scholarly journals A Constitutive Modeling and Experimental Effect of Shock Wave on the Microstructural Sub-strengthening of Granular Copper

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
A. D. Sharma ◽  
A. K. Sharma ◽  
N. Thakur
Keyword(s):  
Particle Size ◽  
Density Measurement ◽  
Electron Microscopic Examination ◽  
Shock Pressure ◽  
Detonation Pressure ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Hardness Tests ◽  
Particle Size Analyzer

Micro-sized copper powder (99.95%; O≤0.3) has been shock-processed with explosives of high detonation velocities of the order of 7.5km/s to observe the structural and microstructural sub-strengthening. Axisymmetric shock-consolidation technique has been used to obtain conglomerates of granular Cu. The technique involves the cylindrical compaction system wherein the explosive-charge is in direct proximity with the powder whereas the other uses indirect shock pressure with die-plunger geometry. Numeric simulations have been performed on with Eulerian code dynamics. The simulated results show a good agreement with the experimental observation of detonation parameters like detonation velocity, pressure, particle velocity and shock pressure in the reactive media. A pin contactor method has been utilized to calculate the detonation pressure experimentally. Wide angled x-ray diffraction studies reveal that the crystalline structure (FCC) of the shocked specimen matches with the un-shocked specimen. Field emissive scanning electron microscopic examination of the compacted specimens show a good sub-structural strengthening and complement the theoretical considerations. Laser diffraction based particle size analyzer also points towards the reduced particle size of the shock-processed specimen under high detonation velocities. Micro-hardness tests conducted under variable loads of 0.1kg, 0.05kg and 0.025kg force with diamond indenter optical micrographs indicate a high order of micro-hardness of the order of 159Hv. Nitrogen pycnometry used for the density measurement of the compacts shows that a compacted density of the order of 99.3% theoretical mean density has been achieved.

scholarly journals Получение карбида бора в низковольтной электрической дуге постоянного тока, инициированной в открытом воздушном пространстве

2018 ◽  
Vol 44 (14) ◽  
pp. 26 ◽  
Author(s):  
А.Я. Пак ◽  
Г.Я. Мамонтов
Keyword(s):  
Boron Carbide ◽  
Arc Discharge ◽  
Electron Microscopic Examination ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Vacuum Equipment ◽  
X Ray ◽  
Gas Atmosphere ◽  
Average Size ◽  
Carbide Particles

AbstractWe describe a method of obtaining ultrafine boron carbide (B_13C_2) powder using the effect of a dc electric arc on a mixture of initial reactants containing carbon and boron. A peculiarity of the proposed method is that it can be implemented using arc discharge operating in open air without any vacuum equipment and protective inert gas atmosphere. X-ray diffraction data showed that the synthesized product in the general case contained three crystalline phases: boron carbide (B_13C_2), graphite (C), and boron oxide (B_2O_3). Electron-microscopic examination showed that the average size of boron carbide particles ranged from ~50 nm to ~2 μm.

The Influence of Calcination Temperature on Quantitative Phase of Hematite from Iron Stone Tanah Laut

2015 ◽  
Vol 1112 ◽  
pp. 489-492
Author(s):  
Ali Mufid ◽  
M. Zainuri
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Thermo Gravimetric Analysis ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Co Precipitation

This research aims to form particles of hematite (α-Fe2O3) with a basis of mineral iron ore Fe3O4 from Tanah Laut. Magnetite Fe3O4 was synthesized using co-precipitation method. Further characterization using X-ray fluorescence (XRF) to obtain the percentage of the elements, obtained an iron content of 98.51%. Then characterized using thermo-gravimetric analysis and differential scanning calorimetry (TGA-DSC) to determine the calcination temperature, that at a temperature of 445 °C mass decreased by 0.369% due to increase in temperature. Further Characterization of X-ray diffraction (XRD) to determine the phases formed at the calcination temperature variation of 400 °C, 445 °C, 500 °C and 600 °C with a holding time of 5 hours to form a single phase α-Fe2O3 hematite. Testing with a particle size analyzer (PSA) to determine the particle size distribution, where test results indicate that the α-Fe2O3 phase of each having a particle size of 269.7 nm, 332.2 nm, 357.9 nm, 412.2 nm. The best quantity is shown at a temperature of 500 °C to form the hematite phase. This result is used as the calcination procedure to obtain a source of Fe ions in the manufacture of Lithium Ferro Phosphate.

