SNOW REGIME CHARACTERISTICS FOR TOURISM IN THE NATURAL PARK MEDVEDNICA, CROATIA

Mount Medvednica, situated at the SE edge of the Alps as an isolated mountain presents an attractive destination for large number of visitors during the whole year. Snow regime over Medvednica (about 1000 m high), presents very risky factor in winter tourism. This study investigates snow cover frequency, duration and quantity for the referent period 1961-1990 at different profiles. At the top of Medvednica snow is falling on average on 54 days and at the altitude of 600 m on 30 days, most frequently 41-70 days, and 21-30 days respectively. Snow winter lasts from 121-239 days at the top to 104-186 days at 600 m a.s.l., but not with continuous snow cover. Days with snow cover >= 30 cm, necessary for alpine skiing and snowboarding, appears in 15% days annually at the top and in 7% of days at 600 m, that is a rather short duration for ski season. Snow cover >= 10 cm, necessary for development of cross-country skiing or snow mobiling has been analysed as well. Because of rather short duration of snow cover >= 30 cm, climatological analysis of relations between minimum temperatures and relative humidity have been done as a base for estimation of snow making possibilities at higher altitudes

Raman and IR spectra of pure and doped forsterite single crystals

Forsterite single crystals were grown by the Czochralski technique in air. The lattice parameters were determined by X-ray power diffraction. The IR and Raman spectra of pure and doped (V3+, V5+, and Ni4+) Mg2SiO4 single crystals were measured at room temperature. We studied the phonon properties and discussed the influence of dopants

Internal Sources of Financing Companies on the Basis of Static and Dynamic Indicators: Comparative Analysis

AbstractThe Republic of Serbia is characterized by an unsatisfactory macroeconomic environment (high degree of illiquidity, high inflation rate, rising unemployment, decline in the level of capacity utilization, followed by the process of globalization, deregulation and liberalization of the market with all its negative connotations to the growth and development of our country). Under such conditions where there is a shortage of liquid assets, the financial capital has moved from the real to the financial sector, which led companies to over-indebtedness and shutdown of their own capacities. Therefore, capital investments largely depend on internal sources of financing and the ability of companies to internally generate funds for investments. In this regard emphasis is placed on the difference in the assessment of the investment ability of companies based on internal sources of financing measured using static and dynamic indicators in order to prove the necessity of applying dynamic coefficients which unfortunately are not present in our domestic practice

Synthesis and characterisation of tin and tungsten sulfide powders for application in tribological materials

