Abubakar Tafawa Balewa University
  • Bauchi, Bauchi State, Nigeria
Recent publications
The treatment of wastewater is very significant for sustainable development, industrialization and population growth which leads to discarding of a lot of effluents which are harmful to the environment and water bodies. Dyes and pigments are organic-based substances that are carcinogenic in nature, and their presence as industrial effluents cause serious effect s to the aquatic and terrestrial life. Therefore, an eco-friendly and less expensive techniques need to be developed to overcome this menace. Carbon nanotube (CNT) membrane-based absorbent materials offer a lot of promise due to their high specific surface area, mesoporous structure, customizable surface characteristics, and excellent chemical stability. They can tolerate challenging of wastewater conditions including acidic, basic, and salty environments at high concentrations or at high temperatures because of these qualities. Even though CNT nanoparticles have been extensively studied for their ability to remove organic dyes from organic wastewater systems, engineering challenges still stand in the way of their widespread use. One route to the removal of these pollutants is the utilization of CNT composites which includes magnetic carbon nanotubes as adsorbents, carbon nanotube-based membranes, carbon nanotube-based nanocellulose membranes, carbon nanotube-based buck paper, and it also talked about mechanism of pollutant adsorption in carbon-based nanocellulose membranes. This chapter discusses techniques used for wastewater treatment. Second, CNT adsorbents of dyes for different wastewater systems are introduced, still in this chapter, it also contains different applications of CNT in wastewater treatment, and also the real wastewater applications. After considering the materials’ scalability and practical usability, cost factors are finally determined.
In this work, the nonlinearity of PIN diode on frequency reconfigurable patch antenna is investigated. To perform frequency reconfiguration, the proposed design makes use of the switching capabilities of a PIN diode. The antenna has a dimension of 41 × 44 mm ² corresponding to 0.33 λ 0 × 0.35 λ 0 , where λ 0 represents the wavelength in free space at 2.4 GHz fabricated on Rogers Duroid RO3003 TM material. In the OFF state of the PIN diode, a single resonance (ISM 5.8 GHz) is achieved. However, in the ON state of the PIN diode, a dual‐resonance (ISM 5.8 GHz and 2.4 GHz) is achieved. A directional and bidirectional radiation pattern can be observed in the E ‐plane at 5.8 GHz and 2.4 GHz, respectively, and omnidirectional radiation patterns can be viewed in the H ‐plane for both 5.8 GHz and 2.4 GHz. The gain is measured to be 4.84 dBi at 2.4 GHz and 5.87 dBi at 5.8 GHz, with total efficiencies of 91.8% and 92.5% at 5.8 GHz and 2.4 GHz, respectively. Two‐tone nonlinear measurements at 2.4 GHz and 5.8 GHz are used to evaluate the PIN diode. Several third‐order intermodulation distortion products (IMD3) frequencies are observed with input powers between 0 and 20 dBm. The IMD3 at 2.4 GHz is −36.18 dBm, while at 5.8 GHz is −47.19 dBm and the third‐order input intercept point (IIP3) of +66.65 dBm is obtained at 2.4 GHz, while +22.69 dBm at 5.8 GHz. Additionally, at 2.4 GHz, the 1‐dB gain compression (P 1‐dB ) could not be identified, showing that the antenna behaves linearly within the spectrum of input power. Similarly, the P 1‐dB is detected at 14.8 dBm input power at 5.8 GHz. The proposed antenna works in the linear region up to an input power level of 15 dBm, where the received signal strength of the IMD3 is minimal, according to the measurement of the nonlinearity caused by the PIN diode. The nonlinearity results confirm that the active reconfigurable antenna designed and implemented in this work is suitable for use in the 2.4 GHz and 5.8 GHz bands for indoor and short‐range communication applications. Furthermore, the assessment of nonlinearity provides a deeper understanding of and helps mitigate the negative effects of nonlinearity on the proposed antenna. This measurement assists in refining biasing, selecting suitable linearization methods, improving the design, and evaluating performance at the system level. Ultimately, it enhances antenna performance and expands frequency reconfigurability by enabling optimization across multiple aspects.
