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A 2-hop LoRa Approach Based on Smart and Transparent Relay-Device
(Springer Nature, Switzerland, 2019) Diop, Mamour; Pham, Congduc; Thiare, Ousmane
LoRa is designed for long-range communication where devices are directly connected to the gateway, which removes typically the need of constructing and maintaining a complex multi-hop network. Nonetheless, even with the advantage of penetration of walls, the range may not sometimes be sufficient. This article describes a 2-hop LoRa approach to reduce both packet losses and transmission cost. To that aim, we introduce a smart, transparent and battery-operated relay-devicethat can be added after a deployment campaign to seamlessly provide an extra hop between the remote devices and the gateway. Field tests were conducted to assess relays’ ability to automatically synchronize to the network without advertising their presence.
4-index theory of gravity
(arXiv, 2019-01-16) Moradpour, H.; Licata, I.; Corda, C.; Salako, Ines G.
Recently, a 4-index generalization of the Einstein theory is proposed by Moulin [1]. Using this method, we find the most general 2-index field equations derivable from the Einstein-Hilbert action. The application of Newtonian limit, the role of gravitational coupling constant and the effects of the properties of ordinary energy-momentum tensor in obtaining a 4-index gravity theory have been studied. We also address the results of building Weyl free 4-index gravity theory. Our study displays that both the Einstein and Rastall theories can be obtained as the subclasses of a 4-index gravity theory which shows the power of 4-index method in unifying various gravitational theories. It is also obtained that the violation of the energy-momentum conservation law may be allowed in 4-index gravity theory, and moreover, the contraction of 4-index theory generally admits a non-minimal coupling between geometry and matter field in the Rastall way. This study also shows that, unlike the Einstein case, the gravitational coupling constant of 4-index Rastall theory generally differs from that of the ordinary 2-index Rastall theory.
Acute toxicity and antimalarial studies of extract of Allophylus spicatus in animals
(Toxicol Res, 2021-01-09) Adebayo, Abiodun H.; Yakubu, Omolara F.; Ishola, Temitope A
Medicinal plants produce a variety of chemical substances with varied physiological effects. They are a huge reservoir of various chemical substances with potential therapeutic properties. Allophylus spicatus is a shrub that belong to the Sapindaceae family. In this study, male albino wistar rats (18) were used for acute toxicity test. Animals were divided into six groups of three rats each. Group A served as the control group while the other groups were dosed orally with 200, 500, 1000, 2000 and 5000 mg/kg body weight of extract and were observed for 14 days. Swiss albino mice (42) were used for the antimalarial study; five groups of six infected mice per group (Groups C–G) were respectively dosed orally with 25 mg chloroquine/kg bw, 200 mg of extract/kg bw, 400 mg/kg bw of extract, 25 mg chl./kg bw+200 mg/kg bw of extract and 25 mg chl./kg bw+400 mg/kg bw extract with three groups serving as the control (Groups A–C) for three days. Acute toxicity test and histology analysis on the liver tissue confrmed the safety of the extract at concentrations less than 1000 mg/kg b/w. Antimalarial studies showed the highest activity in the group administered with 400 mg/kg+25 mg chl./kg b/w. In conclusion, A. spicatus was non-toxic at doses less than 1000 mg/kg and significantly reduced parasitemia count in P. berghei infected mice, thus validating its folkloric usage.
