Laser/Optical Diagnostic Techniques for Plasma Materials Processing

1987 ◽  
Vol 98 ◽  
Author(s):  
Ward C. Roman
Keyword(s):  
Gas Phase ◽  
Synergistic Effects ◽  
Diagnostic Techniques ◽  
Materials Processing ◽  
Gas Temperature ◽  
Optical Diagnostic ◽  
Needed Information ◽  
Starting Point ◽  
Plasma Techniques

ABSTRACTThe application of plasma techniques is emerging as one of the more efficient means of processing materials. Technology transfer of plasma systems, both thermal and nonequilibrium, however, is severely limited by a lack of understanding of the basic mechanisms involved which govern the plasma processes used in many applications including advanced coatings. The aspects of plasma gas temperature, and species concentration and distribution (molecular, atomic, excited) in the gas phase and associated synergistic effects are fragmentary and unclear. Laser/optical diagnostic techniques represent a critical starting point for providing this needed information; they are in-situ, non-intrusive,species and quantum level specific and give excellent spatial and temporal resolution. A survey of Laser/optical diagnostic techniques applicable to plasma materials processing needs is presented. Some examples of the use of different techniques are also given.

Diagnostic Techniques for PACVD Systems for Depositing Protective Coatings

1988 ◽  
Vol 117 ◽  
Author(s):  
Ward C. Roman ◽  
John H. Stufflebeam ◽  
Alan C. Eckbreth
Keyword(s):  
Protective Coatings ◽  
Plasma Chemistry ◽  
Diagnostic Techniques ◽  
Gas Temperature ◽  
Remote Sensors ◽  
Science Base ◽  
Starting Point ◽  
Plasma Species ◽  
Laser Diagnostic

AbstractPACVD techniques for depositing protective coatings are an emerging field in plasma processing technology. Technology transfer is limited by a lack of understanding of the basic mechanisms involved in the gas phase plasma chemistry. The aspects of plasma species concentration and distribution and plasma gas temperature are fragmentary and unclear. Laser diagnostic techniques represent a critical starting point for providing some of this needed information. The techniques are in-situ, nonintrusive, and give excellent spatial and temporal resolution. Numerous diagnostic techniques for detailed coating characterization are available, but a correlation of the PACVD parameters with some of the key coating properties is required. Thus, a predictive capability that is lacking in the present science base can be established together with important phenomenological aspects needed for efficient deposition of high quality protective coatings. As the mechanisms become better understood, use of remote sensors and A.I may then be introduced. This paper will review selected diagnostic techniques available for characterizing these nonequilibrium reactive plasmas and the coatings.

scholarly journals Diagnostic Development for Advanced Power Systems

1980 ◽  
Author(s):  
J. C. F. Wang ◽  
W. L. Flower ◽  
D. R. Hardesty
Keyword(s):  
Power Systems ◽  
Small Angle ◽  
Detection System ◽  
Pulsed Laser ◽  
Diagnostic Techniques ◽  
Particle Sizing ◽  
Gas Temperature ◽  
Test Bed ◽  
Optical Diagnostic ◽  
Scattering Measurements

The high temperatures, pressures, and particulate densities present in coal-fired advanced power systems place severe limitations on conventional probe techniques for thermometry, velocimetry, and gas and particulate analysis. Although laser-based techniques for measuring gas temperature, velocity, and composition have been demonstrated in relatively clean flame gases, little is known regarding their applicability to measurements in the product streams from coal-fired combustors. Hence, a program has been established at Sandia to develop and assess advanced physical sampling and laser-based optical diagnostic techniques. This paper describes some of the techniques under development, including a small-angle near-forward scattering optical arrangement for particle sizing and a system for making Raman-scattering measurements of gas temperature using a pulsed laser and a gated detection system. Also described here is the atmospheric combustor exhaust simulator (ACES) facility being constructed as the test bed for the diagnostic techniques.

Remote sensing of coal-fired MHD by optical diagnostic techniques

1983 ◽  
Author(s):  
D. MURPHREE ◽  
R. COOK ◽  
W. SHEPARD ◽  
L. BAUMAN ◽  
J. GASSAWAY ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Diagnostic Techniques ◽  
Optical Diagnostic

Discovery of an Unexpected Similarity in Ligand Binding Between BRD4 and PPARγ

2019 ◽  
Author(s):  
Lina Humbeck ◽  
Jette Pretzel ◽  
Saskia Spitzer ◽  
Oliver Koch
Keyword(s):  
Cancer Therapy ◽  
Drug Targets ◽  
Synergistic Effects ◽  
Complex Structure ◽  
Peroxisome Proliferator ◽  
Resistance Development ◽  
Peroxisome Proliferator Activated Receptor ◽  
Starting Point ◽  
Fundamental Research ◽  
Important Drug

