Navigation Links
Surface dislocation nucleation: Strength is but skin deep at the nanoscale, Penn engineers discover
Date:3/3/2008

PHILADELPHIA - For centuries, engineers have bent and torn metals to test their strength and ductility. Now, materials scientists at the University of Pennsylvania School of Engineering and Applied Science are studying the same metals but at nanoscale sizes in the form of wires a thousand times thinner than a human hair. This work has enable Penn engineers to construct a theoretical model to predict the strength of metals at the nanoscale. Using this model, they have found that, while metals tend to be stronger at nanoscale volumes, their strengths saturate at around 10-50 nanometers diameter, at which point they also become more sensitive to temperature and strain rate. Such prediction of different strength regimes of nano-solids is important for future application and engineering design of nanotechnology.

Such small-volume materials with relatively large surface areas are now routinely employed in microchips and nanoscience and technology, and their mechanical properties can differ vastly from their macroscale counterparts. Typically, smaller is stronger. A gold wire 200 nanometers in diameter can be 50 times stronger per area than centimeter-sized single-crystal gold. Engineers investigated the "smaller is stronger" trend.

Ju Li, an associate professor in the Department of Materials Science and Engineering at Penn, and his collaborators at the Georgia Institute of Technology have combined transition state theory, explicit atomistic energy landscape calculation and computer simulation to establish a theoretical framework to predict the strengths of small-volume materials. Unlike previous models, their prediction can be directly compared with experiments performed at realistic temperature and loading rates. This research appeared as a cover article in Volume 100 of Physical Review Letters.

Their study demonstrated that the free, exterior surface of nanosized materials can be fertile breeding grounds of dislocations at high stre
'/>"/>

Contact: Jordan Reese
jreese@upenn.edu
215-573-6604
University of Pennsylvania
Source:Eurekalert  

Page: 1 2

Related biology technology :

