76 research outputs found

    Applied Ergonomics

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    The ergonomic injuries and solutions have been extensively studied in the construction industry; however, the prevalence of work-related injuries, risky activities, and effective solutions in the transportation industry are not understood. This study aims to explore the prevalence of work-related injuries, risky activities, and potentially ergonomic solutions among transportation workers. The approach to this study included exploration of worker type, injury types, and activities of top concern through historical injury data and an online survey, and proposal and evaluation of ergonomic solutions through onsite observations and field experiments. Results from this study found that back injuries were the most common type of injury sustained. Performing lifting and pushing/pulling activities have caused the most injuries. Back exoskeletons and ergonomic handles were identified as potential solutions to help reduce the risk of injury. Additionally, higher platforms were also suggested to help prevent workers from being forced to perform activities by exerting their back excessively

    Life Cycle Integration of Building Information Modeling in Infrastructure Projects

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    Building Information Modeling (BIM) can provide solutions to many challenges of asset management, such as missing data, incompatible software, and an unclear business process. However, current implementation of BIM in infrastructure projects has only considers limited factors, such as technology application and digital information delivery, while issues of system compatibility and information needs are still missing. Different aspects of a business are interdependent and an incompatible development of various factors might result in different levels of BIM implementation or even project failure. Comprehensive research is needed to explore the key factors and challenges of BIM implementation in infrastructure projects. This study conducted interviews and surveys with key stakeholders of infrastructure projects to explore the challenges and potential solutions of BIM implementation. Interviews were conducted with 37 professionals and surveys were conducted with 102 professional stakeholders, including owners, designers, contractors, and software vendors. Four main factors, challenges, and potential solutions were identified from content analysis of the interviews and further validated by the surveys. These factors include process factor (when), technology factor (how), people factor (who), and information factor (what). Corresponding solutions are proposed to refine the current workflow and practices

    Life Cycle Integration of Building Information Modeling in Infrastructure Projects

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    Building Information Modeling (BIM) can provide solutions to many challenges of asset management, such as missing data, incompatible software, and an unclear business process. However, current implementation of BIM in infrastructure projects has only considers limited factors, such as technology application and digital information delivery, while issues of system compatibility and information needs are still missing. Different aspects of a business are interdependent and an incompatible development of various factors might result in different levels of BIM implementation or even project failure. Comprehensive research is needed to explore the key factors and challenges of BIM implementation in infrastructure projects. This study conducted interviews and surveys with key stakeholders of infrastructure projects to explore the challenges and potential solutions of BIM implementation. Interviews were conducted with 37 professionals and surveys were conducted with 102 professional stakeholders, including owners, designers, contractors, and software vendors. Four main factors, challenges, and potential solutions were identified from content analysis of the interviews and further validated by the surveys. These factors include process factor (when), technology factor (how), people factor (who), and information factor (what). Corresponding solutions are proposed to refine the current workflow and practices

    Study of dynamic vibration characteristics and suppression of CNC machine tool during operation

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    The rapid development of aerospace, automobile, national defense and other manufacturing industries has continuously improved the performance requirements of high speed and high positioning accuracy of the CNC machine tool feed system. As the thermal deformation error increases, the system structural rigidity decreases, the vibration increases, and accuracy of machine tool reduces. Existing research mainly focuses on the properties of mechanical and single thermal feed system, and less considers the dynamic performance under the action of thermal-mechanical coupling. For the improvement of feed system performance, it is very beneficiary. This paper takes the high-speed tool of CNC feed system as objective, combined with the actual working conditions to analyze the thermal characteristics, dynamic characteristics and vibration characteristics of the system under the effect of thermal-mechanical coupling. The thermal resistance and convective heat transfer of the key joint surface, the application of moving thermal loads, and the establishment of a simulation model to complete the steady-state temperature field, transient temperature field and thermal-structure coupling analysis. The results show that the maximum temperature rise of the feed system is 21.08 °C, The maximum thermal deformation is 17.264 um. The study found that the parameters such as flow rate and airflow temperature have a significant impact on the cooling effect, so the cooling device was further optimized. This paper proposes a control method for cutting chatter of CNC machine tools based on coupling of characteristics of thermal and mechanical. The thermal characteristic of the feed system and the thermal-mechanical coupling vibration characteristic test provides the maximum temperature error of 3.2 %, verifying the correctness of the theoretical method and analysis model. The highest temperature obtained by the test is 39.7 °C, indicating that the high-speed feed system has a large thermal effect. The relative error of the vibration amplitude of the test and simulation is 12.5 %, which verifies coupling in terms of thermal-mechanical. The accuracy of the vibration analysis method; the experiment depicts that the vibration amplitude increases by 19.7 % under the coupling effect of thermal and mechanical, indicating the effectiveness of dynamic characteristics of the high-speed feed system considering the thermal-mechanical coupling effect

    Association between alcohol consumption and latent fasting blood glucose trajectories among midlife women

