14 research outputs found

    Mechanical properties of high strength eco-concrete containing crushed waste clay brick aggregates as replacement for sand

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    Utilization of clay brick wastes for production of high strength eco-concrete enables the combat of raw resources depletion due to excessive mining as well as mitigating environmental pollution caused by demolition of old brick structures in an effort to achieve environmental sustainability in line with the sustainable development goals (SDGs). This study investigates the beneficial usage of crushed clay brick as partial replacement for natural sand in producing high strength eco-friendly concrete. The replacement percentages of the crushed clay brick in respect to sand are 0, 10, 20, 30, 40 and 50% by weight using a mix proportion ratio of 1:1:2 at a constant water-cement ratio of 0.25, aiming at the 28 days compressive strength of about 40 MPa. The chemical characterization of the crushed clay brick and cement was conducted via X-ray fluorescence (XRF). The mechanical properties tests were performed on about 80 specimens using 100 x 100 x 100 mm for cubes, 100 x 100 x 500 mm for beams and 100 x 200 mm diameter for cylinders after 7, 14 and 28 days of curing in water. Results showed that concrete containing crushed clay brick as partial replacement for sand compare favourably well with the control. Consequently, it is suggested that generated clay brick wastes can be crushed and used as replacement for natural sand for the production of eco-friendly high strength concrete

    The use of recycled concrete aggregate for concrete production incorporating calcined clay as pozzolanic admixture

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    Concrete is the most widely used construction material thereby required a lot of raw resources to keep up with its demand. This leads to depletion of raw resources as well as a continuous build-up of demolished concrete wastes (DCW). In most developing nations like Nigeria, the usual way of disposing these DCW is landfilling. However, recycling has become a viable options for conserving the raw resources and reducing greenhouse gases. This study examines the alternative way of reusing concrete wastes for production of fresh structural concrete. The DCW was obtained from the demolition of an existing concrete building and were treated by soaking in water to help reduce the amount of adhered mortar. A mix ratio of 1:1:2 was adopted with a water-cement ratio of 0.25 to attain a relatively high strength concrete and superplasticizer was added to ensure workable mixes. The recycled aggregates (RCA) were used as partial and complete substitute for natural coarse aggregates in percentages of 0, 20, 40, 60, 80 and 100%, while calcined clay was added as pozzolanic admixture into the mixes at 15% and 20% partial replacement for cement. Tests carried out include the physical characterization of the constituent materials and the compressive strength of the hardened concretes were determined after 7, 14 and 28 days of curing in water using cubes of 100 mm Ă— 100 mm Ă— 100 mm. Results showed that the recycled concrete aggregates has high water absorption due to its porous interface. Moreso, results clearly indicate a continual decreasing trend in the compressive strength as the percentages of the RCA increases, however, a significant increase in compressive strength was observed when calcined clay was added as substitute for cement thereby improving the strength development of concrete

    A Tool for Biotechnological Advancement 1

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    Bioinformatics has been a useful tool for the advancement and enhancement of biotechnology in recent times with its application in various fields. Bioinformatics has thereby helped invent useful products and create solutions to problems in aspects including utilization of the genome attributes of various living organisms to acquire a better understanding of their biology. It has been used to understand the biology of pathogenic microorganism’s product developments such as reverse vaccinology, drug discovery, personalized medicine, waste clean-up, climate change, and crop improvement. We highlight, in the section, some of the bioinformatics components of biotechnology that are used for translational research in the life sciences

    Follicular fluid content and oocyte quality: from single biochemical markers to metabolomics

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    The assessment of oocyte quality in human in vitro fertilization (IVF) is getting increasing attention from embryologists. Oocyte selection and the identification of the best oocytes, in fact, would help to limit embryo overproduction and to improve the results of oocyte cryostorage programs. Follicular fluid (FF) is easily available during oocyte pick-up and theorically represents an optimal source on non-invasive biochemical predictors of oocyte quality. Unfortunately, however, the studies aiming to find a good molecular predictor of oocyte quality in FF were not able to identify substances that could be used as reliable markers of oocyte competence to fertilization, embryo development and pregnancy. In the last years, a well definite trend toward passing from the research of single molecular markers to more complex techniques that study all metabolites of FF has been observed. The metabolomic approach is a powerful tool to study biochemical predictors of oocyte quality in FF, but its application in this area is still at the beginning. This review provides an overview of the current knowledge about the biochemical predictors of oocyte quality in FF, describing both the results coming from studies on single biochemical markers and those deriving from the most recent studies of metabolomic

    Antioxidant potential and antibacterial activities of Allium cepa (onion) and Allium sativum (garlic) against the multidrug resistance bacteria

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    Abstract Background The increase in the demand for synthetic drugs due to the surge in the cases of drug-resistant infectious organisms has led to the search for new medicines in plants. Some plants have phytochemicals that can serve medicinal purposes. This study focuses on the antibacterial activity and antioxidant potential of Allium sativum and Allium cepa extract on bacterial isolates isolated from the wound of diabetic patients. Agar well-diffusion method was used for the antibacterial susceptibility. Proteus mirabilis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Escherichia coli were used for this study. The total phenolic content of the extract was determined using standard Spectrophotometric techniques. Results The ethanolic extract of each plant had higher inhibitory effects against the bacterial isolates than the aqueous extracts. The zone of inhibition of each ethanolic section ranged from 3 to 12.5 mm, while the aqueous extracts ranged from 4 to 10 mm. The highest antimicrobial activity was observed at 150 mg/ml in A. sativum ethanolic extract when tested against Staphylococcus aureus, which resulted in a zone of inhibition of 12.5 mm. The aqueous and ethanolic extracts of A. cepa have higher phenolic content than that of A. sativum. Conclusion This research showed that the ethanolic and aqueous extracts of both plants vary in their abilities to serve act as antioxidants and antimicrobials
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