A study on the performance of sodium mercaptobenzothiazole (NMBT) collector on the flotation of Black Mountain ore

This paper investigated the performance of Sodium Mercaptobenzothiazole (NMBT) as a collector in the flotation of Black Mountain ore. The ore contains metals such as lead, copper and zinc and the associated minerals of economic importance are chalcopyrite, galena and sphalerite respectively, with traces of silver. The study evaluated the effectiveness of the collector and how pH affects the recovery of minerals in particular copper. The performance of the collector was influenced by mineral surface chemistry. The experimental test work was conducted at varying pH levels using Denver flotation cell in order to investigate the collector performance in a basic medium. The experiments were conducted at two different test runs of slightly basic solutions of pH 8.5 and 9.0. The results of both fresh ore and floated ore samples were analysed using XRF. Although Black mountain ore contains small quantities of copper as compared to other ores, a significant amount was recovered (±78% of the available copper in the ore), as an indication of the performance of NMBT

Environmental distribution and genetic diversity of vegetative compatibility groups determine biocontrol strategies to mitigate aflatoxin contamination of maize by Aspergillus flavus

Published online: 27 Oct 2015Maize infected by aflatoxin-producing Aspergillus flavus may become contaminated with aflatoxins, and as a result, threaten human health, food security and farmers’ income in developing countries where maize is a staple. Environmental distribution and genetic diversity of A. flavus can influence the effectiveness of atoxigenic isolates in mitigating aflatoxin contamination. However, such information has not been used to facilitate selection and deployment of atoxigenic isolates. A total of 35 isolates of A. flavus isolated from maize samples collected from three agroecological zones of Nigeria were used in this study. Ecophysiological characteristics, distribution and genetic diversity of the isolates were determined to identify vegetative compatibility groups (VCGs). The generated data were used to inform selection and deployment of native atoxigenic isolates to mitigate aflatoxin contamination in maize. In co-inoculation with toxigenic isolates, atoxigenic isolates reduced aflatoxin contamination in grain by > 96%. A total of 25 VCGs were inferred from the collected isolates based on complementation tests involving nitrate non-utilizing (nit−) mutants. To determine genetic diversity and distribution of VCGs across agroecological zones, 832 nit− mutants from 52 locations in 11 administrative districts were paired with one self-complementary nitrate auxotroph tester-pair for each VCG. Atoxigenic VCGs accounted for 81.1% of the 153 positive complementations recorded. Genetic diversity of VCGs was highest in the derived savannah agro-ecological zone (H = 2.61) compared with the southern Guinea savannah (H = 1.90) and northern Guinea savannah (H = 0.94) zones. Genetic richness (H = 2.60) and evenness (E5 = 0.96) of VCGs were high across all agro-ecological zones. Ten VCGs (40%) had members restricted to the original location of isolation, whereas 15 VCGs (60%) had members located between the original source of isolation and a distance > 400 km away. The present study identified widely distributed VCGs in Nigeria such as AV0222, AV3279, AV3304 and AV16127, whose atoxigenic members can be deployed for a region-wide biocontrol of toxigenic isolates to reduce aflatoxin contamination in maize

Bioremediation: Data on Pseudomonas aeruginosa Effects on the Bioremediation of Crude Oil Polluted Soil

This data article details Pseudomonas aeruginosa effects on the bioremediation of soil that had been polluted by different concentrations, 5% w/w and 8% w/w, of raw (for simulating oil spills from wellheads) and treated (for simulating oil spills from flow lines/storage tanks) crude oil. UV/VIS spectrophotometry instrumentation was used for obtaining absorbance measurements from the Nigerian Escravos Light blend (sourced from Chevron® Nigeria) of crude oil polluting soil samples, which, thus, also simulates light and heavy onshore oil spillage scenarios, in a 30-day measurement design. Data on bioremediation effects of Pseudomonas aeruginosa added to the crude oil polluted soil samples, and which were monitored at intervals via the absorbance measurement techniques, are presented in tables with ensuing analyses for describing and validating the data presented in graphs. Information from the presented data in this article is useful to researchers, the oil industries, oil prospecting communities, governments and stakeholders involved in finding solution approach to the challenges of onshore oil spills. This information can also be used for furthering research on bioremediation kinetics such as biostimulant analyses, polluting hydrocarbon content/degradation detailing, by Pseudomonas aeruginosa strain of microorganism, on petroleum pollutant removal from soil that had been polluted by crude oil spillage

An Examination of Modelling, Simulation and Detection of Fault Behaviours in HVDC Monopolar System

Purpose: Some previous researchers work on the HVDC Monopolar systems using Matlab/Simulink environment to carry out their analyses. We continue this discussion of Monopolar HVDC systems. Methodology: The analyses that are carried out include double phase-to-ground fault, single phase-to-ground fault and three phase-to-ground fault at the AC side of the rectifier and the DC line to ground fault.  Findings: It is discovered, among others, that for three phase-to-ground fault, the voltages at the AC side of the rectifier, the DC line voltage and the voltage at the inverter side of the load are completely zero but that the current in the rectifier will increase from its standard value though will be less harmful and the current of the inverter side will decrease from its original value. It is further discovered that the fastest transient will be the case when fault is applied to the DC transmission system and that transmission network is of critical importance in high voltage transmission lines and engineers can also use this result to identify different faults in the transmission lines and the care of power quality is highly important because of electrical energy demand. Unique Contribution to Theory, Practice and Policy: The current in the rectifier decreases from its standard value but will be less harmful. The causes of decrease in DC transmission line depend on severity of the fault such as single phase to ground, double line to ground and three phase-to ground at the rectifier side. &nbsp