1. CaviWipes(R): Taking Surface Disinfection to a New Level
2. Arthrosurface Raises $4 Million of Preferred Equity Financing
3. Harland Medical Systems to Offer March Plasma Systems Surface Materials
4. Surface Logix Achieves Objectives With SLx-4090 in Phase 2a Clinical Trial
5. Decision Biomarkers Awarded U.S. Patent for Protein Array Surface Chemistry
6. Sureshield Coatings Company Established to Market Industry-Leading Portfolio of Advanced Coatings for Metal Surfaces
7. Hill-Rom Introduces New Wound Therapy Surface With Innovative Safety and Treatment Features
8. Physicists pin down spin of surface atoms
9. New York Strengthens Emergency Preparedness with Cardinal Health Ventilators
10. Strengthening fluids with nanoparticles
11. SpectraScience Strengthens Leadership Team With Four Key Hires
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Surface dislocation nucleation: Strength is but skin deep at the nanoscale, Penn engineers discover
(Date:9/23/2014)... , Sept. 23, 2014 /PRNewswire/ - BIOREM Inc. (TSXV: BRM) ("Biorem" ... million bringing Q3 orders to date to $5 million. The ... America . "We continue to see new ... CEO. "With these orders, our backlog has climbed to over ... BIOREM is a leading clean technology company that designs, manufactures ...
(Date:9/23/2014)... Mass. (PRWEB) September 23, 2014 Cambridge ... by Semantic Web technology, was named in the recent ... Gartner, Inc. , The report details key insights ... , According to Gartner analysts Michael Shanler and ... accelerate innovation activities, expose complex relationships with scientific stakeholders, ...
(Date:9/23/2014)... SC (PRWEB) September 23, 2014 Dr. ... my third book on healthcare offers a three phase ... 21st century healthcare delivery system that would go far ... state’s responsibility regarding the delivery of healthcare.” , “Every ... safety has failed to provide discernable progress throughout that ...
(Date:9/22/2014)... 2014 Pearl's Premium Ultra Low Maintenance ... tolerant grass seed this week with the release of ... coincides with the fact that it is time to ... believe. , As of the date 6/4/13, Pearl's ... by industry experts and the media including: The ...
Breaking Biology Technology:Cambridge Semantics Identified in Gartner’s ‘Hype Cycle for Life Sciences 2014’ Report 2Dr. Ira Williams Offers the Healthcare Solution Necessary for Patient Safety Improvement 2Pearl's Premium Ultra Low Maintenance Lawn Seed Announces A Major Breakthrough In Drought Tolerant Grass Seed 2
... 3 Human Genome Sciences, Inc. (Nasdaq: HGSI ... 26,697,250 newly issued shares of its common stock at a ... 3,482,250 shares sold upon exercise by the underwriters of their ... the Company from the offering are approximately $356.7 million, after ...
... Aug. 3 Known medically as atopic dermatitis (AD), ... Scratching the affected area of skin may result ... and crusting of the skin.(2) Immuno-modulators called topical calcineurin ... with mild, moderate or severe eczema(3) who fail to ...
... Md., Aug. 3 Micromet, Inc. (Nasdaq: ... for the treatment of cancer, inflammation and autoimmune diseases, ... from the European Medicines Agency (EMEA) for BiTE antibody ... is a novel therapeutic antibody that activates a patient,s ...
Cached Biology Technology:Human Genome Sciences Announces Closing of Public Offering 2Human Genome Sciences Announces Closing of Public Offering 3Five Questions About Protopic (tacrolimus) Ointment 2Five Questions About Protopic (tacrolimus) Ointment 3Five Questions About Protopic (tacrolimus) Ointment 4Micromet Receives European Orphan Drug Designation for Treatment of Acute Lymphoblastic Leukemia with BiTE Antibody Blinatumomab 2Micromet Receives European Orphan Drug Designation for Treatment of Acute Lymphoblastic Leukemia with BiTE Antibody Blinatumomab 3Micromet Receives European Orphan Drug Designation for Treatment of Acute Lymphoblastic Leukemia with BiTE Antibody Blinatumomab 4
(Date:9/22/2014)... at the University of Chicago have shown that after ... only a handful of pathogenic microbe species remain behind ... and discovered that some can become deadly when provoked ... illness. , The findings, published in mBio , ... Microbiology, may lead to better monitoring and treatment of ...
(Date:9/22/2014)... STATION The smell of cut grass in recent ... signalling distress, but new research says the aroma also ... is need for protection, the plant signals the environment ... recognized as a feeding queue for parasitic wasps to ... lay eggs in the pest insect," said Dr. Michael ...
(Date:9/22/2014)... in a plant,s biological clock one that modulates ... , Transcription factors, or genetic switches, drive gene expression ... light, rain, soil quality, or even animals grazing on ... one, called FBH1, that reacts to temperature tweaking ... keeping it on a consistent track. , "Temperature helps ...
Breaking Biology News(10 mins):Critically ill ICU patients lose almost all of their gut microbesand the ones left aren't good 2Critically ill ICU patients lose almost all of their gut microbesand the ones left aren't good 3Mown grass smell sends SOS for help in resisting insect attacks, researchers say 2Mown grass smell sends SOS for help in resisting insect attacks, researchers say 3Genetic switch regulates a plant's internal clock based on temperature 2
... While patients hospitalized for a heart attack have long ... analysis by researchers from the Duke Clinical Research Institute ... percent higher risk of dying. , The researchers call ... Meanwhile, they advise cardiologists to begin treatment with sufficient ...
... by fruit fly geneticists for more than a decade ... in mice. , Writing in the May 6 edition ... a streamlined method for creating a "genetic mosaic mouse"--a ... clusters of cells with mutated genes. , The new ...
... statistical method, described in the open-access journal PLoS Biology, ... locations in the genome that influence a particular physical ... by John Storey, Joshua M. Akey, and Leonid Kruglyak, ... them identify all the genomic elements that produce specific ...
Cached Biology News:Morphine for Chest Pain Increases Death Risk 2Morphine for Chest Pain Increases Death Risk 3Mosaic mouse technique offers a powerful new tool to study diseases and genetics 2Mosaic mouse technique offers a powerful new tool to study diseases and genetics 3Improved statistical tools reveal many linked loci 2
... Zyagen tissue microarrays are derived from ... to rigorous quality control procedures to ensure ... are manually assembled in one block, sectioned ... mounted on coated slides. Sections are large ...
... real-time PCR detection system uses a fixed ... nm) and a photomultiplier tube for fluorescence ... built on an DNA Engine thermal cycler ... This item includes the thermal cycler, 96-well ...
... The MyiQ detection system is used ... I, FAM, VIC, TET, or JOE fluorophores ... simultaneous collection of fluorescence data from 96 ... quantitation, and customizable end-point analysis. The system ...
... Microdissection , CapSure HS and CapSure Macro ... extraction of populations of pure cells from ... Capture Microdissection., Ensure the Integrity of ... All CapSure LCM Caps have a patented ...
Biology Products: