Within the last two decades, the experimental technology for the study of high temperature solid-vapor and liquid-vapor equilibria has mushroomed so fast that. both academic and industrial research ers desirous of working in this field -- be they physical chemists, metallurgists, ceramists, petrologists, crystal chemists, or mem bers of any of the several branches of materials science -- find themselves in the situation that in order to learn the art of the latest techniques, a period of apprenticeship or residency needs be spent at an institution or laboratory currently engaged in this type of solid-vapor or liquid-vapor research. The tech niques for control of the vapor phase at total pressures of one atmosphere or greater have not been well defined in the literature. Therefore, the purpose of this volume will be to serve as a labora tory manual for the control, calibration, and measurement of high temperature-high pressure equilibria. The avowed aims of this treatment of experimental techniques are: (1) to give, in terms understandable at the graduate student level, the laboratory procedures necessary to the design and utilization of good experimental technique, (2) to list the limitations, dangers, and technical pitfalls inherent or intrinsic to the described techniques, (3) to give theory and specific data only where they are essential to the experimental design, (4) to give with each chapter references that are extensive enough to serve as a bibliography of the state-of-the-art of technique development within the last decade."

This volume offers an introduction into the technology programs and international projects of reusable orbital transport systems. Besides the technological requirements, meteorological and air chemical aspects in regard to the environmental compatibility of future transport systems are the most important topics. The aim of the symposium was to investigate the classical disciplines and methods of aeronautics and astro- nautics in connection with meteorological and air chemical methods and models. For this purpose an attempt was made to identify technological optimization parameters in respect to the air chemical environmental compatibility of future orbital transport systems.

The subject of this volume is the observation and modelling of the gravity wave field in the atmosphere. The focus is on the question of how to include the effects of small-scale gravity waves in sophisticated global climate models.
The book comprises 26 chapters, including contributions from distinguished experts in observation and theory, along with results from studies of gravity wave parameterization within comprehensive climate models.

Ayla Neusel The idea of holding an International Women's University ifu as part of the EXPO 2000'W orld Exposition was born in Lower Saxony in the mid-1990s. In 1992, Lower Saxony's then Minister of Science Helga Schuchardt had set up a Women's Research Commission that in 1994 presented its report with the programmatic title "Promoting Women's Interests Means Academic Reform - Women's Research Means a Critique of Science". A spin-off, so to speak, of this commission's was nd the idea of a women's university as an EXPO project. The 2 Lower Saxony Women's Research Commission (1995-1997) stated: "From 15 July until 15 Oc- tober, an International Women's University is to be Q~ganised offering an interdis- ciplinary, international, multimedia, postgraduate study programme". Initially conceived as a purely research-oriented university, ijiJ evolved into an academic project for women scientists on an international scale. The ifu concept was based on the (self-) image of science as an ongoing, evolving, forward- looking research project. The unique concept of the International Women's University as an academic reform project was founded on three key principles: 1. Problem Orientation of Teaching and Research The choice of the globally relevant controversial issues Work - Information - Body - Migration - City - Water and the idea of addressing these issues from the perspective of the natural and engineering sciences, the humanities and so- cial sciences as well as art, consciously focusing on questions of practical rele- vance, gave rise to a problem-oriented, interdisciplinary approach.

In this, the only book available to combine both theoretical and practical aspects of x-ray diffraction, the authors emphasize a "hands on" approach through experiments and examples based on actual laboratory data. Part I presents the basics of x-ray diffraction and explains its use in obtaining structural and chemical information. In Part II, eight experimental modules enable the students to gain an appreciation for what information can be obtained by x-ray diffraction and how to interpret it. Examples from all classes of materials -- metals, ceramics, semiconductors, and polymers -- are included. Diffraction patterns and Bragg angles are provided for students without diffractometers. 192 illustrations.

This book was written with the objective of providing geotechnical engineers with a practical guideline on how to cope with landslides as well as of acquaint ing them with the present state of physical fundamentals and scientific expla nations for the phenomenon of landslides. The book is based on my personal experiences, gathered over decades of work as geotechnical engineer on construction sites in Austria and many other parts of the world, which I also use in my lectures at the Technical University of Graz, Austria. The method of stabilizing lands lides by short-circuit conductors has been developed by myself and has been patented in Germany and Italy. A number of publications already exists (see References) on this method, and of course I also deal in this book with its theoretical and practical aspects. Here I want to thank my assistants, Messrs. J. Dalmatiner, K. Eigenberger, E. Garber, H. Kienberger, R. Potscher, and W. Prodinger, for working with me on various projects and for assisting me in the drafting of some chapters of this book, Mr. A. Trippl for preparing the illustrations, and my wife for many a Sunday worked through with me."

