Žene u poduzetništvu- ženski udio u stvaranju gubitka u srednjim i malim poduzećima

The paper explores the ownership structure of small and medium-sized enterprises (SMEs), which fell into a debt crisis due to business failures, in order to indicate the differences between male and female entrepreneurs. We conducted the empirical research on a sample of 186 small and medium-sized loss-making enterprises in the Republic of Serbia. The results obtained by descriptive statistical analysis of the observed sampleshow that the participation of female companies among loss-making enterprises is considerably low. The ratio of companies owned by women and those owned by men was 18.8%: 81.2%. Furthermore, we have recorded a significant difference in the amounts of debt, indicating that female companies have significantly lower debt rates when compared to those owned by men. The findings of this research can be applied as a strategic framework for policymakers to encourage female entrepreneurship.Rad istražuje vlasničku strukturu malih i srednjih poduzeća, koja su upala u dužničku krizu uslijed propusta u poslovanju, kako bi se ukazalo na razlike između muških i ženskih poduzetnika. Empirijsko istraživanje je sprovedeno na uzorku od 186 malih i srednjih poduzeća, koja su poslovala s gubitkom u Republici Srbiji. Na osnovu dobivenih rezultata primjenom deskriptivne statističke analize posmatranog uzorka, dokazano je da je zastupljenost ženskih poduzeća, koja su poslovala s gubitkom veoma niska. Udio poduzeća čiji su vlasnici žene iznosio je samo 18.8%, u usporedbi sa 81.2% poduzeća u vlasništvu muškaraca. Takođe, utvrđeno je da postoji značajna razlika u visini duga, pri čemu je utvrđeno da ženska poduzeća imaju značajno niže stope dugovanja za razliku od poduzeća u vlasništvu muškaraca. Rezultate ovog istraživanja mogu primjeniti kreatori politika kao strateški okvir u cilju poticanja ženskog poduzetništva

Modeliranje ekološko-energetskih i ekonomskih performansi održivih tehnologija upravljanja čvrstim otpadom

Definisanje optimalnog i održivog sistema upravljanja komunalnim čvrstim otpadom na lokalnom nivou predstavlja veoma složen zadatak pri čijem se rešavanju donosioci odluka suočavaju sa brojnim izazovima i usaglašavanjem niza protivurečnosti. Najveći napori prilikom projektovanja ovakvih sistema su usmereni ka minimizaciji negativnih uticaja na životnu sredinu, unapređenju energetske efikasnosti, kao i ekonomskoj održivosti rešenja. Osnovni naučni cilj ove disertacije je formiranje efikasne metodologije i algoritma za procenu i izbor održivih tehnologija upravljanja komunalnim čvrstim otpadom u gradovima i opštinama Republike Srbije. Sama metodologija je bazirana na principu višekriterijumskog odlučivanja (VKO) i primeni metode Ocenjivanja životnog ciklusa (LCA). Definisanje osnovnih ulaznih parametara, odnosno sastava i generisanih količina komunalnog otpada, predstavlja praktično početnu fazu rešavanja postavljenog zadatka. U tom smislu, detaljno je prikazano stanje u sektoru upravljanja otpadom u Republici Srbiji i gradu Kragujevcu. Nakon definisanja osnovnih ciljeva, procene potrebne infrastrukture i predviđenih tehnologija tretmana dat je predlog većeg broja alternativnih rešenja za sisteme upravljanja otpadom na gradskom i regionalnom nivou. Modeliranje scenarija upravljanja sprovedeno je u skladu sa strukturom tri primenjena softverska alata (DSS, IWM2 i EASETECH). Valorizaciji i rangiranju alternativnih opcija kao i samom izboru optimalne varijante, prethodilo je definisanje i izbor relevantnih kriterijuma. Kroz varijacije vrednosti rejtinga pojedinih kriterijuma analiziran je mogući obim uticaja raznih zainteresovanih strana uključenih u proces odlučivanja. Takođe, izvršene su i dopunske simulacije za tri karakteristična sastava otpada različitog geografskog porekla, sa ciljem sagledavanja eventualnih uticaja na rangiranje užeg kruga izabranih scenarija. Najbolje ocenjeni scenariji predviđaju kompostiranje kao opciju tretmana biološkog dela otpada, kao i instalaciju postrojenja za sekundarnu separaciju ambalažnog otpada. Takođe, ovi scenariji uključuju i mehaničko‐biološki tretman mešanog dela komunalnog otpada kao i energetsko iskorišćenje RDF i SRF frakcija. Dodatno vrednovanje, pre svega ekoloških karakteristika pojedinih tehnologija tretmana i scenarija upravljanja, realizovano je kroz primenu LCA softverskih alata. Posebna pažnja, pored ostalih standardnih kategorija uticaja, posvećena je faktoru globalnog zagrevanja (GWP). U ovom delu disertacije sproveden je i postupak VKO na bazi rezultata dobijenih kroz LCA kalkulacije odabranih parametara. Formirana metodologija izbora optimalnih sistema upravljanja komunalnim čvrstim otpadom poseduje veliku fleksibilnost u pogledu mogućnosti njene primene na bilo koju lokalnu samoupravu na teritoriji Republike Srbije.Defining the optimal and sustainable municipal solid waste management system at the local level is a very complex task. In solving this problem, decision makers must face a number of challenges and coordinate a series of contradictions. The greatest efforts when designing such systems are aimed at minimizing negative impacts on the environment, improve energy efficiency as well as economic sustainability solutions. The aim of research in this thesis is the establishment of an effective methodology and algorithms for the evaluation and selection of sustainable technologies for municipal solid waste in cities and municipalities of the Republic of Serbia. The developed methodology is based on the principle of multi‐criteria decision making (MCDM) and application method of Life cycle assessment (LCA). Definition of basic input parameters, concerning generated waste quantity and composition, represent the initial stage of solving the task. In this regard, the detailed analyze of the current waste management sector in the Republic of Serbia and the city of Kragujevac was carried out. After defining the objectives and assessing the necessary infrastructure and treatment technologies a numerous of alternative solutions for waste management systems at city and regional level were given. Modeling of scenarios was conducted in accordance with the structure of the three applied software tools (DSS, IWM2 and EASETECH). Definition and selection of relevant criteria preceded evaluation and ranking of alternative options as well as the choice of the optimal variant. Through variations of the rating of some criteria the possible extent of the impact of the various stakeholders involved in the decision‐making process were analyzed. In addition, some extra simulations for three typical waste composition of different geographical origin were made, in order to examine the possible impact on the ranking of the selected scenarios. The highest rating scenarios include composting of organic waste components as well as the installation of facilities for secondary separation of packaging waste. Also, these scenarios include mechanical‐biological treatment of municipal waste and energy utilization of RDF and SRF factions. In addition, evaluation of environmental characteristics of treatment technologies and scenarios has been realized through the application of LCA software. Among standard impact categories the emphasis was on global warming potential factor (GWP). This part of the thesis was dedicated to MCDM procedure based on the results obtained through LCA calculations of selected parameters. The methodology for selection of optimal waste management system developed within this thesis has got a great level of flexibility in terms of its applicability to any local government in Republic of Serbia