Background and Aims Antimicrobial resistance (AMR), a global health crisis of mounting urgency, has been further complicated by the ongoing COVID‐19 pandemic. The intricate relationship between these two phenomena is especially pronounced in low‐ and middle‐income countries (LMICs) due to the distinct obstacles encountered by their healthcare systems and policy structures. This study aims to explore the complex challenges arising from the coexistence of these two crises in LMICs and proffer specific recommendations for holistic management. Methods An exhaustive bibliographic survey was executed, employing search queries in specialized databases such as PubMed, SCOPUS, and Web of Science's SCI‐EXPANDED index. The timeframe for the literature search extended from January 2020 to January 2023. The search strategy employed key terms including antibiotic resistance, AMR, COVID‐19 pandemic, low‐ and middle‐income countries, SARS‐CoV‐2, and LMICs. Results The pandemic has aggravated various drivers of AMR in LMICs, including limited capabilities, weak frameworks, and socioeconomic factors. New challenges have emerged, such as disruptions in the antibiotic supply chain and an increased risk of healthcare‐associated infections. The interaction between these drivers presents a complex problem that demands a coordinated response. Specific recommendations include strengthening health systems, funding research and innovation, and enhancing infection prevention control measures. Conclusion The coexistence of AMR and the COVID‐19 pandemic in LMICs demands an integrated approach involving multiple stakeholders. Emphasis must be placed on constructing aligned regulatory frameworks, nurturing regional collaborations, and focusing on accessible therapeutic options. The study underscores the necessity for actionable strategies to achieve sustainable access to clean water and sanitation and also highlights the importance of long‐term planning, funding, and specialized expertise in emerging modalities like phage therapy.
Background: The Covid-19 pandemic affected healthcare delivery globally. The impact was more for individuals with chronic diseases requiring regular visits to the hospital. This study aimed to assess the impact of the pandemic on care for patients with Sickle cell disease (SCD) in Nigeria. Methods: This was a cross-sectional survey involving 435 SCD patients from the six geopolitical zones of Nigeria. Data was collected through pre-tested and validated, semi-structured questionnaires using Google forms online and face-to-face interviews at the Clinic. Results: Teaching hospitals were the most utilised health facility by the respondents 269 (61.8%). Bone pain was the most frequent crisis 318 (70.7%) with a significant increase in frequency during the pandemic when compared with the preceding year, p =0.004. Many of the respondents 227(52.2%) required hospitalization during the pandemic. Major concerns expressed for accessing care include fear of exposure to Covid-19-infected patients or health workers who have been exposed to Covid and conversion of regular health facilities to Covid-19 treatment centres. During the Pandemic, 102 (23.4%) respondents had easy access to their doctors and telemedicine was available to 87(20%) but 56 (12.9%) and 97 (22.3%, ) had difficulties in getting blood transfusion and accessing laboratory tests respectively. Up to 139(32.9%) did not have difficulties getting pain relief, 169 (38.9%) had their routine medications while 166 (38.2%) had their income significantly affected during the pandemic. Conclusion: The findings revealed challenges in accessing routine medical care, concerns about exposure to COVID-19, and disruptions in healthcare services. This article discusses the implications of the survey results and proposes strategies to strengthen sickle cell care in preparation for future pandemics.
The study was carried out to investigate the sensory and nutritive value of Clarias gariepinus smoked using two different sources of energy from neem and eucalyptus wood. The fuel was sourced from the tree Azadirachta indica and Eucalyptus camaldulensis. The fish were smoked using the local smoking kilns made from drums with a wire mesh placed on each of them. The neem/eucalyptus wood was introduced from the vent. Temperature of 70 °C was maintained in the smoking oven for the first hour, then it was reduced to 40 – 50 °C until the end of the drying period. There were also significant differences in proximate composition in terms of moisture, protein, lipid and crude ash content, between the fish smoked using neem and eucalyptus (P<0.05). The sensory evaluation was carried out by a 10- man evaluation panel using the 7-point hedonic scale and the nutritional composition was evaluated according to methods outlined by one-way analysis of variance. The sensory evaluation showed there was a significant difference (P<0.05) between the fish smoked using neem and eucalyptus wood in color, flavor and general acceptability. According to the results of the sensory evaluation, it could be said that eucalyptus was a better energy source for smoked C. gariepinus than neem wood.