An Adaptive Genetic Algorithm with Recursive Feature Elimination Approach for Predicting Malaria Vector Gene Expression Data Classification using Support Vector Machine Kernels
(Walailak J Sci & Tech, 2021-07-27) Arowolo, Micheal Olaolu; Adebiyi, Marion Olubunmi; Nnodim, Chiebuka Timothy
Adsorption of Heavy Metals Contaminants in Used Lubricating Oil Using Palm Kernel and Coconut Shells Activated Carbons
(Science Publishing Group, 2020-03-10) Boadu, Kwasi Opoku; Joel, Ogbonna Friday; Essumang, David Kofi
This research work investigated the adsorption of some heavy metals contaminants in used lubricating oil using chemically activated carbon adsorbents produced from palm kernel and coconut shells. The adsorption mechanism was able to remove some heavy metals such as zinc, chromium, cadmium and magnesium contaminants from the used lubricating oil to appreciable levels. For instance, zinc from initial concentrations of 16.475±0.950 ppm before to 10.375±0.171 ppm after filtration processes for used lubricating oil sample A. Also, for coconut shell from an initial concentration of 14.575±0.272 ppm to 5.450±0.3000 ppm after filtration processes. It was observed that the coconut shell activated carbons was effective in the removal of lead metals while palm kernel cannot. However, the activated carbons produced from palm kernel and coconut shells are not suitable for the removal of both copper and iron metals. For example, after the filtration process with the palm kernel shell activated carbon, the mean concentration of copper metal increases for virgin (C) 0.001± 0.000 to 0.075±0.013 ppm and used lubricating oil samples (A&B) from 0.150±0.008 to 0.400±0.018 ppm and from 0.220±0.096 to 0.230±0.008 ppm respectively. Also, in the case of the coconut shell activated carbon, the mean concentration of copper in virgin lubricating oil remains the same 0.001±0.000 whereas for used lubricating oils samples (i.e. A&B) it increases from 0.150±0.008 to 0.780±0.014 and from 0.220±0.096 to 0.790±0.026 respectively. Also, the equilibrium adsorption data were analyzed using the Langmuir isotherm model. The fit of this isotherm model to the equilibrium adsorption data was determined, using the linear coefficient of correlation (R 2 ). The following R2 values were obtained; Copper (0.8185), Cadmium (0.8347), Lead (0.9349), Chromium (0.9378), Iron (0.9927), Zinc (0.9953), and Magnesium (0.9997) respectively. From the results obtained and statistics point of view, it can be concluded that the Langmuir model shows a better fit due to the high coefficient of correlation(R 2≈ 1). The recovered oil could be also re-used
Advanced Burkitt Lymphoma in Sub-Saharan Africa Pediatric Units
(Research Gate, 2019-11) Bouda, Gabrielle C.; Traore, Fousseyni; Couitchere, Line; Raquin, Marie-Anne; Guedenon, Koffi M.; Pondy, Angele; Moreira, Claude; Rakotomahefa, Mbola; Harif, Mhamed; Patte, Catherine
Purpose To evaluate the results of an intensive polychemotherapy regimen for Burkitt lymphoma (BL) in sub-Saharan African pediatric centers. Patients and Methods Children with advanced-stage BL (stages II bulky, III, and IV) treated with the GFAOP–Lymphomes Malins B (GFALMB) 2009 protocol in 7 centers between April 2009 and September 2015 were prospectively registered. Treatment regimen contained a prephase with cyclophosphamide followed by 2 induction courses (cyclophosphamide, vincristine, prednisone, high-dose methotrexate [HDMTX]), 2 consolidation courses (cytarabine, HDMTX), and a maintenance phase only for stage IV. HDMTX was given at the dose of 3 g/m2. Results Four hundred patients were analyzed: 7% had stage II bulky, 76% stage III, and 17% stage IV disease. Median age was 7.3 years, and sex ratio was 1.9:1 (male:female). A total of 221 patients received the whole protocol treatment and 195 achieved complete remission (CR), 11 of them after a second-line treatment. Treatment abandonment rate was 22%. One hundred twenty-five patients died, of whom 49 deaths were related to treatment toxicity. A total of 275 patients are alive, including 25 despite treatment abandonment, but only 110 are known to be in CR with a follow-up . 1 year, indicating a high rate of loss to follow-up. Twelve-month overall survival (OS) was 60% (95% CI, 54% to 66%) and 63%, 60%, and 31%, respectively, for stage II bulky, III, and IV. Patients with stage III disease who started second induction course within 34 days had OS of 76%, versus 57% (P = .0062) beyond 34 days. Coclusion The GFA-LMB2009 protocol improved patients’ survival. Early dose intensity of treatment is a strong prognostic factor. Improving supportive care and decreasing loss to follow-up are crucial.
Advances in biotechnological applications of waste cooking oil
(Case Studies in Chemical and Environmental Engineering, 2021-10-31) Awogbemi, Omojola; Von Kallon, Daramy Vandi; Aigbodion, Victor Sunday
Waste cooking oil (WCO) is generated when edible vegetable oil is used for frying food items. Inappropriate disposal of WCO exacerbates environmental pollution, block drains and contaminates terrestrial and aquatic habitats while its consumption deleteriously impacts human and animal health. In this review, the current efforts into the biotechnological conversion and applications of WCO as feedstock for biofuel, bisabolene, biolubricants, liquid detergents, dishwashing soap and aromatherapy candle, plasticizer, polyurethane foam, surfactants, asphalt rejuvenator are discussed. Aspects related to the global scenario of WCO generation, their physico-chemical properties and avenues of their utilization are also presented. These applications ensure appropriate utilization of WCO as valuable household commodities and industrial products. More investigations are needed for the deployment of WCO for the production of valuable products and to promote circular economy.