Effect of Process on the Dielectric Properties of BaTiO3-Based X9R Ceramics

2014 ◽  
Vol 906 ◽  
pp. 18-24 ◽  
Author(s):  
Bao Lin Zhang ◽  
Bin Bin Zhang ◽  
Ning Ning Wang ◽  
Jing Ming Fei
Keyword(s):  
Particle Size ◽  
Dielectric Properties ◽  
Milling Time ◽  
Sintering Temperature ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Sintered Ceramic ◽  
X Ray ◽  
Particle Size Analyzer

The effect of milling time and sintering process on the dielectric properties of BaTiO3-based X9R ceramics was investigated. The characterization of the raw powders and the sintered ceramic was carried out by X-ray diffraction and scanning electron microscopy. The particle size distribution of the mixed powders was examined by Laser Particle Size Analyzer. The results shown that with the milling time extended, the Cruie Peak was depressed, or even disappeared. Moreover, with the rise of sintering temperature, the dielectric constant of the ceramics increased and the dielectric loss decreased gradually. Eventually, by milling for 11h and sintering at 1090°Cfor 2h, good dielectric properties were obtained, which were ε25°C≥ 2526, εr/εr25°C≤± 12% (–55~200°C), tanδ≤1.12% (25°C).

scholarly journals Synthesis of Silver Nanoparticles Using Muntingia Calabura L. Leaf Extract as Bioreductor and Applied as Glucose Nanosensor

2018 ◽  
Vol 34 (6) ◽  
pp. 3088-3094 ◽  
Author(s):  
Abdul Wahid Wahab ◽  
Abdul Karim ◽  
Nursiah La Nafie ◽  
Nurafni Nurafni ◽  
I. Wayan Sutapa
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Reduction Method ◽  
Measurement Range ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Muntingia Calabura

Silver nanoparticles have been synthesized by reduction method using extract of Muntingia calabura L. leaf a bioreductor. The process of silver nanoparticles formation was monitored by UV-Vis method. The results showed that the absorbance values increased according to the increase of reaction time. Maximum absorption of silver nanoparticle was obtained at a wavelength of 41-421 nm. The size of silver nanoparticles was determined using a PSA (Particle Size Analyzer) with a particle size distribution of 97.04 nm. The functional groups compound that contribute in the synthesis was analyzed using Fourier Transform Infrared Spectroscopy (FTIR). Morphology of the silver nanoparticles was observed by an Scanning Electron Microscope instrument and the structure characterization of the compounds were analyzed using X-Ray Diffraction. The glucose nanosensor based on silver nanoparticles have the measurement range of 1 mM - 4 mM with the regretion (R2) is 0,9516, the detection limit of sensor is 3,2595 mM, the sensitivity of sensor is 2,0794 A. mM-1. mM-2.

An Investigation on the Application of Cryogenic Ball Milling to Ibuprofen Particle and Its Characteristics

2006 ◽  
Vol 505-507 ◽  
pp. 355-360 ◽  
Author(s):  
Kyong Yop Rhee ◽  
Hyun Kab Cho ◽  
Jai Sung Hong
Keyword(s):  
Particle Size ◽  
Ball Milling ◽  
Weight Ratio ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Chemical Changes ◽  
Ball Milling Process ◽  
Particle Size Analyzer ◽  
Before And After ◽  
Size Of Particles

