Discriminacion a un martir: The ballad of Felix Longoria

This thesis looks at how the Felix Longoria Affair propelled Hector P. Garcia, Lyndon B. Johnson and the American G.I. Forum into the national limelight, while also leaving the Longorias, Three Rivers and Texas in a state of disrepair. The affair in general helped expose injustices that were occurring to Mexicans American in Texas at the time, but left the family, Three Rivers and Texas in a battle over the legacy of how each would be seen in the annals of history

Analysis of human physical vulnerability using static equilibrium techniques of a Hazard flood for the determination of unsafe areas in the city of Catacaos - Piura, Peru

Heavy rains and El Nio phenomenon are recurring natural phenomena at a national level. These can cause floods due to the overflowing of rivers, which, when close to cities, can cause both human and material losses. The district of Catacaos, located in the city of Piura, was the one with the highest number of injuries due to the flood caused by El Nio phenomenon in 2017. This phenomenon causes a large amounts of rainfalls due to the presence of abnormally warm waters along the northern coast of Peru [1]. It is for this reason that the need arose to carry out an analysis of the physical vulnerability due to instability of people through static equilibrium, in said district, in order to present maps of unsafe areas in the face of this phenomenon. In this investigation, flood hazard maps are generated simulating the one presented in 2017, using 2D hydraulic modeling. For the generation of vulnerability curves, the instability analysis is performed by moment and drag force. Finally, maps with unsafe areas are made using ArcGis software. Where the results obtained indicate that 29.37% of the city was flooded. Likewise, the vulnerability maps generated show us that women and men over 18 years of age in the city of Catacaos would be vulnerable to dragging and overturning in the face of floods in 16.54% and 13.21%, respectively, of the total studied area. This information will be useful for the development of future evacuation plans during floods, carried out by national entities. © Published under licence by IOP Publishing Ltd

Verification of a low fidelity fast simulation framework through RANS simulations

© 2019, The Author(s). Verification and validation of simulation models are critical steps in engineering. This paper aims at verifying the suitability of reduced order aerodynamic models used in an aeroservoelastic framework designed to analyze the flight dynamics of flexible aircraft, known as the Cranfield Accelerated Aircraft Loads Model. This framework is designed for rapid assessment of aircraft configurations at the conceptual design stage. Therefore, it utilizes or relies on methods that are of relatively low fidelity for high computational speeds, such as modified strip theory coupled with Leishmann–Beddoes unsteady aerodynamic model. Hence, verification against higher order methods is required. Although low fidelity models are widely used for conceptual design and loads assessments, the open literature still lacks a comparison against higher fidelity models. This work focuses on steady-trimmed flight conditions and investigates the effect of aerodynamic wing deformation under such loads on aerodynamic performance. Key limitations of the reduced order models used, namely fuselage and interference effects, are discussed. The reasons for the overall agreement between the two approaches are also outlined

Correlation between Ct-values and symptoms of COVID-19 patients

Background: Currently available RT-PCR methods for the diagnosis of COVID-19 can give an estimate of the viral load. The cycle threshold value (Ct-value) of the PCR correlates inversely with the viral load; low Ct-values indicate high viral loads and vice versa. Higher viral loads have been seen to correlate with disease severity and infectivity. Therefore, we studied the correlation of the Ct-value of RT-PCR and the most common symptoms of COVID-19 individually. Methods: A prospective and descriptive study was carried out with the subjects that attended our laboratory for a COVID-19 test from September 14, 2020, to January 30, 2021. Subjects filled out a questionnaire with demographic and clinical information prior to taking the naso and oropharyngeal samples. The samples were processed by Vircell SARS-CoV-2 Real-time PCR Kit (Granada, Spain). Statistical analyses were performed using IBM SPSS software. Results: We included 657 positive subjects with complete information, with a median age of 36 (27-47) and a male predominance of 477 (72.6%). Of these, 395 (60.1%) were symptomatic and the median number of symptoms was 2 (0-5). The most predominant symptoms were headache 271 (68.6%), cough 229 (58%), and myalgias 180 (45.6%). The median Ct-value for gene N was 30 (23-36) and for gene E was 31 (23-35). In comparison between symptomatic and asymptomatic subjects, asymptomatic patients had a higher Ct-value (lower viral load) in both genes and a lower age (p Conclusions: The viral load correlates with symptoms within COVID-19, having found that higher viral loads were correlated with symptoms such as headache, cough, and fever, while lower viral loads were correlated with dyspnea, diarrhea, and alterations of smell or taste senses

