Separation of n-hexane - ethyl acetate mixture by azeotropic batch distillation with heterogeneous entrainers

In this article, a systematic study of the separation of the n-hexane - ethyl acetate mixture with an entrainer by heterogeneous azeotropic batch distillation is performed. Based upon the thermodynamic behaviour of the ternary mixtures, potential entrainers partially miscible with one or two original azeotropic components are chosen. In all cases, the entrainer adds a heterogeneous binary or ternary azeotrope that is the lowest boiling point in the ternary diagram. Therefore, it leaves the column by the overhead stream which is subcooled to get two liquid phases in the decanter. The phase with the highest amount of the original component is removed as distillate product whereas the entrainer – rich phase is continuously refluxed to the column. Considering methanol, acetonitrile, water and nitromethane as heterogeneous entrainers, screening was performed based on the composition of the unstable heteroazeotropic mixture, the ratio of both liquid phases in the condensed top vapour and the purity of the distillate product determined by the liquid – liquid envelope at the decanter temperature. The process feasibility analysis is validated by using rigorous simulation with the batch process simulator ProSimBatch. Simulation results are then corroborated in a bench experimental column for the selected entrainer, showing several advantages of heterogeneous batch distillation compared to homogeneous systems

Heterogeneous Extractive Batch Distillation of Chloroform - Methanol – Water : Feasibility and Experiments

A novel heterogeneous extractive distillation process is considered for separating the azeotropic mixture chloroform – methanol in a batch rectifying column, including for the first time an experimental validation of the process. Heterogeneous heavy entrainer water is selected inducing an unstable ternary heteroazeotrope and a saddle binary heteroazeotrope with chloroform (ternary diagram class 2.1-2b). Unlike to well-known heterogeneous azeotropic distillation process and thanks to continuous water feeding at the column top, the saddle binary heteroazeotrope chloroform – water is obtained at the column top, condensed and further split into the liquid – liquid decanter where the chloroform-rich phase is drawn as distillate. First, feasibility analysis is carried out by using a simplified differential model in the extractive section for determining the proper range of the entrainer flowrate and the reflux ratio. The operating conditions and reflux policy are validated by rigorous simulation with ProSim Batch Column® where technical features of a bench scale distillation column have been described. Six reproducible experiments are run in the bench scale column matching the simulated operating conditions with two sequentially increasing reflux ratio values. Simulation and experiments agree well. With an average molar purity higher than 99%, more than 85% of recovery yield was obtained for chloroform and methanol

Practical residue curve map analysis applied to solvent recovery in non-ideal binary mixtures by batch distillation processes

Batch distillation inherent advantages has initiated recent search for process feasibility rules enabling the separation of azeotropic or difficult zeotropic binary mixtures thanks to the addition of an entrainer. A systematic procedure enabling to find suitable process and eventually suitable entrainer for the separation of zeotropic or azeotropic binary mixture is described. It brings together into practical use batch distillation process feasibility rules, chemical affinity insight and thermodynamic data analysis available in the literature. The procedure has been implemented in a wizard computer tool and is illustrated on the separation of the water – acetonitrile binary homoazeotrope. Through this tool, all possible 224 feasibility rules and 326 batch distillation sequence processes are checked systematically for each entrainer

PLASMD BEARING A CDNA COPY OF THE GENOME OF BOVINE VIRAL DIARRHEA VIRUS, CHIMERIC DERIVATIVES THEREOF, AND METHOD OF PRODUCING AN INFECTIOUS BOVINE WRAL DARRHEAVIRUS USING SAD PLASMID

A plasmid bearing a cDNA copy of the genome of bovine viral diarrhea virus (BVDV), chimeric derivatives of the plasmid and a method of producing an infectious bovine viral diarrhea virus using the plasmid are disclosed. The invention relates to a plasmid DNA molecule that replicates easily in E. coli and contains a sufficient portion of the genome of BVDV, cloned as cDNA, to be a suitable template to produce RNA in vitro which, upon transfection into bovine cells, gives rise to infectious BVDV. The BVDV created by the process of the invention can be engineered for use as a vector in many advantageous applications

REGSOLexpert: Entrainer Selection Tool for waste solvent recovery by batch distillation processes