This book describes and analyses various aspects of Israeli climate. This work also elucidates how both man and nature adjust to various climates. The first part (Chapters 1-9) deals with the meteorological and climatological network stations, the history of climate research in Israel, analysis of the local climate by season, and a discussion of the climate variables their spatial and temporal distribution. The second part (Chapters 10-14) of this work is devoted to a survey of applied climatology. This part presents information on weather forecasting, rainfall enhancement, air quality monitoring, and various climatological aspects of planning. There is no sharp division between theoretical and applied climatology topics. Moreover, though various sections seem exclusively theoretical, they also include important applications for various real life situations (such as rainfall intensities (Section 5. 3), frost, frost damage (Section 6. 2. 4), degree-days (Section 6. 2. 5) and heat stress (Section 6. 2. 6). Professionals and university students of geography and earth science, meteorology and climatology, even high school students majoring in geography will be able to use this book as a basic reference work. Researchers in atmospheric science can also use this work as an important source of reference. Students of agriculture will also gain theoretical and practical insights. Even architects and engineers will gain another perspective in their fields.

One of our most important objectives as hu have provided basic principles from scientific mans is to discover and pass on ways of living journals and books and summarized the expe with our environment. Every form of life, in riences of people actually living in earth shel cluding human, depends on nature's ability to ters. produce clean air, pure water and fertile soil In the growth and development of any field and to recycle wastes. It is our duty to live in a of knowledge, there comes a time when theory manner that enhances and preserves these nat requires testing, when concepts need to be re ural processes. Earth sheltering-the use of fined in the light of experience. Such is the case earth cover to moderate and improve living with earth sheltering. A good foundation of conditions in buildings-is an old but recently principles has been laid, mostly through the ex rediscovered technique. It holds much promise cellent efforts of such organizations as the Un for allowing us to use less energy and preserve derground Space Center of the University of more space for natural and human needs. It also Minnesota, the School of Architecture at Okla gives the individual and society alike a real way homa State University, and the many design to achieve self-reliance and independence from professionals active in earth sheltering. These limited sources of fossil fuels."

This book presents basic information on material science (geochemistry, geophysics, geology, mineralogy, etc.), interaction between subsystem consisting earth system (atmosphere, hydrosphere, litho (geo) sphere, biosphere, humans) and in earth-planet system and evolution of earth-planetary system. The nature-humans interactions are described and new view on earth, planets and humans (integration of anthropocentrism and naturecentrism) are presented.

The idea for the present Spilite Volume was born during the Spilite Symposium at the XXIIIrd session of the International Geological Con- gress in Prague, 1968. At that time, only a restricted number of petro- logists working on spilites was present and, therefore, the group assem- bled agreed that a Symposium Volume should also include recent papers by many other spilite specialists. At the same time it was agreed that the papers presented at the Symposium should be returned to the authors for changes and additions. This procedure of upgrading and amending the papers has continued until this year (1973) for various technical and editorial reasons. The information presented here is, therefore, up-to- date. To those familiar with the spilite problem it is obvious that the time had come for a review of its state. Also, the existing litera- ture had become so voluminous that a monographic review was necessary. Following a modern trend, the authorship for this review was spread among specialists with variable experience. For readers not necessarily familiar with the spilite problem, a brief summary is presented here. A short historical note is followed first by the observations, then by the interpretations, finally by some of the major features of scientific logic as they pertain to the problem of the primary or secondary origin of some of the rocks termed spilites and keratophyres.

