bluuebunny/crossref_metadata_2025 huggingface dataset:
Degrading Land: An Environmental History Perspective of the Cape Verde Islands
Authors: Lindskog Per A. , Delaite Benoit
Published: June 2007

This paper discusses changes in land and vegetation cover and natural resources of the Cape Verde Islands since their colonisation. This isolated group of islands in mid-Atlantic was first colonised by the Portuguese around 1460. The paper discusses both physical and human causes of land-cover changes, including changes in climate, land-use, land tenure, economic, political and social systems. The actual consequences of the first centuries of European colonisation of the Cape Verde Islands were very different from the idealised view of tropical islands as Gardens of Eden that was current in Europe during the early colonial period. The sources discussed in this paper provide evidence of catastrophic degradation of the land and vegetation of these islands: from a dry but 'well-wooded' savanna with 'great quantity of grass', and 'streamlets of water' at the time of colonisation to a near desert landscape today, especially at the lower altitudes. A major cause of this degradation, perhaps indirect but still decisive, may have been a political and economic system that permitted an appallingly shortsighted exploitation of the land. The major direct mechanism of this process was probably overexploitation of the vegetation-cover by people and their goats. Despite the evidence for human causes behind this ecological disaster, the possibility cannot be excluded that there has also been a change in climate purely due to physical causes. If, however, the first colonisers had been conscious of the fragility of the ecosystem they came to occupy, these islands could still have profited from the advantages of a dry savanna with trees and a continuous grass cover, as do the Bermudas, which have remained a 'terrestrial paradise' thanks to the protection of the cedar forests since their first settlement in 1622. The reason why the 'fortunate' islands of Cape Verde should be reafforested thus becomes evident. Human beings frequently have a good perception of the symptoms of environmental degradation, but they rarely perceive the causes of such changes. In particular, they do not see themselves as agents in relation to nature. Instead they attribute environmental degradation either to God, destiny, etc., or to more earthly powers, which results in resignation relative to environmental problems. Compared to the length of human life most environmental changes, e.g. land degradation and climatic changes, are slow processes, noticeable only over decades. This may explain why it is difficult for humans to comprehend the causal mechanisms behind such changes. It may be crucial to understand these human perceptual processes if the human causes of environmental degradation are to be countered.
Deforestation in the Owambo Region, North Namibia, Since the 1850s
Authors: Siiskonen Harri
Published: June 2007

Early European travellers were impressed by the trees and forests of the Owambo region, north Namibia. As they became better acquainted with the Owambo way of life, Europeans began to warn of deforestation in the region. This article explores environmental change and especially deforestation in the Owambo region since the 1850s. The paper discusses the crucial elements affecting deforestation in north Namibia: population growth and settlement patterns, land use practices, the structure of production, consumption patterns of wood, and valuations related to forests.
The Politics of Fire and Forest Regeneration in Colonial Bengal
Authors: Sivaramakrishnan K.
Published: June 2007

This paper contends that recent scholarly interest in systems of colonising knowledge, whether called 'scientific forestry' or 'development', has paid inadequate attention to the historical processes shaping such knowledge production in specific colonial locations. Taking a processual approach, the paper examines the conflicted constitution of scientific forestry in India through regionally varied experiences of forest management in Bengal sal ( Shorea robusta ) forests. The case of fire, and disputes surrounding its perceived role in forest regeneration across eastern India, is used to understand and demonstrate the complex mutually transformative linkages between social categories like nature, culture, history and power.
Legal Instruments for Sustainable Environmental Management inNepal
Authors: Oli Krishna Prasad
Published: June 2007

Recent and current environmental legislation in Nepal is described, and its relation to sustainable development analysed. Modern legislation often conflicts with traditional local patterns of land management. Examples of these traditional arrangements are given, and it is argued that to be successful in the long term, development programmes instigated by government and line agencies must take more account of established local practices.
From Resource Scarcity to Pollution Problem: The Production and Environmental Impact of a Swedish Alum Works, 1723-1877
Authors: Svidén John , Eklund Mats
Published: June 2007

Wood scarcity at Lovers Alum Works (LAW) restricted the amount of alum produced during a large part of the period of activity (1723-1810s). The increasing local scarcity of wood and the insufficient road network were the main reasons why LAW started to use alum-shale as fuel in the beginning of the nineteenth century. When the fossil energy source replaced wood the short term fluctuations in alum production between different years became much smaller and the production of alum in the region was able to expand. This has been interpreted as an example of how geospheric raw materials enabled the rapid production expansion during the early industrial revolution.Cadmium and sulphur emissions were estimated from element analysis of the shale and data on the use of shale and other raw-materials. During the shale fuel period (1810s-1877) the emissions of volatile substances such as cadmium and sulphur increased.Pollution and resource scarcities are two different forms of environmental impact which tend to have different effects at different times in regard to production. Resource scarcity problems tend to have a regulating effect on production while pollution problems tend to lack this self-regulating effect on production.
The Two Cultures Revisited: Environmental History and the Environmental Sciences
Authors: Worster Donald
Published: June 2007