Alms-Begging and Human Right in Yoruba Land

Existing studies claimed that begging activities in South-western Nigeria are encouraged largely by cultural influences and uneven distri ution of the n tion‟s resources. They further claim that the cultural activities re tr ce le to the or system which encourages mothers of twins to sing and dance for money. This paper investigates the claims by dr wing insights from the i le, Qur‟ n, f Literary Corpus, nd relev nt or proverbs. Findings show, among other things, that the claim about cultural influence, nonprovision of free education, and failure of the Nigerian government to break the cycle of poverty as the causes of alms-begging are mere excuses. The practice of polygamy with its attendant indiscriminate procreation among Nigerians is the major cause of alms-begging in the nation. It argues that any suggestion to improve the economy of Nigeria as well as economically empower individuals in the country will be a mirage or an exercise in futility if the problem caused by polygamy and indiscriminate procreation is not addressed

Strength and durability effect of modified zeolite additive on concrete properties

Abstract:This paper presents an investigation into the effect of a modified zeolite additive (PWC) on strength and durability behaviour of concrete. The additive, a blend of selected alkaloids and zeolite, is commercially available and effectively used in soil stabilization for road construction. However, its influence on behaviour and performance for use in concrete has not been explored. In this research, concrete samples were prepared by incorporating PWC and/or 30% fly ash in the mixes. PWC was used in proportions of 0.6 %, 0.8%, and 1.0 % of the weight of cement. Concretes or mortars of 0.5 water/cementitious ratio were subjected to split tensile strength, compressive strength, oxygen permeability, sorptivity, and porosity tests. Hydration behaviour of the cementitious systems and the pozzolanic effect of PWC additive were studied using differential thermal analysis and thermogravimetric analysis. Results show that PWC is effective in improving concrete strength when used at optimum proportions found to be between 0.6 % and 1.0 %. Sorptivity property of concrete was improved with use of PWC regardless of its proportion in the mix, while permeability of concrete improved only in the presence of 30 % fly ash

Effect of canker size on availability of cassava planting materials in Nigeria

Cassava (Manihot esculenta L.) production is highly limited by cassava anthracnose disease (CAD) which causes significant losses in planting materials. An experiment was laid out at Ihiagwa, Owern in Nigeria with eighteen treatments replicated three times. Disease severity was scored on a scale of 1-5, and disease incidence was recorded as the percentage of infected plants in each host plant line. In all the three trials, TMS 30211 (425 mm) had cankers high up on the stem, showing that they were infected later in life. This will lead to more disease - freestems. Cultivars Akwakwuru (39.6 mm2), TMS 30555 (31.6 mm2), and Nwaocha (43.7 mm2), had the large canker size on whole plant, young stem, shoot and maturing stem. These cultivars had low resistance to anthracnose. In all the trials, TMS 4(2)1425, and TMS 30211, had the smallest canker size (1.80 and 6.3 mm2, respectively) on whole plant, young stems, shoots and maturing stems. TMS 4(2)1425 and TMS 30211 had higher resistance to anthracnose and can be recommended for further improvement through breeding, because plants producing smaller – size lesions survive much longer and would also mature and produce flowers needed for breeding for improving resistance to CAD and other diseases

Essential parameters for strength-based service life modelling of reinforced concrete structures - a review

Abstract: While there are a number of carbonation-induced service life models and extensive data that has been present-ed in the literature, most do not capture all the necessary parameters to allow their universal application to re-inforced concrete structures. Results in the literature generally show an existence of a strong fundamental relationship between car-bonation and compressive strength of concrete, but hardly any model has been successful in developing a uni-versal functional relationship for service life prediction. It is often the case that models developed on the basis of a particular data set fail to apply when treated to another data from other authors. These issues indicate the underlying complexity of attempting to determine and emerge the empirical or mathematical functions capable of adequately capturing the key influential parameters affecting observed performance. In a critical review of literature, a variety of parameters in the strength-based models are compiled for a range of potentially plausi-ble models and then examined. Specific interest has been given to models that account or have the potential to account for complex cementitious systems, various types of climates or field exposure conditions. It is found that there is potential to introduce robustness into few selected models that seem, from the literature examina-tion, to closely relate to service life situations and /or needs in Sub-Saharan Africa, among other regions

Various Egusi Melon Seeds existing in Southwestern Nigerian Markets

Egusi is a common name for oil rich seeds of Egusi melon used mainly as soup condiment. The medium sized usually comes to mind anytime the name egusi is mentioned. But there exists a variety of crops in family Cucurbitaceae used for same purpose which is not commonly known even among the elites in Crop Science in Nigeria and beyond. In the course of a research on egusi, different types of seed forms were identified. There were six different types of egusi kernels (bojuri, itoo, serewe, igbaa, bara and wewe) based on size, colour and type sold in Nigerian markets; however, bara and serewe were the most common types of egusi found in Nigeria