620 research outputs found
Evaluating the Strength Characteristics of Clay- Gravel Mixtures
Shear strength is one of the most important soil properties in almost all geotechnical engineering problems. Therefore, this study was aimed at investigating the effect of gravel on the shear strength of clayey soil. Two clayey soil samples were obtained from a dug pit from different locations in Osogbo, Osun State and the gravels were collected locally. Three different gradations of gravel (2-6mm, 6-12mm, and 12-20 mm) were mixed in a dry state in percentages of 5, 10, 15, 20, 30, 40 and 50% with the collected clay soil respectively. Initially, some physical properties of clayey soil and the gravel, which include specific gravity, particle size analysis, liquid limit and plastic limit, were determined in accordance with BS 1377-3:2018. Consequently, the California Bearing Ratio (CBR) and Consolidated - Undrained (CU) triaxial compression tests at three different confining pressures of 50, 100 and 150 kN/m2, with a loading rate of 0.5 mm/min were carried out on the clay-gravel mixtures in accordance with BS 1377 (1990). The results from the CBR test indicated that the CBR value of the clay-gravel mixtures was higher than that of pure clay. The result of shear strength showed that the cohesion and effective angle of internal friction increases as the concentration of gravel increases from 0 to 50%. As the gravel size was increased from 6-12mm, effective cohesion reduces and angle of internal friction increases. It concluded that locally available gravel can be used to improve the strength properties of clayey soil for engineering construction
An augmented moment method for stochastic ensembles with delayed couplings: I. Langevin model
By employing a semi-analytical dynamical mean-field approximation theory
previously proposed by the author [H. Hasegawa, Phys. Rev. E {\bf 67}, 041903
(2003)], we have developed an augmented moment method (AMM) in order to discuss
dynamics of an -unit ensemble described by linear and nonlinear Langevin
equations with delays. In AMM, original -dimensional {\it stochastic} delay
differential equations (SDDEs) are transformed to infinite-dimensional {\it
deterministic} DEs for means and correlations of local as well as global
variables. Infinite-order DEs arising from the non-Markovian property of SDDE,
are terminated at the finite level in the level- AMM (AMM), which
yields -dimensional deterministic DEs. Model calculations have been made
for linear and nonlinear Langevin models. The stationary solution of AMM for
the linear Langevin model with N=1 is nicely compared to the exact result. The
synchronization induced by an applied single spike is shown to be enhanced in
the nonlinear Langevin ensemble with model parameters locating at the
transition between oscillating and non-oscillating states. Results calculated
by AMM6 are in good agreement with those obtained by direct simulations.Comment: 18 pages, 3 figures, changed the title with re-arranged figures,
accepted in Phys. Rev. E with some change
The effects of dietary treatment on the morphometrics and haematological characteristics in Clarias gariepinus
Fingerling of Clarias gariepinus have been reported to have an optimal protein requirement of 40%. Not much is known about the effect that varying this protein level has in the haematological characteristics (i.e packed cell volume, red blood cell count, haemoglobin concentration and mean corpuscular haemoglobin concentration) and on some landmarks measured along the fish's body. The haematological parameter are useful in assessing the effect of dietary treatment on leanness or robustness in the fish. The results of these experiment reveals that of the 17 landmarks measured on the bodies of the fish species fed dietary protein levels of no protein 11% (low protein), 29% (sub optimal) and 40% (optimal), only four of the landmarks show significant difference. Also, analysis of the haematological characteristics show significant difference in haematoant (PCV) and erthroycte count (RBC) in all the treatment
Deference and subordination: Gender roles and other variables in addressing and referring to husbands by Yoruba women
The Yoruba society, like many patriarchal traditions, tends to espouse male supremacy - an ideology that is reflected, often, in many of the cultural values and beliefs of the people. The use of address terms in Yoruba constitutes an aspect of linguistic practices where there is inequality in the use of language between male and male, female and female as well as between male and female. The study reported in this paper focuses on the use of first names (FN), teknonyms (TKM) and pet names (PN) as address forms by Yoruba-speaking women in the city of Ile-Ife in interaction with their husbands. It describes the pattern of use according to a number of social factors including age, level of educational attainment, region of origin and speech context. The paper demonstrates that while these factors are important determinants of address usage by Yoruba women, gender role-expectation (child-rearing) and the relations of power between Yoruba women and men interact in some crucial way in the women's language behaviour. This is particularly so because of the social changes that have been taking place within the Yoruba culture over the last three decades or so
Relative Impact Of Transport Infrastructure Investment On Sectoral Growth In Nigeria
