bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and mechanical properties of stainless-steel specimens, made by additive method, after pulsed electron beam treatment
Authors: Teresov A D , Petrikova E A , Krysina O V , Prokopenko N A , Ivanov Yu F , Akhmadeev Yu H , Semenov G V
Published: November 2021

The article presents a method for finishing the surface of metal products made by sequential electron-beam surfacing, which consists in modifying the surface with an intense low-energy electron beam of submillisecond duration. On the example of 308LSi stainless steel, the results of such processing are demonstrated, the optimal modes of exposure are determined. It is shown that as a result of pulsed electron-beam processing, a homogeneous polycrystalline structure without cracks is formed on the surface with unchanged, relative to the initial material, elemental composition, strength (microhardness) and tribological (wear rate) properties. In this case, the surface roughness is reduced to 2.1 times in the longitudinal direction relative to the surfacing plane, to 5.2 times in the transverse direction. Tensile tests of specimens showed anisotropy of mechanical properties depending on the direction of tension relative to the surfacing plane, which decreases after surface pulse electron-beam processing.
Gas-discharge plasma application for ion-beam treatment of the holes’ inner surfaces
Authors: Sivin D O , Korneva O S , Ivanova A I , Vakhrushev D O
Published: November 2021

The possibility to modify the holes and pipes’ inner surface with focused high-intensity low-energy ion beams was first shown in this work. The studies were carried out using an axially symmetric single-grid system for the ions’ extraction from a free plasma boundary with subsequent ballistic focusing of the ion beam. Ion implantation of the inner surface was carried out in the region of the ion beam defocusing. The studies considered the effect of a nitrogen ions’ beam with energy of 1.4 keV on the inner surface of a tube with a diameter of 20 mm made of stainless steel AISI 321. The beams were formed with a repetition rate of 40 kHz and pulse durations of 5, 7.5 and 10 μs. It is shown that the mutual deposition of the sputtered material on the tube’ opposite sides partly compensates for ion sputtering. As a result of implantation of the inner surface of a pipe made of stainless steel AISI 321, the nitride layers with a thickness of more than 15 microns with a nitrogen dopant content of 22-30 at.% were obtained.
Electron beam modification of the structure and properties of silumins with various silicon concentrations
Authors: Zaguliaev D V , Klopotov A A , Ivanov Y F , Ustinov A M , Abzaev Y A , Teresov A D
Published: November 2021

This work intended to analyse the structure and properties of hypoeutectic silumin treated by a pulsed electron beam. The study has shown that the silumin surface modified by a pulsed electron beam fractures due to the formation and propagation of microcracks along the boundaries of high-speed crystallization cells. In the untreated material (the concentration of silicon in the alloy is irrelevant) microcracks tend to originate and propagate along the phase boundaries between aluminum and silicon. The research has revealed that the plasticity of irradiated AK5M2 silumin is 1.6 higher and the strength is 1.1 lower than these characteristics of the untreated material; the irradiated AK10M2H silumin fractures at higher (by ≈ 30%) applied stress and higher (by 30%) plastic deformation than the untreated material.
Adhesion strength of Tii_xCx – DLC multilayer nanocomposite thin films coated by ion-plasma deposition on martensitic stainless steel produced by selective laser melting followed by plasma-nitriding and burnishing
Authors: Lezhnin N V , Makarov A V , Kuznetsov V P , Vladimirov A B , Skorynina P A , Sirosh V A
Published: November 2021

[Ti0.2C0.8/a-C]40 multilayer thin films composed of forty pairs of TiC and pure carbon layers were formed on a selective laser melted (SLM) martensitic stainless steel by means of ion-plasma deposition process. SLM steel was pre-treated by one of the two following schemes: (1) oil quenching from 1040°C followed by heating to 480°C for 4 hours and air cooling (HT), finish milling (FM); (2) HT, FM, ion-plasma nitriding followed by burnishing. Mechanical failure mode and critical load Lc
for damaging the coatings were determined using linear scratch tests performed at linearly-increased normal force. Indentation by conical diamond tip were carried out in order to asses an elastic recovery and energy dissipation coefficient defined as the ratio of plastic to total deformation energy. The scratch test results showed that the post-processing of the substrate strongly influenced the failure mode of the coating and increased the critical load from 320 mN to 920 mN. Indentation revealed that nitriding and burnishing before coating deposition increase the elastic recovery of the [Ti0.2C0.8/a-C]40 coating-substrate system from 24% to 68%. The energy dissipation coefficient drops from 79% to 45%.
Simulation of the evolution of agglomerated SiO2 particles in thermal plasma flow
Authors: Shekhovtsov V V
Published: November 2021

The paper studies the behavior of agglomerated SiO2 particles in thermal plasma processing. The main stages are determined for their transformation to the hollow melt droplets. The proposed model, which includes partial encapsulation of gas, allows describing and analyzing the evolution stages for the particle size and the shell thickness in the ranges of 50-150 μm agglomerated particles and their 0.2-0.6 porosity.
Studying the influence of the energy parameters of the plasma dynamic synthesis process on the dispersed products of the W–C system
Authors: Sivkov A A , Shanenkov I I , Nikitin D S , Nassyrbayev A , Rakhmatullin I A , Tsimmerman A I
Published: November 2021