For a present study, a cryogenic ball milling process was applied to reduce the Ibuprofen particles to submicron in order to enlarge their dissolution rate. The cryogenic ball milling was performed using 6 mm zirconia balls at a temperature of -180 °C or lower. The effects of milling time, the weight ratio of ball to Ibuprofen, and milling speed on the particle size were investigated. SEM and particle size analyzer were used to analyze the shape and size of particles before and after ball milling. The chemical changes before and after the cryogenic ball milling process were examined through XRD (x-ray diffraction) analysis. The results show that the size of Ibuprofen particles was reduced to about 1/20 of its initial size and the particle size showed negligible change after six hours of ball milling. The effect of weight ratio and the milling speed on the particle size was almost negligible. The results also show that cryogenic ball milling yielded no chemical changes in the particle.

Characteristics of TiB2 Coating on the Surface of Copper Alloy Prepared by Vibrating Electrospark Deposition

2010 ◽  
Vol 105-106 ◽  
pp. 477-480
Author(s):  
Cheng Luo ◽  
Shi Jie Dong ◽  
Xiang Xiong
Keyword(s):  
Spot Welding ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Electrospark Deposition ◽  
Gradient Distribution ◽  
Sheet Steels ◽  
Hardness Tests ◽  
Tib2 Coating ◽  
Coated Sheet ◽  
Stress Accumulation

Functional TiB2 coating was prepared onto the surface of Cr-Zr-Cu electrodes by vibrating electrospark deposition in order to extend their service life during resistance spot welding of Zinc coated sheet steels. The microstructure and mechanical properties of the coatings have been characterized by scanning electron microscopy, energy dispersive analysis, X-ray diffraction and micro-hardness tests respectively. The results indicate that cracks appear in the coating due to the tensile stress accumulation and delamination of the coating is related to mismatch in the equivalent valence electron. Cu diffuses obviously from the substrate to the surface of the coating, forming a gradient distribution and making the bonding of the interface between the coating and the substrate an atomic one. TiB2 coating is oxidized during deposition under high temperature of electrosparking. The micro-hardness of the coating is approximately 500HV, which is much bigger than the hardness of the uncoated ones.

scholarly journals Study on the Crystal Structure and Microstructure Evolution of Shock-processed Titanium Powder

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Akash Deep Sharma
Keyword(s):  
Particle Size ◽  
Titanium Powder ◽  
Diagnostic Techniques ◽  
Critical Parameters ◽  
X Ray Diffraction ◽  
Particle Size Reduction ◽  
Particle Size Analyzer ◽  
Rapidly Solidified ◽  
Structure And Microstructure ◽  
Rule Out

Titanium powder was rapidly solidified by using shock-wave consolidation technique. The critical parameters were controlled by intrumented detonics and pin-oscillography. The compacted specimens were investigated for structural and microstructural strengthening by using standard diagnostic techniques. The density of the final product was found to be greater than 96% of the theoretical value. X-ray diffraction pattern reveals intact crystalline structure without the presence of any undesired phases. The particle size reduction indicated by XRD was supported by laser diffraction based particle size analyzer. Results from energy dispersive spectroscopy rule out the possibility of any segregation within the compacts. Scanning electron microscopy showed crack-free, voids-free, melt-free, fracture-less compacts of titanium with the uni-directional dendrites orientation without any grain-growth.   

scholarly journals Novel NiMgOH-rGO-Based Nanostructured Hybrids for Electrochemical Energy Storage Supercapacitor Applications: Effect of Reducing Agents

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1144
Author(s):  
Konda Shireesha ◽  
Thida Rakesh Kumar ◽  
Tumarada Rajani ◽  
Chidurala Shilpa Chakra ◽  
Murikinati Mamatha Kumari ◽  
...  
Keyword(s):  
Particle Size ◽  
Cyclic Voltammetry ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Uv Visible

