Effect of Conductivity and Environmental Pressure on Electro-Plasma Process (EPP)

2009 ◽  
Author(s):  
M. A. Wahab ◽  
Jiandong Liang ◽  
Shengmin Guo
Keyword(s):  
Surface Modification ◽  
Surface Morphology ◽  
Input Voltage ◽  
Power Input ◽  
Total Power ◽  
Metallic Surfaces ◽  
Plasma Process ◽  
Electrolytic Solution ◽  
Environmental Pressure ◽  
Unique Surface

Electrolytic plasma process is an efficient surface modification method for metallic materials. With proper control of the process parameters Electro-Plasma Process (EPP) could generate unique surface morphology, which is suitable for effective cleaning of the metallic surfaces and inherently, good adhesion strength can be achieved for eventual coating the surfaces. Increasing input voltage beyond the conventional Faraday region of electrolysis, luminous discharge is observed on the surface of one of the electrodes. The electrode surface must be covered by layers of bubbles before the discharge could be set in. The discharge of energy is then taken place in an explosive way with localized high temperature. The combination of heat and kinetic impact could effectively remove the surface contaminants and could produce a unique surface morphology. In this paper, the conditions of process control parameters and the resultant surface conditions that could be achieved are studied. It has been found that elevated temperature is beneficial towards the plasma formation on electrodes; and the increase of temperature essentially increases the kinetic energy of electrons in the electrolytic solution and a high electrolyte temperature assists the boiling process and the chemical reactions that generate bubbles. The conductivity of the electrolytic solution could also affect the threshold voltage and the current density, but the total power input does not vary significantly with conductivity. Environmental pressure has been proved to be the single most critical important factor for Electro Plasma Process; and by increasing the pressure level the total breakdown energy tends to increase and more importantly, the resultant surfaces manifest that the energy consumed for surface modification increases with pressure.

scholarly journals Polydopamine-Assisted Surface Modification for Bone Biosubstitutes

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Shishu Huang ◽  
Nuanyi Liang ◽  
Yang Hu ◽  
Xin Zhou ◽  
Noureddine Abidi
Keyword(s):  
Tissue Engineering ◽  
Surface Modification ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Coating Layer ◽  
Tissue Scaffolds ◽  
Surface Modifier ◽  
Biomaterial Surface ◽  
Superior Surface ◽  
Unique Surface

Polydopamine (PDA) prepared in the form of a layer of polymerized dopamine (DA) in a weak alkaline solution has been used as a versatile biomimetic surface modifier as well as a broadly used immobilizing macromolecule. This review mainly discusses the progress of biomaterial surface modification inspired by the participation of PDA in bone tissue engineering. A comparison between PDA-assisted coating techniques and traditional surface modification applied to bone tissue engineering is first presented. Secondly, the chemical composition and the underlying formation mechanism of PDA coating layer as a unique surface modifier are interpreted and discussed. Furthermore, several typical examples are provided to evidence the importance of PDA-assisted coating techniques in the construction of bone biosubstitutes and the improvement of material biocompatibility. Nowadays, the application of PDA as a superior surface modifier in multifunctional biomaterials is drawing tremendous interests in bone tissue scaffolds to promote the osteointegration for bone regeneration.

scholarly journals Mass Production of Plasma Activated Water: Case Studies of Its Biocidal Effect on Algae and Cyanobacteria

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3167
Author(s):  
Jan Čech ◽  
Pavel Sťahel ◽  
Jozef Ráheľ ◽  
Lubomír Prokeš ◽  
Pavel Rudolf ◽  
...  
Keyword(s):  
Plasma Source ◽  
Power Input ◽  
Biologically Active ◽  
Hydrodynamic Cavitation ◽  
Total Power ◽  
Flow Conditions ◽  
Liquid Environment ◽  
Efficient Treatment ◽  
Discharge Performance ◽  
Plasma Activated Water

Efficient treatment of contaminated water in industrially viable volumes is still a challenging task. The hydrodynamic cavitation plasma jet (HCPJ) is a promising plasma source for industrial-scale generation of biologically active environments at high flow rates of several m3/h. The combined effect of a hydro-mechanical phenomenon consisting of hydrodynamic cavitation and electrical discharge in cavitation voids was found to be highly efficient for large-volume generation of reactive oxygen species, ultraviolet (UV) radiation, and electro-mechanical stress in a liquid environment. Here, the persistence of biocidal properties of HCPJ-activated water (i.e., plasma-activated water (PAW)) was tested by the study of algae and cyanobacteria inactivation. Algae and cyanobacteria cultivated in media containing PAW (1:1) were completely inactivated after 72 h from first exposure. The test was performed at a total power input of up to 0.5 kWh/m3 at the treated liquid flow rate of 1 m3/h. A beneficial modification of our previous HCPJ design is described and thoroughly characterized with respect to the changes of hydrodynamic flow conditions as well as discharge performance and its optical characteristics. The modification proved to provide high biocidal activity of the resulting PAW, which confirms a strong potential for further design optimization of this promising water (liquid) plasma source.

