Search

A two-dimensional model is proposed for energy efficiency assessment through the simulation of heat transfer in building envelopes, considering the influence of the surrounding environment. The model is based on the Du Fort–Frankel approach that provides an explicit scheme with a relaxed stability condition. The model is first validated using an analytical solution and then compared to three other standard schemes. Results show that the proposed model offers a good compromise in terms of high accuracy and reduced computational efforts. Then, a more complex case study is investigated, considering non-uniform shading effects due to the neighboring buildings. In addition, the surface heat transfer coefficient varies with wind velocity and height, which imposes an addition non-uniform boundary condition. After showing the reliability of the model prediction, a comparison over almost 120 cities in France is carried out between the two- and the one-dimensional approaches of the current building simulation programs. Important discrepancies are observed for regions with high magnitudes of solar radiation and wind velocity. Last, a sensitivity analysis is carried out using a derivative-based approach. It enables to assess the variability of the solution according to the modeling of the two-dimensional boundary conditions. Moreover, the proposed model computes efficiently the solution and its sensitivity to the modeling of the urban environment. [ABSTRACT FROM AUTHOR]

Abstract: Kyanite and zoisite eclogites from the Limousin area in the Variscan French Massif Central (FMC) have been formed by deep subduction to 100km depth at peak pressure–temperature conditions around 660°C and 2.9GPa. They belong to a thin tectonic unit comprising ophiolitic bodies devoid of HP-UHP markers and forming a transported suture zone now separating the two main lithotectonic units of the FMC with contrasted tectono-metamorphic features (namely the lower and upper allochthons). Composition of kyanite–eclogites is similar to supra-subduction-zone basalts found in back-arc basins or island arcs (LREE depleted, negative Nb–Ta anomalies, εNd: +6 to +9). Zoisite eclogites have the major-element fingerprint of ultrabasic iron-rich plagioclase cumulates common in continental intrusions or forming Fe–Ti oceanic gabbros. The distribution of immobile trace-elements is however more comparable to alkaline Si-undersaturated rocks, but the Sr–Nd isotopic composition (87Sr/86Sr: 0.706; εNd: −3 to −5) suggests the intervention of an old radiogenic crustal component during their petrogenesis. The chemical composition of hydrous zoisite eclogites does not correspond closely to a common magmatic precursor. It is thus suggested that, by analogy with well exposed worldwide HP-UHP terranes, at least a part of the trace-element signature and the isotopic compositions are controlled by channelled fluid–rock interaction at UHP conditions, leading to localised segregation of zoisite that hosts nearly all Sr and LREE budgets of the bulk eclogite. Sr–Nd isotopic composition of these samples is thus controlled by zoisite and probably represents the isotopic composition of the fluid phase present during UHP recrystallisation. Zircons extracted from a zoisite eclogite were dated in-situ by LA-ICP-MS. Crystallisation of the magmatic precursor is bracketed between 489 and 475Ma and the UHP event is dated at 412±10Ma, in agreement with published ages for the Eo-Variscan HP stage in the FMC. A late resetting of the U–Pb isotopic system at 382±7Ma is related to an anatectic high pressure–medium pressure event, well known in the Limousin area. The oceanic eclogites dated in this study are tentatively linked to the Galicia–South Brittany Lower Paleozoic Ocean; they show evidence of the existence of an intra-oceanic subduction zone at the Lower Ordovician and of partial closure of this oceanic domain by ocean–continent subduction during Early Devonian. [Copyright &y& Elsevier]

Mantle xenoliths from Puy Beaunit (French Massif Central) are compositionally varied, ranging from relatively fertile spinel lherzolites to refractory spinel dunites. Fertile peridotites have registered a modal (amphibole-bearing lherzolites) and cryptic metasomatic event that took place before the last Permian (257 Ma) melting episode. Depletion processes have been constrained by chemical modelling: the depletion is related to different degrees of partial melting, but two major melt extraction episodes are needed to explain the range of major element composition. The second event was responsible for the local large-scale dunitification of former residues. The first melting event (F˜25%) and metasomatic enrichment are attributed to an ancient fluid and/or liquid infiltration that could be related to a pre-Variscan regional subduction (located to the north of the Beaunit area). Texture acquisition and major deformation of the mantle xenoliths were sub-contemporaneous of the subduction and would result from lithospheric delamination. The second melting event (F˜17%) produced high-Mg basalts with calc-alkaline trace element signature that gave rise to the Permian underplating episode recognised in western Europe. [ABSTRACT FROM AUTHOR]