U doktorskoj disertaciji su prikazani postupci sinteze prahova sulfida kalaja i volframa za primenu u tribološkim materijalima određivanjem optimalnih parametara procesa sinteze na osnovu rezultata termodinamičkog modelovanja primenom softverskog paketa HSC Chemistry® verzija 9.9.2.3. Upotreba termodinamičkog predviđanja u optimizaciji procesa sinteze je primenjena u cilju dobijanja unapređenog načina sinteze sulfida kalaja i volframa sa tehnološki optimalnim brojem operacija, što doprinosi pojednostavljenju postupka i uštedi energije. Proces sinteze je dodatno optimizovan variranjem količine i sastava polaznih materijala, kao i osnovnih procesnih parametara (temperatura i trajanje procesa sinteze). Takođe je izvršen odabir adekvatnog aditiva radi povećanja efikasnosti procesa sinteze, čiji je pozitivan uticaj potvrđen eksperimentalnim rezultatima. Pored toga, proces sinteze sufida kalaja je okarakterisan metodom termičke analize, simultanom diferencijalnom skenirajućom kalorimetrijom i termogravimetrijskom analizom (DSC – TGA). U okviru doktorske disertacije za potrebe sinteze sulfida volframa izvršena je i sinteza oksidnog prekursora metodom ultrazvučnog sprej raspršivanja. Nakon procesa sinteze izvršena je karakterizacija sintetisanih prahova različitim instrumentalnim metodama. Karakterizacija sintetisanih prahova je obuhvatila analizu hemijskog sastava optičkom emisionom spektroskopijom sa indukovano spregnutom plazmom (ICP - OES), određivanje faznog sastava i stepena kristalizacije rendgenskom difrakcionom analizom (XRD) sa Rietveldovom metodom pomoću Powder Cell i RIFRANE® programa, ispitivanje morfologije kao i elementalnog sastava skenirajućom elektronskom mikroskopijom sa energodisperzionom analizom (SEM - EDS). Ova doktorska disertacija je urađena u okviru realizacije projekta tehnološkog razvoja koje je finansiralo Ministarstvo prosvete, nauke i tehnološkog razvoja Republike Srbije, evidencioni broj 34033 ”Inovativna sinergija nus-produkata, minimizacije otpada i čistije proizvodnje u metalurgiji” (2011-u toku).This PhD thesis presents the process of synthesis of tin and tungsten sulfides powders for application in tribological materials by determining the optimal parameters of the synthesis process based on the results of the thermodynamic modeling. The thermodynamic modeling of the synthesis process was determined using HSC Chemistry® software modelling package, version 9.9.2.3. The thermodynamic modeling was applied in order to obtain an improved method of tin and tungsten sulfides synthesis with a technologically optimal number of operations, which contributes to the simplification of the process and energy savings. Further optimization of the synthesis process was done by varying quantity and composition of the starting materials for synthesis, as well as the basic process parameters (temperature, duration of the process of synthesis). The selection of adequate additives for process efficiency increase was also investigated. In addition, the synthesis process of tin sulfides was also characterized by the thermal analysis method, simultaneous differential scanning calorimetry and thermogravimetry (DSC-TGA). As a part of this doctoral dissertation, the synthesis of oxide precursor for tungsten sulfide synthesis was carried out by using the ultrasonic spray pyrolisis method. After the synthesis process, the characterization of powders with different instrumental methods was performed. The characterization of the synthesized powders included analysis of chemical composition by inductively coupled plasma optical emission spectroscopy (ICP - OES), phase composition identification and degree of crystallinity were analysed by X-ray diffraction (XRD) by employing the Rietveld method with the help of PowderCell Software and the RIFRANE® program and examination of morphology, as well as elemental composition by scanning electron microscopy with energy-dispersive spectroscopy (SEM - EDS). This PhD thesis is part of the technological development project funded by the Ministry of Education, Science and Technological Development of the Republic of Serbia, No. 34033 ”Innovative synergy of by-products, waste minimization and clean technologies in metallurgy” (2011-in progress)

SNOW REGIME CHARACTERISTICS FOR TOURISM IN THE NATURAL PARK MEDVEDNICA, CROATIA

Mount Medvednica, situated at the SE edge of the Alps as an isolated mountain presents an attractive destination for large number of visitors during the whole year. Snow regime over Medvednica (about 1000 m high), presents very risky factor in winter tourism. This study investigates snow cover frequency, duration and quantity for the referent period 1961-1990 at different profiles. At the top of Medvednica snow is falling on average on 54 days and at the altitude of 600 m on 30 days, most frequently 41-70 days, and 21-30 days respectively. Snow winter lasts from 121-239 days at the top to 104-186 days at 600 m a.s.l., but not with continuous snow cover. Days with snow cover >= 30 cm, necessary for alpine skiing and snowboarding, appears in 15% days annually at the top and in 7% of days at 600 m, that is a rather short duration for ski season. Snow cover >= 10 cm, necessary for development of cross-country skiing or snow mobiling has been analysed as well. Because of rather short duration of snow cover >= 30 cm, climatological analysis of relations between minimum temperatures and relative humidity have been done as a base for estimation of snow making possibilities at higher altitudes

Guidelines for sustainable urban land use from the perspective of urban morphology at the example of New Belgrade

