59 research outputs found

    Study for obtaining the energy certificate in a hockey club building located in Terrassa

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    The main objective of this project is to carry out an energy certification of Club Egara, located in Terrassa, in order to improve the energy efficiency of the club. Two energy certifications have been planned, a basic one and an exhaustive one, which will be conducted using the CE3X software, a specialized program for energy certifications. After comparing the certifications with the actual energy consumption of the building, several alternatives will be analyzed that can contribute to improving the energy efficiency of the building

    Modeling the 21cm global signal from first stars and black holes.

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    The aim of this project is to predict the 21-centimeter global signal generated by the transition between two hyperfine levels of the atomic hydrogen coming from the high-redshift universe. This signal is supposed to be generated during the epoch of formation of first structures because, once luminous objects are formed, they will emit UV radiation that penetrates primordial hydrogen and that is able to alter its spin temperature. This process ends up in a global signal in the 21-centimeter band that begins when the first structures start to form and so the spin temperature decouples from the photon temperature. The signal saturates when reionization completes since there is no more atomic hydrogen that can emit or absorb in the 21- centimeter band. The 21 centimeter signal thus, depends on the ionization and thermal histories of the intergalactic medium. Three relevant processes determine these two histories: X-ray heating responsible for the increase of the kinetic temperature of the gas, Lyman-alpha photons that couple the spin temperature of the gas to its kinetic temperature and UV ionizing photons that drive the cosmic reionization. A crucial role is thus played by the sources that firstly formed in the universe (stars and black holes) since they can emit photons at all the different frequencies of our interest. In the first part of the thesis, we adopted a standard analytical model for structure formation based on the Press-Schechter formalism in order to obtain thermal and ionization histories (and thus the 21-centimeter global signal) consistent with already published results. In the second part of the thesis, we used the semi-numerical code Cosmic Archaeology Tool (shortly CAT) developed within our research group (Trinca et al., 2021). CAT is able to follow the evolution of dark matter halos tracking merger history using the extended PressSchechter formalism and provides an ab.initio description of their baryonic evolution, starting from the formation of the first stars and black holes in mini-halos at z=20-30. The model is well anchored to observations of galaxies and AGN at z<6 and it predicts a reionization history consistent with observations. We then estimated the 21- centimeter global signal using the same formalism described above but with the rate of formation and emission properties of the sources (stars and accreting black holes) provided by CAT. We obtained a 21- centimeter global signal with an absorption feature between z=23 and z=19 and with a depth of 150 mK. The timing and the depth of this feature is consistent with many other semi-numerical models that account for star formation in mini-halos, but it is not consistent with the detection claimed by the EDGES collaboration (Bowman et al., 2018) since it has a depth three times stronger. We tried to reproduce this depth considering an additional radio background produced by the emission of early accreting black hole seeds adopting the same formalism of Ewall-Wice et al. (2018). We found that considering only black holes which are accreting with an Eddington ratio larger than 0.01 we may reproduce the observed depth of 500 mK

    Exploring the Dynamics of Glycolytic Regulation Through Two Enzymes: Human Enolase and Liver Pyruvate Kinase

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    Understanding how conformational dynamics play a role in metabolic regulation is an important objective in various biological disciplines. Using Molecular Dynamics (MD) simulations, we attempt to elucidate the dynamics involved in regulating two glycolytic enzymes: human liver pyruvate kinase (hL-PYK) and human enolase. Despite being metabolically coupled, both enzymes are regulated quite differently: hL-PYK can undergo allosteric modulation, while enolase is competitively inhibited. In the hL-PYK study, we discern a mechanism of allostery induced by the allosteric activator fructose-1,6-bisphosphate, and the inhibitor alanine. In the case of enolase, previous studies have attempted to make isoform-specific inhibitors of the enzyme; to further explore this objective, we compare the dynamics of two conserved isozymes, enolase 1 and 2, through MD simulations. As a proof of concept, we find compounds that discriminate between the two homologues by performing ensemble virtual screening on MD derived free enolase structures

