bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative analysis of strange meson production in heavy ion collisions
Authors: Borisov V S , Berdnikov A Ya , Berdnikov Ya A , Kotov D O , Mitrankov Iu M
Published: December 2021

The study of deconfinement state of nuclear matter called quark-gluon plasma (QGP) and phase transition of QGP to hadronic gas is the main goal of high energy physics. Some of the important signatures of QGP formation in heavy-ion collisions include strangeness enhancement at intermediate values of the transverse momentum (ρT
) and a jet quenching effect at high ρT values. Nuclear modification factors (RAB
) for light hadrons are used to quantify these effects. The K
*0 and φ mesons can serve as a good probes to investigate QGP properties, because these mesons contain (anti)strange quark and its yields can be measured in a wide ρT
range. Comparison of experimental data with theoretical model calculations is important for understanding the evolution of heavy-ion collision. One of the most commonly used event generators to describe experimental results of collider experiments is Pythia8. This paper shows, that Pythia8 predicts RAB
values of K
*0 and φ less than RAB
values in experimental data. Consequently, additional (hidden)strange particle production mechanisms are involved.
A new limit on the resonant absorption of solar axions obtained via 169Tm-containing bolometer
Authors: Abdelhameed A H , Bakhlanov S V , Bauer P , Bento A , Bertoldo E , Canonica L , Derbin A V , Drachnev I S , Iachellini N Ferreiro , Fuchs D , Hauff D , Kuzmichev A M , Laubenstein M , Lis D A , Lomskaya I S , Mancuso M , Muratova V N , Nagorny S , Nisi S , Petricca F , Proebst F , Rothe J , Ryabchenkov V V , Sarkisov S E , Semenov D A , Subbotin K A , Trushin M V , Unzhakov E V , Zharikov E V
Published: December 2021

A newly developed experimental technique based on 169Tm-containing cryogenic bolometer detector was employed in order to perform the search for solar axions. The inclusion of target material into the active detector volume allowed for significant increase in sensitivity to axion parameters. A short 6.6 days measurement campaign with 8.18 g detector crystal yielded the following limits on axion couplings:

|
g

A
γ

(

g

A
N

0

+

g

A
N

3

)

≤
1.44
×

10

−
14

GeV

−
1

and

|
g

A
e

(

g

A
N

0

+

g

A
N

3

)

≤
2.81
×

10

−
16

. The achieved results demonstrate high scalability potential of presented experimental approach.
New measurement of the β-spectrum of 210Bi with a silicon 4πβ-spectrometer
Authors: Alekseev I E , Bakhlanov S V , Derbin A V , Drachnev I S , Kotina I M , Kuzmichev A M , Lomskaya I S , Mikulich M S , Muratova V N , Niyazova N V , Semenov D A , Trushin M V , Unzhakov E V
Published: December 2021

The shape of 210Bi β-spectrum was measured using a spectrometer based on Si(Li) detectors with a 4π geometry. Full absorption spectrometer allows for a direct measurement of the β-spectra without using the electron backscattering corrections for the response function. The measured value of nuclear shape factor C(W)=1+(-0.4378±0.0072)W+ (0.0526±0.0021) W2 is in agreement with the results of previous studies.
Tubular topological bright-dark and dark laser solitons
Authors: Rosanov N N , Veretenov N A , Fedorov S V
Published: December 2021

We investigate, analytically and numerically, tubular topological laser solitons, which serve as intermediate link between 2D- and 3D-dissipative optical solitons in media with nonlinear amplification and absorption of light or in large-size laser with such a medium. Features of both 3D-dark solitons (with nonvanishing intensity at periphery for all spatial dimensions) and bright-dark solitons (vanishing in two of three dimensions) are studied, including their stability.
The raman spectroscopy method for evaluation of structural changes in hard tissues of teeth after in-office whitening
Authors: Timchenko E V , Timchenko P E , Frolov O O , Magsumova O A , Volova L T , Postnikov M A , Kozlova T V
Published: December 2021

Start The experiments in evaluation of hard tissues using the Raman spectroscopy method have been made. Spectral differences between the tooth enamel and dentin before and after the in-office whitening procedure were found as a result of the work. It was shown with the use of the Raman spectroscopy method that the whitening process causes changes of tooth enamel and dentin related to the changes of organic and mineral components.
Energy flows in tight focus of optical vortices
Authors: Stafeev S S , Kotlyar V V
Published: December 2021

In this paper we investigated tight focusing of optical vortex with topological charge m = 2 and left circular polarization. The simulation was based on Richards-Wolf equation. Light with wavelength 532 nm was focused by aplanatic lens with numerical aperture NA=0.95. It was shown that the longitudinal component of Poynting vector has negative values on the optical axis. The reason of the energy backflow is due to the fact that the projection of the spin flow onto the optical axis is negative and exceeds in absolute value the projection of the orbital energy flow, which is always positive.
X-ray spectral diagnostics of the local environment of zinc in the arachidic acid layers
Authors: Kremennaya M A , Yu Lysenko V , Novikova N N , Yakunin S N , Rogachev A V , Yalovega G E
Published: December 2021

