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Papers by M Umar

Research paper thumbnail of The Neo-Deterministic Seismic Hazard map (NDSHA) of Sumatra compared with official 2010 and 2017 derived from PSHA method

IOP Conference Series: Materials Science and Engineering

Typical seismic hazard problem lies on determination of ground motion characteristics associated ... more Typical seismic hazard problem lies on determination of ground motion characteristics associated with future earthquakes. Strong ground motion characteristics such as Peak Ground Acceleration (PGA) is important information for engineers in order to provide earthquake resistant building. The Indonesian government has provided update of maps of PGA by released a series official PSHA (Probabilistic Seismic Hazard Assessment) maps in 1978, 2002, 2010 and 2017. On the other hand, the NDSHA (Neo-Deterministic Seismic Hazard Assessment) method has been developed and successfully applied to Sumatra. Because of the availability of numerical PGA data for the official PSHA 2010 and 2017, this paper discusses the comparison of PGA between derived from NDSHA and that of official PSHA updated in 2010 and 2017. The spatial resolution of the PGA digital map of PSHA is 0.01 degree and NDSHA is 0.1 degree. Due to the different resolution, a program and a script are developed to incorporate PSHA data ...

Research paper thumbnail of 2D Seismic Interpretation to Understand the Structural Geometry of Cretaceous Sand Packages, Jabo Field, Pakistan

This study is focused on interpretation of 2D seismic reflection profiles coupled with borehole l... more This study is focused on interpretation of 2D seismic reflection profiles coupled with borehole logs of Jabo Field (JF). The seismic interpretation revealed the configuration of basin fill deposits, subsurface geological structural geometries and their association with tectonic interventions in JF, Lower Indus Basin, Pakistan. Primarily, the tectonic stresses control the dimensions, geometry and style of deformation of geological structures which contribute in development of hydrocarbon trapping system. We have studied the structural geometries of Cretaceous sand packages which serve as a reservoir in oil & gas prone JF. Isochron and isopach maps were prepared to delineate the geological structure of Top of Lower Goru (TLG), Top of Middle Sand (TMDS) and Top of Basal Sand (TBSL). TLG forms a three-way dip closure bounded by a NE-SW trending major fault of the JF; the geological structure at TMDS level is a two-way fault bounded since to the north and south it is bounded by dipping b...

Research paper thumbnail of Comparative Proximate Analysis of Five Commercially Sold Maggi as Condiments in Gwagwalada, North Central, Nigeria

Determination of the proximate, nutritionally valuable mineral in five samples of food seasonings... more Determination of the proximate, nutritionally valuable mineral in five samples of food seasonings label as, A, B, C, D, & E food condiments readily consumed in Nigeria were obtained from Gwagwalada Central Market Abuja. Investigating the concentrations of some mineral elements such as, iron (Fe), zinc (Zn), and two heavy metals, cadmium (Cd) and lead (Pb) were carried out using AA320N Atomic Absorption Spectrophotometer (AAS) after acid digestion with 2:1 HNO3/HClO4. The result shows that all samples contained high levels of protein (13.63% ±0.53%) with mean value moisture, ash, fat, fiber, and carbohydrate for all samples levels being (3.94%±0.64%), (57.51% ±4.27%), (5.11% ±0.20%), (0.02% ±0.00%) and (18.41% ±0.41%) respectively. Sample D has high Fe concentration with (0.04 ±0.01 μg/g) and Sample B & C has low Fe concentration with (0.01 ±0.00 μg/g). Sample D & E has high Zn concentration with (0.03 ±0.01 μg/g) and sample A, B & C has low Zn concentration with (0.02 ±0.01 μg/g). I...

Research paper thumbnail of The Lewis-Acidity of Square-Planar Nickel(11) Complexes. 11* A Kinetic Investigation of the Addition of Substituted Phenanthrolines to Bis(0,O-diethyl phosphorodithioato-S,S')nicke1(11), Bis(0-ethylxanthato)nickel(~~) and Bis(4-mercapto- pent-3-en-2-onato)nicke1(11) in Toluene

The rates of the addition reaction between substituted phenanthrolines and the square-planar nick... more The rates of the addition reaction between substituted phenanthrolines and the square-planar nickel complexes bis(0,O-diethyl phosphorodithioato-S,S ')nickel(u), Ni(dtp),, bis(0-ethy1xanthato)nicke1(11), Ni(~an)~, and bis(4-mercaptopent-3-en-2-onato)nickel(11), Ni(sacac),, have been measured in toluene by the stopped-flow technique. For Ni(~an)~, the second-order rate constants, kf, are in the range (1-8) x lo5 1. mol-' s-', AH$ is 16f 2 kJ mol-' and there is a significant substituent effect. For Ni(dtp),, k, is (1-3)x lo4 1. mol-' s-', AH& is 24&2 kJmo1-I and there is a minor subst~tuent effect. For Ni(sacacL, kf is about 5 x lo2 1. mol-' s-', AH,: is 50 kJ mol-' and there is no substituent effect. The results are discussed in terms of the relative importance of Ni-N bond formation and displacement of the in-plane ligands in the transition state.

Research paper thumbnail of Superconductivity of twisted double bi-layer graphene in chiral model

Journal of Physics: Conference Series

Taking into account the sp -hybridization effect for valence electrons in carbon atoms, a very si... more Taking into account the sp -hybridization effect for valence electrons in carbon atoms, a very simple chiral model of graphene was suggested some years ago [1]. This model used as a special order parameter the unitary SU(2) -matrix U with the kink-like (or domain wall) structure for the description of electrons in a mono-atomic graphene sheet. However, later the new graphene physics began since studying twisted multilayer configurations revealing unconventional superconducting properties (twist-tronics) [2]. Within the scope of the chiral model these twisted configurations can be described by the so-called “product ansatz” U = U1U2 ▪ ▪ ▪ Un . As an example, the special case of twisted double bi-layer graphene (TDBG) configuration is studied and the corresponding twist angles, for which the superconductivity takes place, are found.

