bluuebunny/crossref_metadata_2025 huggingface dataset:
PROPAGATION MODEL ACCURACY FOR MFP
Authors: TOLSTOY A.
Published: April 2003

The selection of a propagation model for use in many underwater acoustic applications has been understood to be highly important for quite some time. However, it has not previously been understood how various models might actually degrade Matched Field Processing (MFP) performance even when input parameters are known exactly. That is, acoustic propagation models have not previously been benchmarked within the context of MFP where acoustic amplitudes and phases need to be highly accurate depending on the nature of the processor of interest, such as for a high resolution Capon processor. This paper discusses the SCOOTER, ORCA, and KRAKEN models, and a high angle PE model within the context of MFP. These models are compared to the SAFARI data generated for the Workshop97 geoacoustic inversion CAL case. In general it seems that all the abovementioned models show excellent accuracy for use with the Linear Processor. However, it is found that KRAKEN may experience unexpected difficulties at unpredictable frequencies where these errors can affect high resolution processing (as demonstrated by geoacoustic inversions via the RIGS method),14 that SCOOTER and PE require relatively long CPU times for high accuracy, and that how accurately parameters are interpolated, e.g., sound-speed profiles, can also be important. It should be noted that all of the models discussed in this work may be considered to be very accurate in the context of most applications, particularly those involving data.
WHAT ABOUT ADIABATIC NORMAL MODES?
Authors: TOLSTOY A.
Published: April 2003

In this paper we closely examine the performance of several propagation models, i.e., KRAKEN (coupled and adiabatic) and PE (energy-conserving), applied to a number of the SWAM'99 range-dependent shallow water test cases (FLAT, DOWN, and UP). We begin by considering range-independent behavior (including the ORCA model) in: the CAL case of Workshop'97 (Vancouver, '97),9 the first segment of FLATa, and the Benchmark Wedge test case3 but with a flat bottom of 200 m depth. We next examine the proper Benchmark Wedge behavior for the sloping bottom for our PE (conserving and nonconserving) and for our normal mode model (KRAKEN, adiabatic and coupled). These preliminary tests confirm that the models are behaving properly under known conditions and that the input parameters have been appropriately set. Thus, when we study the models' behavior on the new SWAM'99 cases we will have some confidence that they are being applied properly. It is nontrivial to run these models even when one is familiar with them. The SWAM'99 test cases which are examined here are run only to 10 km range (five-step segments) and at a single frequency of 25 Hz. No elasticity is considered. We find that all the models generally agree, but there are quantitive differences. Since there are no proper benchmark solutions for these SWAM'99 test cases, it is difficult to determine to what extent any of them are in error. However, for the purposes of Matched Field Processing, particularly the tomographic geoacoustic inversion using adibatic normal modes (KRAKEN), it is likely that the simple adiabatic normal mode KRAKEN model is sufficiently accurate under most circumstances, i.e., unless there is a loss or gain of a critical mode.
ENHANCED RAY THEORY
Authors: MALTSEV NICK
Published: April 2003

The numerical problems of SWAM'99 workshop are quite challenging for any method of sound field calculation. This report presents a detailed description of the enhanced ray theory approach briefly outlined in Ref. 2. It contains a new method of phase and amplitude computation along the ray, a new method of calculation of eigenrays, and a new method of analytic approximation of sound-speed and density. An application of these methods is presented.
THREE-DIMENSIONAL TIME DOMAIN MODELING OF ULTRASONIC WAVE PROPAGATION IN CONCRETE IN EXPLICIT CONSIDERATION OF AGGREGATES AND POROSITY
Authors: SCHUBERT FRANK , KOEHLER BERND
Published: April 2003

Concrete as strongly heterogeneous and highly-packed composite material represents a very important but also very difficult object for ultrasonic nondestructive testing (NDT). Due to the high scatterer density, ultrasonic wave propagation in this material consists of a complex mixture of multiple scattering, mode conversion and diffusive energy transport. In order to obtain a better understanding of the effect of aggregates and porosity on elastic wave propagation in concrete and to optimize imaging techniques, e.g. synthetic aperture focusing technique (SAFT),1 it is useful to model the wave propagation and scattering process explicitly in the time domain. In this paper, the three-dimensional EFIT-Code (EFIT: Elastodynamic Finite Integration Technique)2 with periodic boundary conditions is used to model attenuation and dispersion of a plane longitudinal wave propagating in a synthetic three-dimensional concrete plate. Systematic parameter studies are carried out in order to demonstrate the effect of porosity and that of different aggregates. Finally, the simulation results are compared with former plane strain simulations, revealing significant differences in attenuation and signal-to-noise ratio between the two-dimensional and the more realistic three-dimensional case.
ACOUSTIC EXCITATION OF SCHOLTE-STONELEY AND LAMB WAVES ON A REINFORCED CYLINDRICAL SHELL
Authors: PONCELET O. , GERARD A. , DESCHAMPS M. , GURAN A. , BELINSKIY B. , DAUER J. , ÜBERALL H.
Published: April 2003

The scattering of sound from a submerged elastic cylindrical shell, evacuated and bare of reinforcements, is known to excite the pseudo-Lamb S 0 wave propagating circumferentially around the shell, and also the Scholte-Stoneley (A) wave, but the latter only in a limited frequency region. For thin shells (of less than 10% thickness), excitation of the A 0 wave has not been observed in a distinct resonant fashion, at least at moderate frequencies around and above coincidence. (Its excitation in a nonresonant fashion, i.e., immediately beyond the locus of its generation, has, however, recently been observed experimentally.1) We show here that even the presence of internal attachments to the shell will not cause the excitation of the A 0 wave, while greatly extending the excitation region of the A wave, however. A modification of resonance frequencies by the internal attachments ("frequency doubling") is discussed, and is explained by the phase matching principle of resonance excitation.
ON THE VIBRATION OF MEMBRANE PARTIALLY PROTRUDING ABOVE THE SURFACE OF LIQUID
Authors: FILIPPENKO GEORGE V. , KOUZOV DANIIL P.
Published: April 2003

