bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ostwald ripening in immiscible polyolefin blends
Authors: Mirabella Francis M. , Barley Jeffrey S. 
Published: April 2003

AbstractThe coarsening in the quiescent melt of the phase‐segregated particles of a polymer blend, composed of a narrow molecular weight fraction of an unbranched high‐density polyethylene (HDPE) and a highly branched (100 ethyl branches/1000 C atoms) hydrogenated polybutadiene (HPB) was studied. The system was effectively binary, due to the narrow molecular weight and composition distributions of each component. The system was composed of 90 wt % of the HDPE and 10 wt % of the HPB and it formed a two‐phase system in the melt at 177°C. The blend was precipitated from xylene solution in order to obtain an initially intimately mixed system. This was the third study in a series of studies of the coarsening of phase‐segregated particles in polymer blends. This study was unique in that the system studied was binary in this case while the previous systems were multicomponent. Since the present system was binary, exact thermodynamic calculations of the phase state of this system could be applied with a high level of confidence. The droplet phase particles, which were mainly composed of the HPB, were observed to coarsen on storage in the melt for times of from 5 s to 1 h. At the shortest storage time of 5 s the particles had an average radius of about 0.05 μm and coarsened to about 0.2 μm after 1 h storage in the melt state. Particle dimensions were measured by scanning electron microscopy of n‐heptane‐etched and gold‐coated sections. It was found that the volume of the particles increased linearly with time and that the rate constant of coarsening was Kexp = 1.23 × 10−18 cm3/s and this agreed fairly well with the rate constant calculated from Ostwald ripening theory of Kce = 0.86 × 10−18 cm3/s. In contrast the rate constant for direct particle diffusion and coalescence was Kc = 3.6 × 10−20 cm3/s. Since this was two orders of magnitude smaller than the rate constant for Ostwald ripening, it was concluded that, although the linear increase of volume with time was also consistent with the particle diffusion and coalescence mechanism, this was not a significant contributor to the coarsening mechanism. The major cause for the insignificance of the particle diffusion and coalescence mechanism was the high melt viscosity of the matrix polymers. The application of the Ostwald ripening theory to this system could be made with a high level of confidence because it was binary. It was found that the phase concentration of the droplet phase apparently underwent a rapid increase during the first 1‐2 min of storage in the melt, indicating that the system did not reach phase equilibrium (i.e., did not completely phase‐segregate) for about 1‐2 min. This further indicated that the long‐time coarsening regime was not entered until after this length of time. The particle size distributions remained approximately self‐similar over the period of coarsening, as predicted by Ostwald ripening theory. © 1995 John Wiley & Sons, Inc.
Self‐consistent field equations in the distribution function theory of polymeric liquids
Authors: Gan Hin Hark , Eu Byung Chan 
Published: April 2003

AbstractIn the distribution function approach to the conformational and thermodynamic properties of polymeric liquids site‐site (pair) distribution functions are essential components of the theory. These site‐site pair distribution functions are basically mean fields obeying integral equations. In our recent works, a set of self‐consistent field equations has been proposed for site‐site pair correlation functions which allow us to study conformational and thermodynamic properties of polymeric liquids. In this article, we present a short review of the theory and its applications to a number of aspects of polymeric liquids we have made until now. We also present a self‐consistent version of the polymer reference interaction site model where the integral equations for the intramolecular site‐site correlation functions are obtained from the Kirkwood hierarchy on the basis of the present theory. The present theory is shown to predict correctly the scaling properties associated with swollen and collapsed polymers in good and poor solvents, respectively. At finite densities, self‐consistent solutions of the intra‐ and intermolecular equations yield the structures and thermodynamics of polymer melts which are favorably compared with Monte Carlo simulation results. Self‐consistent theory results are found to be more accurate than the non‐self‐consistent approaches that use an ideal Gaussian chain conformation distribution function. © 1995 John Wiley & Sons, Inc.
Light‐scattering studies on phase separation in a binary blend with addition of diblock copolymers
Authors: Sung Lipiin , Han Charles C. 
Published: April 2003