Estimation of Material Removal by Profilometer Measurements in Mass Finishing

2014 ◽  
Vol 611-612 ◽  
pp. 615-622
Author(s):  
Luana Bottini ◽  
Alberto Boschetto ◽  
Francesco Veniali
Keyword(s):  
Plastic Deformation ◽  
Surface Modification ◽  
Surface Morphology ◽  
Process Parameters ◽  
Material Removal ◽  
Machining Process ◽  
Local Surface ◽  
Mass Finishing ◽  
Barrel Finishing ◽  
The Relationship

This paper presents a new procedure to estimate the material removal (MR) in such conditions or operations where small amount of material or wear occur. The monitoring of material removal is essential to understand the machining mechanisms of several processes such as super finishing ones. For example the study of some mass finishing (MF) operations, i. e. the barrel finishing (BF) and the spindle finishing (SF), have been always limited by the difficulty to measure the local surface modification. Thus there is no knowledge about the relationship between process parameters and obtainable surface quality. The procedure is based on profilometer measurements typically used to characterized local surface morphology. An algorithm automatically finds the most representative peak of the profile. The comparison between the Abbot-Firestone curves, related to peaks achieved in different condition, permits to measure the volume of material removed by the operation. This method overcomes the well-known problem to repositioning the instrument in the same place when the part is moved from machining process to measurement one. In the case of BF, experimental demonstrated the reliability of this methodology to provide the evolution of material removed as a function of working time. Moreover the graphical plot of the representative peak at different times gave important information about machining mechanism. In particular it allowed to verify assumptions regarding the plastic deformation and the peak cutting which takes place.

Surface Modification of EPDM Rubber by Reactive Argon-Oxygen Plasma Process

2002 ◽  
Vol 374 ◽  
pp. 45-52 ◽  
Author(s):  
Jorge Carlos Narciso Dutra ◽  
Marcos Massi ◽  
Choyu Otani ◽  
Rita De Cassia Lazzarini Dutra ◽  
Milton Faria Diniz ◽  
...  
Keyword(s):  
Surface Modification ◽  
Oxygen Plasma ◽  
Plasma Process ◽  
Epdm Rubber

scholarly journals Nanotubular oxide layers formed on the Ti-based implants surfaces-application and possible damages: a review

10.30544/401 ◽  
2018 ◽  
Vol 24 (4) ◽  
Author(s):  
Dragana Ranko Barjaktarević ◽  
Veljko R Djokić ◽  
Ivana D. Damnjanović ◽  
Marko P. Rakin
Keyword(s):  
Surface Modification ◽  
Oxide Layer ◽  
Electrochemical Anodization ◽  
Surrounding Tissue ◽  
Medical Implants ◽  
Metallic Surfaces ◽  
Implant Surface ◽  
Oxide Layers ◽  
Damage Initiation ◽  
Artificial Hip Joints

Implant surface properties define the interaction of the implant with the surrounding tissue. To obtained advanced biological, mechanical and physical properties, metallic implants are often exposed to different kinds of surface modification. The electrochemical anodization process is an efficient method for nanostructured surface modification, which leads to the formation of nanotubular oxide layers on metallic surfaces. These obtained layers could be applied in biomedicine due to their chemical stability, biocompatibility and non-toxic nature in the human body. As a part of different kinds of medical implants such as dental implants, artificial hip joints, bone plates, screws, spinal fixation devices or stents, an oxide layer significantly increases cells adhesion and plays a significant role in improving the rate of osseointegration. However, an important topic in research of implants with a nanotubular oxide layer is integrity during fixation and exploitation and possible damage initiation and development. This review article aims to present the application of nanotubular oxide layers in biomedicine and to explain their influence on the biocompatibility and osseointegration of medical implants. Influence of the layers properties, such as roughness or contact angle, and the influence of their morphology on biocompatibility and osseointegration, as well as the influence of fixation and exploitation on the damage of the nanotubular oxide layer, are considered.

