4,959 research outputs found

    ^25Mg NMR study of the MgB_2 superconductor

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    ^25Mg NMR spectra and nuclear spin-lattice relaxation time, T_1, have been measured in polycrystalline ^25MgB_2 with a superconducting transition temperature T_c = 39.0 K in zero magnetic field. From the first order and second order quadrupole perturbed NMR spectrum a quadrupole coupling frequency nu_Q = 222(1.5) kHz is obtained. T_1T = 1090(50) sK and Knight shift K_c = 242(4) ppm are temperature independent in the normal conducting phase. The ^25Mg Korringa ratio equals to 0.95 which is very close to the ideal value of unity for s-electrons. The comparison of the experimental nu_Q, T_1T, and K_c with the corresponding values obtained by LDA calculations shows an excellent agreement for all three quantities.Comment: 4 pages including 4 eps-figures, revtex

    Embodied Energy Audit of Residential Building

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    Buildings consume a vast amount of energy during the life cycle stages of construction, use and demolition. Total life cycle energy use in a building consists of two components: embodied and operational energy. Embodied energy is expended in the processes of building material production, on-site delivery, construction, maintenance, renovation and final demolition. Operational energy is consumed in operating the buildings. In this paper the review is given about energy consumption of the residential building. Energy required for various materials is calculated and energy efficient alternatives are suggested. Studies have revealed the suggestion of energy efficient alternatives materials and comparison of energy consumed by using each material. Current interpretations of embodied energy are quite unclear and vary greatly as change in site source of raw materials and embodied energy databases suffer from the problems of variation and incomparability

    Ключевые принципы менеджмента качества в зерновом производстве

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    Целью исследования является построение усовершенствованной системы ключевых принципов менеджмента качества зерна, как базиса управления конкурентоспособностью продукции национальных производителей. Достижению указанной цели способствует решение следующих задач: систематизировать принципы, используемые для приведения качества продукции в соответствие динамично изменяющимся требованиям заинтересованных сторон; исследовать современные требования к менеджменту качества пищевых продуктов и тенденции их изменения

    DNA Authentication of St John’s Wort (Hypericum perforatum L.) Commercial Products Targeting the ITS Region

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    open access articleThere is considerable potential for the use of DNA barcoding methods to authenticate raw medicinal plant materials, but their application to testing commercial products has been controversial. A simple PCR test targeting species-specific sequences within the nuclear ribosomal internal transcribed spacer (ITS) region was adapted to screen commercial products for the presence of Hypericum perforatum L. material. DNA differing widely in amount and extent of fragmentation was detected in a number of product types. Two assays were designed to further analyse this DNA using a curated database of selected Hypericum ITS sequences: A qPCR assay based on a species-specific primer pair spanning the ITS1 and ITS2 regions, using synthetic DNA reference standards for DNA quantitation and a Next Generation Sequencing (NGS) assay separately targeting the ITS1 and ITS2 regions. The ability of the assays to detect H. perforatum DNA sequences in processed medicines was investigated. Out of twenty different matrices tested, both assays detected H. perforatum DNA in five samples with more than 103 ITS copies µL−1 DNA extract, whilst the qPCR assay was also able to detect lower levels of DNA in two further samples. The NGS assay confirmed that H. perforatum was the major species in all five positive samples, though trace contaminants were also detected

    Senjata tradisional daerah Nusa Tenggara Timur

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    Proyek Penelitian, Pengkajian, dan Pembinaan Nilai-Nilai Budaya menggali nilai-nilai budaya dari setiap suku bangsa/daerah. Penggalian ini mencakup aspek-aspek kebudayaan daerah dengan tujuan memperkuat penghayatan dan pengamalan Pancasila guna tercapainya ketahanan nasional di bidang sosial budaya. Untuk melestarikan nilai-nilai budaya dilakukan penerbitan hasil-hasil penelitian yang kemudian disebarluaskan kepada masyarakat umum. Pencetakan naskah yang beljudul Senjata Tradisional Daerah Nusa Tenggara Timur, adalah usaha untuk mencapai tujuan yang dimaksud

    Sharp change over from compound nuclear fission to shape dependent quasi fission

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    Fission fragment mass distribution has been measured from the decay of 246^{246}Bk nucleus populating via two entrance channels with slight difference in mass asymmetries but belonging on either side of the Businaro Gallone mass asymmetry parameter. Both the target nuclei were deformed. Near the Coulomb barrier, at similar excitation energies the width of the fission fragment mass distribution was found to be drastically different for the 14^{14}N + 232^{232}Th reaction compared to the 11^{11}B + 235^{235}U reaction. The entrance channel mass asymmetry was found to affect the fusion process sharply.Comment: 4 pages,6 figure

    Combinatorial CRISPR-Cas9 screens for de novo mapping of genetic interactions.

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    We developed a systematic approach to map human genetic networks by combinatorial CRISPR-Cas9 perturbations coupled to robust analysis of growth kinetics. We targeted all pairs of 73 cancer genes with dual guide RNAs in three cell lines, comprising 141,912 tests of interaction. Numerous therapeutically relevant interactions were identified, and these patterns replicated with combinatorial drugs at 75% precision. From these results, we anticipate that cellular context will be critical to synthetic-lethal therapies
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