bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Situ Micro‐Sized Gel‐Forming Injectable Implant Using Biodegradable Amphiphilic Graft Copolymer
Authors: Cho Kuk Young , Lee Seongnam , Park Jung‐Ki 
Published: May 2007

AbstractA synthesized graft polymer is used as a biodegradable polymer for an in situ gel‐forming injectable implant system. The amphiphilic character of the polymer in the graft structure lowered the viscosity of the polymer solution, which enabled easy injection. A micro‐sized gel can be obtained with this system, which has not been found for previous in situ gel‐forming systems with poly[(D,L‐lactide)‐co‐glycolide] copolymer. In addition, a protein particle embedded gel exhibits good in vitro drug release performance as a result of the enhanced stability and shorter diffusion length.magnified image
Embeddings in the Strong Reducibilities Between 1 and npm
Authors: Watson Phil 
Published: May 2007

AbstractWe consider the strongest (most restricted) forms of enumeration reducibility, those that occur between 1‐ and npm‐reducibility inclusive. By defining two new reducibilities (which we call n1‐ and ni‐reducibility) which are counterparts to 1‐ and i‐reducibility, respectively, in the same way that nm‐ and npm‐reducibility are counterparts to m‐ and pm‐reducibility, respectively, we bring out the structure (under the natural relation on reducibilities strong with respect to') of the strong reducibilities. By further restricting n1‐ and nm‐reducibility we are able to define infinite families of reducibilities which isomorphically embed the r. e. Turing degrees. Thus the many well‐known results in the theory of the r. e. Turing degrees have counterparts in the theory of strong reducibilities. We are also able to positively answer the question of whether there exist distinct reducibilities ≤y and ≤a between ≤e and ≤m such that there exists a non‐trivial ≤y‐contiguous ≤z degree.
Computability of String Functions Over Algebraic Structures Armin Hemmerling
Authors: Hemmerling Armin 
Published: May 2007

AbstractWe present a model of computation for string functions over single‐sorted, total algebraic structures and study some basic features of a general theory of computability within this framework. Our concept generalizes the Blum‐Shub‐Smale setting of computability over the reals and other rings. By dealing with strings of arbitrary length instead of tuples of fixed length, some suppositions of deeper results within former approaches to generalized recursion theory become superfluous. Moreover, this gives the basis for introducing computational complexity in a BSS‐like manner. Relationships both to classical computability and to Friedman's concept of eds computability are established. Two kinds of nondeterminism as well as several variants of recognizability are investigated with respect to interdependencies on each other and on properties of the underlying structures. For structures of finite signatures, there are universal programs with the usual characteristics. For the general case of not necessarily finite signature, this subject will be studied in a separate, forthcoming paper.
Predicate Modal Logics Do Not Mix Very Well
Authors: Gasquet Olivier 
Published: May 2007

AbstractThe problem of completeness for predicate modal logics is still under investigation, although some results have been obtained in the last few years (cf. [2, 3, 4, 7]). As far as we know, the case of multimodal logics has not been addressed at all. In this paper, we study the combination of modal logics in terms of combining their semantics. We demonstrate by a simple example that in this sense predicate modal logics are not so easily manipulated as propositional ones: mixing two Kripke‐complete predicate modal logics (one with the Barcan formula, and the other without) results in a Kripke‐incomplete system.
Quadrilaterizing an Orthogonal Polygon in Parallel
Authors: Dietel Jana , Hecker Hans‐Dietrich 
Published: May 2007

AbstractWe consider the problem of quadrilaterizing an orthogonal polygon P, that is to decompose P into nonoverlapping convex quadrangles without adding new vertices. In this paper we present a CREW‐algorithm for this problem which runs in O(log N) time using Θ(N/log N) processors if the rectangle decomposition of P is given, and Θ(N) processors if not. Furthermore we will show that the latter result is optimal if the polygon is allowed to contain holes.
Extending Independent Sets to Bases and the Axiom of Choice
Authors: Keremedis Kyriakos 
Published: May 2007

AbstractWe show that the both assertions “in every vector space B over a finite element field every subspace V ⊆ B has a complementary subspace S” and “for every family 𝒜 of disjoint odd sized sets there exists a subfamily ℱ={Fj:j ϵω} with a choice function” together imply the axiom of choice AC. We also show that AC is equivalent to the statement “in every vector space over ℚ every generating set includes a basis”.
S‐Storage Operators
Authors: Nour Karim 
Published: May 2007

