10 research outputs found

    Method of continuous non-destructive observation of profiles made of polymer fibre composite materials for the registration of crack formation

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    The relevance of the study is conditioned by the absence of the necessary devices and structures made of composite materials such as stingers with holes for registering cracks. The purpose of the study is to develop the design and manufacturing technology of stringer-type profiles made of composite materials with micro-holes in the cross-section or inside which hollow polymer fibres are laid, while the holes did not significantly affect the strength of the product and the specified strength properties of the product are preserved. The task of manufacturing products from a polymer composite material is solved by a method that includes pre-laying hollow longitudinal fibres or introducing bundles coated with anti-adhesive lubricant at specified cross-section points of stringers with subsequent pressing when laying pre-cut layers of composite material in a mould (polymerisation of the binder). After cooling, decompressing, removing the bundles with anti-adhesive grease (the second option) and stripping the product, special sensors are installed, a vacuum is created inside the holes or pressure is applied within 0.1-0.2 atm. At the same time, the holes do not significantly affect the strength of the product and the specified properties of the product are preserved. The study suggests a method for continuous and autonomous monitoring of the integrity of profiles made of polymer fibre composite materials for registering the formation of cracks based on the introduction of longitudinal micro-holes or hollow fibres under pressure or vacuum into their structure, followed by recording changes in the pressure value. The advantage of the proposed method is that it allows making a product from composite materials with increased physical and mechanical properties, increasing operational safety, increasing service life, and reducing the cost of routine inspections due to continuous monitoring of the occurrence and development of damage in real time. At the same time, the reliability of the design significantly increases, which leads to an improvement in the quality of the produc

    Digital method for analysing speckle-interferometric images of material deformation

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    Residual stresses arising from the technological processes of manufacturing aircraft structures can considerably affect the bearing capacity of the structure, which justifies the need to assess the level of these stresses. The study analysed the speckle interferometric images in terms of the parameter image intensity. This method allows assessing the picture of the change in this parameter both in a particular band, and performing a comparative analysis in a number of bands. Due to the presence of a correlation between the material deformation and the intensity of the image, the dynamics of the variation of the stress state (residual stresses) is estimated. When decoding the holograms, the authors used the Aleksandrov-Bonch-Bruevich vector equation. Double exposure of speckle holograms was applied and photo processing of the hologram was performed. It is shown that, depending on the position of the beam from the hole, there is a change in the image intensity. It was proved that the method employed in the study does not depend on external factors. The proposed approach allows taking a fresh look at the picture of stress state analysis and evaluating the qualitative and quantitative processes in the deformation zone, namely around the drilled hole in the plate

    Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats

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    In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security

    Detection of novel coronaviruses in bats in Myanmar

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    The recent emergence of bat-borne zoonotic viruses warrants vigilant surveillance in their natural hosts. Of particular concern is the family of coronaviruses, which includes the causative agents of severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and most recently, Coronavirus Disease 2019 (COVID-19), an epidemic of acute respiratory illness originating from Wuhan, China in December 2019. Viral detection, discovery, and surveillance activities were undertaken in Myanmar to identify viruses in animals at high risk contact interfaces with people. Free-ranging bats were captured, and rectal and oral swabs and guano samples collected for coronaviral screening using broadly reactive consensus conventional polymerase chain reaction. Sequences from positives were compared to known coronaviruses. Three novel alphacoronaviruses, three novel betacoronaviruses, and one known alphacoronavirus previously identified in other southeast Asian countries were detected for the first time in bats in Myanmar. Ongoing land use change remains a prominent driver of zoonotic disease emergence in Myanmar, bringing humans into ever closer contact with wildlife, and justifying continued surveillance and vigilance at broad scales
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