674 research outputs found

    Accelerated Test Method to Identify Freeze-Thaw Durability of Aggregates

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    INDOT currently identifies freeze-thaw durable aggregate using ITM210, a 90-day concrete beam freeze-thaw test. To accelerate this procedure, the 8-day Hydraulic Fracture Test (HFT) was investigated and modified. Samples from 18 quarries and six RCA sources were subjected to HFT and ITM210. Statistical analysis demonstrated that HFT can predict the ITM210 results with reasonable accuracy. The modified HFT procedures and equipment are recommended as a quick screening tool for predicting ITM210 test results

    STOCHASTIC WEALTH DYNAMICS AND RISK MANAGEMENT AMONG A POOR POPULATION

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    The literature on economic growth and development has focused considerable attention on questions of risk management and the possibility of multiple equilibria associated with poverty traps. We use herd history data collected among pastoralists in southern Ethiopia to study stochastic wealth dynamics among a very poor population. These data yield several novel findings. Although covariate rainfall shocks plainly matter, household-specific factors, including own herd size, account for most observed variability in wealth dynamics. Despite longstanding conventional wisdom about common property grazing lands, we find no statistical support for the tragedy of the commons hypothesis. It appears that past studies may have conflated costly self-insurance with stocking rate externalities. Such self-insurance is important in this setting because weak livestock markets and meager social insurance cause wealth to fluctuate largely in response to biophysical shocks. These shocks move households between multiple dynamic wealth equilibria toward which households converge following nonconvex path dynamics. The lowest equilibrium is consistent with the notion of a poverty trap. These findings have broad implications for the design of development and relief strategies among a poor population extraordinarily vulnerable to climatic shocks.common property, covariate risk, Ethiopia, idiosyncratic risk, poverty traps, social insurance, Risk and Uncertainty, O1, Q12,

    Hydraulic Fracture Test to Determine Aggregate Freeze-Thaw Durability

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    The freeze-thaw durability of carbonate aggregates can vary greatly from durable to highly susceptible to freeze-thaw distress. Using nondurable aggregate in concrete pavement exposed to freeze-thaw cycles may lead to serious distress and greatly decrease the pavement’s service life. The testing needed to identify freeze-thaw durable aggregates can take several months to complete. The main objective of this study was to develop a reliable, quick test method for determining the freeze-thaw resistance of carbonate quarried aggregates in Indiana using the Hydraulic Fracture Test (HFT) equipment. Aggregate samples collected from 18 quarried carbonate sources from across Indiana that represented a range of freeze-thaw performance were subjected to HFT using the existing MnDOT HFT equipment and the newly developed INDOT HFT equipment. Aggregates from the same sources also were used to produce concrete beams that were subjected to the INDOT modified AASHTO T161-B freeze-thaw test (ITM 210) which evaluates the dilation of concrete beams exposed to freeze-thaw cycles. The experimental data were analyzed statistically and linear regression models were developed to predict the average percent dilation and the durability factor of freeze-thaw test beams using parameters obtained from HFT results. Comparing the modeled and measured test results, the favored model predicts dilations based on the INDOT HFT results. These modeled dilations, when compared to measured dilations gave an adjusted R2 value of 0.85, indicating the model has a high degree of certainty. The modified INDOT HFT equipment, refined test procedures and data analysis developed during this study are recommended as screening tools for predicting AASHTO T161/ASTM C666 FT test results in 8-days. Further testing is recommended to refine and validate the models before they are fully implemented as an acceptance standard

    Metaverse Survey & Tutorial: Exploring Key Requirements, Technologies, Standards, Applications, Challenges, and Perspectives

