polyvinyl ester green composites were synthesized with walnut shell powder (wsp) by in-situ polymerization technique. the green composites have been evaluated for mechanical properties such as tensile strength, tensile modulus and hardness. sliding wear loss, specific wear rate and coefficient of friction were investigated by using computerized pin-on–disc machine at normal applied loads of 20,...

introduction: the efficacy of erbium-doped yttrium aluminum garnet (er:yag) laser for root debridement in comparison with curettes has been the subject of many recent investigations. considering the possibility of chemical and ultra-structural changes in root surfaces following laser irradiation, this study sought to assess the effects of scaling and root planing (srp) with curettes and er:yag ...

objective: the aim of this study was to evaluate and compare the effect of dental surface treatment with er:yag , nd:yag ,co2 lasers and sodium ascorbate to recently laser bleached enamel by scanning electron microscope (sem). methods: 15caries-free extracted human third molars were selected for this study. the samples were bleached by heydent jw power activated by diode laser 810 nm. after 7 d...

We study a large ensemble of nuclear spins interacting with a single electron spin in a quantum dot under optical excitation and photon detection. At the two-photon resonance between the two electron-spin states, the detection of light scattering from the intermediate exciton state acts as a weak quantum measurement of the effective magnetic (Overhauser) field due to the nuclear spins. In a coh...

This paper describes experiments that determine how the inter-pulse interval between rectangular pulses in a train of pulses alters the threshold of electroporation of 1-pamitoyl 2-oleoyl phosphatidycholine bilayer lipid membranes. The bilayers were exposed to a train of sixteen 100-micros duration pulses. Threshold voltage and the sequence number of the pulse in the train, where onset of the e...

in this research, the effect of catalyst type on the cnts synthesis was investigated. the carbonnanotubes (cnts) were produced on stainless steel substrates and two of catalyst with differentcharacteristics by using thermal chemical vapor deposition (tcvd) method. the catalysts have theimportant role for the growth carbon nanotubes (cnts). acetylene gas (c2h2) diluted by nh3 wasused as the reac...

application of edible coatings to enhance storage life of fresh fruit has recently been under considerable attention. this experiment was conducted in order to explore the effect of chitosan coating and storage temperature on the postharvest life of pomegranate (punica granatum l.) fruit. therefore, pomegranate fruits ‘rabbab-e-neyriz’ were dipped in 0, 1 and 2% aqueous chitosan solutions, air ...

there is no single standard technique or methodology to characterize the size, structure, number, and chemical composition of airborne carbon nanotubes.  existing analytical instruments and analytical techniques for evaluating nanoparticle concentrations cannot simultaneously provide morphology, state of agglomeration, surface area, mass, size distribution and chemical composition data critical...

in recent years, it has become evident that it is necessary to systematically and accurately define particle characteristics in order to understand the potential toxicity of nanoparticles to biological systems. the properties that need to be emphasized are size, shape, dispersion, doping, aggregation, functionalization, physical and chemical properties, surface area, and surface chemistry. rout...