bluuebunny/crossref_metadata_2025 huggingface dataset:
Change Management
Authors: Travassos Ricardo Jorge , Martins Nuno Sérgio , Sousa João Pedro , Mota Ricardo Barata
Published: June 2021

The present markets affect organizations by triggering the need for change. However, in addition to flexibility, it is considered the implementation of procedures to alleviate the ‘weather'. So, change management is fundamental in organizations that move in innovative and disruptive environments. The present work seeks to provide a tool that will allow the collection and structuring of the constituent data necessary for the management of new projects/products, creating relevant information to strategic decision makers, stating that the exploratory cycle of the process intends to create organizational knowledge that will 'situate' all team members within the various projects. It will consist of a literary review followed by the presentation of a case study, which can be applied in an SME due to its technical simplicity. The objective is to support the proposal as a promoter of information and knowledge management. The work ends with a critical analysis of the contents, exposure of limitations, and suggestions for possible future work associated with the current theme.
An Explorative Study of Coping Mechanisms Towards Vulnerability and Victimization Within Commercial Sexual Exploitation in India
Authors: Nair Vipin Vijay , Sahni Sanjeev P. , Andzenge Dick D. T.
Published: June 2021

Trafficking for commercial sexual exploitation constitutes more than 59% of the entire trafficking industry. An efficient rehabilitation model reflects the utilization of the victim's coping mechanism to overcome the stress and trauma of past victimization. The main aim of the study is to explore various coping mechanisms utilized by both victims of commercial sexual exploitation and individuals vulnerable to commercial sexual exploitation at rehabilitation and protective homes in India. The research utilized the participatory action research with stress coping behavior scale to understand the various employed coping mechanism by the beneficiaries of rehabilitation and protective (R&P) homes. In total, 30 victims of commercial sexual exploitation and 30 individuals vulnerable to commercial sexual exploitation, aged 18-50 years, participated in the study. The statistical analysis identified pursual of specific coping by participants and measured risk ratio reflected the relative risk of alcohol and drug use over prior exposure to commercial sexual exploitation.
Understanding Decisions to Share Minor Public Safety Incidents on Twitter Through a Collective Action Theory Lens
Authors: Almoqbel Mashael Yousef , Alraihan Marwa Khalid , Wohn Donghee Yvette
Published: June 2021

Social media feeds provide a lot of information that would be of great value to law enforcement. Previous research dedicated considerable attention to sharing large-scale public safety incidents on social media. However, little research focused on minor public safety incidents. According to collective action theory, rational people would not participate in a public good unless there are external incentives other than the benefit from the public good. In this research, the authors use this theory to test public safety as the public good and see if such incentives have an effect on people's decisions to share incidents. They utilize a survey of U.S. adults with a sample of 285 participants. In this research, they hypothesize a positive relationship between decisions to share and engage in public safety on social media and 1) incident location proximity, 2) relationship with the victim, and 3) coercion. Results show general support for the theory's assumptions.
Modeling and Solution Algorithm for Optimization Integration of Express Terminal Nodes With a Joint Distribution Mode
Authors: Meng Fanchao , Ji Qingran , Zheng Hongzhen , Wang Huihui , Chu Dianhui
Published: June 2021

The rapid development of e-commerce has led to increased pressure on the express delivery industry to transport products to customers in a timely manner. The problem of how to deliver an increasing volume of express orders to customer clusters in a timely manner and at low cost with the joint distribution mode is becoming urgent. In this study, an express terminal node optimization and integration model is presented with an option to detach single customer clusters. In addition, the simulated annealing algorithm (SAA) based on neighborhood search that includes four rules is proposed to solve the problem. Contrast experiments are performed with SAA, the immune genetic algorithm (IGA), and the CPLEX solver. The experimental results indicate that IGA is less effective than SAA, and the running time of the IGA is longer. The CPLEX solver is less effective than the SAA, too. Additionally, the experimental results also show that every neighborhood rule proposed in this study plays a role in the optimization process.
Emotions and Spillover Effects of Social Networks Affective Well Being
Authors: Rubin Eran , Beuk Frederik
Published: June 2021

A growing body of literature supports the notion that the well-being of individuals is influenced by their social networks site (SNS) experiences. In this research, the authors analyze the effect of such SNS experience perceptions, termed social networks affective well-being (SNAWB) on behavior in non-SNS sites. Specifically, the authors ask if the visual interface design of a non-SNS site affects the level to which the decisions made in that site are influenced by the decision maker's SNAWB. Relating to theory on emotion and action readiness, this research hypothesizes on the expected effects of a visual interface design that includes elements that may trigger SNS-related emotions. To test the hypothesis, this paper conducts two experiments: 1) an online experiment and 2) a controlled lab experiment with eye-tracking. The results show that individuals' decisions are affected by the level to which the website interface design may trigger SNS emotions. The results further provide evidence on the emotional process leading to different effects according to the type of decision made.
Reducing Intubation Time in Adult Cardiothoracic Surgery Patients With a Fast-track Extubation Protocol
Authors: Ellis Myra F. , Pena Heather , Cadavero Allen , Farrell Debra , Kettle Mollie , Kaatz Alexandra R. , Thomas Tonda , Granger Bradi , Ghadimi Kamrouz
Published: June 2021

Background

Prolonged intubation after cardiac surgery increases the risk of morbidity and mortality and lengthens hospital stays. Factors that influence the ability to extubate patients with speed and efficiency include the operation, the patient’s baseline physiological condition, workflow processes, and provider practice patterns.

