The importance of rural and urban areas in the spatio-functional organization of Serbia

Захваљујући просторно-функцијским односима, процесима и променама који се одвијају у простору, све је теже прецизно детерминисати урбаност или руралност одређеног подручја. Традиционална дихотомна подела која разликује рурална подручја од урбаних, не узима у обзир све већу комплексност којом се одликују ова подручја. Проблематика просторне делимитиције руралних и урбаних подручја интензивно је изучавана у европским истраживањима, укључујући и Србију. Већина ових истраживањима била је заснована на примени јасних правила и критеријума за издвајање урбаних и руралних подручја. Основни циљ докторске дисертације је утврђивање методологије за просторну делимитацију руралних и урбаних подручја у Србији. Предложени модел заснован је на примени фази логике у процесу одлучивања. Истраживање је засновано на вишедимензионалном приступу, који интегрише физичко-географске, демографске, социоекономске и функцијске карактеристике геопростора Србије. Предложени модел укључује примену седам варијабли (број становника, дневне миграције, удео активног становништва које обавља занимање у секундарном и терцијарном сектору, индекс промене броја становника, густина насељености, удео природних површина и доступност) различитих тежина и 254 правила на основу којег је изграђен фази систем закључивања (ФИС). Добијени резултати наглашавају различите степене припадности насеља руралним или урбаним подручјима у Србији. Истраживање је обухватило 4.604 насеља у Србији. На основу добијених резултата дат је преглед добијених класа насеља које садрже различите степене припадности руралним или урбаним подручјима и у складу са тим идентификовани су савремене тенденције могући правци просторно-функцијске организације Србије.Due to the spatio-functional relations, processes, and changes taking place in an area, it is getting difficult to accurately determine urbanity and rurality of a certain area. The traditional dichotomous division which differentiates rural from urban areas does not take into consideration the growing complexity which characterizes these areas. The problem of spatial delimitation of rural and urban areas has been studied intensively in European researches, including the ones in Serbia. The majority of these studies have been based on the application of the clear rules and criteria of differentiation between urban and rural areas. The main aim of the doctoral thesis is to determine the methodology for the spatial delimitation of rural and urban areas in Serbia. The suggested model is based on the application of the fuzzy logic in the inference process. The research is based on multi-dimensional approach which integrates both socio-economic and functional characteristics of the geospace of Serbia. The suggested model includes the application of seven indicators (population number, daily migrations, the share of active population performing an occupation in secondary and tertiary sector, the index of change in the population number, population density, the share of natural areas and accessibility) of different weights and 254 rules which the fuzzy inference system (FIS) is based on. The obtained results highlight the various levels of the areas belonging to rural or urban areas in Serbia. The research comprised 4,604 settlements in Serbia. On the basis of the obtained results, a preview of the obtained classes of settlements which contain various levels of belonging to rural or urban areas has been presented. Accordingly, modern tendencies and possible directions of spatio-functional organizations of Serbia have been identified

Jarosite sludge - utilization and valuable metals recovery applying roasting-leaching process

