bluuebunny/crossref_metadata_2025_split huggingface dataset:
An analytical solution for a jointed shield‐driven tunnel lining
Authors: Lee K. M. , Hou X. Y. , Ge X. W. , Tang Y. 
Published: August 2002

AbstractThis paper presents an analytical solution for the prediction of internal forces and displacements of a jointed segmental precast circular tunnel lining. The effects of joint stiffness on the performance of the tunnel lining are discussed. The ‘force method’ is used to determine the internal forces and displacements of jointed tunnel lining. Five shield‐driven tunnel cases are adopted to study the effects of joint stiffness, soil resistance, joint distribution and joint number on the internal forces and displacements of circular tunnels. Laboratory model tests are conducted to verify the proposed analytical solution. Copyright © 2001 John Wiley & Sons, Ltd.
Numerical modelling of the driving response of thin‐walled open‐ended piles
Authors: Liyanapathirana D. S. , Deeks A. J. , Randolph M. F. 
Published: August 2002

AbstractThe driving response of thin‐walled open‐ended piles is studied using numerical simulation of the wave propagation inside the soil plug and the pile. An elastic finite element analysis is carried out to identify the stress wave propagation in the vicinity of the pile toe. It is found that the shear stress wave has the highest magnitude above the bottom of the soil plug. Below the bottom of the soil plug, the vertical stress wave has the highest magnitude. Although the shear stress wave propagating in the radial direction is similar in magnitude to the vertical stress wave at the bottom of the soil plug, it decays rapidly while travelling downwards. The highest vertical stress at the bottom of the soil plug appears after the vertical stress wave interacts with the shear stress wave travelling in the radial direction. Initially, the vertical stress wave propagates with the dilation wave velocity in both the radial and vertical directions. After it interacts with the shear stress wave, the vertical stress wave starts to propagate with the shear wave velocity in the radial direction and with the axial wave velocity downwards. It is concluded that at the bottom of the soil plug, the interaction between the waves travelling in radial and vertical directions is important.The capabilities of several one‐dimensional pile‐in‐pile models to reproduce the driving response given by a two‐dimensional axisymmetric finite element model is studied. It is seen that when the base of the soil plug fails, a one‐dimensional pile‐in‐pile model can be used to achieve results in agreement with the finite element model. However, when the pile is unplugged, where the base of the soil plug does not fail, a reduced finite element mesh that permits the radial wave propagation inside the soil plug must be used. Copyright © 2001 John Wiley & Sons, Ltd.
Consolidation of double‐layered ground with vertical drains
Authors: Tang Xiao‐Wu , Onitsuka Katsutada 
Published: August 2002

AbstractVertical drains are usually installed in subsoil consisting of several layers. Due to the complex nature of the problem, over the past decades, the consolidation properties of multi‐layered ground with vertical drains have been analysed mainly by numerical methods. An analytical solution for consolidation of double‐layered ground with vertical drains under quasi‐equal strain condition is presented in this paper. The main steps for the computation procedure are listed. The convergence of the series solution is discussed. The comparisons between the results obtained by the present analytical method and the existing numerical solutions are described by figures. The orthogonal relation for the system of double‐layered ground with vertical drains is proven. Finally, some consolidation properties of double‐layered ground with vertical drains are analysed. Copyright © 2001 John Wiley & Sons, Ltd.
Effectiveness of two conservative modes of physical therapy in women with urinary stress incontinence
Authors: Arvonen Tiina , Fianu‐Jonasson Aino , Tyni‐Lenné Raija 
Published: August 2002

