9,437 research outputs found

    Perbedaan Persepsi Mahasiswa Senior dan Junior Mengenai Profesi Akuntan pada Program S1 di Universitas Katolik Widya Mandala Surabaya

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    Accounting profession is work that has to be done in a professional and great responsibility towards the public,so that every student who will pursue this work should have the right attitudes and perceptions of the accounting profession. Therefore, when students still in the university they need to be taught to has a positive perception of accounting profession. This research used comparative with hypothesis testing aims to provide empirical evidence on differences in perceptions between senior and junior students of the accounting profession. The samples consist of senior students who have passed all internal and external courses (class of 2007 and 2008) and junior students who have passed the semester 1 (class of 2009 and 2010). The numbers of samples used by proportionate random sampling are 72 samples from senior students and 102 samples from junior students. The tool used is questionaire that contain list of statements. The results showed that there was no difference in perception between senior and junior students of the accounting profession in the bachelor of accounting at Widya Mandala Catholic University Surabaya

    Study of the Staebler-Wronski degradation effect in a-Si:H based p-i-n solar cell

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    Conversion of solar energy into electricity using environmentally safe and clean photovoltaic methods to supplement the ever increasing energy needs has been a cherished goal of many scientists and engineers around the world. Photovoltaic solar cells on the other hand, have been the power source for satellites ever since their introduction in the early sixties. For widespread terrestrial applications, however, the cost of photovoltaic systems must be reduced considerably. Much progress has been made in the recent past towards developing economically viable terrestrial systems, and the future looks highly promising. Thin film solar cells offer cost reductions mainly from their low processing cost, low material cost, and choice of low cost substrates. These are also very attractive for space applications because of their high power densities (power produced per kilogram of solar cell pay load) and high radiation resistance. Amorphous silicon based solar cells are amongst the top candidates for economically viable terrestrial and space based power generation. Despite very low federal funding during the eighties, amorphous silicon solar cell efficiencies have continually been improved - from a low 3 percent to over 13 percent now. Further improvements have been made by the use of multi-junction tandem solar cells. Efficiencies close to 15 percent have been achieved in several labs. In order to be competitive with fossil fuel generated electricity, it is believed that module efficiency of 15 percent or cell efficiency of 20 percent is required. Thus, further improvements in cell performance is imperative. One major problem that was discovered almost 15 years ago in amorphous silicon devices is the well known Staebler-Wronski Effect. Efficiency of amorphous silicon solar cells was found to degrade upon exposure to sunlight. Until now their is no consensus among the scientists on the mechanism for this degradation. Efficiency may degrade anywhere from 10 percent to almost 50 percent within the first few months of operation. In order to improve solar cell efficiencies, it is clear that the cause or causes of such degradation must be found and the processing conditions altered to minimize the loss in efficiency. This project was initiated in 1987 to investigate a possible link between metallic impurities, in particular, Ag, and this degradation. Such a link was established by one of the NASA scientists for the light induced degradation of n+/p crystalline silicon solar cells

    Highly Efficient Midinfrared On-Chip Electrical Generation of Graphene Plasmons by Inelastic Electron Tunneling Excitation

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    Inelastic electron tunneling provides a low-energy pathway for the excitation of surface plasmons and light emission. We theoretically investigate tunnel junctions based on metals and graphene. We show that graphene is potentially a highly efficient material for tunneling excitation of plasmons because of its narrow plasmon linewidths, strong emission, and large tunability in the midinfrared wavelength regime. Compared to gold and silver, the enhancement can be up to 10 times for similar wavelengths and up to 5 orders at their respective plasmon operating wavelengths. Tunneling excitation of graphene plasmons promises an efficient technology for on-chip electrical generation and manipulation of plasmons for graphene-based optoelectronics and nanophotonic integrated circuits.Comment: 12 pages, 7 figure

    An Evaluation of the Use of Egg Yolk, Artemia nauplii, Microworms and Moina as Diets in Larval Rearing of Helostoma temmincki Cuvier and Valenciennes

