bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three‐dimensional numerical modelling of free surface flows with non‐hydrostatic pressure
Authors: Koçyigit Musteyde B. , Falconer Roger A. , Lin Binliang 
Published: November 2002

AbstractA three‐dimensional numerical model is developed for incompressible free surface flows. The model is based on the unsteady Reynolds‐averaged Navier–Stokes equations with a non‐hydrostatic pressure distribution being incorporated in the model. The governing equations are solved in the conventional sigma co‐ordinate system, with a semi‐implicit time discretization. A fractional step method is used to enable the pressure to be decomposed into its hydrostatic and hydrodynamic components. At every time step one five‐diagonal system of equations is solved to compute the water elevations and then the hydrodynamic pressure is determined from a pressure Poisson equation. The model is applied to three examples to simulate unsteady free surface flows where non‐hydrostatic pressures have a considerable effect on the velocity field. Emphasis is focused on applying the model to wave problems. Two of the examples are about modelling small amplitude waves where the hydrostatic approximation and long wave theory are not valid. The other example is the wind‐induced circulation in a closed basin. The numerical solutions are compared with the available analytical solutions for small amplitude wave theory and very good agreement is obtained. Copyright © 2002 John Wiley & Sons, Ltd.
Computational bifurcation and stability studies of the 8: 1 thermal cavity problem
Authors: Salinger Andrew G. , Lehoucq Richard B. , Pawlowski Roger P. , Shadid John N. 
Published: November 2002

AbstractStability analysis algorithms coupled with a robust Newton–Krylov steady‐state iterative solver are used to understand the behavior of the 2D model problem of thermal convection in a 8: 1 differentially heated cavity. Parameter continuation methods along with bifurcation and linear stability analysis are used to study transition from steady to transient flow as a function of Rayleigh number. To carry out this study the steady‐state form of the governing PDEs is discretized using a Galerkin/least‐squares finite element formulation, and solved on parallel computers using a fully coupled Newton method and preconditioned Krylov iterative linear solvers. Linear stability analysis employing a large‐scale eigenvalue capability is used to determine the stability of the steady solutions. The boundary between steady and time‐dependent flows is determined by a Hopf bifurcation tracking capability that is used to directly track the instability with respect to the aspect ratio of the system and with respect to mesh resolution. The effect of upwinding stabilization terms in the finite element formulation on the computed value of critical Rayleigh number is investigated. The Hopf bifurcation signaling the onset of flow is determined to occur at a critical Rayleigh number of Ra=3.0604×105. Copyright © 2002 John Wiley & Sons, Ltd.
Parallel computations of natural convection flow in a tall cavity using an explicit finite element method
Authors: Dunn Timothy A. , McCallen Rose C. 
Published: November 2002

AbstractAn explicit finite element method was used to predict a natural convection flow in an enclosed cavity. The problem considered was a differentially heated, tall (8:1), rectangular cavity with a Rayleigh number of 3.4 × 105 and Prandtl number of 0.71. The incompressible Navier–Stokes equations were solved using a Boussinesq approximation for the buoyancy force. The algorithm was developed for efficient use on massively parallel computer systems with emphasis on time‐accurate simulations. It was found that the average temperature and velocity values can be captured with a relatively coarse grid, while the oscillation amplitude and period appear to be grid sensitive and require a refined computation. Copyright © 2002 John Wiley & Sons, Ltd.
Application of the FIDAP code to the 8:1 thermal cavity problem
Authors: Gresho P. M. , Sutton S. B. 
Published: November 2002

AbstractWe present results using FIDAP on 3 meshes with 3 different elements (Q1Q0, Q2P‐1, Q2Q‐1) employed on each. Whereas the bulk of the results were obtained via the ‘classical’ Galerkin finite element method (GFEM) and the trapezoidal (TR) time integrator, we also tested several alternative options: flux‐conservative formulation, energy‐conservative formulation, streamline upwinding, mass lumping, backward Euler time stepping, and one additional element (Q2Q1). The most accurate of these options was the Q2Q‐1 element in the advective formulation, no upwinding, trapezoidal time integration, and consistent mass; i.e. straight GFEM. Copyright © 2002 John Wiley & Sons, Ltd.
Parenting and attachment among toddlers with congenital anomalies: Examining the Strange Situation and attachment Q‐sort
Authors: Clements Melissa , Barnett Douglas 
Published: November 2002