Allognissode, F.K, Diop, M.A, Ezzinbi, K, Ogouyandjou, C. (2019) Stochastic partial functional integrodifferential equations driven by a sub-fractional Brownian motion, existence and asymptotic behavior, Random Operators and Stochastic Equations. https://doi.org/10.1515/rose-2019-2009
(De Gruyter, 2019-05-10) Allognissode, Fulbert Kuessi; Diop, Mamadou Abdoul; Ezzinbi, Khalil; Ogouyandjou, Carlos
This paper deals with the existence and uniqueness of mild solutions to stochastic partial functional integro-differential equations driven by a sub-fractional Brownian motion S[H/Q] (t), with Hurst parameter H∈(1\2,1). By the theory of resolvent operator developed by R. Grimmer (1982) to establish the existence of mild solutions, we give sufficient conditions ensuring the existence, uniqueness and the asymptotic behavior of the mild solutions. An example is provided to illustrate the theory.
Almost sure asymptotic stability for some stochastic partial functional integrodifferential equations on Hilbert spaces
(Taylor and Francis Online, 2019-04-25) Dieye, Moustapha; Diop, Mamadou Abdoul; Ezzinbi, Khalil
In this work, we study the asymptotic behavior of the mild solutions of a class of stochastic partial functional integrodifferential equation on Hilbert spaces. Using the stochastic convolution developed, we establish the exponential stability in mean square with p ≥ 2. Also, pathwise exponential stability is proved for p> 2. We extend the result of an example is provided for illustration.
Ameliorative effect of Ruzu herbal bitters on high-fat diet induced non-alcoholic fatty liver disease in Wistar rats
(Pharmacy & Pharmacognosy Researc, 2020-12-09)
Context: One of the world's most widespread and frequent liver diseases is the non-alcoholic fatty liver disease (NAFLD). Aims: To evaluate the preventives activities of Ruzu herbal bitters (RHB), which is an anti-obesity therapeutic concoction used widely in Nigeria on high–fat diet (HFD) induced NAFLD in albino Wistar rats. Methods: A total number of twenty-five rats were isolated and divided equally into five groups. Group 1, the normal control group was placed on normal rat diet and normal saline (1 mL/kg body weight daily) for twelve weeks. The remaining four groups 2-5 were placed on HFD for twelve weeks; adding to the following treatment schedules by oral gavage: group 2 received pioglitazone 4 mg/kg daily, group 3 received RHB 0.6 mL/kg daily, group 4 received normal saline 1 mL/kg daily and group 5 received fenofibrate 10 mg/kg daily (s.c). The animals were sacrificed and biochemical markers of liver function, lipid profile, glycemic index, and histopathological assessment of the liver of the rats were determined. Results: Rat treated with RHB and other treated groups significantly (p<0.05) reduced the liver index, fasting blood glucose, and activities and concentrations of liver function enzymes and molecules when compared to untreated NAFLD group. Scoring of hepatic steatosis also showed the ameliorative role of the treatment on NAFLD. Conclusions: This study reveals that RHB and other treatment options assessed could prevent HFD–induced NAFLD and could be explored as another therapeutic approach to fenofibrate and pioglitazone in NAFLD management. Contexto: Una de las enfermedades hepáticas más extendidas y frecuentes del mundo es la enfermedad del hígado graso no alcohólico (NAFLD). Objetivos: Evaluar las actividades preventivas de los amargos de hierbas Ruzu (RHB), que es un brebaje terapéutico contra la obesidad utilizado ampliamente en Nigeria en la NAFLD inducida por una dieta alta en grasas (HFD) en ratas Wistar albinas. Métodos: Se aisló un total de veinticinco ratas y se dividió por igual en cinco grupos. Grupo 1, el grupo de control normal recibió una dieta normal para ratas y solución salina normal (1 mL/kg de peso corporal al día) durante doce semanas. Los cuatro grupos restantes 2-5 se colocaron en HFD durante doce semanas; añadiendo a los siguientes programas de tratamiento por sonda oral: el grupo 2 recibió 4 mg/kg de pioglitazona al día, el grupo 3 recibió 0,6 mL/kg de RHB al día, el grupo 4 recibió 1 mL/kg de solución salina normal al día y el grupo 5 recibió 10 mg/kg de fenofibrato al día (s.c.). Los animales fueron sacrificados y se determinaron marcadores bioquímicos de función hepática, perfil lipídico, índice glucémico y evaluación histopatológica del hígado de las ratas. Resultados: Las ratas tratadas con RHB y otros grupos tratados redujeron significativamente (p<0,05) el índice hepático, la glucosa en sangre en ayunas y las actividades y concentraciones de las enzimas y moléculas de la función hepática en comparación con el grupo NAFLD no tratado. La puntuación de la esteatosis hepática también mostró el papel mejorador del tratamiento en NAFLD. Conclusiones: Este estudio revela que la RHB y otras opciones de tratamiento evaluadas podrían prevenir la NAFLD inducida por HFD y podrían explorarse como otro enfoque terapéutico para el fenofibrato y la pioglitazona en el manejo de la NAFLD
