Mogućnost predviđanja optimalnog perioda eksploatacije motornih vozila

By systematic observing the systems of armament and motor vehicle in their exploitation, and by analyzing the observed malfunctions and factors that influence their occurrence can be created a substantial data basis. By processing these data, with the application of the theory of reliability, can be obtained parameters necessary for designing the new and maintenance of existing motor vehicles.Sistemskim praćenjem motornog vozila u eksploataciji, analiziranjem uticaja svih faktora koji utiču na pojavu neispravnosti, može se stvoriti neophodna baza podataka. Obradom tih podataka, uz primenu teorije pouzdanosti, dobijaju se neophodni parametri za projektovanje novih i održavanje postojećih motornih vozila

Trendovi razvoja hidrodinamičkih menjača motornih vozila

In this paper actual trends and solutions in motor vehicles turbo gear box has been discussed. The results of statistical analysis of complete world wide production of turbo gear box for motor vehicles has been also presented. they show the basic design parameters and the spread of characteristic conceptions and solutions in actual passenger cars turbo gear box production.U radu se analiziraju aktuelna rešenja transmisija sa hidrodinamičkim prenosnikom snage, kao i mogućnosti koje ona pružaju u pogledu poboljšanja performansi i ekonomičnosti motornih vozila. Na osnovu statističke analize celokupne svetske produkcije hidrodinamičko-zupčastih menjača, u radu su prikazani njihovi osnovni konstruktivni parametri kao i rasprostranjenost pojedinih koncepcija i savremenih konstruktivnih rešenja

Aktuelni trendovi razvoja i primene dijagnostike na vozilima

Lately there are more and more effective objective methods for evaluation of technical condition of mobile systems, based on implementation of automatic diagnostic systems. Automatization of process of diagnostics significantly influences on the main indicators of effectiveness of used mobile systems. Owing to it, time for giving diagnosis is shorter, need for higher education of operator-diagnostician is reduced, costs of diagnostic process are decreased etc. Presentation of diagnostic results of technical condition of mobile systems is realized by application of modern devices with usage of adequate computer techniques.U poslednje vreme pojavljuje se sve više efikasnih objektivnih metoda ocene tehničkog stanja mobilnih sistema, zasnovanih na primeni automatskih dijagnostičkih sistema. Automatizacija procesa dijagnostike značajno utiče na osnovne pokazatelje efektivnosti korišćenih mobilnih sistema. Zahvaljujući njoj, značajno se skraćuje vreme uspostavljanja dijagnoze, smanjuje potreba za visokim obrazovanjem operatoradijagnostičara, snižavaju troškovi prpcesa dijagnostike i td. Predstavljanje rezultata dijagnosticiranja tehničkog stanja mobilnih sistema ostvaruje se primenom savremenih uređaja uz korišćenje odgovarajuće računarske tehnike

Dijagnostika vozila kao osnova njihovog održavanja

The special problem in the maintenance of motor vehicles is the objective identification of the state of vital components and definition of their replacement period or revitalization. Reliability of composite systems and its diagnostic are the main topic of current themes concerning vehicles. Application of diagnostic methods in order to define technical condition of motor vehicle is important, esp. in dynamic regime. For example, method of diagnostics of braking – according to curve, change in brake force on wheels, diagnostics of motor sus – according to indicator diagram, diagnostics of different mechanisms according to parameters of vibroacoustic process etc. This paper gives possibilities applications objective diagnostic methods, and it is implemented for the analysis of the state of a motors vehicle.U održavanju motornih vozila poseban problem predstavlja objektivno utvrdjivanje stanja vitalnih komponenata i definisanje perioda njihove zamene, odnosno revitalizacije. Primena dijagnostičkih metoda radi utvrđivanja tehničkog stanja motornog vozila je značajna, naročito u dinamičkim režimima. Na primer: metoda dijagnostike kočenja - prema krivoj promene kočione sile na točkovima, dijagnostika motora sus - prema indikatorskom dijagramu, dijagnostika različitih mehanizama prema parametrima vibroakustičkih procesa i td. Težište sadašnjih tema u oblasti vozila su na pouzdanosti složenih sistema i njihovoj dijagnostici. U radu su date mogućnosti primene objektivnih metoda dijagnostike pri utvrdjivanju stanja motornih vozila

