Rural Off-grid Hybrid Wind/Hydro Renewable Power Generation for Rapid Development in Africa

Many rural communities in Africa located far away from transmission corridors do not enjoy electricity supply and cannot hope to be connected to their national grids in the foreseeable future. However, many among such communities have small hydro potential and moderate wind resources. In this paper, an off-grid, hybrid, wind-hydro power generation model is proposed for such communities. Candidate sites for this model would possess small hydro capacity of up to 500 kW and annual mean wind speed of 7 – 10 m/s at 10 m hub height. The operation of an existing small, run-of-river hydro station in conjunction with a hypothetical, in-situ wind farm feeding loads typical of rural areas was simulated to demonstrate the feasibility of the scheme. Simulation results for the system operation were found to be satisfactory. Further, it was demonstrated that, in spite of being an off-grid scheme, the wind turbine generators, aided by the STATCOM are capable of Low Voltage Ride Through in the event of a severe three-phase fault on a major feeder in accordance with grid code requirements. It is anticipated that, with the provision of subsidy by government and/or development agencies, implementation of this model will translate into rapid economic and social transformation of numerous rural areas across Africa

The potential for using risk models in future lung cancer screening trials

Computed tomography screening for early diagnosis of lung cancer is one of the more potentially useful strategies, aside from smoking cessation programmes, for reducing mortality and improving the current poor survival from this disease. The long-term success of lung cancer screening will be dependent upon identifying populations at sufficient risk in order to maximise the benefit-to-harm ratio of the intervention. Risk prediction models could potentially play a major role in the selection of high-risk individuals who would benefit most from screening intervention programmes for the early detection of lung cancer. Improvements of developed lung cancer risk prediction models (through incorporation of objective clinical factors and genetic and molecular biomarkers for precise and accurate estimation of risks), demonstration of their clinical usefulness in decision making, and their use in future screening programmes are the focus of current research

A descriptive study of the verbal piece in Ebira (a language of Kwara State of Nigeria).

This study aims at presenting an adequate description of the verbal piece which forms the core of the grammar of Ebira language. Ebira is one of the lesser known languages of Nigeria in which little scholarly work has yet been done. Ebira is my mother tongue. Chapter One gives the general introduction and describes the location (with sketch maps), the linguistic and cultural background of the language, and summarises the linguistic framework of the study. Chapter Two gives a description of the phonology, including the vowel harmony system, essential to an understanding of the grammar of the language. Chapter Three describes syntactic juncture features which include the vowel elision patterns and morpho-phonemic tone changes which affect the verbal piece. Chapters Four, Five, and Six form the major part of the thesis and describe the verbal piece in its various structures, functions and its distribution in the phrase, the clause, and sentence including the serial verb constructions. Chapter Seven concludes the thesis with an analysed narrative text demonstrating, in typical connected speech, the various units described. Appendix 1 is a chart of monosyllabic verbs in the language, Appendix 2 shows the list of monosyllabic verbs, and Appendix 3 presents some sample spectrograms showing words of contrastive vowel harmony sets

Effect of moisture sorption hysteresis on thermodynamic properties of two millet varieties

Application of reversible thermodynamic principles to gain fundamental understanding of food–water interactions in foods has met with limited success due to the presence of moisture sorption hysteresis which is a manifestation of irreversibility. This study was aimed at understanding the nature and extent of influence of hysteresis on thermodynamic properties of two millet varieties namely EX-BORNO and SOSAT C88. Moisture sorption data (adsorption and desorption) in the water activity and temperature ranges of 0.07 – 0.98 and 30°C – 70°C, respectively were used. Ratio of latent heat of moisture sorption to the latent heat of pure water was determined using Clausius-Clapeyron equation. Effect of moisture content on ratio of latent heat of sorption to latent heat of pure water was determined using Gallaher model. Net integral enthalpy was determined at constant spreading pressure with monolayer moisture contents calculated using Brunauer-Emmett-Teller (BET) and Guggenheim-Anderson-de Boer (GAB) models. Spreading pressure was determined using an analytical procedure. Gibbs equation was used to evaluate net integral entropy. Net isosteric heat of sorption and differential entropy were evaluated and used to investigate the enthalpy‐entropy compensation theory. Latent heat of moisture sorption in the two millet varieties decreased with increase in moisture content and approached latent heat of pure water at a ‘free water’ point of between 32% and 42% moisture content (d.b.) in adsorption and desorption, respectively. Desorption latent heat of moisture was higher than the adsorption values and the difference decreased with increase in moisture content. Monolayer moisture content decreased with increase in temperature, with the GAB being higher than the BET values. Desorption monolayer moisture was higher than that of adsorption. Spreading pressure increased with increase in water activity, with adsorption isotherm being higher than that of desorption and temperature having no significant effect. Net integral enthalpy decreased with increase in moisture content with effect of hysteresis being more marked in EX-BORNO than in SOSAT C88. Net integral entropy decreased with increase in moisture content to minimum values and thereafter, maintained sinusoidal trend with adsorption curve lagging behind desorption and varnishing at 18% and 16% (db) moisture content in EX-BORNO and SOSAT C88 respectively. Net isosteric heat of sorption and differential entropy decreased with increase in moisture content with effect of hysteresis being more pronounced in EX-BORNO. Moisture sorption process in the grains was found to be enthalpy driven with differential enthalpy varying linearly with differential entropy. Inequality in isokinetic and harmonic mean temperatures confirmed the enthalpy‐entropy compensation theory. Hysteresis was found to have effect on the isokinetic temperature, causing the values of desorption isokinetic temperature to be higher than the adsorption values