Biomass is a renewable alternative energy source with almost zero‐carbon footprint. This work focused on the physicochemical analysis and wet torrefaction of shea nut chaff (SNC) biomass. The SNC is a semi‐solid waste generated during the production process of shea nut butter and is least studied for its bioenergy potential. Wet torrefaction or hydrothermal carbonization studies of sun‐dried SNC were conducted at different temperatures (180–260°C), residence times (15–30 min) and water‐to‐biomass (W/B) ratios (5–15:1). Characterization studies of the torrefied biomass for different temperatures were conducted using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM) analyses. The best‐fit analysis of variance (ANOVA) model for wet torrefaction mass yield was 2FI, with p ‐values of <0.05, and a regression coefficient ( R ² ) of 0.9443. The yield of torrefied SNC attained at 260°C, 45 bar, W/B ratio of 5, and 10‐min residence time was 55.5 wt.%, and the corresponding energy yield was 89.5%. Both temperature and W/B ratio had significant effect on torrefaction yield. There was a significant improvement in the volatile matter, fixed carbon, moisture, and heating value reduction in the torrefied SNC compared to the raw SNC making it a potential bioenergy source. However, high ash content is a major concern even after torrefaction.
Objectives Increase in body mass index (BMI) increases the risk of developing high blood pressure (BP). Several studies also indicate that high BP is associated with age. Controversies have been found regarding the association of BMI with high BP and age. Hence, this study was conducted to investigate the association between BP, BMI, and age. Material and Methods Using the Inter-university Consortium for Political and Social Research (ICPSR 131103) Study on the Effects of Mindfulness on Lifestyle Behavior and BP, prospectively gathered data were retrospectively analyzed. A randomized controlled study was conducted. Using the statistical MedCalc program, the patient demographic data – including their age, BMI, and BP – were statistically examined. Statistical significance was determined using a 0.05 P -value. Results Of the 37 participants, 43.3% had a normal BMI. One-fourth (40.5%) of the people were obese. 13.5% and 32.4% of the people had normal systolic (SBP) and diastolic (DBP) BP, respectively. Age, SBP, or DBP did not significantly correlate with BMI. Nevertheless, there was a positive and substantial correlation between BMI, age, SBP, DBP, weight, and height. Conclusion According to the study’s findings, there are no appreciable positive connections between BMI and either SBP or DBP, or age. However, the weakly positive relationships between SBP and DBP and age suggest that regular BP monitoring is necessary.
Breeding for trypanotolerance could be a more sustainable control strategy against African animal trypanosomiasis. This study examined the biochemical indices of crossbred/composite cattle, N’dama and WF breeds under natural trypanosome challenge to assess trypanotolerance capacity. Serum total protein, albumin, globulin, ALT, AST, ALP, bilirubin, creatinine and urea were compared among cattle genotypes, genotypic groups, anaemic and non-anaemic, and parasitaemic and aparasitaemic groups. Non-anaemic cattle had higher (p < 0.05) total protein and albumin compared to anaemic cattle. Globulin, albumin/globulin, ALT, ALP, and creatinine did not differ significantly between cattle genotypes but AST was highest in anaemic NDxWF (38.50 ± 6.19 U/l) while indirect bilirubin and urea were highest in non-anaemic 75NDx25WF. Aparasitaemic cattle had higher total protein, albumin and ALP but lower creatinine than parasitaemic cattle. AST and total bilirubin were highest in ND(GUxWFxMU) (33.18 ± 1.78 U/l) and ND(GUxWF) (0.30 ± 0.03 mg/dl), respectively and least in parasitaemic WF (24.63 ± 3.57 U/l) and NDxWF (0.19 ± 0.03 mg/dl), respectively. Creatinine, indirect bilirubin and urea were highest in 75NDx25WF (1.23 ± 0.26 mg/dl, 0.23 ± 0.03 mg/dl, and 39.68 ± 3.05 mg/dl, respectively) and lowest in ND (0.28 ± 0.10 mg/dl), parasitaemic WF (0.11 ± 0.03mg/dl), and ND(BOxWF) (22.84 ± 3.05 mg/dl), respectively. Crossbred/composite cattle and N’Dama had higher serum total protein, albumin, AST, total and indirect bilirubin, but lower creatinine compared to WF cattle indicating better body nutrient reserves, lower oxidative stress challenge and stronger trypanotolerance capacity.
