bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperaturvariationen und Jahrringe | Temperature variation and tree rings
Authors: Esper Jan , Treydte Kerstin , Frank David C. , Gärtner Holger , Büntgen Ulf
Published: June 2007

The paper reviews some of the current objectives, concepts and results of dendroclimatic research focusing on long-term temperature trends and large-scale, tree-ring based temperature reconstructions. We discuss the significance of single treering parameters, their qualities and limitations, and address the issue of emphasizing climatic signals in long series of tree-ring records. We conclude with a discussion of current challenges faced by dendroclimatological research.
Fossile Föhren – präzises Werkzeug der Paläoklimaforschung: Stand der Jahrringforschung an fossilen Bäumen und Vernetzung hochauflösender Archive | Fossil pine trees – accurate tool in paleoclimatic research
Authors: Kaiser Klaus Felix , Schaub Matthias
Published: June 2007

A comparison of different high-resolution archives, such as tree rings, ice cores and marine varves show high degrees of similarity and reveal significant hemispheric climatic events (Older Dryas, Gerzensee Deviation, onset of Younger Dryas). Even the eruption of the Laachersee volcano (Eifel, Germany) 13 070 years ago is recorded synchronously in all of these archives. Trees from the Zurich area extend the absolute tree-ring chronology back to 12 449 years BP. This extension is relevant for quaternary research as well as for calibrating the 14C curve and other archives. The recent findings from the Uetliberg may provide further progress in filling the existing gaps in the Lateglacial tree-ring chronologies.
Bibliografie und Glossar zur Dendrochronologie: zwei neue Informationsquellen für die Jahrringforschung | The «Bibliography of Dendrochronology» and the «Glossary of Dendrochronology»: two new online tools for tree-ring research
Authors: Dobbertin Michèle Kaennel , Grissino-Mayer Henri D.
Published: June 2007

Two new online products are available to the international tree-ring research community: the Bibliography of Dendrochronology,which currently has 10 000 references and is the world's largest online bibliography specialised in tree-ring research,and the Glossary of Dendrochronology, a searchable database of 351 terms and definitions in English, German,French, Spanish, Italian and Portuguese. Both databases are the result of the collaboration of numerous tree-ring scientists from around the world.
Perceptions du pâturage boisé: résultats d'un sondage effectué au Communal de La Sagne NE | Public perception of the wooded pasture: Results of a survey carried out in Le Communal (a common pasture) of La Sagne NE
Authors: Miéville-Ott Valérie , Barbezat Vincent
Published: June 2007

Traditionally the wooded pasture was a place of production,but its functions have evolved and changed within the contexts of landscape and forest management. Today the wooded pasture is the object of a multitude of expectations with regard to its environment, its landscape or its cultural value. It is important to record and characterise these changes in order to develop new management policies, which take account of the different expectations. This was the reason for our survey, carried out with 94 participants during a discovery day spent in Le Communal of La Sagne. Almost two-thirds of those surveyed see the wooded pasture, above all, as a place to find relaxation and a landscape to which they can relate. The majority come to wooded pasture to walk, to gather new energy and to experience nature. There are, however, divergences in the expectations of the local population, the farmers, and the townspeople. Within the framework of a new, integrated management of this area, co-operation between the actors and a wide information policy should assure the social sanction of interventions.
Effiziente Erfassung der Kronendichte mit Hilfe fotografischer Senkrechtaufnahmen | Efficient data assessment of canopy density with the help of vertical photographic exposures
Authors: Coch Thomas , Bertiller René , Trachsler Beat
Published: June 2007

From the point of view of silvicultural and nature protection the canopies of forests represent an important characteristic value. However, conventional forestry methods do not allow for a differentiated ecological assessment of the changed situation of radiation following light tending interventions. The method presented here enables the collection of exact and reproducible values on the actual density of the canopy from the ground, which calls for no specialist demands on workers or equipment. The paper describes the technology of vertical exposures for both analogue and digital photographic technology. In addition, we present a specially developed programme,which allows the automatic evaluation of the digital canopy exposures. We give two examples for areas of application of the method (finely structured map of trees along a water course and documentation of forestry intervention for the resumption of traditional middle forest management). The presented methodology enables an objective assessment of measures to manage the conditions of light in forests (e.g., special forest reserves), which is significantly superior to a visual assessment with regard to accuracy and reproducibility.
Gegen die Miniermotte Cameraria ohridella resistente Aesculus-Arten in Europa – eine Literatur-Übersicht | Aesculus species resistant to the horse-chestnut leaf-miner Cameraria ohridella in Europe: a survey of the literature
Authors: Vienne Françoise
Published: June 2007

Owing to urban aesthetics and the loss encountered in nurseries,the question arises of whether it would not make more sense to replace Aesculus hippocastanum with other Aesculusspecies less susceptible to Cameraria ohridella. Two suitable candidates exist to fill this role: A. chinensis and A. x carnea (including two variants). It will, however, be difficult to replace the susceptible horse-chestnut with these Aesculus species. On the one hand, it would mean a loss of biodiversity and, on the other, the risk ensues of a host change to indigenous Acer species. Should this occur, losses could be considerable. An analysis of the host plant's spectrum has so far failed to deliver clear evidence of the provenance. Despite intensive investigation the exact provenance of the moth has still not been identified – even though it has limited the search area.
Vergleichende Untersuchungen zu ausgewählten mechanischen Eigenschaften von Eibe und Fichte | Comparative studies on selected mechanical properties of yew and spruce (reviewed paper)
Authors: Märki Christoph , Niemz Peter , Mannes David
Published: June 2007

