Search results for "Molar"
showing 10 items of 1069 documents
Structure-property relationships of polycarbonate diol-based polyurethanes as a function of soft segment content and molar mass
2014
Segmented thermoplastic polyurethanes (PUs) have been synthesized with polycarbonate diol as soft segment and 4,4′-diphenylmethane diisocyanate and butanediol as hard segment. Two different series employing two different soft-segment molar mass, 1000 and 2000 g/mol, and by changing the hard-segment content from 32 to 67% have been investigated with the aim to elucidate the effect of the different content variations on the properties. Morphological, thermal, and mechanical properties have been studied by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), wide angle X-ray diffraction, atomic force microscopy, tensile and…
Asaru osmolaritāte dažādu profesiju pārstāvjiem
2019
Bakalaura darbs ir uzrakstīts latviešu valodā datorsalikumā uz 34 lapaspusēm. Tas satur 19 attēlus, 4 tabulas, 33 atsauces uz literatūras avotiem. Darba mērķis bija novērtēt vides faktoru ietekmi uz asaru osmolaritāti, salīdzināt ar ārā strādājošo dalībnieku rezultātiem ar iekšā strādājošo dalībnieku rezultātiem. Pētījums tika veikts 2. posmos, 1. posms anketēšanas daļa kurā piedalījās 200 cilvēku, 2. posms kurā notika osmolaritātes mērījumi, piedalījās 105 cilvēki. Rezultāti pieradīja, kad gaisa relatīvais mitrums atstāj ietekmi uz asaru osmolaritāti un nav būtisku izmaiņu starp dalībnieku grupām.
Effectiveness of interceptive treatment of class III malocclusions with skeletal anchorage: A systematic review and meta-analysis
2017
Recently, new strategies for treating class III malocclusions have appeared. Skeletal anchorage appears to reduce the dentoalveolar effects while maximising the orthopaedic effect in growing patients. The purpose of this systematic review and meta-analysis is to examine the effectiveness of bone anchorage devices for interceptive treatment of skeletal class III malocclusions. Searches were made in the Pubmed, Embase, Scopus and Cochrane databases, as well as in a grey literature database, and were complemented by hand-searching. The criteria for eligibility were: patients who had undergone orthodontic treatment with skeletal anchorage (miniplates and miniscrews). Patients with syndromes or …
Densities, Refractive Indices, and Excess Molar Volumes of Binary and Ternary Systems Containing Isobutyl Alcohol, Ethanol, 2-Methylpentane, and Meth…
2000
This paper reports experimental densities and refractive indices of binary and ternary systems containing isobutyl alcohol, ethanol, 2-methylpentane, and methyl tert-butyl ether over the whole composition range of mixtures at 298.15 K and atmospheric pressure. From these data, excess molar volumes VE have been calculated. These results are fitted to the Redlich−Kister and Cibulka polynomial equations to derive the binary and ternary coefficients, respectively.
Standard partial molar volumes of alcohols in aqueous dodecyltrimethylammonium bromide solutions
1990
Density measurements of water-dodecyltrimethylammonium bromide (DTAB)-alcohol ternary systems as a function of alcohol and surfactant concentrations were carried out at 25°C. The alcohols were propanol (PrOH), 2-propanol (2-PrOH) and hexanol (HexOH). The apparent molar volume Vϕ,R of alcohols have been calculated and the standard (infinite dilution) partial molar volumes of alcohols V R at each surfactant concentration were obtained by means of a least squares fit of Vϕ,R vs. the alcohol concentration. The V R vs. surfactant concentration curves have been rationalized in terms of the partial molar volume of alcohol in the aqueous V f and the micellar V b phases and the distribution constant…
Heat capacities and volumes of suspensions in the presence of surfactants
2004
Abstract Density and heat capacity measurements of water–surfactant–silica ternary systems were carried out as functions of the silica and the surfactant concentrations at 298 K. From these properties, the apparent molar volume and heat capacity of the surfactant in a given water+silica mixture were evaluated. As well, the apparent specific volume and heat capacity of silica, at a given concentration, in the water+surfactant mixtures as functions of the surfactant concentration were calculated. Some surfactants (decyltrimethylammonium bromide, sodium octanoate, sodium decanoate, sodium dodecanoate, sodium decylsulfate, sodium perfluorooctanoate and N , N -dimethyldodecylamine- N -oxide) wer…
Densities, refractive indices, and derived excess properties of tert-butyl alcohol, methyl tert-butyl ether and 2-methylpentane binary and ternary sy…
2000
Abstract This paper reports experimental densities and refractive indices of the binary systems tert-butyl alcohol (TBA)+methyl tert-butyl ether (MTBE), TBA+2-methylpentane, and MTBE+2-methylpentane, and the ternary system TBA+MTBE+2-methylpentane, over the entire range of composition at 303.15 K. Excess molar volumes and changes of refractive indices were evaluated from the experimental data obtained. These derived properties were fitted to variable-degree polynomials. The experimental values of physical properties were compared with the values estimated by different methods of prediction.
Densities, refractive indices, and derived excess properties of the binary systems tert-butyl alcohol+toluene, +methylcyclohexane, and +isooctane and…
1999
Abstract This paper reports experimental densities and refractive indices of the binary systems tert -butyl alcohol (TBA)+toluene, +isooctane, and +methylcyclohexane, and toluene+methylcyclohexane, and the ternary system TBA+toluene+methylcyclohexane, over the entire range of composition at 298.15 K. Excess molar volumes and changes of refractive indices were evaluated from the experimental data obtained. These derived properties were fitted to variable-degree polynomials. The experimental values of physical properties were compared with the values estimated by different methods of prediction.
Prevalence of Third Molar in Opg and Role of Them in Orthodontics
2021
ABSTRAKTS Mērķis: Šī retrospektīvā pētījuma mērķis bija izpētīt trešo molāru ietekmi uz ortodontiskās ārstēšanas gaitu. Pētījumā galvenā uzmanība tiek pievērsta retinētiem trešajiem molāriem, premolāru ekstrakcijām, lai iegūtu iespējamu vietu šķilties trešajiem molāriem un pārbaudīt literatūras datus par trešo molāru ietekmi uz incisīvu saspiestību. Metodes: Tika analizēti 81 rentgena uzņēmumu ( ortopantomogrammas- OPG) no 81 pacienta. OPG ietvēra dzimumu, dzimšanas datumu, reģistrēšanas datumu, esošo trešo molāru daudzumu, trešo molāru ekstrakciju pirms ortodontiskās ārstāšanas un kāda veida ortodontiskās aparatūras izmantoja pēc trešo molāru ekstrakcijas. Rezultāti: No 81 pētījuma dalībni…
Cariostatic effect of a light-cured, resin-reinforced glass-ionomer for bonding orthodontic brackets in vivo
1998
The aim of this study was to evaluate in vivo the cariostatic potential of the resin-reinforced glass-ionomer (Vitremer core build-up restorative; 3M Dental Product Division) when used as a bonding agent for orthodontic brackets. The mineral distribution and topography of the enamel surface adjacent to the bracket base was determined by quantitative microradiography (TMR) and confocal laser scanning microscopy (CLSM). The study was designed in split-mouth technique using 9 pairs of premolars to be extracted for orthodontic reasons. One tooth of each pair was bonded with the resin-reinforced glass-ionomer, and the control contralateral premolar with the non-fluoridated composite (Concise, 3M…