The article describes the behaviour of the Zn ions in aqueous subphase in presence of arachidic acid films at the air/liquid interface first studied by XANES spectroscopy in the fluorescent mode under total external reflection conditions. Fingerprint analysis of experimental spectra was carried out to determine the local structure of zinc ions in arachidic acid. It showed that zinc is surrounded by oxygen atoms, which may correspond to the interaction of zinc ions with polar groups of arachidic acid.
Numerical simulation of a plasmonic lens for laser light focusing
Authors: Kozlova E S , Kotlyar V V
Published: December 2021

In this paper, the design of a plasmonic lens in gold and silver thin films for focusing the light with radial polarization is presented. Using the finite difference time domain method the optimal parameters of the plasmonic lens design are found. It was shown that the silver plasmonic lens produces a tight focal spot with a full width at half maximum of 0.38 of the incident light wavelength.
Comparison of the focused optical vortices produced by high-aperture phase conventional and spiral zone plates
Authors: Savelyeva A A , Kozlova E S , Kotlyar V V
Published: December 2021

Using the FDTD simulation, sharp focusing of a linearly polarized Gaussian beam with an embedded topological charge m = 3 by a phase zone plate and focusing of a Gaussian beam by a phase spiral zone plate with topological charge m = 3 were studied. The obtained results showed that proposed elements formed different patterns of intensity at a focal plane. The spiral zone plate forms a focal spot with three petals. At a distance of 13.5 μm from the focus, the lobe structure of the intensity (and energy flux) is replaced by an annular distribution.
Light-emitting p-i-n GaP/GaPAs NW encapsulated in a flexible PDMS membrane
Authors: Mukhangali S M , Neplokh V , Kochetkov F M , Moiseev E I , Miroshnichenko A S , Deriabin K B , Nasibulin A G , Islamova R M , Mukhin I S
Published: December 2021

Our work is aimed at the method of fabricating arrays of semiconductor III-V NWs transferred into a flexible polymer membrane made of polydimethylsiloxane. GaP/GaPAs NWs with an axial p-i-n structure were synthesized by molecular beam epitaxy. The synthesized NW arrays on substrates were encapsulated into a silicone membrane by the G-coating method in a swinging-bucket centrifuge. After membranes were treated in a plasma mixture of O2/CF2 gases to open the NWs tops, which ensured the application of conductive transparent contacts - single-walled carbon nanotubes obtained by aerosol chemical method. At the last technological stage, the membranes were separated from substrates by peeling with a razor blade and the second carbon nanotubes contact was formed. The obtained LED NW/silicone membranes were characterized by I-V and the electroluminescence spectroscopy measurements.
Synthesis and study of the electrical conductive properties of Cs2Fe2TiO16 in various gas atmospheres
Authors: Rogova D A , Yu Sinel’shchikova O , Besprozvannykh N V , Morozov N A
Published: December 2021

In this work, titanate Cs2Fe2Ti6O16 with a hollandite-type structure was synthesized by solid-phase synthesis. The electrical conductivity of the obtained ceramics was investigated in the temperature range from 25 to 800 °C in air and in the presence of an argon-hydrogen mixture (3% H2). It was found that the electrical conductivity of the compound under consideration depends on the composition of the atmosphere — the activation energy of conduction changes (0.57 eV in air and 0.91 eV in the presence of hydrogen). The volumetric and grain-boundary contributions to the total resistance of the sample in the gases under consideration are separated by impedance spectroscopy at a temperature of 800 °C.
Effect of Nd, Pr substitutional atoms on the magnetic and magnetostrictive properties in (Tb-Dy)(Fe-Co)2 Laves phases
Authors: Politova G A , Ganin M A , Mikhailova A B , Morozov D A , Pankov K E , Dankin D G , Tereshina I S
Published: December 2021

Polycrystalline TbxDy1-xR0.1Fe2-zCoz (R = Nd, Pr, x = 0.2, 0.3; z = 0, 1.3) cubic Laves phase alloys with MgCu2-type structure were prepared by arc melting followed by homogenizing annealing. The crystal structure, magnetic properties, and magnetostriction have been investigated. Compounds with high values of magnetostrictive susceptibility were found in the temperature range 150-300 K. Compounds with partial substitution of cobalt for iron demonstrate a change in the sign of anisotropic magnetostriction. This work continues the search for magnetostrictive materials with inexpensive neodymium and praseodymium.
Quasistationary states in a quantum dot formed at the edge of a topological insulator by magnetic barriers with finite transparency
Authors: Khomitsky D V , Lavrukhina E A
Published: December 2021

A model of quasistationary states is constructed for the one-dimensional edge states propagating along the edge of a two-dimensional topological insulator based on HgTe/CdTe quantum well in the presence of magnetic barriers with finite transparency. The lifetimes of these quasistationary states are found analytically and numerically via different approaches including the solution of the stationary Schrödinger equation with complex energy and the solution of the transmission problem for a double barrier structure. The results can serve as a guide for determining the parameters of magnetic barriers creating the quantum dots where the lifetimes for the broadened discrete levels are long enough for manipulation with their occupation numbers by external fields.
Spectral and correlation analysis of microturbulences in the spherical Globus-M/M2 tokamaks
Authors: Ponomarenko A M , Bulanin V V , Gusev V K , Minaev V B , Petrov A V , Petrov Yu V , Yashin A Yu
Published: December 2021