Angiotensin converting enzyme-2 receptor (ACE2) present on human cell membrane surfaces is a critical receptor for binding of SARS-CoV-2 to invade cells. Severe burden of recent COVID-19 pandemic was of global public health importance. Using bioinformatics tools, protein sequence and structural features of ACE2 protein can be obtained. Protein sequences can be compared with structures of ACE2 proteins from same individuals (or patients) of different clinical status. This can either be from data obtained from disease states or already deposited annotated data. Then assess for effectiveness of a pool of bio-molecular attributes such structural neighbor profiles which help describe micro-environment of single amino polymorphisms (SAPs). Then engage predictive and modeling tools to predict key mutational loci- particularly involving SAPs and their functions in relation to disease states. Generated data can contribute to ontology, screens to identify biomarkers and open up paths to development of research protocols in therapeutics and diagnostics.
As a follow-up to a previous report on the wide distribution and prevalence of Varroa destructor in Nigeria, this study proposed to determine the haplotype of the mites collected in that study, using mitochondrial DNA cytochrome oxidase 1 (mtDNA cox1) barcoding. Therefore, a total of 114 mites, from 12 localities, were successfully sequenced at either both or one direction of the cox1 partial gene. Blast and alignment showed that all sequences obtained from Nigeria were 100% identical to the Korean K1-1/K1-2 haplotype [GQ379056-58] but also to K1-3 which is indiscernible from the related haplotype based only on cox1. An on-going whole genome sequencing on these mites is aiming to help retrace the spread and understand the country-wide population structure of Varroa in Nigeria.
The best possible use of natural resources and the large amounts of trash produced by industrial and human activity is necessary for sustainable development. Due to the threat of global climate change and other environmental challenges, waste management systems are changing, leading to more instances of water resource management. The waste generated must be controlled from a sustainability point of view. Typically, the conventional disposal of Agricultural Wastewater (AW) and biomass can be achieved by recycling, reusing, and converting them into a variety of green products. To improve the AW quality for the purposes of environmental sustainability, Sustainable Development Goals (SDGs) 6 and 14, dealing with clean water, sanitation, and life below water, are very important goals. Therefore, the present investigation evaluates the effectiveness of a Bench-scale Activated Sludge Reactor (BASR) system for AW treatment. The BASR was designed to focus on getting the maximum possible utilization out of a biosorbent derived from oil palm waste activated hydrochar (OPAH). This is in accordance with SDG 9, which targets inorganic and organic waste utilization for added value. An experiment was developed using the Response Surface Methodology (RSM). A Hydraulic Retention Time (HRT) of 1-3 days was used in the bioreactor's setup and operation, and Mixed Liquor Suspended Solids (MLSS) concentrations of 4000-6000 mg/L were used. BASR was fed with AW with initial mean concentrations of 4486 ± 5.63 mg/L and 6649 ± 3.48 for the five-day Biochemical Oxygen Demand (BOD 5) and Chemical Oxygen Demand (COD) experiments, respectively. The results obtained showed that maximum reductions of 84.66% and 72.07% were recorded for BOD 5 and COD, respectively. Through RSM optimization, the greatest reductions in the amounts of organic materials were achieved with a 2-day HRT and an MLSS dosage of 5000 mg/L. Substrate elimination thresholds were assessed using the first-order, the Grau second-order, and the modified Stover-Kincannon models. The reported observations were found to be perfectly fit by the modified Stover-Kincannon model, with high R 2 values of 0.9908 and 0.9931 for BOD 5 and COD, respectively. As a result, the model may be used to design the BASR system and forecast how the reactor would behave.
