Absorption saturation intensity of InGaAs-InAlAs MQW under tensile and compressive strain

The main magnetic parameters sensitive to the structure of steels are the parameters of their saturation loop of magnetic hysteresis: the coercive force Hcs and remanent magnetization Mrs. The saturation magnetization or saturation intensity Mr is most sensitive to the phase composition of steels. The variety of steel grades and modes of technological treatment (e.g., heat treatment, mechanical load) determined the use of magnetic structurescopy and magnetic characteristics — the coercive force Hc, remanent magnetization Mr , and specific hysteresis losses Wh on the subloops of the magnetic hysteresis of steels — as control parameters in diagnostics of the stressed and structural states of steel structures and pipelines. It has been shown that changes in Hc, Mr , and Wh are more sensitive to structural stresses and structures of steels than the parameters of the saturation hysteresis loop of magnetic hysteresis (Hcs, Mrs, and Mrs). The formulas for calculating Hc, Mr and Wh are presented to be used for estimation of changes in the parameters upon heat treatment of steels. Features of the structural sensitivity of the subloop characteristics and expediency of their use for magnetic structural and phase analyzes are determined. Thus, the range of changes in Ìr attributed to the structural changes in steels upon gradual Hm decrease is many times wider compared to the range of possible changes in Mrs under the same conditions. Conditions (relations between the magnetic parameters) and recommendations regarding the choice of the field strength Hm are given which provide the justified use of Hc, Mr and Wh parameters in magnetic structurescopy

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Polyhedral Oligomeric Silsesquioxane /Platelets Rich Plasma/Gelrite-Based Hydrogel Scaffold for Bone Tissue Engineering

Current Pharmaceutical Design ◽

10.2174/1381612826666200311124732 ◽

2020 ◽

Vol 26 (26) ◽

pp. 3147-3160

Author(s):

Saeedeh Ahmadipour ◽

Jaleh Varshosaz ◽

Batool Hashemibeni ◽

Leila Safaeian ◽

Maziar Manshaei

Keyword(s):

Bone Fractures ◽

Compressive Strain ◽

Gelation Time ◽

Polyhedral Oligomeric Silsesquioxane ◽

Local Drug Delivery ◽

Gelling Agent ◽

Control Group ◽

Hydrogel Scaffold ◽

Alizarin Red ◽

Oligomeric Silsesquioxane

Background: Polyhedral oligomeric silsesquioxane (POSS) is a monomer with silicon structure and an internal nanometric cage. Objective: The purpose of this study was to provide an injectable hydrogel that could be easily located in open or closed bone fractures and injuries, and also to reduce the possible risks of infections caused by bone graft either as an allograft or an autograft. Methods: Various formulations of temperature sensitive hydrogels containing hydroxyapatite, Gelrite, POSS and platelets rich plasma (PRP), such as the co-gelling agent and cell growth enhancer, were prepared. The hydrogels were characterized for their injectability, gelation time, phase transition temperature and viscosity. Other physical properties of the optimized formulation including compressive stress, compressive strain and Young’s modulus as mechanical properties, as well as storage and loss modulus, swelling ratio, biodegradation behavior and cell toxicity as rheometrical parameters were studied on human osteoblast MG-63 cells. Alizarin red tests were conducted to study the qualitative and quantitative osteogenic capability of the designed scaffold, and the cell adhesion to the scaffold was visualized by scanning electron microscopy. Results: The results demonstrated that the hydrogel scaffold mechanical force and injectability were 3.34±0.44 Mpa and 12.57 N, respectively. Moreover, the scaffold showed higher calcium granules production in alizarin red staining compared to the control group. The proliferation of the cells in G4.5H1P0.03PRP10 formulation was significantly higher than in other formulations (p<0.05). Conclusion: The optimized Gelrite/Hydroxyapatite/POSS/PRP hydrogel scaffold has useful impacts on osteoblasts activity, and may be beneficial for local drug delivery in complications including a break or bone loss.

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External uniaxial compressive strain induced built-in electric field in bilayer two-dimensional As2S3 for photocatalytic water splitting: A first-principles study

Applied Surface Science ◽

10.1016/j.apsusc.2020.147701 ◽

2021 ◽

Vol 535 ◽

pp. 147701 ◽

Cited By ~ 1

Author(s):

Xuefei Liu ◽

Bing Lv ◽

Zhao Ding ◽

Zijiang Luo

Keyword(s):

Electric Field ◽

Water Splitting ◽

First Principles ◽

Compressive Strain ◽

Two Dimensional ◽

Photocatalytic Water Splitting ◽

First Principles Study

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Dynamics of carbon nanotube-based mode-locking fiber lasers

Nanophotonics ◽

10.1515/nanoph-2020-0269 ◽

2020 ◽

Vol 9 (9) ◽

pp. 2731-2761 ◽

Cited By ~ 1

Author(s):

Lin Huang ◽

Yusheng Zhang ◽

Xueming Liu

Keyword(s):

