scholarly journals Rapidly Reversible Organic Crystalline Switch for Conversion of Heat into Mechanical Energy

2021 ◽  
Author(s):  
Madushani Dharmarwardana ◽  
Srimanta Pakhira ◽  
Raymond P. Welch ◽  
Carlos Caicedo Narvaez ◽  
Michael A. Luzuriaga ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Ambient Temperature ◽  
Temperature Change ◽  
Temperature Regime ◽  
Room Temperature ◽  
Mechanical Energy ◽  
Reversible Systems ◽  
Physical Force ◽  
Original Length

<div> <div> <div> <p>Solid state thermosalience—a sudden exertion of an expansive or contractive physical force following a temperature change in a solid state compound—is rare, few are reversible systems, and most of these are limited to a dozen or so cycles before the crystal degrades or they reverse slowly over the course of many minutes or even hours. In this work, we show a fully reversible actuator that is stable at room temperature for multiple years and is capable of actuation for more than two hundred cycles at near ambient temperature. Specifically, the crystals shrink to 90% of its original length instantaneously upon heating beyond 45 °C and expands back to its original length upon cooling below 35 °C. This temperature regime is important because it occurs around physiologically important temperatures. Furthermore, the phase transition occurs instantaneously, with little obvious hysteresis, allowing us to create real-time actuating thermal fuses that cycle between on and off rapidly. </p> </div> </div> </div>

scholarly journals Rapidly Reversible Organic Crystalline Switch for Conversion of Heat into Mechanical Energy

2020 ◽  
Author(s):  
Madushani Dharmarwardana ◽  
Srimanta Pakhira ◽  
Raymond P. Welch ◽  
Carlos Caicedo Narvaez ◽  
Michael A. Luzuriaga ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Ambient Temperature ◽  
Temperature Change ◽  
Temperature Regime ◽  
Room Temperature ◽  
Mechanical Energy ◽  
Reversible Systems ◽  
Physical Force ◽  
Original Length

<div> <div> <div> <p>Solid state thermosalience—a sudden exertion of an expansive or contractive physical force following a temperature change in a solid state compound—is rare, few are reversible systems, and most of these are limited to a dozen or so cycles before the crystal degrades or they reverse slowly over the course of many minutes or even hours. In this work, we show a fully reversible actuator that is stable at room temperature for multiple years and is capable of actuation for more than two hundred cycles at near ambient temperature. Specifically, the crystals shrink to 90% of its original length instantaneously upon heating beyond 45 °C and expands back to its original length upon cooling below 35 °C. This temperature regime is important because it occurs around physiologically important temperatures. Furthermore, the phase transition occurs instantaneously, with little obvious hysteresis, allowing us to create real-time actuating thermal fuses that cycle between on and off rapidly. </p> </div> </div> </div>

scholarly journals Rapidly Reversible Organic Crystalline Switch for Conversion of Heat into Mechanical Energy

2020 ◽  
Author(s):  
Madushani Dharmarwardana ◽  
Srimanta Pakhira ◽  
Raymond P. Welch ◽  
Carlos Caicedo Narvaez ◽  
Michael A. Luzuriaga ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Ambient Temperature ◽  
Temperature Change ◽  
Temperature Regime ◽  
Room Temperature ◽  
Mechanical Energy ◽  
Reversible Systems ◽  
Physical Force ◽  
Original Length

<div> <div> <div> <p>Solid state thermosalience—a sudden exertion of an expansive or contractive physical force following a temperature change in a solid state compound—is rare, few are reversible systems, and most of these are limited to a dozen or so cycles before the crystal degrades or they reverse slowly over the course of many minutes or even hours. In this work, we show a fully reversible actuator that is stable at room temperature for multiple years and is capable of actuation for more than two hundred cycles at near ambient temperature. Specifically, the crystals shrink to 90% of its original length instantaneously upon heating beyond 45 °C and expands back to its original length upon cooling below 35 °C. This temperature regime is important because it occurs around physiologically important temperatures. Furthermore, the phase transition occurs instantaneously, with little obvious hysteresis, allowing us to create real-time actuating thermal fuses that cycle between on and off rapidly. </p> </div> </div> </div>

Rapidly Reversible Organic Crystalline Switch for Conversion of Heat into Mechanical Energy

2020 ◽  
Author(s):  
Madushani Dharmarwardana ◽  
Srimanta Pakhira ◽  
Raymond P. Welch ◽  
Carlos Caicedo Narvaez ◽  
Michael A. Luzuriaga ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Ambient Temperature ◽  
Temperature Change ◽  
Temperature Regime ◽  
Room Temperature ◽  
Mechanical Energy ◽  
Reversible Systems ◽  
Physical Force ◽  
Original Length

