448 research outputs found
The dynamics of a self-phoretic Janus swimmer near a wall
We study the effect of a nearby planar wall on the propulsion of a phoretic
Janus micro-swimmer driven by asymmetric reactions on its surface which absorb
reactants and generate products. We show that the behaviour of these swimmers
near a wall can be classified the swimmers are
absorbing or producing reaction solutes
their swimming directions are such that the inert or active face is at the
front. We find that the wall-induced solute gradients always promote swimmer
propulsion along the wall while the effect of hydrodynamics leads to
re-orientation of the swimming direction away from the wall.Comment: 6 pages, 6 figure
How walls affect the dynamics of self-phoretic microswimmers
We study the effect of a nearby planar wall on the propulsion of a spherical
phoretic micro-swimmer driven by reactions on its surface. An asymmetric
coverage of catalysts on its surface which absorb reactants and generate
products gives rise to an anisotropic interfacial flow that propels the
swimmer. We analyse the near-wall dynamics of such a self-phoretic swimmer as a
function of the asymmetric catalytic coverage of the surface. By an analysis of
the fundamental singularities of the flow and concentration or electrostatic
potential gradients generated we are able to obtain and rationalise a phase
diagram of behaviours as a function of the characteristics of the swimmer
surface. We find a variety of possible behaviours, from "bound states" where
the swimmer remains near the wall to "scattering" or repulsive trajectories in
which the swimmer ends far from the wall. The formation of some of the bound
states is a purely wall-phoretic effect and cannot be obtained by simply
mapping a phoretic swimmer to a hydrodynamic one
Evaluation of the performance of maize genotypes (Zea mays L.) for yield and other agronomic traits
A study was conducted at the Faculty of Agriculture, Research Farm, Bayero University, Kano State, (Lat. 11º541N, Long. 8º251E; 466m above sea level) between July and November 2015. The treatments consisted of twenty five genotypes which comprises of six parents, 15 cross and four checks derived from partial diallel cross, laid out in 5x5 lattice design and replicated three times; these were tested for fourteen characters to evaluate their performance. The means sum of squares due to genotypes indicated highly significant differences (P<0.01) for plant height, kernel weight kg days to 50% pollen shed, and grain yield per hectare, while non-significant difference was observed for other traits. The significant differences observed revealed the presence of substantial variability among the genotypes. P5 recorded the highest grain yield of (1075.56kg/ha), while P2P5 recorded the highest yield of (897.78kg/ha), indicating that, the highest yield obtained may be due to the combination of P5 which appears as the higher yielding parent. P2P3 recorded the lowest yield of (222.22kg/ha). It is therefore recommended that P5 has the highest yield, and can be used for hybridization programs to come up with new improved varieties
Institutions, Telecommunications and Economic Performance in Nigeria
One of the views that is fast and widespread across countries is the view that telecommunications plays a pivotal role in economic development. This has led to massive reformation of institutions in the sector. The reformation of the institutions is contingent on the theoretical underpinnings that good institutions enhance the efficiency of the telecommunications sector. This in turn, directly and through other sectors improves economic performance. This paper sets out to examine the separate effects of the reform and the reformed telecommunications on the various measures of economic performance. We estimated the Modified Engle-Granger cointegration test that allows for structural break using Nigeria’s data for the period 1984-2011. A step dummy variable is used to measure the effects of the reform on the various indicators of economic performance, while a slope dummy is used to measure the effects of the reformed telecommunications sector on economic performance. The results of this model show that the reform and the reformed telecommunications have significant effects on economic performance. Their effects on growth are found to be statistically significant both in the short-run and in the long-run. The effects, however, on unemployment and Poverty are found to be significant only in the long-run. In addition, we found the effects of the reform to be the most important. This, we recommend that the regulatory body should concentrate more effort in designing and improving good institutions that will enable the maximum benefits from telecommunications to be derived. Keywords: Institutions, Telecommunications, Economic Performance and MEG JEL Classification Codes: E02, O43, O1
Intra-colonial Population of Macrotermes bellicosus (Smeathman) [Isoptera: Termitidae] in Sokoto, Semi-Arid Zone of North-Western Nigeria
The intra- colonial population of individuals within the mounds of mound- building termite, Macrotermes bellicosus (Smeathman) occurring in some selected Local Government Areas of Sokoto State were studied. A total of 72 cone shaped mounds were selected based on their heights. Populationswere estimated by randomly collecting and counting core samples from the mounds using a small bucket as the mounds were being excavated. At the end of the excavation, the total sand removed from the mound was crushed and measured using the same bucket. Total number of termites from a mound was extrapolated from the above estimates. Results indicate the presence of five different castes; reproductives, workers, minor and major soldiers and nymphs. The population of individuals per moundapart from the reproductives, ranged between 14158.00 and 24777.67 with an average of 18,795.49 termites per mound. The nymphs were the largest (5,942.60) closely followed by the workers (5,547.70), while the minor soldiers are the least with 3,279.38. Significant difference (p<0.05) occurred between minor soldiers and nymphs, major soldiers and nymphs, minor soldiers and workers and minor soldiers and nymphs in some of the studied areas. The present study show M. bellicosus to have high population within individual mounds enough to cause damage if ignored. Being a pestiferous species that could promote erosion, appropriate control strategies are required for its control.Key words: Macrotermes bellicosus, Mounds- building termites, intra-colonial Population, Mounds, Castes
