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Publikacije (45102)

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E. Husak, A. Kovacevic, I. Karabegović

Clearances between rotating and stationary parts in a screw compressor are set to ensure the efficient operation and allow for thermal deformation without unwanted contacts. The change in clearances is caused by both pressure and temperature changes within the machine. If clearances are too large, the increased leakage flows will reduce efficiency. However, if the nominal clearances are too small, contacts between the rotating and stationary parts can occur as a consequence of rotor and casing deformations. In order to determine the operational clearances, a numerical analysis of deformation of screw compressor rotors and casing has to be performed. This paper discusses how the temperature of rotor and casing surfaces calculated from the one-dimensional chamber model in the SCORG could be used as a boundary conditions for a steady state thermal and structural analysis of a screw compressor solid parts. Deformations of rotors and casing under temperature load were calculated using a commercial Finite Element Analysis code ANSYS. Operational clearance are estimated from these deformations and some recommendations for further work are proposed.

Yoga and mindfulness improve the blood circulation and thereby reduces the causes of hypertension hearth attack or stroke. Complete yoga breathing has the role in oxygenating the blood and therefore assists fresh nutrients to reach all peripheral vessels and capillaries. Yoga helps to prevent various circulatory ailments and illnesses such as high blood pressure, shallow breathing, muscle tension and coronary heart disease. During moderate to intense yoga exercise hearth rate increases and as a result hearth pumps more blood, systolic blood pressure rise and blood volume increases. It provides better circulation and formation of new capillaries. The purpose of this review is to investigate the efficacy of yoga exercise on circulatory system, pulse and hearth rate, systolic and diastolic blood pressure and cardiovascular function. A review of literature was conducted from Pubmed, Research Gate, Medline and Google Scholar.

V. Stefanović, S. Urošević, Željko Stević, I. Mladenović-Ranisavljević

The research in this article aimed at determining the importance of occupational safety and health (OSH) factors at work as criteria for development of the OSH climate. Based on the views of 28 responsible persons of the OSH management system, the significance of the criteria was determined using the rough step-wise weight assessment ratio analysis method. The obtained results show that development of the OSH climate in organizations primarily depends on the factors of the work environment and the commitment of the management to the OSH system. The results also point out that education of employees in the field of safety at work has a significant impact. A comparison of the obtained results was made in the sensitivity analysis using the full consistency method. The specific dimensions of the safety climate at work were determined and ranking of the OSH factors was performed.

Ana Maravić, T. Rončević, Lucija Krce, Nada Ilić, B. Galić, Vedrana Čulić Čikeš, Ivana Carev

Abstract Halogenated boroxine dipotassium trioxohydroxytetrafluorotriborate, K2[B3O3F4OH] (boroxine) was previously shown to be very effective in inhibition of several carcinoma cell lines, including the skin cancer. Here, we investigated its antimicrobial potential by targeting the multidrug-resistant opportunistic pathogens associated with skin and wound infections. The antimicrobial testing against eleven bacterial and four fungal species revealed good activity of boroxine against pathogenic filamentous fungi Penicillium funiculosum and Aspergillus niger (MIC50 64 and 128 µg/ml), and a moderate bioactivity against the yeast Candida albicans (MIC50 512 µg/ml). Among the tested multidrug-resistant bacteria, the best antibacterial effect, stable over a 24-h period, was observed against the methicillin-resistant Staphylococcus aureus strain (MRSA) at MIC of 1024 µg/ml. The atomic force microscopy (AFM) used to investigate the morphology of S. aureus cells revealed indentations on its cell envelope after the boroxine exposure. These results show that in addition to the antitumor effect, boroxine exerts wide spectrum antimicrobial activity, thus may help preventing the development of skin and wound-related opportunistic infections.

Ervin Karić, I. Petric, V. Mićić

The aims of this study were to determine improved kineticparameters in five kinetic models for oxidation of n-butane intomaleic anhydride in an industrial fixed-bed reactor, and tosimulate the reactor performance. On the basis of the measuredprocess parameters, inlet and outlet concentrations of n-butanewere calculated and then used to fit the kinetic models. Theindustrial fixed-bed reactor was approximated by 10 continuousstirred tank reactors (CSTR) connected in series. Based on thecalculated outlet concentration of n-butane from the industrialreactor, the outlet concentration of n-butane from thepenultimate reactor was calculated. Then the concentrations ofn-butane were calculated until the inlet concentration of nbutanein the first reactor was obtained. Kinetic parameterswere determined by comparing the inlet concentrations of nbutanein the first reactor with the inlet concentration of nbutaneobtained on the basis of the measured processparameters in the industrial fixed-bed reactor. Kinetic modelswith improved kinetic parameters showed better simulationresults compared to kinetic models with the existing kineticparameters. The best agreement of simulation results andmeasured values was achieved with application of the kineticmodel 2 (Equations (2a-c)). The smallest deviations ofnumerical simulation in comparison with measured values of theoutlet pressure of reaction mixture were 0.45, 0.75 and 0.75%for application of the kinetic model 3 (Equations (3a-c)). Thepercentage deviations of numerical simulation with improvedkinetic parameters and the existing kinetic parameters incomparison with measured values of inside reactor temperaturewere in the range 0.90-5.36% and in the range 4.17-9.78%(kinetic model 2, Equations (2a-c)), respectively.