Process characteristics of screw impellers with a draught tube for Newtonian liquids. The power input

1981 ◽  
Vol 46 (9) ◽  
pp. 2007-2020 ◽  
Author(s):  
Pavel Seichter ◽  
Jiří Dohnal ◽  
František Rieger
Keyword(s):  
Reynolds Number ◽  
Experimental Verification ◽  
Power Input ◽  
Creeping Flow ◽  
Total Power ◽  
Geometrical Parameters ◽  
Draught Tube ◽  
Process Characteristics ◽  
Wide Range ◽  
Newtonian Liquids

An expression has been proposed for the power input of a screw impeller with a draught tube in the creeping flow regime based on the analogy with extruder screws. Experimental verification has confirmed practical utility of the expression in a wide range of geometrical parameters of the impeller and for the Reynolds number for mixing below 20. The total power input of the impeller is expressed as a sum of the input inducing the drag flow and the input to create the pressure flow. The former of the inputs may be deduced from the theory of extruders while an empirical approach based on experiment has been used to formulate an expression for the latter.

scholarly journals Surface Modification of Materials by Plasma Process and UV-induced Grafted Polymerization for Biomedical Applications

Shinku ◽  
2007 ◽  
Vol 50 (10) ◽  
pp. 609-614 ◽  
Author(s):  
Ko-Shao CHEN ◽  
Su-Chen CHEN ◽  
Wei-Cheng LIEN ◽  
Jui-Che TSAI ◽  
Yuan-An KU ◽  
...  
Keyword(s):  
Surface Modification ◽  
Biomedical Applications ◽  
Plasma Process ◽  
Modification Of Materials

The Study of Surface Morphology and Roughness of Silicon Wafers Treated by Plasma

2020 ◽  
Vol 980 ◽  
pp. 88-96
Author(s):  
Jin Rui Bai ◽  
Rui Xiang Hou
Keyword(s):  
Surface Morphology ◽  
Plasma Treatment ◽  
Silicon Wafer ◽  
Processing Time ◽  
Surface Region ◽  
Silicon Wafers ◽  
Plasma Process ◽  
Plasma Doping ◽  
Atom Force Microscope ◽  
The Way

Plasma is generally used for the doping of semiconductors. During plasma doping process, plasma interacts with the surface of semiconductor. As a result, defects are induced in the surface region. In this work, the surface morphology and roughness of silicon wafer caused by plasma treatment is studied by use of atom force microscope (AFM). It is found that, during the plasma process, each of the processing time of plasma, location of silicon wafer in plasma and the way of placement of silicon wafer has an influence on the surface morphology and roughness and the reason is discussed. The interaction between plasma and the surface of silicon wafer is qualitatively discussed.

INFLUENCE OF THE MANAGED FORESTS ON CO2 BALANCE IN EARTH’S ATMOSPHERE

2021 ◽  
Vol 43 (1) ◽  
pp. 54-66
Author(s):  
Gennadiy BULATKIN
Keyword(s):  
Indirect Costs ◽  
Power Input ◽  
Nitrogen Fertilizers ◽  
Total Power ◽  
Natural Form ◽  
Earth’S Atmosphere ◽  
Aspen Tree ◽  
Co2 Balance ◽  
Earth's Atmosphere ◽  
The Impact

Technical energy costs required for forest cultivation, estimation of C-CO2 fluxes in model experiments with coniferous species of pine Pinus sylvestris L. and leaves species, natural form and gene modified clone of the ordinary aspen tree Populus tremula L., have been analyzed. At plantation cultivation of transgenic aspen clone with nitrogen fertilizers indirect costs of technical energy made up 85 % of total power input. A new three-stage method has been developed for assessing the impact of forests on the CO2 balance in the Earth's atmosphere. The final value of CO2 sink from the atmosphere at afforestation depends on the way wood is used.

Development of a Plasma Process for Microfluidic Devices in the Prospect of Cell Attachment

2010 ◽  
Vol 89-91 ◽  
pp. 598-603
Author(s):  
Nathalie Vo Tan Tho ◽  
Hervé Willaime ◽  
Patrick Tabeling ◽  
Farzaneh Arefi-Khonsari ◽  
D. Mantovani ◽  
...  
Keyword(s):  
Surface Modification ◽  
Vapor Deposition ◽  
Low Temperatures ◽  
Cell Attachment ◽  
Chemical Vapor ◽  
Microfluidic Devices ◽  
Microfluidic System ◽  
Plasma Process ◽  
Dry Process ◽  
Inner Surface

Plasma processing has been developed to produce selective chemistry in the inner surface of a microfluidic system. This dry process is an alternative solution to the Chemical Vapor Deposition (CVD) process that allows us to work at low temperatures thus avoiding the degradation of the substrate by heat. The present study focused on the surface modification of PDMS in order to make them more hydrophilic and capable to exhibit a high percentage of COOH functions which will provide a good asset for future cell attachment.

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