Effect of equivalent sites on the dynamics of bimetallic nanoparticles

Using a Sutton and Chen interatomic potential, we study the molecular dynamics of Au- Pd nanoparticles with an initial icosahedral structure at different temperatures and concentrations, where each relative concentration of the 561-atom particles was made by placing atoms of the same species at equivalent sites, in order to identify under which conditions the melting transition temperature appears for each particle. In addition, we compute global order parameters in order to correlate the obtained results with the caloric curves of each particle. As a result, we observe that the melting transition temperature depends on the relative atomic positions of gold and palladium. The melting transition temperature of the Au-Pd alloy particles appears at higher temperature than that of the pure-gold particle. From the analysis of the structure of the particles, we found that the melting temperature increases with the proportion of gold atoms, and for those particles with a higher concentration of palladium on the surface, we observe an early migration of gold atoms before the melting transition temperature appears

Morphology development of an airfoil by numerical analysis

Abstract As aerial application is not quite feasible for small croplands with current aircrafts in the market, because their higher operational speed. An adequate solution is to generate morphology in the airfoil of the wing of an aircraft, that would allow to decrease the operational speed of the aircraft by increasing the lift that the wing can generate at lower speed without the issue of reach the stall speed. Different airfoils were evaluated in order to compare their characteristics of high-lift and low Reynolds number with those of the NACA 4415, which is the current airfoil of the chosen agricultural aircraft. Such evaluation was carried out by numerical analysis in two dimensions, using Computational Fluid Dynamics software (CFD) at the same air conditions. It is observed that some airfoils obtain much better lift, compare with the base airfoil, but the geometry became very complex. The GOE 449 airfoil was selected due to the minimum geometric changes to do in order to perform the morphology from the original airfoil obtaining 26% more lift. In order to obtain the minimum geometric changes as possible in the morphology from the NACA 4415 airfoil to seek the GOE 449 lift performance a new airfoil was obtained. The aerodynamics properties of this airfoil, called FUSION, are close to the GOE 449 airfoil, obtaining a 7% less lift. It is expected to substitute the use of any auxiliary mechanism like flaps, slats or airbrakes, using smart materials in order to increase the operational capacities of the aircraft and replace the weight of this by payload

Flexible high aspect ratio wing: Low cost experimental model and computational framework

Aircraft concepts of tomorrow, such as high aspect ratio wing aircraft, are far more integrated between technical disciplines and thus require multidisciplinary design approaches. Design tools able to predict associated dynamics need to be developed if such wing concepts are to be matured for use on future transport aircraft. The Cranfield University Beam Reduction and Dynamic Scaling ( BeaRDS) Programme provides a framework that scales a conceptual full size aircraft to a cantilevered wing model of wind tunnel dimensions, such that there is similitude between the static and dynamic behaviour of the model and the full size aircraft. This process of aeroelastically scaled testing combines the technical disciplines of aerodynamics, flight mechanics and structural dynamics, to provide a means by which future concept aircraft can be de-risked and explored . Data acquisition from wind tunnel testing can then be used to validate fluid-structure interaction frameworks that model the aeroelastic effect on the flight dynamics of the aircraft. This paper provides an overview of the BeaRDS methodology, and focuses on the Phase I of the programme, being the development of a reduced Cranfield A-13 aircraft cantilevered wing, to mitigate risk associated with the manufacturing and instrumentation app roach. It is shown that a low cost acquisition system of commercial Inertial Measurement Units (IMUs) can measure the response of the wing within the desired frequency range. Issues associated with the Phase I testing are discussed, and methods are proposed for the Phase II programme that allow these problems to be resolved for a larger scale flexible wing with active control surfaces

