15,044 research outputs found
Energy Cost Analysis of Incorporating Air Intake Cooling System in Omotosho Phase 1 Thermal Power Plant
The gas turbine power plants in Nigeria are sited in locations where the standard ambient air temperature condition of 150 C rarely occurs. This off – rated temperature condition brings about a low thermal performance of the power plants. One method that can be used to improve the thermal performance of gas turbine power plants is to reduce the temperature of air entering them by using combustion turbine air – inlet cooling technology. This paper presents the energy cost analysis of incorporating air – intake cooling system in Omotosho Phase I Thermal Power Station. Data obtained from the power station were used for the economic analysis. The analysis indicates that four hundred and ninety eight million, one hundred and thirty eight thousand, seven hundred naira and sixty kobo only as profit. Thus retrofitting the existing gas turbine power plant with air – intake cooling system is economically viable. It also provides a better system performance and is an attractive investment opportunity. Keywords: Energy, cooling, ambient air temperature, cost analysis, profit, efficiency, power output
Sympathetic Blockade for Dysrhythmia Management in Heart Failure: Rationale and Therapeutic Progression to Intervention
Continuous ganglionic blockade is being used increasingly to help manage ventricular tachydysrhythmias. The purpose of this chapter is to discuss the physiologic and anatomic basis of ventricular tachydysrhythmias in detail that are mediated by the sympathetic nervous system and to discuss appropriate indications for the use of sympathetic ganglion blocks. These blocks can be instituted as both destination and bridging therapeutic options to control these dysrhythmias. These blocks therefore have value in the heart failure patient population since they offer a means of controlling the dysrhythmias that can be devastating to an already compromised myocardium
Assessment of Budgetary Allocation to Agricultural Sector and its effect on Agricultural Output in Rivers State, Nigeria (1999-2010)
This research focused on the assessment of budgetary allocation to the agricultural sector and it effect on agricultural output in Rivers state, between (1999-2010). The research only utilized secondary data generated by the Rivers state government of Nigeria through the ministry of agriculture. The objectives of the research was to examine the agricultural output of some selected crops such as cassava, yam, oil palm and plantain, and to examine the relationship between the budgetary allocation to the agricultural sector and the various output mentioned above as well as investigate the entire budgetary allocation to agricultural sector for a period of 12 years. Simple regression, percentages, and tables, were used as analytical techniques. The coefficient of determination,[R2] showed a very poor relationship between budgetary allocation to agricultural sector and output, meaning R2, was not significant for the four different equations. This is because allocation to agricultural sector was miss-applied. Keywords: Budget, Allocation, Agricultural Outpu
Compressive Inverse Scattering II. SISO Measurements with Born scatterers
Inverse scattering methods capable of compressive imaging are proposed and
analyzed. The methods employ randomly and repeatedly (multiple-shot) the
single-input-single-output (SISO) measurements in which the probe frequencies,
the incident and the sampling directions are related in a precise way and are
capable of recovering exactly scatterers of sufficiently low sparsity.
For point targets, various sampling techniques are proposed to transform the
scattering matrix into the random Fourier matrix. The results for point targets
are then extended to the case of localized extended targets by interpolating
from grid points. In particular, an explicit error bound is derived for the
piece-wise constant interpolation which is shown to be a practical way of
discretizing localized extended targets and enabling the compressed sensing
techniques.
For distributed extended targets, the Littlewood-Paley basis is used in
analysis. A specially designed sampling scheme then transforms the scattering
matrix into a block-diagonal matrix with each block being the random Fourier
matrix corresponding to one of the multiple dyadic scales of the extended
target. In other words by the Littlewood-Paley basis and the proposed sampling
scheme the different dyadic scales of the target are decoupled and therefore
can be reconstructed scale-by-scale by the proposed method. Moreover, with
probes of any single frequency \om the coefficients in the Littlewood-Paley
expansion for scales up to \om/(2\pi) can be exactly recovered.Comment: Add a new section (Section 3) on localized extended target
Microleakage after Thermocycling of Three Self-Etch Adhesives under Resin-Modified Glass-Ionomer Cement Restorations
This study was designed to
evaluate microleakage that appeared on Resin-Modified
Glass-Ionomer Cement (RMGIC) restorations.