The gap between the sciences and the humanities persists in our intellectual life, with significant consequences. The new field of environmental history represents an opportunity to bridge that gap, since it requires historians to become more conversant with the environmental sciences and apply their insights to the study of the past. I give examples of where that conversation has been has been helpful in rewriting history. However, the scientists are in need of the historians and humanists more than they commonly acknowledge. Environmental problems have their source in human culture, and to solve those problems we need the insights of the humanities.
Tar Production in Colonial North America
Authors: Airaksinen Mikko
Published: June 2007

It was only natural for the large countries and colonial powers of the 18th century to employ their heavily wooded areas and possessions as sources of forest products. This is how the French wanted to use Canada, the British, America and the Swedish, their eastern half, Finland. It was not solely the natural environment that determined the choice of these areas, however, but also other aspects of the environment: political, military, economic and colonial. To illustrate this, we will examine the example of tar-making.
Down by the Riverside: The Disappearing Bottomland Hardwood Forest of Southeastern North America
Authors: Saikku Mikko
Published: June 2007

The rapid expansion of European culture since the fifteenth century has greatly altered the face of the countryside all over the world. Among the most dramatic examples of this are the changes in North American nature wrought by Europeans since the seventeenth century. It has been estimated that between the arrival of the first European colonists in the early seventeenth century and the adoption of sustainedyield forestry in the first decades of the twentieth century, the original forest cover of the United States over that same period was reduced by more than 80 percent.1 This article traces the history of human impact on bottomland hardwood forests of the southeastern United States, to show how enormous were the alterations brought about by Europeans in the southeastern bottomland hardwood forest ecosystem. Documentation of the different human activities in the area, from prehistoric times to the twentieth century, aims to place the dramatic decline of this forest type in a broader context of human-induced environmental change in North America.
Lessons from South Africa: War and Wildlife Protection in the Southern Sudan, 1917-1921
Authors: Carruthers Jane
Published: June 2007

For a few years at the end of the First World War, James Stevenson-Hamilton, warden of the Kruger National Park in South Africa, was employed in the Sudan civil service, Despite the dissimilar human history and natural environments of South Africa and the Southern Sudan, Stevenson-Hamilton's experiences in Mongalla province were informed by his professional life in South Africa and his comments on the game protection initiatives in the Sudan at that time are relevant to the modern conservation doctrine of sustainable yield. In the early 1920s Stevenson-Hamilton was responsible for drafting Sudanese game protection legislation which endured for a number of decades.
Conflicts Over Water in 'The Little Drought Age' in Central Mexico
Authors: Endfield Georgina H. , O'Hara Sarah L.
Published: June 2007

Mexico represents one of the most climatically sensitive regions of the world. Over the Colonial period, prolonged drought episodes had severe impacts on all sectors of society, particularly indigenous rural populations. This paper employs a variety of colonial historical records to document the nature and extent of these impacts within the context of prevailing social, political and economic conditions. It is clear that access to water has long been a source of contention especially during drought episodes. Resource monopolisation by individuals and institutions such as the church served to exacerbate this situation particularly during the 18th century.
Ecology and Ideology in the General SystemsCommunity
Authors: Hammond Debora
Published: June 2007

This paper gives an account of the participatory, democratic and pluralistic perspectives of Boulding and other important figures in the General Systems Community (GSC). It contrasts their perspectives with the technocratic approach of H.T. Odum, as analysed in particular by Peter Taylor. It argues that GSC's concern with systems in relation to their environment is more complex than simply mediated energy, information or currency flows crossing the boundaries of Odum's systems. This ensures there is no privileged place for an outside observer/manipulator of the GSC system; in fact, the analyst is often part of the GSC system. Moreover, the interactions within GSC systems are not reduced to a simple metric, such as Odum's energy currency.
'Wilderness' and the Multiple layers of Environmental Thought
Authors: Haila Yrjö
Published: June 2007

'Wilderness' has become a widely used term in environmentalist discussion as a symbol for caring about nature. I review first the historical background: the term was adopted by US environmentalists in the 19th century to describe a nostalgic striving to get into contact with pure, unspoiled nature outside of human influence, in a sanctuary of genuineness and originality; this ideal was strengthened by its adoption by American nationalists. The background, however, lies in European Romanticism. Adoration of supposedly untouched nature arose as a counterpart to the depiction of nature as a unified system obeying eternal laws, amenable to human, rational exploitation. This idea of 'wilderness' cannot, however, be given any accurate empirical meaning and it rests on an assumption that a boundary can be drawn between 'natural' and 'unnatural' human activity, but this is impossible; furthermore, all assumed 'wilderness' areas have actually been inhabited by aboriginal people for millenia. The idea of 'wilderness' thus brings forth one example of how nature has been constituted as the 'other' of the western society. In this constitution, 'nature' and 'natural culture' have always belonged together. As an alternative, I discuss the possibility of recognising an element of 'wildness' inside human everyday existence. Henry David Thoreau was a pioneer of this view. Wildness everywhere present is a totally different idea from a wilderness having a concrete reference somewhere 'outside of' human influence. Thus, the fact of ecological crisis actually means rediscovery of nature rather than 'end of nature' as suggested by the famous slogan of Bill McKibben. I finish by suggesting that Thoreau's ever-present 'wildness' might be used as a building block along the path toward a 'nature contract', that is, a changed relationship to nature such that the prevailing attitude of domination and exploitation would be substituted with respect and care. This requires that the radical contextuality of human existence be recognised, and uncontrollable, 'wild' elements in this position be respected.
Ecological Metaphors and Environmental Rhetoric: An Analysis of
The Ecologist
and
Our Common Future
Authors: Coutinho Marilia
Published: June 2007

