Structural behaviour of metakaolin infused concrete structure

This work researched into the use of metakaolin as a partial substitute for cement in concrete, metakaolin was obtained by the calcination of kaolin clay to about 700 0C Cement was replaced with the metakaolin at 0, 5, 10, 15, 20, 25, 30, and 35% at water cement ratio of 0.5. Tests such as chemical analysis, compressive strength, flexural or modulus of rupture and bond strength were carried out on the concrete samples. Chemical analysis results showed that the metakaolin is a class “N” pozzolan, while the mechanical test showed that the strength of concrete increased from 5% to 20% replacement, and the strength peaked at 20%, but decreased above this value; concrete made with metakaolin performed better than the control sample at all the percentage replacements used in this work.Keywords: Metakaolin, Calcination, Pozzolan, Chemical test, Mechanical tes

COMPARATIVE STUDY OF CORROSION PERFORMANCE OF ALUMINIUM- ZINC COATED, GALVANIZED AND ELECTROPLATED STEELS IN TOMATO JUICE

Metallic materials are given prominent considerations in agro-based machinery especially in fruit juice processing, storage and use as disposable cans. Such metallic materials include Electroplated Steel (ES), Galvanized Steel (GS) and Aluminum-zinc coated steel (Aluzinc). This study evaluated the corrosion performance of Aluzinc, GS and ES in tomato juice. The medium was chosen due to its social and economic importance. Samples of Aluzinc, GS and ES were prepared by cutting into 3 x 3 cm2 from 1 mm thick plate. Three of each of the prepared samples were used for Potentiostatic Polarization Experiments (PPE) while 18 samples each were used for Weight Loss Method (WLM). Each of the prepared samples for WLM was cleaned, weighed and immersed in the media for 30 days. The samples were removed at the end of immersion, cleaned and reweighed. The results obtained for the corrosion rates in mm/y using PPE in tomato juices were 0.0061, 0.0065 and 0.0148 for Aluzinc, GS and ES respectively. The measured pH values for the media ranged from 4.1 to 8.3. Aluzinc had the lowest corrosion rate in tomato juice followed by GS and ES after 30 days of immersion using WLM

Clients’ Perception of Quality of Multidrug-Resistant Tuberculosis Treatment and Care in Resource-Limited Setting: Experience from Nigeria

Background: Quality care is essential to the well-being and survival of people with multidrug-resistant tuberculosis (MDR-TB). The aim of this study is to explore how MDR- TB patients, who were voluntarily hospitalized, perceived care and treatment strategy and to assess the influence of psychosocial factors on their perception of care and treatment strategy in Nigeria. Methods: The study enrolled 98 MDR-TB patients on voluntary confinement in four MDR-TB hospitals in Nigeria. Patients’ perceptions of quality of care and treatment strategy were evaluated with 28-item and 6-item instruments, respectively. Bivariate analysis was used to test for an association and multivariate analysis for factors that might contribute to the perceived quality of care. Results: Seventy-eight per cent (78%) of the participating patients perceived the quality of care to be good. Patients with better psychosocial well-being had five times higher odds to report good quality of care. Conclusion: The majority of MDR-TB patients perceived the quality of inpatient care to be good in Nigerian hospitals; however, their psychological health influenced their perception significantly. Health care providers need to improve treatment strategies to encourage acceptance of care as poor perception to health care service delivery may deter treatment completion and also cause relapse among clients on treatment

A Tale of Two Markets: How Lower-end Borrowers Are Punished for Bank Regulatory Failures in Nigeria

In 2009, the Nigerian banking system witnessed a financial crisis caused by elite borrowers in the financial market. Regulatory response to the Nigerian crisis closely mirrored the international response with increased capital and liquidity thresholds for commercial banks. While the rise of consumer protection on the agenda of prudential supervisors internationally was logical in that consumer debt was the main cause of the global recession, the Nigerian banking reforms of 2009 disproportionately affected access by poorer consumers, who ironically had little to do with the underlying causes of the crisis. As lending criteria become more stringent, poorer consumers of credit products are pushed into informal markets because of liquidity-induced credit rationing. Overall, consumer protection is compromised because stronger consumer protection rules for the formal sector benefits borrowers from formal institutions who constitute the minority of borrowers in all markets. While the passage of regulation establishing credit bureaux and the National Collateral Registry will, in theory, ease access to credit especially by lower-end borrowers, the vast size of the informal market continues to compound the information asymmetry problem, fiscal policies to tackle structural economic issues such as unemployment and illiteracy remain to be initiated, and bank regulators continue to pander to elite customers with policy responses that endorse too big to fail but deems lower-end consumers too irrelevant to save. The essay concluded that addressing the wide disparity in access to credit between the rich and poor through property rights reforms to capture the capital of the informal class, promoting regulation to check loan concentration, and stimulating competition by allowing Telecommunication Companies (TELCOs) and fintech companies to carry on lending activities because of their superior knowledge of lower-end markets will facilitate greater access. The risk of systemic failure deriving from consumer credit in Nigeria is insignificant compared to the consumer vulnerabilities resulting from the exposure of consumers to unregulated products in the informal market