Mixture concepts are nowadays used in a great number of subjects of the - ological, chemical, engineering, natural and physical sciences (to name these alphabetically) and the theory of mixtures has attained in all these dis- plines a high level of expertise and specialisation. The digression in their development has on occasion led to di?erences in the denotation of special formulations as 'multi-phase systems' or 'non-classical mixtures', 'structured mixtures', etc., and their representatives or defenders often emphasise the di?erences of these rather than their common properties. Thismonographisanattempttoviewtheoreticalformulationsofprocesses which take place as interactions among various substances that are spatially intermixedandcanbeviewedtocontinuously?llthespacewhichtheyoccupy as mixtures. Moreover, we shall assume that the processes can be regarded to becharacterisedbyvariableswhichobeyacertaindegreeofcontinuityintheir evolution, so that the relevant processes can be described mathematically by balance laws, in global or local form, eventually leading to di?erential and/or integralequations, towhichtheusualtechniquesoftheoreticalandnumerical analysis can be applied. Mixtures are generally called non-classical, if, apart from the physical laws (e. g. balances of mass, momenta, energy and entropy), also further laws are postulated, whicharelessfundamental, butmaydescribesomefeaturesofthe micro-structure on the macroscopic level. In a mixture of ?uids and solids - thesearesometimescalledparticleladensystems-thefractionofthevolume that is occupied by each constituent is a signi?cant characterisation of the micro-structure that exerts some in?uence on the macro-level at which the equations governing the processes are formulated. For solid-?uid mixtures at high solids fraction where particle contact is essential, friction between the particles gives rise to internal stresses, which turn out to be best described by an internal symmetric tensor valued variable.

Reflecting the historic first European seismic code, this professional book focuses on seismic design, assessment and retrofitting of concrete buildings, with thorough reference to, and application of, EN-Eurocode 8. Following the publication of EN-Eurocode 8 in 2004-05, 30 countries are now introducing this European standard for seismic design, for application in parallel with existing national standards (till March 2010) and exclusively after that. Eurocode 8 is also expected to influence standards in countries outside Europe, or at the least, to be applied there for important facilities. Owing to the increasing awareness of the threat posed by existing buildings substandard and deficient buildings and the lack of national or international standards for assessment and retrofitting, its impact in that field is expected to be major.

Written by the lead person in the development of the EN-Eurocode 8, the present handbook explains the principles and rationale of seismic design according to modern codes and provides thorough guidance for the conceptual seismic design of concrete buildings and their foundations. It examines the experimental behaviour of concrete members under cyclic loading and modelling for design and analysis purposes; it develops the essentials of linear or nonlinear seismic analysis for the purposes of design, assessment and retrofitting (especially using Eurocode 8); and gives detailed guidance for modelling concrete buildings at the member and at the system level. Moreover, readers gain access to overviews of provisions of Eurocode 8, plus an understanding for them on the basis of the simple models of the element behaviour presented in the book.

Also examined are the modern trends in performance- and displacement-based seismic assessment of existing buildings, comparing the relevant provisions of Eurocode 8 with those of new US prestandards, and details of the most common and popular seismic retrofitting techniques for concrete buildings and guidance for retrofitting strategies at the system level. Comprehensive walk-through examples of detailed design elucidate the application of Eurocode 8 to common situations in practical design. Examples and case studies of seismic assessment and retrofitting of a few real buildings are also presented.

From the reviews
"This is a massive book that has no equal in the published literature, as far as the reviewer knows. It is dense and comprehensive and leaves nothing to chance. It is certainly taxing on the reader and the potential user, but without it, use of Eurocode 8 will be that much more difficult. In short, this is a must-read book for researchers and practitioners in Europe, and of use to readers outside of Europe too. This book will remain an indispensable backup to Eurocode 8 and its existing Designers Guide to EN 1998-1 and EN 1998-5 (published in 2005), for many years to come. Congratulations to the author for a very well planned scope and contents, and for a flawless execution of the plan." AMR S. ELNASHAI

"The book is an impressive source of information to understand the response of reinforced concrete buildings under seismic loads with the ultimate goal of presenting and explaining the state of the art of seismic design. Underlying the contents of the book is the in-depth knowledge of the author in this field and in particular his extremely important contribution to the development of the European Design Standard EN 1998 - Eurocode 8: Design of structures for earthquake resistance. However, although Eurocode 8 is at the core of the book, many comparisons are made to other design practices, namely from the US and from Japan, thus enriching the contents and interest of the book." EDUARDO C. CARVALHO"

The field of Luminescence Dating has reached a level of maturity. Both research and applications from all fields of archaeological science, from archaeological materials to anthropology and geoarchaeology, now routinely employ luminescence dating. The advent of optically stimulated luminescence (OSL) techniques and the potential for exploring a spectrum of grain aliquots enhanced the applicability, accuracy and the precision of luminescence dating. The present contribution reviews the physical basis, mechanisms and methodological aspects of luminescence dating; discusses advances in instrumentations and facilities, improvements in analytical procedures, and statistical treatment of data along with some examples of applications across continents, covering all periods (Middle Palaeolithic to Medieval) and both Old and New World archaeology. They also include interdisciplinary applications that contribute to palaeo-landscape reconstruction.

