Some aspects of stabilization and degradation of nigerian natural rubber (II): The environmental degradation of DBHBT-modified unprocessed,unvulcanized nigerian natural rubber

3,5-Di-tert-butyl-4-hydroxybenzyl thioglycollate (DBHBT) was bound to the natural rubber (Hevea Brasilenisis) latex using 4,4'-azobiscyanovaleric (AZBN) acid-ferrous sulfate redox system. The degradation of various dilutions of the master batch as cast films under environmental influence has been investigated using spectroscopic method. Latex-bound DBHBT protects natural rubber latex against environmental degradation with an optimum concentration around 50%. The formation of C?0 groups by some pathways independent of ? OH groups and allylic hydrogen atoms has been suggested in the natural weathering of DBHBT-modified and unprocessed natural rubber.     

Physicochemical Properties of Caribbean Sweet Potato (Ipomoea batatas (L) Lam) Starches

The proximate compositions and physicochemical properties of 21 Caribbean sweet potato (Ipomoea batatas (L) Lam) starches were investigated. Proximate composition, amylose, reducing and non-reducing sugars were determined using standard methods. Swelling power and solubility were evaluated and pasting properties of the starches were determined using Rapid Visco Analyzer. Moisture (8.0–12.4%), protein (0.0–0.2%), ash (0.1–0.5%), and reducing (0.3–2.3%) and non-reducing sugar (0.1–0.2%) contents of starches were significantly different (P < 0.05) among the cultivars. Amylose content varied significantly between 12.8–21.3%. Swelling power and solubility ranged between 7.8–31.1% and 1.5–9.6%, respectively. Pasting properties such as peak viscosity measured in Rapid Visco Units (143.2–288.8 RVU), breakdown viscosity (29.4–162.6 RVU), and setback viscosity (15.0–78.8 RVU), pasting temperature (73.5–87.7 °C) and time to pasting temperature (3.6–4.5 min) varied significantly among the cultivars. Breakdown viscosity was poorly correlated with final viscosity attained (r = − 0.0507, P < 0.05); however, pasting temperature was correlated (r = 0.479, P < 0.05) with setback viscosity. The variability observed in the physicochemical properties of the starches was related to specific requirements for use in the production of noodles, pasta, and inclusion in bread and weaning food formulations.     

3200m^3／h真空变压吸附富氧装置的运用

通过介绍贵阳特殊钢有限公司新建成的3200m^3/h真空变压吸附装置的基本原理，工艺流程以及设备在炼钢上的应用，比较了吸附法相对深冷法的优越性。     

A review on conversion of triglycerides to on‐specification diesel fuels without additional inputs

Dependence on fossil fuels for global energy supply has continued to generate concerns about climate change and sustainable development. It has motivated the search for carbon‐neutral alternative resources for the production of transportation fuels to replace crude oil. Although biodiesels have recently emerged as a close substitute to petrol diesel, their use in compression ignition engines designed to run on petro‐diesel fuels are linked to adverse effects on the engines' performance and life span. This informed efforts at upgrading biodiesel or direct conversion of triglycerides to hydrocarbon mixtures that are identical or similar to that of petro‐diesel through hydrodeoxygenation. Moreover, it seems that commercial methods for the conversion of triglycerides to diesel fuels depends on inputs (methanol and hydrogen) derived from fossil fuels. However, it will be desirable to do so without inputs from fossil fuels. Hence, reaction paths for direct conversion of triglycerides to on‐specification hydrocarbons fuels without hydrogen gas input are discussed and suggested strategies are in cognisance of green chemistry principles. Copyright © 2012 John Wiley & Sons, Ltd.     

Design for comfort in Nigeria — a bioclimatic approach

Most of the previous analyses of climate of Nigeria have been for agricultural use or weather prediction purposes. They have little or no application for building design. This paper examines and analyses the climate of Nigeria with respect to building design parameters — temperature, relative humidity, air velocity and solar radiation, with a view to providing design recommendations for the achievement of physiological comfort. It accesses the current methods of climatic analysis with respect to building design. It then develops bioclimatic charts for various cities for the country using a combination of a general atmospheric circulation model approach and control potential techniques. Finally, design recommendations are then suggested for typical cities in the country.     

Centimeter and millimeter wave attenuation by atmospheric gases and rainfall at a tropical station

The radiowave attenuation due to oxygen and water vapour has been computed over the frequency range 3–350 GHz making use of the mean surface air pressure, temperature and water vapour at Ile-Ife (geog. lat 7.5°N, long 4.5°E) in Southern Nigeria. It is observed that the attenuation at this tropical location is generally higher than at temperate climates. A similar analysis was performed for rainfall attenuation using rainfall intensity measurements. The results obtained with three different expressions for the rain height showed that a rain height of 3 km is a reasonable assumption for estimating earth-space rainfall attenuation at this location. It is found that for frequencies above 200 GHz, the polarization dependence of the specific attenuation due to rainfal becomes negligible. The computed attenuation is lower that that predicted using the corresponding CCIR rain climate data. The results show that whilst the contribution of oxygen and water vapour to the total atmospheric attenuation could be neglected when compared with rainfall attenuation up to about 150 GHz, the contribution becomes significant for frequencies above 190 GHz.     

Expectation-based 3D edge bundling

Multimedia Tools and Applications - In the visualization of the node-link graph, it is common to use edge-bundling algorithms to reduce the visual clutter caused by the increase in nodes and...