Microstructure and tensile properties of magnesium matrix nanocomposite reinforced by high mass fraction of nano-sized particles including TiC and MgZn2

2020 ◽  
Vol 819 ◽  
pp. 153348 ◽  
Author(s):  
Kai-bo Nie ◽  
Ya-chao Guo ◽  
Paul Munroe ◽  
Kun-kun Deng ◽  
Xin-kai Kang
Keyword(s):  
Tensile Properties ◽  
Mass Fraction ◽  
High Mass ◽  
Magnesium Matrix ◽  
Matrix Nanocomposite

Mechanical Milling and its Influence on Microstructure and Electric Conductivity of High Mass Fraction TiC / Cu Composites

2013 ◽  
Vol 815 ◽  
pp. 790-795
Author(s):  
Jie Yan ◽  
Kai Yong Jiang
Keyword(s):  
Electrical Conductivity ◽  
Relative Density ◽  
Electric Conductivity ◽  
Ball Milling ◽  
Mechanical Milling ◽  
Mass Fraction ◽  
Milling Time ◽  
High Mass ◽  
Powder Metallurgy Method ◽  
X Ray Diffraction

The TiC-Cu composites with different mass fraction were prepared by powder metallurgy method. The effect of ball milling time and sintering temperature on the morphology, relative density and electrical conductivity of TiC/Cu composites has been investigated. As-milled sintered compacts were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and conductivity measurements. The results demonstrate that under laboratory conditions with the milling time increasing grains are remarkable refined. Mechanical milling can bring about changes of lattice parameters, the grain size first decrease and then increase as milling time increasing. Relative density showed strong dependency on the milling time. The effect of the grain being refined by ball milling is helpless to improve electrical conductivity of composites. For the composites with TiC content<50wt.%, as milling time prolonging the electric conductivity decreases while for the 50%TiC-Cu the conductivity are not be impacted.

scholarly journals Numerical simulation of the effect of material catalytic converter on gas emission

2018 ◽  
Vol 204 ◽  
pp. 04018
Author(s):  
Suheni ◽  
Rudy Sunoko ◽  
Slamet Wahyudi ◽  
Amin S Leksono
Keyword(s):  
Numerical Simulation ◽  
Mass Fraction ◽  
Thermal Condition ◽  
Catalytic Converter ◽  
Human Life ◽  
High Mass ◽  
Gas Emission ◽  
Rest Time ◽  
Fluent Software ◽  
Co Gas

The disposal of gas emission from vehicle is the biggest contributor to the environmental pollution which generates most carbon monoxide, hydrocarbon, and lead (Pb=Plumbum). Those substance particulates are pollutants and harmful for both the environment and human life. One of the innovations that can reduce the pollutive particulates is to reduce CO gas by assembling a catalytic converter are displayed. In order to find out the effect of catalytic converter absorption toward (CO) gas particulate, varied with various materials in an environmentally friendly catalytic converter, a simulation using fluent software is carried out. From the simulation, it is seen a significant thermal condition and CO mass fraction absorption from various different materials, by applying mass fraction of CO=0.04;N2=0.8796; and O2=0.12, the decrease of high mass fraction (decrease of CO=0.004 mass fraction) occurs at the channel centre area due to the mass fraction of various materials that moves away from the center with a longer rest time (high conversion) at the surrounding channel.

scholarly journals Microstructure and room temperature tensile properties of 1 μm-SiCp/AZ31B magnesium matrix composite

2015 ◽  
Vol 3 (2) ◽  
pp. 155-161 ◽  
Author(s):  
M.J. Shen ◽  
X.J. Wang ◽  
M.F. Zhang ◽  
B.H. Zhang ◽  
M.Y. Zheng ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Matrix Composite ◽  
Room Temperature ◽  
Magnesium Matrix Composite ◽  
Magnesium Matrix

Effects of Different Sr Additions on As Cast Microstructure and Tensile Properties of AS31 Alloy

2014 ◽  
Vol 788 ◽  
pp. 110-114 ◽  
Author(s):  
Ji Xue Zhou ◽  
Dong Qing Zhao ◽  
Jin Wei Wang ◽  
Shou Qiu Tang ◽  
Wei Hong Li
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Elevated Temperature ◽  
Magnesium Alloy ◽  
Ambient Temperature ◽  
Tensile Properties ◽  
Mass Fraction ◽  
Chinese Script ◽  
Polyhedral Shape ◽  
Cast Microstructure

Effects of different Sr additions (0.1%-1%Sr, mass fraction) on as-cast microstructure and tensile properties both at ambient temperature and elevated temperature of AS31 magnesium alloy were studied. The experimental results show that the addition of Sr could refine the grain size obviously and modify the eutectic Mg2Si from Chinese script shape to polyhedral shape or fine fibers shape. The addition of Sr to AS31 alloy improved the tensile strength at ambient temperature, and the ultimate strength at 150°C first decrease and then increase with the Sr addition increase from 0.1% to 1%Sr.

scholarly journals An ALMA study of hub-filament systems I. On the clump mass concentration within the most massive cores

2021 ◽  
Author(s):  
Michael Anderson ◽  
Nicolas Peretto ◽  
Sarah E Ragan ◽  
Andrew J Rigby ◽  
Adam Avison ◽  
...  
Keyword(s):  
Surface Density ◽  
Mass Fraction ◽  
Massive Star ◽  
High Mass ◽  
Physical Processes ◽  
Concentrate Mass ◽  
Star Forming ◽  
Sample Bias ◽  
Significant Difference ◽  
Infrared Brightness

