191 research outputs found

    Feasibility of extracting a Σ\Sigma^- admixture probability in the neutron-rich Λ10^{10}_{\Lambda}Li hypernucleus

    Full text link
    We examine theoretically production of the neutron-rich Λ10^{10}_{\Lambda}Li hypernucleus by a double-charge exchange (π\pi^-, K+K^+) reaction on a 10^{10}B target with distorted-wave impulse approximation calculations. The result shows that the magnitude and shape of the calculated spectrum at 1.20 GeV/c by a one-step mechanism πpK+Σ\pi^-p \to K^+ \Sigma^- via Σ\Sigma^- doorways caused by a ΣpΛn\Sigma^-p \leftrightarrow \Lambda n coupling can explain the recent experimental data, and the Σ\Sigma^- admixture probability in Λ10^{10}_{\Lambda}Li is found to be the order of 101^{-1} %. The (π\pi^-, K+K^+) reaction provides a capability of extracting properties of wave functions with Λ\Lambda-Σ\Sigma coupling effects in neutron-rich nuclei, together with the reaction mechanism.Comment: 13 pages, 3 figure

    Effect of repeated heating on thermal behavior of crude palm oil

    Get PDF
    Thermal behavior of crude palm oil (CPO) is important to determine the optimal fractionation process and product yield. In this study, the effects of repeated heating on thermal behavior of CPO were examined by differential scanning calorimetry. CPO was heated at 80°C for 5 min, and heating was repeated five times to simulate the common conditions experienced by an oil before reaching the refinery. The result revealed that the thermal behavior of CPO changed after heating. The change, however, occurred only in the behavior of the high-melting stearin peak but not in the low-melting olein peak. Overheating split the stearin peak at 17.30°C to two peaks at 18.88 and 17.30°C and formed a new peak at 11.28°C. Apparently, a new substance has been synthesized

    Hyperonic mixing in five-baryon double-strangeness hypernuclei in a two-channel treatment

    Full text link
    Properties of hypernuclei ΛΛ5_{\Lambda \Lambda}^5H and ΛΛ5_{\Lambda \Lambda }^5He are studied in a two-channel approach with explicit treatment of coupling of channels ^3\text{Z}+\Lambda+\Lambda and \alpha+\Xi. Diagonal \Lambda\Lambda and coupling \Lambda\Lambda-\Xi N interactions are derived within G-matrix procedure from Nijmegen meson-exchange models. Bond energy \Delta B_{\Lambda\Lambda} in ΛΛ5_{\Lambda \Lambda}^5He exceeds significantly that in ΛΛ5_{\Lambda \Lambda}^5H due to the channel coupling. Diagonal \Xi\alpha attraction amplifies the effect, which is sensitive also to \Lambda-core interaction. The difference of the \Delta B_{\Lambda\Lambda} values can be an unambiguous signature of the \Lambda\Lambda-\Xi N coupling in \Lambda\Lambda hypernuclei. However, improved knowledge of the hyperon-nucleus potentials is needed for quantitative extraction of the coupling strength from future data on the \Lambda\Lambda hypernuclear binding energies.Comment: 11 pages with 3 figures; Phys. Rev. C, accepte

    The Λ\Lambda-Σ\Sigma coupling effect in the neutron-rich Λ\Lambda-hypernucleus Λ10_{\Lambda}^{10}Li by microscopic shell model

    Full text link
    We investigate the structure of the neutron-rich Λ\Lambda-hypernucleus Λ10_{\Lambda}^{10}Li by using microscopic shell-model calculations considering a Λ\Lambda-Σ\Sigma coupling effect. The calculated Σ\Sigma-mixing probability in the Λ10_{\Lambda}^{10}Li ground state is found to be about 0.34 % which is coherently enhanced by the Λ\Lambda-Σ\Sigma coupling configurations, leading to the energy shift 0.28 MeV which is about 3 times larger than that in Λ7_{\Lambda}^{7}Li. The importance of the Σ\Sigma configuration obtained by the ΣN\Sigma N interaction and the potentiality of the neutron-rich environment are discussed.Comment: 6 figure

    Determination of iodine value of palm oil based on triglyceride composition

    Get PDF
    The triglyceride (TG) composition of palm oil is normally determined by high-performance liquid chromatography (HPLC). The HPLC chromatograms indicated a good separation of most of the TG components in the oil. The TG can be classified based on either the TG groups, i.e., triunsaturated, monosaturated, disaturated, or trisaturated, or the number of double bonds, i.e., zero, one, two, three, or four double bonds. The more unsaturated the fatty acid, the greater the iodine value (IV). Therefore, it is hypothesized that the IV of an oil can be determined based upon the TG composition of the oil. Based on the TG groups, stepwise regression analysis showed that the areas of the disaturated, trisaturated, and triunsaturated TG peaks could predict the IV with a coefficient of determination (R2) of 0.990. The regression based on the number of double bonds yielded a good regression equation with R2=0.992. The important variables were the peak area of the fatty acids that contained zero, one, two, and three double bonds. This study concludes that the TG composition can be used to predict the IV of palm oil. The best prediction model is obtained by using the number of double bonds in the TG as the independent variable

