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101.
In this paper, a new approach for powder cold compaction simulations is presented. A density-dependent plastic model within
the framework of finite strain multiplicative hyperelastoplasticity is used to describe the highly nonlinear material behaviour;
the Coulomb dry friction model is used to capture friction effects at die-powder contact; and an Arbitrary Lagrangian–Eulerian
(ALE) formulation is used to avoid the (usual) excessive distortion of Lagrangian meshes caused by large mass fluxes. Several
representative examples, involving structured and unstructured meshes are simulated. The results obtained agree with the experimental
data and other numerical results reported in the literature. It is shown that, contrary to other Lagrangian and adaptive h-remeshing approaches recently reported for this type of problems, the present approach verifies the mass conservation principle
with very low relative errors (less than 1% in all ALE examples and exactly in the pure Lagrangian examples). Moreover, thanks
to the use of an ALE formulation and in contrast with other simulations, the presented density distributions do not present
spurious oscillations.
Received: 20 March 2002 / Accepted: 15 October 2002
The partial financial support of the Ministerio de Ciencia y Tecnología (grant number DPI 2001-2204) is gratefully acknowledged. 相似文献
102.
We present some new lower bounds on the optimal information rate and on the optimal average information rate of secret sharing schemes with homogeneous access structure. These bounds are found by using some covering constructions and a new parameter, the k-degree of a participant, that is introduced in this paper. Our bounds improve the previous ones in almost all cases. 相似文献
103.
104.
Loranger Michel; Pépin Michel; Gignac Guy; Benoit Geneviève 《Canadian Metallurgical Quarterly》1995,36(1):59
Presents results of 3 studies on the psychometric properties of the LP-ABC (M. Loranger and M. Pépin, 1993), a French-language instrument for assessing general functioning in adults with mental retardation. The studies involved a total of 299 male and female Canadian adults with mental retardation. Results confirm the internal consistency, construct validity, criterion validity, discriminant validity, interrater reliability, and test–retest reliability of the LP-ABC. (English abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
105.
Francisco Jos Alguacil Concepcin Caravaca María Isabel Martín 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2003,78(10):1048-1053
The transport of chromium(VI) through a flat‐sheet supported liquid membrane containing Cyanex 921 as a carrier has been investigated. The permeation of the metal is investigated as a function of various experimental variables: hydrodynamic conditions, concentration of chromium(VI) and HCl in the feed phase, carrier concentration and diluent in the membrane and strippant concentration in the stripping phase. The mass transfer coefficient and the thickness of the aqueous boundary layer were calculated from the experimental data. Furthermore, the selectivity of Cyanex 921‐based flat‐sheet supported liquid membrane towards different metal ions and the behaviour of the system against other carriers are presented. Copyright © 2003 Society of Chemical Industry 相似文献
106.
107.
The authors suggest that academic institutions build business-oriented policies and practices into the development of any nurse-run clinic to set the stage for financial independence when special or development funding ends. One university-affiliated program that provides 4,000 to 5,000 annual visits drastically changed its strategies when threatened with closure after free rent and other subsidies were withdrawn. The growing emphasis on ambulatory care roles for nurses at all levels makes such clinics critical to the success of the broad-based curricula of nursing education programs, as well as the clinic's value to communities they serve. Funding difficulties frequently threaten the existence of such nurse-run clinics once the initial grant funding is no longer available. This has caused a new emphasis on running such clinics in a business-wise manner. Among the strategies initiated were: direct full-pay at the time of service; a realistic business management plan; aggressive planned marketing; contracts and agreements with other agencies; obtaining provider status with selected HMOs. 相似文献
108.
J Sánchez A Torres J Serrano J Román C Martín L Pérula F Martínez P Gómez 《Canadian Metallurgical Quarterly》1997,20(5):403-408
BACKGROUND: Locally advanced thyroid cancer invading the tracheal cartilage represents a difficult treatment dilemma during thyroidectomy. METHODS: A retrospective chart review was performed to determine the results of laryngotracheal resection or tracheal cartilage shave with adjuvant radiotherapy in patients with locally advanced thyroid cancer invading the upper airway. RESULTS: Of 597 patients undergoing thyroidectomy for thyroid cancer, 40 were found to have laryngotracheal invasion. Thirty-five patients with superficial invasion underwent cartilage shave procedures with adjuvant radiotherapy; five with full-thickness invasion underwent radical resection, including tracheal sleeve resection (n = 3) or total laryngectomy (n = 2). Histologic subtypes included papillary (n = 32), follicular (n = 2), Hurthle cell (n = 1), medullary (n = 3), and anaplastic (n = 2). Of the cartilage shave group, 25 are currently alive with no evidence of disease at a mean follow-up of 81 months (range 1-290). Six developed isolated local/regional recurrence and were managed with total laryngectomy (n = 1), tracheal resection (n = 1), cervical lymphadenectomy (n = 1), or repeat radiotherapy (n = 3). All six patients remain free of disease at a mean follow-up of 5 years. Of those who underwent initial laryngotracheal resection, four remain free of disease at a mean follow-up of 5 years. The rates of 10-year disease-free survival and overall survival for all patients were 47.9% (95% confidence interval [CI] 24.8, 71.0) and 83.9% (95% CI 70.3, 97.5), respectively. CONCLUSIONS: These data suggest that adequate management of thyroid cancer with laryngotracheal invasion can be achieved with a more conservative surgical approach and adjuvant radiotherapy, reserving more radical resections for extensive primary lesions or locally recurrent disease. 相似文献
109.
110.