AbstractIn 1990, J. L. Krivine introduced the notion of storage operator to simulate, for Church integers, the “call by value” in a context of a “call by name” strategy. In the present paper we define for every λ‐term S which realizes the successor function on Church integers the notion of S‐storage operator. We prove that every storage operator is an S‐storage operator. But the converse is not always true.
On Shattering, Splitting and Reaping Partitions
Authors: Halbeisen Lorenz 
Published: May 2007

AbstractIn this article we investigate the dual‐shattering cardinal ℌ, the dual‐splitting cardinal 𝔖 and the dual‐reaping cardinal 𝔎, which are dualizations of the well‐known cardinals 𝔥 (the shattering cardinal, also known as the distributivity number of P(ω)/fin), s (the splitting number) and 𝔠 (the reaping number). Using some properties of the ideal 𝔍 of nowhere dual‐Ramsey sets, which is an ideal over the set of partitions of ω, we show that add(𝔍) = cov(𝔍) = ℌ. With this result we can show that ℌ > ω1 is consistent with ZFC and as a corollary we get the relative consistency of ℌ > 𝔱 t, where t is the tower number. Concerning 𝔖 we show that cov(M) ⩽ 𝔖 𝔯 (where M is the ideal of the meager sets). For the dual‐reaping cardinal 𝔖 we get p 𝔖 ⩽ 𝔭 ⩽ 𝔯 (where 𝔭 is the pseudo‐intersection number) and for a modified dual‐reaping number 𝔖′ we get 𝔖′ ⩽ 𝔬 (where 𝔬 is the dominating number). As a consistency result we get 𝔖 < cov(𝔐).
Grasping Infinity by Finite Sets
Authors: Formato Ferrante , Gerla Giangiacomo 
Published: May 2007

AbstractWe show that the existence of an infinite set can be reduced to the existence of finite sets “as big as we will”, provided that a multivalued extension of the relation of equipotence is admitted. In accordance, we modelize the notion of infinite set by a fuzzy subset representing the class of (finite) wide sets.
Computability Over Structures of Infinite Signature
Authors: Hemmerling Armin 
Published: May 2007

AbstractContinuing the paper [7], in which the Blum‐Shub‐Smale approach to computability over the reals has been generalized to arbitrary algebraic structures, this paper deals with computability and recognizability over structures of infinite signature. It begins with discussing related properties of the linear and scalar real structures and of their discrete counterparts over the natural numbers. Then the existence of universal functions is shown to be equivalent to the effective encodability of the underlying structure. Such structures even have universal functions satisfying the s‐m‐n theorem and related features. The real and discrete examples are discussed with respect to effective encodability. Megiddo structures and computational extensions of effectively encodable structures are encodable, too. As further variants of universality, universal functions with enumerable sets of program codes and such ones with constructible codes are investigated. Finally, the existence of m‐complete sets is shown to be independent of the effective encodability of structures, and the linear and scalar structures are discussed once more, under this aspect.
Choice Principles and Compactness Conditions
Authors: Banaschewski Bernhard 
Published: May 2007

AbstractIt is shown in Zermelo‐Fraenkel Set Theory that Cκ, the Axiom of Choice for κ‐indexed families of arbitrary sets, is equivalent to the condition that the frame envelope of any κ‐frame is κ‐Lindelöf, for any cardinal κ.
Other Proofs of Old Results
Authors: Kotlarski Henryk 
Published: May 2007

AbstractWe transform the proof of the second incompleteness theorem given in [3] to a proof‐theoretic version, avoiding the use of the arithmetized completeness theorem. We give also new proofs of old results: The Arithmetical Hierarchy Theorem and Tarski's Theorem on undefinability of truth; the proofs in which the construction of a sentence by means of diagonalization lemma is not needed.
An Algorithm for Simulating Equilibrium Adsorption Characteristics of Branched Copolymer Chains at Solid‐Liquid Interface
Authors: Austine Juedu , Mohite Lalaso V. , Juvekar Vinay A. 
Published: May 2007

