Structural validation of a realistic wing structure: the RIBES test article

Several experimental test cases are available in literature to study and validate fluid structure interaction methods. They, however, focus the attention mainly on replicating typical cruising aerodynamic conditions forcing the adoption of fully steel made models able to operate with the high loads generated in high speed facilities. This translates in a complete loss of similitude with typical realistic aeronautical wing structures configurations. To reverse this trend, and to better study the aerolastic mechanism from a structural point of view, an aeroelastic measurement campaign was carried within the EU RIBES project. A half wing model for wind tunnel tests was designed and manufactured replicating a typical metallic wing box structure, producing a database of loads, pressure, stress and deformation measurements. In this paper the design, manufacturing and validation activities performed within the RIBES project are described, with a focus on the structural behavior of the test article. All experimental data and numerical models are made freely available to the scientific community

Acute cardiorespiratory responses to inspiratory pressure threshold loading

This is a non-final version of an article (under the working title "Acute cardiovascular and ventilatory responses to inspiratory pressure threshold loading") published in final form in Medicine & Science in Sports & Exercise, 42(9), 1696-1703, 2010 .Purpose: We tested the acute responses to differing pressure threshold inspiratory loading intensities in well-trained rowers. The purpose of this study was to evaluate 1) how the magnitude of inspiratory pressure threshold loading influences repetition maximum (RM), tidal volume (VT), and external work undertaken by the inspiratory muscle; and 2) whether the inspiratory muscle metaboreflex is activated during acute inspiratory pressure threshold loading. Methods: Eight males participated in seven trials. Baseline measurements of maximal inspiratory pressure (PImax), resting tidal volume (VT), and forced vital capacity (FVC) were made. During the remaining sessions, participants undertook a series of resistive inspiratory breathing tasks at loads corresponding to 50%, 60%, 70%, 80%, and 90% of PImax using a pressure threshold inspiratory muscle trainer. The number of repetitions completed at each load, VT, heart rate (fc), and measures of arterial blood pressure was assessed continuously during each trial. Results: A standardized cutoff of 10% FVC was used to define the RM, which decreased as loading intensity increased (P < 0.05). This response was nonlinear, with an abrupt decrease in RM occurring at loads ≥70% of PImax. The most commonly used inspiratory muscle training regimen of 30RM corresponded to 62.5% ± 4.6% of PImax and also resulted in the highest external work output. Tidal volume (VT) decreased significantly over time at 60%, 70%, and 80% of PImax (P < 0.05), as did the amount of external work completed (P<0.05). Conclusions: Although all loads elicited a sustained increase in fc, only the 60% load elicited a sustained rise in mean arterial blood pressure (P = 0.016), diastolic blood pressure (P = 0.015), and systolic blood pressure (P = 0.002), providing evidence for a metaboreflex response at this load

Evolution of the Spin Gap Upon Doping a 2-Leg Ladder

The evolution of the spin gap of a 2-leg ladder upon doping depends upon the nature of the lowest triplet excitations in a ladder with two holes. Here we study this evolution using various numerical techniques for a t-t'-J ladder as the next-near-neighbor hopping t' is varied. We find that depending on the value of t', the spin gap can evolve continuously or discontinuously and the lowest triplet state can correspond to a magnon, a bound magnon-hole-pair, or two separate quasi-particles. Previous experimental results on the superconducting two-leg ladder Sr12Ca2Cu24O41 are discussed.Comment: 4 pages, latex, submitted to PR

