Showing papers by "Wolfgang Wagner published in 1999"

A New Equation of State for Argon Covering the Fluid Region for Temperatures From the Melting Line to 700 K at Pressures up to 1000 MPa

Abstract: This work reviews the available data on thermodynamic properties of argon and presents a new equation of state in the form of a fundamental equation explicit in the Helmholtz energy. The functional form of the residual part of the Helmholtz energy was developed by using state-of-the-art linear optimization strategies and a new nonlinear regression analysis. The new equation of state contains 41 coefficients, which were fitted to selected data of the following properties: (a) thermal properties of the single phase (pρT) and (b) of the liquid–vapor saturation curve (ps, ρ′, ρ″) including the Maxwell criterion, (c) speed of sound w, isochoric heat capacity cv, second and third thermal virial coefficients B and C and second acoustic virial coefficient βa. For the density, the estimated uncertainty of the new equation of state is less than ±0.02% for pressures up to 12 MPa and temperatures up to 340 K with the exception of the critical region and less than ±0.03% for pressures up to 30 MPa and temperatures bet...

Theory and method of social representations

Abstract: This paper gives an overview of social representation theory, definitions of the key terms and of the social processes leading to a representation and to social identity. Six empirical studies are presented and details of their methods and findings are given to illustrate this social psychological approach. These studies are about the ontogenesis of gender, the public sphere in Brazil, madness on British television, images of androgyny in Switzerland, individualism and democracy in post-communist Europe and metaphorical thinking about conception. The methods are ethnography, interviews, focus-groups, content analysis of media, statistical analysis of word associations, questionnaires and experiments. Finally, social representation theory is compared to theories of attitudes, schemata and social cognition.

A study of vegetation cover effects on ERS scatterometer data

Abstract: The scatterometer flown onboard the European remote-sensing satellites ERS-1 and ERS-2 is a vertically polarized radar operating at 5.3 GHz (C-band) and has a spatial resolution of 50 km. In a number of studies, the sensitivity of the ERS scatterometer to vegetation has been demonstrated, but it is not yet clear which vegetation parameters are of primary importance to explain the ERS scatterometer signal. In this paper, the effects of land cover and seasonal vegetation development are investigated by comparing ERS scatterometer data with land cover information, normalized difference vegetation index (NDVI) data sets, and meteorological observations. As a study area, the Iberian Peninsula was chosen. The Iberian Peninsula is characterized by the Mediterranean climate that has a wet winter and a dry summer. This allows the authors to better differentiate the effects of the annual vegetation and precipitation cycle on the temporal evolution of the backscattering coefficient /spl sigma//spl deg/. It is shown that the ERS scatterometer has only limited capabilities for monitoring the vegetation development within a given year because most of the temporal variability of /spl sigma//spl deg/ is due to soil moisture changes. On the other hand, it might be of merit for vegetation discrimination on large scales (regional to global) because the percentage area of forests, bushes, and shrubs within one ERS scatterometer pixel is found to explain a significant part of the spatial variability of the signal.

High Cure Rates and Reduced Long-Term Toxicity in Pediatric Hodgkin's Disease: The German-Austrian Multicenter Trial DAL-HD-90

Abstract: PURPOSE: To further reduce therapy-related late effects in patients with pediatric Hodgkin's disease (HD) while maintaining the high cure rates achieved with vincristine, prednisone, procarbazine, and doxorubicin (OPPA) or OPPA/cyclophosphamide, vincristine, prednisone, and procarbazine (COPP) chemotherapy and involved-field radiotherapy. The risk of testicular dysfunction was addressed by substituting etoposide for procarbazine (OEPA) in the induction therapy for boys. Radiation doses and fields were further reduced. PATIENTS AND METHODS: Three hundred nineteen boys and 259 girls younger than 18 years with previously untreated HD, enrolled onto the study between 1990 and 1995, were allocated to treatment group (TG)1 (early stages), TG2 (intermediate stages), or TG3 (advanced stages). All groups underwent two cycles of OEPA (boys) or OPPA (girls) for induction chemotherapy. TG2 and TG3 continued on additional two or four cycles, respectively, of COPP. Low-dose radiotherapy was given to the initially invol...