Fuzzy stochastic model of underground development system selection.

Investiciono okruženje skopčano sa rudarskom industrijom je veoma svojstveno kada se uporedi sa okruženjima koje susrećemo u tipičnim proizvodnim industrijama. Neke od karakterisitka rudarstva, koje su često naznačene kao jedinstvene su: visok intenzitet investicija, dugi predproizvodni periodi, visok rizik i neobnovljivost resursa. Investiranje u sistem otvaranja rudnika predstavlja dobar primer ireverzibilne investicije. Takva investicija zahteva pažljivu analizu, jer nakon njene realizacije ona se ne može nadoknaditi bez značajnog gubitka vrednosti. Očigledno je da izbor sistema otvaranja podzemnog rudnika pripada strateškom planiranju...The investment environment associated with the mining industry is unique when compared with the environment encountered by typical manufacturing industries. Some of the characteristics of mining which are often proclaimed as unique are as follows: capital intensity, long preproduction periods, high risk and non-renewable resource. Mines’ development system investments provide a good example of irreversible investment. Such investment requires careful analysis because, once the investment takes place, it cannot be recouped without significant loss a value. Obviously, the selection of an underground mine development system belongs to strategic planning..

Pain therapy after lumbar discectomy

Cilj: Svrha istraživanja utvrditi je moguću prednost primjene Tramadoluma, Diclofenacuma i Dexamethasonuma u liječenju postoperacijskog bola nakon lumbalne discektomije u odnosu na uobičajenu postoperacijsku primjenu Tramadoluma i Metamizolum Natricuma. Metode: Istraživanjem je obuhvaćeno 46 ispitanika prosječne životne dobi od 45.29 ± 14.06 godina. U svih ispitanika učinjena je otvorena lumbalna discektomija. U prvoj skupini od 23 bolesnika postoperacijski su primjenjivani Tramadolum i Metamizolum Natricum, a kod druge skupine od 23 bolesnika Tramadolum, Dexamethasonum i Diclofenacum. Obrazac za praćenje postoperacijskog bola sastojao se iz dva dijela: prvog, koji je ispunjavao liječnik i koji je sadržavao podatke o kliničkom nalazu, dok je drugi dio obrasca ispunjavao bolesnik i bilježio podatke o preoperacijskom bolu te bolne smetnje dva dana i osam dana nakon operacije, stupnjujući ih prema skali od 0 do 10. U statističkoj obradi rabljen je program Statistica 5.0. Značajnost razlika određivana je Studentovim t-testom za nezavisne uzorke, dok se značajnost razlika između pojedinih uzoraka s obzirom na bolnost i vrijeme anketiranja utvrđivala Studentovim t-testom za zavisne uzorke. Rezultati: Rezultati istraživanja neovisno o mjerenju preoperacijskog bola govore da skupina ispitanika tretirana Tramadolumom, Dexamethasonumom i Diclofenacumom ima značajno manju bolnost u području noge (p < 0.01), dok je bolnost u križima nešto manja, još uvijek u području statističke značajnosti (p = 0.03; p = 0.01) u odnosu na skupinu ispitanika tretiranih Tramadolumom i Metamizolum Natricumom. Rasprava: Rezultati istraživanja potvrđuju učinkovitost i prednost kombinirane primjene Tramadoluma, Diclofenacuma i Dexamethasonuma u kupiranju postopercijskog bola nakon lumbalne discektomije u odnosu na primjenu Tramadoluma i Metamizolum Natricuma.Aim: The aim is to determine possible advantage of application of Tramadolum, Diclofenacum and Dexamethasonum in therapy of postoperative pain after lumbar discectomy in relation to standard postoperative application of Tramadolum and Metamizolum Natricum. Methods: The research covered 46 patients with mean age of 45.29 ± 14.06. All patients underwent open lumbar discectomy. The first group, consisting of 23 patients, was treated with Tramadolum and after the surgery , and the other one, also with 23 patients, was treated with Tramadolum, Dexamethasonum and Diclofenacum. The VAS questionnaire of postoperative pain consisted of two parts: the first one, filled in by a surgeon, included clinical findings, and the second one, filled in by a patient, contained data entered by the patient on postoperative