AbstractStress incontinence is the most prevalent form of female urinary incontinence and it affects approximately 5% of younger women to nearly 50% of elderly women. Women have traditionally been treated with pelvic floor muscle exercises alone or with the use of vaginal cones. A new treatment mode, vaginal balls, has been developed. The aim of this study was to compare pelvic floor muscle training with and without vaginal balls and to collect information on women's subjective feelings about the two training modes. The study was carried out as a prospective randomized clinical trial. Thirty‐seven women aged 25–65 were assigned either to a pelvic floor muscle training program or to a training program using weighted vaginal balls for 4 months. Treatment outcomes were assessed by a pad‐test with a standardized bladder volume, vaginal palpation, and by women's self‐reported perceptions. The sense of coherence score was compared with the score for a normal population. Ninety‐three percent of the women completed the study. Both training modes were effective in reducing urinary leakage: with vaginal balls (P < 0.0001) and without (P < 0.019); and increasing pelvic floor muscle strength: with vaginal balls (P < 0.0039) and without (P < 0.0002). However, the reduction of urinary leakage after four months of exercise in the training group with vaginal balls was significantly better (P < 0.03) than the results in the group training with pelvic floor muscle exercises alone. The study found the weighted vaginal balls to be a good alternative for training pelvic floor muscles in women with stress urinary incontinence. Neurourol. Urodynam. 20:591–599, 2001. © 2001 Wiley‐Liss, Inc.
Selective suppression of sphincter activation during sacral anterior nerve root stimulation
Authors: Bhadra Narendra , Grünewald Volker , Creasey Graham , Mortimer J. Thomas 
Published: August 2002

AbstractThe purpose of this work was to electrically activate small‐diameter motor fibers in the sacral anterior roots innervating the urinary bladder, without activating the large‐diameter fibers to the sphincter. Quasitrapezoidal current pulses were applied through tripolar spiral nerve electrodes on selected anterior sacral roots during acute experiments on eight dogs, maintained under pentobarbital anesthesia. Pressures were recorded from the bladder and sphincter with catheter‐mounted gauges. Stimulation with biphasic quasitrapezoidal pulses showed decrease in sphincter recruitment with increasing pulse amplitudes. The minimum current amplitude that resulted in maximum sphincter suppression was used to stimulate the roots with trains of 20 Hz pulses, with 60 mL of saline filling the bladder. Pressures were also recorded when 100 μs rectangular pulse trains at 20 Hz, both continuous and intermittent, were applied. Trains of stimuli were applied before and after dorsal root rhizotomy. Suppression of sphincter activation was defined to be a percentage, [(Maximum pressure −Minimum pressure)/Maximum pressure × 100. The results from 22 roots in eight animals show that with single pulses, the average percentage suppression of sphincter activation was 76.3% (± 14.0). The minimum current for maximum sphincter suppression was 1.29 mA (± 0.62). The average bladder pressure evoked was 50 cm of water during pulse train stimulation, with no significant difference due to pulse type. With pulse trains, the sphincter pressures were significantly higher when the bladder was filled. Evacuation of fluid occurred in three animals with average flow rates of 1.0 mL/s. Neurourol. Urodynam. 21:55–64, 2002. © 2002 Wiley‐Liss, Inc.
Quantitative measurements of cerebral metabolic rate of oxygen utilization using MRI: a volunteer study
Authors: An Hongyu , Lin Weili , Celik Azim , Lee Yueh Z. 
Published: August 2002

AbstractQuantitative estimates of cerebral metabolic rate of oxygen utilization using magnetic resonance imaging can have profound implications for the understanding of brain metabolic activity as well as the investigation of cerebrovascular disease. In this study, five normal volunteers were studied. All images were acquired on a Siemens 1.5 T scanner (Siemens Medical Systems Inc, Erlangen, Germany). Cerebral blood flow (CBF) was obtained in vivo with a dynamic imaging approach and the acquired images were post‐processed with the singular value decomposition method (SVD). In addition, a multi‐echo gradient echo/spin echo sequence was employed to provide MR estimates of oxygen extraction fraction (MR_OEF) in vivo. Subsequently, an absolute measure of MR cerebral metabolic rate of oxygen utilization (MR_CMRO2) was obtained in all subjects by taking the product of CBF and MR_OEF. A mean MR_CMRO2 of 28.94 ± 3.26 ml/min/100 g and 12.57 ± 3.11 ml/min/100 g was obtained for gray matter and white matter, respectively, suggesting that the gray matter utilizes more oxygen than white matter under normal physiological conditions. These results yield a gray matter to white matter CMRO2 ratio of 2.37 ± 0.37, which is comparable to the reported values in the literature. More studies are needed to further improve on the accuracy as well as shortening the required data acquisition time so that the proposed approaches can be utilized in a routine clinical setting. Copyright © 2001 John Wiley & Sons, Ltd.
Security‐enhanced packet video with dynamic multicast throughput adjustment
Authors: Chao Han‐Chieh , Wu T. Y. , Chen Jiann‐Liang 
Published: August 2002

