bluuebunny/crossref_metadata_2025 huggingface dataset:
Processing a Locally Sourced Gypsum Material for Medical and Industrial Applications
Authors: Ajaka Oyedele E , Ogunyebi Omolara O
Published: June 2020

Gypsum is a favourite when it comes to mimicking certain features of human body and enhancing some properties of industrial products made from it. Gypsum is widely used for medical purposes such as design of dental prosthetics and limbs support in orthopaedics; but the gypsum powder used for these products are usually well processed. Gypsum ore samples were obtained from a mine at Ibese in Ogun State, Nigeria and processed in a multistage de-gritting operation to obtain a grit-free powder which was converted to gypsum plaster (Plaster of Paris, POP) at about 220oC. The plaster powder so produced was used with property enhancing additives like calcium carbonate, sodium chloride, warm water and others to produce some medical and industrial products. Some of the medical products were tested at the State Specialist Hospital Ado-Ekiti and were found to conform with the required standard for such applications in medicine (especially dentistry and orthopedic). Other products such as chalk and wallboards were also produced from the processed gypsum and these also performed satisfactorily. Results of property tests showed that the products will have long service life.Keywords— multistage processing, de-gritting, property enhancer, dewatering, durability, dental, orthopaedics.
Capacity Analysis of a Full Duplex Device-to-Device Wireless Network using Voronoi diagrams and Distance Distributions
Authors: Ochia Okechukwu E. , Obi Elvis
Published: June 2020

Full duplex (FD) and Device-to-Device (D2D) communication are two revolutionary protocols that have enabled better spectrum utilization and more reliable data delivery in wireless networks.  In addition, stochastic geometry tools have become necessary to characterize the randomness in the present networks with respect to the irregular architecture and the competing access schemes. This work analyses the performance of a mobile network comprising nodes which are randomly distributed in a square area, which are equipped with FD radios, and can communicate using D2D. The base station (BS) nodes and user nodes in the network are modelled as points of a homogenous binomial point process (BPP) and a homogeneous Poisson point process (PPP) respectively. The network area is tessellated into cells using Voronoi diagrams which approximates to a nearest BS-to-user node association policy. The user nodes can cache popular file objects which are available in a centralized server in the network and other nodes in proximity can request for such objects and receive them using D2D. Using well known distance distribution expressions and stochastic geometry analysis, the distribution of the signal-to-interference ratio (SIR), the D2D and FD collaboration probabilities and the average coverage probability are derived. It is shown that a network-wide quality of service is maintained without additional spectrum utilization when the user nodes can be intelligently tuned to transmit and receive using FD and/or D2D modes. Keywords— Device-to-Device Communication, Full Duplex Communication, stochastic geometry analysis, Voronoi diagrams, Distance    Distributions
Effects of Welding Power Input on the Microstructure and Impact Toughness of the Heat Affected Zone of 304L Austenitic Stainless Steel
Authors: Oyetunji Akinlabi , Bodude Muideen A , Ayoola Wasiu A , Kutelu Bolarinwa J
Published: June 2020

The effects of welding power input on the microstructural characteristics and impact behaviour of the Heat Affected Zone (HAZ) of type 304L austenitic stainless steel were investigated. This is with a view to optimize the welding process and ensure high weldment integrity of the heat affected zone.  Chemical analysis of the as-received 304L austenitic stainless steel was determined using an Optical Emission Spectrometry AR 4 30 metal analyzer. Thereafter, 30 samples of the as-received 304L austenitic stainless steel plate with dimensions  of 70 mm length, 45 mm breadth and 8 mm thickness  were cut and labeled into A, B and C each of 10 numbers. The grouped samples were further cut into two equal halves with hacksaw and welded using Gas Metal Arc Welding (GTAW) process and 304L electrode to produce butt joint HAZ square geometry samples. The obtained HAZ and as-received samples were machined to standard charpy impact test specimens.  Also, the HAZ and as-received specimens were prepared for microscopy studies using optical microscopy. Results obtained showed that the microstructures are composed majorly of mixture of austenite and ferrite phases, also variations in volume fraction and grain size of the phases were observed under varied range of power input. In addition, chromium carbide formation and precipitation due to sensitization was seen at the grain boundaries. Optimum impact toughness (IT) of 42 J was obtained for HAZ sample at power input of 12.0 KW while the least IT of 39 J was obtained from sample welded using power input of 4.6 KW as compared with the as-received with IT of 58 J.Keywords - 304L austenitic stainless steel; gas metal arc welding; impact toughness; microstructures;
Power Quality Events Segmentation in a Voltage Waveform using Joint Triggering Point Detection Scheme
Authors: Okelola Muniru O , Amoo Abdullahi L , Soremekun Rasaki K
Published: June 2020