AbstractThis study assessed parent and child predictors of attachment in a sample of 72 toddlers with neurological (e.g., cerebral palsy) and non‐neurological (e.g., cleft lip and palate) birth defects and their mothers. Parenting quality (e.g., sensitivity) was expected to be more important in predicting the attachment relationship than type and severity of child medical condition. Parenting and indices of severity of child condition were measured via researcher observation. Attachment was measured via the Strange Situation and parent reported Attachment Q‐sort. Parenting quality was better for children with more severe appearance disfigurements. Strange Situation and Q‐sort assessments of attachment were not significantly related. Children with neurological impairments were at greater risk for developing insecure attachments than were children with non‐neurological conditions. Parenting quality also directly predicted Strange Situation assessed attachment security and Q‐sort comfort seeking/exploration but not standard Q‐sort criterion scores. Parenting quality partially mediated the relation between child medical condition and attachment security. Results suggest child medical factors influence parenting, and thereby, child attachment. ©2002 Michigan Association for Infant Mental Health.
Representation theory for classes of initial value problems with quaternionic analysis
Authors: Gürlebeck Klaus , Sprößig Wolfgang 
Published: November 2002

AbstractWe consider time‐dependent Stokes problems for the case of low Reynolds number in smoothly bounded domains. By using a finite difference time discretization, the problem is reduced to a sequence of steady‐state Stokes problems. These boundary value problems are solved by means of hypercomplex analysis. In the second part, we consider initial boundary value problems of the so‐called Galpern–Sobolev type. An implicit time discretization method is deduced. Making use of a modified Teodorescu transform and suitable quaternionic Hilbert space projections, we obtain a representation of the solution. Copyright © 2002 John Wiley & Sons, Ltd.
Complex‐distance potential theory, wave equations, and physical wavelets
Authors: Kaiser Gerald 
Published: November 2002

AbstractPotential theory in ℝn is extended to ℂn by analytically continuing the Euclidean distance function. The extended Newtonian potential ϕ(z) is generated by a (non‐holomorphic) source distribution δ˜(z) extending the usual point source δ(x). With Minkowski space ℝn, 1 embedded in ℂn+1, the Laplacian Δn+1 restricts to the wave operator □n,1 in ℝn, 1. We show that δ˜(z) acts as a propagator generating solutions of the wave equation from their initial values, where the Cauchy data need not be assumed analytic. This generalizes an old result by Garabedian, who established a connection between solutions of the boundary‐value problem for Δn+1 and the initial‐value problem for □n,1 provided the boundary data extends holomorphically to the initial data. We relate these results to the physical avelets introduced previously. In the context of Clifford analysis, our methods can be used to extend the Borel–Pompeiu formula from ℝn+1 to ℂn+1, where its riction to Minkowski space ℝn, 1 provides solutions for time‐dependent Maxwell and Dirac equations. Copyright © 2002 John Wiley & Sons, Ltd.
Effects of conceptual assignments and conceptual change discussions on students' misconceptions and achievement regarding force and motion
Authors: Eryilmaz Ali 
Published: November 2002

