Non-monotonic temperature dependent transport in graphene grown by Chemical Vapor Deposition

Temperature-dependent resistivity of graphene grown by chemical vapor deposition (CVD) is investigated. We observe in low mobility CVD graphene device a strong insulating behavior at low temperatures and a metallic behavior at high temperatures manifesting a non-monotonic in the temperature dependent resistivity.This feature is strongly affected by carrier density modulation. To understand this anomalous temperature dependence, we introduce thermal activation of charge carriers in electron-hole puddles induced by randomly distributed charged impurities. Observed temperature evolution of resistivity is then understood from the competition among thermal activation of charge carriers, temperature-dependent screening and phonon scattering effects. Our results imply that the transport property of transferred CVD-grown graphene is strongly influenced by the details of the environmentComment: 7 pages, 3 figure

Z_3 Strings and their Interactions

We construct Z_3 vortex solutions in a model in which SU(3) is spontaneously broken to Z_3. The model is truncated to one in which there are only two dimensionless free parameters and the interaction of vortices within this restricted set of models is studied numerically. We find that there is a curve in the two dimensional space of parameters for which the energy of two asymptotically separated vortices equals the energy of the vortices at vanishing separation. This suggests that the inter-vortex potential for Z_3 strings might be flat for these couplings, much like the case of U(1) strings in the Bogomolnyi limit. However, we argue that the intervortex potential is attractive at short distances and repulsive at large separations leading to the possibility of unstable bound states of Z_3 vortices.Comment: 8 pages; mainly corrected typos in table

Evaluation of the Dietary Effect of Hallabong Peel Oil on Growth, Hematological, and Immune Gene Expression in Rock Bream, Oplegnathus fasciatus Challenged with Edwardsiella tarda

In the present study we evaluated the dietary effect of Hallabong peel oil (HPO) on growth, disease resistance, and immune gene expression of rock bream, Oplegnathus fasciatus challenged with Edwardsiella tarda after a 4 week feeding trial with 5 treatments: control-C, probiotic–P, HPO (0.1%), HPO (0.5%), and P+HPO, diets. All fish groups were assessed for growth performance, innate immune parameters, serum biochemical profile, and immune gene expression in head kidney on 2nd, and 4th week, and 1st, 3rd and 7th day post infection with Edwardsiella tarda. Fish fed the HPO enriched diets showed increased growth performance with significantly decreased (P>0.05) mortality compared with the control and probiotic diet groups. The positive effects of HPO enriched diet were also found in all assessed innate immune and biochemical parameters which included increased respiratory burst and lysozyme activity, with significantly increased erythrocyte and leukocytes counts, increased serum protein, decreased glucose, triglycerides, cholesterol level in serum compared with control diet fed fish. Moreover, the probiotic bacterial count in the intestine of fish was enhanced with the HPO diet and the P+HPO diet compared to fish fed the probiotic diet. The head kidney of HPO enriched diet fed fish showed up-regulated expression of inflammatory cytokines genes such as TNFα, IL-1β, and FST, after 4th week of feeding trial which was increased ~2 to 3 times on 1dpi and 3 dpi. These results indicate that limonene rich (91.26%), HPO enriched diets enhance growth and immunity and enhance disease resistance of Oplegnathus fasciatus challenged against E. tarda

Atomic Layer Deposition of Ni Thin Films and Application to Area-Selective Deposition

Ni thin films were deposited by atomic layer deposition (ALD) using bis(dimethylamino-2-methyl-2-butoxo)nickel [Ni(dmamb)(2)] as a precursor and NH3 gas as a reactant. The growth characteristics and film properties of ALD Ni were investigated. Low-resistivity films were deposited on Si and SiO2 substrates, producing high-purity Ni films with a small amount of oxygen and negligible amounts of nitrogen and carbon. Additionally, ALD Ni showed excellent conformality in nanoscale via holes. Utilizing this conformality, Ni/Si core/shell nanowires with uniform diameters were fabricated. By combining ALD Ni with octadecyltrichlorosilane (OTS) self-assembled monolayer as a blocking layer, area-selective ALD was conducted for selective deposition of Ni films. When performed on the prepatterned OTS substrate, the Ni films were selectively coated only on OTS-free regions, building up Ni line patterns with 3 mu m width. Electrical measurement results showed that all of the Ni lines were electrically isolated, also indicating the selective Ni deposition. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3504196] All rights reserved.ope

Pathogenicity and Immune Response of Starry Flounder, Platichthys stellatus, Infected with Vibrio anguillarum

