Mathematical Modelling of Adsorption

Treballs Finals de Grau d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2013-2014, Tutors: Santiago Esplugas Vidal i Nicolau Goula i MasllorensThe selection of a particular model to solve a problem is given by the nature of the system (i.e. what phenomenon is actually more important than the other), the acceptable complexity of the equations to represent it, and the computing resources available to find a solution (which are inversely proportional to the time the engineer needs to wait to get the result). These points determine what are the necessary assumptions to be made to develop a mathematical model. For the model development a study of what are the relationships and factors involved in the adsorption process has been made. Once different models have been developed with the help of mathematical software, a computational simulation was made to verify to verify whether they conform to reality. Due to the differential nature of the adsorption processes, it has been resorted to numerical methods to develop the necessary software required for the simulation. The verification of the adjustment to the reality of each of the models developed in this work has been done by comparing the profiles of concentrations and temperatures that can be obtained from the simulation of a determined column

Estudio de la Combustión Usando Software de Dinámica de Fluidos Computacional (ANSYS)

Treballs Finals de Màster d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2015-2016, Tutors: Jordi Bonet Ruiz, Joan Llorens LlacunaThis work is a study of the effect of water addition to a combustion chamber. Starting from a review of the art and literature to understand the NOx formation phenomena and then, using the commercial computational fluid dynamics software ANSYS FLUENT to perform a sensitivity analysis of this water addition. More specifically, first is a description of what can be found when searching for computational fluid dynamics and water injection engines. Secondly, there is shown the structure and the main characteristics of a simulation performed in ANSYS FLUENT. Finally, there’s posed a sensitivity analysis in order to see the effect of the water addition to a combustor, and the influence of the contact mode used to implement this addition

Evaluation of commercial-off-the-shelf wrist wearables to estimate stress on students

Wearable commercial-off-the-shelf (COTS) devices have become popular during the last years to monitor sports activities, primarily among young people. These devices include sensors to gather data on physiological signals such as heart rate, skin temperature or galvanic skin response. By applying data analytics techniques to these kinds of signals, it is possible to obtain estimations of higher-level aspects of human behavior. In the literature, there are several works describing the use of physiological data collected using clinical devices to obtain information on sleep patterns or stress. However, it is still an open question whether data captured using COTS wrist wearables is sufficient to characterize the learners' psychological state in educational settings. This paper discusses a protocol to evaluate stress estimation from data obtained using COTS wrist wearables. The protocol is carried out in two phases. The first stage consists of a controlled laboratory experiment, where a mobile app is used to induce different stress levels in a student by means of a relaxing video, a Stroop Color and Word test, a Paced Auditory Serial Addition test, and a hyperventilation test. The second phase is carried out in the classroom, where stress is analyzed while performing several academic activities, namely attending to theoretical lectures, doing exercises and other individual activities, and taking short tests and exams. In both cases, both quantitative data obtained from COTS wrist wearables and qualitative data gathered by means of questionnaires are considered. This protocol involves a simple and consistent method with a stress induction app and questionnaires, requiring a limited participation of support staff.Agencia Estatal de Investigación | Ref. TIN2016-80515-

Blockchain applications in education: a systematic literature review

Blockchain is one of the latest technologies attracting increasing attention from different actors in diverse fields, including the educational sector. The objective of this study is to offer an overview of the current state of the art related to blockchain in education that may serve as a reference for future initiatives in this field. For this, a systematic review of reference journals was carried out. Eleven databases were systematically searched and eligible papers that focused on blockchain in education that made significant contributions, and not only generic statements about the topic, were selected. As a result, 28 articles were analyzed. Lack of precision, and selection and analysis bias were then minimized by involving three researchers. The analysis of the selected papers provided invaluable insight and answered the research questions posed about the current state of the application of blockchain in education, about which of its characteristics can benefit this sector, and about the challenges that must be addressed. Blockchain may become a relevant technology in the educational field, and therefore many proofs of concept are being developed. However, there are still some relevant technological, regulatory and academic issues to be addressed to pave the way for the mainstream adoption of this technology

Study of cross-sectional shapes of ideally hard cylinders to achieve invisibility for oblique incidence

