Production and characterization of activated carbon from leather waste, sawdust, and lignite

Powdered activated carbon (PAC) was prepared from leather buffing waste, sawdust and lignite by carbonization at temperatures between 500 – 800oC followed by steam activation. Experimental results reveal a general decrease in yield of carbon residue with increase in temperature of carbonization. Samples of lignite recorded the highest yield (49.80 – 67.70%) followed by leather buffing dust (30.70 – 39.70%) and sawdust (25.10 – 37.20%). Activated carbon from these precursors, were also evaluated for percentage ash, fixed carbon, pH and bulk density. Adsorption studies carried out with methylene blue indicate that low temperature carbonization of precursors such as leather buffing waste favour production of carbon with better adsorption efficiency while high temperature carbonization produced carbon with better efficiency from sawdust and lignite. Activated carbon from sawdust and leather buffing waste show result which compare favourably with the reference carbon used. These carbons are recommended for use in the adsorption of dyes or decolourization of organic compounds and other substances in aqueous solutions.Key words: Activated carbon, carbonization, Steam activation, Adsorption efficiency, Leather buffing wast

Cost Management Practice of Construction Firms and Its Influencing Factors: Lessons from Southwestern Nigeria

The growing need at maintaining steady cost projection of construction projects has been an issue of serious concern to both the clients and the construction practitioners on sites. Also, cost deviation from initial cost plan and cost budget has been prevalent on construction sites and no concerted efforts have been made at addressing this phenomenon. This study therefore examined the factors that are considered to be affecting the cost management practice of construction firms in the southwestern Nigeria and also proffered possible ways of ameliorating the factors. Using survey approach, one hundred copies each of structured questionnaires were distributed to clients, contractors and consultants on construction sites in the study area while 72, 77 and 78 copies were duly filled and returned by the respondents respectively. Relative Importance Index (RII) technique was used for the analysis. The results revealed that poor leadership and in appropriate management, inefficient deployment of resources, excessive wastage of materials on sites, complex payment mechanisms, theft of materials on sites and variation during construction works are the prevailing factors affecting construction cost management practice in the study area. It was concluded that extra focus should be placed on the identified factors with a view to reducing cost of construction, enhancing construction performance and building confidence within the construction industry in the study area

Structural Modification of Cellulosic Fabric via Esterification Using Balanites aegyptiaca Seed Oil

Cellulose fabrics were esterified by using varying volume of Balanites aegyptiaca seed oil. X-ray diffraction analysis was carried on the esterified fabrics and unesterified fabric. The crystallographs of all esterified fabrics gave almost the same profile different from that of control fabric. The control fabric gave a sharp single peak at 24.033º diffractometer angle. Esterified fabrics gave a slightly broad split peaks at lower diffractometer angles which ranged from 20.080 – 22.690º, suggesting that there was structural modification of cellulose. The inter-atomic distance (d-spacing) for control fabric was 3.7027 Å. There was increase in d-spacing which ranged from 3.9192 – 4.4216 Å for esterified fabric. The peak width increased from 1.5º (control) to range of 1.6 – 2.8º (esterified) fabrics. The peaks intensity increased from 5489 (control) to highest value (7798) for 30 cm3 of oil esterified fabric. The crystallite size reduced from 9.9 nm (control) to a maximum value (9.2 nm) for 40 cm3 and to minimum value (5.3 nm) for 10 cm3 oil esterified fabrics. The percentage crystallinity reduced from 65% (control) to a range of 62–63% for esterified fabrics. From the results obtained, it can be concluded that reduction in crystallite size, increase in d-spacing, intensity and peak width were due to the presence of a bulky ester group in the cellulose chain; this may also have led to the observed decrease in percentage crystallinity of the esterified fabrics. This structural modification is expected to have direct consequences on the physical and mechanical properties as well as the dyeing properties of the esterified fabrics

Potato value chain development project in Cameroon. Internal midterm review report

The “ONE WORLD – No Hunger” Initiative (SEWOH) by the German Federal Ministry for Economic Cooperation and Development (BMZ) is part of the G7 goal to free 500 million people from hunger and malnourishment by 2030. SEWOH intends to contribute significantly to reducing poverty and hunger in developing countries in general and Cameroon in particular. The Cameroonian project is part of the framework of the global project – “Green Innovation Centres for the Agriculture and Food Sector” (ProCISA). The project that started in November 2014 is being implemented in close cooperation with the Ministry of Agriculture and Rural Development (MINADER) and the Ministry of Livestock, Fisheries and Animal Industries (MINEPIA), and other partners. It focuses, among others, on the potato value chain to introduce technical and institutional innovations along with the capacity building to increase efficiency and productivity for increased income from potato farming in the West, North-West, and Adamawa regions. With its value chain focus on production and commercialization, ProCISA also targets job creation and the role of women and youth in agriculture and food security. The capacity building around Good Agricultural Practices (GAP) is essential and a significant component in the ProCISA approach. In the implementation of one of its objectives, ProCISA signed a grant agreement with the International Potato Center (CIP) due to its technical expertise on the potato food systems to implement a project titled “Potato Value Chain Development in Cameroon (PVCD),” which started in December 2018. PVCD project built on preliminary interventions conducted by CIP as a consultant from October 2016 to November 2018. In this light, the overall goal of the PVCD project is to promote sustainable intensification of potato production and provide business opportunities for small to medium-sized enterprises through innovative production practices, capacity building, and developing appropriate business models. In a specific manner, the project is structured in five (05) components as follows: Policy engagement and Advocacy (i); Training at scale on good agricultural practices (ii); Seed production and Variety promotion (iii); Promotion of innovations and business models (iv); and M&E and Knowledge sharing (v)

