Challenges facing Administrators of Public Secondary Schools in Nigeria and the Way Forward

Secondary school education is the education that offered post-primary school education. It is the education that prepares the student for career choice in life. The public secondary school are handled by administrators in Nigeria who oversees the administration and ensure the aims and objectives of the schools are realized. It has been observed that these public secondary school administrators are facing many challenges. This article discusses the challenges facing administrators of public secondary schools in Nigeria. We adopted secondary data to provide empirical fact to support every point raised in the paper. The secondary data were sorted online and through print materials. The paper identified: inadequate funding, inadequate infrastructural facilities, poor capacity building programme, shortage of professional teachers, inadequate ICT facilities, shortage of instructional resources, insecurity and poor supervision as challenges facing the public secondary school administrators in Nigeria. Increasing in the funding of public secondary schools were among the recommendations given in this paper for the effective administration of the public secondary schools by the administrators

Performance comparison of baseline routing protocols in pocket switched network

Pocket Switched Network (PSN) is a branch of Delay Tolerant Network (DTN) which is intended to work in a challenged network. Challenged network is network with lack of infrastructure such as disaster area. As such, the network has intermittent connectivity. PSN provides a new paradigm to distribute messages in the network by taking advantage of roaming nodes from one place to another. In this paper, network performances of eight PSN routing protocols are investigated namely, First Contact, Direct Delivery, Epidemic, PRotocol using History of Encounter and Transitivity (PRoPHET), Spray and Wait, Binary Spray and Wait, Fuzzy Spray, Adaptive Fuzzy Spray and Wait. The performance metrics are packet delivery ratio, overhead ratio and average latency. Opportunistic Network Environment (ONE) simulator is used to evaluate the network performance. Experiments show that Epidemic has the best performance in term of message delivery ratio, but it has the highest overhead ratio. Direct Delivery has the lowest overhead ratio (zero overhead ratio) and PRoPHET has the lowest latency average

Interfacial friction in upward annular gas–liquid two-phase flow in pipes

Accurate prediction of interfacial friction between the gas and liquid in annular two-phase flow in pipes is essential for the proper modelling of pressure drop and heat transfer coefficient in pipeline systems. Many empirical relationships have been obtained over the last half century. However, they are restricted to limited superficial liquid and gas velocity ranges, essentially apply to atmospheric pressures, and the relationships are only relevant for pipes with inner diameters between 10 and 50 mm. In this study, we carried out experiments in a large diameter flow loop of 101.6 mm internal diameter with the superficial gas and liquid ranges of 11–29 m/s and 0.1–1.0 m/s respectively. An examination of published interfacial friction factor correlations was carried out using a diverse database which was collected from the open literature for vertical annular flow. The database includes measurements in pipes of 16–127 mm inner diameter for the liquid film thickness, interfacial shear stress, and pressure gradient for air-water, air-water/glycerol, and argon-water flows. Eleven studies are represented with experimental pressures of up to 6 bar. Significant discrepancies were found between many of the published correlations and the large pipe data, primarily in the thick film region at low interfacial shear stress. A correlation for the interfacial friction factor was hence derived using the extensive database. The correlation includes dimensionless numbers for the effect of the diameter across pipe scales to be better represented and better fit the wide range of experimental conditions, fluid properties, and operating pressures

Void fraction development in gas-liquid flow after a U-bend in a vertically upwards serpentine-configuration large-diameter pipe

We investigate the effect of a return U-bend on flow behaviour in the vertical upward section of a large-diameter pipe. A wire mesh sensor was employed to study the void fraction distributions at axial distances of 5, 28 and 47 pipe diameters after the upstream bottom bend. The study found that, the bottom bend has considerable impacts on up-flow behaviour. In all conditions, centrifugal action causes appreciable misdistribution in the adjacent straight section. Plots from WMS measurements show that flow asymmetry significantly reduces along the axis at L/D = 47. Regime maps generated from three axial locations showed that, in addition to bubbly, intermittent and annular flows, oscillatory flow occurred particularly when gas and liquid flow rates were relatively low. At this position, mean void fractions were in agreement with those from other large-pipe studies, and comparisons were made with existing void fraction correlations. Among the correlations surveyed, drift flux-type correlations were found to give the best predictive results