Tungsten carbide and its different crystalline phases are widely used for production of metalworking tools due to their excellent physical and mechanical characteristics. However, there is still a problem of synthesizing the cubic modification of tungsten carbide. This paper demonstrates the results on studying the influence of the energy parameters of the plasma dynamic synthesis process on the dispersed products of the W–C system. It was revealed that the initial energy parameters directly influence the phase composition of synthesized products. There were found the optimal conditions for synthesizing the dispersed products from the standpoint of the high output of cubic tungsten carbide phase (more than 85 wt.%). According to transmission electron microscopy data, all the products are characterized by the presence of particles with a core-shell structure embedded into the amorphous carbon matrix.
Study of particles of plasma dynamic synthesis product in the Ti-O system by high-resolution transmission electron microscopy
Authors: Sivkov A A , Vympina Y N , Rakhmatullin I A , Ivashutenko A S , Shanenkova Y L , Tsimmerman A I
Published: November 2021

The paper demonstrates the possibility of obtaining a dispersed product in the Ti-O system by the method of plasma dynamic synthesis. It was revealed that the product consists of two modifications of TiO2: anatase and rutile. The degree of crystallinity is at a level of ~ 98.0%, which indicates the practical absence of an amorphous component. The predominant phase is anatase, which is confirmed by the results of quantitative X-ray phase analysis and high-resolution transmission electron microscopy.
Study of steam methane reforming in plasma generated by nanosecond surface gas discharge
Authors: Filatov I E , Kuznetsov D L , Uvarin V V
Published: November 2021

The paper represents the results of the experimental study of steam methane reforming under the action of spark discharge on water surface. Values of conversion rate and output of reaction products at methane pressures of 1 to 5 atm were obtained, and specific energy consumption of reforming process was determined. Pulse generator with a voltage amplitude up to 200 kV and a pulse duration of 15 ns was used to power the discharge. Although an increase in pressure decreases both the methane conversion rate and the energy deposition into the gas mixture, the conversion efficiency and specific energy consumption remain the same. The obtained minimum value of specific energy consumption for steam methane reforming amounted to 10 eV/molecule.
Plasma-solution synthesis of particles containing transition metals
Authors: Smirnova K V , Shutov D A , Ivanov A N , Rybkin V V
Published: November 2021

The paper proposes a new method for the synthesis of powders containing transition metals using a plasma-solution system. The reactor was an H-shaped glass cell, the two parts of which were separated by a cellophane membrane. A discharge consisting of two discharges - with a liquid cathode and a liquid anode - a high voltage is applied to titanium electrodes located above the surface of the solution. Aqueous solutions of zinc, iron, cadmium, cobalt, nickel, and copper nitrates were used as the liquid phase. Under the action of the discharge on the liquid anode, in the region of contact of the discharge with the solution the formation of a colloidal suspension was observed. The kinetics of the process of synthesis of solid-phase particles in solution under the action of a discharge have been studied. The chemical composition and morphology of the formed solid phase have been established. The mechanisms of chemical reactions occurring in the solution under the action of plasma, and the mechanisms of formation of transition metal oxides in the process of calcining the synthesized powders have been proposed.
Droplets generation conducting during laser-plasma treating of metals in electric field
Authors: Yu Ivanov A , Sitkevich A L , Vasil’ev S V
Published: November 2021

Evolution of plasma plume generation on the surface of metal irradiated by laser beam with the mean radiation flux density ~ 106 W/cm2 in the external electric field with different polarity and field strength from 0 to 106 V/m was experimentally investigated. It is shown that the mean size of metal droplets carried out from the irradiated zone of target becomes materially (in several times) smaller when of the external electric field strength amplitude grow, independently to its polarity. It is essential that the mentioned differences (at the considered parameters of laser radiation) are observed only at the initial stage of the laser plume development, because after the steam-plasma cloud reaches the electrode an electric breakdown (short-circuit) occurs, and the external field in the interelectrode gap disappears. Electric breakdown leads to the spasmodic increase of electron density and temperature of plasma and to effective absorption of laser radiation by plasma torch (shielding of the target). In consequence of shielding droplets generation happens only during electric field existence. This explains decrease by several times of the characteristic size of the target substance droplets in spite of short duration of electric field existence.
The study of instabilities role of plasma in the high-voltage discharge formation initiated by optical radiation at high pressures in high-voltage optically triggered switches
Authors: Lipchak A I , Barakhvostov S V , Volkov N B , Chingina E A , Turmyshev I S
Published: November 2021

The paper presents the experimental results of triggering a high-voltage gas gap by YAG: Nd3+ laser radiation. The gas gap was used as the primary switch of a high-current pulsed e-beam RADAN-type accelerator. As a result, an operating regime when the instability and delay time appeared to be minimal was experimentally found. The developed gas gap and the found operating regimes sustain the switching instability no more than 0.3 ns. The physical mechanisms determining the switch-on delay and the obtained level of instability are discussed.
Investigation of the effect of condensed phase on the energy conditions for the initiation of the plasma-chemical process of flue gas cleaning by a pulsed electron beam
Authors: Sazonov R , Kholodnaya G , Ponomarev D , Egorov I , Poloskov A , Serebrennikov M
Published: November 2021