Accurate and timely detection of power quality (PQ) events is imperative for adequate corrective measures to be taken. This paper presents a method of PQ event detection development called joint triggering point detection (JTPD) scheme with a view to achieving a more accurate PQ event detection in a voltage waveform. The JTPD combines the advantage of cumulative sum (CUSUM) algorithm for the statistical distribution of a signal waveform and the discrete wavelet transform (DWT) for change-point detection. The performance of JTPD scheme using detection rate was compared with CUSUM and DWT schemes and based on the analysis, the detection rate of JTPD, CUSUM and DWT were 100%, 95% and 50% respectively. With this, the proposed approach outperformed CUSUM and DWT schemes by 5% and 50% respectively. Hence, the proposed approach is suitable for accurate detection of voltage dip, swell and interruption PQ events Keywords: Cumulative Sum, Discrete Wavelet Transform, Joint Triggering Point Detection, Power Quality, Voltage Waveform
Modification of Institute for Agricultural Research Multi-Crop Thresher for Improved Performances
Authors: Idris Sunusi I , Mohammed Usman S , Sale Nura A , Dalha Ibrahim B
Published: June 2020

In millet producing areas of Nigeria, the predominant method of threshing is traditional. It involves beating the millet panicle with a stick, over a log of wood or by pounding using mortar and pestle. This method is inefficient, time-consuming, labor intensive, prone to drudgery, uneconomical, low output and gives product contaminate with extraneous material such as stones and sand. Though imported threshers are effective in millet threshing; they are expensive, complexed in design and required skillful personnel for operation. An Institute for Agricultural Research  (IAR) multi-crop thresher for sorghum, millet, and wheat was modified for improved performances. The performance of the modified thresher was evaluated using Ex-borno variety of pearl millet. Two levels of moisture content; 9.21% and 10.81%, four feed rates levels; 3, 4, 5 and 6 kg/min, four levels of drum speed; 700, 800, 900 and 1000 rpm were considered during the experiment. The test results indicated as high as 98.78% threshing efficiency, a minimum of 1.02% grain damage, maximum cleaning efficiency of 97.19%, and 2.50% scatter loss and maximum throughput capacity of 194.02 kg/hr. In comparison to the previous thresher, threshing efficiency, mechanical grain damage, cleaning efficiency, scatter losses, and throughput capacity have improved by 2.01%, 330.56%, 9.79%, 10.78%, and 69.86% respectively. The developed thresher is anticipated to increase the farmer’s productivity due to improved performances.Keywords: Millet, Threshing Efficiency, Cleaning Efficiency, Feed Rate, cylinder Speed
Evaluation of the Performance of a Rotary screen Cowpea Cleaner-A Response Surface Approach
Authors: Aderinlewo Adewole A , Ayokambi Samuel A , Dairo Olawale U , Adeosun Olayemi J
Published: June 2020

The performance of a rotary screen cowpea cleaner was evaluated at angles of inclination of 5, 10, 15 and 20o, screen speed of 115, 145 , 200 , 280  and 300 rpm with corresponding air velocity of 0.3, 1.3, 2.2, and 2.7 m/s using two varieties of cowpea namely Ife brown and IT90K-277-2.  The results show that for Ife brown the highest cleaning efficiency of 71.12% was obtained at angle   of inclination of 5o, screen speed of 315 rpm and air velocity of 3.5 m/s. The highest cleaning efficiency for IT90K-277-2 of 68.89% was also obtained at the same angle of inclination, screen speed and air velocity. Response surface plots for both varieties showed that increase in air velocity produced more increase in the cleaning efficiency than increase in screen speed. Mathematical equations for predicting the cleaning efficiency for both varieties were also determined. Keywords— Rotary screen, cowpea, cleaning efficiency
A Study on Suitability of Foamed Sandcrete Solid Block with Fly-Ash as Partial Replacement of Sand
Authors: Popoola Monsuru O , Apampa Olanrewaju A , Adekitan Olasunkanmi
Published: June 2020

In this study, the properties of foamed sandcrete solid block (FSSB) with varying percentage of sand replacement with fly-ash were investigated. These properties include workability, wet and dry density, stability, water absorption capacity and compressive strength. 150mm cube specimens were used for the determination of both the compressive strength and the dry density of the FSSB. The plastic density was investigated using a container of known volume, and its workability determined using the slump test. The fly-ash content was varied from 0 to 50% at interval of 10%. The specimens without the fly-ash served as the control. At the designed density of 1500kg/m3, the results for the control specimens at 28 day curing age was 3.74N/mm2. As for 50% sand replacement with fly-ash, the compressive strength were 2.37 N/mm, and 3.31 N/mm2 at 7-days 28-days curing age respectively, both satisfied the minimum compressive strength of 1.8N/mm2 and 2.5N/mm2 at the curing age of 7-days and 28-days respectively for conventional sandcrete block for building wall unit as allowed by Nigerian Industrial Standard (N.I.S). The result also shows an appreciable decrease in density of FSSB with 1411.8kg/m3, as compared to dense sandcrete solid block with average of 1950kg/m3, which will significantly reduce the overall dead load of the building structure. FSSB with 50% sand replacement with fly-ash also showed a much improved water absorption capacity of 9.81% as control specimen of 11.73%. Fly-ash can be used to reduce the quantity of sand used in FSSB production; thus ridding our environment of potentially harmful wastes, as well as reduce the consumption of non-renewable resources. Keywords— Foamed Sandcrete, Compressive Strength, fly-ash, dry density, stability, cement
Comparison of Conventional Schlumberger and Modified Schlumberger Arrays in Estimating Aquifer Parameters in A Typical Basement Complex, Southwestern Nigeria
Authors: Fajana Akindeji O , Sanuade Oluseun A , Olawunmi Omolade T , Oyebamiji Ajibola R
Published: June 2020