Optimización de la cristalización con metanol para una separación altamente eficiente del ácido palmítico en mezclas de ácidos grasos de palma usando metodología de superficie de respuesta

The objective of the current study was to develop parameters for the separation of palmitic acid (PA) from a crude palm oil saturated fatty acid (SFAs) mixture by using the methanol crystallization method. The conditions of methanol crystallization were optimized by the response surface methodology (RSM) with the D-optimal design. The procedure of developing the solvent crystallization method was based on various different parameters. The fatty acid composition was carried out using a gas chromatography flame ionization detector (GC-FID) as fatty acid methyl esters. The highest percentage of SFAs was more than 96% with the percentage yield of 87.5% under the optimal conditions of fatty acids-to-methanol ratio of 1: 20 (w/v), the crystallization temperature of -15 °C, and the crystallization time of 24 hours, respectively. The composition of separated SFAs in the solid fraction contains 96.7% of palmitic acid (C16:0) as a dominant component and 3.3% of stearic acid (C18:0). The results showed that utilizing methanol as a crystallization solvent is recommended because of its high efficiency, low cost, stability, availability, comparative ease of recovery and its ability to form needle-like crystals which have good filtering and washing characteristics.El objetivo del presente estudio fue desarrollar parámetros para la separación de ácido palmítico (PA) en mezclas de ácidos grasos saturados (SFAs) de aceites de palma crudo mediante el método de cristalización con metanol. Las condiciones de cristalización con metanol se optimizaron utilizando la metodología de superficie de respuesta (RSM) con el diseño D-Optimal. El procedimiento de desarrollo del método de cristalización con disolvente se basó en diversos parámetros diferentes. La composición de ácidos grasos se llevó a cabo por cromatografía de gases (GC-FID) como ésteres metílicos de ácidos grasos usando un detector de ionización de llama. El porcentaje más alto de SFAs fue mayor del 96% con un rendimiento porcentual de 87,5% bajo las condiciones óptimas de relación de ácidos grasos:metanol de 1:20 (p/v), una temperatura de cristalización de -15ºC y un tiempo de cristalización de 24 horas. La composición de la fracción de SFAs separada en fracción sólida contiene 96,7% de ácido palmítico (C16:0) como principal componente y 3,3% de ácido esteárico (C18:0). Los resultados mostraron recomendar metanol como disolvente de cristalización debido a su alta eficiencia, bajo coste, estabilidad, disponibilidad, facilidad comparativa de recuperación y su capacidad para formar cristales de aguja que tienen buenas características de filtración y lavado

Influence of Intra row spacing on growth and fodder yield of Lablab (Lablab purpureus [L]) in Semi – Arid Sokoto Nigeria

A Field experiment was conducted in 2010 and repeated in 2011 cropping seasons at the Usmanu Danfodiyo University Teaching and Research Farm, Dabagi to determine the effect of intra row spacing on growth and yield of Lablab purpureus. Treatments consisted three intra row spacings (20, 30 and 40cm) laid out in a Randomized Complete Block Design (RCBD) replicated three times. The results of the trial showed that intra row spacing significantly (P < 0.05) affected stand establishment count with 20cm producing the highest (43.3)number of stands and plant height at week 3 after sowing in 2011 cropping season. Tallest plants (42.2 cm) were produced by 20cm intra row spacing. Leaf number was significant (P< 0.05) at 9 weeks after sowing in 2010 cropping season. Thirty (30) cm intra row spacing produced the highest no. of leaves (25). Leaf length was not significantly affected (P > 0.05) by intra row spacing. The longest leaf (9.9 cm) was produced by 30 cm intra row spacing. Leaf width was also not significantly affected (P > 0.05) by intra row spacing with 30 cm intra row spacing producing the widest leaf (8.9 cm). Dry matter yield was not affected (P > 0.05) by intra row spacing however, 30 cm intra row spacing produced the highest dry matter yield of 1707.7 kg/ha. It was concluded from this research that 30 cm intra row spacing produced the highest dry matter yield of Lablab purpureus (L) and is recommended for semi arid Sokoto environment.Keywords: Row spacing, Fodder yield, Lablab purpureu

Upward gas–liquid two-phase flow after a U-bend in a large-diameter serpentine pipe

