bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of corrosion on the mechanical behavior of steel undergoing plastic deformation
Authors: Apostolopoulos Ch. Alk. , Michalopoulos D. 
Published: January 2007

AbstractIn the present study the influence of the degree of plastic strain, due to various levels of plastic deformation during bending, on the mechanical properties of class BSt 500s tempcore steel was investigated, under various levels of salt spray corrosion. The resulted mass loss was of realistic levels and comparable to the one created by natural environmental causes. The results showed that even though an increase in plastic deformation resulted in an expected marginal increase in strength properties, it had a negative effect in ductility. The international community has not reached a consensus yet concerning the minimum required bending roll diameter, for stirrup production, which ranges between 4–10 times the diameter of the steel bar to be bent. It was also shown that this combination is crucial since strain fractures were recorded under the minimum required values set by the most current design guide‐lines and design oriented research. The results of this investigation are intended to offer an in depth understanding of the impact of the underestimated factor of corrosion on the mechanical properties of steel undergoing plastic deformation in corrosive environments and to show the need of re‐examination of existing codes.
Nonstandard models that are definable in models of Peano Arithmetic
Authors: Ikeda Kazuma , Tsuboi Akito 
Published: January 2007

AbstractIn this paper, we investigate definable models of Peano Arithmetic PA in a model of PA. For any definable model N without parameters in a model M, we show that N is isomorphic to M if M is elementary extension of the standard model and N is elementarily equivalent to M. On the other hand, we show that there is a model M and a definable model N with parameters in M such that N is elementarily equivalent to M but N is not isomorphic to M. We also show that there is a model M and a definable model N with parameters in M such that N is elementarily equivalent to M, and N is isomorphic to M, but N is not definably isomorphic to M. And also, we give a generalization of Tennenbaum's theorem. At the end, we give a new method to construct a definable model by a refinement of Kotlarski's method. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On witnessed models in fuzzy logic
Authors: Hájek Petr 
Published: January 2007

AbstractWitnessed models of fuzzy predicate logic are models in which each quantified formula is witnessed, i.e. the truth value of a universally quantified formula is the minimum of the values of its instances and similarly for existential quantification (maximum). Systematic theory of known fuzzy logics endowed with this semantics is developed with special attention paid to problems of arithmetical complexity of sets of tautologies and of satisfiable formulas. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Neumann problems for nonlinear hemivariational inequalities
Authors: Hu Shouchuan , Papageorgiou Nikolaos S. 
Published: January 2007

AbstractIn this paper we study nonlinear Neumann problems driven by the p ‐Laplacian and having a nonsmooth potential. Using techniques from the nonsmooth critical point theory, we prove two existence theorems and a multiplicity result. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lower limb nerve injuries in children
Authors: Senes Filippo M. , Campus Riccardo , Becchetti Flavio , Catena Nunzio 
Published: January 2007

AbstractThe aim of this paper is to emphasize the seriousness of pediatric peripheral nerve injuries of lower limbs and to stress the importance of early exploration of the injured nervous trunk in order to reduce the number of unfavorable outcomes. Among 136 traumatic peripheral nerve injuries in the children we treated, 31 nerve injuries of the lower limbs were observed. Causes of injury and time to recovery were evaluated. The sciatic nerve was involved in 19 cases, peroneal nerve in 11, root avulsions of the spinal cord in 1. We observed complete recovery in 12 cases and incomplete or no recovery at all in 19. The mean time to recovery in patients who underwent surgery was 18 months (range: 1–32). Considering the rate of spontaneous recovery of postinjection nerve injuries of the sciatic nerve and early onset of skeletal deformities, a closed nerve injury of the lower limb with no recovery within 3 months should always undergo surgery, even if complete functional outcome is not always guaranteed. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
ApproximateL(δ1,δ2,…,δt)‐coloring of trees and interval graphs
Authors: Bertossi Alan A. , Pinotti Cristina M. 
Published: January 2007

