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The design of numerical tools to model the behavior of building materials is a challenging task. The crucial point is to save computational costs and maintain the high accuracy of predictions. There are two main limitations on the time scale choice, which places an obstacle to solving the above issues. The first one is the numerical restriction. A number of research studies are dedicated to overcome this limitation and it is shown that it can be relaxed with innovative numerical schemes. The second one is the physical restriction. It is imposed by the properties of a material, the phenomena itself, and the corresponding boundary conditions. This study is focused on the study of a methodology that enables to overcome the physical restriction on the time grid; a so‐called average reduced model is suggested. It is based on smoothing the time‐dependent boundary conditions. Besides this, the approximate solution is decomposed into average and fluctuating components. The primer is obtained by integrating the equations over time, whereas the latter is a user‐defined EM. The methodology is investigated for both heat diffusion and coupled heat and mass transfer. It is demonstrated that the signal core of the boundary conditions is preserved and the physical restriction can be relaxed. The model proved to be reliable, accurate, and efficient also in comparison with the experimental data of 2 years. The implementation of the scarce time‐step of 1h is justified. It is shown, that by maintaining the tolerable error, it is possible to cut computational effort up to almost four times in comparison with the complete model with the same time grid. [ABSTRACT FROM AUTHOR]

This article proposes an efficient explicit numerical model with a relaxed stability condition for the simulation of heat, air, and moisture transfer in porous material. Three innovative approaches are combined to solve the system of two differential advection‐diffusion equations coupled with a purely diffusive equation. First, the DU FORT‐FRANKEL scheme is used to solve the diffusion equation, providing an explicit scheme with an extended stability region. Then, the two advection‐diffusion equations are solved using both the SCHARFETTER‐GUMMEL numerical scheme for the space discretisation and the two‐step RUNGE‐KUTTA method for the time variable. This combination enables to relax the stability condition by one order. The proposed numerical model is evaluated on three case studies. The first one considers quasi‐linear coefficients. The theoretical results of the numerical schemes are confirmed by our computations. Indeed, the stability condition is relaxed by a factor of 40 compared to the standard EULER explicit approach. The second case provides an analytical solution for a weakly nonlinear problem. A very satisfactory accuracy is observed between the reference solution and the one provided by the numerical model. The last case study assumes a more realistic application with nonlinear coefficients and ROBIN‐type boundary conditions. The computational time is reduced 10 times by using the proposed model in comparison with the explicit EULER method. [ABSTRACT FROM AUTHOR]

Objective To assess the use of local haemostatic agents ( HAs) in a prospective multicentre large series of partial nephrectomies ( PNs)., Patients and Methods Prospective National Observational Registry on the Practices of Haemostasis in Partial Nephrectomy ( NEPHRON): the study was conducted in 54 French urological centres from 1 June to 31 December 2010., In all, 570 consecutive patients undergoing a PN were enrolled in this study in a prospective manner. The data was collected prospectively via an electronic case-report form: five different sheets were included for preoperative, perioperative, postoperative and follow-up data respectively. Information related to haemostasis was analysed., Results The median patient age was 60 years and the mean (range) tumour size was 3.68 (0.19-15) cm., An HA was primarily used in 71.4% of patients, with a statistically significant difference among surgical approaches (P = 0.024)., In 91.8% of cases, a single use of a HA was sufficient for achieving haemostasis. The HA was used either alone (13.9%) or in association with sutures (80.3%)., One or more additional haemostatic action(s) was needed in 12.3% of the cases., When comparing patients who received a HA with those who did not receive a HA, there was no statistical difference between the groups for tumour size ( P = 0.542), collecting system drainage ( P = 0.538), hospital stay ( P = 0.508), operation time ( P = 0.169), blood loss ( P = 0.387) or transfusion rate ( P = 0.713)., Conclusion HAs are widely used by urologists during PN. Progress is needed for standardising HA application, especially for the timing of application. For the time being, the role of the HA in nephron-sparing surgery is still to be evaluated. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the overall survival postnephrectomy for renal cancer for patients aged over 80 years, and to identify preoperative prognostic factors that might influence therapeutic strategies. Methods: In a retrospective study in five French departments of urology, 179 patients aged over 80 years with renal cell carcinoma underwent radical nephrectomy between 1990 and 2011. The following data were collected: age, sex, body mass index, Charlson Comorbidity Index, American Society of Anesthesiology class, Eastern Cooperative Oncology Group Performance Status, type of surgery, period of follow-up, survival, death etiology, symptoms, Fuhrman grade and tumor-nodes-metastasis stage. Results: After a 29.6-month follow up, 89 patients (49.7%) died. Death etiologies were: cancer for 46 (52%) patients, immediate or distant perioperative complications for five patients (6%) and three patients (3%) respectively, cardiovascular disease for 16 patients (18%), other cancers for three patients (3%) and unknown for 16 patients (18%). In a multivariate analysis, T-stage, M-stage and Charlson Comorbidity Index were identified as independent prognostic factors. Patients were divided into three groups (good, intermediate and bad prognosis) with significantly different survivals of 91, 36 and 22 months ( P < 0.0001), respectively. Conclusions: Preoperative data, including T-stage, M-stage and Charlson Comorbidity Index represent significant independent prognostic factors for survival for patients aged over 80 years. These data might help the clinician in selecting the most suitable candidates for radical nephrectomy among elderly patients with renal cancer. [ABSTRACT FROM AUTHOR]