A review and investigations of some properties of foamed aerated concrete

The paper presents the results of investigation conducted on foamed aerated concrete a lightweight concrete - with a view to determining its potential as a construction material in Nigeria. The properties investigated on foamed aerated concrete having a designed density of 1600kg/m3 were: workability, density, compressive strength, tensile strength, and the water absorption capacity. The results showed that at the designed density adopted for this work, the material was workable and repeatable. Other results at 28 days of curing are: (i) compressive strength of 15. 43N/mm2, 13.89N/mm2 respectively for air-cured and water-cured specimens, (ii) modulus of rupture of 2.53N/mm2 (ii) splitting tensile strength of 1.63N/mm2, and (iv) the water absorption capacity of 1.03% The tensile strength to compressive strength ratio was more than 10%. These properties improved with time. It can be concluded that the foamed aerated concrete used for this work is repeatable, and of adequate strength for use as a construction material.Keywords: Aerated Concrete, Compressive Strength, Tensile Strength, Workabilit

Evaluation of Geotechnical and Structural Performance of Cement-Stabilized Soil with Saw Dust Ash (SDA)

Availability of good soils for the construction of Civil engineering works is pivotal to the development and progress of any nation. Where good soils are lacking, it is necessary to make the soil fit through soil improvement methods. This study investigates the geotechnical performance of soil stabilized with the blend of cement and saw dust ash (SDA). The blend consists of 9% cement by weight and up to 10% of SDA at interval of 2%. The tests conducted on both stabilized and unstabilized soils samples at three different locations, identified as A, B, and C were: particle size distribution, natural moisture content, Atterberg’s limits, compaction, California Bearing Ratio (CBR) and Unconfined Compression Strength (UCS). The results showed decrease in plasticity index from high to medium, increase in CBR values: 4 – 10% for sample A, 2 – 12% for sample B and 5 – 8% for sample C, and increase in unconfined compression strength values: 45.23 – 65.88 kN/m2 for sample A, 34.01 – 59.18 kN/m2 for B and 41.80 – 63.94 kN/m2 for C. The results of this investigation showed that improvement of soil for construction purpose can be achieved when SDA is applied as a stabilizer in a cement-stabilized soil, up to 6% by weight of cement. Specifically, improved shear stress demonstrated up to 6% replacement is an indication of fitness for application of such soil in the design of footing, especially for columns, where shear stresses usually control the footing thickness

A Review of Some Agricultural Wastes in Nigeria for Sustainability in the Production of Structural Concrete

A review of agricultural wastes available in Nigeria that is suitable for use in concrete industry, in order to attain sustainability in structural concrete production and practice, is presented in this paper. The wastes reviewed are: Cassava Peel Ash (CPA), Empty Palm Oil Fruit Brunch Ash (EPO-FBA), Rice Husk Ash (RHA), and Saw Dust Ash (SDA). Others were Palm Kernel Shell Ash (PKSA), Groundnut Husk Ash (GHA), Corncob Ash (CA), and Egg Shell Powder (ESP). The study revealed that some agricultural wastes that have potential for use as supplementary cementing material (SCM) for cement in the production of structural concrete abounds in Nigeria. It was also revealed that the necessity of standardization of procedures for testing of such wastes so that structural performance index can be compared. In addition, there is also the need for the development of classification methods similar to that of fly ash, so that their use can be enhanced. Using these waste materials in concrete will lead to sustainability in concrete production, reduction in the use of natural non-renewable resources, innovativeness in the use of wastes, and the development of small-scale industries

Artificial intelligence potential for net zero sustainability: Current evidence and prospects

oai:repository.uel.ac.uk:8xqzxThis comprehensive review explores the nexus between AI and the pursuit of net-zero emissions, highlighting the potential of AI in driving sustainable development and combating climate change. The paper examines various threads within this field, including AI applications for net zero, AI-driven solutions and innovations, challenges and ethical considerations, opportunities for collaboration and partnerships, capacity building and education, policy and regulatory support, investment and funding, as well as scalability and replicability of AI solutions. Key findings emphasize the enabling role of AI in optimizing energy systems, enhancing climate modelling and prediction, improving sustainability in various sectors such as transportation, agriculture, and waste management, and enabling effective emissions monitoring and tracking. The review also highlights challenges related to data availability, quality, privacy, energy consumption, bias, fairness, human-AI collaboration, and governance. Opportunities for collaboration, capacity building, policy support, investment, and scalability are identified as key drivers for future research and implementation. Ultimately, this review underscores the transformative potential of AI in achieving a sustainable, net-zero future and provides insights for policymakers, researchers, and practitioners engaged in climate change mitigation and adaptation