Research paper thumbnail of Electrical Conductivity of PA6/Graphite and Graphite Nanoplatelets Composites using Two Processing Streams

March 2021

The percolation threshold (PT) of any polymer/particulate carbon composite depends on the process... more The percolation threshold (PT) of any polymer/particulate carbon composite depends on the processing, the dispersed state of the filler, the matrix used and the morphology attained. Sonication technique was used to make PA6/G and PA6/GNP composites employing in situ polymerisation, after which their electrical conductivity behaviours were investigated. While overhead stirring and horn sonication were used to distribute and disperse the carbon fillers, the composites were made in 2 streams 40/10 and 20/20. The 40/10 stream implies that while dispersing the carbon fillers in PA6 monomer, 40% amplitude of sonication was applied for 10 minutes whereas the 20/20 stream implies 20% amplitude of sonication for 20 minutes. In both streams, the dispersing strain imparted on the monomer/carbon mixture was 400 in magnitude. Purely ohmic electrical conductivity behaviour was attained at 9.75 G wt. % for IG 40/10 system. For composites in the IG 20/20 system, same was attained at 10.00 G wt. %. ...

Research paper thumbnail of Physicians' Compliance with Anti-Malarial Treatment Guidelines Among Under Five Children Attending Secondary Health Facilities in Sokoto Metropolis

European Journal of Health Sciences

Introduction: Rational use of drugs against most common and life‑threatening tropical diseases su... more Introduction: Rational use of drugs against most common and life‑threatening tropical diseases such as malaria remains a huge challenge, particularly in sub-Saharan African region. The correct use of antimalarial drugs is the key not only to therapeutic success but also to deterring the spread of drug resistance malaria. Aims: To assess the physicians’ compliance with the national anti’-malaria treatment guidelines among Under five (U-5) years children in secondary health facilities in Sokoto metropolis. Methods: This was a cross-sectional study conducted as an exit interview among 292 mothers/caregivers of febrile U-5 children with antimalarial prescription, that presented to the out-patient clinics of the selected secondary health facilities in Sokoto metropolis. Simple random sampling technique using balloting option was used to select 2 secondary Health facilities in the metropolis, Proportionate allocation was done to allocate study subjects to the selected Health facilities ba...

Research paper thumbnail of Application of ANN Modelling and GA Optimization for Improved Creep and Corrosion Properties of Spin-Arc Welded AA5083-H111 Alloy

Russian Journal of Non-Ferrous Metals

Abstract In this work, an attempt is made to identify the optimized parameter combination for imp... more Abstract In this work, an attempt is made to identify the optimized parameter combination for improved creep and corrosion properties of AA5083-H111 alloy weldments processed by Spin-Arc gas metal arc welding (SA-GMAW) process. For this, the Artificial Neural Network (ANN) coupled with Genetic Algorithm (GA) was used as a statistical tool. Experiments were conducted by considering the input parameters namely welding current, filler spinning speed and filler spin diameter. The weld quality was assessed by measuring microhardness, corrosion resistance and steady-state creep rate. Initially, ANN was used to establish the relationship between input and output process variables. Different learning algorithms such as quick propagation (QP), back batch propagation (BBP) and incremental batch propagation (IBP) were used for predicting the output parameters. Prediction accuracy of the different learning algorithms was compared, and the best algorithm was used for the GA optimization technique. The optimum parameters were found to be 134 A of welding current, 1050 rpm of filler spinning speed and 1 mm of filler spin diameter. Among the input parameters, the filler spinning speed was identified as the most influential factor (40.11%) that effected the formation and distribution of second phase particles through which improved corrosion and creep properties were achieved.

Research paper thumbnail of Suture Materials in Dental Surgeries: A Review

Annals of SBV

Surgical sutures are used for securing and restoring active or trauma-induced wounds by binding t... more Surgical sutures are used for securing and restoring active or trauma-induced wounds by binding tissues together to facilitate the woundhealing process. A wide range of sutures are used in dental practice. The main type includes absorbable and nonabsorbable suture materials. Recently, the production of newer suture materials is increasing depending on its wound-healing properties and its ability to approximate wounds. This article describes and reviews the characteristics of suture materials, its types, and uses in various management. It also discusses about recent and emerging suture material patterns.

Research paper thumbnail of Application of Genetic Algorithm Technique for Machining Parameters Optimization in Drilling of Stainless Steel

Mechanics and Mechanical Engineering

This work is aimed at developing relations between the pertinent variables that affect drilling p... more This work is aimed at developing relations between the pertinent variables that affect drilling process of stainless steel using artificial neural network. The experiments were conducted on vertical CNC machining centre. The parameters used were spindle speed and feed rate. The effect of machining parameters on entry burr height, exit burr height and surface roughness was experimentally evaluated for different spindle speeds and feed rates. A model was established between the drilling parameters and experimentally obtained data using ANN. The predicted values and measured values are fairly close, which indicates that the developed model can be effectively used to predict the burr height and surface roughness in drilling of stainless steel. Genetic algorithm (GA) technique was used in this work to identify the optimized drilling parameters. Confirmation test was conducted with the optimized parameters and it was found that confirmation test results were similar to that of GA-predicte...

Research paper thumbnail of Roller sliding in engine valve train: Effect of oil film thickness considering lubricant composition

Tribology International

Abstract In roller follower valve train, proper rolling of roller reduces the chances of fatigue ... more Abstract In roller follower valve train, proper rolling of roller reduces the chances of fatigue failure and power losses. During engine operation, the roller does slip on the camshaft surface. The oil film thickness plays an important role on the roller sliding which necessitates experimental investigations. A modern gasoline engine valve train has been instrumented using advanced sensors for real time measurement of oil film thickness and roller slip, simultaneously. Rise in oil film thickness at cam/roller interface increased the tendency of roller slip. Drag due to shear of lubricant and rise in contact loading at very high camshaft speeds resulted in reduction of roller sliding. Presence of anti-wear agents and friction modifiers increased the tendency of roller sliding.

