usman aliyu - Academia.edu (original) (raw)

Papers by usman aliyu

Global Journal of Research In Engineering, 2020

Integration of Distributed Generations (DGs) at distribution network levels have changed the stru... more Integration of Distributed Generations (DGs) at distribution network levels have changed the structure from being radial to mesh; thereby causing fault currents to be fed from all the sources connected to the network. Another operational requirement is that DGs can get disconnected from the network due to disturbances or maintenance requirements leading to new network topology. This research work has, therefore, proposed an adaptive protection scheme that relies on modern communication infrastructure for its implementation, after optimally siting and sizing of DG and investigation of impact of DG on the protection system and reliability of the system. Herein, modified particle swarm optimization (MPSO) has been deployed for the optimal relay parameters values (operation time, pick up current and time dial settings). Standard communication protocol (IEC 61850) has been chosen to facilitate the communication amongst the various devices in the adaptive protection framework developed.

Concrete has been identified as one of the most common building material with high embodied energ... more Concrete has been identified as one of the most common building material with high embodied energy. Investigations on lightweight concrete using oil palm shell (OPS) as coarse aggregate were attempts to find an alternative material to the use of crushed granite in concrete with a view to reducing environmental pollution resulting from the accumulation of OPS as waste from palm oil mills. This paper investigated some important characteristics of concrete made with OPS as coarse aggregate and rice husk ash (RHA) partially replacing Ordinary Portland Cement (Ashment) as binding agent. The compressive strength of the Ashment:OPS concrete at 28 days was found to be 62% higher than the minimum required strength of 17N/mm and 22% lighter, for structural lightweight concrete recommended by ASTM C330. Ashment:OPS concrete can therefore be used in lightweight structures. The use of this concrete will reduce environmental pollution. This is because the major constituents of the concrete; OPS a...

This paper presents the position and trajectory tracking control scheme for the ball and plate sy... more This paper presents the position and trajectory tracking control scheme for the ball and plate system (BPS) using the double feedback loop structure (a loop within a loop) for effective control of the system. The inner loop was designed using linear algebraic method by solving a set of Diophantine equations. The outer inner loop was designed using sensitivity approach. Simulation results showed that the plate was stabilized at 0.3546 seconds, and the ball was able to settle at 1.7087 seconds, when given a circular trajectory of radius 0.4 m with an angular frequency of 1.57 rad/sec, with a trajectory tracking error of 0.0095 m, which shows that the controllers have adaptability, strong robustness and control performance for the ball and plate system.

Sixty sesame accessions from eight locations in Nigeria were assessed for agro-morphological trai... more Sixty sesame accessions from eight locations in Nigeria were assessed for agro-morphological traits using random amplified polymorphic DNA (RAPD) markers. DNA was isolated using modified cetyltrimethyl ammonium bromide extraction method. The cultivars were assessed for genetic diversity using eight random amplified polymorphic DNA markers. The agronomic assessment was also conducted and the results showed that germination period ranged 3-7 d. Mean 100-seed weight was 3.6±0.3 mg, while mean seed pod was 56 pods per plant, with days to flowering ranging 48-62 d. Seeds size ranged 50.6-79.3 mm, while plant height was 1.4±1.7 m. Dendrogram generated using unweighted pair groups mean arithmetic analysis separated the accessions into six major groups of two clusters and some independent cultivars with a bootstrap value of 45-60%. The polymorphic information content (PIC) values ranged from 0.3-0.9. The RAPD marker OPT-10 showed polymorphic characteristics, while OPB-11 was monomorphic wit...

International Journal of Research in Medical Sciences

Background: Soft tissue sarcomas are a rare group of heterogeneous tumours that consist of severa... more Background: Soft tissue sarcomas are a rare group of heterogeneous tumours that consist of several neoplasia which differentiate into different cell lines. They could arise from the mesodermal or ectodermal embryonic germ layers. Rhabdomyosarcoma is the most common soft tissue tumour in the paediatric age group in most studies, while in adults, malignant fibrous histocytoma, liposarcoma and fibrosarcoma are seen to be more predominant. The study aims to highlight the histological patterns, clinical presentation, associated risk factors and the patients’ performance status at presentation.Methods: This is a 5-year retrospective between the period of 2010 to 2015 of all cancer patients diagnosed with soft tissue sarcoma, seen in the department of radiotherapy and oncology, a tertiary health centre in Sokoto Nigeria. Data collected included socio-demographic, histological type, clinical features, and performance status.Results: A total of 123 patients were reviewed during the study per...

FUOYE Journal of Engineering and Technology

This study presents the transient stability enhancement capability of Unified power flow controll... more This study presents the transient stability enhancement capability of Unified power flow controller (UPFC) as an effective Flexible AC Transmission System (FACTS) device in a multi-machine power system. The test system was a reduced Nigerian 330kV power system and the focus was on the effect of disturbances on the largest generating unit (Egbin) in the system. The analysis was conducted by simulating a 3-phase fault at two locations; on the terminal of the largest generator unit at Egbin bus and the bus with the largest load at Ikeja–west. The response of the system in both cases was compared with and without the device in operation. Simulations were carried out using the Power System Simulation for Engineering (PSS/E) software. Results showed that, with the UPFC in the network, system transient stability was enhanced considering that critical clearing time of the system was increased from 380ms to 590ms when the fault was at Egbin generator terminal and from 470ms to 510ms followin...