The wood of the yew (Taxus baccata L.) has long been known for its toughness and its strength, although only few scientifically proven reference values for the individual mechanical properties of this wood species exist. In this work selected elastomechanic properties of yew wood and were investigated and compared with those of spruce wood (Picea abies (L.) Karsten), showing values for yew which were conspicuously higher than those of spruce.
Délimitation d'une réserve forestière totale: approche par l'étude de la végétation | Vegetation study to determine the optimal surface area of an unmanaged forest reserve
Authors: Vittoz Pascal , Buttler Alexandre , Junod Pascal
Published: June 2007

Forestry law in Switzerland allows cantonal authorities to define forest reserve areas of at least 5 ha. During a university field-training course in botany, postgraduate students carried out vegetation studies to determine the most appropriate size for an area of completely unmanaged forest reserve within a forest division near Bevaix (canton of Neuchâtel). On the 50 plots of an experimental grid a phytosociological survey and forest mensurations were carried out and the amount of dead wood was determined. Plant biodiversity and tree regeneration were studied by means of a plant survey. Each plot was assigned a score depending on its specific value to a forest reserve. Results suggest that a surface area of 7 ha is most likely to achieve the goal. The grid points of the chosen plots are permanently marked in the field, in order to facilitate further inventories and follow-up studies.
Erfassung von Waldlücken mittels Laserscanning | Mapping of Woodland Gaps through Laserscanning (reviewed paper)
Authors: Mathys Lukas
Published: June 2007

Woodland gaps are structural landscape elements that affect most forest functions. The article describes two conceptually and methodologically complementary approaches to map woodland gaps using laserscanning. Resulting maps on structural properties of the Canton Geneva indicate that laserscanning enables the consistent monitoring of forest and landscape structure for resource management.
The Evolution of Stakeholders' Participation in a Process of Forest Policy Reform in Kyrgyz Republic (reviewed paper)
Authors: Kouplevatskaya-Yunusova Irina
Published: June 2007

National forest policy reform based on participation proves to be a complex multi-layer process in the course of which all the participants are subject to continuous adaptation to the permanently changing context. The example of Kyrgyzstan shows that participation is not only a procedure for deliberative democracy or collaborative learning, but also a means for re-appropriation of power by the stronger stakeholders.
Wie gross wird Heterobasidion annosum s.l.? – Eine Literaturübersicht | Clonal size of Heterobasidion annosum s.l.
Authors: Queloz Valentin , Holdenrieder Ottmar
Published: June 2007

We present a literature review on the size of H. annosum s.l.clones. As a rule, the largest diameter of a genet is smaller than 30 m, only in single cases up to 55 m were measured. The maximum age of an individual genet is estimated to around 200 years. The differences between the various intersterility groups and species within H. annosum s.l. are small. Potential factors which may delimit the mycelial life span are discussed.
Effiziente Kommunikation, Koordination und Kooperation im Netzwerk Holz dank IFIS – ein neues integriertes und webbasiertes Informationssystem | IFIS: a new integrated and web-based information system for efficient communication, co-ordination and co-operation in the wood network
Authors: Lemm Renato , Erni Vinzenz , Thees Oliver
Published: June 2007

The globalisation of wood markets is bringing substantial adjustments to the logistics of the forestry and wood sectors. Suitable, branch-specific data solutions to set up an efficient supply chain and for marketing purposes, which illustrate,as cheaply and as simply as possible, the network of all participants involved and support the co-ordination,communication and co-operation between them, as well as the internal functionality of the individual partners in the network, have been lacking until now. This is why, in close collaboration with the software company Ramco Systems Ltd. with its particularly future-oriented conceptual solutions,the Federal Institute for Forest, Snow and Landscape Research (WSL) and practicing foresters are working on a component and web-based system «IFIS». The system is being conceived, developed and tested as an extremely flexible and cost-efficient system of information. One innovative aspect is that it offers a business model in the shape of an associative solution. The system will be on offer at the end of 2006.
Extraction, Liquid‐Liquid
Authors: Stevens G. W. , Lo Teh C. , Baird Malcolm H. I.
Published: June 2007

Liquid–liquid extraction, also known as solvent extracting, is a well‐established separation technique that depends on the unequal distribution of a solute between two immiscible liquids. The initial feed liquid containing the solute is brought into contact with a solvent that is selected to have a greater affinity for the solute. The partition of the solute can be enhanced by adding a chemical extractant to the solvent; this practice is widespread in the hydrometallurgical and nuclear industries. Most industrial extractors operate continuously with countercurrent flow of the two phases. In mixer–settlers, the phases are contacted as a well‐agitated dispersion of drops, which are then sent to settling tanks for phase disengagement. In extraction columns, the dispersed drops move countercurrently against the flow of the second (continuous) phase. The physics, chemistry, and practice of extraction, with brief descriptions of important industrial extraction processes and equipment, are presented. Research on hydrodynamic aspects of process design, eg, axial mixing, drop dispersion, and coalescence, is reviewed. New extraction techniques, eg, membrane extraction, supercritical exctraction, and two‐phase aqueous extraction, are discussed.
Web Browsers
Authors: Marimuthu Ramesh , Agrawal M. , Rao H. Raghav , Salam A. F.
Published: June 2007

A browser is an application that allows people to view Web pages on the World Wide Web (a term first coined by Tim Berners‐Lee of CERN, Geneva), or at a local area network. The first browser, called Mosaic, was developed in 1993 at the University of Illinois, by Marc Andreessen—now at Netscape Communications Corp.—and others. This development resulted in an explosion of the popularity of the Web, and as interest mounted, other software developers created more advanced browsers. In addition to reading text, people using the latest browsers can watch video, listen to audio, and run various other applications.