AbstractIn recent years, the Internet population has increased at an explosive rate. Many problems exist because Internet packets are not encrypted and the bandwidth is not large enough. In this research, we propose a datagram encryption technique and dynamic bandwidth throughput adjustment. Security is enhanced using secret keys selected from a Key‐Database. Not only is a double encryption tunnel offered but also the whole plaintext can be encrypted more than one key depending on the encryption block size chosen. Copyright © 2001 John Wiley & Sons, Ltd.
Dynamic market‐driven allocation of network resources using genetic algorithms in a competitive electronic commerce marketplace
Authors: Ye Jian , Papavassiliou Symeon 
Published: August 2002

AbstractIn this paper, we propose a practical algorithm which finds cost‐efficient routes from Service Provider (SP) to Content Provider (CP) dynamically in a multi‐operator networking environment, using Genetic Algorithm (GA) concepts. The proposed algorithm is a kind of stochastic algorithm searching process in the solution space by emulating biological selection and reproduction. Copyright © 2001 John Wiley & Sons, Ltd.
On the number of spanning trees in directed circulant graphs
Authors: Lonc Zbigniew , Parol Krzysztof , Wojciechowski Jacek M. 
Published: August 2002

AbstractLetgk(n) [respectively,fk(n)] be the maximum number of spanning trees in directed circulant graphs (respectively, regular directed graphs) withnvertices and out‐degrees equal tok> 1. We show thatgk(n) =kn(1+o(1))andfk(n) =kn(1+o(1)). Moreover, we prove thatg2(n) = ⌊(2n+ 1)/3⌋. © 2001 John Wiley & Sons, Inc.
Development of inhibition by ephrin‐A5 on outgrowth of embryonic spinal motor neurites
Authors: Wang H. , Chadaram S. R. , Norton A. S. , Laskowski M. B. 
Published: August 2002

AbstractThe spinal motor pool maps systematically onto the surface of muscles. This map is detectable in rat embryonic muscles, and is partially restored after reinnervation. Recent evidence shows that either overexpression or deletion of the ephrin‐A5 gene significantly disrupts the map, suggesting that ephrin‐A5 plays a critical role in the formation of this topography. Several studies have demonstrated that ephrin‐A5 is a repulsive molecule in the nervous system, including the neuromuscular system. To examine the development of sensitivity of ventral spinal axons to this inhibitory ligand, slices of E11 to E15 embryonic rat spinal cords were cocultured with membranes derived from ephrin‐A5‐expressing cell lines. We detected a progressive expression of inhibition by ephrin‐A5 between E11 and E15. By E15, rostral and caudal spinal neurites showed clear differences in responsiveness to the ephrin‐A5 ligand. Further, we found that at this age caudal neurites are more sensitive to changes of ephrin‐A5 concentration along a gradient. In addition, growth cones of caudal, more than rostral, neurites tended to assume a collapsed shape in the presence of the ligand. These results demonstrate a progressive development of sensitivity to ephrin‐A5, and suggest a divergence in this sensitivity between rostral and caudal spinal cord neurites. These results provide further insight into how subtle rostrocaudal differences in the development of sensitivity to ephrin‐A5 may explain, in part, neuromuscular topography. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 233–243, 2001
Subspace correction multi‐level methods for elliptic eigenvalue problems
Authors: Chan Tony F. , Sharapov Ilya 
Published: August 2002

AbstractIn this work, we apply the ideas of domain decomposition and multi‐grid methods to PDE‐based eigenvalue problems represented in two equivalent variational formulations. To find the lowest eigenpair, we use a “subspace correction” framework for deriving the multiplicative algorithm for minimizing the Rayleigh quotient of the current iteration. By considering an equivalent minimization formulation proposed by Mathew and Reddy, we can use the theory of multiplicative Schwarz algorithms for non‐linear optimization developed by Tai and Espedal to analyse the convergence properties of the proposed algorithm. We discuss the application of the multiplicative algorithm to the problem of simultaneous computation of several eigenfunctions also formulated in a variational form. Numerical results are presented. Copyright © 2001 John Wiley & Sons, Ltd.
Multiple imputation for missing data†‡
Authors: Patrician Patricia A. 
Published: August 2002