The development of an effective method of drilling oil and gas wells to depths of 3-5 km and more is a complex problem of great practical interest. "Deep Hole Drilling With Explosives" is a distinctive and very interesting work of the engineer A. P. Ostrovskii, who more than twenty years ago, by his original suggestions, made a start in investigating the field of so-called non-bit processes of shattering rocks when drilling holes, a.nd, with his co-workers, developed a fundamentally new explosive method of drilling deep holes. This book discusses the new trend in worldwide a.pplication of explosives in technology and the national economy; it presents considerable experimental material on the effect of explosions in solid media, material that is not only interesting to specialists in mining but also to physicists. Many phenomena discussed by the author and cited in the book still await explanation, but the fact that these phenomena have been already subjected to experimental study undoubtedly adds to our knowledge of one of the most meagerly investigated areas of the science of explosions-concerning the shattering effect of explo sions on solid media. July 29, 1960 Professor M. A. Sadovskii Corresponding Member of the Academy of Sciences of the USSR 1 INTRODUCTION Together with the perfection of turbine drilling and the introduction of electrical drills in the USSR, new methods have been developed for shattering rock and drilling deep oil and gas wells without the use of a bit."

Ten years have passed since the last symposium on "Rock Deformation" was held in Los Angeles. The intervening period has seen striking advances in X-ray and experimental structural petrology. The Symposium of the Working Group on X-Ray and Experimental Structural Petrology, held at the invitation of the Deutsche Forschungsgemeinschaft on 17 and 18 February, 1969, in the Mineralogy Institute of the Technische Hochschule Darmstadt, was intended to display the progress made in this field. A meeting on the same had been held in 1968 at the Mineralogy Institute of the Technische Hochschule Aachen. The outcome of many years of effort has been the development of new, automated in- struments for the X-ray processing of specimens. The X-ray and optical data so obtained are processed by computer to give complete texture diagrams; it is also possible to rotate the coordinates, and to make an indirect determination of data which have not been measured. In experimental structural petrology, the temperature and pressure dependence of the translational system has been studied in minerals from various types of rock formation which had not previously been investigated, and deductions were made concerning certain mineral parageneses. The original contributions on field findings were conceived and executed so as to point up the possible links with experimental work on structural petrology. They determine for a given mineral facies the pressure and temperature ranges to be applied in experimen- tal studies of deformation in single crystals and in rocks.

La obra titulada: "ni creacion ni evolucion" es un tratado sobre la "decodificacion del origen del hombre en la tierra." Mas que un simple libro es una tesis o teoria basada en un analisis logico, minuciosamente elaborado con el fin de demostrar el origen del hombre, de las razas y del tiempo. Se trata de una teoria seria y responsable fundamentada en conceptos y postulados que podrian esclarecer verdades que la humanidad desconoce y ha desconocido por miles de anos las cuales se han mantenido bajo un velo de misterio. Tratamos ademas sobre el reordenamiento del tiempo como elemento basico en la definicion del origen del hombre y de la historia. Es un tratado en el que el ser humano ha de descubrir su verdadera identidad como ser universal descendiente de extra-inteligencias desde antes de su aparicion en la tierra sin que haya pasado por ningun tipo transformacion, experiencia o etapa evolutiva. Esta obra busca dar respuestas claras y precisas a confusiones e interrogantes que la humanidad ha arrastrado durante toda la historia. Los temas a tratar son: 1ro. La decodificacion del origen del hombre en la Biblia. 2do. El origen segun las ciencias. 3ro. Origen de las razas. 4to. Codificacion del tiempo. 5to. Decodificacion del origen despues de los dinosaurios. 6to. Codificacion del futuro.

There is no shortage of general books on the subject of acid rain, or of symposium proceedings reviewing work ranging from atmospheric chemistry and deposition processes to freshwater acidification and effects on vegetation. In contrast, the collection of papers from this Workshop is focussed on a much smaller subject, the processes of acid deposition at high altitude sites. Interest in deposition at high elevation sites comes largely from observed vertical gradients in the degree of forest damage at sites in the Federal Republic of Germany and the eastern United States. These gradients show that damage to Norway spruce and fir increases with altitude at sites in Bavaria and the Black Forest, and that Red spruce are declining at high elevation sites in the Appalachian Mountains. With the large scale of scientific interest in forest decline, cany research groups, during the last five years, have been examining atmospheric chemistry, deposition processes, and effects on vegetation and soils at upland sites. In particular there have been many recent studies of cloud and precipitation chemistry, which show much larger concentrations of all ions in cloud water than in rain or snow. These studies have also shown that processes of wet and dry deposition and also the chemistry of the air at hill tops are modified strongly by orographic effects.

