1,221 research outputs found

    On quantization of singular varieties and applications to D-branes

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    We calculate the ring of differential operators on some singular affine varieties (intersecting stacks, a point on a singular curve or an orbifold). Our results support the proposed connection of the ring of differential operators with geometry of D-branes in (bosonic) string theory. In particular, the answer does know about the resolution of singularities in accordance with the string theory predictions.Comment: LaTeX2e, 17 pages, misprints correcte

    ANALISIS FAKTOR RISIKO YANG BERHUBUNGAN DENGAN KEJADIAN STUNTING PADA BALITA DI WILAYAH KERJA PUSKESMAS JAILOLO KABUPATEN HALMAHERA BARAT

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    Stunting didefinisikan sebagai keadaan tubuh yang Z-score tinggi badan menurut usianya berada di bawah garis normal yaitu kurang dari -2SD dikategorikan pendek dan kurang dari -3SD dikategorikan sangat pendek (Sarmin & Darmin, 2021). Stunting adalah gangguan tumbuh kembang sebagai akibat dari kekurangan gizi kronis dan infeksi berulang yang menyerang anak di bawah usia lima tahun terutama selama 1000 Hari Pertama Kehidupan. Desain penelitian yang digunakan dalam penelitian ini adalah analitik observasional dengan pendekatan cross sectional. Penelitian dilaksanakan di wilayah kerja Puskesmas Jailolo Kabupaten Halmahera Barat. Sampel dalam penelitian ini adalah balita dan ibu yang ada di wilayah Puskesmas Jailolo Kabupaten Halmahera Barat sebanyak 93 responden dengan menggunakan teknik simple random sampling. Variabel penelitian terdiri dari variabel bebas (riwayat pemberian ASI eksklusif, pola pemberian makan, pengetahuan ibu, dan pendapatan keluarga) dan variabel terikat (kejadian stunting). Pengambilan data dilakukan dengan wawancara menggunakan kuesioner. Data penelitian ini dianalisis menggunakan analisis univariat, analisis bivariat, dan analisis multivariat. Hasil analisis menunjukkan bahwa terdapat hubungan yang signifikan antara riwayat pemberian ASI eksklusif (p =0,002), pola pemberian makan (p=0,000), pengetahuan ibu (p=0,000), pendapatan keluarga (p=0,000) dengan kejadian stunting di wilayah kerja Puskesmas Jailolo Kabupaten Halmahera Barat. Hasil analisis multivariat menunjukkan nilai exp ? variabel pola pemberian makan sebesar 19,483 dengan nilai signifikan 0,000. Kesimpulan dalam penelitian ini yaitu balita yang dengan pola pemberian makan kurang tepat berisiko mengalami stunting sebesar 19,483 kali dibanding dengan balita dengan pola pemberian makan yang tepat

    Motion and gravitational radiation of a binary system consisting of an oscillating and rotating coplanar dusty disk and a point-like object

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    A binary system composed of an oscillating and rotating coplanar dusty disk and a point mass is considered. The conservative dynamics is treated on the Newtonian level. The effects of gravitational radiation reaction and wave emission are studied to leading quadrupole order. The related waveforms are given. The dynamical evolution of the system is determined semi-analytically exploiting the Hamiltonian equations of motion which comprise the effects both of the Newtonian tidal interaction and the radiation reaction on the motion of the binary system in elliptic orbits. Tidal resonance effects between orbital and oscillatory motions are considered in the presence of radiation damping.Comment: 26 pages, 8 figure

    D-Terms, Unification, and the Higgs Mass

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    We study gauge extensions of the MSSM that contain non-decoupling D-terms, which contribute to the Higgs boson mass. These models naturally maintain gauge coupling unification and raise the Higgs mass without fine-tuning. Unification constrains the structure of the gauge extensions, limiting the Higgs mass in these models to roughly less than 150 GeV. The D-terms contribute to the Higgs mass only if the extended gauge symmetry is broken at energies of a few TeV, leading to new heavy gauge bosons in this mass range.Comment: 30+1 pages, 7 figure

    Non-commutative tachyon action and D-brane geometry

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    We analyse open string correlators in non-constant background fields, including the metric gg, the antisymmetric BB-field, and the gauge field AA. Working with a derivative expansion for the background fields, but exact in their constant parts, we obtain a tachyonic on-shell condition for the inserted functions and extract the kinetic term for the tachyon action. The 3-point correlator yields a non-commutative tachyon potential. We also find a remarkable feature of the differential structure on the D-brane: Although the boundary metric GG plays an essential role in the action, the natural connection on the D-brane is the same as in closed string theory, i.e. it is compatible with the bulk metric and has torsion H=dBH=dB. This means, in particular, that the parallel transport on the brane is independent of the gauge field AA.Comment: 12 pages, no figure

    Poly(ionic liquid)–ionic liquid membranes with fluorosulfonyl derived anions: characterization and biohydrogen separation