Local Problem

Progression to extubation lacked consistency and coordination across the team. The purpose of the project was to engage interprofessional stakeholders to reduce intubation times after cardiac surgery by implementing fast-track extubation and redesigned care processes.

Methods

This staged implementation study used the Define, Measure, Analyze, Improve, and Control approach to quality improvement. Barriers to extubation were identified and reduced through care redesign. A protocol-driven approach to extubation was also developed for the cardiothoracic intensive care unit. The team was engaged with clear goals and given progress updates.

Results

In the preimplementation cohort, early extubation was achieved in 48 of 101 patients (47.5%) who were designated for early extubation on admission to the cardiothoracic intensive care unit. Following implementation of a fast-track extubation protocol and improved care processes, 153 of 211 patients (72.5%) were extubated within 6 hours after cardiac surgery. Reintubation rate, length of stay, and 30-day mortality did not differ between cohorts.

Conclusions

The number of early extubations following cardiac surgery was successfully increased. Faster progression to extubation did not increase risk of reintubation or other adverse events. Using a framework that integrated personal, social, and environmental influences helped increase the impact of this project.
The relationship between pressure and volume when using Rapid Rhino(r) packs in the management of epistaxis
Authors: Mackeith S. , Hettige R. , Falzon A. , Draper M.
Published: June 2021

Despite the popularity of Rapid Rhino packs, there are no clear guidelines regarding the volume of air to be inflated when used in the management of epistaxis. The manufacturers suggest that subjective assessment by pilot cuff palpation is used to guide inflation. However, studies have clearly demonstrated that clinicians are poor at judging balloon pressure by pilot cuff palpation when used in other settings. Our objective was to investigate the relationship between the volume of air inflated and the resultant intra-nasal pressure generated by nasal balloon packing. Twelve healthy subjects were packed with 5.5 cm Rapid Rhino packs, which were connected to a manometer and 20 ml syringe via a 3-way tap in a closed circuit. Increments of 2.5 mls of air were inflated and the resultant intra-nasal pack pressure was measured. There appeared to be a linear relationship between increasing volume and pack pressure. However, between individuals, there was a large variation in the intra-nasal pack pressure produced for a given fixed volume of air inflated. This is presumably due to variations in nasal anatomy. It may be that a manometer-measured, pressure guided nasal pack inflation technique would represent best practice, especially for less experienced staff.
Impairment of nasal mucociliary clearance in former smokers with stable chronic obstructive pulmonary disease relates to the presence of a chronic bronchitis phenotype
Authors: Koblizek V. , Tomsova M. , Cermakova E. , Papousek P. , Pracharova S. , Mandalia R.A.A. , Ceral J. , Novosad J. , Fila L. , Sedlak V. , Ruta J. , Bartos V. , Salajka F. , Hrnciarik M.
Published: June 2021

Background: Associations between nasal and bronchial impairment have been repeatedly described in chronic obstructive pulmonary disease (COPD), whereas nasal mucociliary clearance (MCC) in COPD patients is not yet fully understood. We studied nasal MCC parameters in COPD patients and compared them with healthy adults (HA) and with cystic fibrosis (CF) patients with compromised MCC. Methodology: An observational study of 98 COPD ex-smokers and subjects from control groups evaluated for nasal MCC time (NMCCt) and by digital video microscopy of nasal mucosa recording ciliary beat frequency (CBF) and ciliary beat pattern. Results: The NMCCt was decreased in HA compared to those with COPD and decreased in those with COPD compared to those with CF. CBF in COPD was lower compared to HA. The index of ciliary dyskinesia in COPD patients differed from HA. We detected higher NMCCt and lower nasal CBF in patients with chronic bronchitis phenotype (CB) compared to non-CB patients. Conclusions: We confirmed the presence of impaired nasal MCC in COPD ex-smokers. These impairments were apparent predominantly in the CB phenotype.
A multi-centre study on quality of life and absenteeism in patients with CRS referred for endoscopic surgery
Authors: Sahlstrand-Johnson P. , Ohlsson B. , Von Buchwald C. , Jannert M. , Ahlner-Elmqvist Marianne
Published: June 2021

Aims: This study summarises the health-related quality of life (HRQOL) scores and absenteeism caused by sinus problems in patients awaiting surgery with the diagnoses recurrent acute rhinosinusitis (RARS), chronic rhinosinusitis with nasal polyps (CRS+NP) or CRS without nasal polyps (CRS-NP), in a prospective multi-centre study. Methodology: Two hundred and seven patients with RARS, CRS+NP or CRS-NP were enrolled. EP3OS definitions of CRS and NP were used. The patients completed the 22 Sinonasal Outcome Test (SNOT-22), the short-form 36-item questionnaire (SF-36), the Hospital Anxiety and Depression Scale (HAD) and a total Visual Analogue Scale (VAS) regarding rhinosinusitis symptoms. Results: SNOT-22 and VAS scores indicated severe disease. Comparison of the HRQOL scores in the three rhinosinusitis subgroups showed statistical differences in nine of the SNOT-22 items and in the SF-36 subscale of bodily pain. Mean scores of SF-36 were significantly lower than that of the normal Swedish population. According to the HAD scores, 28% of the patients had probable or possible anxiety or depression disorder. Fifty-seven percent of the patients reported absenteeism from work due to sinus problems. Conclusions: RARS, CRS+NP and CRS-NP significantly decrease HRQOL. Some statistically significant differences in HRQOL were found between the three rhinosinusitis subgroups. Absenteeism due to chronic sinus conditions is considerable.
Allergic rhinitis and associated factors in schoolchildren from Bogota, Colombia
Authors: Penaranda A. , Aristizabal G. , Garcia E. , Vasquez C. , Rodriguez-Martinez C.E. , Satizabal C.L.
Published: June 2021