In-silico and in-vivo comparative evaluation of the cardioprotective potential of Yellow turmeric and White turmeric in Mn-induced cardiac oxidative stress

Introduction The effect of the ethanol extracts of Curcuma longa Linn (yellow turmeric) and Curcuma zedoaria Rosc (white turmeric) on cardiac oxidative stress in rats exposed to manganese was evaluated in this study. Methods We divided 60 Wistar rats into 12 groups (n = 5) with some administered different concentrations of yellow or white turmeric extract. The animals except the control groups were exposed to manganese on days 1,3, and 7. All the animals were sacrificed on the 8th day and the hearts were harvested for biochemical assays. Ferric-reducing antioxidant power (FRAP) and the levels of cardiac superoxide dismutase, reduced glutathione, nitric oxide, and lipid peroxidation in rats were determined. Additionally, in silico studies were performed to further compare the cardioprotective potential of the two species of turmeric. Results The results showed that rats treated with manganese alone had decreased levels of FRAP, superoxide dismutase, and glutathione but increased levels of nitric oxide and lipid peroxidation were observed. The Mn-induced oxidative stress was ameliorated in animals co-treated with yellow or white turmeric. The yellow turmeric showed better activity than white turmeric. In the in-silico evaluation, phytocompounds from yellow turmeric had higher binding energy against Nuclear factor erythroid 2-related factor 2 (NRF2) protein than the ones from white turmeric. Bioactive compounds from white turmeric did not violate any of Lipinski's rules of five or three, despite having lower binding energy. Conclusion These findings suggest that ethanol extract of yellow and white turmeric may have the potential to ameliorate manganese-induced cardiac oxidative stress

Mycotoxicology Society of Nigeria Mycotoxicology, 2015, 2: 28-34 Mycotoxin Contamination of Maize and Guinea corn from Markets in Plateau State, Nigeria

ABSTRACT Maize (Zea mays) and guinea corn (Sorghum bicolor) are major food items in Plateau state, Nigeria. A multistage sampling technique was used to select the markets and store/warehouses used for this study; sample collection employed a simple random sampling method from different sampling points within designated areas. A total of 18 representative samples were collected and analyzed for the following mycotoxins: aflatoxins (Aflatoxin B 1 -AFB 1 , Aflatoxin B 2 -AFB 2 , Aflatoxin G 1 -AFG 1 and Aflatoxin G 2 -AFG 2 ), fumonisins (Fumonisin B 1 -FB 1 and Fumonisin B 2 -FB 2 ) and cyclopiazonic acid (CPA). Out of 12 samples analyzed for Aflatoxins, AFB 1 was detected in 5, AFB 2 in 1, AFG 1 in 1 and AFG 2 in 6 samples respectively. The highest concentration of AFB 1 and AFG 2 were found in maize samples from Pankshin market. Only maize samples from Mangu market were contaminated with AFB 2 and also harboured the lowest concentration of AFG 2. AFG 1 contamination occurred in only guinea corn from Shendam market. and FB 1 was detected in all 18 samples analyzed. The mycotoxin CPA was not detected in any of the samples. Aflatoxins levels in analyzed samples were regarded as safe based on Nigerian and European Union maximum permissible levels of 4µg/kg. With the exception of two samples, FB 1 levels in analyzed maize samples were within European Union maximum permissible levels of 1,000 to 3000µg/kg. The health and food safety implications of these results for the human and animal population are further discussed

Comparative Study of Superabsorbent Polymers and Pre‐soaked Pumice as Internal Curing Agents in Rice Husk Ash Based High‐Performance Concrete