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    In this paper, we present a comprehensive survey of the metaverse, envisioned as a transformative dimension of next-generation Internet technologies. This study not only outlines the structural components of our survey but also makes a substantial scientific contribution by elucidating the foundational concepts underlying the emergence of the metaverse. We analyze its architecture by defining key characteristics and requirements, thereby illuminating the nascent reality set to revolutionize digital interactions. Our analysis emphasizes the importance of collaborative efforts in developing metaverse standards, thereby fostering a unified understanding among industry stakeholders, organizations, and regulatory bodies. We extend our scrutiny to critical technologies integral to the metaverse, including interactive experiences, communication technologies, ubiquitous computing, digital twins, artificial intelligence, and cybersecurity measures. For each technological domain, we rigorously assess current contributions, principal techniques, and representative use cases, providing a nuanced perspective on their potential impacts. Furthermore, we delve into the metaverse's diverse applications across education, healthcare, business, social interactions, industrial sectors, defense, and mission-critical operations, highlighting its extensive utility. Each application is thoroughly analyzed, demonstrating its value and addressing associated challenges. The survey concludes with an overview of persistent challenges and future directions, offering insights into essential considerations and strategies necessary to harness the full potential of the metaverse. Through this detailed investigation, our goal is to articulate the scientific contributions of this survey paper, transcending a mere structural overview to highlight the transformative implications of the metaverse

    Keragaan dan Keragaman Genetik Karakter Agronomi Galur Mutan Putatif Gandum Generasi M5

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    The cultivation of wheat in Indonesia especially at medium-low altitude faces problems such as high temperatures whicheffect negativelyon the yield. The aims of this research was to obtain informations on performance, genetic variability and heritability of agronomic characters of wheat putative mutant lines on M5 generation. Genotypes evaluated in the study consisted of 98 putative mutant lines of M5 generation and six varieties as checks, namely Dewata, Selayar, Oasis, Rabe, Kasifbey, and Basribey. The research was conducted at Research Station of IOCRI (Indonesian Ornamental Crops Research Institute), Cipanas. Genotypes were arranged in an augmented, randomized block design. Result of the experiment showed that high heritability estimates were observed for plant height (83.03%), tiller number (61.75%), days to flowering (85.41%), days to maturity (67.45%), spike length (70.25%), spikelet number (65.08%), unfilled grain number (71.49%), seed number per spike (75.16%), seed weight per spike (81.69%), and seed weight per plant (74.21%). The estimated genotypic coefficient of variation (GCV) were high for unfilled grain number(26.35%) and seed weight per plant (18.35%). Based on seed weight per plant, 30 best putative mutant lines were selected

    Podoconiosis and soil-transmitted helminths (STHs): double burden of neglected tropical diseases in Wolaita zone, rural southern Ethiopia

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    Background Both podoconiosis and soil-transmitted helminth (STH) infections occur among barefoot people in areas of extreme poverty; however, their co-morbidity has not previously been investigated. We explored the overlap of STH infection and podoconiosis in Southern Ethiopia and quantified their separate and combined effects on prevalent anemia and hemoglobin levels in podoconiosis patients and health controls from the same area. Methods and Principal Findings A two-part comparative cross-sectional study was conducted in Wolaita zone, southern Ethiopia. Data were collected from adult patients presenting with clinically confirmed podoconiosis, and unmatched adult neighborhood controls living in the same administrative area. Information on demographic and selected lifestyle factors was collected using interviewer-administered questionnaires. Stool samples were collected and examined qualitatively using the modified formalin-ether sedimentation method. Hemoglobin level was determined using two different methods: hemoglobinometer and automated hematology analyzer. A total of 913 study subjects (677 podoconiosis patients and 236 controls) participated. The prevalence of any STH infection was 47.6% among patients and 33.1% among controls (p<0.001). The prevalence of both hookworm and Trichuris trichiura infections was significantly higher in podoconiosis patients than in controls (AOR 1.74, 95% CI 1.25 to2.42, AOR 6.53, 95% CI 2.34 to 18.22, respectively). Not wearing shoes and being a farmer remained significant independent predictors of infection with any STH. There was a significant interaction between STH infection and podoconiosis on reduction of hemoglobin level (interaction p value = 0.002). Conclusions Prevalence of any STH and hookworm infection was higher among podoconiosis patients than among controls. A significant reduction in hemoglobin level was observed among podoconiosis patients co-infected with hookworm and ‘non-hookworm STH’. Promotion of consistent shoe-wearing practices may have double advantages in controlling both podoconiosis and hookworm infection in the study area