Ksenija Dumičić, B. Novkovska, Emina Resić

Abstract This special issue of Business Systems Research is highlights recent advances and trends in post-transition countries, taking into account statistical modelling approach. Nine papers that have been selected for this special issue present improvements and new techniques (methodology) in statistical modelling and their use in various aspects of development in post-transition countries

S. Ozen, S. Marks, P. Brogan, N. Groot, N. de Graeff, T. Avčin, B. Bader-Meunier, P. Doležalová et al.

OBJECTIVES IgA vasculitis (IgAV, formerly known as Henoch-Schönlein purpura) is the most common cause of systemic vasculitis in childhood. To date, there are no internationally agreed, evidence-based guidelines concerning the appropriate diagnosis and treatment of IgAV in children. Accordingly, treatment regimens differ widely. The European initiative SHARE (Single Hub and Access point for paediatric Rheumatology in Europe) aims to optimize care for children with rheumatic diseases. The aim therefore was to provide internationally agreed consensus recommendations for diagnosis and treatment for children with IgAV. METHODS Recommendations were developed by a consensus process in accordance with the EULAR standard operating procedures. An extensive systematic literature review was performed, and evidence-based recommendations were extrapolated from the included papers. These were evaluated by a panel of 16 international experts via online surveys and subsequent consensus meeting, using nominal group technique. Recommendations were accepted when ⩾80% of experts agreed. RESULTS In total, 7 recommendations for diagnosis and 19 for treatment of paediatric IgAV were accepted. Diagnostic recommendations included: appropriate use of skin and renal biopsy, renal work-up and imaging. Treatment recommendations included: the importance of appropriate analgesia and angiotensin-converting enzyme inhibitor use and non-renal indications for CS use, as well as a structured approach to treating IgAV nephritis, including appropriate use of CS and second-line agents in mild, moderate and severe disease along with use of angiotensin-converting enzyme inhibitors and maintenance therapy. CONCLUSION The SHARE initiative provides international, evidence-based recommendations for the diagnosis and treatment of IgAV that will facilitate improvement and uniformity of care.

Introduction: Congenital hydronephrosis (CH) is a condition with dilated renal pelvis with or without dilation of renal calyces. Aim: To examine the role of magnetic resonance urography in the detection of congenital hydronephrosis in comparison to dynamic renal scintigraphy (DRS). Patients and methods: Resarch included 58 (n=58) patients with diagnosis of congenital unilateral or bilateral dilatation of kidney duct system. Each patient had a one-time or multiple hospitalization at the Nephrology Department of the Pediatric Clinic, with performed: ultrasound which confirmed CH, voiding cystourethrography / voiding urosonography was confirmed based on which the vesicoureteral reflux (VUR) was established / excluded, dynamic renal scintigraphy and magnetic urography (analysis was made by CHOP-fMRU software) on the basis of which the uterine anatomy and the relative renal function were evaluated. Results: Male patients were represented in 40 cases (69%). The average age was 4.4 ± 4.3 years with the youngest patient at the age of 2 months, and the oldest was 17 years old. According to diagnostic entities, the most common diagnosis was ureteropelvic junction (UPJ) obstruction in over half of cases (30 or 51.7%), followed by subjects with ureterovesical junction (UVJ) obstruction (11 or 19%), VUR was recorded in 9 (15.5%) cases, and pyelon fissus in 7 (12.1%), and one case (1.7%) was recorded with bilateral megaureter. Comparison of the value of the renal function obtained with DRS and CHOP-fMRU methods shows that there were no statistically significant differences between two methods. In the case of right kidney, the mean DRS value was 53.4 ± 18.4% (range 13-100%), while CHOP-fMRU was 51.8 ± 22.4 (range 0-96.7%). In the case of left kidney, the average value according to the DRS method was 46.9 ± 18.9% (range 0-87%) and according to CHOP-fMRU 47.6 ± 21.5% (range 8.3-100%). The correlation coefficients of both right and left kidneys show a highly statistically significant correlation between these two methods. Conclusion: Magnetic resonance urography in the pediatric population in CH based on results should be an integral part of the management of these patients, especially in congenital obstructive uropathy, in complex and associated congenital anomalies, as it provides morphological and functional data on the state of the kidneys and urinary tract.

