The determination of the thermophysical properties of some solid propellants have been made. The two thermal properties measured were specific heat and thermal diffusivity. The specific heat was measured by using a differential scanning calorimeter (DSC) and thermal diffusivity was measured by the flash diffusivity method. The samples used included both single crystal and pressed powders of ammonium perchlorate (AP), HMX and RDX.The measurements of the propellants' specific heat required the modification of both the DSC equipment and the technique to accommodate the decomposition products from the samples. A flowthrough cover was installed for this purpose. The computerized control and analysis for the DSC was also changed. The specific heat of AP, HMX and RDX was measured using both small single crystals and small amounts of powder. The specific heat of the HMX in both its normal phase (beta) and the delta phase were obtained. There proved to be little difference in the specific heat between these two phases of the HMX.The thermal diffusivity of HMX in pressed powder form was determined. It was necessary to develop a method of holding powdered samples so that propellants would not see the laser pulse directly in order to avoid excessive temperature rises or radiant energy transmission. A cup was designed to allow the powder to be pressed into it and to not allow an alternate heat path when the sample was under test.
Local-scale opportunities to address challenges of the water-food nexus in the developing world need to be embraced. Borehole-garden permaculture is advocated as one such opportunity that involves the sustainable use of groundwater spilt at hand-pump operated borehole supplies that is otherwise wasted. Spilt water may also pose health risks when accumulating as a stagnant pond. Rural village community use of this grey-water in permaculture projects to irrigate borehole gardens is proposed to primarily provide economic benefit whereby garden-produce revenue helps fund borehole water-point maintenance. Water-supply sustainability, increased food/nutrition security, health protection from malaria, and business opportunity benefits may also arise. Our goal has been to develop an, experience-based, framework for delivery of sustainable borehole-garden permaculture and associated benefits. This is based upon data collection and permaculture implementation across the rural Chikwawa District of Malawi during 2009-17. We use, stakeholder interviews to identify issues influencing uptake, gathering of stagnant pond occurrence data to estimate amelioration opportunity, quantification of permaculture profitability to validate economic potential, and critical assessment of recent permaculture uptake to identify continuing problems. Permaculture was implemented at 123 sites representing 6% of District water points, rising to 26% local area coverage. Most implementations were at, or near, newly drilled community-supply boreholes; hence, amelioration of prevalent stagnant ponds elsewhere remains a concern. The envisaged benefits of permaculture were manifest and early data affirm projected garden profitability and spin-off benefits of water-point banking and community micro-loan access. However, a diversity of technical, economic, social and governance issues were found to influence uptake and performance. Example issues include greater need for improved bespoke garden design input, on-going project performance assessment, and coordinated involvement of multi-sector governmental-development bodies to underpin the integrated natural-resource management required. The developed framework aims to manage the identified issues and requires the concerted action of all stakeholders. Based on the probable ubiquity of underlying issues, the framework is expected to be generalizable to the wider developing world. However, this particular application of permaculture represents a fraction of its greater potential opportunity for rural communities that should be explored.
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Dynamic thermal and bioenergetics models were applied to help define issues, identify alternatives, and quantify effects of various reservoir releases improvement options for Bull Shoals and Norfork Dams in northern Arkansas.
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