The problem of free oscillations of membrane partially submerged into the layer of liquid is considered in the rigorous mathematical statement. The exact analytical solution of the problem is constructed. The eigen frequencies and the eigen functions of vibrating membrane basing on analyses of exact solution are calculated. The influence of liquid's level on eigen frequencies and on eigen functions is analysed.
CONDITIONAL INDEPENDENCE RELATIONS IN POSSIBILITY THEORY
Authors: VEJNAROVÁ JIŘINA
Published: April 2003

The goal of this paper is to survey and briefly discuss various rules of conditioning proposed in the framework of possibility theory, as well as various conditional independence relations suggested for these rules. These conditioning rules and conditional independence relations are confronted with formal properties of conditional independence. Special attention is paid to the conditioning in the sense of measure-theoretic approach (based on the notion of a t-norm) recently introduced by de Cooman. It is shown that this approach to conditioning and the related conditional independence notion generalizes and unifies some of the previously suggested rules and conditional independence relations. The properties of the proposed conditional independence relation completely correspond to those possessed by stochastic conditional independence.
ON THE STRUCTURE OF PROBABILITY FUNCTIONS IN THE NATURAL WORLD
Authors: PARIS J. B. , WATTON P. N. , WILMERS G. M.
Published: April 2003

The purpose of this paper is to describe the underlying insights and results obtained by the authors, and others, in a series of papers aimed at modeling the distribution of 'natural' probability functions, more precisely the probability functions on {0, 1}n which we encounter naturally in the real world as subjects for statistical inference, by identifying such functions with large, random, sentences of the propositional calculus. We explain how this approach produces a robust parameterized family of priors, Jn, with several of the properties we might have hoped for in the context, for example marginalisation, invariance under (weak) renaming, and an emphasis on multivariate probability functions exhibiting high interdependence between features.
A NON-SPECIFICITY MEASURE FOR CONVEX SETS OF PROBABILITY DISTRIBUTIONS
Authors: ABELLAN JOAQUIN , MORAL SERAFIN
Published: April 2003

In belief functions, there are two types of uncertainty which are due to lack of knowledge: randomness and non-specificity. In this paper, we present a non-specificity measure for convex sets of probability distributions that generalizes Dubois and Prade's non-specificity measure in the Dempster-Shafer theory of evidence.
LIMIT T-NORMS AS A BASIS FOR THE CONSTRUCTION OF NEW T-NORMS
Authors: SMUTNÁ DANA
Published: April 2003

Transformation of the Minimum t-norm TM by means of a non-decreasing transformation φ of the unit interval [0, 1] yielding triangular norm is studied. Full characterization of such φ is given. In the same spirit, transformations of the Drastic product TD are studied.
AN AXIOMATIC APPROACH TO A CLASS OF RANKING FUNCTIONS FOR TRIANGULAR FUZZY NUMBERS
Authors: RICCI ROBERTO GHISELLI
Published: April 2003

This paper deals with the problem of ranking a set of alternatives, represented by triangular fuzzy numbers, in decision-making situations. A new approach is followed through the definition of some axiomatic requirements which represent the essential properties that characterize an arbitrary ranking function. A notion of degree of risk associated to every ranking function is proposed to discriminate equivalent alternatives.
THE INFLUENCE OF ION IRRADIATION ON THE ABSOLUTE QUANTUM PHOTOYIELD OF DIAMOND FILMS STUDIED BY ELECTRON SPECTROSCOPY AND H+ PHOTODESORPTION
Authors: LAIKHTMAN A. , HOFFMAN A.
Published: April 2003

In this study we report on absolute quantum photoyield (QPY) measurements from well-defined defective diamond surfaces in the 140–200 nm spectral range. The effect of defects in polycrystalline diamond films on their photoemission properties is studied by intentionally introducing damage using room temperature 30 keV Xe + ion bombardment to doses ranging from 2×1013 to 2×1015 ions/cm 2. Ion bombardment results in a drastic degradation of the QPY, to less than 1% at 140 nm, even at the lowest implantation dose compared to ~11.5% measured for the unimplanted diamond film. Analysis of the ion-damaged diamond films is performed by photon-stimulated ion desorption (PSID) measurements of H +, high resolution C(KLL) Auger electron spectroscopy and X-ray photoelectron spectroscopy. These measurements reveal that the decay in photoemission is due to the gradual formation of nondiamond carbon in the near-surface region. This damage leads to a change of the electron affinity from negative to positive, as determined by secondary electron emission measurements. PSID measurements reveal that the ion-bombarded diamond films remain hydrogen-terminated. MW hydrogen plasma treatment results in complete regeneration of the photoemission properties for diamond films implanted to Xe + doses of up to 2×1014 cm -2; only partial recovery was obtained for films irradiated with a higher ion dose.
SPECTROMICROSCOPY STUDIES WITH HIGH SPATIAL RESOLUTION
Authors: KISKINOVA MAYA
Published: April 2003

This paper reviews some recent achievements of synchrotron radiation XPS microscopy in the characterization of surfaces and interfaces of morphologically complex and multiphase materials. Using selected results obtained with the scanning photoelectron microscope built at the synchrotron light source ELETTRA in Trieste, the novel information provided by combining chemical sensitivity with submicron spatial resolution is presented.
SCANNING PROBE MICROSCOPY APPLIED TO MATERIALS SCIENCE AND BIOLOGY
Authors: PERFETTI PAOLO , CRICENTI A. , GENEROSI R.
Published: April 2003