Knowledge about interrelationships between different proteins is crucial in fundamental research for the elucidation of protein networks and pathways. Furthermore, it is especially critical in chemical biology to identify further key regulators of a disease and to take advantage of polypharmacology effects. A comprehensive scaffold-based analysis uncovered an unexpected relationship between bromodomain-containing protein 4 (BRD4) and peroxisome-proliferator activated receptor gamma (PPARγ). They are both important drug targets for cancer therapy and many more important diseases. Both proteins share binding site similarities near a common hydrophobic subpocket which should allow the design of a polypharmacology-based ligand targeting both proteins. Such a dual-BRD4-PPARγ-modulator could show synergistic effects with a higher efficacy or delayed resistance development in, for example, cancer therapy. Thereon, a complex structure of sulfasalazine was obtained that involves two bromodomains and could be a potential starting point for the design of a bivalent BRD4 inhibitor.

The Undiscovered Potential of Essential Oils for Treating SARS-CoV-2 (COVID-19)

2020 ◽  
Vol 26 (41) ◽  
pp. 5261-5277
Author(s):  
Peter J. Wilkin ◽  
Minnatallah Al-Yozbaki ◽  
Alex George ◽  
Girish K. Gupta ◽  
Cornelia M. Wilson
Keyword(s):  
Essential Oils ◽  
Clinical Symptoms ◽  
Synergistic Effects ◽  
World Health Organisation ◽  
Diagnostic Techniques ◽  
World Health ◽  
Clinical Aspects ◽  
Traditional Use ◽  
In Silico Studies ◽  
The World

On 11th March 2020, the World Health Organisation (WHO) announced a pandemic caused by a novel beta-coronavirus SARS-CoV-2, designated COVID-19. The virus emerged in December 2019 in Wuhan, China, has spread across the world as a global pandemic. The traditional use of medicines from plants can be traced back to 60,000 years. Global interest in the development of drugs from natural products has increased greatly during the last few decades. Essential oils (EOs) have been studied through the centuries and are known to possess various pharmaceutical properties. In the present review, we have highlighted the current biology, epidemiology, various clinical aspects, different diagnostic techniques, clinical symptoms, and management of COVID-19. An overview of the antiviral action of EOs, along with their proposed mechanism of action and in silico studies conducted, is described. The reported studies of EOs' antiviral activity highlight the baseline data about the additive and/or synergistic effects among primary or secondary phytoconstituents found in individual oils, combinations or blends of oils and between EOs and antiviral drugs. It is hoped that further research will provide better insights into EOs' potential to limit viral infection and aid in providing solutions through natural, therapeutically active agents.

scholarly journals Multi-Targeting Bioactive Compounds Extracted from Essential Oils as Kinase Inhibitors

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2174 ◽  
Author(s):  
Annalisa Maruca ◽  
Delia Lanzillotta ◽  
Roberta Rocca ◽  
Antonio Lupia ◽  
Giosuè Costa ◽  
...  
Keyword(s):  
Essential Oils ◽  
Binding Affinity ◽  
Structural Changes ◽  
Kinase Inhibitors ◽  
Synergistic Effects ◽  
Data Bank ◽  
Binding Modes ◽  
Starting Point ◽  
Target Action ◽  
Potential Resource

Essential oils (EOs) are popular in aromatherapy, a branch of alternative medicine that claims their curative effects. Moreover, several studies reported EOs as potential anti-cancer agents by inducing apoptosis in different cancer cell models. In this study, we have considered EOs as a potential resource of new kinase inhibitors with a polypharmacological profile. On the other hand, computational methods offer the possibility to predict the theoretical activity profile of ligands, discovering dangerous off-targets and/or synergistic effects due to the potential multi-target action. With this aim, we performed a Structure-Based Virtual Screening (SBVS) against X-ray models of several protein kinases selected from the Protein Data Bank (PDB) by using a chemoinformatics database of EOs. By evaluating theoretical binding affinity, 13 molecules were detected among EOs as new potential kinase inhibitors with a multi-target profile. The two compounds with higher percentages in the EOs were studied more in depth by means Induced Fit Docking (IFD) protocol, in order to better predict their binding modes taking into account also structural changes in the receptor. Finally, given its good binding affinity towards five different kinases, cinnamyl cinnamate was biologically tested on different cell lines with the aim to verify the antiproliferative activity. Thus, this work represents a starting point for the optimization of the most promising EOs structure as kinase inhibitors with multi-target features.