Ameliorative Effect of Zingiber officinale on Chemical Induced DNA Damage in Rats Using PCR Analysis
(Biointerface Research in Applied Chemistry, 2020-09-12) Okesola, Mary Abiola; Ogunlana, Olubanke; Afolabi, Israel; Onasanya, Amos
Ginger rhizomes have been reportedly used in folk medicine for the management of various ailments. This study, therefore, investigates the ameliorative effect of the ethanolic extract of ginger (Zingiber officinale) rhizomes against DNA damage in rats induced with different carcinogens. Fifteen Wistar rats grouped into 3 of 5 rats per group were used for the study. The first set of blood samples was first collected before the animals were orally treated with heavy metals. After 14 days of induction, the second set of blood was collected. The third phase of blood collection was done after administering an ethanolic extract of Z. officinale for 14 days. The UV wavelength absorption spectrum and conventional PCR analysis were carried out on DNA extracts of all the animals. Cluster analysis of optical density (OD) and PCR data were carried out as well as genomic instability, similarity, and diversity using the best 3 Random Amplified Polymorphic DNA (RAPD) primers. The PCR –DNA concentration analysis showed the Z. officinale extract's ameliorative effect against lead acetate, cadmium chloride, and arsenic trioxide-induced DNA damage with a significant (p < 0.05) reduction in DNA concentration of the treated rats when compared with induced rats. The cluster analysis of optical density values revealed close similarity between the control animals' DNA, a slight similarity with treated animals' DNA, and a significant difference with the induced animal DNA. These results indicated the ameliorative properties of Z. officinale against these heavy metals induced DNA damage in rats
Analysis of climate extreme indices
(Elsevier, 2019-01-14) Adeyeri, Oluwafemi E.; Lawin, Agnidé Emmanuel; Laux, P.; Ishola, K.A; Ige, S.O
This study investigates trends of climate extreme indices in the Komadugu-Yobe Basin (KYB) based on observed data of the period 1971–2017 as well as regional climate model (RCM) simulations for the historical period (1979–2005), the near future (2020–2050), and the far future (2060–2090). In order to correct change points in the time historical series, the Adapted Caussinus Mestre Algorithm for homogenising Networks of Temperature series homogeneity test is used. The magnitude of the linear trends is estimated using the Sen's slope estimator and Mann-Kendall's test is performed to check the statistical significance of the trends. Future trends are assessed using the ensemble mean of eight regional climate model data under two emission scenarios, provided by the Coordinated Regional Climate Downscaling Experiment (CORDEX). Therefore, the projected rainfall and temperature have been corrected for biases by using empirical Quantile Mapping. In the observations, warm spell duration, warm day-, and warm night frequencies exhibit statistically significant positive trends. Although there is a positive trend in the annual total rainfall, the number of consecutive wet (dry) days decreases (increases). The future climate also shows a continuing positive trend in the temperature extreme indices as well as more frequent extreme rainfall events. Therefore, it is pertinent for decision-makers to develop suitable adaptation and mitigating measures to combat climate change in the Basin.
Analysis of forced vibrations
(International Journal for Computational Civil and Structural Engineering. International Journal for Computational Civil and Structural Engineering, 15(3) 131-148 (2019)., 2019) Shitikova, Mariana V.; Kandu, Vladimir V.
In the present paper, the force driven dynamic response of a nonlinear plate embedded in a viscoelastic medium, damping features of which are described by the Kelvin-Voigt fractional derivative model, is studied. The motion of the plate is described by three coupled nonlinear differential equations with due account for the fact that the plate is being under the conditions of the internal combinational resonance accompanied by the external resonance, resulting in the interaction of three modes corresponding to the mutually orthogonal displacements. A comparative analysis of numerical calculations for the cases of free and forced vibrations has been carried out.