We present an experimental study on the flow behaviour of gas and liquid in the upward section of a vertical pipe system with an internal diameter of 101.6 mm and a serpentine geometry. The experimental matrix consists of superficial gas and liquid velocities in ranges of 0.15–30 m/s and from 0.07 to 1.5 m/s, respectively, which cover bubbly to annular flow. The effects on the flow behaviours downstream of the 180° return bend are significantly reduced when the flow reaches an axial distance of 47 pipe diameters from the U-bend. Therefore, reasonably developed flow is attained at this development length downstream of the bend. Other published measurements for large-diameter film thickness show similar trends with respect to the superficial gas velocity. However, the trends differ from those of small-diameter pipes, with which the film thickness decreases much faster with increasing gas flow. As a result, only a few of the published correlations for small pipe data agreed with the experimental data for large pipe film thickness. We therefore modified one of the best-performing correlations, which produced a better fit. Qualitative and statistical analyses show that the new correlation provides improved predictions for two-phase flow film thickness in large-diameter pipes

Response of aluminium honeycomb sandwich panels subjected to foam projectile impact - an experimental study

Aluminium honeycomb sandwich panels have potential applications as a protective mechanism that can be used to prevent failure of an important structure subjected to impact loading. Therefore it is important to fully understand the resistance of the sandwich panels subjected to impact loading conditions. The main objective of this work was to study the resistance of sandwich panels with different aluminium honeycomb cores, air sandwich panels (no core between the two face sheets) and monolithic plates of equivalent mass subjected to impact from foam projectiles. The deformation and the elastic spring-back of the honeycomb sandwich panels and the monolithic plates have been compared and discussed. The resistance of the panels and plates has been quantified by their back-face deflection with respect to the projectile impulse. Five different types of aluminium honeycombs have been used as the core material. The front-face sheet and the back-face sheet of the honeycomb sandwich panels are made of aluminium plate with 1 mm thickness. Cylindrical ALPORAS aluminium foams with a relative density between 9% and 11% are employed as the metal foam projectiles. They are fired at several hundred metres per second towards the centre of the panels and plates using a gas gun. The deflection histories of the back-face have been measured using a laser displacement sensor. From the deflection histories, the maximum deflection and the final deflection of the back-face can be distinguished. Deformation modes and failure modes of the individual component have been observed and classified into several categories. Moreover, the deflections of the honeycomb sandwich panels have been compared with deflections from air sandwich panels. It is found that the honeycomb sandwich panels outperform both the air sandwich panels and the monolithic plates within an impulse range of 2.25 kNsm(-2) similar to 4.70 kNsm(-2). Outside this operational range, the advantages associated with employing the honeycomb sandwich panels as a protective structure upon impact of foam projectiles diminishes. (C) 2014 Elsevier Ltd. All rights reserved

Investigation of the osteometry of the skull of the one-humped camels. Part II: sex dimorphism and geographical variations in adults

Sexual dimorphism in the skull of different species has been of importance in archaeological, forensic and anatomical studies; also, a variation in phenotypic and genetic traits across geographic space is a recurring phenomenon in biological species. This study investigated 10 adult camels from each of three geographical locations in northern Nigeria, for sex- and location-based variations in the skulls. In one location, male skulls had greater absolute osteometric values but there were no significance differences in relative proportions between sexes. Moreover, all index values (skull, cranial and facial) indicate no sexual dimorphism in all locations. There were some variations in the osteometry of the frontal region, and neurocranial volume between the locations. In addition it was observed that the skull index of Nigerian camels was similar to the Malha type documented in literature but wide variations exist in many other craniometric dimensions of the skull. This suggests a definite difference in phenotype and probable origin

Osteometry of the skull of one-humped camels. Part I: immature animals

The aim of this study was to investigate osteometric indices of immature camels (2-3 years old) in Nigeria. The cranial length, viscerocranial length, maximum zygomatic width, neurocranial volume, skull and facial index for females and males were 22.1 cm and 22.3 cm; 16.3 cm and 16.7 cm; 15.8 cm and 16.1 cm; 479 ml and 496 ml; 40.9 and 41.3, and 96.4 and 96.2 respectively. The mean orbital horizontal and vertical diameters of young camels were similar to each other giving a near complete circular shape. The foramen magnum index was over 100 because of a relatively higher height than width. The data were compared with those of other types of immature camels in the literature and will be useful for anatomical, developmental, anthropological and clinical studies of camels