Chapter 31 - Application of nanochitosan in tagging and nano-barcoding of aquatic and animal meats

Nanochitosans obtained from crustacean shells are biodegradable and biocompatible offering valuable functional, nutritional, and binding properties. Their low toxicity favors diverse industrial applications in various research models and can enable their use in the tagging of commercially sold aquatic and animal meat, easily contaminated by microbial sources during packaging, storage, and transportation. In this capacity, nanochitosans have been applied in fingerprinting for tracking and identifying the manufacturing and expiry dates of commercially sold meats and fish, as well as delivery of antioxidants and antimicrobials in these food products without affecting product consistency, composition, and organoleptic property. This chapter reviews current research on chitosan-based nanoparticles as barcodes and biosensors in tagging and monitoring aquatic and animal meats; and highlights methods of fish tagging and coding, and the benefits as well as the properties of materials used as biosensors in nano-barcoding of fish and meat

Nanochitosan derived from marine bacteria

Nanochitosans are polysaccharides produced by the alkalescent deacetylation of chitin and comprise a series of 2-deoxy-2 (acetylamino) glucose linked by ß-(1-4) glycosidic linkages. These are naturally formed from the deacetylation of shellfish shells and the exoskeleton of aquatic arthropods and crustaceans. Reports of chitosan production from unicellular marine bacteria inhabiting the sea, and possessing distinct animal- and plant-like characteristics abound. This capacity to synthesize chitosan from chitin arises from response to stress under extreme environmental conditions, as a means of survival. Consequently, the microencapsulation of these nanocarriers results in new and improved chitosan nanoparticles, nanochitosan. This nontoxic bioactive material which can serve as an antibacterial agent, gene delivery vector as well as carrier for protein and drug release as compared with chitosan, is limited by its nonspecific molecular weight and higher composition of deacetylated chitin. This chapter highlights the biology and diversity of nanochitosan-producing marine bacteria, including the factors influencing their activities, survival, and distribution. More so, the applications of marine bacterial nanochitosans in transfection and gene delivery; wound healing and drug delivery; feed supplement development and antimicrobial activity are discussed

Utilization of nanochitosan for enzyme immobilization of aquatic and animal-based food packages

Studies have identified the properties of enzymes, functionalized molecules, and compounds in food industry applications as edible coatings and encapsulations, that assure prolonged food quality and standards. These molecules present benefits of longer shelf-life by delayed deterioration and inhibition of the proliferation of spoilage and mycotoxigenic microorganisms. However, challenges of reduced nutrient levels, miniaturized size, and low chemical stability remain concerning. Chitosan polymers naturally formed from the deacetylation of shellfish shells and exoskeletons of aquatic arthropods and crustaceans offer improved benefits when functionalized into nanoparticles as nanochitosans. These polysaccharides produced by the alkalescent deacetylation of chitin, comprise a series of 2-deoxy-2 (acetylamino) glucose linked by ß-(1-4) glycosidic linkages. This chapter considers the health impacts and

Nanochitosan derived from marine bacteria

Nanochitosans are polysaccharides produced by the alkalescent deacetylation of chitin and comprise a series of 2‐deoxy‐2 (acetylamino) glucose linked by ß‐(1‐4) glycosidic linkages. These are naturally formed from the deacetylation of shellfish shells and the exoskeleton of aquatic arthropods and crustaceans. Reports of chitosan production from unicellular marine bacteria inhabiting the sea, and possessing distinct animal‐ and plant‐like characteristics abound. This capacity to synthesize chitosan from chitin arises from response to stress under extreme environmental conditions, as a means of survival. Consequently, the microencapsulation of these nanocarriers results in new and improved chitosan nanoparticles, nanochitosan. This nontoxic bioactive material which can serve as an antibacterial agent, gene delivery vector as well as carrier for protein and drug release as compared with chitosan, is limited by its nonspecific molecular weight and higher composition of deacetylated chitin. This chapter highlights the biology and diversity of nanochitosan‐producing marine bacteria, including the factors influencing their activities, survival, and distribution. More so, the applications of marine bacterial nanochitosans in transfection and gene delivery; wound healing and drug delivery; feed supplement development and antimicrobial activity are discussed