This work investigates the processes of dissipation of the charge and energy of a pulsed electron beam in gas compositions (nitrogen, carbon dioxide and oxygen) in the presence of ammonium sulphate and nitrate. A pulsed electron beam generated by the TEA-500 accelerator (Tomsk, Russia) with an electron energy of up to 410 keV, a beam current of up to 5 kA (I0
), and a half-amplitude voltage pulse duration of 60 ns was injected into a 46 cm long drift chamber filled with a gas mixture. The pulsed electron beam current (IFC
) passing through the drift chamber was registered using a sectioned calorimeter with beam charge monitor function, and the efficiency of the current passage of the beam was determined as the ratio qFC/q0
, where q0
is the beam charge measured at the place of its injection into the chamber drift. The pressure in the drift chamber varied (375, 560 and 760 Torr, humidity value 15% ± 5% and 50% ± 5%). The geometric dimensions of the plasma-chemical reactor for initiating plasma-chemical reactions of flue gas cleaning were determined.
Creating nanoscale luminescence centres in silver halides suitable for infrared application
Authors: Korsakova E A , Lisenkov V V , Zhukova L V , Orlov A N , Korsakov A S , Osipov V V , Lvov A E , Platonov V V , Salimgareev D D
Published: November 2021

This study shows the possibility of creating luminescence centres in silver halide media using substances based on rare-earth elements such as neodymium, ytterbium and dysprosium. These luminescent substances in the form of fine particles of both nanoscale and microscale dimensions can be introduced into the AgCl0.25Br0.75 ceramic matrix highly transparent in the spectral range of 0.5–35 μm. Our theoretical and experimental studies showed that the introduction of luminescent nanoparticles or microparticles at the amount of 0.5 wt.% into AgCl0.25Br0.75 ceramics neither reduces the level of its transmission in the MIR region nor shortens the range of transmission. What is more, we proved that the luminescent properties of nanoparticles remain well preserved after doping silver halide ceramic media with them. Therefore, silver halides doped with rare-earth elements in question can be used for developing the sources of coherent middle infrared radiation, with appropriate energy levels being excited by optical radiation or pulsed electric field.
Evaluation of the effect of pre-sowing electron irradiation of barley seeds on plant development and disease incidence
Authors: Loy N N , Sanzharova N I , Gulina S N , Suslova O V , Chizh T V , Vorobyov M S , Yu Doroshkevich S
Published: November 2021

The effect of electron irradiation of barley seeds of the Vladimir variety on the development of plants, disease incidence and productivity in controlled greenhouse conditions has been studied. It was found that the effectiveness of the effect of seed treatment with low-energy electronic radiation in the dose range of 30–150 kGy on the morphometric parameters of barley largely depends on the accelerating voltage – 130 kV (mode 1) and 160 kV (mode 2). It was noted that irradiation suppressed the formation of chlorophyll a and b and carotenoids in barley leaves at all doses and irradiation regimes and, at the tendency level, reduced the infestation of Bipolaris sorokiniana plants in the tillering and heading phases. It was shown that irradiation of seeds caused an increase in the total tillering of plants (mode 2), but at the same time reduced the productive tillering. Electron irradiation caused an increase in the mass of 1000 grains and did not affect the yield of grain and straw.
Ytterbium impulse laser for surface modification of tool steel with B4C-Al powders
Authors: Mishigdorzhiyn U L , Ulakhanov N S , Nomoev A V , Lupsanov A B
Published: November 2021

The paper deals with a new application solution of Ytterbium Picosecond Pulsed Fiber Laser for surface modification of 3Kh2V8F hot-work tool steel (the analog of AISI H21 steel). Surface modification was conducted by B4C-Al powders from preplaced pastes followed by laser heating. The ratio of B4C-Al powders was taken as 5/1 by weight and the paste thickness was approximately 1 mm. Laser treatment was conducted according to the following parameters: 1070 nm of wavelength, 100 W of power, 1 mJ of pulse energy, 100 ns pulse duration, pulse frequency range from 50 kHz to 90 kHz. Several tracks with different widths were obtained as a result of treatment depending on velocity of the laser move. EDS analysis showed that B4C particles were not completely dissolved in the weld beads. However, an enhanced concentration of boron (8-12 wt.%) was revealed in the vicinity of B4C particles. The aluminum concentration was low (up to 0.79 wt.%) on the surface of the weld beads.
Investigative study of the radiation damage on fuel clad of miniature neutron source reactor using computational tools
Authors: Alhassan S , Beliavskii S V , Nesterov V N
Published: November 2021

Core conversion requires some evaluation of the reactor safety. Changes to the reactivity worth, shutdown margin, power density and material properties are crucial to the proper functioning of the reactor. The focus of this article is to study the neutron flux distribution in the reactor core and radiation damage on candidate clads. The Ghana Research Reactor-1 (GHARR-1) operates at maximum power of 30 kW in order to attain a flux of 1.0× 1012 n·cm–2·s for the high enriched uranium core. Using the GHARR-1 core geometry, considering 348 fuel pins, the multiplication factor (Keff) is calculated at enrichments of 10%, 12.5%, 16%, 20%, 30% and 90.2%. The spectrum of neutron flux generated in the 26 group is also calculated at the specified enrichments. The ion/particle interactions with the targets (clad) were studied in the Stopping and Range of Ion in Matter code to establish the best clad material based on recorded defects and vacancies generated. From the calculations and simulations, the best choice from the candidate clads based on the assessment is SiC. The calculation of the fuel campaign length gives 7.5 years. The defects sustained by the prospective clad showed low susceptibility to swelling and other forms of deformation.
Nanocomposite films of CNPs/CuO structures by electrophoresis method
Authors: Aung Nay Win , Pugachevskii M A , Kuzmenko A P , Than Myo Min
Published: November 2021