Background: Allergic rhinitis is one of the most frequent chronic diseases among children. The objective of the study was to assess the prevalence of and the factors associated with self-reported allergic rhinitis symptoms in schoolchildren from Bogota, Colombia. Methodology/principal: We followed the International Study of Asthma and Allergies in Childhood (ISAAC) methodology. Our sample included 3,256 children aged 6 - 7 and 3,830 adolescents aged 13 - 14 years. Results: The prevalence of self-reported allergic rhinitis symptoms was 30.8% among children and 36.6% among adolescents. Factors associated with self-reported allergic rhinitis among children included current asthma and atopic dermatitis symptoms; use of acetaminophen in the first year of life and in the last 12 months; antibiotic use in the first year of life; high- school and university maternal education; smokers at home; and caesarean delivery. Among adolescents, associated factors included current asthma and atopic dermatitis symptoms; current acetaminophen use once per month; frequent fast-food consumption; cat exposure at home; and smoking. Conclusion: Further exploration of factors associated with allergic rhinitis symptoms is needed.
Sinonasal malignant melanoma: an analysis of 115 cases assessing outcomes of surgery, postoperative radiotherapy and endoscopic resection
Authors: Lund V.J. , Chisholm E.J. , Howard D.J. , Wei W.I.
Published: June 2021

Background: Melanomas account for 4% of sinonasal malignancies. We present the largest single institution series reported thus far and analyze the outcome with reference to lymph node involvement, radiotherapy and endoscopic resection. Methodology: Survival and recurrence data were analyzed on sinonasal melanoma cases collected from 1963-2010 to compare treatment strategies and to ascertain factors predicting outcome. Results: 115 cases (mean age 65.9) were treated at our institution during this period. All underwent surgical resection of the tumour, 31 (27%) endoscopically, and 51 (44%) also received radiotherapy. Five year overall survival was 28% and disease-free survival was 23.7%. Local control was achieved for a median of 21 months, 5-year disease control rate of 27.7%. Endoscopically resected cases showed a significant overall survival advantage up to 5 years. Radiotherapy did not improve local control or survival. Cervical metastases conferred a dramatically worse outcome. Conclusions: Endoscopic resection of sinonasal melanoma does not prejudice outcome. The role of radiotherapy is unproven.
An ICT-Based Extension Services’ Adoption Model for Public Extension Officers: A Case in Mali
Authors: Kante Macire
Published: June 2021

The realization of higher yield and therefore agricultural productivity cannot be achieved without information. That information is disseminated in developing countries, particularly Mali by government-led extension services. However, there are few (public) extension officers to disseminate that information. That makes the use of other means such as ICT one of the best way to disseminate the extension services. This paper, firstly, looked at the drivers and challenges of the adoption of ICT based extension services by public extension officers in Mali from the literature to propose a conceptual framework. Secondly, the study assessed the survey questionnaire and thirdly, evaluated the proposed model. A sequential exploratory research design was followed. It consisted of conducting indept-interviews with 12 key stakeholders (agricultural scientist, policymakers, IT professional and head of extension services) in Bamako and Koulikoro. These data were analysed using computer-assisted qualitative data analysis software (RQDA) to contextualise the proposed conceptual framework. Thereafter, a survey questionnaire was designed and administered to 21 public extension officers in in Bamako, Kati and Koulikoro. Quantitative Data was analysed using Partial Least Square Structural Equation Modelling with the aid of the software Smartpls 3.2.8. This study validated a questionnaire of 19 items out of 26 for the next phase of the study with more respondents. Additionnaly, the results revealed that Relative Advantage, High Cost, Compatibility, Complexity, ICT-Skills and Policy explained 48.4% of the variance of the adoption of ICT based extension services by public extension officers.
PREDICTION OF SHEAR RESISTANCE FACTOR IN FLAT SLABS DESIGN USING CRITICAL PERIMETER OF SUPPORTING COLUMNS
Authors: Idagu FO , Ogarekpe NM , Ugama TI
Published: June 2021

The distribution of shear stresses at the slab–column connection of flat slabs become non–uniform in the presence of unbalanced moment. The shear resistance (β) factor is used to account for this distribution of shear stresses due to the transfer of unbalanced moment at the slab–column connections. The provisions of the American, Canadian, European and Model codes, regarding the transfer of unbalanced moment at slab–column connections of flat slabs are compared. The relationship of β-factor to the ratio of critical perimeter to the control perimeter of an internal column have been plotted as a simplified approach and additional approximate factors have been found for an internal corner column and various locations of cantilevered edge, corner and internal corner columns encountered in practice by engineers. These additional approximate factors have been proposed for inclusion in European code for situations where adjacent spans do not differ by more than 25%.http://dx.doi.org/10.4314/njt.v36i1.1
A NEURO FUZZY MODEL FOR THE INVESTIGATION OF DETERIORATION OF METALLIC PIPE CONVEYING FLUID UNDER DIFFERENT PIPE BURIAL DEPTH, SOIL TYPES AND PROPERTIES
Authors: Akano TT , Fakindele OA , Mgbemere HE , Amechi JC
Published: June 2021