Literature on the relationship between infrastructure investment and economic growth revealed divergent of results especially across sample periods and sizes, and model specifications. This study examined the relative impact of transport infrastructure investment on sectoral growth in Nigeria. Ex post facto research design was employed using annual secondary data sourced from CBN, WDI (2016). The investigation of the sectors of the Nigerian economy showed that road transport infrastructure was most significant (= 29.65291, t= 2.69504, p>0.05), with industrial sector productivity (= -0.686874, t=-1.38578, p>0.05) and agricultural sector productivity (=-0.495217, t= -0.73817, p>0.05) not exerting a significant effect on economic growth in Nigeria. It was also evident that health sector productivity (= -144.6662, t= [-2.70142, p<0.05) and education sector productivity (= -18.36868, t= -2.74476, p<0.05) exert a significant negative effect on economic growth in Nigeria at 5% level of significance. It was thus concluded that road transport infrastructure does not have a significant effect on sectoral growth in Nigeria. Hence it was recommended that the government should embark on development policies that will aim at strengthening the sub-sector of theeconomy so that it can operate in its full capacity and improve its contribution to economic growth. Literature on the relationship between infrastructure investment and economic growth revealed divergent of results especially across sample periods and sizes, and model specifications. This study examined the relative impact of transport infrastructure investment on sectoral growth in Nigeria. Ex post facto research design was employed using annual secondary data sourced from CBN, WDI (2016). The investigation of the sectors of the Nigerian economy showed that road transport infrastructure was most significant (= 29.65291, t= 2.69504, p>0.05), with industrial sector productivity (= -0.686874, t=-1.38578, p>0.05) and agricultural sector productivity (=-0.495217, t= -0.73817, p>0.05) not exerting a significant effect on economic growth in Nigeria. It was also evident that health sector productivity (= -144.6662, t= [-2.70142, p<0.05) and education sector productivity (= -18.36868, t= -2.74476, p<0.05) exert a significant negative effect on economic growth in Nigeria at 5% level of significance. It was thus concluded that road transport infrastructure does not have a significant effect on sectoral growth in Nigeria. Hence it was recommended that the government should embark on development policies that will aim at strengthening the sub-sector of theeconomy so that it can operate in its full capacity and improve its contribution to economic growth. Key words: Road transport infrastructure, Investment, Sectoral growth and Nigeri
An effective vision technique for microchip lead inspection
A new effective method for the microchip lead inspection for the chip manufacturing industry has been developed in this work. In contrast to the gray scale pattern matching technique this approach employs selected parameters of binary blobs to perform fault detection and measurements. This leads to a significant reduction of image processing time. A special combination of gray level filtering techniques with gray morphological operations enhances the borders of the lead images. Newly developed threshold calibration technique significantly improves the measurement accuracy. A unique statistical analysis has been developed to identify all possible lead defects in the chips. This method is rotationally and scale invariant and able to detect defective leads for the chips with different specifications. The minimum required information about the microchip is the number of leads
Natal and neonatal teeth: Literature review and report of seven cases in a Nigerian Tertiary Hospital
Teeth that are present in newborn infants are called "natal teeth" while teeth that erupt within the first 4 weeks after birth are called "neonatal teeth". The incidence of the appearance of natal and neonatal teeth has been reported to be between one in every 1000 and one in every 6000 births. Natal teeth may be uncomfortable for a nursing mother and present a risk of aspiration and swallowing by the infant if they are loose. Also, they may cause irritation and trauma to the infant\u27s soft tissues. Under these circumstances, these teeth need to be extracted. This paper presents 7 cases of natal and neonatal teeth. Three of the cases presented with natal molar teeth which are rare. The clinical features, complications and management are discussed
Voices of girls with disabilities in rural Iran
This paper investigates the interaction of gender, disability and education in rural Iran, which is a relatively unexplored field of research. The responses of 10 female students with disabilities from Isfahan indicated that the obstacles they faced included marginalization, difficulties in getting from home to school, difficulties within the school building itself, and discrimination by teachers, classmates and school authorities. The data collected for the study contain a wide range of conservative gendered discourses, and show how traditional gender beliefs interact with disability to aggravate the problems faced in education by young women with disabilities. It is hoped that the findings will raise awareness among policy-makers of the many formidable obstacles that make it difficult for young women with disabilities to achieve their full potential in education
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