scholarly journals In Situ Observation of Electron-Beam-Induced Formation of Nano-Structures in PbTe

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 163
Author(s):  
Iryna Zelenina ◽  
Igor Veremchuk ◽  
Yuri Grin ◽  
Paul Simon
Keyword(s):  
Electron Beam ◽  
Gas Phase ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Atomic Scale ◽  
In Situ Observation ◽  
Nano Structures ◽  
Transmission Electron ◽  
Initial Crystal

Nano-scaled thermoelectric materials attract significant interest due to their improved physical properties as compared to bulk materials. Well-shaped nanoparticles such as nano-bars and nano-cubes were observed in the known thermoelectric material PbTe. Their extended two-dimensional nano-layer arrangements form directly in situ through electron-beam treatment in the transmission electron microscope. The experiments show the atomistic depletion mechanism of the initial crystal and the recrystallization of PbTe nanoparticles out of the microparticles due to the local atomic-scale transport via the gas phase beyond a threshold current density of the beam.

scholarly journals An Atmospheric Origin for HCN-Derived Polymers on Titan

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 965
Author(s):  
Zoé Perrin ◽  
Nathalie Carrasco ◽  
Audrey Chatain ◽  
Lora Jovanovic ◽  
Ludovic Vettier ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Gas Phase ◽  
Formation Process ◽  
Upper Atmosphere ◽  
Gas Mixture ◽  
Space Probe ◽  
Atmospheric Haze ◽  
Formation And Evolution ◽  
Haze Formation

Titan’s haze is strongly suspected to be an HCN-derived polymer, but despite the first in situ measurements by the ESA-Huygens space probe, its chemical composition and formation process remain largely unknown. To investigate this question, we simulated the atmospheric haze formation process, experimentally. We synthesized analogues of Titan’s haze, named Titan tholins, in an irradiated N2–CH4 gas mixture, mimicking Titan’s upper atmosphere chemistry. HCN was monitored in situ in the gas phase simultaneously with the formation and evolution of the haze particles. We show that HCN is produced as long as the particles are absent, and is then progressively consumed when the particles appear and grow. This work highlights HCN as an effective precursor of Titan’s haze and confirms the HCN-derived polymer nature of the haze.

scholarly journals Chemical Modification as a Method of Improving Biocompatibility of Carbon Nonwovens

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3198
Author(s):  
Justyna Frączyk ◽  
Sylwia Magdziarz ◽  
Ewa Stodolak-Zych ◽  
Ewa Dzierzkowska ◽  
Dorota Puchowicz ◽  
...  
Keyword(s):  
Surface Modification ◽  
Cellular Response ◽  
Fiber Surface ◽  
Thermal Conversion ◽  
Cartilage Tissue ◽  
Polar Component ◽  
Nonwoven Fabrics ◽  
Biological Compatibility ◽  
Starting Point

It was shown that carbon nonwoven fabrics obtained from polyacrylonitrile fibers (PAN) by thermal conversion may be modified on the surface in order to improve their biological compatibility and cellular response, which is particularly important in the regeneration of bone or cartilage tissue. Surface functionalization of carbon nonwovens containing C–C double bonds was carried out using in situ generated diazonium salts derived from aromatic amines containing both electron-acceptor and electron-donor substituents. It was shown that the modification method characteristic for materials containing aromatic structures may be successfully applied to the functionalization of carbon materials. The effectiveness of the surface modification of carbon nonwoven fabrics was confirmed by the FTIR method using an ATR device. The proposed approach allows the incorporation of various functional groups on the nonwovens’ surface, which affects the morphology of fibers as well as their physicochemical properties (wettability). The introduction of a carboxyl group on the surface of nonwoven fabrics, in a reaction with 4-aminobenzoic acid, became a starting point for further modifications necessary for the attachment of RGD-type peptides facilitating cell adhesion to the surface of materials. The surface modification reduced the wettability (θ) of the carbon nonwoven by about 50%. The surface free energy (SFE) in the chemically modified and reference nonwovens remained similar, with the surface modification causing an increase in the polar component (ɣp). The modification of the fiber surface was heterogeneous in nature; however, it provided an attractive site of cell–materials interaction by contacting them to the fiber surface, which supports the adhesion process.

In Situ Optical Analysis of the Gas Phase during the Deposition of Silicon Carbide from Methyltrichlorosilane

1996 ◽  
Vol 143 (5) ◽  
pp. 1654-1661 ◽  
Author(s):  
M. Ganz ◽  
N. Dorval ◽  
M. Lefebvre ◽  
M. Péalat ◽  
F. Loumagne ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Gas Phase ◽  
Optical Analysis
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