<div> <div> <div> <p>Solid state thermosalience—a sudden exertion of an expansive or contractive physical force following a temperature change in a solid state compound—is rare, few are reversible systems, and most of these are limited to a dozen or so cycles before the crystal degrades or they reverse slowly over the course of many minutes or even hours. In this work, we show a fully reversible actuator that is stable at room temperature for multiple years and is capable of actuation for more than two hundred cycles at near ambient temperature. Specifically, the crystals shrink to 90% of its original length instantaneously upon heating beyond 45 °C and expands back to its original length upon cooling below 35 °C. This temperature regime is important because it occurs around physiologically important temperatures. Furthermore, the phase transition occurs instantaneously, with little obvious hysteresis, allowing us to create real-time actuating thermal fuses that cycle between on and off rapidly. </p> </div> </div> </div>

scholarly journals Rapidly Reversible Organic Crystalline Switch for Conversion of Heat into Mechanical Energy

2020 ◽  
Author(s):  
Jeremiah Gassensmith ◽  
Madushani Dharmarwardana ◽  
Srimanta Pakhira ◽  
Raymond Welch ◽  
Carlos Caicedo-Narvaez ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Ambient Temperature ◽  
Temperature Change ◽  
Temperature Regime ◽  
Room Temperature ◽  
Mechanical Energy ◽  
Reversible Systems ◽  
Physical Force ◽  
Original Length

Abstract Solid state thermosalience—a sudden exertion of an expansive or contractive physical force following a temperature change in a solid state compound—is rare, few are reversible systems, and most of these are limited to a dozen or so cycles before the crystal degrades or they reverse slowly over the course of many minutes or even hours. In this work, we show a fully reversible actuator that is stable at room temperature for multiple years and is capable of actuation for more than two hundred cycles at near ambient temperature. Specifically, the crystals shrink to 90% of its original length instantaneously upon heating beyond 45 °C and expands back to its original length upon cooling below 35 °C. This temperature regime is important because it occurs around physiologically important temperatures. Furthermore, the phase transition occurs instantaneously, with little obvious hysteresis, allowing us to create real-time actuating thermal fuses that cycle between on and off rapidly.

scholarly journals Rapidly Reversible Organic Crystalline Switch for Conversion of Heat into Mechanical Energy

2020 ◽  
Author(s):  
Madushani Dharmarwardana ◽  
Srimanta Pakhira ◽  
Raymond P. Welch ◽  
Carlos Caicedo Narvaez ◽  
Michael A. Luzuriaga ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Ambient Temperature ◽  
Temperature Change ◽  
Temperature Regime ◽  
Room Temperature ◽  
Mechanical Energy ◽  
Reversible Systems ◽  
Physical Force ◽  
Original Length

<div> <div> <div> <p>Solid state thermosalience—a sudden exertion of an expansive or contractive physical force following a temperature change in a solid state compound—is rare, few are reversible systems, and most of these are limited to a dozen or so cycles before the crystal degrades or they reverse slowly over the course of many minutes or even hours. In this work, we show a fully reversible actuator that is stable at room temperature for multiple years and is capable of actuation for more than two hundred cycles at near ambient temperature. Specifically, the crystals shrink to 90% of its original length instantaneously upon heating beyond 45 °C and expands back to its original length upon cooling below 35 °C. This temperature regime is important because it occurs around physiologically important temperatures. Furthermore, the phase transition occurs instantaneously, with little obvious hysteresis, allowing us to create real-time actuating thermal fuses that cycle between on and off rapidly. </p> </div> </div> </div>

scholarly journals Rapidly Reversibly Organic Crystalline Switch for Conversion of Heat into Mechanical Energy

2020 ◽  
Author(s):  
Madushani Dharmarwardana ◽  
Srimanta Pakhira ◽  
Raymond P. Welch ◽  
Carlos Caicedo Narvaez ◽  
Michael A. Luzuriaga ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Ambient Temperature ◽  
Temperature Change ◽  
Temperature Regime ◽  
Room Temperature ◽  
Mechanical Energy ◽  
Reversible Systems ◽  
Physical Force ◽  
Original Length

<div> <div> <div> <p>Solid state thermosalience—a sudden exertion of an expansive or contractive physical force following a temperature change in a solid state compound—is rare, few are reversible systems, and most of these are limited to a dozen or so cycles before the crystal degrades or they reverse slowly over the course of many minutes or even hours. In this work, we show a fully reversible actuator that is stable at room temperature for multiple years and is capable of actuation for more than two hundred cycles at near ambient temperature. Specifically, the crystals shrink to 90% of its original length instantaneously upon heating beyond 45 °C and expands back to its original length upon cooling below 35 °C. This temperature regime is important because it occurs around physiologically important temperatures. Furthermore, the phase transition occurs instantaneously, with little obvious hysteresis, allowing us to create real-time actuating thermal fuses that cycle between on and off rapidly. </p> </div> </div> </div>