This article is organized as follows: The next section discusses the Web browser technology. We then focus on alternative browsers, mobile browsers, and browsers for disabled people. The following section takes a look at communication and information exchange. Then, various business models of electronic commerce are discussed. The next section touches on the issue of security. Finally, the last section summarizes issues that are at the frontiers of WWW research.

Introduction

Internet and the World Wide Web (
WWW
)

Alternative Browsers

Communication and Information Exchange

Electronic Commerce

Security

Research Issues

Conclusion
Attenuators
Authors: Sundararajn Raji , Peterson Edward , Nowlin Robert
Published: June 2007

The sections in this article are

Application

Types

Specifications

Passive Attenuators

Insertion Loss

Fixed Attenuators

Variable Attenuators

Active Attenuators

Additional Types

Acknowledgment
Calculus
Authors: Holbert Keith E. , Heger A. Sharif
Published: June 2007

The sections in this article are

History

Notation and Definitions

Differential Calculus

Integral Calculus

Additional Topics in Calculus
Magnetic Tape Equipment
Authors: Coughlin Thomas M. , Davies David H.
Published: June 2007

The sections in this article are

Basic Elements of Magnetic Tape Drives

Fundamentals of Magnetic Recording on Tape

Specific Equipment Implementations of Magnetic Tape Recording
Network Design: Algorithms and Examples
Authors: Somani Arun K.
Published: June 2007

This article addresses the issues in data network design. We discuss graph models for network, issues in topology design and optimization, link and node capacity assignment, path search Algorithms, and network flow assignments. The network can support point‐to‐point packet‐switched, connection‐oriented circuit‐switched, virtual circuit‐switched connections. We also address performance issues such as blocking probability, throughput, and delay and how to account for them in the design of a network. The issue of fault tolerance in network design is also examined. The design is explained using a context of wavelength division multiplexed (WDM) fiber‐optic network.

Although Estrin‐first proposed the idea of a reconfigurable system in the form of a fixed plus variable structure computer in 1960it has only been in recent years that reconfigurable fabrics have reached sufficient density to make them a compelling implementation platform for high Performance applications and embedded systems. In this article, intended for the non‐specialist, we describe some of the basic concepts, tools and architectures associated with reconfigurable computing.
DC–DC Power Converters
Authors: Erickson Robert W.
Published: June 2007

DC–DC power converters employ switched‐mode circuitry to change dc voltages and currents with efficiencies approaching 100%. Basic converter circuits can reduce the voltage (buck converter), increase the voltage (boost converter) or both (buck‐boost, Cuk, and SEPIC converters). Transformer‐isolated circuits include the bridge, forward, and flyback converters.

Loss mechanisms include conduction loss arising from resistances or forward voltage drops of the power components, and switching loss generated during the transistor and diode switching transitions. Synchronous rectifiers can be employed to reduce the significant conduction loss caused by diode forward voltage drops in low‐voltage applications.

The discontinuous conduction mode may arise when the inductor current is sufficiently small, which causes the output voltage to be strongly load‐dependent.

Voltage‐mode control employs pulse‐width modulation to regulate the converter output voltage or other quantities through variation of the transistor duty cycle. Another popular technique is current‐mode control, in which a circuit eauses the peak transistor current to follow a control reference signal.

Averaging methods are commonly employed to model the dynamics and efficiency of dc–dc power converters. The state‐space averaging method leads to an equivalent circuit model that predicts the converter small‐signal transfer functions. The circuit averaging technique is easily applied to simulate the converter transfer functions, in both continuous and discontinuous conduction modes, using computer programs such as SPICE.

Introduction

Converter Circuit Topologies

Analysis of Converter Waveforms

Transformer Isolation

Switch Implementation

Discontinuous Conduction Mode

Current‐Mode Control

DC‐DCConverter Modeling
Artificial Intelligence in Semiconductor Manufacturing
Authors: May Gary S. , Kim Tae Seon , Triplett Gregory , Yun Ilgu
Published: June 2007

The sections in this article are

Introduction

Artificial Intelligence Tools

Process Modeling

Optimization

Process Monitoring and Control

Process Diagnosis

Yield Modeling

Conclusion
Modeling and Simulation
Authors: White K. Preston
Published: June 2007

The sections in this article are

Models and Model Theory

Mathematical Systems Models

Classification of System Models

Some Common Model Forms

Simulation

Continuous System Simulation

Discrete‐Event Simulation

Modeling and Simulation Issues

Model Validation
Surface Acoustic Wave Devices
Authors: Morgan David P.
Published: June 2007

A surface‐acoustic‐wave (SAW) device employs an acoustic wave guided along the surface of a piezoelectric crystal, in which the stresses and strains of the wave are coupled to electric fields. The wave has a low velocity, typically 3500 m/s, and propagates with low attenuation. These features enable compact low‐loss devices to be developed for electronics applications at frequencies up to several GHz. Arrays of metal electrodes are used to generate, detect or reflect the waves. This technology has enormous versatility because standard lithographic techniques can be used to fabricate almost arbitrary geometries.

This article summarises the nature of surface waves and some relevant propagation effects, including diffraction. The interdigital transducer, used in all these devices for wave generation, is described. A survey of suitable materials is given, including quartz, lithium niobate and lithium tantalate. Transversal bandpass filters are weighted using apodisation or withdrawal weighting. They are widely used in TV receivers, as well as in professional equipment which calls for very high performance devices. For radar, SAW pulse compression filters perform a correlation operation, increasing the range capability. Other devices perform correlation for spread‐spectrum communication waveforms, an example being the SAW non‐linear convolver which is capable of instantaneous programmability. For mobile telephony there has been a strong demand for miniature low‐loss bandpass filters, and a wide variety of novel SAW devices have been developed. For example, impedance element filters give 1 dB loss at 900 MHz, with 30 MHz bandwidth and a package size of 2 × 2 mm
2
. For IF filtering in the CDMA mobile phone system, a modified type of transversal filter called the R‐SPUDT enables both low loss and small size to be obtained. For GSM IF circuits, transverse‐coupled resonator filters have been developed to give a very narrow bandwidth of 200 kHz.