Research paper thumbnail of The Optimation of Crude Fiber Content of Diet for Fattening Madura Beef Cattle to Achieve Good A:P Ratio and Low Methane Production

IOP Conference Series: Earth and Environmental Science

Research paper thumbnail of Spectrum of chronic liver disease due to hepatitis ?C? virus infection

The American Journal of Gastroenterology

Purpose: To determine the clinical spectrum of HCV infection in wellcharacterized group of patien... more Purpose: To determine the clinical spectrum of HCV infection in wellcharacterized group of patients with cirrhosis and chronic hepatitis in Pakistani population. Methods: This Clinical Study was conducted in Holy Family Hospital, Distric Head Quarter Hospital and consultant's private clinics from January, 1996 to December, 1998. A thorough and complete physical examinasion was performed and recorded on a performed performa. Information regarding age, sex, occupation, injections, needle stick injuries, sharing of syrings and equipment, blood transfusion, surgical procedures, trauma and family history of Hepatitis and jaundice was recorded. Results: We observed male predominance 57% and middle age group to account for majority of the patient. 63% were cirrhotic with mean age 54 years. 37% chronic hepatitis with mean age 46 years. Most patients presented with complications of portal hypertension e.g. Ascites (60%) in cirrhotic group. Chronic hepatitis was mostly a symptomatic disease (25%). Conclusions: We conclude that HCV infection is the most frequent cause of chronic liver disease. Most of the cases presented with features of advance decompensated liver disease and remained undiagnosed due to lack of education & poor health facilities. Used Syringes, unscreened blood and dental procedure still remained the most common mode of spread of the disease. Simple measures such as use of disposable syringes, transfusion of screened blood, misuse of disposable razors by barbers and possible awareness programme as well as early diagnosis and treatment of HCV infection can greatly reduce the spread of this disease.

Research paper thumbnail of Seroprevalence of Hepatitis B and Listeriosis Co-Infection among Patients Attending Sickbay Hospital, Ahmadu Bello University, Zaria, Kaduna, Nigeria

Asian Journal of Medicine and Health

Aims: A cross-sectional research study on the seroprevalence of hepatitis B and listeriosis co-in... more Aims: A cross-sectional research study on the seroprevalence of hepatitis B and listeriosis co-infection among patients attending Sickbay Hospital, Ahmadu Bello University, Zaria was carried out, with view to characterize, identify and to determine the antimicrobial sensitivity profile of Methodology: A total of 100 venous blood samples were collected from consenting patients presented to the study area suspected with hepatic disorders. The samples were centrifuged and the blood sera were obtained. The sera were qualitatively screened for HBsAg by immunochromatographic technique using rapid diagnostic device kit. Reactive sera for HBsAg were further confirmed by ELISA kits. Listeria monocytogenes was isolated from the HBV seropositive samples by standard methods and identified using biochemical characterizations. Results: The results showed that the overall seroprevalence of hepatitis B was found to be 11 (11%) in the study area, with females and males accounting for 3 (8.6%) and 8 (12.3%) seroprevalences respectively. The prevalence of hepatitis B — listeriosis co-infection was found to be 4 (36.4%). A statistical relationship (p= .56) was found between hepatitis B— listeriosis co-infection and the age of the patients. There is no significant difference between the prevalence of Hepatitis B — Listeriosis co-infection and the gender. All sex has equal chance of contacting the disease. Conclusion: The seroprevalence of 11% HBsAg obtained in this study signifies high endemicity of HBV infection in the study area. There is presence of mixed infections of hepatitis B and listeriosis in the study area. The Listeria monocytogenes isolated from HBV seropositive patients was found to be highly sensitive to Penicillin (100%) and Ampicillin (100%) but resistant to Chloramphenicol (0%), Ofloxacin (0%) and Gentamicin (0%).

Research paper thumbnail of Characterization of lettuce big-vein associated virus and Mirafiori lettuce big-vein virus infecting lettuce in Saudi Arabia

Archives of Virology

During 2014 and 2015, 97 lettuce plants that showed big-vein-disease-like symptoms and seven weed... more During 2014 and 2015, 97 lettuce plants that showed big-vein-disease-like symptoms and seven weed plants were collected from the Riyadh region. DAS-ELISA revealed that 25% and 9% of the lettuce plants were singly infected with LBVaV and MiLBVV, respectively, whereas 63% had a mixed infection with both viruses. The results were confirmed by multiplex reverse transcription polymerase chain reaction using primers specific for LBVaV and MiLBVV. LBVaV and MiLBVV were also detected in Sonchus oleraceus and Eruca sativa, respectively. The nucleotide sequence of LBVaV and MiLBVV Saudi isolates ranged from 94.3-100%, and their similarities to isolates with sequences in the GenBank database ranged from 93.9 to 99.6% and 93.8 to 99.3%, respectively. Olpidium sp. was present in the roots of lettuce plants with big-vein disease and it was shown to facilitate transmission of both viruses.

Research paper thumbnail of Enhancement of Selection, Bubble and Insertion Sorting Algorithm

Research Journal of Applied Sciences, Engineering and Technology, 2014

In everyday life there is a large amount of data to arrange because sorting removes any ambiguiti... more In everyday life there is a large amount of data to arrange because sorting removes any ambiguities and make the data analysis and data processing very easy, efficient and provides with cost less effort. In this study a set of improved sorting algorithms are proposed which gives better performance and design idea. In this study five new sorting algorithms (Bi-directional Selection Sort, Bi-directional bubble sort, MIDBiDirectional Selection Sort, MIDBidirectional bubble sort and linear insertion sort are presented. Bi-directional Selection Sort and MIDBiDirectional Selection Sort are the enhancement on basic selection sort while Bidirectional bubble sort and MIDBidirectional bubble sort are the enhancement on basic bubble sort by changing the selection and swapping mechanism of data for sorting. Enhanced sorting algorithms reduced the iteration by half and quarter times respectively. Asymptotically complexities of these algorithms are reduced to O (n 2 /2) and O (n 2 /4) from O (n 2). Linear insertion sort is the enhancement of insertion sort by changing the design of algorithm (convert two loops to one loop). So asymptotically this algorithm is converted to linear time complexity from quadratic complexity. These sorting algorithms are described using C. The proposed algorithms are analyzed using asymptotic analysis and also using machine-running time and compared with their basic sorting algorithms. In this study we also discuss how the performance and complexity can be improved by optimizing the code and design.

