An exact analytical solution for the second order slip-corrected Reynolds lubrication equation

Izvedena je opšta Rejnoldsova jednačina podmazivanja za uslove strujanja sa klizanjem primenom opštih graničnih uslova klizanja drugog reda i pokazano je da ona ima tačno analitičko rešenje. Rešenje je dobijeno tansformacijom zavisno promenljive što je dovelo do mogućnosti analitičkog proračuna raspodele pritiska i masenog protoka u mikroležaju. Na taj način, poređenjem sa datim analitičkim rešenjem omogućena je provera eksperimentalnih i numeričkih rezultata za strujanje gasa u mikroležajima.We derive a general slip-corrected compressible Reynolds lubrication equation, valid for any choice of the slip velocities, and show that it possesses the exact analytical solution. It is obtained by a suitable transformation of the dependent variable, and it yields both the pressure distribution in the bearing and the mass flow rate through it. It can be usefully applied for testing the other, experimental or numerical results obtained under the same or similar physical conditions, against this solution

The exact analytical solution for the gas lubricated bearing in the slip and continuum flow regime

The exact analytical solution for the compressible two-dimensional gas flow in the microbearing is presented. The general slip-corrected Reynolds lubrication equation is derived and it is shown that it possesses an exact analytical solution. It is obtained by a suitable transformation of the independent variable, and it provides the pressure distribution in the bearing as well as the mass flow rate through it. By neglecting the rarefaction effect, this solution is also applicable to the continuum gas flow in the bearing, which also does not exist in the open literature. The obtained analytical solution can be usefully applied for testing the other, experimental or numerical results

Procena stanja oralnog zdravlja hospitalizovanih osoba sa shizofrenijom

Background. It is considered that over 450 million people worldwide suffer from some form of mental disorder; studies conducted in other countries have shown that schizophrenia is among the most frequent. Oral health has a significant place in the general human health and should not be separated from mental health. Studies conducted in other countries have shown an increased prevalence of oral diseases in patients with schizophrenia. The aim of this study was to evaluate the oral health of hospitalized patients with schizophrenia, in particular to determine the prevalence of dental caries, diseases of periodontium and soft tissue examination and to concider possible risk factors that contribute to the existing problems with the oral health in hospitalized patients with schizophrenia. Patients and methods. The study included 190 hospitalized patients with schizophrenia treated at the Clinic for Psychiatric Disorders "Dr Laza Lazarevic" Belgrade (study group) and 190 healthy subjects, patients of the Department of Periodontology and Oral Medicine, School of Dental Medicine, University of Belgrade (control group). All data were obtained by thorough dental examination of participants, using cetrain indices for assessing oral health (DMF index, CPITN index, and OHI-S index). In addition, by anamnesis and clinical examination have been detected signs and symptoms of diseases of the oral soft tissues were detected. Specially designed questionnaire (by the type of standardized interview) provided data on the use of dental health services, exerting of eating habits and bad habits to oral health, as well as the habits of oral hygiene. Socio-economic and demographic characteristics of the participants, as well as data on psychiatric disorders (for the study group) were obtained from medical records (medical history) . Primary obtained data entered the program SPSS 17.0 and analyzed by descriptive statistical methods, methods for testing hypotheses and application regression models...Osnov problema. Smatra se da preko 450 miliona ljudi širom sveta pati od nekog oblika mentalnog poremećaja, a istraţivanja sprovedena u drugim zemljama pokazala su da je shizofrenija meĎu najzastupljenijima. Oralno zdravlje zauzima značajno mesto u celokupnom zdravlju čoveka i ne treba ga razdvajati od mentalnog zdravlja. Istraţivanja sprovedena u drugim zemljama pokazala su povećanu zastupljenost oralnih bolesti kod pacijenata sa shizofrenijom. Cilj ove studije bio je da proceni stanje oralnog zdravlja hospitalizovanih osoba sa shizofrenijom, konkretno da odredi prevalenciju karijesa, oboljenja potpornog aparata zuba i mekih tkiva usne duplje i ispita moguće faktore rizika koji doprinose postojećim problemima sa oralnim zdravljem hospitalizovanih osoba sa shizofrenijom. Pacijenti i metod. U istraţivanju je učestvovalo 190 hospitalizovanih osoba sa shizofrenijom, lečenih na Klinici za psihijatrijske bolesti „Dr Laza Lazarević“ Beograd (studijska grupa) i 190 zdravih ispitanika, pacijenata Klinike za parodontologiju i oralnu medicinu Stomatološkog fakulteta Univerziteta u Beogradu (kontrolna grupa). Svi podaci su dobijeni pomoću sistematskog stomatološkog pregleda ispitanika, kojim su odreĎeni indeksi za procenu oralnog zdravlja (KEP indeks, CPITN indeks i OHI-S indeks). Pored toga, anamnezom i kliničkim pregledom registrovano je prisustvo simptoma i znakova oboljenja mekih tkiva usne duplje. Posebno dizajniranim upitnikom (po tipu standardizovanog intervjua) dobijeni su podaci o korišćenju usluga stomatološke zdravstvene zaštite, upraţnjavanju navika u ishrani i loših navika prema oralnom zdravlju, kao i o navikama u odrţavanju oralne higijene. Socio-ekonomska i demografska obeleţja ispitanika, kao i podaci o psihijatrijskoj bolesti (u studijskoj grupi) dobijeni su iz medicinske dokumentacije (istorije bolesti). Primarno dobijeni podaci uneti su u program SPSS 17.0 i analizirani deskriptivnim statističkim metodama, metodama za testiranje hipoteza i primenom regresionih modela..

