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In this work, the effect of indium (In) and gallium (Ga) dopants on the structural, optical and electrical properties of ZnO thin films was studied. ZnO thin films were deposited on glass substrates at 400°C using the spray pyrolysis deposition technique. X-ray diffraction (XRD) results indicated that both undoped and doped ZnO films had (002) preferred orientation. The undoped ZnO films were found to exhibit high transmittance above 80%, while indium-doped (In:ZnO) and galliumdoped (Ga:ZnO) films had transmittance above 60% and 70% respectively. From the Hall Effect measurements, doping improved the conductivity of the ZnO thin films however, In:ZnO films showed higher electrical conductivity compared to Ga:ZnO films. Electron probe microanalysis (EPMA) results were used to confirm the presence of the respective dopants in the thin film samples. [ABSTRACT FROM AUTHOR]

A stoichiometric cordierite-mullite composite formulation has been prepared by mechanical activation from indigenous kaolin, talc, alumina, aluminium hydroxide and a new secondary silica source (silica gel). Phase formation behaviour of the samples has been studied from the XRD patterns of the sintered samples. The XRD analysis showed mullite and cordierite as phases for samples sintered at 1150oC and 1300oC for a soaking period of 2hrs. A comparison of the peaks formed shows that all the diffraction peaks change after mechanical activation. This reflects the partial amorphization and structural disordering in alumina, magnesium and quartz. It can also be noted that at 2 theta angle of 10.40 where characteristically cordierite peaks are formed, samples CD3a and CD3b show signs of cordierite peaks. SEM studies showed those different milling times as expected resulted in powders with different particle sizes, shapes, and most importantly degrees of agglomeration. [ABSTRACT FROM AUTHOR]

In this article, the preparation and characterization of kaolin/polyethylene composites are presented. Microstructural characteristics of six different kaolin-polyethylene composites with varying percentage compositions of kaolin and polymer were produced using a modified melt compounding approach, was explored. The characterization methods employed are scanning electron microscopy (SEM), attenuated total reflectance mid Infrared (ATR-MIR), X-ray powder diffraction (XRD), thermogravimetric and differential thermal analysis (TGA-DTA), compressive, flexural strengths and impact resistance analysis. The implications of the results are discussed for the design of kaolin/polymer composites for constructional purposes. POLYM. COMPOS., 35:1507-1515, 2014. © 2013 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Despite the attractive combinations of cell/surface interactions, biocompatibility, and good mechanical properties of Ti-6Al-4V, there is still a need to enhance the early stages of cell/surface integration that are associated with the implantation of biomedical devices into the human body. This paper presents a novel, easy and reproducible method of nanoscale and nanostructured hydroxyapatite (HA) coatings on Ti-6Al-4V. The resulting nanoscale coatings/nanostructures are characterized using a combination of Raman spectroscopy, scanning electron microscopy equipped with energy dispersive x-ray spectroscopy. The nanostructured/nanoscale coatings are shown to enhance the early stages of cell spreading and integration of bone cells (hFOB cells) on Ti-6Al-4V surfaces. The improvements include the acceleration of extra-cellular matrix, cell spreading and proliferation by nanoscale HA structures on the coated surfaces. The implications of the results are discussed for the development of HA nanostructures for the improved osseointegration of Ti-6Al-4V in orthopedic and dental applications., (© 2024 Wiley Periodicals LLC.)

Microplastic ingestion by marine organisms presents a challenge to both ecosystem functioning and human health. We characterized microplastic abundance, shape, size, and polymer types ingested by the West African mangrove oyster, Crassostrea tulipa (Lamarck, 1819) sampled from estuaries and lagoons from the Gambia, Sierra Leone, Ghana, Benin, and Nigeria using optical microscopy and Fourier transform infrared (FTIR) techniques. A total of 780 microplastics were isolated in the whole tissues of the 250 oysters (n = 50 oysters per country). The abundance and distribution of microplastics in the oysters followed the pattern: the Gambia > Ghana > Sierra Leone > Nigeria > Benin. The Tanbi wetlands in the Gambia recorded the highest average of 10.50 ± 6.69 per oyster while the Ouidah lagoon in Benin recorded the lowest average of 1.80 ± 1.90 per oyster. Overall, microplastic numbers varied significantly (p < 0.05) among the five countries. Microfibers, particularly those within 1001-5000 μm size, dominated the total microplastic count with a few fragments and films. No spherical microplastics were isolated in the oysters. In the Sierra Leone and Benin oysters, fragments and films were absent in the samples. Microplastic between the 1001 and 5000 μm size class dominated the counts, followed by 501-1000 μm, 101-500 μm, and 51-100 μm. Five polymer groups namely polyethylene, polyester, nylon, polypropylene, and polyamide were identified across the five countries, with polyethylene occurring in oysters from all five countries and polyester occurring in all but the oysters from Nigeria. This diversity of polymers suggests varied sources of microplastics ingested by the studied oysters. The absence of microspheres across the five supports findings from other studies that they are the least ingested and highly egested by the oysters., (© 2024. The Author(s).)

The purpose of this data article is to report the quantum mechanical analysis by generalized gradient approximation (GGA) exchange-correlation functional using density functional theory (DFT). The predictions were based on the elastic constants and mechanical properties of stoichiometric hydroxyapatite (HAp) crystal. The elastic stiffness constants in hexagonal symmetry were obtained by fitting the Hookes' law for the energy-strain and stress-stain relations. Some of the theoretical datasets were compared to measured mechanical properties of produced HAp pellets obtained through micro and nanoindentation experiments. The datasets show considerable anisotropy in the stress-strain behaviour and are discussed in the context of the mechanical properties of HAp which are useful for tissue engineering. We also provide a pedagogical snapshot on the use of the datasets herein to teach and interpret DFT based atomistic simulations in a typical blended online teaching set-up for engineering students using a new pedagogy, CACPLA (Communicate, Active, Collaborate, Practice, Learning and Assessment)., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Research and academia have been recently affected by the Coronavirus (COVID-19), and physical classrooms and laboratory experiments have been affected significantly due to the recent laboratory closures. This has led to innovative approaches to curb this problem. To address these difficulties in teaching bioengineering related courses that is of significant interest to students of the Faculty of Engineering in Ahmadu Bello University, Zaria, Nigeria, and of course, useful for engineering-based higher education institutions (HEI), a transitional pedagogy: Communicate, Active, Collaborate, Problem-based Solving, Learning and Assessment (CACPLA), which encompasses blended learning, was developed as a new teaching and learning strategy. In this study, we show that this new strategy can initiate a steady transition from physical classrooms to full online instruction for some subjects in engineering. This method has been trialled as an exercise for a module as part of an envisioned biomedical engineering degree programme which can be integrated with local industries and research institutions in sub-Saharan Africa. The teaching materials and environment were carefully designed and 253 students of third and final year classes participated as the experimental group. Also, the effect of critical thinking, pre-lecture, and post lecture on the overall performance of the students was assessed. Two questionnaires were designed for data collection, (a) for technical questions, (b) for receptiveness. The result of a student survey suggests favourable reception of the teaching methodology, which aided their understanding of the general bioengineering concept as applied to the materials chemistry and mechanical measurements context. It was noticed that 80% of the students indicated that the blended learning method was sufficient in achieving the learning outcomes of the study. The method is envisioned as a useful and sustainable complement to traditional teaching pedagogies and workshops due to the convenience and relatively high accessibility to Zoom and Google Meet Apps which can be readily employed without incurring significant costs., (© The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2022, Springer Nature or its licensor holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)