bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of the mechanical properties of epitaxial gallium nitride for applications in MEMS
Authors: Enns Y , Kazakin A , Mizerov A , Shubina K , Morozov I , Mokhov D , Bouravleuv A
Published: December 2020

This article presents the results of the experimental determination of the mechanical parameters of a GaN films grown by molecular beam epitaxy on silicon substrates. The values of Young’s modulus and internal stresses for GaN films with different growth parameters have been determined. The study was carried out by contact and optical methods on the formed cantilever and beam microstructures. The measured values can be used to develop the design and evaluate the characteristics of MEMS based on gallium nitride films.
Formation of metal catalytic centers from atomic flows of matter for the growth of carbon nanostructures using PECVD method
Authors: Klimin V S , Rezvan A A , Morozova J V , Ageev O A
Published: December 2020

Consider formation of nickel catalytic centers from atomic flows obtained by the method of vacuum resistive evaporation. A model of formation kinetics of catalytic centers of nickel from atomic flows has been constructed. A complete model of theoretical studies of the formation of catalytic centers of nickel on a silicon surface is shown. A dependence of cluster concentration on normalized formation time is obtained. According to the results of theoretical studies, it was learned that flux of nickel atoms to substrate is F = 1.296 * 1018, residence time of nickel atom on substrate in adsorbed state is tg = 5.135 * 10−7, and concentration of adsorbed atoms as a function of time is N = 6.657 * 1011.
Luminescent vertically oriented nanosheets MoS2 by low temperature MOCVD
Authors: Khattab Y , Alexandrov S E , Mukhin I
Published: December 2020

Controlled growth orientation of MoS2 thin films is the key requirement to realize their vast number of applications, as material has strong anisotropic properties, in addition chemically active edge sites over inert in-plane MoS2 flakes is very important for catalytic activities. Here, we demonstrate growth dense and edge-enriched vertically oriented MoS2 (V-MoS2) using MOCVD technique with deposition temperature as low as 250°C. SEM results demonstrated the vertically oriented growth and high density of edge terminated MoS2 sheets. While Raman and XPS confirm MoS2 composition of sheets with good quality. At Room temperature, there is strong photoluminescence emission from sheets due few layer structures.
Electrical properties of InGaN nanostructures with branched morphology synthesized via MBE on p-type Si(111)
Authors: Gridchin V O , Kotlyar K P , Reznik R R , Borodin B R , Kudryashov D A , Alekseev P A , Cirlin G E
Published: December 2020

The work is devoted to the study of electrical properties of InGaN nanostructures with branched morphology (NSs) on p-type Si substrates. It was found that the IV curves between InGaN NSs and p-Si are close to linear, which could indicate a tunneling conductivity. Such unique structures as InGaN NSs on p-Si can be used as building blocks for water splitting devices and tandem solar cells.
The influence of the morphology of oxidized copper nanoparticles on the electrical properties of microstructures obtained by dry aerosol printing
Authors: Kornyushin D V , Efimov A A , Khabarov K M , Ivanov V V
Published: December 2020

The influence of the morphology of oxidized copper nanoparticles on the deposition efficiency, packing density, and resistivity of microstructures obtained by dry aerosol printing was studied. It has been established that the thermal treatment of aerosol nanoparticles allows to vary their morphology from branched submicron agglomerates to compact spherical nanoparticles with a size of 20-50 nm. It is shown that the use of spherical nanoparticles in comparison with agglomerates allows one to obtain densely packed nanoparticles on substrate. Moreover, obtaining of semiconductor microstructures from oxidized copper nanoparticles on a plastic substrate with a resistivity of 0.01 Ohm • m was demonstrated.
Ordering mechanism of silver nanoparticles synthesized in a ZnO:Al polycrystalline film by sol gel method
Authors: Sokura L A , Snezhnaia Zh G , Nevedomskiy V N , Shirshneva-Vaschenko E V , Romanov A E
Published: December 2020

The optical absorption spectra and structural properties of ZnO:Al films with an intermediate layer of silver nanoparticles with a different number of inserted layers of silver nitrate solution are studied. The study of optical properties showed that with an increase in the number of layers, the intensity of the plasmon absorption peak of nanoparticles increases. Consequently, with an increase in the number of layers, their density increases, it was confirmed by studies of the obtained samples structural properties by transmission electron microscopy.
The study of Si/Ge interdiffusion using molecular dynamics simulation
Authors: Bastrakova M V , Mukhamatchin K R , Kuznetsov Yu M , Dorokhin M V
Published: December 2020