This study compared the interpretation results of the Vertical Electrical Sounding (VES) data acquired using the conventional Schlumberger and modified Schlumberger arrays with a view to assessing the effectiveness of the modified Schlumberger arrays of VES as alternatives to the conventional Schlumberger array at sites with space constraint during geophysical exploration. A total of thirty (30) VES data for both conventional Schlumberger and modified Schlumberger arrays were collected across different rock units within Federal University Oye-Ekiti campus and Irare estate in Oye-Ekiti metropolis, south-western Nigeria, with electrode spacing (
Moisture Diffusivity and Activation Energy Estimation of White Yam (Dioscorea rotundata) Slices Using Drying Data from a Refractance WindowTM Dryer
Authors: Akinola Akinjide A , Ezeorah Stanley N
Published: June 2020

The objective of this study was to estimate the moisture diffusivity of different sizes of white yam slices at different temperatures using a Refractance WindowTM dryer. To achieve this objective, dehydration of 1.5, 3.0 and 4.5 mm thick yam slices was performed with water temperatures of 65, 75, 85 and 95 oC in the flume of a Refractance WindowTM dryer. Variation of moisture content with dehydration time data were obtained during the dehydration operations. The activation energies of dehydration for different sizes of yam slices were estimated for the temperatures considered. For the process conditions studied, the effective moisture diffusivities varied from 5.35 x 10-08 to 1.45 x 10-07 m2/s. The effective moisture diffusivity, Deff, at a specified temperature was observed to increase with increasing yam slice size. The effective moisture diffusivity, Deff, at a specified yam slice size is observed to increase with increasing dehydrating temperature. The activation energy, Ea, for the yam slices, ranged from 23.21 to 28.30 (kJ/mol) and it was observed to increase with increasing thickness of the yam slices. The activation energy values estimated were within the range observed for other equipment. This study is important in that, the moisture diffusivities and activation energy parameters estimated will be useful in the design, modelling, and optimization of such dryers. Keywords: Yams; Moisture Diffusivity; Activation Energy; Refractance WindowTM Dryer
Dynamical Control Model of the Cascaded Kainji-Jebba Hydropower Operating Head
Authors: Ogunbiyi Olalekan , Thomas Cornelius T , Omeiza Isaac A. O. , Akanni Jimoh , Olufeagba Benjamen J.
Published: June 2020

Operation and design of control system for the cascaded Kainji-Jebba hydropower system poses a great challenge to researchers and engineers. The difficulties arose from the fact that the system is affected by several nonlinear interacting factors such as variations in inflows, stochastic factors that are weather related, availability of the turbo-alternators, and numerous other constraints that are influenced by the system dynamics. All these makes the mathematical representation of the system difficult. This paper presents the development of a dynamical model for the operation and optimal control of the operating heads of the cascaded system. The mathematical models were developed from energy conversion equation and Bernoulli’s equation. The model was calibrated and tuned using measured data. Upon validation by comparing the response of the model with measured head, a deviation within  was observed, making it a good prediction of the system response and appropriate for control system design. Keywords— Control model, Discharge, inflows, Operating head, Turbo-alternators
Performance Analysis of Particle Swarm Optimization for Feature Selection
Authors: Bajeh Amos O , Funso Bukola O , Usman-Hamza Fatima E
Published: June 2020

One of the key task in data mining is the selection of relevant features from datasets with high dimensionality. This is expected to reduce the time and space complexity, and consequently improve the performance of data mining algorithms for tasks such as classification. This study presents an empirical study of the effect of particle swarm optimization as a feature selection technique on the performance of classification algorithms. Two dataset from different domains were used: SMS spam detection and sentiment analysis datasets. Particle swarm optimization is applied on the datasets for feature selection. Both the reduced and raw dataset are separately classified using C4.5 decision tree, k-nearest neighbour and support vector machine. The result of the analysis showed that the improvement of classifier performance is case-dependent; some significant improvements are noticed in the sentiment analysis datasets and not in the SMS spam dataset. Although some marginal effect are observed on performance, it implies that with particle swarm optimization features selection the space complexity is reduced while maintaining the accuracy of the classifiers. Keywords—classification, feature selection, machine learning, particle swarm optimization, text mining
Feasibility of Using Bitterness and Foaming Properties as Surrogate Instrument in Assessing Antioxidant Potentials of Selected Eggplant Cultivars
Authors: Ogunbusola Eunice M , Daramola Bode
Published: June 2020

