bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fine structure and formation mechanism of particulate phase‐inversion poly(vinylidene fluoride) membranes
Authors: Lin Dar‐Jong , Beltsios Konstantinos , Chang Cheng‐Liang , Cheng Liao‐Ping 
Published: June 2003

AbstractThe structure and formation mechanism of a microporous phase‐inversion poly(vinylidene fluoride) (PVDF) membrane exhibiting a relatively loosely packed agglomerate of semicrystalline globules are explored. The membrane has been prepared by the coagulation of a solution of PVDF in dimethylformamide by the action of 1‐octanol, which is a soft nonsolvent. Experimental observations pertain to the globule surface, which is dominated by a grainy nanostructure; the globular interior, which exhibits a range of fine structures (e.g., twisted sheets and treelike branches); and the globule–globule connections, which exhibit a sheetlike or ropelike structure. On the basis of the observed structural details and phase diagram considerations, it is proposed that the membrane structure is the result of a unique combination of a polymer crystallization and a liquid–liquid phase‐separation process, with end‐result globular structural features of remarkable uniformity. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1578–1588, 2003
Appreciating the beauty of science ideas: Teaching for aesthetic understanding
Authors: Girod Mark , Rau Cheryl , Schepige Adele 
Published: June 2003

AbstractA large literature exists in which scientists describe their field as beautiful and the work they do as inspiring and passionate. Science teaching should strive to foster learning of substantive and powerful science ideas in ways that connect to the beauty inherent in those ideas. Our conception of learning science, that of learning for aesthetic understanding, achieves this goal by building on a framework of aesthetic experiences proposed by Dewey. This study is an articulation of the major components of aesthetic understanding, pedagogy designed to foster it, and the results of a pilot study designed to investigate its effectiveness. Responses to a survey and a semistructured interview are compared for students in two, fourth grade classrooms. The instructional goals were different in each classroom; one taught for the goal of aesthetic understanding, the second for the goal of conceptual understanding. Survey results indicate that the pedagogical moves were effective in scaffolding aesthetic understanding in treatment class students. More interesting, however, are student reports of the quality of the learning experience in the treatment class. © 2003 Wiley Periodicals, Inc. Sci Ed 87:574–587, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.1054
Confidence intervals for the 50 per cent response dose
Authors: Faraggi D. , Izikson P. , Reiser B. 
Published: June 2003

AbstractConfidence intervals for the 50 per cent response dose are usually computed using either the Delta method or Fieller's procedure. Recently, confidence intervals computed by inverting the asymptotic likelihood ratio test have also been recommended. There is some controversy as to which of these methods should be used. By means of an extensive simulation study we examine these methods as well as confidence intervals obtained by the approximate bootstrap confidence (ABC) procedure and an adjusted form of the likelihood ratio based confidence intervals. Copyright © 2003 John Wiley & Sons, Ltd.
Assessing the appropriateness of combining economic data from multinational clinical trials
Authors: Cook John R. , Drummond Michael , Glick Henry , Heyse Joseph F. 
Published: June 2003

AbstractBecause of the potential for large variability among countries in the utilization and cost of health care resources, it is important to assess the appropriateness of combining economic data across the countries in a multinational clinical economic trial. We show how available tests for interaction can be applied to economic endpoints, including cost‐effectiveness ratios and net health benefits. This analysis includes a characterization of possible interactions being quantitative or qualitative in nature. In the absence of interaction, a pooled estimate of the economic endpoint should be representative of the participating countries. We explore the analytic issues by further analysing data from the Scandinavian Simvastatin Survival Study (4S). Copyright © 2003 John Wiley & Sons, Ltd.
Model‐driven design of collaborative Web applications
Authors: Matera M. , Maurino A. , Ceri S. , Fraternali P. 
Published: June 2003

AbstractThis paper introduces a model‐driven approach to the design of collaborative Web‐based applications, i.e. applications in which several users play different roles, in a collaborative way, to pursue a specific goal. The paper illustrates a conference management application (CMA), whose main requirements include: (i) the management of users profiles and access rights based on the role played by users during the conference life cycle; (ii) the delivery of information and services to individual users; (iii) the management of the sequence of activities that lead to the achievement of a common goal. The presented approach is based on WebML, a conceptual modelling language for the Web. The paper also highlights some general properties—as understood by the practical experience of CMA development—that a Web modelling language should feature in order to fully support the development of collaborative applications. Copyright © 2003 John Wiley & Sons, Ltd.
Spreadsheet method for temperature calculation of unprotected steelwork subject to fire
Authors: Wong M. B. , Ghojel J. I. 
Published: June 2003

