Transient Localized Material Properties Changes by Ultrafast Laser-Pulse Manipulation of Electron Dynamics in Micro/Nano Manufacturing

2011 ◽  
Vol 1365 ◽  
Author(s):  
Xin Li ◽  
Lan Jiang ◽  
Cong Wang ◽  
Hai-Lung Tsai
Keyword(s):  
Material Properties ◽  
Chemical Characteristic ◽  
Ultrafast Laser ◽  
Photon Absorption ◽  
Electron Dynamics ◽  
Physical Chemical ◽  
Picosecond Time Scale ◽  
Change Mechanisms ◽  
Nanoscale Manufacturing ◽  
Electron Photon

ABSTRACTA femtosecond (fs) pulse duration is shorter than many physical/chemical characteristic times, such as the electron-photon relaxation time, which makes it possible to control electron dynamics. This paper reviews our recent progress which proposes to change electron dynamics (selective excitation/ionization) and electron densities/temperatures in materials to control the following properties and processes: 1) the transient (femtosecond-to-picosecond time scale), localized (nanometer-to-micrometer length scale) material properties, 2) the corresponding photon absorption process, and 3) phase change mechanisms, by manipulating fs pulse-train number/delay for high-precision micro/nanoscale manufacturing.

scholarly journals Modelling of Physical, Chemical, and Material Properties of Solid Oxide Fuel Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Jakub Kupecki
Keyword(s):  
Fuel Cells ◽  
Power Systems ◽  
Solid Oxide Fuel Cells ◽  
Material Properties ◽  
3D Models ◽  
Solid Oxide ◽  
System Level ◽  
Oxide Fuel ◽  
Physical Chemical ◽  
Modelling Techniques

This paper provides a review of modelling techniques applicable for system-level studies to account for physical, chemical, and material properties of solid oxide fuel cells. Functionality of 0D to 3D models is discussed and selected examples are given. Author provides information on typical length scales in evaluation of power systems with solid oxide fuel cells. In each section, proper examples of previous studies done in the field of 0D–3D modelling are recalled and discussed.

Adjustments of dielectrics craters and their surfaces by ultrafast laser pulse train based on localized electron dynamics control

2013 ◽  
Vol 52 (17) ◽  
pp. 4035 ◽  
Author(s):  
Yanping Yuan ◽  
Lan Jiang ◽  
Xin Li ◽  
Cong Wang ◽  
Lei Yuan ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Pulse Train ◽  
Ultrafast Laser ◽  
Electron Dynamics ◽  
Ultrafast Laser Pulse

Ultrafast Dynamics of Sub-Wavelength Periodic Surface Structuring during Femtosecond Laser Processing of Dielectrics

2014 ◽  
Vol 1035 ◽  
pp. 426-431
Author(s):  
Yan Ping Yuan ◽  
Ji Min Chen ◽  
Fu Rong Liu
Keyword(s):  
Femtosecond Laser ◽  
Laser Fluence ◽  
Chemical Characteristic ◽  
Quantum Model ◽  
Electron Dynamics ◽  
Periodic Surface ◽  
Ablation Crater ◽  
Surface Structuring ◽  
Femtosecond Laser Processing ◽  
Sub Wavelength

A femtosecond laser pulse duration is shorter than many physical/chemical characteristic times, which makes it possible to control electron dynamics such as ionizations and electron densities. This study expermetally investigtes the effects of laser fluence on sub-wavelength periodic surface structuring based on ultrafast laser electron dynamics control. A quantum model for the sub-wavelength periodic surface structuring is also proposed, which considers both the wave properties in the photon particle-properties based plasma model for photon-electron interactions and transient localized changes of material properties. It shows that the laser fluence strongly affects the ablation crater shapes. The prediction of ablation crater shape and periodicity is in agreement with experimental data.

Ultrafast laser control of electron dynamics in atoms, molecules and solids

2011 ◽  
Vol 153 ◽  
pp. 9 ◽  
Author(s):  
Matthias Wollenhaupt ◽  
Thomas Baumert
Keyword(s):  
Ultrafast Laser ◽  
Electron Dynamics ◽  
Laser Control

scholarly journals Influence of the composition and synthesis technology on the physical chemical and performance properties of foam materials

2020 ◽  
Vol 329 ◽  
pp. 02038
Author(s):  
Engel Galimov ◽  
Nazirya Galimova ◽  
Elmira Sharafutdinova ◽  
Vladimir Samoylov ◽  
Egor Danilov
Keyword(s):  
Experimental Data ◽  
Comparative Analysis ◽  
Porous Materials ◽  
Significant Influence ◽  
Material Properties ◽  
Metal Foams ◽  
Review Of The Literature ◽  
Physical Chemical ◽  
Carbon Foams ◽  
And Performance

The comparative analysis of a combination of primary properties of foam materials made using the different starting components and technologies was made. According to the review of the literature and analysis of the experimental data, the paper shows a significant influence the starting components and process approaches have on the properties of the materials. The comparison of material properties revealed that the properties of syntactic carbon foams are higher than those of other porous materials, including metal foams, and comply with the specification.

scholarly journals Effects of Hydrochemistry of Urban Runoff in Surface Water Quality in Enugu Urban Area, Enugu State, South-East Nigeria.

2018 ◽  
pp. 7-20
Author(s):  
Obuka E.N. ◽  
Okwu-delunzu V.U. ◽  
Chukwu K.
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Urban Area ◽  
Water Samples ◽  
Surface Water Quality ◽  
Urban Runoff ◽  
Chemical Characteristic ◽  
Anthropogenic Factors ◽  
Human Populations ◽  
Physical Chemical

Bacterial contamination of water and its associated human health problems are of concern to most people because surface water diseases have troubled human populations for centuries. The aim of this research is to determine the effects of hydrochemistry of urban runoff on surface water quality in Enugu urban area. The water samples were collected from six major rivers in the study area (Ekulu, Asata, Aria, Idaw, Ayo and Ogbete river) with 13 stations of runoff measurement in Enugu urban area. Physico-chemical data was collected by dividing the basin into 13 sub-catchments areas and these were confined mainly within the existing layout. The water samples collected from various strategic points from the study area were analyzed through laboratory tests. The first layer consists of Physical, chemical, and microbiological parameter. These were summarized and imported for statistical analysis and data processing. The result shows that rivers in the study area were highly polluted. The average quantity of Faecal Coliform in Enugu urban River was 17066.67cfu, and average Total Coliform pollution 25400 cfu. These changes were as a result of human and animal excreta flushed into surface water via runoff. The study noted that the physical, chemical and microbiological parameter of the basin, as well as geographical dispositions, combined with anthropogenic factors, are strong causative factors of runoff which causes pollution in surface water quality in the study area. Physio-chemical characteristic shows the hydrochemistry properties of runoff and the extent of pollution in surface water in the study area. The work recommends that there should be effective enforcement of legislation and improve in construction of modernize drainage channel which will collect discharge instead of channelling waste to rivers.

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