This paper discusses two different environmental political projects, the journal
The Ecologist
and the report
Our Common Future
. The former deems it necessary to substitute current patterns of production and transformation of the social structure with radical alternatives, claiming that they lie at the roots of our environmental as well as social crisis. The latter rejects this thesis and prescribes minor administrative changes, regarding the environmental problems as management problems with management solutions. Both, however, employ terms and often concepts derived from Ecosystem Ecology to build up their ideas of 'stability', 'limits' and 'control'. Since the environmental issue has recently become an unavoidable problem for scientific as well as political fields, there is a great deal of traffic between these two domains, leading to concepts and ideas in one domain being transported to the other.
Nature's Ombudsmen: The Evolution of Environmental Representation in Sweden
Authors: Hillmo Thomas , Lohm Ulrik
Published: June 2007

In Sweden, during the 20th century, a number of different groups or institutions have nominated themselves as being Nature's representatives. This essay deals with the ideas, motives or reasons for nature conservation advanced by these groups. Three successive regimes of regulation are identified, which can be codified on the basis of their underlying characteristics as 'entailed estate', 'common land' and 'reservation'. The essay also reflects on the growing political interest in nature conservation and the gradual shift of power from the individual to the state, and how this transfer of power is authorised.
Forest Rights, Privileges and Prohibitions: Contextualising State Forestry Policy in Colonial Tanganyika
Authors: Neumann Roderick P.
Published: June 2007

This paper analyses the development of state forest management in Tanganyika and its effects on African access and use rights within the larger context of British colonial governance. It explores how the ideologies and interests represented by scientific forestry, the League of Nations Mandate, indirect rule, and the general process of African peasantisation intersected in complex and contradictory ways to restructure African forest rights. Efforts to resolve contradictions resulted sometimes in the spatial segregation of African and Forest Department interests, sometimes in uneasy compromise, and, ultimately, in a steady erosion of peasant access to forest lands and resources.
Simulating the Past: Reconstructing Historical Land Use and Modeling Hydrological Trends in a Watershed Area in Java
Authors: Nibbering Jan Willem , de Graaff Jan
Published: June 2007

Historical data on land use can be used as input into watershed models to simulate past hydrological conditions and erosion. A better understanding of past conditions is useful to position the present situation on a dynamic scale and to assess future trends and options therefrom. Conversely, knowledge acquired from bio-physical studies of the present can be used to get a better grasp of certain phenomena in the past. This has been done with a watershed model which was developed for the upper Konto watershed area in Java. After a general introduction on conditions in the upper Konto watershed area and the purpose and design of the watershed model, this article describes the origin, nature and quality of the historical land use data, and how they were interpreted, complemented, balanced and eventually incorporated into the model. The results of the simulation of historical watershed conditions are presented and their plausibility is discussed in the light of historical evidence. A comparison of the modeling results for past conditions and for present conditions shows that the hydrological effects one may wish to achieve with land use changes in the future specified in different development scenarios are unlikely to be of the same order of magnitude as the changes that have occurred over the last 150 years.
Confronting the Pitfalls of Current Environmental History: An Argument for an Organisational Approach
Authors: Uekoetter Frank
Published: June 2007

The essay outlines and criticises three prominent features of current environmental history writing: the idea of history as negative progress, the rhetoric of 'on the one hand' - 'on the other hand', and the use of the term 'capitalism'. It is argued that these notions impede rather than help historical analysis and should be abandoned in favour of more differentiated concepts. As an alternative, the essay proposes focusing on the process of organising responses to perceived environmental problems. This process is subdivided into six stages, with special obstacles and problems to be solved at each of them. The 'organisational approach' offers a useful analytic tool for understanding the rationale behind the seemingly irrational, and allows analysis of the degree in which societies were able to control and regulate their environmental impact. After discussing the advantages of this approach over current ways of writing environmental history, the essay concludes with a brief reflection on how an organisational approach would allow historians to contribute to contemporary environmental discussions in a more productive way.
The Climate of Tübingen A.D. 1596-1605, on the basis of Martin Crusius' Diarium
Authors: Telelis Ioannis G.
Published: June 2007

Martinus Crusius (1526-1607), one of the 16th century's German humanists, kept personal notes in diary form for the period 1596-1605. This academic professor has provided us in his
Diarium
(Diary) with a systematic collection of daily records of various personal, historic and literary notes. But he was also interested in recording the day-to-day weather, extreme weather events and other environmental phenomena, such as phenological events, vine-harvest dates etc. Over 3,000 descriptive daily records of weather and other environmental phenomena have been derived from the
Diarium
. Assessment of the data is attempted considering various historic and philological parameters relevant to the author, his time, his work and the Diary he kept. Data on snow and snow-cover are discussed in this paper. Crusius' terminology on snow is approached, and the numbers of days with snowfall and snow-cover for the period 1597-1605 in Tübingen (Germany) are compared with averages of the 20th century relevant meteorological data.
How Terms Shape Forests: 'Niederwald', 'Mittelwald' and 'Hochwald', and their Interaction with Forest Development in the Canton of Zurich, Switzerland
Authors: Bürgi Matthias
Published: June 2007