• D-optimum criterion is applied to select an optimal experiment duration. • Identifiability of parameters is demonstrated. • Thermal conductivity is estimated over the reduced measurement plan. • Parameter estimation problem is solved with hybrid optimization method. • Reliability of the model for one year experiment is achieved. The in situ estimation of the thermal properties of existing building wall materials is a computationally expensive procedure. Its cost is highly proportional to the duration of measurements. To decrease the computational cost a methodology using a D-optimum criterion to select an optimal experiment duration is proposed. This criterion allows to accurately estimate the thermal properties of the wall using a reduced measurement plan. The methodology is applied to estimate the thermal conductivity of the three-layer wall of a historical building in France. Three different experiment sequences (one, three and seven days) and three spatial distributions of the thermal conductivity are investigated. Then using the optimal duration of observations the thermal conductivity is estimated using the hybrid optimization method. Results show a significant reduction of computational time; and reliable simulation of physical phenomena using the estimated values. [ABSTRACT FROM AUTHOR]

Abstract: The origin of magmatic layering is still hotly debated. To try to shed some light on this problem, two ultramafic–mafic layered xenoliths from Puy Beaunit (French Massif Central) were investigated in detail. The nodules belong to a stratiform intrusion emplaced in the deep crust during the Permian (257±6 Ma; Féménias, O., Coussaert, N., Bingen, B., Whitehouse, M., Mercier, J.-C., Demaiffe, D., 2003. A Permian underplating event in late- to post-orogenic tectonic setting. Evidence from the mafic–ultramafic layered xenoliths from Beaunit (French Massif Central). Chem. Geol. 199 293–315.). The 3 to 5 cm thick nodules have, in common, a central orthopyroxenite layer; the succession of layers is, respectively, norite–orthopyroxenite–norite (PBN 00-01) and norite–orthopyroxenite–harzburgite (PBN 00-03). The variations of both major (by electron microprobe) and trace, essentially the RE, elements (by LA-ICP-MS) were measured in major mineral phases (orthopyroxene, clinopyroxene, plagioclase, spinel) along cross-section perpendicular to the layering. Strong grain size, chemical and textural variations occur along these sections: they can be continuous or discontinuous, symmetrical or asymmetrical. Such complex variations cannot be solely related to a single magmatic history (fractional crystallisation, mineral sorting). Other processes such as element enrichment by residual liquid channelling along layer boundaries and/or sub-solidus recrystallisation and element redistribution must be invoked. It appears, in particular, that element distribution in the central orthopyroxenite layer could result from the injection of micro-sills of orthopyroxene-rich liquid between previously consolidated layers. [Copyright &y& Elsevier]

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., (© 2013 The Authors. BJU International © 2013 BJU International.)

Purpose: The present study assessed the incidence and histopathological features of incidentally diagnosed prostate cancer (PCa) in specimens from radical cystoprostatectomy (RCP) for bladder cancer. The patient outcomes also were evaluated., Methods: We retrospectively reviewed the histopathological features and survival data of 4,299 male patients who underwent a RCP for bladder cancer at 25 French centers between January 1996 and June 2012. No patients had preoperative clinical or biological suspicion of PCa., Results: Among the 4,299 RCP specimens, PCa was diagnosed in 931 patients (21.7%). Most tumors (90.1%) were organ-confined (pT2), whereas 9.9% of them were diagnosed at a locally advanced stage (≥pT3). Gleason score was <6 in 129 cases (13.9%), 6 in 575 cases (61.7%), 7 (3 + 4) in 149 cases (16.0%), 7 (4 + 3) in 38 cases (4.1%), and >7 in 40 cases (4.3%). After a median follow-up of 25.5 months (interquartile range 14.2-47.4), 35.4% of patients had bladder cancer recurrence and 23.8% died of bladder cancer. Only 16 patients (1.9%) experienced PCa biochemical recurrence during follow-up, and no preoperative predictive factor was identified. No patients died from PCa., Conclusions: The rate of incidentally diagnosed PCa in RCP specimens was 21.7%. The majority of these PCas were organ-confined. PCa recurrence occurred in only 1.9% of cases during follow-up.