Social media use and impact during the holiday travel planning process

Through an empirical study among holiday travellers, residing in the Former Soviet Union Republics, this paper presents a comprehensive view of role and impact of social media on the whole holiday travel planning process: Before, during and after the trip, providing insights on usage levels, scope of use, level of influence and trust. Findings suggest that social media are predominantly used after holidays for experience sharing. It is also shown that there is a strong correlation between perceived level of influence from social media and changes made in holiday plans prior to final decisions. Moreover, it is revealed that user-generated content is perceived as more trustworthy when compared to official tourism websites, travel agents and mass media advertising

shape optimization using structural adjoint and rbf mesh morphing

Abstract Adjoint solvers are acquiring nowadays a growing importance in shape optimization especially when dealing with fluid dynamic applications; their use for structural optimization is however still limited. In this work an optimization workflow based on the synergic use of a structural continuum-discrete adjoint variable solver and the commercial morpher RBF Morph™ is presented. Shape sensitivity information with respect to the objective function is exported as deformation maps on the interested geometry and transferred to the morpher that, after a proper filtering and setup, allows to update automatically the numerical grid. By employing a gradient based logic it is finally possible to achieve an evolutionary optimization. The proposed method effectiveness is shown with two examples: a cantilever beam and a structural bracket

Understanding the Relationships between Tourists’ Emotional Experiences, Perceived Overall Image, Satisfaction, and Intention to Recommend

The purpose of this study is to empirically test an integrative model linking tourists&#039; emotional experiences, perceived overall image, satisfaction, and intention to recommend. The model was tested using data collected from domestic tourists visiting Sardinia, Italy. Results show that tourists&#039; emotional experiences act as antecedents of perceived overall image and satisfaction evaluations. In addition, overall image has a positive influence on tourist satisfaction and intention to recommend. The study expands current theorizations by examining the merits of emotions in tourist behavior models. From a practical perspective, the study offers important implications for destination marketers

Algunas motivaciones históricas en la Teoría de Grafos

Nuestro propósito es el de referirnos a algunos problemas cuya resolución llevó a introducir o utilizar conceptos que ahora se incluyen en la Teoría de Grafos y dar así una muy somera introducción a la misma. Ella permite abordar el estudio de cuestiones muy diversas, algunas con origen en meros pasatiempos pero otras en importantes y variadas preguntas de la ciencia o la técnica. Precisamente, es ésta toma de las razones del ímpetu y desarrollo que la teoría presenta actualmente. Puede tomársela como ejemplo de la utilidad del proceso de abstracción y síntesis -propio del quehacer matemático- que del análisis de diferentes casos particulares infiere una estructura fundamental que los comprende y unifica

A Decisive Role of [18F] Fdg PET/CT for Diagnosis of Neoplastic Vascular Thrombosis: Report of A Case

The combined use of PET scan with CT and fluorodeoxyglucose ([18F]FDG) can modify, in selected oncologic patients, the clinical management and care. We report here the case of a 63-year old female who showed increase serum level of CEA 3 years following left colectomy for cancer. Ultrasound and CT (computed tomography) of the abdomen showed a single lesion in the segment II of the liver with portal thrombosis. [18F] FDG PET/CT revealed two lesions (the first area was histologically proven to be a colorectal carcinoma metastasis, the second one corresponded to the portal thrombosis). No antithrombotic drugs were administered and patient underwent chemotherapy for 4 courses (eloxatin plus 5-fluorouracil anf leucovorin). Liver resection was performed 2 weeks after the end of chemotherapy, and intraoperative ultrasound revealed a normal portal flow

Retroperitoneal pararenal isolated neurofibroma: report of a case and review of literature

The neurofibroma is a tumour of neural origin. This kind of neoplasm, though, is generally skin located. Rare cases in deep organs or in the peritoneal cavity are also reported in the literature. There are two types of neurofibromas, localized and diffuse; the latter is associated with von Recklinghausen disease and always occurs together with skin neurofibromas. Here we report the case of a 47-year-old man affected by retroperitoneal neurofibroma, but not associated with von Recklinghausen disease. A computed tomography (CT) scan described a retroperitoneal pararenal lesion with no clear involvement of adjacent viscera. We describe the diagnostic modality, treatment planning and the timing of treatment of this neoplasm, reviewing also the literature