A virtual test-bed for the prediction of holistic effective elastic properties of UD composites

Most existing computational approaches are restrictive in their predictive capabilities by using non-representative virtual geometric domains (RVEs) of test materials. The strategy proposed here relaxes these restrictions by utilizing statistically representative 3D RVEs with appropriate boundary conditions and a robust homogenization implementation based on a micromechanical modelling philosophy. The strategy was implemented as a self-consistent, rigorous, virtual testing framework analogous to a physical experimental testing scheme. The strategy proposed in this work was shown to give a holistic set of elastic properties of the test composites considered when compared with other predictive approaches. Also, parametric studies were carried out to explore the different features of the virtual framework. Therefore, this virtual test-bed strategy represents a suitable substitute for realistic experiments and can be used in designing different virtual experiments

Management Control System for Effective Job Performance Among Librarians in Federal And State University Libraries : Evidence From South East Nigeria

In this study, we assessed the management control system used for effective job performance among librarians in five federal university libraries and five State university libraries in South East, Nigeria. Our 38-item questionnaire was validated by three experts: one from the Department of Science Education (Education Measurement and Evaluation unit) and two from the Department of Library and Information Science at the University of Nigeria, Nsukka. Later we used descriptive statistics and found out that the university libraries adopted performance appraisal system, duties rotation system, controlled activities system and regulation of staff attendance to a great extent, and also that the management control system has contributed to the effective job performance since it enables employees to understand their job expectations and to encourage librarians’ positive work attitude. Based on these findings, we recommended that performance appraisal and staff evaluation should be performed from time to time to identify areas which require improvements. Henceforth, federal and state governments in Nigeria should make funds available for university libraries to enable them adopt effective management control system and procure facilities and resources to enhance job performance in their libraries among other

Busy hour traffic congestion analysis in mobile macrocells

Traffic congestion during busy hour (BH) deteriorates the overall performance of cellular network and may become unmanageable unless effective and efficient methods of congestion control are developed through real live traffic data measurement and analysis. In this work, real live traffic data from integrated GSM/GPRS network was used for traffic congestion analysis. The analysis was carried out on 10 congesting cells using network management system (NMS) statistics data span for three years period. Correlation test showed that traffic channel (TCH) congestion depend only on call setup success rate (CSSR) and BH traffic at cell level. An average correlation coefficient value of 0.9 was observed between TCH congestion and CSSR while 0.6 was observed between TCH congestion and BH traffic. The correlation test is important when selecting input for congestion prediction modeling.Keywords: traffic congestion; correlation coefficient; macrocells and key performance indicato

ASSESMENT OF PALM KERNEL SHELL AS A COMPOSITE AGGREGATE IN CONCRETE

This  manuscript  presents  a report on  the  physical properties of palm kernel shell used  here  as a coarse aggregate  and  their  effect  on the strength properties of palm kernel shell concrete.Laboratory research was carried out to observe the effects of replacing crushed granite with palm kernel shell on the compressive strength and density of palm kernel shell concrete. Mix design of 1:2:4 and a water-cement ratio of 0.6 were used to produce concrete specimen cubes of size 150mm3.A total of 60 cubes were made and wholly submerged in water to cure for 28days at intervals of 7days i.e. 7, 14, 21 and 28 days after which their densities and compressive strengths were determined. Granite was replaced with palm kernel shell in the mix at 25% interval resulting in three replicates of specimen cubes at each curing age. Compressive strength and density decreased continuously as palm kernel shell was added to the mix for all the Curing ages tested. The 28day compressive strength of the palm kernel shell concrete ranged from 12.71 to 16.63N/mm2, whereas the density ranged between 1562 to 2042 kg/m3. Physical properties tests conducted include sieve analysis, bulk density, moisture content and specific gravity to describe aggregates. The Specific gravities of Sharp Sand, Crushed Granite and Palm Kernel Shell were found to be 2.5, 2.76 and1.301 while their bulk densities are 1650, 1545, and 634 kg/m3 respectively. Water absorption capability tests on crushed granite and palm kernel shell were observed to be 6% in both 1hr and 24hrs and 11% in 1hr and 21.5% in 24hrs respectively. All the aggregates utilized in this research work demonstrated their suitability in concrete production given the observations and physical properties result present