Given the prevailing concerns about greenhouse gas emissions, global warming, and the growing demand for renewable resources, the pavement industry, among others, is actively engaged in researching and exploring low-carbon materials and technologies. Despite the growing interest in low-carbon asphalt pavement, there is still a significant knowledge gap regarding the use of various waste materials and technologies to achieve this goal. This study aims to close this gap by conducting a systematic review and scientometric assessment of the existing studies on the use of waste materials and technologies for low-carbon asphalt pavement. The study spans the years 2008 to 2023, and the scientometric analysis was conducted using the VOS viewer application. The study identifies materials and technologies in this area by examining co-authored country studies, publication sources, and keyword co-occurrence. It should be noted that a limited number of waste materials that allow CO2 emissions reduction was analyzed in this study. However, other waste categories, such as bio-oils and polymers, which can provide positive either environmental or economic impacts on the production of paving materials, were not considered in the scope of the study. Based on the current review, it was found that integrating recycled waste materials like recycled asphalt pavement, biochar, or crumb rubber with alternative mixing technologies such as warm mix asphalt and cleaner energy can significantly reduce CO2 emissions. China and the United States were identified as key research contributors to the low-carbon pavement. Furthermore, biomass-based fuel and electric construction equipment lower carbon and greenhouse gas emissions by 36–90% and 67–95%, respectively. However, before various recycled waste materials and technologies can be widely used in the asphalt industry, various challenges need to be addressed, including cost concerns, performance and durability concerns, standardization and regulations, availability, integration with existing facilities, and insufficient field and long-term data. The review identified critical research gaps, such as the absence of a homogeneous and reliable standard method for low-carbon asphalt pavement, limited field performance data, and a life cycle assessment approach in analyzing the emission reduction effects. The reviews will aid in the paradigm shift to a more carbon-friendly pavement industry that uses recycled waste materials and technologies.
Agro-industrial biorefinery effluent (AIBW) is considered a highly polluting source responsible for environmental contamination. It contains high loads of chemical oxygen demand (COD), and phenol, with several other organic and inorganic constituents. Thus, an economic treatment approach is required for the sustainable discharge of the effluent. The long-term process performance, contaminant removal and microbial response of AIBW to rice straw-based biochar (RSB) and biochar-based geopolymer nanocomposite (BGC) as biosorbents in an activated sludge process were investigated. The adsorbents operated in an extended aeration system with a varied hydraulic retention time of between 0.5 and 1.5 d and an AIBW concentration of 40-100% for COD and phenol removal under standard conditions. Response surface methodology was utilised to optimize the process variables of the bioreactor system. Process results indicated a significant reduction of COD (79.51%, 98.01%) and phenol (61.94%, 74.44%) for BEAS and GEAS bioreactors respectively, at 1 d HRT and AIBW of 70%. Kinetic model analysis indicated that the Stover-Kincannon model best describes the system functionality, while the Grau model was better in predicting substrate removal rate and both with a precision of between R2 (0.9008-0.9988). Microbial communities examined indicated the abundance of genera, following the biosorbent addition, while RSB and BGC had no negative effect on the bioreactor's performance and bacterial community structure of biomass. Proteobacteria and Bacteroidetes were abundant in BEAS. While the GEAS achieved higher COD and phenol removal due to high Nitrosomonas, Nitrospira, Comamonas, Methanomethylovorans and Acinetobacter abundance in the activated sludge. Thus, this study demonstrated that the combination of biosorption and activated sludge processes could be promising, highly efficient, and most economical for AIBW treatment, without jeopardising the elimination of pollutants or the development of microbial communities.