AbstractTime‐resolved light‐scattering measurements have been conducted to investigate the influence of a diblock copolymer additive on the phase boundaries and the kinetics of the phase separation of a polymer blend. The blend studied was a polystyrene‐d8/polybutadiene (PSD/PB) mixture with a diblock copolymer composed of the same homopolymers. It was observed that the critical temperature of the blend, which has an upper critical solution temperature (UCST), decreased with increasing copolymer content and the kinetics of the phase separation via a spinodal decomposition mechanism slowed down in the presence of the copolymer. The features of the spinodal peak position and intensity as a function of time with and without copolymer additive were analyzed for near and off‐critical compositions in various temperature jumps. The intermediate and late‐stage growth rates do not follow a universal scaling function with the addition of diblock copolymers. © 1995 John Wiley & Sons, Inc.
Study of the molecular mobility of collagen
Authors: Mezghani S. , Lamure A. , Lacabanne C. 
Published: April 2003

AbstractThe dielectric relaxations of a biopolymer, collagen, have been studied by means of the thermally stimulated current (TSC) technique. To investigate effects of water on TSC spectra, complementary measurements by differential scanning calorimetry (DSC) have been performed. In dehydrated collagen, three spectral bands were recorded in the temperature range of ‐180‐60°C, labelled α, β1, and γ in the order of decreasing temperature. The TSC spectrum of hydrated collagen exhibits a supplementary band labelled β2. By using the fractional polarization method, the γ and β1 modes have been attributed to localized movements of nonpolar (apolar) sequences and polar sequences, respectively. The α mode has been associated with delocalized movements of the collagen macromolecules. Finally the β2 mode has been attributed to reorientations of bound water molecules inside the collagen fibers. © 1995 John Wiley & Sons, Inc.
Time‐resolved synchrotron X‐ray study of crystalline phase transition in poly(aryl ether ketone ketone) containing alternated terephthalic/isophthalic moieties
Authors: Hsiao Benjamin S. , Ho Rong‐Ming , Cheng Stephen Z. D. 
Published: April 2003

AbstractUnique crystallization and melting behavior in poly(aryl ether ketone ketone) containing alternated terephthalic and isophthalic moieties were studied by time‐resolved synchrotron x‐ray methods. Recently, this material has been shown to exhibit three polymorphs (forms I, II, and III). In this work, we further investigated their distinctive thermal properties and found that form I is the dominating and the most thermally stable phase while form II is favored by fast nucleation conditions and is the least stable phase. On the other hand, form III represents a minor intermediate phase that usually coexists with form I and can be transferred from form II and to form I. Structural and morphological changes in form I have been followed by simultaneous wide‐angle x‐ray diffraction (WAXD)/small‐angle x‐ray scattering (SAXS) measurements during cold‐ or melt‐crystallization and subsequent melting. In all cases, a larger dimensional change was found in the crystallographic a‐axis than the b‐axis during heating and cooling. This may be due to the greater lateral stress variation with respect to temperature along the a direction of the primary lamellae which is induced by either the formation of secondary lamellae or the preferential chain‐folding direction in poly(aryl ether ketone ketone)s. During the phase transitions of form II ← III in the cold‐crystallized specimen and form III ← I in the melt‐crystallized samples, lamellar variables (long period, lamellar thickness, and invariant) obtained from SAXS remain almost constant. This indicates that the density distribution in the long spacing is independent of the melting in form II or III. For melt‐crystallization, the corresponding changes in unit‐cell dimensions and lamellar morphology during the annealing‐induced low endotherm are most consistent with the argument that these changes are due to the melting of thin lamellar population. © 1995 John Wiley & Sons, Inc.
Heat capacities of poly(amino acid)s and proteins
Authors: Zhang Ge , Lebedev B. V. , Wunderlich Bernhard , Zhang Jing‐Ye 
Published: April 2003