Sixty class V cavities (h × w × l = 2 mm × 2 mm × 3 mm) were cut on thirty extracted
third molars, which were randomly allocated to
three experimental groups.
All the buccal cavities were pretreated with polyacrylic acid,
whereas the lingual cavities were treated with three one-step
Self-Etch adhesives, respectively, Xeno III (Dentsply Detrey GmbH,
Konstanz, Germany), iBond exp (Heraeus Kulzer gmbH & Co. KG,
Hanau, Germany), and Adper Prompt-L-Pop (3M ESPE AG, Dental
products Seefeld, Germany). All cavities were completely filled
with RMGIC, teeth were thermocycled for 800 cycles, and leakage was
evaluated. Results were expressed as means ± standard deviations (SDs). Microleakage scores were analysed by means of generalized linear mixed models (GLMMs) assuming an ordinal logistic link function. All results were considered to be significant at the 5% critical level (P < .05).
The results showed that bonding RMGIC to dentin with a Self-Etch adhesive rather than using polyacrylic acid did not influence microleakage scores (P = .091), except for one tested Self-Etch adhesive, namely, Xeno III (P < .0001). Nevertheless, our results did not show any significant difference between the three tested Self-Etch adhesive systems.
In conclusion, the pretreatment of dentin with Self-Etch adhesive system, before RMGIC filling, seems to be an alternative to the conventional Dentin Conditioner for the clinicians as suggested by our results (thermocycling) and others (microtensile tests)
Raman microprobe characterization of electrodeposited S-rich CuIn(S,Se)2 for photovoltaic applications: Microstructural analysis
This article reports a detailed Raman scattering and microstructural characterization of S-rich CuIn(S,Se)2 absorbers produced by electrodeposition of nanocrystalline CuInSe2 precursors and subsequent reactive annealing under sulfurizing conditions. Surface and in-depth resolved Raman microprobe measurements have been correlated with the analysis of the layers by optical and scanning electron microscopy, x-ray diffraction, and in-depth Auger electron spectroscopy. This has allowed corroboration of the high crystalline quality of the sulfurized layers. The sulfurizing conditions used also lead to the formation of a relatively thick MoS2 intermediate layer between the absorber and the Mo back contact. The analysis of the absorbers has also allowed identification of the presence of In-rich secondary phases, which are likely related to the coexistence in the electrodeposited precursors of ordered vacancy compound domains with the main chalcopyrite phase, in spite of the Cu-rich conditions used in the growth. This points out the higher complexity of the electrodeposition and sulfurization processes in relation to those based in vacuum deposition techniques
Neural crest requires Impdh 2 for development of the enteric nervous system, great vessels, and craniofacial skeleton
Mutations that impair the proliferation of enteric neural crest-derived cells (ENCDC) cause Hirschsprung disease, a potentially lethal birth defect where the enteric nervous system (ENS) is absent from distal bowel. Inosine 5′ monophosphate dehydrogenase (IMPDH) activity is essential for de novo GMP synthesis, and chemical inhibition of IMPDH induces Hirschsprung disease-like pathology in mouse models by reducing ENCDC proliferation. Two IMPDH isoforms are ubiquitously expressed in the embryo, but only IMPDH2 is required for life. To further understand the role of IMPDH2 in ENS and neural crest development, we characterized a conditional Impdh2 mutant mouse. Deletion of Impdh2 in the early neural crest using the Wnt1-Cre transgene produced defects in multiple neural crest derivatives including highly penetrant intestinal aganglionosis, agenesis of the craniofacial skeleton, and cardiac outflow tract and great vessel malformations. Analysis using a Rosa26 reporter mouse suggested that some or all of the remaining ENS in Impdh2 conditional-knockout animals was derived from cells that escaped Wnt1-Cre mediated DNA recombination. These data suggest that IMPDH2 mediated guanine nucleotide synthesis is essential for normal development of the ENS and other neural crest derivatives
Anderson localization of a weakly interacting one dimensional Bose gas
We consider the phase coherent transport of a quasi one-dimensional beam of
Bose-Einstein condensed particles through a disordered potential of length L.