AbstractGiven a vector (δ1,δ2,…,δt) of nonincreasing positive integers, and an undirected graphG= (V,E), anL(δ1,δ2,…,δt)‐coloring ofGis a functionffrom the vertex setVto a set of nonnegative integers such that ∣f(u) −f(v)∣ ≥ δi, ifd(u,v) =i, 1 ≤i≤t, whered(u,v) is the distance (i.e., the minimum number of edges) between the verticesuandv. An optimalL(δ1,δ2,…,δt)‐coloring forGis one minimizing the largest integer used over all such colorings. Such a coloring problem has relevant applications in channel assignment for interference avoidance in wireless networks. This article presents efficient approximation algorithms forL(δ1,δ2,…,δt)‐coloring of two relevant classes of graphs—trees, and interval graphs. Specifically, based on the notion of strongly simplicial vertices,O(n(t+ δ1)) andO(nt2δ1) time algorithms are proposed to find α‐approximate colorings on interval graphs and trees, respectively, wherenis the number of vertices and α is a constant depending ontand δ1,…,δt. Moreover, anO(n) time algorithm is given for theL(δ1,δ2)‐coloring of unit interval graphs, which provides a 3‐approximation. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 49(3), 204–216 2007
Leonhard Euler: A brief appreciation
Authors: Assad Arjang A. 
Published: January 2007

AbstractApril 15, 2007, marks the 300th anniversary of Leonhard Euler's birth. This article pays tribute to the great mathematician who originated graph theory. We provide an overview of his life and his mathematical works, with particular emphasis on the historical development of the concept of Euler paths and cycles. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 49(3), 190–198 2007
Preconditioners for the discretized time‐harmonic Maxwell equations in mixed form
Authors: Greif Chen , Schötzau Dominik 
Published: January 2007

AbstractWe introduce a new preconditioning technique for iteratively solving linear systems arising from finite element discretization of the mixed formulation of the time‐harmonic Maxwell equations. The preconditioners are motivated by spectral equivalence properties of the discrete operators, but are augmentation free and Schur complement free. We provide a complete spectral analysis, and show that the eigenvalues of the preconditioned saddle point matrix are strongly clustered. The analytical observations are accompanied by numerical results that demonstrate the scalability of the proposed approach. Copyright © 2007 John Wiley & Sons, Ltd.
On multiscale FE analyses of heterogeneous structures: from homogenization to multigrid solvers
Authors: Miehe C. , Bayreuther C. G. 
Published: January 2007

AbstractHeterogeneous structures like composites often need a fine‐scale resolution of micro‐effects which influence the macroscopic overall response. This is of particular relevance in the fully non‐linear range of large strains and inelastic material response of the constituents. Suitable solution methods introduce a multifield scenario of hierarchically superimposed states on different length scales. For big differences of micro‐ and macro‐scales, the argument of scale separation induces the application of homogenization methods. Such types of physical multiscale approaches can be treated by nested multilevel finite element analyses that discretize both the fine‐scale micro‐structure as well as the macroscopic boundary‐value problem. In contrast, small‐scale differences require full resolution of the heterogeneous structure. Effective solution methods for the resulting large‐scale problems with strongly oscillating properties are suitably designed geometric multigrid techniques, which may be considered as numerical multiscale approaches. In both scenarios, a key ingredient is the suitable formulation of scale bridging algorithms that govern the transfer between different scales. The paper outlines new mesh‐bridging techniques in a deformation‐driven context for fully non‐linear response, which exploit in a non‐trivial manner weak constraints on the average deformation in typical finite element patches. The framework is based on an incremental variational structure of finite inelasticity. The proposed new formulations provide variational‐based homogenization algorithms for physical multiscale scenarios and problem‐dependent optimal finite element grid transfers for numerical multiscale scenarios of heterogeneous materials. Copyright © 2007 John Wiley & Sons, Ltd.
Deposition of highly efficient microcrystalline silicon solar cells under conditions of low H2 dilution: the role of the transient depletion induced incubation layer
Authors: van den Donker M. N. , Rech B. , Finger F. , Houben L. , Kessels W. M. M. , van de Sanden M. C. M. 
Published: January 2007