The article discusses the results of ordering a composite of carbon nanoparticles (CNPs) coated copper oxide (CuO) on the silicon substrate by the electrophoresis method and, particles size and chemical composition have analyzed by Raman spectroscopy, an Atomic Force Microscope, and Scanning Electron Microscope. Carbon nanoparticles from Single-walled Carbon Nanotubes (SWCNTs) using the centrifugation method are applied by a pipette (by the drop method) on the silicon substrate with copper electrodes under the direct electric field to obtain CNPs-CuO nanocomposite films. It has been shown that carbon nanoparticles in solutions upon dispersion in an ultrasonic bath and subsequent centrifugation have a limiting particle size of 38 nm and CNPs solution can be controlled to obtain the nanocomposite films by the electrophoretic forces.
Investigation of the role of chemically active radicals in the antibacterial properties of a low-temperature plasma jet at ambient pressure mixed with argon and air
Authors: Ashurbekov N A , Isaeva Z M , Rabadanov K M , Shakhsinov G S , Murtazaeva A A , Israpov E K
Published: November 2021

The work is devoted to the study of a low-temperature plasma jet of atmospheric pressure in a mixture of air with argon, used in plasma medicine. The intensities of the spectral emission bands of OH– (309 nm), N2 (337 nm), and N2 (356 nm) in different parts of the plasma jet were investigated depending on the argon flow rate and the amplitude of voltage pulses at the electrodes of the dielectric barrier discharge. The antibacterial effect of such a plasma jet on the surface of biological tissues has been experimentally investigated. Numerical simulation of ionization processes in the studied plasma source has been performed in the COMSOL Multiphysics software using. The dynamics of the distribution of excited molecules in the plasma torch as well as the kinetic plasma processes inside the plasma torch affecting the spatial distribution of its main characteristics have been analyzed.
Combined electric discharge “arc + discharge with liquid electrolyte cathode”
Authors: Tazmeev G K , Timerkaev B A , Tazmeev K K
Published: November 2021

A combination of an electric arc and discharge with a liquid electrolyte cathode in a single discharge gap has been created. The plasma column of discharge with liquid electrolyte cathode formed a “hollow cylinder”. The electric arc was burned in a vapor-gas environment inside the “hollow cylinder”. The gas discharge current with liquid electrolyte cathode was set in the range of 5-10 A, and the arc current varied in the range of 1-10 A. Aqueous solutions of sodium chloride with a specific electrical conductivity of 10-15 mS/cm were used as a liquid electrolyte. Spectral studies have been carried out in the visible range of radiation. In the experiments, copper and duralumin metal cathodes were used.
Thrust characteristics of compact high-voltage pulsed plasma thruster utilizing liquid propellant
Authors: Buldashev S A , Emlin R V , Morozov P A , Punanov I F , Shcherbakov Ye N , Yashnov L Yu
Published: November 2021

In this work, we present the results on thrust performance of 0.5 kg sub-joule pulsed plasma thruster prototype based on a high-voltage transformer with magnetic storage capable of work at frequency of 400 Hz. The discharge unit is made of ferroelectric ceramics with an option for utilizing liquid propellant. In case of vacuum oil as a propellant, we obtained values of thrust of ~ 80 nN·s per discharge and 33 μN·s for 400 pulses in 1 second.
Methods of increasing the dielectric strength of the accelerating gap in an electron source with a plasma cathode
Authors: Moskvin P V , Devyatkov V N , Shin V I , Vorobyov M S , Koval N N , Lopatin I V
Published: November 2021

This work represents the investigations for decreasing acceleration gap breakdown probability of plasma source of electrons SOLO, with grid stabilization of the boundaries of the arc cathode plasma. We increased the distance to the treated target, bent the transportation channel of the electron beam, created additional plasma in the anode space, and increased the beam front. The effect of the above measures on the breakdown probability when the target is exposed of a low-energy electron beam with a power density of up to 0.5 MW/cm2 with a diameter of 2.5 cm was investigated separately. Beam deflection is most effective at relatively long pulse durations of 150 μs and accelerating voltage of 20 kV, rather than a lower one. It was possible to double the maximum power for the same beam transport length applied to a low-melting target. Preionization in the anode proved to be effective for relatively short beams of 15 μs duration.
Subnanosecond switching of standard thyristors triggered in impact-ionization wave mode by a high-voltage PCSS driver
Authors: Gusev A , Prudaev I , Lavrinovich I , de Ferron A , Novac B M , Pecastaing L
Published: November 2021