Several factors may contribute directly or indirectly to the structural failure of metallic pipes. The most important of which is corrosion. Corrosivity of pipes is not a directly measurable parameter as pipe corrosion is a very random phenomenon. The main aim of the present study is to develop a neuro-fuzzy model capable of establishing corrosion rate criterion as a function of pipe burial depth, soil types, and properties for the prediction of deterioration of metallic pipe conveying fluid. The proposed model includes a fuzzy model and the artificial neural network (ANN) to determine soil corrosivity potential (CoP) based on soil properties. The combination contains the data of linguistic variables characterising various soil properties, and learning capability of the system that constructs relationships among those soil properties and CoP. Subsequently, the artificial neuro-fuzzy inference system (ANFIS) maps each element of its input membership function to an output membership function between 0 and 1 to determine the deterioration rate (CoP) of metallic fluid-conveying-pipe. Field data from buried fluid pipes were examined to illustrate the application of the proposed model. The ultimate goal is the ability to access the current and future life of oil pipe, given a set of circumstances, and also appropriate adoptable methodology in view of a preventive maintenance measure for the pipes in a given operating environment. Results reveal that with more than 40% clay content quickens corrosion of buried fluid pipes more than any other considered factor. http://dx.doi.org/10.4314/njt.v36i1.10
MODELLING OF RESPONSES FROM ORTHOGONAL METAL CUTTING OF MILD STEEL USING CARBIDE INSERT TOOL
Authors: Onifade MK , Igboanugo AC , Osarenmwinda JO
Published: June 2021

The purpose of this research was to develop models for the prediction of responses from orthogonal metal cutting process that are responsible for the machinability ratings of this technological system. Mild steel work-piece material that is representative sample for various industrial applications was machined. The various industrial applications of this representative sample range from mechanical shafts to fasteners, screws and hydraulic jack. These machine elements require high degree of surface finish. A fifteen-run based Box-Behnken response surface design was created using widely established machining parameters, namely cutting speed, feed rate and depth of cut. The optimum predicted responses from the orthogonal cutting process for the optimal process parameters are 0.1742 micron, 0.4933 micron, 0.1845 micron, 0.3673 micron, 794.6839 seconds and 19.642 seconds for the Ra, Rz, Rq, Rt, TL and M/C time respectively. The associated desirabilities for these optimum responses are 1.000000, 1.000000, 1.000000, 1.000000, 0.524122, and 0.361858 respectively.   http://dx.doi.org/10.4314/njt.v36i1.13
PRELIMINARY MULTIDOMAIN MODELLING AND SIMULATION STUDY OF A HORIZONTAL AXIS WIND TURBINE (HAWT) TOWER VIBRATION
Authors: Iliyasu I , Iliyasu I , Tanimu IK , Obada DO
Published: June 2021

Renewable energy sources have gained much attention due to the recent energy crisis and the urge to get clean energy. Among the main options being studied, wind energy is a strong contender because of its reliability due to the maturity of the technology, good infrastructure and relative cost competitiveness. It is also interesting to note that there are physical limits to the potential height of a wind turbine tower since the mechanical structure of wind turbines are thus very flexible and tend to oscillate. This makes the design of wind turbines a demanding task. In this paper, the oscillation of a wind turbine tower due to imbalance in the masses of the blades is modeled in maplesim and the effect of the tower height on its oscillation was simulated. For a wind turbine with three rotor blades, two of which have masses of 10 kg, a mass moment of inertia of approximately 20 kg/m2 and one of the blades has a moment of inertia which is 1% less than the other blades. The simulation showed the most stable system for the most energy capture for this case study to be a rotor speed of 5.5rad/s at a height of 10m. At this angular frequency the deflection of the top of the wind turbine was approximately 1mm.  http://dx.doi.org/10.4314/njt.v36i1.16
AUTOMATIC GENERATION OF ROOT LOCUS PLOTS FOR LINEAR TIME INVARIANT SYSTEMS
Authors: Durutoye N , Ogunbiyi O
Published: June 2021

Design and analysis of control systems often become difficult due to the complexity of the system model and the design techniques involved. This paper presents the development of a Tools Box in Microsoft Excel for control engineer that uses root locus as a time domain technique for system design and analysis. The Tool Box can also serve as a computer-aided graphical analytical tool for trainers. The work was done in two phases: the first phase is the development of a programmable algorithms for root locus using the angle condition and bisection method while the second phase is the implementation of the developed algorithms. The implementation was done using Microsoft Excel (R) Visual Basic Application (VBA). Results of simulations for different systems show the potential of the Tool Box as an alternative for other software package and the ease of using it on the readily available Microsoft Excel environment.   http://dx.doi.org/10.4314/njt.v36i1.20
RECEIVE SIGNAL STRENGTH PREDICTION IN THE GSM BAND USING WAVELET DECOMPOSITION
Authors: Danladi A , Silika NW , Vasira PG
Published: June 2021

In this work, GSM receive signal strength was monitored in an indoor environment. Samples of  GSM receive signal strength was measured on a Mobile Equipment (ME). One-dimensional multilevel wavelet decomposition technique was used to predict the fading phenomenon of the GSM receive signal strength measured. Wavelet prediction revealed that the GSM receive signal strength is attenuated due to the slow fading phenomenon, which fades about 3 times faster than the radio wavelength. The prediction is further validated using probability density functions in terms of Gaussian and Rayleigh distributions. It is observed that, significant part of the signal strength measured is dominated by good signal (- 101 dBm to – 74 dBm) with an average of – 88.8842 dBm and the signal strength followed more of Gaussian than Rayleigh distribution. This confirmed the wavelet prediction.  http://dx.doi.org/10.4314/njt.v36i1.22
VOLTAGE COMPENSATION USING ARTIFICIAL NEURAL NETWORK: A CASE STUDY OF RUMUOLA DISTRIBUTION NETWORK
Authors: Uhumnwangho R , Omorogiuwa E , Offor G
Published: June 2021

