The purpose of this study is to synthesize nano-grained Calcium Hydroxyapatite (HAp) through slip casting technique. For this, hydroxyapatite powders were synthesized using two methods, wet chemical method and Ammoniacal method. The as-prepared powders and calcined powders were characterized using XRD, FTIR, to study the phases of the powders. The hydroxyapatite powder calcined at 1000°C for 2h...

The tetragonal to monoclinic (t ! m) phase transformation during low temperature ( 100 8C) degradation (LTD) of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) sintered in air at different temperatures was investigated. It is found that the sintering temperature affected the density, crystalline phase and microstructure of the sintered body, as well as the LTD behavior. Also, the ons...

A HfSiO4 ceramic was prepared by a conventional solid state synthesis method by sintering at 1600 °C. The morphology of the sintered surface was characterized using scanning electron microscopy and atomic force microscopy and the average surface roughness was about 118 nm. The sintered HfSiO4 ceramic has εr = 7.0, Qu × f = 25 000 and τf = -44 ppm °C(-1) at 10 GHz. It exhibits promising thermal ...

The build-up dose in the megavoltage photon beams can be a limiting factor in intensity-modulated radiation therapy (IMRT) treatments. Excessive surface dose can cause patient discomfort and treatment interruptions, while underdosing may lead to tumor repopulation and local failure. Dose in the build-up region was investigated for IMRT delivery with solid brass compensator technique(compensator...

OBJECTIVES The implantable continuous-flow left ventricular assist devices (LVADs) HeartMate II (HM II) and HeartWare HVAD (HW) underwent design modifications. The impact of these changes on life-threatening pump malfunctions was evaluated. METHODS We retrospectively analysed pump malfunctions due to thrombosis or cable damage in patients supported with primarily implanted HM II (n = 191) and...

recently, the use of renewable energies has increased to  environmental pollution, limitation of fossil energy resources and energy security  one of the means that enable us to use such energies is fuel cells (fc). however, there are many problems  in the commercialization of fc from an economically and operation perspective. one of the most important problems is heat management. new heat pipes...

This study addresses the development of a compact reactor for oxidative steam-reforming of methanol (OSRM) to produce hydrogen in autothermal mode for fuel cells. The string reactor uses catalytically active brass wires with a diameter of 500 mm placed in parallel into a tube. The micro-channels in the reactor for gases are formed between the wires presenting hydrodynamics similar to the one in...

OBJECTIVE To determine the effect of exposure to metal dusts, fumes and high temperature levels among brass workers in comparison to a control group. STUDY DESIGN Analytical cross-sectional study. METHODOLOGY One hundred and fifty four brass workers were matched for age with 154 controls selected from the local population. An interviewer-administered questionnaire was used to determine the ...

Inductively coupled plasma-optical emission spectroscopy (ICP-OES) was used to determine the bulk metal elemental composition of 62 modern bronze sculptures cast in Paris in the first half of the twentieth century from the collections of The Art Institute of Chicago and the Philadelphia Museum of Art. As a result, a comprehensive survey of the alloy composition of the sculptures of many promine...

Improvement of die life in the hot forging of brass alloys is considered vital from both technical and economical points of view. In this research, pin-ondisc tests were carried out at a range of temperatures to evaluate the influence of plasma nitriding and duplex nitriding-physical vapour deposition (PVD), including TiN-TiAlN and TiN-TiAlN-CrAlN coatings, on the tribological properties of AIS...