An experimental data set for benchmarking 1-D, transient heat and moisture transfer models of hygroscopic building materials. Part II: Experimental, numerical and analytical data

This paper presents the experimental results on spruce plywood and cellulose insulation using the transient moisture transfer (TMT) facility presented in Part I [P. Talukdar, S.O. Olutmayin, O.F. Osanyintola, C.J. Simonson, An experimental data set for benchmarking 1-D, transient heat and moisture transfer models of hygroscopic building materials-Part-I: experimental facility and property data, Int. J. Heat Mass Transfer, in press, doi:10.1016/j.ijheatmasstransfer.2007.03.026] of this paper. The temperature, relative humidity and moisture accumulation distributions within both materials are presented following different and repeated step changes in air humidity and different airflow Reynolds numbers above the materials. The experimental data are compared with numerical data, numerical sensitivity studies and analytical solutions to increase the confidence in the experimental data set.     

Aflatoxigenic fungi and mycotoxins in food: a review

Abstract

Food contamination is a common phenomenon in the production, distribution and consumption of processed and agricultural commodities all over the world. Food safety is now taking the frontal stage in food production, processing and distribution. This study assessed the presence of aflatoxigenic fungi and mycotoxins in foods, occurrence, control, socio-economic and health implications. This study also gave comprehensive information on the safety and mycological quality of foods as well the effect on the people and economy of various countries. The review revealed the various aflatoxigenic fungi in foods, their distribution in agricultural produce and their effects on reduction in yield and quality with attendant consumer health implications and resulting significant economic losses. In developing countries, majority of the people do not know the inherent dangers of consuming mouldy produce or food contaminated with fungi and moulds with possible contamination by mycotoxigenic fungi because of lack of awareness about the danger involved. In view of this, there is need for general and public education to sensitise the people on the economic and health hazards posed by mycotoxins. Control measures such as good agricultural practices, crop selection, proper washing and cooking practices of food commodities should be emphasized to the people. Regulatory control, fast and effective analyses and detection, good produce handling and storage should be encouraged as this will assist in mitigating the side effects of mycotoxins in foods particularly in the tropical and sub-tropical countries, and in Africa nations where there is enabling environment that promotes fungal growth, shortage of food and drought of modern storage and processing infrastructures.     

Catalysed oxidation of quinoline in model fuel and the selective extraction of quinoline-N-oxide with imidazoline-based ionic liquids

Synthesised vanadium-coordinated N,N-bis(o-hydroxybenzaldehyde)phenylene diamine catalyst, [VO(sal-HBPD)] and supported catalyst, p[VO(sal-HBPD)] were employed for the oxidation of quinoline. The use of [VO(sal-HBPD)] and p[VO(sal-HBPD)] for the oxidation of quinoline, (Quinoline-to-H₂O₂ ratio 1:7) showed oxidation selectivity as quinoline-N-oxide (100%) was recorded as the oxidation product. Quinoline-N-oxide was confirmed as the oxidation product through GC–MS. Density functional theory (DFT) revealed hydroxylperoxido-species [VOO(sal-HBPD)] (II) as the reactive oxidized oxidovanadium specie responsible for the oxidation. Ionic liquids, 1-butyl-3-methylimidazolium chloride and 1-butyl-3-methylimidazolium nitrate extracted 96% and 87% quinoline-N-oxide respectively.     

Changes in evaporative emissions from gasoline in the Nigeria market

The evaporative emissions from multicomponent fuel are expected to change significantly with the progress of evaporation. This study presents the findings of air emission associated with changes (increase) in evaporation process of gasoline. The parameters measured in the experiment included the weight loss, density, viscosity of gasoline, and the evaporation rate. Results showed that the parameters changed significantly as evaporation progressed. The weight loss was from 3.02% to 5.45% after 30 m and presented a logarithmic curve with time. The density measurements of the gasoline samples were 728.5–746.7 kg/m³. The evaporation rate which was 1.22 × 10^?5–2.14 × 10^?5 kg/s showed great increase with decrease in density and kinematic viscosity at ambient temperature with sample C (from Lagos) having the highest evaporation rate. The emission rate was observed to be inversely proportional to the sample density. Most of the changes might be attributed to the air emission of volatile hydrocarbons such as benzene, toluene, ethyl benzene, and xylene (BTEX) from gasoline surface to the environment.     

Kinetics of thermal degradation of a Japanese oil sand

Thermal degradation characteristics of a Japanese oil sand at different heating rates (10, 20, and 30 °C/min), and 30 ml/min air flow rate have been investigated. The kinetic parameters have been calculated based on three stages of weight loss and/or the conversion of the sample. These include, stage 1 (SI): volatilization of moisture content and the light hydrocarbon (20–227 °C), stage 2 (SII): combustion of heavy hydrocarbon (227–527 °C), and stage 3 (SIII): oxidative decomposition of carbonaceous organic matter (502–877 °C). The results showed that the rate of change of the oil sand conversion with time $\left(\frac{d\alpha }{\mathit{dt}}\right)$ was affected by the heating rate. The time taken by the system to reach 0.99 conversion was observed as 85, 50, and 35 min at the heating rates of 10, 20, and 30 °C/min, respectively. The frequency factor, A, at SI was between 0.09 and 0.54 min^?1, while the activation energy, E_a, was 11.2–12.5 KJmol^?1 (the percentage weight loss, W_t, was 0–3.6 %w/w; and the conversion, α, was 0–0.2.). At SII, the values of A and E_a were 2.1–5.5 min^?1 and 17.6–19 KJmol^?1, respectively (W_t = 3.1–15.88 %w/w; α = 0.17–0.86.). The value of A at SIII was 5.5E11–1.1E13 min^?1, while E_a was 160–200 KJmol^?1 (W_t = 15.33–17.99 %w/w; and α = 0.84–0.99).     

Ethiopian sign language recognition using deep convolutional neural network

Multimedia Tools and Applications - In recent years, several technologies have been utilized to bridge the communication gap between persons who have hearing or speaking impairments and those who...     

The capital budgeting evaluation practices (2014) of contractors in the Hong Kong construction industry

Capital budget evaluation plays a crucial role in financial management. This places a firm in a competitive position. Recent development points to the need for implementing capital budgeting in construction organizations due to the capital-intensive nature of construction business. The aim here is to investigate the trends in the practice of capital budget evaluation among construction contractors operating in Hong Kong over a 20-year period. A longitudinal survey approach is used; four cross-sectional surveys were conducted between 1994 and 2014. The findings indicate that ‘formal financial evaluation’ is the most common technique used for capital budget evaluation. In addition, the practice of capital budget evaluation is more pronounced in the large-sized firms. A comparative analysis of the results of the four surveys reveals that there are variations in the degree and frequency of use of capital budget evaluation techniques over the study period. Further research is needed to understand the challenges associated with the use of sophisticated capital budget evaluation techniques in the construction industry of Hong Kong.