AbstractThis paper addresses the plasma deposition of highly efficient microcrystalline silicon (μc‐Si:H) p‐i‐n solar cells under conditions of high SiH4 utilization and low H2 dilution. It was established that the transient depletion of the initially present SiH4 source gas induces the formation of an amorphous incubation layer that prevents successful crystallite nucleation in the i‐layer and leads to poor solar cell performance. The effect of this transient depletion induced incubation layer on solar cells was made visible through dedicated solar cell deposition series and selected area electron diffraction measurements. Applying a gas flow procedure at plasma ignition it was succeeded to prepare state‐of‐the‐art μc‐Si:H material and solar cells under low hydrogen dilution conditions, highlighted by μc‐Si:H solar cells of up to 9·5% efficiency prepared using an undiluted source gas flow consisting solely of SiH4. Copyright © 2007 John Wiley & Sons, Ltd.
Modelling the influence of the orientation and fibre reinforcement on the Negative Poisson's ratio in composite laminates
Authors: Hadi Harkati El , Bezazi Abderrezak , Scarpa Fabrizio , Alderson Kim , Alderson Andrew 
Published: January 2007

AbstractThe variation of through‐thickness Poisson's ratio with fibre type and orientation has been investigated using a specially developed Fortran program. Glass fibre/epoxy resin composites were always found to be conventional, but negative Poisson's ratio values of up to ν13 = –0.746 were produced over certain orientation angles for Kevlar and carbon reinforcements. This underlines the need for anisotropic pre‐preg material. A range of [±β /±θ ]s angles were investigated for carbon fibre laminates and it was found that auxetic behaviour could be generated for β up to 45°. All the findings of this work have extended the range of laminates which can be engineered to be auxetic either by material (i.e. Kevlar as well as carbon) or by orientation (i.e. by introducing further β layers other than the 0° and 90° previously investigated). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Measurement and analysis of truck and rail shipping environment in India
Authors: Singh S. P. , Sandhu A. P. S. , Singh J. , Joneson E. 
Published: January 2007

AbstractFree trade agreements have been on the rise in all regions of the world in the past decade. This has allowed for global distribution and marketing of products in an international market. Products once produced for domestic markets must now be able to compete in international markets without trade barriers. Increased international commerce and manufacturing have forced many packaging and logistics engineers to broaden their true understanding of the global distribution environment. India is a recent entrant on the global arena for manufacturing and services. While China's economic developments have dominated global headlines, India's own growth has been impressive as well, with a gross domestic product rising 5% per annum on average since 1990. India is hence primed to follow China as the next low‐cost manufacturing super power. With an increasing interest from multinational corporations in conducting commerce with India, there arises a great need to understand the conditions of the transportation infrastructure there to promote logistical understanding of the distribution environments. This paper provides a brief overview of the road and rail transportation environment in India. It also provides the results of a 2 year study that measured and analysed truck and rail transport vibration for the major freight distribution routes between New Delhi, Bangalore, Mumbai, Chennai, Hyderabad and Kolkatta. Copyright © 2007 John Wiley & Sons, Ltd.
Students' mental models of the environment
Authors: Shepardson Daniel P. , Wee Bryan , Priddy Michelle , Harbor Jon 
Published: January 2007

AbstractWhat are students' mental models of the environment? In what ways, if any, do students' mental models vary by grade level or community setting? These two questions guided the research reported in this article. The Environments Task was administered to students from 25 different teacher‐classrooms. The student responses were first inductively analyzed in order to identify students' mental models of the environment. The second phase of analysis involved the statistical testing of the identified mental models. From this analysis four mental models emerged: Model 1, the environment as a place where animals/plants live—a natural place; Model 2, the environment as a place that supports life; Model 3, the environment as a place impacted or modified by human activity; and Model 4, the environment as a place where animals, plants, and humans live. The dominant mental model was Mental Model 1. Yet, a greater frequency of urban students than suburban and rural students held Mental Model 3. The implications to environmental science education are explored. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 327–348, 2007
By how much does increased nuchal translucency increase the risk of adverse pregnancy outcome in chromosomally normal fetuses? A study of 16 260 fetuses derived from an unselected pregnant population
Authors: Westin M. , Saltvedt S. , Almström H. , Grunewald C. , Valentin L. 
Published: January 2007