An irreversible phase transition in 1-n-butylindeno[2,1-c]pyran-3,9-dione

2012 ◽  
Vol 68 (10) ◽  
pp. o413-o416 ◽  
Author(s):  
Andrei S. Batsanov ◽  
Judith A. K. Howard ◽  
Na Wu ◽  
Zhen Yang ◽  
Todd B. Marder
Keyword(s):  
Phase Transition ◽  
Ambient Temperature ◽  
Single Crystal ◽  
Title Compound ◽  
Room Temperature ◽  
Side Chain ◽  
Compound C ◽  
Planar Conformation ◽  
Triclinic Phase ◽  
Out Of Plane

At ambient temperature, the title compound, C16H14O3, is triclinic, with then-butyl side chain disordered in an out-of-plane orientation. On cooling below 240 K, it converts into a different triclinic phase with an ordered planar conformation and denser packing, which is retained on warming to room temperature. The transition (occasionally) proceeds from single crystal to single crystal.

Photoresponsive character in double-doped La2/3(Ca2/3Sr1/3)1/3MnO3 thin film

2005 ◽  
Vol 83 (7) ◽  
pp. 699-704 ◽  
Author(s):  
Y. Wang ◽  
R Ren ◽  
C Chen ◽  
D Ren ◽  
K Jin ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Transition ◽  
Solid State ◽  
Room Temperature ◽  
Rf Magnetron Sputtering ◽  
Solid State Reaction Method ◽  
Metallic State ◽  
Reaction Method ◽  
Temperature Range ◽  
Cw Laser

A Ca, Sr double-doped La2/3(Ca2/3Sr1/3)1/3MnO3 thin film with a thickness of about 60~nm was deposited on (100) LaAlO3 substrates using the RF magnetron sputtering method from the bulk compound prepared using the solid-state reaction method. The experimental results show that a phase transition from the ferromagnetic metallic state to the paramagnetic insulating state occurs at 341 K (near to Tp, the highest peak temperature). The R–T curve deviation of the thin film with the application of CW laser is dramatic in the low-temperature range and Δ R/R is positive. At 276 K, the Δ R/R reaches the maximum, about 41 %, and the temperature of the photo-induced resistance maximum of this double-doped thin film appears near to room temperature range, which offers a new method for the application of CMR photo-electric devices.PACS Nos.: 78.66.–w, 81.07–b

TEM of Phase Transitions in Tridymite and Cristobalite Based Materials.

2000 ◽  
Vol 6 (S2) ◽  
pp. 358-359
Author(s):  
Gustaaf Van Tendeloo
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
High Temperature ◽  
Solid State ◽  
Wide Temperature Range ◽  
Room Temperature ◽  
Paraelectric Phase ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Extended Defects

We have determined the structure of the paraelectric phase of BaAl2O4, which is a stuffed tridymite, by different TEM techniques and we will describe the phase transition between the ferroelectric room temperature phase and the paraelectric high temperature phase. We have also obtained HREM images of the higly radiation sensitive acristobalite phase of (Si0,9 Ge0,1)O2 and analysed the extended defects in this material.The stuffed tridymite BaAl2O4 is ferroelectric at room temperature and undergoes a paraelectric-ferroelectric (PEFE) phase transition. The transition is reversible, takes place over a wide temperature range (400K-670K) and has a dynamical character. BaAl2O4 is easily obtained by solid state reaction of BaCO3, and A12O4,. The stoichiometric amounts of the initial reagents were mixed, grinded in an agate mortar under acetone and pressed into a pellet. The pellet was annealed in alumina crucibles at 1000 °C and 1300 °C for 40 h in air and furnace cooled.

ON THE FERROMAGNETIC PHASE TRANSITION IN NANO ZnO:Mn BY ELECTRON PARAMAGNETIC RESONANCE

2009 ◽  
Vol 23 (15) ◽  
pp. 3221-3229 ◽  
Author(s):  
P. VINOTHA BOORANA LAKSHMI ◽  
B. RANGANATHAN ◽  
N. RAJKUMAR ◽  
K. RAMACHANDRAN
Keyword(s):  
Phase Transition ◽  
Electron Paramagnetic Resonance ◽  
Solid State ◽  
Room Temperature ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Ferromagnetic Phase Transition ◽  
Electron Paramagnetic

Nanocrystalline samples of Zn 1-x Mn x O (x = 0.0, 0.01, 0.02, 0.1 and 0.2) were synthesized by solid state reaction and characterized by X-ray diffraction and electron paramagnetic resonance (EPR) at room temperature. EPR studies showed an evidence of ferromagnetism above room temperature.

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