Research paper thumbnail of Pumping Speed Measurement of the Rotary Vane Vacuum Pump by Using Numerical and Experimental Approaches

Volume 7: Fluids Engineering Systems and Technologies, 2014

Pumping speed is the main performance parameter of a vacuum pump. In the present work, pumping sp... more Pumping speed is the main performance parameter of a vacuum pump. In the present work, pumping speed for a three-vane rotary vacuum pump is quantified using both experimental and numerical approaches. The numerical methodology assumes continuum flow (Knudsen number < 0.1), thus allowing the use of Navier Stokes equation. Commercial computational fluid dynamics (CFD) solver i.e. Fluent, is used to discretize the governing equations. Moving / dynamic mesh technique is used for the internal flow volumes of the pump to reproduce the change-in-time shape. Complete process starting from the CAD modeling to CFD simulations is discussed in detail. The adopted approaches are generic and can be used to find the pumping speed of any other rotary vane vacuum pump. The vane pump is also tested using an assessment system, which is constructed according to DIN28432 standard. Results of experimentally measured pumping speed are in good agreement with the one computed numerically.Copyright © 2014 by ASME

Research paper thumbnail of Antibacterial Susceptibility of Heavy Metals Tolerant Bacteria Isolated from NILEST Tannery Effluent

Journal of Advances in Medical and Pharmaceutical Sciences, 2016

Background: The emergence of multiple antibiotics resistance among bacterial population poses a p... more Background: The emergence of multiple antibiotics resistance among bacterial population poses a potential threat to human health. The coexistence of metal/antibiotic resistance in bacterial strains suggests the role of heavy metals as a factor which can also contribute to drug resistance phenomenon since heavy metal pollution results in selective pressure that leads to the development of multiple drug resistance among bacterial populations probably through horizontal gene transfer. Aim: This study was aimed to isolate, identify, and determine the antibiogram profile of heavy metals tolerant bacteria from the tannery effluent at Nigerian Institute of Leather and Science Technology (NILEST), Zaria, using standard microbiological methods. Methodology: Tannery effluent was cultured on heavy metals incorporated nutrient agar. The resultant isolates were purified by sub-culturing on fresh heavy metals incorporated nutrient agar Original Research Article Oko et al.; JAMPS, 8(3): 1-10, 2016; Article no.JAMPS.26580 2 and the antibiogram profile was determined using agar diffusion method. Results: The bacteria isolated include Bacillus cereus (18.75%), Escherichia coli (12.50%), Klebsiella aerogenes (18.75%), Klebsiella pneumoniae (6.25%), Pseudomonas aeruginosa (12.50%), Proteus mirabilis (6.25%), and Staphylococcus aureus (25.00%) with Staphylococcus aureus being the most prevalent. In this study, heavy metals tolerant bacteria isolated from the tannery effluent were multidrug resistant as each of the isolates was able to resist the activity of one or more of the antibiotics across the three classes of antibiotics studied. Gentamicin was highly resisted followed by ampicillin and amoxicillin. Kanamycin and Nalidixic acid were more effective followed by Ciprofloxacin and Streptomycin. The β-lactams/penicillins were generally not very effective as compared to the glycopeptides and the quinolones. Staphylococcus aureus and Escherichia coli were highly resistant to six (6) out of the nine (9) antibiotics tested with Escherichia coli showing 100% resistance to ampicillin and amoxicillin. However, Bacillus cereus was moderately resistant to seven (7) out of the nine (9) antibiotics tested but highly resistant to gentamicin. Ampicillin and cefixime showed no activity against Proteus mirabilis and Klebsiella pneumoniae. However, Proteus mirabilis and Klebsiella aerogenes were 100% resistant to gentamicin. Kanamycin was inactive against Klebsiella pneumoniae. The Multiple Antibiotic Resistance (MAR) indices of all isolates were greater than 0.2. Conclusions: The recovery of heavy metals tolerant bacteria from the tannery effluent is an indication that the effluent is laden with heavy metals. The high antibiotic resistance profile of the isolates in this study is an indication of the correlation between heavy metals tolerance and antibiotic resistance. The identified heavy metals tolerant bacterial strains could be useful for bio-remediation of heavy metals contaminated wastewaters and soil environments even though they are potential threat to successful chemotherapy if incriminated in infections.

Research paper thumbnail of Ruminal Condition Between Madura Cattle and Ongole Crossbred Cattle Raised Under Intensive Feeding

Journal of the Indonesian Tropical Animal Agriculture, 2011

Research paper thumbnail of Prevalence of Bacterial, Trichomonas and Candidal Vaginosis among Females in Angwan-Fulani, Palladan in Zaria, Nigeria

Journal of Applied Life Sciences International, 2016

Aims: This study was conducted to determine the prevalence of agents of vaginitis among females i... more Aims: This study was conducted to determine the prevalence of agents of vaginitis among females in Angwan-Fulani, Palladan-Zaria. Study Design: Experimental design used was a completely randomized design (CRD). Place and Duration of Study: Original Research Article Akafyi et al.; JALSI, 5(2): 1-6, 2016; Article no.JALSI.25649 2 Methodology: Total of 150 Samples of High Vaginal Swabs (HVS) were collected from the participants and examined for pathogenic organisms. Demographic information was collected using structured questionnaire. Samples were examined using standard bacteriological methods and microscopically. Direct wet-mount preparation for the detection of Trichomonas vaginalis was employed following a preliminary growth of the parasite in a selective Diamond&#39;s medium. Results: The results of this study indicated that 139 (92.66%) out of 150 samples had at least one infection. The organisms isolated include Candida albicans, Streptococcus pyogenes, Staphylococcus aureus and Trichomonas vaginalis. The age group &gt;25 years had the highest prevalence. Mixed infections were observed. Conclusion: The findings showed that vaginitis is common in the study area. Urgent attention is needed by Health Authority for wider screening and treatment.