A brief description of the scanning probe microscopies is given, with particular attention to atomic force microscopy (AFM) and near field optical microscopy (SNOM). We show examples of AFM used in friction mode and in topographic mode. The basic principles of SNOM are also presented, together with images obtained on artificial diamond films and on neuron networks.
COMPARATIVE STUDY OF IONIZED METAL PLASMA Ta, TaN AND MULTISTACKED Ta/TaN STRUCTURE AS DIFFUSION BARRIERS FOR Cu METALLIZATION
Authors: LI C. Y. , HE LEI , WU J. J. , QIAN Y. , KOH L. T. , YU B. , FOO P. D. , XIE JOSEPH , ZHANG D. H.
Published: April 2003

The properties of the ion-metal-plasma (IMP) deposited Ta, TaN and multistacked Ta/TaN between Cu and SiO 2 have been investigated in the Cu /barrier layer/ SiO 2/ Si structures using four-point probe, atomic force microscopy (AFM), X-ray diffraction (XRD), Rutherford back scattering (RBS), tunneling electron microscopy (TEM) and metal-pulse techniques. It was found that the multistacked Ta/TaN barrier shows the best metallurgical and thermal stability among three of them, and the superior stability is found to result mainly from the nanocrystalline microstructure rather than the density and grain size of the barrier materials. The microstructure, which contains nanocrystalline grain and amorphous-like matrix, can better retard the intermixing and diffusion of Cu, Ta, O and Si atoms, due likely to reduction of grain boundaries that are the main passway for the diffusion of these elements.
SURFACE STRUCTURES OF α-Fe2O3(0001) PHASES DETERMINED BY LEED CRYSTALLOGRAPHY
Authors: KETTELER GUIDO , WEISS WERNER , RANKE WOLFGANG
Published: April 2003

We present a dynamical tensor low energy electron diffraction (LEED) study of α- Fe 2 O 3(0001) surface structures that form in an oxygen pressure range from 10-5 to 1 mbar. Epitaxial α- Fe 2 O 3(0001) films were prepared on Pt(111) in defined oxygen partial pressures at temperatures of around 1100 K. In 1 mbar O 2 strongly relaxed oxygen-terminated surface structures are formed, while in 10-5 mbar O 2 three different surface structures yield rather good Pendry R factors. Further experimental evidence from scanning tunneling spectroscopy (STM) and ion scattering spectroscopy (ISS), in combination with a critical review of the literature, is only consistent with a hydroxyl termination forming in 10-5 mbar O 2. The stabilization of both structures is discussed on the basis of electrostatic arguments considering the boundary conditions at the oxide–gas as well as the oxide–substrate interface (autocompensation). For oxygen pressures between 10-4 and 10-1 mbar O 2, the two domains coexist as analyzed using a new, modified version of the symmetrized automated tensor LEED program package.

The system investigated in this study turns out to be very complex and the LEED analysis alone is not capable of identifying the involved surface structures unambiguously. Only in combination with results from other surface-sensitive methods was it possible to deduce models for the most likely surface structures.
AFM STUDIES OF VARIOUS NIOBIUM AND ALUMINIUM THIN FILMS FOR THEIR USE IN JOSEPHSON JUNCTIONS
Authors: NASEEM SHAHZAD
Published: April 2003

Nb thin films have been prepared with e-beam evaporation under UHV conditions, and by RF magnetron sputtering. Al thin films were deposited by resistive heating in the UHV chamber. The preparation of these films and the trilayers of Nb/AlO x /Nb are intended for their use in Josephson junctions. Surface studies of these films are undertaken by using an atomic force microscope in the noncontact mode. These studies have revealed that the sputter-deposited Nb film surface is smoother than that of the UHV e-beam evaporated with R rms values of 3.5 and 4.0 nm respectively. Al thin films have a very smooth surface, with an R rms value of only 0.9 nm. Consequently, UHV-evaporated Nb thin films deposited on top of Al thin films are smoother, with a surface roughness of 1.8 nm.
FRESH TUBULAR LONG BONE AUTOGRAFTS AND ALLOGRAFTS IN THE HEALING OF CANINE ULNAR DEFECT FIXED WITH INTRAMEDULLARY KIRSCHNER WIRE
Authors: Tuominen Tapio , Jämsä Timo , Tuukkanen Juha , Lindholm T. Sam , Jalovaara Pekka
Published: April 2003

We developed a model where a 2-cm full-thickness canine ulnar defect bridged with a tubular diaphyseal bone transplant was stabilized with an intramedullary Kirschner wire. This model was used to compare tubular autografts and allografts in the reconstruction of segmental ulnar defects in 12 adult beagle dogs. The dogs were followed for nine months and X-ray radiographs were taken every three weeks. The overall healing was good and all the dogs were able to walk normally during the follow-up. After nine months, the ulnas were harvested and mechanical testing and histological analyses were made. Of the ulnar defects, 4/6 in the autograft group and 3/6 in the allograft group had a complete union. Of the Kirschner wires, 6/12 had broken during the follow-up. This did not have any effect on the bone union, however. The autograft group had better results in mechanical testing although the difference was statistically significant only for maximal absorbed energy. We conclude that the segmental ulnar defect model fixed with an intramedullary wire seems to be a feasible alternative in bone transplant studies, although the semirigid fixation resulted in breakage of the wire in many cases. The overall healing was good after both autograft and allograft transplantations, but autografts seemed to be slightly better.
RISKY OPTIONS SIMPLIFIED
Authors: SCHWEIZER MARTIN
Published: April 2003

We study a general version of a quadratic approach to the pricing of options in an abstract financial market. The resulting price is the expectation of the option's discounted payoff under the variance-optimal signed martingale measure, and we give a very simple proof of this result. A conjecture of G. Wolczyńska essentially says that this measure coincides with the minimal signed martingale measure in a certain class of models. We show by a counterexample that this conjecture is false.
PRICING DEFAULTABLE DEBT: SOME EXACT RESULTS
Authors: WANG D. F.
Published: April 2003

