Optical and photovoltaic properties of indium selenide thin films prepared by van der Waals epitaxy

Indium selenide thin films have been grown on p-type gallium selenide single crystal substrates by van der Waals epitaxy. The use of two crucibles in the growth process has resulted in indium selenide films with physical properties closer to these of bulk indium selenide than those prepared by other techniques. The optical properties of the films have been studied by electroabsorption measurements. The band gap and its temperature dependence are very close to those of indium selenide single crystals. The width of the fundamental transition, even if larger than that of the pure single crystal material, decreases monotonously with temperature. Exciton peaks are not observed even at low temperature, which reveals that these layers still contain a large defect concentration. The current–voltage characteristic of indium selenide thin film devices was measured under simulated AM2 conditions. The solar conversion efficiency of these devices is lower than 0.6%. The high concentration of defects reduces the diffusion length of minority carriers down to values round to 0.2 μ[email protected] ; [email protected]

An epidemiological study on the composition of urinary stones in Morocco in relation to age and sex

Objective: To study the composition of urinary stones, evaluate the percentage of each stone type and assess the association between the stone type and the sex and age in Moroccan stone formers. Subjects and methods: This epidemiologic study of urolithiasis was carried out in the Rabat-Salé region (Morocco) between 2008 and 2013. A series of 828 urinary stones from 537 men and 265 women was analyzed using Fourier transform infrared spectroscopy in order to evaluate the percentage of each stone type. The results were compared to the patients’ demographic data in order to assess the association between the stone type and the sex and age. Results: The overall sex ratio (male/female) was 2.03:1, and the majority of patients were aged between 40 and 60. The majority of stones were composed of calcium oxalate (66.6%), followed by anhydrous uric acid (18.1%), carbapatite (7.9%), struvite (4.4%) and cystine (0.6%). Anhydrous uric acid stones in this study accounted for a relatively higher rate in males and females compared to that reported in other studies. Our results also showed a higher percentage of carbapatite stones in females compared to males and an increase of the prevalence of anhydrous uric acid stones with age. In addition, the percentage of calcium oxalate stones decreased, while that of carbapatite stones increased with age

(MoO 3 ) 1−x (V 2 O 5 ) x thin films: Elaboration and characterization

International audienceno abstrac

Structural and optical properties of MoO3 and V2O5 thin films prepared by Spray Pyrolysis

International audienceno abstrac

A biokinetic model to describe the distribution and excretion of arsenic by man following acute and chronic intakes of arsenite/arsenate compounds by ingestion.

An empirical mathematical model, comprising 17 compartments, has been produced to describe the biokinetics of ingested inorganic arsenic (As) in man — required to interpret bioassay data and to predict As tissue concentrations resulting from acute and chronic intakes of inorganic As. The rate constants used to describe the bi-directional transfer of As between compartments were chosen to result in model outcomes that match published data on the distribution of As in tissues and on the retention and excretion of radioisotopes of As administered to human subjects. The model was deployed in acute and chronic intake modes to produce predictions of tissue concentrations and excretion levels. Under conditions of chronic daily intake (1 μg d-1) for 50 years predicted final tissue concentrations vary by a factor of ∼2. Highest concentrations are predicted to occur in skin and bone (∼230ng kg-1). Tissue concentrations in all tissues other than bone are predicted to reach equilibrium after ∼100 days, and at this time, the amount of As excreted in urine has also reached approximate equilibrium at 79% of the daily dietary intake. This level then remains relatively constant unless intake ceases when tissue levels of As fall rapidly. Data on organic and inorganic As concentrations in urine were used to predict inorganic As intake and average tissue content for the USA population. Predicted tissue concentrations ranged from 2.3 μg kg -1 in skin to 1.1 μg kg-1 in muscle for an average inorganic As intake of 9.3 μg d-1