A study of hourly voltage log taken over a period of six months from Rumuola Distribution network Port Harcourt, Rivers State indicates that power quality problems prevalent in the Network are undervoltage/voltage sags and overvoltage/voltage swells. This paper aims at addressing these power quality problems in the distribution network using artificial neural network (ANN) controller based dynamic voltage restorer (DVR). The artificial neural networks controller engaged to controlling the dynamic voltage restorer were trained with input and output data of proportional integral (PI) controller and of unit amplitude generator obtained during simulation. All simulations and modeling were carried out in MathLab/Simulink. Proposed dynamic voltage restorer was tested with replicated model of Rumuola substation by simulating with sample of average voltage for Omerelu, Waterlines, Rumuola, Shell Industrial and Barracks feeders. Simulation results showed that DVR is effective in compensating for under-voltage and over-voltage in Rumuola Distribution network Port Harcourt, Rivers State. http://dx.doi.org/10.4314/njt.v36i1.23
A RAPID HEALTH IMPACT ASSESSMENT OF THE UNIVERSITY OF ILORIN DAM
Authors: Bilewu SO , Ayanshola AM , Salami AW
Published: June 2021

Many Dams have been constructed in different parts of the world and for different purposes. While these dams have in most cases served the reason for their construction, the resultant environmental impact have been a subject of concern. The creation of a reservoir not only changes the ecology and hydrology of the environment, the lives of nearby residents is also affected. This study assessed the impact of the University of Ilorin Dam on the health condition of the University community. The Dam was built for the main purpose of water supply to university community. Data on the water related disease reported and documented at the university clinic was obtained to cover pre and post construction period while the perception and behavioral pattern of the community as related to water and sanitation was studied with the help of a structured questionnaire. The chi-squared test was applied to establish that a relationship do exist between the dam construction and the occurrence of some diseases especially Malaria. The study have also shown that the dam imposes no significant negative health impact on the university community. http://dx.doi.org/10.4314/njt.v36i1.28
FREQUENCY ANALYSIS OF RAINFALL FOR FLOOD CONTROL IN PATANI, DELTA STATE OF NIGERIA
Authors: Okeke OB , Ehiorobo JO
Published: June 2021

The Niger Delta Region of Nigeria is within the mangrove forest region and is crisscrossed by series of streams and creeks. As a result of the high rainfall volume within this region there is a tendency for severe flooding to occur. These flood events have severe consequences on lives and properties. It is therefore necessary to carry out a flood frequency analysis in this area in order to predict the potentials for the occurrence of flooding and take necessary measures for their remediation. In this study, peak monthly rainfall for thirty three years from 1981 – 2013 were acquired for Patani area in the Niger Delta region of Nigeria from NIMET and CBN. Five probability distributions, namely Normal, Log normal, Log-Pearson, Gumbel  and Foster’s Type -1  were selected for frequency analysis of the precipitation data using return periods of 2, 5, 10, 25, 50, 100 and 200 years respectively. The predicted values were subjected to goodness of fit tests using ANFIS tool in the MATLAB 7.0 software. The results of the tests and analyses show that the Gumbel Distribution best describes the precipitation data for the region and can therefore be used for the prediction of flooding within the study area followed by the Foster’s Type- I distribution. The Normal Distribution was on the other hand found the least suitable for describing the precipitation data for Patani area.  http://dx.doi.org/10.4314/njt.v36i1.34
DEVELOPMENT AND TESTING OF MULTI-LEVEL TEMPERATURE PROBE FOR UNDERWATER APPLICATION IN WETLAND SYSTEMS
Authors: Udom IJ , Mbajirogu CC , Daniyan I
Published: June 2021

Temperature variation in wetland systems is of great importance. Temperature exerts a strong influence on chemical and biological processes leading to water quality treatment and is therefore important for wetland designers trying to both calculate accurate rates of treatment as well as optimize wetland systems for pollutant removal. Temperature fluctuations can result in thermal inversions. Temperature measurements are important for understanding hydrological and ecological processes in wetlands. Temperature measurements in underwater conditions is challenging in terms of cost and thorough insulation for optimal performance. This work presents the design and development of a water-resistant, adjustable multi-sensor temperature probe for underwater temperature measurement. It consists of three digital sensors DS18B20 interfaced with Atmega 328P microprocessor. The system is equipped with a 20×4 LCD display which displays up to three temperature profiles at varied depths. Validation of the instrument with the hand-held mercury-in-glass thermometer at different temperature regimes showed a +/- 0.5 accuracy within a temperature range of -10oC to +85oC. http://dx.doi.org/10.4314/njt.v36i1.38
OPTIMISATION OF COMPRESSIVE STRENGTH OF PERIWINKLE SHELL AGGREGATE CONCRETE
Authors: Egamana S , Sule S
Published: June 2021

