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

Liquid drying plays an important role in the drying field because more than one third of materials are in liquid form that need to be dried. We received a significant response to our Call for Papers for this special issue. More than 16 abstracts are obtained and after peer review, 11 papers were selected. These 11 papers focus on investigations of spouted bed drying, spray drying, fluidized bed drying, fluidized bed spray granulator, etc. In spray drying, some typical feeds are experimentally investigated. For example, some authors investigated optimal operating conditions for special products, such as the extracts of chicory roots and extracts of ginkgo biloba leaves. Some authors experimented with spray drying pure lactose solutions, as well as lactose–casein mixtures with casein and whey protein isolate. During the investigation of the relationship between the transition temperature and crystallinity in spray drying, the researchers found that the material with the lowest glasstransition temperature, ascorbic acid, is almost completely crystalline under virtually all spray-drying conditions, whereas the material with the highest glass-transition temperature, lactose, is partly amorphous and partly crystalline under different spray-drying conditions. The addition of casein to the spray-dried powders was found to delay the onset of crystallization of the powders when stored in humid conditions, such that crystallization occurred later and at higher moisture contents. In the issue, two types of fluidized bed dryers, i.e., vibro-fluidized bed dryer and spouted fluidized bed dryer, are investigated. These two types of FBD all used inert particles during drying. In the investigation of vibro-fluidized bed drying, they found that the effect of the dimensionless vibration numbers on the drying dynamics depended on the amplitude and frequency of vibration. The vibration with lower amplitude and higher frequency would provide the highest powder production. In spouted-bed drying of xanthan suspension, the authors found that materials retention in the bed might occur when the suspension was fed continuously. Because more users are concerned with the final product properties, such as morphology, particle size distribution, etc., one paper studied the morphology of spray-dried products by adding the additives into the feed. The authors found that spray-dried powders at higher outlet temperatures have higher percentages of hollow particles. The larger vacuole was mostly found in the larger sized powders. The addition of gelatine, decaglycerin monolaurate, or ethanol to D-limonene and gum arabic and maltodextrin solution allowed easy formation of vacuoles in the spray-dried particles. On the other hand, the agglomerated products can be obtained using a fluidized-bed spray granulation process using two methods; i.e., internal integration and supplying dust into the spray region. The authors found that the deep height of the bubbling fluidized bed significantly affected the agglomeration among the dusts and droplets from the spray. They suggested that the bed pressure drop and bed mass must be controlled during the process. The other important parameters are the fluidization velocity and air temperature. After we edited this special issue on liquid drying, we found that some very interesting and important topics were not covered; e.g., freeze drying, spray-freeze drying, supercritical fluid drying, etc. We hope that potential authors who are doing work on these topics can make contributions to Drying Technology in the future. Finally, we would like to thank all the authors who made their contributions to this special issue. The efforts of all the referees for this special issue are appreciated very much. Without their valuable time, it would not have been possible to produce such a collection. We hope all of you and other potential authors keep making your contributions to our journal.

Guest Editorial: Recent R&D in Liquid Drying

It has been a quarter of a century since I assumed the duties of Editor-in-Chief of this journal. Our editorial team has undergone several mutations over this period. The journal sprung up from now...