pains and painful discomforts two and eight days after the surgery, with the scale from 0 to 10. Statistical 5.0 programme was used in statistical analysis. Statistical significance of differences was determined by Student’s independent samples T-test, while significance of differences between individual samples in respect of pain and time of filling in the questionnaire was determined by Student’s dependent samples T-test. Results: The research results, not considering measurement of preoperative pain, show that the group treated with Tramadolum, Dexamethasonum and Diclofenacum experienced significantly lower pain in the leg area (p< 0.01), while pain in sacral area was somewhat lower but still with statistical significance (p = 0.03; p = 0.01) compared to the group receiving Tramadolum and Metamizolum Natricum. Conclusion: The research results confirm efficiency and advantage of combined therapy with Tramadolum, Diclofenacum and Dexamethasonum in coping with postoperative pain after lumbar discectomy compared to the therapy with Tramadolum and Metamizolum Natricum

Spontaneous Regression of Intervertebral Disc Herniation – Case Reports

Lumbar disc hernia (LDH) is a common cause of low back pain and radicular leg pain. It is well known that the majority of LDH patients recover spontaneously. Since the advent of MRI, a spontaneous regression of fragment size of disc hernia occurs, as well as mitigation of subjective difficulties and neurological disorders. Therefore, surgical treatment is not always method of choice in this disease. Two cases of conservatively treated large disc extrusion which result in significant reduction of difficulties, with simultaneous reduction in fragment size of hernia which is documented by MR

Effects of solvent and structure on the reactivity of 2-substituted nicotinic acids with diazodiphenylmethane in aprotic solvents

The rate constants for the reactions of diazodiphenylmethane (DDM) with 2-substituted nicotinic acids in nine aprotic solvents at 30°C were determined. The obtained second order rate constants in aprotic solvents, were correlated using the Kamlet-Taft solvatochromic equation in the complete form: log k = log k0 + s

NUMERICAL INVESTIGATION OF THE INFLUENCE OF THE DOUBLY CURVED BLADE PROFILES ON THE REVERSIBLE AXIAL FAN CHARACTERISTICS

Abstract. In reversible axial fans a change in the direction of the impeller rotation is accompanied with a change in the direction of the working fluid flow. To satisfy the flow reversibility, the impeller blades are usually designed with straight symmetrical profiles. The flow reversibility may also be achieved by using asymmetrical blade profiles in which, to satisfy the equality of the leading and trailing angle of the profiles, the mean line of the profile has to have a double curvature in the shape of the stretched letter 'S'. The paper numerically investigates the influence of the doubly curved blade profiles on the reversible axial fan characteristics. Numerical simulations are carried out on an axial fan only with the impeller, with the blades that have double-curved mean line profiles for different values of the angles at the profile ends. For numerical simulation the ANSYS CFX software package is used. Results of the numerical simulation are shown in diagrams Δp(Q), h(Q) and P(Q) at different angles of the profile ends. On the basis of the simulation and analysis of the characteristics, appropriate conclusions are proposed, along with the most advantageous profile of the blades

An Investigation Into Hybrid Aluminium/Composite Cardan Shaft

It is a well-known fact that natural resources are becoming increasingly scarce. Consequently, whenever possible in the machine element manufacture, metallic materials should be replaced with new artificial materials. This paper studies the possibility of replacing two cardan shafts of a truck TURBO ZETA 85.14B with one shaft made of aluminium and a composite material, while the basic requirements concerning the given load transfer and fundamental natural frequencies remain satisfied