541 research outputs found
Energy price increases in developing countries : case studies of Colombia, Ghana, Indonesia, Malaysia, Turkey, and Zimbabwe
When domestic energy prices in developing countries fall below opportunity costs, price increases are recommended to conserve fiscal revenue and to ensure efficient use of resources. Using six case studies, the authors investigate the effect of energy price increases on the poor, inflation, growth, public revenues, and industrial competitiveness. The effect on household in various income classes depends on the energy commodity's share in the household budget and the price elasticity of demand. For energy as a whole (electricity and fuels, traditional and commercial), budget shares often decline with income. So in terms of income distribution, taxing energy is not ideal. But commercial fuel consumption increases greatly with income, so any subsidies applied will largely benefit nonpoor urban households. For each commercial energy source (electricity, kerosene, diesel, and gasoline) proportionate household spending will generally be lower, and some energy sources will be luxuries. In no instance does energy spending exceed 10 percent of the typical household budget for any income group. The effect on industry is generally modest, since cost shares for energy typically range from 0.5 to 3 percent (with typical value being 1.5). In addition, many industries are flexible enough to substitute when energy prices increase. Energy prices tended to increase in adjustment and liberalization programs, and industrial output usually increased even with the higher energy prices. This suggests that the effects of the price increase is modest compared with the effects of other changes in the environment. There are exceptions, of course, such as energy-intensive industries with limited possibilities for substitution. Estimating the effects on public deficits is straight-forward, even with uncertainty about demand elasticities: energy price increases reduce the drain on public resources significantly. It is harder to trace the effects on inflation and growth in national income. The effects on inflation will generally not be severe, and inflation may even be reduced in the intermediate to long run, through lowered public deficits. Income growth rates were generally higher after the years of energy price adjustments than they were in the years before the price increases (with one exception). Income growth rates were higher during the years of price increases than before in about half of the case study countries.Markets and Market Access,Environmental Economics&Policies,Climate Change,Engineering,Economic Theory&Research,Economic Theory&Research,Environmental Economics&Policies,Access to Markets,Markets and Market Access,Energy and Environment
Morphological features and differential counts of Plasmodium knowlesi parasites in naturally acquired human infections
Background: Human infections with Plasmodium knowlesi, a simian malaria parasite, are more common than previously thought. They have been detected by molecular detection methods in various countries in Southeast Asia, where they were initially diagnosed by microscopy mainly as Plasmodium malariae and at times, as Plasmodium falciparum. There is a paucity of information on the morphology of P. knowlesi parasites and proportion of each erythrocytic stage in naturally acquired human infections. Therefore, detailed descriptions of the morphological characteristics and differential counts of the erythrocytic stages of P. knowlesi parasites in human infections were made, photographs were taken, and morphological features were compared with those of P. malariae and P. falciparum. Methods: Thick and thin blood films were made prior to administration of anti-malarial treatment in patients who were subsequently confirmed as having single species knowlesi infections by PCR assays. Giemsa-stained blood films, prepared from 10 randomly selected patients with a parasitaemia ranging from 610 to 236,000 parasites per mu l blood, were examined. Results: The P. knowlesi infection was highly synchronous in only one patient, where 97% of the parasites were at the late trophozoite stage. Early, late and mature trophozoites and schizonts were observed in films from all patients except three; where schizonts and early trophozoites were absent in two and one patient, respectively. Gametocytes were observed in four patients, comprising only between 1.2 to 2.8% of infected erythrocytes. The early trophozoites of P. knowlesi morphologically resemble those of P. falciparum. The late and mature trophozoites, schizonts and gametocytes appear very similar to those of P. malariae. Careful examinations revealed that some minor morphological differences existed between P. knowlesi and P. malariae. These include trophozoites of knowlesi with double chromatin dots and at times with two or three parasites per erythrocyte and mature schizonts of P. knowlesi having 16 merozoites, compared with 12 for P. malariae. Conclusion: Plasmodium knowlesi infections in humans are not highly synchronous. The morphological resemblance of early trophozoites of P. knowlesi to P. falciparum and later erythrocytic stages to P. malariae makes it extremely difficult to identify P. knowlesi infections by microscopy alone.Publisher PDFPeer reviewe
Preparative and N.M.R. studies of polyphosphorus ligands and their complexes
A wide range of diphosphines and their complexes with chromium, molybdenum, and tungsten carbonyl moieties has been synthesised and characterised, arid studied by proton, C-13 and P-31 n.m.r. spectroscopy. In many cases the diphosphines have one or more centres of chirality, and this leads to the formation of diastereomers that are readily distinguishable by n.m.r. The P-31 chemical shifts occur in specific ranges that are often structurally diagnostic, and are interpreted in terms of 'group contributions’, 'coordination chemical shifts', and the effects of chelate 'ring strain’.
In order to obtain values of geminal and vicinal P-31 to proton coupling constants which can be used to assess conformational details, recourse was had to C-13/H -1 two-dimensional heteronuclear chemical shift correlation experiments. These use effective chemical shifts introduced by the presence of a single C -13 nucleus to reduce the extent of second-order character in the spectrum and hence give values of N(PC) and N(PH) together with their relative signs.