In this work, the effect of the incidence angle on struts for reducing electromagnetic blockage using ideal hard cylinders in the antenna area is analyzed. Firstly, the characterization of the invisibility of a given object in terms of an equivalent blockage width is discussed. Then, ideally hard cylinders with oblong cross sectional shapes and hard surfaces for different incidence angles are analyzed. It is shown that the variation of incidence angle in azimuth is very sensitive in terms of blockage for TM polarization. Finally, design chart of ideal struts which reduce blockage simultaneously for TE and TM cases that give some performance goals for a final realized struts are presented

Double hybrid lubricant additives consisting of a phosphonium ionic liquid and graphene nanoplatelets/hexagonal boron nitride nanoparticles

Tribological performance of polyalphaolefin 32, PAO, is investigated by adding two nanomaterials (graphene nanoplatelets, GnP, and hexagonal boron nitride nanoparticles, h-BN) and an ionic liquid ([P6,6,6,14][DEHP], IL1, [P2,4,4,4][DEP], IL2, or [P6,6,6,14][(iC8)2PO2], IL3). Designed double hybrid nanodispersions are PAO/1 wt% ILX/0.05 wt% GnP/0.1 wt% h-BN (X = 1, 2 or 3). The best anti-friction behavior corresponds to PAO/IL3/GnP/h-BN (40% reduction compared to that achieved with PAO). Anti-wear behavior is similar for the three double hybrid nanodispersions. Roughness of the worn surface tested with PAO is higher than that obtained for each of the nanodispersions. Tribo-film formation and repair effect on worn surfaces due to ILs and nanoparticles are revealed. Some positive synergies were found between each IL and GnP/h-BN as hybrid PAO additivesMinistry of Science and Innovation (Spain) and the European Regional Development Fund supported this work through the project ENE2017-86425-C2-2-R. This research was also financially supported by Xunta de Galicia, Spain (Grant ED431C 2020/10)S

Hybrid combinations of graphene nanoplatelets and phosphonium ionic liquids as lubricant additives for a polyalphaolefin

Tribological performance of three ionic liquids (ILs), trihexyltetradecylphosphonium bis(2-ethylhexyl)phosphate (IL1), tributylethylphosphonium diethylphosphate (IL2) and trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate (IL3) combined with graphene nanoplatelets (GnP) as hybrid additives for a polyalphaolefin (PAO 32) base oil was studied. For this purpose, several dispersions were prepared by mixing, stirring, and then sonicating according to the following combinations: PAO 32 + (a wt%) IL + (b wt%) GnP, where a and b represent the concentration of the additives added to the PAO 32 base oil. In this study a is 0 or 1 and b is 0.05 or 0.1. Three PAO 32 + 1 wt% IL mixtures were also prepared. Thermophysical properties and stability against sedimentation of the dispersions were studied by means of a rotational viscometer and visual observation, respectively. Furthermore, friction and wear behaviors were analyzed using a ball-on-disk configuration tribometer operating in rotational mode and both a 3D optical profiler and a scanning electronic microscope, respectively. Confocal Raman microscopy was used to identify compounds in the tribofilms formed on the wear tracks. The hybrid combinations of PAO 32/ILs/GnP improved the friction reduction of the corresponding binary PAO 32/GnP nanolubricants and PAO 32/IL mixtures. Interestingly, the hybrid dispersions with low concentrations of GnP (with 0.05 wt% GnP) are more effective than those of 0.1 wt% GnP. Results also show that the addition of both 0.05 wt% graphene nanoplatelets and 1 wt% IL led to friction reductions up to 36% and wear reductions up to 27%, compared with the capabilities of neat PAO 32. IL1 and IL3, containing the trihexyltetradecylphosphonium cation, generate the hybrid lubricants with the best combined properties (stability, viscosity and tribological properties) of all the lubricants testedThis work was supported by the Spanish Ministry of Science, Innovation and Universities and the ERDF programme (FEDER in Spanish) through ENE2017-86425-C2-2-R project, and by the Xunta de Galicia (ED431D 2017/06, ED431E 2018/08 and ED431C 2020/10)S

