scholarly journals Static and Dynamic Performance of a Morphing Trailing Edge Concept with High-Damping Elastomeric Skin

Aerospace ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 22 ◽  
Author(s):  
Maurizio Arena ◽  
Christof Nagel ◽  
Rosario Pecora ◽  
Oliver Schorsch ◽  
Antonio Concilio ◽  
...  
Keyword(s):  
Smart Materials ◽  
Dynamic Performance ◽  
Dynamic Tests ◽  
Trailing Edge ◽  
Aerodynamic Loads ◽  
System A ◽  
Adaptive Structure ◽  
Elastic Skin ◽  
Kinematic Mechanisms

Nature has many striking examples of adaptive structures: the emulation of birds’ flight is the true challenge of a morphing wing. The integration of increasingly innovative technologies, such as reliable kinematic mechanisms, embedded servo-actuation and smart materials systems, enables us to realize new structural systems fully compatible with the more and more stringent airworthiness requirements. In this paper, the authors describe the characterization of an adaptive structure, representative of a wing trailing edge, consisting of a finger-like rib mechanism with a highly deformable skin, which comprises both soft and stiff parts. The morphing skin is able to follow the trailing edge movement under repeated cycles, while being stiff enough to preserve its shape under aerodynamic loads and adequately pliable to minimize the actuation power required for morphing. In order to properly characterize the system, a mock-up was manufactured whose structural properties, in particular the ability to carry out loads, were also guaranteed by the elastic skin. A numerical sensitivity analysis with respect to the mechanical properties of the multi-segment skin was performed to investigate their influence on the modal response of the whole system. Experimental dynamic tests were then carried out and the obtained results were critically analysed to prove the adequacy of the adopted design approaches as well as to quantify the dissipative (high-damping) effects induced by the rubber foam on the dynamic response of the morphing architecture.

Neurochemistry of L-Glutamate Transport in the CNS: A Review of Thirty Years of Progress

2001 ◽  
Vol 66 (9) ◽  
pp. 1315-1340 ◽  
Author(s):  
Vladimir J. Balcar ◽  
Akiko Takamoto ◽  
Yukio Yoneda
Keyword(s):  
Molecular Biology ◽  
Glutamate Transport ◽  
Mammalian Brain ◽  
Activity Data ◽  
System A ◽  
Recent Developments ◽  
The Central Nervous System ◽  
Health And Disease ◽  
Disease Analysis

The review highlights the landmark studies leading from the discovery and initial characterization of the Na+-dependent "high affinity" uptake in the mammalian brain to the cloning of individual transporters and the subsequent expansion of the field into the realm of molecular biology. When the data and hypotheses from 1970's are confronted with the recent developments in the field, we can conclude that the suggestions made nearly thirty years ago were essentially correct: the uptake, mediated by an active transport into neurons and glial cells, serves to control the extracellular concentrations of L-glutamate and prevents the neurotoxicity. The modern techniques of molecular biology may have provided additional data on the nature and location of the transporters but the classical neurochemical approach, using structural analogues of glutamate designed as specific inhibitors or substrates for glutamate transport, has been crucial for the investigations of particular roles that glutamate transport might play in health and disease. Analysis of recent structure/activity data presented in this review has yielded a novel insight into the pharmacological characteristics of L-glutamate transport, suggesting existence of additional heterogeneity in the system, beyond that so far discovered by molecular genetics. More compounds that specifically interact with individual glutamate transporters are urgently needed for more detailed investigations of neurochemical characteristics of glutamatergic transport and its integration into the glutamatergic synapses in the central nervous system. A review with 162 references.

scholarly journals A Highly Versatile Polymer Network Based on Liquid Crystalline Dendrimers

2021 ◽  
Vol 22 (11) ◽  
pp. 5740
Author(s):  
Ramón Cervera-Procas ◽  
José-Luis Serrano ◽  
Ana Omenat
Keyword(s):  
Smart Materials ◽  
Liquid Crystalline ◽  
Organic Dyes ◽  
Polymer Network ◽  
Viscoelastic Behavior ◽  
Diverse Range ◽  
Polymeric Systems ◽  
System A ◽  
Porous Microstructure ◽  
Solvent Molecules