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    Five day old Helostoma temmincki larvae measing 4.6 ± 0.1 mm in total length were stocked into 12 larval culture tanks at the rate of 1000 larvae/tank (l0 larvae/l). The larvae were fed Diet I (Egg yolk), Diet II (Egg yolk + Artemia naupliz), Diet III (Egg yolk +microworms), and Diet IV (Egg yolk + Moina) for iz period of4 weeks. After 1 week of rearing, larvae fed Diet III measun'ng 8. 4 mm total length and 7.0 mg weight were larger than larvae fed the other diets (P < 0.05). A t the end of two weeks, larvae fed Diets II, III and IV were larger than larvae fed Diet I (P < 0.05). FrOm" week 3 onwards, larvae fed Diet IV were consistently larger (P <0.05). This experiment shows that microworms were very suitable as a starter feed and that Moina was suitable for feeding Helostoma temmincki larvae after week 2 under tropical conditions

    BaFe2As2 Surface Domains and Domain Walls: Mirroring the Bulk Spin Structure

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    High-resolution scanning tunneling microscopy (STM) measurements on BaFe2As2-one of the parent compounds of the iron-based superconductors-reveals a (1x1) As-terminated unit cell on the (001) surface. However, there are significant differences of the surface unit cell compared to the bulk: only one of the two As atoms in the unit cell is imaged and domain walls between different (1x1) regions display a C2 symmetry at the surface. It should have been C2v if the STM image reflected the geometric structure of the surface or the orthorhombic bulk. The inequivalent As atoms and the bias dependence of the domain walls indicate that the origin of the STM image is primarily electronic not geometric. We argue that the surface electronic topography mirrors the bulk spin structure of BaFe2As2, via strong orbital-spin coupling

    Characterizing anomalies in distributed strain measurements of cast-in-situ bored piles

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    This paper describes the method of identifying typical defects of bored cast-in-situ piles when instrumenting using Distributed Optical Fiber Strain Sensing (DOFSS). The DOFSS technology is based on Brillouin Optical Time Domain Analyses (BOTDA), which has the advantage of recording continuous strain profile as opposed to the conventional discrete based sensors such as Vibrating Wire strain gauges. In pile instrumentation particularly, obtaining distributed strain profile is important when analysing the load-transfer and shaft friction of a pile, as well as detecting any anomalies in the strain regime. Features such as defective pile shaft necking, discontinuity of concrete, intrusion of foreign matter and improper toe formation due to contamination of concrete at base with soil particles, among others, may cause the pile to fail. In this study, a new technique of detecting such defects is proposed using DOFSS technology which can potentially supplement the existing non-destructive test (NDT) methods. Discussion on the performance of instrumented piles by means of maintained load test are also presented

    Analyticity and the NcN_c counting rule of SS matrix poles

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    By studying ππ\pi\pi scattering amplitudes in the large NcN_c limit, we clarify the NcN_c dependence of the SS matrix pole position. It is demonstrated that analyticity and the NcN_c counting rule exclude the existence of SS matrix poles with M,ΓO(1){\cal M}, \Gamma\sim O(1). Especially the properties of σ\sigma and f0(980)f_0(980) with respect to the 1/Nc1/N_c expansion are discussed. We point out that in general tetra-quark resonances do not exist.Comment: This paper replaces hep-ph/0412175. The latter is withdraw

    Graphene Transport at High Carrier Densities using a Polymer Electrolyte Gate

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    We report the study of graphene devices in Hall-bar geometry, gated with a polymer electrolyte. High densities of 6 ×1013/cm2\times 10^{13}/cm^{2} are consistently reached, significantly higher than with conventional back-gating. The mobility follows an inverse dependence on density, which can be correlated to a dominant scattering from weak scatterers. Furthermore, our measurements show a Bloch-Gr\"uneisen regime until 100 K (at 6.2 ×1013/cm2\times10^{13}/cm^{2}), consistent with an increase of the density. Ubiquitous in our experiments is a small upturn in resistivity around 3 ×1013/cm2\times10^{13}/cm^{2}, whose origin is discussed. We identify two potential causes for the upturn: the renormalization of Fermi velocity and an electrochemically-enhanced scattering rate.Comment: 13 pages, 4 figures, Published Versio
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