An orbital-free molecular dynamics study of melting in K_20, K_55, K_92, K_142, Rb_55 and Cs_55 clusters

The melting-like transition in potasium clusters K_N, with N=20, 55, 92 and 142, is studied by using an orbital-free density-functional constant-energy molecular dynamics simulation method, and compared to previous theoretical results on the melting-like transition in sodium clusters of the same sizes. Melting in potasium and sodium clusters proceeds in a similar way: a surface melting stage develops upon heating before the homogeneous melting temperature is reached. Premelting effects are nevertheless more important and more easily established in potasium clusters, and the transition regions spread over temperature intervals which are wider than in the case of sodium. For all the sizes considered, the percentage melting temperature reduction when passing from Na to K clusters is substantially larger than in the bulk. Once those two materials have been compared for a number of different cluster sizes, we study the melting-like transition in Rb_55 and Cs_55 clusters and make a comparison with the melting behavior of Na_55 and K_55. As the atomic number increases, the height of the specific heat peaks decreases, their width increases, and the melting temperature decreases as in bulk melting, but in a more pronounced way.Comment: LaTeX file. 6 pages with 17 pictures. Final version with minor change

Geographical patterns in blood lead in relation to industrial emissions and traffic in Swedish children, 1978–2007

<p>Abstract</p> <p>Background</p> <p>Blood lead concentrations (B-Pb) were measured in 3 879 Swedish school children during the period 1978–2007. The objective was to study the effect of the proximity to lead sources based on the children's home and school location.</p> <p>Methods</p> <p>The children's home address and school location were geocoded and their proximity to a lead smelter and major roads was calculated using geographical information system (GIS) software. All the statistical analyses were carried out using means of generalized log-linear modelling, with natural-logarithm-transformed B-Pb, adjusted for sex, school year, lead-exposing hobby, country of birth and, in the periods 1988–1994 and 1995–2007, parents' smoking habits.</p> <p>Results</p> <p>The GIS analysis revealed that although the emission from the smelter and children's B-Pb levels had decreased considerably since 1978, proximity to the lead smelter continued to affect levels of B-Pb, even in recent years (geometric mean: near smelter: 22.90 μg/l; far from smelter 19.75 μg/l; p = 0.001). The analysis also revealed that proximity to major roads noticeably affected the children's B-Pb levels during the period 1978–1987 (geometric mean near major roads: 44.26 μg/l; far from roads: 38.32 μg/l; p = 0.056), due to the considerable amount of lead in petrol. This effect was, however, not visible after 1987 due to prohibition of lead in petrol.</p> <p>Conclusion</p> <p>The results show that proximity to the lead smelter still has an impact on the children's B-Pb levels. This is alarming since it could imply that living or working in the vicinity of a former lead source could pose a threat years after reduction of the emission. The analysis also revealed that urban children exposed to lead from traffic were only affected during the early period, when there were considerable amounts of lead in petrol, and that the prohibition of lead in petrol in later years led to reduced levels of lead in the blood of urban children.</p

Antiferromagnetic metal phase in an electron-doped rare-earth nickelate

Long viewed as passive elements, antiferromagnetic materials have emerged as promising candidates for spintronic devices due to their insensitivity to external fields and potential for high-speed switching. Recent work exploiting spin and orbital effects has identified ways to electrically control and probe the spins in metallic antiferromagnets, especially in noncollinear or noncentrosymmetric spin structures. The rare earth nickelate NdNiO3 is known to be a noncollinear antiferromagnet where the onset of antiferromagnetic ordering is concomitant with a transition to an insulating state. Here, we find that for low electron doping, the magnetic order on the nickel site is preserved while electronically a new metallic phase is induced. We show that this metallic phase has a Fermi surface that is mostly gapped by an electronic reconstruction driven by the bond disproportionation. Furthermore, we demonstrate the ability to write to and read from the spin structure via a large zero-field planar Hall effect. Our results expand the already rich phase diagram of the rare-earth nickelates and may enable spintronics applications in this family of correlated oxides.Comment: 25 pages, 4 figure