The Nanoindentation Response of Silicon and Related Structurally Similar Materials

As the applications of heterogeneous materials expand, aluminum laminates of similar materials have attracted much attention due to their greater bonding strength and easier recycling. In this work, an alloy design strategy was developed based on accumulative roll bonding (ARB) to produce laminates from similar materials. Twin roll casting (TRC) sheets of the same composition but different cooling rates were used as the starting materials, and they were roll bonded up to three cycles at varying temperatures. EBSD showed that the two TRC sheets deformed in distinct ways during ARB processes at 300°C. Major recrystallizations were significant after the first cycle on the thin sheet and after the third cycle on the thick sheet. The sheets were subject to subsequent aging for better mechanical properties. TEM observations showed that the size and distribution of nano-precipitations were different between the two sheet sides. These nano-precipitations were found to significantly promote precipitation strengthening, and such a promotive effect was referred to as hetero-deformation induced (HDI) strengthening. Our work provides a new promising method to prepare laminated heterogeneous materials with similar alloy TRC sheets.

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A Damage Model to Trabecular Bone and Similar Materials: Residual Resource, Effective Elasticity Modulus, and Effective Stress under Uniaxial Compression

Symmetry ◽

10.3390/sym13061051 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1051

Author(s):

Gennady Kolesnikov ◽

Rudolf Meltser

Keyword(s):

Mathematical Modeling ◽

Trabecular Bone ◽

Bone Tissue ◽

Uniaxial Compression ◽

Effective Stress ◽

Analytical Solutions ◽

Energy Criterion ◽

Empirical Models ◽

Mechanical State ◽

Similar Materials

Experimental research of bone strength remains costly and limited for ethical and technical reasons. Therefore, to predict the mechanical state of bone tissue, as well as similar materials, it is desirable to use computer technology and mathematical modeling. Yet, bone tissue as a bio-mechanical object with a hierarchical structure is difficult to analyze for strength and rigidity; therefore, empirical models are often used, the disadvantage of which is their limited application scope. The use of new analytical solutions overcomes the limitations of empirical models and significantly improves the way engineering problems are solved. Aim of the paper: the development of analytical solutions for computer models of the mechanical state of bone and similar materials. Object of research: a model of trabecular bone tissue as a quasi-brittle material under uniaxial compression (or tension). The new ideas of the fracture mechanics, as well as the methods of mathematical modeling and the biomechanics of bone tissues were used in the work. Compression and tension are considered as asymmetric mechanical states of the material. Results: a new nonlinear function that simulates both tension and compression is justified, analytical solutions for determining the effective and apparent elastic modulus are developed, the residual resource function and the damage function are justified, and the dependences of the initial and effective stresses on strain are obtained. Using the energy criterion, it is proven that the effective stress continuously increases both before and after the extremum point on the load-displacement plot. It is noted that the destruction of bone material is more likely at the inflection point of the load-displacement curve. The model adequacy is explained by the use of the energy criterion of material degradation. The results are consistent with the experimental data available in the literature.

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Muslim-Jewish Sexual Liaisons Remembered and Imagined in 20th-Century Yemen

International Journal of Middle East Studies ◽

10.1017/s0020743820001105 ◽

2021 ◽

Vol 53 (1) ◽

pp. 39-55

Author(s):

Mark S. Wagner

Keyword(s):

20Th Century ◽

Rural Areas ◽

Mass Migration ◽

Jewish Society ◽

Conversion To Islam ◽

Similar Materials ◽

Sexual Encounters ◽

Identity Crises

AbstractDespite mutual taboos against exogamy, memoirs and similar materials written by Jews from Yemen contain a number of anecdotes describing love affairs and sexual encounters between Muslims and Jews prior to the mass migration of the vast majority of Yemen's Jews to Israel in 1949–50. These stories associate these liaisons with vulnerability, poverty, and marginalization. In them, sex and conversion to Islam are intrinsically connected, yet this interreligious intimacy leads not to resolution but to ongoing identity crises that persist beyond the community's realignment with a majority-Jewish society. The staging of the anecdotes in rural areas where shariʿa norms held only nominal sway, in watering places and hostels where strangers might interact, and at dusk, when identity is difficult to discern, heightened their ambiguity.