Monitoring soil moisture over the Canadian Prairies with the ERS scatterometer

Abstract: The capability of the scatterometers onboard the European Remote Sensing Satellites (ERS-1 and ERS-2) for soil moisture retrieval is investigated. The ERS scatterometer consists of three antennas that illuminate the Earth's surface from three different viewing directions. This allows the authors to study the dependence of the backscattering coefficient /spl sigma//sup 0/ on the azimuth and the incidence angle. An analysis of ERS scatterometer data over the Canadian Prairie region shows that land surfaces are slightly anisotropic with respect to the azimuth angle. It is proposed to consider the azimuthal anisotropy as an additional error source to /spl sigma//sup 0/. The variation of /spl sigma//sup 0/ with the incidence angle was found to be linked to vegetation, but independent of soil moisture. Based on these observations, a method for the normalization of the backscattering coefficient with respect to the incidence angle is proposed. The normalized backscattering coefficient at an incidence angle of 40/spl deg/, /spl sigma//sup 0/(40), is sensitive to vegetation and, in the case of moderate vegetation (grassland to sparsely forested areas), to the soil moisture content. Soil moisture maps derived from ERS-1 scatterometer measurements are compared to maps representing conditions on annually cropped land showing agreement. Results suggest that, over the Canadian Prairies, estimates of the total water content in the soil profile might be possible with an accuracy of about 10% of field capacity if little or no rainfall has occurred for three days before radar image acquisition.

Impact of Preoperative Bimodality Induction Including Twice-Daily Radiation on Tumor Regression and Survival in Stage III Non–Small-Cell Lung Cancer

Abstract: PURPOSE: The objective of this prospective study was to assess the feasibility, toxicity, and efficacy of an intensive trimodality approach in stage III non–small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Fifty-four patients with NSCLC and biopsy-proven N2 nodes (IIIA; n = 25) or N3 nodes or T4 lesions (IIIB; n = 29) were administered two initial cycles of ifosfamide, carboplatin, and etoposide; subsequent radiotherapy (45 Gy, twice-daily 1.5 Gy) with concurrent carboplatin and vindesine; and surgery if the patient's disease was resectable or conventional radiotherapy (16 Gy, 2 Gy/d) if the patient's disease was not resectable or incompletely resectable. RESULTS: Thirty-seven patients (69%) responded to preoperative induction. Forty of 54 patients (74%) had disease that was resectable, with 34 (63%) complete resections (R0). A substantial pathologic response (tumor regression [TR] > 90%) was achieved in 27 of 54 patients (50%) and is revealed as an independent predictor for long-term survival after ...

The Modernization of Tradition: Thinking about Madness in Patna, India

Abstract: Thirty-nine educated middle-class residents of Patna, India, were interviewed about a vignette describing the behaviour of a seemingly mad man or woman. The interview explored their representations...

Amifostine--a radioprotector in locally advanced head and neck tumors.

Abstract: Purpose There are some preliminary informations about the beneficial use of amifostine in avoiding side effects in patients with head and neck tumors who underwent radiotherapy. Patients and method Amifostine was given as daily intravenous application (500 mg) 10 to 15 minutes prior to radiotherapy in 20 patients. The results were compared with another collective of patients which was similar. Results According to the WHO score mucositis became manifest in 10 patients (Grade I) and 4 patients (Grade II) in the amifostine group vs 9 patients (Grade II), 6 patients (Grade III) and 1 patient (Grade IV) in the control group. Xerostomia has been seen in 15 patients (Grade I) and 5 patients (Grade II) after administration of amifostine. Without the drug 2 patients suffered from xerostomia (Grade I), 8 patients (Grade II) and 8 patients (Grade III), respectively. Administering amifostine had been feasible and non problematic. Only a small rate of toxic side effects like nausea (11%) or emesis (4%) was documented. Conclusions Amifostine is an effective radioprotector decreasing acute and late side effects in patients with head and neck tumors.

Monitoring noise susceptibility: sensitivity of otoacoustic emissions and subjective audiometry.