Research paper thumbnail of The Neo-Deterministic Seismic Hazard map (NDSHA) of Sumatra compared with official 2010 and 2017 derived from PSHA method

IOP Conference Series: Materials Science and Engineering

Typical seismic hazard problem lies on determination of ground motion characteristics associated ... more Typical seismic hazard problem lies on determination of ground motion characteristics associated with future earthquakes. Strong ground motion characteristics such as Peak Ground Acceleration (PGA) is important information for engineers in order to provide earthquake resistant building. The Indonesian government has provided update of maps of PGA by released a series official PSHA (Probabilistic Seismic Hazard Assessment) maps in 1978, 2002, 2010 and 2017. On the other hand, the NDSHA (Neo-Deterministic Seismic Hazard Assessment) method has been developed and successfully applied to Sumatra. Because of the availability of numerical PGA data for the official PSHA 2010 and 2017, this paper discusses the comparison of PGA between derived from NDSHA and that of official PSHA updated in 2010 and 2017. The spatial resolution of the PGA digital map of PSHA is 0.01 degree and NDSHA is 0.1 degree. Due to the different resolution, a program and a script are developed to incorporate PSHA data ...

Research paper thumbnail of 2D Seismic Interpretation to Understand the Structural Geometry of Cretaceous Sand Packages, Jabo Field, Pakistan

This study is focused on interpretation of 2D seismic reflection profiles coupled with borehole l... more This study is focused on interpretation of 2D seismic reflection profiles coupled with borehole logs of Jabo Field (JF). The seismic interpretation revealed the configuration of basin fill deposits, subsurface geological structural geometries and their association with tectonic interventions in JF, Lower Indus Basin, Pakistan. Primarily, the tectonic stresses control the dimensions, geometry and style of deformation of geological structures which contribute in development of hydrocarbon trapping system. We have studied the structural geometries of Cretaceous sand packages which serve as a reservoir in oil & gas prone JF. Isochron and isopach maps were prepared to delineate the geological structure of Top of Lower Goru (TLG), Top of Middle Sand (TMDS) and Top of Basal Sand (TBSL). TLG forms a three-way dip closure bounded by a NE-SW trending major fault of the JF; the geological structure at TMDS level is a two-way fault bounded since to the north and south it is bounded by dipping b...

Research paper thumbnail of Comparative Proximate Analysis of Five Commercially Sold Maggi as Condiments in Gwagwalada, North Central, Nigeria

Determination of the proximate, nutritionally valuable mineral in five samples of food seasonings... more Determination of the proximate, nutritionally valuable mineral in five samples of food seasonings label as, A, B, C, D, & E food condiments readily consumed in Nigeria were obtained from Gwagwalada Central Market Abuja. Investigating the concentrations of some mineral elements such as, iron (Fe), zinc (Zn), and two heavy metals, cadmium (Cd) and lead (Pb) were carried out using AA320N Atomic Absorption Spectrophotometer (AAS) after acid digestion with 2:1 HNO3/HClO4. The result shows that all samples contained high levels of protein (13.63% ±0.53%) with mean value moisture, ash, fat, fiber, and carbohydrate for all samples levels being (3.94%±0.64%), (57.51% ±4.27%), (5.11% ±0.20%), (0.02% ±0.00%) and (18.41% ±0.41%) respectively. Sample D has high Fe concentration with (0.04 ±0.01 μg/g) and Sample B & C has low Fe concentration with (0.01 ±0.00 μg/g). Sample D & E has high Zn concentration with (0.03 ±0.01 μg/g) and sample A, B & C has low Zn concentration with (0.02 ±0.01 μg/g). I...

Research paper thumbnail of The Lewis-Acidity of Square-Planar Nickel(11) Complexes. 11* A Kinetic Investigation of the Addition of Substituted Phenanthrolines to Bis(0,O-diethyl phosphorodithioato-S,S')nicke1(11), Bis(0-ethylxanthato)nickel(~~) and Bis(4-mercapto- pent-3-en-2-onato)nicke1(11) in Toluene

The rates of the addition reaction between substituted phenanthrolines and the square-planar nick... more The rates of the addition reaction between substituted phenanthrolines and the square-planar nickel complexes bis(0,O-diethyl phosphorodithioato-S,S ')nickel(u), Ni(dtp),, bis(0-ethy1xanthato)nicke1(11), Ni(~an)~, and bis(4-mercaptopent-3-en-2-onato)nickel(11), Ni(sacac),, have been measured in toluene by the stopped-flow technique. For Ni(~an)~, the second-order rate constants, kf, are in the range (1-8) x lo5 1. mol-' s-', AH$ is 16f 2 kJ mol-' and there is a significant substituent effect. For Ni(dtp),, k, is (1-3)x lo4 1. mol-' s-', AH& is 24&2 kJmo1-I and there is a minor subst~tuent effect. For Ni(sacacL, kf is about 5 x lo2 1. mol-' s-', AH,: is 50 kJ mol-' and there is no substituent effect. The results are discussed in terms of the relative importance of Ni-N bond formation and displacement of the in-plane ligands in the transition state.

Research paper thumbnail of Superconductivity of twisted double bi-layer graphene in chiral model

Journal of Physics: Conference Series

Taking into account the sp -hybridization effect for valence electrons in carbon atoms, a very si... more Taking into account the sp -hybridization effect for valence electrons in carbon atoms, a very simple chiral model of graphene was suggested some years ago [1]. This model used as a special order parameter the unitary SU(2) -matrix U with the kink-like (or domain wall) structure for the description of electrons in a mono-atomic graphene sheet. However, later the new graphene physics began since studying twisted multilayer configurations revealing unconventional superconducting properties (twist-tronics) [2]. Within the scope of the chiral model these twisted configurations can be described by the so-called “product ansatz” U = U1U2 ▪ ▪ ▪ Un . As an example, the special case of twisted double bi-layer graphene (TDBG) configuration is studied and the corresponding twist angles, for which the superconductivity takes place, are found.