In this paper, a regression model is developed to predict and optimise the compressive strength of periwinkle shell aggregate concrete using Scheffe’s regression theory. The results obtained from the derived regression model agreed favourably with the experimental data. The model was tested for adequacy using a student t-test at 95% confidence level and was found to be adequate. A computer programme coded in basic language was used to select the mix ratios that optimized the compressive strength of periwinkle shell aggregate concrete. The optimum compressive strength was found to be 19.50N/mm2corresponding to a mix ratio of 1:3:6 (cement, sand and periwinkle shell) at a water-cement ratio of 0.65. With the formulated model, the mix ratios corresponding to a desired strength value can be predicted with reasonable accuracy and without waste of time. http://dx.doi.org/10.4314/njt.v36i1.5
DEVELOPED PROBABILISTIC REDUCTION FACTORS FOR LOPHIRA ALATA (EKKI) TIMBER JOISTS SUBJECTED TO CREEP-RUPTURE
Authors: Kaura JM , Lawan A , Salihu AA
Published: June 2021

Wood experiences a significant loss of strength and stiffness when loaded over period of time. This phenomenon is known as creep-rupture. Several models were developed for the estimation of the reduction of load carrying capacity of timber with time. In this paper, the results of time dependent structural reliability analysis of timber joist produced with Lophiraalata (Ekki) timber specie was presented. Three load duration models were considered in the study, namely: The Model proposed by Wood, Gerhards model, and Nielsen. The timber joist was designed in accordance with the Eurocode 5. The uncertainties in all the basic design variables were fully accommodated in the time dependent reliability analysis. The entire process was implemented using a developed MATLAB program employing First Order Reliability Method (FORM). Time dependent mathematical models for modification of safety index to account for the effect of load duration were proposed. The use of both Gerhards and Nielsen model, for the design of Lophiraalata timber members was recommended.  http://dx.doi.org/10.4314/njt.v36i1.6
COMPARATIVE STUDY OF BS 8110 AND EUROCODE 2 IN STRUCTURAL DESIGN AND ANALYSIS
Authors: Nwoji CU , Ugwu AI
Published: June 2021

This work was undertaken to compare the use of BS 8110 and Eurocode 2 in the design of structures and focused on outlining the relative gains and/or shortcomings of Eurocode 2 and BS 8110 under certain criteria which are loading, analysis, ease of use and technological advancement. To accomplish this, the analysis and design of the main structural elements in reinforced concrete building was undertaken using the two codes. A modest medium rise building was loaded using the two code and analyzed. Analysis was done using CSI start tedds to obtain the shear force and bending moment envelopes. For the beam, it was found that Eurocode 2 gave higher internal supports moments. For the case of maximum span moments and shear force values, the Euroode 2 values lagged behind. Column load and moments values were generally lower for Euroode 2. In summary, the comparative benefits of using Euroode 2 are that it is logical and organized, less restrictive and more extensive than the BS 8110. The new Eurocodes are claimed to be the most technically advanced code in the world and therefore should be adopted by Nigerian engineers.Â http://dx.doi.org/10.4314/njt.v36i3.14
BESSEL FUNCTIONS FOR AXISYMMETRIC ELASTICITY PROBLEMS OF THE ELASTIC HALF SPACE SOIL: A POTENTIAL FUNCTION METHOD
Authors: Ike CC , Onah HN , Nwoji CU
Published: June 2021

Elasticity problems are formulated using displacement methods or stress methods. In this paper a displacement formulation of axisymmetric elasticity problem is presented. The formulation uses the Boussinesqâ€“ Papkovich â€“ Neuber potential function. The problem is then solved by assuming Boussinesq â€“ Papkovich - Neuber potential functions in the form of Bessel functions of order zero and of the first kind. The potential functions are then made to satisfy the governing field equations and the associated boundary conditions for the particular problem of a point load at the origin of the semi-infinite linear elastic isotropic soil mass. The unknown parameters of the function are thus determined and used to find the stresses, strains and displacement fields in the loaded soil. The results obtained were identical with the results obtained by Boussinesq.Â http://dx.doi.org/10.4314/njt.v36i3.16
GLASS-FIBRE REINFORCED COMPOSITES: THE EFFECT OF FIBRE LOADING AND ORIENTATION ON TENSILE AND IMPACT STRENGTH
Authors: Adekomaya O , Adama K
Published: June 2021

The primary objective of this research work is to analyse the effect of fibre loading and orientation on the tensile and impact strength of the polymeric composite materials. Fibre reinforced composite materials have been reported to have attracted many applications in view of its low weight and superior strength when compared with the metal matrix composite. While researches have established the weight reduction of fibre reinforced polymer material, few works have reported the impact of orientation on the manufacturing of polymer composite. In this study, series of experimental works were done to demonstrate the manufacturing of glass-fibre reinforced epoxy resin with special attention on the influence of oriented reinforced composite material. The composites were manufactured using hand-lay technique with three different fibre loadings (10, 20, and 30 wt. %) and at two different fibre orientations (30o and 60o). Key of the finding drawn from this research form the basis of discussion and, composite with 60o fibre orientation showed better tensile strength when compared with the neat resin and other oriented (G10E30) fibre reinforced composite. Similar observations were also noticed on the impact strength of these composites which signify the improved mechanical properties of oriented reinforced composite materials.Â http://dx.doi.org/10.4314/njt.v36i3.17
STRENGTH CHARACTERIZATION OF FOUNDATION SOILS AT FEDERAL UNIVERSITY LOKOJA BASED ON STANDARD PENETRATION TESTS DATA
Authors: Sadeeq JA , Salahudeen AB
Published: June 2021

