Characterization of self-propagating exothermic reaction in bimetallic Zr/Al reactive multilayer nanofoil

2016 ◽  
pp. 320-329
Keyword(s):  
Exothermic Reaction

Characterization of Debris Formed in Magnetic Field-Assisted EDM Using Two-Phase Dielectric Fluid

2020 ◽  
Vol 19 (04) ◽  
pp. 629-640
Author(s):  
Hardik Beravala ◽  
Pulak M. Pandey
Keyword(s):  
Magnetic Field ◽  
Electrical Discharge Machining ◽  
Exothermic Reaction ◽  
Liquid Argon ◽  
Diameter Distribution ◽  
Dielectric Fluid ◽  
Two Phase ◽  
Argon Gas ◽  
Dielectric Fluids

The present research was focussed to investigate the influence of liquid-gaseous dielectric on debris formation in magnetic field-assisted electrical discharge machining. The air and argon gas were used to make two-phase dielectric fluids such as liquid-air and liquid-argon gas, respectively. Experimentation was conducted to compare the effect of different liquid-gaseous dielectric environments on debris formation. The morphology and diameter distribution of debris were analyzed. In addition, the effect on elemental analysis, phase transformation and magnetic property of debris was investigated. The experimental results showed the exothermic reaction due to air from liquid–air dielectric, and inert property of argon gas from liquid-gaseous dielectric affected the formation of debris. The XRD results confirmed the formation of oxides in the debris produced using liquid-air mixed dielectric. The oxide-free debris formed while using the argon gas. Low saturation of magnetization was found in the debris, formed in the liquid–air dielectric which showed the weak attraction toward magnet when compared with that in the liquid–argon gas mixed dielectric.

Fabrication and Performance Characterization of Al/Ti Multilayer Energetic Films

2012 ◽  
Vol 557-559 ◽  
pp. 1782-1786
Author(s):  
Cheng Yang ◽  
Yan Hu ◽  
Rui Qi Shen ◽  
Ying Hua Ye ◽  
Shou Xu Wang ◽  
...  
Keyword(s):  
Exothermic Reaction ◽  
Rf Magnetron Sputtering ◽  
Multilayer Films ◽  
Atomic Ratio ◽  
Bilayer Thickness ◽  
Relative Thickness ◽  
Exothermic Reactions ◽  
And Performance ◽  
Dsc Curves

Al/Ti multilayer films with bilayer thicknesses of 50nm, 100nm and 200nm were prepared by RF magnetron sputtering alternate Al and Ti layers. The relative thickness of Al and Ti layers was maintained at a 1:1 ratio in order to obtain a 1:1 atomic ratio. XRD measurements show that the compound of AlTi is the final product of the exothermic reactions. DSC curves show that the values of heat release in Al/Ti multilayer films with bilayer thicknesses of 50nm, 100nm and 200nm are 457.99 J∙g-1, 493.42 J∙g-1 and 696.81 J∙g-1, respectively. The exothermic reaction in Al/Ti multilayer films lead to more intense electric explosion. Al/Ti multilayer bridge films with modulation period of 50nm explode more rapidly and intensely than other bridge films because decreasing the bilayer thickness results in an increased reaction velocity.

scholarly journals Production and characterization of Al-Cu and Al-Ni nanoparticles

2015 ◽  
Vol 1758 ◽  
Author(s):  
Alexander Vorozhtsov ◽  
Marat Lerner ◽  
Nikolay Radkevich ◽  
Sergey Bondarchuk ◽  
Dongsheng Wen
Keyword(s):  
Electron Microscope ◽  
Binary Systems ◽  
Bimetallic Nanoparticles ◽  
Exothermic Reaction ◽  
Electrochemical Process ◽  
Reaction Products ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Wire Method

ABSTRACTThe present work deals with the production and characterization of metal and bimetallic nanopowders.The electric explosion wire method for production of metal nanopowders is presented. The method enables to produce both metal and bimetallic nanoparticles (BMNP) with controlled content of metals within one particle. An alternative method to obtain bimetallic nanoparticles is also suggested using a spontaneous electrochemical process from salt solutions. BMNP for both Al-Cu and Al-Ni have been prepared and studied.The oxidation, ignition and thermal reactivity of the BMNP of Al-Cu and Al-Ni in a simultaneous thermogravimetric (TG) and differential scanning calorimetry (DSC) experiments have been carried out. The microstructure has been characterized with a scanning electron microscope (SEM) and transmission electron microscope (TEM). The phase compositions of the reaction products have been investigated with X-ray diffraction.By comparing the peak temperature of the first exothermic reaction in DSC and the phase transition temperatures in the respective binary systems, it has been found that for Al-Cu BMNP the melting of an alloy played a pivotal role for the early ignition reaction. The comparison of the reactivity of BMNP with that of aluminum nanoparticles has shown a greater reactivity of BMNP Al-Cu and Al-Ni.

