Time filter

Source Type

Balanga, Philippines

Bataan Peninsula State University is the only state university in the province of Bataan in the Philippines. Wikipedia.

Dizon J.R.C.,Andong National University | Dizon J.R.C.,Bataan Peninsula State University | Gorospe A.B.,Andong National University | Shin H.-S.,Andong National University
Superconductor Science and Technology | Year: 2014

Rare-earth-Ba-Cu-O (REBCO) based coated conductors (CCs) are now being used for electric device applications. For coil-based applications such as motors, generators and magnets, the CC tape needs to have robust mechanical strength along both the longitudinal and transverse directions. The CC tape in these coils is subjected to transverse tensile stresses during cool-down and operation, which results in delamination within and between constituent layers. In this study, in order to explain the behaviour observed in the evaluation of c-axis delamination strength in Cu-stabilized GdBCO CC tapes by anvil tests, numerical analysis of the mechanical stress distribution within the CC tape has been performed. The upper anvil size was varied in the analysis to understand the effect of anvil size on stress distribution within the multilayered CC tape, which is closely related to the delamination strength, delamination mode and delamination sites that were experimentally observed. The numerical simulation results showed that, when an anvil size covering the whole tape width was used, the REBCO coating film was subjected to the largest stress, which could result in low mechanical delamination and electromechanical delamination strengths. Meanwhile, when smaller-sized anvils were used, the copper stabilizer layer would experience the largest stress among all the constituent layers of the CC tape, which could result in higher mechanical and electromechanical delamination strengths, as well as high scattering of both of these delamination strengths. As a whole, the numerical simulation results could explain the damage evolution observed in CC tapes tested under transverse tensile stress, as well as the transverse tensile stress response of the critical current, Ic. © 2014 IOP Publishing Ltd. Source

Corpuz M.N.C.,University of the Philippines at Los Banos | Corpuz M.N.C.,Bataan Peninsula State University | Paller V.G.V.,University of the Philippines at Los Banos | Ocampo P.P.,University of the Philippines at Los Banos
Raffles Bulletin of Zoology | Year: 2015

Three estuarine-linked streams (Bulusan, Iyam, and Pansipit rivers) in different protected areas were investigated to evaluate the influence of environmental and habitat variables on gobioid assemblages (Gobiidae and Eleotridae). The study collected a total of 1,071 specimens belonging to 19 species, and 17 genera. Twelve gobiids and seven eleotrids were recorded from the three rivers. Four gobioid species comprised 57.17% of the total abundance. These were Giuris margaritacea (Eleotridae), Glossogobius celebius (Gobiidae) Bostrychus sinensis (Eleotridae) and G. giuris (Gobiidae) (in order of importance). Log10-transformed abundance data were used in indirect (detrended correspondence analysis, DCA), and direct (canonical correspondence analysis, CCA) gradient ordination analysis. DCA (50.76% variability on the first and second ordination axes) revealed the gobioid assemblage variability as a response of species abundance to stream gradients. Species variation along the longitudinal stream gradient profile (upstream and downstream dwellers) was also emphasised. From the 19 environmental variables, CCA (71.49% variability on the first and second ordination axes) recognised substratum types, distance to sea, and land use pattern as the most weighted causative environmental parameters influencing the gobioid assemblages (within and between stream variations). Bray-Curtis similarity analysis using species and abundance data registered low similarity percentages (18–40%) between the three rivers, validating the high beta diversity estimated in DCA1 axis. © National University of Singapore. Source

Dizon J.R.C.,Andong National University | Dizon J.R.C.,Bataan Peninsula State University | Oh S.S.,Korea Electrotechnology Research Institute | Sim K.D.,Korea Electrotechnology Research Institute | Shin H.S.,Andong National University
Journal of the Korea Institute of Applied Superconductivity and Cryogenics | Year: 2013

In this study, the homogeneity of critical current, Ic, along the lengthwise direction in the coated conductor (CC) tape under uniaxial tension was investigated using a multiple voltage tap configuration. Initially, a gradual and homogeneous Ic degradation occurred in all subsections of the tape up to a certain strain value. This was followed by an abrupt Ic degradation in some subsections, which caused scattering in Ic values along the length with increasing tension strain. The Ic degradation behaviour was also explained through n-value as well as microstructure analyses. Subsections showed Ic scattering corresponding to damaged areas of the CC tape revealed that transverse cracks were distributed throughout the gauge length. This homogeneous Ic degradation behaviour under tension is similar with the case under torsion strain but different with the case under hard bending which were previously reported. This behaviour is also different with the case using Bi-2223 HTS tapes under tension strain. Source

Gorospe A.,Andong National University | Gorospe A.,Aurora State College of Technology | Nisay A.,Andong National University | Dizon J.R.,Andong National University | And 2 more authors.
Physica C: Superconductivity and its Applications | Year: 2013

The electromechanical property behaviour of 2G coated conductor (CC) tapes fabricated by multi-layer deposition process both in the in-plane and transverse direction should be understood. The CC tapes are used in the fabrication of epoxy resin-impregnated coils. In such case, the Lorentz force due to the high magnetic field applied as well as the thermal stress due to the difference in coefficient of thermal expansion (CTE) among constituent layers during cooling to cryogenic temperature will induce transversely applied load to the surface of CC tapes in coils. Hence, the CC tape should have a good mechanical property in the transverse direction in order to maintain its superior performance under magnetic field. In this study, a test frame which gives precisely aligned transverse load was devised. Using the fixture, the delamination behaviours including the delamination strength of the GdBCO CC tapes under transverse tensile loading were investigated. Large variation on the delamination strength of the CC tapes was recorded and might have resulted from the slit edge effect and the inhomogeneity of the CC tapes. The Ic degradation behaviour under transverse load was related to the location where delamination occurred in the sample. © 2013 Elsevier B.V. All rights reserved. Source

Dedicatoria M.J.,Andong National University | Dizon J.R.C.,Andong National University | Dizon J.R.C.,Bataan Peninsula State University | Shin H.-S.,Andong National University | Sim K.-D.,Korea Electrotechnology Research Institute
Journal of the Korea Institute of Applied Superconductivity and Cryogenics | Year: 2012

The measurement of the coefficient of thermal expansion (CTE) of polypropylene laminated paper (PPLP) as electric insulating material is important for its practical superconducting device application. The thermal strain induced to HTS tapes and its insulating material during cooling from room temperature might largely affect the critical current (Ic) of HTS tapes. In this study, the thermal contraction of PPLP material was measured during cooling from 300 K to 77 K using double extensometers. Initially, the CTE of a brass tape was measured and it was compared with a reference data. It was found that the measured thermal expansion data of the brass material approaches that of the reference one. Based on the results, it was then confirmed that the measurement technique could be applied to thin and flexible samples. Therefore, the same measurement procedure was applied to PPLP material using double extensometers. As a result, the linear CTE of the PPLP at 77 K has been measured to be ~ 15. 3 × 10-6/K. Also, it was found that the thermal contraction characteristics of PPLP was dominated by polypropylene on the cross direction (higher thermal contraction) while it was dominated by Kraft paper on the machine direction (lower thermal contraction). Overall, this measurement procedure could be adopted for the determination of CTE of flexible materials such as PPLP. Source

Discover hidden collaborations