Analysis of situ elemental concentration log data for lithology and mineralogy exploration— A case study
(Elsevier, 2021-09-26) Konaté, Ahmed Amara; Ma, Houalin; Pan, Heping; Khan, Nasir
Metamorphic rocks are diverse with more compositions, structures, and textures that are complex. Rock type identification and prediction from metamorphic rocks using well log data are difficult tasks. This study shows the use of cross plot technique, Pearson correlation, and factor analysis in metamorphic rocks interpretation using borehole geochemical data from the 4390–5089 m interval depth of the Chinese Continental Scientific Drilling Main hole. Lithological identification abilities, correlation between geochemical and geophysical logs, and build a factor model which link in situ chemical element to minerals were studied. The results show that Potassium and Thorium logs are the most discriminating logs in metamorphic rocks. Pearson correlation shows that Potassium and Thorium are the largest contributors to the gamma ray responses. Factor analysis results show a 2 factor model-where factor 1 (amphibole mineral) and factor 2 (K-feldspar mineral) described 76.261% of the variation in log responses. These statistical methods can be a very helpful tool in helping the task of geoscientists in the context of research drillings.
Analysis the Dynamics of SIHR Model: Covid-19 Case in Djibouti
(Applied Mathematics,, 2021-10-14) Souleiman, Yahyeh; Mohamed, Abdoulrazack; Ismail, Liban
The Covid-19 epidemic is an emerging infectious disease of the viral zoonosis type caused by the coronavirus strain SARS-CoV-2, it is classified as a human-to-human communicable disease and is currently a pandemic worldwide. In this paper, we propose conceptual mathematical models of the epidemic dynamics of four compartments. We have collected data from the Djibouti health ministry. We study the positivity, boundedness, existence and uniqueness of the weak solution. Next, we define the Basic reproduction number by the method of the DFE and EEP. Then, we study the local and global stability and the bifurcation analysis of equilibrium to examine its epidemiological relevance. Finally, we analyze the fit of the data in comparison with the result of our mathematical results, to validate the model and estimate the important model parameters and prediction about the disease. We consider the real cases of Djibouti from 15th March to 15th May 2021.
Analytical Model for the Estimation of Leak Location in Natural Gas Pipeline
(2019-09-28) Obibuike Ubanozie, Julian; Ekwueme Toochukwu, Stanley; Ohia Nnaemeka, Princewill; IgwiloChinwuba, Kevin; Onyejekwe Ifeanyi, Michael; lgbojionu Chemazu, Anthony
Mathematical model for leak location in natural gas pipeline has been developed in this paper. The model employs an isothermal steady state approach. Leak occurrence in the pipeline divides the pipeline into two sections-the upstream and downstream sections respectively. Analyses of leak incidences were carried out in the two pipeline sections giving rise to two equations being developed to address the leak localization. The first leak equation was developed by considering the upstream section of the pipeline while the second leak equation was developed by considering the downstream section of the pipeline. The two equations were analytically developed by slight modification of the Weymouth’s equation for gas flow in horizontal pipeline. Matlab software was used in the model simulation.
Anisotropic Stark effect of carbon monoxide: emergent orbital cooperativity
(2019-06-25) Jibiao, Li; Xiaosong, Zhu; Emeka, Oguzie
Applying external electric fields to molecules gives rise to spectral shifting and splitting, a phenomenon known as the Stark effect. However, a fundamental question of how electronic structures of molecules are modified by electric fields is still not well understood. By applying electric fields to a carbon monoxide molecule, herein we have successfully addressed the fundamental question at orbital scales and discovered that the Stark effect exhibits anisotropic characters depending on the direction of the electric fields with respect to the molecular axis. Based on the fact that applying electric fields along the molecular axis always preserved the orthogonality between the sigma and pi electrons, we found that orbital resemblance-based cooperativity can only operate within either the sigma system in which sigma electrons somehow prefer to resemble each other or the pi electron system in which the 1π electrons experience polarization-based self-resemblance.