Results of the studies on turbulences carried out on the Globus-M2 and Globus-M tokamaks are presented. The main focus was on the analysis of the data obtained using Doppler backscattering method (DBS). The developed codes for the analysis of DBS signals allowed to study the effects of turbulences on the operational mode of the tokamak. A description of the data processing codes is also included. The analysis performed indicates the suppression of turbulence and the formation of a velocity shear during the L-H transition. It was also successfully used to study density fluctuations during and between edge localized modes (ELMs). Spectral and correlation analysis also led to the discovery of limit-cycle oscillations (LCO) and quasi coherent fluctuations (QCFs) during the I-phase.
Large Eddy Simulation with wall functions of Ahmed body
Authors: Kolmogorov Dmitry K. , Hüppe Andreas , Menter Florian , Garbaruk Andrey V.
Published: December 2021

Large Eddy Simulation with Wall Function (WFLES) is known to be a cheap alternative to classical LES methods for simulation of flow where large and complex computational meshes are typically required. This makes it attractive for engineering applications. However experience of applying such methods to complex turbulent flows with flow separation and reattachment is still little-known in literature. In this work WFLES of flow around simplified car body with slant angle equal to 25 degrees and ReL = 2.8 · 106 is carried out on Octree mesh to demonstrate the capabilities and limitations of the method in such type of the flow. The results on a series of meshes show that even though the general flow topology is well captured, the critical part of the flow on the slant is hardly predicted even on 100 mln mesh. It is concluded that the prediction of separation above the slant requires significant mesh refinement even in the frame of WFLES.
Influence of contraction of a cesium pulse-periodic discharge on its luminous efficacy and spectral properties
Authors: Bogdanov A A , Gavrish S V , Martsinovsky A M , Stolyarov I I
Published: December 2021

The paper presents the results of a study of pulse-periodic discharge cesium lighting lamps with discharge tubes 5 mm in diameter and an interelectrode distance of 55 and 22 mm. The cesium pressure varied from 10 to 750 Torr at a constant triangular current pulse with an amplitude of 80 A. It is shown that the maximum of the luminous efficacy (~ 65 lm/W) corresponds to a pressure of ~ 130 Torr. It was found that a discharge column in the long tube at a pressure of ~ 300 Torr contracted into a bright pinch with a diameter close to that of the electrodes (2 mm). The pinch was localized along the surface of the tube and moves randomly on it. Contraction leads to a repeated increase in the luminous efficacy with pressure up to ~ 70 lm/W. Wall stabilization limits the plasma temperature on the axis of the pinch (it was found from the recombination continuum) to the level of 6000 – 6500 K. The column in short tube is localized along the axis of the tube over the entire power range. The temperature in it quickly rises to 13000-– 14000 K after the maximum of the luminous efficacy.
Nonlinear optical dynamics of two-dimensional super-lattices of quantum V-emitters
Authors: Bayramdurdiyev Davut Ya. , Malikov Ramil F. , Ryzhov Igor V. , Malyshev Victor A.
Published: December 2021

We study theoretically the nonlinear optical response of a super-lattice of regularly arranged three-level identical quantum emitters with a doublet in the excited state to the action of a monochromatic electromagnetic field quasi-resonant to optical transitions in the emitter, using into account the dephasing of the system. The total retarded dipole-dipole interaction of the emitters is accounted for in the mean-field approximation. This interaction plays the role of positive feedback, which (in combination with the immanent nonlinearity of emitters themselves) leads to multistability of the super-lattice response. The stability of different response branches is analyzed using the Lyapunov exponents’ method. Another important property of the super-lattice is its high reflectance in a certain frequency range; i.e., within this range, the super-lattice operates as a perfect nanometer mirror; moreover, reflection can be switched to transmission changing slightly the incident field amplitude (bistability). The possibility of the application of the above-mentioned super-lattice optical properties in nanophotonics is discussed.
Influence of roughness parameters of surface on the emissivity of germanium single crystals
Authors: Tretiakov S A , Molchanov S V , Kaplunov I A , Ivanova A I
Published: December 2021

In this paper observed values of emissivity for germanium single crystals with various surfaces received by classical methods of processing (polishing, grinding by the powders F400, F800), and also for the raw surface after a cut. The received values will allow further thermovision researches of germanium single crystals by methods of active thermal control and IR-defectoscopy with minimization of measurement errors.
Investigation influence of switching tests coatings of magnetically controlled contacts on the surface structure
Authors: Loginov D S , Baskakova A V , Litvinov V G , Kholomina T A , Rybin N B , Trusov E P
Published: December 2021

The results of spectral noise power density measurements of reed switches 10 samples with and without Au-Ru coating are analyzed. The dependences of the spots area formed during switching tests on the electrodes on various noise parameters are constructed.
Schottky diodes based on 4H-SiC epitaxial layers
Authors: Strel’chuk A M , Kalinina E V
Published: December 2021

Forward and reverse current-voltage (IV) characteristics of Cr-SiC (4H) Schottky diodes based on epitaxial layers with doping (1-3)· 1015 cm-3 were studied in the temperature range of 300-550 K. It is shown that in many cases the IV characteristics are close to ideal, but a significant spread of the forward IV characteristics of diodes manufactured in the same way on the same epitaxial layer was found, probably due to the spread of the Schottky barrier heights reaching 0.3 eV. Heating of the diode, as well as packaging, can also change the Schottky barrier height. An alternative explanation suggests the presence of a powerful shunt.
Characterization of Irradiated Wood Plastic Composites (WPCs) Consumer Product
Authors: Harun Siti Nur Idayu , Othman Siti Amira
Published: December 2021

