3,041 research outputs found
Hygrothermal Performance of Worship Spaces: Preservation, Comfort and Energy Consumption
The energy problem, one the most important on a global scale, greatly affects the environment. Much of the current energy consumption occurs in existing buildings, including heritage buildings with varying protected status. Energy intervention and heritage conservation conflict to some extent, as research focuses more on the search for improved energy efficiency solutions for materials and systems than on their application to heritage buildings. This study describes experimental research on environmental conditioning techniques in spaces of worship in a temperate climate in southern Spain. Buildings were monitored and assessed in the implementation of different environmental techniques—active and combined (passive and active)—with the aim of improving the thermal comfort conditions of the faithful while preserving the cultural heritage of these buildings. The need for a control system of RH and the air system was concluded, as well as radiant floors and radiators, which, in the considered case studies, would barely affect the artworks. 24- and 12-h operation are better suited to heritage preservation than occasional use. All operation schedules are valid for thermal comfort.Universidad de Malaga
Universidad de Sevill
Synthesis of Propargylamines by Cross-Dehydrogenative Coupling
Propargylamines are versatile compounds for heterocyclic synthesis, some of which are current drugs prescribed to treat patients with Parkinson’s disease. There are different methods to synthesize propargylamines, however, modern chemistry has moved progressively to rely on new strategies that meet the principles of Green Chemistry. In this context, propargylamines are readily accessible by the cross-dehydrogenative coupling (CDC) of two C-H bonds (i.e., NCsp3-H and Csp-H bonds); surely, CDC can be considered the most atom-economic and efficient manner to form C-C bonds. The aim of this review is to provide a comprehensive survey on the synthesis of propargylamines by the CDC of amines and terminal alkynes from three fronts: (a) transition-metal homogeneous catalysis, (b) transition-metal heterogeneous catalysis and (c) photoredox catalysis. A section dealing with the asymmetric synthesis of chiral propargylamines is also included. Special attention is also devoted to the proposed reaction mechanisms.This work was generously supported by the Spanish Ministerio de Ciencia, Innovación y Universidades (MICIU; grant no. CTQ2017-88171-P), the Generalitat Valenciana (GV; grant no. AICO/2017/007) and the Instituto de Síntesis Orgánica (ISO). I.B. is also grateful to the Spanish MICIU for a Juan de la Cierva-incorporación grant (no. IJCI-2017-33706)
A Hubble Constant Estimate from Galaxy Cluster and type Ia SNe Observations
In this work, we constrain the Hubble constant parameter,, using a
combination of the Pantheon sample and galaxy clusters (GC) measurements from
minimal cosmological assumptions. Assuming the validity of the cosmic distance
duality relation, an estimator is created for that only depends on simple
geometrical distances, which is evaluated from Pantheon and a GC angular
diameter distance sample afterward. The statistical and systematic errors in GC
measurements are summed in quadrature in our analysis. We find in confidence level. This
measurement presents an error of around 9\%, showing that future and better GC
measurements can shed light on the current Hubble tension.Comment: 7 pages, two figure
Synchronized network activity in developing rat hippocampus involves regional hyperpolarization-activated cyclic nucleotide-gated (HCN) channel function.
The principal form of synchronized network activity in neonatal hippocampus consists of low frequency 'giant depolarizing potentials' (GDPs). Whereas contribution of both GABA and glutamate to their generation has been demonstrated, full understanding of the mechanisms underlying these synchronized activity bursts remains incomplete. A contribution of the h-current, conducted by HCN channels, to GDPs has been a topic of substantial interest. Here we focus on HCN1, the prevalent HCN channel isoform in neonatal hippocampus, and demonstrate an HCN1 spatiotemporal expression pattern in both CA3 principal cells and interneurons that correlates with the developmental profile of GDPs. Abrogation of HCN physiological function in CA3, via the selective I(h)-blocker ZD7288, disrupts GDP generation. Furthermore, ZD7288 specifically abolishes spontaneous bursting of the CA3 pyramidal cells at frequencies typical of GDPs without major influence on interneuronal firing. These findings support a pivotal role for HCN channels expressed by CA3 neurons, and particularly CA3 pyramidal cells, in GDP-related network synchronization
Tensile Testing of 3D Printed TPU Samples for Pediatric Biomaterial Applications
Additive Manufacturing (AM) has, in recent years, become one of the most widespread and preferred prototyping methods. The most popular additive manufacturing method is Fused Deposition Modeling. FDM’s popularity is primarily attributed to its 3 major strengths of rapid prototyping, variability in material choice, and subject specific nature. The medical industry is one of the larger industries that has benefited from 3D printing especially in the terms of medical trainers. Unfortunately, most medical trainers that are developed (either being 3d printed or through traditional manufacturing processes) are poor substitutes for the human body. This can be attributed to either a poor design or poor material choice. FDM printing is the obvious solution to these issues, but one of the largest problems in 3D printing for engineers is that the properties of most filaments after extrusion are not well-known. Additionally, 3D prints are rarely 100% solid in FDM which makes assuming the material properties of the base materials inaccurate.