Carbon Nanotube ◽

Fiber Lasers ◽

Modulation Depth ◽

Laser System ◽

Physical Nature ◽

Mode Locking ◽

Environmental Stability ◽

Saturation Intensity ◽

Soliton Dynamics ◽

Deep Modulation

AbstractCarbon nanotube (CNT) can work as excellent saturable absorber (SA) due to its advantages of fast recovery, low saturation intensity, polarization insensitivity, deep modulation depth, broad operation bandwidth, outstanding environmental stability, and affordable fabrication. Its successful application as SA has promoted the development of scientific research and practical application of mode-locked fiber lasers. Besides, mode-locked fiber laser constitutes an ideal platform for investigating soliton dynamics which exhibit profound nonlinear optical dynamics and excitation ubiquitous in many fields. Up to now, a variety of soliton dynamics have been observed. Among these researches, CNT-SA is a key component that suppresses the environmental perturbation and optimizes the laser system to reveal the true highly stochastic and non-repetitive unstable phenomena of the initial self-starting lasing process. This review is intended to provide an up-to-date introduction to the development of CNT-SA based ultrafast fiber lasers, with emphasis on recent progress in real-time buildup dynamics of solitons in CNT-SA mode-locked fiber lasers. It is anticipated that study of dynamics of solitons can not only further reveal the physical nature of solitons, but also optimize the performance of ultrafast fiber lasers and eventually expand their applications in different fields.

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Constitutive Modeling of the Densification Behavior in Open-Porous Cellular Solids

Materials ◽

10.3390/ma14112731 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2731

Author(s):

Ameya Rege

Keyword(s):

Constitutive Model ◽

Cell Walls ◽

Compressive Strain ◽

Pore Collapse ◽

Compressive Response ◽

Linear Elastic ◽

Nonlinear Springs ◽

Different Types ◽

Point Of Intersection ◽

Good Agreement

The macroscopic mechanical behavior of open-porous cellular materials is dictated by the geometric and material properties of their microscopic cell walls. The overall compressive response of such materials is divided into three regimes, namely, the linear elastic, plateau and densification. In this paper, a constitutive model is presented, which captures not only the linear elastic regime and the subsequent pore-collapse, but is also shown to be capable of capturing the hardening upon the densification of the network. Here, the network is considered to be made up of idealized square-shaped cells, whose cell walls undergo bending and buckling under compression. Depending on the choice of damage criterion, viz. elastic buckling or irreversible bending, the cell walls collapse. These collapsed cells are then assumed to behave as nonlinear springs, acting as a foundation to the elastic network of active open cells. To this end, the network is decomposed into an active network and a collapsed one. The compressive strain at the onset of densification is then shown to be quantified by the point of intersection of the two network stress-strain curves. A parameter sensitivity analysis is presented to demonstrate the range of different material characteristics that the model is capable of capturing. The proposed constitutive model is further validated against two different types of nanoporous materials and shows good agreement.

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Strain Effects on the Electronic and Thermoelectric Properties of n(PbTe)-m(Bi2Te3) System Compounds

Materials ◽

10.3390/ma14154086 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4086

Author(s):

Weiliang Ma ◽

Marie-Christine Record ◽

Jing Tian ◽

Pascal Boulet

Keyword(s):

Density Functional ◽

Lattice Thermal Conductivity ◽

Compressive Strain ◽

Van Der Waals Interactions ◽

Functional Theory ◽

Band Engineering ◽

Seebeck Coefficients ◽

The Density Functional Theory ◽

P Type ◽

Narrow Band Gap Semiconductors

Owing to their low lattice thermal conductivity, many compounds of the n(PbTe)-m(Bi2Te3) homologous series have been reported in the literature with thermoelectric (TE) properties that still need improvement. For this purpose, in this work, we have implemented the band engineering approach by applying biaxial tensile and compressive strains using the density functional theory (DFT) on various compounds of this series, namely Bi2Te3, PbBi2Te4, PbBi4Te7 and Pb2Bi2Te5. All the fully relaxed Bi2Te3, PbBi2Te4, PbBi4Te7 and Pb2Bi2Te5 compounds are narrow band-gap semiconductors. When applying strains, a semiconductor-to-metal transition occurs for all the compounds. Within the range of open-gap, the electrical conductivity decreases as the compressive strain increases. We also found that compressive strains cause larger Seebeck coefficients than tensile ones, with the maximum Seebeck coefficient being located at −2%, −6%, −3% and 0% strain for p-type Bi2Te3, PbBi2Te4, PbBi4Te7 and Pb2Bi2Te5, respectively. The use of the quantum theory of atoms in molecules (QTAIM) as a complementary tool has shown that the van der Waals interactions located between the structure slabs evolve with strains as well as the topological properties of Bi2Te3 and PbBi2Te4. This study shows that the TE performance of the n(PbTe)-m(Bi2Te3) compounds is modified under strains.

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