Critical review of recent development in fiber reinforced adobe bricks for sustainable construction

Open Access via Springer Compact Agreement. The authors gratefully acknowledge the research support fund provided by the Sudanese Ministry of Higher Education, School of Engineering University of Khartoum and the School of Engineering, University of Aberdeen.Peer reviewedPublisher PD

Numerical Simulation of Conjugate Heat Transfer in Forced Convective Boundary Bilayered Cylindrical Pipe with Different Peclet Numbers

The heat transfer performance of bilayered composite systems through which thermally developing laminar fluids flow for cases in which axial conduction is either significant or negligible has been investigated. The heat transfer problems considered as two dimensional conjugate problems with appropriate boundary conditions were solved via computational fluid dynamics (CFD) approach in ANSYS 16.0. A parametric study was conducted to investigate the effects of Péclet number (Pe), ratio of the thermal conductivity of the laminate composite (k21) and the laminate composite dimensionless-thickness ratio  on the wall-fluid interfacial temperature and interfacial heat flux for Pe of 5, 100 and 1000, varying between 0.4 and 1.6, Bi of 5, kwf of 20, k21 between 0.025 and 1, and  of 0.71. The effect of Pe was found to be more pronounced on the interfacial heat flux. Also, the changes in k21 and were shown to reduce with reduction in Pe. Keywords— Composite cylinder, convective heat transfer, Numerical simulation; thick-walled pipes

SMEs’ innovativeness and technology adoption as downsizing strategies during COVID-19: the moderating role of financial sustainability in the tourism industry using structural equation modelling

This study aims to identify why firms, specifically SMEs in the hospitality and tourism industry, downsized during the recent global economic distress caused by COVID-19. This study applied a quantitative methodology by distributing online questionnaires to SME owners and managers who operate in the tourism industry of the UAE. We analysed the collected data using structural equation modelling. A total of 320 questionnaires were analysed using the PLS-SEM analytic tool. Our findings revealed that the investigated constructs, namely financial sustainability, SMEs’ innovativeness, and technology adoption predict the implementation of downsizing strategies during economic distress. However, financial sustainability failed to expedite SMEs’ innovativeness and technology adoption during this period. Therefore, the findings of this study show the impacts of financial strength, technology adoption, and innovativeness on implementing downsizing strategies, and provide suggested recommendations in light of the observed results

DNA barcoding of Tribolium castaneum (Coleoptera: Tenebrionidae) from selected states in Nigeria based on mitochondrial DNA sequences

Tribolium castaneum also known as red flour beetle is one of the most important pests of stored grain product with a cosmopolitan distribution in Nigeria and all over the world contributing to food spoilage. The aim of this study was to characterize the T. castaneum by morphometric and molecular analyses. Samples of yam flour with evidence of the red flour beetles present inside were obtained from four locations in Kwara, Kogi, Oyo and Ekiti states in Nigeria. Morphological and molecular identifications of T. castaneum were carried out using standard methods. A dissecting microscope was used to identify the beetles and measurements were taken using ImageJ. Genomic DNA was extracted and checked on 1.5% agarose gel to confirm the presence of DNA. Species-specific primers were used to amplify mitochondrial cytochrome oxidase I (COI) gene of T. castaneum and the PCR amplicon size was also checked on 1.5% agarose. Morphometric measurements showed that the highest mean number (33.00±4.24 mm) of T. castaneum larvae observed was recorded on day 61 in Ilorin and the lowest was in Iwo, Osun state (4.00±0.00 mm) on the same day. The mean of the total body length of larvae from sampling sites was (1.31±0.37 mm) with minimum and (1.63±1.14 mm) maximum lengths respectively. There was no significant difference (p>0.05) between the mean length of the larvae collected from the study locations. Aligned cytochrome oxidase subunit 1 (COI) sequences of 313bp were analyzed. Phylogenetic analysis inferred by maximum likelihood method showed that the T. castaneum sequences analyzed for this study and sequences obtained from GenBank formed a monophyletic group. The molecular and phylogenetic analyses confirmed the presence of a single species of T. castaneum. The results from this study showed low levels of genetic diversity and variability in the studied T. castaneum populations. The observed genetic similarity in T. castaneum could be due to the fact that they were probably from similar origin when compared with those in the GenBank database. However, further studies are needed with more samples to characterize T. castaneum species from stored food grains across Nigeria

Medium-Scale Farming as a Policy Tool for Agricultural Commercialisation and Small-Scale Farms Transformation in Nigeria

Recent evidence suggests that the changing structure of land ownership in sub-Saharan Africa is one of the major new trends affecting African agri-food systems. Research in several African countries shows a rapid rise of medium-scale farms (MSFs) of 5–50ha. MSFs have become an important force for increasing agricultural production, particularly in countries with significant unutilised arable land and potential for area expansion, such as Ghana, Nigeria, Tanzania and Zambia. Most African countries’ national agricultural investment plans and policy strategies officially regard the smallholder farming sector as the main vehicle for achieving agricultural growth, food security, and poverty reduction objectives. However, many governments have adopted land and financial policies that implicitly encourage the rise of emergent MSFs. Given the documented rise in MSFs in many African countries, the APRA Nigeria Work Stream 1 team developed a research agenda focused on understanding the potentially complex ways in which these farms affect the productivity and commercialisation potential of small-scale farms (SSFs). We investigated the characteristics of MSFs, the processes that produces them, their relative importance in the agricultural commercialisation process, the relationship between farm scale and productivity, and whether MSFs influence the behaviour and welfare of the millions of SSF households around them. Our findings are based on two years of survey data on MSFs and nearby SSFs in 2019 and 2021 in Ogun and Kaduna states. This policy brief summarises our main findings, drawing upon several APRA-supported reports