Changes in forests are influenced by, and themselves influence, such local conditions as soil, climate and exposure, and also the demands put on the forests by society. Forestry has played a crucial role, since the 19th century at least, in the way these demands are fulfilled through the use and management of forests. This paper describes a regional case study of the history of forestry practices in the north-eastern part of the central plateau of Switzerland during the 19th century, based on an analysis of official documents connected with forestry. The analysis examines, in particular, how the creation of new terms such as 'Niederwald' (i.e., simple coppice forest) and 'Mittelwald' (coppice-with-standards forests) influenced the way in which forestry officials classified forests, which, in turn, influenced how forestry was planned and implemented. During the 19th century, community authorities increasingly took to transforming coppice forests into high forests. This trend was critically observed by forestry officials, who themselves conducted similar transformations in the cantonal forests directly managed by them. According to a classification of stand descriptions which used definite criteria for the different forest types, most of the decline of coppice-with-standards forests occurred after the middle of the 20th century. This development is discussed with respect to changing demands for the different sorts of timber produced in the different forest types.
Environment and Social History: Kalahandi, 1800-1950
Authors: Pati Biswamoy
Published: June 2007

This paper examines the social history of Kalahandi in western Orissa over the 1800-1950 period, in an attempt to explore the roots of the famine which haunts the region even today. It delineates the pre-colonial origins of the crisis, and the way Kalahandi's colonisation reinforced the problems.
Changes in Landscape or in Interpretation? Reflections Based on the Environmental and Socio-economic History of a Village in NE Botswana
Authors: Dahlberg Annika C. , Blaikie Piers M.
Published: June 2007

In semi-arid Africa, environmental change continues to be debated, focusing particularly on the status and significance of land degradation and on local versus scientific knowledge claims. This paper suggests an approach for using different types of data sources, and for bringing together understandings of ecosystem dynamics and of people's interaction with the environment, and thereby achieving 'closure' in a highly contested terrain. The environmental and socio-economic history of a village in north-eastern Botswana is investigated using oral histories of villagers, aerial photographs (1964 and 1988), and official records. At first, descriptions of the environment appear confusing and contradictory, and at odds with official records. Rainfall is the focal point around which most explanations of environmental change turn. Here scientists find no long-term change, while villagers perceive a decline. Overstocking has been a main concern for policymakers throughout this century, while villagers do not see this as a problem. These, and ensuing contradictory perceptions, are partly resolved by identifying the main components linking the wider society to the local and to the environment, and by seeking a shared meaning between local and official versions, as well as between different local versions, of environmental change. We found, instead of contradiction, a striking convergence between, on the one hand, recent scientific understanding of the unpredictability and complexity of semi-arid dynamics and, on the other hand, the description and explanation of change offered by villagers themselves.
Anti-Erosion Policies in the Mountain Areas of Lesotho: the South African Connection
Authors: Driver Thackwray
Published: June 2007

Commercial agriculture in the dry interior of South Africa is heavily reliant upon irrigation water from the Orange River. Most of this vital water does not fall as rain on South African soil but as rain and snow in the mountains of Lesotho. At various times over the past century fears have been expressed over the impact of soil erosion in the mountain areas of Lesotho on South African water resources. These fears have, on occasion, been translated into political pressure on Lesotho to implement anti-erosion policies such as grazing control in the mountain areas. This paper concentrates on the first period of anti-erosion policies in the mountain areas of Lesotho in the late 1940s and early 1950s, and examines the importance of South African pressures to the adoption of these policies. During this period the issue of soil erosion became an important element in the debate about the transfer of the High Commission Territories (Lesotho, Swaziland and Botswana) to South African control and an issue that caused a great deal of concern amongst Lesotho's colonial officials. The subsequent development of an apartheid ideology changed the nature of South African demands in relation to the transfer of the High Commission Territories, and the issue of soil erosion rapidly dropped from the political agenda. The rise and fall of soil erosion as an issue of concern in this period had more to do with internal South African politics than it did with the reality of environmental conditions in the mountain areas of Lesotho.
Were Health Resorts Bad for your Health? Coastal Pollution Control Policy in England, 1945-76
Authors: Hassan John
Published: June 2007

A case study of beach pollution illustrates economic and political influences that have shaped environmental policy in Britain. The need to provide irrefutable evidence that there was a risk to public health, before tangible steps were taken to control pollution, was a characteristic feature of official policy. The consequent deterioration of the holiday industry's prime asset - the marine environment - is traced from the early nineteenth century. The postwar period is selected for detailed study. The paper will explore why, despite the growth of opposition to the pumping of raw sewage into the sea, this traditional method of waste disposal continued to be relied upon until the recent past.
Gastrointestinal Agents
Authors: Jacoby Henry I.
Published: June 2007

The primary aim in antiulcer therapy is either prevention of acid secretion from the gastric parietal cells or neutralization of the acid before it comes into contact with the ulcerated areas of the gastrointestinal tract. Long established therapy of duodenal ulcers, included diet, antacids, and anticholinergics. Of these, only antacids have been shown conclusively to be effective. The antacids can produce healing, but only when given in large and frequent doses. Antacids include aluminum hydroxide gel, precipitated calcium carbonate, magnesia and alumina suspension, magnesium oxide, magnesium trisilicate, magaldrate, and sodium bicarbonate.