AbstractIn an ongoing effort to understand the thermodynamic properties of proteins, solid‐state heat capacities of poly(amino acid)s of all 20 naturally occurring amino acids and 4 copoly(amino acid)s have been previously reported on and were analyzed using our Advanced THermal Analysis System (ATHAS). We extend the heat capacities of poly(L‐methionine) (PLMFT) and poly(L‐phenylalanine) (PLPHEA) with new low temperature measurements from 10 to 340 K. In addition, analyses were performed on literature data of a first protein, zinc bovine insulin dimer C508H752O150N130S12Zn, using both the ATHAS empirical addition scheme and computation with an approximate vibrational spectrum for the protein. For the solid state, agreement with the measurement could be accomplished to ±1.6% for PLMET, ±3.5% for PLPHEA, and ±3.2% for insulin, linking the macroscopic heat capacity to its microscopic cause, the group and skeletal vibrational motion. For each polymer, one set of parameters, Θ1 and Θ3, of the Tarasov function representing the skeletal vibrational contribution to the heat capacity are obtained from a new optimization procedure [PLMET: 542 K and 83 K (number of skeletal vibrations Ns = 15); PLPHEA: 396 K and 67 K (Ns = 11); and insulin monomer: 599 K and 79 K (Ns = 628), respectively]. Enthalpy, entropy, and Gibbs free energy have been derived for the solid state. © 1995 John Wiley & Sons, Inc.
A MOLECULAR MODEL POTENTIAL STUDY OF THE HOMO–LUMO GAP IN A LOW-DIMENSIONAL CRYSTAL
Authors: LETELIER JORGE RICARDO , TORO-LABBÉ ALEJANDRO , CHIU YING-NAN 
Published: April 2003

We study the effect of some crystal vibrations on the electron distribution and the gap HOMO–LUMO in a linear chain of atoms where, the valence electrons move in a model potential constructed by combining atromic boxes. It is found that at the turning points, these two levels collapse together for a chain with an even number of atoms while for a chain with an odd number of atoms these two levels never touch each other.The effect of some asymmetric crystal vibrations on the electron density distribution and the gap HOMO–LUMO is also analyzed for a low-dimensional solid whose repeating unit consists of a square arrangement of atoms where the valence electrons move in a CAB model potential.
ON-LINE VISUALIZATION AND NAVIGATION OF THE GLOBAL WEB STRUCTURE
Authors: HUANG MAO LIN , EADES PETER , LAI WEI 
Published: April 2003

The current generation of web browsers, such as Netscape and Microsoft Explorer, excites people because of the structure of hyper-documents that provides users with an effective and convenient way to move in cyberspace. This is done through clicking on a series of hyperlinks embedded in hyper-documents. However, this arrangement does not give users a visual "map" to guide them in their web journey. It does not provide sense of "space" while the user is exploring the (cyber) space; instead it only gives a series of lists. This is mainly because of the difficulty of constructing such a huge, complex, and dynamic map with an (virtually) unlimited number of nodes and edges. Because the whole web is partially unknown, it is difficult for mapmaker to draw the map. Further, the computation of the overall geometrical structure of such a huge map (with millions or perhaps billions of nodes) is impossible as most visualization algorithms have super-linear time complexity and only scale to a few hundred nodes. Most existing visualization techniques and current research interests emphasize "site mapping". That is, they try to find an effective way of constructing a structured geometrical map for one web site (a local map). This can only guide the user through a very limited region of cyberspace, and does not help users in their overall journey through the cyberspace. In this paper, we look at the whole journey through the cyberspace as one graph; a huge and partially unknown graph. We use our new on-line exploratory visualization technique [7] to maintain and display a subset of this huge graph incrementally. The Visual Web Browser consists of three major components: a fast accessible linkage server, a filtering mechanism, and an on-line exploratory visualization. The framework of these components provides the user with a dynamic graphical map for guiding the web journey.
PREACHING FOR A RESPONSE? JONAH'S MESSAGE TO THE NINEVITES RECONSIDERED
Authors:   Moberly
Published: April 2003

AbstractJonah's message to the Ninevites is unusual in specifying a time limit before judgment comes. But while the MT and most manuscripts read "forty days" the LXX reads "three days". The history of interpretation of both "forty" and "three" is briefly surveyed before a fresh proposal is offered. The LXX represents a perception of what would be appropriate for Jonah to say, on the assumption that his message is faithful to his commission. The MT depicts a Jonah who does not want the Ninevites to respond.
THE DISTRIBUTION OF MESSAGES IN THE KINGDOM OF JUDAH IN LIGHT OF THE LACHISH OSTRACA
Authors: Na'aman Nadav 
Published: April 2003