Research paper thumbnail of Electrical Conductivity of PA6/Graphite and Graphite Nanoplatelets Composites using Two Processing Streams

March 2021

The percolation threshold (PT) of any polymer/particulate carbon composite depends on the process... more The percolation threshold (PT) of any polymer/particulate carbon composite depends on the processing, the dispersed state of the filler, the matrix used and the morphology attained. Sonication technique was used to make PA6/G and PA6/GNP composites employing in situ polymerisation, after which their electrical conductivity behaviours were investigated. While overhead stirring and horn sonication were used to distribute and disperse the carbon fillers, the composites were made in 2 streams 40/10 and 20/20. The 40/10 stream implies that while dispersing the carbon fillers in PA6 monomer, 40% amplitude of sonication was applied for 10 minutes whereas the 20/20 stream implies 20% amplitude of sonication for 20 minutes. In both streams, the dispersing strain imparted on the monomer/carbon mixture was 400 in magnitude. Purely ohmic electrical conductivity behaviour was attained at 9.75 G wt. % for IG 40/10 system. For composites in the IG 20/20 system, same was attained at 10.00 G wt. %. ...

Research paper thumbnail of Physicians' Compliance with Anti-Malarial Treatment Guidelines Among Under Five Children Attending Secondary Health Facilities in Sokoto Metropolis

European Journal of Health Sciences

Introduction: Rational use of drugs against most common and life‑threatening tropical diseases su... more Introduction: Rational use of drugs against most common and life‑threatening tropical diseases such as malaria remains a huge challenge, particularly in sub-Saharan African region. The correct use of antimalarial drugs is the key not only to therapeutic success but also to deterring the spread of drug resistance malaria. Aims: To assess the physicians’ compliance with the national anti’-malaria treatment guidelines among Under five (U-5) years children in secondary health facilities in Sokoto metropolis. Methods: This was a cross-sectional study conducted as an exit interview among 292 mothers/caregivers of febrile U-5 children with antimalarial prescription, that presented to the out-patient clinics of the selected secondary health facilities in Sokoto metropolis. Simple random sampling technique using balloting option was used to select 2 secondary Health facilities in the metropolis, Proportionate allocation was done to allocate study subjects to the selected Health facilities ba...

Research paper thumbnail of Application of ANN Modelling and GA Optimization for Improved Creep and Corrosion Properties of Spin-Arc Welded AA5083-H111 Alloy

Russian Journal of Non-Ferrous Metals

Abstract In this work, an attempt is made to identify the optimized parameter combination for imp... more Abstract In this work, an attempt is made to identify the optimized parameter combination for improved creep and corrosion properties of AA5083-H111 alloy weldments processed by Spin-Arc gas metal arc welding (SA-GMAW) process. For this, the Artificial Neural Network (ANN) coupled with Genetic Algorithm (GA) was used as a statistical tool. Experiments were conducted by considering the input parameters namely welding current, filler spinning speed and filler spin diameter. The weld quality was assessed by measuring microhardness, corrosion resistance and steady-state creep rate. Initially, ANN was used to establish the relationship between input and output process variables. Different learning algorithms such as quick propagation (QP), back batch propagation (BBP) and incremental batch propagation (IBP) were used for predicting the output parameters. Prediction accuracy of the different learning algorithms was compared, and the best algorithm was used for the GA optimization technique. The optimum parameters were found to be 134 A of welding current, 1050 rpm of filler spinning speed and 1 mm of filler spin diameter. Among the input parameters, the filler spinning speed was identified as the most influential factor (40.11%) that effected the formation and distribution of second phase particles through which improved corrosion and creep properties were achieved.

Research paper thumbnail of Suture Materials in Dental Surgeries: A Review

Annals of SBV

Surgical sutures are used for securing and restoring active or trauma-induced wounds by binding t... more Surgical sutures are used for securing and restoring active or trauma-induced wounds by binding tissues together to facilitate the woundhealing process. A wide range of sutures are used in dental practice. The main type includes absorbable and nonabsorbable suture materials. Recently, the production of newer suture materials is increasing depending on its wound-healing properties and its ability to approximate wounds. This article describes and reviews the characteristics of suture materials, its types, and uses in various management. It also discusses about recent and emerging suture material patterns.

Research paper thumbnail of Application of Genetic Algorithm Technique for Machining Parameters Optimization in Drilling of Stainless Steel

Mechanics and Mechanical Engineering

This work is aimed at developing relations between the pertinent variables that affect drilling p... more This work is aimed at developing relations between the pertinent variables that affect drilling process of stainless steel using artificial neural network. The experiments were conducted on vertical CNC machining centre. The parameters used were spindle speed and feed rate. The effect of machining parameters on entry burr height, exit burr height and surface roughness was experimentally evaluated for different spindle speeds and feed rates. A model was established between the drilling parameters and experimentally obtained data using ANN. The predicted values and measured values are fairly close, which indicates that the developed model can be effectively used to predict the burr height and surface roughness in drilling of stainless steel. Genetic algorithm (GA) technique was used in this work to identify the optimized drilling parameters. Confirmation test was conducted with the optimized parameters and it was found that confirmation test results were similar to that of GA-predicte...

Research paper thumbnail of Roller sliding in engine valve train: Effect of oil film thickness considering lubricant composition

Tribology International

Abstract In roller follower valve train, proper rolling of roller reduces the chances of fatigue ... more Abstract In roller follower valve train, proper rolling of roller reduces the chances of fatigue failure and power losses. During engine operation, the roller does slip on the camshaft surface. The oil film thickness plays an important role on the roller sliding which necessitates experimental investigations. A modern gasoline engine valve train has been instrumented using advanced sensors for real time measurement of oil film thickness and roller slip, simultaneously. Rise in oil film thickness at cam/roller interface increased the tendency of roller slip. Drag due to shear of lubricant and rise in contact loading at very high camshaft speeds resulted in reduction of roller sliding. Presence of anti-wear agents and friction modifiers increased the tendency of roller sliding.

