395 research outputs found

    Orthodontic-Prosthodontic Rehabilitation: a Case Report

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    A 25 year-old female came to the Department of Prosthodontics, complaining of problems with masticatory function, described as pain in both temporomandibular joints during mastication and dissatified with esthetics in the upper jaw. After a thorough clinical escaminations, diagnostic casts and X-ray analysis it was determined that the patent had oligodontium of 10 teeth (14, 15, 17, 18, 24, 25, 28, 38, 44, 48), discoloration of incisors caused by hypomaturated enamel (amelogenesis imperfecta), disproportion of the front teeth (in completely defined microdontia), Angle class II/1 (deep overbite) and compression of the front teeth. The case history showed that the problems were of a congenital nature apart from the frontal compression, caused by inadequate orthodontic therapy at a younger age. Despite numerous congenital abnormalities, the patient had no systemic disorders. In consultation with an orthodontist, the patient commenced orthodontic therapy with a fixed orthodontic appliance in the upper jaw for placing the teeth in the right position for fabrication of a semicircular bridge. After 6 months of orthodontic therapy, a fixed prosthodontic appliance 600321 123006 (upper jaw) was made of metal ceramic. The aim of the therapy was to replace missing teeth, protect existing teeth with hypomaturated enamel and readjust occlusal height. With the new intermaxillary relations and teeth contour esthetic and functional concordance was achieved. After therapy the patient had no pain in the temporomandibular joints

    Orthodontic-Prosthodontic Rehabilitation: a Case Report

    Get PDF
    A 25 year-old female came to the Department of Prosthodontics, complaining of problems with masticatory function, described as pain in both temporomandibular joints during mastication and dissatified with esthetics in the upper jaw. After a thorough clinical escaminations, diagnostic casts and X-ray analysis it was determined that the patent had oligodontium of 10 teeth (14, 15, 17, 18, 24, 25, 28, 38, 44, 48), discoloration of incisors caused by hypomaturated enamel (amelogenesis imperfecta), disproportion of the front teeth (in completely defined microdontia), Angle class II/1 (deep overbite) and compression of the front teeth. The case history showed that the problems were of a congenital nature apart from the frontal compression, caused by inadequate orthodontic therapy at a younger age. Despite numerous congenital abnormalities, the patient had no systemic disorders. In consultation with an orthodontist, the patient commenced orthodontic therapy with a fixed orthodontic appliance in the upper jaw for placing the teeth in the right position for fabrication of a semicircular bridge. After 6 months of orthodontic therapy, a fixed prosthodontic appliance 600321 123006 (upper jaw) was made of metal ceramic. The aim of the therapy was to replace missing teeth, protect existing teeth with hypomaturated enamel and readjust occlusal height. With the new intermaxillary relations and teeth contour esthetic and functional concordance was achieved. After therapy the patient had no pain in the temporomandibular joints

    Tribological Potential of Hybrid Composites Based on Zinc and Aluminium Alloys Reinforced with SiC and Graphite Particles

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    The paper reviews contemporary research in the area of hybrid composites based on zinc and aluminium alloys reinforced with SiC and graphite particles. Metal matrix composites (MMCs) based on ZA matrix are being increasingly applied as light-weight and wear resistant materials. Aluminium matrix composites with multiple reinforcements (hybrid AMCs)are finding increased applications because of improved mechanical and tribological properties and hence are better substitutes for single reinforced composites. The results of research show that the hybrid composites possess higher hardness, higher tensile strength, better wear resistance and lower coefficient of friction when compared to pure alloys

    Procena kvaliteta polu-prirodnih travnjaka centralne Srbije koriŔćenjem fitocenoloÅ”kih i numeričkih analiza

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    The aim of this paper is to present a numeric-statistical model by which it is possible to evaluate the quality of the observed grassland upon floristic and vegetation assessment. Thanks to this new methodological approach, the impact of each individual plant species on overall quality of the grassland could be estimated. The main goal was to determine species which significantly determine the pastoral value of the grassland. The quality (pastoral value) of the grassland was calculated using the numerical values of quality index of each individual species of each relevĆ© of the community. For testing this numerical method, the total of 11 relevĆ©s of 4 grassland communities of hilly-mountainous area of Mt. Kopaonik was used. Analyzed vegetation includes previously unpublished phytocenological relevĆ©s as result of our own field research. All analyzed relevĆ©s were obtained using the method of the Swiss-French phytocenological school. The results showed that the best and the worst quality were determined for the ass. Festuco-Brometum erectii, and the ass. Nardetum strictae, respectively. Species that highly contributed to good and bad quality of grassland were Arrhenatherum elatius, Festuca rubra, Dactylis glomerata, Trifolium repens, etc., and Carduus alpestris, Hieracium hoppeanum, Ornithogalum umbelatum, respectively.Travnjaci predstavljaju jedan od najznačajnijih prirodnih resursa; na teritoriji Srbije obuhvataju oko 1.400.000 ha. Koriste se kao izvor stočne hrane ali i kao resurs materija koje se primenjuju u farmaceutskoj industriji. Uzimajući u obzir njihov veliki značaj istraživanja na travnjacima u svrhu ispitivanja njihovog kvaliteta vrÅ”e se u Srbiji od 60-ih godina dvadesetog veka na ovamo. Cilj ovog rada je prikazivanje metode kojom se numerički ocenjuje kvalitet travnjaka, a pored toga se prikazuje i doprinos svake, pojedinačne vrste ukupnom kvalitetu. Doprinos vrste, koji je konkretan broj - pozitivan ili negativan, zavisi od njene pokrovnosti i numeričkog indeksa kvaliteta. Zahvaljujući dobijenim vrednostima doprinosa svake vrste kvalitetu izvrÅ”ena je podela na klastere. To je najpre izvrÅ”eno metodom k-means clustering, zadata su četiri klastera, u prvom je samo jedna vrsta Agrostis vulgaris, u drugom su vrste koje pozitivno utiču na kvalitet, u trećem vrste koje negativno utiču na kvalitet a u četvrtom klasteru su neutralne vrste. Ova podela je proverena metodom glavnih komponenti, i na grafikonu je uočljivo razdvajanje vrsta na pomenute klastere. Zahvaljujući ovoj metodi moguće je za kratko vreme dobiti podatke o kvalitetu nekog travnjaka i podatke o vrstama koje tu žive. Ti podaci o konkretnom travnjaku su dovoljni da se proceni njegova upotrebna vrednost kada je u pitanju stočarska proizvodnja a da se pritom izbegnu skupe hemijske analize

