Engineering strain to achieve stable 92 Zr targets on carbon backing

Vacuum ◽  
2017 ◽  
Vol 145 ◽  
pp. 14-18 ◽  
Author(s):  
Khushboo ◽  
S.R. Abhilash ◽  
G.R. Umapathy ◽  
H. Duggal ◽  
D. Kabiraj ◽  
...  
Keyword(s):  
Engineering Strain ◽  
Carbon Backing

Ultrathin Platinum Crystal Surface Structures

1985 ◽  
Vol 43 ◽  
pp. 394-395
Author(s):  
R. L. Hines
Keyword(s):  
Crystal Surface ◽  
Surface Structures ◽  
Platinum Surface ◽  
Platinum Surfaces ◽  
Resolution Level ◽  
Experimental Facilities ◽  
Carbon Backing ◽  
Mesh Grid ◽  
Atom Layer

The importance of atom layer terraces or steps on platinum surfaces used for catalysis as discussed by Somorjai justifies an extensive investigation of the structure of platinum surfaces through electron microscopy at the atomic resolution level. Experimental and theoretical difficulties complicate the quantitative determination of platinum surface structures but qualitative observation of surface structures on platinum crystals is now possible with good experimental facilities.Ultrathin platinum crystals with nominal 111 orientation are prepared using the procedure reported by Hines without the application of a carbon backing layer. Platinum films with thicknesses of about ten atom layers are strong enough so that they can be mounted on grids to provide ultrathin platinum crystals for examination of surface structure. Crystals as thin as possible are desired to minimize the theoretical difficulties in analyzing image contrast to determine structure. With the current preparation procedures the crystals frequently cover complete openings on a 400 mesh grid.

Deformation effects on transgranular carbide precipitation in 304 stainless steels

1992 ◽  
Vol 50 (1) ◽  
pp. 260-261
Author(s):  
A.H. Advani ◽  
L.E. Murr ◽  
D.J. Matlock ◽  
W.W. Fisher ◽  
P.M. Tarin ◽  
...  
Keyword(s):  
Stainless Steels ◽  
True Strain ◽  
Carbide Precipitation ◽  
Material Research ◽  
Chromium Depletion ◽  
Engineering Strain ◽  
Twin Fault ◽  
Heat Treated ◽  
Strain Induced Martensite ◽  
The Relationship

Plastic deformation is a key variable producing accelerated intergranular (IG) carbide precipitation and chromium-depletion (sensitization) development in stainless steels. Deformation above 20% also produces transgranular (TG) carbides and depletion in the material. Research on TG carbides in SS is, however, limited and has indicated that the precipitation is site-specific preferring twin-fault intersections in 316 SS versus deformation-induced martensite and martensite lath-boundaries in 304 SS. Evidences indicating the relation between martensite and carbides were, however, sketchy.The objective of this work was to fundamentally understand the relationship between TG carbides and strain-induced martensite in 304 SS. Since strain-induced martensite forms at twin-fault intersections in 304 SS and the crystallography of the transformation is well understood, we believed that it could be key in understanding mechanisms of carbides and sensitization in SS. A 0.051% C, 304 SS deformed to ∽33% engineering strain (40% true strain) and heat treated at 670°C/ 0.1-10h was used for the research. The study was carried out on a Hitachi H-8000 STEM at 200 kV.

scholarly journals Effects of carbon concentration, oxygen, and controlled pH on the engineering strain Lactiplantibacillus casei E1 in the production of bioethanol from sugarcane molasses

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Song Wang ◽  
Ran Tian ◽  
Buwei Liu ◽  
Hongcai Wang ◽  
Jun Liu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
High Performance ◽  
Ethanol Yield ◽  
Starter Culture ◽  
Market Price ◽  
Sugarcane Molasses ◽  
Engineering Strain ◽  
Carbohydrate Utilization ◽  
Cane Molasses

AbstractSugarcane molasses are considered a potential source for bioethanol’s commercial production because of its availability and low market price. It contains high concentrations of fermentable sugars that can be directly metabolized by microbial fermentation. Heterofermentative lactic acid bacteria, especially Lactiplantibacillus casei, have a high potential to be a biocatalyst in ethanol production that they are characterized by strong abilities of carbohydrate metabolism, ethanol synthesis, and high alcohol tolerance. This study aimed to evaluate the feasibility of producing ethanol by Lactiplantibacillus casei used the ethanologen engineering strain L. casei E1 as a starter culture and cane molasses as substrate medium. The effects of environmental factors on the metabolism of L. casei E1 were analyzed by high-performance liquid chromatography (HPLC) system, and the gene expression of key enzymes in carbon source metabolism was detected using quantitative real-time PCR (RT–qPCR). Results showed that the strain could grow well, ferment sugar quickly in cane molasses. By fermenting this bacterium anaerobically at 37 °C for 36 h incubation in 5 °BX molasses when the fermenter’s pH was controlled at 6.0, ethanol yield reached 13.77 g/L, and carbohydrate utilization percentage was 78.60%. RT-qPCR results verified the strain preferentially ferment glucose and fructose of molasses to ethanol at the molecular level. In addition, the metabolism of sugars, especially fructose, would be inhibited by elevating acidity. Our findings support the theoretical basis for exploring Lactic acid bacteria as a starter culture for converting sugarcane molasses into ethanol.

