Wyniki wyszukiwania - BazTech

1

Fabrication and properties of zinc oxide thin film prepared by sol-gel dip coating method

Kayani Z. N., Iqbal M., Riaz S., Zia R., Naseem S.

Materials Science Poland

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2015

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Vol. 33, No. 3

515--520

EN

ZnO thin films were deposited on a glass substrate by dip coating technique using a solution of zinc acetate, ethanol and distilled water. Optical constants, such as refractive index n and extinction coefficient k, were determined from transmittance spectrum in the ultraviolet-visible-near infrared (UV-Vis-NIR) regions using envelope methods. The films were found to exhibit high transmittance, low absorbance and low reflectance in the visible regions. Absorption coefficient µ, and the thickness of the film t were calculated from interference of transmittance spectra. The direct optical band gap of the films was in the range of 3.98 to 3.54 eV and the thickness of the films was evaluated in the range of 173 to 323 nm, while the refractive index slightly varied in the range of 1.515 to 1.622 with an increase in withdrawal speed from 100 to 250 mm/s. The crystallographic structure of the films was analyzed with X-ray diffractometer. The films were amorphous in nature.

2

Influence of annealing on structural, morphological and optical properties of Cd x Zn1-x O nanopowder prepared by Co-precipitation method

Ali F. M., Abu-Assy M. K., El-Gazzar S., Iqbal M., Hussain M.

Materials Science Poland

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2012

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Vol. 30, No. 3

248--253

EN

Structural and optical properties of Cd x Zn1-x O (x = 0.0, 0.025, 0.050, 0.075, 0.1) nanopowder, synthesized by co-precipitation method have been investigated. The effect of annealing on the structural and morphological properties was studied using X-ray diffraction. The samples with x = 0.0 up to 0.075 exhibit wurtzite hexagonal phase, whereas, the sample with x = 0.1 shows two phases: wurtzite hexagonal ZnO and cubic CdO phase. This behavior is explained on the basis of solubility of CdO in ZnO. Energy Dispersive X-ray analysis (EDX) results revealed the existence of Cd, Zn, and O elements in the nanopowder. Transmission Electron Microscopy (TEM) images confirm that the particle size of the prepared samples is in nano range. The optical band gap values obtained from the absorption spectra show that absorption depends on Cd composition. By doping of ZnO with CdO, a red shift in the absorption edge was observed.

3

Attributes of Occupational Injury Among Workers in the Chemical Industry and Safety Issues

Khan M. M. A., Halim Z. I., Iqbal M.

International Journal of Occupational Safety and Ergonomics

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2006

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Vol. 12, No. 3

327--341

EN

Case-study research was carried out with a view to find the attributes of occupational injury among workers in the chemical industry and to enhance safety issues. Injury data were collected and processed in terms of different variables, such as age, gender, skills, type of hazard, etc. Pareto analysis was then applied to find a pattern of occupational injury among the workers. The study revealed that 79.52% of the injured workers were in the 40–59 age group; 57.14% of accidents occurred during the 1st shift; 73.26% of accidents caused injury to hands, feet, chest to thigh, arms and eyes; and 70.93% of injuries were caused by pumps, carrying and lifting, vehicles, pipelines, valves, and grinding. Surprisingly, no one was injured in the group of temporary workers. The paper also provides specific suggestions followed by some action plans.

4

Spline regularization of numerical inversion of Mellin transform

Iqbal M.

Foundations of Computing and Decision Sciences

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2000

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Vol. 25, No. 1

49-64

EN

There is described a method for inverting the Mellin transform. In the method there are applied the expansion in Laguerre polynomials, the conversion to the Laplace transformation and a convolution integral equation. The quality of the method is testified for ill-posed problems considered in the literature.