Highly functional macromolecules with a well-defined architecture are the key to designing efficient and smart materials, and these polymeric systems can be tailored for specific applications in a diverse range of fields. Herein, the formation of a new liquid crystalline polymeric network based on the crosslinking of dendrimeric entities by the CuI-catalyzed variant of the Huisgen 1,3-dipolar cycloaddition of azides and alkynes to afford 1,2,3-triazoles is reported. The polymeric material obtained in this way is easy to process and exhibits a variety of properties, which include mesomorphism, viscoelastic behavior, and thermal contraction. The porous microstructure of the polymer network determines its capability to absorb solvent molecules and to encapsulate small molecules, like organic dyes, which can be released easily afterwards. Moreover, all these properties may be easily tuned by modifying the chemical structure of the constituent dendrimers, which makes this system a very interesting one for a number of applications.

Sub-Structure Pseudo-Dynamic Response Test of a Pseudo-Elastic Bracing System Made of Shape Memory Alloy

2005 ◽  
Vol 297-300 ◽  
pp. 628-634 ◽  
Author(s):  
Kenichi Ohi ◽  
Jae Hyouk Choi
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Original Position ◽  
Small Displacement ◽  
Structural System ◽  
Dynamic Tests ◽  
System A ◽  
Hysteretic Damper ◽  
Bracing System ◽  
Fail Safe

This paper deals with shape memory alloy. As a first step to assess the applicability of this kind of alloy in a structural system, a tension bar made of this kind of alloy that exhibits pseudo-elasticity at room temperature is used herein as a passive bracing system. This paper describes sub-structure pseudo-dynamic tests on pseudo-elastic bracing system with hysteretic damper. A pseudo-elastic bracing system is better to be used with other hysteretic elements such as a hysteretic damper. A damper provides energy dissipation within small displacement levels, and a pseudo-elastic bracing system works in turn as a back-up/fail-safe system when an accidental failure of damper or damper interface occurs, and also it helps to pull back the structure to the original position by uninstalling the damper after earthquake.

scholarly journals Characterization of Sputtered Shape Memory Alloy Ni-Ti Films by Cross-sectional TEM and SEM

2008 ◽  
Vol 14 (S3) ◽  
pp. 85-86
Author(s):  
R.M.S. Martins ◽  
A. Mücklich ◽  
N. Schell ◽  
R.J.C. Silva ◽  
K.K. Mahesh ◽  
...  
Keyword(s):  
Thin Films ◽  
Shape Memory ◽  
Smart Materials ◽  
Functionally Graded ◽  
Sensors And Actuators ◽  
Successful Development ◽  
Cross Sectional ◽  
Mechanical Devices ◽  
Ti Films

Ni-Ti Shape Memory Alloys (SMAs) have been attracting attention as smart materials because they can work as sensors and actuators at the same time. Miniaturization of mechanical devices is evolving toward sub-micron dimensions raising important questions in the properties of Ni-Ti films. In thin films it is essential to investigate the microstructure to understand the origin of the thickness limit. The design of functionally graded films has also been considered but for their successful development it is important to characterize the variations in crystalline structure.

scholarly journals Experimental characterization of the turbulent boundary layer over a porous trailing edge for noise abatement

2019 ◽  
Vol 443 ◽  
pp. 537-558 ◽  
Author(s):  
Alejandro Rubio Carpio ◽  
Roberto Merino Martínez ◽  
Francesco Avallone ◽  
Daniele Ragni ◽  
Mirjam Snellen ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Experimental Characterization ◽  
Trailing Edge ◽  
Noise Abatement

Kinetic characterization of human thyroperoxidase. Normal and pathological enzyme expression in Baculovirus System: A molecular model of functional expression

