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Luminescence of doped CdS nanocrystals: effect of doping and capping agent

100%

Hasanzadeh J. , Farjami Shayesteh S.

Optica Applicata

2011

tom Vol. 41, nr 4

921--928

Cu and Fe doped cadmium sulfide nanoparticles were prepared with a wet chemical synthesis by mixing the reactants in double distilled water solvent. Thioglycerol (TG) was employed as the capping agent and also the reaction catalyst. The estimated particle size of prepared samples was found in the range 3-4 nm. Properties of particles were investigated using photoluminescence spectroscopy (PL) and X-ray diffraction analysis (XRD). XRD pattern of samples reveals a hexagonal crystal structure at room temperature. We have studied effect of doping and TG concentration on the luminescence of doped CdS nanocrystals. There is a noticeable increase of the PL intensity when TG concentration increased. The PL spectra include two bands, due to emission of traps and surface state.

Respiratory Morbidity Induced by Occupational Inhalation Exposure to High Concentrations of Wheat Flour Dust

70%

Neghab M. , Soltanzadeh A. , Alipour A. , Hasanzadeh J. , Alipour H.

International Journal of Occupational Safety and Ergonomics

2012

tom Vol. 18, No. 4

563--569

Introduction. The main purpose of this study was to investigate the respiratory effects of exposure to high airborne concentrations of wheat flour dust. Methods. This cross-sectional study was carried out at a local wheat flour mill in Shiraz, southern Iran. Thirty-five male workers exposed to flour dust and 32 healthy male nonexposed employees were investigated. The prevalence of respiratory symptoms among them was evaluated and parameters of their pulmonary function were measured. Moreover, to assess the extent to which subjects were exposed to flour dust, airborne concentrations of its inhalable and respirable fractions were measured.Results. Airborne concentrations of dust exceeded current permissible level. The prevalence of regular cough, productive cough, wheezing, phlegm and dyspnea was significantly higher in exposed subjects than in nonexposed employees. Similarly, both acute and chronic significant (p < .05) decrements in most parameters of pulmonary function were noted. Conclusions. Our findings provide corroborative evidence to further support the notion that exposure to flour dust is associated with a significant increase in the prevalence of respiratory symptoms as well as ventilator disorders of the lungs.

Assessment of functional parameters and comfort of a new computer mouse as compared with other types of input devices

61%

Dehghan N. , Choobineh A. , Razeghi M. , Hasanzadeh J. , Irandoost M. , Ebrahimi S.

International Journal of Occupational Safety and Ergonomics

2015

tom Vol. 21, No. 4

493--497

Background. This study was conducted to assess functional parameters and comfort of a new computer mouse (Ergomice) as compared with three other input devices. Materials and methods. Functional parameters (i.e., task completion time and error rate) of each device were assessed by 10 participants using standardized software based on Standard No. ISO 9241-9:2000. Comfort evaluation was also undertaken for each device using the visual analogue scale technique. Statistical analysis including the Wilcoxon signed-rank test and the Friedman test was performed using SPSS version 16. Results. The functional parameters of the standard mouse were better than those of the other devices. However, no significant difference was observed between this mouse and Ergomice. Overall comfort evaluation showed that the standard mouse and Ergomice were more comfortable to work with. The comfort level of hand/wrist posture in the Ergomice was higher than that of the other three devices. Conclusion. The design features of Ergomice could improve its functional properties. Hand/wrist posture comfort of Ergomice was judged to be high compared with that of the other devices.