An exact analytical solution for the second order slip-corrected Reynolds lubrication equation

Izvedena je opšta Rejnoldsova jednačina podmazivanja za uslove strujanja sa klizanjem primenom opštih graničnih uslova klizanja drugog reda i pokazano je da ona ima tačno analitičko rešenje. Rešenje je dobijeno tansformacijom zavisno promenljive što je dovelo do mogućnosti analitičkog proračuna raspodele pritiska i masenog protoka u mikroležaju. Na taj način, poređenjem sa datim analitičkim rešenjem omogućena je provera eksperimentalnih i numeričkih rezultata za strujanje gasa u mikroležajima.We derive a general slip-corrected compressible Reynolds lubrication equation, valid for any choice of the slip velocities, and show that it possesses the exact analytical solution. It is obtained by a suitable transformation of the dependent variable, and it yields both the pressure distribution in the bearing and the mass flow rate through it. It can be usefully applied for testing the other, experimental or numerical results obtained under the same or similar physical conditions, against this solution

Three paradoxes

Mada na prvi pogled izgleda da tri paradoksa kojima ću se ovde baviti nemaju ništa bitno zajedničko, smatram da sva tri sadrže skrivenu dvosmislenost iste vrste, i na osnovu toga nudim rešenje. Prvi je poznat u literaturi kao 'direktni argument', drugi je jedan od standardnih argumenata za fatalizam a treći je Mekgijev kontraprimer za modus ponens.Although it may seem that the three paradoxes I deal with in this paper have nothing in common, I believe that they all involve an equivocation of the same kind. The first is known as the 'direct argument', the second is one of the standard arguments for fatalism, and the third is McGee's counterexample to modus poenes

