Macro-micro feedback links of water management in South Africa : CGE analyses of selected policy regimes

The pressure on an already stressed water situation in South Africa is predicted to increase significantly under climate change, plans for large industrial expansion, observed rapid urbanization, and government programs to provide access to water to millions of previously excluded people. The present study employed a general equilibrium approach to examine the economy-wide impacts of selected macro and water related policy reforms on water use and allocation, rural livelihoods, and the economy at large. The analyses reveal that implicit crop-level water quotas reduce the amount of irrigated land allocated to higher-value horticultural crops and create higher shadow rents for production of lower-value, water-intensive field crops, such as sugarcane and fodder. Accordingly, liberalizing local water allocation in irrigation agriculture is found to work in favor of higher-value crops, and expand agricultural production and exports and farm employment. Allowing for water trade between irrigation and non-agricultural uses fueled by higher competition for water from industrial expansion and urbanization leads to greater water shadow prices for irrigation water with reduced income and employment benefits to rural households and higher gains for non-agricultural households. The analyses show difficult tradeoffs between general economic gains and higher water prices, making irrigation subsidies difficult to justify.Water Supply and Sanitation Governance and Institutions,Town Water Supply and Sanitation,Water Supply and Systems,Water and Industry,Water Conservation

Alimentation complémentaire de 38 nourrissons sénégalais

Une enquête de consommation alimentaire par pesée a été faite pendant 3 jours chez 38 nourrissons sénégalais afin d'apprécier la part de l'alimentation complémentaire dans la couverture de leurs besoins nutritionnels. Les apports recommandés en énergie et en protéines sont satisfaits respectivement à 49 et à 74%. Les besoins nutritionnels sont couverts à des niveaux variables : calcium 38%, fer 24%, vitamine A 39%, B1 51%, B2 43%, PP 82%, C 54%, folates 8%, B12 263%. En tenant compte de l'estimation des apports assurés par le lait maternel, les apports recommandés en énergie et en protéines sont satisfaits pendant la période étudiée. (Résumé d'auteur

Archiving scientific data

We present an archiving technique for hierarchical data with key structure. Our approach is based on the notion of timestamps whereby an element appearing in multiple versions of the database is stored only once along with a compact description of versions in which it appears. The basic idea of timestamping was discovered by Driscoll et. al. in the context of persistent data structures where one wishes to track the sequences of changes made to a data structure. We extend this idea to develop an archiving tool for XML data that is capable of providing meaningful change descriptions and can also efficiently support a variety of basic functions concerning the evolution of data such as retrieval of any specific version from the archive and querying the temporal history of any element. This is in contrast to diff-based approaches where such operations may require undoing a large number of changes or significant reasoning with the deltas. Surprisingly, our archiving technique does not incur any significant space overhead when contrasted with other approaches. Our experimental results support this and also show that the compacted archive file interacts well with other compression techniques. Finally, another useful property of our approach is that the resulting archive is also in XML and hence can directly leverage existing XML tools

A new DC micro-grid system using renewable energy and electric vehicles for smart energy delivery

This paper proposes a new DC micro-grid system, which fully utilizes the renewable energy and electric vehicle for smart energy delivery. The proposed DC grid incorporates the AC supply module, standby energy module, renewable energy module, and storage energy module together, to execute the energy distribution. Hence, this grid system can offer a high quality power for the three types of loads, namely 110V AC single-phase output, 48V DC output, and 100V DC output. The control strategy of the grid system for performing smart energy delivery will be discussed in the full paper. The simulation results will be also given to verify the four operation modes of the grid system.published_or_final_versionThe 2010 IEEE Vehicle Power and Propulsion Conference (VPPC), Lille, France, 1-3 September 2010. In Proceedings of VPPC, 2010, p. 1-

A new approach to urban water management: Safe and sure

This paper introduces a new approach to water management that is 'Safe & SuRe'. This includes presenting a conceptual framework to link the emerging threats of climate change and variability, rapid urbanization and population growth, energy constraint and tightening environmental regulation through to their consequences on social, economic and environmental recipients. The framework allows identification of the role and need for mitigation, adaptation and coping strategies. The paper proposes definitions and discusses what engineering, organizational and/or social options can potentially develop the degree of resilience and sustainability needed to deal with these 21st century threats. The paper goes on to propose how these approaches might be objectively assessed and identifies gaps in our knowledge that require further research

Safety Consideration for Emerging Wireless Technologies-Evaluations of Temperature Rise in Eyes for RF Radiations up to 10 GHz

© 2018 IEEE. The study of temperature rise distribution in the human eye under plane electromagnetic wave exposure up to 10 GHz is presented in this paper. The effects of different frequencies and different blood perfusion rates of sclera to thermal calculations are investigated by finite difference method. The results reveal that the changes in the thermal parameter produce a maximum relative standard deviation of ~15% in the temperature rise in lens

Etude de la productivité et de la sensibilité de diverses variétés de tomate (Lycopersicon esculentum Mill) à la virose du jaunissement et de l’enroulement en cuillère des feuilles au Sénégal

Après l’oignon, la tomate est le plus important légume au Sénégal. Elle est très sensible au virus Tomato Yellow Leaf Curl (TYLCV). Quatorze variétés de tomate ont été testées pour évaluer leur productivité et leur résistance au TYLC à différents stades phénologiques (floraison, fructification et maturité) dans un dispositif en blocs complets randomisés comptant trois répétitions. Les résultats ont montré que le nombre de fruits/grappe a varié entre les variétés. La masse unitaire des fruits était plus élevée pour Bybal, Roma VF et Lety F1. La longueur des fruits de Thoriya et Lety F1 était plus importante. Roma VF et Bybal ont présenté les plus gros fruits. TY75 et Ponchita ont produit les rendements en fruits consommables les plus élevés. Roma VF et Lety F1 ont produit les rendements non consommables les plus élevés. Globalement, TY75 et Roma VF ont été plus productives. Une résistance au virus a été observée chez douze variétés et une forte sensibilité chez deux autres (Roma VF et Xina). Ces résultats pourraient intéresser les sélectionneurs, les firmes semencières et les agriculteurs dans leur choix de variétés de tomate à cultiver.Mots clés : Tomate, Lycopersicon esculentum, TYLCV, Sénéga

Fatigue strengthening of damaged steel members using wire arc additive manufacturing

In this study, a directed energy deposition (DED) process called wire arc additive manufacturing (WAAM) is employed for the fatigue strengthening of damaged steel members. Three steel specimens with central cracks were tested under a high-cycle fatigue loading (HCF) regime: (1) the reference specimen; (2) the WAAM-repaired specimen with an as-deposited profile, and (3) the WAAM-repaired specimen machined to reduce stress concentration factors (SCF). The corresponding finite element (FE) simulation of the WAAM process was calibrated using static experimental results, which revealed the main mechanism. The process was found to introduce compressive residual stresses at the crack tip owing to the thermal contraction of the repair. The FE results also revealed that stress concentration exists at the root of the as-deposited WAAM; this stress concentration can be mitigated by machining the WAAM to a pyramid-like shape. The fractography analysis indicated that the cracks were initiated at the WAAM-steel interface, and microscopic observations revealed that the microcracks were arrested by the porosities in the melted interface. The results of this pioneering study suggest that WAAM repair is a promising technique for combating fatigue damage in steel structures