The therapy for duodenal ulcers changed drastically upon the introduction of cimetidine (an H
2
blocker) in the United States in 1977. Omeprazole is a potent antisecretory agent and is used only for acute therapy of ulcerative disease and esophagitis.

Drugs acting by mechanisms not related to inhibition of gastric acid secretion have been introduced into therapy in the United States. Use of sucralfate and misoprostil therapy also has been changed by the acceptance that
Helicobacter pylori
, an organism able to withstand the acid media of the stomach, is associated with gastritis and ulcerative disease.

Laxatives facilitate the passage and elimination of feces. Laxatives have traditionally been classified as bulking agents: contact, stimulant; saline, osmotic; and emollients, lubricant.

Commonly used antidiarrheals work by one of two mechanisms: effects on net intestinal secretion, or a decrease in intestinal propulsive motility.

Antiemetics may act at a variety of physiological locations, eg, blockade of dopamine and effects at the chemoreceptor trigger zone, vestibular apparatus, or serotonin (5‐HT
3
) receptors. Gastric prokinetics are a new class of agent that can augment gastric emptying.
Dipole Antennas
Authors: Furse Cynthia M. , Gandhi Om P. , Lazzi Gianluca
Published: June 2007

Dipole antennas and their associated arrays are among the most common antennas used for communication systems and measurement of electric and magnetic fields. This article describes the basic nature of these antennas and some of their applications. Variations such as biconical and bow‐tie antennas, slot dipoles, folded dipoles, sleeve dipoles, and shunt‐fed dipoles are also described.
Spreadsheet Programs
Authors: Leon Linda A. , Przasnyski Zbigniew H.
Published: June 2007

At one end of the spectrum a spreadsheet can be viewed as a large and powerful calculator. However, modern spreadsheets provide a sophisticated modeling environment with an interface that can be productively used by an end‐user novice and an operations research/management scientist (OR/MS) expert alike. Users of spreadsheets can broadly be classified into two categories, those that use spreadsheets in a “static” fashion typically for all kinds of business data processing such as financial statements, inventory tracking, sales management, and budgeting applications to more complex decision support applications, including optimization, forecasting, simulation, and strategic planning. The wide range of applications and base of end users has made spreadsheets a universal modeling platform. By developing an application in the spreadsheet environment, the model can be circulated among a wide range of users without having to worry about specialized software packages and learning curves. Although the different spreadsheet packages and versions are not identical, they are compatible enough that they can support the basic function of each other's models and thereby not hurt the widespread use of a developed model. The examples used throughout this article have all been modeled with Excel 2003.

Brief Historical Overview

Spreadsheet Packages and Users

Spreadsheet Features

Limitations of Spreadsheets and Special Considerations

Profiles of Typical Users

DSS
Tools and Applications

Future Developments
Narrow Band Gap Semiconductors
Authors: Lin H. H. , Kuo J. B.
Published: June 2007

The sections in this article are
Plasma Displays
Authors: Mikoshiba Shigeo
Published: June 2007

The sections in this article are

Glow Discharges in
PDP
s and Light Emission

Structures and Fabrication Techniques of Plasma Display Panels

Driving of Plasma Display Panels

Picture Quality of Plasma Displays

Present Status and Future Trends of
PDP
s
Electrostatic Discharge
Authors: Ashton Robert A.
Published: June 2007

This article will discuss electrostatic discharge with an emphasis on its effect on modern integrated circuits. Topics covered include why ESD is a concern in the electronics industry, precautions that are taken in the design and manufacture of electronics because of ESD, how circuits are tested for their ability to survive an ESD event, elements of how integrated circuit protection circuits are designed, and discussion of the failure mechanisms involved in ESD events. ESD is a subcategory of a wider class of failures in integrated circuits caused by electrical stress outside of the intended range of operation known as electrical overstress (EOS).

Introduction

ESDConcerns in Modern Electronics

Failure Modes

Dealing WithESD

Measurement ofESDRobustness

ESDProtection

ESDTrends
Database Models
Authors: Urban Susan D.
Published: June 2007

A database model is a tool for describing the data that are to be stored in a database, providing an abstract, conceptual layer that protects the users and developers of database applications from the need to be concerned with low‐level implementation details. Many different database models have been developed over the years, ranging from database‐dependent models that are associated with specific types of database management systems to database‐independent models that provide conceptual modeling front‐ends for database application development. This article provides an overview of the basic concepts associated with conceptual, relational, and object‐based database models. Conceptual modeling techniques are presented using the entity‐relationship model and the semantic extensions of the enhanced entity‐relationship model. The relational data model is presented as one of the most widely used models associated with a specific type of database management system. Techniques for mapping from conceptual models to the relational model are also presented. Throughout the article, the role of database semantics and semantic integrity constraints is emphasized. The article ends with an overview of the object‐oriented data model and the object‐relational data model, with a discussion of new directions for data modeling in advanced applications.

Fundamental Data Modeling Concepts

Development of Database Models

Conceptual Data Modeling

The Relational Data Model

Object‐Based Models
Token Ring Local Area Networks
Authors: Strole Norman C. , Bux Werner , Love Robert D.
Published: June 2007

The token ring access protocol evolved through a series of university and corporate research projects, followed by several international standards activities beginning in the 1970s and continuing for two decades into the 1990s. The token access protocol with a ring topology was the basis for both the IEEE 802.5 Token Ring and the ANSI X3T9.5 FDDI standards in the 1980s. This article focuses on the IEEE 802.5 protocol and operation with some comparisons with FDDI in specific areas. Several factors that distinguish token ring operation from other LAN protocols, such as fault detection, fault isolation, priority access protocol, and ring performance are discussed in depth.

