Metal Surface Treatment with Particle Fluxes Taking into Account the Internal Boundary

2016 ◽  
Vol 685 ◽  
pp. 413-416 ◽  
Author(s):  
E.S. Parfenova ◽  
Anna G. Knyazeva
Keyword(s):  
Ion Implantation ◽  
Surface Treatment ◽  
Metal Surface ◽  
Internal Boundary ◽  
Model Parameters ◽  
Isothermal Model ◽  
Initial Stage ◽  
Before And After ◽  
Implantation Process ◽  
Particle Fluxes

In this paper, the isothermal model of the initial stage of ion implantation process taking into account internal boundary is presented. It is assumed that implantable impurity generates mechanical perturbations. These waves can propagate with different velocities before and after the border. The examples of the waveform evolution at transition across the boundary for different combinations of the model parameters are presented.

The Mathematical Modeling of the Initial Stage of Ion Implantation into the Target with Coating

2017 ◽  
Vol 743 ◽  
pp. 138-141
Author(s):  
Elena S. Parfenova
Keyword(s):  
Mathematical Modeling ◽  
Ion Implantation ◽  
Internal Boundary ◽  
Isothermal Model ◽  
Initial Stage ◽  
Before And After ◽  
Implantation Process

The paper presents a non-isothermal model of the initial stage of ion implantation process. The model takes into account the existence of internal interfaces. The model assumes that the implantable impurity generates mechanical perturbations. These disturbances can propagate at different speeds before and after internal boundary. The examples of the waveform evolution in transition across the border are shown.

The Vacancy Generation Influence on the Initial Stage of Ion Implantation

2015 ◽  
Vol 1097 ◽  
pp. 29-34
Author(s):  
E.S. Parfenova ◽  
Anna G. Knyazeva
Keyword(s):  
Surface Layer ◽  
Ion Implantation ◽  
Metal Surface ◽  
Impurity Concentration ◽  
Coupled Model ◽  
Irreversible Processes ◽  
Concentration Profiles ◽  
Thermodynamics Of Irreversible Processes ◽  
Vacancy Generation ◽  
Initial Stage

The coupled model is presented to describe the elements penetration into the surface layer of metal during the process of ion implantation. Mechanical stresses arising due to the interaction of particles with the surface affect the redistribution of the implanted impurity. In addition, the existence of vacancies in the metal surface and their generation under the stresses influence are taken into account. The kinetic law is written on the basis of the thermodynamics of irreversible processes. The solution had been found numerically. As a result, the distributions of impurity concentration and deformations have been obtained for various time moments. The comparison of the concentration profiles with vacancies and without their have been given.

Dynamics of Diffusion and Mechanical Waves Interaction under Conditions of Metal Surface Treatment with Particle Fluxes

2014 ◽  
Vol 1040 ◽  
pp. 466-471
Author(s):  
E.S. Parfenova ◽  
A.G. Knyazeva ◽  
Yu.P. Azhel
Keyword(s):  
Surface Treatment ◽  
Particle Flux ◽  
Wave Interaction ◽  
Stress Wave Propagation ◽  
Problem Solution ◽  
Isothermal Model ◽  
Coupled Problem ◽  
Initial Stage ◽  
Mechanical Waves ◽  
Waves Interaction

A coupled isothermal model at the initial stage of a solid body surface treatment with particle flux is presented in this paper. The model takes account of the interaction of two different scale processes: impurity diffusion and mechanical stress wave propagation. The transition to dimensionless variables is briefly described. The examples of the coupled problem solution illustrating the wave interaction under the action of one pulse and two successive pulses are given.

The Features of Diffusion and Mechanical Waves Interaction at the Initial Stage of Metal Surface Treatment by Particle Beam under Nonisothermal Conditions

2016 ◽  
Vol 712 ◽  
pp. 99-104 ◽  
Author(s):  
Elena S. Parfenova ◽  
Anna G. Knyazeva
Keyword(s):  
Metal Surface ◽  
Substrate Surface ◽  
Relaxation Times ◽  
Particle Beam ◽  
Model Parameters ◽  
Initial Stage ◽  
Mechanical Waves ◽  
Mass Flows ◽  
Waves Interaction ◽  
Nonisothermal Conditions

The paper presents a mathematical model of the initial stage of ion implantation into the metal surface. The model takes into account the finiteness of relaxation times of heat and mass flows. The relation of introduced impurity concentration, stresses and strains arising as a result of particles impact to the substrate surface and substrate temperature by varying model parameters is numerically investigated.

scholarly journals Effect of sizing agent on interfacial properties of carbon fiber-reinforced PMMA composite

2021 ◽  
Vol 30 ◽  
pp. 2633366X2097865
Author(s):  
Li Jian
Keyword(s):  
Shear Strength ◽  
Surface Treatment ◽  
Photoelectron Spectroscopy ◽  
Resin Composite ◽  
Contact Angles ◽  
Static Contact ◽  
Before And After ◽  
C Value ◽  
Interlayer Shear Strength ◽  
Pmma Resin

The surface treatment of carbon fibers (CFs) was carried out using a self-synthesized sizing agent. The effects of sizing agent on the surface of CFs and the interface properties of CF/polymethyl methacrylate (PMMA) composites were mainly studied. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and static contact angle were used to compare and study the CFs before and after the surface treatment, including surface morphology, surface chemical element composition, and wettability of the surface. The influence of sizing agent on the mechanical properties of CF/PMMA resin composite interface was investigated. The results show that after sizing treatment, the CF surface O/C value increased by 35.1% and the contact angles of CF and resin decreased by 16.2%. The interfacial shear strength and interlayer shear strength increased by 12.6%.

