removing dissolved oxygen from aqueous solutions by vacuum degassing

Review of membrane contactors designs and applications of different modules in industry

Nov način primene membranskih procesa u prečišćavanju voda iz različitih industrija je korišćenje membranskih kontaktora. Tehnologija membranskih kontaktora ima primene u tretmanu otpadnih voda, farmaceutskoj industriji fermentaciji, proizvodnji poluprovodnika, ekstrakciji proteina, karbonizaciji pića, uklanjanju isparljivih organskih komponenata (VOC) iz otpadnog gasa i tako dalje. Membranski sistemi projektovani da formiraju kontakt između dve komponente (tečno / tečno, tečno/gas i gas/gas) su zajednički definisani kao membranski kontaktori. Membranski kontaktori su uređaji koji postižu prenos materije u sistemu gas/tečnost ili tečnost/tečnost bez disperzije jedne faze unutar druge. Membrana se koristi za separaciju i transport radne komponente mnogo lakše u odnosu na druge usled razlika u fizičkim i/ili hemijskim karakteristikama između membrane i komponenata. Postoji nekoliko prednosti pri korišćenju membranskih kontaktora u odnosu na konvencionalne metode. Neke od njih su: ne postoji plavljenje pri visokim protocima, zadržavanje radnih karakteristika pri niskim protocima, odsustvo emulzije, nema razlike gustina traženih fluida i velika površina. Glavni cilj ovog rada je bio pregled karakteristika i primene membranskih kontaktora, posebno primene kontaktora za izdvajanje rastvorenog kiseonika iz vodenih rastvora uz pomoć vakuuma.New way for applying membrane processes for purification water in different industries is using membrane contactors. Membrane contactor technology has applications in wastewater treatment, pharmaceuticals, fermentation semiconductor manufacturing, protein extraction, carbonation of beverages VOC removal from waste gas and so forth. Membrane systems that are designed to form an interface between two components (liquid/liquid, liquid/gas, and gas/gas) are commonly referred to as membrane contactors. The membrane contactors are devices that achieve gas/liquid or liquid/liquid mass transfer without dispersion of one phase within the other. The membrane is used to accomplish a particular separation and transport of one component more easily than another because of differences in physical and/or chemical properties between the membrane and the permeating components. There are a few advantages to using membrane contactors in contrast to conventional methods. Some of them are no flooding at high flow rates, no unloading at low flow rates, absence of emulsions, no density difference between fluids required, and high interfacial area. The main goal in this paper has been a general review of membrane contactor designs and operations, especially in applying of contactors for removing dissolved oxygen from aqueous solutions by vacuum degassing

Use of linear radiofrequency device in liver resection

Background/Aim. Linear radiofrequency device (LRFD) is disposable tool designed for liver parenchyma transection using controlled radiofrequency to 'seal' blood vessels and bile ducts, making liver resection easier and safer compared to classical resectional techniques. The aim of this study was to determine real value of the LRFD compared to the standard 'keliclasia' technique. Methods. This prospective study analyzed the significant intraoperative parameters and postoperative results of the 200 patients who underwent surgery at the Surgery Clinic of Clinical Centre in Niš, between January 1, 2001, and January 1, 2009. The patients were divided into two groups: the control Keli group (144 patients) with the 'keliclasia' resection technique and the control RF group (with resection performed using LRFD - Tissue Link / Dissection Sealer (DS - 3.0) (56 patients). The following parameters were analyzed: duration of liver ischemia, liver parenchyma transection time, intraoperative blood loss, significant intraoperative and postoperative complication rate, duration of hospitalization and mortality. Results. LRFD was used in 56 liver resections. The average duration of liver ischemia in the RF group was shorter than in the Keli group (7 versus 22 minutes). Parenchymal liver transection was significantly slower in the RF group than in the Keli group (2.05 versus 4.34 cm2/minutes, respectively). There was less intraoperative bleeding using LRFD 'Keliclasia' tehniquethan in the control group (390 mL compared to 420 mL, respectively). After the use of LRFD two cases of biliary leak and 4 pleural effusions were registered. Conclusion. LRFD is simple device for safe liver transection with decreased need for liver ischemia and singificant reducing of the intraoperative blood loss. High price for disposable device and slow parenchyma transection are disadvantages of this device

Simulation of a classical swine fever outbreak in rural areas of the Republic of Serbia

Several different strategies for control and eradication of classical swine fever (CSF) were compared using a Monte Carlo method-based simulation model. The control strategy analysed in this paper, in addition to other CSF control measures, includes application of biosecurity measures on pig farms and rural backyard holdings. Elements of the control strategy are based on applicable regulations and include the simulation of detection of the disease, setting up the protected and surveillance zones, standstill of pig movements and restricted movement of animals, vehicles, equipment, and people with strong control measures in protection and surveillance zones, euthanasia of susceptible pigs, protective vaccination of pigs, compensation etc. During the simulation, different output parameters were compared such as: duration of epidemic of a disease, number of affected holdings and animals, direct costs such as those for dead or culled animals, costs of surveillance, disposal of infectious materials, cleaning and disinfection. Depopulation of affected animals with early diagnostics and vaccination in the protection and surveillance zone proved to be the most effective measures to stop the spread and for the eradication of the disease. Moreover, during the simulation, systematic implementation of biosecurity measures in all pig production clusters was demonstrated to be an appropriate strategy for sustainable control of CSF and the establishment of a stable epidemiological situation

Thermal analysis of physical and chemical changes occuring during regeneration of activated carbon