Општи циљ овог истраживања је унапређење теоретског дискурса концепта одрживог развоја града, разрадом специфичне области одрживог коришћења градског земљишта са позиције урбане морфологије, уз истовремени допринос расправи о одрживом развоју Новог Београда, систематизацијом и формирањем препорука за одрживо коришћење градског земљишта са становишта урбане морфологије, које могу да буду од користи као инпути приликом планирања реконструкције постојеће структуре и њеног евентуалног погушћавања новом изградњом. Истраживање је концептуално спроведено кроз три широко засноване целине: 1/ истраживање теоретских и методолошких основа, 2/ методолошка разрада са утврђивањем оперативног приступа и 3/ операционализација на актуелном примеру стамбених суперблокова Новог Београда. Обрађен је практични и теоријски дискурс коришћења градског земљишта и доказана холистичка природа феномена и узајамност утицаја теоријске и практичне сфере. Детаљно је разрађен и дефинисан феномен одрживог коришћења градског земљишта и позиција теме у европској пракси. Разјашњена је могућа дилема у вези са терминологијом: (амерички термин „land use planning“ (директан превод: „планирање коришћења земљишта“), широко обухвата тему коришћења градског земљишта и практично се своди на „урбанистичко планирање“, док је термин „sustainable urban land use“ (одрживо коришћење градског земљишта) у директној вези са идејом одрживог развоја и корен црпе из дефиниције коју разрађује Агенда 21, чиме се тежиште преноси на укупне ефекте/последице заузимања овог природног ресурса. Детаљном разрадом, систематизоване су области деловања и формиран оквир за анализе одрживог коришћења земљишта са позиције морфолошког аспекта: 1/површина у контексту типологије; 2/садржаји у контексту доступности; 3./промене које се дешавају у дистрибуцији садржаја кроз време; 4/елементи форме која се гради на земљишту кроз аспект одрживе изградње; и 5/интеракције у урбаном простору (оне које су изазване одређеним начинима заузимања/коришћења земљишта) кроз однос јавног и приватног...The overall objective of this research is to improve the theoretical discourse of sustainable development of the city through elaboration of a specific domain of sustainable urban land use from the urban morphology perspective, and to contribute to the debate on sustainable development of New Belgrade by systematization of a guidelines for sustainable urban land use from the perspective of urban morphology that can be of use as an input in planning the reconstruction of the existing structure and its possible thickening with the new construction. The research was conducted in three conceptually broad-based entities: 1 /theoretical and methodological basis, 2 /methodological approach elaboration with establishing the operational approach and 3 /operationalization on the example of housing superblocks of New Belgrade. Practical and theoretical discourses of urban land use were elaborated, holistic nature of the phenomenon and correlation between theoretical and practical spheres were proved. Phenomenon of sustainable urban land use were elaborated in detail, defined and explained the position it takes within European practice. The possible dilemma with the terminology were clarify: (American based notion “land use planning” widely encompasses use of urban land and virtually means “urban planning”, while the notion of „sustainable urban land use” is in direct connection to the idea of sustainable development and is rooted in Agenda 21 definition, what shifts focus to overall effects/consequences of occupation of this natural resource). By further detailed elaboration, activity fields were systematized and analytical frame for sustainable urban land use from the viewpoint of urban morphology was created: 1./ surface within the context of the typology; 2/uses/activities/functions within the context of accessibility; 3/changes that occur in distribution of uses through time; 4/some of elements of form which is built on the land through the aspect of sustainable building, and finally 5/interaction in urban space (those that have been caused by specific way of land occupancy/use) through public and private relation..

On the kinetics of the hydrogen evolution reaction on zinc in sulfate solutions

The kinetics and mechanism of the hydrogen evolution reaction (her) were studied on zinc in 1.0 mol dm-3 Na2SO4 at 298 K, in the pH range 4.4 - 10. It was found that a combination of classical potentiostatic steady-state voltammetry (PSV) and electrochemical impedance spectroscopy (EIS) can help to elucidate dilemmas concerning the mechanism of this reaction. Thus, over the whole potential region, the reaction path of the her on zinc cannot be presented by the classical Volmer-Tafel-Heyrovsky route. It was found that the very complex S-shape of the polarization curves could be explained by two parallel reaction mechanisms for the her. The first reaction mechanism is a consecutive combination of three steps, in which the surface zinc oxide plays an active role in the her, and second reaction mechanism is a consecutive combination of a Volmer step, followed by a Heyrovsky step. The second mechanism is dominant in the more negative potential region where the active sites for the her are metallic zinc

Development potential of rural tourism (the case of "Tešnjarske vešeri" festival)

Rural tourism is a very broad concept which includes not only holidays in the countryside a range of other tourist activities in rural areas, such as traditional festivals. Tourist festivals are devoted to different local products which are famous in rural parts of Serbia. Some of the most popular Serbian festivals are the Grape Festivals in Sremski Karlovci, Erdevik, Banoštor, Irig, Erdevik, Vršac, Župa, Palić, Aleksandrovac, Hajdukovo, Smederevo, Topola; Plum Days in Osečina and Koštunići; Cabbage Days in Futog, Barbeque in Leskovac; BaconDdays in Kačarevo; Ham Days in Mačkat; Golden Pot of Danube in Petrovaradin, Apatin; Mushroom Days in Fruška gora, Valjevo and Divčibare, Medical Herbs Days in Soko Banja; Bee Days in Zaječar. This paper deals with the development potential of rural areas associated with these festivals by analyzing the case of “Tešnjarske večeri”. This festival provides a diverse cultural and ethnographic entertaining program, combining visual and performing arts, and celebrates the vibrant life of the local community