AbstractMissing data occur frequently in survey and longitudinal research. Incomplete data are problematic, particularly in the presence of substantial absent information or systematic nonresponse patterns. Listwise deletion and mean imputation are the most common techniques to reconcile missing data. However, more recent techniques may improve parameter estimates, standard errors, and test statistics. The purpose of this article is to review the problems associated with missing data, options for handling missing data, and recent multiple imputation methods. It informs researchers' decisions about whether to delete or impute missing responses and the method best suited to doing so. An empirical investigation of AIDS care data outcomes illustrates the process of multiple imputation. © 2002 John Wiley & Sons, Res Nurs Health 25:76–84, 2002.
Urine flowing: A phenomenological study of living with a urinary catheter†
Authors: Wilde Mary H. 
Published: August 2002

AbstractThe experience of living with a long‐term urinary catheter was investigated with a community‐dwelling sample of 14 adults ranging in age from 35 to 95 who had worn a catheter for 6 months to 18 years. Data were obtained by audiotaped face‐to‐face interviews. Merleau‐Ponty's phenomenology and van Manen's methodology guided the study. Living with a urinary catheter was found to be like living with the forces of flowing water. People were keenly aware of the flow of urine through their catheters, and they noticed when their bags needed emptying or when urine drainage seemed sluggish or obstructed. The metaphor of urine flowing like water may provide a teaching heuristic for assisting clients in adjusting to living with a catheter. Implications for further research focus on understanding the relationship between sensitivity to the dynamics of urine flow and urinary tract infection. © 2002 John Wiley & Sons, Res Nurs Health 25:14–24, 2002.
Do environmental disturbances of an individual's growth and development influence the later bone involution processes? A study of two mediaeval populations
Authors: Rewekant Artur 
Published: August 2002

AbstractAge‐dependent cortical bone loss was studied in two mediaeval Polish populations differing with regard to socio‐economic status, as well as the intensity of the occurrence of skeletal indicators of living conditions in the early stages of ontogenesis (compression of the skull base and the narrowing of the lumbar vertebral canal). Cortical bone loss was analysed on the basis of the radiographs of the second metacarpal. Cedynia population (better living conditions) is characterized by higher arithmetic means for the height of the skull base in comparison with Słaboszewo group (low socio‐economic status). In the case of the vertebral canal index, significant interpopulation differences apply only to men. Similar patterns of difference between groups under study regarding bone loss was also found. It turned out that males from Cedynia had more bone mass in adultus and maturus age categories; in females, these differences concern only adultus category. The study involved an analysis of a relationship between the characteristics measuring reactions to environmental stress in early stages of growth and the intensity of bone loss in adult life. We believe that the results presented justify a conclusion that both phenomena may be interrelated to a considerable degree. Copyright © 2001 John Wiley & Sons, Ltd.
Optimal sequence of landfills in solid waste management
Authors: André Francisco J. , Cerdá Emilio 
Published: August 2002

AbstractGiven that landfills are depletable and replaceable resources, the right approach, when dealing with landfill management, is that of designing an optimal sequence of landfills rather than designing every single landfill separately. In this paper, we use Optimal Control models, with mixed elements of both continuous‐and discrete‐time problems, to determine an optimal sequence of landfills, as regarding their capacity and lifetime. The resulting optimization problems involve splitting a time horizon of planning into several subintervals, the length of which has to be decided. In each of the subintervals some costs, the amount of which depends on the value of the decision variables, have to be borne. The obtained results may be applied to other economic problems such as private and public investments, consumption decisions on durable goods, etc. Copyright © 2001 John Wiley & Sons, Ltd.
Fluorosilicone elastomer based on the poly[(3,3,3‐trifluoropropyl)methyl‐siloxane‐co‐(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)methylsiloxane]
Authors: Furukawa Yutaka , Shin‐ya Seiji , Saito Masayuki , Narui Shin‐ichiro , Miyake Haruhisa 
Published: August 2002

