Hawking Temperature in Taub-NUT (A)dS spaces via the Generalized Uncertainty Principle

Using the extended forms of the Heisenberg uncertainty principle from string theory and the quantum gravity theory, we drived Hawking temperature of a Taub-Nut-(A)dS black hole. In spite of their distinctive natures such as asymptotically locally flat and breakdown of the area theorem of the horizon for the black holes, we show that the corrections to Hawking temperature by the generalized versions of the the Heisenberg uncertainty principle increases like the Schwarzschild-(A)dS black hole and give the reason why the Taub-Nut-(A)dS metric may have AdS/CFT dual picture.Comment: version published in General Relativity and Gravitatio

Search for excited quarks in the y+jet final state in proton-proton collisions at s=8 TeV

A search for excited quarks decaying into the γ+jet final state is presented. The analysis is based on data corresponding to an integrated luminosity of 19.7 fb −1 collected by the CMS experiment in proton–proton collisions at s=8 TeV at the LHC. Events with photons and jets with high transverse momenta are selected and the γ+jet invariant mass distribution is studied to search for a resonance peak. The 95% confidence level upper limits on the product of cross section and branching fraction are evaluated as a function of the excited quark mass. Limits on excited quarks are presented as a function of their mass and coupling strength; masses below 3.5 TeV are excluded at 95% confidence level for unit couplings to their standard model partners

Proposal Of A Process Intensification And Green Technology On Ethyl Acetate Production

Although reactive distillation column is not a new concept, it has gained renewed interest in recent years as an effective way to pursue intensification of conventional chemical processes. Reactive distillation operations were first used by the chemical and petrochemical industry in esterification processes to separate reaction products from the reactants to increase product yields. Reactive distillation technology combines chemical synthesis steps with separations by distillation. This combination can lead to intensified, high-efficiency process systems with significant green engineering attributes. Among several approaches to process intensification are hybrid combinations of separation and reaction for chemical synthesis. These combinations offer new process alternatives that may have greatly improved efficiencies (e.g., in reduced energy requirements, lower solvent use, reduced equipment investment, and greater selectivity). Many of these potential advantages are intimately linked to the principles and challenges for green engineering. This work presents a study of establishment of a complete reactive distillation system for production of ethyl acetate via esterification of acetic acid with ethanol using ASPEN PLUS. Ethyl acetate is an important organic solvent widely used in the production of varnishes, ink, synthetic resins, and adhesive agents. Ethyl acetate is normally produced via reversible reaction of acetic acid with ethanol. There are only a few papers in the literature on the subject of the production of ethyl acetate via reactive distillation. A suitable NRTL (nonrandom two-liquid) model parameter set for calculating of liquid activity coefficients has been established with excellent prediction of the compositions and temperatures for the four azeotropes in the system. The predicted four azeotropes in this system include three homogeneous azeotropes of ethanol/ethyl acetate, ethanol/water and ethanol/ethyl acetate/water and also one heterogeneous azeotrope of ethyl acetate/water. A reactive distillation column with an overhead decanter can be designed to achieve over 93 wt% of ethyl acetate composition at organic phase top product stream while the bottom product stream is designed to be rich in acetic acid so that it can be recycled and mixed with fresh acid makeup stream to serve as acid feed to reactive distillation column. Since the purity of the optimum top organic product specification in industry, an additional column is designed to purify the ethyl acetate product of the reactive distillation column to over 99.5 wt%. The top draw of the second column will be recycled back to the decanter. Concluding, the process intensification of ethyl acetate production by reactive distillation was composed by two columns, including the reactive distillation column and the second column, one decanter, and two recycle streams. The optimum operating condition of the overall system will also be studied to minimize the total operating cost and the size of the plant wide of the overall system while meeting product specifications

Design And Analysis Of A Classical Controller To The Residual Oil In A Small Scale Semibatch Extractor

The main effects of the variables concerned with the isothermal and isobaric supercritical extraction of grape oil are determined using a two levels factorial design. It is verified that the solvent velocity can be manipulated to control the residual oil content in the solids. Disturbances in the mean diameter of the particles can not be controlled during the extraction process. Parameter sensitivity supported the design and the performance investigation of the classical controller to the residual oil in the solid material. The proposed procedure was able to control the extraction process under individual and simultaneous step disturbances in the initial content of oil in the solids and in the solvent inlet concentration. © 2005 Elsevier B.V. All rights reserved.20C14411446Asteasuain, M., Brandolin, A., Sarmoria, C., Simultaneous Design and control of a Semibatch Styrene Polymerization Reactor (2004) Industrial & Engineering Chemistry Research, 43 (17), pp. 5233-5247Flores-Cerrillo, J., MacGregor, J.F., Control of Batch Product Quality by Trajectory Manipulation using Latent Variable Models (2004) Journal of Process Control, 14 (5), pp. 539-553Garcia-Munoz, S., Kourti, T., MacGregor, J.F., Model Predictive Monitoring for Batch Processes (2004) Industrial & Engineering Chemistry Research, 43 (18), pp. 5929-5941Grau, M.D., Puigjaner, L., Batch and Semibatch Reactors Modelling and Validation Based on Online pH Measurement (2000) Chemical Engineering Communications, 178, pp. 49-65Rezende, D.F., (1998) PhD Thesis (in portuguese), , 174p, LOPCA/FEQ/UNICAMP, S.P. BrasilSovová, H., Rate of Vegetable Oil Extraction with Supercritical CO2-I. Modelling of Extraction Curves (1994) Chemical Engineering Science, 49 (3), pp. 409-414Sovová, H., Kucera, J., Jez, J., Rate of Vegetable Oil Extraction with Superitical CO2-II. Extraction of Grape Oil (1994) Chemical Engineering Sciense, 49 (3), pp. 415-420Srinivasan, B., Bonvin, D., Visser, E., Dynamic Optimization of Batch Process-II. Role of Measurements in Handling Uncertainty (2003) Computers & Chemical Engineering, 27 (1), pp. 27-4

Guitarra sepia n.sp. from the Southwestern Atlantic (Demospongiae, Poecilosclerida, Guitarridae): first record of a Guitarra without placochelae

This work reports on the first record of Guitarra Carter, 1874 for the southern/southeastern Brazilian Coast. Guitarra sepia n. sp. is described from the coasts of Santa Catarina, São Paulo and Rio de Janeiro states, from depths of 3 - 25 m. The new species is devoid of placochelae. Its status as belonging to Guitarridae was derived from its possession of spiny isochelae comparable to those in Guitarra and Tetrapocillon, followed by a cladistic analysis where a closer relationship to Guitarra indica Dendy, 1916 and Guitarra fimbriata Carter, 1874 was obtained. Reorganizing specimens kept for seven days in seawater enriched to 100 µm silica did not produce placochelae derived microscleres