A general procedure to systematize the search of several alternatives enabling the separation of non-ideal binary mixtures such as pressure-swing distillation, azeotropic and extractive distillation is presented. The use of heterogeneous entrainers is specially highlighted

Characterization of Physicochemical Properties of Soils as Influenced by Different Land Uses in Bedele Area in Ilubabor Zone, Southwestern Ethiopia

Important morphological and physic chemical properties of soils of Bedele area were investigated to reveal the effect of different land uses (forest, grazing and cultivated lands) and to provide the baseline data for future research and development. Following site selection and field morphological studies of one freshly opened profile on each land use type, the physicochemical properties of the soils were characterized in the laboratory both on disturbed and undisturbed soil samples collected from each genetic horizon. The results of the study revealed that the soil morphological, physical and chemical properties varied with land uses. For instance, the surface horizons of the forest, grazing and cultivated lands were sandy loam, clay loam and loam in texture, respectively. Among the surface horizon the highest CEC (42.00 cmol(+) kg-1, OC (10.74%) total  N (0.667%), available P (5.2 mg kg-1) for Olsen method and (9.51 mg kg-1) for the Bray II, were observed in the forestland whilst the lowest were recorded in the cultivated field. On the other hand, available Fe and Mn were below the toxic level to plant growth in the different land uses while soil pH (H20), under all the land uses qualify for strongly acidic (pH 4.50-5.25) throughout the entire depth of the respective profile.  Generally, the intensity of soil degradation was severe under the cultivated field. Therefore, reducing the intensity of cultivation and adopting integrated soil fertility management could maintain the existing soil condition and replenish the degraded soil chemical properties of the study area. Keywords: morphology, physicochemical, Bedele, cultivated, forest and grazing lan

Multiple immunofluorescence labelling of formalin-fixed paraffin-embedded (FFPE) tissue

<p>Abstract</p> <p>Background</p> <p>Investigating the expression of candidate genes in tissue samples usually involves either immunohistochemical labelling of formalin-fixed paraffin-embedded (FFPE) sections or immunofluorescence labelling of cryosections. Although both of these methods provide essential data, both have important limitations as research tools. Consequently, there is a demand in the research community to be able to perform routine, high quality immunofluorescence labelling of FFPE tissues.</p> <p>Results</p> <p>We present here a robust optimised method for high resolution immunofluorescence labelling of FFPE tissues, which involves the combination of antigen retrieval, indirect immunofluorescence and confocal laser scanning microscopy. We demonstrate the utility of this method with examples of immunofluorescence labelling of human kidney, human breast and a tissue microarray of invasive human breast cancers. Finally, we demonstrate that stained slides can be stored in the short term at 4°C or in the longer term at -20°C prior to images being collected. This approach has the potential to unlock a large in vivo database for immunofluorescence investigations and has the major advantages over immunohistochemistry in that it provides higher resolution imaging of antigen localization and the ability to label multiple antigens simultaneously.</p> <p>Conclusion</p> <p>This method provides a link between the cell biology and pathology communities. For the cell biologist, it will enable them to utilise the vast archive of pathology specimens to advance their <it>in vitro </it>data into <it>in vivo </it>samples, in particular archival material and tissue microarrays. For the pathologist, it will enable them to utilise multiple antibodies on a single section to characterise particular cell populations or to test multiple biomarkers in limited samples and define with greater accuracy cellular heterogeneity in tissue samples.</p

Integrated benthic exchange dynamics and biogeochemical processes under varying environmental conditions

Organic matter mineralization rates and burial efficiency in deep-sea sediments depend on the carbon export from the overlaying water. How deep-sea benthic systems may respond to changes of water column productivity and dynamics is yet poorly understood. Similarly, the contribution of coastal permeable sediments to global mineralization rates is not yet well quantified, due to the difficulty in accounting for complex factors that influence biogeochemical processes in sands (e.g. pore water advection and groundwater discharge). In the perspective that in situ observations of benthic systems need to be disseminated and improved in a way to be capable to determine whether a system is changing on either short/long time scales, this work represents a next step for taking full advantage of one of the techniques that have this potential, i.e. aquatic eddy correlation. Furthermore, this work advances our understanding of dynamic benthic exchange processes in deep-sea and permeable sediments. The techniques that were applied and improved during this thesis, can provide important information on the status of ecosystems, and may therefore also contribute to ecosystem based management strategies