AbstractThe determination of fire resistance level of a structural member in a building requires an efficient and accurate assessment of its limiting temperature in an enclosure fire environment. A significant discrepancy in the results of calculation of the limiting temperature could lead to an increase in the size of the structural member or an increase in the thickness of the fire protection materials. In either case, the cost of construction may increase. This paper introduces an efficient and accurate method for temperature prediction of steel members under four‐sided fire exposure conditions. The method is based on the heat transfer principles commonly adopted in current codes of practice. However, the proposed method emphasizes the effect of gaseous composition of the combustion products on the evaluation of heat transfer coefficients that most codes of practice ignore. In addition, the complex forms of heat transfer coefficients have been simplified for practical use while the accuracy is still maintained. This method is well suited for practising engineers performing structural design for fire as the calculation procedure can be carried out entirely on a spreadsheet. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of creep and shrinkage in reinforced concrete frame–shear wall system with high beam stiffness
Authors: Maru Savita , Sharma R. K. , Nagpal A. K. 
Published: June 2003

AbstractThe behaviour of frames and frame–shear wall systems with regard to creep and shrinkage with high beam stiffness has been largely unexplored until recently since no procedure has been available. For low beam stiffness the most widely used procedure available in literature for determining creep and shrinkage effects in reinforced concrete building frames and frame–shear wall systems designated herein as approximate procedure, AP has been recommended for buildings having flexible slab systems and with a limited number of storeys. Recently an accurate procedure termed Consistent Procedure (CP) has been developed which is applicable to low as well as high beam stiffness and requires no restriction on number of storeys. In this paper, using CP, studies are reported for frame–shear wall systems with high beam stiffness. The effect of introduction of shear walls on load transfer among vertical members considering creep and shrinkage is studied. It is shown that the presence of shear wall alters significantly the load transfer among vertical members. It is also shown that whereas differential vertical deflections between adjacent vertical members are small owing to high stiffness of beams, the load transfer between them can be significant. Copyright © 2003 John Wiley & Sons, Ltd.
Theoretical analysis of post‐peak flexural behaviour of normal‐ and high‐strength concrete beams
Authors: Ho J. C. M. , Kwan A. K. H. , Pam H. J. 
Published: June 2003

AbstractA new method of analysing the post‐peak flexural behaviour of reinforced concrete beams has been developed and applied to normal‐ and high‐strength concrete beams. It was revealed that at the post‐peak stage the neutral axis depth keeps on increasing, and at a certain point the strain in the tension reinforcement starts to decrease, even though the curvature is increasing monotonically. Such strain reversal in the tension reinforcement occurs in all concrete beams and has significant effects on the post‐peak behaviour and flexural ductility of concrete beams. Therefore, the stress path dependence of the tension reinforcement needs to be taken into account in the analysis. By means of a parametric study, the variation of ultimate concrete strain with tension steel ratio and the effects of various structural parameters on flexural ductility have been studied. Based on the numerical results, design values of ultimate concrete strain that are independent of tension steel ratio have been recommended and a simple formula for predicting the flexural ductility of reinforced normal‐ and high‐strength concrete beams has been developed. Copyright © 2003 John Wiley & Sons, Ltd.
Impact wave propagation in tall buildings using advanced spectral element method
Authors: Horr A. M. , Safi M. 
Published: June 2003

AbstractOne of the major divisions in analysis and design of tall buildings is to account for forces induced by flying‐object impact and the subsequent progressive collapse. During the past three decades, problems of contact mechanics have been considered by some authors, and special attention has been devoted to high‐speed impact. Impact wave propagation in tall buildings may be analysed using the conventional finite element method. However, in order to guarantee stability and accuracy of the solution, the number of elements used to model the structure may be very large indeed; more precisely, accurate results can be obtained after a substantial computational effort. In this respect, an improved complex spectral element method is developed for analysing the wave propagation problems in large structures. The purpose of this paper is to obtain the resulting dynamic responses of a tall building induced by a high‐speed impact of a flying object. Copyright © 2003 John Wiley & Sons, Ltd.
Fluid viscous dampers for high‐rise buildings
Authors: McNamara Robert J. , Taylor Douglas P. 
Published: June 2003

AbstractUsing supplemental fluid viscous dampers to dissipate energy and reduce building response to dynamic inputs is gaining worldwide acceptance. The concept of supplemental dampers added to a structure is that they absorb much of the energy input to the structure from a transient, not by the structure itself, but rather by supplemental damping elements. This paper presents an application of fluid viscous dampers in a high‐rise structure to suppress the anticipated wind‐induced accelerations. The description of the damping system, the design criteria and cost data are discussed. The viscous damper system proves to be a very cost‐effective method to reduce wind motions. Copyright © 2003 John Wiley & Sons, Ltd.
Structural performance of multi‐outrigger‐braced tall buildings
Authors: Wu J. R. , Li Q. S. 
Published: June 2003