Time is a major factor in Quaternary science. Without a trustworthy chronometer any interpretation of changes in proxy data of stratigraphical origin is on weak ground. In fact, any attempt at a sound reconstruction of timing and rates of past climatic change as well as the response of the biosphere can only be achieved on the basis of a reliable chronology. Moreover, all correlations and comparisons through time on a continental or global scale depend heavily on the reliability of the time-scale used. Therefore the establishment of an absolute time-scale is a fundamental goal. In this contribution we refer to the term "absolute time-scale" as a time-scale consisting of ages determined on the basis of sidereal years. Traditional stratigraphical methods of absolute dating include the Swedish glacial varve chronology, already developed early in this century by De Geer (1912) and since then continuously improved (e.g. Stromberg 1985; Cato 1987). Unfortunately, however, a spatial correlation with other stratigraphies outside Fennoscandia is difficult.

CEOS was established under the auspices of the Economic Summit of Industrialized Nations in 1984 in response to a recommendation from a panel of experts in remote sensing within the Working Group on Growth, Technology and Employment (CEOS, 2009). The panel recognized the collective value of the world's Earth remote sensing capabilities and the advantages that would be gained by the coordination of civil Earth observing satellite missions. By cooperating in mission planning and the development of compatible data products, applications, services and policies, the national space programs would maximize the bene?ts of their individual inve- ments and be able to better address the environmental challenges of the entire international community. CEOS was to serve as the focal point for this inter- tional coordination and to provide the forum for the change of policy and technical information. The members of CEOS are governmental organizations that are international or national in nature and are responsible for a civil space-borne Earth observation program that is currently in operation or in an advanced stage of system devel- ment. CEOS also has established Associate Members that are similar governmental organizations with a civil space-segment activity in an early stage of system dev- opment or those with a signi?cant ground-segment activity that supports CEOS objectives. Associate Members may also be existing satellite coordination group and scienti?c or governmental bodies that are international in nature and have a signi?cant programmatic activity that likewise is aligned with the goals of CEOS.

The outflow of heat from the earth's interior, the terrestrial heat flow, and the temperature field at depth are determined by deep-seated tectonic processes. The knowledge of the re gional heat flow pattern is thus very important in geophysics and provides a useful tool for studying crustal and litho spheric structure and understanding the nature of their evo lution. In order to use the results of heat flow measurements for regional studies and/or to correlate the observed surface geothermal activity with other geophysical or geological fea tures, a map showing the surface distribution of heat flow is necessary. Since 1963, when the first comprehensive listing of all available heat flow data appeared (Lee, 1963), several at tempts have been made to up-date the list, to classify all the data and to interpret them with respect to tectonics, deep structure and to use them for constructing surface heat flow maps. The first listing was subsequently revised by Lee and Uyeda (1965); numerous new data which were published there after were included in successive catalogs compiled by Simmons and Horai (1968) and then again by Jessop et al. (1976). The map showing the surface heat flow pattern may also be of great value for practical purposes, in view of the recent world-wide search for applicable sources of geothermal energy."

Year by year the Earth sciences grow more diverse, with an inevitable increase in the degree to which rampant specialization isolates the practitioners of an ever larger number of subfields. An increasing emphasis on sophisticated mathematics, physics and chemistry as well as the use of advanced technology have set up barriers often impenetrable to the uninitiated. Ironically, the potential value of many specialities for other, often non-contiguous ones has also increased. What is at the present time quiet, unseen work in a remote corner of our discipline, may tomorrow enhance, even revitalize some entirely different area. The rising flood of research reports has drastically cut the time we have available for free reading. The enormous proliferation of journals expressly aimed at small, select audiences has raised the threshold of access to a large part of the literature so much that many of us are unable to cross it. This, most would agree, is not only unfortunate but downright dangerous, limiting by sheer bulk of paper or difficulty of compre hension, the flow of information across the Earth sciences because, after all it is just one earth that we all study, and cross fertilization is the key to progress. If one knows where to obtain much needed data or inspiration, no effort is too great. It is when we remain unaware of its existence (perhaps even in the office next door) that stagnation soon sets in.