Utilisation of superabsorbent polymers (SAP) and pre‐soaked lightweight aggregates (LWA) as internal curing (IC) agents for the mitigation of autogenous shrinkage and micro‐cracking of high strength/highperformance concrete (HSC/HPC) have been well researched and documented in literature. Rice husk ash (RHA) on the other hand has been adjudged to be of good pozzolanic activity and a possible alternative to silica fume (SF) in low water/binder (W/B) concrete production. An experimental comparative study was conducted in the current work to assess the effectiveness of the two known ICagents on rice husk ash (RHA) based HPC. HPC mixtures of fc,cube28=60 MPa minimum target strength produced and internally cured with 0.3% content of SAP by weight of binder (bwob) and varied content of pre‐soaked pumice (5 to 10% in steps of 2.5%) by weight of coarse aggregate (bwocg) were cast using 100 mm cubes samples. Thereafter, the samples were cured for 7, 14, 28 and 56 days by water immersion before subjecting them to compressive strength test. The results showed 0.2% bwob SAP HPC (SHPC1) to be the best performed internally cured HPC at the early ages with similar long‐term strength values as 5 and 7.5% bwocg saturated pumiced HPC (PHPC1&2). The study thereby recommends SAP content of 0.2% bwob and saturated pumice content up to 7.5% bwocg for use as ICagent in HPC

An Economic Evaluation of Home Management of Malaria in Uganda: An Interactive Markov Model

BACKGROUND: Home management of malaria (HMM), promoting presumptive treatment of febrile children in the community, is advocated to improve prompt appropriate treatment of malaria in Africa. The cost-effectiveness of HMM is likely to vary widely in different settings and with the antimalarial drugs used. However, no data on the cost-effectiveness of HMM programmes are available. METHODS/PRINCIPAL FINDINGS: A Markov model was constructed to estimate the cost-effectiveness of HMM as compared to conventional care for febrile illnesses in children without HMM. The model was populated with data from Uganda, but is designed to be interactive, allowing the user to adjust certain parameters, including the antimalarials distributed. The model calculates the cost per disability adjusted life year averted and presents the incremental cost-effectiveness ratio compared to a threshold value. Model output is stratified by level of malaria transmission and the probability that a child would receive appropriate care from a health facility, to indicate the circumstances in which HMM is likely to be cost-effective. The model output suggests that the cost-effectiveness of HMM varies with malaria transmission, the probability of appropriate care, and the drug distributed. Where transmission is high and the probability of appropriate care is limited, HMM is likely to be cost-effective from a provider perspective. Even with the most effective antimalarials, HMM remains an attractive intervention only in areas of high malaria transmission and in medium transmission areas with a lower probability of appropriate care. HMM is generally not cost-effective in low transmission areas, regardless of which antimalarial is distributed. Considering the analysis from the societal perspective decreases the attractiveness of HMM. CONCLUSION: Syndromic HMM for children with fever may be a useful strategy for higher transmission settings with limited health care and diagnosis, but is not appropriate for all settings. HMM may need to be tailored to specific settings, accounting for local malaria transmission intensity and availability of health services

Composition of unfermented, unroasted, roasted cocoa beans and cocoa shells from Peninsular Malaysia

Composition of cocoa beans depends on origin and cocoa processing such as fermentation, drying and roasting. However, less research has been conducted to analyse the composition of Peninsular Malaysia cocoa bean at different processing stages. Thus, the purpose of this study was to determine the proximate, phytosterol level, antioxidant content and activity of Peninsular Malaysia unfermented, unroasted, roasted cocoa beans and cocoa shells. Analysis involved was proximate analysis, total phenolic compound (Folin–Ciocalteu reagent assay), antioxidant activity (2,2-diphenyl-1-picrylhydrazyl scavenging assay) and phytosterol composition. Results show that the crude fiber of unroasted cocoa beans and cocoa shells increased from 17.19 to 28.45% and 13.86 to 16.06% respectively after roasting process. The roasting process is suspected to increase the dietary fiber content of cocoa products due to the interaction between polysaccharides, protein, polyphenolic and Maillard products at high temperature. The total phenolic content in cocoa bean and cocoa shells ranged from 2.42 to 10.82 µg GAE/ml. The unfermented cocoa beans contain significantly (p < 0.05) higher antioxidant activity (92.3%) compared to other samples. This study shows that cholesterol, stigmasterol and β-sitosterol were present in roasted cocoa beans and cocoa shells. Hence, the information on the composition of Malaysia unfermented, unroasted, roasted cocoa beans and cocoa shells are needed to enrich the databases composition as a reference for the cocoa industry