This study investigated the self-healing behavior of different copolymers using time-dependent resonant spectroscopy (TDRS). Samples of four copolymers were damaged and their acoustic resonance spectra were measured continuously over several hours. The spectra showed changes indicating the microscopic structure was evolving as the samples healed. Analysis of resonance peak frequencies and quality factors over time revealed preliminary healing timeframes ranging from hours to over 10 hours, with higher molecular weight, higher ion content copolymers healing more slowly. TDRS was found to be an effective method for determining copolymer healing rates and correlating them to material composition.
ABC Digital también pondrá a disposición de sus lectores un sitio especialmente desarrollado y optimizado para visualizarse desde teléfonos móviles. Se trata del portal iABC (www.iabc.com.py). Es la primera web de este tipo en Paraguay. Su lanzamiento oficial está previsto para hoy en la Expo de Mariano Roque Alonso.
[Group Apple Pen] Hello 5 Coffee marketing planning project.Trang Nguyen
Hello 5 Coffee Marketing Plan was made by group Apple Pen - a group of students from International School of Business (ISB) - University of Economics Hochiminh City
ABC Digital también pondrá a disposición de sus lectores un sitio especialmente desarrollado y optimizado para visualizarse desde teléfonos móviles. Se trata del portal iABC (www.iabc.com.py). Es la primera web de este tipo en Paraguay. Su lanzamiento oficial está previsto para hoy en la Expo de Mariano Roque Alonso.
[Group Apple Pen] Hello 5 Coffee marketing planning project.Trang Nguyen
Hello 5 Coffee Marketing Plan was made by group Apple Pen - a group of students from International School of Business (ISB) - University of Economics Hochiminh City
Traditional shortening experiments utilizing isolated myocytes have provided scientists a valuable functional assay. These studies, however, have been limited to techniques that could not replicate the mechanical environment of the heart. New technology now provides investigators the ability to reliably attach myocytes, mechanically stretch them, make direct force measurements and control cell length intelligently. This webinar reviews best-practices and techniques for attaching, stretching, and studying isolated cells.
During this exclusive webinar sponsored by IonOptix, presenters Ben Prosser and Michiel Helmes discuss methodology, best-practices, and show attendees how to attach isolated myocytes to ensure accurate force measurements. In addition, Ben Prosser reviews an application of myocyte stretching and loading. Michiel Helmes discusses the importance of both mechanical loading and measuring force, and how controlling myocyte length to regulate force development enables generation of work loops and a host of mechanical studies.
Key Topics:
Why it is important to mechanically load single myocytes and how to do master the technique
The value of measuring force in single cell applications of cardiac function research
Why it is important to control myocyte length
The value of combining force measurements with other indices of contraction and cellular function
Presenters:
Benjamin L. Prosser, PhD
Department of Physiology
Perelman School of Medicine
University of Pennsylvania
Michiel Helmes, PhD
Department of Physiology
VU University Medical Center Amsterdam & IonOptix
X ray crystallography and X ray DiffractionFaisal Hussain
This is the short description about x ray crystallography.
simplest and easy to understand.
Procedure of X ray Diffraction.
Advantages and Disadvantages of X ray Crystallography
Traditional shortening experiments utilizing isolated myocytes have provided scientists a valuable functional assay. These studies, however, have been limited to techniques that could not replicate the mechanical environment of the heart. New technology now provides investigators the ability to reliably attach myocytes, mechanically stretch them, make direct force measurements and control cell length intelligently. This webinar reviews best-practices and techniques for attaching, stretching, and studying isolated cells.
During this exclusive webinar sponsored by IonOptix, presenters Ben Prosser and Michiel Helmes discuss methodology, best-practices, and show attendees how to attach isolated myocytes to ensure accurate force measurements. In addition, Ben Prosser reviews an application of myocyte stretching and loading. Michiel Helmes discusses the importance of both mechanical loading and measuring force, and how controlling myocyte length to regulate force development enables generation of work loops and a host of mechanical studies.
Key Topics:
Why it is important to mechanically load single myocytes and how to do master the technique
The value of measuring force in single cell applications of cardiac function research
Why it is important to control myocyte length
The value of combining force measurements with other indices of contraction and cellular function
Presenters:
Benjamin L. Prosser, PhD
Department of Physiology
Perelman School of Medicine
University of Pennsylvania
Michiel Helmes, PhD
Department of Physiology
VU University Medical Center Amsterdam & IonOptix
X ray crystallography and X ray DiffractionFaisal Hussain
This is the short description about x ray crystallography.
simplest and easy to understand.
Procedure of X ray Diffraction.