This research paper emphasizes the characterization of irradiated wood plastic composites for consumer product. Throughout this research, it is precisely conducted to observe the mechanical and physical properties of WPCs and their ability to fit in the market globally. The study also carried out to promote WPCs product that came naturally from renewable sources. WPCs in this research can be defined as mixture of wood that can be replaced with pineapple fiber in a polymer matrix. Composite that used in this research mainly consists of 40% polyethylene (PE), 50 % pineapple fiber and the rest is coupling agent that enhance the WPCs mixture. After undergoes several processes such making the raw sample of WPCs mixture, the WPCs were then irradiated under required dose levels of 0.5, 1, 1.5, 2, 2.5 kGy with the aid of the Gamma Cell Irradiator. Soon after, the irradiated WPCs then undergoes characterization process using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDX). Diagnosis on the morphology of WPCs found that there was significant difference between the radiated and irradiated surfaces.
Production and Characterization of Activated Carbon from Baobab Fruit Shells by Chemical Activation Using ZnCl2, H3PO4 and KOH
Authors: Nedjai R , Kabbashi N A , Alam M Z , Al-Khatib M F R
Published: December 2021

Chemical agents have a good influence on the formation of activated carbons, surface characteristic, and its adsorption properties. In this study, the effect of activating agents (ZnCl2, KOH, and H3PO4) on baobab fruit shell (BFS) were evaluated. The characteristics of the baobab fruit shell based activated carbon (BF-ACs) were evaluated through the yield and iodine number. BF-ACs were also characterized by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), and nitrogen (N2) adsorption. SEM analysis illustrates those porous structures formed on the surface of BF-ACs were with different sizes. The XRD analysis show that the main structures of BF-ACs are amorphous. FT-IR data demonstrates the presence of different surface groups on the produced BF-ACs. Among activating agent, the KOH was observed to the most appropriate for the production of activated carbon with a large surface area (1029.44 m2/g) from baobab fruit shell.
The Comparison of Microstructure and Mechanical Behavior of Stainless Steel 316L Using Near Net Shaped and Fully Embedded Methodologies Using DED Metal Advanced Manufacturing
Authors: Vandever Marcie , Shanmugam Ragavanantham , Ramoni Monsuru , Romine Peter , Whiting Harry
Published: December 2021

The objective of this research is to compare the microstructure and mechanical behavior of 3D printed SS 316L using near net shaped and fully embedded manufacturing extraction techniques. Research findings will allow us to determine if two different manufacturing extraction methodologies of a 3D printed stainless steel part will affect the overall performance of test specimens. Research will implement advanced manufacturing, part designing, part modeling, part simulation, part production, CT X-ray scanning, material characterization, and material testing. Printing of test specimens will be done with a Optomec Lens 3D Hybrid Machine Tool Direct Energy Deposition (DED) metal printer. The DED metal printer will be used for prototype printing and printing test samples. The areas of study will also include modeling and design using SolidWorks CAD software. A comparison of printing orientation/configuration, internal composition, and testing of material structure in the areas of stress to complete failure of test specimens. The internal structure analysis will observe the porosity effects of 3D metal printing with near net shaped and cocoon style print parameters. The study will also address the amount of time, production, strength, composition, and overall performance of SS 316L printed material.
Computer-Assisted in Coiled Tubing Perforation Limitations: A Case Study from MA-X Gas Well
Authors: Han Kung Yee , Sidek Akhmal , Supee Aizuddin , Junin Radzuan , Jaafar Zaidi , Nasir Ahmad Nabil Md , Tarmidi Zakri , Omar Shaziera
Published: December 2021

This paper seeks to determine the optimum operating conditions for deploying casing perforation guns based on CT to target depths in gas well MA-X by utilising Orpheus Model in CERBERUS. Orpheus assisted to solve the complicated scenarios and complex analysis involves mathematical modelling which is necessitates for computer processing powers. This study investigated four different Coiled Tubing (CT) intervention operational variables namely borehole assembly, CT grade outer diameter (OD), well fluid type and fractional reducer application included examined two scenarios which are running tools in (RIH) and pulling out from borehole (POOH). Only CT workstring with outer diameter between 1-1/4 inch and 2-7/8 inch is considered due to the wellbore completion minimum restriction. Constrained by economic and logistical reasons, only fresh water, 2% KCl, 15% HCl, sea water and diesel will be considered for the well bore fluid. Fractional reducer effects was simulated and analysed. Based on simulation results, the CT outer diameter 1-3/4 inch workstring optimized operation, the CT grade is QT1000 increased mechanical properties. A suitable well fluid is sea water with application of friction reducer improve CT perforation performances to achieve maximum target depth.
Velocity Flow Field Characteristic on Nozzle Cavity using Central Composite Design of Computational Method for Dry Ice Blasting System
Authors: Hidayat Mat Mohamad Nur , Md Basir Md Faisal , Farid Sies Mohamad
Published: December 2021

In the development of dry ice blasting nozzle geometry, the critical process parameters depend on particle jet velocity. However, very few researchers have attempted sensitivity on the velocity flow area of specific nozzle geometric parameters. A numerical simulation approach was performed in this paper using Ansys Fluent to investigate different nozzle parameters on the velocity flow field. A two-dimensional model is solved iteratively using averaged Navier-Stokes under Eulerian flow description. It was found that the velocity value increases that reach 550 m/s with an increment of the nozzle area ratio of up to 20 without influencing convergent angle and the velocity magnitude drop linearly from 525 m/s to 505 m/s in with the rise of divergent length that swell up to 700 mm and with constant convergent angle and convergent length.
Optimization of Tool Path Length on Three-Dimensional Drilling Application Using Ant Colony Algorithm
Authors: Rusman Muhammad Danial Ikmal bin , Abdullah Haslina , Zakaria Mohamad Shukri , Talib Norfazillah , Kiow Lee Woon , Saleh Aslinda
Published: December 2021

The lower machining time is important characteristic in the drilling machining process. Drilling process costs will increase if the machining time is high. Therefore, the main objective of this research is to develop Ant Colony Algorithm (ACO) to reduce the machining time by obtain the optimal tool path length. By using this algorithm, it can minimize the tool path length and significantly decreasing the machining time of drilling process. Simulating in 3-dimensional drilling on ACO has been constructed to minimize the shortest path of the drilling process. There are two type of workpiece has been used, which is simple block with 10 holes and complex block design that has 154 holes. ACO algorithm has been developed in Matlab R2017b to determine the optimal parameters of ACO of tool path length in drilling. Besides, simulation also has been done to investigate the effect of ACO parameter which is weight of pheromone (α), weight of trail (β), evaporation coefficient (e), and number of iterations. As a result, by define the parameter of iteration number at 900, the optimum parameter of weight of pheromone (α) is 5, weight of trail (β) is 4 and evaporation coefficient (e) is 0.4. Based on these parameters, the minimal tool path length obtain for simple and complex model are 286.965 mm and 6770.9860 mm respectively. Then, the result of tool path length of ACO simulation has been compared with the Mastercam outcome. ACO achieves a total tool path length of 286.965 mm while Mastercam achieved 569.878 mm for simple block design. Meanwhile, for complex block design, ACO produces a total tool path length of 6770.9860 mm while Mastercam has generate 55828.9050 mm of tool path length. By comparing these two approaches, ACO and Mastercam, ACO has that the short total tool path length by 49.64% on simple block design and 87.87% for complex block design.
Advantages of Using Hybrid System Method in Industrialised Building System (IBS)
Authors: Azmin Izzati , Kassim Umar
Published: December 2021

Hybrid System method is one of the technology implements in Industrialised Building System (IBS). Methods has been acquaint in many ways in order to improve Industrialised Building System (IBS) in Malaysia. Other country such as United Kingdom also have used the term Hybrid for their concrete process known as Hybrid Concrete Construction (HCC). While in Malaysia, Hybrid System comes with a method that combines one component with two different method which are the precast component and cast-in situ method. This two combination method has called a Hybrid System method and started implements by Jabatan Kerja Raya (JKR) for mostly a government projects in Kedah state in Malaysia on 2017. Industrialised Building System has been well known as a fast completion, saving cost, and less labour needed in construction. However, the issues by using Hybrid System method has double up the time completion, splurging the cost, and enlarge the labour since it needs to cast-in situ the components, let the concrete cured and more material usage. The significance of study for this research is the new method of IBS Hybrid System is a pilot project in Kedah by JKR. Thus, this research is to control the delay involves in projects that apply IBS Hybrid System. Hence, this paper is to identify the advantages of using Hybrid System method in Industrialised Building System (IBS).
Performance and Kinetic Study on Oil Removal Via Electrocoagulation Treatment
Authors: Lam Jillin Soo Ai , Shoparwe Noor Fazliani , Khairudin Nurulbahiyah Ahmad , Tan Lian See , Lee Kee Quen
Published: December 2021

Electrocoagulation (EC) is a reliable technology for wastewater treatment. It has been applied in treating various source of wastewater from tannery, electroplating, dairy, textile processing, oil and oil-in-emulsion. It is crucial to strengthen the fundamental of the EC treatment on oily water sample for further studies. However, in depth studies on the performance of EC treatment on oily water sample is still requires in depth studies. In this research, a series of experiment has been conducted on the performance of EC treatment including effect of the amount of sodium chloride (NaCl), applied voltage and pH to determine the efficiency in oil removal. The EC treatment took placed in room temperature and constantly agitated for 30 minutes meanwhile samples were collected for every 5 minutes for UV–Vis analysis. Then, the efficiency of the treatment was determined followed by simulating the results in kinetic models. The highest efficiency of EC treatment was achieved with 89.26% of oil removal with the addition of 7.5g of NaCl, 4V of applied voltage and at pH 6. In addition, the results have better fitness towards pseudo second order (PSO) which indicates the mechanism of EC treatment is chemisorption.
Identification of Sharp Edge Non-Slender Delta Wing Aerodynamic Coefficient Using Neural Network
Authors: Rahman Fahmi Izzuddin Abdul , Mat Shabudin , Radzi Nor Haizan Mohamed , Nasir Mohd Nazri Mohd , Sallehudin Roselina
Published: December 2021

