Piezoceramic Actuator Placement for Acoustic Control of Panels

Optimum placement of multiple traditional piezoceramic actuators is determined for active structural acoustic control of flat panels. The structural acoustic response is determined using acoustic radiation filters and structural surface vibration characteristics. Linear Quadratic Regulator (LQR) control is utilized to determine the optimum state feedback gain for active structural acoustic control. The optimum actuator location is determined by minimizing the structural acoustic radiated noise using a modified genetic algorithm. Experimental tests are conducted and compared to analytical results. Anisotropic piezoceramic actuators exhibit enhanced performance when compared to traditional isotropic piezoceramic actuators. As a result of the inherent isotropy, these advanced actuators develop strain along the principal material axis. The orientation of anisotropic actuators is investigated on the effect of structural vibration and acoustic control of curved and flat panels. A fully coupled shallow shell finite element formulation is developed to include anisotropic piezoceramic actuators for shell structures

Analysis and Testing of Plates with Piezoelectric Sensors and Actuators

Piezoelectric material inherently possesses coupling between electrostatics and structural dynamics. Utilizing linear piezoelectric theory results in an intrinsically coupled pair of piezoelectric constitutive equations. One equation describes the direct piezoelectric effect where strains produce an electric field and the other describes the converse effect where an applied electrical field produces strain. The purpose of this study is to compare finite element analysis and experiments of a thin plate with bonded piezoelectric material. Since an isotropic plate in combination with a thin piezoelectric layer constitutes a special case of a laminated composite, the classical laminated plate theory is used in the formulation to accommodated generic laminated composite panels with multiple bonded and embedded piezoelectric layers. Additionally, the von Karman large deflection plate theory is incorporated. The formulation results in laminate constitutive equations that are amiable to the inclusion of the piezoelectric constitutive equations yielding in a fully electro-mechanically coupled composite laminate. Using the finite element formulation, the governing differential equations of motion of a composite laminate with embedded piezoelectric layers are derived. The finite element model not only considers structural degrees of freedom (d.o.f.) but an additional electrical d.o.f. for each piezoelectric layer. Comparison between experiment and numerical prediction is performed by first treating the piezoelectric as a sensor and then again treating it as an actuator. To assess the piezoelectric layer as a sensor, various uniformly distributed pressure loads were simulated in the analysis and the corresponding generated voltages were calculated using both linear and nonlinear finite element analyses. Experiments were carried out by applying the same uniformly distributed loads and measuring the resulting generated voltages and corresponding maximum plate deflections. It is found that a highly nonlinear relationship exists between maximum deflection and voltage versus pressure loading. In order to assess comparisons of predicted and measured piezoelectric actuation, sinusoidal excitation voltages are simulated/applied and maximum deflections are calculated/measured. The maximum deflection as a function of time was determined using the linear finite elements analysis. Good correlation between prediction and measurement was achieved in all cases

Experimental and Numerical Analysis of Structural Acousticcontrol Interior Noise Reduction

The research results contained in this technical report were performed under the NASA grant entitled "Experimental and Numerical Structural Acoustic Control for Interior Noise Reduction". The report is based essentially on partial progress of the Ph.D. dissertation prepared by Jeffrey S. Bevan under direct guidance of Dr. Chuh Mei. The document presents a finite element formulation and control of sound radiated from cylindrical panels embedded with piezoceramic actuators. The extended MIN6 shallow shell element is fully electrical-structural coupled. A piezoelectric modal actuator participation (PMAP) is defined which indicates the actuator performance to each of the offending modes. Genetic algorithm is also employed to validate the sensor and actuator locations determined by the PMAP criteria. The work was conducted at the Department of Aerospace Engineering, Old Dominion University. Mr. Travis L. Turner, Structural Acoustics Branch, NASA Langley Research Center is the technical monitor

Silent progression in disease activity-free relapsing multiple sclerosis.

ObjectiveRates of worsening and evolution to secondary progressive multiple sclerosis (MS) may be substantially lower in actively treated patients compared to natural history studies from the pretreatment era. Nonetheless, in our recently reported prospective cohort, more than half of patients with relapsing MS accumulated significant new disability by the 10th year of follow-up. Notably, "no evidence of disease activity" at 2 years did not predict long-term stability. Here, we determined to what extent clinical relapses and radiographic evidence of disease activity contribute to long-term disability accumulation.MethodsDisability progression was defined as an increase in Expanded Disability Status Scale (EDSS) of 1.5, 1.0, or 0.5 (or greater) from baseline EDSS = 0, 1.0-5.0, and 5.5 or higher, respectively, assessed from baseline to year 5 (±1 year) and sustained to year 10 (±1 year). Longitudinal analysis of relative brain volume loss used a linear mixed model with sex, age, disease duration, and HLA-DRB1*15:01 as covariates.ResultsRelapses were associated with a transient increase in disability over 1-year intervals (p = 0.012) but not with confirmed disability progression (p = 0.551). Relative brain volume declined at a greater rate among individuals with disability progression compared to those who remained stable (p < 0.05).InterpretationLong-term worsening is common in relapsing MS patients, is largely independent of relapse activity, and is associated with accelerated brain atrophy. We propose the term silent progression to describe the insidious disability that accrues in many patients who satisfy traditional criteria for relapsing-remitting MS. Ann Neurol 2019;85:653-666

