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9. Plasma Kinetic Theory

Author

Chaudhary, Kashif, primary, Imam, Auwal Mustapha, additional, Rizvi, Syed Zuhaib Haider, additional, and Ali, Jalil, additional

Published
2018
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14. Plasma kinetic theory

Author

George, Kyzas, Athanasios, Mitropoulos, Chaudhary, Kashif, Imam, Auwal Mustapha, Haider Rizvi, Syed Zuhaib, Ali, Jalil, George, Kyzas, Athanasios, Mitropoulos, Chaudhary, Kashif, Imam, Auwal Mustapha, Haider Rizvi, Syed Zuhaib, and Ali, Jalil

Abstract

The description of plasma using fluid model is mostly insufficient and requires the consideration of velocity distribution which leads to kinetic theory. Kinetic theory of plasma describes and predicts the condition of plasma from microscopic interactions and motions of its constituents. It provides an essential basis for an introductory course on plasma physics as well as for advanced kinetic theory. Plasma kinetics deals with the relationship between velocity and forces and the study of continua in velocity space. Plasma kinetics mathematical equations provide aid to the readers in understanding simple tools to determine the plasma dynamics and kinetics as described in this chapter. Kinetic theory provides the basics and essential introduction to plasma physics and subsequently advanced kinetic theory. Plasma waves, oscillations, frequencies, and applications are the subjects of kinetic theory. In this chapter, mathematical formulations essential for exploring plasma kinetics are compiled and described simplistically along with a precise discussion on basic plasma parameters in simple language with illustrations in some cases.

Published
2020

18. OPTIMIZATION OF TISSUE CULTURE PROTOCOL FOR REGENERATION AND DIRECT MULTIPLICATION OF MORINGA OLEIFERA BY SEED GERMINATION

Author

Asfandyar Chaudhary, Kashif Ali and Farid, Neha

Subjects
Callus Induction Medicinal Plants Moringa oleifera Plant Growth Regulators Regeneration Sterilization
Abstract

Moringaoleifera(G.H.No.:95436,Dr.MuneebaKhan,CentreforPlantConservation,University of Karachi) known as the miracle tree, is a plant of great importance. The plant is well known for its diverse medicinal and nutritional properties. The objective of the research is focused on tissue culture of Moringaoleifera through callus induction, direct multiplication as well as from seed culture.Thestudyisalsofocusedonoptimizationofsterilizationprotocolandmediaforthetissue culture processes. As expected, Moringaoleifera gave promising results using MS Media supplementedwithdifferentconcentrationsofPlantGrowthRegulatorssuchasIAA,NAA,BAP, Kinetin and 2,4-D. Seed initiation gave optimum results on MS Basal media. Direct multiplication of the plant was observed with optimum results on MS media supplemented with 0.1 mgL-1BAP. For callus induction, effects of Plant Growth Regulator and photoperiod were observed. In Dark conditions, maximum growth was seen on MS media supplemented with 2, 4-D (2 mgL-1), and that in light conditions, MS media with 2,4-D (2 mgL-1and 3 mgL-1) gave almost similar results. Initially, seed coats were removed inside the Laminar Flow Hood but this was affecting the sterilization negatively. Seed sterilization was then modified by removing seed coats and sterilizing them outside the Laminar Flow Hood. The seeds were then transferred to the LFH for furthersterilization,andthenculturedonthe growthmedia.Forthesterilizationoftheexplantfor directmultiplicationandcallusinduction,firstlyEthanolwasusedwhichcausedbleachingeffect. Later, Ethanol was removed from the protocol, reducing the bleaching effect to zero, and sterilization was maximized.

Published
2019
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19. Thin Film Deposition : Solution Based Approach

Author

Chaudhary, Kashif Tufail

Subjects
Technology & Engineering / Materials Science
Abstract

The wet chemical processing opens the way to deposit thin film with the versatility and ease for a variety of materials. Liquid film deposition involves the application of a liquid precursor on a substrate which is then converted to the required coating material in a subsequent post-treatment step. Different non-vacuum solution based deposition techniques have been developed to grow thin films with high efficiency and functionality. Spin coating is one of an effective technique for thin film fabrication due to low cost, uniformity, less hazardous, and capability of easy scaling up. The typical process involves depositing a small amount of a fluid onto the center of a substrate and then spinning the substrate at high speed. Dip coating is another simple, cost effective route with feasibility to scale-up for commercial production. The dip coating process can be divided into three important technical stages, immersion, withdrawal and evaporation. The coating may be subjected to further heat treatment in order to burn out residual compounds and induce crystallization of the functional oxides. Spray coating is a promising technique to grow thin film in research and industry to prepare thin and thick films. It is an easy approach to fabricate thin film with uniform distribution at small scale from a few nanometers to micrometers in thickness. Inkjet printing is the emerging promising technique to develop large-scale, and flexible thin films. The inkjet printing process allow easy customization to grow variety of complex structures.