The coefficients of mutual diffusion of silicon into germanium (and vice-versa) at temperatures of 900-1300K were found based on molecular dynamics simulation. For the characteristic temperature Tc=1100 K, which is close to the melting point of Ge, we determined the thickness of the diffusing layer for each type of atom. It is shown that the depth of diffusing significantly depends on the sintering time, and silicon atoms penetrate 1.5 times deeper into bulk germanium than germanium into silicon.
Research of the effect of solvents on the rheological characteristics of drop-on-demand inkjet liquid toner
Authors: Klimontov K A , Vaganov V V , Kruglov A I
Published: December 2020

In this work the relationship of the rheological characteristics of liquid toner with external factors (shear strain rate, temperature) depending on the solvent used is investigated, experiments with a number of solvents (sulfolane, 3-methoxypropionitrile or acetonitrile) are carried out.
The study of the AlN/Si(111) epitaxial structures grown by PA MBE via coalescence overgrowth of AlN nanocolumns
Authors: Shubina K Yu , Mokhov D V , Berezovskaya T N , Nikitina E V , Mizerov A M , Bouravleuv A D
Published: December 2020

The AlN/Si(111) epitaxial structures were synthesized by coalescence overgrowth of AlN nanocolumns using PA MBE technique. Such epitaxial structures can be used as a buffer layer for obtaining high quality AlN and GaN layers. Structural, electrical and chemical properties of these samples were studied. For the first time it was demonstrated that the etching of the obtained type of AlN/Si(111) structures in KOH can become a promising method for obtaining high quality free-standing AlN and GaN.
Optical properties of InGaN/GaN QDs nanorods by top-down fabrication after KOH treatment
Authors: Kotlyar K P , Menzelincev A K , Kiseleva E M , Shcherbakova V B , Shilov V A , Smolina E O , Berezovskaya T N , Dragunova A S , Kryzhanovskaya N V , Nikitina E V , Soshnikov I P , Cirlin G E
Published: December 2020

In this paper, we demonstrate and investigate the process of wet chemical etching in KOH solutions of InGaN quantum dots/GaN nanorods with the average height of heterostructure 330 nm and lateral size up to 120 nm. Morphological studying showed a significant thinning of nanorods to 40-80 nm and the shape transformation from trapezoidal to cylindrical, which led to the formation of an optimal resonator for the light-based GaN material. In this case, the photoluminescence intensity of the structure with nanorods increased in comparison with the initial planar LED structure, decreasing the impact of sidewall defects, which in turn led to the dramatic increase of the photoluminescence intensity. Further etching leads to a thinning of the GaN-p type block of the nanorods and the formation of a sharpened top, which is accompanied by a decrease in the photoluminescence intensity.
Overexpression of the recombinant IbpA protein from Acholeplasma laidlawii in Escherichia coli cells increases thermotolerance
Authors: Chernova L S , Fedorova M S , Vishnyakov I E , Kayumov A R
Published: December 2020

The presence of a gene encoding small heat shock protein IbpA in Acholeplasma laidlawii (AlIbpA) appears to be one of the key factors determining the high adaptive capabilities of this mycoplasma. Previously, we showed a participation of the N-and C-terminal regions of AlIbpA in functions of chaperone in vitro. The aim of this work was to establish the involvement of the N - and C-terminal motifs of the recombinant AlIbpA in the survival of Escherichia coli cells under temperature stress in vivo. To determine this, we used genetically engineered versions of the AlIbpA with truncations and mutations in the N - and C-terminal domains. Viability was determined by counting CFU and differential fluorescent staining. Studies have shown that hyperproduction of the N-termini-modified IbpA from AlIbpA is able to exhibit thermotolerance E. coli cells.

