894 research outputs found

    Dark Matter in the Left Right Twin Higgs Model

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    In the left-right twin Higgs model, one of the neutral Higgses is a natural candidate for WIMP dark matter. We analyzed the dark matter relic density in this framework and identified regions of parameter space that provide the right amount of dark matter. We also studied the dark matter in the more general inert Higgs doublet model in which the mass splittings between the dark matter and other particles do not follow the relations in the left-right twin Higgs model.Comment: 18 page

    Pengaruh Kompetensi Profesional terhadap Kinerja Pustakawan Universitas Hsanuddin

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    Penelitian ini bertujuan untuk mengetahui dan menganalisis komptensi yang terdiri daripengetauan, keterampilan, dan sikap terhadap kinerja Pustakawan UniversitasHasanuddin. Dan untuk mengetahui dan mengnalisis kompetensi yang dominan yangberpengaruh terhadap kinerja pustakawan Universitas Hasanuddin.Pendekatan penelitian ini adalah pendekatan deskriptif kualitatif. Jenis penelitian inibertsifat survey yaitu menganalisis fakta yang menunjang keterangan yang diperlukanuntuk mendukung penelitian dalam memecahkan dan menjawab pokok permasalahanyang diajukan yaitu analisis kompetensi yang berpengaruh terhadap kinerja PustakawanUniversitas Hasanuddin. Dan data diperoleh melalui penyebaran kuesioner, data dianalisissecara deskriptif dan analisis regresi berganda.Hasil penelitian menunjukkan bahwa, hasil uji secara simultan menunjukkan bahwa nilaiF hitung sebesar 87,270 dengan tingkat signifikansi sebesar 0.000 yang menunjukkanbahwa terdapat pengaruh yang signifikan variabel pengetahuan, keterampilan, dan sikapterhadap kinerja pustakawan Universitas Hasanuddin. Hasil uji secara parsialmenunjukkan bahwa koefisien variabel pengetahuan sebesar 0.352 dengan nilai t hitung2,195 dengan signifikansi sebesar 0.035 yang menunjukkan bahwa pengetahuanberbengaruh secara positif, signifikan dan dominan tehadap kinerja pustakawanUniversitas Hasanuddin, yang berarti bahwa semakin tinggi tingkat pengetahuan, makasemakin tinggi pula wawasan keilmuan pustakawan untuk meningkatkan kinerjanya.Secara parsial menunjukkan bahwa koefisien keterampilan sebesar 0.296 dengansignifikansi sebesar 0.0046 yang menunjukkan bahwa keterampilan berpengaruh terhadapkinerja pustakawan Universitas Hasanuddin, yang berarti bahwa semakin tinggi skill yangdimiliki pustakawan akan semakin meningkat kenerjanya. Secara parsial menunjukkanbahwa koefisien sikap pustakawan sebesar 0.315 dengan signifikansi sebesar 0.001 yangmenunjukkan bahwa sikap pengaruh terhadap kinerja pustakawan, yang berarti bahwapeningkatan kompetensi akan berpengaruh terhadap sikap/periluku pustakawan yangmengarah pada peningkatan kinerja pustakawan Universitas Hasanuddin

    Electrochemical performances of vitreous materials in the system Li2O–V2O5–P2O5 as electrode for lithium batteries

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    International audienceGlass composition 25Li2O–50V2O5–25P2O5 has been investigated as a potential material for electrode. Electrical properties as well as electrochemical performances of this glass composition have been characterized and results show a capacity less than 80mAhg−1 when tested in the [3–4.5V] potential window. To the best of our knowledge, this is the first lithiated amorphous material reported as a potential positive electrode material. Glasses, due to their wide available compositions in a given system and their easy processing, pave the way to new type of electrode material

    Factors Influencing the Impact of Aggressive and Violent Media on Children and Adolescents

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    The influence of aggressive and violent media on children and adolescents has been a topic of concern for several decades. Research on this topic has suggested that both short term and long term exposure to aggressive/violent media can negatively impact this population. The purpose of this literature review is to discuss relevant research on the topic and examine various factors that may impact the risk of being influenced by this type of media. These factors can include time spent viewing media, content of the media viewed, gender, age, psychological characteristics, family, and peers. Various theoretical approaches to explaining the influence of violent media are also examined, as well as directions for future research