Abstract: The capacity of different audiological methods to detect a high noise susceptibility was examined in 20 normally hearing and 26 especially noise-susceptible subjects. The latter were selected from 422 soldiers in field studies: they had shown a temporary threshold shift (TTS) in pure tone audiometry (PTA) after regular training with firearms. In laboratory experiments, the TTS-positive soldiers were re-examined using greatly reduced sound intensities, which caused no TTS in a control subject group. Before and after acoustic stimulation, different subjective (PTA, high frequency audiometry (HFA), upper limit of hearing (ULH)) and objective (transiently evoked otoacoustic emissions (TEOAE), distortion products (DPOAE)) audiological tests were performed. After exposure to low impact noise in the laboratory, in both PTA and HFA, a TTS was observed in 11.5% (N = 3) of the noise-susceptible group (compared to 0% in the control group). In the TTS-positive group, deterioration of the ULH occurred in 28% (...

The relationship between auditory threshold and evoked otoacoustic emissions.

Abstract: The aim of this study was to compare transiently evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) in normal hearing ears (n = 44) and ears with cochlear hearing loss (HL) to obtain defined data on qualitative and quantitative correlations. In addition, we wanted to determine the reliability with which a clinical examiner could predict a typical, idealized audiometric configuration from TEOAE measurements. In the hearing-impaired subjects (n = 149), a 50% reduction of OAE incidence was caused by a mean HL of 10.5 dB for TEOAE compared to 27 dB SPL for DPOAE. A 90% incidence reduction was found at a mean threshold elevation of 33 dB for TEOAE and 51 dB for DPOAE. Correlation between TEOAE amplitudes and HL was in general rather low (r = -0.1 to -0.5), while DPOAE amplitudes showed a slightly better correlation with HL (r = -0.3 to -0.6). In general, efforts to derive an audiogram from evoked OAE have been more promising for DPOAE than for TEOAE. However, our studies showed that approximately 40% of the ears with HL could be categorized correctly into one of five typical audiometric patterns from TEOAE measurements. Additionally, a cochlear HL in or near the medium frequency range was much more likely to cause a reduction in TEOAE than an isolated low- or high-frequency lesion. Accordingly, TEOAE were often preserved in ears with isolated HL in the high or low frequencies.

Norms and Foreign Policy: Constructivist Foreign Policy Theory

Abstract: Center for International Relations/Peace and Conflict Studies, Institute for Political Science, University of Tübingen Address: Melanchthonstr. 36, D-72074 Tübingen Phone: ++49 (0)7071 29-78372 Fax: ++49 (0)7071 29-2417 WWW Homepage: http://www.uni-tuebingen.de/uni/spi/ab2menu.htm Copyright: H. Boekle, V. Rittberger, W.Wagner Tübingen 1999 ISBN 3-927604-32-1 Editor: Volker Rittberger Redaktion: Klaus Stodick WWW-Layout: Jürgen Plieninger IfP, Center for International Relations/Peace and Conflict Studies, TAP 34A

Vergleich von ringförmiger und sektoraler Stadtstruktur bei Nachbarschaftsexternalitäten im monozentrischen System

Abstract: In der Stadtokonomie ergeben sich die Formen der sektoralen und der ringformigen Stadtstruktur als mogliche Ergebnisse der Segregation von demographisch verschiedenen Haushalten mit Nachbarschaftsexternalitaten. Rose-Ackerman [1973] postuliert, dass die Ringstruktur die Folge der Minimierung der Grenzlange zwischen schwarzen und weisen Haushalten sei. Diese Annahme wird in der New-Urban-Economics-Literatur recht haufig ubernommen. In diesem Beitrag wird auf der Grundlage eines Alonso-Mills-Muth-Modells gezeigt, dass Rose-Ackermans Hypothese nur in Situationen zulassig ist, in denen eine Gruppe deutlich in der Minderheit ist. In der Mehrheit der moglichen Verhaltnisse der Gruppengrosen ist eine sektorale Stadtstruktur vorteilhaft. Werden anstelle der Grenzlangen die an der Grenze anfallenden negativen Externalitaten verglichen, nimmt der Bereich der Gruppengrosenverhaltnisse, in denen die Sektorstruktur vorteilhaft ist, noch zu.