AbstractThe optimum designs of multi‐outriggers in tall building structures are presented and discussed in this paper, through the analysis of structural performance of outrigger‐braced frame‐core structures. The influences of the locations of outriggers and the variations of structural element stiffness on the base moment in core, top drift and fundamental vibration period of such tall building structures are analysed in detail. A non‐linear optimum design procedure for reducing the base moment in the core is presented based on the penalty function method. The computer programs are developed on the basis of the proposed methods for analysing the behaviour and optimum design of multi‐outrigger structures. A series of figures presented in this paper can be used for the design purposes of outrigger‐braced tall building structures. Copyright © 2003 John Wiley & Sons, Ltd.
Reduced order control for wind‐induced vibrations of tall buildings
Authors: Li Q. S. 
Published: June 2003

AbstractThe design of a structural control system for a tall building may not be easy owing to the large number of degrees of freedom involved. Obviously, it is much easier to design a structural control system for the reduced‐order system than for the full‐order system. Model reduction is thus useful when control systems are implemented in civil engineering structures. A reduced‐order modelling technology for vibration control of wind‐excited tall buildings is presented and its performance is studied. The important issues associated with wind‐induced vibrations, model condensations and reduced‐order control are addressed. Finally, a numerical example, a tall building with an active tuned mass damper or a passive tuned mass damper, is given to show the efficiency of the reduced‐order control technique. Copyright © 2003 John Wiley & Sons, Ltd.
Wind Turbine Control for Load Reduction
Authors: Bossanyi E. A. 
Published: June 2003

AbstractThis article reviews techniques for the control of wind turbines during power production. Pitch control is used primarily to limit power in high winds, but it also has an important effect on structural loads. Particularly as turbines become larger, there is increasing interest in designing controllers to mitigate loads as far as possible. Torque control in variable‐speed turbines is used primarily to maximize energy capture below rated wind speed, and to limit the torque above rated, but it can also be used to reduce certain loads. The design of the control algorithms is clearly of prime importance. Additional sensors such as accelerometers and load sensors can also help the controller to achieve its objectives more effectively. By controlling the pitch of each blade independently, it is also possible to achieve important further reductions in loading. It is important to be able to quantify the benefits of any new controller. Although computer simulations are useful, field trials are also vital. The variability of the real wind means that particular care is needed in the design of the trials. Copyright © 2003 John Wiley & Sons, Ltd.
Immunocontraception of captive exotic species. III. Contraception and population management of fallow deer (Cervus dama)
Authors: Deigert Fred A. , Duncan Ann E. , Frank Kim M. , Lyda Robin O. , Kirkpatrick Jay F. 
Published: June 2003

AbstractImmunocontraception has become an increasingly valuable tool in the population management of captive exotic ungulates. Although porcine zona pellucida vaccine (PZP) was used successfully in other cervids, a previous study with fallow deer (Cervus dama) suggested that the vaccine did not work in this species. In the current study, PZP was tested in two captive herds of fallow deer. Antibody titers were monitored over a 3‐year period to evaluate three different adjuvant protocols, and the vaccine was applied to an entire herd to determine the impact on fawning rates. In a semi‐free‐ranging herd, antibody titers rose from preimmunization levels of 2.6% of positive control serum to 56.5% 4 weeks after initial inoculations, to 65.1% at 1 year, and to 81.3% at 2 years, after a single annual booster was applied. Fawn production in this herd was reduced significantly over 3 years. The adjuvant protocol of Freund's Modified Adjuvant® (FMA) for the initial inoculation followed by a booster with Freund's Incomplete Adjuvant® (FIA), and the protocol of FMA for the initial inoculation followed in 3 weeks by a booster with FMA both produced significantly higher antibody titers than the 3× FIA (3 weeks apart) protocol after year 1. The FMA+FMA protocol produced significantly higher titers than the 3× FIA protocol at year 2, but was not different from the titers produced by the FMA+FIA protocol at year 2. Zoo Biol 22:261–268, 2003. © 2003 Wiley‐Liss, Inc.
On the systematic position of the lichen genus Heppia
Authors: Schultz Matthias , Büdel Burkhard 
Published: June 2003

AbstractThe systematic position of the lichen genus Heppia in the order Lichinales was investigated. 18S rDNA sequence data were analyzed using a Bayesian approach to infer phylogeny using Markov chain Monte Carlo methods. The Lichinales are divided at family level into the sister groups Lichinaceae and Peltulaceae. The genus Heppia forms a highly supported clade in the family Lichinaceae. It is shown that the genus Heppia is morphologically well circumscribed within the Lichinaceae. As a nomenclatural consequence, the family name Heppiaceae is placed into synonymy under the older name Lichinaceae.
Bone mineral density and biochemical markers of bone turnover in aseptic loosening after total hip arthroplasty
Authors: Wilkinson J. Mark , Hamer Andrew J. , Rogers Angela , Stockley Ian , Eastell Richard 
Published: June 2003