Power thyristors triggered in impact-ionization wave mode are capable to replace spark gap switches, bringing major advantages into repetitive pulsed power industrial applications. Low power thyristors remained for the moment out of the research focus, most likely because of the challenging driver, which must provide a sufficiently fast and powerful triggering pulse. This paper describes subnanosecond switching of standard off-the-shelf low-power thyristors in impact-ionization wave mode, running by the PCSS trigger generator based on the laser diode and GaAs switches. Several types of thyristors with a rated voltage from 0.6 kV to 2.2 kV have been tested running by both a commercial FID and by the tailored PCSS generators. The triggering and current flow stages were examined. For the 1.6 kV thyristor (TO-247 package), the following parameters have been obtained: switching time 250 ps, dI/dt up to 12 kA/μs, amplitude 85 A and FWHM about 60 ns. In this mode, the first 103 pulses have not revealed any thyristor degradation.
Influence of the cathode region preionization on the operating parameters of the eptron
Authors: Bokhan P A , Lavrukhin M A , Zakrevsky D E
Published: November 2021

Investigations of the operating parameters of a plasma-cathode switch based on a capillary discharge in helium and neon in the burst mode are presented. An increase in the efficiency of the switch is demonstrated when an additional preionization pulse is applied at a low pulse repetition frequency (5 kHz). The compression ratio of voltage pulses more than 300 is achieved at a pulse repetition frequencies less than 40 kHz.
Formation of the voltage pulses up to 400 kilovolts with front pulse less than 10 nanoseconds
Authors: Kozlov B A , Makhanko D S
Published: November 2021

This work presents basic information about the design, manufacturing technology, and application of small-sized sealed-off spark-gaps in metal-ceramic design with hydrogen filling up to 120 atmospheres at an operating voltage of 100-400 kV with switching energy of up to 10 Joules in pulsed X-ray flaw detectors. The main factors affecting the mechanical strength and stability of the spark-gap operation are described. The results of an experimental study of the switching characteristics of the RO-49 spark gap-sharpeners are presented.
Picosecond semiconductor generator for capacitive sensors calibration
Authors: Patrakov V E , Pedos M S , Rukin S N
Published: November 2021

The paper describes a semiconductor picosecond pulse generator that can be used to calibrate capacitive high voltage sensors of MV range. The generator is designed as a base unit, to which external pulse converters are connected. In the base unit, semiconductor devices – first a semiconductor opening switch (SOS) and then a semiconductor sharpener (SS) – generate an output pulse with a rise time of 220 ps and a subsequent flat-top of 2 ns in duration. The pulse amplitude is around 1 kV across 50 Ω load. An external diode sharpener generates a pulse with 120 ps rise time and 500-ps flat-top at the amplitude of 850 V. To switch the semiconductor sharpeners to the conducting state, the shock-ionization wave mode is used. Additional pulse converters make it possible to generate output pulses across 50 Ω load with the rise time of 70-150 ps, the pulse duration of 135-310 ps, and the amplitude of 130–480 V. The electrical diagram of the generator and waveforms of the output pulses are presented. An example of the calibration of capacitive sensors of a multi-gigawatt picosecond generator is also shown.
Spatial distribution and time evolution of metal-containing plasma of a low-current atmospheric pressure discharge with magnesium cathode
Authors: Savkin K P , Sorokin D A , Oks E M , Yushkov G Yu
Published: November 2021

The spatial intensity distribution and temporal dynamics of the plasma generated by an atmospheric pressure discharge with magnesium cathode in an argon flow are investigated in a coaxial geometry discharge system. The repetition rate of unipolar pulses was 56 kHz and the pulse duration was 12 μs. The steady-state amplitude of the discharge current was 100 mA at a voltage of about 130 V. Under this operating mode, a local melting of the active cathode surface took place. The evaporated magnesium atoms were captured by the working gas flow and formed a green glow plume around the positive discharge column outside the anode nozzle. The image of the plasma formation was projected onto the entrance slit of the monochromator. The spatial distribution of the radiation intensity and evolution in time of its selected monochromatic components were measured. The radiation spectrum contained groups of ion and magnesium atom lines with wavelengths of 285.21 nm (singlet resonant Mg I); 383.08, 383.36, 383.9 nm (triplet Mg I); 517.3, 517.5, 518.1 nm (triplet Mg I). The results of this work are promising with regard to studying open-type spontaneous radiation sources, as well as the generation of combined gas-metal plasma flows at atmospheric pressure.
A new type of non-thermal atmospheric pressure plasma source based on a waveguide bridge
Authors: Tikhonov V N , Gorbatov S A , Ivanov I A , Tikhonov A V
Published: November 2021

A new type of microwave source of non-thermal atmospheric pressure plasmas, presented earlier by the authors, has both the characteristics of a dielectric barrier discharge (in terms of the configuration and low gas temperature) and an ability to form a “clean” plasma jet like a classical microwave plasma torch. However, the need to use a circulator leads to a significant increase in complexity, cost and weight of the installation as a whole. The basis of the presented plasma source is a three-decibel waveguide bridge with connection through a narrow wall. Both output arms of the bridge are loaded on identical short-circuited segments of waveguides. The discharge tube passes across the waveguides at a distance of a quarter of the wavelength from the short circuit. Since the output arms of the bridge are always loaded symmetrically, the generator’s power which is reflected from the short circuits or not be absorbed in the microwave discharge, enters the decoupled arm of the bridge that is connected to the matched load. Thus, the magnetron is protected from the reflected wave without the need for an expensive circulator, in any case.
A Review: Deep Learning Classification Performance of Normal and COVID-19 Chest X-ray Images
Authors: Markom M A , Mohd Taha S , Adom A H , Abdull Sukor A S , Abdul Nasir A S , Yazid H , Tan E S M M , Markom A M
Published: November 2021