This study attempt to circumvent the hurdle associated with the utilization of laborious and expensive procedure to assess some health promoting properties of eggplant fruits. The feasibility of using simple and cheap procedure as a surrogate tool to gain insight into the antioxidant potentials of eggplant cultivars was evaluated. Some eggplants cultivars obtained fresh were used for the work. Extracts from the garden eggs were analysed for relative reducing power, total phenolic content and radical scavenging activity using DPPH. Physical and Sensory attributes such as foaming ability and stability, and level of bitterness were also carried out. Results showed that assessment of some antioxidant markers notably total phenolic content (2.266 – 6.406), radical scavenging activity (35.00 – 82.50) and relative reducing power (0.139 – 1.145), showed positive correlation (r = 0.60281 - 0.803348; r = 0.861877 -0.905333; and r = 0.851459 - 0.958941) with bitterness, foaming capacity and foaming stability respectively. Simple and cheap quality control protocol could be used as surrogate tool to gain insight into the antioxidant markers, a health promoting endowment of some eggplants. Keywords - Eggplants, bitterness, foaming capacity, surrogate tool, antioxidant potentials.
Numerical Simulation of Conjugate Heat Transfer in Forced Convective Boundary Bilayered Cylindrical Pipe with Different Peclet Numbers
Authors: Omosehin Oluwasegun S , Adelaja Adekunle O
Published: June 2020

The heat transfer performance of bilayered composite systems through which thermally developing laminar fluids flow for cases in which axial conduction is either significant or negligible has been investigated. The heat transfer problems considered as two dimensional conjugate problems with appropriate boundary conditions were solved via computational fluid dynamics (CFD) approach in ANSYS 16.0. A parametric study was conducted to investigate the effects of Péclet number (Pe), ratio of the thermal conductivity of the laminate composite (k21) and the laminate composite dimensionless-thickness ratio  on the wall-fluid interfacial temperature and interfacial heat flux for Pe of 5, 100 and 1000, varying between 0.4 and 1.6, Bi of 5, kwf of 20, k21 between 0.025 and 1, and  of 0.71. The effect of Pe was found to be more pronounced on the interfacial heat flux. Also, the changes in k21 and were shown to reduce with reduction in Pe. Keywords— Composite cylinder, convective heat transfer, Numerical simulation; thick-walled pipes.
Characterization of Recycled Polyethylene Terephthalate Powder for 3D Printing Feedstock
Authors: Nwogu Chukwunonso N , Uche Remy , Igbokwe John O , Okoronkwo Chukwunenye A
Published: June 2020

This paper assessed the suitability of PET powder produced by crushing used plastic bottles as 3D printing feedstock. Characterization of the powder was done through determining its flow property, coefficient of friction, bulk density, flexural and tensile strengths and compared with those of ABS, PLA, PVA, Nylon and HDPE which are used conventionally 3D printing of plastic parts. Two grades of PET bottles were used in this study: grade one which is designated PET1 with intrinsic viscosity values ranging from 0.78-0.80 (used for water bottles) and grade two which is designated PET2 with intrinsic viscosity values ranging from 0.80-0.85 (used for carbonated drinks bottles). The results of the tests performed showed that PET1 has bulk density, coefficient of friction, flexural strength and tensile strength values of 0.16 g/m3, 0.43, 82.1 MPa and 63.4 MPa respectively while PET2 has bulk density, coefficient of friction, flexural strength and tensile strength values of 0.15 g/m3, 0.22, 82.7 MPa and 57.8 MPa respectively. The Experimental results show that both PET1 and PET2 have very good flow property, and are suitable for 3D printing. This study solves two major problems: plastic waste management and availability of locally produced 3D printing feedstock, which is currently the greatest challenge of 3D printing in Nigeria. Keywords— 3D printing feedstock, Characterization, Intrinsic viscosity, PET powder.
Effect of Selected Electronic Waste Dump Sites on Quality of Surrounding Water Bodies in Abuja, Nigeria
Authors: Ndububa Olufunmilayo I , Oyije Alexander O
Published: June 2020

Due to inappropriate management of vast amount of waste produced by various human activities, urban surface and ground water resources have been under danger of pollution. It is noted that solid waste management is a universal issue and that it is a growing source of worry in developed and developing countries due to the increase in urbanization, changes in consumer pattern, and industrialization which all directly transform to an increase in solid waste generation. The sampling points used of the research are Electronic Waste (e waste) dump sites of Guzape, Karmo and Kubuwa areas of Abuja with terrains of flowing surface water bodies/ pond water. The sample sites were chosen to investigate the impact of e-waste on the water quality of surrounding water bodies in the environment. Parameters measured from collected water samples are pH, Temperature, Conductivity, Turbidity, Dissolved Oxygen, Total Dissolved Solids, Total Suspended Solids, Calcium, Magnesium, Ammonia Nitrogen, Nitrate Nitrogen, Nitrite Nitrogen, Phosphate, Biochemical Oxygen Demand, Chemical Oxygen Demand, Bicarbonate, Manganese, Copper, Zinc, Lead, Cadmium and Chromium. Results showed heavy metal values for Cadmium and Manganese in the water samples were above the maximum permitted level as compared with standards for drinking water, it is inferred that the impact of E waste in the environment contributed to the presence of heavy metals in the water samples. Copper, Zinc, and Chromium were also detected in all water samples collect except for a sample with the absence of Chromium in the water sample.Key words: Disposal sites, Electronic waste, Water quality
Comparison of Nigerian Barite Production with some Top Barite Producing Countries
Authors: Kolawole Funsho O , Olugbemi Oluwamayowa M , Madueke Chioma I , Kolawole Shola K
Published: June 2020

