scholarly journals The tensile strength of compressed dust samples and the catastrophic disruption threshold of pre-planetary matter

2020 ◽  
Vol 497 (2) ◽  
pp. 2418-2424
Author(s):  
I L San Sebastián ◽  
A Dolff ◽  
J Blum ◽  
M G Parisi ◽  
S Kothe
Keyword(s):  
Tensile Strength ◽  
Solar System ◽  
Formation Process ◽  
Filling Factor ◽  
Object Size ◽  
Planetary Formation ◽  
Volume Filling ◽  
Second Stage ◽  
Brazilian Disc Test ◽  
Impact Experiments

ABSTRACT During the planetary formation process, mutual collisions among planetesimals take place, impacting on their porosities. The outcome of these collisions depends, among other parameters, on the tensile strength of the colliding objects. In the first stage of this work, we performed impact experiments into dust samples, assembled with material analogous to that of the primitive Solar System, to obtain highly compressed samples that represent the porosities measured in chondritic meteorites. In the second stage, we obtained the tensile strengths of the compressed dust samples by the Brazilian Disc Test. We found a correlation between the tensile strength and the volume filling factor of the compressed dust samples and obtained the corresponding critical fragmentation strength in mutual collisions and its dependence on the volume filling factor. Finally, we give prescriptions for the catastrophic disruption threshold as a function of the object size, for different values of the volume filling factor.

scholarly journals Sticky or not sticky? Measurements of the tensile strength of microgranular organic materials

2020 ◽  
Vol 497 (3) ◽  
pp. 2517-2528 ◽  
Author(s):  
D Bischoff ◽  
C Kreuzig ◽  
D Haack ◽  
B Gundlach ◽  
J Blum
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Filling Factor ◽  
Planet Formation ◽  
Organic Materials ◽  
Material Failure ◽  
Volume Filling ◽  
Water Ice ◽  
Lift Off

ABSTRACT Knowledge of the mechanical properties of protoplanetary and cometary matter is of key importance to better understand the activity of comets and the early stages of planet formation. The tensile strength determines the required pressure to lift off grains, pebbles, and agglomerates from the cometary surface and also describes how much strain a macroscopic body can withstand before material failure occurs. As organic materials are ubiquitous in space, they could have played an important role during the planet-formation process. This work provides new data on the tensile strength of five different microgranular organic materials, namely, humic acid, paraffin, brown coal, charcoal, and graphite. These materials are investigated by the so-called Brazilian Disc Test and the resulting tensile strength values are normalized to a standard grain size and volume filling factor. We find that the tensile strength of these materials ranges over four orders of magnitude. Graphite and paraffin possess tensile strengths much higher than silica, whereas coals have very low tensile-strength values. This work demonstrates that organic materials are not generally stickier than silicates, or water ice, as often believed.

Insulating Composites Made from Sulfur, Canola Oil, and Wool

2020 ◽  
Author(s):  
Israa Bu Najmah ◽  
Nicholas Lundquist ◽  
Melissa K. Stanfield ◽  
Filip Stojcevski ◽  
Jonathan A. Campbell ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Canola Oil ◽  
Building Blocks ◽  
Atom Economy ◽  
Flame Resistance ◽  
Sustainable Building ◽  
Second Stage ◽  
Wool Fibers ◽  
Insulating Properties ◽  
Polysulfide Polymer

An insulating composite was made from the sustainable building blocks wool, sulfur, and canola oil. In the first stage of the synthesis, inverse vulcanization was used to make a polysulfide polymer from the canola oil triglyceride and sulfur. This polymerization benefits from complete atom economy. In the second stage, the powdered polymer is mixed with wool, coating the fibers through electrostatic attraction. The polymer and wool mixture is then compressed with mild heating to provoke S-S metathesis in the polymer, which locks the wool in the polymer matrix. The wool fibers impart tensile strength, insulating properties, and flame resistance to the composite. All building blocks are sustainable or derived from waste and the composite is a promising lead on next-generation insulation for energy conservation.

scholarly journals A numerical and experimental study on the tensile behavior of plasma shocked granite under dynamic loading

2017 ◽  
Vol 50 (2) ◽  
pp. 41-62
Author(s):  
Ahmad Mardoukhi ◽  
Timo Saksala ◽  
Mikko Hokka ◽  
Veli-Tapani Kuokkala
Keyword(s):  
Experimental Study ◽  
Tensile Strength ◽  
Mechanical Behavior ◽  
Thermal Shock ◽  
Dynamic Loading ◽  
Split Hopkinson Pressure Bar ◽  
Tensile Behavior ◽  
Brazilian Disc ◽  
Brazilian Disc Test ◽  
Plasma Shock