The article concludes with a superficial survey of the theory of these devices.

Introduction

Interdigital Transducers

Propagation Effects

Materials

Basic
SAW
Filters

Low‐Loss Bandpass Filters

Leaky Surface Waves

Analysis Methods
Solid and Physical Modeling
Authors: Rossignac Jarek R.
Published: June 2007

The sections in this article are

Introduction

Topological Domain

Geometric Domain and Representation Schemes

Triangle Meshes

Curved BReps

Constructive Solid Geometry

Parameters, Constraints, and Features

Variational Geometry

Morphological Transformations and Analysis

Human‐Shape Interaction

Conclusions
Multicomponent sorption of hexane isomers in zeolite BETA
Authors: Bárcia Patrick S. , Silva José A. C. , Rodrigues Alírio E.
Published: June 2007

Breakthrough curves of single, binary, ternary, and quaternary mixtures of hexane (C6) isomers n‐hexane (nHEX), 3‐methylpentane (3MP), 2,3‐dimethylbutane (23DMB), and 2,2‐dimethylbutane (22DMB) were performed in commercial pellets of zeolite BETA (BEA structure), covering the temperature range between 423 and 523 K and partial pressures up to 30 kPa. From these data, single and multicomponent adsorption equilibrium isotherms were collected. A tri‐site Langmuir model (TSL) was developed to interpret the equilibrium data based on considerations about zeolite structure, and a dynamic adsorption model was tested predicting with a good accuracy the behavior of multicomponent fixed‐bed experiments. At the partial pressures studied, the sorption hierarchy in the zeolite BETA is nHEX >>> 3MP > 23DMB >> 22DMB. BEA structure demonstrates a significant selectivity between C6 isomers, especially at low coverage, giving a good perspective regarding their separation by adsorption processes. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Loeffler endocarditis: What have we learned?
Authors: Benezet‐Mazuecos Juan , de la Fuente Adolfo , Marcos‐Alberca Pedro , Farre Jeronimo
Published: June 2007

Loeffler endocarditis, eosinophilic endomyocardial disease or fibroplastic endocarditis appears to be a subcategory of the Hypereosinophilic syndrome in which the heart is predominantly involved. It is an uncommon myocardial disease, thought to be secondary to eosinophils damage, characterized by fibrous thickening of the endocardium of one or both ventricles, leading to apical obliteration and multiple cardiovascular complications. Despite all the efforts, the ultimate responsible mechanisms of this entity remain unresolved. Many theories have been raised trying to explain this phenomenon, but nowadays the enigma in relation to the different patterns of evolution continues. In this concise review we discuss the different pathophysiologic theories postulated and the management of the cardiovascular complications. Perhaps it will serve to assist in recognition of patients with the same condition around the world. Am. J. Hematol. 82:861–862, 2007. © 2007 Wiley‐Liss, Inc.
Effect of zinc oxide on the viscosity, tack, and peel strength of ENR 25‐based pressure‐sensitive adhesives
Authors: Poh B. T. , Chow S. K.
Published: June 2007

Viscosity, loop tack, and peel strength of epoxidized natural rubber (ENR 25 grade)‐based pressure‐sensitive adhesive was studied in the presence of zinc oxide. The zinc oxide concentration was varied from 10–50 parts per hundred parts of rubber (phr). Coumarone–indene resin with loading from 20 to 100 phr was chosen as the tackifier resin. Toluene was used as the solvent throughout the experiment. The adhesive was coated on the substrate using a SHEEN hand coater to give a coating thickness of 60 μm. Viscosity of the adhesive was determined by a HAAKE Rotary Viscometer whereas the loop tack and peel strength were measured by a Llyod Adhesion Tester operating at 30 cm/min. Results show that viscosity and loop tack of adhesive increases with increasing zinc oxide concentration. For the peel strength, it increases with zinc oxide concentration up to 30–40 phr and drops after the maximum value. This observation is associated with the effect of varying degree of wettability of the adhesive on the substrate. However, for a fixed zinc oxide concentration, loop tack and peel strength exhibit maximum value at 80 phr resin loading after which both properties decrease with further addition of resin, an observation which is attributed to phase inversion. From this study, the optimum adhesion property is achieved by using 40 phr zinc oxide and 80 phr coumarone–indene resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effects of experimental reduction of light and nutrient enrichments (N and P) on seagrasses: a review
Authors: Leoni Vanina , Vela Alexandre , Pasqualini Vanina , Pergent‐Martini Christine , Pergent Gérard
Published: June 2007

Excessive nutrient discharge, linked to human activities, is one of the main causes of the decline of seagrass meadows since it modifies two essential parameters controlling their primary production: the nutrient concentrations (especially nitrogen and phosphorus) and the irradiance.

To investigate the behaviour of seagrass under varied conditions of light and/or nutrient concentrations, it is necessary to experimentally manipulate nutrient enrichment and light, either in situ or in artificial ecosystems. The available experimental information concerning the influences of light reduction and nutrient enrichments (N and P) on seagrass meadows are summarized.