AbstractAn algorithm is developed for simulating adsorption of tree type block‐branched copolymer chains, of arbitrary architecture, from dilute solutions to solid surfaces. A continuum form of the self‐consistent field (SCF) theory is used. The chain architecture is first represented by a convergent tree‐graph, which is then converted into a special type of the connectivity matrix. This matrix is used for computing the configurational statistics of the chains in the adsorbed layer. The crucial step in the algorithm is to compute the junction (branch point) probability weights. A stepwise procedure for computing these probability weights is described. The capability of the algorithm has been demonstrated using illustrative examples.magnified image
Monte Carlo Simulation of Uniaxial Deformation of Polyethylene‐Like Polymer Glass: Role of Constraints and Deformation Protocol
Authors: Mulder Tim , Li Jing , Lyulin Alexey V. , Michels Matthias A. J. 
Published: May 2007

AbstractThe deformation of a glassy amorphous polymer has been simulated by Monte Carlo. A molecular model with constrained chemical bonds (rigid‐bond model) and one with chemical bonds represented by Gaussian springs (flexible‐bond model) have been compared. Furthermore, two different deformation protocols have been tested. Comparisons on the basis of stress–strain behavior, contributions of various interactions to stress and energy, evolution of density and distribution of dihedral angles, and of pair correlation functions show that both the introduction of constrained bonds and the deformation protocol influence the results dramatically. The results obtained using the flexible‐bond model, employing a deformation protocol in which all the monomers are displaced affinely with the box size, show the best agreement with experimental facts.magnified image
Monte Carlo Simulation of Controlled/Living Radical Polymerization in Emulsified Systems
Authors: Tobita Hidetaka , Yanase Fumihiko 
Published: May 2007

AbstractA new MC simulation method is proposed for the controlled/living radical polymerization in a dispersed medium, assuming an ideal miniemulsion system. This tool is used to consider the effects of particle size on the polymerization rates and the molecular weight distributions. For NMP, the polymerization kinetics are basically governed by two conflicting factors, (i) the confined space effect that promotes the coupling reaction between a radical and a trapping agent and (ii) the isolation effect of radicals into different particles that suppresses the overall frequency of bimolecular termination. For RAFT polymerization, a significant rate enhancement by reducing the particle size could be observed only for the systems with fast fragmentation of adduct radicals.magnified image
Small local governments as community builders
Authors: Sokolow Alvin D. 
Published: May 2007

AbstractWhile small local governments lack the advantages of revenue base, adequate staff, and professionalization, the limitations of small size are replaced by its advantages: proximity to constituency, responsiveness, and flexibility. The external (federal) assistance of the 1970s helped bring about substantial local improvements and surety aided community‐building efforts. Nonetheless, major small‐town projects continue to be driven by local priorities and views; success of such efforts depends on the quality of local leadership and the leadership agenda itself, volunteer action, multiple assignments to public employees, and ad hoc‐but effective—administration.
Defining the public interest: Citizen participation in metropolitan and state policy making
Authors: Persons Georgia A. 
Published: May 2007

AbstractThe legitimacy of policy making at the regional level, as with policy making at more conventional levels of government, depends on the quality of representation. Citizen appointments and voluntary committees bypass the expense of the electoral process, but lack value when restricted to token advisory roles in potential conflict with other, “financially articulate” interests. Experience shows that lay citizen representatives can make sound decisions on the technical issues that typify regional problems, when information is properly shared. Regional entities must demonstrate the will to establish their legitimacy.
It's never too late to run — and win! the graying of women in local politics
Authors: Macmanus Susan A. 
Published: May 2007

AbstractOlder women are playing an increasingly significant role in Florida local politics. This phenomenon has implications for politics — both local and at other levels — nationwide. As the national age profile continues to resemble Florida's, intergenerational conflict may become the norm as a smaller group of working‐age taxpayers are expected to accept the policies of a less conservative population of retires and older politicians.
An element‐wise, locally conservative Galerkin (LCG) method for solving diffusion and convection–diffusion problems
Authors: Thomas C. G. , Nithiarasu P. 
Published: May 2007

AbstractAn element‐wise locally conservative Galerkin (LCG) method is employed to solve the conservation equations of diffusion and convection–diffusion. This approach allows the system of simultaneous equations to be solved over each element. Thus, the traditional assembly of elemental contributions into a global matrix system is avoided. This simplifies the calculation procedure over the standard global (continuous) Galerkin method, in addition to explicitly establishing element‐wise flux conservation. In the LCG method, elements are treated as sub‐domains with weakly imposed Neumann boundary conditions. The LCG method obtains a continuous and unique nodal solution from the surrounding element contributions via averaging. It is also shown in this paper that the proposed LCG method is identical to the standard global Galerkin (GG) method, at both steady and unsteady states, for an inside node. Thus,
the method, has all the advantages of the standard GG method while explicitly conserving fluxes over each element.Several problems of diffusion and convection–diffusion are solved on both structured and unstructured grids to demonstrate the accuracy and robustness of the LCG method. Both linear and quadratic elements are used in the calculations. For convection‐dominated problems, Petrov–Galerkin weighting and high‐order characteristic‐based temporal schemes have been implemented into the LCG formulation. Copyright © 2007 John Wiley & Sons, Ltd.
Thermally irreversible organic photochromic compounds for optical memory
Authors: Barachevsky V. A. , Strokach Yu. P. , Puankov Yu. A. , Krayushkin M. M. 
Published: May 2007