    Low-loss slot waveguides with silicon (111) surfaces realized using anisotropic wet etching

    Get PDF
    We demonstrate low-loss slot waveguides on silicon-on-insulator (SOI) platform. Waveguides oriented along the (11-2) direction on the Si (110) plane were first fabricated by a standard e-beam lithography and dry etching process. A TMAH based anisotropic wet etching technique was then used to remove any residual side wall roughness. Using this fabrication technique propagation loss as low as 3.7dB/cm was realized in silicon slot waveguide for wavelengths near 1550nm. We also realized low propagation loss of 1dB/cm for silicon strip waveguides

    The Current State of Climate Change Perceptions and Policies in Myanmar: 2014 Report

    Get PDF
    This report was constructed to assess the current perceptions and policies regarding climate change in Myanmar. It is comprised of a country report outlining current policies relating to climate change, as well as results from two stakeholder perception surveys conducted at the local and national level in Myanmar. The stakeholder perception survey was administered to 33 local stakeholders and 12 national stakeholders from government organizations, farmers’ groups, universities, and research institutes. Results indicate that the primary concern regarding climate change is mostly concentrated on rainfall trends, such as drought and flooding. In addition, local stakeholders have concerns over heat stress, whereas national stakeholders are less concerned with the issue. Only 11 local stakeholders report that their institution currently has a division or staff member working on climate change issues. Seven of 12 national stakeholders reported that their institutions did have a division or staff member working on climate change issues

    The Symptoms of Autism Spectrum Disorders in Adolescence and Adulthood

    Full text link
    This article describes the symptoms of autism spectrum disorders (ASD) manifested by 405 individuals between the ages of 10 and 53 years, all of whom had an ASD diagnosis. Data were collected using the Autism Diagnostic Interview–Revised (ADI-R) to assess the pattern of autism symptoms in adolescence and adulthood. Findings include that although virtually all sample members met the criteria for Autistic Disorder earlier in their childhood, just over half (54.8%) would have met autism criteria if current scores were used to complete the diagnostic algorithm; that adolescents were more likely to improve in the Reciprocal Social Interaction domain than the adults, whereas the adults were more likely to improve in the Restricted, Repetitive Behaviors and Interests domain, and there were no differences in severity of symptoms between cohorts in the Communication domain; and that individual symptoms showed unique trajectories, with greatest symptom abatement between lifetime and current ADI-R ratings for speaking in at least three-word phrases and the least symptom improvement for having friendships. Findings were interpreted in the context of life course development, reformulations of diagnostic criteria, and changing service contexts for individuals with autism spectrum disorders.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44621/1/10803_2004_Article_474978.pd

    Opportunities and obstacles to the elimination of malaria from Peninsular Malaysia: knowledge, attitudes and practices on malaria among aboriginal and rural communities

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Despite continuous efforts by the government and private sectors, malaria is still a public health problem in rural Peninsular Malaysia. This study investigated household knowledge, attitude and practices (KAP) regarding malaria in two malaria endemic communities, forest-aboriginal and rural communities, in the Lipis district of Pahang state, Malaysia.</p> <p>Methods</p> <p>A descriptive cross-sectional study with a semi-structured questionnaire was carried out among 100 and 123 households from forest-aboriginal and rural areas, respectively.</p> <p>Results</p> <p>Knowledge about malaria and its transmission is significantly higher among the rural participants than the aborigines (86.2% vs 76%, p < 0.01). However, use of medicinal plants and beliefs in witchcraft and sorcery in treating febrile diseases were significantly higher among the aboriginal population (p < 0.01). There were no significant differences between the two communities in terms of the knowledge about malaria symptoms, attitudes towards its severity and practices in preventive measures against malaria by using mosquito bed nets. However, the knowledge and practice of different preventive measures to combat malaria, such as insecticide and the elimination of breeding areas, was significantly higher among the rural population than the aborigines (p < 0.001).</p> <p>Conclusions</p> <p>Both communities were aware of malaria as a disease, but knowledge, attitudes and practices were inadequate. Providing efficient health education to people residing in malaria endemic areas would improve their understanding about malaria prevention in order to bring about the elimination of malaria from the country.</p
    corecore