This paper describes the synthesis and characterization of NiMgOH-rGO nanocomposites made using a chemical co-precipitation technique with various reducing agents (e.g., NaOH and NH4OH) and reduced graphene oxide at 0.5, 1, and 1.5 percent by weight. UV-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, a particle size analyzer, and cyclic voltammetry were used to characterize the composite materials. The formation of the NiMgOH-rGO nanocomposite with crystallite sizes in the range of 10–40 nm was inferred by X-ray diffraction patterns of materials, which suggested interlayers of Ni(OH)2 and Mg(OH)2. The interactions between the molecules were detected using Fourier-transform infrared spectroscopy, while optical properties were studied using UV-visible spectroscopy. A uniform average particle size distribution in the range of 1–100 nm was confirmed by the particle size analyzer. Using cyclic voltammetry and galvanostatic charge/discharge measurements in a 6 M KOH solution, the electrochemical execution of NiMgOH-rGO nanocomposites was investigated. At a 1 A/g current density, the NiMgOH-rGO nanocomposites prepared with NH4OH as a reducing agent had a higher specific capacitance of 1977 F/g. The electrochemical studies confirmed that combining rGO with NiMgOH increased conductivity.

scholarly journals Electric polarization properties of BaTiO3-BiFeO3 as nanomultiferroic material produced by sol-gel method

2018 ◽  
Vol 204 ◽  
pp. 05005 ◽  
Author(s):  
Dwita Suastiyanti ◽  
Maykel T.E. Manawan ◽  
Marlin Wijaya
Keyword(s):  
Particle Size ◽  
Sol Gel ◽  
Sinter Time ◽  
Weight Ratio ◽  
Electric Polarization ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Particle Size Analyzer ◽  
Dominant Phase

The nanomultiferroic material which is synthesized in this research used sol-gel method. The research used weight ratio of BaTiO3: BiFeO3 of 2: 1. Gel formed after heating at 80-90°C was calcined at 350°C for 4 hours and then sintered at 700,750 and 800°C for 2, 4 and 6 hours respectively. Powder produced after sintering was characterized by X-Ray Diffraction (XRD) test using XRD Phillips PW 1835 type, 20°-100° diffraction angle and CuKα, electric polarization properties test and particle size measurement using Particle Size Analyzer of Beckman Coulter DelsaTM Nano instrument. From the characterization results, it is obtained that the dominant phase is Barium Bismuth Iron (III) Oxide (BaBiFe2O5). Electrical polarization properties such as remanent, coersivity and saturation reach maximum value at sinter temperature of 750° C and sinter time of 6 hours. This result is supported by the smallest particle size of powder (54-57 nm) and also supported by the largest number of dominant phase (98.79%) at same condition.

Phagocytosis of pulmonary deposited particles by Type 1 alveolar epithelium

1989 ◽  
Vol 47 ◽  
pp. 922-923
Author(s):  
C. L. Sanders ◽  
K. E. McDonald ◽  
R. R. Adee ◽  
K. E. Lauhala
Keyword(s):  
Particle Size ◽  
Size Range ◽  
Intratracheal Instillation ◽  
Alveolar Epithelium ◽  
Electron Microscopic Examination ◽  
Type I ◽  
Electron Microscopic ◽  
Particle Size Range ◽  
Adult Rats ◽  
Air Space

The role of the alveolar epithelium in removal of deposited particles from the alveolar air space has not been well defined. Type II cells, although in close proximity to particles, do not participate in the phagocytosis of particles. How ever, a variety of alveolarly deposited particulates are phagocytized by type I cells. The rapid and efficient phagocytosis of particles in the air space by macrophages minimizes particle entry into more fixed tissues of the lung.Female, Wistar, young adult rats were given a single intratracheal instillation of either 25 mg iron oxide with a particle size range of 0.3-1.1 micron or 3 mg latex beads with a particle size range of 0.3-0.6 micron, suspended in 1.0 ml 0.9% NaCl solution. Groups of 2-3 rats were killed by halothane overexposure at 5-180 minutes after instillation. The lungs were fixed in situ with McDowellTrumps. Lung tissue was embedded in plastic and stained-with uranyl acetate and lead citrate for electron microscopic examination.

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