Vegetables grown in mining areas can accumulate significant amounts of heavy metals (HMs), which can cause serious developmental disorders and have long-term negative effects on public health. In the present study, the HMs contamination level in vegetables grown around the Riruwai mining area in Kano State, Nigeria, was investigated. Fifteen (15) vegetable samples were collected, including lettuce (Lacuta sativa L.), tomato (Solanum lycopersicum L.), and bean (Phaseolus vulgaris L.), as well as their corresponding soils. The levels of As, Cd, Cr, Hg, Mn, Ni, Pb, and Zn in all the samples were determined using Microwave Plasma Atomic Emission Spectrometry, and the measured concentrations were used to calculate the bioaccumulation factor (BAF). The results of the study revealed that HMs concentrations in the investigated vegetables were found to be significantly high, with the majority of levels exceeding the WHO/FAO (2007) recommended limit, and the concentration of HMs in the soil decreased in the order of Zn > Mn > Cr > Pb > As > Ni > Cd > Hg, with As, Pb, and Zn exceeding the WHO/FAO (2001) recommended limit. Pollution levels were found to significantly differ between HMs and vegetable types. BAF results revealed that cadmium is an accumulator of all the studied vegetables (BAFs > 1), while mercury was found to be an accumulator of L. sativa. Higher concentrations of these metals in vegetables and soil, particularly arsenic, cadmium, lead, and zinc, necessitate immediate scientific attention and further research to determine the optimum concentration required for human health. Planting of vegetables for human and animal consumption should be stopped until this is accomplished.
In this research, a modified hybrid Dai-Yuan and Hestenes-Stiefel (DYHS) conjugate gradient (CG) algorithm is presented, with develops sufficient descent property. The hyperplane projection method is also used and the algorithm is a convex combination of DY and HS parameters. With some reasonable assumptions, the global convergence property is obtained under accelerated step size. The numerical experiment demonstrate that the DYHS algorithm is more effective and robust than other existing methods for solving nonlinear monotone equations and signal recovery problems. Mathematics Subject Classification: 65K05, 90C52, 90C26
Novel transmission routes can allow infectious diseases to spread, often with devastating consequences. Ectoparasitic varroa mites vector a diversity of RNA viruses, having switched hosts from the eastern to western honey bees (Apis cerana to Apis mellifera). They provide an opportunity to explore how novel transmission routes shape disease epidemiology. As the principal driver of the spread of deformed wing viruses (mainly DWV-A and DWV-B), varroa infestation has also driven global honey bee health declines. The more virulent DWV-B strain has been replacing the original DWV-A strain in many regions over the past two decades. Yet, how these viruses originated and spread remains poorly understood. Here, we use a phylogeographic analysis based on whole-genome data to reconstruct the origins and demography of DWV spread. We found that, rather than reemerging in western honey bees after varroa switched hosts, as suggested by previous work, DWV-A most likely originated in East Asia and spread in the mid-20th century. It also showed a massive population size expansion following the varroa host switch. By contrast, DWV-B was most likely acquired more recently from a source outside East Asia and appears absent from the original varroa host. These results highlight the dynamic nature of viral adaptation, whereby a vector's host switch can give rise to competing and increasingly virulent disease pandemics. The evolutionary novelty and rapid global spread of these host-virus interactions, together with observed spillover into other species, illustrate how increasing globalization poses urgent threats to biodiversity and food security.