Određivanje dinamičnosti motornih vozila sa hidrodinamičkim prenosnikom snage

In process of projecting of vehicle transmission, which contains hydrodynamic power transmitter, is necessary to correct estimate stability of velocity action. It is also necessary to estimate other factors of transitional processes of unstationary fluid movement in their work area. Goal of this work is to determinate mathematical formulas that could be used for definition of physicality of dynamic processes in work area of hydrodynamic power transmitters.Pri projektovanju transmisije vozila, koja u svom sastavu ima hidrodinamički prenosnik snage neophodna je pravilna ocena stabilnosti brzine dejstva i drugih pokazatelja prelaznih procesa koji su povezani sa nestacionarnim kretanjem tečnosti u njihovom radnom prostoru. Cilj ovog rada je dolaženje do matematičkih izraza koji omogućavaju tačnije definisanje fizikalnosti dinamičkih procesa koji se odvijaju u radnim prostoru hidrodinamičkih prenosnika snage

Performance of the Product of Three Nakagami-m Random Variables

An output signal from a multi-section wireless relay communication system is equal to the product of the signal envelopes from individual sections. In this paper, a three-sections relay system is considered in the presence of Nakagami-m fading at each section. First, random variable (RV) is formed as the product of three Nakagami-m RVs. For such product, the moments are determined in the closed forms. The first moment is the mean of the signal; the second moment is the average power of the signal, and the third moment is skewness. Then, the Amount of Fading (AoF) is calculated. AoF is a measure of the severity effect of fading in a particular channel model. Besides, all system performance are shown graphically and the parameters influence has been analyzed and discussed

Short communication: Pepino mosaic virus, a new threat for Serbia’s tomatoes

Aim of study: To report the occurrence of Pepino mosaic virus (PepMV) on tomato in Serbia and to genetically characterize Serbian PepMV isolates.Area of study: Tomato samples showing virus-like symptoms were collected in the Bogojevce locality (Jablanica District, Serbia).Material and methods: Collected tomato samples were assayed by DAS-ELISA using antisera against eight economically important or quarantine tomato viruses. Three selected isolates of naturally infected tomato plants were mechanically transmitted to tomato ‘Novosadski jabučar’ seedlings. For confirmation of PepMV infection, RT-PCR was performed using specific primers PepMV TGB F/PepMV UTR R. Maximum-likelihood phylogenetic tree was constructed with 47 complete CP gene sequences of PepMV to determine the genetic relationship of Serbian PepMV isolates with those from other parts of the world.Main results: The results of DAS-ELISA indicated the presence of PepMV in all tested samples. Mechanically inoculated ‘Novosadski jabučar’ seedlings expressed yellow spots and light and dark green patches, bubbling, and curled leaves. All tested tomato plants were RT-PCR positive for the presence of PepMV. The CP sequence analysis revealed that the Serbian PepMV isolates were completely identical among themselves and shared the highest nucleotide identity of 95.1% (99.2% aa identity) with isolate from Spain (FJ263341). Phylogenetic analysis showed clustering of the Serbian PepMV isolates into CH2 strain, but they formed separate subgroup within CH2 strain.Research highlights: This is the first data of the presence of PepMV in protected tomato production in Serbia. Considering increased incidence and rapid spread in Europe, the presence of PepMV on tomato could therefore represent serious threat to this valuable crop in Serbia

Multihazard susceptibility assessment: A case study – Municipality of Štrpce (Southern Serbia)

The municipality of Štrpce (Southern Serbia) is an area located within Šar Mountain National Park, which is of great ecological importance. Due to the vicinity of settlements, it is necessary to analyze the terrain's susceptibility to natural hazards. The main goal of this research was to determine locations that are highly vulnerable at times of natural hazards (such as earthquakes, erosion, torrential flooding, snow avalanches, and forest fires). The first step in this research was to analyze seismic hazards for a 475 years return period (VII–VIII MCS for the observed area), which was possible by means of Geographic Information Systems. The second step was to determine the intensity of erosion and total sediment production using the Erosion Potential Model. The third step was related to the analysis of the potential of torrential floods using the Flash Flood Potential Index. The Avalanches Potential Index method was used as the fourth step. The fifth step included the analysis of a terrain susceptibility to the occurrence of forest fires. Following the five criteria analysis, weight coefficients were assigned to each of the analyzed parameters by using the Analytical Hierarchy Process (AHP), which provided results of the total susceptibility to natural hazards of the territory of Štrpce. Results indicated that over 45% of the municipality is highly or very highly susceptible to various natural hazards. This article represents a significant step toward a better understanding of natural hazards and it provides a unique knowledge basis for establishing the management and mitigation guidelines and measures, not only within the researched area but at regional and national levels as well