In this letter, I consider the issue of pricing risky debt by following Merton's approach. I generalize Merton's results to the case where the interest rate is modeled by the CIR term structure. Exact closed forms are provided for the risky debt's price.
LÉVY–KHINTCHINE REPRESENTATION ON LOCAL STURM–LIOUVILLE HYPERGROUPS
Authors: RENTZSCH CHRISTIAN
Published: April 2003

We introduce local Sturm–Liouville hypergroups and prove a Lévy–Khintchine formula for generators of convolution semigroups on these hypergroups. Then we show that many well-known hypergroups are local Sturm–Liouville hypergroups. Moreover, we study the canonical form of the generators on the given examples.
QUANTUM DYNAMICAL ENTROPY FOR COMPLETELY POSITIVE MAP
Authors: KOSSAKOWSKI A. , OHYA M. , WATANABE N.
Published: April 2003

A dynamical entropy for not only shift but also completely positive (CP) map is defined by generalizing the AOW entropy1 defined through quantum Markov chain and AF entropy defined by a finite operational partition. Our dynamical entropy is numerically computed for several models.
WHITE NOISE ANALYSIS ON A NEW SPACE OF HIDA DISTRIBUTIONS
Authors: KUBO I. , KUO H.-H. , SENGUPTA A.
Published: April 2003

Let {α(n); n≥0} be a sequence of positive numbers satisfying certain conditions. A Gel'fand triple [Formula: see text] associated with the sequence {α (n); n ≥ 0} has been introduced on a white noise space (ℰ′,μ) by Cochran, Kuo and Sengupta. In this paper we obtain additional conditions on the sequence {α(n); n≥0} in order to carry out white noise distribution theory on the space (ℰ′,μ). Moreover, we show that the Bell numbers satisfy these additional conditions.
TIGHTNESS OF SOBOLEV CAPACITIES IN INFINITE DIMENSIONAL SPACES
Authors: PUGACHEV O. V.
Published: April 2003

We prove tightness of capacities generated by Sobolev classes of all orders in locally convex spaces under quite mild conditions on the space and on the measure.
INNOVATION IN COMMUNICATING IDEAS ABOUT THE FUTURE
Authors: RINGLAND GILL
Published: April 2003

We in ICL have understood some of the challenges and opportunities of the future, but have not yet found a way of communicating this effectively to our customers. This paper describes the background to our innovation in experimenting with using virtual reality to communicate ideas about the future, and the lessons learnt so far.
COMPETITION AND IT-BASED INNOVATION IN BANKING SERVICES
Authors: UCHUPALANAN KITTIWAT
Published: April 2003

This article examines the dynamic relationships between competitive strategy and information technology (IT)-based product and process innovation in financial services. The study draws on detailed case studies of five IT-based innovations: Interbranch Online service, Automated Teller Machine service, Credit Card service, Remote Banking service, and Electronic Funds Transfer at Point of Sale service. It examines the development of these innovations in the Thai banking industry from the mid-1960s. The results indicate the limitations of the Reverse Product Cycle model approach, and an alternative conceptual framework and a country-specific innovation model are proposed. Possible avenues for further research on innovation in services and service innovation are suggested, together with steps towards developing a unified approach to innovation and competition for both the service and manufacturing functions.
A COMPLEX SYSTEMS APPROACH TO LEARNING IN ADAPTIVE NETWORKS
Authors: ALLEN PETER M.
Published: April 2003

In today's economy, the key ingredients in success and survival are adaptability and the capacity to learn and change. Recent progress in the theory of complex systems provides a new basis for our understanding of how this may actually occur, and the factors on which it depends. Complex systems thinking shows what assumptions underlie the reduction of some part of reality to a mechanical model. They demonstrate that the simplicity and "knowledge" derived from such representations can lead to an understanding that entirely misses the most important, strategic changes that may occur. Complex systems models reveal the key processes that underlie "learning", and recognise the limits to knowledge and the inherent reality of uncertainty. They demonstrate the fundamental importance of internal, microdiversity within systems, as the source of exploration that drives learning. These ideas are explained and presented in a simple model of emergent co-evolution, where the exploration of internal diversity leads to the formation of a complex, with synergetic attributes. The paper describes and models briefly the uncertainties inherent in the definition and development of a new product or service. A further model involving complex products is briefly described which shows the importance of "search" in "knowledge generation" for the success of adaptive industrial networks and clusters. All this leads to the statement of a "law of excess diversity" which states that the long-term survival of a system requires more internal diversity than appears requisite at any time.
RULE-BASED DECISION MAKING AND ITS APPLICABILITY TO ENVIRONMENTAL-RELATED TRADE DISPUTES IN THE WORLD TRADE ORGANISATION (WTO)
Authors: HADDOCK JANET
Published: April 2003

How environmental-related trade disputes are handled within the WTO have become the subject of increasingly intense debate amongst environmentalists. This paper considers whether the process used in dispute settlement is appropriate for environmental-related cases, given their complex nature. The paper looks at the adequacy of the current approach in terms of the extent to which dispute decisions can be seen to meet the main WTO objectives of maximisation of economic welfare — a concept that requires recognition of social and environmental costs and values. The author suggests an alternative approach, using a comprehensive data analysis framework, and shows that such an approach is not in evidence currently. While such an approach is considered as a conceptually ideal method for analysis, a number of practical limitations to its implementation are noted.
Optical Diagnostics for Thin Film Processing
Authors: Herman Irving P.
Published: April 2003

▪ Abstract  Optical diagnostics are used to probe the plasma or neutral gas above the substrate, particles in the gas or on the surface, the film surface and reactor walls, the film itself, and the substrate during thin film processing. The development and application of optical probes are highlighted, in particular for analyzing plasma/gas phase intermediates and products and film composition, and performing metrology, thermometry, and endpoint detection and control. Probing etching (particularly plasma etching) and deposition (particularly epitaxy) are emphasized.
Uric Acid and Survival in Chronic Heart Failure
Authors: Anker Stefan D. , Doehner Wolfram , Rauchhaus Mathias , Sharma Rakesh , Francis Darrel , Knosalla Christoph , Davos Constantinos H. , Cicoira Mariantonietta , Shamim Waqar , Kemp Michel , Segal Robert , Osterziel Karl Josef , Leyva Francisco , Hetzer Roland , Ponikowski Piotr , Coats Andrew J.S.
Published: April 2003

Background—

Serum uric acid (UA) could be a valid prognostic marker and useful for metabolic, hemodynamic, and functional (MFH) staging in chronic heart failure (CHF).