AbstractThe purpose of this study was to investigate the effects of conceptual assignments and conceptual change discussions on students' achievement and misconceptions about force and motion. The study was conducted with 6 physics teachers and their 18 classes, consisting of 396 high school physics students. The teachers administered the Force Misconception and Force Achievement Tests to their physics classes as a pretest. The results obtained were used to match the 18 classes statistically. Students assigned to the conceptual assignment protocol completed five conceptual assignments about force and motion. Students assigned to the discussion method participated in conceptual change discussions. At the end of the 8‐week treatment period, the same tests were administered to all students as a posttest. The data were analyzed by using multivariate analysis of covariance, followed by protected univariate F test and step‐down analysis. The statistical results showed that the conceptual change discussion was an effective means of reducing the number of misconceptions students held about force and motion. The conceptual change discussion was also found significantly effective in improving students' achievement in force and motion. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 1001–1015, 2002
EDXRF studies on Chinese Yue ware
Authors: Wu J , Leung J. P.L , Li Z. , Stokes M. J. 
Published: November 2002

AbstractAbstractThe major and trace element composition of Chinese Yue ware, widely recognized
as the earliest Chinese porcelain (probably the earliest worldwide), is analysed
using non‐destructive, energy‐dispersive x‐ray fluorescence (EDXRF). The results
are subject to multivariate statistical analysis. Different compositional
patterns were found for specimens from different production sites (Cixi, Ningbo,
Shaoxin, Shangyu City, Zhejiang province). In particular the specimens excavated
at Hangzhou palace, called Mise (mysterious colour) ware, can be identified by
a small number of key element concentrations. Copyright © 2002 John
Wiley & Sons, Ltd.
Analysis of pigments from Spanish works of art using a portable EDXRF spectrometer
Authors: Ferrero J. L. , Roldán C. , Juanes D. , Rollano E. , Morera C. 
Published: November 2002

AbstractNowadays there is an intensive program for the conservation, restoration and analysis of the impressive and extensive Spanish cultural heritage. In the last few years, the Unidad de Arqueometria of the ICMUV has carry out a great quantity of in situ EDXRF analysis of pigments on materials of historic and cultural interest (altarpieces, frescoes, canvas, sculptures, etc.) from museums and churches of the whole of the Spanish geography. Here we present a few examples of the analysis of works of art using x‐ray fluorescence spectrometry with a portable system based on x‐ray tubes and a non‐cryogenic Si‐PIN detector. EDXRF qualitative and non‐destructive analyses of stone, pigments and preparation layer of a polychrome sculpture from the Iberian period are compared with results obtained with destructive analytical techniques. The identification of inorganic key elements in a mural painting from the 14th and 15th centuries allowed the characterization of the pigments and techniques used by the artists and were a great help in the restoration process. The EDXRF analysis of a partially burnt medieval altarpiece allowed us to establish the elemental composition of the pigments from damaged and non‐damaged areas. Finally, we present part of the systematic EDXRF analysis of the pigments on canvas from the work of Joaquín Sorolla with the objective of constructing a wide database on their pictorial materials. Copyright © 2002 John Wiley & Sons, Ltd.
Evacuation of hydatid liver cysts using laparoscopic trocar
Authors: Kayaalp Cuneyt 
Published: November 2002

AbstractSeveral methods of reducing the likelihood of spilling live scolices during surgical removal of hydatid liver disease have been described. The aim was to determine the effectiveness and safety of laparoscopic trocar insertion for evacuation of hydatid liver cysts. This technique was used for 30 cysts in 19 patients who had surgery for hydatid liver disease. After establishing protection of the operative area, a laparoscopic trocar was inserted into the cyst at the most prominent point and the cyst was aspirated with large‐bore suction and filled with a scolicidal agent. The technique was not attempted in two small cysts (< 6 cm) located near the major blood vessels or in a single intraparenchymal cyst. Insertion of the trocar was successful in all remaining cysts, and there were no complications during the insertion or the evacuation. Successful evacuation (excellent and good outcomes) in unilocular, multilocular, and degenerated cysts were 100%, 84%, and 57%, respectively (p=0.144), with a total success rate of 82%. Although successful evacuation was achieved in both anterior (92%) and posterior‐superior located cysts (73%) (p=0.203), excellent outcomes were higher for the anterior cysts (73%) than for the posterior‐superior cysts (13%) (p=0.005). Successful evacuation outcomes for the large (τ 10 cm), middle‐sized (6 to 10 cm), and small cysts (< 6 cm) were 100%, 79%, and 67%, respectively (p=0.591). The patients have been followed for a mean of 11 months (range 3 to 24 months), and no recurrence has been recorded. Insertion and evacuation of the hydatid liver cysts with a laparoscopic trocar is a safe and effective procedure, and its limitations are minimal.
Results of pancreaticoduodenectomy for pancreatic cancer: Extended versus standard procedure
Authors: Iacono Calogero , Accordini Simone , Bortolasi Luca , Facci Enrico , Zamboni Giuseppe , Montresor Ettore , Marinello Peter Domenico , Serio Giovanni 
Published: November 2002