The protocols for experimentally reducing light vary considerably but all light reduction experiments show a decrease in seagrass vitality and physiological changes (e.g. promotes an increase in chlorophyll and tissue nitrogen), depending on the species‐specific tolerance (light optima).

A wide range of protocols for experimentally increasing nutrient levels have been applied, including varying the nutrient species quantities and ratios, as well as the sources and frequency of additions. Responses to N and/or P enrichment range from stimulation to direct or indirect inhibition, varying depending upon the species, the protocol implemented, the nutrient source (water column versus sediments), and other environmental conditions (e.g. interactions with factors such as temperature, grazing and light).

Both light reduction and nutrient enrichment, can cause seagrass decline, through similar internal mechanisms, promoting an imbalance of internal nutrient supply ratios. Similar physiological responses can thus be observed (e.g. increase of N, P and chlorophyll contents of leaves).

This study shows the close link between the physiology and morphology of seagrasses, with regard to environmental modifications. It also highlights their ability to provide information on environmental conditions by means of their responses.

Copyright © 2007 John Wiley & Sons, Ltd.
Entwicklung und Validierung einer hygrothermischen Raumklima‐Simulationssoftware WUFI®‐Plus
Authors: Lengsfeld Kristin , Holm Andreas
Published: June 2007

Gut abgestimmte raumklimatische Bedingungen bzgl. Wärme, Feuchte und Luftqualität sind notwendig um negative Auswirkungen auf die Nutzer und die Bausubstanz zu vermeiden. Der vorliegende Beitrag beschäftigt sich mit dem Einfluss verschiedener Wandaufbauten auf den Feuchteverlauf und die Pufferung von Feuchtespitzen in Innenräumen. Anstelle von aufwendigen Versuchen werden zunehmend Softwareprogramme zur Simulation der raumklimatischen Parameter verwendet. Das Fraunhofer‐Institut für Bauphysik (IBP) hat die Software WUFI®‐Plus [1] zur hygrothermischen Simulation des Raumklimas entwickelt. Damit ist es möglich, die Temperatur und Feuchte in Wand‐ und Deckenkonstruktionen sowie in der Raumluft und den Energieverbrauch eines Gebäudes zu simulieren. Im Rahmen des internationalen IEA‐Annex 41 Projektes “Moist‐Eng” wurde ein “common exercise” zur Validierung solcher Softwaremodelle durchgeführt. Zur Ermittlung des Feuchtepufferverhaltens wurden Versuche in Holzkirchen in zwei identischen Versuchsräumen mit verschiedenen Wandinnenoberflächen durchgeführt. Die Messergebnisse wurden für Validierungsberechnungen der 13 am “common exercise” beteiligten Softwaretools verwendet.
Thermischer Komfort – die extraphysikalischen Aspekte
Authors: Bischof Wolfgang , Hellwig Runa Tabea , Brasche Sabine
Published: June 2007

Der Grad der Zufriedenheit mit den thermischen Umgebungsbedingungen von Aufenthaltsräumen wird im derzeitigen Normwerk als Funktion physikalischer und thermophysiologischer Parameter ermittelt. Aus Untersuchungen zur Befindlichkeit von Büroarbeitern ist seit längerem bekannt, dass die Zufriedenheit mit raumklimatischen Bedingungen auch durch extraphysikalische Variablen beeinflusst wird. Anhand von Daten aus der ProKlimA‐Studie wurde untersucht, inwieweit extraphysikalische Variablen das Temperaturempfinden, die thermische Behaglichkeit, die Zufriedenheit mit und die Erwartungshaltung bezüglich der Raumtemperatur beeinflussen. Im Ergebnis multipler logistischer Regressionsanalysen zeigt sich, dass thermisches Empfinden weitgehend unabhängig von extraphysikalischen Einflüssen ist. Thermische Behaglichkeit und Zufriedenheit jedoch stehen in deutlicher Wechselwirkung mit extraphysikalischen Variablen, zu denen neben demographischen Charakteristika auch Tätigkeitsmerkmale, Arbeitszufriedenheit und die Belüftungsart des Gebäudes oder Raumes gehören. Aus diesen z. T. sehr starken und signifikanten Wechselwirkungen kann bereits heute geschlussfolgert werden, dass zumindest bei der Analyse und Bewertung von raumklimatischen Beschwerden auch extraphysikalische Einflüsse einzubeziehen sind.
“3‐Liter‐Haus” im Bestand – Messkonzept und Messergebnisse von 3 Heizperioden
Authors: Weyand Nicole , Heinrich Hermann , Dahlem Karl‐Heinz
Published: June 2007

In Deutschland sind über 80% aller Gebäude energetisch gesehen Altbauten, die ganz wesentlich zum Energieverbrauch und zur Umweltbelastung beitragen. Im konkreten Beispiel wurde ein Mehrfamilienwohngebäude in Ludwigshafen neben der “üblichen” Renovierung energetisch besonders wirkungsvoll saniert. Ziel des Projektes war die Sanierung eines Gebäudes im Bestand als “3‐Liter‐Haus” (30 kWh/m2a). Um dies zu erreichen wurden die Transmissionswärmeverluste verringert, die passiven Solargewinne erhöht und durch eine Lüftungsanlage mit Wärmerückgewinnung die Lüftungswärmeverluste reduziert. Das Gebäude wurde über 3 Heizperioden messtechnisch begleitet und es zeigte sich, dass bei einem größeren Gebäude die mittleren Verbräuche gut mit dem berechneten Bedarf korrelieren. Für einzelne Wohnungen gibt es jedoch große Abweichungen vom Mittelwert. Gerade im Hinblick auf den kommenden Energieausweis als Energiebedarfs‐ und Energieverbrauchspass ist die Frage des Nutzerverhaltens bei einer kleinen Anzahl von Wohneinheiten von großer Bedeutung. Die gemessenen Daten aus diesem Projekt liefern hierzu interessante Ergebnisse, die den verbrauchsorientierten Energieausweis für Gebäude mit wenigen Wohneinheiten in Frage stellen.
Energetisch und bauphysikalisch optimierte Sanierung eines Baudenkmals in Görlitz
Authors: Conrad Christian , Häupl Peter , Petzold Hans , Löber Henning
Published: June 2007