AbstractObjectiveIn this study we aimed to estimate the magnitude of a possible increase in risk of adverse outcome in fetuses with normal karyotype and increased nuchal translucency (NT), and to determine how well NT measurements can distinguish between fetuses with normal and adverse outcome.MethodsWe studied 16 260 consecutive fetuses with normal karyotype derived from an unselected pregnant population. The following cut‐offs for increased risk of adverse outcome were chosen a priori: NT ≥ 95th percentile, ≥ 3 mm, ≥ 3.5 mm, and ≥ 4.5 mm. The positive and negative likelihood ratios (+LR, − LR) of the risk cut‐offs with regard to fetal malformation, miscarriage, perinatal death, termination of pregnancy and total adverse outcome were calculated, and receiver–operating characteristics (ROC) curves were drawn.ResultsThe total rate of adverse outcome was 2.7%. + LR and − LR of NT ≥ 3.0 mm were: for lethal or severe malformation, + LR 15.0 (95% CI 7.0–28.6), − LR 0.89 (95% CI 0.81–0.95); for malformation of at least intermediate severity, + LR 8.1 (95% CI 4.3–14.0), − LR 0.95 (95% CI 0.92–0.97); for termination of pregnancy, + LR 41.6 (95% CI 17.1–86.6), − LR 0.67 (95% CI 0.41–0.85); for any adverse outcome, + LR 6.4 (95% CI 3.4–11), − LR 0.96 (95% CI 0.94–0.98). The odds for these adverse outcomes increased with increasing NT. NT ≥ 3 mm did not significantly increase the risk of miscarriage or perinatal death. Areas under ROC curves for NT were small, with 95% CI below or only slightly above 0.5.ConclusionOur likelihood ratios can be used to calculate the individual risk of unfavorable outcome, but NT screening cannot reliably distinguish between normal and adverse outcome in fetuses with normal karyotype. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Synthesis, structure and magnetic properties ofβ-MnO
2
nanorods
Authors: Kim HaeJin , Lee JinBae , Kim Young-Min , Jung Myung-Hwa , Jagličić Z. , Umek P. , Dolinšek J. 
Published: January 2007

Abstract
We present synthesis, structure and magnetic properties of structurally well-ordered single-crystalline β-MnO2nanorods of 50–100 nm diameter and several µm length. Thorough structural characterization shows that the basic β-MnO2material is covered by a thin surface layer (∼2.5 nm) of α-Mn2O3phase with a reduced Mn valence that adds its own magnetic signal to the total magnetization of the β-MnO2nanorods. The relatively complicated temperature-dependent magnetism of the nanorods can be explained in terms of a superposition of bulk magnetic properties of spatially segregated β-MnO2and α-Mn2O3constituent phases and the soft ferromagnetism of the thin interface layer between these two phases.
An asymmetric Neumann problem with weights
Authors: Gossez J.-P. , Arias M. , Campos J. , Cuesta M. 
Published: January 2007

We prove the existence of a first nonprincipal eigenvalue for an asymmetric Neumann problem with weights involving the

p

-Laplacian (cf. (1.2) below). As an application we obtain a first nontrivial curve in the corresponding Fučik spectrum (cf. (1.4) below). The case where one of the weights has meanvalue zero requires some special attention in connexion with the (PS) condition and with the mountain pass geometry.

Résumé

Nous démontrons l'existence d'une première valeur propre non principale pour un problème de Neumann asymétrique avec poids faisant intervenir le

p

-laplacien (cf. (1.2) ci-dessous). Comme application nous obtenons une première courbe non triviale dans le spectre de Fučik correspondant (cf. (1.4) ci-dessous). Le cas où l'un des poids est de moyenne nulle demande une attention particulière en liaison avec la condition de Palais–Smale et avec la géométrie du col.
Clinical‐pathological study of the healing of wounds provoked on the dorso‐lingual mucosa in 186 albino rats
Authors: Camacho‐Alonso Fabio , López‐Jornet Pía 
Published: January 2007