Editorial: Leadership in Drying R&D

It has been universally accepted that R&D is central to the growth and sustainability of national economies. Advanced economies have been devoting appreciable amounts of financial resources to industrial R&D effort. Of course, there are fluctuations in the funding levels depending on the state of the national and global economies. Statistics show that western economies cut down their R&D budgets during the recession of 2008–2009 to a much greater extent than the Asian counterparts did. So long as the fluctuations in funding levels are not excessive this may not cause discernible harm since the time scale of R&D is rather long. However, ‘‘stop-and-go’’ R&D does not lead to valuable outcomes since the induction periods for start-up of R&D projects are typically long as well. R&D intensity of a country is often expressed in terms of the fraction of GDP devoted to R&D by the public and private sectors combined. As I have pointed out in my mini-book entitled Perspectives on Innovation, Globalization and R&D, this simple number is only a nominal indicator of the ‘‘true indicator’’ since the real number should depend also on the efficiency and effectiveness of R&D, policies of public and private sectors and the cost of talent and material resources, which vary widely amongst nations. One can correct for the cost by accounting for the ‘‘purchasing power parity’’ but it still does not correct for shortage and quality of talent available for R&D. For example, studies show that the manpower cost for R&D in Europe is about 70% of the total R&D budget, while it is 40% in the USA and only about 30% in Asia (excluding Japan, which is more like the western developed economies). The result is that even high-end R&D is now being outsourced to India and China, amongst some other nations, to benefit from low costs and ready availability of trained manpower. As the globe becomes flatter and manpower costs rise in these countries over time, outsourcing may not be a sustainable solution. Development of local talent would be the way to go. In its extensive report on Global R&D Funding Forecast for 2010, Battelle (Cleveland, OH, USA) has provided an in-depth look at the global R&D scene. This, in my opinion is a ‘‘must read’’ for anyone anywhere who has anything to do with R&D from postgraduate students to policymakers at the highest levels. The full 15MB report can be freely downloaded online. I shall refer to only a few statistics from this report to make a few simple points. A particularly noteworthy example is that of a Chinese telecom company founded just two decades ago (Huawei), which is now the third largest manufacturer of mobile infrastructure equipment in the world. Low-cost manufacturing in China was essential for its initial growth, but the recent growth to world class standard is attributed to high level of R&D the company devotes to innovation 10% of its revenues, which is highly respectable even for the high-tech sector anywhere. Over half of its 60,000 employees are in R&D and R&D centres are globalized in locations like Bangalore, Moscow and Stockholm, aside from China. This powerful combination of financial resources and human resources has clearly resulted in a global powerhouse. There are many examples of R&D-driven growth around the world but this to me is a truly spectacular example. When one wants to move from the initial inevitable imitation phase to the innovation phase, R&D is the only option. As I have pointed out in my book, novelty and renovation are not innovation although often they do masquerade as such. R&D requires high-end talent and high-quality education in science and technology. Again, there is no better example than China’s in this respect as well. Chinese universities admitted about 5.5 million students in 2006 up from just 1 million in 1997. Of the 5 million students about 1 million are research students. Chinese academics contribute many more patents than their counterparts elsewhere, e.g., 16% of the total vs. just 1% for Japan, 4% for USA and 2% for South Korea. These large differences are readily explained in terms of the fact that all the top academic institutions in China are fully supported by the state. Basic research will get 15% of China’s R&D budget by 2020, which augurs well for innovation in the longer term. The Battelle report points out that a significant fraction of the foreign direct investment in China goes into establishment of R&D centers. Additionally, what is interesting to note is that China devotes a very significant level of support for academic research, especially for its top 34 universities. Since 1998 there has been a dramatic increase in the scientific output Drying Technology, 29: 255–256, 2011 Copyright # 2011 Taylor & Francis Group, LLC ISSN: 0737-3937 print=1532-2300 online DOI: 10.1080/07373937.2011.555292

R&D as a Growth Engine for National Economies

A summary is presented of a long teaching experiment to incorporate principles of process design in a chemical engineering science course. Students are assigned real world dryer design problems following a series of lectures clarifying the basic terminology, psychrometry and principles of drying. Selected references relevant to specific dryer design problems are also provided. The instructor and teaching assistants act as consultants to the design groups consisting of up to six students. This paper will refer to authors' recent experiences with this assignment using design of spouted bed dryers for grains as illustration.

Arun S. Mujumdar

Papers

Guest Editorial: Recent R&D in Liquid Drying

Editorial: Leadership in Drying R&D

R&D as a Growth Engine for National Economies

Dryer design project - a tool to teach drying and design to undergraduates

A Review of: “ELECTRO-OSMOSIS” By K.P. Tikhomolova Ellis Horwood, London, 1993