AbstractFluorosilicone elastomer based on the poly[(3,3,3‐trifluoropropyl)methylsiloxane‐co‐(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)methylsiloxane] was studied. First, the synthesis of fluorosilicone polymer based on the poly[(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)methylsiloxane] (PNFHMS) was examined by the polymerization of 1,3,5‐tris(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)‐1,3,5‐trimethylcyclotrisiloxane (C4F9D3) by sodium hydroxide. On the contrast of the polymerization of the commercially available 1,3,5‐tris(3,3,3‐trifluoropropyl)‐1,3,5‐trimethylcyclotrisiloxane (CF3D3), the polymerization of C4F9D3 with sodium hydroxide resulted in the formation of 1,3,5,7‐tetrakis(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)‐1,3,­5,7‐tetramethylcyclotetrasiloxane : [C4F9CH2CH2(CH3)SiO]4 (C4F9D4) as the major product. It was due to the easy occurrence of the depolymerization by the back‐biting mechanism, because C4F9D4 is more stable ­than 1,3,5,7‐tetrakis(3,3,3‐trifluoropropyl)‐1,3,5,7‐tetramethylcyclotetrasiloxane : [CF3CH2CH2(CH3)SiO]4 (CF3D4). The above result made us to conclude that it was difficult to apply the polymer based on PNFHMS to heat vulcanizable elastomers and to investigate the elastomer based on the poly[(3,3,3‐trifluoropropyl)methylsiloxane‐co‐(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)methylsiloxane]. C4F9D3 and CF3D3 were co‐polymerized successfully by sodium hydroxide and formulated with the silica treated by CF3D3. The use of silica treated with methylsilyl unit failed, because creep‐hardening phenomenon occurred. This elastomer was evaluated about some mechanical properties, and the resistance to organic solvents, and a fuel. The advantage that can be detected from the introduction of [C4F9C2H4‐(CH3)SiO] unit was that the resistance to the polar solvents such as acetone and dimethylformamide was improved. Copyright © 2001 John Wiley & Sons, Ltd.
Preparation method of porous polymer materials by radiation technique and its application
Authors: Kumakura M. 
Published: August 2002

AbstractThe radiation polymerization of hydrophilic hydroxyethyl methacrylate monomer solution at temperatures below 0 °C leads to the formation of a porous structure in the polymers. The melting peak of the eutectic water–monomer composition at the eutectic point (above −24 °C) could be distingushed and a glass transition temperature was observed at −96 °C.The porous structure was developed after melting small ice pieces in the polymers after polymerization. The porous structure formed above 0 °C contained discontinuous pores and that formed below 0 °C had continuous pores leading to reticular structure. In a mixture of water –dioxane –monomer, the pore diameter decreased with increasing monomer concentration. Replacing dioxane with decane led to a maximum pore diameter at 70% monomer concentration. The pore diameter in 70% monomer concentration using water and dioxane was 1∼4 µm, maximum activity in immobilized enzyme tablets was observed at this diameter. The porous structure was also varied by controlling the polymerization temperature. The durability of the immobilized enzyme tablets was demonstrated by the retention of high enzyme activities after repeated batch enzyme reactions. Copyright © 2001 John Wiley & Sons, Ltd.
Stereoregular silicon‐containing ­polymers
Authors: Kawakami Yusuke 
Published: August 2002

AbstractOptically active (R)‐methylphenylpropargylsilane and (S)‐2‐(1‐naphthyl)‐2‐phenyl‐5,5‐dimethyl‐1‐oxa‐2,5‐disilacyclopentane were prepared, and stereoregular and optically active polymers were obtained via hydrosilylation or ring‐opening polymerization. Both polymerization reactions proceeded stereoselectively, and the tacticity of the polymers reflected the optical purity of the monomers. Copyright © 2001 John Wiley & Sons, Ltd
Synthesis of novel chiral monomers by ­means of Umani‐Ronchi–Savoia ­allylation and their polymerization
Authors: Itsuno Shinichi , El‐Shehawy Ashraf A. 
Published: August 2002

AbstractUmani‐Ronchi–Savoia allylation is one of the most successful and useful methods for the preparation of optically pure secondary amines bearing two stereogenic centers at both α‐positions. We have prepared novel chiral amine monomers by means of this methodology as a key step of the synthesis. Diastereoselective allylation of chiral imines (3–5) derived from (S)‐valine gave optically pure secondary amines 6. Hydrogenation of the allylic group followed by introduction of a polymerizable 4‐vinylphenyl group led to enantiopure monomer 9. Prenylzinc reagents were also found to react with the imines to yield the corresponding optically pure amines 7. Since prenyl addition product does not inhibit the radical polymerization, chiral monomers 7b, 7d could be prepared directly by prenylzinc addition to imine having a polymerizable group. These chiral monomers were easily polymerized with styrene under radical polymerization conditions. Copyright © 2001 John Wiley & Sons, Ltd.