1,206 research outputs found
Evaluación de la resistencia biaxial de paneles de fábrica de ladrillo reforzados exteriormente con fibra de carbono
Este estudio es la continuación de un estudio previo de otras dos tesinas que caracterizaron, tanto
es comportamiento de la obra de fábrica, como el comportamiento de la misma después de sufrir un
proceso de reparación.
El objetivo de este trabajo es estudiar las posibilidades de aplicación de un refuerzo estructural,
de materiales compuestos, aplicado a elementos de obra de fábrica.
El paso previo es presentar el estado actual del conocimiento sobre la materia. A posteriori una
presentación de los tipos de materiales utilizados para el estudio así como una pequeña caracterización de
los mismos.
El primer paso de este estudio es caracterizar el comportamiento del refuerzo con fibras de
carbono mediante la construcción de unas probetas tipo para caracterizar los dos comportamientos
extremos de la obra de fabrica, el trabajo a cortante puro y a compresión pura.
A partir de estos resultados, se diseñan seis (6) métodos de refuerzo, sobre paneles de obra de
fábrica de las mismas características que los trabajos anteriores. Para poder realizar una comparación
realista de los resultados. Dichos refuerzo son diseñados para tratar de extraer la máxima información de
los mismos, involucrando el mayor número de variables posible.
Dichos paneles de obra de fábrica reforzados se ensayan a un estado de carga biaxial mediante la
aplicación dos cargas, vertical y horizontal .
El paso final del trabajo es dar la explicación de los resultados obtenidos, así como unas
conclusiones de si es factible realizar un refuerzo con materiales compuestos, sobre un material de obra
de fábrica, y sobre cual es el material más adecuado para ello
Application of ion chromatography in determination of carboxylic acids and inorganic anions in selected drugs
[EN] The focus of this work is the analysis of various drugs as well as the validation of a method for the analysis of the ascorbic acid in drugs using ion chromatography with suppressed conductivity. In order to do this different columns and equipment from two well established companies in the field of the ion chromatography was used
Study of the 5G NB-IoT protocol with low density LEO Constellations of nanosatellites
The NB-IoT protocol, specified by 3GPP, is one of most popular and widely used technology for low-power wide-area (LPWA) networks. To further strengthen the potential of this technology, 3GPP is currently developing an extension of the NB-IoT protocol for non-terrestrial networks (NTN), so that terrestrial coverage could be extended using satellite-based network deployments and reach global coverage. The first part of this Master's Thesis focuses on the development of a MATLAB simulation software for the characterization of a NB-IoT NTN deployment scenario in terms of satellite coverage footprint (e.g. SNR distributions) and dynamics of the satellite link during a satellite pass (e.g. time evolution of the SNR and Doppler).Among the simulator inputs, there are the satellite height, the spherical geometry of the earth, the parameters associated with the satellite, such as orbit or speed, the transmission power, frequency, pathloss, etc... The simulator allows selecting the different inputs such as NTN parameters, link budget parameters or antenna type. These inputs, which are completely configurable, are used to obtain a set of outputs that allow to characterize the NB-IoT NTN scenario, such as the characterization of the satellite coverage footprint, the antenna pointing or the characterization of the satellite pass. For each characterization, the different parameters and results obtained, such as SNR heatmaps, Doppler frequency or propagation delay, are studied in more detail. The second part of the study is aimed at evaluating the performance of the NB-IoT NTN protocol over a satellite link. For this purpose, different numerical simulations have been performed, to estimate the minimum SNR and achievable spectral efficiency of the protocol for different communication models channels (e.g. AWGN and TDL channels, frequency offsets), different protocol configurations (e.g. number of repetitions, modulation and coding schemes) as well as considering different channel estimators. The analysis has been conducted for both downlink and uplink data channels (e.g. NPDSCH and NPUSCH). Simulations of NPDSCH Block Error Rate (BLER) and NPUSCH Block Error Rate (BLER) from the MATLAB LTE toolbox, modified and adapted to non-terrestrial communications with LEO satellites, are performed
Old ‘counter-revolution’, new ‘terrorism’ : historicizing the framing of violence in Xinjiang by the Chinese state
China has declared a war on terrorism in Xinjiang, identifying violence in the region as a top security threat. However, what nowadays is officially constructed as ‘terrorism’ was framed as ‘counter-revolution’ in the past. Informed by the concept of macrosecuritization and the agenda of critical terrorism studies, this article examines the changing nature of Chinese state framing of violence in Xinjiang. Through a comparative analysis of the discursive construction of the Baren (1990) and Maralbeshi (2013) violent incidents, I find that the terror lexicon has replaced old narratives of counter-revolution to legitimize a sustained crackdown under a novel geopolitical context. The construction of violence in Xinjiang as terrorism, I argue, is contingent, limited and unstable. It marginalizes factors other than an extremist or separatist agency in the incubation of the violence, in particular the frictions created by the crackdown with which the Chinese government is trying to placate the unrest
Confidence-Based Learning in Investment Analysis
The aim of this study is to determine the effectiveness of using multiple choice tests in subjects related to the administration and business management. To this end we used a multiple-choice test with specific questions to verify the extent of knowledge gained and the confidence and trust in the answers. The tests were performed in a group of 200 students at the bachelor's degree in Business Administration and Management. The analysis made have been implemented in one subject of the scope of investment analysis and measured the level of knowledge gained and the degree of trust and security in the responses at two different times of the course. The measurements have been taken into account different levels of difficulty in the questions asked and the time spent by students to complete the test. The results confirm that students are generally able to obtain more knowledge along the way and get increases in the degree of trust and confidence in the answers. It is confirmed as the difficulty level of the questions set a priori by the heads of the subjects are related to levels of security and confidence in the answers. It is estimated that the improvement in the skills learned is viewed favourably by businesses and are especially important for job placement of students
