The development of a wind tunnel DAQ system by using Labview tools

This paper presents the experimental three-year learning activity developed by a group of teachers in a wind tunnel facility. The authors, leading a team of students, carried out a project consisting of the design, assembly and testing of a wind tunnel. The project included all stages of the process from its initial specifications to its final quality flow assessments, going through the calculation of each element, and the building of the whole wind tunnel. The group of (final year) students was responsible for the whole wind tunnel project as a part of their bachelor degree project. The paper focuses on the development of wind tunnel data acquisition software. This automatic tool is essential to improve the automation of the data acquisition of the wind tunnel facility systems, in particular for a 6DOF multi-axis force/torque sensor. This work can be considered as a typical example of real engineering practice: a set of specifications that has to be modified due to the constraints imposed throughout the project, in order to obtain the final resul

A wind tunnel two-dimensional parametric investigation of biplane configurations

This paper presents an experimental and systematic investigation about how geometric parameters on a biplane configuration have an influence on aerodynamic parameters. This experimental investigation has been developed in a two-dimensional approach. Theoretical studies about biplanes configurations have been developed in the past, but there is not enough information about experimental wind tunnel data at low Reynolds number. This two-dimensional study is a first step to further tridimensional investigations about the box wing configuration. The main objective of the study is to find the relationships between the geometrical parameters which present the best aerodynamic behavior: the highest lift, the lowest drag and the lowest slope of the pitching moment. A tridimensional wing-box model will be designed following the pattern of the two dimensional study conclusions. It will respond to the geometrical relationships that have been considered to show the better aerodynamic behavior. This box-wing model will be studied in the aim of comparing the advantages and disadvantages between this biplane configuration and the plane configuration, looking for implementing the box-wing in the UAV?s field. Although the box wing configuration has been used in a small number of existing UAV, prestigious researchers have found it as a field of high aerodynamic and structural potential

Experimental investigation on box-wing configuration for UAS

The range for airframe configurations available for UAS is as diverse as those used for manned aircraft and more since the commercial risk in trying unorthodox solutions is less for the UAS manufacturer. This is principally because the UAS airframes are usually much smaller than the manned aircraft and operators are less likely to have a bias against unconventional configurations. One of these unconventional configurations is the box-wing, which is an unconventional solution for the design of the new UAS generation. The existence of two wings separated in different planes that are, however, significantly close together, means that the aerodynamic analysis by theoretical or computational methods is a difficult task, due to the considerable interference existing. Considering the fact that the flight of most UAS takes place at low Reynolds numbers, it is necessary to study the aerodynamics of the box wing configuration by testing different models in a wind tunnel to be able to obtain reasonable results. In the present work, the study is enhanced by varying not only the sweepback angles of the two wings, but also their position along the models’ fuselage. Certain models have shown being more efficient than others, pointing out that certain relative positions of wing exists that can improve the aerodynamics efficiency of the box wing configuration

A Spectral Analysis of laser Doppler anemometry Turbulent Flow Measurements in a Ship Air Wake

Helicopters are one of the most important tactical elements in maritime operations. The necessity to improve the conditions in which the landing and take-off operations are carried out leads to the study of the flow that separates from the ship’s superstructure over the flight deck. To investigate this flow a series of wind tunnel experiments have been performed by testing a sub-scale model of a frigate. Measurements of the flow velocity have been taken by means of laser Doppler anemometry in five points that simulate the last path of the landing trajectory. The data obtained in these experiments is analyzed in the frequency domain where the corresponding spectra are calculated. Onboard measurements from an actual full-scale frigate are analyzed and compared with the wind tunnel results. Conclusions obtained consist of a series of illustrative values of turbulent energy frequency ranges, which are valuable for any study in this field. The comparison shows a similarity between both experiments, reasserting the role of the wind tunnel measurements in these kind of studies

Developing models for future real-time platforms: Virtual simulation and design of new components and systems for aircraft and remotely piloted aircraft systems

In the development of electrified and other vehicle systems, the modelling and simulation of the vehicle is very important. With these tools the preliminary design, as well as later detailed studies of the systems developed, allow engineers to spend less time on each phase of their projects or address them with an integrated approach. In addition, this integrated approach provides the possibility of building hardware-in-the loop models with all the components required. This vehicle modelling and simulation has gained more interest with the increasing use of a wide variety of RPAS, ranging from light weight micro aircraft to large vehicles of various tons. For this reason, the previously-described building tools are the final objective of the developing models to be used in real-time platform projects. The first step presented in this paper is to build a simulator that reproduces the behaviour of a selected aircraft and validate it. This paper presents the study of the performances and behaviour of an OPV used to validate the simulator developed later. At the end, some preliminary tests and estimations of the performances for the selected OPV with an electric motor are presented

Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

Flow study over bluff bodies based on visualization technique

Flow visualization is a very important part of the study of fluid dynamics processes analyzed in many fields of physics and engineering. The present study explores flow visualization experiment technique applied to blunt shaped bluff bodies placed inside towing tank. Vortex shedding in circular cylinders has been studied in depth, being able to visualize the classical von Kármán vortex street. Moreover, the vortex shedding in cylinders of square section has been studied so that the differences between bodies with different section can be compared. A comparison between theoretical and experimental values of vortex shedding frequencies has been obtained; a high correlation with them shows the appropriate experimental procedure. Finally, this paper tries to advocate the use of the towing tank technique as a method to support the theoretical lectures related with some fluid mechanics concepts quite difficult to understand