Tribological enhancement using Mn3O4-Graphene nanocomposites as additives for potential transmission fluids of electric vehicles

This research reports the antifriction and antiwear properties of Mn3O4-Graphene nanocomposites (Mn3O4-G) as additives of a paraffinic base oil commonly used in the formulation of electric vehicles transmission oils, G-III base oil. Four G-III base oil nanodispersions have been designed, G-III base oil + 0.025 wt% Mn3O4-G, G-III base oil + 0.050 wt% Mn3O4-G, G-III base oil + 0.075 wt% Mn3O4-G and G-III base oil + 0.100 wt% Mn3O4-G, to know the optimal concentration of nanoadditive. Tribological experiments were carried out with these nanolubricants and with neat G-III base oil at pure sliding conditions under a working load of 9.43 N. All tested nanolubricants led to similar friction coefficients in comparison to that obtained using G-III base oil. Tribological specimens tested with formulated nanolubricants revealed less wear than that obtained with G-III base oil, obtaining the greatest wear reduction using the G-III base oil + 0.075 wt% Mn3O4-G nanolubricant, with reductions of 25, 50 and 64% in wear scar diameter, maximum depth and transversal area, respectively. Moreover, by means of confocal Raman microscopy and roughness evaluation of worn tribological specimens, it was concluded that synergetic effect, tribofilm formation and rolling mechanisms happenThis research is supported by Xunta de Galicia (ED431C 2020/10), by the State Research Agency (AEI) of Spain and the European Regional Development Fund (ERDF, FEDER in Spanish) through the PID2020-112846RB-C22 project. JMLDR and RR are granted by the Program for the requalification, international mobility, and attraction of talent in the Spanish university system, modality Margarita SalasS

Promoting critical thinking skills through debates in engineering education. A case study on manufacturing.

Argumentation and decision-making are fundamental in the training of industrial engineers to effectively develop their critical thinking skills. Despite this, engineering education focuses on technical aspects that hardly promote the development of these skills in the classroom. To promote them, a specific training programme in critical thinking for industrial engineers was proposed, which, among other activities, included short debates on socio-scientific problems. This paper presents the impact of a debate on manual versus mass production on 30 students of the Degree in Industrial Technologies Engineering at the University of Malaga (Spain) acting as listeners. To assess this impact, we analyse the argued decisions made by the listeners about the problem before and after the activity, finding that the initial position of the majority was manual manufacturing based on social evidence, and the final position was mass production based on scientific-technical evidence such as economic aspects or the quality of the manufactured product. The arguments used by the debaters were scientifically vague but had an essential effect on changing decisions, especially the evidence used, which the listeners made their ownUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Sistema de cartografía arqueológica predictiva : PRONOS

Aufgrund des aktuellen Fachkräftemangels fällt es Organisationen zunehmend schwerer, qualifizierte Arbeitnehmer und Arbeitnehmerinnen zu gewinnen. Um in diesem „Kampf“ um potenzielle Arbeitnehmer und Arbeitnehmerinnen als attraktiver Arbeitgeber hervorzugehen, bauen immer mehr Organisationen mittels Employer Branding eine starke Arbeitgebermarke auf. Gleichzeitig erwartet die Öffentlichkeit, dass Organisationen gesellschaftliche Verantwortung übernehmen. Mit dem Fokus auf das Berufsfeld Kommunikationsmanagement verknüpft die vorliegende Bachelorarbeit diese beiden Themen. Dabei wird der Fragestellung nachgegangen, welche Rolle Corporate Social Responsibility (CSR) bei der Bewertung der Arbeitgeberattraktivität durch Kommunikationsmanagement-Absolventen während der Jobsuche spielt. Theorien wie die Signaling-Theorie, die Theorie der sozialen Identität und der Person-Organisations-Fit-Ansatz können dabei positive Auswirkungen von CSR auf die Arbeitgeberattraktivität begründen. Die Ergebnisse der Bachelorarbeit können jedoch zeigen, dass CSR von Kommunikationsmanagement-Absolventen eher als zweitrangig behandelt wird. Grund hierfür ist auch der wahrgenommene manipulative Charakter von CSR