98 research outputs found

    Topological analysis of the power grid and mitigation strategies against cascading failures

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    This paper presents a complex systems overview of a power grid network. In recent years, concerns about the robustness of the power grid have grown because of several cascading outages in different parts of the world. In this paper, cascading effect has been simulated on three different networks, the IEEE 300 bus test system, the IEEE 118 bus test system, and the WSCC 179 bus equivalent model, using the DC Power Flow Model. Power Degradation has been discussed as a measure to estimate the damage to the network, in terms of load loss and node loss. A network generator has been developed to generate graphs with characteristics similar to the IEEE standard networks and the generated graphs are then compared with the standard networks to show the effect of topology in determining the robustness of a power grid. Three mitigation strategies, Homogeneous Load Reduction, Targeted Range-Based Load Reduction, and Use of Distributed Renewable Sources in combination with Islanding, have been suggested. The Homogeneous Load Reduction is the simplest to implement but the Targeted Range-Based Load Reduction is the most effective strategy.Comment: 5 pages, 8 figures, 1 table. This is a limited version of the work due to space limitations of the conference paper. A detailed version is submitted to the IEEE Systems Journal and is currently under revie

    Strong decays of Tcc+T_{cc}^+ at NLO in an effective field theory

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    The Tcc+T_{cc}^+ exotic meson, discovered by the LHCb Collaboration in 2021, can be interpreted as a molecular state of D(∗)0D^{(*)0} and D(∗)+D^{(*)+} mesons. We compute next-to-leading-order (NLO) contributions to the strong decay of Tcc+T_{cc}^+ in an effective field theory for DD mesons and pions, considering contributions from one-pion exchange and final-state rescattering. Corrections to the total width, as well as the differential distribution in the invariant mass of the final-state DD meson pair are computed. The results remain in good agreement with LHCb experimental results when the NLO contributions are added. The leading uncertainties in the calculation come from terms which depend on the scattering length and effective range in DD meson scattering.Comment: 26 pages, 7 figure

    Polarized TMD fragmentation functions for J/ψJ/\psi production

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    We calculate the matching, at leading order, of the transverse momentum dependent fragmentation functions (TMDFFs) for light quarks and gluons fragmenting to a J/ψJ/\psi onto polarized non-relativistic QCD (NRQCD) TMDFFs. The NRQCD TMDFFs have an operator-product-expansion in terms of non-perturbative NRQCD production matrix elements. Using the results we obtain, we make predictions for the light quark fragmentation contribution to the production of polarized J/ψJ/\psi in semi-inclusive deep inelastic scattering (SIDIS) both for unpolarized and longitudinally polarized beams. These results are an important contribution to polarized J/ψJ/\psi production in SIDIS, and thus are needed for comparison with experiments at the future Electron-Ion Collider.Comment: 27 pages, 7 figure

    Polarized J/ψJ/\psi production in semi-inclusive DIS at large Q2Q^2: Comparing quark fragmentation and photon-gluon fusion

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    We compare the relative importance of different mechanisms for polarized J/ψJ/\psi production in semi-inclusive deep inelastic scattering processes at large Q2Q^2. The transverse momentum dependent (TMD) factorization framework and non-relativistic quantum chromodynamics are used to study the leading contributions from light quark fragmentation to polarized J/ψJ/\psi, and compared to direct production via photon-gluon fusion, which can proceed through color-singlet as well as color-octet mechanisms. We identify kinematic regimes where light quark fragmentation dominates, allowing for the extraction of the 3S1[8]^3S_1^{[8]} matrix element, as well as regimes where photon gluon fusion dominates, suggesting that the gluon TMD parton distribution function can be probed.Comment: 22 pages, 7 figure

    Vermont Healthy Kids\u27 Meals: Parents\u27 Perspectives

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    Introduction. Childhood obesity has increased for decades. Options on kids’ menus in restaurants typically involve unhealthy choices such as fries, chicken fingers, and grilled cheese, with soda as the drink. When healthy options are the default choice, children are more likely to eat them. Though initially skeptical of modifications, restaurants will enact changes to maintain customer satisfaction and profits, and there is no significant difference in price of healthier kids’ meals.Methods. 187 paper and electronic surveys were administered throughout Vermont to explore attitudes towards availability, cost, and importance of healthy kids’ meals, as well as income, education, and children in the household. Open-ended questions sought parental opinions.Results. 69% of parents believe healthier food options at restaurants would cost more; however, 95% were willing to pay more. 89% of parents reported feeling concerned or highly concerned about sugary drinks, and 62% of parents were very likely to choose the healthier food option at a restaurant. The majority of parents who reported difficulty in finding healthy meals felt the amount of fruits/vegetables was the most important nutritional factor. Low income Vermonters were most concerned about cost.Conclusions. The majority of parents are concerned about kids’ meal nutrition and are likely to purchase healthier options, even at increased prices. If restaurants enact changes to kids’ menus, prices should remain the same to ensure families of all socioeconomic classes will be able to purchase healthier meals. Priority modifications to meals should include increased amounts of fruits/vegetables and elimination of added sugar.https://scholarworks.uvm.edu/comphp_gallery/1236/thumbnail.jp

    Learning to Swim: What Influences Success?