During the conventional roast–leach–electrolysis (RLE) zinc production process, precipitation of the jarosite-type compounds is widely used to remove iron and other metal impurities from the solution. Above mentioned compounds, with the general formula MFe3(SO4)2(OH)6, (M+=NH4, Na, K, Ag, etc.), in addition to iron, contain a high concentration of Pb, Cd, Cr, As, Zn, In, Ga, Ge as metal oxides and/or sulfates [1]. Consequently, jarosite is considered hazardous yet valuable waste [2]. In addition, every year around 6-7 million tonnes of jarosite waste is generated globally [3]. Due to large waste volumes and its chemical characteristics, jarosite requires a lot of storage space and monitoring. Unfortunately, this type of waste is often landfilled causing serious environmental problems and irreversible metal and value losses. Hence, an urgent solution for both managing and utilization/recycling is required, to face needs regarding ecological demands and circular economy goals. In this paper, jarosite sludge, as a specific type of hazardous industrial waste, is used to investigate transformation to the targeted compounds through the comprehensive thermodynamic analysis and experimental roasting process tests. The roasting was conducted to transform iron into insoluble hematite (Fe2O3), valuable metals (Zn, Cu, and In) into water-soluble sulfates, and to keep Pb in the form of water-insoluble anglesite (PbSO4). The solid residue obtained after roasting was used in leaching tests to further evaluate the efficiency of the targeted phase transformations. Theoretical considerations of chemical reactions and phase thermodynamics were performed using the HSC Chemistry v.9.2.3 software [4] to define potential chemical reactions, examine the feasibility of the target transformations, and set the limiting reaction parameters. Further, in the first part of the experimental work, the influence of the roasting process and reaction parameters on the transformation of jarosite sludge phases into target compounds was investigated. This included variations in the reaction time, temperature, and furnace atmosphere influence. The leaching conditions were kept constant (temperature of 25 °C, during 60 min, and solid to liquid ratio of 1/5) to determine the efficiency of phase transformations in the samples obtained by roasting. Changes in the chemical and mineralogical composition and microstructure were analyzed using different analytical methods, including XRD and SEM analysis. According to the obtained results of the roasting process, it was determined that the phase transformation of jarosite sludge compounds into targeted insoluble hematite and water-soluble sulfates occurs at 730 °C, the time required is 60 min in the air (oxidizing) atmosphere of 1-2 [dm3/h]/kg of the input material, which is in accordance with the results of the theoretical indications. Also, it is experimentally confirmed that the introduction of sulfate into the roasting atmosphere leads to the incomplete transformation of jarosite and the formation of the unwanted Fe2(SO4)3. Leaching results of the sample obtained by the abovementioned optimal roasting conditions show that only 4.5% of Fe is leached while the rest remains as solid targeted hematite. Also, more than 75% of In and more than 90% of other targeted metals (Cu and Zn) are leached, indicating the high efficiency of the roasting process. Phase transformation was confirmed by SEM analysis, showing that hexagonal crystals of jarosite, dominating in the starting material, were completely replaced with the globular microstructure of Fe2O3, in the roasted samples. SEM analysis of the leaching residue also confirmed the absence of the water-soluble sulfates and the presence of the anglesite as water-insoluble sulfate. The phase composition of the samples is confirmed by XRD analysis. This research shows that the proposed process enables the recycling of jarosite through metal transformation and further utilization. The obtained products can be used in industry, while the metal ions can be selectively separated from the sulfate solution and returned to the production streams. This approach contributes to the utilization of jarosite, as hazardous waste, in order to obtain valuable metals, and generally reduces the negative environmental impact by decreasing the amount of disposed waste and reducing the need for primary exploitation

Meteorological parameters in the design of thermal protection of buildings

Analizirani su relevantni meteorološki parametri za 15 lokacija u Hrvatskoj za razdoblje 1961-1990. To su: srednje mjesečne, sezonske i godišnje temperature zraka, najniža i najviša srednja dnevna temperatura zraka s podacima o prekoračenju u danima, standardna vanjska temperatura zraka, globalno zračenje, difuzno zračenje, maksimalne dnevne količine oborina, srednje mjesečne, sezonske i godišnje količine oborina te vrijednosti relativne vlažnosti zraka i tlaka vodene pare.Relevant meteorological parameters for 15 locations in Croatia are analyzed for the 1961 - 1990 period. These parameters are: mean monthly, seasonal and annual air temperatures, minimum and maximum average daily air temperature with overstepping values in days, standard outside air temperature, global radiation, diffuse radiation, maximum daily precipitation, mean monthly, seasonal and annual precipitation, relative humidity of air and water vapor pressure

Ispitivanje kvaliteta podzemnih, izvorskih i rečnih voda sa područja jugoistočne Srbije

