We investigate defects in bulk zinc oxide by performing embedded cluster calculations within the density functional theory using the PBE functional. We obtain and discuss equilibrium structures and vibrational spectra of interstitial hydrogen species and of hydrogen complexes at zinc vacancies and at substitutional atoms like copper, beryllium, manganese and calcium in zinc positions. All of th...

In the past decades, there is a growing interest in the design and synthesis of composite microspheres with a dielectric solid sphere (e.g., silica, polystyrene) covered by metallic and their corresponding metal oxides shell, such as copper[1], gold[2], silver[3,4], iron oxide[5], zinc oxide[6,7], titanium oxide[8,9] and zirconium dioxide[10]. Such materials may exhibit a few unique electrical,...

In the past decades, there is a growing interest in the design and synthesis of composite microspheres with a dielectric solid sphere (e.g., silica, polystyrene) covered by metallic and their corresponding metal oxides shell, such as copper[1], gold[2], silver[3,4], iron oxide[5], zinc oxide[6,7], titanium oxide[8,9] and zirconium dioxide[10]. Such materials may exhibit a few unique electrical,...

A lthough cosmetics, from Greek kósmesis (adorn), now refers to external products used to beautify the skin, hair, eye, or other parts of the body, cosmesis was not the first objective of primitive eye painting. The first aim of body painting in primitive cultures may have been to protect people from evil spirits, which could enter their body through vulnerable openings, such as the eyes. The s...

background: the purpose of this study was to evaluate the levels of zinc (zn), copper (cu), iron (fe) and zinc/ cop­per ratio in the serum of patients with cutaneous leishmaniasis in qom province, center of iran. methods: serum levels of zinc and copper were determined by flame atomic absorption spectrophotometer and serum iron concentration was measured by using an auto analyzer. the study gro...

backgroundmany studies reported that copper, zinc and magnesium play important roles in the pathogenesis and development of neonatal hyperbilirubinemia. exchange transfusion and intensive phototherapy are known two modalities of therapy for severe neonatal hyper bilirubinemia, but the effect of them on those trace elements is unknown.materials and methodscopper, zinc and magnesium serum levels ...

soil contamination in the vicinity of the abandoned lakan lead and zinc mine was studied. the results showed that over the past decades, the environmental pollution was caused by lead, zinc tailings dam and acid mine drainage. the average of lead, zinc, cadmium, copper and nickel is 1295, 4273, 27, 185 and 92 mg/kg, respectively in the soils of tailings dam. these metals were continuously dispe...

background : incidence of  white  spots due  to  demineralization of  enamel  and  gingival problems  is  an  unacceptable  result  of  orthodontic  treatment.  plaque  accumulation  and bacterial biofilm growth are responsible for these phenomena. the resin-based dental composites used as bonding agents in orthodontics play a major role in mentioned problems. as recent researches assert the an...