Introduction

Brief History of Ring Networks

Token Ring Technology

Token Ring Access Protocol, Monitoring, and Recovery

Multi‐Ring Networks

Dedicated (“Switched”) Token Rings

Fddi Token Protocol

Lan Evolution

Conclusion
Management of Documentation Projects
Authors: Hackos JoAnn T.
Published: June 2007

The sections in this article are

Management of Documentation Projects

Phase 1. Information Planning—Identifying The Users' Information Needs

Phase 2. Content Specification—Presenting the Details of the Design

Phase 3: Implementation—Turning Design into an Information Product

Phase 4. Production—Ensuring Accurate, Complete Information for the User

Phase 5. Evaluation—Reviewing the Project Successes and Failures
Information Retrieval and Publishing
Authors: Culbertson Michael
Published: June 2007

The sections in this article are

Forms of Communication in Electrical Engineering

Bibliographic Tools

Document Retrieval
Controlling the phase separation of gas–liquid flows at horizontal T‐junctions
Authors: Baker G. , Clark W. W. , Azzopardi B. J. , Wilson J. A.
Published: June 2007

The phase split that occurs naturally at T‐junctions has been further enhanced to provide a viable partial gas–liquid separator. Previous experimental investigations have mainly considered only single junctions but here the performance of a separator system consisting of two T‐junctions in series is reported. The addition of control valves on the exit pipes extends previous fundamental studies and incorporates the concept of control and flexibility. A simple active control strategy is proposed on the basis of two control valves, one associated with an automatic level control, the other optimizing liquid residence time, leading to the development of a conceptual T‐separator. Experiments were performed in the stratified and slug flow patterns using air and kerosene at ambient temperatures. © 2007 American Institute of Chemical Engineers AIChE J, 2007
A new heat balance for flow boiling
Authors: Collado Francisco J. , Monné Carlos , Pascau Antonio
Published: June 2007

Recently, one of the authors suggested calculating void fraction, an essential element in thermal‐hydraulics, working with the “thermodynamic” quality instead of the usual “flow” quality. However, the standard heat balance is currently stated as a function of the “flow” quality. Therefore, we should search a new energy balance between the mixture enthalpy, based on “thermodynamic” quality, and the absorbed heat. This work presents the results of such analysis based on accurate measurements of the axial profile of the cross‐sectional average void fraction in the region of boiling with subcooling for water at medium and high pressures taken by Moscow Power Institute (MPI) and Argonne National Laboratory (ANL). As main results, we find that, under uniform heat flux, the mixture enthalpy suffers an abrupt reduction of its slope upon passing saturation point, and a new slip ratio could balance heat with such mixture enthalpy. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Diffuse large B‐cell lymphoma in the young in Japan: A study by the Osaka Lymphoma Study Group
Authors: Yamauchi Amane , Fujita Shigeki , Ikeda Junichiro , Nakamichi Itsuko , Fukuhara Shiro , Hino Masayuki , Kanakura Yuzuru , Ogawa Hiroyasu , Sugiyama Haruo , Kanamaru Akihisa , Aozasa Katsuyuki
Published: June 2007

Clinicopathological and immunophenotypical characteristics in 24 patients with diffuse large B‐cell lymphoma (DLBCL) under 30 years of age in Osaka, Japan were examined, and the results compared to those of DLBCL patients aged over 40 years in Osaka and of young DLBCL patients in Western countries. The level of LDH and IPI score at initial diagnosis were significantly lower in young than older patients. The sex ratio (M:F) and age range (median) in the young and older groups were 1.18 and 11–30 (24.8) years and 1.59 and 42–87 (62.4) years, respectively. Extranodal presentation was higher in the young group (83.3% versus 60.0%, P < 0.05). Based on immunophenotyping with anti‐CD10, bcl‐6, and MUM1 antibodies, the cases were categorized as germinal center B‐cell (GCB) (CD10+ or CD10–, bcl‐6+, MUM1+) or non‐GCB phenotype. The frequency of GCB type was significantly lower in the young group than older group (25% vs. 54%, P < 0.05), and much lower than that reported for young patients in Western countries. In situ hybridization revealed one of the young patients to be positive for Epstein‐Barr virus (EBV). In the older group, none of 31 cases showed EBV positivity. Three year event‐free and overall survival rates of young patients were better than those of the older patients, although not significantly different. DLBCL in the young in Japan is characterized by a much lower frequency of the GCB phenotype compared to that in Western countries. Am. J. Hematol. 82:893–897, 2007. © 2007 Wiley‐Liss, Inc.
Hygrische Materialmodellierung und ihre Abhängigkeit vom Prozess und der Prozessdynamik
Authors: Scheffler Gregor , Plagge Rudolf , Häupl Peter
Published: June 2007