Advantages and Disadvantages of X ray Crystallography
X ray crystallography and X ray DiffractionFaisal Hussain
This is the short description about x ray crystallography.
simplest and easy to understand.
Procedure of X ray Diffraction.
Pros and Cons of X ray Crystallography
Auckland Volcanic Field Olivine Research Poster for AGU Fall 2013_Smidelainesmid
This poster was presented at the American Geophysical Union's Fall 2013 scientific conference. It describes research results from chemical analyses of olivine minerals found in the deposits of the Auckland Volcanic Field, New Zealand. This research is a part of the publicly-funded DEtermining VOlcanic Risk in Auckland project.
Auckland Volcanic Field Olivine Research Poster for AGU Fall 2013_Smid
Self-Healing Materials
1. INVESTIGATION OF SELF-HEALING
COPOLYMERS UTILIZING TIME
DEPENDENT RESONANT
SPECTROSCOPY
Nicholas R. Bowers, Physics Major
Kenneth A. Pestka II,Assistant Professor
Joseph N. Kistner, Physics Major
Rollins College
!
Stephen J. Kalista Jr.
Union College
2. • Idea. Explore self-healing behavior of
copolymers by analyzing changes in
their acoustic properties over time
• Goal. Determine healing timeframe for
different copolymers to identify factors
that may influence the healing process
PURPOSE OF INVESTIGATION
3. • Triggered by sufficient energy transfer
• Three proposed phases of healing
• Instantaneous elastic molten state
• Welding and sealing
• Solid polymer interdiffusion and realignment
• Compositional variation, damage amount and mechanism, and sample age
and deterioration may all influence the healing action of these polymers
[1] S. J. Kalista,T. C.Ward,“Thermal characteristics of the self-healing response in poly (ethylene-co-methacrylic acid) copolymers”,
Journal of the Royal Society Interface. (2006).
Adapted from [1].
SELF-HEALING BEHAVIOR OF
COPOLYMERS
4. SELF-HEALING COPOLYMERS
• Poly (ethylene-co-methacrylic
acid) copolymers (EMAA
copolymers)
• Four different materials
developed by DuPont which
differ in molecular weight,
ionic content, and material age
6. SELF-HEALING COPOLYMERS
Nucrel (Non-ionic) Suryln (Ionic)
Greater
Molecular Weight
Lesser
Molecular Weight
60% of Acid Groups
Neutralized by Na
30% of Acid Groups
Neutralized by Na
7. • Prepared samples
• Damaged samples
• Placed samples in scanning
cell
• Scanned samples continuously
over several hours
SELF-HEALING COPOLYMERS
8. • Resonance spectrum depends on microscopic
structure and sample geometry
• Microscopic structure evolves throughout the
healing process
• Expect changes in the resonance spectrum
during healing process
• Analyze trends in the time evolution of the
spectrum to quantify healing mechanism
ACOUSTIC AND ULTRASONIC
TIME DEPENDENT RESONANT
SPECTROSCOPY (TDRS)
9. • Resonance spectrum depends on microscopic
structure and sample geometry
• Microscopic structure evolves throughout the
healing process
• Expect changes in the resonance spectrum
during healing process
• Analyze trends in the time evolution of the
spectrum to quantify healing mechanism
ACOUSTIC AND ULTRASONIC
TIME DEPENDENT RESONANT
SPECTROSCOPY (TDRS)
10. • Resonance spectrum depends on microscopic
structure and sample geometry
• Microscopic structure evolves throughout the
healing process
• Expect changes in the resonance spectrum
during healing process
• Analyze trends in the time evolution of the
spectrum to quantify healing mechanism
ACOUSTIC AND ULTRASONIC
TIME DEPENDENT RESONANT
SPECTROSCOPY (TDRS)
11. • Resonance spectrum depends on microscopic
structure and sample geometry
• Microscopic structure evolves throughout the
healing process
• Expect changes in the resonance spectrum
during healing process
• Analyze trends in the time evolution of the
spectrum to quantify healing mechanism
ACOUSTIC AND ULTRASONIC
TIME DEPENDENT RESONANT
SPECTROSCOPY (TDRS)
12. EVOLUTION OF RESONANCE PEAKS DURING HEALING
Overlapping
Resonance Peaks
Nucrel 960
8x8mm Sample
Damaged by Nail
18. PRELIMINARY RESULTS
AND SUMMARY
• Preliminary results
• Establish healing timeframe estimates for four EMAA copolymers
• ConfirmTDRS is a useful tool for determining healing timeframe
• Are consistent with the three-phase healing model
• Correlation between material composition and healing timeframe
• Correlations between healing timeframes and sample age, size, and
damage amount are being explored