Methods and Results—

For the derivation study, 112 patients with CHF (age 59±12 years, peak oxygen consumption [V̇
o
2
] 17±7 mL/kg per minute) were recruited. In separate studies, we validated the prognostic value of UA (n=182) and investigated the relationship between MFH score and the decision to list patients for heart transplantation (n=120). In the derivation study, the best mortality predicting UA cutoff (at 12 months) was 565 μmol/L (9.50 mg/dL) (independently of age, peak V̇
o
2
, left ventricular ejection fraction, diuretic dose, sodium, creatinine, and urea;
P
<0.0001). In the validation study, UA ≥565 μmol/L predicted mortality (hazard ratio, 7.14;
P
<0.0001). In 16 patients (from both studies) with UA ≥565 μmol/L, left ventricular ejection fraction ≤25% and peak V̇
o
2
≤14 mL/kg per min (MFH score 3), 12-month survival was lowest (31%) compared with patients with 2 (64%), 1 (77%), or no (98%,
P
<0.0001) risk factor. In an independent study, 51% of patients with MFH score 2 and 81% of patients with MFH score 3 were listed for transplantation. The positive predictive value of not being listed for heart transplantation with an MFH score of 0 or 1 was 100%.

Conclusions—

High serum UA levels are a strong, independent marker of impaired prognosis in patients with moderate to severe CHF. The relationship between serum UA and survival in CHF is graded. MFH staging of patients with CHF is feasible.
Dopamine-Mediated Inhibition of Renal Na,K-ATPase Is Reduced by Insulin
Authors: Banday Anees Ahmad , Asghar Mohammad , Hussain Tahir , Lokhandwala Mustafa F.
Published: April 2003

Recently we have reported that rosiglitazone treatment of obese Zucker rats reduced plasma insulin and restored the ability of dopamine to inhibit Na,K-ATPase (NKA) in renal proximal tubules. The present study was performed to test the hypothesis that a chronic increase in levels of insulin causes a decrease in expression of the D1 receptor and its uncoupling from G proteins, which may account for the diminished inhibitory effect of dopamine on NKA in obese Zucker rats. We conducted experiments in primary proximal tubule epithelial cells obtained from Sprague-Dawley rat kidneys. These cells at 80% to 90% confluence were pretreated with insulin (100 nmol/L for 24 hours) in growth factor–/serum-free medium. SKF-38393, a D1 receptor agonist, inhibited NKA activity in untreated cells, but the agonist failed to inhibit enzyme activity in insulin-pretreated cells. Basal NKA activity was similar in untreated and insulin-pretreated cells. Measurement of D1 receptors in the plasma membranes revealed that [
3
H]SCH-23390 binding, a D1 receptor ligand, as well as D1 receptor protein abundance, was significantly reduced in insulin-pretreated cells compared with untreated cells. SKF-38393 (10 μmol/L) elicited significant stimulation of [
35
S]GTPγS binding in the membranes from control cells, suggesting that the D1 receptor–G protein coupling was intact. However, the stimulatory effect of SKF-38393 was absent in membranes from insulin-pretreated cells. We suggest that chronic exposure of cells to insulin causes both the reduction in D1 receptor abundance and its uncoupling from G proteins. These phenomena might account for the diminished inhibitory effect of dopamine on NKA activity in hyperinsulinemic rats.
LA LITTÉRATURE SELON MANFALŪTĪ
Authors: Hallaq Boutros
Published: April 2003

Considérée par la critique dominante comme sentimentaliste, larmoyante, voire naïve, la littérature de Manfalūtī se revendique, pour sa part, d'un projet grandiose et quelque peu paradoxal: il s'agit d'afirmer l'autonomie du littéraire par rapport au politique compris comme gestion de la vie de la cité (La littérature, un monde autotélique) et, en même temps, de concevoir la littérature comme une mission prophétique (La littérature, un monde prophétique) et de l'investir dans une tâche de modernisation, l'émergence du moi (la littérature, procès d'individualisation). En rupture totale avec la dynamique de la Nahda ce projet se veut comme une refondation du littéraire qui s'apparente, malgré les apparences, à la démarche de Gibrān qui a des accointances certaines avec le projet radical du premier romantisme allemand appelé romantisme d'Iéna.
Expert testimony in court. 2: In the witness box
Authors: Casey Patricia
Published: April 2003

Thorough preparation is essential before going into the witness box as an expert witness. This involves, among other things, rereading all the case notes and other relevant documentation and being familiar with recent research in areas related to the case. Areas of probable disagreement between experts should be discussed during consultation with counsel, since cross-examination is likely to focus on these. A specific protocol applies in the courtroom, especially when in the witness box. The approach to examination-in-chief is outlined and the tactics used during cross-examination are described, as these can be used to undermine the evidence of the witness.
Invited commentary on Expert testimony in court
Authors: Chiswick Derek
Published: April 2003

Patricia Casey's papers (2003a, b, this issue) cover the situation regarding expert witnesses in England and Wales and in Ireland. The situation in Scotland is outlined below.
Invited commentary on The mental health of prisoners
Authors: Maden Tony
Published: April 2003

