Search results for "testing."

Effect of different sintering process on flexural strength of translucency monolithic zirconia

2018

Background Sintering process is responsible for the strength of zirconia restoration. This study evaluated the effect of different sintering temperatures and sintered-holding times on flexural strength of translucency monolithic zirconia. Material and Methods One hundred and thirty five zirconia bar specimens (width-length-thickness = 10×20×1.5 mm) were prepared from yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic and randomly divided into nine groups to be sintered at different temperatures [decreasing- (SD, 1350°C), regular- (SR, 1450°C), and increasing- (SI, 1550°C) sintering temperature] and different sintered-holding times [shortening- (HS, 60 min), regular- (HR, …

Fracture resistance of roots filled with three different obturation techniques

2012

Objectives: The aim of this study was to compare in vitro root fracture resistance following root canal filling with AH 26 using lateral condensation, BeeFill, and Thermafil techniques. Study Design: Eighty extracted human mandibular premolars with similar dimensions were selected. In order to standardize the roots, measurements were taken in two separate regions of the teeth—at the cemento-enamel junction and 8 mm apically from the junction—buccolingual as well as mesiodistal for every tooth. Teeth were then randomly divided into five groups (n=16). With the exception of the non-prepared group (Group 1), instrumentation was done in all groups. In group 2, instrumentation but no filling was…

Influence of artificial aging and ZrO2 nanoparticle-reinforced repair resin on the denture repair strength

2019

Background The purpose of this study was to evaluate the effect of aging process on the tensile strength (TS) of repaired acrylic denture base using ZrO2 nanoparticles (nano-ZrO2)-reinforced autopolymerized resin. Material and Methods A total of 240 heat-polymerized acrylic resin specimens (n=10) were prepared and sectioned creating 2 mm-repair-gap. Autopolymerized acrylic resin, pure and modified with 2.5, 5, and 7.5wt% nano-ZrO2 were used for specimens repair. TS of repaired specimens were measured using the universal testing machine after water immersion at 37oC for 2, 7 and 30 days. At each time interval, half the immersed specimens underwent thermo-cycling aging process (5000 cycles at…

Construct validity of the Moral Development Scale for Professionals (MDSP)

2011

Olle Söderhamn1,2, John Olav Bjørnestad1, Anne Skisland1, Christina Cliffordson21Faculty of Health and Sport Sciences, University of Agder, Grimstad and Kristiansand, Norway; 2Department of Nursing, Health and Culture, University West, Trollhättan, SwedenAbstract: The aim of this study was to investigate the construct validity of the Moral Development Scale for Professionals (MDSP) using structural equation modeling. The instrument is a 12-item self-report instrument, developed in the Scandinavian cultural context and based on Kohlberg’s theory. A hypothesized simplex structure model underlying the MDSP was tested through structural equation modeling. …

Vēža ģenētiskās testēšanas laboratorijas izveide Rīgā

2016

Onkoloģiskā saslimšana ir mūsdienās viena no smagākajām diagnozēm, no kuras ik gadu mirst liels cilvēku skaits pasaulē un Latvijā. Katru gadu pieaug pacientu skaits, kuriem ir diagnosticēts kāds no ļaundabīgā audzēja veidiem. Onkoloģijas pacienti ir visas pasaules mēroga problēma, un arī Latvijā vēža pacientu skaita pieaugums ir epidēmijas līmenī pašlaik. Diemžēl Latvijā ir novērojama tendence, ka vēzis tiek diagnosticēts vēlajās tā stadijās. Vēža diagnosticēšana tā agrākajā stadijā nozīmē pacienta dzīvildzes rādītāju pagarinājumu vai pat slimības remisiju. Vēža ģenētika sniedz visaptverošu informāciju par vēža slimības attīstību, tās iespējamajām lokācijām un daudzos gadījumos ar ģenētiskā…

A new series of π-extended tetrathiafulvalene derivatives incorporating fused furanodithiino and thienodithiino units: a joint experimental and theor…

2004

A new family of tetrathiafulvalenes has been prepared. The materials exhibit complex redox behaviour related to the electronic influence of the 1,4-dithiin moieties embedded within the framework of the molecules. The X-ray crystal structure of compound 4 reveals an unusual non-planar conformation of the heterocyclic compound, with the TTF fragment adopting a boat conformation. Theoretical calculations, performed at the DFT level (B3P86/6-31G*), confirm the boatlike structure (C2v symmetry) as the most stable conformation for this family of tetrathiafulvalenes. Upon oxidation, electrons are extracted from the whole molecule and the radical cations and dications remain highly distorted from p…

Heart rate responses during the modified six-minute walk test among Special Olympics athletes

2021

Objective: The construct validity of the modified six-minute walk test (m6MWT) was examined by addressing the following questions: 1) do participants attain a steady state plateau in heart rate (HR) within the range of 110-150 beats per minute? 2) at what percentage of their predicted HR maximum were participants during each minute of the test? Material and Methods: Participants were 36 (male=56%) Special Olympics athletes aged 34.4 years (SD = 12.7). Following familiarization, participants completed the m6MWT while wearing a Polar Team 2 heart rate monitor. Results: By the end of the first minute, average heart rate was 120bpm, and a factorial repeated measures ANOVA revealed that steady s…

Mesoscopic and Microscopic Investigation on Poly(vinyl alcohol) Hydrogels in the Presence of Sodium Decylsulfate

2007

The structure of poly(vinyl alcohol) (PVA) hydrogels formed as a result of freeze/thaw treatments of aqueous solutions of the polymer (11 wt % PVA) in the freshly prepared state is analyzed through the combined use of small (SANS) and ultrasmall (USANS) angle neutron scattering techniques. The structure of these hydrogels may be described in terms of polymer rich regions, with dimensions of the order of 1-2 microm, dispersed in a water rich phase, forming two bicontinuous phases. The PVA chains in the polymer rich phase form a network where the cross-linking points are mainly crystalline aggregates of PVA having average dimensions of approximately 45 A. The structural organization of freeze…

Who can go back to work when the COVID-19 pandemic remits?

2020

AbstractThis paper seeks to determine which workers affected by lockdown measures can return to work when a government decides to apply lockdown exit strategies. This system, which we call Sequential Selective Multidimensional Decision (SSMD), involves deciding sequentially, by geographical areas, sectors of activity, age groups and immunity, which workers can return to work at a given time according to the epidemiological criteria of the country as well as that of a group of reference countries, used as a benchmark, that have suffered a lower level of lockdown de-escalation strategies. We apply SSMD to Spain, based on affiliation to the Social Security system prior to the COVID-19 pandemic…

Approccio computazionale per la certificazione di strutture aeronautiche in materiale composito

Il processo di certificazione di strutture in materiale composito utilizzate per componenti aero-strutturali è principalmente analitico supportato dall’evidenza dei test a livello di coupon, elementi, sub-componenti, componenti e full-scale. Il processo di certificazione stabilisce che specifiche metodologie di test e particolari controlli dei processi vengano applicati per la qualifica del materiale e dei vari componenti, per verificare la conformità del progetto ai requisiti richiesti. Le procedure (basate su tecniche statistiche) per la caratterizzazione di materiali compositi, comportano l’impegno di una quantità molto grande di risorse ad ogni livello: il criterio di base infatti vuole…