To evaluate discriminant validity, reliability, internal consistency, and dimensional structure of the World Health Organization Quality of Life-BREF (WHOQOL-BREF) in a heterogeneous Iranian population. A clustered randomized sample of 2,956 healthy with 2,936 unhealthy rural and urban inhabitants aged 30 and above from two dissimilar Iranian provinces during 2006 completed the Persian version of the WHOQOL-BREF. We performed descriptive and analytical analysis including t-student, correlation matrix, Cronbach's Alpha, and factor analysis with principal components method and Varimax rotation with SPSS.15. The mean age of the participants was 42.2 +/- 12.1 years and the mean years of education was 9.3 +/- 3.8. The Iranian version of the WHOQOL-BREF domain scores demonstrated good internal consistency, criterion validity, and discriminant validity. The physical health domain contributed most in overall quality of life, while the environment domain made the least contribution. Factor analysis provided evidence for construct validity for four-factor model of the instrument. The scores of all domains discriminated between healthy persons and the patients. The WHOQOL-BREF has adequate psychometric properties and is, therefore, an adequate measure for assessing quality of life at the domain level in an adult Iranian population.

We have developed low-voltage (<2 V) flexible organic field-effect transistors (OFETs) with high carrier mobility using gelatin as a moisture-induced ionic gate dielectric system. Ionic concentration in the gelatin layer depends on the relative humidity condition during the measurement. The capacitance of the dielectric layer used for the calculation of field-effect carrier mobility for the OFETs crucially depends on the frequency at which the capacitance was measured. The results of frequency-dependent gate capacitance together with the anomalous bias-stress effect have been used to determine the exact frequency at which the carrier mobility should be calculated. The observed carrier mobility of the devices is 0.33 cm2/Vs with the capacitance measured at frequency 20 mHz. It can be overestimated to 14 cm2/Vs with the capacitance measured at 100 kHz. The devices can be used as highly sensitive humidity sensors. About three orders of magnitude variation in device current have been observed on the changes in relative humidity (RH) levels from 10 to 80%. The devices show a fast response with a response and recovery times of ∼100 and ∼110 ms, respectively. The devices are flexible up to a 5 mm bending radius.

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Atomic layer deposited (ALD) (TiO2)x(Al2O3)1-x(TiAlO) alloy gate dielectrics on In0.47Ga0.53As/InP substrates are shown to produce high quality interfaces between TiAlO and InGaAs. The surface morphology and interfacial reaction of nanolaminate ALD TiAlO on In0.53Ga0.47As are studied using atomic force microscopy and x-ray photoelectron spectroscopy. Measured valence and conduction band offsets are found to be 2.85 ± 0.05 and 1.25 ± 0.05 eV, respectively. Capacitance-voltage characteristics show low frequency dispersion (∼11%), interface state density (∼4.2 × 1011 cm−2eV−1), and hysteresis voltage (∼90 mV). Ga-O and As-O bonding are found to get suppressed in the gate stacks after post deposition annealing. Our experimental results suggest that higher oxidation states of In and Ga at the In0.53Ga0.47As surface and As diffusion in the dielectric are effectively controlled by Ti incorporation in Al2O3.

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