    Intrinsic thermal vibrations of suspended doubly clamped single-wall carbon nanotubes

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    We report the observation of thermally driven mechanical vibrations of suspended doubly clamped carbon nanotubes, grown by chemical vapor deposition (CVD). Several experimental procedures are used to suspend carbon nanotubes. The vibration is observed as a blurring in images taken with a scanning electron microscope. The measured vibration amplitudes are compared with a model based on linear continuum mechanics.Comment: pdf including figures, see: http://www.unibas.ch/phys-meso/Research/Papers/2003/NT-Thermal-Vibrations.pd

    The Amplitude of Non-Equilibrium Quantum Interference in Metallic Mesoscopic Systems

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    We study the influence of a DC bias voltage V on quantum interference corrections to the measured differential conductance in metallic mesoscopic wires and rings. The amplitude of both universal conductance fluctuations (UCF) and Aharonov-Bohm effect (ABE) is enhanced several times for voltages larger than the Thouless energy. The enhancement persists even in the presence of inelastic electron-electron scattering up to V ~ 1 mV. For larger voltages electron-phonon collisions lead to the amplitude decaying as a power law for the UCF and exponentially for the ABE. We obtain good agreement of the experimental data with a model which takes into account the decrease of the electron phase-coherence length due to electron-electron and electron-phonon scattering.Comment: New title, refined analysis. 7 pages, 3 figures, to be published in Europhysics Letter

    Vortex Motion Noise in Micrometre-Sized Thin Films of the Amorphous Nb0.7Ge0.3 Weak-Pinning Superconductor

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    We report high-resolution measurements of voltage (V) noise in the mixed state of micrometre-sized thin films of amorphous Nb0.7Ge0.3, which is a good representative of weak-pinning superconductors. There is a remarkable difference between the noise below and above the irreversibility field Birr. Below Birr, in the presence of measurable pinning, the noise at small applied currents resembles shot noise, and in the regime of flux flow at larger currents decreases with increasing voltage due to a progressive ordering of the vortex motion. At magnetic fields B between Birr and the upper critical field Bc2 flux flow is present already at vanishingly small currents. In this regime the noise scales with (1-B/Bc2)^2 V^2 and has a frequency (f) spectrum of 1/f type. We interpret this noise in terms of the properties of strongly driven depinned vortex systems at high vortex density.Comment: 8 pages, 5 figures, version accepted for publication in PR

    Correlation of the liquid mixture viscosities

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    In this paper forty two selected correlation models for liquid mixture viscosities of organic compounds were tested on 219 binary and 41 ternary sets of experimental data taken from literature. The binary sets contained 3675 experimental data points for 70 different compounds. The ternary sets contained 2879 experimental data points for 29 different compounds. The Heric I, Heric-Brewer II, and Krishnan-Laddha models demonstrated the best correlative characteristics for binary mixtures (overall absolute average deviation < 2%). The Heric I, Heric-Brewer II, Krishnan-Laddha and Heric II models demonstrated the best correlative characteristics for ternary mixtures (overall absolute average deviation < 3%)

    Body Composition and Functional Abilities in Terms of the Quality of Professional Ballerinas

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    The objective of this research was to determine the variability of the sample of professional ballerinas in the space of characteristics of their body composition and some functional characteristics according to the requirements of their roles in ballet. The sample of examinees was comprised of 30 professional ballerinas, members of the Croatian National Theatre Ballet (15 soloists and 15 members of the corps de ballet). The data showed that the soloists were characterized by a significantly larger knee diameter, significantly lower thickness of skin folds on the trunk and the lower fat body mass percentage, as well as by greater grip strength. Aerobic capacity was only moderately more developed than in fit people who participated in physical exercising because of recreational reasons, and there were no differences between soloists and the members of the corps
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