COMPARISON OF ORAL CLONIDINE WITH ORAL MIDAZOLAM IN MANAGING AGITATION FOLLOWING SEVOFLURANE ANESTHESIA – A PROSPECTIVE, RANDOMIZED, DOUBLE BLINDED STUDY

ABSTRACT:Objective: Emergence agitation is a major problem during recovery from anesthetic agents like sevoflurane, particularly in children. This study had compared the effects of oral clonidine with oral midazolam in reducing the incidence of emergence agitation following sevoflurane anesthesia.Methods: 50 children of ASA status I and II aged between 3-8 years were randomly allotted to one of the two groups, each group comprising 25 children. Group I children were given oral Midazolam 0.5 mg/kg and Group II children were given oral Clonidine 4 mcg/kg 30 min before the induction of anesthesia. Emergence reaction was analyzed using modified objective pain scale in all children following sevoflurane administration.Results: The total agitation score was significantly less in clonidine group in comparison to midazolam group during the first hour of post operative period (P<0.05).No remarkable change in the hemodynamics or oxygen saturation was observed in both groups.Conclusion: Premedication of oral clonidine 4 microgram per kg is superior to oral midazolam 0.5 mg per kg in reducing the incidence of emergence agitation following sevoflurane anesthesia.Keywords: sevoflurane, recovery, emergence agitation, clonidine, midazolam

Differences in vision performance in different scenarios and implications for design.

To design accessibly, designers need good, relevant population data on visual abilities. However, currently available data often focuses on clinical vision measures that are not entirely relevant to everyday product use. This paper presents data from a pilot survey of 362 participants in the UK, covering a range of vision measures of particular relevance to product design. The results from the different measures are compared, and recommendations are given for relative text sizes to use in different situations. The results indicate that text needs to be 17-18% larger for comfortable rather than perceived threshold viewing, and a further 20% larger when users are expected to wear their everyday vision setup rather than specific reading aids.The survey was funded by the Engineering and Physical Sciences Research Council (EPSRC) through the i~design 3 grant (Award Number: RG45089). The survey itself was conducted by the National Centre for Social Research under the direction of the research team. As well as the authors of this paper, several others made substantial contributions to the design and analysis of this survey, including Felicia Huppert, Pat Langdon, Kai Ruggeri, Eddy Elton, Jose Liht and John Ryan. Further analysis was funded by EPSRC through the KT-EQUAL project (grant number EP/G030898/2).This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.apergo.2016.02.00

Off-grid Hybrid Renewable Power Generation as a Vehicle for Accelerated Rural Development in Africa

Many rural communities in Africa located far away from transmission corridors do not enjoy electricity supply and cannot hope to be connected to their national grids in the foreseeable future. However, many among such communities have small hydro potential and moderate wind resources. In this paper, an off-grid, hybrid, wind-hydro power generation model is proposed for such communities. Candidate sites for this model would possess small hydro capacity of up to 500 kW and annual mean wind speed of 7-10 m/s at 10m hub height. The operation of an existing small, run-of-river hydro station in conjunction with a hypothetical, in-situ wind farm feeding loads typical of rural areas was simulated to demonstrate the feasibility of the scheme. Simulation results for the system operation were found to be satisfactory. It is anticipated that, with the provision of subsidy by government and/or development agencies, implementation of this model will translate into rapid economic and social transformation of numerous rural areas across Afric

Activation Loop Dynamics Determine the Different Catalytic Efficiencies of B Cell– and T Cell–Specific Tec Kinases

Itk and Btk are nonreceptor tyrosine kinases of the Tec family that signal downstream of the T cell receptor (TCR) and B cell receptor (BCR), respectively. Despite their high sequence similarity and related signaling roles, Btk is a substantially more active kinase than Itk. We showed that substitution of six of the 619 amino acid residues of Itk with those of Btk was sufficient to completely switch the activities of Itk and Btk. The substitutions responsible for the swap in activity are all localized to the activation segment of the kinase domain. Nuclear magnetic resonance and hydrogen-deuterium exchange mass spectrometry analyses revealed that Itk and Btk had distinct protein dynamics in this region, which could explain the observed differences in catalytic efficiency between these kinases. Introducing Itk with enhanced activity into T cells led to enhanced and prolonged TCR signaling compared to that in cells with wild-type Itk. These findings imply that evolutionary pressures have led to Tec kinases having distinct enzymatic properties depending on the cellular context. We suggest that the weaker catalytic activities observed for T cell–specific kinases is one mechanism to regulate cellular activation and prevent aberrant immune responses

A conserved isoleucine maintains the inactive state of Bruton’s tyrosine kinase

Despite high homology among non-receptor tyrosine kinases, different kinase families employ a diverse array of regulatory mechanisms. For example, the catalytic kinase domains of the Tec family kinases are inactive without assembly of the adjacent regulatory domains, whereas the Src kinase domains are autoinhibited by the assembly of similar adjacent regulatory domains. Using molecular dynamic simulations, biochemical assays, and biophysical approaches, we have uncovered an isoleucine residue in the kinase domain of the Tec family member Btk that, when mutated to the closely related leucine, leads to a shift in the conformational equilibrium of the kinase domain toward the active state. The single amino acid mutation results in measureable catalytic activity for the Btk kinase domain in the absence of the regulatory domains. We suggest this isoleucine side chain in the Tec family kinases acts as a ‘wedge’ that restricts the conformational space available to key regions in the kinase domain, preventing activation until the kinase domain associates with its regulatory subunits and overcomes the energetic barrier to activation imposed by the isoleucine side chain