454 research outputs found

    Thermo-Electro-Mechanical Modeling of Power Transmission Line Failures across Four US States

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    The failure of overhead transmission lines in the United States can lead to significant economic losses and widespread blackouts, affecting the lives of millions. This study focuses on the reliability of transmission lines, specifically examining the effects of wind, ambient temperature, and current demands on lines, incorporating minimal and significant pre-existing damage. We develop a Thermo-Electro-Mechanical Model to analyze the transmission line failures across sensitive and affected states of the United States, integrating historical data on wind and ambient temperature. By combining numerical simulation with historical data analysis, our research assesses the impact of varying environmental conditions on the reliability of transmission lines. Our methodology begins with a deterministic approach to model temperature and damage evolution, using phase-field modeling for fatigue and damage, coupled with electrical and thermal models. Later, we adopt the Probability Collocation Method to investigate the stochastic behavior of the system, enhancing our understanding of uncertainties in model parameters, conducting sensitivity analysis, and estimating the probability of failures over time. This approach allows for a comprehensive analysis of factors affecting transmission line reliability, contributing valuable insights into improving power line's resilience against environmental conditions

    Comparative study on technical efficiency of mechanized and traditional rice farm in Nepal

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    The study was conducted among 274 mechanized and 220 traditional rice farms using multistage sampling technique to assess the technical efficiency in rice production among mechanized and traditional farmers in Jhapa, Sunsari and Bardiya districts.  The Cobb-Douglas functional form of the stochastic production frontier was employed to obtain the technical efficiency in mechanized and traditional rice farms. The overall technical efficiency of the mechanized and traditional rice farm ranged from 40.31 to 92.23 and 31.21 to 85.02%t with the mean technical efficiency of 80.56 and 70.11% respectively. The scope of increasing output by adopting the technology adopted by the best performer was 19.44% in mechanized and 29.89% in traditional rice farm respectively. Majority of the farmers were operating at an efficiency level 70-80% and 60-70% in mechanized and traditional farms respectively. The average technical efficiency of mechanized rice farm was higher than that of traditional rice farm and the difference was significant. There was scope of increasing output through rational use of existing resources in both farm categories. Manures, chemical fertilizers had significant and positive effect to total yield of rice kg/ha. The effect of machine use to total yield of rice was positive and significant. Rice farms adopting machines were more technically efficient compared to traditional rice farm

    A Thermo-Electro-Mechanical Model for Long-Term Reliability of Aging Transmission Lines

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    Integrity and reliability of a national power grid system are essential to society's development and security. Among the power grid components, transmission lines are critical due to exposure and vulnerability to severe external conditions, including high winds, ice, and extreme temperatures. The combined effects of external agents with high electrical load and presence of damage precursors greatly affects the conducting material's properties due to a thermal runaway cycle that accelerates the aging process. In this paper, we develop a thermo-electro-mechanical model for long-term failure analysis of overhead transmission lines. A phase-field model of damage and fatigue, coupled with electrical and thermal modules, provides a detailed description of the conductor's temperature evolution. We define a limit state function based on maximum operating temperature to avoid excessive overheating and sagging. We study four representative scenarios deterministically, and propose the Probabilistic Collocation Method (PCM) as a tool to understand the stochastic behavior of the system. We use PCM in forward parametric uncertainty quantification, global sensitivity analysis, and computation of failure probability curves in a straightforward and computationally efficient fashion, and we quantify the most influential parameters that affect the failure predictability from a physics-based perspective

    Multi-Scenario and Stochastic Thermo-Electro-Mechanical Modeling of Failure in Power Transmission Lines

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    Transmission lines, crucial to the power grid, are subjected to diverse environmental conditions such as wind, temperature, humidity, and pollution. While these conditions represent a consistent impact on the transmission lines, certain unpredictable conditions such as unexpected high wind, wildfire, and icing pose catastrophic risks to the reliability and integrity of the transmission lines. These factors in the presence of initial damage and electrical loads greatly affect the material properties. In this paper, we develop a comprehensive thermo-electro-mechanical model to investigate the long-term effect of unexpected high wind, wildfire, and ice on transmission lines. This study offers an in-depth perspective on temperature and damage evolution within the power lines by incorporating a phase field model for damage and fatigue, alongside thermal and electrical models. We define a state function to assess the failure, considering damage and temperature. We study three scenarios deterministically to establish a basic understanding and analyze the stochastic behavior using the Probabilistic Collocation Method (PCM). We utilize PCM for forward uncertainty quantification, conducting sensitivity analysis, and evaluating the probability of failure. This approach offers an in-depth examination of the potential risks associated with transmission lines under unfavorable circumstances.arXiv admin note: text overlap with arXiv:2406.1960

    Selective blockade of interferon-α and -β reveals their non-redundant functions in a mouse model of West Nile virus infection

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    Although type I interferons (IFNs) were first described almost 60 years ago, the ability to monitor and modulate the functional activities of the individual IFN subtypes that comprise this family has been hindered by a lack of reagents. The major type I IFNs, IFN-β and the multiple subtypes of IFN-α, are expressed widely and induce their effects on cells by interacting with a shared heterodimeric receptor (IFNAR). In the mouse, the physiologic actions of IFN-α and IFN-β have been defined using polyclonal anti-type I IFN sera, by targeting IFNAR using monoclonal antibodies or knockout mice, or using Ifnb-/- mice. However, the corresponding analysis of IFN-α has been difficult because of its polygenic nature. Herein, we describe two monoclonal antibodies (mAbs) that differentially neutralize murine IFN-β or multiple subtypes of murine IFN-α. Using these mAbs, we distinguish specific contributions of IFN-β versus IFN-α in restricting viral pathogenesis and identify IFN-α as the key mediator of the antiviral response in mice infected with West Nile virus. This study thus suggests the utility of these new reagents in dissecting the antiviral and immunomodulatory roles of IFN-β versus IFN-α in murine models of infection, immunity, and autoimmunity