This volume covers the interdisciplinary field of disaster mitigatition against earthquakes with special emphasis on prevention of total collapse of existing low rise buildings towards reduction of life losses and economical assets. Rehabilitation of thousands of low-rise buildings in many big cities located in earthquake prone areas, is practically impossible even though there are experimentally and analytically approved intervention techniques to protect these existing buildings. It is simply not possible to find a proper way and proper amount of financial support to do this job. It will be more realistic to change the target to be achieved in a relatively short time, especially if time shortage starts to become the most critical issue. The new target can be specified as the prevention of total collapse of low-rise low-cost existing buildings, at least to save as much lives and property as possible. Simple prescriptive techniques, which can be implemented by the building owners, should be prepared. The cost of the improvement techniques, all kinds of legal, economical and social issues for convincing people, and promotions such as tax exemptions should be discussed in detail. Writers of all chapters are leading researchers and engineers working in the field of structural and earthquake engineering. The book will start with an introduction chapter written by Prof. Helmut Krawinkler of Stanford University. In this chapter, past and present of studies towards seismically safe design and construction will be introduced, as well as potential future trends in structural and earthquake engineering. In other chapters, different subjects will be presented under three main titles, namely; determination of seismic risks, seismic safety assessment of existing buildings, and measures for prevention of total collapse.

GKSS SCHOOL OF ENVIRONMENTAL RESEARCH The National Research Laboratory GKSS (member of the Hermann von Helmholtz-Association of German Reserach Centres) located in Geesthacht, near Hamburg, is engaged in environmental research. The main interest of the research center focuses on regional climatology and climate dynamics, interdecadal variations in the state of the Baltic and North Sea and related estuaries, and the flow ofheavy metals, nutrients, and other materials in river catchments to the coastal zones. This research aims at-developing an under standing ofchanges in the environment, both as a result ofinternal (natural) dynamics and as a result of anthropogenic interference. In an effort to dis seminate the results of these research activities, as well as to initiate a broad discussion among senior scientists in the field, and younger colleagues from all areas of the globe, the Institutes of Hydrophysics and Atmospheric Physics at GKSS have instituted the GKSS School of Environmental Research. Appliedenvironmental research has always containedanelement ofaware ness ofthe societal implications and boundary conditions associated with en vironmental concerns. Consequently, the School of Environmental Research adheres to the philosophy that all discussion regarding environmental change should incorporate a social component. This necessity has been well acknowl edged and is apparent by the incorporation ofsocial scientists into the series of lectures. Senior scientists from Europe and North America were invited to give lectures to "students" from all parts of the globe."

by Julius S6lnes An Advanced Study Institute on engineering seismology and earthquake engineering was held in Izrrir, 'rurkey July 2-13, 1973 under the auspices of the Scientific Affairs Division of NATO. The Institute was organized by an organizing committee headed by the two scientific directors and with representation by the Turkish National Science Foundation, Turkish National Committee for Earthquake Engineering, the Middle East Technical University and the Aegean University. 93 scientists and engineers of 18 countries took part in the work of the Institute which comprised 10 working days with lectures, discussions and panel meetings. The main lecture topics of the Institute were covered in five main sections: 1. Generic causes of earthquakes. 2. Ground motion and foundation response. 3. Earthquake response of structures and design consi derations. 4. Codes and regulations; implementation. 5. Earthquake hazards and emergency planning. Upon completion of each section, general discussion and short presentations by several of the participants took place and summary statements were offered by the main lecturers. The atmosphere of the meetings was in- VI formal and cordial thus giving rise to many unorthodox and newly conceived ideas."

Among basic human needs, food is foremost. Finding sufficient, affordable food is still the major concern of one in every five persons on earth. Rice is the basic staple for more than half of the world - and will continue to be well into the future. For this reason, the Interna tional Rice Research Institute (IRRI) has set the goal of improving the well-being of present and future generations of rice farmers and consumers, particularly those with low incomes. As we look toward the 21st century, several important issues cloud food security. World population is growing by almost 100 million people per year, and it is not likely to plateau before the end of the next century. This means that food demand will at least double, and may quadruple. The technologies of the Green Revolution have provided an unprecedented leap in annual rice production, enough to feed 600 million more people, but have had unforeseen social and environmental costs. Loss of genetic diversity and misuse of pesti cides endanger the sustainability of the Green Revolution. Soil ero sion, rural to urban popUlation migration, and increased competition for land and water between urban and agricultural sectors further threaten the sustainability of rice production. Finally, human activi ties may be changing the global climate. Any change in global climate is a potential challenge to the food security offuture generations. The world cannot afford to be unprepared."