Published
2019

20. Plasma Kinetic Theory

Author

Chaudhary, Kashif, Imam, Auwal Mustapha, and Ali, Syed Zuhaib Haider Rizvi and Jalil

Subjects
GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Published
2018

31. Laser-Induced Plasma and its Applications

Author

Chaudhary, Kashif

Subjects
Science / Chemistry / Physical & Theoretical
Abstract

The laser irradiation have shown a range of applications from fabricating, melting, and evaporating nanoparticles to changing their shape, structure, size, and size distribution. Laser induced plasma has used for different diagnostic and technological applications as detection, thin film deposition, and elemental identification. The possible interferences of atomic or molecular species are used to specify organic, inorganic or biological materials which allows critical applications in defense (landmines, explosive, forensic (trace of explosive or organic materials), public health (toxic substances pharmaceutical products), or environment (organic wastes). Laser induced plasma for organic material potentially provide fast sensor systems for explosive trace and pathogen biological agent detection and analysis. The laser ablation process starts with electronic energy absorption (~fs) and ends at particle recondensation (~ms). Then, the ablation process can be governed by thermal, non-thermal processes or a combination of both. There are several types of models, i.e., thermal, mechanical, photophysical, photochemical and defect models, which describe the ablation process by one dominant mechanism only. Plasma ignition process includes bond breaking and plasma shielding during the laser pulse. Bond breaking mechanisms influence the quantity and form of energy (kinetic, ionization and excitation) that atoms and ions can acquire. Plasma expansion depends on the initial mass and energy in the plume. The process is governed by initial plasma properties (electron density, temperature, velocity) after the laser pulse and the expansion medium. During first microsecond after the laser pulse, plume expansion is adiabatic afterwards line radiation becomes the dominant mechanism of energy loss.

Published
2016

34. Potassium Doping Effect on Cu2ZnSn(S,Se)4 Thin Film Absorber Layer Deposited via Spray Pyrolysis

Author

Salleh, Mohd Shahril, Chaudhary, Kashif Tufail, Mazalan, Elham, and Ali, Jalil

Abstract

This article reports on the role of potassium (K) as dopant in Cu2ZnSn (S,Se)4, CZTSSe thin film in context of optical properties. Thin film precursor solution is prepared in dimethyl sulfoxide (DMSO) solvent, and doped by K with six different concentrations. The prepared solution are deposited on heated soda lime glass (SLG) substrates using spray pyrolysis technique, followed by selenization process using three-step temperature approach. UV-Visible spectra show high absorption coefficient, α, more than 104cm-1 and bandgaps in narrow range 0.98eV to 1.10eV. X-ray diffractograms show that all samples exhibit kesterite structure with preferential orientation along (112) orientation. Field Emission Scanning Electron Microscopy was used to determine the morphologies of the K-doped CZTSSe thin films. 1.5 mol % of K has shown better characteristics as an absorber layer among other tested samples.

Published
2020

35. Quantification of calcium using localized normalization on laser-induced breakdown spectroscopy data

Author

Mohd Sabri, Nursalwanie, Haider, Zuhaib, Chaudhary, Kashif Tufail, Abd Aziz, Muhammad Safwan, Ali, Jalil, Abdul Wahab, Zaidan, Abbas, Zulkifly, Mohd Sabri, Nursalwanie, Haider, Zuhaib, Chaudhary, Kashif Tufail, Abd Aziz, Muhammad Safwan, Ali, Jalil, Abdul Wahab, Zaidan, and Abbas, Zulkifly

Abstract

This paper focuses on localized normalization for improved calibration curves in laser-induced breakdown spectroscopy (LIBS) measurements. The calibration curves have been obtained using five samples consisting of different concentrations of calcium (Ca) in potassium bromide (KBr) matrix. The work has utilized Q-switched Nd:YAG laser installed in LIBS2500plus system with fundamental wavelength and laser energy of 650 mJ. Optimization of gate delay can be obtained from signal-to-background ratio (SBR) of Ca II 315.9 and 317.9 nm. The optimum conditions are determined in which having high spectral intensity and SBR. The highest spectral lines of ionic and emission lines of Ca at gate delay of 0.83 µs. From SBR, the optimized gate delay is at 5.42 µs for both Ca II spectral lines. Calibration curves consist of three parts; original intensity from LIBS experimentation, normalization and localized normalization of the spectral line intensity. The R2 values of the calibration curves plotted using locally normalized intensities of Ca I 610.3, 612.2 and 616.2 nm spectral lines are 0.96329, 0.97042, and 0.96131, respectively. The enhancement from calibration curves using the regression coefficient allows more accurate analysis in LIBS.

Published
2016

41. Non-vacuum Deposition Methods for Thin Film Solar Cell: Review.

Author

Ruisheng Yang, Mazalan, Elham, Chaudhary, Kashif Tufail, Haider, Zuhaib, and Ali, Jalil

Subjects
THIN film devices, SOLAR cells, SOLAR energy, EMISSIONS (Air pollution), RENEWABLE energy sources
Abstract

Solar power is a promising abundant, pollution free, inexhaustible and clean source of energy. Development of cost-effective solar system with high conversion efficiency is the key challenge in field of solar panel manufacturing industry. Different non-vacuum deposition methods have been developed to reduce the cost of solar panel system along with high conversion efficiency. In this paper, a review is presented with major focus on three non-vacuum deposition methods, as spin coating, dip coating and spray coating. Each mentioned deposition technique is discussed in details along with role of different deposition parameters on the characteristics of grown solar thin films. [ABSTRACT FROM AUTHOR]

Published
2017
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43. Modified Add-Drop Microring Resonator for Temperature Sensing

Author

Mohamad, Azam, primary, Bahadoran, Mahdi, additional, Ahmad Noorden, Ahmad Fakhrurrazi, additional, Aziz, Safwan, additional, Chaudhary, Kashif, additional, Jalil, Muhammad Arif, additional, Ali, Jalil, additional, Ong, Chee Tiong, additional, and Yupapin, Preecha. P., additional

Published
2015
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