Barite is a very important industrial minerals used as weighting material in the petroleum industry. The nature of barite ores, geology of barite ores based on location were discussed. This paper presents top barite producing countries in the world, their production and consumption of barite, as well as their reserve. Despite all the barite deposits in Nigeria, which is approximately 15 million tonnes, it still imports barite from other countries for use in the drilling of oil and gas in Nigeria. This of course brings about unnecessary expenses been incurred by the government of Nigeria. Some of the challenges faced with the mining and processing of the Nigerian Barite were discussed. Proposed solutions to the mentioned challenges were also stated. The main challenge of the Nigerian barite is not with the American Petroleum Institute (API) standard, but the policies which do not favour investors. Investment by private companies into the mineral sector of Nigeria will bring about a lot of revenue to the government, if the right things are set in place. Keywords— Barite, producing countries, low-grade
Development of Finite Element Model for the Control of Solidification Shrinkage in Al-Si (A8011) Alloy Castings
Authors: Dacosta Olusanya F , Adejuyigbe Samuel B , Olorunfemi Bayode , Adekunle Adefemi
Published: June 2020

The objective of this research work is to determine a realistic way of minimizing shrinkage in Aluminium-Silicon (Al-Si) alloy castings using finite element modelling. Finite Element method was used to discretize and solve the governing equations developed for the models using the commercial software, Comsol Multi-Physics. The models developed were validated from experimental data obtained from the foundry using six samples which were used to study the temperature profiles and nature of the solidification of the alloys. A comparison of the temperature profiles generated from the experiments and simulations show that in 64% of the processes, there were no significant differences between the experimental and simulated values. In comparing the Niyama values obtained from the experiments and those from the simulations, there were no significant differences in 46% of the processes. Threshold Niyama values of 0.143 (°C-s)1/2/mm was also established. Below these threshold values, it is predicted that shrinkage will occur in castings from these metals.Keywords— Aluminium alloy, Al-Si (A8011), Castings, Finite Element, Shrinkage, Solidification
Evaluation of Intelligent Wells Performance in a Five-Spot Arrangement
Authors: Grema Alhaji S , Kolo Abubakar S , Taura Usman H , Grema Modu B
Published: June 2020

The efficiency of water flooding processes can be improved by installing intelligent wells which are good candidates for control and optimization. Optimal control theory based on adjoint formulations was found to be efficient for reservoir optimization. However, this solution approach is local and may not be suitable for comparing design alternatives. In this work, an approach for determining an optimal starting point for optimal control theory procedure was developed to give near global optima. The performance in terms of net present value (NPV) of two forms of five-spot pattern was compared. The method results to similar performances of the two alternatives because it was formulated to give true optimal solution trajectories. It was found that regular five-spot pattern results to a NPV in excess of $4,900 over inverted design. Respective increase in oil and water productions of 0.23% and 0.22% were recorded for former design against the later.Keywords: intelligent wells; adjoint; optimal control theory; global optimum; water flooding.
Some Thermodynamic Properties of White Yam (Dioscorea rotundata) Slices Dehydrated in a Refractance WindowTM Dryer
Authors: Akinola Akinjide A , Ezeorah Stanley N
Published: June 2020

The objective of this study is to estimate the changes in Enthalpy, Entropy and Gibbs Free Energy of yam slices dehydrated at different temperatures using a Refractance WindowTM dryer. Dehydration of 1.5, 3.0 and 4.5 mm thick yam slices, was performed with water temperatures of 65, 75, 85 and 95oC in the flume of a Refractance WindowTM dryer. During the dehydration operations, the moisture-content history data were recorded. For the process conditions considered, the moisture content history data was used to calculate the moisture diffusivity and the activation energy of dehydration of the samples. Subsequently, changes in Enthalpy, , Entropy, , and Gibbs Free Energy, ), were calculated. For the process conditions studied, the changes in, , , and, varied from 20,381.33 to 25,217.05 J.mol-1., -140.69 to -122.29 J.mol-1.K-1.and 67,934.80 to 70,220.15 J.mol-1, respectively. This study is essential as knowledge of these thermodynamic parameters are useful for the optimal design and sizing of preservation dryers for argo-products. Keywords— Enthalpy; Entropy; Gibbs Free Energy; Refractance WindowTM Dryer; Yam
Development of Improved Drainage System for Storm Water flow at Isale koko Ilorin, Kwara State, Nigeria
Authors: Mokuolu Olubunmi A , Evans Victory E , Salami Wahab A
Published: June 2020