Synthetic studies have also been undertaken on the triphosphine ligand (Ph2P)2CHCH2PPhH, which has a chiral phosphorus atom, and its complexes. When all three phosphorus atoms are coordinated to the same metal atom this leads to considerable ring strain, but nonetheless such complexes are stable, but show interesting variations in their n.m.r. properties. The presence of the P-H bond in this triphosphine and its complexes permits base-catalysed addition reactions with species such as (Ph2P2)2C=CH2 to yield derivatives of the pentaphoshine [(Ph2P)2CHCH2]2PPh in a regio- and even stereo-selective manner. This behaviour has been studied, and several new complexes have been prepared and their n.m.r. properties have been determined
A STUDY OF AN OPTIMUM PARABOLIC TROUGH CONCENTRATOR DESIGN FOR POSSIBLE POWER GENERATION IN MALAYSIA
The aim of this research work is to design an optimum parabolic trough concentrator,
where the optimum design parameters are identified by using simulation method. A new
parabolic trough concentrator model was proposed. The new model, based on a standard
model of a parabolic trough concentrator, has back copper tubes attached to the
parabolic concentrator. The back copper tubes are expected to pick up the surplus heat
on the iron concentrator due to incoming solar radiation that is not reflected.
Simulations were carried out by using software programmed specifically for this
research work and by using the outcomes from simulation, an experimental new model
was fabricated based on optimum design parameters. The optimisers that were identified
by simulations are the rim angle, concentration ratio, acceptance half-angle and
receiver's absorber tube size. The optimum value for rim angle is 90° and concentration
ratio is 10. The acceptance half-angles falls in the range between 1.55° and 1.72°, where
the optimum diameter for the receiver's absorber tube range between 27 mm and
30 mm. A rim angle of 90° can be obtained when the parabolic depth becomes equal to
the focus point. The receiver's absorber tube diameter size was 30 mm, where for the
concentration ratio to be 10, the width was calculated as 1.0 m and depth and focus
point was set at 0.25 m. The length of the concentrator at 1.83 m was determined by
using the thermal module simulation and was also subjected to the budget availability.
The simulation software was used to evaluate the performance of the new design with
the optimum parameters by using the meteorological data for Bayan Lepas, Ipoh,
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Cameron Highlands, Kuantan and Senai. The maximum instantaneous simulated outlet
fluid temperature achieved is 133.8 °C for Ipoh. The maximum instantaneous
experimental outlet temperature achieved on the 61
h July 2003 by using the prototype
model was ( 143.8 ± 0.5 ) oc, at an average direct and diffuse solar insolation of
2.57 MJ/m2 and 0.81 MJ/m2 respectively, with a mass flowrate ofO.Ol kg/sand ambient
temperature of ( 31.3 ± 0.5 ) °C. The performance of the model with and without the
back tubes was compared where the difference between average values was
(11.8 ± 4.0 )°C, which was approximately ( 14.0 ± 5.0) % increase in the outlet fluid
temperature. The working fluid used in this research work is saturated water
Analysis and design of an elevated reinforced concrete water tank of the Intze type
Call number: LD2668 .R4 1966 S21
Polymerase chain reaction of dried blood spots to detect parasite DNA in individuals with lymphatic filariasis
Lymphatic filariasis caused by Brugia malayi has traditionally been detected in the blood of infected individuals by microscopy.Screening for blood-stage
microfilaria (mf) by microscopy is labour intensive with user fatigue and poor specimen handling responsible for false negative results. Recently a method to detect the DNA from circulating microfilaria using the polymerase chain reaction(PCR) has been described (Lizotte et al., 1994 ). However,the specimen collection method described was unsuitable for routine screening in field situations.The aim of the study reported here was to adapt the PCR method to a simple blood spot sampling and DNA extraction method suitable for remote areas without compromising the sensitivity of PCR. Blood spots were collected from individuals in Kelantan and Terengganu to optimise the
technique. A one tube DNA extraction method was developed and coupled to a nested PCR assay that was field tested on an endemic community in Sabah. There was 100% sensitivity when comparing PCR to microscopy but only 70% sensitivity when comparing microscopy to PCR. The increased sensitiyity of PCR coupled with simple sample collection and DNA extraction provides a valuable alternative to microscopy for detecting B. malayi positive individuals in endemic regions of the world
R Factor To Determine The Reynolds Number Of Saturated Water Flowing In Tubes.
Fluid flowing in a tube is commonly used in practice for heating and cooling applications. The flow in a
tube can be laminar or turbulent, entirely depending on the flow conditions. It is therefore, useful to know
the nature of the flow, especially in evaluating the Nusselt number
Designing A Solar Thermal Cylindrical Parabolic Trough Concentrator By Simulation.
The focus on renewable energy in Malaysia gained momentum with the active involvement of the government and the private sector. This move can potentially help in diversifying
the country's energy options besides relying on oil, natural gas, coal and hydro power
Relation-Theoretic Contraction Principle In Metric Spaces Using Multiplicative Contraction
Alam and Imdad have presented a novel application of the Banach contraction principle on a complete metric spaces with a binary relation. We have extended the concept of binary relation with the multiplicative contraction in a complete metric spaces. We have also included corollary to demonstrate our results
Simulation Of Heat Transfer Coefficient Due To Wind Blowing Across Cylindrical Receiver Of A Parabolic Trough Concentrator.
The evaluation of the heat transfer coefficient due to wind, hw over certain surfaces can be considered as tedious, if it is carried out in an environment where the temperature changes significantly. Reynolds, Prandtl and Nusselt numbers are used to compute the wind heat transfer coefficient. The parameters defining these numbers are dependent on the temperature
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