background: groundwater is the most important source of water supply in industries and agricultures; therefore the need to protect this valuable resource against pollution is felt more than ever. in this study, the possible impact of yazd municipal solid waste landfill was investigated on the chemical quality of the area’s groundwater. methods: groundwater samples were collected from three well...

Ion implantation creates alterations in surface properties of solids such as corrosion and hardness. The AISI316L stainless steel is being widely used both in artificial knee and hip joints in bio-medical applications. In the present study, the AISI316L SS was implanted with two different ions namely argon and oxygen separately at 100 KeV with a dose of 1x10ions/cm2 at the temperature of 32°C. ...

The fracture and fatigue characteristics of several cemented carbide grades are investigated as a function of their microstructure. In doing so, the influence of binder chemical nature and content (Co and 76wt%Co-24wt%Ni), as well as carbide grain size on hardness, flexural strength, fracture toughness and fatigue crack growth (FCG) behavior is evaluated. Mechanical testing is combined with a d...

As silicon devices keep shrinking in size while the circuits become more complex, they require low dielectric constant materials instead of silicon dioxide. SiOC films as low dielectric constant materials deposited by chemical vapor deposition were analyzed by Fourier transform infrared spectroscopy, elipsometry and nano-indentation to find the correlation between the dielectric constant and pr...

In this research at the first Metoprolol drug and its fullerene derivative were optimized. Natural bond orbital (NBO), nuclear Indepndent chemical shift (NICS) and finally IR calculations, for these compounds were carried out at the B3LYP/6-31G* quantum chemistry level. Different parameters such as energy levels, the amount of chemical shift in different atoms, the amount of HOMO/LUMO, chemical...

For the first time, Zr–Ge–N films were deposited on silicon and steel substrates by sputtering a Zr–Ge composite target in reactive Ar– N2 mixture. The films were characterised by electron probe microanalysis, X-ray diffraction, micro-Raman spectroscopy and depth-sensing indentation. The effects of the Ge content and substrate bias voltage on the films’ structure, internal stress, hardness and ...

The behavior of electrons in general many-electronic systems throughout the density functionals of energy is reviewed. The basic physico-chemical concepts of density functional theory are employed to highlight the energy role in chemical structure while its extended influence in electronic localization function helps in chemical bonding understanding. In this context the energy functionals acco...

Assessing the molecular mechanism of a chemical-biological interaction and bonding stands as the ultimate goal of any modern quantitative structure-activity relationship (QSAR) study. To this end the present work employs the main chemical reactivity structural descriptors (electronegativity, chemical hardness, chemical power, electrophilicity) to unfold the variational QSAR though their min-max...

The objectives of the study were to formulate hydroxypropyl methyl cellulose-based controlled release matrix tablets for theophylline with varying drug:polymer ratios (1:1 and 1:2) and differing tablet hardness (5, 6 and 7 kg/cm(2)), and to evaluate the tablet's physico-chemical properties such as hardness, uniformity of weight, friability, drug content and in vitro drug release. Initially, gra...

Composite resins may undergo wear by the action of chemical substances (e.g., saliva, alcohol, bacterial acids) of the oral environment, which may affect the material's structure and surface properties. This study evaluated the effect of acidic substances on the surface properties of a micro-hybrid composite resin (Filtek Z-250). Eighty specimens were prepared, and baseline hardness and surface...