The study deals with mineral characterisation of natural waters from South-East Serbia. The contents of aluminium, arsenic, calcium, cadmium, cobalt, chromium, cooper, iron, potassium, magnesium, manganese, sodium, nickel, lead and zinc were analysed in spring, ground and river waters by inductively coupled plasma-atomic emission spectrometry (ICPAES) technique. The study area was in the Southern Serbia, and included slopes of Rtanj, Ozren, Bukovik, Vrdenik and Čemernik mountains, and the valley of South Morava. Obtained contents were compared with Serbian regulations on the quality of water for human use, and directive of World Health Organization (WHO) for maximum allowed concentrations of chemical substances. High contents of macro-elements, namely calcium, magnesium and potassium, were detected in several spring and ground water samples which are believed to be due to direct influence of rock minerals. Some water samples contained iron, manganese and copper in concentration up to 168.3, 8.10 and 14.9 μg dm-3, respectively, but within the permissible limits. Other heavy metals were not detected in analysed samples. Based on the derived results, tested ground and spring water samples have significant potential to be used as sources for the production of bottled water, but further investigations are necessary. Additional investigations have to be focused on complete physical, chemical and microbiological assessments of water resources. Systematic hydrogeological assessment also should be performed in all seasons. In the meantime, precautionary measures should be immediately taken to protect and preserve these water resources.Ovaj rad predstavlja analizu kvaliteta prirodnih voda iz jugoistočne Srbije. Sadržaj arsena, aluminijuma, kalcijuma, kadmijuma, kobalta, hroma, bakra, gvožđa, kalijuma, magnezijuma, mangana, natrijuma, nikla, olova i cinka je određivan u izvorskim i podzemnim vodama, kao i u rečnoj vodi. Analiza navedenih elemenata je izvedena ICP-AES tehnikom. Analizirani su uzorci voda iz oblasti jugoistočne Srbije, uključujući područja planine Rtnja, Ozrena, Bukovika, Vrdenika i Čemernika, kao i područje doline reke Južne Morave. Određeni sadržaji analiziranih elemenata su poređeni sa važećim pravilnicima Republike Srbije i preporukama Svetske zdravstvene organizacije (SZO). Visoki sadržaj makro-elemenata, odnosno kalcijuma, magnezijuma i kalijuma uočeni su u izvorskim i nekoliko uzoraka podzemnih voda, što može biti posledica direktnog uticaja magmatskih stena. Pojedini uzorci voda su sadržali nešto više sadržaje gvožđa, mangana i bakra u koncentraciji do 168,3, 8,10 i 14,9 μg dm-3, redom, ali u granicama propisanim Pravilnikom i u skladu da preporukama SZO. Ostali teški metali nisu detektovani u ispitivanim uzorcima. Na osnovu dobijenih rezultata se može zaključiti da testirani uzorci podzemnih i izvorskih voda imaju značajan potencijal u smislu proizvodnje flaširane vode, uz neophodna dodatna istraživanja. Dodatna istraživanja bi trebalo usmeriti na kompletnu hemijsku analizu i ispitivanje fizičkih i mikrobioloških karakteristika uzoraka voda. Pored toga, neophodno je sprovesti sistematsko hidrogeološko ispitivanje izdašnosti podzemnih i izvorskih voda tokom svih godišnjih doba. U međuvremenu treba preduzeti mere predostrožnosti kako bi se ovi vodeni resursi zaštitili i očuvali

Natural radionuclides in soil profiles surrounding the largest coal-fired power plant in Serbia

This study evaluates the influence of the largest Serbian coal-fired power plant on radionuclide concentrations in soil profiles up to 50 cm in depth. Thirty soil profiles were sampled from the plant surroundings (up to 10 km distance) and analyzed using standard methods for soil physicochemical properties and gamma ray spectrometry for specific activities of natural radionuclides (K-40, Ra-226 and Th-232) Spatial and vertical distribution of radionuclides was determined and analyzed to show the relations between the specific activities in the soil and soil properties and the most influential factors of natural radionuclide variability were identified. The radiological indices for surface soil were calculated and radiological risk assessment was performed. The measured specific activities were similar to values of BACKGROUND: levels for Serbia. The sampling depth did not show any significant influence on specific activities of natural radionuclides. The strongest predictor of specific activities of the investigated radionuclides was soil granulometry. All parameters of radiological risk assessment were below the recommended values and adopted limits. It appears that the coal-fired power plant does not have a significant impact on the spatial and vertical distribution of natural radionuclides in the area of interest, but technologically enhanced natural radioactivity as a consequence of the plant operations was identified within the first 1.5 km from the power plant