AbstractFor some photochromic compounds (58 diarylethenes and 9 fulgimides), the results of our spectral and kinetic studies are presented. Aiming at targeted synthesis of new photochromic compounds, the structure – photochromic behavior relationship (SPBR) for the synthesized compounds has been analyzed. The perspectives for application of these compounds in development of recording media for use in optical memory devices are outlined. Copyright © 2007 John Wiley & Sons, Ltd.
Relative stabilities and molecular structures of the isomeric enol ethers and carboxylic esters derived from α‐acetyl‐γ‐butyrolactone and α‐acetyl‐δ‐valerolactone
Authors: Taskinen Esko 
Published: May 2007

AbstractRecently recorded 17O NMR spectra of compounds studied in a previous work (Taskinen E. Acta Chem. Scand. 1985; B39: 489–494) dealing with the thermodynamics of isomerization of the enol ethers of α‐acetyl‐γ‐butyrolactone reveal an error in compound identification, caused by an unexpected isomerization reaction during the synthetic procedure. Thus, acid‐catalyzed treatment of the lactone with HC(OR)3 in the respective alcohol ROH is shown to lead initially to the desired enol ethers which, however, are gradually isomerized to a mixture of the enol ethers and an ester of 2‐methyl‐4,5‐dihydrofuran‐3‐carboxylic acid. As a result, only one of the two isomeric compounds detected in the previous equilibration study was the expected enol ether (the thermodynamically more stable E isomer) of α‐acetyl‐γ‐butyrolactone, while the other, dominating species was the respective carboxylic ester. In the present work, the evidence provided by the 17O NMR spectra is presented, and the relative stabilities of the isomeric compounds are discussed on the basis of computational enthalpy data. The treatment is also extended to the respective isomeric compounds derived from α‐acetyl‐δ‐valerolactone. Copyright © 2007 John Wiley & Sons, Ltd.
Kinetics and mechanism of the reaction of an arenediazonium ion with hydrophilic aminocarboxylic acids in aqueous buffered solution
Authors: Fernández‐Alonso Alejandra , Bravo‐Díaz Carlos 
Published: May 2007

AbstractThe reaction of 4‐nitrobenzenediazonium ion, 4NBD, with the aminocarboxylic acids (AA) glycine and serine was studied under acidic conditions by using Linear Sweep Voltammetry (LSV), which allows simultaneous monitoring of 4NBD loss and product formation. Voltammograms of the reaction mixture are complex, showing up to five reduction peaks. The reduction peaks at Ep = −0.5 and −1.0 V, not detected in the absence of AA, are associated to products formed in the course of the reaction. The variation of their peak current, ip, with time shows a complex behavior; that of ip (Ep = −1.0 V) follows a biphasic profile with ip increasing with time up to a maximum after which a decrease is detected, suggestive of formation and subsequent decomposition of a transient intermediate, meanwhile ip (Ep = −0.5 V) increases with time after an induction period. The peaks at Ep = −0.1 and −0.8 V are associated to the reduction of the diazonium group of 4NBD and, in the presence of AA ([AA] >>> [4NBD]), their peak currents decrease exponentially with time following clean first‐order kinetics for more than 3t1/2. The variation of kobs with [AA] at a given pH is linear with an intercept equal to zero and that of log(kobs) with pH at constant [AA] is also linear. Kinetic evidence is consistent with a reaction mechanism involving an irreversible, rate‐limiting bimolecular step which leads to the formation of an unstable triazene, which further decomposes yielding 4‐nitroaniline among other reaction products. Copyright © 2007 John Wiley & Sons, Ltd.
Acid assisted proton transfer in 4‐[(4‐R‐phenylimino)methyl]pyridin‐3‐ols: NMR spectroscopy in solution and solid state, X‐ray and UV studies and DFT calculations
Authors: Perona Almudena , Sanz Dionisia , Claramunt Rosa M. , Pinilla Elena , Torres M. Rosario , Elguero José 
Published: May 2007