COVID19 chest X-ray has been used as supplementary tools to support COVID19 severity level diagnosis. However, there are challenges that required to face by researchers around the world in order to implement these chest X-ray samples to be very helpful to detect the disease. Here, this paper presents a review of COVID19 chest X-ray classification using deep learning approach. This study is conducted to discuss the source of images and deep learning models as well as its performances. At the end of this paper, the challenges and future work on COVID19 chest X-ray are discussed and proposed.
A Brief Review on Atmospheric Air Plasma
Authors: Zabidi N Z A , Zaaba S K , Eh Sut K D , Mohamad C W S R , Masiman R I
Published: November 2021

Atmospheric pressure air plasma is an attractive technology because it is easy to set up and handle, cheap, and safe. In this paper, a brief review on air plasma configuration and the results of air plasma is presented. One of the important properties of any plasma treatment is the generation of reactive atom species such as oxygen(O), nitrogen(N) also known as RONS, and other ions molecules particles. Air plasma has been found to have the same effect when treating surfaces. Surface modification, hydrophilicity, and decontamination effect were observed when materials are exposed to air plasma. The advancement of air plasma technology will improve the surface processing technology by reducing its operating cost.
Study on Optical Properties of Milk based on Light Propagation Theory
Authors: Muhamad Kamil N A I , Wan Ismail W Z , Balakrishnan S R , Sahrim M , Ismail I , Jamaludin J
Published: November 2021

The light propagation in milk based on experimental and theoretical analysis is reviewed. The review is done on light propagation theory which consists of light absorbance, reflection, and scattering. The study covers on types of milk, milk quality and modelling methods based on Mie scattering and Monte Carlo algorithm. The experiments consist of spectrometry methods where visible (VIS) and near infra-red (NIR) are used. Many spectrometry experiments and theoretical modelling are discussed to observe and analyse optical properties of milk.
The Effect of Parameter Variation on Spiral Flow Inducing Cannula Performances
Authors: Muzamil Mustafa F , Shafii N S , Abdul Kadir M R , Che Aziz M N , Osman K , Dillon J , Darlis N , Md Khudzari A Z
Published: November 2021

Spiral flow-inducing cannula has been shown in previous research to exhibit a considerable effect on flow hemodynamic. However, there is still room for improvement. In this study, several design variations were tested to determine which variants were the best in terms of flow reduction. Computational Fluid Dynamics (CFD) software was used to simulate flow within a spiral flow-inducing cannula with several variations from chamber width and angle differences. The variants were compared against each other by using several flow parameters and a selection method was employed to determine which model was the best. It was found that a variant that has the widest chamber (14 mm) and biggest angle opening (70°) from the chamber to the cannula tube was the best in several parameters, and as such was chosen as the best variant. When compared with the standard straight cannula, the reduction in flow output was recorded to be 30% which is deemed significantly. In conclusion, spiral flow cannula recorded better hemodynamic effects with lower outflow velocity and wall shear stress value.
Finite Element Analysis (FEA) of Local Hyperthermia on Soft Tissue
Authors: Yahud S , Ibrahim N F A
Published: November 2021

Finite Element Analysis (FEA) is a method for simulating a local hyperthermia (HT) effect on the soft tissue liver by exposing it to an external heat higher than normal core body temperature. Local HT treatments are most commonly used to treat cancer tissue smaller than 3 cm in size by using radiofrequency ablation (RFA) technique. The radiofrequency probe provides an intense external heat source within the target zone with temperatures exceeding 50 °C, but its maximum temperature should not approach 100 °C. In this paper, the main idea is to study the effect of tumor diameter size on the exposure time, thermal exposure intensity and applied voltage. There are five (5) different tumor diameter tissue sizes that would be treated: 1 cm, 1.5 cm, and 2 cm of tumor tissue diameter treated with a monopolar of plain electrode, and 2 cm, 2.5 cm, and 3 cm of tumor diameter tissue treated with 4-prong retractable antennas of an electrode. The findings showed that the exposure time is influenced by the tumor diameter tissue and the voltage applied, with the bigger tumor diameter tissue necessitating the longest time exposure with a high voltage. The temperature range of 50-100 °C has been given by all of the voltage supplied. Both electrodes provide thermal damage between 6-20 minutes, which is 6 – 18.5 minutes for a plain electrode with a voltage supply of 20-35 V applied to 1cm, 1.5cm and 2 cm of tumor diameter tissue, and 10.5 – 12.5 minutes for a 4-prongs electrode with a voltage supply of 22-45 V applied to 2 cm, 2.5 cm and 3 cm of tumor tissue.
Influence of Carrying Unstable Load on Thoracic Kinematics While Walking on a Curved Path
Authors: Ngoc D K , Salleh A F , Salim M S , Omar N , Basarrudin K S , Sakeran H , Halim I , Usman J , Lim C C
Published: November 2021