Pharmaceutics

Thermosensitive alginate–poloxamer (ALG–POL) copolymer with an optimal POL content was synthesize... more Thermosensitive alginate–poloxamer (ALG–POL) copolymer with an optimal POL content was synthesized, and it was used to combine with silk fibroin (SF) for building ALG–POL/SF hydrogels with dual network structure. Mesoporous bioactive glass (BG) nanoparticles (NPs) with a high level of mesoporosity and large pore size were prepared and they were employed as a vehicle for loading insulin-like growth factor-1 (IGF-1). IGF-1-loaded BG NPs were embedded into ALG–POL/SF hydrogels to achieve the controlled delivery of IGF-1. The resulting IGF-1-loaded BG/ALG–POL/SF gels were found to be injectable with their sol-gel transition near physiological temperature and pH. Rheological measurements showed that BG/ALG–POL/SF gels had their elastic modulus higher than 5kPa with large ratio of elastic modulus to viscous modulus, indicative of their mechanically strong features. The dry BG/ALG–POL/SF gels were seen to be highly porous with well-interconnected pore characteristics. The gels loaded with ...

Compendium of New Techniques in Harmonic Analysis, Sep 5, 2018

Pan African Medical Journal Conference Proceedings

Introduction : cerebrospinal meningitis (CSM) is an epidemic-prone vaccine preventable disease as... more Introduction : cerebrospinal meningitis (CSM) is an epidemic-prone vaccine preventable disease associated with high mortality and morbidity, especially in developing countries like Nigeria. It is regarded as a priority disease in the Integrated Disease Surveillance and Response (IDSR) system in Nigeria. We analyzed surveillance data to describe the epidemiology of CSM in Kebbi State, 2015 - 2016. Methods : we reviewed surveillance data abstracted from Kebbi State IDSR data-base for the years 2015 - 2016. A suspected case of CSM was defined as: any person with sudden onset of fever (>38.5oc rectal or 38oc axillary) and one of the following signs: neck stiffness, altered consciousness or other meningeal signs. A confirmed case was defined as a suspected case confirmed by isolation of Neisseria meningitidis from Cerebro-spinal fluid (CSF) or blood. We computed frequencies and proportions. Results : a total of 2088 suspected cases of CSM were reported during the period under review with a cumulative attack rate of 48.6/100,000 and 2.3/100,000 in 2015 and 2016 respectively. Mean age was 12.9 ± 9.5 years. Males constituted 1183 (56.7%) of the reported cases. Persons aged 10-15 years accounted for the highest number of cases 720 (34.5%). All patients were treated with Intra-muscular or Intra-venous Ceftriaxone according to the national treatment guidelines. Only 140 (6.7%) patients, had their CSF samples taken of which 76 (54.3%) were positive for Neisseria meningitides serotype C. Ninety three of the total patients died during the reporting period (case fatality rate 4.5%). Amongst those that died, only 2 (2.2%) were laboratory confirmed. One thousand two hundred and fifty four (60.1%) of the cases had a single dose of Meningococcal polysaccharide vaccine, 803 (38.5%) were unvaccinated. Conclusion : the laboratory component of the surveillance system and the vaccination coverage were poor. We recommended further improvement in laboratory surveillance and vaccination activities in the State.

Pharmaceutics, Jan 17, 2018

Chitosan(CH)-polylactide(PLA) copolymers containing varied PLA percentages were synthesized using... more Chitosan(CH)-polylactide(PLA) copolymers containing varied PLA percentages were synthesized using a group-protection method and one of them with solubility in water-based solvents was used to prepare CH-PLA/hyaluronic acid (HA) complex microspheres for the delivery of transforming growth factor-β1 (TGF-β1). An emulsification processing method was developed for producing TGF-β1-loaded CH-PLA/HA microspheres using sodium tripolyphosphate (TPP) as ionic crosslinker and the size of the microspheres was devised to the micron level in order to achieve high encapsulating efficiency. The encapsulating efficiency, swelling property and release administration of the microspheres could be synergistically regulated by PLA component, the applied TPP dose and the incorporated HA amount. In comparison to CH/HA microspheres, the CH-PLA/HA microspheres had greatly reduced TGF-β1 release rates and were able to administrate the TGF-β1 release at controlled rates over a significant longer period of tim...

2006 IEEE Power Engineering Society General Meeting, 2006

JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH, 2015

This paper seeks to assess the reactions of Nigeria’s stock market to monetary policy innovations... more This paper seeks to assess the reactions of Nigeria’s stock market to monetary policy innovations during the period of global financial crisis on the basis of monthly data over the period January, 2007 to August, 2011. In particular, stock market return was regressed against major monetary policy instruments; money stock (M1, and M2) and monetary policy rate (MPR). The theoretical