Risk Assessment of the Lead intake by consumption of red deer and wild boar meat in Southern Spain

International audienceThe presence of heavy metals in big game meat may pose a risk to human health. The main objective of this work was to carry out a risk assessment study (using a probabilistic and point-estimate approach) of lead intake by consumption of red deer and wild boar meat in Southern Spain based on Spanish data collected in the period 2002-2006. In general, the concentration levels found for wild boar meat (mean= 1291 µg/Kg) were much higher than those observed in red deer meat (mean=326 µg/Kg). The results from a point-estimate risk assessment showed that the estimated average intake of lead among different exposure scenarios varied from 0.1 to 6.5 and from 0.3 to 38 µg/Kg/week for red deer and wild boar meat, respectively; and from 0.3 to 35 µg/Kg/week for individuals consuming both red deer and wild boar meat, and that estimated intake of lead by consumption of big game meat differed significantly between hunters and non-hunters, it being higher for hunters. Besides this, results from the probabilistic risk assessment study corroborated that risk is greater in hunter populations, reaching a maximum in individuals consuming only wild boar and both types of meat, with 0.4 and 0.2 % population above the PTWI (Provisional Tolerable Weekly Intake), respectively. Likewise, the hunter populations consuming wild boar and both types of big game meat (red deer and wild boar meat) were exposed to the maximum Pb level (56 μg/Kg/week) which corresponded to 224 % PTWI, approximately. Further data and studies will be needed to give a complete risk estimation in which it will be crucial to consider the contribution to the Pb intake level of other foods in the diet of both population groups

The STARMEN trial indicates that alternating treatment with corticosteroids and cyclophosphamide is superior to sequential treatment with tacrolimus and rituximab in primary membranous nephropathy

A cyclical corticosteroid-cyclophosphamide regimen is recommended for patients with primary membranous nephropathy at high risk of progression. We hypothesized that sequential therapy with tacrolimus and rituximab is superior to cyclical alternating treatment with corticosteroids and cyclophosphamide in inducing persistent remission in these patients. This was tested in a randomized, open-label controlled trial of 86 patients with primary membranous nephropathy and persistent nephrotic syndrome after six-months observation and assigned 43 each to receive six-month cyclical treatment with corticosteroid and cyclophosphamide or sequential treatment with tacrolimus (full-dose for six months and tapering for another three months) and rituximab (one gram at month six). The primary outcome was complete or partial remission of nephrotic syndrome at 24 months. This composite outcome occurred in 36 patients (83.7%) in the corticosteroid-cyclophosphamide group and in 25 patients (58.1%) in the tacrolimus-rituximab group (relative risk 1.44; 95% confidence interval 1.08 to 1.92). Complete remission at 24 months occurred in 26 patients (60%) in the corticosteroid-cyclophosphamide group and in 11 patients (26%) in the tacrolimus-rituximab group (2.36; 1.34 to 4.16). Anti-PLA2R titers showed a significant decrease in both groups but the proportion of anti-PLA2R-positive patients who achieved immunological response (depletion of anti-PLA2R antibodies) was significantly higher at three and six months in the corticosteroid-cyclophosphamide group (77% and 92%, respectively), as compared to the tacrolimus-rituximab group (45% and 70%, respectively). Relapses occurred in one patient in the corticosteroid-cyclophosphamide group, and three patients in the tacrolimus-rituximab group. Serious adverse events were similar in both groups. Thus, treatment with corticosteroid-cyclophosphamide induced remission in a significantly greater number of patients with primary membranous nephropathy than tacrolimus-rituximab

IgA Nephropathy in Elderly Patients.

Some studies suggest that the incidence of IgA nephropathy is increasing in older adults, but there is a lack of information about the epidemiology and behavior of the disease in that age group. In this retrospective multicentric study, we analyzed the incidence, forms of presentation, clinical and histologic characteristics, treatments received, and outcomes in a cohort of 151 patients ≥65 years old with biopsy-proven IgA nephropathy diagnosed between 1990 and 2015. The main outcome was a composite end point of kidney replacement therapy or death before kidney replacement therapy. We found a significant increase in the diagnosis of IgA nephropathy over time from six patients in 1990-1995 to 62 in 2011-2015 (P value for trend =0.03). After asymptomatic urinary abnormalities (84 patients; 55%), AKI was the most common form of presentation (61 patients; 40%). Within the latter, 53 (86%) patients presented with hematuria-related AKI (gross hematuria and tubular necrosis associated with erythrocyte casts as the most important lesions in kidney biopsy), and eight patients presented with crescentic IgA nephropathy. Six (4%) patients presented with nephrotic syndrome. Among hematuria-related AKI, 18 (34%) patients were receiving oral anticoagulants, and this proportion rose to 42% among the 34 patients older than 72 years old who presented with hematuria-related AKI. For the whole cohort, survival rates without the composite end point were 74%, 48%, and 26% at 1, 2, and 5 years, respectively. Age, serum creatinine at presentation, and the degree of interstitial fibrosis in kidney biopsy were risk factors significantly associated with the outcome, whereas treatment with renin-angiotensin-aldosterone blockers was associated with a lower risk. Immunosuppressive treatments were not significantly associated with the outcome. The diagnosis of IgA nephropathy among older adults in Spain has progressively increased in recent years, and anticoagulant therapy may be partially responsible for this trend. Prognosis was poor. This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2019_07_16_CJASNPodcast_19_08_.mp3