This project seeks to test 3D printed samples at numerous different infills of a common 3D printing material known as Thermoplastic Polyurethane of TPU using ASTM D638. The test samples will be printed across numerous printers with the same settings to determine whether different printers influence the material properties after a print. Once tensile testing has been completed the curves will be imported into an FEA software to be tested on numerous bone geometries to determine if TPU is a suitable material to use to mimic pediatric bones
Inducing a topological transition in graphene nanoribbon superlattices by external strain
Armchair graphene nanoribbons, when forming a superlattice, can be classified into different topological phases, with or without edge states. By means of tight-binding and classical molecular dynamics (MD) simulations, we studied the electronic and mechanical properties of some of these superlattices. MD shows that fracture in modulated superlattices is brittle, as for unmodulated ribbons, and occurs at the thinner regions, with staggered superlattices achieving a larger fracture strain than inline superlattices. We found a general mechanism to induce a topological transition with strain, related to the electronic properties of each segment of the superlattice, and by studying the sublattice polarization we were able to characterize the transition and the response of these states to the strain. For the cases studied in detail here, the topological transition occurred at ∼3-5% strain, well below the fracture strain. The topological states of the superlattice - if present - are robust to strain even close to fracture. The topological transition was characterized by means of the sublattice polarization of the states.Fil: Flores Gutierréz, Esteban. Universidad de Chile; ChileFil: Mella, José D.. Universidad de Chile; ChileFil: Aparicio, Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad de Mendoza. Facultad de Ingenieria; ArgentinaFil: Gonzalez, Rafael I.. Universidad Mayor; Chile. Centro para el Desarrollo de la Nanociencia y la Nanotecnología; ChileFil: Parra, C.. Universidad Mayor; ChileFil: Bringa, Eduardo Marcial. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad de Mendoza. Facultad de Ingenieria; Argentina. Universidad Mayor; ChileFil: Munoz, Francisco. Centro para el Desarrollo de la Nanociencia y la Nanotecnología; Chile. Universidad de Chile; Chil
Language and Cultural Awareness of a Non-Native ESP Teacher
Introduction. The relation between culture and language is a central issue in foreign language teaching and research where the need to give cultural content the same value as language content and language skills has been stressed. However, conceptualization of teacher language awareness, by focusing largely on formal aspects of language, largely neglects culture as a component of teacher cognition. This paper expands the category of ESP-teacher language awareness suggesting the inclusion of cultural awareness as a separate component of teacher cognition. This concept extension actualizes ESP teaching in the situation shaped by unprecedented mobility and intercultural contacts.
Materials and Methods. The historic-logical method was used to determine shortcomings of pedagogical experience and the need to teach culture in ESP. Grounded theory, as an inductive methodology, was utilized to generate conceptual expansion theoretically tied with research in medical and business communication as well as with data on population movement and international s cientific cooperation.
Results. We defined ESP-cultural knowledge as a system comprising the permanent (know-that) and temporary (know-of) cultural manifestations in a society as well as how they are manifested through language (know-how). That system practical representation is exemplified in medicine and business English discourse. The study expands the structure of ESP-TLA, claiming the focus on cultural awareness as part of ESP discourse which fosters cultural-response education.
Discussion and Conclusion. Such claim is pertinent to practitioners involved in the tourism industry, health care, economics, and academic activities such as research and development. This paper is relevant for teachers of English for Specific purposes in the fields mention ed above as well as for researchers engaged in analyzing the problems and methods of teaching a foreign language. However, because of the multiple manifestations and complexity of student motivation to get ESP course, the paper acknowledges the difficulties in addressing cultural content salient to all student s in class, an aspect meriting further research
Large Nc QCD and Harmonic Sums
In the Large-Nc limit of QCD, two--point functions of local operators become
Harmonic Sums. I review some properties which follow from this fact and which
are relevant for phenomenological applications. This has led us to consider a
class of Analytic Number Theory Functions as toy models of Large-Nc QCD which I
also discuss.Comment: Based on my talk at "Raymond Stora's 80th Birthday Party", LAPP, July
11th 201
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