Post-impact Analysis of Sediments and Macro Bottom Fauna of Osondu River in Okigwe, Imo State, Nigeria

Sediment characteristics and macrobottom fauna of Osondu River in Okigwe, Imo State, Nigeria were sampled and analyzed. The sampling was done in January and June 2012 as part of post impact study of a massive road construction and demolition activities that took place in Okigwe. The aim of the study was to survey the river in order to determine the grain size distribution of the sediments and the associated macro fauna. Benthic macrofauna was sampled using an improvised core of cylindrical stainless steel pipe and an open iron frame with an attached net bag. Results showed that sediments consisted of mud made up of silt and clay. The macrobenthic fauna consisted of annelids, molluscs and arthropods. The diversity indices signified low density. It is concluded that Osondu River is susceptible to pollution effects from construction and demolition runoffs. We therefore recommend that adequate measures be taken through legislation to regulate dumping of wastes in to the river

Development of a Solar-Powered Integrated Wireless Soil Moisture Meter

In this study, we developed a solar-powered integrated wireless soil moisture meter that can easily measure in situ soil moisture, soil temperature, and hydrogen potential (pH) using nature\u27s solar energy. Knowledge of soil moisture content and other relevant soil-specific parameters is essential for irrigation scheduling, fertilizer selection, and fertigation. Also, considering that the electricity supply in some developing countries is either erratic or unavailable, this research aims to bridge the gap in electricity availability and ease of measurement and integrate more soil-specific parameters. The sensor system was developed using the frequency domain (FD) technique for fast response. These parameters were measured sequentially at an interval of about 5 seconds, with the readings displayed simultaneously on a Bluetooth-connected device (e.g., an Android phone) located about 50 meters away from the developed system. The different sensors are classified and adequately labeled to identify the parameter to be measured. The performance evaluation carried out indicated a reasonably functioning device that is cost-effective. The results obtained showed that the system was resourceful as it not only measured the parameters of interest (soil moisture, temperature, and pH) but also gave a prompt response in measurement and transmission. Overall, the developed wireless soil moisture meter provides instantaneous data on pH, moisture, and temperature circulation across soil layers. The system is promising as it can be integrated into large-scale automated irrigation systems for agricultural lands

Mapping academic literature on governing inclusive green growth in Africa: geographical biases and topical gaps

A strong indigenous capacity for credible, salient and legitimate knowledge production is crucial to support African countries in developing their economies and societies inclusively and sustainably. In this article, we aim to quantify the current and historic capacity for African knowledge production to support the green economy in Africa, and identify important topical gaps. With a focus on topics relating to Governing Inclusive Green Growth in Africa (GIGGA), our research mapped how much Africa-focused research is being produced, from where and which African countries have higher or lower supply; and the topical focus of the research, mapping it against the African GIGGA policy discourses visible in government strategies. To do this we undertook a systematic review using a two-stage process, mapping the literature for GIGGA. This resulted in 960 verified citations. Content analysis of core metadata and article abstracts enabled mapping of the research focus. The analysis revealed a significant role for South Africa as both the pre-eminent producer of GIGGA literature as well as the geographic focus of GIGGA research, with Nigeria, Ethiopia and Kenya representing emerging loci of credible, African-relevant knowledge production. Topically, there was a strong emphasis on development, policy and environment while topics important for growth that is inclusive in character were infrequent or absent. Overall the results reinforced the view that investment is needed in research on inclusive green growth, linked to capacity building for knowledge production systems in Africa. Furthermore, from a policy perspective, policy makers and academics need to actively explore best to collaborate to ensure that academic research informs government policy