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Kesan Bentuk Hujung Elektrod Terhadap Kimpalan Rintangan Bintik Mikro Sambungan Titanium-Nikel

Jurnal Teknologi ◽

10.11113/jt.v69.1622 ◽

2014 ◽

Vol 69 (1) ◽

Author(s):

Hussain Zuhailawati ◽

Emee Marina Salleh ◽

Alaa Muhsin Saeed

Keyword(s):

Spot Welding ◽

Failure Load ◽

Chemical Properties ◽

Dissimilar Materials ◽

Base Metals ◽

Microstructural Characteristics ◽

Similar Materials ◽

Physical And Chemical ◽

Alloy Filler ◽

And Chemical Properties

Micro resistance spot welding of dissimilar materials is more challenging than that of similar materials due to differences in physical and chemical properties of the base metals. Fortunately, the incorporation of filler alloys at the interfaces of the two overlapped dissimilar metals can successfully overcome this difficulty. This study evaluated the mechanical behavior and microstructural characteristics of titanium-to-nickel spot-welded with and without the incorporation of 71Ag-28Cu-1Mg using round, rectangular and ring-shaped tip electrodes. Results showed that the round electrode gave the joints with the highest failure load and microhardness values since its highest current density produced a smaller contact area with the workpieces, causing the deepest penetration of the welded nugget. Addition of Ag-Cu-Mg alloy filler during spot welding improved weldability over that of joints made without filler.

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Cobaltites as perspective thermoelectrics

MRS Proceedings ◽

10.1557/proc-0886-f01-07 ◽

2005 ◽

Vol 886 ◽

Cited By ~ 2

Author(s):

Jiri Hejtmánek ◽

Miroslav Veverka ◽

Karel Knižek ◽

Hiroyuki Fujishiro ◽

Sylvie Hebert ◽

...

Keyword(s):

Degrees Of Freedom ◽

Phonon Scattering ◽

Configurational Entropy ◽

Energy Difference ◽

Charge Carriers ◽

Material Research ◽

Cobalt Ions ◽

Similar Materials ◽

Physical Background ◽

Open Question

AbstractThe recent material research of mixed cobalt oxides is strongly motivated by the potential of some of them to be used as chemically stable high temperature thermoelectric material. This fact together with both the theoretical and experimental ambitions to fulfill the severe criteria needed for efficient thermoelectric conversion intensified both their theoretical and experimental research. Nonetheless, despite the investigations of the prototype materials represented by 3D perovskites Ln1−xAxCoO3 (Ln = La, Y, rare-earth, A = alkaline-earth) and 2D cobaltites of NaxCoO2 type, the concise physical background of their transport and magnetic properties remain still a matter of debate. This is likely due to a fact that cobalt ions can be stabilized either in low-spin state (diamagnetic for “pure” Co3+), with filled t2g levels and empty eg states, or magnetic ones, with filled eg states. As the energy difference between respective states is due to comparable strength of crystal field and Hund's energies rather small, the thermodynamically most stable ground-state, with eventually different character of charge carriers, can be critically influenced by an interplay of additional degrees of freedom - orbital and charge. The challenge for unequivocal theoretical model represents the thermoelectric power of mixed cobaltites where, up to now, somewhat ambiguous models based either on “classical” approach, associated with diffusion of itinerant charge carriers, or more exotic - based on configurational entropy of quasi-itinerant carriers - are often used for similar materials. Simultaneously, the open question remains the assessment of the dominant mechanism of phonon scattering in 2D cobaltites.

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The Study on the Ratio of Similar Material in Landslide Model Test

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.261-263.1679 ◽

2011 ◽

Vol 261-263 ◽

pp. 1679-1684

Author(s):

Xiao Ling Liu ◽

Shi Mei Wang ◽

Yun Zhi Tan ◽

Xin Jiang Hu ◽

Dai Peng Zhao

Keyword(s):

Model Test ◽

Influence Factors ◽

Deformation Modulus ◽

High Strength ◽

Similar Material ◽

Talcum Powder ◽

Angle Of Internal Friction ◽

Similar Materials ◽

Mixed Material ◽

Landslide Model

The choice of similar materials and the design of mix proportions is a key step in landslide model test. On the basis of experiment, we conduct a research for the similar materials which may sufficing volume weight, cohesive force, angle of internal friction, deformation modulus, and the infiltration coefficient on the same time. Then we put forward two kinds of schemes: one is the mixed material of high-strength glass micro beads and talcum powder; the other is the mixed material of lead beads, river sands, rubber powder and talcum powder. By analyzing the result of mix proportions test, We concluded the regularity that similar index varies along with different content of the similar material ingredients and found the notable influence factors , which provides important reference for the components of similar materials in the landslide model test.

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