This paper presents a numerical and experimental study on the mechanical behavior of plasma shocked rock. The dynamic tensile behavior of plasma shock treated Balmoral Red granite was studied under dynamic loading using the Brazilian disc test and the Split Hopkinson Pressure Bar device. Different heat shocks were produced on the Brazilian disc samples by moving the plasma gun over the sample at different speeds. Microscopy clearly showed that as the duration of the thermal shock increases, the number of the surface cracks and their complexity increases (quantified here as the fractal dimension of the crack patterns) and the area of the damaged surface grows larger as well. At the highest thermal shock duration of 0.80 seconds the tensile strength of the Brazilian disc sample drops by approximately 20%. In the numerical simulations of the dynamic Brazilian disc test, this decrease in tensile strength was reproduced by modeling the plasma shock induced damage using the embedded discontinuity finite element method. The damage caused by the plasma shock was modeled by two methods, namely by pre-embedded discontinuity populations with zero strength and by assuming that the rock strength is lowered and conform to the Weibull distribution. This paper presents a quantitative assessment of the effects of the heat shock, the surface microstructure and mechanical behavior of the studied rock, and a promising numerical model to account for the pre-existing crack distributions in a rock material.

Boron Behavior During the Evolution of the Early Solar System: The First 180 Million Years

Elements ◽  
2017 ◽  
Vol 13 (4) ◽  
pp. 231-236 ◽  
Author(s):  
Charles K. Shearer ◽  
Steven B. Simon
Keyword(s):  
Solar System ◽  
Solar Nebula ◽  
Nuclear Reactions ◽  
Terrestrial Planets ◽  
The Sun ◽  
Planetary Formation ◽  
Light Elements ◽  
Early Solar System ◽  
Spallation Reactions ◽  
Magma Oceans

The behavior of boron during the early evolution of the Solar System provides the foundation for how boron reservoirs become established in terrestrial planets. The abundance of boron in the Sun is depleted relative to adjacent light elements, a result of thermal nuclear reactions that destroy boron atoms. Extant boron was primarily generated by spallation reactions. In the initial materials condensing from the solar nebula, boron was predominantly incorporated into plagioclase. Boron abundances in the terrestrial planets exhibit variability, as illustrated by B/Be. During planetary formation and differentiation, boron is redistributed by fluids at low temperature and during crystallization of magma oceans at high temperature.

scholarly journals The Volume Filling Factor of the WIM

1997 ◽  
Vol 166 ◽  
pp. 301-304
Author(s):  
Elly M. Berkhuijsen
Keyword(s):  
Electron Density ◽  
Filling Factor ◽  
Local Electron ◽  
Volume Filling ◽  
Local Electron Density ◽  
Warm Ionized Medium

AbstractA compilation of data on the volume filling factor fv of the warm ionized medium (WIM) as a function of the local electron density ne indicates that approximately fv ∝ n−1e over 4 decades. This result is expected for a fractal ISM.

Ultrafast Tunable Near-Field Radiative Thermal Modulator Made of Ge3Sb2Te6

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Lu Lu ◽  
Jinlin Song ◽  
Kun Zhou ◽  
Han Ou ◽  
Qiang Cheng ◽  
...  
Keyword(s):  
Filling Factor ◽  
Radiative Heat ◽  
Near Field ◽  
Underlying Mechanism ◽  
Modulation Effect ◽  
Special Configuration ◽  
Volume Filling ◽  
Resonance Modes ◽  
Thermal Modulator ◽  
Two Phases

We show numerically the phase change material Ge3Sb2Te6 (GST) with special configuration as a heat modulator in the regime of near-field radiative heat transfer (NFRHT). The ability of GST to allow ultrafast reversible switch between two phases endows it great potential in practical modulation application. By designing silicon carbide (SiC) nanoholes (NHs) filled with GST, this configuration could achieve a considerable modulation effect and large near-field radiative heat flux. The underlying mechanism can be explained by the observation that the entire configuration supports either hyperbolic modes or surface phonon polaritons (SPhPs) resonance modes and even the combination of both modes, thereby resulting in the remarkable modulation effect. In addition, the effects of the volume filling factor and graphene coverage are also investigated at the vacuum gap distance of 100 nm. With graphene coverage, the modulation factor can be further improved to as high as 0.72 achieved at the volume filling factor of 0.6 with temperature difference of 20 K. The proposed configuration has the potential to effectively modulate heat in the near-field regime for designing heat modulation applications in the future.

scholarly journals Effects of Using Limestone as a Filler and Starbit E-55 Asphalt as a Binder on the Performance of AC-WC Mixture