    Community-based control of a neglected tropical disease: the mossy foot treatment and prevention association

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    Podoconiosis (endemic non-filarial elephantiasis, also known as mossy foot) is a non-communicable disease now found exclusively in the tropics, caused by the conjunction of environmental, genetic, and economic factors. Silicate particles formed by the disintegration of lava in areas of high altitude (over 1,000 m) and seasonal rainfall (over 1,000 mm per annum) penetrate the skin of barefoot subsistence farmers, and in susceptible individuals cause lymphatic blockage and subsequent elephantiasis [1]. Although an estimated one million Ethiopians (of a total population of 77 million) are afflicted with podoconiosis [2], which creates a huge economic burden in endemic areas [3], no national policy has yet been developed to control or prevent the condition, and most affected communities remain unaware of treatment options

    Podoconiosis in East and West Gojam Zones, Northern Ethiopia

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    Background: Podoconiosis is a neglected tropical disease (NTD) that is prevalent in red clay soil-covered highlands of tropical Africa, Central and South America, and northern India. It is estimated that up to one million cases exist in Ethiopia. This study aimed to estimate the prevalence of podoconiosis in East and West Gojam Zones of Amhara Region in northern Ethiopia. Methodology/Principal Findings: A cross-sectional household survey was conducted in Debre Eliyas and Dembecha woredas (districts) in East and West Gojam Zones, respectively. The survey covered all 17,553 households in 20 kebeles (administrative subunits) randomly selected from the two woredas. A detailed structured interview was conducted on 1,704 cases of podoconiosis identified in the survey. Results: The prevalence of podoconiosis in the population aged 15 years and above was found to be 3.3% (95% CI, 3.2% to 3.6%). 87% of cases were in the economically active age group (15–64 years). On average, patients sought treatment five years after the start of the leg swelling. Most subjects had second (42.7%) or third (36.1%) clinical stage disease, 97.9% had mossy lesions, and 53% had open wounds. On average, patients had five episodes of acute adenolymphangitis (ALA) per year and spent a total of 90 days per year with ALA. The median age of first use of shoes and socks were 22 and 23 years, respectively. More men than women owned more than one pair of shoes (61.1% vs. 50.5%; x2 = 11.6 p = 0.001). At the time of interview, 23.6% of the respondents were barefoot, of whom about two-thirds were women. Conclusions: This study showed high prevalence of podoconiosis and associated morbidities such as ALA, mossy lesions and open wounds in northern Ethiopia. Predominance of cases at early clinical stage of podoconiosis indicates the potential for reversing the swelling and calls for disease prevention interventions

    Village Baseline Study: Site Analysis Report for Yabello – Borana, Ethiopia

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    The village baseline of Denbela Saden village in the CCAFS benchmark site of Yabello in Ethiopia took place from 10th to 12th August 2011. Focus group discussions were conducted separately for men and women. Denbela Saden is a Borana pastoralist village located in a semi-arid area where the dominant vegetation is grass, scrub and acacia trees. It faces inadequate and low quality pasture due to encroachment by bushes, livestock overstocking, and human settlement, all related to a government policy of encouraging permanent settlement of the pastoralists as opposed to the former system of nomadism. The increasing population and the settlement of the community have amplified the need for crop cultivation to complement weakened pastoral production. Cultivation is dependent on often inadequate and unreliable rainfall, and takes place in the valley beds. Crop residues are not incorporated into the soil but used to feed animals. Not surprisingly, yields are very low. Government agricultural extension services do not add much value to cultivators because they focus on livestock services in this area. Two parallel governance systems co-exist in Denbela Saden village, namely the traditional customary system and the modern government system, and the challenge is to create a win–win situation where the operations of these systems are synchronized. The government describes the area as chronically food insecure, and it is not surprising that more than half of the 16 groups/organisations working in the region address food security issues
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