Delta wing formed a vortical flow on its surface which produced higher lift compared to conventional wing. The vortical flow is complex and non-linear which requires more studies to understand its flow physics. However, conventional flow analysis (wind tunnel test and computational flow dynamic) comes with several significant drawbacks. In recent times, application of neural network as alternative to conventional flow analysis has increased. This study is about utilization of Multi-Layer Perceptron (MLP) neural network to predict the coefficient of pressure (Cp
) on a delta wing model. The physical model that was used is a sharp edge non-slender delta wing. The training data was taken from wind tunnel tests. 70% of data is used as training, 15% is used as validation and another 15% is used as test set. The wind tunnel test was done at angle of attack from 0°-18° with increment of 3°. The flow velocity was set at 25m/s which correspond to 800,000 Reynolds number. The inputs are angle of attack and location of pressure tube (y/cr) while the output is Cp
. The MLP models were fitted with 3 different transfer functions (linear, sigmoid, and tanh) and trained with Lavenberg-Marquadt backpropagation algorithm. The results of the models were compared to determine the best performing model. Results show that large amount of data is required to produce accurate prediction model because the model suffer from condition called overfitting.
Mechanical and Physical Properties of Cross-Laminated Timber Made from Batai using Different Glue Spread Amounts
Authors: Liew Kang Chiang , Maining Ezzia Stecy
Published: December 2021

This study aimed to determine the mechanical and physical properties of the Cross-Laminated Timber (CLT) glued with different amounts of glue. Cost of glue is the outmost importance where it will help in reducing the CLT manufacturing cost. Four different amounts of glue spread were used where the glue that used was phenol-resorcinol formaldehyde (PRF);150, 200, 250 and 300g/m2. The testing of the CLT was conducted by following BS EN 408:2010, BS EN 16351:2015, ASTM D 2718 method B, ASTM D 143-94 and Japanese Agricultural Standard (JAS) 1152:2007. The analysis of physical tests that have been carried out are density, moisture content, shrinkage and swelling of the CLT’s thickness. Meanwhile, the mechanical tests were compression parallel and perpendicular to the grain, three-point bending test (flatwise and edgewise of CLT) and shear test. The highest density was shown by the CLT that using 300 g/m2 which the value was 316.41 kg/m3. Whereas the highest moisture content was shown by CLT that used 250 g/m2 with 15.49% in value. The highest thickness shrinkage percentage was 2.50%, CLT with 200g/m2 while the highest thickness swelling percentage was 5.60% which the CLT used 150 g/m2. For the flatwise bending test, it shows that the CLT that used 300 g/m2 has the highest MOE and MOR value which were 510.63N/mm2 and 8.39 N/mm2. The MOE and MOR value for edgewise bending also shows that CLT that used 300 g/m2 was the best with 1528.70 N/mm2and 13.48 N/mm2. In compression perpendicular to grain test, the CLT with 150 g/m2 shows the highest value of MOE which was 5.89 N/mm2 while CLT that used 200 g/m2 has the highest value of compressive strength with 9.10N/mm2. However, for compression parallel to grain test, the CLT that used 300 g/m2 shows the best performance with 1002.78 N/mm2 and 13.75 N/mm2 of MOE and compressive strength value. Lastly, for the shear test, the highest shear strength value was 0.39 N/mm2 which belongs to CLT that used 150 g/m2. Thus, CLT that used 300 g/m2 of glue spread amount is the best CLT which, the more the amount of glue, the better the performance of the CLT.
CFD Simulation on Improving Water Quality based on Various Aerator Models to Demonstrate Cost Performance Analysis
Authors: Norbashah N N , Rani M F H , Kamarrudin N S , Shahriman A B , Razlan Z M , Wan W K , Hashim M S M , Ibrahim I. , Rahman A , Ibrahim Z. , Faizi M K , Hassan M A S M , Abd Manap A A , Zainuddin I F
Published: December 2021

There are many types of aerator that can be used to perform a water treatment process either from air to water or from water to air approaches. Other than focusing on the performance itself, the usage cost of aerator should be forecasted in detail too to have a sustainable and economical method in remediating the polluted water. Therein, the cost performance analysis was demonstrated by performing a computational fluid dynamics (CFD) simulation on improving water quality based on various aerator models. The simulation was focused in a small-scale aeration tank that consists of a mixing chamber, air duct, and a few of bubble diffusers. The improvement of water quality was assessed by calculating the number of gas bubble particles produced by 4 different configurations of aerator model, namely aerator model A, B, C and D, respectively. Results found that the aerator model D (5 bubble diffuser at 620 L/min) produces the highest number of gas particles up to 72.2%. However, the aerator model C (5 bubble diffuser at 300 L/min) was found to achieve the most efficient and sustainable approach based on energy consuming and cost of aerator configuration when compared to the other aerator models.
Study the Structure Characterization of Porcelain Formulation at Different Sludge Content
Authors: Alias Suffi Irni , Johar Banjuraizah , Adam Syed Nuzul Fadzli , Taib Mustaffa Ali Azhar , Othman Fatin Fatini , Fhan Khor Shing
Published: December 2021

