54 research outputs found

    Effect of Punch Diameters on Shear Extrusion of 6063 Aluminium Alloy

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    This paper reports the effect of punch diameters on the shear extrusion of 6063 Aluminium alloy. During the shear extrusion process, Aluminium billets of considerable diameter 30 mm and height 25 mm were inserted in a die hole and different punches of diameter 12 mm, 14 mm, 16 mm and 18 mm respectively were allowed to come in contact to perform the shear operation. The setup took place under a hydraulic press with maximum capacity of 600 kN. This work is aimed at studying the selection of the optimum punch diameter for shear extrusion using local groundnut oil as the lubricant. Different extrusion pressures were measured and the punch with a diameter of 18 mm gives the highest load of 77.7 kN while the punch with a diameter of 12 mm gives the lowest load of 51.2 kN. An indication shows that, an increase in the punch diameters led to an increase in the height of the extrudates and this in turn reduces the stress induce

    Characterization of surface roughness of laser deposited Titanium alloy and copper using AFM

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    Abstract: Laser Metal Deposition (LMD) is the process of using the laser beam of a nozzle to produce a melt pool on a metal surface usually the substrate and metal powder is been deposited into it thereby creating a fusion bond with the substrate to form a new material layer against the force gravity. A good metal laminate is formed when the wettability between the dropping metal powder and the substrate adheres. This paper reports the surface roughness of laser deposited titanium alloy and copper (Ti6Al4V + Cu) using the Atomic Force Microscopy (AFM). This AFM is employed in order to sense the surface and produce different manipulated images using the micro-fabricated mechanical tip under a probe cartridge of high resolution. The process parameters employed during the deposition routine determines the output of the deposit. A careful attention is given to the laser deposited Ti6Al4V + Cu samples under the AFM probe because of their single tracked layers with semi-circular pattern of deposition

    Experiences pertaining to child nutrition and care provision among early care and education stakeholders, sponsors, and center directors during the COVID-19 pandemic: A multi-method study

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    Purpose: This study used multiple methods (interviews, survey) to assess experiences of stakeholders, sponsors, and center-based early care and education (ECE) program directors pertaining to child nutrition (e.g., provision of nutritious foods, mealtime practices, CACFP administration/use) and the provision of child-care (i.e., day-to-day ECE operations and programming) during the COVID-19 pandemic. Methods: Participants included stakeholders from 22 national and state agencies associated with the Child and Adult Care Food Program (CACFP) who also work to promote nutrition and quality child-care, representatives of 17 CACFP sponsor organizations, and 40 center-based ECE program directors who participated in interviews, as well as 100 ECE directors who completed surveys. Data were collected across four states. Thematic analyses of interviews and descriptive methods were used to analyze data collected. Results: Six main themes emerged from stakeholders, sponsors, and ECE program directors' focusing on: experiences during the temporary closure of several ECE programs; additional responsibilities and unanticipated expenses for ECE programs; difficulty in keeping up with constantly changing COVID-19 guidance; encounters during shifts from in-person to virtual training and monitoring; changes to nutrition practices at ECE; and the need to prioritize ECE funding. Conclusions: Findings highlight challenges and supports to ECE programs and could inform future efforts to enhance child-care quality and child nutrition in the U.S. during pandemic situations

    Principles for transformative ocean governance

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    With a focus on oceans, we collaborated across ecological, social and legal disciplines to respond to the United Nations call for transformation in the ‘2030 Agenda for Sustainable Development’. We developed a set of 13 principles that strategically and critically connect transformative ocean research to transformative ocean governance (complementing the UN Decade for Ocean Science). We used a rigorous, iterative and transparent consensus-building approach to define the principles, which can interact in supporting, neutral or sometimes conflicting ways. We recommend that the principles could be applied as a comprehensive set and discuss how to learn from their interactions, particularly those that reveal hidden tensions. The principles can bring and keep together partnerships for innovative ocean action. This action must respond to the many calls to reform current ocean-use practices which are based on economic growth models that have perpetuated inequities and fuelled conflict and environmental decline

    Principles for transformative ocean governance

    Get PDF
    With a focus on oceans, we collaborated across ecological, social and legal disciplines to respond to the United Nations call for transformation in the ‘2030 Agenda for Sustainable Development’. We developed a set of 13 principles that strategically and critically connect transformative ocean research to transformative ocean governance (complementing the UN Decade for Ocean Science). We used a rigorous, iterative and transparent consensus-building approach to define the principles, which can interact in supporting, neutral or sometimes conflicting ways. We recommend that the principles could be applied as a comprehensive set and discuss how to learn from their interactions, particularly those that reveal hidden tensions. The principles can bring and keep together partnerships for innovative ocean action. This action must respond to the many calls to reform current ocean-use practices which are based on economic growth models that have perpetuated inequities and fuelled conflict and environmental decline

    Principles for transformative ocean governance

    Get PDF
    With a focus on oceans, we collaborated across ecological, social and legal disciplines to respond to the United Nations call for transformation in the ‘2030 Agenda for Sustainable Development’. We developed a set of 13 principles that strategically and critically connect transformative ocean research to transformative ocean governance (complementing the UN Decade for Ocean Science). We used a rigorous, iterative and transparent consensus-building approach to define the principles, which can interact in supporting, neutral or sometimes conflicting ways. We recommend that the principles could be applied as a comprehensive set and discuss how to learn from their interactions, particularly those that reveal hidden tensions. The principles can bring and keep together partnerships for innovative ocean action. This action must respond to the many calls to reform current ocean-use practices which are based on economic growth models that have perpetuated inequities and fuelled conflict and environmental decline
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