2019 ◽  
Vol 258 ◽  
pp. 04005
Author(s):  
Faizul Chasanah ◽  
Fajariesta Arta Putra
Keyword(s):  
Tensile Strength ◽  
Asphalt Concrete ◽  
Indirect Tensile Strength ◽  
Permeability Test ◽  
Second Stage ◽  
Performance Requirements ◽  
Indirect Tensile ◽  
Asphalt Content ◽  
Properties Of Materials ◽  
Last Stage

Asphalt concrete can be made through several methods including hot mix using Starbit E-55 asphalt as a binder and limestone as filler. This research aimed to determine the feasibility of the use of limestone as filler in AC-WC mixture and to identify the effects of limestone addition on the Marshall Characteristics, Durability, Indirect Tensile Strength (ITS), and Permeability. The first stage was to test the properties of materials consisting of aggregate, asphalt, and limestone. The second stage was to determine the optimum asphalt content with 0%, 25%, 50%, 75%, and 100% filler proportions, and the last stage was to conduct the Marshall, Immersion, ITS, and Permeability tests. The results showed that limestone has been in accordance with the performance requirements specified for a filler of AC-WC mixture using Starbit E-55 asphalt as a binder. There was a change in the Marshall characteristics of optimum asphalt content. The durability increased, and the ITS values of AC-WC mixture improved along with the increase in limestone proportion. However, the permeability test indicated that the mixture has a poor drainage feature towards water after variation in filler proportions was performed.

Kinetics of Mixed Low-Level Waste Incapsulation Using Iron Phosphate Chemically Bonded Cement

2006 ◽  
Vol 932 ◽  
Author(s):  
A.S. Aloy ◽  
T.I. Koltsova ◽  
E.N. Kovarskaya ◽  
M.Yu. Silin
Keyword(s):  
Formation Process ◽  
Iron Phosphate ◽  
Structural Formation ◽  
Low Level ◽  
Second Stage ◽  
Bivalent Iron ◽  
Acid Reaction ◽  
The Moment ◽  
Two Stages ◽  
Kinetics Of

ABSTRACTThe iron phosphate cement (IPC) structure formation process has been studied by Mossbauer spectroscopy. The IPC is formed as a result of interaction of iron oxides with orthophosphoric acid and could be used as a matrix for immobilization of low-level radioactive waste.The structural formation process has been shown may be considered to consist of two stages. The first stage lasts to the moment of setting, when the diffusion process goes on in the liquid phase. At this stage the main fragments of the structural polymeric frame of the IPC are developed consisting of iron (+2) and (+3) phosphates. The rate of the oxides-with-phosphoric-acid reaction as well as the time of hardening depends on the bivalent iron content.The second stage begins from the moment of setting when the diffusion becomes slower. At this stage the process is characterized by the negligible increase in the iron phosphates (+2), (+3) content and transformation of the previously formed phosphates.The nuclear gamma-resonance (NGR) parameters have been determined of FeH3(PO4)2·2.5H2O, forming in the hematite (Fe2O3) based IPC: isomeric shift (IS) = 0.46 mm/s, quadrupole splitting (QS) = 0.197 mm/s, FWHM =0.282 mm/s.

scholarly journals Effect of Adding of Green Betel Leaf Extract and Honey on Mechanical Properties of Chitosan/PVA Hydrogel Wound Plaster

2021 ◽  
Vol 2110 (1) ◽  
pp. 012013
Author(s):  
N L F Chamidah ◽  
A B Rahanti ◽  
M D Kadasih ◽  
F D Sharfina ◽  
L Rohmawati
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Leaf Extract ◽  
Base Material ◽  
New Materials ◽  
Betel Leaf ◽  
Second Stage ◽  
Extract Concentration ◽  
Two Stages ◽  
Pva Hydrogel

Abstract Wound plasters on the market still have drawbacks, including lack of elasticity and stinging. Thus, there is a need for new materials from nature to be used as the base material for wound plasters, namely betel leaf extract and honey composited with PVA/chitosan. This study purpose to find out mechanical properties of wound plaster of chitosan/PVA with the composition of betel leaf extract and honey. The first stage is making hydrogel by mixing PVA and chitosan, and the second stage is extracting green betel leaves and honey by the maceration method. Then the two stages were mixed with a composition of 5wt%, 15wt%, and 25wt% green betel leaf extract. The results were tested for tensile strength to determine the elasticity properties of the wound plaster. In this study, the 25wt% betel leaf extract concentration had the best tensile strength value of 0.219 MPa, and the modulus of elasticity was 0.11 MPa.

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