This study investigated the effect of carrying unstable load on thoracic kinematics while walking on a curved path. Three-dimensional spinal kinematics were defined as the rotations between thoracic and the Virtual laboratory coordinate system (Tho/Virtual lab) which consisted of lateral bending (LB), flexion/extension (FE) and axial rotation (AR) in the frontal plane, sagittal plane and transverse plane, respectively. Eight healthy young adults (4 males and 4 females) performed loads carrying and walking on one meter radius curved path. Spinal kinematics was determined at the left leg heel strike and just before the right toe off during the curved path walking. As a result, a significant main effect of load intensity was found only on FE of (Tho/Virtual lab) at both left leg heel strike and right leg toe off. The study concluded that an increase in the load intensity of unstable load from 10% of body weight likely to generate more thorax extension.
Development and Analysis of Three-Dimensional Printed Hand Cast: Finite Element and Comfortability Analysis
Authors: Aziz A U A , Yassin N A , Seng G H , Ramlee M H
Published: November 2021

Bone fracture treatment aims for restoring the function of a broken bone, and for scaphoid fracture, the conventional cast is an example of commonly used treatment. However, due to its downsides, the development of customized three-dimensional (3D) printed hand cast is getting more attention. It is lightweight, easy to manage, has good ventilation and hygienic properties. Hence, this study aims to fabricate customized 3D printed hand cast in treating scaphoid fracture. Three designs were made and analysed accordingly based on three different tests, including Finite Element Analysis (FEA), comfortability, and clinical effectiveness test. Design 2 was chosen as the best design as it produced lower stress and displacement in FEA and higher total mean score for clinical effectiveness. In conclusion, the fabricated casts were proven to help in restoring the broken bone besides providing comfort to the patient.
Optimized Thickness of Meniscal Component in Partial Knee Replacement Analysed with Computer Simulation
Authors: Imran Ahmed
Published: November 2021

Computer simulation with programming and Matlab graphics was used to analyse effects of meniscal component thickness on lengths of ligament fibres in partially replaced human knee with uni-compartmental arthroplasty. A circular femoral, a flat tibial and a matching meniscal component were modelled in the sagittal plane with four intact ligaments represented as fibres that showed non-linear elastic behaviour. Shapes of the prosthetic components, attachments of the ligament fibres and their material properties were from anatomical studies in the literature. The components when placed on respective bones with surgical guidelines and an optimized thickness of the meniscal insert achieved nearly fixed lengths of ligament fibres during motion. Changes in thickness of the insert either stretched or slackened the fibres with variable effects during flexion of the joint. For example, a 2 mm thicker insert stretched a fibre of anterior cruciate ligament by 4.7% at 30° and 3.2% at 120° flexion. Such variations in component selection are probable due to surgical judgments. Stretched ligaments could increase joint stiffness, while slack ligaments could increase joint laxity – either of these effects has potential for affecting the joint kinematics. Computer models of the replaced knee validated with anatomical studies allow insight in the mechanics of the replaced knee and effects of surgical errors.
The Influence of Saracen Archery Grasping Techniques and Forearm Muscles Activation on Shooting Performance in Traditional Archery: A Pilot Study
Authors: Kamarudin N F , Salleh A F , Salim M S , Kasim M F , Omar N , Masnan M J , Lim C C
Published: November 2021

The purpose of this study is to understand the influence of four grasping techniques recommended by Saracen Archery and associated forearm muscles activation on traditional archer’s shooting performance. Each archer has shot 6 arrows in each grasping technique to the target, EMG activities of muscle Flexor Digitorum Superficialis (MFDS) and muscle Extensor Digitorum (MED) were collected in bow arm during aiming phase. The shooting performance was indicated by the distance from arrow hitting point on the target to the bull’s eye. The results revealed that each subject has specific grasping technique to obtain the best shooting performance. The grasping technique that generated the best performance is not as recommended by Saracen Archery. All subjects indicated that the best shooting performance was obtained when MED activated more than MFDS.
Development of Real Time Arsenic Heavy Metal Concentration Monitoring System
Authors: Bakar A H A , Hilmi W N W Q W , Uda M N A , Parmin N A , Noor A M , Zakaria Z , Norali A N , Fook C Y , Rosly Syafiq
Published: November 2021

This paper focuses on the ongoing development of real-time monitoring system with implementing the Internet of Things (IoT) element for arsenic heavy metal concentration in paddy field using pH sensor for data collection. The pH sensor will detect the hydrogen ion concentration from the prepared soil put in pot contained with various arsenic concentration. The developed system is then compared with the pH sensor in the market to verify its accuracy and sensitivity. The collected data will be transferred wirelessly into data cloud so that it can store the previous and current reading data. Besides, the system’s function is also to ensure the safeness of paddy plant to be planted with knowing the right amount of arsenic concentration can be passed.
Investigation of the Pressure and Flow Dynamics during Aspiration Thrombectomy: A Mathematical Modelling Study
Authors: Marconi Riccardo , Yang Ying , Naire Shailesh
Published: November 2021

