Preliminary Design of Reactive Distillation Columns

A procedure that combines feasibility analysis, synthesis and design of reactive distillation columns is introduced. The main interest of this methodology lies on a progressive introduction of the process complexity. From minimal information concerning the physicochemical properties of the system, three steps lead to the design of the unit and the specification of its operating conditions. Most of the methodology exploits and enriches approaches found in the literature. Each step is described and our contribution is underlined. Its application is currently limited to equilibrium reactive systems where degree of freedom is equal to 2 or less than 2. This methodology which provides a reliable initialization point for the optimization of the process has been applied with success to different synthesis. The production of methyl-tert-butyl-ether (MTBE) and methyl acetate are presented as examples

Potential Routes for Thermochemical Biorefineries

This critical review focuses on potential routes for the multi-production of chemicals and fuels in the framework of thermochemical biorefineries. The up-to-date research and development in this field has been limited to BTL/G (biomass-to-liquids/gases) studies, where biomass-derived synthesis gas (syngas) is converted into a single product with/without the co-production of electricity and heat. Simultaneously, the interest on biorefineries is growing but mostly refers to the biochemical processing of biomass. However, thermochemical biorefineries (multi-product plants using thermo-chemical processing of biomass) are still the subject of few studies. This scarcity of studies could be attributed to the limitations of current designs of BTL/G for multi-production and the limited number of considered routes for syngas conversion. The use of a platform chemical (an intermediate) brings new opportunities to the design of process concepts, since unlike BTL/G processes they are not restricted to the conversion of syngas in a single-reaction system. Most of the routes presented here are based on old-fashioned and new routes for the processing of coal- and natural-gas-derived syngas, but they have been re-thought for the use of biomass and the multi-production plants (thermochemical biorefinery). The considered platform chemicals are methanol, DME, and ethanol, which are the common products from syngas in BTL/G studies. Important keys are given for the integration of reviewed routes into the design of thermochemical biorefineries, in particular for the selection of the mix of co-products, as well as for the sustainability (co-feeding, CO2 capture, and negative emissions).Ministerio de Educación FPU Program (AP2010-0119)Ministerio de Economía y Competitividad ENE2012-3159

Identification of RNA binding motif proteins essential for cardiovascular development

Background We recently identified Rbm24 as a novel gene expressed during mouse cardiac development. Due to its tightly restricted and persistent expression from formation of the cardiac crescent onwards and later in forming vasculature we posited it to be a key player in cardiogenesis with additional roles in vasculogenesis and angiogenesis. Results To determine the role of this gene in cardiac development, we have identified its zebrafish orthologs (rbm24a and rbm24b), and functionally evaluated them during zebrafish embryogenesis. Consistent with our underlying hypothesis, reduction in expression of either ortholog through injection of morpholino antisense oligonucleotides results in cardiogenic defects including cardiac looping and reduced circulation, leading to increasing pericardial edema over time. Additionally, morphant embryos for either ortholog display incompletely overlapping defects in the forming vasculature of the dorsal aorta (DA), posterior caudal vein (PCV) and caudal vein (CV) which are the first blood vessels to form in the embryo. Vasculogenesis and early angiogenesis in the trunk were similarly compromised in rbm24 morphant embryos at 48 hours post fertilization (hpf). Subsequent vascular maintenance was impaired in both rbm24 morphants with substantial vessel degradation noted at 72 hpf. Conclusion Taken collectively, our functional data support the hypothesis that rbm24a and rbm24b are key developmental cardiac genes with unequal roles in cardiovascular formation

Identification of RNA binding motif proteins essential for cardiovascular development