AbstractIn Western experience, the long‐term survival benefit after extended pancreaticoduodenectomy (EPD) in patients with pancreatic ductal adenocarcinoma is still controversial. The aim of this work was to evaluate weather EPD for pancreatic ductal adenocarcinoma prolongs long‐term survival compared to standard pancreaticoduodenectomy (SPD). From November 1992 to September 1996, we performed pancreatic resections in 30 patients affected by stage I–III pancreatic ductal adenocarcinoma: 13 patients underwent SPD and 17 patients underwent EPD, consecutively. The two groups of patients were similar for all the demographic, clinical, and pathological characteristics, and all the intraoperative factors considered except the number of resected lymph nodes (mean number per case=34.2 ± 15.5 in the EPD group versus 12.8 ± 3.6 in the SPD group, p<0.001) and the operative time (median time per case=375 minutes in the EPD group versus 270 minutes in the SPD group, p=0.009). Patients in the two groups experienced a similar postoperative course. The estimated survival probability at 1 and 3 years after operation was 0.76 (95% confidence interval [CI]: 0.49 to 0.90) and 0.24 (95% CI: 0.07 to 0.45) in the EPD group; 0.31 (95% CI: 0.09 to 0.55) and 0.08 (95% CI: 0.00 to 0.29) in the SPD group (p=0.014). According to a Cox model, the treatment was associated with R0 patients’ long‐term survival (SPD versus EPD: hazard ratio (HR)=4.82, 95% CI: 1.66 to 14.00, p=0.004). Grading of tumor differentiation was confirmed to be a relevant prognostic factor (poor versus moderate: HR=4.33, 95% CI: 1.49 to 12.61, p=0.007), whereas type of resection had no significant effect (pylorus‐preserving versus hemigastrectomy: HR=1.49, 95% CI: 0.56 to 3.95, p=0.42). The proportion of R0 patients with local recurrence was lower in the EPD group (20.0% versus 70.0%, p=0.034).
Does radical resection improve the survival in patients with carcinoma of the gallbladder who are 75 years old and older?
Authors: Onoyama Hirohiko , Ajiki Tetsuo , Takada Moriatsu , Urakawa Tomoaki , Saitoh Yoichi 
Published: November 2002

AbstractRadical resections have been reported to improve the surgical outcome for patients with carcinoma of the gallbladder, in recent years surgeons have had more opportunities to operate on elderly patients. We investigated whether the survival rate of aged patients who had radical resections were better than rates for those who had simple cholecystectomy. Of the 300 patients treated for carcinoma of the gallbladder between 1971 and 1999, 206 resected cases (except pancreaticoduodenectomy and hepatectomy) were divided into two groups: age 75 years or older, 54 patients (the older group), and age less than 75 years, 152 patients (the younger group). Clinical features and progression of the carcinomas did not differ between the two groups. In the older group, 22 patients (40.7%) had simple cholecystectomy, 32 (59.3%) had radical resections; in the younger group, 65 patients (42.8%) had simple cholecystectomy, and 87 (57.3%) had radical resection. None of the older patients who had radical resection died postoperatively. Postoperative survival was not different between the two groups. In the older group the 5‐year survival rate for patients who had radical resections was better (60.9%) than the rate for those who had simple cholecystectomy (14.1%) (p=0.0098). Radical resection is effective for the aged patients with the carcinoma of gallbladder.
Surgery of chronic pancreatitis: Chronicle of confusion and despair
Authors: Modlin Irvin M. , Kidd Mark , Hults Christopher , Hinoue Toshi 
Published: November 2002

