admission. This proportion could already be greater in some parts of the country and may increase if referrals of cases of self-poisoning increase faster than the facilities for their assessment and management. The provision of social work and psychiatric expertise in casualty departments may be one means of preventing unnecessary medical admissions without risk to the patients. Dr Blake's and Dr Bramble's figures do not demonstrate, however, that any advantage would attach to medical teams taking over assessment from psychiatrists except that, by implication, assessments would be completed sooner by staff working on the ward full time. What the figures actually suggest is that if assessment of overdoses were left to house doctors there would be an increase in admissions to psychiatric units (by 19°U), outpatients (by 5O°'), and referrals to social services (by 140o). So for house doctors to assess overdoses would provide no economy for the psychiatric or social services. The study does not tell us what the consequences would have been for the six patients who the psychiatrists would have admitted but to whom the house doctors would have offered outpatient appointments. E J SALTER

Vitamin D deficiency.

Impatti, adattamento e vulnerabilita Le cause e le responsabilita dei cambiamenti climatici sono state trattate sul numero di ottobre della rivista Cda. Approfondiamo l’argomento presentando il documento: “Cambiamenti climatici 2007: impatti, adattamento e vulnerabilita” votato ad aprile 2007 dal secondo gruppo di lavoro del Comitato Intergovernativo sui Cambiamenti Climatici (Intergovernmental Panel on Climate Change). Si tratta del secondo di tre documenti che compongono il quarto rapporto sui cambiamenti climatici.

/pdf/climate-change-2007-impacts-adaptation-and-vulnerability-31xc1cf4d3.pdf

Climate Change 2007: Impacts, Adaptation and Vulnerability.

Renewable technologies are considered as clean sources of energy and optimal use of these resources minimize environmental impacts, produce minimum secondary wastes and are sustainable based on current and future economic and social societal needs. Sun is the source of all energies. The primary forms of solar energy are heat and light. Sunlight and heat are transformed and absorbed by the environment in a multitude of ways. Some of these transformations result in renewable energy flows such as biomass and wind energy. Renewable energy technologies provide an excellent opportunity for mitigation of greenhouse gas emission and reducing global warming through substituting conventional energy sources. In this article a review has been done on scope of CO2 mitigation through solar cooker, water heater, dryer, biofuel, improved cookstoves and by hydrogen.

https://www.beren.sakarya.edu.tr/sites/beren.sakarya.edu.tr/file/1380752545-07-RenewEn.pdf.pdf

Role of renewable energy sources in environmental protection: A review

The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

Ultracapacitors: Why, How, and Where is the Technology

Artificial neural networks (ANNs) constitute a class of flexible nonlinear models designed to mimic biological neural systems. In this entry, we introduce ANN using familiar econometric terminology and provide an overview of ANN modeling approach and its implementation methods. † Correspondence: Chung-Ming Kuan, Institute of Economics, Academia Sinica, 128 Academia Road, Sec. 2, Taipei 115, Taiwan; ckuan@econ.sinica.edu.tw. †† I would like to express my sincere gratitude to the editor, Professor Steven Durlauf, for his patience and constructive comments on early drafts of this entry. I also thank Shih-Hsun Hsu and Yu-Lieh Huang for very helpful suggestions. The remaining errors are all mine.

Artificial neural networks

Knowledge of heat transfer during melting and freezing in enclosures is important in the design of heat exchangers using phase change materials (PCMs) for thermal energy storage. While freezing heat transfer is governed mainly by conduction, melting of a PCM generally invokes free convective currents in the melt phase depending on the orientation and geometry of the heat transfer surfaces. In this paper, a finite element simulation is carried out to predict the flow and temperature fields as well as the rate of heat storage during melting of a PCM in a horizontal cylindrical annulus heated from an isothermal inside surface. A novel yet simple method is suggested and validated numerically to enhance the heat storage rate in a PCM. The technique involves simply “flipping” the horizontal cylinder, i.e., turning it through 180° about its own axis, at an optimum time during the melting process. It is found that up to 18% enhancement in the energy storage rate can be achieved with this simple technique.

Passive Enhancement Technique for Free Convection-Dominated Melting of Phase Change Material in Horizontal Cylindrical Annulus

This chapter considers water the liquid to be removed by thermal means using air as the drying medium. Similar calculation procedures are also applicable to other liquids and gases, which are insoluble and non-reacting with these liquids. Most temperature-dependent sorption isotherm equations used for calculation of the heat of sorption give discontinuity at critical moisture content. In batch drying, conditions inside the dryer vary both in space and in time, which makes the calculations more complicated than in the case of continuous drying. The basic parameters that need to be calculated are material holdup in the dryer and material residence time necessary to complete the specified drying duty. Psychrometric charts, most commonly used to determine air humidity on the basis of wet and dry bulb temperatures, are prepared in orthogonal coordinates with temperature as the abscissa and humidity as the ordinate.

Basic Process Calculations in Drying

Radio-Frequency Drying with 50 Omega Technology

Fresh food are consumed in large quantities worldwide. During the supply chain, microbial growth in fresh food can lead to the production of a number of metabolites, which make food highly susceptible to spoilage and contamination. The quality of fresh food changes in terms of smell, tenderness, color and texture, which causes a decrease in freshness and consumers acceptance. Therefore, the quality monitoring of fresh food has become an essential part in the supply chain. As traditional analysis methods are highly specialized, expensive and have a small scope of application, which cannot be applied to the supply chain to realize real-time monitoring. Recently, sensing materials have received a lot of attention from researchers due to the low price, high sensitivity and high speed. However, the progress of research on sensing materials has not been critically evaluated. The study examines the progress of research in the application of sensing materials for fresh food quality monitoring. Meanwhile, indicator compounds for spoilage of fresh food are analyzed. Moreover, some suggestions for future research directions are given.

Arun S. Mujumdar

Papers

Passive Enhancement Technique for Free Convection-Dominated Melting of Phase Change Material in Horizontal Cylindrical Annulus

Basic Process Calculations in Drying

Radio-Frequency Drying with 50 Omega Technology

Sensing materials for fresh food quality deterioration measurement: a review of research progress and application in supply chain.

Research on the Vegetable Shrinkage During Drying and Characterization and Control Based on LF-NMR