Strength characteristics of foundation soils in the Permanent site of the Federal University Lokoja in Kogi State were evaluated based on standard penetration test (SPT) results using some conventional analytical models proposed by different researchers. The study was carried out in order to take precise engineering decisions on the type of foundations suitable for the proposed structures and to determine the optimal depth of foundation embedment.Â  The SPT N-values were first corrected to the standard average energy of 60% (N60) before they were used to correlate soil properties. Evaluation of the soil properties were done at foundation embedment depths of 0.6, 2.1 and 3.6 m. Results show that bearing capacity generally increased with boring depth. Based on the Meyerhof allowable bearing pressure estimation method, foundation pressures in the range of 150 â€“ 600Â  kN/m2 were evaluated for use in the study area at shallow depths (depths in the range of 0.6 - 3.6 m).http://dx.doi.org/10.4314/njt.v36i3.2
PRESSURE ANALYSIS AND FLUID CONTACT PREDICTION FOR ALPHA RESERVOIR (A PARTIALLY APPRAISED FIELD) ONSHORE NIGER DELTA.
Authors: Ogbamikhumi A , Akanzua-Adamczyk AH , Ahiwe L
Published: June 2021

The study field is green, with limited well penetrations. The objective reservoir (Alpha Reservoir) is a relatively shallow one, with 6 wells penetration. Two of the wells are wet (Water-Up-To) while the rest penetrated hydrocarbon bearing intervals (Gas-Down-To). As pressure data was not acquired in the water leg of the reservoir, pressure gradient analysis was done with the field-wide hydrostatic profile for contact and fluid prediction. Also, an evaluation of the possibility of having an oil rim within the region of fluid-type uncertainty was carried out. The predicted results revealed that the objective reservoir has the potential of having oil rim of a possible gradient 0.20psi/ft., with a column height of less than or equal to 20ft. Such an oil column if present is deemed insignificant. Therefore, the reservoir can be developed as a non- associated gas reservoir with a predicted Gas-Water-Contact of 7529ftss.Â http://dx.doi.org/10.4314/njt.v36i3.20
ALUMINA PHASE TRANSFORMATION FROM THERMAL DECOMPOSITION OF AMMONIUM ALUM SYNTHESIZED FROM KANKARA KAOLIN
Authors: Bawa SG , Ahmed AS , Okonkwo PC
Published: June 2021

Thermal stability of transitional alumina phases produced from ammonium alum using Kankara kaolin as starting material was studied. Wet beneficiation method was employed to purify the starting material, after which it was calcined and dealuminated with sulphuric acid. The elemental composition, mineralogical, and physiological analyses were carried out using X-ray fluorescence (XRF), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) techniques respectively. The ammonium alum was thermally treated by varying the calcination temperature from 700 to 1200Â°C and varying the time of calcination from 1 to 4 h. The formation of gamma alumina began at calcination temperature of 825Â°C for calcination time of 3 h, which was found to be lower than reported works of 900Â°C. It was found to be stable at higher temperature of 1125Â°C, above which phase transformation to alpha alumina was observed. The observed wide range of thermal stability of the gamma alumina phase gives it good advantage to be used for high temperature applications, such as support for catalyst promoters. Alpha alumina phase formation began at 1150Â°C and was fully formed at 1200Â°C. BET specific surface area of 166 m2/g was obtained for the gamma alumina phase which was high enough for it application as support for catalyst, catalyst and adsorbent.Â http://dx.doi.org/10.4314/njt.v36i3.23
SPEED CONTROL OF DC MOTOR ON LOAD USING FUZZY LOGIC CONTROLLER (A CASE STUDY OF EMERGENCY LUBE OIL PUMP MOTOR OF H25 HITACHI TURBINE GENERATOR)
Authors: Ekpoudom II , Archibong IE , Itaketo UT
Published: June 2021

This paper presents the development of a fuzzy logic controller for the driver DC motor in the lube oil system of the H25 Hitachi gas turbine generator. The turbine generator is required to run at an operating pressure of 1.5bar with the low and the high pressure trip points being 0.78 bar and 1.9 bar respectively. However, the driver DC motor speed drifted from the desired speed of 1450 revolutions per minutes (rpm) to as low as 1414 rpm. It is against this backdrop, that this project work was envisaged to design a controller capable of controlling the speed of the DC motor in order to achieve the desired speed rating of 1450 rpm. In modelling the motor, the transfer function method was used to develop a linear approximation to the actual motor. After computing the total inertia of the motor shaft, the motor model was simulated for the speed response in MATLAB and Simulink environment, and the response showed that the motor attained an actual maximum speed of 1414 rpm at settling time of 0.3 seconds.Â  Based on expert knowledge of the lube oil system, a fuzzy logic controller was designed and this resulted in the issuance of a control action to correct the actual speed of the motor from 1414 rpm to the desired speed of 1450 rpm. Â http://dx.doi.org/10.4314/njt.v36i3.29
AN EXPERIMENTAL STUDY ON THE USE OF POLYPROPYLENE WASTE IN BITUMINOUS MIX
Authors: Otuoze HS , Shuaibu AA
Published: June 2021

The work focuses on assessing the Marshall properties of High Density Polypropylene (HDPP) waste and its potentiality to mitigate pavement failures due to environmental and traffic loading. Based on design, 4.5, 5.0, 5.5, 6.0 and 6.5% bitumen contents were arbitrarily selected to prepare one hundred and five (105) Marshall specimens having respectively 0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0% HDPP waste in Polymer Modified (PM) asphalt concrete. The specimens were tested for stability, flow, compacted density of the mix (CDM) and void analysis. Optimum parameter for Marshall properties obtained are 27.68kN, 2.54mm, 2.45g/cm3, 3.39%, 16.2% and 74.10% respectively for stability, flow, CDM, VIM, VMA and VFB. The results revealed enhanced engineering properties of 2% HDPP at an optimal bitumen content of 5.5% and could satisfy strength and durability requirements of heavy traffic situation.http://dx.doi.org/10.4314/njt.v36i3.3
COMPARATIVE ANALYSIS AND IMPLEMENTATION OF DIJKSTRA'S SHORTEST PATH ALGORITHM FOR EMERGENCY RESPONSE AND LOGISTIC PLANNING
Authors: Eneh AH , Arinze UC
Published: June 2021