The Nearly Classical Behavior of a Pure Fluid on the Critical Isochore Very Near the Critical Point Under the Influence of Gravity

Abstract: Comprehensive measurements of the isothermal compressibility along the critical isochore in the critical region of pure sulfur hexafluoride (SF6) and pure carbon dioxide (CO2) were carried out. All measurements were performed with a multicell apparatus, especially designed for pρT measurements in the critical region. The height of the measuring cells was either 30 or 11 mm. Independent of the cell height, we found for both fluids nearly “classical” values for the critical exponent γ in the limiting approach to the critical point. However, at a certain distance from the critical point {(T − T c) ≈ 90 mK or τ ≈ 2.82 × 10−4 for SF6 and (T − T c) ≈ 55 mK or τ ≈ 1.81 × 10−4 for CO2}, we observed a transition to values of the critical exponents which nearly meet the predictions of the renormalization-group theory. Since in the fitting range (T − T c ≥ 1 mK) the correlation length (ξ ≤ 0.5 μm) is very much smaller than the geometrical dimensions of the measuring cells, we conclude that the reason for the different behavior is an explicit gravity effect governing the inner critical region. The two different loci of the transition points for sulfur hexafluoride and carbon dioxide can be attributed to the different gravity impact on the fluid corresponding to the different critical densities of the two substances.

SIBERIA-SAR imaging for boreal ecology and radar interferometry applications

Abstract: Radar remote sensing has become an increasingly important tool for observations of forest ecosystems. SIBERIA merges the advantages of operational SAR satellites by analysing dual-frequency composites and interferometric products. SIBERIA demonstrates the feasibility of radar remote sensing technology for large-scale vegetation mapping and combines and refines state-of-the-art technology and techniques. Where interferometric coherence allows, high quality digital elevation models will be generated.

Characterization of silicon microstrip detectors using an infrared laser system

Abstract: An infrared laser system with variable wavelength is used to study fundamental properties of silicon microstrip detectors. Results of measurements concerning charge sharing among adjacent readout strips and depletion mapping are presented. The results are interpreted in a model framework which describes the charge sharing with the help of the so-called η -function. The wavelength dependence of the η -function is studied. Surface effects important for short wavelengths are observed.

Results of fast neutron therapy of adenoid cystic carcinoma of the salivary glands.

Abstract: Introduction Patients with adenoid cystic carcinoma (ACC) of the salivary glands in the head and neck region have been reported to benefit from neutron radiotherapy according to significant clinical experience. A prospective clinical trial on the efficacy and treatment related morbidity of fast neutron radiotherapy was performed between 1986 and 1995 at the (d+T) 14 MeV neutron generator in Munster.

A New Apparatus for Combined Measurements of the Viscosity and Density of Fluids for Temperatures from 233 To 523 K at Pressures up to 30 Mpa

Abstract: A new apparatus for measuring the viscosity and density of fluids is presented. The main element of the instrument is an electronically controlled magnetic suspension coupling. For the density measurement (buoyancy principle according to the single-sinker method), this coupling is used for the contactless transfer of the forces acting on a sinker in the measuring cell to an analytical balance. The coupling also serves as a frictionless bearing for a slender rotating cylindrical body which is slowed down due to the viscous drag of the fluid surrounding the cylinder. The viscosity of the fluid can be directly determined from the decay rate of the rotational frequency. The new combined viscometer-densimeter covers a viscosity range of 5 to 150 μPa·s and a density range from 20 to 2000 kg·m−3 at temperatures from 233 to 523 K and pressures up to 30 MPa. Test measurements on the viscosities and densities of nitrogen and carbon dioxide at 253, 293, and 523 K at pressures up to 30 MPa show an estimated total uncertainty of ±0.6 to ±1.0% in viscosity and of ±0.02 to ±0.05% in density.

Vulvar carcinoma: a retrospective analysis of 80 patients.