    In Situ Pyrolysis of 3D Printed Building Blocks for Functional Nanoscale Metamaterials

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    This study presents a novel approach for investigating the shrinkage dynamics of 3D-printed nanoarchitectures during isothermal pyrolysis, utilizing in situ electron microscopy. For the first time, the temporal evolution of 3D structures is tracked continuously until a quasi-stationary state is reached. By subjecting the 3D objects to different temperatures and atmospheric conditions, significant changes in the resulting kinetic parameters and morphological textures of the 3D objects are observed, particularly those possessing varying surface-to-volume ratios. Its results reveal that the effective activation energy required for pyrolysis-induced morphological shrinkage is approximately four times larger under vacuum conditions than in a nitrogen atmosphere (2.6 eV vs. 0.5–0.9 eV, respectively). Additionally, a subtle enrichment of oxygen on the surfaces of the structures for pyrolysis in nitrogen is found through a postmortem electron energy loss spectroscopy study, differentiating the vacuum pyrolysis. These findings are examined in the context of the underlying process parameters, and a mechanistic model is proposed. As a result, understanding and controlling pyrolysis in 3D structures of different geometrical dimensions not only enables precise modification of shrinkage and the creation of tensegrity structures, but also promotes pyrolytic carbon development with custom architectures and properties, especially in the field of carbon micro- and nano-electromechanical systems

    Pancreatic ductal adenocarcinoma and chronic pancreatitis may be diagnosed by exhaled-breath profiles:a multicenter pilot study

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    Background: The diagnosis of pancreatic adenocarcinoma and chronic pancreatitis often rely on expensive and invasive diagnostic approaches, which are not always discriminative since patients with chronic pancreatitis and pancreatic adenocarcinoma may present with similar symptoms. Volatile organic compounds (VOCs) in expired breath, could be used as a non-invasive diagnostic biological marker for detection of pancreatic pathology. Detection and discrimination of pancreatic pathology with an electronic nose has not yet been reported. Purpose: The objective of this pilot study was to determine the diagnostic potential of an electronic nose to identify pancreatic adenocarcinoma and chronic pancreatitis by analyzing volatile organic compoundg (VOC) profiles in exhaled air. Patients and methods: In a multicenter study, the exhaled air of 56 chronic pancreatitis patients, 29 pancreatic adenocarcinoma patients, and 74 disease controls were analyzed using an electronic nose based on 3 metal oxide sensors (MOS). The measurements were evaluated utilizing an artificial neural network. Results: VOC profiles of chronic pancreatitis patients could be discriminated from disease controls with an accuracy of 0.87 (AUC 0.95, sensitivity 80%, specificity 92%). Also, VOC profiles of patients with pancreatic adenocarcinoma differed from disease controls with an accuracy of 0.83 (AUC 0.87, sensitivity 83%, specificity 82%). Discrimination between chronic pancreatitis and pancreatic adenocarcinoma showed an accuracy of 0.75 (AUC 0.83, sensitivity 83%, specificity 71%). Conclusion: An electronic nose may be a valuable diagnostic tool in diagnosis of pancreatic adenocarcinoma and chronic pancreatitis. The current study shows the potential of an electronic nose for discriminating between chronic pancreatitis, pancreatic adenocarcinoma and healthy controls. The results from this proof-of-concept study warrant external validation in larger cohorts

    X-ray Near Field Speckle: Implementation and Critical Analysis

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    We have implemented the newly-introduced, coherence-based technique of x-ray near-field speckle (XNFS) at 8-ID-I at the Advanced Photon Source. In the near field regime of high-brilliance synchrotron x-rays scattered from a sample of interest, it turns out, that, when the scattered radiation and the main beam both impinge upon an x-ray area detector, the measured intensity shows low-contrast speckles, resulting from interference between the incident and scattered beams. We built a micrometer-resolution XNFS detector with a high numerical aperture microscope objective and demonstrate its capability for studying static structures and dynamics at longer length scales than traditional far field x-ray scattering techniques. Specifically, we characterized the structure and dynamics of dilute silica and polystyrene colloidal samples. Our study reveals certain limitations of the XNFS technique, which we discuss.Comment: 53 pages, 16 figure
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