Mit der zunehmenden Anwendung der bauphysikalischen Bauteilsimulation in Forschung und Baupraxis steigen auch die Qualitätsanforderungen an dieses Werkzeug. Das hygrothermische Verhalten von Konstruktionen unter definierten äußeren Einflüssen soll, bei einem vertretbaren Kosten‐ und Zeitaufwand, nicht nur schnell, sondern auch genau und zuverlässig vorhersagbar sein. Einen großen Einfluss auf die Simulationsergebnisse haben dabei die verwendeten Materialfunktionen. Im vorliegenden Beitrag wird zunächst ein Materialmodell vorgestellt, mit dem die Verknüpfung aus thermodynamischen Grundlagen abgeleiteter Funktionen mit einfachen, in der Ingenieurpraxis bekannten Kennwerten sowie der Struktur des Baustoffes hergestellt wird. Das Modell besitzt dadurch die Vorteile der einfachen Handhabung bei gleichzeitiger Erweiterbarkeit auf andere Problemstellungen, da es bzgl. der Modellierung von Transportvorgängen keinen prinzipiell einschränkenden Voraussetzungen unterliegt. Es ist für die wissenschaftliche Weiterentwicklung offen und beispielsweise hinsichtlich der Modellierung des Salztransportes und von Salzkristallisationsprozessen erweiterbar. Im zweiten Teil des Artikels werden Ergebnisse aus Feuchteprofilmessungen mit Simulationsrechnungen auf der Basis des vorgestellten Modells verglichen. Die Grundlage dieser Untersuchungen bilden die Daten dynamischer Ad‐ und Desorptionsmessungen. Es wurden Feuchtegehalt und Feuchtepotenzial simultan in verschiedenen Positionen über der Zeit erfasst. Die Rohdaten der Experimente bestehen dabei aus Tripeln von Wassergehalt, Relativer Luftfeuchte und Temperatur, jeweils an verschiedenen Probekörperpositionen über der Zeit. Der anschließende Vergleich zwischen gemessenen und berechneten Daten zeigt deutlich die Einflüsse der Hysterese der Feuchtespeicherung sowie der Prozessdynamik. Daraus lassen sich Grenzen und Möglichkeiten der verwendeten Materialmodellierung aufzeigen, was im Anschluss diskutiert wird.
Gekoppelter Wärme‐ und Stofftransport einschließlich der Korrosionsprozesse in porösen Baustoffen mit dem Simulationsprogramm AStra
Authors: Espinosa Rosa Maria , Franke Lutz , Deckelmann Gernod , Gunstmann Carsten
Published: June 2007

Zur Beschreibung von Wärme‐ und Feuchtetransportvorgängen gekoppelt mit Stofftransportprozessen in porösen Baustoffen ist ein Differentialgleichungssystem bestehend aus der Energieerhaltungsgleichung und den Massenerhaltungsgleichungen aller beteiligten Stoffe einschließlich des Wassers aufzulösen. Hierzu ist die Modellierung der stattfindenden Phasenumwandlungen der vorliegenden Stoffe und der chemischen Reaktionen der Porenlösung mit der Baustoffmatrix erforderlich. Zu unterscheiden sind dazu inerte, nicht reaktive Baustoffe und reaktionsfähige, zementgebundene Baustoffe. Für die numerische Simulation dieser Vorgänge bzw. die praktische Handhabbarkeit der Problemlösung wurde eine benutzerfreundliche Programmoberfläche AStra geschaffen, die neben dem eigentlichen Berechnungsmodul die benötigten Pre‐ und Postprocessing Möglichkeiten beinhaltet.

Für die Berechnung des zeitlichen Verlaufs eines lösenden oder treibenden Angriffs auf zementgebundene Baustoffe wird durch eine in Abhängigkeit der beteiligten Spezies geeignete Vorauswahl von ablaufenden Reaktionen der Rechenaufwand für die Vorhersage von Nichtgleichgewichtszuständen optimiert und damit die Möglichkeit geschaffen zeitliche Abhängigkeiten mit vertretbarem Berechnungsaufwand zu beschreiben. Zusätzlich können mechanische Beanspruchungen als Folge von Kristallisationsvorgängen zumindest qualitativ vorhergesagt werden. Im Folgenden werden eine Übersicht der implementierten Berechnungsmodelle sowie drei Anwendungsbeispiele von AStra vorgestellt.
Analyse des Gefüge‐ und Feuchtezustandes in mineralischen Baustoffen mit der Mikro‐Röntgen‐3D‐Computertomografie
Authors: Weise Frank , Onel Yener , Goebbels Jürgen
Published: June 2007