2015 ◽  
Vol 404 ◽  
pp. 9-15 ◽  
Author(s):  
Fiorella S. Belforte ◽  
Alexandra M. Targovnik ◽  
Rodolfo M. González-Lebrero ◽  
Carolina Osorio Larroche ◽  
Cintia E. Citterio ◽  
...  
Keyword(s):  
Molecular Model ◽  
Functional Expression ◽  
Kinetic Characterization ◽  
Enzyme Expression ◽  
System A ◽  
Baculovirus System

scholarly journals Influence of Drying in Hyptis pectinata Essential Oil

2018 ◽  
Vol 10 (4) ◽  
pp. 96
Author(s):  
Núbia Angélica de Ávila Branquinho ◽  
Fabiano Guimarães Silva ◽  
Osvaldo Resende ◽  
Luiz Cláudio Almeida Barbosa ◽  
Daniel Emanuel Cabral de Oliveira ◽  
...  
Keyword(s):  
Essential Oil ◽  
Anhydrous Sodium Sulfate ◽  
Fixed Bed ◽  
Chemical Characterization ◽  
Automated System ◽  
Caryophyllene Oxide ◽  
System A ◽  
Different Temperatures ◽  
Drying Conditions

The present study assessed the effects of drying at different temperatures (35, 45 and 55 °C) and air velocities (1 and 2 m s-1) on the content and chemical characteristics of Hyptis pectinata essential oil. Drying was conducted in a fixed-bed dryer, and the temperatures and air velocities were controlled and recorded by an automated system. A 350±0.12 g quantity of fresh leaves was used for each of the four repetitions in each dryer. From the material obtained after drying, 60 g of each repetition was used to extract essential oil by the hydrodistillation method. Dichloromethane was used as the solvent, and anhydrous sodium sulfate was used as the desiccating agent. Gas chromatography in the forms of GC-MS and GC-FID were used for the chemical characterization of the essential oil compounds. Decreasing drying times and decreasing concentrations of essential oils were observed with increasing temperatures. A GC-MS analysis of the essential oil from H. pectinata leaves led to the identification of 19 compounds. A sesquiterpene called caryophyllene oxide was the most abundant compound under all drying conditions, with the highest concentration at a temperature of 55 °C, ranging from approximately 42 to 53%.

scholarly journals Boundary Detection and Enhancement of Islanding Operation Investigation Under Fault Condition

2017 ◽  
Author(s):  
Aref Pouryekta ◽  
Vigna K. Ramachandaramurthy ◽  
Sanjeevikumar Padmanaban ◽  
Lucian MIHET-POPA
Keyword(s):  
Distribution Systems ◽  
Dynamic Performance ◽  
Boundary Detection ◽  
Sensitivity Factor ◽  
Voltage Sensitivity ◽  
Autonomous Operation ◽  
System A ◽  
Autonomous Mode ◽  
Dynamic Voltage ◽  
Islanding Operation

Distribution systems can form islands when faults occur. Each island represents a subsection with variable boundaries subject to the location of a fault(s) in the system. A subsection with variable boundaries is referred to as island in this paper. For operation in autonomous mode, it is imperative to detect the island configurations and stabilize these subsections. This paper presents a novel scheme for the detection of islanding boundaries and stabilizing the system during autonomous operation. In the first stage, a boundary detection method is proposed to detect the configuration of the island. In the second stage a dynamic voltage sensitivity factor (DVSF) is proposed to assess the dynamic performance of the system. In the third stage, a wide area load shedding program is adopted based on DVSF to shed the load in weak busbars and stabilize the system. The proposed scheme is validated and tested on a generic 18-bus system using a combination of EMTDC/PSCAD and MATLAB softwares.

Cyclic voltametry and microwave characterization of smart materials based on polymer electrolyte composites

1997 ◽  
Author(s):  
Alan Barnes ◽  
Anthony Despotakis ◽  
T.C. P. Wong ◽  
Alan P. Anderson ◽  
Barry Chambers ◽  
...  
Keyword(s):  
Polymer Electrolyte ◽  
Smart Materials ◽  
Cyclic Voltametry ◽  
Microwave Characterization
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