Conflict Management Strategies and Administrative Effectiveness among Tertiary Institutions in Sokoto Metropolis
This paper examined conflict management strategies and administrative effectiveness in tertiary institutions in Sokoto metropolis. The study employed a correlational survey research design with questionnaire as the instrument of data collection. The population comprised all the eight tertiary institutions in the area. A sample of 168 lecturers were selected as respondents across four tertiary institutions. Two researcher developed instruments titled “Conflict Management Strategies Questionnaire” (CMSQ) and “Administrative Effectives Scale” (AES), with reliability indices of 0.82 and 0.85 respectively, were used for data collection. Data were analysed using Multiple Regression Analysis. The study established a significant relationship between dialogue, competition, prevention, and communication on one hand and administrative effectiveness on the other hand. It is recommended that tertiary institutions institutionalize dialogue as a conflict management strategy because through dialogue, team members develop skills to think together and to accept differences, thereby avoiding crises and improving performance
Preliminary Study: The Influences of Environmental Management Practices and Customer Satisfaction towards Customer Loyalty
Green hotel is one of the efforts taken towards achieving environmental sustainability through environmental management practices applied in the hotel. However, up until November 2014, there were only 10 out of 1935 hotels registered with the Ministry of Tourism and Culture, Malaysia received ASEAN Green Hotel Award. This study attempts to examine the environmental management practices in non-green hotels, and also the relationship between environmental management practices, customer satisfaction and customer loyalty among guests in a non-green hotel. Respondents were selected using a random sampling technique and data was analysed using SPSS. The findings show that all the environmental management practices have a positive relationship with customer satisfaction and customer loyalty
Optimization of RBF-SVM hyperparameters using genetic algorithm for face recognit
Manual grid-search tuning of machine learning hyperparameters is very time-consuming. Hence, to curb this problem, we propose the use of a genetic algorithm (GA) for the selection of optimal radial-basis-function based support vector machine (RBF-SVM) hyperparameters; regularization parameter C and cost-factor γ. The resulting optimal parameters were used during the training of face recognition models. To train the models, we independently extracted features from the ORL face image dataset using local binary patterns (handcrafted) and deep learning architectures (pretrained variants of VGGNet). The resulting features were passed as input to either linear-SVM or optimized RBF-SVM. The results show that the models from optimized RBFSVM combined with deep learning or hand-crafted features yielded performances that surpass models obtained from Linear-SVM combined with the aforementioned features in most of the data splits. The study demonstrated that it is profitable to optimize the hyperparameters of an SVM to obtain the best classification performance.
Keywords: Face Recognition, Feature Extraction, Local Binary Patterns, Transfer Learning, Genetic Algorithm and Support Vector Machines
Public relations perspectives on electoral reforms as a panacea for consolidating Nigeria’s democracy
Abstract. Electoral reforms have been considered as sustainable means of improving on the quality of elections in Nigeria, this is especially as it avails the country, tremendous opportunities in admitting new policies such as new techniques, technologies and improved systems of protecting the welfare of electorates. It is evident from the literature that, public relations overtime has been a unifying factor in accelerating Nigeria’s democracy and sustaining its need for periodic elections and encouraging the conduct of free, fair and transparent elections by the Independent National Electoral Commission (INEC). Based on the level of malpractices and issues associated with the conduct of elections in Nigeria, it was concluded in this paper that, there are several benefits attached to the process of electoral reforms in Nigeria, hence, it gives government the opportunity to revamp its electoral policies through campaigns, introduction of new technologies, voting and more importantly, the nature of conducting elections bearing in mind that, poorly adopted electoral policies normally lead to the outbreak of crisis from aggrieved parties. It is recommended amongst others that, government at all levels should consider periodic electoral reforms as a strategy for development and as such; they should ensure that only people with credibility are charged with the mandate of presiding over electoral reform committees (ERC).Keywords. Electoral reforms, Public relations, Democracy and elections.JEL. D72, D73, D78
Comparative Review of the Magnitude of Transaction Costs in Construction Procurement Projects between Developed and Developing Countries
Contracting business in public sector within various counties has a transaction cost to incur. This paper reviews transaction costs magnitude of developed and developing countries using standard sampling and procedure by analyzing data from four (4) developed countries; United States of America, United Kingdom, Newzealand, and Czech Republic and two (2) developing countries in Africa; Ghana and Nigeria. According to thefindings Newzealand have the highest TCs magnitude among all countries compared of about 16.5% averagely and with Czech Republic with 0.13% minimum that are incurred by stakeholders when bidding public sector construction projects. This is an important comparison and strengthens the assumption that there is a significant link between transaction costs incurred in bidding and public sector procurement, and that reducing such costs must be important for the contracting firms of various countries.
Keywords: Construction, Comparison, Magnitude, Procurement, Transaction Cost
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