AbstractThe aims of this study were to determine whether subjects with aseptic loosening after total hip arthroplasty (THA) have regional differences in periprosthetic bone mineral density (BMD) and systemic biochemical markers of bone turnover compared to subjects with successful implants.Proximal femoral and pelvic BMD were measured by dual energy X‐ray absorptiometry and bone turnover markers were assayed in 49 subjects 12.6 ± 4.3 (mean ± SD) years after cemented THA. Femoral BMD was lower in Gruen zones 2, 5, 6, and 7 in subjects with a loose femoral implant (n = 17) compared to those (n = 32) with fixed femoral implants (P < 0.05 all comparisons). This BMD difference was greatest (−31%, P = 0.02) in the proximal and medial region of the femur. Subjects with femoral loosening had higher levels of the bone resorption marker N‐telopeptides of type‐I collagen (P = 0.02) than those with a fixed femoral implant. No differences in pelvic BMD or bone turnover markers were found between subjects with loose (n = 18) versus fixed (n = 31) pelvic implants.This study suggests that failure of femoral components after cemented THA is associated with region‐specific decreases in BMD and an increase in urinary excretion of N‐telopeptide cross‐links of type‐I collagen. These surrogate outcome markers may be of value in monitoring response to antiresorptive therapies used to treat periprosthetic osteolysis, although the diagnosis of aseptic loosening remains clinical and radiological. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Noninvasive fatigue fracture model of the rat ulna
Authors: Tami A. E. , Nasser P. , Schaffler M. B. , Tate M. L. Knothe 
Published: June 2003

AbstractFatigue damage occurs in response to repeated cyclic loading and has been observed in situ in cortical bone of humans and other animals. When microcracks accumulate and coalesce, failure ensues and is referred to as fatigue fracture. Experimental study of fatigue fracture healing is inherently difficult due to the lack of noninvasive models. In this study, we hypothesized that repeated cyclic loading of the rat ulna results in a fatigue fracture. The aim of the study was to develop a noninvasive long bone fatigue fracture model that induces failure through accumulation and coalescence of microdamage and replicates the morphology of a clinical fracture. Using modified end‐load bending, right ulnae of adult Sprague‐Dawley rats were cyclically loaded in vivo to fatigue failure based on increased bone compliance, which reflects changes in bone stiffness due to microdamage. Preterminal tracer studies with 0.8% Procion Red solution were conducted according to protocols described previously to evaluate perfusion of the vasculature as well as the lacunocanalicular system at different time points during healing. Eighteen of the 20 animals loaded sustained a fatigue fracture of the medial ulna, i.e. through the compressive cortex. In all cases, the fracture was closed and non‐displaced. No disruption to the periosteum or intramedullary vasculature was observed. The loading regime did not produce soft tissue trauma; in addition, no haematoma was observed in association with application of load. Healing proceeded via proliferative woven bone formation, followed by consolidation within 42 days postfracture. In sum, a noninvasive long bone fatigue fracture model was developed that lends itself for the study of internal remodeling of periosteal woven bone during fracture healing and has obvious applications for the study of fatigue fracture etiology. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Cod in fjords and coastal waters of North Norway: distribution and variation in length and maturity at age
Authors: Berg Erik , Albert Ole Thomas 
Published: June 2003

Abstract
The distribution of cod along the Norwegian coast and in fjords from 62°N north to the Russian border was examined using data from annual trawl surveys carried out between 1995 and 2001. Based on differences in growth zones of the otoliths, cod are traditionally classified into two types: Northeast Arctic cod and coastal cod. Both types were found throughout the area investigated. The catch rate of both increased northwards and from offshore to inshore. In a statistical model of length at age, abiotic factors such as area and year of capture explained more of the variance than biotic factors such as sex, stage of maturity, and type of cod. Length at age increased in a southward direction and was higher for cod captured offshore than for those captured inshore. In a statistical model of the proportion mature at age, area, type, and year of capture explained more of the variance than sex and depth of capture. On average, coastal cod attained 50% maturity (M50) more than a year younger than a year younger than Northeast Arctic cod attained maturity. Although there were relatively large differences in age at maturity between neighbouring areas, age at maturity was lowest in the south and inshore, and in general, lower inshore than offshore. As genetic analysis clearly indicates that cod in the study area consist of at least two genetically separated stocks, it is likely that the differences found here in age at M50 might have a genetic component.