Porcelain formulation in the form of pellets have been studied by substituted fluxing materials with treated FGD sludge at different percentages. In this work, treated FGD sludge was added in percentages from 5% up to 15% uniaxially pressed at 11 MPa, dried and then sintered at temperature 1200 °C for 3 hours. Weight loss, volume shrinkage/expand, bulk density, densification, porosity and flexural strength were investigated on sintered samples. This demonstrated that the treated FGD sludge addition in porcelain formulation has influenced on the sintered samples. It was concluded that the treated FGD sludge waste could be used as a suitable raw material source for production of porous porcelain ceramic due to their organic and inorganic content.
Engine Performance Analysis by Studying Heat Transfer in the Valve Seat through Steady-State Thermal Simulation
Authors: Hassan M A S M , Shahriman A B , Razlan Z M , Kamarrudin N S , Khairunizam W K N , Hashim M S M , Harun A , Ibrahim I , Azizul Aziz I , Ibrahim Z , Faizi M K , Rani M F H , Rahman A , Rani M F H , Rojan M A , Murali R
Published: December 2021

As the engine reached high speed, the exhaust valve temperature increased exponentially due to the exhaust gas produced by the combustion process between the mixture of air and fuel within the combustion chamber of the internal combustion engine. The valve is subjected to thermal loading due to high temperature and pressure within the cylinder, which must withstand a material temperature for sustainable and optimal operation. To avoid this loss, a perfect medium must be prepared to ensure that the heat is extracted smoothly. This can be done when the valve is in contact with the seat and there is a periodic heat transfer contact. Therefore, it is imperative to research the correlation between valve and valve seat to understand the two sections’ heat transfer mechanism. In this study, thermal contact analysis was used to identify heat transfer between the valve and the valve seat as both parts are interconnected. This research also has an interest in studying the two surface conduction mechanisms as the exhaust valve closed in steady-state conditions. Thus, this study portrays a significant method, particularly for the determining the distribution of temperature, heat flux, and heat flux direction between the valve and its seat using ANSYS Workbench.
Mathematical modeling of monochromatic acoustic wave diffraction on a system of bodies and on flat screens
Authors: Daeva S G , Beskin A L , Trokhachenkova N N
Published: December 2021

Some problems of diffraction of a monochromatic acoustic wave on surfaces of complex shapes are considered. To solve such problems, an approach is applied, in which the problem is reduced to a boundary hypersingular integral equation, where the integral is understood in the sense of a finite value according to Hadamard. Such approach allows solving diffraction problems both on solid objects and on thin screens. To solve the integral equation, the method of piecewise constant approximations and collocations, developed in the previous works of the author, is used. In the present study, examples of modeling the diffraction of an acoustic wave by bodies with partial filling are given. It is shown how the filling of bodies influences the acoustic pressure field, and the field direction patterns are given. An example of applying this approach to solving the problem of sound propagation in an urban area is also given: the diffraction of an acoustic wave from a point source on a system of buildings is considered. The presented results demonstrate that this method allows constructing reflected fields and analyze their characteristics on surfaces of complex shapes.
Application of the algorithm for calculating the boundaries of built-up areas from satellite images to calculating the areas of flooded land and the environmental potential of the territories of settlements
Authors: Ilyushina T V , Sizov A P , Belenko V V
Published: December 2021

The processes of flooding of the territory of settlements cause significant economic damage to the national economy. Up-to-date space information provides research on flooding over large areas. Analysis of the dynamics of flooding in the Khabarovsk Region for 2016-2019 using remote sensing methods and statistical data analysis showed that the optimal software product for processing multi-time satellite images is the MapInfo Professional GIS application. It is established that the dynamics of the areas of flooded land in settlements has similar trends, significantly differing in quantitative indicators. The most favorable year was 2017, when the least amount of land was affected by flooding. In 2019, the amount of flooded land was the maximum. 2016 and 2018 occupy an intermediate position. The proportion of flooded land was the highest in large and medium-sized cities, the lowest in rural settlements, and the small towns occupied an intermediate position due to the landscape and geographical features of the research objects. The relative decline in the value of the territory environmental potential (EFP) was also the highest in large and medium-sized cities, and the lowest in rural areas. According to the years, the increase in the temporary decline in EFP due to flooding and withdrawal from economic use of land is as follows: 2017-2016-2018-2019, which is due to the dynamics of the hydrological and climatic characteristics of these years.
Using waterfall, iterative and spiral models in ERP-system implementation projects under uncertainty
Authors: Yu Stepanov D
Published: December 2021

The article considers the use of cascade and multi-pass implementation models of corporate information systems in case of business and technological uncertainty. A review of waterfall, iterative and spiral ERP-systems implementation models is given. The business and technological uncertainties inherent in software systems implementation projects are introduced. The basic principles of development complex applications in ERP-systems are analyzed, including the rules of evolution and functionality. One compares business uncertainty for refined requirements in the waterfall and Agile-based implementation models, which operate with a change request and allocation requirements to a new round of development respectively. There is no or minimal technological uncertainty in ERP-systems implementation projects, however high business uncertainty exists, which can not be decreased by any basic implementation approaches. The application area of the waterfall and multi-pass implementation models is clarified for ERP projects from scratch, rollout and evolution under business uncertainty.
Wavelet transform-based cross-correlation in the time-delay estimation applications
Authors: Sharkova S B , Faerman V A
Published: December 2021