Psychiatrists have always been concerned about the mental health of prisoners. If they did not devote much energy to their treatment, it was only because they had more-pressing problems, including how to squeeze ten patients into nine beds. In any case, it was someone else's job to look after prisoners. Luke Birmingham's article (Birmingham, 2003, this issue) could not be more timely, as this situation has now changed. With the publication of The Future Organisation of Prison Healthcare (Prison Service & NHS Executive Working Group, 1999), and the creation of a joint Department of Health and Home Office task force, the Government has made it clear that the problem of mentally disordered offenders belongs to the National Health Service (NHS). There is a plan, there is a partnership and there are targets. Can those of us who have been worrying about prisoners with mental illness sit back and relax, as the solution unfolds?
IGDA. 4: Evaluation of symptoms and mental state
Authors:   IGDA Workgroup, WPA
Published: April 2003

All patients presenting for psychiatric care should receive a comprehensive descriptive psychopathological evaluation. This should include a broad symptomatological assessment specifying the time frames of the findings, as well as a mental state examination at the time of the patient interview (Table 4.1).
Progress in Linear Programming-Based Algorithms for Integer Programming: An Exposition
Authors: Johnson Ellis L. , Nemhauser George L. , Savelsbergh Martin W.P.
Published: April 2003

This paper is about modeling and solving mixed integer programming (MIP) problems. In the last decade, the use of mixed integer programming models has increased dramatically. Fifteen years ago, mainframe computers were required to solve problems with a hundred integer variables. Now it is possible to solve problems with thousands of integer variables on a personal computer and obtain provably good approximate solutions to problems such as set partitioning with millions of binary variables. These advances have been made possible by developments in modeling, algorithms, software, and hardware. This paper focuses on effective modeling, preprocessing, and the methodologies of branch-and-cut and branch-and-price, which are the techniques that make it possible to treat problems with either a very large number of constraints or a very large number of variables. We show how these techniques are useful in important application areas such as network design and crew scheduling. Finally, we discuss the relatively new research areas of parallel integer programming and stochastic integer programming.
Zur Adhäsion von polymeren. Fortschrittsbericht
Authors: Jacobasch H.‐J. , Freitag K.‐H.
Published: April 2003

Nach einem Überblick über die Theorie der Adhäsion und die Methoden zur Haftkraftmessung werden Möglichkeiten zur experimentellen Bestimmung der Adhäsionskonstanten von Polymeren dargestellt. Es werden die Ergebnisse von Untersuchungen mitgeteilt, die die Bestimmung der VAN‐DER‐Waals‐Hamaker‐Konstanten faserbildender Polymere sowie die Erfassung des Anteils polarer Kräfte bei der Haftung von Faserstoffen zum Gegenstand haben.
Pfropfcopolymerisation auf strahlenchemisch erzeugte Peroxide im Polyamid
Authors: Sawtschenko L. , Dunsch L. , Jobst K.
Published: April 2003

Die Bildung von Peroxiden des Polyamids bei Einwirkung ionisierender Strahlung und deren Zerfallskinetik werden untersucht. Mittels verschiedener Monomere werden die Möglichkeiten und die Kinetik von Modifizierungsreaktionen für das peroxidierte Polyamid bestimmt und der Einfluß der Versuchsparameter (Bestrahlungsbedingungen, Pfropfbedingungen, Art des Monomers u. a.) auf die Kinetik und den Mechanismus der Pfropfcopolymerisation charakterisiert.
Untersuchung der Strukturübergänge in Polycaproamid‐Fasern mittels der Radiothermo‐Lumineszenz
Authors: Dimov K. , Denev E. , Fasliev F.
Published: April 2003

Mittels der Radiothermo‐Lumineszenz (RTL) wird der Einfluß der technologischen Parameter der Orientierungsreckung auf die Strukturübergänge in Polycaproamid‐Fasern untersucht. Anhand der Temperaturabhängigkeit der Intensität der RTL‐Spektren (Leuchtkurven) wurden die Relaxationsprozesse identifiziert, Schlußfolgerungen bezüglich der Vollständigkeit ihres Verlaufs gezogen und die Temperaturen der entsprechenden Übergänge bestimmt.
Molekularstatistische Theorien polymerer Netzwerke. Fortschrittsbericht
Authors: Heinrich G. , Straube E. , Helmis G.
Published: April 2003

In einer Übersicht werden statistisch‐mechanische Theorien polymerer Netzwerke diskutiert und ihre Leistungsfähigkeit zur Erklärung der mechanischen Eigenschaften der Netzwerke untersucht. Es zeigt sich, daß ein tieferes Verständnis der Struktur‐Eigenschafts‐Korrelation polymer Netzwerke im kautschukelastischen Zustand möglich ist, wenn bei der Formulierung einer statistischen Mechanik der Netzwerke die Undurchdringbarkeit der Netzwerkketten berücksichtigt wird.
Zur Kinetik der Ethylen‐Propylen‐Copolymerisation mit Vanadium(III)amid
Authors: Radwan F. , Ulbricht J.
Published: April 2003

Die Copolymerisation von Ethylen und Propylen bei konstantem Konzentrationsverhältnis der Monomere wurde mit dem Katalysatorsystem V(NPh2)3. Tetrahydrofuran. Dioxan und Ethyl‐ aluminium‐ dichlorid bei Normaldruck untersucht. Der Einfluß des Molverhältnisses der Aluminium‐ zur Vanadiumverbindung auf die Bruttopolymerisations‐ geschwindigkeit der Copolymerisation und auf die Zusammensetzung und die Lösungsviskosität der Copolymere wurde bestimmt. Anhand der gewonnenen Ergebnisse wird die Reaktivität der gebildeten polymerisationsaktiven Zentren diskutiert.
Niederdruckkapillarviskosimeter zur rheologischen Charakterisierung niedrigviskoser schwach konzentrierter Suspensionen und Polymerlösungen
Authors: Friedrich Chr. , Schnabel R. , Reher E. O.
Published: April 2003