Among areas prone to flood disaster yearly in Ilorin is Isale koko.  The study involved the reconnaissance survey to ascertain the current capacity of the existing drainage in the flood disaster prone area of Isale Koko, Ilorin, Kwara State, Nigeria. The dimension of the drainage network of the area was taken at eight (8) various points and the average area of the drainage was obtained to be 0.44m². The already existing drainage in the area was divided into 3 sections for easy computations of flow value, length, depth and width. The rainfall intensity for the study area was found to be 98.49mm/hr. The rational method and Manning’s equation were used for the surface runoff and the proposed drainage respectively. The peak flow of the area and maximum flow velocity in the drains were determined to be 48.46mᶟ/s and 2.21mᶟ/s respectively. The best hydraulic section method was employed to obtain new drainage dimensions for both rectangular and trapezoidal channels. The new designed rectangular channel had dimensions of 1.16m × 0.812m while the trapezoidal channel had dimensions of 1.43m×0.72m×0.87m. The area of both channels was obtained to be 0.67m². A comparative analysis was carried against the average area of the pre-existing drainage that showed a 53.3% increase in drainage area; proving that the current drainage infrastructure of the area is grossly inadequate. Sequel to the analysis, the trapezoidal shaped drainage was recommended for the study area. Keywords—Drainage, Flood, Infrastructure, Runoff, Storm water
Effect of Process Parameters on the Surface Roughness and Kerf Width of Mild Steel during Plasma Arc Cutting Using Response Surface Methodology
Authors: Agbonoga Ekhaesomi A , Adedipe Oyewole , Okoro Uzoma G , Usman Fidelis J , Obanimomo Kafayat T , Lawal Sunday A
Published: June 2020

This study investigated the effects of process parameters of plasma arc cutting (PAC) of low carbon steel material using analysis of variance. Three process parameters, cutting speed, cutting current and gas pressure were considered and experiments were conducted based on response surface methodology (RSM) via the box-Behnken approach. Process responses viz. surface roughness (Ra) and kerf width of cut surface were measured for each experimental run. Analysis of Variance (ANOVA) was performed to get the contribution of process parameters on responses. Cutting current has the most significant effect of 33.43% on the surface roughness and gas pressure has the most significant effect on  kerf width of  41.99% . For minimum surface roughness and minimum kerf width, process parameters were optimized using the RSM. Keywords: Cutting speed, cutting current, gas pressure,   surface roughness, kerf width
Template Matching Based Sign Language Recognition System for Android Devices
Authors: Jimoh Kudirat O , Ajayi Anuoluwapo O , Ogundoyin Ibrahim K
Published: June 2020

An android based sign language recognition system for selected English vocabularies was developed with the explicit objective to examine the specific characteristics that are responsible for gestures recognition. Also, a recognition model for the process was designed, implemented, and evaluated on 230 samples of hand gestures.  The collected samples were pre-processed and rescaled from 3024 ×4032 pixels to 245 ×350 pixels. The samples were examined for the specific characteristics using Oriented FAST and Rotated BRIEF, and the Principal Component Analysis used for feature extraction. The model was implemented in Android Studio using the template matching algorithm as its classifier. The performance of the system was evaluated using precision, recall, and accuracy as metrics. It was observed that the system obtained an average classification rate of 87%, an average precision value of 88% and 91% for the average recall rate on the test data of hand gestures.  The study, therefore, has successfully classified hand gestures for selected English vocabularies. The developed system will enhance the communication skills between hearing and hearing-impaired people, and also aid their teaching and learning processes. Future work include exploring state-of-the-art machining learning techniques such Generative Adversarial Networks (GANs) for large dataset to improve the accuracy of results. Keywords— Feature extraction; Gestures Recognition; Sign Language; Vocabulary, Android device.
Development of Electromagnet for Laboratory Water Treatment Experiments
Authors: Ajiboye Aye T , Yusuf Abdulrahman O , Yusuf Kamorudeen O , Ogunlela Ayodele O
Published: June 2020

Water is said to be magnetized when it flows across the magnetic field and magnetized water finds its application in many areas of life. Despite the numerous benefits of magnetized water, very little works have been reported on the development of magnet for water magnetizer application. In most of the reported works, the detailed theoretical analysis and design procedure required for the development of the magnet was not accounted for; hence the need for the present study. Electromagnetic means of producing flux density is considered in this study due to its advantage of flux density variation, which is not achievable with the use of its permanent magnet counterparts. The design equation of short electromagnet was derived from the existing equations of coil magnetic flux density and then used for the air core electromagnet design. The variation of the magnetic flux density with the distance between two electromagnets was empirically investigated. The performance of the developed electromagnet is satisfactory, as the flux density varies between 814.6 and 510G corresponding to the gap (0 - 4cm) between the coils (i.e., water pipe diameter). Keywords— Air core, Coils, Iron core, Magnetic flux density, Magnetized water
Development of an Instrumentation System for a Laboratory Model Food Product Dryer
Authors: Ajiboye Aye T , Yusuf Abdulrahman O , Odewole Michael M
Published: June 2020

To achieve optimal dryer performance, the process parameters required for both the optimization and control of the drying process must be made available via the instrumentation system. A few works have been reported on the development of instrumentation systems for handling drying system parameters. Out of which, some are deficient in the number of drying process parameters that can be handled, while others are unreliable and inaccurate. Therefore, there is the need to develop a microcontroller-based instrumentation system that can monitor, measure, control, display and store the main drying process parameters and sample weight with a high degree of reliability and accuracy. In this study, the sensors were selected based on system specifications and interfaced with the microcontroller. The codes for controlling, logging and displaying of drying parameters were developed and installed on the microcontroller. When tested at steady-state conditions, the system yielded satisfactory results with maximum control and detection errors being 2.0% and 1.8% for the temperature and sample weight, respectively. The developed system can be used for efficient computation of both the dry and wet basis sample moisture content values and also detect the set sample weight. Keywords— Dryer, Drying parameters, Instrumentation system, Moisture content, Sensor.
Evaluation of the Hydraulic Conductivity of Compacted Laterite-Metakaolin Mixtures for Solid Waste Leachate Containment
Authors: Umar Sa’eed Y , Elinwa Augustine U
Published: June 2020