    Intellectual Property Right on Basmati Rice: Current Scenario and Evidences of Origin, Diversity, Cultivation and Use Values of Basmati Rice in Nepal

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    Basmati rice, also called the king/prince of rice landraces has very special values in Nepalese society as well as in other countries of Indian Subcontinent. With the objectives of collecting, analyzing and documenting Basmati related information in Nepal, we visited different sites; carried out key informant surveys; organized focus group discussions, online interaction and discussion meetings; requested all relevant offices/ persons/ stakeholders through phone, website, and letter to share information; organized high level official meeting, and Basmati rice expert meeting; documented video documentary and did online as well as library search. Because of its high market value at global level, many countries and organizations have been attempting to get intellectual property rights (mainly patent and geographical indication tag) on Basmati rice. India applied for GI tag to Basmati rice in the European Union (EU) in July 2018, and Nepal submitted opposition letter along with proofs and evidences of origin, diversity, cultivation and use values of Basmati rice on 9 December 2020. A total 133 Basmati type rice landraces are grown in 60 districts of Nepal. Basmati rice is traditionally grown, sold, and consumed in geographically localized areas of Nepal since ancient time. International and national scientists have defined lower altitude of Nepal as one of the centers of origin of Basmati rice. Many Nepalese basmati rice landraces have been characterized and evaluated using morphological traits, isozymes and DNA markers. Four basmati type of rice landraces have been registered in National Seed Board. Many community seed banks have maintained different types of Basmati rice landraces. National Agriculture Genetic Resources Center and International genebanks have collected more than 80 and conserved 68 basmati landraces. Basmati rice landraces have geo-linked traits. The historical culture of production, consumption and marketing of native basmati rice in Nepal should always be favored by both national and international rules and regulations. Nepal has ample and valid evidences to get geographical indication (GI) right on Basmati rice

    Social relationships as predictors of extended employment beyond the pensionable age: a cohort study

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    The aim is to examine whether characteristics of social relationships predict extended employment beyond the pensionable age among Finnish public sector workers. The study population consisted of 4014 participants (83% women, age 62.56 ± 1.21) of the Finnish Retirement and Aging Study followed between 2014 and 2019. Extended employment was defined as the difference between actual retirement date and individual age-related pensionable date and classified into three groups: no extension (retired on pensionable age or extended by < 3 months), short extension (3 months–< 1 year), and long extension (≥ 1 year) beyond the pensionable date. Characteristics of social relationships and engagement were assessed 18 months prior to the pensionable date. Social engagement was classified into consumptive social participation, formal social participation, informal social participation, and other social participation. Data were analyzed using multinomial regression analysis. Of total study participants, 17.8% belonged to short- and 16.5% belonged to long-extension group. Adjusted for age, occupational status, self-rated health and depression, and having a working spouse (OR 2.34, 95% CI 1.39–3.95) were associated with long extension of employment beyond the pensionable age when compared to no extension among men. Likewise, among women, living alone (OR 1.60, 95% CI 1.28–2.00), having a working spouse (1.85, 1.39–2.45), and high consumptive (1.32, 1.07–1.65), high formal (1.47, 1.17–1.85), and other social participation (0.79, 0.63–0.98) were associated with long extension. Having a working spouse, living alone, and high consumptive social participation were associated with short extension. Several characteristics of social relationships, such as having a working spouse, living alone, and high frequency of social engagement, predicted an extension of employment beyond the pensionable age

    Like Mother(-in-Law) Like Daughter? Influence of the Older Generation’s Fertility Behaviours on Women’s Desired Family Size in Bihar, India

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    This paper investigates the associations between preferred family size of women in rural Bihar, India and the fertility behaviours of their mother and mother-in-law. Scheduled interviews of 440 pairs of married women aged 16–34 years and their mothers-in-law were conducted in 2011. Preferred family size is first measured by Coombs scale, allowing us to capture latent desired number of children and then categorized into three categories (low, medium and high). Women’s preferred family size is estimated using ordered logistic regression. We find that the family size preferences are not associated with mother’s fertility but with mother’s education. Mother-in-law’s desired number of grandchildren is positively associated with women’s preferred family size. However, when the woman has higher education than her mother-in-law, her preferred family size gets smaller, suggesting that education provides women with greater autonomy in their decision-making on childbearing

    Therapeutic opportunities within the DNA damage response

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    The DNA damage response (DDR) is essential for maintaining the genomic integrity of the cell, and its disruption is one of the hallmarks of cancer. Classically, defects in the DDR have been exploited therapeutically in the treatment of cancer with radiation therapies or genotoxic chemotherapies. More recently, protein components of the DDR systems have been identified as promising avenues for targeted cancer therapeutics. Here, we present an in-depth analysis of the function, role in cancer and therapeutic potential of 450 expert-curated human DDR genes. We discuss the DDR drugs that have been approved by the US Food and Drug Administration (FDA) or that are under clinical investigation. We examine large-scale genomic and expression data for 15 cancers to identify deregulated components of the DDR, and we apply systematic computational analysis to identify DDR proteins that are amenable to modulation by small molecules, highlighting potential novel therapeutic targets
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