Annona senegalensis extract demonstrates anticancer properties in N-diethylnitrosamine-induced hepatocellular carcinoma in male Wistar rats
(Biomedicine & Pharmacotherapy, 2020) Yakubu, Omolara F.; Metibemu, Damilohun S.; . Adelani, Isaacson B
Background: Hepatocellular carcinoma (HCC) is a common and leading cancer around the globe. This study investigated the anticancer properties of extract of Annona senegalensis in N-diethylnitrosamine (DEN) - induced hepatocellular carcinoma in male Wistar rats. Methods: Rats were simultaneously induced with a combination of 100 mg/kg b.wt of DEN and 0.5 mL/kg of carbon tetrachloride (CCl4) intraperitoneally once a week for three weeks in a row. Thereafter, animals were treated with 100 mg/kg and 200 mg/kg b.wt of A. senegalensis extract daily for 21days. Analysis using gas chromatography-mass spectrometry (GC–MS) was carried out to discover the phytoconstituents contained in the n-hexane extract of A. senegelensis. The levels of liver function parameters and antioxidant enzyme activities were determined via spectrophotometric analysis. Reverse transcriptase-polymerase chain reaction technique was used to assess the gene expression patterns of BCL-2, P53, P21, IL-6, FNTA, VEGF, HIF, AFP, XIAP, and EGFR mRNAs. Results: Treatment of DEN-induced hepatocellular carcinoma Wistar rats with the extract caused significant (p < 0.05) decrease in the activities of ALT and AST. It also resulted in a reduction of the concentration of MDA and a significant increase (p < 0.05) in SOD and GSH activities. IL-6, BCL-2, VEGF, EGFR, XIAP, FNTA, and P21 mRNAs expressions were significantly (p < 0.05) downregulated after treatment. Histopathological analysis revealed that the extract improved the liver architecture. Conclusion: A. senegelensis n-hexane extract demonstrates its anticancer properties by improving the liver architecture, increasing the antioxidant defense systems, downregulating the pro-inflammatory, anti-apoptotic, angiogenic, alpha-fetoprotein and farnesyl transferase mRNAs expression and hitherto up-regulate the expression of tumor suppressor (P21 and P53) mRNAs.
Anopheles metabolic proteins in malaria transmission, prevention and control: a review
(Parasites Vectors, 2020) Adedeji, Eunice Oluwatobiloba; Ogunlana, Olubanke Olujoke; Fatumo, Segun
The increasing resistance to currently available insecticides in the malaria vector, Anopheles mosquitoes, hampers their use as an effective vector control strategy for the prevention of malaria transmission. Therefore, there is need for new insecticides and/or alternative vector control strategies, the development of which relies on the identification of possible targets in Anopheles. Some known and promising targets for the prevention or control of malaria transmission exist among Anopheles metabolic proteins. This review aims to elucidate the current and potential contribution of Anopheles metabolic proteins to malaria transmission and control. Highlighted are the roles of metabolic proteins as insecticide targets, in blood digestion and immune response as well as their contribution to insecticide resistance and Plasmodium parasite development. Furthermore, strategies by which these metabolic proteins can be utilized for vector control are described. Inhibitors of Anopheles metabolic proteins that are designed based on target specificity can yield insecticides with no significant toxicity to non-target species. These metabolic modulators combined with each other or with synergists, sterilant, and transmission-blocking agents in a single product, can yield potent malaria intervention strategies. These combinations can provide multiple means of controlling the vector. Also, they can help to slow down the development of insecticide resistance. Moreover, some metabolic proteins can be modulated for mosquito population replacement or suppression strategies, which will significantly help to curb malaria transmission
Anti-wear and Hardness Values of Functional Value-Added Zn-ZnO-Rice Husk Ash Composite Coating of Mild Steel
(Revue des Composites et des Matériaux Avancés-Journal of Composite and Advanced Materials, 2021-01) Chikodi, Daniel-Mkpume Cynthia; Nnamdi, Obikwelu Daniel Oray; Sunday, Aigbodion Victor
This paper presents the anti-wear and hardness values of electrodeposited Zn-ZnO XRHA composite coating. Chloride-based bath was employed for the deposition bath. The deposition parameters were 0g, 10g and 20g rice husk ash (RHA) particulate loading, 15 minutes deposition, 1.4A current, 400 rpm stirring rate and 75℃ bath temperature. The composition, morphology, occurred phases, hardness and wear resistance for the RHA, mild steel substrate and developed coatings were studied. Equipment used for analyzing the coatings properties were x-ray fluorescence spectrometer, scanning electron microscope (SEM) with attached energy dispersive spectrometer (EDS), X-ray diffractometer (XRD), EMCO Test Dura-scan microhardness tester and CERT UMT-2 tribological tester. Results showed that the Zn-ZnO-20RHA coated substrate had the highest hardness result toping the bare substrate by about 170% increment value. The trend of the wear loss for the developed Zn-ZnO-XRHA descended relative to increased particulate loading.

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