Research paper thumbnail of The Optimation of Crude Fiber Content of Diet for Fattening Madura Beef Cattle to Achieve Good A:P Ratio and Low Methane Production

IOP Conference Series: Earth and Environmental Science

Research paper thumbnail of Spectrum of chronic liver disease due to hepatitis ?C? virus infection

The American Journal of Gastroenterology

Purpose: To determine the clinical spectrum of HCV infection in wellcharacterized group of patien... more Purpose: To determine the clinical spectrum of HCV infection in wellcharacterized group of patients with cirrhosis and chronic hepatitis in Pakistani population. Methods: This Clinical Study was conducted in Holy Family Hospital, Distric Head Quarter Hospital and consultant's private clinics from January, 1996 to December, 1998. A thorough and complete physical examinasion was performed and recorded on a performed performa. Information regarding age, sex, occupation, injections, needle stick injuries, sharing of syrings and equipment, blood transfusion, surgical procedures, trauma and family history of Hepatitis and jaundice was recorded. Results: We observed male predominance 57% and middle age group to account for majority of the patient. 63% were cirrhotic with mean age 54 years. 37% chronic hepatitis with mean age 46 years. Most patients presented with complications of portal hypertension e.g. Ascites (60%) in cirrhotic group. Chronic hepatitis was mostly a symptomatic disease (25%). Conclusions: We conclude that HCV infection is the most frequent cause of chronic liver disease. Most of the cases presented with features of advance decompensated liver disease and remained undiagnosed due to lack of education & poor health facilities. Used Syringes, unscreened blood and dental procedure still remained the most common mode of spread of the disease. Simple measures such as use of disposable syringes, transfusion of screened blood, misuse of disposable razors by barbers and possible awareness programme as well as early diagnosis and treatment of HCV infection can greatly reduce the spread of this disease.

Research paper thumbnail of Seroprevalence of Hepatitis B and Listeriosis Co-Infection among Patients Attending Sickbay Hospital, Ahmadu Bello University, Zaria, Kaduna, Nigeria

Asian Journal of Medicine and Health

Aims: A cross-sectional research study on the seroprevalence of hepatitis B and listeriosis co-in... more Aims: A cross-sectional research study on the seroprevalence of hepatitis B and listeriosis co-infection among patients attending Sickbay Hospital, Ahmadu Bello University, Zaria was carried out, with view to characterize, identify and to determine the antimicrobial sensitivity profile of Methodology: A total of 100 venous blood samples were collected from consenting patients presented to the study area suspected with hepatic disorders. The samples were centrifuged and the blood sera were obtained. The sera were qualitatively screened for HBsAg by immunochromatographic technique using rapid diagnostic device kit. Reactive sera for HBsAg were further confirmed by ELISA kits. Listeria monocytogenes was isolated from the HBV seropositive samples by standard methods and identified using biochemical characterizations. Results: The results showed that the overall seroprevalence of hepatitis B was found to be 11 (11%) in the study area, with females and males accounting for 3 (8.6%) and 8 (12.3%) seroprevalences respectively. The prevalence of hepatitis B — listeriosis co-infection was found to be 4 (36.4%). A statistical relationship (p= .56) was found between hepatitis B— listeriosis co-infection and the age of the patients. There is no significant difference between the prevalence of Hepatitis B — Listeriosis co-infection and the gender. All sex has equal chance of contacting the disease. Conclusion: The seroprevalence of 11% HBsAg obtained in this study signifies high endemicity of HBV infection in the study area. There is presence of mixed infections of hepatitis B and listeriosis in the study area. The Listeria monocytogenes isolated from HBV seropositive patients was found to be highly sensitive to Penicillin (100%) and Ampicillin (100%) but resistant to Chloramphenicol (0%), Ofloxacin (0%) and Gentamicin (0%).

Research paper thumbnail of Characterization of lettuce big-vein associated virus and Mirafiori lettuce big-vein virus infecting lettuce in Saudi Arabia

Archives of Virology

During 2014 and 2015, 97 lettuce plants that showed big-vein-disease-like symptoms and seven weed... more During 2014 and 2015, 97 lettuce plants that showed big-vein-disease-like symptoms and seven weed plants were collected from the Riyadh region. DAS-ELISA revealed that 25% and 9% of the lettuce plants were singly infected with LBVaV and MiLBVV, respectively, whereas 63% had a mixed infection with both viruses. The results were confirmed by multiplex reverse transcription polymerase chain reaction using primers specific for LBVaV and MiLBVV. LBVaV and MiLBVV were also detected in Sonchus oleraceus and Eruca sativa, respectively. The nucleotide sequence of LBVaV and MiLBVV Saudi isolates ranged from 94.3-100%, and their similarities to isolates with sequences in the GenBank database ranged from 93.9 to 99.6% and 93.8 to 99.3%, respectively. Olpidium sp. was present in the roots of lettuce plants with big-vein disease and it was shown to facilitate transmission of both viruses.

Research paper thumbnail of Enhancement of Selection, Bubble and Insertion Sorting Algorithm

Research Journal of Applied Sciences, Engineering and Technology, 2014

In everyday life there is a large amount of data to arrange because sorting removes any ambiguiti... more In everyday life there is a large amount of data to arrange because sorting removes any ambiguities and make the data analysis and data processing very easy, efficient and provides with cost less effort. In this study a set of improved sorting algorithms are proposed which gives better performance and design idea. In this study five new sorting algorithms (Bi-directional Selection Sort, Bi-directional bubble sort, MIDBiDirectional Selection Sort, MIDBidirectional bubble sort and linear insertion sort are presented. Bi-directional Selection Sort and MIDBiDirectional Selection Sort are the enhancement on basic selection sort while Bidirectional bubble sort and MIDBidirectional bubble sort are the enhancement on basic bubble sort by changing the selection and swapping mechanism of data for sorting. Enhanced sorting algorithms reduced the iteration by half and quarter times respectively. Asymptotically complexities of these algorithms are reduced to O (n 2 /2) and O (n 2 /4) from O (n 2). Linear insertion sort is the enhancement of insertion sort by changing the design of algorithm (convert two loops to one loop). So asymptotically this algorithm is converted to linear time complexity from quadratic complexity. These sorting algorithms are described using C. The proposed algorithms are analyzed using asymptotic analysis and also using machine-running time and compared with their basic sorting algorithms. In this study we also discuss how the performance and complexity can be improved by optimizing the code and design.