Making sense of terrorism : a narrative approach to the study of violent events
How does violence become understood as terrorism? In this article, we show how a narrative approach to the study of violent events offers a conceptually productive way to understand the process of “seeing” an event as a terrorist act, one that explicitly integrates the phenomenology of violence. While the collective practice of defining terrorism in academia and the policy arena has struggled to produce a universal definition, we identify a set of “common sense” characteristics. We argue that if the framing of violent events prominently features these characteristics as discursive anchors, this primes processes of sensemaking toward interpreting violence as terrorism. While terrorism markers are often articulated as being pragmatic and apolitical indicators of terrorist acts, we show that they are indeed at the core of political contests over historical and physical facts about violent events. The narrative approach we develop in this article underscores that intuitive leanings toward interpreting violence as terrorism are a sign of political agency precisely because they are produced through the stories political agents tell
STED imaging performance estimation by means of Fourier transform analysis
Due to relatively high powers used in STED, biological samples may be affected
by the illumination in the process of image acquisition. Similarly, the performance of the
system may be limited by the sample itself. Optimization of the STED parameters taking into
account the sample itself is therefore a complex task as there is no clear methodology that can
determine the image improvement in an objective and quantitative manner. In this work, a
method based on Fourier transform formalism is presented to analyze the performance of a
STED system. The spatial frequency distribution of pairs of confocal and STED images are
compared to obtain an objective parameter, the Azimuth Averaged Spectral Content Spread
(AASCS), that is related to the performance of the system in which the sample is also
considered. The method has been first tested on samples of beads, and then applied to cell
samples labeled with multiple fluorescent dyes. The results show that a single parameter, the
AASCS, can be used to determine the optimal settings for STED image acquisition in an
objective way, only by using the information provided by the images from the sample
themselves. The AASCS also helps minimize the depletion power, for better preservation of
the samples.Peer ReviewedPostprint (published version
Thin shell dynamics in Lovelock gravity
We study matching conditions for a spherically symmetric thin shell in
Lovelock gravity which can be read off from the variation of the corresponding
first-order action. In point of fact, the addition of Myers' boundary terms to
the gravitational action eliminates the dependence on the acceleration in this
functional and such that the canonical momentum appears in the surface term in
the variation of the total action. This procedure leads to junction conditions
given by the discontinuity of the canonical momentum defined for an evolution
normal to the boundary. In particular, we correct existing results in the
literature for the thin shell collapse in generic Lovelock theories, which were
mistakenly drawn from an inaccurate analysis of the total derivative terms in
the system
Impaired, "easy prey" saved by the she-empowering state : official narratives of "Xinjiang women" in China's "People's War on Terror"
This work was supported by the British Academy [Grant Number PF20_100052].Feminist approaches to international security have revealed persistent gendered stereotypes in the construction of women in contexts of political violence and terrorism, including the Global War on Terror. Acknowledging the parallelism with the United States-led enterprise in its endeavor to “save” a female population and re-posing one of the most significant questions in gender-informed security studies, this article asks “Where are the women in China’s ‘People’s War on Terror’ (PWoT)?” It takes the idea of agency as pivotal in answering this question and investigates how the Chinese state has (im)mobilized, through concealment or deployment, the idea of and potential for agency when positioning Uyghur and other Turkic Muslim women in Xinjiang as specific subjects in the context of the PWoT. The article reveals the establishment of a gendered hierarchy of power in the Chinese counterterrorism playbook, one that fixes “Xinjiang women” as securitized and passive victims in need of rescuing by a state that continues to suppress their agency, despite official claims to the contrary.Publisher PDFPeer reviewe
RELATIONSHIP BETWEEN EXTERNAL LOAD AND DIFFERENCES IN COUNTERMOVEMENT JUMP IN AN OFFICIAL MATCH OF PROFESSIONAL FEMALE SOCCER PLAYERS.
The purpose of the present study was to correlate the external load of an official soccer match with the percent change in the countermovement jump variables in professional soccer players and to analyze the differences between moments (pre, immediately post and 24 hours post-match). The main findings were the correlations between the percentage of change in the CMJ variables and the external load very strong between JH1 with ACC4; JH2 with D23, HSR, ACC1 and DCC2; JT1 with ACC4; PP1 with ACC3; RFDB1 with ACC4; RPD1 and RPD2 with D7. On the other hand, differences were found in PF between pre and post, in PP between post and 24h, RFDB between pre and post. Through our results we conclude that the change in the vertical jump with countermovement is correlated with the external load performed during a match in professional players, so that the assessment of the mechanical variables of the jump on force platforms is a practical option to assess fatigue after a soccer match. An individual analysis is also necessary to know the intra-player differences because the group analysis is influenced by the external load
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