The Effect of Kelvin Effect on the Equilibrium Effective Radii and Hygroscopic Growth of Atmospheric Aerosols

In this paper we extracted microphysical properties of six types of atmospheric aerosols from Optical Properties of Aerosols and Clouds (OPAC) and numerically analyzed the analytical expressions for the changes in the equilibrium relative humidity (RH), effective radius, effective hygroscopic growth, the magnitudes and fractional changes in the effective radii  and the effective hygroscopic growth on the effects of surface tension (the Kelvin effect) on ambient atmospheric aerosols. The expressions were applied to two - one parameter models. We discovered from the analysis of the data extracted that, to the lowest order error, the change in the equilibrium RH, effective radii and effective hygroscopic growth depend on the compositions of the aerosols. From the two models used, we also discovered that the fractional changes in the ambient RH, effective radii and effective hygrosocopic growth, also depend on the aerosols compositions. Finally, we discovered that the magnitude of the Kelvin effect and its consequences on the atmospheric aerosols depend on the hygroscopicity of the aerosols. Keywords: Kelvin effect, effective radius, effective hygroscopic growth, atmospheric aerosols, ambient Relative Humidity

Structural Modification of Cellulosic Fabric via Esterification Using Jatropha curcas Seed Oil

This paper presents the results of x-ray diffraction of a cellulose fabric treated with oils extracted from the seed of Jatropha curcas; the oils were extracted with hexane under reflux while the fabric was purified by scouring, bleaching and mercerization to remove dirt and coloring matter in order to make it suitable for esterification. Apart from the controlled sample which was un-esterified, other samples of the same fabric were treated with different volume and concentration of the oil under the same temperature. The x-ray diffraction analysis carried out on all samples showed that while the control sample had a sharp single peak at 24.033° all the esterified samples showed broad split peaks at angles ranging from 20.308o to 22.809o; also while the control sample had inter-atomic (or d-spacing) of 3.702 Å those of the treated sample ranged from 3.8984 Å to 4.3727 Å, in addition to these the peak width increased from 1.5o in the control sample to between 1.9o to 2.8o in the treated samples. Other significant results showed that the peaks intensity increased from 5489 to highest value 8313 in the sample treated with 20 cm3 of oil. Crystallinity was observed to reduce from 65% in the control to about 63% for esterified fabrics samples and lastly, crystallite size reduced from 9.9 nm to between 5.3 nm to 7.7 nm. The observed structural modifications in treated fabric may have direct influence on the physical, mechanical properties as well as dye-ability of the treated samples. The result of water Imbibition also revealed structural modification as there was a decrease in the amount of water imbibed by esterified fabric, indicating a reduction in the number of OH groups in the new cellulose derivative as revealed in the x – ray analysis. Hence the esterified fabric will be less susceptible to microbial attack during storage

Appraisal of Potato Production Practices in the Adamawa and West regions of Cameroon. Baseline Survey Report

We conducted a baseline survey to appraise the current potato practices and farming systems in the Adamawa and West regions of Cameroon where a GIZ-funded project (ONE WORLD – No Hunger, or SEWOH) titled "Green Innovation Centers for the Agricultural and Food Sector" (ProCISA) is being implemented. We employed a mix of qualitative and quantitative methods to gather and analyze data/information. This study focused on potato farmers that have been into potato production for at least two years. We developed a structured questionnaire which was administered to small- and medium-sized potato growers based on a literature review and consultation with key stakeholders. The questionnaire was pretested through ten in-depth interviews with selected farmers in the Adamawa and West regions. Local enumerators were recruited in each region and trained to administer the questionnaire in the field. In total, 341 questionnaires were completed (141 in Adamawa and 200 in the West region) in 133 villages (35 in Adamawa and 98 in the West region) using a modified systematic random sampling technique to ensure even representation. The collected data was then coded and analyzed. Farmers in both regions cultivate an area typically not more than 1 hectare (ha), but in Adamawa, farmers grow only one round of potatoes, while in the West they cultivate two in a year (i.e., during the rainy season from March to October). Top challenges to farmers in our survey area include low access to quality seed, poor management and agronomic practices, and limited access to credit, fertilizers and pesticides. In Adamawa, just over half of the farmers (51%) reported having received no agricultural training in the past, compared to just 43% in the West region. Thus, interest in and willingness to participate in future trainings are high