Search results for "R-phase"
showing 7 items of 7 documents
Danger zone analysis using cone beam computed tomography after apical enlargement with K3 and K3XF in a manikin model
2015
Background The objective of the study was to evaluate and compare how apical enlargement with K3 and K3XF nickel-titanium (NiTi) rotary instruments reduces the root thickness in the danger zone and affects canal transportation and centering ability in mandibular molar mesial canals in a manikin extracted tooth model. Material and Methods Seventy-two mesial root canals of first mandibular molars were instrumented. Initial and post-instrumentation Cone Beam Computed Tomography scans were performed after root canal preparation up to size 25, 30, 35 and 40 files. Canal transportation, canal centering and remaining root dentin thickness toward the danger zone were calculated in sections 1, 2 and…
Four-phase rhinomanometry: a multicentric retrospective analysis of 36,563 clinical measurements
2015
Rhinomanometry can still be considered as the standard technique for the objective assessment of the ven- tilatory function of the nose. Reliable technical requirements are given by fast digital sensors and modern information technology. However, the xyimaging of the pressure-flow relation typically shows loops as a sign of hysteresis, with the need for resolution of the breath in four phases. The three pillars of 4-phase rhinomanometry (4PR) are the replacement of estimations by measurements, the introduc- tion of parameters related to the subjective sensing of obstruction, and the graphical information regarding the disturbed function of the nasal valve. In a meta-analysis of 36,563 clini…
Tehnisko kļūdu novērtēšana un izskaušana rinomanometrijā
2016
KOPASAVILKUMS Ievads: Jaunas metodes tiek ieviestas, lai rastu vienkāršākus un ātrākus risinājumus spiediena caurules fiksācijai rimomanometrijā. Svarīgi ir pētīt ietekmes uz gaisa plūsmu, lai izvairītos no kļudainiem mērījumiem. Ar datorprogrammu saistītā rinomanometrija pamazām tiek aizstāta ar PNIF ierīci, jo tā ir lētāka un vieglāka lietošanā, līdz ar to ir svarīgi vispirms novērot korelāciju starp abām metodēm. Mērķis: Diplomdarba mērķis bija apzināties un piefiksēt kļūdas un sarežģījumus, kādi rodas veicot četru fāzu rinomanometriju, izmantojot dažādas spiediena caurulītes piestiprināšanas metodes. Vēlviens uzdevums bija apzināties un piefiksēt kļūdas, kas rodas PNIF testa procesā, kā…
Deguna plūsmas fizisko modeļu eksperimenti
2016
Jau vairākus gadus rinomanometrija ir vispāratzīta deguna elpošanas pretestības diagnostikas metode. Ar četru fāzu rinomanometrijas ieviešanu, radās cilpu fenomens, radot diskusijas par tās izcelsmi. Izmēģinājuma mērķis ir izpētīt cilpas rašanos rinomanometrijas mērījumos un dažādu formu rezistoru ietekmi. Izmēģinājuma laikā tika izveidoti dāžādi rezistori, kas izgatavoti no vara caurulēm un mērījumi tika konstatēti ar mērāmierīci 4 Rhino no uzņēmuma Rhinolab/ Vācijā. Pētījumā tika reģistrēti 120 mērījumi. Vairākos mērījumos tika konstatētas histerēzes cilpas, kas saistītas ar gaisa plūsmas recirkulācijas biežumu. Biežums un plūsmas ātrums nosaka histerēzes cilpas rašanos ne caur nulli četr…
The role of water in the photocatalytic degradation of acetonitrile and toluene in gas-solid and liquid-solid regimes
2006
Photocatalytic degradation of acetonitrile and toluene was carried out both in gas-solid and in liquid-solid regimes by using commercialTiO2samples (Merck and Degussa P25). The investigation was mainly aimed to study the influence of water present in the reaction environment on the mechanism and degradation rate of two probe molecules. In gas-solid regime, the reacting mixture consisted of toluene or acetonitrile, oxygen, nitrogen, and water vapour. The main degradation product of toluene wasCO2with small amounts of benzaldehyde. In the presence of water vapour, the activity ofTiO2Merck remained stable but greatly decreased if water was absent.TiO2Degussa P25 continuously deactivated, even …
Current status of AlInN layers lattice-matched to GaN for photonics and electronics
2007
We report on the current properties of Al1-x InxN (x approximate to 0.18) layers lattice- matched ( LM) to GaN and their specific use to realize nearly strain- free structures for photonic and electronic applications. Following a literature survey of the general properties of AlInN layers, structural and optical properties of thin state- of- the- art AlInN layers LM to GaN are described showing that despite improved structural properties these layers are still characterized by a typical background donor concentration of ( 1 - 5) x 10(18) cm(-3) and a large Stokes shift (similar to 800 meV) between luminescence and absorption edge. The use of these AlInN layers LM to GaN is then exemplified …
Dentinal microcracks after root canal instrumentation using instruments manufactured with different NiTi alloys and the SAF system: A systematic revi…
2021
Aim: The aim of this systematic analysis was to assess the prevalence of dentinal microcracks at various levels (3, 6, and 9 mm from the apex) after using instruments made with conventional, R-Phase, and M-Wire NiTi alloys and the SAF system. Materials and Methods: Electronic searches were conducted in the databases Embase, Cochrane Library, Scopus, PubMed, and Web of Science. To arrange search methods, “MeSH” terms and/or keywords typically associated with the subject were paired with the Boolean operators “AND” and “OR.” Additional searches were conducted on the websites of four separate endodontic journals. After reading the titles and excluding duplicates, 1000 of the 1343 documents ori…