AbstractThe evolution of surgery for pancreatitic disease has been arduous owing to the technical difficulties of addressing the organ and the lack of understanding the mechanisms of the disease processes involving it. In particular, the tardy advance of surgery in the management of chronic pancreatitis exemplifies these problems. Because no specific target has been identified, mechanical intervention has for the most part reflected intuitive or creative attempts to address perceived pathologic issues such as sphincter disease, calculi, and fibrotic masses. The past and present remain a confusion of etiologies and diagnoses. Treatment remains for the most part a dramatically disappointing scenario, and both patients and their physicians are frustrated. Although the remarkable technologic progress exhibited by the odyssey of operative strategy from simple drainage, to ductal drainage, to the complex refinements of extensive resection is a testimonial to surgical skill and determination, it has been nullified to a large extent by the inability to address the initiating factors of the disease or alter those that engender progress of the pathology. It is not unreasonable to recognize that we are facing an enigmatic disease process generically classified as “chronic pancreatitis” for want of any more specific terminology. In the light of our current knowledge and experience, intervention should probably be modest in the extreme and limited to centers and individuals with expertise or who are involved in specific studies to determine the precise criteria and techniques necessary for optimum intervention. It is important that when charting such a course future surgeons involved in the management of chronic pancreatitis have an understanding of the historical evolution of the subject. As Theodor Billroth, the greatest of the surgical innovators remarked: “An awareness of the past is necessary to comprehend the present, and without it no consideration of the future is possible.”
Neutrophils and the calcium‐binding protein MRP‐14 mediate carrageenan‐induced antinociception in mice
Authors: Pagano Rosana L. , Dias Maria Angela Amorim , Dale Camila S. , Giorgi Renata 
Published: November 2002

Background: We have previously shown that the calcium‐binding protein MRP‐14 secreted by neutrophils mediates the antinociceptive response in an acute inflammatory model induced by the intraperitoneal injection of glycogen in mice.Aim: In an attempt to broaden the concept that neutrophils and MRP‐14 controls inflammatory pain induced by different type of irritants, in the present study, after demonstrating that carrageenan (Cg) also induces atinociception in mice, we investigated the participation of both neutrophils and MRP‐14 in the phenomenon.Methods: Male Swiss mice were injected intraperitoneally with Cg and after different time intervals, the pattern of cell migration of the peritoneal exudate and the nociceptive response of animals submitted to the writhing test were evaluated. The participation of neutrophils and of the MRP‐14 on the Cg effect was evaluated by systemic inoculation of monoclonal antibodies anti‐granulocyte and anti‐MRP‐14.Results: Our results demonstrate that the acute neutrophilic peritonitis evoked by Cg induced antinociception 2, 4 and 8 h after inoculation of the irritant. Monoclonal antibodies anti‐granulocyte or anti‐MRP‐14 reverts the antinociceptive response only 2 and 8 h after Cg injection. The antibody anti‐MRP‐14 partially reverts the antinociception observed after 4 h of Cg injection while the anti‐granulocyte antibody enhances this effect. This effect is reverted by simultaneous treatment of the animals with both antibodies. After 4 h of Cg injection in neutrophil‐depleted mice a significant expression of the calcium‐binding protein MRP‐14 was detected in the cytoplasm of peritoneal macrophages. This suggests that the enhancement of the effect observed after treatment with the anti‐neutrophil antibody may be due to secretion of MRP‐14 by macrophages. It has also been demonstrated that endogenous opioids and glucocorticoids are not involved in the antinociception observed at the 4th hour after Cg injection.Conclusion: These data support the hypothesis that neutrophils and the calcium‐binding protein MRP‐14 are participants of the endogenous control of inflammatory pain in mice despite the model of acute inflammation used.