Green water re-capitalization for optimizing agricultural productivity in Eastern and Southern Africa

Irrigated farmingWater policy

Resummations in the Bloch-Nordsieck model

We studied different levels of resummations of the exactly solvable Bloch-Nordsieck model in order to be able to compare the approximations with an exact result. We studied one-loop perturbation theory, 2PI resummation and Schwinger-Dyson equations truncated in a way to maintain Ward-identities. At all levels we carefully performed renormalization. We found that although the 2PI resummation does not exhibit infrared sensitivity at the mass shell (the one-loop perturbation theory does), but it is still far from the exact solution. The method of truncated Schwinger-Dyson equations, however, is exact in this model, so it provides a new way of solving the Bloch-Nordsieck model. This method can also be generalized to other, more complicated theories.Comment: 12 pages, 3 figures, revtex

Assessing water availability under pastoral livestock systems in drought-prone Isiolo District, Kenya

Water availability / Water demand / Surface water / Groundwater / Wells / Salinity / Livestock / Grazing / Land use / Water supply / Drainage / GIS / Databases / Cost recovery

THE JOINT EFFECT OF ORGANIZATIONAL STRATEGY, ORGANIZATIONAL CULTURE AND EXTERNAL ENVIRONMENT ON ORGANIZATIONAL PERFORMANCE OF LARGE PRIVATE HEALTH FACILITIES IN KENYA

The goal of this study was to determine the joint effect of organizationalstrategy, organizational culture and external environment on organizationalperformance, using data from Sixty-one large private health facilities inKenya. A descriptive cross-sectional design grounded on positivism researchphilosophy was used. Multiple linear regression analyses were employed toanalyze the data. Generally, the results revealed that the joint effect oforganizational strategy, culture and external environment on performancedimensions, which include efficiency, effectiveness, relevance and financialviability was statistically significant. Consequently, it was concluded thatorganizational culture and strategy are not separated from the externalenvironment in which they are embedded. It was recommended that in orderto maximize on performance, the private health facilities must establish anoptimal balance among the three factors

INFLUENCE OF EXTERNAL ENVIRONMENT ON THE RELATIONSHIP BETWEEN ORGANIZATIONAL STRATEGYCULTURE CO-ALIGNMENT AND PERFORMANCE OF LARGE PRIVATE HEALTH FACILITIES IN KENYA

The aim of this study was to assess the influence of the external environment onthe relationship between organizational strategy-culture co-alignment andperformance of large private health facilities in Kenya. The study was based onthe Configuration and Contingency theories, adopting a descriptive crosssectionaldesign grounded on the positivism research philosophy. The studytargeted a population of 61 large private health facilities in Kenya. Data from therespondents were collected through a questionnaire. Fifty eight (58) out of SixtyOne (61) study facilities returned completed questionnaire items. Descriptivestatistics, one sample t-test and Baron-Kenny moderated regression analysis wereused. The results showed no statistically significant influence of the externalenvironment on the relationship between organizational strategy-culture coalignmentand organizational performance. In effect, the study questioned thevalue of focusing on environmental commitments as a means of achievingperformance improvements. It was concluded that the external environment doesnot increase competitive benefits to organizations that are implementing strategyculturefit

Offsetting of CO₂ emissions by air capture in mine tailings at the Mount Keith Nickel Mine, Western Australia: Rates, controls and prospects for carbon neutral mining

The hydrated Mg-carbonate mineral, hydromagnesite [Mg₅(CO₃)₄(OH)₂•4H₂O], precipitates within mine tailings at the Mount Keith Nickel Mine, Western Australia as a direct result of mining operations. We have used quantitative mineralogical data and δ¹³C, δ¹⁸O and F¹⁴C isotopic data to quantify the amount of CO₂fixation and identify carbon sources. Our radiocarbon results indicate that at least 80% of carbon stored in hydromagnesite has been captured from the modern atmosphere. Stable isotopic results indicate that dissolution of atmospheric CO₂ into mine tailings water is kinetically limited, which suggests that the current rate of carbon mineralization could be accelerated. Reactive transport modeling is used to describe the observed variation in tailings mineralogy and to estimate rates of CO₂ fixation. Based on our assessment, approximately 39,800 t/yr of atmospheric CO₂ are being trapped and stored in tailings at Mount Keith. This represents an offsetting of approximately 11% of the mine's annual greenhouse gas emissions. Thus, passive sequestration via enhanced weathering of mineral waste can capture and store a significant amount of CO₂. Recommendations are made for changes to tailings management and ore processing practices that have potential to accelerate carbonation of tailings and further reduce or completely offset the net greenhouse gas emissions at Mount Keith and many other mines

Surface Crystallization in a Liquid AuSi Alloy

X-ray measurements reveal a crystalline monolayer at the surface of the eutectic liquid Au_{82}Si_{18}, at temperatures above the alloy's melting point. Surface-induced atomic layering, the hallmark of liquid metals, is also found below the crystalline monolayer. The layering depth, however, is threefold greater than that of all liquid metals studied to date. The crystallinity of the surface monolayer is notable, considering that AuSi does not form stable bulk crystalline phases at any concentration and temperature and that no crystalline surface phase has been detected thus far in any pure liquid metal or nondilute alloy. These results are discussed in relation to recently suggested models of amorphous alloys.Comment: 12 pages, 3 figures, published in Science (2006