AbstractThe behaviour of Schiff bases of 3‐hydroxy‐4‐pyridincarboxaldehyde and 4‐R‐anilines (RH, CH3, OCH3, Br, Cl, NO2) in acid media has been described. 1H, 13C, 15N‐NMR chemical shifts allow to establish the protonation site and its influence on the hydroxyimino/oxoenamino tautomerism. DFT calculations, electronic spectra and X‐ray diffraction are in agreement with the NMR conclusions. Copyright © 2007 John Wiley & Sons, Ltd.
Low‐temperature controlled free‐radical polymerization of vinyl monomers in the presence of a novel cyclic dixanthate under γ‐ray irradiation
Authors: Hua Daoben , Ge Xueping , Tang Jing , Zhu Xiulin , Bai Ruke , Pan Caiyuan 
Published: May 2007

AbstractThe free‐radical polymerization of methyl acrylate (MA) has been studied in the presence of a novel cyclic dixanthate under γ‐ray irradiation (80 Gy min−1) at room temperature (∼28 °C), −30 °C, and −76 °C respectively. The resultant polymers have controlled molecular weights and relatively narrow molecular weight distributions, especially at low temperatures (i.e., −30 and −76 °C). The polymerization control may be associated with the temperature: the lower the temperature is, the more control there is. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry analysis of poly(methyl acrylate) (PMA) samples shows that there are at least three distributions: [3‐(MA)n‐H]+ cyclic polymers, [3‐(MA)n‐THF‐H]+, and [3‐(MA)n‐(THF)2‐H]+ linear PMAs. The relative content of the cyclic polymers markedly increases at a lower temperature, and this may be related to the reduced diffusion rate and the suppressed chain‐transfer reaction at the low temperature. It is evidenced that the good control of the polymerization at the low temperature may be associated with the suppressed chain‐transfer reaction, unlike reversible addition–fragmentation chain transfer polymerization. In addition, styrene bulk polymerizations have been performed, and gel permeation chromatography traces show that there is only one cyclic dixanthate moiety in the polymer chain. This article is the first to report the influence of a low temperature on controlled free‐radical polymerizations. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2847–2854, 2007
High‐quality SiO2/GaN interface for enhanced operation field‐effect transistor
Authors: Niiyama Yuki , Shinagawa Tatsuyuki , Ootomo Shinya , Kambayashi Hiroshi , Nomura Takehiko , Yoshida Seikoh 
Published: May 2007

AbstractThe interface quality in GaN metal–oxide–semiconductor (MOS) capacitors was dramatically improved by annealing after SiO2 deposition. The interface state density (Dit) of samples annealed at 900–1000 °C was estimated to be ∼2 × 1011 cm–2 eV–1 at 0.2 eV under the conduction band based on the calculation of the Terman method. Using this SiO2, it is expected that GaN MOSFETs can be operated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
ZnO nanocrystallites obtained by oxidation of zinc arachidate – arachidic acid composite multilayers
Authors: Singh Sukhvinder , Srinivasa R. S. , Talwar S. S. , Major S. S. 
Published: May 2007

AbstractZnO nanocrystallites were prepared by the oxidation of Zinc Arachidate–Arachidic Acid (ZnA–AA) composite multilayers grown on quartz and freshly cleaved mica substrates. Control of zinc content in the multilayers was achieved by the manipulation of the subphase pH and the variation in the number of monolayers transferred. FTIR studies of multilayers show a gradual decrease in ZnA content as the subphase pH is reduced. X‐ray reflection studies show the presence of a single layered structure in all the as‐deposited multilayers transferred at different subphase pH. These observations suggest molecular level mixing of ZnA and arachidic acid molecules. The precursor multilayers were oxidized in the temperature range of 100–700 °C. The formation of ZnO is confirmed by UV–Visible spectroscopy. Atomic force micrographs show that the oxidation treatment resulted in either large agglomerates of ZnO nanocrystallites or isolated nanocrystallites, depending on the zinc content of the precursor multilayers. Typically, 7 monolayers ZnA–AA transferred at subphase pH of 5.0 on mica and oxidized at 700 °C resulted in uniformly distributed, isolated and nearly mono‐dispersed nanocrystallites of size 11 ± 3 nm. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)