71 research outputs found
Essays in Development Economics
The first paper examines the crop composition effects in 50 African countries from 1960 to 2013. The paper aims to assess the effects of climate extremes and other non-climate-related factors on major agricultural outputs across African countries. The estimation results, using fixed effect regression and ordinary least square both individually and jointly for all African countries, shows that climate extremes are not altogether bad news as it increases hectares planted of some crops. The policy recommendations for the paper are for crop mix and/or substitutability of crops owing to relative changes in the climate-and non-climate-related factors, effective fertilizer policies and increasing agricultural workers productivity in the African countries.
The second paper contributes to the policy debate on the role of political institutions as an intervening factor for the relationship between natural resource abundance (of different types) and growth performance in African countries. Using panel data econometrics for 28 Sub-Saharan African countries from 1960 to 2012, the research finds that good quality institutions can aid economic growth, and natural resource endowments are beneficial in the selected countries and not a curse. The research culminates with discussions on improving executive constraints, political participation and political openness, as these are intrinsic in the institutional measure adopted, in other to optimise the benefits of natural resource endowments.
The third paper compares the results of Datta and Reimer (2013) which is based on 100 countries over 17 years with a similar but expanded analysis of 43 African countries over 22 years. Using various econometric techniques and model specifications, the paper finds a statistically significant reciprocal relationship between income and malaria using both database. This research further finds that income is the largest driver of the negative reciprocal relationship between income and malaria using both database, and lastly that the magnitude of the effect of income on malaria is higher using the Datta and Reimer (2013) database than in the database of 43 African countries. The research culminates with recommendation on increased economic growth for the African countries and effective distribution of insecticide-treated nets in countries where malaria is rife
Fungal Airsporal Contamination of Different Hospital Environments in Lagos, Nigeria
Hospital infections caused by fungi have been frequently reported in hospitalized patients, with a high morbidity and mortality, making it increasingly important to the awareness of air quality. This study is designed to isolate, identify and investigate the occurrence of airborne fungal spores present in various working environments of some selected hospitals within Lagos State, Nigeria. Air samples at six working area (reception, out-patient, male ward, female ward, maternity ward and operating theatre) of the selected hospitals were obtained on triplicate of Sabouraud dextrose agar plates, every week days for six consecutive weeks. Isolated fungi were subsequently identified using both microscopic and macroscopic characteristics. Seven species of fungi belonging to three genera were recovered during this study period; Aspergillus niger, A. flavus, A. fumigatus, A. species, Candida species, Penicillium citrinum and P. species. The most abundant fungus encountered in this study is A. niger with P. species being the least isolated fungus from all the investigated hospitals. Of the six working areas sampled in the eight hospitals, the reception and out-patient areas appeared to record the highest occurrence of encountered fungi while the examined operating theatre rooms had the least fungal airsporal contaminant. It was gathered from this study that despite the daily cleaning of the investigated hospital working environments with different antiseptic and disinfectants, fungal contaminant was observed throughout the sampled period. We thereby conclude that the hospital environments are continuously monitored in order to identify and eliminate the sources of these fungal spores
Comparative Studies of the Corrosion Inhibition Efficacy of a Dicationic Monomer and Its Polymer against API X60 Steel Corrosion in Simulated Acidizing Fluid under Static and Hydrodynamic Conditions
N1,N1-diallyl-N6,N6,N6-tripropylhexane-1,6-diaminium chloride (NDTHDC) and
its polymer poly(N1,N1-diallyl-N6,N6,N6-tripropylhexane-1,6-diaminium chloride) (poly-
NDTHDC) were synthesized and tested against API X60 carbon steel corrosion in 15 wt %
HCl solution. Weight loss, electrochemical, and surface analysis techniques were used. Results
show that poly-NDTHDC is better than NDTHDC. Moreover, 1000 mg/L NDTHDC protected
the studied surface by 79.1% at 25 °C, while 100 mg/L poly-NDTHDC afforded 86.1%
protection. Inhibition efficiency increases with temperature (up to 60 °C) but depreciates
thereafter. NDTHDC and poly-NDTHDC perform better under the hydrodynamic condition
than the static condition. TGA and FTIR results reveal that poly-NDTHDC is chemically and
thermally stable
Corrosion Inhibition on Mild Steel by Phosphonium Salts in 1M HNO3 Aqueous Medium
The corrosion inhibition on mild steel by phosphonium salts in 1 M HNO3 medium has been investigated by weight loss and polarization techniques. The result revealed that these derivatives are excellent inhibitors. Potentiostatic polarization, impedance and electrochemical noise studies showed mixed type inhibitors. Ellipsometer, quantum chemical and FTIR results indicated Phosphonium bromide derivatives exhibit excellent corrosion protective thin layer performance
Chemical Additives for Corrosion Control in Desalination Plants
The addition of chemical additives has been considered as a standard
operation in water treatment systems. This chapter discusses the chemical
additives used for the control of corrosion in desalination systems. Specifically,
corrosion inhibitors for various metallurgies, biocides, and oxygen scavengers
are covered. The pros and cons of the additive chemicals have been
highlighted. The need to utilize green corrosion inhibitors based on plants and
ionic liquids materials have been emphasized. This class of materials are
environmentally friendly, cheap, and readily available
The consequence of societal secrecy for the financial constraints faced by firms
This is the author accepted manuscriptDoes the level of societal secrecy aggravate or alleviate access to finance? We explore this question for 51,249 firms in 39, predominantly developing, countries, from 2006 to 2015. We find a strong positive relationship between cultural orientation towards secrecy in a country and financial constraints faced by its firms. Our results are robust to several considerations and emphasize the adverse consequence of societal secrecy for perpetuating financing obstacles for firms
Preliminary Evaluation of a Laboratory-Prepared Voges-Proskauer Medium
The performance of a Voges-Proskauer (VP) medium prepared from basic chemical reagents in the laboratory was compared with that of a commercial VP medium, obtained from Oxoid (Basingstoke, UK), using 64 coded laboratory cultures. The sensitivity of the laboratory-prepared VP medium was 100% and the specify was 96%. The percentage accuracy of the laboratory medium was 98.4% and colour development on which the result of the VP reaction depends was more intense in the laboratory-prepared medium than in the Oxoid medium. This blind study indicates that reasonable accuracy can be achieved when VP reaction is determined using a medium prepared in the laboratory with basic chemical reagents. It is suggested that the laboratory prepared medium can conveniently replace the commercial VP medium in the determination of VP reaction in laboratories with limited resources.
Key words: Voges-Proskauer medium, evaluation, cost, Enterobacteriaceae
Journal of Medical Laboratory Sciences Vol.12(1) 2003: 15-2
N1,N1,N12,N12-Tetramethyl-N1, N12-dioctyldodecane-1,12-diaminium bromide: Its synthesis and application in inhibition of mild steel corrosion in 15% HCl
Anticorrosion and dispersive adsorption studies of natural andrographolide on carbon steel in acid-chloride environments
Corrosion Inhibition of Carbon Steel in Acidic Environment by Papaya Seed as Green Inhibitor
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