Spatial distribution and ecology of orchids (Orchidaceae) of western Serbia

Orhideje su poznate po bogatstvu taksona, kompleksnoj ekologiji i velikom broju ugroženih vrsta. Osnovni ciljevi ove disertacije su utvrđivanje prostorne distribucije i diverziteta orhideja zapadne Srbije, kao i utvrđivanje ekoloških preferencija i konzervacionog statusa orhideja. Za svaki takson izrađene su karte rasprostranjenja u zapadnoj Srbiji. Za ispitivanje uticaja nadmorske visine, 19 bioklimatskih faktora i heterogenosti staništa na bogatstvo taksona u pojedinim UTM kvadratima 10 × 10 km, kao i analizu bogatstva taksona orhideja duž gradijenta nadmorske visine korišćena je regresiona analiza. OMI (eng. outlying mean index) analiza je korišćena za analizu ekoloških niša i faktora koji utiču na brojnost i distribuciju orhideja. Utvrđeno je prisustvo 57 vrsta i podvrsta orhideja, među kojima je 7 novih taksona za floru Srbije. Utvrđeno je da planina Tara predstavlja najvažniji centar diverziteta orhideja u zapadnoj Srbiji, sa 34 registrovana taksona u UTM kvadratu CP76. Rezultati ovog istraživanja su pokazali da nadmorska visina i heterogenost staništa značajno utiču na bogatstvo taksona u UTM kvadratima 10 × 10 km, dok maksimalne vrednosti nadmorskih visina i minimalne vrednosti temperaturnih varijabli najsnažnije utiču na bogatstvo prstastotuberoidnih orhideja. Utvrđeno je da se najviše taksona orhideja javlja u područjima srednjih nadmorskih visina (1000-1100 m). Najveći broj taksona orhideja je registrovan na krečnjacima, u zajednicama klasa Festuco-Brometea, Quercetea pubescentis i Molinio-Arrhenatheretea. Definisano je 6 ekoloških grupa šumskih i 8 ekoloških grupa orhideja zeljastih tipova vegetacije. Određeni su IUCN statusi ugroženosti, kao i faktori ugrožavanja orhideja zapadne Srbije, sa predlogom mera zaštite i konzervacionim prioritetima.Orchids are known for their taxa richness, complex ecology and a large number of endangered species. The main objectives of this dissertation are the determination of spatial distribution and diversity of orchids in western Serbia, and the determination of ecological preferences and conservation status of orchids. Distribution maps were made for each taxon in western Serbia. Regression analysis was used to explore the influence of elevation, 19 bioclimatic factors and the habitat heterogeneity on the taxa richness within individual UTM 10 × 10 km grid cells, as well as to analyse the taxa richness along the elevational gradient. The OMI (outlying mean index) analysis was used to analyse ecological niches and factors affecting the abundance and distribution of orchids. The presence of 57 orchid species and subspecies was recorded, among which 7 new taxa to the flora of Serbia. Mt. Tara represents the most important center of diversity of orchids in western Serbia, with 34 taxa recorded in CP76 UTM grid cell. Results of this study showed that elevation and habitat heterogeneity significantly affect the taxa richness in UTM 10 × 10 km grid cells, whereas the maximum values of elevations and minimum values of temperature variables most significantly affect the richness of orchids with palmate and fusiform tubers. It has been found that most of orchid taxa occur in the middle elevations (1000-1100 m). The largest number of orchid taxa was recorded on limestone, in the communities of the classes Festuco-Brometea, Quercetea pubescentis and Molinio-Arrhenatheretea. Six ecological groups of forest orchids and eight ecological groups of orchids of herbaceous vegetation types were defined. IUCN threatened status, as well as the threats to orchids of western Serbia were determined, with a proposal for protection measures and conservation priorities

Evaluation of oral health in hospitalized patients with schizophrenia

Osnov problema. Smatra se da preko 450 miliona ljudi širom sveta pati od nekog oblika mentalnog poremećaja, a istraţivanja sprovedena u drugim zemljama pokazala su da je shizofrenija meĎu najzastupljenijima. Oralno zdravlje zauzima značajno mesto u celokupnom zdravlju čoveka i ne treba ga razdvajati od mentalnog zdravlja. Istraţivanja sprovedena u drugim zemljama pokazala su povećanu zastupljenost oralnih bolesti kod pacijenata sa shizofrenijom. Cilj ove studije bio je da proceni stanje oralnog zdravlja hospitalizovanih osoba sa shizofrenijom, konkretno da odredi prevalenciju karijesa, oboljenja potpornog aparata zuba i mekih tkiva usne duplje i ispita moguće faktore rizika koji doprinose postojećim problemima sa oralnim zdravljem hospitalizovanih osoba sa shizofrenijom. Pacijenti i metod. U istraţivanju je učestvovalo 190 hospitalizovanih osoba sa shizofrenijom, lečenih na Klinici za psihijatrijske bolesti „Dr Laza Lazarević“ Beograd (studijska grupa) i 190 zdravih ispitanika, pacijenata Klinike za parodontologiju i oralnu medicinu Stomatološkog fakulteta Univerziteta u Beogradu (kontrolna grupa). Svi podaci su dobijeni pomoću sistematskog stomatološkog pregleda ispitanika, kojim su odreĎeni indeksi za procenu oralnog zdravlja (KEP indeks, CPITN indeks i OHI-S indeks). Pored toga, anamnezom i kliničkim pregledom registrovano je prisustvo simptoma i znakova oboljenja mekih tkiva usne duplje. Posebno dizajniranim upitnikom (po tipu standardizovanog intervjua) dobijeni su podaci o korišćenju usluga stomatološke zdravstvene zaštite, upraţnjavanju navika u ishrani i loših navika prema oralnom zdravlju, kao i o navikama u odrţavanju oralne higijene. Socio-ekonomska i demografska obeleţja ispitanika, kao i podaci o psihijatrijskoj bolesti (u studijskoj grupi) dobijeni su iz medicinske dokumentacije (istorije bolesti). Primarno dobijeni podaci uneti su u program SPSS 17.0 i analizirani deskriptivnim statističkim metodama, metodama za testiranje hipoteza i primenom regresionih modela...Background. It is considered that over 450 million people worldwide suffer from some form of mental disorder; studies conducted in other countries have shown that schizophrenia is among the most frequent. Oral health has a significant place in the general human health and should not be separated from mental health. Studies conducted in other countries have shown an increased prevalence of oral diseases in patients with schizophrenia. The aim of this study was to evaluate the oral health of hospitalized patients with schizophrenia, in particular to determine the prevalence of dental caries, diseases of periodontium and soft tissue examination and to concider possible risk factors that contribute to the existing problems with the oral health in hospitalized patients with schizophrenia. Patients and methods. The study included 190 hospitalized patients with schizophrenia treated at the Clinic for Psychiatric Disorders "Dr Laza Lazarevic" Belgrade (study group) and 190 healthy subjects, patients of the Department of Periodontology and Oral Medicine, School of Dental Medicine, University of Belgrade (control group). All data were obtained by thorough dental examination of participants, using cetrain indices for assessing oral health (DMF index, CPITN index, and OHI-S index). In addition, by anamnesis and clinical examination have been detected signs and symptoms of diseases of the oral soft tissues were detected. Specially designed questionnaire (by the type of standardized interview) provided data on the use of dental health services, exerting of eating habits and bad habits to oral health, as well as the habits of oral hygiene. Socio-economic and demographic characteristics of the participants, as well as data on psychiatric disorders (for the study group) were obtained from medical records (medical history) . Primary obtained data entered the program SPSS 17.0 and analyzed by descriptive statistical methods, methods for testing hypotheses and application regression models..