A Study on the Uniaxial Tension of FCC Metals at Nano Level Using MD

2008 ◽  
Vol 32 ◽  
pp. 255-258
Author(s):  
Bohayra Mortazavi ◽  
Akbar Afaghi Khatibi
Keyword(s):  
Molecular Dynamics ◽  
Uniaxial Tension ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Face Centered Cubic ◽  
Engineering Strain ◽  
Fcc Metals ◽  
Engineering Stress ◽  
Nano Science ◽  
Face Centered

Molecular Dynamics (MD) are now having orthodox means for simulation of matter in nano-scale. It can be regarded as an accurate alternative for experimental work in nano-science. In this paper, Molecular Dynamics simulation of uniaxial tension of some face centered cubic (FCC) metals (namely Au, Ag, Cu and Ni) at nano-level have been carried out. Sutton-Chen potential functions and velocity Verlet formulation of Noise-Hoover dynamic as well as periodic boundary conditions were applied. MD simulations at different loading rates and temperatures were conducted, and it was concluded that by increasing the temperature, maximum engineering stress decreases while engineering strain at failure is increasing. On the other hand, by increasing the loading rate both maximum engineering stress and strain at failure are increasing.

Mechanical Properties of Single-Walled Carbon Nanotubes under Large Axial Deformation

2010 ◽  
Vol 97-101 ◽  
pp. 3910-3915
Author(s):  
Kun Cai
Keyword(s):  
Carbon Nanotubes ◽  
Axial Strain ◽  
Single Walled Carbon Nanotubes ◽  
Mapping Method ◽  
Axial Deformation ◽  
Engineering Strain ◽  
Single Walled Carbon ◽  
Graphitic Sheet ◽  
Zigzag Pattern ◽  
Walled Carbon Nanotubes

The deformation of single-walled carbon nanotubes (SWCNTs) under large axial strain is studied by a geometrical mapping method. The interactions between atoms in carbon nanotubes (CNTs) are described by Tersoff-Brenner potential. Results show the strain energy depends on chirality but hardly on tubes’ radii. For graphitic sheet under large axial deformation, the elastic moduli decrease with the increase of engineering strain under tension. The modulus reaches the peak value as the axial engineering strain reaches -0.08 for armchair pattern and -0.15 for zigzag pattern under compression.

Reverse‐Engineering Strain in Nanocrystallites by Tracking Trimerons

2021 ◽  
pp. 2007413
Author(s):  
Rachel Nickel ◽  
C.‐C. Chi ◽  
Ashok Ranjan ◽  
Chuenhou Ouyang ◽  
John W. Freeland ◽  
...  
Keyword(s):  
Reverse Engineering ◽  
Engineering Strain

Numerical Analysis of Plane-Strain Tension Test for Rate-Dependent Solids

1992 ◽  
Vol 59 (3) ◽  
pp. 485-490 ◽  
Author(s):  
P. Tugˇcu
Keyword(s):  
Numerical Analysis ◽  
Strain Rate ◽  
Plane Strain ◽  
Rate Sensitivity ◽  
Tension Test ◽  
Engineering Strain ◽  
Plane Strain Tension ◽  
Rate Dependent ◽  
Strain And Strain Rate ◽  
Strain Rate Hardening

The plane-strain tension test is analyzed numerically for a material with strain and strain-rate hardening characteristics. The effect of the prescribed rate of straining is investigated for an additive logarithmic description of the material strain-rate sensitivity. The dependency to the imposed strain rate so introduced is shown to have a significant effect on several features of the load-elongation curve such as the attainment of the load maximum, the onset of localization, and the overall engineering strain.

Microstructural Effect and Material Homogenization of Thermal-Hydroforming Magnesium Alloy Tubes

2011 ◽  
Vol 465 ◽  
pp. 459-462 ◽  
Author(s):  
Lin Wang ◽  
Luen Chow Chan ◽  
Ting Fai Kong
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloy ◽  
Tensile Tests ◽  
Heat Treatment Condition ◽  
Material Strength ◽  
Forming Process ◽  
Engineering Strain ◽  
Treatment Conditions ◽  
Metal Forming Process ◽  
Microstructural Effect

The microstrctural evolution pre and post heat treatment is critical to achieve a successful product for metal forming process. This paper aims to investigate the microstructual effect of the magnesium alloy tubes undergone various heat treatment conditions to achieve material homogenization. The heat treatment conditions under various periods of time (1, 2, 6, 12 and 30 hours) at 400 °C were employed to investigate the microstructural effect on hydroforming magnesium tubes. The greatly reduced impurity embedded in grain boundaries and more uniform grain sizes do indicate the improvement of material strength and ductility. To validate the conclusion, corresponding tensile tests at the different temperatures (20 °C and 200 °C) were carried out. The increased engineering strain in two directions (hoop and longitudinal) implies that the microstructural evolution is unquestionably useful to enhance the ductility of the magnesium tubes. Subsequently, the tubes after optimal heat treatment condition at 400 °C for 6 hours were used to further carry out the thermal hydroforming process for validation. The defect-free hydroformed tubes were produced under the same working condition, which is unable to be achieved for tubes without the heat-treatment process.

Static Recovery Activation Energy of Pure Aluminum at Room Temperature

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Yeh An-Chou ◽  
Chuang Ho-Chieh ◽  
Kuo Chen-Ming
Keyword(s):  
Activation Energy ◽  
Room Temperature ◽  
Pure Aluminum ◽  
Pure Copper ◽  
Tensile Tests ◽  
Engineering Strain ◽  
Static Recovery ◽  
Thermally Activated ◽  
Recovered Strain ◽  
Dislocation Annihilation

Thermally activated energy, which varies linearly with static recovered strain, is calculated from static recovery experiments of pure aluminum initially plastically deformed by strain-rate-controlled tensile tests up to 10% engineering strain at room temperature. The activation energy at the initial static recovery is 20 kJ mol−1, which is much less than that of pure copper and attributed to the dislocation annihilation by glide or cross-slip as well as higher stacking fault energy. Once dislocation annihilation processes are exhausted, more energy is required for subgrains to form and then grow. Eventually the recovered strain is slowed down and gradually saturated.

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