scholarly journals Plasma Exosomal miRNA Levels after Radiotherapy Are Associated with Early Progression and Metastasis of Cervical Cancer: A Pilot Study

2021 ◽  
Vol 10 (10) ◽  
pp. 2110
Author(s):  
Oyeon Cho ◽  
Do-Wan Kim ◽  
Jae-Youn Cheong
Keyword(s):  
Cervical Cancer ◽  
Pilot Study ◽  
Biological Functions ◽  
Patients With Cancer ◽  
Initial Stage ◽  
Exosomal Mirnas ◽  
Early Progression ◽  
Before And After ◽  
Microenvironmental Factors ◽  
Exosomal Mirna

Plasma exosomal miRNAs are key regulators of cell-cell interactions associated with several biological functions in patients with cancer. This pilot study aimed to investigate the log2 fold change (log2FC) of the expression of exosomal miRNAs and related mRNAs in the blood of patients with cervical cancer to identify prognostic markers better than those currently available. We sequenced plasma exosomal RNA from 56 blood samples collected from 28 patients with cervical cancer, who had been treated with concurrent chemoradiotherapy (CCRT). Changes in the expression of miRNAs and mRNAs before and after CCRT were represented as log2FC. Their biological functions were studied by miRNA-mRNA network analysis, using ingenuity pathway analysis, after the selection of two groups of miRNAs, each associated with early progression (EP) and metastasis, also described as initial stage. Seven patients experienced EP, three of whom died within four months after progression. Reduced levels of miR-1228-5p, miR-33a-5p, miR-3200-3p, and miR-6815-5p and increased levels of miR-146a-3p in patients with EP revealed unresolved inflammation, with accompanying increased expression of PCK1 and decreased expression of FCGR1A. Increased levels of miR-605-5p, miR-6791-5p, miR-6780a-5p, and miR-6826-5p and decreased levels of miR-16-1-3p (or 15a-3p) were associated with the degree of metastasis and led to the systemic activation of myeloid, endothelial, and epithelial cells, as well as neurons, phagocytes, and platelets. Log2FCs in the expression of miRNAs and mRNAs from plasma exosomes after CCRT are associated with EP and metastasis, reflecting unresolved inflammation and systemic microenvironmental factors, respectively. However, this study, supported by preliminary data insufficient to reach clear conclusions, should be verified in larger prospective cohorts.

scholarly journals Control of Local Hardness Gradient of Metal Surface by Inclined Surface Treatment Using Ultrasonic Nanocrystal Surface Modification

2021 ◽  
Vol 8 (2) ◽  
pp. 533-546
Author(s):  
Yeong-Kwan Jo ◽  
Yeong-Wook Gil ◽  
Do-Sik Shim ◽  
Young-Sik Pyun ◽  
Sang-Hu Park
Keyword(s):  
Surface Modification ◽  
Surface Treatment ◽  
Metal Surface ◽  
Incident Angle ◽  
Surface Hardness ◽  
Parameter Study ◽  
Local Hardness ◽  
Practical Usefulness ◽  
Inclined Surface ◽  
Hardness Gradient

AbstractWe propose an effective method to control the local hardness and morphology of a metal surface by tilting the incident angle of a horn during ultrasonic nanocrystal surface modification (UNSM). In this study, surface treatment using UNSM was performed on an S45C specimen and a parameter study was conducted for optimization. The process parameters were the feeding rate, static load, striking force, and processing angle (Ф). In particular, the Ф was analyzed by tilting the horn by 0°, 10°, 20°, 30°, 40°, and 45° to understand its effect on surface hardness and changes in the morphology. From fundamental experiments, some important phenomena were observed, such as grain-microstructure changes along the processing and thickness directions. Furthermore, to verify the practical usefulness of this study, a flat and a hemispherical specimen of S45C material were treated using UNSM with various values of Ф. A significant change in hardness (an increase from 2–45%) and a gradual hardness gradient on the tested specimens could be easily realized by the proposed method. Therefore, we believe that the method is effective for controlling the mechanical hardness of a metal surface.

A New Hafnium-Beryllium System Prioduced by Ion Implantation and Annealing Techniques

1983 ◽  
Vol 27 ◽  
Author(s):  
J.C. Soares ◽  
A.A. Melo ◽  
M.F. DA Silva ◽  
E.J. Alves ◽  
K. Freitag ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystals ◽  
Room Temperature ◽  
Low Dose ◽  
Correlation Method ◽  
High Dose ◽  
Tetrahedral Sites ◽  
Time Differential ◽  
Before And After ◽  
Beryllium Foil

ABSTRACTLow and high dose hafnium imolanted beryllium samoles have been prepared at room temperature by ion implantation of beryllium commercial foils and single crystals. These samples have been studied before and after annealing with the time differential perturbed angular correlation method (TDPAC) and with Rutherford backscattering and channeling techniques. A new metastable system has been discovered in TDPAC-measurements in a low dose hafnium implanted beryllium foil annealed at 500°C. Channeling measurements show that the hafnium atoms after annealing, are in the regular tetrahedral sites but dislocated from the previous position occupied after implantation. The formation of this system is connected with the redistribution of oxygen in a thin layer under the surface. This effect does not take place precisely at the same temperature in foils and in single crystals.

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