1,720,990 research outputs found
A new method for estimating the EFV distillation curve
Get PDFThis work presents a new method to estimate the equilibrium flash vaporization (EFV) distillation curve from standard laboratory analytical assay procedures. In this method, experimental data are utilized by a chemical process simulator to obtain the EFV curve. Any simulator able to model petroleum can be used for this task. To evaluate the performance of the proposed method, several types of petroleum were analyzed experimentally in this work. The obtained curves were compared with those produced by other methods showing a good match. The main advantage of the proposed method is its non-dependence on experimental data.Fil: Tarifa, Enrique Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Jujuy; ArgentinaFil: Erdmann, Eleonora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Humana, D.. Universidad Nacional de Jujuy; ArgentinaFil: Martínez, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentin
Design assessment of polymeric membranes modules to separate carbon dioxide from a binary mixture with methane
No full textThis work presents the performance assessment of diverse membrane arrangements to separate carbon dioxide (CO2) from a binary mixture with methane (CH4). For the purpose, we employ computer modeling to represent different polymeric modules, which are able to split an inlet CH4/CO2 gaseous mixture into sweet and acid products. Aim of the process is to achieve a high-purity CO2 permeate, reducing the CH4 losses. Novelty, we compare the performances of different existing commercial polymers, available for gas industries: cellulose acetate, polycarbonates, polyamides, polyamide-imides, polyamides thin-film composites, among others. The importance of the use of different materials is the possibility to replicate total membrane area, transport properties, and operating conditions. Finally, a comparative and integral discussion of the simulations considers three fundamental aspects: hydrocarbon recovery, residual gas quality, and compression power to carry out the separation.Fil: Gutierrez, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Ale Ruiz, Elisa Liliana. Universidad Nacional de Salta. Facultad de Ingeniería; ArgentinaFil: Erdmann, Eleonora. Universidad Nacional de Salta. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentin
Surface modifications of Volcanic Glasses (Perlites) by water vapor
Get PDFHydrothermal treatments on expanded volcanic glasses (perlites) were studied. The main objective of this paper is to obtain an activated surface able to interact with specific chemical substances. The above mentioned treatment consists on exposing the glass surface to water vapor at temperatures over 250°C at the correspondent vapor pressure during different periods of time and for different size of particles. The glass surface modifications were studied by IR, DTA-TG and adsorption techniques. The grade of surface activation was tested by studying the chemical interaction with polysiloxane polymers.Fil: Abalos, Raúl Mauro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Erdmann, Eleonora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Destefanis, Hugo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentin
Already Used and Candidate Polymeric Membranes for CO2 Separation Plants
Get PDFThis chapter presents the already in used polymeric membranes and the potential candidates for the CO2 acid gas separation. Mainly, this work describes the characteristics of each membrane arrangement and the differences according to transport properties, conditions, and quality of the products. In addition to this, it is described the type of membranes according to the capacity to separate CO2 from sources such as CO2/CH4 mixture, natural gas, and flue gases. Also, the energy requirement to accomplish a certain product specification is presented, this last used for the transport of natural gas. Finally, we summarize the characteristics of the potential membranes and challenges for industrial applications.Fil: Gutierrez, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Ale Ruiz, Elisa Liliana. Instituto Tecnológico de Buenos Aires; Argentina. Universidad Nacional de Salta; ArgentinaFil: Erdmann, Eleonora. Instituto Tecnológico de Buenos Aires; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Effects of Preparation Methods of Organoclays with Polyvinyl Alcohol in their Compatibility with HDPE. Thermal Stability
Get PDFIn this paper, the effect of polyvinyl alcohol addition on organoclay obtained by in situ polymerization and subsequent alcoholysis of polyvinyl acetate is studied. The incorporation of the monomer is carried out following two procedures. The first is the incorporation of the monomer by direct contact between the monomer and the organoclay. The second procedure involves a first step of impregnating the organoclay with propyl alcohol and the subsequent incorporation of the monomer. Both procedures consist of the polymerization in situ via a free radical mechanism. PVA modified clays showed substantial improvements in thermal properties with respect to the organoclay (MMTHDTMA), corresponding to the greater stability to clay obtained by direct contact with the monomer, PVAMMT/HDTMA (VA). The clays prepared by both methodswere incorporated into a HDPE matrix by melt blending, to study the effect of the method of preparing the organoclay with PVA in the polymer/clay compatibility and the effect on their thermal properties. The material characterization techniques were performed using X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermal analysis (TG, DTG, DSC) and transmission electron microscopy (TEM). The results show a clear improvement in the HDPE thermal properties with the addition of organoclays containing PVA and allow a discussion of effect of preparation on compatibility and improved thermal properties.Fil: Carrera, María Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigación Para la Industria Química (i); ArgentinaFil: Erdmann, Eleonora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigación Para la Industria Química (i); Argentina. Instituto Tecnologico de Buenos Aires; ArgentinaFil: Destefanis, Hugo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigación Para la Industria Química (i); Argentin
Energy requirements, GHG emissions and investment costs in natural gas sweetening processes
Get PDFCurrently, different technologies are being employed to remove CO2and H2S from the natural gas. Based on chemical phenomenon, the absorption using alkanolamines is probably the most extended process for the acid gas removal. However, membrane technologies are considered as an alternative in specific cases for their better performances, cleanness, energy requirements, operative costs and location flexibility. The aim of this article is to estimate, compare and analyze the energy requirements, greenhouse gases (GHG) emissions and investment costs of three Natural Gas Sweetening processes. For the study, a regular process using methyldiethanolamine (MDEA), the absorption process using recompressed vapor and a membrane system were simulated using Aspen Hysys v8.8. For the first case, real data from the gas plant Aguaragüe (Argentina) was used to validate the model. To establish a proper comparison, a natural gas with 4 mol.% of CO2is considered as the inlet stream of each configuration. Specifically, compression and pump power, specific total heat, removed CO2, CH4wastes and capital costs were estimated and compared for each case. Additionally, a discussion including different aspects in regard to the energy efficiency of the processes was conducted. Although the proposed membrane system demonstrated to reduce the energy requirements (77% and 72%) and emissions (80% and 76%) in respect to both absorption processes, the CH4losses were higher by more than 6 factor. Moreover, the investment cost of the technology is 12% higher than the required capital of a conventional amine process.Fil: Gutierrez, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Ale Ruiz, Elisa Liliana. Universidad Nacional de Salta. Facultad de Ingenieria; ArgentinaFil: Erdmann, Eleonora. Instituto Tecnológico de Buenos Aires; Argentin
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