Mit den angewendeten Sanierungsmassnahmen an einem barocken Gebäude in Görlitz (Innendämmung Straßenfassade, WDVS Hoffassade, Solaranlage, Lüftungsanlage mit WRG, Grauwassernutzung und Fußbodenabwasserheizung) wurden unter Einhaltung der Auflagen des Denkmalschutzes die Energieeffizienzklasse A+ erreicht, die Belange des Umweltschutzes berücksichtigt und die Dauerhaftigkeit und Zuverlässigkeit der Konstruktionen gewährleistet. Die erreichten Ergebnisse werden u.a. mit instationären Simulationsrechnungen (Wärme‐, Luft‐ und Feuchtetransport in kapillarporösen Baustoffen) für die einzelnen Bauteile und instationären Simulationsrechnungen anlagentechnischer Komponenten verifiziert. Dabei wird bauphysikalisch der Einfluss der hohen Bauwerksmasse ganzjährig quantifiziert. Die Auswirkungen der eingesetzten Anlagentechnik auf historische Bauteile, wie z. B. die Holzbalkendecken, werden untersucht. Auf der Grundlage der Erfahrungen zur Vermeidung der Kondensat‐ und Reifbildungen bei hochdämmenden geneigten Verglasungen wurde gemeinsam mit einem ortsansässigen Glaswerk eine neue Wärmeschutzverglasung mit einer außenliegenden Beschichtung entwickelt/kombiniert und eingesetzt.
Salztransport und Phasenumwandlung – Modellierung und numerische Lösung im Simulationsprogramm Delphin 5
Authors: Nicolai Andreas , Grunewald John , Zhang Jianshun S.
Published: June 2007

Der Artikel gibt einen Überblick über die im Simulationsprogramm Delphin 5 implementierten Gleichungen, die den Zusammenhang zwischen Wärme‐ und Feuchtetransport sowie Salztransport einschl. Phasenumwandlungen in kapillarporösen Baustoffen beschreiben. Ausgehend von einem Konvektions‐Diffusionsmodell für den Transport von binären Salzlösungen wurde das Simulationsprogramm um ein Modell für Salzgemische erweitert, welches den Transport und die Phasenumwandlungskinetik von Na‐K‐Cl‐NO3‐SO4‐H2O‐Systemen beschreibt. Ein kinetisches Modell für die Lösung und Kristallisation von Salzen wird vorgestellt, welches ebenso für Hydratations‐ und Dehydratationsreaktionen verwendet werden kann. Weitere Schwerpunkte des Artikels sind die Modellierung der thermodynamischen Eigenschaften von Salzlösungen sowie deren Auswirkungen auf die Materialfunktionen und die gekoppelten Wärme‐ und Feuchtetransportprozesse.
Erläuterungen und Anwendungsbeispiel zum vfdb‐Leitfaden Ingenieurmethoden des Brandschutzes
Authors: Hosser Dietmar , Dehne Michael
Published: June 2007

Das vfdb‐Referat 4 hat in den vergangenen acht Jahren einen Leitfaden “Ingenieurmethoden des vorbeugenden Brandschutzes” erarbeitet. Er dient bei der Erstellung oder Überprüfung von Brandschutzkonzepten als Hilfestellung zur sinnvollen Auswahl und Anwendung von Nachweismethoden und Eingangsdaten. In diesem Beitrag werden das Gesamtkonzept und die Verknüpfungen der einzelnen Kapitel des Leitfadens erläutert. Etwas ausführlicher wird auf Schutzziele und Sicherheitsanforderungen für die Nachweise eingegangen, von denen die nachzuweisenden Szenarien und Kriterien und die passenden Nachweismethoden abhängen. Die Anwendung des Leitfadens wird am Beispiel einer Versammlungsstätte veranschaulicht, wobei Fragen bezüglich der Rauchableitung und des Brandschutzes der tragenden Konstruktion behandelt werden.
Der Umbau des denkmalgeschützten Dieselkraftwerkes Cottbus – eine Herausforderung an die Ingenieure
Authors: Meyer Simone , Weineck Monika , Dahlitz Andreas , Osterrieder Peter , Schulze Uwe
Published: June 2007

Die Stadt Cottbus hat sich der Herausforderung gestellt, dem seit knapp 50 Jahren stillgelegten Dieselkraftwerk (DKW) eine neue Nutzung zu geben. Werner Issel, einer der bekanntesten Architekten im Kraftwerksbau, fertigte 1926 den Gebäudeentwurf. 1928 wurde im DKW mit der Stromerzeugung begonnen, diese aber bereits 30 Jahre später beendet. Zeitgleich stellte man das DKW unter Denkmalschutz. Anfang 2008 wird in diesem Gebäude das Kunstmuseum der Brandenburgischen Kulturstiftung seine Besucher empfangen. Die an diesem Umbauprojekt beteiligten Planungs‐ und Prüfingenieure zeigen aus dem vielschichtigen Anforderungskomplex interessante Details zum Brand‐ und Wärmeschutz. Dabei galt es, sowohl die denkmalrechtlichen Ansprüche als auch die nutzungstechnischen Erfordernisse eines öffentlichen Gebäudes entsprechend zu würdigen.
High‐pressure inactivation of dried microorganisms
Authors: Espinasse V. , Perrier‐Cornet J‐M. , Marecat A. , Gervais P.
Published: June 2007