The first-line antituberculosis drugs, and their fixed-dose combination induced abnormal sperm morphology and histological lesions in the testicular cells of male mice

Rifampicin (RIF), Isoniazid (INH), Ethambutol (EMB), Pyrazinamide (PZA), and/or their fixed-dose combination (FDC) are extensively prescribed in the cure of Tuberculosis (TB) globally. In spite of the beneficial effect, these drugs are capable of inducing cellular toxicity. Existing information on the genotoxic effects of the first-line anti-TB drugs is limited and contentious. Herein, we evaluated the reproductive genotoxicity of RIF, INH, EMB, PZA, and their FDC utilizing the mouse sperm morphology assay. Histological examination of the testes of exposed mice was also performed. Male Swiss albino mice (11–13 weeks old) were intraperitoneally exposed for 5 consecutive days to each of the anti-TB drugs at four different doses of 6.25, 12.5, 25, and 50 mg/kg bw of PZA; 2.5, 5.0, 10, and 20 mg/kg bw of RIF; 1.25, 2.5, 5.0 and 10 mg/kg bw of INH; 3.75, 7.5, 15 and 30 mg/kg bw of EMB; and 7, 14, 28 and 56 mg/kg bw of FDC corresponding respectively to ×0.25, ×0.5, ×1 and ×2.0 of the standard daily dose. In comparison with the negative control (normal saline), there was no significant difference in the testicular weight and organo-somatic index of exposed mice. There was an increase (p > 0.05) in the frequency of abnormal spermatozoa at most of the tested doses of each drug and a dose-dependent decrease with the FDC. Each of the anti-TB drugs except the FDC induced pathological lesions in the testes. These findings suggest that the individual first-line anti-TB drug unlike the FDC has the potential to provoke testicular anomalies in male mice

Self-medication for infants with colic in Lagos, Nigeria

<p>Abstract</p> <p>Background</p> <p>Infantile colic is a self-limiting condition that is distributed worldwide. It is often misdiagnosed as an organic disease for which an infant is admitted to the hospital. Many studies have described the aetiopathogenesis, pharmacologic and non-pharmacologic management of colic but none has evaluated self-medication for infants with colic. The aim of this study was therefore to determine the knowledge of Nigerian mothers about colic, their home-based management, extent of self-medication for the infants with colic and the types of medicines involved.</p> <p>Methods</p> <p>It is a prospective study conducted at the vaccination clinics of 20 primary health care centres, each from different Local Government Areas in Lagos, Nigeria. Eight hundred mothers that brought their infants for vaccination between April and September, 2006 were interviewed with open-and close-ended questionnaire.</p> <p>Results</p> <p>Six hundred and eighty three (85.4%) mothers claimed they had a good knowledge of colic. Incessant and excessive cry was the main clinical feature of colic identified by 430(62.9%) mothers. Three hundred and seventy eight (67.7%) infants were treated by self-medication, 157 (28.1%) sought medical intervention and 17 (3.1%) were treated at a traditional birth attendant home. Herbal medicines constituted 51.8% of the self-medicated medicines, of which 48 (26.2%) were "Ororo Ogiri". Nospamin^®(49.5%) and Gripe water^®(43.0%) were the two frequently prescribed and self-medicated medicines for infants with colic.</p> <p>Conclusion</p> <p>Nigerian mothers are deficient in their knowledge of colic. Self-medication was the most frequently used home-based intervention. Health education would appear necessary to improve parental management of this self-limiting condition.</p

Thermal energy processes in direct steam generation solar systems : boiling, condensation and energy storage

Direct steam generation coupled is a promising solar-energy technology, which can reduce the growing dependency on fossil fuels. It has the potential to impact the power-generation sector as well as industrial sectors where significant quantities of process steam are required. Compared to conventional concentrated solar power systems, which use synthetic oils or molten salts as the heat transfer fluid, direct steam generation offers an opportunity to achieve higher steam temperatures in the Rankine power cycle and to reduce parasitic losses, thereby enabling improved thermal efficiencies. However, its practical implementation is associated with non-trivial challenges, which need to be addressed before such systems can become more economically competitive. Specifically, important thermal-energy processes take place during flow boiling, flow condensation and thermal-energy storage, which are highly complex, multi-scale and multi-physics in nature, and which involve phase-change, unsteady and turbulent multiphase flows in the presence of conjugate heat transfer. This paper reviews our current understanding and ability to predict these processes, and the knowledge that has been gained from experimental and computational efforts in the literature. In addition to conventional steam-Rankine cycles, the possibility of implementing organic Rankine cycle power blocks, which are relevant to lower operating temperature conditions, are also considered. This expands the focus beyond water as the working fluid, to include refrigerants also. In general, significant progress has been achieved in this space, yet there remain challenges in our capability to design and to operate high-performance and low-cost systems effectively and with confidence. Of interest are the flow regimes, heat transfer coefficients and pressure drops that are experienced during the thermal processes present in direct steam generation systems, including those occurring in the solar collectors, evaporators, condensers and relevant energy storage schemes during thermal charging and discharging. A brief overview of some energy storage options are also presented to motivate the inclusion of thermal energy storage into direct steam generation systems