In this paper, we propose a solution method via hybrid spectral conjugate gradient and signal recovery problem (ANHSCG) to solve nonlinear monotone equations. This has been done using the hybrid conjugate gradient (CG) parameters of Dai-Yuan (DY), conjugate descent (CD), Hestenes-Stiefel (HS), Liu-Storey (LS) and the corresponding search direction of spectral conjugate gradient method. The search direction has proved to be adequately descent regardless of the step-size. Under reasonable assumptions, the convergence of the algorithm is established. Additionally, numerical tests are run on a set of benchmark test problems to illustrate the effectiveness and competitiveness of the new algorithm compared with other existing alternatives. Finally, some applications of the proposed algorithm is explored. Mathematics Subject Classification: 65K05, 90C52, 90C26
With the proliferation of mobile devices and diverse mobile applications, wireless operators are experiencing phenomenal growth in the demand for mobile services around the world. These demands have led to the technological responses such as the advancement in radio access, coding and modulation schemes as well as spectrum (carrier) aggregation and cognitive radio capabilities. The aspect of spectrum or carrier aggregation uses cognitive radio technology that implements the dynamic spectrum access for spectrum utilization by sensing and using the underutilized spectrum on co-primary basis without interference to the primary users. In this work, an energy-based, non-parametric TVWS spectrum sensing algorithm was implemented in MATLAB environment. The developed sensing algorithm was aimed at finding free TVWS frequency channel(s) that would be used during spectrum aggregation of channels from TVWS and LTE-A spectrums. The chosen free channel would be configured as the component carrier two (CC2) at the configuration management platform of the TVWS eNode B. The result showed the instantaneous TV channels statuses; free, busy and interfered by computing the PSD expressed in dB while the estimated received power level in dBm for free channels was computed for the UHF range from channel 21 through channel 69. The detectable TV signals’ threshold value was set at -114 dBm. In the ten simulation five cycles carried out, the developed algorithm instantaneously selected channels: 68,34,48,60 and 28 corresponding to the centre (carrier) frequencies of 850MHz, 578MHz, 690MHz, 786MHz and 530MHz, would be dynamically configured as the component carrier two (CC2) in the TVWS eNode Bs during spectrum aggregation process.
Handover is a process in mobile communications in which a connected cellular call or a data session is transferred from one cell site (base station) to another without disconnecting the session. Cellular services are based on mobility and handover allows the user to be moved from one cell site or another for better network performance. There are many handover decision algorithms presented in literature. Generally, system metrics or network parameters are used as measure to decide whether or not to invoke a handover process. For wireless communication networks, the 3GPP and IEEE usually set minimum threshold level that when satisfied would initiate handover process from serving cell to the target cell. It is left to the system engineers to develop their own algorithms based on the network peculiarities to maintain and enhance the network key performance indicators (KPIs). Toward this direction, this paper is focused on reviewing the handover decision algorithms for wireless communication network highlighting the system metrics used and the area of applications
\noindent The use of collocation process for constructing numerical methods for solving ordinary differential equations has been attractive for stiff and problems with highly oscillatory solutions. In this paper, a class of block hybrid collocation methods has been developed which can efficiently solve stiff and highly oscillatory differential equations in block solution form. The block hybrid collocation methods are derived based on collocation at the polynomial nodes which are very effective for solving highly oscillatory systems. The block solution methods arising from the continuous formulation are discussed for various examples with applications. The methods are self-starting and produce dense output within the integration interval. The convergence of the derived methods is determined theoretically and asymptotic error constants are calculated. Improved performance over some known standard methods is achieved for a broad class of problems with oscillating solutions. Preliminary numerical calculations using our new methods clearly show improved performance, efficiency and effectiveness compared to some methods with strong algebraic stability properties. Efficiency curves of the solutions plotted, show rapid convergence of the proposed second-derivative block hybrid collocation methods. (2010) Mathematics Subject Classification:34M10,35B05,35B35,65L05
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1,115 members
Abbagana Mohammed
  • Civil Engineering Programme
Ahmed Olatunde
  • Department of Medical Biochemistry
Abdullahi Musa Kirfi
  • OtoRhinoLaryngology
Muhammad Baffah Aminu
  • Department of Obst and Gynae
Muhammad Abubakar
  • National Centre for Petroleum Research and Development
Abubakar Tafawa Balewa Road, 740272, Bauchi, Bauchi State, Nigeria
Head of institution
Prof. Saminu Abdulrahman Ibrahim