OBJECTIVETo evaluate wound healing of incisions created in the upper aerodigestive tract.STUDY DESIGN AND SETTINGIn this prospective and blind study, 186 adult rats were assigned to six groups to create incisions in the tongue. In the first three groups, the wounds were made with a steel scalpel; no substance was applied to the wound in the first group, but N‐butyl‐2‐cyanoacrylate was applied in the second group, and trichloroacetic acid at 50 percent in the third group. In the fourth, fifth, and sixth groups, the wounds were caused by cryosurgery, electrocautery, and CO2 laser. Hemostasis, postoperative oral intake, and wound healing were measured. Statistical analysis was performed with analysis of variance.RESULTSThe wounds to which N‐butyl‐2‐cyanoacrylate was applied showed no hemorrhaging and faster reepithelialization and resolution of the inflammatory response.CONCLUSIONSN‐butyl‐2‐cyanoacrylate is a good hemo‐static for managing wounds in the oral mucosa provoked by steel scalpel.© 2007 American Academy of Otolaryngology‐Head and Neck Surgery Foundation. All rights reserved.
Propofol versus sevoflurane: Bleeding in endoscopic sinus surgery
Authors: Beule Achim G. , Wilhelmi Frank , Kühnel Thomas S. , Hansen Ernil , Lackner Karl J. , Hosemann Werner 
Published: January 2007

OBJECTIVEReduction of intraoperative bleeding is desirable to improve intraoperative visibility and to avoid complications.STUDY DESIGNProspective, controlled, randomized, double‐blinded study.SETTINGInclusion criteria were chronic rhinosinusitis with nasal polyps that involved all paranasal sinuses, Lund‐CT score ≤ 12, and double‐blind preoperative randomization of narcotics. Exclusion criteria included abnormal coagulation, perioperative blood pressure outside the range of 70 to 140 mmHg systolic and 50 to 90 mmHg diastolic and perioperative medication. Total blood loss (mL), blood loss per minute (mL/min), platelet function, and parameter for endoscopic vision were evaluated.RESULTSForty‐six patients (22 sedated with sevoflurane/fentanyl, 24 sedated with propofol/fentanyl) completed the study. Total blood loss (300.1 ± 168.5 mL/276.9 ± 201.3 mL), blood loss per minute, and endoscopic vision showed no group difference. Platelet function was significantly impaired 45 minutes after onset of surgery in both groups, but more pronounced after propofol anesthesia.CONCLUSIONUnder conditions of balanced circulatory parameter, equal blood loss and endoscopic vision can be achieved with both tested anesthetic regimens. During extended operations demonstrated thrombocyte impairment by propofol may become clinically relevant.© 2007 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.
Endoscopic versus external repair of orbital blowout fractures
Authors: Jin Hong‐Ryul , Yeon Je‐Yeob , Shin See‐Ok , Choi Young‐Seok , Lee Dong‐Wook 
Published: January 2007

OBJECTIVESThis study evaluates the usefulness of endoscopic repair compared to external repair in the treatment of blowout fracture (BOF) of the orbit.STUDY DESIGN AND SETTINGThis retrospective study comprised 100 patients who had had surgical repair of orbital BOF since 1992. Forty‐eight of the 100 had undergone endoscopic repair, 48 patients had had external repair, and four patients underwent surgery that combined the two approaches. The two basic approaches were evaluated and compared with respect to technique, results and complications.RESULTSEndoscopically, transnasal and transantral approaches had been used for reduction and support of fractured medial and inferior walls, respectively. In the external approach, various transorbital incisions were made and the fractured wall was repaired with alloplastic or autologous materials. Complete or partial resolution of preoperative diplopia was achieved in 94% of the endoscopic group and 83% of the external group (NS). Enophthalmos was improved in 89% of the endoscopic group and 76% of the external group (NS). Though the endoscopic group had no significant complications, the external group had ectropions, significant facial scars, extrusion of inserted Medpor, and intra‐orbital hematoma.CONCLUSIONSEndoscopic repair appears to be a safe and effective technique for the treatment of BOF of the orbit.© 2007 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.