Study on photocatalysis of TiO 2 nanotubes prepared by methanol-thermal synthesis at low temperature

TiO₂ nanotubes were synthesized by the solvothermal process at low temperature in a highly alkaline water–methanol mixed solution. Their characteristics were identified by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), specific surface area (BET), Fourier transform infrared spectroscopy (FTIR) and UV–Vis absorption spectroscopy. The as-prepared samples were tested by the photodegradation reaction of methylene blue (MB) dye under visible-light irradiation. The ratios of methanol and water, as well as calcination temperature, affected the morphology, nanostructure and photocatalytic performance. The methanol solvent plays an important role in improving crystallization of the anatase phase, which affects the photocatalytic reaction. Titanate nanotubes were synthesized in methanol–water volume ratios of 10:90, 20:80 and 30:70 which still had high absorbability. Titania nanotubes formed at a calcination temperature of 300 °C using methanol–water volume ratio of 30:70 showed highest photocatalytic performance, much higher than that using water solvent and TiO₂–P25 powder.     

Water Aid and the Third World - a Partnership in Low-cost Technology

W ateraid , a registered charity, is working with local partners in Africa and Asia on small-scale primary water supply projects, basic sanitation and hygiene education, for poor Third-World communities. Programmes are aimed at lasting development, not disaster relief. Low-cost technologies are used, preferably including proven local techniques. This, combined with training local staff, increases the probability of replication occurring through WaterAid's local operational partners.
Methods employed fully involve the benefiting community; their participation is of course essential if they are to run and maintain their new supply successfully.
Finally it is expected that poor communities achieving their own protected water supply will gain confidence to tackle other development needs.     

CONSUMPTION OF RISKY FOODS AMONG ADULTS AT HIGH RISK FOR SEVERE FOODBORNE DISEASES: ROOM FOR IMPROVED TARGETED PREVENTION MESSAGES

Foodborne disease is of particular concern in populations at risk for severe consequences, including the elderly and persons with immune‐compromising conditions. Using data from the Foodborne Diseases Active Surveillance Network (FoodNet) Population Survey, we examined the association of risky food consumption with gender, age, immune status, income and education. Gender, age and immune status were associated with consumption of risky foods. More males than females ate at least one risky food while persons aged ≥65 years were less likely than those 18–44 to eat risky foods. In the 18–44 group, those with immunosuppressive conditions were more likely to eat risky foods (P < 0.001). In the ≥65 group, those taking immunosuppressive drugs were more likely than healthy persons to eat risky foods (P < 0.001). Our findings suggest that young adults with immune‐compromising conditions and elderly persons who take immunosuppressive drugs report eating more risky foods than their healthy counterparts.     

CALCULATION OF SHALLOW SHELL SUBJECT TO INFLUENCE OF LOAD LOCAL EFFECT BY THE DIFFERENCE TECHNIQUE ON IRREGULAR NETWORKS

In this paper, a methodology for the calculation of shallow shell with positive Gauss radius, and boundaries supported on the rectangular plane subject to influence of uniform load and concentrated forces has been considered. In order to solve differential equations (written in the form that assumes deflections as unknowns) of bending shallow shell theory, the author has used the finite difference technique on irregular networks. A detailed algorithm has been formulated that enables to solve the problem by computer. By the above algorithm, the author has obtained numerical results in the form of internal forces and deflections diagrams. © 1997 by John Wiley & Sons, Ltd.     

木鳖果热泵低温干燥工艺研究

木鳖果是越南的一种常见高营养水果,近年来越南木鳖果产业发展迅速,但对其干燥研究较少,本文采用热泵低温干燥的方法,对木鳖果进行了干燥研究,确定木鳖果干燥的最佳工艺参数,并分析比较干燥对营养成分的影响。结果表明：风速不变,风温越高干燥物料所需时间越短,感官评定就越差,胡萝卜素损失越大;风温不变,风速越高干燥物料所需时间越短,感官评定越差,胡萝卜素损失越大;木鳖果热泵干燥最佳工艺参数为：风温：50 ℃;风速：10 m/s。     

Concentrated solutions of preservatives: their technological and analytical advantages in cosmetic products

Introducing concentrated solutions of preservatives (CSP) provides a methodology both for the use of preservative systems and for their routine control in cosmetic products.
From some typical examples, characteristics of such CSP are described and it is shown how the accurate determination of every component present in the initial liquid blend eliminates the tedious determinations in the finished product where only a single analysis of one preservative is necessary.
Quick and simple methods are described for the analysis of CSP containing parabens, Germall 115® and Kathon CG®. An appropriate new analytical approach is given for routine controls without any tedious extraction and /or costly equipment.
In addition it is shown how this methodology provides a number of substantial advantages at every step of development of new products, storage of raw materials and manufacturing, leading to increased safety and ensuring energy and time savings.
Les mélanges liquides concentrés de conservateurs: leur intérêt technologique et analytique dans les produits cosmétiques     

Water Quality Changes in a Septic Tank Effluent Discharged to the Chalk

B ucket-type samplers were installed in the unsaturated zone to intercept septic tank effluent descending through the Chalf at Snowdown, Kent. Better than 90 per cent removal of BOD and COD, and of the order of 99 per cent removal of coiform bacteria, were observed after downward percolation through 2.1 m of Chalk. Nitrification of ammonia had begun at that depth, but not at intermediate depth. The results, though limited, suggest that septic tank effluent is purified in the Chalk in a similar way to settled sewage.