During delivery of video service, most of management control systems are able to collect useful data from different OSI layers that help in indication quality of video service. Recently, a mathematical model has been proposed which, only with a help of data collected at PHY (physical) and MAC (Media Access Control) layers and after appearance of certain degradations in transmission channel, estimates QoS (Quality of Service) indicators and then objective QoE (Quality of Experience). In this paper, we analyse that mathematical model, but only in the case of sudden occurrence of significant disturbance in transmission channel. In addition, we have chosen AIC criterion instead of the vector one in order to define the size of L-value. Validation and verification of the model are done in DSL (Digital Subscriber Line) environment during IPTV (Internet Protocol Television) service delivering and NS2 respectively.

Amela Teskeredžić, Hurma Begić-Jahić

The problem of blindness and other visual impairment is very important because it affects millions of people in the world. For those suffering from innate visual impairment, it is very difficult to imagine the world like it is, the fight begins from early school stages and continues until the end of life. This paper describes how the learning of basic geometric shapes, and their different positions, has an impact on the formation of a mental scheme in orientation and mobility. Geometry and its knowledge represent only one small part necessary for a safer and more independent movement of blind people. The research has shown that the quarterly individual work, on the adoption of geometric concepts and positions in students, is making progress in overcoming the recent problems. Spatial visualization implies understanding and imaginary movements, which, with spatial orientation and recognition of parts and relationships in the micro and macro environment, require mental rotation in relation to the position of the body. Therefore, it all together influences the formation of the mental scheme of the blind people, which is the basis for orientation and movement.

S. Grgić, Elvira Čeljuska-Tošev, J. Nikolić, F. Markotic, M. Vukojevič, Helien Bebek-Ivanković, I. Kuzman

SUMMARY Pandemic influenza A virus (H1N1) 2009 causes a disease that is epidemiologically and clinically not significantly different from seasonal influenza, but there are differences. The aim of the study was to display and compare epidemiological and clinical characteristics of pandemic influenza in children. At Dr. Fran Mihaljević University Hospital for Infectious Diseases in Zagreb, in the first two seasons, the incidence of pandemic influenza virus A (H1N1) in particular was exhaustively analyzed only in patients with laboratory-confirmed pandemic influenza A virus (H1N1) 2009. In hospitalized children with documented influenza pandemic, moderate form of the disease predominated, which ultimately meant shorter hospital stay and fewer complications. Otitis media was the rarest complication in children in both seasons. In conclusion, children younger than 5 years, especially boys, were vulnerable groups for pandemic influenza, presenting as a mild disease with low mortality and few complications. Most of the affected children with influenza did not have important risk factors such as asthma and obesity, highlighted by other authors as significant risk factors.

Dušanka M. Krajnović, Stana Ubavić, N. Bogavac-Stanojević

Background and objectives: Pharmacotherapy literacy (PHTL) is an individual’s capacity to obtain, evaluate, calculate, and comprehend basic information about pharmacotherapy and pharmacy-related services necessary to make appropriate medication-related decisions, regardless of the mode of content delivery (e.g., written, oral, visual images and symbols). It is already proven that low PHTL of parents can cause serious problems in the treatment of a pediatric population. We aimed to identify the differences in parental PHTL levels, socio-demographic and health-related characteristics (chronic disease of a child, breastfeeding of a child, annual visits to a pediatrician, parental-self-estimation of health status) between rural and urban areas and to investigate the influence of living in rural areas on a low PHTL level. Materials and methods: Our study was cross-sectional with a validated 14-item instrument (“Parental pharmacotherapy literacy questionnaire—Serbian”), which assessed overall PHTL and its three domains of knowledge, understanding and numerical skills necessary for the safe use of medicines. We analyzed 250 parents of pre-school children (1–7 years old) in rural areas and 182 parents from urban areas in Serbia. Results: Every tenth parent from rural and every fourth parent from urban areas had the highest PHTL level or more than 85% correct answers. However, 51% and 28% of parents in rural and urban areas, respectively, had a low PHTL level (less than 65% correct answers), [Х2(1, n = 432) = 33.2; p < 0.001]. Parents from different areas statistically differed in age, education level, employment, breastfeeding and annual visits to pediatrician rate. Those from rural areas had almost twice the probability of low PHTL levels (ORa = 2.033; p = 0.003) than their urban counterparts, independently of other examined parental characteristics. Conclusions: Parents from rural areas have more difficulties to obtain, evaluate, calculate and comprehend basic information related to pharmacotherapy than parents from urban areas.

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