Advanced Materials Research Vols. 875-877

Abstract: The speeds of sound in near saturated and subcooled liquid phases of R-1234yf have been measured using a ultrasonic sensor. The measurements were conducted at the temperature range from 0 to 80 °C, and the pressure range from 0.316 to 2.52 MPa. In order to validate the ultrasonic sensor, the measurement in pure water at the temperature range from 0 to 80 °C was also performed. The measurement result of water was compared with those calculated from REFPROP (based on IAPWS-95) and PROPATH (based on IAPWS-IF97). The result of water agrees well with that calculated from REFPROP within a maximum deviation of 0.28%, except for that at temperature of 80 °C. And it agrees well also with that calculated from PROPATH within a maximum deviation of ±0.2%. The measurement results for near saturated and subcooled liquid phases of R-1234yf were compared with those calculated from REFPROP and JSRAE thermodynamic table.

Abstract: This study investigated the use of an eddy current technique for detecting side transverse cracks in a railhead. Quantitative analysis of defect signals in a railhead with side transverse cracks was realized through actual defect detection and finite-element simulation. In eddy current testing of the railhead, first, the general pattern of variation in the detected signals was obtained for different sizes of cracks via actual defect detection of rail samples. Then, finite-element simulation was used to verify the accuracy of the experimental results and to test the relationships between the detected signals and the size and depth of the cracks. The simulation results show that an extremely linear relation between crack depth and output signals in quantitative length of crack cases. In the results, simulation results can be applied to the analysis of the actual detected data. The eddy-current-defect detection method that combined experiment with simulation was very effective and can be applied in future research.

Abstract: The dynamic properties of rock bolts are characterized by measurement. The acceleration and strain of a rock bolt specimen were recorded using axial impact testing in laboratory environment. The systems dynamic properties such as natural frequencies and damping are characterized by using spectral analysis and Wavelet method. The characterized dynamic properties are used to update and calibrate a system simulation model, which is a multiple-degree-of-freedom system involving roof mass, the roof bolt, grout interface and head connections. The proposed approach enables accurately and effectively quantifying system dynamic parameters and establishing the analytical model for the design, development and performance monitoring of roof bolting systems.

Abstract: Thin films of MXN (M stands for early transition metal and X = Si, Ge, Sn) are studied as protective coatings. To extend the knowledge about the formation of nanocomposite films, various MXN systems have been compared. TiSiN, TiGeN, TiSnN, NbSiN, ZrSiN and CrSiN thin films were deposited by reactive magnetron sputtering, from confocal targets in a mixed Ar/N2 atmosphere. The chemical reactivity of germanium and tin with nitrogen is significantly lower than that of Si and Ti. Therefore, the TiGeN and TiSnN systems are different from TiSiN. Important changes in the morphology and structure of MXNfilms are induced by X addition. Nanocrystalline composite films are formed in all these investigated ternary systems.

Abstract: Tamarind gum obtains from the endosperm of tamarind seed. Polysaccharide is the main component as about 78.85%. It consists of three types of monosaccharide as glucose, xylose and galactose. Since it is a hydrocolloid that give viscous solution in aqueous. The objective of this work is to observe the solubility of tamarind gum at room temperature by simple turbidity measurement of the solutions. The tamarind gum concentrations from 0.07 to 0.97wt% and two particle sized as <75 and 75-355 μm were interested variables. The relationship between the viscosity and solubility of the solution was investigated. We found that both turbidity and viscosity reached constant values at the same time. At this time, it could be noted that represented the saturated time of dissolution. For higher tamarind gum concentrations and with less particle size (<75 μm), the results showed that the saturated time of solubility appeared faster due to more specific area for dissolving and also the solubility rate increasing.

Abstract: Removed at authors request

Abstract: In this study, the workability, the compressive strength and the water penetration depth under pressure for concrete incorporate with quarry waste as fine aggregate were investigated. The mix proportions of concrete were set into two classes of water to cement ratio (w/c = 0.4, 0.6). The first class (C1), the mix proportion is 1.0:0.6:2.0:4.0 (Cement: Water: Fine: Coarse). And the second class (C2), the mix proportion is 1.0:0.4:1.5:3.0 and adding the superplasticizer 1% of cement weight. The natural river sand, which use in concrete, was partially replaced by quarry dust at the rates of 0% (no quarry dust), 50% and 100 % by weight of fine aggregate. The results show that concrete containing quarry wastes as fine aggregate decreased the workability and do not significantly affect the 28-day compressive strength whereas concrete incorporating with quarry dusts reduces the water penetration depth.

Abstract: Subsurface interlaminar defects represent the main threat to wide application of layered materials. For subsurface defects the buckling of an exfoliating layer is characteristic. Thin exfoliating a layer at compression buckling, causing big tension on limit of defect. It can become considerable the reason of the general destruction of a design at loading smaller settlement level.

Abstract: The paper shows the first results of the optical performance analysis carried out on the DSSC integrated glassblock, an innovative building product developed at the Department of Architecture of the University of Palermo. In the field of a research that is being conducted in order to define innovative solutions for the construction of photovoltaic and energy efficient translucent building envelopes, different hypotheses of integration of DSSC into the glassblock have been foreseen. The integration of glassblock with third generation PV systems allows to define a novel building-PV product that meets the current requirements of the BIPV (Building Integrated Photovoltaics) market. By means of OptiCAD® software, several numerical simulations were conducted to analyse the solar factor, the light transmittance and the shading coefficient of the device.

Abstract: Density functional theory calculations at the generalized gradient approximation level are performed on cube clusters that comprise both the metal lattice (Pd) and the interstitial lattice (H). The calculations consider H on the octahedral sites of the metal lattice, i.e., cubes structures Pd₄H_4-x (x=0–4). For each structure, the cell volume, the total energy, the bulk modulus and the derivative of the bulk modulus have been calculated. Zero point energy (ZPE) corrections have been included using the direct method. The calculations confirm that including ZPE effects in the harmonic approximation has a significant effect on the calculated properties by increasing the cell-volumes and decreasing the bulk modulus. The absorption energies of hydrogen in palladium without including ZPE are found to be exothermic processes. When the ZPE is included, adding the first three Hs atom are exothermic processes while the fourth atom is found to be endothermic.