Abstract The physical processes behind the transfer of mass from parsec-scale clumps to massive-star-forming cores remain elusive. We investigate the relation between the clump morphology and the mass fraction that ends up in its most massive core (MMC) as a function of infrared brightness, i.e. a clump evolutionary tracer. Using ALMA 12 m and ACA we surveyed 6 infrared-dark hubs in 2.9 mm continuum at ∼3″ resolution. To put our sample into context, we also re-analysed published ALMA data from a sample of 29 high mass-surface density ATLASGAL sources. We characterise the size, mass, morphology, and infrared brightness of the clumps using Herschel and Spitzer data. Within the 6 newly observed hubs, we identify 67 cores, and find that the MMCs have masses between 15–911 M⊙ within a radius of 0.018–0.156 pc. The MMC of each hub contains 3–24 per cent of the clump mass (fMMC), becoming 5–36 per cent once core masses are normalised to the median core radius. Across the 35 clumps, we find no significant difference in the median fMMC values of hub and non-hub systems, likely the consequence of a sample bias. However, we find that fMMC is ∼7.9 times larger for infrared-dark clumps compared to infrared-bright ones. This factor increases up to ∼14.5 when comparing our sample of 6 infrared-dark hubs to infrared-bright clumps. We speculate that hub-filament systems efficiently concentrate mass within their MMC early on during its evolution. As clumps evolve, they grow in mass, but such growth does not lead to the formation of more massive MMCs.

Adaptive Wiebe Function Parameters for a Port-Fuel Injected Hydrogen-Fueled Engine

2019 ◽  
Author(s):  
Shah Saud Alam ◽  
Christopher Depcik
Keyword(s):  
Experimental Data ◽  
Mass Fraction ◽  
Internal Combustion Engines ◽  
Operating Conditions ◽  
High Mass ◽  
Parameter Determination ◽  
Complete Combustion ◽  
Burn Rate ◽  
The Impact ◽  
Wiebe Function

Abstract Current unmanned aerial vehicle (UAV) propulsion technologies includes hydrogen fuel cells, battery systems, and internal combustion engines (ICE). However, relying on a single propulsion technology might result in a limited operational range. This can be mitigated by utilizing a hybrid configuration involving a battery pack and an ICE or a fuel cell for charging. Due to its significant weight advantage and high mass-specific energy content, hydrogen (H2) is an ideal fuel for both power plant options. However, use of H2 with an ICE requires precise operational control through combustion process simulation with the predictive approximation of the mass fraction burned profile. In this area, the relatively simple single-Wiebe function is widely deployed for a variety of different fuels, as well as combustion regimes. In general, the description of the single-Wiebe function includes the extent of complete combustion (a), magnitude of the maximum burn rate (m), and combustion duration (θd). However, the literature often provides values for these parameters without necessarily relating them to operational characteristics that can influence ICE power. As a result, it is critical to correlate the burn rate of the fuel to ICE operating parameters, such as the engine compression ratio, inlet pressure, mean piston speed, exhaust gas recirculation level, equivalence ratio, and spark timing. Therefore, in an attempt to physically define these parameters, this effort performs a sensitivity analysis using linear regression (least squares method) to assess the impact of engine operating conditions on the Wiebe function in comparison to experimental data for port-fuel injected hydrogen ICEs. The result is a model that can estimate the values of a, m, and θd in combination with a relatively high coefficient of determination (R2) when compared to the experimental mass fraction burned profiles. Finally, others can expand this methodology to any experimental data for engine and fuel-specific Wiebe parameter determination.

scholarly journals The Effects of Main-Sequence Mass Loss on Surface C/N Abundance Ratios During the Ascent of the First Giant Branch

1989 ◽  
Vol 106 ◽  
pp. 228-228
Author(s):  
J. A. Guzik ◽  
T. E. Beach
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Mass Fraction ◽  
Main Sequence ◽  
High Mass ◽  
Core Material ◽  
Main Sequence Stars ◽  
Rapid Rotation ◽  
Final Mass ◽  
Evolution Modeling

The surface C/N abundance ratios of many cluster and field G and K giants following the 1st dredge-up phase are much lower than predicted from standard stellar evolution modeling. The occurrence of substantial mass loss, either during or immediately after the main-sequence phase would both reduce the mass fraction of the unprocessed envelope necessary to contaminate with CN-cycle products, as well as allow CN-processing of a greater amount of core material during the earlier high-mass phase. Willson, Bowen and Struck-Marcell (1987) have proposed that a combination of pulsation and rapid rotation could drive substantial mass loss in main-sequence stars of initial mass 1-3 MΘ. We evolved a grid of 16 mass-losing models from the zero-age main sequence through 1st dredge-up. The models have initial masses of 1.25, 1.5, 1.75 and 2.0 MΘ, and exponentially decreasing mass-loss rates with e-folding times 0.2, 0.4, 1.0 and 2.0 Gyr; all models evolve toward a final mass of 1.0 M". Since the mass-loss epoch is short-lived, most of the models reach 1.0 M0 rapidly, and follow the evolutionary track of a standard 1 MΘ model redward away from the main sequence and up the 1st giant branch. The convecuve envelope deepens during 1st dredge-up to homogenize the outer 3/4 of the star's final mass.

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