This study aimed to develop a device to facilitate grinding experiments with microvibration for analyzing the vibration effect on surface finish of ground surfaces. A microvibration device was designed and fabricated. It can be used to provide microvibration to the workpiece vertically and/or horizontally during grinding. The relationship of the driving voltage, vibration displacement, and freq...

Cocrystal formation rates during dry grinding and liquid-assisted grinding were investigated by X-ray powder diffractometry and Raman spectroscopy. Two polymorphic forms of piracetam were used to prepare known piracetam cocrystals as model substances, i.e.,piracetam-citric acid and piracetam-tartaric acid cocrystals. Raman spectroscopy in combination with principal component analysis was used t...

the efficacy of correctly applied fissure sealants has been revealed in the prevention of caries. saliva and moisture contamination of the etched enamel surface before sealant placement can decrease the bonding strength of the sealant to the enamel. the aim of this study was to test the new bonding agents containing nano-fillers in order to reduce the negative effect of saliva contamination on ...

background: up to today, the most complete risk assessment tool for repetitive movements of upper limbs has been the occupational repetitive actions (ocra) method. the index of the analysis is relatively accurate. several risk factors such as repeated motion, force, body condition, additional effective factors and return period can be useful for future preventive measures. the present study eva...

PURPOSE This study was to evaluate the effect of grinding of the inner metal surface during the porcelain try-in stage on metal-porcelain bonding considering the maximum temperature and the vibration of samples. MATERIALS AND METHODS Ninety-one square prism-shaped (1 × 1 × 1.5 mm) nickel-chrome cast frameworks 0.3 mm thick were prepared. Porcelain was applied on two opposite outer axial surfa...

background: repair bond strength of different composite resins has been assessed in few studies. in addition, reports on the effi cacy of surface treatments are debated. therefore, this in vitro study was conducted to evaluate the effect of three surface treatments on two nanocomposites versus a microhybrid composite. materials and methods: in this experimental study, 135 composite blocks (45 s...

Cement powder size classification efficiency significantly affects quality of final product and extent of energy consumption in clinker grinding circuits. Static and dynamic or high efficiency air separators are being used widely in closed circuit with multi-compartment tube ball mills, High Pressure Grinding Rolls (HPGR) and more recently Vertical Roller Mills (VRM) units in cement plants ...

OBJECTIVE Lock and key factory workers are under the risk of metal pneumoconiosis and occupational asthma. In this cross-sectional study, it's aimed to evaluate the relationship between metal dust exposure and respiratory symptoms, pulmonary function tests of workers in different section of lock and key factory. METHODS 54 male workers (mean age, 32.8 ± 5.4) in a security and safety products ...

Silicon nanowire (SiNW) arrays were produced by electroless method on polycrystalline Si substrate, in HF/ AgNO3 solution. Although the monocrystalline silicon wafer is commonly utilized as a perfect substrate, polycrystalline silicon as a low cost substrate was used in this work for photovoltaic applications. In order to study the influence of etching time (which affects the SiNWs length) on d...

Objectives: This study was conducted to evaluate the effect of grinding and sandblasting on the microstructure, biaxial flexural strength and reliability of two yttria stabilized tetragonal zirconia (Y-TZP) ceramics. Methods: Two Y-TZP powders were used to produce fine grained and coarse grained microstructures. Sixty discs from each material were randomly divided into six groups of ten. For ea...