Dried microorganisms are particularly resistant to high hydrostatic pressure effects. In this study, the survival of Saccharomyces cerevisiae was studied under pressure applied in different ways. Original processes and devices were purposely developed in our laboratory for long‐term pressurization. Dried and wet yeast powders were submitted to high‐pressure treatments (100–150 MPa for 24–144 h at 25°C) through liquid media or inert gas. These powders were also pressurized after being vacuum‐packed. In the case of wet yeasts, the pressurization procedure had little influence on the inactivation rate. In this case, inactivations were mainly due to hydrostatic pressure effects. Conversely, in the case of dried yeasts, inactivation was highly dependent on the treatment scheme. No mortality was observed when dried cells were pressurized in a non‐aqueous liquid medium, but when nitrogen gas was used as the pressure‐transmitting fluid, the inactivation rate was found to be between 1.5 and 2 log for the same pressure level and holding time. Several hypotheses were formulated to explain this phenomenon: the thermal effects induced by the pressure variations, the drying resulting from the gas pressure release and the sorption and desorption of the gas in cells. The highest inactivation rates were obtained with vacuum‐packed dried yeasts. In this case, cell death occurred during the pressurization step and was induced by shear forces. Our results show that the mechanisms at the origin of cell death under pressure are strongly dependent on the nature of the pressure‐transmitting medium and the hydration of microorganisms. Biotechnol. Bioeng. 2008;99: 180–188. © 2007 Wiley Periodicals, Inc.
Adhesion and viability of waterborne pathogens on p‐DADMAC coatings
Authors: van der Mei Henny C. , Rustema‐Abbing Minie , Langworthy Don E. , Collias Dimitris I. , Mitchell Michael D. , Bjorkquist Dave W. , Busscher Henk J.
Published: June 2007

The attachment of waterborne pathogens onto surfaces can be increased by coating the surfaces with positive charge‐enhancing polymers. In this paper, the increased efficacy of polydiallyldimethylammonium chloride (p‐DADMAC) coatings on glass was evaluated in a parallel plate flow chamber with the use of waterborne pathogens (Raoultella terrigena, Escherichia coli, and Brevundimonas diminuta). p‐DADMAC coatings strongly compensated the highly negative charges on the glass surface and even yielded a positively charged surface when applied from a 500 ppm solution. Whereas none of the strains adhered from water to glass due to electrostatic repulsion, R. terrigena and E. coli readily adhered in high numbers to p‐DADMAC coated glass slides applied from 1, 100, or 500 ppm aqueous solutions. B. diminuta only adhered to a positively charged p‐DADMAC coating applied from a 500 ppm solution. In addition, all p‐DADMAC coatings indicated strong contact killing with the bacterial species used in this study by live/dead staining techniques. In summary, this paper demonstrates the potential of p‐DADMAC coatings to strongly enhance bacterial adhesion. Moreover, once adhered, bacterial viability can be reduced by the positively charged ammonium groups in the coating. Biotechnol. Bioeng. 2008;99: 165–169. © 2007 Wiley Periodicals, Inc.
Das Rätsel der Alterung: Viele Theorien, viele offene Fragen
Authors: Zwilling Robert
Published: June 2007

Man könnte meinen, dass “Alterung” bloß ein Teil des allgemeinen Prozesses von “Werden” und “Vergehen” sei, welchem alles Existierende unterworfen ist.

Die Wissenschaft konnte jedoch zeigen, dass das Altern von Organismen erst als ein Ergebnis der Evolution in die Welt gekommen ist.

Viele Theorien ebenso wie fortgeschrittene molekulare Techniken werden bemüht, um dem Rätsel der Alterung auf die Spur zu kommen. Ein Ende dieses Weges ist noch nicht abzusehen, jedoch könnten in seinem weiteren Verlauf Entwicklungen auf uns warten, welche Medizin, Ökonomie und sogar das Zusammenleben der Menschen in großem Ausmaß verändern.
Was ein Pilz über das Altern verrät: Podospora anserina – ein altes Modell mit neuen Perspektiven
Authors: Osiewacz Heinz D.
Published: June 2007

Untersuchungen zur Erarbeitung der molekularen Mechanismen des Alterns und der Kontrolle der Lebensspanne bei dem Modellorganismus Podospora anserina haben zur Herausarbeitung einer zentralen Bedeutung der Mitochondrien geführt. Bei der Generierung von ATP in diesen Organellen kommt es zur Bildung von ROS, die zu Schädigungen der verschiedenen Zellbestandteile führen. Trotz der Existenz verschiedener zellulärer Schutzsysteme häufen sich solche Schäden im Laufe des Alterns an und es kommt zum Zelltod. Eingriffe in diese Maschinerie führen zu einer Lebensverlängerung. Allerdings ist der Preis in vielen Fällen eine verminderte “Fitness” der entsprechenden Individuen. Hauptziel der Forschung muss es sein, Bedingungen zu finden, die zu einer Form “gesunden” Alterns führen, d.h. des Alterns möglichst ohne Funktionsbeeinträchtigungen in späteren Lebensabschnitten.
Die Grenzen der Lebensdauer. Von welchen zellulären Faktoren wird das Altern bestimmt?
Authors: Rensing Ludger
Published: June 2007