In Situ Polymerization of PEGDA Foam for Bone Defects

2015 ◽  
Author(s):  
A. Forghani ◽  
L. Garber ◽  
C. Chen ◽  
R. Devireddy ◽  
J. Pojman ◽  
...  
Keyword(s):  
Adult Stem Cells ◽  
Fluorescent Dyes ◽  
In Situ Polymerization ◽  
Cell Damage ◽  
Exothermic Reaction ◽  
Glycol Diacrylate ◽  
Polymeric Scaffold ◽  
Poly Ethylene

The purpose of this study is to develop a novel bone replacement using in situ polymerization of thiol-acrylate with adipose tissue derived adult stem cells (ASCs). Specifically, Poly(ethylene glycol) diacrylate-co-trimethylolpropane tris (3-mercaptopropionate) (PEGDA-co-TMPTMP) was synthesized with 10% Hydroxyapatite (HA) foam by an amine-catalyzed Michael addition reaction. Initial characterization studies were performed to determine the temperature profile during the exothermic reaction showing a peak temperature of 50°C. To prevent hyperthermic cell damage and death during the exothermic polymerization procedure, the hASCs were encapsulated in alginate. Characterization of the 3-D structure and interconnectivity of pores in the polymeric foam scaffolds were performed using FIB-SEM and Micro-CT showing uniform distribution of HA. Cell viability experiments within the polymeric scaffold were performed using Vybrant® MTT cell profileration method, as well as fluorescent dyes: Calcein-AM (live) and Ethidium homodimer-1 (dead) showing viability of cells inside the samples.

Characterization of copolymerization of acrylonitrile with the functionalized comonomers in dimethyl sulfoxide solvent and copolymers suitable for carbon fibers

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Wang Yan Xiang ◽  
Liu Yulan ◽  
Wang Limin ◽  
Yang Yizhen ◽  
Wang Chengguo
Keyword(s):  
Carbon Fibers ◽  
Itaconic Acid ◽  
Exothermic Reaction ◽  
Spin Interaction ◽  
Scanning Calorimetry ◽  
Paramagnetic Resonance ◽  
Rate Of Polymerization ◽  
Electron Paramagnetic ◽  
Radical Solution

AbstractFree-radical solution copolymerization of acrylonitrile (AN) with four comonomers including itaconic acid (IA), acrylamide (AM), methyl acrylate (MA) and ammonium salt of itaconic acid (AIA) were carried out respectively. Every copolymerization process has been named as AN/IA system, AN/AM system, AN/MA system and AN/AIA system respectively, and the attained polymer is regarded as AN/IA, AN/AM, AN/MA and AN/AIA copolymer respectively. Effect of different comonomers on the polymerization kinetics and viscosity of the spinning drop are discussed in detail. The exothermic reaction of polyacrylonitrile (PAN) precursors is determined by differential scanning calorimetry (DSC), and effect of the different comonomers on the stabilization exotherm properties of PAN precursors were also studied. It has been shown that the rate of polymerization decreases distinctly with an increase of IA content, the ammonium modification can obviously increase the hydrophilicity of copolymer. The falling ball viscosity of AN/IA system is lower when compared with the other three systems, but when under the low concentration of monomer, AN/MA system has the highest viscosity. Electron paramagnetic resonance (EPR) indicates that the peak width change for the different copolymer be mainly caused by the spin-spin interaction. The copolymer of AN/AM has the lowest starting-exothermal reaction temperature and AM can alleviate the exothermic reaction and moderate the stabilization exotherm

Effect of Mechanical Activation on Ti-50Ni Powder Blends Reactivity

2010 ◽  
Vol 636-637 ◽  
pp. 544-549 ◽  
Author(s):  
Filipe Neves ◽  
Francisco Manuel Braz Fernandes ◽  
Jose Brito Correia
Keyword(s):  
Mechanical Activation ◽  
Energy Input ◽  
Exothermic Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Temperature Reaction ◽  
Short Period ◽  
Powder Blends ◽  
Different Levels