The Influence of Serbia’s Historical Constitutions on Its Modern Constitutional Identity : 30 Years Since the Return of Liberal Democratic Constitutionality

Any kind of future constitutional development of one country is in large part bound by the constitutional tradition and ever-lasting constitutional development of the country in question. Determining the right milestones, long term historical trends and traces of surviving constitutional identity markers presents a daring quest for a constitutional law scholar, especially when a country that is subjected to such analysis has a rich, but quite diverse constitutional history, as the Republic of Serbia. In this chapter authors strive to discover distinctive periods of the Serbian constitutionality, examine their characteristics and establish a possible connection of historical constitutions to the present Serbian constitutional identity

Jedan test primer primene IDS otvorenog i zatvorenog koda

Computer users who still primarily work in networks require that the access to their data and resources in general is granted only to those that they allow to - just as in the case of physical property, the users of computer systems want the so-called computer security. The Internet, as the best known computer network, connects millions of people around the world granting them access primarily to a large amount of information and its users need to have the necessary means in order to achieve a given level of security. Systems for detecting intrusion in a computer system (IDS-instrusion detection system), solve the problem of unwanted network access. There are open-source and closed-commercial code IDS and it is important to have an insight into their advantages and disadvantages.Korisnici računara, koji danas pre svega rade u mrežama, imaju zahtev da pristup njihovim podacima i resursima uopšte imaju samo oni kojima se pristup dozvoli - analogno sigurnosti fizičke imovine, korisnici računarskih sistema žele takozvanu računarsku sigurnost. Internet, kao najpoznatija računarska mreža, povezuje milione ljudi širom sveta, obezbeđujući im pristup pre svega velikoj količini informacija, i korisnicima su potrebna sredstva sposobna da ostvare zadati stepen sigurnosti. Sistemi za detekciju upada u računarski sistem (IDS - intrusion detection system) rešavaju problem eliminacije neželjenih pristupa mreži. Postoje IDS otvorenog i zatvorenog - komercijalnog koda i važno je imati uvid u njihove prednosti i mane

Orchid species Anacamptis morio as a potential bioremediator of As, Cd and Pb

In this study concentration of toxic elements as, Cd, and Pb were determined in different soil types and belonging orchid species Anacamptis morio vital parts, in order to examine accumulation patterns and provide new insights about the potential use of this orchid in bioremediation technology. Soils developed on limestone, serpentine, and the chert were subjected to the BCR sequential extraction. Samples of orchid roots and tubers, as underground parts, and stems, leaves, and inflorescences, as above-ground organs, were also analyzed for the content of as, Cd and Pb. During this research, it was observed that metal content in soil is directly proportional to its content in the plant, more specifically in roots, which suggests that A. morio can potentially be used in the phytostabilization of contaminated sites. Values for BCF factors showed Cd immobilization in roots regardless of the soil type. A certain level of arsenic was transferred from roots to leaves indicating the potential for accumulation of this element into aboveground organs. Assessment of the phytoremediation potential of this orchid or another plant species from diverse environments is important as it provides information about the possibility of their future application in environmental remediation programs