Meteorological parameters in the design of thermal protection of buildings

Analizirani su relevantni meteorološki parametri za 15 lokacija u Hrvatskoj za razdoblje 1961-1990. To su: srednje mjesečne, sezonske i godišnje temperature zraka, najniža i najviša srednja dnevna temperatura zraka s podacima o prekoračenju u danima, standardna vanjska temperatura zraka, globalno zračenje, difuzno zračenje, maksimalne dnevne količine oborina, srednje mjesečne, sezonske i godišnje količine oborina te vrijednosti relativne vlažnosti zraka i tlaka vodene pare.Relevant meteorological parameters for 15 locations in Croatia are analyzed for the 1961 - 1990 period. These parameters are: mean monthly, seasonal and annual air temperatures, minimum and maximum average daily air temperature with overstepping values in days, standard outside air temperature, global radiation, diffuse radiation, maximum daily precipitation, mean monthly, seasonal and annual precipitation, relative humidity of air and water vapor pressure

Comparative studies on osmosis based encapsulation of sodium diclofenac in porcine and outdated human erythrocyte ghosts

The objective of our study was to develop controlled drug delivery system based on erythrocyte ghosts for amphiphilic compound sodium diclofenac considering the differences between erythrocytes derived from two readily available materials - porcine slaughterhouse and outdated transfusion human blood. Starting erythrocytes, empty erythrocyte ghosts and diclofenac loaded ghosts were compared in terms of the encapsulation efficiency, drug releasing profiles, size distribution, surface charge, conductivity, surface roughness and morphology. The encapsulation of sodium diclofenac was performed by an osmosis based process - gradual hemolysis. During this process sodium diclofenac exerted mild and delayed antihemolytic effect and increased potassium efflux in porcine but not in outdated human erythrocytes. FTIR spectra revealed lack of any membrane lipid disorder and chemical reaction with sodium diclofenac in encapsulated ghosts. Outdated human erythrocyte ghosts with detected nanoscale damages and reduced ability to shrink had encapsulation efficiency of only 8%. On the other hand, porcine erythrocyte ghosts had encapsulation efficiency of 37% and relatively slow drug release rate. More preserved structure and functional properties of porcine erythrocytes related to their superior encapsulation and release performances, define them as more appropriate for the usage in sodium diclofenac encapsulation process

Infrared and Raman spectra of LiV2O5 single crystals

The phonon dynamics of LiV2O5 single crystals is studied using infrared and Raman spectroscopy techniques. The infrared-active phonon frequencies and dielectric constants are obtained by oscillator fitting procedure of the reflectivity data measured at room temperature. The Raman scattering spectra are measured at room temperature and at T=10 K in all nonequivalent polarized configurations. The assignment of the phonons is done by comparing the infrared and Raman spectra of LiV2O5 and NaV2O5. The factor-group-analysis of the LiV2O5 crystal symmetry and of its constituent layers is performed to explain the symmetry properties of the observed modes. We concluded that layer symmetry dominates in the vibrational properties of this compound.Comment: 10 pages, 5 figure

Genetic algorithm applied to the optimization of quantum cascade lasers with second harmonic generation

A computational model for the optimization of the second order optical nonlinearities in GaInAs/AlInAs quantum cascade laser structures is presented. The set of structure parameters that lead to improved device performance was obtained through the implementation of the Genetic Algorithm. In the following step, the linear and second harmonic generation power were calculated by self-consistently solving the system of rate equations for carriers and photons. This rate equation system included both stimulated and simultaneous double photon absorption processes that occur between the levels relevant for second harmonic generation, and material-dependent effective mass, as well as band nonparabolicity, were taken into account. The developed method is general, in the sense that it can be applied to any higher order effect, which requires the photon density equation to be included. Specifically, we have addressed the optimization of the active region of a double quantum well In 0.53Ga0.47As/Al0.48In0.52As structure and presented its output characteristics