1,974 research outputs found
Post-harvest handling practices and associated food losses and limitations in the sweetpotato value chain of southern Ethiopia
Household food insecurity is a chronic problem in Ethiopia; the situation is being exacerbated by high population growth rates and recurring droughts in the country. The interest to address post-harvest value chain (VC) constraints leading to food losses has increased significantly to provide adequate nutrition to the growing population. In this study, mapping of sweetpotato VC not only quantifies the degree of losses but establish links between distinct VC constraints and respective food losses and limitations. Harvest and handling at farm level and shelf life issues at distribution were identified as vulnerable hot-spots of the sweetpotato food losses. Apart from physical and biological factors, demand and supply mismatch during the main harvest season at the wet markets leads to food (up to 25%) and economic losses (33â75%) followed by deficiencies in the lean season. A multi-stakeholder cooperation is required to mitigate food losses, which can have a high impact on the nutritional and financial status of the producers, market operators, and the consumers
The future of bioethanol
Yeasts have been domesticated by mankind before horses. After the mastering of alcoholic fermentation for centuries, yeasts have become the protagonist of one of the most important biotechnological industries worldwide: the production of bioethanol. This chapter will initially present some important challenges to be overcome in this industry, both in first and second generation biofuel production. Then, it will briefly revisit some advances obtained in recent years. Finally, it will present and discuss some opportunities, in the scope of metabolic engineering and synthetic biology, that will likely be present in the future of bioethanol
Multi-objective possibilistic model for portfolio selection with transaction cost
AbstractIn this paper, we introduce the possibilistic mean value and variance of continuous distribution, rather than probability distributions. We propose a multi-objective Portfolio based model and added another entropy objective function to generate a well diversified asset portfolio within optimal asset allocation. For quantifying any potential return and risk, portfolio liquidity is taken into account and a multi-objective non-linear programming model for portfolio rebalancing with transaction cost is proposed. The models are illustrated with numerical examples
Influence of Demagnetization Effect on Giant Magneto Impedance of soft Ferromagnetic Metal
The large change in electromagnetic impedance in ferromagnetic state of soft
magnetic metals in presence of biasing magnetic field is associated with change
in screening of electromagnetic field. The screening depends on the
permeability of the metal. Apart from dependence on intrinsic properties of
metal the permeability depends on size of the sample. It is observed that the
decrease in MI in amorphous ferromagnetic ribbon of Fe40Ni40B20 alloy is large
for long sample whereas corresponding change is small for short one with same
biasing field. As intrinsic magnetic properties and bias field are same and the
demagnetization factor increases with reduction of length of the sample the
reduction of MI effect is associated with demagnetization field.Comment: 14 pages,4 figure
Slower Speed and Stronger Coupling: Adaptive Mechanisms of Self-Organized Chaos Synchronization
We show that two initially weakly coupled chaotic systems can achieve
self-organized synchronization by adaptively reducing their speed and/or
enhancing the coupling strength. Explicit adaptive algorithms for
speed-reduction and coupling-enhancement are provided. We apply these
algorithms to the self-organized synchronization of two coupled Lorenz systems.
It is found that after a long-time self-organized process, the two coupled
chaotic systems can achieve synchronization with almost minimum required
coupling-speed ratio.Comment: 4 pages, 5 figure
Analysis of Hysteresis Loops of 316L(N) Stainless Steel under Low Cycle Fatigue Loading Conditions
AbstractLow cycle fatigue tests were carried out on 316 L(N) stainless steel at room temperature employing strain amplitudes ranging from ± 0.3 to ±1.0% and a strain rate of 3Ă10â3sâ1. The material showed initial hardening for a few cycles followed by prolonged softening, saturation and final failure. The fatigue life was found to decrease with increase in strain amplitude. The analysis of stable hysteresis loops showed non-Masing behaviour for this material. The elasto-plastic response of the material under cyclic loading was characterized taking into account isotropic and kinematic hardening occurring during cycling. The material parameters were obtained from the experimental hysteresis loops and cyclic stress response of the material. Finite element analysis of elasto-plastic deformation was carried out to obtain the stabilized hysteresis loop and cyclic stress response of the material. The predicted hysteresis loops showed good agreement with experimental results. The low cycle fatigue life prediction was carried out based on plastic strain energy dissipation with cycling
Mineralogical Alterations During Laboratory-scale Carbon Sequestration Experiments for the Illinois Basin
AbstractDuring geological sequestration of carbon dioxide, the injected CO2 will react with formation fluids and rocks in the injection zone and overlying cap rocks. The resulting acidification of the fluids may result in the dissolution of solid phases and the formation of new solid phases which can cause changes in rock composition and overall fabric. We are conducting laboratory-scale geochemical and mineralogical studies on reservoir and cap rock samples in the Illinois Basin that complement the on-going Illinois Basin - Decatur Project (IBDP), a large-scale one million tonne demonstration of geologic sequestration in the Mt Simon Sandstone, Illinois USA. Mt. Simon Sandstone, Eau Clare Shale, and Knox Supergroup samples from the IBDP injection and deep monitoring wells and locations with rocks analogous to those at the IBDP site have been selected for simulated reactions using synthetic brine and CO2 in modified Parr pressure reactors at pressure and temperature conditions that correspond to ambient reservoir conditions (9.87 to 20.7MPa and 38 to 50°C) and for varying amounts of time (1 to 9 months). Using petrographic techniques and XRD analysis, samples have been analyzed before and after reactor experiments to define the mineralogical and textural baseline and report observed changes. Brine composition has also been analyzed for geochemical changes. The ReactŸ and Differential Evolution geochemical modeling programs are being used to simulate changes in mineral mass and brine chemistry. Post-reaction analyses of rock and brine samples from the Mt. Simon Sandstone show evidence of dissolution of diagenetic clays, increased porosity, and possible illitization of clay minerals. Three, six, and nine month post-reaction Eau Claire Shale rock and brine sample analyses indicate some degree of brine-rock-CO2 reaction by showing weathered illite, mixed clay, feldspar, biotite, and pyrite crystals. Post-reaction Potosi Dolomite rock and brine samples show evidence of dissolution of dolomite. Overall, petrographic and geochemical observations from these experiments suggest that the Mt. Simon Sandstone reservoir and Eau Claire cap rock system serve as good CO2 sequestration site. The competency of the Knox Supergroup as a CO2 sequestration target is still under investigation
A new "polarized version" of the Casimir Effect is measurable
We argue that the exactly computable, angle dependent, Casimir force between
parallel plates with different directions of conductivity can be measured.Comment: One Figure, 11 page
Higher order conductivity corrections to the Casimir force
The finite conductivity corrections to the Casimir force in two
configurations are calculated in the third and fourth orders in relative
penetration depth of electromagnetic zero oscillations into the metal. The
obtained analytical perturbation results are compared with recent computations.
Applications to the modern experiments are discussed.Comment: 15 pages, 4 figure
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