This paper presents the results of a study conducted to investigate the benefits of using metakaolin (MK) with laterite as liner material for containment of municipal solid waste (MSW). Laboratory tests were conducted on laterite specimens treated with MK at concentrations of 0 - 20 % by weight of the soil and compacted using four types of compaction energies. Hydraulic conductivity was determined based on permeation of the compacted laterite - MK mixtures with deionized water (DW) and municipal solid waste leachate (MSWL), respectively. Deionized water was the reference permeant fluid.  The results showed that hydraulic conductivity generally decreased with increase in the percentage addition of MK to the soil. From an economic and sustainability point of view, it has been found from the results that 5 % MK can be added to soil and compacted at moulding water content of 14.1 % using the West African Standard (WAS) compaction energy to achieve the regulatory hydraulic conductivity of less than or equal to 1 x 10-9 m/s for compacted soil liner. The natural logarithm of the hydraulic conductivity experimental results were computed and used to develop regression equations for estimating hydraulic conductivity given MK contents and compaction energies. The results of the two-way analysis of variance (ANOVA) test carried out at 5 % level of significance showed that calculated F-statistics are statistically significant and the measured values of hydraulic conductivity compare well with the predicted values. The developed models can therefore be used to give good estimates of hydraulic conductivity of soils having similar properties with the laterite investigated in this study. Therefore, the developed models can be used to give good estimates of hydraulic conductivity of soils having similar properties with the laterite investigated in this study. Keywords ­_ Deionized water, Hydraulic conductivity, Leachate, Metakaolin, Municipal solid waste.
Fortalecimiento de competencias laborales y la gestión de calidad de los servicios públicos
Authors: Tarazona-Pimentel Tonny H.
Published: June 2020

La presente investigación tuvo el objetivo de demostrar que el fortalecimiento de competencias laborales, tiene efecto en la gestión de calidad de los servicios públicos en la sede del Gobierno Regional y Municipal de Huánuco, durante el 2018. El estudio fue de tipo cuasi experimental con diseño pre y post test, prospectivo y longitudinal. La muestra la conformaron 356 personas, entre funcionarios y servidores públicos que laboraban en el gobierno Regional y Municipalidad de Huánuco, seleccionados no probabilísticamente. Se aplicaron previo consentimiento informado un cuestionario de conocimiento y destrezas, previamente validadas y fiabilizados. Se realizó el análisis descriptivo y en el inferencial se utilizó la prueba de rangos de Wilcoxon. En los resultados se observó que antes de la intervención, 42.7%(152) de usuarios manifestaron estar muy insatisfechos y 4.5%(16) satisfechos en cuanto a los servicios públicos municipales y regionales; en tanto en el post test se evidenció una diferencia significativa, dado que se incrementó a 40.4%(144) quienes manifestaron estar satisfechos y disminuyó a un 1.1%(4) la insatisfacción. Se concluye que el fortalecimiento de competencias laborales, tiene efecto en la gestión de calidad de los servicios públicos del Gobierno Regional y Municipal de Huánuco (Z=-16.363 con un p < 0.05).
A evasão no contexto da expansão da pós-graduação stricto sensu: uma discussão necessária
Authors: Magalhães Ana Maria Silva , Real Giselle Cristina Martins
Published: June 2020

A pós-graduação stricto sensu brasileira teve seu marco conceitual e regulatório a partir dos anos de 1960, quando passa a ser organizada no formato de sistema, que veio a ser gerenciado pela Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). Esse contexto permitiu que ocorresse significativa expansão e institucionalização da pós-graduação no Brasil nesse período de pouco mais de 50 anos. No entanto, esse crescimento é acompanhado de outras questões, como, por exemplo, a evasão, que para esse nível vem sendo pouco discutida. Com isso, o presente artigo possui como objetivo contribuir para as discussões acerca da evasão e da permanência na pós-graduação, a partir da análise das políticas que induzem o seu controle pelo órgão gestor. Para tanto, utiliza documentos oficiais de planejamento e avaliação, bem como números relativos ao ingresso, titulação e evasão presentes nas estatísticas oficiais. Como resultados, obteve-se que as políticas adotadas pela CAPES, por meio da avaliação, mostram a concepção de pós-graduação do órgão gestor voltada para a manutenção de um sistema de elite, na medida em que busca a permanência baseada na meritocracia. Infere-se, também, que esse fato pode comprometer as políticas que vêm sendo implementadas para a ampliação desse nível, inclusive por meio da indução de ações afirmativas, que ainda não tem registro de avaliação de efeitos em razão de sua adoção recente.
Educação profissional e tecnológica no Rio Grande do Sul com base em leitura das pesquisas na pós-graduação no estado
Authors: Ferreira Liliana Soares , Calheiros Vicente Cabrera , Siqueira Silvia de
Published: June 2020