The article discusses the application of wavelet analysis for the time-frequency time-delay estimation. The proposed algorithm is wavelet transform-based cross-correlation time delay estimation that applies discrete time wavelet transform to filter the input signal prior to computation of cross-correlation function. The distinguishing feature of the algorithm that it uses the variation of continuous wavelet transform to process the discrete signals instead of dyadic wavelet transform that is normally applied to the case. Another feature that the implication of convolution theorem is used to compute coefficients of the wavelet transform. This makes possible to omit redundant discrete Fourier transforms and significantly reduce the computational complexity. The principal applicability of the proposed method is shown in the course of a computational experiments with artificial and real-world signal. So the method demonstrated expected selectivity for the signals localized in the different frequency bands. The application of the method to practical case of pipeline leak detection was also successful. However, the study concluded that this method provides no specific advantages in comparison with the conventional one. In the future, alternative applications in biological signal processing will be considered.
The electric field dependence of single electron emission in the PIXeY two-phase xenon detector
Authors: Bodnia E. , Bernard E.P. , Biekert A. , Boulton E.M. , Cahn S.B. , Destefano N. , Edwards B.N.V. , Gai M. , Horn M. , Larsen N.A. , Riffard Q. , Tennyson B. , Velan V. , Wahl C. , McKinsey D.N.
Published: December 2021

Dual phase xenon detectors are widely used in experimental
searches for galactic dark matter particles. The origin of single
electron backgrounds following prompt scintillation and proportional
scintillation signals in these detectors is not fully understood,
although there has been progress in recent years. In this paper, we
describe single electron backgrounds in 83mKr
calibration events and their correlation with drift and extraction
fields, using the Particle Identification in Xenon at Yale (PIXeY)
dual-phase xenon time projection chamber. The single electron
background induced by the Fowler-Nordheim (FN) effect is measured,
and its electric field dependence is quantified. The photoionization
of grids and impurities by prompt scintillation and proportional
scintillation also contributes to the single electron background.
Fully-printed metamaterial-type flexible wings with controllable flight characteristics
Authors: Zhilyaev Igor , Anerao Nitesh , Kottapalli Ajay Giri Prakash , Yilmaz Mahmut Cihat , Murat Mustafa , Ranjbar Mostafa , Krushynska Anastasiia
Published: December 2021

Insect wings are an outstanding example of how a proper interplay of rigid and flexible materials enables an intricate flapping flight accompanied by sound. The understanding of the aerodynamics and acoustics of insect wings has enabled the development of man-made flying robotic vehicles and explained basic mechanisms of sound generation by natural flyers. This work proposes the concept of artificial wings with a periodic pattern, inspired by metamaterials, and explores how the pattern geometry can be used to control the aerodynamic and acoustic characteristics of a wing. For this, we analyzed bio-inspired wings with anisotropic honeycomb patterns flapping at a low frequency and developed a multi-parameter optimization procedure to tune the pattern design in order to increase lift and simultaneously to manipulate the produced sound. Our analysis is based on the finite-element solution to a transient three-dimensional fluid–structure interactions problem. The two-way coupling is described by incompressible Navier–Stokes equations for viscous air and structural equations of motion for a wing undergoing large deformations. We 3D-printed three wing samples and validated their robustness and dynamics experimentally. Importantly, we showed that the proposed wings can sustain long-term resonance excitation that opens a possibility to implement resonance-type flights inherent to certain natural flyers. Our results confirm the feasibility of metamaterial patterns to control the flapping flight dynamics and can open new perspectives for applications of 3D-printed patterned wings, e.g. in the design of drones with target sound.
Estimating unprecedented extremes in UK summer daily rainfall
Authors: Kent Chris , Dunstone Nick , Tucker Simon , Scaife Adam A , Brown Simon , Kendon Elizabeth J , Smith Doug , McLean Lynsay , Greenwood Shirley
Published: December 2021

The UNSEEN (unprecedented simulated extremes using ensemble) method involves using a large ensemble of climate model simulations to increase the sample size of rare events. Here we extend UNSEEN to focus on intense summertime daily rainfall, estimating plausible rainfall extremes in the current climate. To address modelling limitations simulations from two climate models were used; an initialised 25 km global model that uses parameterised convection, and a dynamically downscaled 2.2 km model that uses explicit convection. In terms of the statistical characteristics that govern very rare return periods, the models are not significantly different from the observations across much of the UK. Our analysis provides more precise estimates of 1000 year return levels for extreme daily rainfall, reducing sampling uncertainty by 70%–90% compared to using observations alone. This framework enables observed daily storm profiles to be adjusted to more statistically robust estimates of extreme rainfall. For a damaging storm in July 2007 which led to surface water flooding, we estimate physically plausible increases in the total daily rainfall of 50%–100%. For much of the UK the annual chance of record-breaking daily summertime rainfall is estimated to be around 1% per year in the present-day climate. Analysis of the dynamical states in our UNSEEN events indicates that heavy daily rainfall is associated with a southward displaced and meandering North Atlantic jet stream, increasing the advection of warm moist air from across Southern Europe and the Mediterranean, and intensifying extratropical storms. This work represents an advancement in the use of climate modelling for estimating present-day climate hazards and outlines a framework for applying UNSEEN at higher spatial and temporal resolutions.