Footprints- In the Footprints of Squier and Davis: Archeological Fieldwork in Ross County, Ohio

TABLE OF CONTENTS Acknowledgements....................................................................iList of Tables...................................................................vii List of Figures...................................................................ix Contributors .........................................................................xiii Chapter 1 In the Footprints of Squier and Davis : Archeological Fieldwork in Ross County, Ohio Mark J. Lynott................................................................................1 Previous Studies in Ohio ...................................................1 Hopewell Studies Today ................................................................4 Recent Field Research ..........................................................................6 Goal of this Volume ................................................................................12 Chapter 2 In Non-mound Space at the Hopewell Mound Group Jennifer Pederson Weinberger .........................................13 Geophysical Survey .......................................................15Western Village Area.....................................................................16 Near the East Village .....................................................................18 Central Area ............................................................................19 Discussion .......................................................................................19 Chapter 3 Field Studies of the Octagon and Great Circle, High Bank Earthworks Ross County, Ohio N’omi B. Greber and Orrin C. Shane III ..............................................23 Excavations at the Octagon ............................................................25 Geophysics at the Great Circle ............................................................30 Excavations at the Great Circle ..........................................................33 Radiocarbon Assays ...........................................................................41 Comments ....................................................................................44 Addendum ..........................................................................................46 Chapter 4 Spruce Hill Earthworks: The 1995-1996 National Park Service Investigations Bret J. Ruby .............................................................................................49 Background .......................................................................................49 The Spruce Hill Earthworks .......................................................................49 Spruce Hill Revisited ......................................................................53 The 1995-1996 National Park Service Investigations ............................53 Discussion and Conclusions ..............................................................61 Chapter 5 Falling Through a Crack in the Core: The Surprise and Demise of Anderson Earthwork William H. Pickard and Jeffrey W. Weinberger ........................................ 67 History and Setting ..................................................................................68 1993 Excavations ..................................................................................70 Discussion ..............................................................................................72 Conclusion ............................................................................................74 Chapter 6 Middle Woodland and Other Settlement Remains in the Overly Tract Near The Hopeton Earthwork, Ross County, Ohio William S. Dancey .....................................................................................................77 Research Design.............................................................................77 Artifact Categories and their Distributions..............................................80 Discussion............................................................................................92 Chapter 7 Hopewell Occupation at the Hopeton Earthworks: Large Scale Surface Survey Using GPS Technology Jarrod Burks and Dawn Walter Gagliano................................................97 The Survey Area ................................................................................98 Survey Methodology .............................................................................99 Survey Results ...................................................................................99 The Surface Data: A Siteless Approach .................................................103 Discussion and Conclusion .........................................................................106 Notes ...................................................................................................107 Chapter 8 Hopewellian Centers in Context: Investigations In and Around the Hopeton Earthworks Bret J. Ruby And Mark J. Lynott .................................................................109 Surface Survey ......................................................................................110 Redwing Site ...........................................................................................111 Comparisons .........................................................................................118 Conclusions ......................................................................................122 Chapter 9 Searching for Hopewell Settlements: The Triangle Site at the Hopeton Earthworks Mark Lynott ...................................................................................... 125 Field Investigations ............................................................................127 Geophysical Survey ............................................................................128 1998 Season ....................................................................................128 Features, Artifacts and Radiocarbon Dating ........................................130 Animal Remains ...............................................................................137 Plant Remains ................................................................................138 Interpretations ..............................................................................139 Chapter 10 Geophysical Investigations at the Hopeton Earthworks John Weymouth, Bruce Bevan, and Rinita Dalan ...............................145 The Cesium Gradiometer Survey ...........................................................146 Cesium Gradiometer Results ...................................................................146 Geoscan Instrument Surveys ..............................................................148 Comparison of Cesium Magnetic and Resistance Data ........................148 Small Circles...........................................................................................149 Trench Excavations ...................................................................................149 Discussion ................................................................................................152 Conclusions ......................................................................................157 Chapter 11 Archeological and Geoarcheological Study of the Rectangular Enclosure at the Hopeton Works Mark J. Lynott and Rolfe D. Mandel ......................................................159 The Study of the Rectangular Earthwork ................................................161 Geophysical Survey ..............................................................................163 Trench Excavations .............................................................................164 Chronology ........................................................................................170 Geoarcheological Analysis of Trench 1 .................................................172 Interpretations ................................................................................174 Chapter 12 Ohio Hopewell Ritual Craft Production Katherine A. Spielmann ............................................................ 179Raw Material Procurement ....................................................................180 Hopewell Crafting ................................................................................181 Deposition ...........................................................................................186 Conclusions ....................................................................................188 References Cited .....................................................................................................18