AbstractThe article deals with the problem of communication between the capital city of Jerusalem and the kingdom's districts and the distribution of messages from the centre to the periphery in the late First Temple period. It calls attention to the Lachish ostraca that illustrate the ways in which news was spread among officials of the Kingdom of Judah. Letters played an important role in the communication and local officials were accustomed to share letters that they received with neighbouring colleagues. Based on the information they received the officials and local elite were aware of the internal and external policies of the king and his court and were able to form their own opinion on the main problems debated at the time in the court of Jerusalem.
A REASSESSMENT OF THE RADICAL NATURE OF JOB'S ETHIC IN JOB XXXI 13-15
Authors: Neville Richard 
Published: April 2003

AbstractCommentators have concluded that Job xxxi 13-15 represents an ethical high point in the Old Testament and have praised Job for it. Typically Job is seen as recognising the rights of his slaves on the basis that they are his equals as human beings. Given this understanding of Job's words, the high praise seems justified. However, there are reasons to doubt that this is what Job is saying. In the context of his protestation of innocence (Job xxxi) it is doubtful he would defend himself against an accusation so radical that no one would have thought to accuse him of the offence. It would also be out of character for the sages to advocate a revolutionary ethic. Furthermore, it is troubling that there is no consensus on how to derive the proposed meaning from the text, and when the various strategies are investigated they are unconvincing. An alternative interpretation is offered which looks to the language and ideology of personal religion in order to understand the significance of Job's reference to the fact that he and his servants were made in the womb by the same God.
THE PROPHECY FOR "EVERLASTING COVENANT" (JEREMIAH XXXII 36-41): AN EXILIC ADDITION OR A DEUTERONOMISTIC REDACTION?
Authors: Rom-Shiloni Dalit 
Published: April 2003

AbstractThis paper draws attention to the exact relationship between the prophecy for "everlasting covenant" (Jer. xxxii 36-41) and the words of the prophet and his ideological agenda on the one hand, and the redactional level of the Book of Jeremiah on the other. Examination of the genre of the prophetical unit presents it to be a quasi-disputation-speech, and a further testimony to the exilic voices in Jeremiah on the controversy between the Jehoiachin exiles and the remnant. A close reading of the verses gives evidence to five different ways of dependence on and independence from both the words of the prophet and the redactional additions to Jeremiah. Hence, this prophecy demonstrates the composition of a new independent prophecy within exilic context, and thus adduces the question whether the exilic material within Jeremiah can still be restricted to Deuteronomistic circles.
Linezolid Resistance since 2001: SENTRY Antimicrobial Surveillance Program
Authors: Mutnick Alan H , Enne Victoria , Jones Ronald N 
Published: April 2003

BACKGROUND: The oxazolidinone class of antimicrobials has demonstrated remarkable activity against gram-positive cocci. Linezolid has proven to be a first-line therapeutic option for vancomycin-resistant strains. Linezolid clinical trial results and subsequent published case reports cite rare resistance emerging in patients receiving prolonged therapy. OBJECTIVE: To report the initial linezolid-resistant organisms from cases obtained through the SENTRY Antimicrobial Surveillance Program, after screening >40 000 gram-positive cocci without resistance between 1998 and 2000. METHODS: During 2001–2002, 8 resistant strains (from 8 different patients) located in 6 states from 7 different participating SENTRY institutions in the US were identified among bloodstream, respiratory, skin and soft tissue, and urinary tract infection isolates of Enterococcus faecalis, Enterococcus faecium, Staphylococcus epidermidis, and Streptococcus oralis. Resistance was detected by reference broth microdilution methods and confirmed by identical results using Etest (AB BIODISK, Solna, Sweden) and the standardized disk diffusion method. RESULTS: Minimum inhibitory concentration (MIC) and disk diffusion tests showed elevated MICs (≥8 μg/mL) and small inhibitory zone diameters (≤15 mm) for all strains to both linezolid and the investigational oxazolidinone AZD2563. Vancomycin resistance was detected in 2 of the 8 linezolid-resistant strains. All enterococci and the viridans-group streptococcus ( S. oralis) strain showed resistance to erythromycin. E. faecium strains were resistant to penicillins, but susceptible to quinupristin/dalfopristin. Only 3 of the patients had previously received the drug. CONCLUSIONS: Linezolid resistance remains rare, with only 8 isolates among 9833 (0.08%) monitored isolates identified between January 1, 2001, and June 30, 2002. Resistance, however, was no longer limited to enterococci. Clinical laboratories should test linezolid more widely to detect emerging resistance, especially for patients receiving oxazolidinone therapy. Longitudinal surveillance programs are warranted to detect a trend in the development of resistance, determine the molecular mechanism of resistance, and recommend alternative therapies or epidemiologic interventions.
Possible Cefotaxime-Induced Stevens–Johnson Syndrome
Authors: Liberopoulos Evagelos N , Liamis George L , Elisaf Moses S 
Published: April 2003

