22 research outputs found
Experimental Investigation on a 3D Wing Section Hosting Multiple SJAs for Stall Control Purpose
Flow control over aerodynamic shapes in order to achieve performance enhancements has been a lively research area for last two decades. Synthetic Jet Actuators (SJAs) are devices able to interact actively with the flow around their hosting structure by providing ejection and suction of fluid from the enclosed cavity containing a piezo-electric oscillating membrane through dedicated orifices. The research presented in this paper concerns the implementation of zero-net-mass-flux SJAs airflow control system on a NACA0015, low aspect ratio wing section prototype. Two arrays with each 10 custom-made SJAs, installed at 10% and 65% of the chord length, make up the actuation system. The sensing system consists of eleven acoustic pressure transducers distributed in the wing upper surface and on the flap, an accelerometer placed in proximity of the wing c.g. and a six-axis force balance for integral load measurement. A dSPACE™ hardware connected to the software environment Matlab/Simulink® and dSPACE Control-Desk® complete the test architecture. Wind tunnel experiments, on the uncontrolled wing (actuators off), are primarily performed for system identification purpose. The open-loop control operation (actuators on but no feedback) of the wing is implemented and tested, obtaining a stall delay of about 2.8 degrees of AOA. Furthermore, a closed-loop strategy, based on the wing upper surface mean pressure chord-wise distributions signature is adopted to characterize the forthcoming boundary layer detachment. This allows for triggering the controller in stall proximity only, for energy saving purpose. Pertinent results and discussion are provided along with concluding remarks and prospects for future research
Laser irradiated foam targets: absorption and radiative properties
An experimental campaign to characterize the laser radiation absorption of foam targets and the subsequent emission of radiation from the produced plasma was carried out in the ABC facility of the ENEA Research Center in Frascati (Rome). Different targets have been used: plastic in solid or foam state and aluminium targets. The activated different diagnostics allowed to evaluate the plasma temperature, the density distribution, the fast particle spectrum and the yield of the X-Ray radiation emitted by the plasma for the different targets. These results confirm the foam homogenization action on laser-plasma interaction, mainly attributable to the volume absorption of the laser radiation propagating in such structured materials. These results were compared with simulation absorption models of the laser propagating into a foam target
Diagnostic Methodologies of Laser-Initiated 11B(p,α)2α Fusion Reactions
The detection of the ionic products of low-rate fusion reactions, and in particular of the 11B(p,α)2α, is one of the recognized main problems in experiments where these reactions are initiated by tailored interaction of intense and high-energy lasers with matter. A thorough description of this important issue, with a critical comparison of the diagnostic opportunities, is indeed so far. In this work, we describe the common diagnostic methodologies used for the detection of the alpha particles generated by the 11B(p,α)2α reaction and, for each, we outline advantages and limitations, with considerations that can also be applied to other low-rate fusion reactions. We show here that, in general, the univocal characterization of the α products coming from this reaction can be achieved by the simultaneous use of several diagnostic tools placed in close proximity
Directional Track Selection Technique in CR39 SSNTD for lowyield reaction experiments
There is a great interest in the study of p-11B aneutronic nuclear fusion reactions, both for energy production and for determination of fusion cross-sections at low energies. In this context we performed experiments at CELIA in which energetic protons, accelerated by the laser ECLIPSE, were directed toward a solid Boron target. Because of the small cross-sections at these energies the number of expected reactions is low. CR39 Solid-State Nuclear Track Detectors (SSNTD) were used to detect the alpha particles produced. Because of the low expected yield, it is difficult to discriminate the tracks due to true fusion products from those due to natural background in the CR39. To this purpose we developed a methodology of particle recognition according to their direction with respect to the detector normal, able to determine the position of their source. We applied this to the specific experiment geometry, so to select from all the tracks those due to particles coming from the region of interaction between accelerated protons and solid boron target. This technique can be of great help on the analysis of SSNTD in experiments with low yield reactions, but can be also generally applied to any experiment where particles reach the track detector with known directions, and for example to improve the detection limit of particle spectrometers using CR39
Tamoxifen is effective against Leishmania and induces a rapid alkalinization of parasitophorous vacuoles harbouring Leishmania (Leishmania) amazonensis amastigotes
Objectives: This study was performed to investigate the activity of tamoxifen, an antioestrogen widely used in the treatment of breast cancer, against Leishmania. Methods: Drug activity was assessed in vitro against axenically grown promastigotes and amastigotes through cell counting or by measuring the cleavage of MTT, and against intracellular amastigotes by treating infected macrophage cultures and evaluating the number of intracellular parasites. Intravacuolar pH changes induced inside parasitophorous vacuoles of Leishmania (Leishmania) amazonensis-infected macrophages were evaluated using the fluorescent probes SNAFL-calcein and Acridine Orange. Results: Tamoxifen killed L. (L.) amazonensis promastigotes and amastigotes with 50% inhibitory concentrations (IC 50 ) of 16.4+ + + + +0.2 and 11.1+ + + + +0.2 mM, respectively. The drug was also effective against Leishmania (Viannia) braziliensis, Leishmania (Leishmania) major, Leishmania (Leishmania) chagasi and Leishmania (Leishmania) donovani with IC 50 values ranging from 9.0 to 20.2 mM. Tamoxifen induced a rapid and long-lasting alkalinization of the vacuolar environment. We also provide evidence that tamoxifen is more effective against promastigotes and amastigotes at pH 7.5 when compared with cultures at pH 4.5. Conclusions: Tamoxifen effectively kills several Leishmania species and its activity against the parasite is increased by a modulation of the host cell intravacuolar pH induced by the drug
Septic arthritis and arthropathy of the rotator cuff: remember this association
ABSTRACT OBJECTIVE: To describe occurrences of septic glenohumeral arthritis among patients with arthropathy of the rotator cuff, and to highlight the importance of correct diagnosis and surgical procedures. METHODOLOGy: Eight surgical drains were installed in seven patients with glenohumeral pyoarthritis. All the patients presented arthropathy of the rotator cuff (four males and three females). Six patients presented pyoarthritis in the dominant shoulder. The age range was from 53 to 93 years (mean: 74 years). The mean duration of the symptoms before the surgical lavage was six weeks. Six patients underwent treatment consisting of a combination of arthroscopic irrigation and debridement, and one patient was treated by means of open arthrotomy. All the patients received systemic antibiotic therapy in accordance with their bacterial sensitivity. RESULTS: All seven patients achieved satisfactory results, taking into consideration especially the improvement of pain and the patients' satisfaction. The functional assessment was performed using the University of California Los Angeles (UCLA) scale. Only one patient needed to go through another arthroscopic procedure. Staphylococcus aureus was isolated from four cultures and Escherichia coli from one culture. There were two situations in which the patients used empirical antibiotic therapy and the cultures showed negative results. Among the associated procedures, tenotomy of the biceps was performed in four cases, resection of the lateral third of the clavicle due to osteomyelitis in one case and arthrotomy of the knee in one case. CONCLUSION: Surgical treatment was effective in the cases of arthritis associated with arthropathy of the rotator cuff. In patients with arthropathy of the rotator cuff and subclinically altered laboratory signs, the possibility of pyoarthritis should always be suspected