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Blantyre, Malawi

Oluwafemi F.,Abeokuta Federal University of Agriculture | Odebiyi T.,Abeokuta Federal University of Agriculture | Kolapo A.,Polytechnic
World Mycotoxin Journal | Year: 2012

There are indications that significant levels of mycotoxins may be absorbed from inhaled fungal spores. The problem is likely to be most serious with aflatoxins. Indoor airborne fungi in three feed mills in south-western Nigeria were assayed using Sabouraud dextrose agar and coconut agar medium. Fungi isolated include Aspergillus flavus, Rhizopus spp., Aspergillus fumigatus, Aspergillus candidus, Aspergillus niger and Aspergillus terreus with incidence rates of 61, 15, 12, 5, 5 and 2%, respectively. Amount and type of aflatoxins produced in Sabouraud dextrose broth by aflatoxigenic strains of A. flavus isolated at the three mills were strain dependent. Exposure of feed mill workers to aflatoxins was assessed by HPLC analysis of blood samples. Subjects from different occupational groups served as a control group. The mean concentrations of aflatoxin B1, B2, G1 and G2 in blood samples of the feed mill workers varied from 73.4-189.2, <0.1-0.5, 0.3-1.9 and <0.1-3.4 ng/ml, respectively. There was a significant difiference between the mills regarding blood aflatoxin levels of the workers; poorly ventilated mills resulted in higher blood aflatoxin B1 levels. Aflatoxin B1 was not detected in the blood samples of the control group; mean concentrations of aflatoxin B2, G1 and G2 detected in this group varied from <0.1-0.3, 0.4-1.5 and <0.1-0.3 ng/ml, respectively. Results from the present study showed that ventilation of feed mills is an important issue that should be considered to lower the risk of aflatoxin exposure among feed mill workers. © 2012 Wageningen Academic Publishers.

Wellen R.M.R.,Federal University of Pernambuco | Canedo E.L.,Polytechnic | Rabello M.S.,Federal University of Campina Grande
Journal of Applied Polymer Science | Year: 2012

Blends of poly(ethylene terephthalate) (PET) with small amounts of styrene-co-acrylonitrile (SAN) were prepared by melt blending, and cold crystallization of these mixtures was investigated by means of differential scanning calorimetry. The results suggest that SAN interacts with the amorphous phase of PET, as observed by variations in the glass transition temperature and in the morphology of the blends, analyzed by scanning electron microscopy. The addition of 1% SAN promoted a significant reduction in the crystallization rate of PET, in a manner similar to that of an antinucleating agent. However, the crystallinity of the PET/SAN blends was comparable with that of neat PET; hence, mechanical properties were only slightly affected. Kinetic parameters were determined using Avrami theory; Avrami plots presented a nonlinear behavior at the end of crystallization, indicating that cold crystallization proceeds in two stages. © 2012 Wiley Periodicals, Inc.

Thole B.,Polytechnic
Journal of Water Sanitation and Hygiene for Development | Year: 2014

One of the parameters that impact on fluoride sorption capacities of materials in water defluoridation is initial concentration. Water from various sources will have different fluoride concentrations; as such the employment of a particular media in defluoridation requires information on how the media will perform in different concentrations. Consequently, research was carried out to determine how initial fluoride concentrations in raw water affect capacity in defluoridation with bauxite, gypsum, magnesite and their composite, and to investigate the possibility of predicting loading capacity of their compositefilter through initial fluoride concentration to optimize their application in defluoridation. The results showed that sorption capacities increased with increase in initial concentrations. However, higher starting concentrations resulted in larger residualfluoride concentrations; as such the benefit of large sorption capacities obtained was overshadowed. Polynomial relations of capacity (Cs, mg/g) and initial concentration (Co, mg/l), were obtained for bauxite and gypsum. Magnesite obtained a logarithmic relation for Cs and Co. A power relation was obtained between Cs and Co for their composite, Cs = 0:0328C 1:2016 o. Approximation of capacities of this composite from initialfluoride concentrations was feasible. Water defluoridation has become important as a result of dental and skeletal fluorosis.

Mladenovic M.,Virginia Polytechnic Institute and State University | Abbas M.,Polytechnic
Traffic Engineering and Control | Year: 2012

Transportation agencies across the world are facing the need for improvement in the management of transportation networks under their control. One of the challenges is safe and effective control of largescale traffic light systems. As one of the solutions to these requirements, agencies are sometimes installing Adaptive Traffic Control Systems. This paper, which follows on from page 26 of TEC January 2012 is focusing on potential functional requirements for selection, thus establishing the groundwork for their procurement and installation.

Shah B.A.,Veer Narmad South Gujarat University | Surati P.R.,Veer Narmad South Gujarat University | Shah A.V.,Polytechnic
Molecular Crystals and Liquid Crystals | Year: 2013

A new Schiff base compound 4((o-tolylimino)methyl)-3-methyl-1-phenyl-1H- pyrazol-5-ol(4TM-MPP) was synthesized and characterized by elemental analyses, LC-MS, FTIR, and 1H-NMR spectra. The compound exhibits photochromic property under 365 nm UV-light irradiation, which can be observed with solid state reflectance spectra. It suggests that the photoisomerization is due to photoinduced intermolecular hydrogen bond, which results in enol to keto transformation. The chemionics study is carried out using (Ni+2, H+), (Ag+, H+), and (Na+, H +, and OH-) using the UV absorption spectra in solution, which shows logic behavior of INHIBIT, NOR, and XOR, respectively. © 2013 Copyright Taylor and Francis Group, LLC.

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