Ein Kapillarviskosimeter zur Bestimmung des Fließverhaltens niedrigviskoser Stoffsysteme wird vorgestellt. Es besteht aus einer waagerecht angeordneten Kapillare, einer Druckerzeugungseinrichtung, der empfindlichen Druckmeßeinrichtung und der Einrichtung zur Berücksichtigung des hydrostatischen Druckes. Das Viskosimeter dient zur Bestimmung von Fließgrenzen und der Viskositätsfunktion im Bereich kleiner und kleinster Schergeschwindigkeiten. Die Auswahl der Kapillargeometrie und die Auswertung der Versuchsergebnisse werden erläutert.
Zur Kinetik des thermischen Abbaus von Polyethylenterephthalat
Authors: Rafler G. , Blaesche J. , Gajewski H. , Zacharias K.
Published: April 2003

Verschiedene kinetische Auswerteverfahren wurden zur Quantifizierung des thermischen Abbaus von Polyethylen terephthalat herangezogen. Stark abbaufördernde Reaktionsbedingungen gestatten problemlos eine Auswertung mittels eines Zeitgesetzes erster Ordnung. Unter milderen Reaktionsbedingungen sind die Einzelkonstanten durch Reaktionsmodellierung zu ermitteln.
Optimierung von Polystyrolen für immobilisierte Enzym‐Systeme
Authors: Kaufmann R. , Häupke K. , Fischer J. , Schellenberger A.
Published: April 2003

Styrol‐Divinylbenzol‐Copolymere wurden mit Hilfe der statischen Versuchsplanung für immobilisierte Glucoamy lase‐Systeme optimiert. Es wurde gefunden, daß zwei Polystyrolvarianten mit einem Divinylbenzolgehalt von 10 bzw. 21,5 Masse‐% als Träger für das Enzym geeignet sind.
Thermal, thermooxidative and photooxidative degradation of poly(2,6‐dimethyl‐1,4‐phenylene oxide). Review
Authors: Sláma Z.
Published: April 2003

Thermal, thermooxidative and photooxidative degradations of polyphenylene oxide are reviewed. Emphasis is given to analytical data of volatile products formed during the thermal degradation. Changes of the solid substrate, such as the methyl group oxidation, crosslinking and chain scission, are of particular importance during the thermooxidative and photooxidative degradation.
Einsatz von Reglerkombinationen bei der Hersfellung von funktionalisierten Oligobutadienen durch geregelte radikalische Emulsionspolymerisation
Authors: Wendler K. , Lueddeckens G. , Böhm M.
Published: April 2003

Die Herstellung von funktionalisierten Oligobutadienen ist durch radikalische Emulsionspolymerisation mit Dialkylxanthogen‐disulfiden als Kettenüberträger möglich. Es entstehen Oligomere, deren Molmassen mit steigendem Monomerumsatz ansteigen und deren Molmasseverteilung breiter wird. Bei Einsatz von Reglerkombinationen mit entsprechenden Reglerkonstantenverhältnissen läßt sich die molmasseregelnde Wirkung auf höhere Umsätze ausdehnen.
Application of the Žurkov‐Abasov theory for describing the strength properties of polyethylene terephthalate fibres (in Russian)
Authors: Wlochowicz A. , Linek M.
Published: April 2003

The modification of Žurkov equation extending the range of its application to materials characterized by strong flow during stretching is described. For such materials the structural coefficient γ depends on stretching rate and temperature. This results in loss of material strength with increasing stretching rate, when the stretching rate reaches high values, and the temperature dependence is considerably higher than assumed by Žurkov. Moreover, the effect of intermolecular bonds on the stress transfer in material, responsible for linear loss in activation energy of destruction with increase in temperature is considered. The analysis of the Žurkov equation is confirmed by data of measurements carried out on polyester fibres of small stretching ratio.
An investigation of the time dependence of viscosity in the thermal splitting of cellulose xanthate
Authors: Quadrat O. , Pavlík P. , Peška J. , Štamberg J.
Published: April 2003

A rotational viscometer with continuous viscosity recording was used in the investigation of the sol‐gel transition of viscose which was adjusted by dilution to various cellulose contents and various alkalinity. In some cases, the effect of temperature was investigated. Viscosity changes were evaluated quantitatively; the temperature dependence of gelation was used in the activation energy calculation.
Optimum dosing of butadiene in its high‐conversion copolymerization with styrene
Authors: Kalfus M.
Published: April 2003

Based on large‐scale laboratory experiments the five parameters of the previously developed model of the copolymerization were evaluated and the optimum schedules of butadiene dosing during the commercial manufacturing of the rubber in continuous copolymerization and during pilot‐plant batch copolymerization were computed.
Some aspects of the photooxidation mechanism of poly(2,6‐dimethyl‐1,4‐phenylene oxide)
Authors: Wandelt B. , Jachowicz J. , Kryszewski M.
Published: April 2003

The photooxidation of poly(2,6‐dimethyl‐1,4‐phenylene oxide) was studied by using various analytical techniques such as UV, IR, MS spectroscopy as well as viscosity and oxygen uptake measurements. The photooxidation process was found to be diffusion controlled and the rate coefficients of oxygen uptake have similar values as other amorphous polymers. Spectroscopic techniques showed that UV irradiation in the presence of oxygen leads to statistical scission of the polymer and formation of aldehydes.
NMR‐Untersuchungen zur Ermittlung der Anteile unterschiedlicher Beweglichkeit in verzweigtem Polyethylen
Authors: Frigge K.
Published: April 2003

