Application of Multi-Input Multi-Output Feedback Control for F-16 Ventral Fin Buffet Alleviation Using Piezoelectric Actuators

Control of structural vibrations has been a popular topic. Use of MFC piezoelectric actuators and co-located sensors allows for an active rather than passive control method. The F-16 ventral fin is susceptible to buffet induced vibrations and is a perfect test structure for active vibration control for flight-testing. The research follows the previous ACTIVE FIN project and improves on the design by increasing the number of actuator layers, available actuator power, and using multi-input multi-output (MIMO) control algorithms. The research involved experimental identification of the ventral fin and its principle strain directions, selection of system components, determination of mathematical plant model, and design and test of control algorithms. The research resulted in a control system suitable for flight, a practical controller design process, and comparisons of different control algorithms to include single-input single-output (SISO) positive position feedback (PPF), multivariable PPF, two-input two-output linear quadratic Gaussian (LQG), and two-input fouroutput LQG. Controller effectiveness on target modes, actuator power consumption, and controller robustness were tested in the laboratory. The laboratory results showed that reductions of 7.4 dB, 17.7 dB, 15.7 dB and 3.2 dB in modes one, two, three, and four respectively were achieved using the MIMO LQG controller while maintaining sufficient gain and phase margins

Protein Transduction Method for Cerebrovascular Disorders

Many studies have shown that a motif of 11 consecutive arginines (11R) is one of the most effective protein transduction domains (PTD) for introducing proteins into the cell membrane. By conjugating this &#34;11R&#34;, all sorts of proteins can effectively and harmlessly be transferred into any kind of cell. We therefore examined the transduction efficiency of 11R in cerebral arteries and obtained results showing that 11R fused enhanced green fluorescent protein (11R-EGFP) immediately and effectively penetrated all layers of the rat basilar artery (BA), especially the tunica media. This method provides a revolutionary approach to cerebral arteries and ours is the first study to demonstrate the successful transductionof a PTD fused protein into the cerebral arteries. In this review, we present an outline of our studies and other key studies related to cerebral vasospasm and 11R, problems to be overcome, and predictions regarding future use of the 11R protein transduction method for cerebral vasospasm (CV).</p

One-Step Holographic Photoalignment for Twisted Nematic Liquid Crystal Gratings

Liquid crystal gratings, in which liquid crystal molecules are periodically aligned, are fabricated by highly efficient and practical one-step holographic photoalignment method using a photocrosslinkable polymer liquid crystal (PCLC). This method is an innovative fabrication technique for liquid crystal grating containing a twisted nematic alignment, which does not require a conventional complex fabrication process. In this chapter, three types of liquid crystal gratings with twisted nematic alignment are fabricated. Periodic director distributions of these liquid crystal gratings are analyzed based on the elastic continuum theory and observed experimentally using a polarized light optical microscope. Furthermore, the polarization diffraction properties were measured by illumination with a visible laser beam. The resultant liquid crystal gratings exhibit various polarization diffraction properties depending on the director distributions and the polarization states of the incident beams. These polarization diffraction properties are well explained by theoretical analysis based on Jones calculus. These resultant liquid crystal gratings exhibit great potential for application as a diffractive optical element that can simultaneously control the various parameters of the light wave, such as amplitude, polarization states, and propagation direction

Influence of surgical arch reconstruction methods on single ventricle workload in the Norwood procedure

ObjectiveThe study objective was to evaluate various types of Norwood arch reconstruction methods and to show the factors that affect the cardiac workload of the single ventricle. The Norwood procedure is one of the most challenging congenital heart surgeries. Several aortic arch reconstruction techniques have been reported to avoid recoarctation, ensure coronary perfusion, and improve long-term outcomes. Inside the arch, complicated turbulent flow is generated; however, little is known about the cause of the disadvantageous inefficient flow and the surgical techniques to avoid it.MethodsWe created patient-specific computational hemodynamic models of 9 patients who underwent different types of arch reconstruction methods. Four patients had aortic atresia, and 5 patients had aortic stenosis. Flow profiles were defined by echocardiography data corrected with body surface area. Turbulent pulsatile flow was analyzed with the finite volume method. Flow energy loss was calculated to estimate cardiac workload, and wall shear stress was calculated to estimate vessel wall stiffness increase.ResultsRecoarctation and acute arch angles increased wall shear stress and energy loss. In the patients with aortic atresia, a longitudinal incision toward the descending aorta was effective in creating a smooth arch angle. In the patients with aortic stenosis, arch repair with the Damus-Kaye-Stansel procedure in a single anastomotic site was effective in creating sufficient anastomosis space and a smooth arch angle.ConclusionsCreation of a large anastomotic space and a smooth aortic arch angle reduced wall shear stress and energy loss, and should improve long-term cardiac performance after the Norwood procedure

Proton inelastic scattering to continuum studied with antisymmetrized molecular dynamics

Intermediate energy (p,p$'$x) reaction is studied with antisymmetrized molecular dynamics (AMD) in the cases of $^{58}$Ni target with $E_p = 120$ MeV and $^{12}$C target with $E_p =$ 200 and 90 MeV. Angular distributions for various $E_{p'}$ energies are shown to be reproduced well without any adjustable parameter, which shows the reliability and usefulness of AMD in describing light-ion reactions. Detailed analyses of the calculations are made in the case of $^{58}$Ni target and following results are obtained: Two-step contributions are found to be dominant in some large angle region and to be indispensable for the reproduction of data. Furthermore the reproduction of data in the large angle region \theta \agt 120^\circ for $E_{p'}$ = 100 MeV is shown to be due to three-step contributions. Angular distributions for E_{p'} \agt 40 MeV are found to be insensitive to the choice of different in-medium nucleon-nucleon cross sections $\sigma_{NN}$ and the reason of this insensitivity is discussed in detail. On the other hand, the total reaction cross section and the cross section of evaporated protons are found to be sensitive to $\sigma_{NN}$. In the course of the analyses of the calculations, comparison is made with the distorted wave approach.Comment: 16 pages, 7 Postscript figure

Delta degrees of freedom in antisymmetrized molecular dynamics and (p,p') reactions in the delta region

Delta degrees of freedom are introduced into antisymmetrized molecular dynamics (AMD). This is done by increasing the number of basic states in the AMD wave function, introducing a Skyrme-type delta-nucleon potential, and including $NN\leftrightarrow N\Delta$ reactions in the collision description. As a test of the delta dynamics, the extended AMD is applied to (p,p$'$) recations at $E_{\rm lab}=800$ MeV for a $^{12}$C target. It is found that the ratio and the absolute values for delta peak and quasielastic peak (QEP) in the $^{12}$C(p,p$'$) reaction are reproduced for angles \Theta_{\rm lab} \agt 40^\circ, pointing to a correct treatment of the delta dynamics in the extended AMD. For forward angles the QEP is overestimated. The results of the AMD calculations are compared to one-step Monte Carlo (OSMC) calculations and a detailed analysis of multi-step and delta potential effects is given. As important side results we present a way to apply a Gallilei invariant theory for (N,N$'$) reactions up to $E_{\rm lab} \approx 800$ MeV which ensures approximate Lorentz invariance and we discuss how to fix the width parameter $\nu$ of the single particle momentum distribution for outgoing nucleons in the AMD calculation.Comment: 28 pages, revtex, 12 figures included, figures are also available upon request as postscript files from the authors (e-mail: [email protected]), submitted to Phys. Rev.