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    Swimming and water safety skills are important life skills, particularly in Australia, where aquatic activities are regularly enjoyed. Little research has been undertaken exploring children’s swimming and water safety skills, what level they can achieve, and what factors impact their ability to learn these skills. This study explores children aged 5-12 years who participated in the Australian Capital Territory Primary Schools Swim and Survive Program, 2009-2011. Children who were more likely to achieve higher levels were older, were female, attended private school, swam at least once a fortnight, had a swimming pool at home, or visited a public swimming pool. Those who were less likely were Aboriginal or Torres Strait Islander, had a negative experience, and swam less than once a fortnight

    AN OBJECT-ORIENTED SYSTEMS ENGINEERING MODEL DESIGN FOR INTEGRATING SPENT FUEL TREATMENT FACILITY AND CHEMICAL SEPARATION PROCESSES

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    ABSTRACT The mission of the Transmutation Research Program (TRP) at University of Nevada, Las Vegas (UNLV) is to establish a nuclear engineering test bed that can carry out effective transmutation and advanced reactor research and development effort. TRPSEMPro package, developed from previous project period, integrated a chemical separation code from the Argonne National Laboratories (ANL). Current research focus has two folds: development of simulation system processes applied to Spent Fuel Treatment Facility (SFTF) using ASPEN-plus and further interaction of ASPEN+ program from TRPSEMPro interface. More details will be discussed below. ANL has identified three processes simulations using their separation technologies. The first process is to separate aqueous acid streams of acetic acid, nitric acid, water and a variety of fission product nitric salts. Distillation separation method is used to remove the desired components from the streams. The second simulation is to convert plutonium nitrate to plutonium metal. Steps used for the process simulation are precipitation, calcinations, fluorination and reduction. The third process currently under development is vitrification of fission product of raffinate streams. During the process, various waste streams from the plant are mixed and fed to a process that converts them to a solid state glass phase. The vitrification process used by the Hanford and Savannah River facilities was selected as a guideline to develop the prototype simulation process using ASPEN-Plus. Current research is focusing on identifying unit operations required to perform the vitrification of the waste streams. The first two processes are near completion stage. Microsoft Visual Basic (MS VB) has been used to develop the entire system engineering model package, TRPSEMPro. Currently a user friendly interface is under development to facilitate direct execution of ASPEN-plus within TRPSEMPro. The major purpose for the implementation is to create iterative interaction among system engineering modeling, ANL separation model and ASPEN-Plus process that outputs optimized separation/process simulation results. The ASPENplus access interface from TRPSEMPro allows users to modify and execute process parameters derived from the ASPEN Plus simulations without navigating through ASPEN-Plus. All ASPEN-plus simulation results can be also accessible by the interface. Such integration provide a single interaction gateway for researchers interested in SFTF process simulation without struggling with complicate data manipulation and joggling among various software packages

    Ampullary cancers harbor ELF3 tumor suppressor gene mutations and exhibit frequent WNT dysregulation

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    The ampulla of Vater is a complex cellular environment from which adenocarcinomas arise to form a group of histopathologically heterogenous tumors. To evaluate the molecular features of these tumors, 98 ampullary adenocarcinomas were evaluated and compared to 44 distal bile duct and 18 duodenal adenocarcinomas. Genomic analyses revealed mutations in the WNT signaling pathway among half of the patients and in all three adenocarcinomas irrespective of their origin and histological morphology. These tumors were characterized by a high frequency of inactivating mutations of ELF3, a high rate of microsatellite instability, and common focal deletions and amplifications, suggesting common attributes in the molecular pathogenesis are at play in these tumors. The high frequency of WNT pathway activating mutation, coupled with small-molecule inhibitors of β-catenin in clinical trials, suggests future treatment decisions for these patients may be guided by genomic analysis

    Discovery of Novel Antimalarial Compounds Enabled by QSAR-Based Virtual Screening

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    Quantitative structure–activity relationship (QSAR) models have been developed for a dataset of 3133 compounds defined as either active or inactive against P. falciparum. Since the dataset was strongly biased towards inactive compounds, different sampling approaches were employed to balance the ratio of actives vs. inactives, and models were rigorously validated using both internal and external validation approaches. The balanced accuracy for assessing the antimalarial activities of 70 external compounds was between 87% and 100% depending on the approach used to balance the dataset. Virtual screening of the ChemBridge database using QSAR models identified 176 putative antimalarial compounds that were submitted for experimental validation, along with 42 putative inactives as negative controls. Twenty five (14.2%) computational hits were found to have antimalarial activities with minimal cytotoxicity to mammalian cells, while all 42 putative inactives were confirmed experimentally. Structural inspection of confirmed active hits revealed novel chemical scaffolds, which could be employed as starting points to discover novel antimalarial agents
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