Mit Hilfe eines Verfahrens zur Zerlegung der Breitlinien‐NMR‐Spektren werden die Anteile unterschiedlicher Beweglichkeit in verzweigten Polyethylen in Abhängigkeit von der Temperatur, dem Verzweigungsgrad und der thermischen Vorbehandlung bestimmt. Der hochbewegliche Anteil ist stark abhängig vom Verzweigungsgrad, währennd der gesamte bewegliche Anteil in einem größeren Temperaturbereich weitgehend unabhängig vom Verzweigungsgrad ist.
Ab‐initio‐Rechnungen an Polyethylenketten
Authors: Richter W.
Published: April 2003

Am Beispiel von Polyethylen werden die potentiellen Berechnungsmöglichkeiten eines unkonventionellen ab‐initio‐Verfahrens (RP‐Verfahren) bei Polymeren gezeigt. Neben einer kurzen Charakterisierung des Verfahrens werden die Ergebnisse von Berechnungen der Kettenanordnung und der Elektronenbeweglichkeit sowie die ungefähre Rechenzeit mitgeteilt.
Influence of the concentration of growing chains on the polymerization rate of butadiene and the microstructure of the polymer formed in the polybutadienyllithium‐butadienealiphatic hydrocarbon system
Authors: Shamanin V. V. , Melenevskaya E. Yu. , Sgonnik V. N.
Published: April 2003

The theoretical analysis of experimental data on the influence of the concentration of growing chains on the polymerization rate and the microstructure of polybutadiene carried out in this paper confirms previous suggestion that associated forms of living polybutadienyllithium chains directly participate in the progagation stage.
A possibility of observing the structure forming process in polypropylene crystallization
Authors: Bezruk L. I. , Poddubny V. I. , Lipatov Yu. S. , Baranov V. G.
Published: April 2003

The existence of the specific metastable phase made it possible to carry out multistage electron microscopic investigation of the supermolecular structure formation in the crystallization of polypropylene in the oriented state. Comparison with the data of electron diffraction yielded a direct evidence of the fact that the formation of structural units of the supermolecular organization of crystalline PP, i.e. fibrils and lamellae, occurs in the stage of orientation, and crystallization itself only fixes these structures.
Untersuchungen zur Kinetik der photoinitiierten Copolymerisation von Styren und Maleinsäureanhydrid. IV. Bestimmung der scheinbaren Geschwindigkeitskonstanten ka und kw
Authors: Rätzsch M. , Schicht G. , Arnold M.
Published: April 2003

Eine Meßapparatur zur Bestimmung scheinbarer Geschwindigkeitskonstanten nach der Methode der intermittierenden Belichtung wird beschrieben. für einen auf thermische Polymerisation zurückgeführten Nachpolymerisationseffekt wird die Bildung eines Primärradikals in Form eines DIELS‐ALDER‐Addukts aus Styren und Maleinsäureanhydrid angenommen. Mit der früher bestimmten Startgeschwindigkeit wurden die scheinbaren Geschwindigkeitskonstanten für die alternierende Copolymerisation von Styren mit MSA ermittelt.
Zur Temperaturabhängigkeit des IR‐Spektrums von Polymeren. Teil 2. Einfluß des Ordnungszustandes von Polyethylen auf die Temperaturabhängigkeit einiger IR‐Banden
Authors: Dahme A. , Dechant J.
Published: April 2003

Die Temperaturabhängigkeit des IR‐Spektrums von Polyethylen wurde an Proben mit unterschiedlichem Ordnungszustand untersucht. Die verschiedenen IR‐Banden zeigen bei Änderung des Ordnungszustandes ein unterschiedliches Verhalten hinsichtlich ihrer Temperaturabhängigkeit. Dieses Verhalten wird durch die Zuordnung der IR‐Banden zu bestimmten molekularen Strukturen und deren Störung durch thermische Bewegungen interpretiert.
Nucleation in poly(ethylene terephthalate)
Authors: Przygocki W.
Published: April 2003

Measurements of isothermal crystallization kinetics of poly(ethylene terephthalate) including defined solid nucleating agents have been performed by DSC method in broad temperature range. Based on the results and knowledge of growth rate of spherulities in PETP the nucleation rates were calculated. The mechanism of heterogeneous nucleation in PETP was analyzed. The results of the investigation were the basis for proposal of a modified model of heterogeneous nucleation in PETP.
Röntgenographische Charakterisierung des Orientierungszustandes einachsig gereckter Polyvinylidenfluorid‐Folien
Authors: Geiss D. , Ruscher Ch. , Kofer U.
Published: April 2003

Die Beschreibung des Orientierungszustandes einachsig gereckter Polyvinylidenfluorid‐Folien erfolgt auf der Basis röntgenographisch ermittelter Flächenpolfiguren. Die Abweichungen von der Fasertextur werden dargestellt und anhand von Modellvorstellungen diskutiert.
Zum Problem des Fadenbruchs beim Schmelzspinnprozeß organischer Hochpolymere unter Berücksichtigung von makroskopischen Störstellen im Elementarfaden
Authors: Beyreuther R. , Schöne A.
Published: April 2003

Ausgehend von den in der Fadenbildungszone auftretenden Fadenzugkräften und einer hypothetischen Annahme über die Wirkung von im Elementarfaden eingeschlossenen makroskopischen Störstellen (Störpartikel, Blasen, Hohlräume) wird eine Modellvorstellung über die effektiv in einem gestörten Fadenquerschnitt wirkende Spannung entwickelt. Aus Parameterrechnungen im Abzugsgeschwindigkeitsbereich von 1 bis 10 km/min werden quantitative Abschätzungen über minimal erreichbare Elementarfadenfeinheiten und Bedingungen für die notwendige Wirksamkeit von Schmelzefiltern, insbesondere bei Hochgeschwindigkeitsspinnprozessen, abgeleitet.