Cryogenic Optical Performance of a Light-weight Mirror Assembly for Future Space Astronomical Telescopes: Optical Test Results and Thermal Optical Model

A 40 cm diameter mirror assembly was interferometrically tested at room temperature down to 250 degrees Kelvin for thermal deformation. The 2.5 m radius of curvature spherical mirror assembly was constructed by low temperature fusing three abrasive waterjet core sections between two face sheets. The 93% lightweighted Corning ULE mirror assembly represents the current state of the art for future UV, optical, near IR space telescopes. During the multiple thermal test cycles, test results of interferometric test, thermal IR images of the front face were recorded in order to validate thermal optical model

Reply to "Spinal Cord Atrophy Is a Preclinical Marker of Progressive MS"

No abstract availabl

Spinal Cord Atrophy Predicts Progressive Disease in Relapsing Multiple Sclerosis

Objective A major challenge in multiple sclerosis (MS) research is the understanding of silent progression and Progressive MS. Using a novel method to accurately capture upper cervical cord area from legacy brain MRI scans we aimed to study the role of spinal cord and brain atrophy for silent progression and conversion to secondary progressive disease (SPMS). Methods From a single-center observational study, all RRMS (n = 360) and SPMS (n = 47) patients and 80 matched controls were evaluated. RRMS patient subsets who converted to SPMS (n = 54) or silently progressed (n = 159), respectively, during the 12-year observation period were compared to clinically matched RRMS patients remaining RRMS (n = 54) or stable (n = 147), respectively. From brain MRI, we assessed the value of brain and spinal cord measures to predict silent progression and SPMS conversion. Results Patients who developed SPMS showed faster cord atrophy rates (-2.19%/yr) at least 4 years before conversion compared to their RRMS matches (-0.88%/yr, p < 0.001). Spinal cord atrophy rates decelerated after conversion (-1.63%/yr, p = 0.010) towards those of SPMS patients from study entry (-1.04%). Each 1% faster spinal cord atrophy rate was associated with 69% (p < 0.0001) and 53% (p < 0.0001) shorter time to silent progression and SPMS conversion, respectively. Interpretation Silent progression and conversion to secondary progressive disease are predominantly related to cervical cord atrophy. This atrophy is often present from the earliest disease stages and predicts the speed of silent progression and conversion to Progressive MS. Diagnosis of SPMS is rather a late recognition of this neurodegenerative process than a distinct disease phase. ANN NEUROL 202

Evaluation of a primary care-based collaborative care model (PARTNERS2) for people with diagnoses of schizophrenia, bipolar, or other psychoses: study protocol for a cluster randomised controlled trial

YesCurrent NHS policy encourages an integrated approach to provision of mental and physical care for individuals with long term mental health problems. The 'PARTNERS2' complex intervention is designed to support individuals with psychosis in a primary care setting. The trial will evaluate the clinical and cost-effectiveness of the PARTNERS2 intervention. This is a cluster randomised controlled superiority trial comparing collaborative care (PARTNERS2) with usual care, with an internal pilot to assess feasibility. The setting will be primary care within four trial recruitment areas: Birmingham & Solihull, Cornwall, Plymouth, and Somerset. GP practices are randomised 1:1 to either (a) the PARTNERS2 intervention plus modified standard care ('intervention'); or (b) standard care only ('control'). PARTNERS2 is a flexible, general practice-based, person-centred, coaching-based intervention aimed at addressing mental health, physical health, and social care needs. Two hundred eligible individuals from 39 GP practices are taking part. They were recruited through identification from secondary and primary care databases. The primary hypothesis is quality of life (QOL). Secondary outcomes include: mental wellbeing, time use, recovery, and process of physical care. A process evaluation will assess fidelity of intervention delivery, test hypothesised mechanisms of action, and look for unintended consequences. An economic evaluation will estimate its cost-effectiveness. Intervention delivery and follow-up have been modified during the COVID-19 pandemic. The overarching aim is to establish the clinical and cost-effectiveness of the model for adults with a diagnosis of schizophrenia, bipolar, or other types of psychoses.PARTNERS2 is funded by the National Institute for Health Research (NIHR) under its Programme Grant for Applied Research Programme (grant number: RP-PG- 200625). This research was also supported by the NIHR Collaboration for Leadership in Applied Health Research and Care South West Peninsula at the Royal Devon and Exeter NHS Foundation Trust