Altern ist in der Regel ein langsamer Prozess, der wesentlich durch eine Akkumulation von zellulären Schäden verursacht wird. Diese Schäden werden zu einem großen Teil durch reaktive Sauerstoff‐ und Stickstoffspezies (ROS und RNS) erzeugt, die bei der Atmung, durch Hormone und durch äußere Stressfaktoren entstehen. Hinzu kommt bei mitotischem Gewebe eine altersabhängig zunehmende replikative Seneszenz, die ebenfalls zu Erkrankungen (Arteriosklerose, Immunschwäche u.a.) führt. Die replikative Seneszenz beruht wesentlich auf der Erosion der Telomere sowie auf der Blockierung des Zellzyklus durch inhibitorische Proteine (p21 u.a.). Eine Restriktion der Nahrungsaufnahme verzögert die Seneszenz durch eine Verminderung der Aktivität des Insulinsignalwegs und Förderung von Transkriptionsfaktoren (FOXO, PHA‐4). Allgemein sind eine gesunde (nicht zu reichliche!) Ernährung verbunden mit körperlicher und geistiger Aktivität sowie Strategien zur Stressbewältigung Mittel gegen frühzeitiges Altern, während pharmakotherapeutische Manipulationen aller dieser Faktoren mit dem Ziel einer drastischen Verlängerung der Lebensdauer mit großer Skepsis betrachtet werden müssen.
Science Bridge wird “Ort der Ideen 2007”
Authors: Junk Susanne , Nellen Wolfgang
Published: June 2007

Normalerweise macht Science Bridge für Schüler die eigenen Klassenräume zum Ort der Ideen, indem spannende molekularbiologische Experimente direkt in den Unterricht gebracht werden. Am 11. Dezember holt “Science Bridge” als “Ort der Ideen 2007” die Schule stattdessen zum Aktionstag in die Labore und Hörsäle der Universität Kassel. Da Science Bridge die Brücke zwischen Wissenschaft und Schule erfolgreich schlägt, hat die Gesellschaft für Biochemie und Molekularbiologie (GBM) das Kasseler Schülerlabor als Ausrichter für diesen Aktionstag ausgesucht.
DNA – für die Forschung schmilzt sie dahin
Authors: Schrödel Andrea
Published: June 2007

Begonnen hat alles an einem Samstag Ende Februar 1953, als die Struktur der DNA von James D. Watson und Francis Crick durch die Fertigstellung ihres berühmten, aus Draht, Pappe und Klammern zusammengestückelten DNA‐Modells endgültig enträtselt wurde. Heute befasst man sich im Labor eher mit Verfahren zur Zerstörung der DNA, um diese untersuchen zu können. Eines davon ist die Schmelzpunktanalyse.
Schildkrötenfossilien als paläoklimatische Marker
Authors: Karl Hans‐Volker , Hein Juliane
Published: June 2007

Die Klima‐Problematik wird in zunehmendem Maße nationalstaatlich, kontinental und weltpolitisch thematisiert. Dies zeigt ihre fundamentale Bedeutung. Notwendig, um überhaupt gesicherte Aussagen über Umweltveränderungen treffen zu können, sind daher geeignete Paläoklima‐Modelle als Referenzmatrizen. Hierbei spielen die Klimaarchive aus dem von Eiszeiten geprägten Pleistozän eine Schlüsselrolle. Die Korrelation dieser Daten mit rezenten Verhältnissen ermöglicht Prognosen über einen Faunen‐ und Florenwandel.
Damage control surgery in a non-trauma setting
Authors: Jansen J O , Loudon M A
Published: June 2007

A cautious welcome
Maintenance of binge eating through negative mood: A naturalistic comparison of binge eating disorder and bulimia nervosa
Authors: Hilbert Anja , Tuschen‐Caffier Brunna
Published: June 2007

Objective:

To examine negative mood as a proximal antecedent and reinforcing condition of binge eating in binge eating disorder (BED) and bulimia nervosa (BN).

Method:

Using an ecological momentary assessment design, 20 women with BED, 20 women with BN, and 20 nonclinical control women were recruited from the community, provided with a portable minicomputer, and asked to rate their mood and list their thoughts at randomly‐generated beep sounds and before, during, and after episodes of eating.

Results:

In both eating disorder groups mood before binge eating was more negative than before regular eating and at random assessment. Binge eating was followed by a deterioration of mood. The BED group revealed less antecedent negative mood than the BN group and less concomitant negative cognitions about food/eating and stress.

Conclusion:

Affect regulation difficulties likely lead to binge eating in both disorders, but binge eating may not be effective for regulating overall mood. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007.
Pathways to help‐seeking in bulimia nervosa and binge eating problems: A concept mapping approach
Authors: Hepworth Natasha , Paxton Susan J.
Published: June 2007

Objective:

To conduct an in‐depth study, using concept mapping, of three factors related to help‐seeking for bulimia nervosa and binge eating: problem recognition, barriers to help‐seeking, and prompts to help‐seeking.

Method:

Semistructured interviews were conducted to elicit information about help‐seeking with 63 women (18–62 years) with past or present bulimic behaviors.

Results:

Using Leximancer software, factors identified as associated with problem recognition were Changes in Behavior, Interference with Life Roles, Comments about Changes and Psychological Problems. Salient barriers to help‐seeking were Fear of Stigma, Low Mental Health Literacy/Perception of Need, Shame, Fear of Change and Cost. Prompts to help‐seeking were increased Symptom Severity, Psychological Distress, Interference with Life Roles, Health Problems, and Desire to Get Better.

Conclusion:

Results highlighted the need for awareness campaigns to reduce both self and perceived stigma by others towards bulimic behaviors, and the need to enhance awareness of available interventions for people ready to engage in treatment, to increase help‐seeking. © 2007 by Wiley Periodicals, Inc.