Vibrio anguillarum is the aetiological agent of vibriosis, a disease affecting many marine fish species. The occurrence of vibriosis in starry flounder, Platichthys stellatus, grown in an aquaculture farm has demonstrated the urgent need for information on pathogenic infection and immune response for efficient disease management. This is the first study to report Vibrio anguillarum isolation and infection in starry flounder. We evaluated immune responses, serum biochemical parameters, and cumulative mortality of the fish by experimentally challenging healthy fish. The expression levels of five immune genes (TNF, TNFR, IL-6, MHCII, and CXC) were measured by real-time quantitative PCR. The transcriptional levels of the genes encoding tumor necrosis factor (TNF), TNF receptor (TNFR), interleukin-6 (IL-6), the major histocompatibility complex (MHC-II), and a chemokine (CXC) in the head-kidney of V. anguillarum infected fish were significantly upregulated compared with control fish and biochemical indices including the alanine aminotransferase, total serum protein, and glucose levels of infected fish differed significantly from those of control. Additionally, Starry flounder infected with V. anguillarum at 1.67 × 106 and 1.67 × 108CFU/mL showed 53%, and 100% mortality, respectively. This study furthers our understanding of the immune and serum biochemical alterations, and mortality induced by bacterial infections, depending on pathogen concentration. This may advance strategies for control of V. anguillarum in cultured starry flounde

1s-intraexcitonic dynamics in monolayer MoS2 probed by ultrafast mid-infrared spectroscopy

The 1s exciton-the ground state of a bound electron-hole pair-is central to understanding the photoresponse of monolayer transition metal dichalcogenides. Above the 1s exciton, recent visible and near-infrared investigations have revealed that the excited excitons are much richer, exhibiting a series of Rydberg-like states. A natural question is then how the internal excitonic transitions are interrelated on photoexcitation. Accessing these intraexcitonic transitions, however, demands a fundamentally different experimental tool capable of probing optical transitions from 1s 'bright' to np 'dark' states. Here we employ ultrafast midinfrared spectroscopy to explore the 1s intraexcitonic transitions in monolayer MoS2. We observed twofold 1s-3p intraexcitonic transitions within the A and B excitons and 1s-2p transition between the A and B excitons. Our results revealed that it takes about 0.7 ps for the 1s A exciton to reach quasi-equilibrium; a characteristic time that is associated with a rapid population transfer from the 1s B exciton, providing rich characteristics of many-body exciton dynamics in two-dimensional materials.112412Ysciescopu

Accuracy Tests Of American Put Valuation Models For Pharmaceutical Equity Options

This study compares the performance of the Macmillan (1986), Barone-Adesi and Whaley (1987) MBAW model, Ju and Zhong (1999) MQuad model, Black-Scholes model and Put-Call Parity in pricing American put options of pharmaceutical companies. These are evaluated using actual option prices for three companies over 2000 to 2005, as opposed to the previous use of generated binomial option pricing data. We compare the forecasting accuracy by maturity, moneyness, and variance estimate. Contrary to Ju and Zhong (1999), we find that the MBAW outperforms the other models for at-the-money, and out-of-the-money options. The MQuad model performs best for in-the-money options. However, in this case both the MBAW and MQuad models estimates are very similar. Our results are consistent irrespective of option maturities and volatility estimates. These findings raise questions regarding the practice of using actual prices as the true value, compared to the previous results that use simulated prices

Chemical Accident Hazard Assessment by Spatial Analysis of Chemical Factories and Accident Records in South Korea

This study identified the potential chemical accident occurrence in Korea by analyzing the spatial distribution of chemical factories and accidents. The number of chemical factories and accidents in 25-km2 grids were used as the attribute value for spatial analysis. First, semi-variograms were conducted to examine spatial distribution patterns and to identify spatial autocorrelation of chemical factories and accidents. Semi-variograms explained that the spatial distribution of chemical factories and accidents were spatially autocorrelated. Second, the results of the semi-variograms were used in Ordinary Kriging to estimate chemical hazard levels. The level values were extracted from the Ordinary Kriging result and their spatial similarity was examined by juxtaposing the two values with respect to their location. Six peaks were identified in both the factory hazard and accident hazard estimation result, and the peaks correlated with major cities in Korea. Third, the estimated two hazard levels were classified with geometrical interval and could be classified into four quadrants: Low Factory and Low Accident (LFLA), High Factory and Low Accident (HFLA), Low Factory and High Accident(LFHA), and High Factory and High Accident (HFHA). The 4 groups identified different chemical safety management issues in Korea; safe LFLA group, many chemical reseller factories were found in HFLA group, chemical transportation accidents were in the LFHA group, and an abundance of factories and accidents were in the HFHA group. Each quadrant represented different safety management obstacles in Korea, and studying spatial differences can support the establishment of an efficient risk management plan