Research paper thumbnail of Pumping Speed Measurement of the Rotary Vane Vacuum Pump by Using Numerical and Experimental Approaches

Volume 7: Fluids Engineering Systems and Technologies, 2014

Pumping speed is the main performance parameter of a vacuum pump. In the present work, pumping sp... more Pumping speed is the main performance parameter of a vacuum pump. In the present work, pumping speed for a three-vane rotary vacuum pump is quantified using both experimental and numerical approaches. The numerical methodology assumes continuum flow (Knudsen number < 0.1), thus allowing the use of Navier Stokes equation. Commercial computational fluid dynamics (CFD) solver i.e. Fluent, is used to discretize the governing equations. Moving / dynamic mesh technique is used for the internal flow volumes of the pump to reproduce the change-in-time shape. Complete process starting from the CAD modeling to CFD simulations is discussed in detail. The adopted approaches are generic and can be used to find the pumping speed of any other rotary vane vacuum pump. The vane pump is also tested using an assessment system, which is constructed according to DIN28432 standard. Results of experimentally measured pumping speed are in good agreement with the one computed numerically.Copyright © 2014 by ASME

Research paper thumbnail of Antibacterial Susceptibility of Heavy Metals Tolerant Bacteria Isolated from NILEST Tannery Effluent

Journal of Advances in Medical and Pharmaceutical Sciences, 2016

Background: The emergence of multiple antibiotics resistance among bacterial population poses a p... more Background: The emergence of multiple antibiotics resistance among bacterial population poses a potential threat to human health. The coexistence of metal/antibiotic resistance in bacterial strains suggests the role of heavy metals as a factor which can also contribute to drug resistance phenomenon since heavy metal pollution results in selective pressure that leads to the development of multiple drug resistance among bacterial populations probably through horizontal gene transfer. Aim: This study was aimed to isolate, identify, and determine the antibiogram profile of heavy metals tolerant bacteria from the tannery effluent at Nigerian Institute of Leather and Science Technology (NILEST), Zaria, using standard microbiological methods. Methodology: Tannery effluent was cultured on heavy metals incorporated nutrient agar. The resultant isolates were purified by sub-culturing on fresh heavy metals incorporated nutrient agar Original Research Article Oko et al.; JAMPS, 8(3): 1-10, 2016; Article no.JAMPS.26580 2 and the antibiogram profile was determined using agar diffusion method. Results: The bacteria isolated include Bacillus cereus (18.75%), Escherichia coli (12.50%), Klebsiella aerogenes (18.75%), Klebsiella pneumoniae (6.25%), Pseudomonas aeruginosa (12.50%), Proteus mirabilis (6.25%), and Staphylococcus aureus (25.00%) with Staphylococcus aureus being the most prevalent. In this study, heavy metals tolerant bacteria isolated from the tannery effluent were multidrug resistant as each of the isolates was able to resist the activity of one or more of the antibiotics across the three classes of antibiotics studied. Gentamicin was highly resisted followed by ampicillin and amoxicillin. Kanamycin and Nalidixic acid were more effective followed by Ciprofloxacin and Streptomycin. The β-lactams/penicillins were generally not very effective as compared to the glycopeptides and the quinolones. Staphylococcus aureus and Escherichia coli were highly resistant to six (6) out of the nine (9) antibiotics tested with Escherichia coli showing 100% resistance to ampicillin and amoxicillin. However, Bacillus cereus was moderately resistant to seven (7) out of the nine (9) antibiotics tested but highly resistant to gentamicin. Ampicillin and cefixime showed no activity against Proteus mirabilis and Klebsiella pneumoniae. However, Proteus mirabilis and Klebsiella aerogenes were 100% resistant to gentamicin. Kanamycin was inactive against Klebsiella pneumoniae. The Multiple Antibiotic Resistance (MAR) indices of all isolates were greater than 0.2. Conclusions: The recovery of heavy metals tolerant bacteria from the tannery effluent is an indication that the effluent is laden with heavy metals. The high antibiotic resistance profile of the isolates in this study is an indication of the correlation between heavy metals tolerance and antibiotic resistance. The identified heavy metals tolerant bacterial strains could be useful for bio-remediation of heavy metals contaminated wastewaters and soil environments even though they are potential threat to successful chemotherapy if incriminated in infections.

Research paper thumbnail of Ruminal Condition Between Madura Cattle and Ongole Crossbred Cattle Raised Under Intensive Feeding

Journal of the Indonesian Tropical Animal Agriculture, 2011

Research paper thumbnail of Prevalence of Bacterial, Trichomonas and Candidal Vaginosis among Females in Angwan-Fulani, Palladan in Zaria, Nigeria

Journal of Applied Life Sciences International, 2016

Aims: This study was conducted to determine the prevalence of agents of vaginitis among females i... more Aims: This study was conducted to determine the prevalence of agents of vaginitis among females in Angwan-Fulani, Palladan-Zaria. Study Design: Experimental design used was a completely randomized design (CRD). Place and Duration of Study: Original Research Article Akafyi et al.; JALSI, 5(2): 1-6, 2016; Article no.JALSI.25649 2 Methodology: Total of 150 Samples of High Vaginal Swabs (HVS) were collected from the participants and examined for pathogenic organisms. Demographic information was collected using structured questionnaire. Samples were examined using standard bacteriological methods and microscopically. Direct wet-mount preparation for the detection of Trichomonas vaginalis was employed following a preliminary growth of the parasite in a selective Diamond&#39;s medium. Results: The results of this study indicated that 139 (92.66%) out of 150 samples had at least one infection. The organisms isolated include Candida albicans, Streptococcus pyogenes, Staphylococcus aureus and Trichomonas vaginalis. The age group &gt;25 years had the highest prevalence. Mixed infections were observed. Conclusion: The findings showed that vaginitis is common in the study area. Urgent attention is needed by Health Authority for wider screening and treatment.