Aspiration thrombectomy is a life-saving interventional procedure to remove a blood clot from the brain of stroke patients. The pressure and blood flow dynamics during this procedure are crucial in determining the clinical outcomes. A mathematical model based on Hagen-Poiseuille law of fluid flow in a tube is adapted to simulate the pressure and fluid flow characteristics in an in vitro model of an occluded and unoccluded cerebrovascular network that mimics a poor (unilateral) and good (symmetrical) collateral flow within the Circle of Willis. The results show that in the absence of an occlusion, the pressure and pressure drop are higher in the symmetrical network compared to that in the unilateral network. This is due to the additional limb in the symmetrical network that must be supplied, which is absent in the unilateral network. In the presence of an occlusion, the flow reduces in the obstructed vessel, the collateral flow, overall pressure and pressure drop increases in both systems, but is higher for the symmetrical network. The results compare qualitatively with those observed in in vitro studies and with clinical observations. The theoretical framework lays the foundation for more advanced models for the pressure and blood flow dynamics towards clinical applicability.
Numerical Simulation of Transdermal Iontophoretic Drug Delivery System
Authors: Noor A M , Zakaria Z , Johari S , Sabani N , Wahab Y , Manaf A A
Published: November 2021

Transdermal Iontophoretic Drug Delivery System (TIDDS) is a non-invasive method of systemic drug delivery that involves by applying a drug formulation to the skin. The drug penetrates through the stratum corneum, epidermis and dermis layers. Once the drug reaches the dermal layer, it is available for systemic absorption via dermal microcirculation. However, clinical testing of new drug developed for the iontophoretic system is a long and complex process. Recently, most of those major pharmaceutical companies have attempted to consider computer-based bio-simulation strategies as a means of generating the data necessary to help make a better decision. In this work, we used computational modelling to investigate the TIDDS behaviour. Our interest is to study the efficacy of drug diffusion through transdermal delivery, including the thermal effect on the skin. We found that drug will be delivered more efficiently if the electrical potential and the position of electrodes are optimum. We analysed the drug diffusion time of the system using 1,3 and 5 mA DC source. In addition, we also modify the electrode distance from 10 mm to 30 mm long and analysed the effect of delivery time and d effect to the skin thermal. We conclude that, a high electrical current, as instance, a 5 mA DC, delivered the drug faster into the skin but increased the skin temperature because of skin joule heating effect. However, a 30 mm electrodes distance setting decreased the skin temperature significantly than the 10 mm distance with more than 9.7 °C under 5 mA DC and 60 minutes of operation. TIDDS enhanced drug delivery compared to oral consumption and might be suitable used for localizing treatments such as chronic disease. This work provides great potential and is useful to efficiently design of iontophoretic drug delivery system including new drugs delivery applications.
Automated Humidity Control System for Neonatal Incubator
Authors: Alduwaish S , Alshakri O , Alamri R , Alfarieh R , Alqahtani S , Hameed K , Alomari A
Published: November 2021

Premature neonates are nursed in closed incubators to prevent transcutaneous water loss, dehydration, and excessive body cooling. These issues have serious risks that need to be eliminated by controlling the air’s relative humidity (RH) in the incubator. This paper aims to implement a closed-loop control system that maintains desired RH levels inside the incubator with an acceptable settling time and percentage. Designing the prototype is actuator-process-sensor based, and the implementation was in two main phases. First, building the incubator, which involved assembling the incubation space and the humidifier using a readily available ultrasonic piezoelectric transducer. Second, designing the control algorithm which is based on the ON/OFF algorithm with four levels of ON Humidification power. Finally, the results taken are the control system responses to a step input of desired values of relative humidity based on clinical guidance. Response results showed a maximum steady-state error of 2.5 and a minimum settling time of 0.8 min. The results indicate that the control system is fast and stable which meets the desired requirements. The designed control system is beneficial in reducing power usage and creating a safe humidification method for the infant.
Development of IoT Based Cuffless Blood Pressure Measurement System
Authors: Norsuriati M S , Norehan Mohd Sobri M S , Zaidatul Hafiszah H , Mohamad Nazib A , Wan Suhaimizan W Z , Ashok V , Muhammad Mahadi A J
Published: November 2021

Hypertension, commonly known as high blood pressure, is a major concern for people globally and in Malaysia. The hypertensive patient must commute to the hospital visiting their physician regularly for blood pressure (BP) monitoring using a cuff-based device. The patient may feel uncomfortable and pain when the device inflates the cuff and tightens around the arm for a BP measurement. Hence, to overcome this problem, this paper proposed a cuffless BP measurement using pulse transit time (PTT). In this method, a delay time between the peak of Photoplethysmogram (PPG) signals at the fingertip and the earlobe were correlated with BP. These signals were transferred to a computer via Arduino uno microcontroller and analyzed by the MATLAB R2019a software. A preliminary result shows that the developed system is able to record PTT and display the estimated BP value on the ThingSpeak webpage and ThingView apps. With the IoT platform, the cuffless BP can be monitor remotely, and the results can be store on the cloud healthcare system for hypertensive management.
Analysis of Image Processing Using Morphological Erosion and Dilation
Authors: Said K A M , Jambek A B
Published: November 2021

Digital image processing is important for image information extraction. One of the image processing methods is morphological image processing. This technique uses erosion and dilation operations to enhance and improve the image quality by shrinking and enlarging the image foreground. However, morphological image processing performance depends on the characteristics of structuring elements and their foreground image that need to be extracted. This paper studies how the structuring elements affect the performance of morphological erosion and dilation on binary images. The experimental result shows that choosing the right structuring element for morphological erosion and dilation can significantly influence the foreground and background structure of the output image.