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    Unformatted postprintClean and sustainable energy production has become a key global issue concerning the world’s energy shortage and environmental problematic. Despite the recognized potential of biohydrogen (bioH2) for sustainable development, there are still issues regarding its production and purification, such as the elimination of CO2, N2, and other impurities (H2O and H2S), so that an enriched H2 stream can be obtained for efficient energy generation. The use of poly(ionic liquid)s (PILs) and their derived composite materials incorporating ionic liquids (PIL–IL) has been considered as a highly promising strategy to design membranes with improved CO2 separation. In this study, membranes of pyrrolidinium-based PILs containing symmetric or asymmetric fluorosulfonyl derived anions, namely bis(fluorosulfonyl)amide ([FSI]–), (trifluoromethyl)sulfonyl-N-cyanoamide ([TFSAM]–) and (trifluoromethyl)sulfonyl-N-trifluoroacetamide ([TSAC]–), were prepared by the incorporation of different amounts of structurally similar ILs. The PIL–IL membranes were characterized by different techniques (TGA, DSC, FT-IR and Raman) and their CO2/H2 and H2/N2 separation performances were investigated. Higher CO2/H2 selectivities were obtained for PIL FSI–40 [C2mim][FSI] (αCO2/H2 = 9.0) and PIL TFSAM–40 [C2mim][TFSAM] (αCO2/H2 = 7.1) compared to those of PIL–IL membranes containing the conventional [TFSI]– anion at similar or even higher amounts of IL’s incorporation.Andreia S. L. Gouveia is grateful to FCT (Fundação para a Ciência e a Tecnologia) for her Doctoral (SFRH/BD/116600/2016) research grant. Liliana C. Tomé has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 745734. This work was supported by FCT through the project PTDC/CTM-POL/2676/2014. Centro de Química Estrutural acknowledges the financial support of Fundação para a Ciência e Tecnologia (UIDB/00100/2020). Elemental analysis and Raman spectroscopy were performed with the financial support from Ministry of Science and Higher Education of the Russian Federation using the equipment of Center for molecular composition studies of INEOS RAS

    Are they ‘worth their weight in gold’? Sport for older adults: benefits and barriers of their participation for sporting organisations

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    The ageing global population has led to an increased focus on health for older adults. However, older adults have not been a specific priority for some sporting organisations (SOs). Thus, there is an emerging opportunity for this age group to be considered within international sport policy. The aim of this study was to understand the benefits and barriers that SOs encounter when engaging older adults. Eight focus group interviews (n = 49) were held with representatives of Australian national sporting organisations (NSOs), and older adults who were either sport club or non-sport club members. The socioecological model domains, interpersonal, organisational and policy, were used as a framework for thematic analysis, and organisational capacity building concepts were utilised to explain the findings. Common perceived benefits included interpersonal benefits (intergenerational opportunities and role models) and organisational benefits (volunteering, financial contributions and maximised facility usage) for engaging older adults. Common perceived barriers included interpersonal barriers (competing priorities and perceived societal expectations), organisational barriers (lack of appropriate playing opportunities, lack of facility access and lack of club capacity) and policy barriers (strategic organisational focus on children and elite sport and risk management). Whilst participation in sport is not common for older adults, their involvement can be invaluable for sport clubs. It is not anticipated that any policy focus on older adults will significantly increase active participation for this age group. However, any increase in older adults’ sport participation either through actively playing, supporting family and friends and/or volunteering will contribute to the positive health of individuals, sport clubs and the community.Peer reviewedFinal Accepted Versio

    (B-L) Symmetry vs. Neutrino Seesaw

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    We compute the effective coupling of the Majoron to W bosons at \cO(\hbar) by evaluating the matrix element of the (B-L) current between the vacuum and a W+WW^+W^- state. The (B-L) anomaly vanishes, but the amplitude does not vanish as a result of a UV finite and non-local contribution which is entirely due to the mixing between left-chiral and right-chiral neutrinos. The result shows how anomaly-like couplings may arise in spite of the fact that the (B-L) current remains exactly conserved to all orders in \hbar, lending additional support to our previous proposal to identify the Majoron with the axion.Comment: 13 pages, 1 figure, with additional explanations and clarification

    Exponential Metric Fields

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    The Laser Interferometer Space Antenna (LISA) mission will use advanced technologies to achieve its science goals: the direct detection of gravitational waves, the observation of signals from compact (small and dense) stars as they spiral into black holes, the study of the role of massive black holes in galaxy evolution, the search for gravitational wave emission from the early Universe. The gravitational red-shift, the advance of the perihelion of Mercury, deflection of light and the time delay of radar signals are the classical tests in the first order of General Relativity (GR). However, LISA can possibly test Einstein's theories in the second order and perhaps, it will show some particular feature of non-linearity of gravitational interaction. In the present work we are seeking a method to construct theoretical templates that limit in the first order the tensorial structure of some metric fields, thus the non-linear terms are given by exponential functions of gravitational strength. The Newtonian limit obtained here, in the first order, is equivalent to GR.Comment: Accepted for publication in Astrophysics and Space Science, 17 page

    Lifetime of Stringy de Sitter Vacua

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    In this note we perform a synopsis of the life-times from vacuum decay of several de Sitter vacuum constructions in string/M-theory which have a single dS minimum arising from lifting a pre-existing AdS extremum and no other local minima existent after lifting. For these vacua the decay proceeds via a Coleman--De Luccia instanton towards the universal Minkowski minimum at infinite volume. This can be calculated using the thin--wall approximation, provided the cosmological constant of the local dS minimum is tuned sufficiently small. We compare the estimates for the different model classes and find them all stable in the sense of exponentially long life times as long as they have a very small cosmological constant and a scale of supersymmetry breaking > TeV.Comment: 1+16 pages, 2 figures, LaTeX, uses JHEP3 class, v2: references added, inclusion of an additional subclass of de Sitter vacu
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