High-temperature thermal process is a commercial way of regeneration of spent granular activated carbon. The paper presents results of thermal analysis conducted in order to examine high-temperature regeneration of spent activated carbon, produced from coconut shells, previously used in drinking water treatment. Results of performed thermogravimetric analysis, derivative thermogravimetric analysis, and differential thermal analysis, enabled a number of hypotheses to be made about different phases of activated carbon regeneration, values of characteristic parameters during particular process phases, as well as catalytic impact of inorganic materials on development of regeneration process. Samples of activated carbon were heated up to 1000 degrees C in thermogravimetric analyser while maintaining adequate oxidizing or reducing conditions. Based on diagrams of thermal analysis for samples of spent activated carbon, temperature intervals of the first intense mass change phase (180-215 degrees C), maximum of exothermic processes (400-450 degrees C), beginning of the second intense mass change phase (635-700 degrees C), and maximum endothermic processes (800-815 degrees C) were determined. Analysing and comparing the diagrams of thermal analysis for new, previously regenerated and spent activated carbon, hypothesis about physical and chemical transformations of organic and inorganic adsorbate in spent activated carbon are given. Transformation of an organic adsorbate in the pores of activated carbon, results in loss of mass and an exothermic reaction with oxygen in the vapour phase. The reactions of inorganic adsorbate also result the loss of mass of activated carbon during its heating and endothermic reactions of their degradation at high temperatures

Komparativna analiza različitih strategija za kontrolu klasične svinjske kuge upotrebom Monte Carlo simulacije

Several different strategies for control and eradication of Classical Swine Fever (CSF) were compared using a Monte Carlo method-based simulation model. The control strategy analyzed in this paper, in addition to other CSF control measures, includes application of biosecurity measures on pig farms and rural backyard holdings. Elements of the control strategy are based on applicable regulations and include the simulation of detection of the disease, setting up the protected and surveillance zones, standstill of pig movements and restricted movement of animals, vehicles, equipment, and people with strong control measures in protection and surveillance zones, euthanasia of susceptible pigs, protective vaccination of pigs, compensation etc. During the simulation, different output parameters were compared such as: duration of epizootic of a disease, number of affected holdings and animals, direct costs such as those for dead or culled animals, costs of surveillance, disposal of infectious materials, cleaning and disinfection. Depopulation of affected animals with early diagnostics and vaccination in protection and surveillance zone proved to be the most effective measures to stop spreading and eradication of the disease. However, during the simulation, systematic implementation of biosecurity measures in all pig production clusters demonstrated to be appropriate strategy for sustainable control of CSF and setting up a stable epizootiological situation.Nekoliko različitih strategija za kontrolu i iskorenjivanje klasične kuge svinja je upoređivano primenom modela simulacije zasnovanog na Monte Karlo metodi. Kontrolne strategije koje su obrađivane u ovom radu, pored opštih i posebnih mera suzbijanja KKS, uključuju i različite nivoe primenjenih biosigurnosnih mera na komercijalnim, porodičnim farmama i seoskim gazdinstvima na kojima se ga je svinje. Mere neškodljivog uništavanja obolelih životinja i životinja koje su bile u kontaktu sa obolelim životinjama, uspostavljanje zaštitnih zona pod nadzorom, kontrola i zaustavljanje prometa životinja i mehaničkih vektora (vozila i ljudi) unutar zona, rano otkrivanje bolesti i mera vakcinacije su bile uključene u simulaciju. Izlazni parametri kao što su: vreme trajanja epizootije, broj zaraženih gazdinstava i životinja, broj uništenih životinja, troškovi nadzora i direktne štete nastale zbog pojavljivanja bolesti s upoređivani tokom simulacije. Vakcinacija, neškodljivo uklanjanje obolelih životinja i rana dijagnostika su se pokazale kao najefektivnije mere zaustavljanja širenja i iskorenjivanja bolesti. Međutim, kao mera dugoročne strategije kontrole KKS i uspostavljanja stabilne epizootiološke situacije, tokom simulacije pokazala se mera planskog i sistematskog podizanja biosigurnosnih mera u svim klasterima proizvodnje svinja (komercijalne farme, porodične farme tipa A, porodične farme tipa B i seoska gazdinstva)

Mathematical Optimization for the Train Timetabling Problem

AMS Subj. Classification: 90C57; 90C10;Rail transportation is very rich in terms of problems that can be modelled and solved using mathematical optimization techniques. The train scheduling problem as the most important part of a rail operating policy has a very significant impact on a rail company profit considering the fact that from the quality of a train timetable depends a flow of three most important resources on rail network: cars, locomotives and crews. The train timetabling problem aims at determining a periodic timetable for a set of trains that does not violate track capacities and satisfies some operational constraints. In this paper, we developed an integer programming approach for determining an optimal train schedule for a single, one-way track linking two major stations, with a number of intermediate stations between. The application has been tested on a realistic example suggested by the PE “Serbian Railways”. Obtained results show a potential for a practical application of proposed approach

A study on the grindability of Serbian coals

Thermal power plants in the Republic of Serbia are making considerable efforts and even more considerable investments, not only to maintain electricity production at maximum design levels, but even to additionally increase the power output of existing generating units. Capacities of mills used in pulverized coal preparation are identified as one of the main constraints to achieving maximum mill plant capacity, while coal grindability is seen as one of the factors that directly affect capacities of the coal mills utilized in thermal power plants. The paper presents results of experimental investigation conducted for the purpose of determining Hardgrove grindability index of coal. The investigation was conducted in accordance with ISO 5074 and included analysis of approximately 70 coal samples taken from the open pit mine of Kolubara coal basin. Research results obtained indicate that coal rich in mineral matter and thus, of lower heating value is characterized by higher grindability index. Therefore, analyses presented in the paper suggest that characteristics of solid fuels analyzed in the research investigation conducted are such that the use coals less rich in mineral matter i. e. coals characterized by lower grindability index will cause coal mills to operate at reduced capacity. This fact should be taken into account when considering a potential for electricity production increase