O artigo sistematiza o estudo de duzentas e onze teses e dissertações sobre Educação Profissional e Tecnológica em dezoito programas de pós-graduação do Estado do Rio Grande do Sul, através da Análise dos Movimentos de Sentidos. Não somente inventaria, conhece e arrola os trabalhos produzidos, mas compara a abordagem temática em relação à EPT e à pesquisa na pós-graduação, em uma perspectiva de “metaconhecimento”, aprender a conhecer enquanto se conhece. São descritos os aspectos teóricos e metodológicos da pesquisa realizada, as análises e considerações finais, à guisa de uma indagação sobre o sentido de estudar-se o que já foi produzido. Constatou-se que a pesquisa sobre EPT é recente, ainda busca sua estabilidade.  Do mesmo modo, a abordagem da modalidade é tangenciada, pois os trabalhos, de maneira geral, referem-se a aspectos que têm a EPT como localização espaço-temporal, mas não abordam a modalidade em si, contribuindo para que solidifique uma produção teórica que a dimensione e fortaleça. Em decorrência, não há uma abordagem teórica própria e elaborada a partir dessa modalidade.
Políticas públicas em educação e a garantia do direito à educação no contexto de desigualdade social no Brasil
Authors: Mello Rachel Costa de Azevedo , Moll Jaqueline
Published: June 2020

Este artigo resulta de uma pesquisa bibliográfica, que tem por objetivo analisar a relação entre as desigualdades sociais, as desigualdades educacionais, o fracasso escolar e a meritocracia no contexto educacional brasileiro. A meritocracia, enquanto subjetividade, contribui para a permanência das referidas desigualdades e do fracasso escolar. Assim, buscamos compreender a importância da proposição de políticas públicas em educação como forma de enfrentamento das desigualdades educacionais e como garantia do direito à educação. O argumento teórico do artigo fundamenta-se em Arroyo (2010), Ball, Maguire e Braun (2016), Castro (2003a, b), Quijano (2010), Galeano (2017), Teixeira (1994), Bobbio (1992), Moll (2017) e Souza (2009). Concluímos, a partir do diálogo com esses autores, que políticas públicas em educação, de caráter democrático e enquanto diretrizes educativas, podem contribuir com a escola pública no cumprimento de sua função constitucional de ser responsável pela garantia da educação enquanto direito social dos estudantes brasileiros.
Jogo limpo na construção do currículo de aprendizagem de inglês?
Authors: Souza Valeska Virgínia Soares
Published: June 2020

Nesse texto de pesquisa narrativa, narro e componho sentidos de minhas experiências docentes, norteadas pelo uso de jogos digitais e não digitais e permeadas de tensões, incertezas e aprendizagem. Sigo os pressupostos da Pesquisa Narrativa segundo Clandinin e Connelly (2000), que propõem que a narrativa seja ao mesmo tempo o método de pesquisa e o fenômeno pesquisado. As histórias que narro se referem àquelas vividas com estudantes de duas turmas de língua inglesa, que cursavam o centro de idiomas em um Instituto Federal. Para o desenho do currículo do curso, questionei a narrativa dominante do uso de livro didático de renome internacional e planejei a integração de premissas de gamificação e de jogos, no intuito de propiciar engajamento de meus alunos. Mesmo ciente de que estava entrando em campo no entremeio e de que deveria considerar meu conhecimento prático-pessoal e prático-profissional, surpreendi-me quando desempacotei algumas histórias de competição narradas. Busquei subsídios teóricos acerca de currículo e de jogos para compor sentidos das tensões ao negociar o currículo que estava construindo na paisagem de conhecimento profissional. Ao viver dilemas ontológicos, epistemológicos e metodológicos, compreendi como algumas práticas docentes adotadas foram contra o que compreendo como jogo limpo na educação e lancei um novo olhar sobre o conceito de competição.
Gaming alone or together? L2 beginner-level gaming practices
Authors: Gonzalez-Lloret Marta , Diez Ortega María , Payne Scott
Published: June 2020

Games are seen as beneficial for language learning because they facilitate rich, authentic communication, and promote collaborative practices which are effective for language learning. However, most of the studies to date investigating games for L2 learning have focused on intermediate or advanced learners, and we know very little of how games can be best utilized with beginner-level learners. This study investigates beginner-level learners of Spanish engaged in a task-based educational game in which they interacted through an avatar with game characters in a study abroad setting. Although the game is designed to be played individually, we hypothesized that playing collaboratively would bring more language negotiation, which in turn promotes language acquisition (SWAIN, 2000). Four intact first semester classes in a US university participated in the research. Two classes acted as control group and engaged in technology activities that were not the game and two classes played the game either individually or in dyads. Students’ grammar, vocabulary, reading, and writing were compared after the treatment. In addition, pre- and post-treatment motivation surveys were conducted to find out students’ perspectives on the game playing and whether their opinions had changed after the experience. Although students gaming in dyads outperformed the other groups in all measures, the differences were not statistically significant. However, there were clear differences in the learners’ perspective towards playing in dyads versus playing individually. In addition, the qualitative analysis of the data revealed multiple instances of language related episodes which have been demonstrated beneficial for language learning.