In the present study, equiatomic powder blends of Ni and Ti were mechanically activated for a short period of time in a planetary ball mill using different levels of energy input. The characterization of the mechanically activated materials was achieved by scanning electron microscopy, X-ray diffraction, differential thermal analysis and chemical analysis (oxygen and nitrogen measurements). During mechanical activation no phase transformation was induced and the high temperature reaction between Ni and Ti elemental powders was shifted to lower temperatures. Moreover, the temperature and the intensity of the exothermic reaction, i.e. the reactivity observed in the powder blends, decreased with the increase in the level of milling energy input. A maximum oxygen content of 0.39 wt% was measured after mechanical activation.

scholarly journals Thermodynamic Characterization of the Ca2+-Dependent Interaction Between SOUL and ALG-2

2018 ◽  
Vol 19 (12) ◽  
pp. 3802 ◽  
Author(s):  
Taisuke Mikasa ◽  
Masami Kugo ◽  
Seigo Nishimura ◽  
Sigeru Taketani ◽  
Sumio Ishijima ◽  
...  
Keyword(s):  
Exothermic Reaction ◽  
Titration Calorimetry ◽  
Heat Capacity Change ◽  
Dependent Manner ◽  
Recognition Mechanism ◽  
Linked Gene ◽  
Pulldown Assay ◽  
Capacity Change ◽  
Heme Binding Protein

SOUL, a heme-binding protein-2 (HEBP-2), interacts with apoptosis-linked gene 2 protein (ALG-2) in a Ca2+-dependent manner. To investigate the properties of the interaction of SOUL with ALG-2, we generated several mutants of SOUL and ALG-2 and analyzed the recombinant proteins using pulldown assay and isothermal titration calorimetry. The interaction between SOUL and ALG-2 (delta3-23ALG-2) was an exothermic reaction, with 1:1 stoichiometry and high affinity (Kd = 32.4 nM) in the presence of Ca2+. The heat capacity change (ΔCp) of the reaction showed a large negative value (−390 cal/K·mol), which suggested the burial of a significant nonpolar surface area or disruption of a hydrogen bond network that was induced by the interaction (or both). One-point mutation of SOUL Phe100 or ALG-2 Trp57 resulted in complete loss of heat change, supporting the essential roles of these residues for the interaction. Nevertheless, a truncated mutant of SOUL1-143 that deleted the domain required for the interaction with ALG-2 Trp57 still showed 1:1 binding to ALG-2 with an endothermic reaction. These results provide a better understanding of the target recognition mechanism and conformational change of SOUL in the interaction with ALG-2.

Spectroscopic characterization of lithium combustion

2014 ◽  
Vol 1644 ◽  
Author(s):  
Andreas Brockhinke ◽  
Julia Koppmann ◽  
Regina Brockhinke ◽  
Renate Kellermann ◽  
Helmut Eckert ◽  
...  
Keyword(s):  
Exothermic Reaction ◽  
Lithium Carbonate ◽  
Spectroscopic Characterization ◽  
Gas Analysis ◽  
Lithium Oxide ◽  
Spectroscopic Techniques ◽  
Reaction Products ◽  
Gaseous Reaction ◽  
Energy Storage Material

ABSTRACTIn this work, the exothermic reaction of the chemical energy storage material for stranded renewable energy, lithium is analyzed in carbon dioxide (CO2) and air. Spectroscopic techniques were used to characterize the reaction of bulk lithium pellets of up to 1 g weight. In comparison, power plant applicable combustion of atomized lithium spray was analyzed.Electrical high voltage spark was used to overcome to activation energy of the combustion for the experiments with bulk lithium. The lithium spray was successfully ignited by pre-heating the reaction gases (air and CO2).Radiation temperature of the bulk lithium during reaction in air was calculated to 2260 K. The observed green and red emission of the lithium combustion could be demonstrated in the spectral analysis.In CO2 atmosphere the reaction products were found to be lithium carbonate with little lithium oxide. Beside, lithium carbide could be detected in the reaction product of the combustion of bulk lithium. The gaseous reaction product carbon monoxide (CO), which could be further converted with hydrogen from renewable sources to valuable methanol or gasoline, was detected online by gas analysis.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

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