Die Kenntnis des Gefüge‐ und Feuchtzustandes in kapillarporösen Baustoffen ist sowohl aus der Sicht der Bauklimatik als auch aus dauerhaftigkeitsrelevanten Gesichtspunkten von großem Interesse. Neue Möglichkeiten bei der Visualisierung beider Zustandsgrößen eröffnet die 3D‐Computertomografie (3D‐CT). So zeigt dieser Beitrag an Hand zweier Machbarkeitsstudien die Leistungsfähigkeit dieses innovativen zerstörungsfreien Laborprüfverfahrens. Die erste Machbarkeitsstudie erfolgte an einem stark frostgeschädigten Betonbohrkern mit Sichtbetonqualität. Die 3D‐CT Untersuchungen zeigen hier, dass neben der räumlichen Verteilung der Gesteinskörnung und der Zementsteinmatrix auch die besonders interessierende Riss‐ und Feuchteverteilung visualisiert werden kann. Damit ist es perspektivisch möglich, die Interaktion zwischen den frostinduzierten Rissen und der Feuchteverteilung ohne zerstörenden Eingriff zu verfolgen. Das wiederum eröffnet neue Möglichkeiten zur Klärung der zum Teil noch nicht hinreichend bekannten frostinduzierten Schädigungsmechanismen im Beton. Gegenstand der zweiten Machbarkeitsstudie war die nicht nur räumliche sondern auch zeitliche Visualisierung der Feuchteverteilung im Tuffstein während des kapillaren Aufsaug‐versuchs. So konnte hier das Wandern der kapillaren Feuchtefront mit verzögerter Wasseraufnahme des magmatischen Tuffbestandteils Bims räumlich visualisiert werden. Basierend auf diesen Studien werden abschließend die geplanten Arbeiten zur weiteren Erhöhung des Leistungspotentials des Verfahrens aufgezeigt.
Analyse der Genauigkeit des Monatsbilanzverfahrens zur Ermittlung des Kühlbedarfs von Nichtwohngebäuden
Authors: Sofic Mario , Bednar Thomas
Published: June 2007

Am 16. Dezember 2002 hat die EU die Richtlinie 2002/91/EG des Europäischen Parlaments und des Rates über die Gesamtenergieeffizienz von Gebäuden erlassen. Die Mitgliedsstaaten der EU hatten zum 4. Januar 2006 Zeit, diese Richtlinie umzusetzen. Es sollen für bestehende Gebäude als auch für alle Neubauten Energieausweise erstellt werden. Für die Ermittlung der Energiekennzahlen von Gebäuden wird sehr oft das Monatsbilanzverfahren verwendet. Dieses Bilanzverfahren wurde deshalb in der vorliegenden Arbeit einer genaueren Untersuchung unterzogen. Dazu wurde für ein Zonenmodell mit Büronutzung der Kühlbedarf simuliert und nach dem Monatsbilanzverfahren ermittelt. Der Vergleich der bilanzierten mit den simulierten Werten für den Kühlbedarf, hat ergeben, dass in einigen Fällen der Kühlbedarf der sich aus einer Simulationsrechnung ergibt mit dem Bilanzverfahren unterschätzt wird. Daher soll ein Korrekturfaktor für den bilanzierten Kühlbedarf eingeführt werden. Weiterhin haben die Untersuchungen ergeben, dass die Kopplung von Zonen im Bilanzverfahren nicht korrekt berücksichtigt wird.
The Effect of pyrazinamide and rifampicin on isoniazid metabolism in rats
Authors: De Rosa Helene J. , Baldan Helen M. , Brunetti Iguatemy L. , Ximenes Valdecir F. , Machado Rosângela G. P.
Published: June 2007

Hepatotoxicity is the main concern during tuberculosis chemotherapy with the first‐line drugs isoniazid (INH), rifampicin (RMP) and pyrazinamide (PYR). Since these hepatotoxic events have been associated with INH metabolites, the study aimed to measure the area under curve (AUC) parameter for INH and its metabolites acetylisoniazid (AcINH), hydrazine (Hz) and acetylhydrazine (AcHz), when groups of rats were pre‐treated for 21 days with INH alone or in combination with RMP and/or PYR, in the following amounts per kg body weight: INH 100 mg; INH 100 mg + RMP 100 mg; INH 100 mg + PYR 350 mg; INH 100 mg + PYR 350 mg + RMP 100 mg. It was found that co‐administration of RMP, PYR and RMP + PYR caused a significant decrease in the AUC for INH. Co‐administration of PYR was the only treatment that caused a significant increase in the AUC for Hz and a decrease in the AUC for its acetylated product AcHz. The AUC for AcINH was not significantly altered in any experimental group. In conclusion, the increased metabolism of INH in all the drug combinations and the significantly higher production of Hz in the group INH + PYR might be linked with exacerbated hepatotoxic effects of these drug associations. Copyright © 2007 John Wiley & Sons, Ltd.
Surface display of MPH on Pseudomonas putida JS444 using ice nucleation protein and its application in detoxification of organophosphates
Authors: Yang Chao , Cai Ning , Dong Ming , Jiang Hong , Li Jinming , Qiao Chuanling , Mulchandani Ashok , Chen Wilfred
Published: June 2007

Methyl parathion hydrolase (MPH) has been displayed on the surface of microorganisms for the first time using only N‐ and C‐terminal domains of the ice nucleation protein (INPNC) from Pseudomonas syringae INA5 as an anchoring motif. A shuttle vector pINCM coding for INPNC–MPH was constructed and used to target MPH onto the surface of a natural p‐nitrophenol (PNP) degrader, Pseudomonas putida JS444, overcoming the potential substrate uptake limitation. Over 90% of the MPH activity was located on the cell surface as determined by protease accessibility and cell fractionation experiments. The surface localization of the INPNC–MPH fusion was further verified by Western blot analysis and immunofluorescence microscopy. The engineered P. putida JS444 degraded organophosphates as well as PNP rapidly without growth inhibition. Compared to organophosphorus hydrolase‐displaying systems reported, changes in substrate specificity highlight an important potential use of the engineered strain for the clean‐up of specific organophosphate nerve agents. Biotechnol. Bioeng. 2008;99: 30–37. © 2007 Wiley Periodicals, Inc.