TransRoute: a web-based vehicle route planning application is proposed in this paper. This application leverages existing input-output (I/O) efficient implementations of shortest path algorithms (SPAs) to implement the proposed system that will fundamentally address the problems experienced in moving people, goods and services from one location to another. A number of SPAs are evaluated using landau notations. Main functionalities of the system will be implemented as a web-enabled geographic information system (GIS) application based on open-source technologies and object-oriented software development methodology using unified modeling language. Pilot implementation is done based on spatial data of three selected states in Nigeria, pulled from web-based mapping tools like Google Maps and Microsoft Bings respectively. In conclusion, the Dijkstra's algorithm implemented with double bucket dynamic data structure is selected for implementing the proposed route planning system, as past research efforts has proven that it is the fastest with run-time improvements from O(m + n/log C) to O(m) respectively.Â http://dx.doi.org/10.4314/njt.v36i3.30
DETERMINATION OF WEIBULL PARAMETERS AND ANALYSIS OF WIND POWER POTENTIAL IN COASTAL AND NON-COASTAL SITES IN AKWA IBOM STATE
Authors: Udoakah YN , Ikafia US
Published: June 2021

The wind power potential and its viability for commercial energy production across two sites Eket (Latitude 4033â€™N & Longitude 7058â€™E) and Uyo (Latitude 5Â°18â€™53.7â€™â€™N & Longitude 7059â€™39.29â€™â€™E) in Akwa Ibom State were investigated. Using data obtained from the Nigeria Meteorological Agency (MIMET) for both locations for a period of four years (2010-2013), a statistical analysis was performed. The Weibull Distribution Function was used to determine the monthly and yearly wind speed. Resulting from the analysis, the values of the average wind speed, the average daily wind power, the shape parameter (k) and the scale factor(c) were obtained to be 6.7 m/s and 4.3 m/s, 0.91 MW and 0.25 MW, K~ 5.4 and 2.1, and c â‰ˆ 8.8 m/s and 4.6 m/s respectively, for Eket and Uyo. Also, the annual electricity generation was projected to be 40.88 MWh& 10.80 MWh respectively, for Eket and Uyo. The Weibull distribution can be relied on for accurate prediction of wind energy output and resulting from the predicted values, Eket a coastal area was assessed to be viable for commercial wind power production compared to Uyo a non-coastal area.Â http://dx.doi.org/10.4314/njt.v36i3.36
HIGH AND LOW WATER PREDICTION AT LAGOS HARBOUR, NIGERIA
Authors: Badejo OT , Akintoye SO
Published: June 2021

In this work, 500 hourly water level tidal data were used to perform least squares tidal harmonic analysis. Eleven tidal constituents were used for the harmonic analysis. Astronomical arguments (v + u) and the nodal factor (f) were computed for each tidal constituent and at each observational period with a programme written in Matlab environment. The harmonic constants determined from the least squares tidal harmonic analysis were substituted into a tidal prediction model to predict hourly tidal data and tidal predictions at 5 minutesâ€™ intervals. Series of high and low water heights from the tidal predictions made at 5 minutesâ€™ intervals were determined and matched with their corresponding times. Autocorrelation at lags 1 to 30 for the residuals of the observed and predicted tidal data shows that there is no significant correlation in the range of the 30 lags. The series of residuals of the observed and predicted tidal data is therefore white noise. Â Â http://dx.doi.org/10.4314/njt.v36i3.39
SUITABILITY OF BURNT AND CRUSHED COW BONES AS PARTIAL REPLACEMENT FOR FINE AGGREGATE IN CONCRETE
Authors: Ogarekpe NM , Agunwamba JC , Idagu FO , Bejor ES , Eteng OE , Ndem HO , Oloko EO
Published: June 2021

The suitability of burnt and crushed cow bones (BCCB) as partial replacement for fine aggregate in concrete was studied. The percentages of replacements of fine aggregates of 0, 10, 20, 30, 40 and 50%, respectively of BCCB were tested considering 1: 2: 4 and 1: 11/2 :3 concrete mix ratios. The cow bones were burnt for 50 minutes up to 92oC before being crushed. Ninety-six (96) concrete cubes of 1: 2: 4 mix ratio and ninety-six (96) concrete cubes of 1 :Â : 3 mix ratio measuring 150x150x150mm were tested for the compressive strength at 7, 14, 21 and 28 days respectively. The research revealed that the BCCB acted as a retarder in the concrete. Water-cement ratio increased with the increase in the percentage of the BCCB. The mixes of 1:2:4 and 1::3 at 28 days curing yielded average compressive strengths in N/mm2 ranging from 16.49 - 24.29 and 18.71 - 29.73, respectively. For the mix ratios of 1:2:4 and 1:: 3 at 28 days curing age, Â it was observed that increase in the BCCB content beyond 40 and 50%, respectively resulted to the reduction of the average compressive strength below recommended minimum strength for use of concrete in structural works.http://dx.doi.org/10.4314/njt.v36i3.4