Background: We recently identified Rbm24 as a novel gene expressed during mouse cardiac development. Due to its tightly restricted and persistent expression from formation of the cardiac crescent onwards and later in forming vasculature we posited it to be a key player in cardiogenesis with additional roles in vasculogenesis and angiogenesis. Results: To determine the role of this gene in cardiac development, we have identified its zebrafish orthologs (rbm24a and rbm24b), and functionally evaluated them during zebrafish embryogenesis. Consistent with our underlying hypothesis, reduction in expression of either ortholog through injection of morpholino antisense oligonucleotides results in cardiogenic defects including cardiac looping and reduced circulation, leading to increasing pericardial edema over time. Additionally, morphant embryos for either ortholog display incompletely overlapping defects in the forming vasculature of the dorsal aorta (DA), posterior caudal vein (PCV) and caudal vein (CV) which are the first blood vessels to form in the embryo. Vasculogenesis and early angiogenesis in the trunk were similarly compromised in rbm24 morphant embryos at 48 hours post fertilization (hpf). Subsequent vascular maintenance was impaired in both rbm24 morphants with substantial vessel degradation noted at 72 hpf. Conclusion: Taken collectively, our functional data support the hypothesis that rbm24a and rbm24b are key developmental cardiac genes with unequal roles in cardiovascular formation

A Rare Myelin Protein Zero (MPZ) Variant Alters Enhancer Activity In Vitro and In Vivo

expression. variants. that resides within a previously described SOX10 binding site is associated with decreased enhancer activity, and alters binding of nuclear proteins. Additionally, the genomic segment harboring this variant directs tissue-relevant reporter gene expression in zebrafish. variant within a cis-acting transcriptional regulatory element. While we were unable to implicate this variant in disease onset, our data suggests that similar non-coding sequences should be screened for mutations in patients with neurological disease. Furthermore, our multi-faceted approach for examining the functional significance of non-coding variants can be readily generalized to study other loci important for myelin structure and function

Towards Failure Models and Error Propagation in Product Lines

International audienceSafety-critical systems and especially their software components need a thorough verification for failures and potential error propagation. Reliability has to be guaranteed for medical devices in particular. These devices exhibit a broad variability, as well. They have to be suitable for a diverse variety of individual requirements leading to product lines which share a common base functionality, but each product is adapted to different requirements. We present an approach in which failure models are assigned to features which are combined into different product models. Starting with a base model, further product models are derived from it by model transformations. We investigate the structure of the failure models and a possible error propagation. We demonstrate our method using Scade Suite for the model-based product line design of cardiac pacemakers. Formal safety analysis is performed by using the Scade Design Verifier

3D Orthotropic Augmented Finite Element Method for Progressive Damage Analysis of Laminated Composites

In this Ph.D. work, a 3D orthotropic augmented finite element method (A-FEM) that can model arbitrary ply cracking, including matrix cracking and fiber rupture/kinking, was formulated and implemented into a commercial code ABAQUS as a user-defined element. The 3D orthotropic A-FEM can work with 3D cohesive zone model-based interface elements to model coupled intra-ply cracking and delamination. Furthermore, the 3D A-FEM has been extended to account for curved or non-planar composite laminates, which is a critical improvement because the crack configuration in non-planar laminated structures can be very complicated due to instantaneous variation of the local fiber direction, and there have been few models can cope with such complexity.The developed 3D orthotropic A-FEM has been subjected to a rigorous validation procedure. The verification tests start from a single element under monotonic loading and further extend to single aligned and off-axial ply with various crack propagation tests. Crack initiation, propagation, and its coupled evolution with interlaminar delamination have also been tested using angle-ply specimens.After successful validations, the 3D orthotropic A-FEM was employed to analyze six numerical models provided by our industrial collaborator. All these models were multi-directional laminates with various ply orientations and shapes. The A-FEM simulated results were in good agreement with the collaborator&#39;s experimental results. For those non-planar specimens, a newly formulated two-step rotation process has been developed to calculate the instantaneous fiber orientations so that the respective crack configurations can be correctly predicted. This new subroutine successfully predicted a composite radius structure&#39;s crack paths and failure with two different stacking sequences. Additionally, this subroutine was successfully used to study the effects of a possible production imperfection in the radius region and then compared to a perfect radius region model.</p