OBJECTIVE: To report a case of possible cefotaxime-induced Stevens–Johnson syndrome (SJS). CASE SUMMARY: A 72-year-old woman with an upper urinary tract infection developed erosions and blisters on the skin and the mucous membranes, as well as fever and prostration, soon after the administration of cefotaxime. This presentation is consistent with the features of SJS. Resolution of the clinical manifestations was observed after discontinuation of the drug; all other drugs, infections, or immunologic disorders that could have caused this syndrome were carefully excluded. An objective causality assessment revealed that SJS was possibly associated with the use of cefotaxime. DISCUSSION: Although cephalosporins have been associated with an increased risk for SJS and cefotaxime has been suspected of being associated with SJS in a previous case–control study, this is the first full report for cefotaxime-related SJS in the literature. An immunologically mediated reaction may be the underlying mechanism. CONCLUSIONS: Although cefotaxime administration seems to be the underlying cause of the SJS observed in our patient, establishment of a definite causal relationship requires additional cases and supportive data.
Robust adaptive control for non‐linear systems in generalized output‐feedback canonical form
Authors: Krishnamurthy P. , Khorrami F. 
Published: April 2003

AbstractDesign of global robust adaptive output‐feedback dynamic compensators for stabilization and tracking of a class of systems that are globally diffeomorphic into systems in generalized output‐feedback canonical form is investigated. This form includes as special cases the standard output‐feedback canonical form and various other forms considered previously in the literature. Output‐dependent non‐linearities are allowed to enter both additively and multiplicatively. The system is allowed to contain unknown parameters multiplying output‐dependent non‐linearities and, also, unknown non‐linearities satisfying certain bounds. Under the assumption that a constant matrix can be found to achieve a certain property, it is shown that a reduced‐order observer and a backstepping controller can be designed to achieve practical stabilization of the tracking error. If this assumption is not satisfied, it is shown that the control objective can be achieved by introducing additional dynamics in the observer. Sufficient conditions under which asymptotic tracking and stabilization can be achieved are also given. This represents the first robust adaptive output‐feedback tracking results for this class of systems. Copyright © 2003 John Wiley & Sons, Ltd.
Long‐term survival in a patient with del(18)(q12.2q21.1)
Authors: Tinkle Brad T. , Christianson Carol A. , Schorry Elizabeth K. , Webb Thomas , Hopkin Robert J. 
Published: April 2003

AbstractThe 18q‐ syndrome is relatively common among cytogenetic abnormalities occurring in approximately 1 in 40,000 live births. However, interstitial deletions involving 18q12.2 to q21.1 are much less common. Only 15 cases have been reported in the literature. A phenotypic pattern is emerging of mild dysmorphic features, mental retardation, behavior abnormalities, and the lack of serious malformations. We present a 67‐year‐old woman with minor dysmorphic features, moderate mental retardation, hyperphagia, and del(18)(q12.2q21.1). This patient is presented for the natural history of this deletion syndrome as well as the behavioral phenotype. © 2003 Wiley‐Liss, Inc.