Among the possible different types of flow identified in [T. Paul et al., Phys.
Rev. Lett. 98, 210602 (2007)], we focus here on the supersonic stationary
regime where Anderson localization exists. We generalize the diffusion
formalism of Dorokhov-Mello-Pereyra-Kumar to include interaction effects. It is
shown that interactions modify the localization length and also introduce a
length scale L* for the disordered region, above which most of the realizations
of the random potential lead to time dependent flows. A Fokker-Planck equation
for the probability density of the transmission coefficient that takes this new
effect into account is introduced and solved. The theoretical predictions are
verified numerically for different types of disordered potentials. Experimental
scenarios for observing our predictions are discussed.Comment: 20 pages, 13 figure
Studies on Home-Based Management of Malaria in Ogun State, South Western Nigeria
Background: The study area is Olambe, a fast-growing community in Ogun State, Nigeria. It shares the same boundary with Lagos State, Nigeria. It is highly populated due to high cost of rent and high cost of living in Lagos State which made lots of the inhabitants to migrate to neighbouring towns with easy access to Lagos State especially for workers or employees of Lagos State. The effect of home-based management of malaria (HMM) was carried out in Olambe in 2013. HMM is a major means of treatment in this part of Ogun State because the general hospitals or government hospitals available are only in Lagos State and it is quite a distance. A large percentage of the populace receives treatments from private-owned hospitals or solely depends on HMM.
Methods: The sampling population was 250 respondents which are mothers of children under the age of five years. Structured questionnaires and oral interview were used in collecting data from the 250 consenting individuals.
Results: A large percentage of the respondents were traders and not-well educated individuals (65.0%) who believed so much in home-based management of malaria due to financial difficulties, ignorance and distance to hospitals. About 5.5% are not educated and they attributed the ineffectiveness of some malaria drugs to fake drugs. They therefore use different herbal treatments. About 30.5% use both malaria drugs and herbal treatments for the treatment of malaria. The major factor for ineffective HMM in Olambe is wrong dosage of anti-malarial drugs, herbal treatment and wrong diagnosis. Artemisinin- based combination therapies (ACTS) was the preferred anti-malarial drug in this area. There is poor correlation between the reoccurrence of malaria and the type of drug used for the children (p0.05)
Conclusion: This study deduced that few respondents practice HMM correctly while many of them end up in hospitals due to lack of ideal dosage of anti-malarial drugs. A large percentage of respondents take traditional treatments. There is paucity of information on the use of HMM in Olambe, Ogun State, Nigeria and therefore a need to improve HMM, organize programmes to sensitize the area and the local communities around Olambe on the way forward in HMM
Biochemical Oxygen Demand and Carbonaceous Oxygen Demand of the Covenant University Sewage Oxidation Pond
Biochemical Oxygen Demand (BOD) is a measure of the dissolved oxygen
consumed by microorganisms during the oxidation of reduced substances in waters and
wastewaters. It is often used ambiguously in relation to Carbonaceous Oxygen Demand
(CBOD) which is the oxygen consumed during the oxidation of carbonaceous compounds
to carbon dioxide (CO2) and other oxidized end product. BOD is actually the sum of CBOD
and NBOD where NBOD is the Nitrogenous Oxygen Demand which is the oxygen
consumed during the oxidation of nitrogenous compounds (mainly NH3) to nitrates with
nitrites being an unstable intermediate. The major difference between CBOD and NBOD is
that there are two classes of bacteria believed to be responsible for the oxidation of reduced
nitrogen. The BOD5 value of Sewage samples collected from Covenant University
oxidation pond was therefore measured and the samples examined for the presence of
Escherichia coli. The sewage samples collected from four points (starting point (A), two
middle points (B, C), and end point (D) were inoculated on an Eosin Methylene Blue agar
plates and the presence of E. coli was confirmed by the appearance of greenish metallic
sheen colonies on the agar plates and biochemical Tests. The BOD of the effluent at the
different points (A, B, C, D) respectively showed a reduction in microbial load. The
ultimate CBOD was also estimated based on the BOD5 value which is based upon the
exponential (first-order) nature of oxygen demand. This research describes the formulations
of CBOD breakdown using simplified oxidation kinetics
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