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    BackgroundThis investigation sought to elucidate the correlations between alcohol intake and trajectories of fasting blood glucose (FBG) among American women in midlife.MethodsOur analysis was rooted in the foundational data from the Study of Women’s Health Across the Nation (SWAN), a comprehensive longitudinal study centered on US women during their midlife transition. We employed group-based trajectory modeling to chart the FBG trajectories spanning from 1996 to 2005. Employing logistic regression, we gauged the odds ratios (ORs) and 95% confidence intervals (CIs) to draw connections between initial alcohol consumption and FBG trajectory patterns, whilst controlling for predominant potential confounders.ResultsOur cohort comprised 2,578 women in midlife, ranging in age from 42 to 52, each having a minimum of three subsequent FPG assessments. We discerned two distinct FBG trajectories: a low-stable pattern (n = 2,467) and a high-decreasing pattern (n = 111). Contrasted with the low-stable group, our data showcased an inverse relationship between alcohol intake and the high-decreasing FBG trajectory in the fully adjusted model 3. The most pronounced reduction was evident in the highest tertile of daily servings of alcoholic beverages (OR: 0.23, 95% CI: 0.10–0.52, p < 0.001), percentage of kilocalories sourced from alcoholic beverages (OR: 0.30, 95% CI: 0.16–0.58, p < 0.001), and daily caloric intake from alcoholic beverages (OR: 0.31, 95% CI: 0.16–0.62, p < 0.001).ConclusionModerate alcohol consumption may protect against high FPG trajectories in middle-aged women in a dose–response manner. Further researches are needed to investigate this causality in midlife women

    Recent progress on harm, pathogen classification, control and pathogenic molecular mechanism of anthracnose of oil-tea

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    Oil tea (Camellia oleifera), mainly used to produce high-quality edible oil, is an important cash crop in China. Anthracnose of oil tea is a considerable factor that limits the yield of tea oil. In order to effectively control the anthracnose of oil tea, researchers have worked hard for many years, and great progress has been made in the research of oil tea anthracnose. For instance, researchers isolated a variety of Colletotrichum spp. from oil tea and found that Colletotrichum fructicola was the most popular pathogen in oil tea. At the same time, a variety of control methods have been explored, such as cultivating resistant varieties, pesticides, and biological control, etc. Furthermore, the research on the molecular pathogenesis of Colletotrichum spp. has also made good progress, such as the elaboration of the transcription factors and effector functions of Colletotrichum spp. The authors summarized the research status of the harm, pathogen types, control, and pathogenic molecular mechanism of oil tea anthracnose in order to provide theoretical support and new technical means for the green prevention and control of oil tea anthracnose

    Research progress and management strategies of fungal diseases in Camellia oleifera

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    Camellia oleifera Abel, a woody oil plant, that is endemic to China. Tea oil, also referred to as “oriental olive oil,” is a superior quality plant-based cooking oil. The production of tea oil accounts for 8% of the total edible vegetable oil production in the country. Since 2022, the annual output value of C. oleifera industry has exceeded 100 billion yuan, making it one of the major economic contributors to China’s rural revitalization development strategy. In recent years, demand and production have grown in parallel. However, this has led to an increase in the incidence levels of pest and diseases. Pests and diseases significantly reduce the quality and yield of C. oleifera. C. oleifera diseases are mainly caused by pathogenic fungi. C. oleifera anthracnose, soft rot, leaf spot, coal stain, leaf gall disease, and root rot are the most important fungal diseases affecting the C. oleifera industry. However, the same disease may be caused by different pathogenic fungi. C. oleifera can be found in half of China and is found in several climatic zones. The geographical distribution of woody plant diseases is consistent with the distribution of the tree species and the ecology of the range, which also results in a highly complex distribution of fungal diseases of C. oleifera. The management of fungal diseases in C. oleifera is extremely challenging due to the variety of pathogenic fungal species, multiple routes of transmission, the lack of resistant plants, and the environmental safety of chemical measures. The optimal strategy for addressing fungal diseases in C. oleifera is to develop and apply an integrated disease management plan. This review provides a brief overview of the pathogenic species, pathogenesis, pathogenesis, geographical distribution, current management strategies, and potentially new methods of C. oleifera fungal diseases, to provide direction for the development of comprehensive management measures for C. oleifera fungal diseases in the future

    Bose condensation of upper-branch exciton-polaritons in a transferrable microcavity

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    Exciton-polaritons are composite bosonic quasiparticles arising from the strong coupling of excitonic transitions and optical modes. Exciton-polaritons have triggered wide exploration in the past decades not only due to their rich quantum phenomena such as superfluidity, superconductivity and quantized vortices but also due to their potential applications for unconventional coherent light sources and all-optical control elements. Here, we report the observation of Bose-Einstein condensation of the upper polariton branch in a transferrable WS2_2 monolayer microcavity. Near the condensation threshold, we observe a nonlinear increase in upper polariton intensity. This sharp increase in intensity is accompanied by a decrease of the linewidth and an increase of the upper polariton temporal coherence, all of which are hallmarks of Bose-Einstein condensation. By simulating the quantum Boltzmann equation, we show that the upper polariton condensation only occurs for a particular range of particle density. We can attribute the creation of Bose condensation of the upper polariton to the following requirements: 1) the upper polariton is more excitonic than the lower one; 2) there is relatively more pumping in the upper branch; and 3) the conversion time from the upper to the lower polariton branch is long compared to the lifetime of the upper polaritons
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