2,035 research outputs found
Does Cooking Technology Matter? Fuelwood Use and Efficiency of Different Cooking Technologies in Lilongwe District, Malawi
Biomass, mainly firewood and charcoal contributes over 90% of Malawi’s total energy demand. As a result, deforestation is increasing at unprecedented rate and firewood is becoming scarce. Individual assessment of various cooking technologies has been widely done without comparison of various cooking technologies. Therefore, this study has been devoted to compare the performance, cooking time and fuelwood usage of the three-stone fireplace, Rocket and Chitetezo cooking technologies. The study used Specific Fuel consumption (SC) as a proxy for principal indicator of cooking technology efficiency. It measures the amount of wood used per kg of food. Rocket stove has been found to use less time, less fuelwood and produces less smoke.Cooking Technology, Fuelwood, Stove Efficiency
Un Aguilarense en Oxford. Lorenzo Lucena Pedrosa (1807- 1881) primer profesor de Lengua y Literatura Española en la Universidad de Oxford, Inglaterra
The Banks of the Cohomology River
We give sharp bounds on the vanishing of the cohomology of a tensor product
of vector bundles on the n-dimensional projective space in terms of the
vanishing of the cohomology of the factors. For this purpose we introduce
regularity indices generalizing the Castelnuovo-Mumford regularity. As an
application we give a sufficient condition for a vector bundle to have an
unobstructed deformation theory that depends only on the cohomology table of
the bundle. We construct complete families of bundles with such cohomology
tables.Comment: 16 page
Central limit theorems for additive functionals of ergodic Markov diffusions processes
We revisit functional central limit theorems for additive functionals of
ergodic Markov diffusion processes. Translated in the language of partial
differential equations of evolution, they appear as diffusion limits in the
asymptotic analysis of Fokker-Planck type equations. We focus on the square
integrable framework, and we provide tractable conditions on the infinitesimal
generator, including degenerate or anomalously slow diffusions. We take
advantage on recent developments in the study of the trend to the equilibrium
of ergodic diffusions. We discuss examples and formulate open problems
Effects of high energy radiation on the mechanical properties of epoxy/graphite fiber reinforced composites
Publications and theses generated on composite research are listed. Surface energy changes of an epoxy based on tetraglycidyl diaminodiphenyl methane (TGDDM)/diaminodiphenyl sulfone (DDS), T-300 graphite fiber and T-300/5208 (graphite fiber/epoxy) composites were investigated after irradiation with 0.5 MeV electrons. Electron spin resonance (ESR) investigations of line shapes and the radical decay behavior were made of an epoxy based on tetraglycidyl diaminodiphenyl methane (TGDDM)/diaminodiphenyl sulfone (DDS), T-300 graphite fiber, and T-300/5208 (graphite fiber/epoxy) composites after irradiation with Co(60) gamma-radiation or 0.5 MeV electrons. The results of the experiments are discussed
Effects of high energy radiation on the mechanical properties of epoxy graphite fiber reinforced composites
The effects of high energy radiation on mechanical properties and on the molecular and structural properties of graphite fiber reinforced composites are assessed so that durability in space applications can be predicted. A listing of composite systems irradiated along with the maximum radiation dose applied and type of mechanical tests performed is shown. These samples were exposed to 1/2 MeV electrons
Conformally equivariant quantization: Existence and uniqueness
We prove the existence and the uniqueness of a conformally equivariant symbol
calculus and quantization on any conformally flat pseudo-Riemannian manifold
(M,\rg). In other words, we establish a canonical isomorphism between the
spaces of polynomials on and of differential operators on tensor
densities over , both viewed as modules over the Lie algebra \so(p+1,q+1)
where . This quantization exists for generic values of the weights
of the tensor densities and compute the critical values of the weights yielding
obstructions to the existence of such an isomorphism. In the particular case of
half-densities, we obtain a conformally invariant star-product.Comment: LaTeX document, 32 pages; improved versio
Status of Supersymmetric Grand Unified Theories
We begin with a brief discussion of the building blocks of supersymmetric
grand unified theories. We recall some of the compelling theoretical reasons
for viewing supersymmetric grand unification as an attractive avenue for
physics beyond the standard model. This is followed by a discussion of some of
the circumstantial evidence for these ideas.Comment: 12 pages plain LaTeX to be run twice. Invited talk at the XII DAE
Symposium on High Energy Physics, Guwahati, India, Dec. 26, 1996 - Jan. 1,
199
Assessing the impact of loal content policy on youth culture in Mbare Harae: the case of Youth.com
The study sought to establish the impact of using the local content policy in reducing television cultural influences on Mbare youth in Zimbabwe. It is assumed that television has ideological and hegemonic functions which have come to dominate the life styles of the youths on issues of dress styles, musical tastes and language, thus threatening and weakening the long established local cultures. Hence the Zimbabwean government’s local content policy was established to reduce influences of alien cultures. This study, therefore, sought to establish if Mbare youth cultures confirm or reject the imitation of television cultures with regard to dress styles, music tastes and language. In addition, the investigation aimed at establishing the feasibility of using the local content policy to reduce foreign cultural intrusions vis-à-vis globalisation challenges. The three theories utilised in the discussion of the influence of television on Mbare youth culture in this study include the cultivation theory, the theory of hegemony and the uses and gratification theory. A qualitative study was adopted to gather data using focus group discussions, questionnaires and semiotic analysis. The sample of the study consisted of 87 participants and 4 Youth.com programmes. The study revealed that television has ideological and hegemonic functions. As such, it tends to be a dominant influence on the life styles and culture of Mbare youths. The study also established that Youth.com influences youth culture through music. In Zimbabwe music has become the most influential aspect of Youth.com despite not being specified in the local content policy on television broadcasting. Furthermore, the study shows that the implications of globalisation on local television content are undermining government efforts to preserve local cultures through the local content policy. The primary reason for this has to do with the fact that Youth.com programme does not contain a higher quota of local content as stipulated in the policy. However, although the local content policy was viewed as a political gimmick, the the study revealed that it was necessary in view of youths’ vulnerability to television’s ideological and hegemonic influences. Nevertheless, in view of the loopholes revealed by this study, the policy requires to be revised to cater for all the essential cultural elements, such as, music, which are allowing alien cultures to penetrate local ways of life. For instance, the urban groove music has major impacts on the culture of Mbare youths
Effects of high energy radiation on the mechanical properties of epoxy/graphite fiber composites
Studies on the effects of high energy radiation on graphite fiber reinforced composites are summarized. Studies of T300/5208 and C6000/PMR15 composites, T300 fibers and the resin system MY720/DDS (tetraglycidyl-4,4'-diaminodiphenyl methane cured with diaminodiphenyl sulfone) are included. Radiation dose levels up to 8000 Mrads were obtained with no deleterious effects on the breaking stress or modulus. The effects on the structure and morphology were investigated using mechanical tests, electron spin resonance, X-ray diffraction, and electron spectroscopy for chemical analysis (ESCA or X-ray photoelectron spectroscopy). Details of the experiments and results are given. Studies of the fracture surfaces of irradiated samples were studied with scanning electron microscopy; current results indicate no differences in the morphology of irradiated and control samples
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