Abstract: We evaluated the files of 80 women who were treated for vulvar carcinoma. In 13 women radiotherapy was used as primary treatment, in 45 cases postoperatively and in 22 women because of local recurrence. Patients older than 60 years had a significantly worse 5-year survival rate (39%) than younger women (57%) (p=0.02). The 5-year survival rate for patients with negative nodes was 72% versus 46% for the N1- and 47% for the N2-status, respectively (p=0.027). The 5-year actuarial survival rate for patients with tumor manifestation in the clitoris was 77.9% versus 26.1% for patients with tumors in the labia majora (p=0.0044). There was no difference in survival in patients who had been treated with radical vulvectomy and bilateral groin dissection plus local radiotherapy when compared with patients who had been irradiated (whole pelvis) after tumor resection alone. The 5-year survival rates and the median survival time were identical in both groups (61%/62 months).

Radiotherapy on adult patients with soft tissue sarcoma with fast neutrons or photons.

Abstract: Through adjuvant photon radiotherapy, it is possible to improve tumor control as well as avoid ultra radical surgery in patients with soft tissue sarcoma. Similar results have been obtained in cases of incomplete resected G1/G2 sarcoma after applying neutron radiotherapy. We compared the results of a group of patients with soft tissue sarcoma treated with those having received photon therapy (100 patients) or neutron therapy (61 patients). The median dose in the photon treated group was 60 Gy (range 45 to 65 Gy). The neutron therapy group received a median dose of 14. 1 Gy (range 5.0 to 18.57 Gy). Patients treated with mixed-beam irradiation received an average dose of 36.5 Gy photon and 8.5 Gy neutrons. The 5-year survival rate of the photon group rated 43.1%. In the neutron group we found 42.5%, respectively. In both groups the results of surgical resection and grading were of high significance according to survival. 4% of the patients belonging to the photon group developed grade III/IV WHO side effects. In the neutron group side effects grade III/IV WHO were observed in 11% of the cases. Comparing treatment results of neutron and photon therapy we demonstrated that incompletely resected G1 and G2 tumor patients show greater benefit in the case of neutron radiotherapy.

Force measurements on hydrophobized silica surfaces by using AFM

Abstract: Force measurements between SiO2 surfaces with and without adsorbed phenyl groups in aqueous media using the atomic force microscope (AFM) are compared. An oxidized silicon tip and an oxidized silicon wafer were hydrophobized with phenyl groups, and the long-range attraction induced by hydrophobation is shown in force vs. distance curves. The observed differences prove that the silanol groups of the unmodified SiO2 surface are replaced by the phenyl groups.

The HERA-B vertex detector

Abstract: The design of the vertex detector of the HERA-B experiment at DESY is reviewed, and its components are described. The silicon microstrip detectors were optimized for radiation hardness: results from irradiation tests, reproducing the challenging situation in the experiment, are presented. Since spring 1999, much of the system has been installed and is operational. The detector performance and results from track and vertex reconstruction are presented.

SIBERIA - 1st Progress Report

Abstract: This report describes the porgress made and the problems encountered in the first six months of the SIBERIA project. The limited data availability has hampered methodological development and has caused a delay of approximately three months. Nevertheless, preparatory work and first tests based on sample imagery have been performed.

Erste Erfahrungen mit der IAPWS-IF97 : Auswirkungen der neuen Industrie-Formulation auf Kraftwerksprozesse im Vergleich zur IFC-67

Abstract: Since January 1999 the new industrial formulation IAPWS-IF97 has been valid without restriction. The article presents the first empirical values regarding the effects on the thermal efficiency and the calculation of steam boilers when changing from IFC 67 to IAPWS-IF97.

SIBERIA - 2nd Progress Report

Abstract: This report describes the work done during the second six month period of the SIBERIA project. With the increasing availability of ground truth information and ERS SAR imagery methodological questions could be adressed accordingly. Procedures for calculating geocoded incidence angle mask (GIMs), masking of shadow and layover areas, co-registration of satellite and GIS data, calibration of ERS images, filtering, rule- and data-based classification, accuracy assessment, and data transfer have been developed and tested. The results so far suggest that the ERS coherence and the JERS amplitude are the most important parameters for forest and landcover classification.