    America Inc.: The Rise and Fall of a Civil Democracy

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    The field of Curriculum Studies has thoroughly outlined the detrimental effects of corporate ideology on education in terms of curricular mandates, the corporatization of higher education, rampant privatization, and globalization. Educational mandates have created an atmosphere of control in which students are methodically deprived of exploration and creativity through strict adherence to a prescribed curriculum. This results in the de-skilling of teachers and the loss of Self as students are forced to memorize facts based on educational mandates, with teachers having to constantly redirect outlets for creativity in order to teach to the test. As a result of this study, it is evident that educational mandates are the first step in preparing children to become the unknowing participants in a consumer culture. In addition to curriculum mandates, children are also controlled by a system that advocates the use of psychiatric diagnoses and subsequent medication as a means to suppress disruptive forms of behavior that are deemed to be abnormal, such as a child\u27s propensity to play and normal forms of adolescent rebellion. I propose that a culture of defiance is rising out of the attempts to suppress normal behavior as children and adolescents rebel against the system. I also propose that the Self is methodically detached from its creative core and that Object-Relations Theory plays an integral role in understanding the behavior of postmodern consumers

    Maine Campus April 18 2002

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    1965 Acropolis

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    1965 Acropolis yearbook for Whittier College.https://poetcommons.whittier.edu/acropolis/1071/thumbnail.jp

    Improving the Functional Control of Ferroelectrics using Insights from Atomistic Modelling

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    Lead zirconate titanate is a ferroelectric material of considerable interest with a wide range of technological applications. It has been the subject of many experimental and theoretical studies yet there are a number of unsolved questions preventing further miniaturisation and optimisation of this and other ferroelectric materials. Exotic ultra-dense domain morphologies, as an example, offer an exciting avenue for the development of novel nanoelectronics. In this work, large scale molecular dynamics is used to construct a strain-temperature phase diagram of the domain morphology of PbTiO3 ultrathin films. By sampling a wide range of strain values over a temperature range up to the Curie temperature, it is found that epitaxial strain induces the formation of a variety of closure- and in-plane domain morphologies. The local strain and ferroelectric-antiferrodistortive coupling at the film surface vary for the strain mediated transition sequence and this could offer a route for experimental observation of the morphologies. Remarkably, a new nanobubble domain morphology is identified that is stable in the high-temperature regime for compressively strained PbTiO3. It is demonstrated that the formation mechanism of the nanobubble domains morphology is related to the wandering of flux closure domain walls, which is characterised using the hypertoroidal moment. Molecular dynamics calculations, supplemented with electrical measurements from collaborators, are used to provide insight into the microscopic switching properties of near-morphotropic PZT. The simulations and experiments exhibit qualitatively similar hysteretic behaviour of the polarisation at different temperatures, showing widening of the Polarisation - Electric field hysteresis loops, and the decrease of the coercive field towards high temperatures. Remarkably, polarisation switching at low temperatures is shown to occur via a polarisation rotation and growth mechanism that is fundamentally different from the high temperature switching, where nucleation is rate limiting. Analysis of B-cation contributions show that nucleation and switching are facilitated by Zr centred unit cells and, by extension, Ti centred unit cells in Zr-rich environments. Ti-rich clusters in morphotropic PZT, at low temperature, are observed to have suppressed ferroelectric displacements which may incorrectly be perceived as ferroelectrically inactive `dead-layers'. Finally, fundamental insight into the microscopic mechanisms of the ageing processes are provided. From simulations of the prototypical ferroelectric material PbTiO3, it is demonstrated that experimentally observed ageing phenomena can be reproduced from intrinsic interactions of defect-dipoles related to dopant-vacancy associates, even in the absence of extrinsic effects. Variation of the dopant concentration is shown to modify the material's hysteretic response, identifying a universal method to reduce loss and tune the electromechanical properties of inexpensive ceramics for efficient technologies
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