Different levels of humoral immunoreactivity to different wheat cultivars gliadin are present in patients with celiac disease and in patients with multiple myeloma

<p>Abstract</p> <p>Background</p> <p>Immunity to food antigens (gliadin, cow's milk proteins) is in the centre of the attention of modern medicine focused on the prevention of diseases, prevention which is based on the use of appropriate restriction diet. Detection of the enhanced levels of the immune reactions to antigen(s) present in food is from this point of view of great importance because there are reports that some of health disturbances, like celiac disease (CD) and some premalignant conditions, like monoclonal gammopathy of undetermined significance (MGUS), were vanished after the appropriate restriction diets.</p> <p>It is well known that gliadin is toxic to small bowel mucosa of relatively small population of genetically predisposed individuals, who under this toxic action develop celiac disease (CD). As the quantity of immunogenic gliadin could vary between different wheat species, the first aim of this work was to determine the percentage of immunogenic gliadin in ten bread wheat cultivars and in three commercially grown durum wheat cultivars. The second part of the study was initiated by results of previous publication, reporting that sera of some of multiple myeloma (MM) patients showed the presence of elevated levels of anti-gliadin IgA, without the enhanced levels of anti-gliadin IgG antibodies, determined with commercial ELISA test. It was designed to assess is it possible to reveal is there any hidden, especially anti-gliadin IgG immunoreactivity, in serum of mentioned group of patients. For this purpose we tested MM patients sera, as well as celiac disease (CD) patients sera for the immunoreaction with the native gliadin isolated from wheat species used for bread and pasta making in corresponding geographic region.</p> <p>Results</p> <p>Gliadin was isolated from wheat flour by two step 60% ehanolic extraction. Its content was determined by commercial R5 Mendez Elisa using PWG gliadin as the standard. Results obtained showed that immunogenic gliadin content varies between 50.4 and 65.4 mg/g in bread wheat cultivars and between 20 and 25.6 mg/g in durum wheat cultivars.</p> <p>Anti-gliadin IgA and IgG immunoreactivity of patients' sera in (IU/ml) was firstly determined by commercial diagnostic Binding Site ELISA test, and then additionally by non-commercial ELISA tests, using standardized ethanol wheat extracts -gliadin as the antigen.</p> <p>In both patients groups IgA immunoreactivity to gliadin from different cultivars was almost homogenous and in correlation with results from commercial test (except for one patient with IgA(λ) myeloma, they were more then five times higher). But, results for IgG immunoreactivity were more frequently inhomogeneous, and especially for few MM patients, they were more then five times higher and did not correlate with results obtained using Binding Site test.</p> <p>Conclusion</p> <p>Results obtained showed different content of immunogenic gliadin epitopes in various species of wheat.</p> <p>They also point for new effort to elucidate is there a need to develop new standard antigen, the representative mixture of gliadin isolated from local wheat species used for bread production in corresponding geographic region for ELISA diagnostic tests.</p

Microwave-hydrothermal synthesis of TiO2 and zirconium doped TiO2 adsorbents for removal of As(III) and As(V)

Microwave-hydrothermal method was used for the synthesis of TiO2 and TiO2 doped with zirconium. The method was fast and simple and adsorbents were used for removal of As(III) and As(V) from aqueous solutions. The adsorbents were characterized by BET surface area measurements and powder XRD. Experiments showed that TiO2 doped with 10% of Zr using the microwave-hydrothermal method have greater specific surface area and total pore volume in comparison with TiO2 synthesized using the same method. Better removal with doped adsorbent was obtained for both, As(III) and As(V). Further experiments were carried out with Zr doped TiO2 sorbent in order to examine kinetic of adsorption, influence of pH and effect of common anions present in natural waters. (C) 2014 King Saud University. Production and hosting by Elsevier B.V. All rights reserved