This research was funded by the Russian Science Foundation (project No. 17-74-20065), the microscopy assays were funded by RFBR (project № 20-34-90066).
Effect of Mn2+ and Ca2+ Ions on Formation of Structurally Ordered Nanoscale Complexes of DNA with Nuclear Proteins HMGB1 and H1
Authors: Chikhirzhina E V , Osinnikova D N , Polyanichko A M
Published: December 2020

The structural organization of DNA in complex with linker histone H1 and non-histone chromosomal protein HMGB1 in presence of calcium and manganese ions have been studied using FTIR and UV circular dichroism spectroscopy. We have demonstrated that the presence of calcium ions leads to the formation of highly ordered DNA-H1-HMGB1 structures, while manganese ions decrease the order in the earlier reported nanoscale complexes.
Determination of the fear coefficient by pupillograms
Authors: Isaeva O L , Boronenko M P , Zelensky V I , Kiseleva E S
Published: December 2020

Currently, various mathematical models of pupillograms are used to process the results of pupillometric studies. There are also mathematical models of emotions. At the moment, research does’nt combine modeling of pupillograms and modeling of emotions. In our work, an attempt was made to determine the fear coefficient by pupillograms. For research, an optoelectronic installation has been developed. As an example, we give an example of the analysis of pupillograms of people of an older age category. A mathematical model of the pupillogram plot is obtained, obtained in response to fear emotion.
Influence of PEDOT:PSS morphology on performance of bulk heterojunction solar cells
Authors: Loganchuk S M , Yatsenko A N , Varnavskaya A V , Miroshnichenko L G , Chebotarev S N , Irkha V A
Published: December 2020

Influence of morphology of poly(3, 4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) layer on performance of bulk heterojunction (BHJ) organic solar cells is analysed. Morphology depends on next technological factors: dispersity of PEDOT:PSS solution, substrate treatment, drying, PEDOT:PSS treatment. It is shown that samples with layer roughness less 10 nm have the best performance. Layer roughness was studied by atomic force microscopy (AFM).
Optical switching in multilayer structures based on Ge2Sb2Te5
Authors: Tolkach N M , Vishnyakov N V , Lazarenko P I , Sherchenkov A A , Sudakova A U , Nazimov D R
Published: December 2020

In this work, we have studied the phase switching in structures based on the Ge2Sb2Te5 (GST) composition and their optical parameters of reflectivity and transmissivity at 1550 nm wavelength after exposure to the pulse of nanosecond laser at 403 nm wavelength. We investigated 24 nm GST single-layer structure and found about 50% optical losses due to the double reflection and transmission at 1550 nm radiation. To achieve the least optical losses, we added additional SiO2, Si and Si3N4 layers to the structure. This allowed reducing optical losses up to 5 and 4% for absorption and undesirable reflection, respectively, for the amorphous GST layer, and 16 and 5% for absorption and undesirable transmittance, respectively, for the crystalline GST layer.
An optical method for research a magnetic track using speckles of the structure of scattered laser radiation
Authors: Logunov S E , Davydov V V , Rud V Yu , Glinushkin A P
Published: December 2020

A new method for detecting a magnetic track from a moving magnetic object is presented. The features of the formation of a magnetic track from a moving object at a depth are determined. A technique has been developed to research the nature of changes in the magnetic field in a magnetic track using ferromagnetic fluid. The optimal sizes of the ferrofluidic cell and the parameters of laser radiation are established. The results of experimental research are presented.
Investigation of microdisk and microring lasers based on InGaAs/GaAs QWDs by the interferometry method
Authors: Vinogradov A Yu , Moiseev E I , Kryzhanovskaya N V , Fominykh N A , Zubov F I , Kulagina M M , Mintairov S A , Kalyuzhnyi N A , Maximov M V , Zhukov A E
Published: December 2020

The scanning interferometer method is used to measure the line width of microdisk and microring lasers with a diameter of the resonator ranging from 15 to 50 μm and active area based on InGaAs/GaAs quantum well-dots. Above the threshold, the spectral width of the line did not exceed 3 pm for all samples under study.
Photoionization of polarized argon atoms in a magnetic field
Authors: Viktorov E A , Bezuglov N N , Klyucharev A N , Pastor A A , Serdobintsev P Yu , Khodorkovskii M A
Published: December 2020

Ionization of three-photon excited polarized states of argon atoms by circularly polarized probe light was studied in a supersonic beam. The revealed oscillation structure in the observed photoionization signals due to the Larmor precession of excited atomic states in a magnetic field allowed finding novel data for the Landé g-factors. We derived analytical formulas for the photoelectron current and explained the various types of the detected oscillations in terms of the principal lines among multiplet components of optical transitions. Our results indicate the possibility of implementing Doppler-free spectroscopy involving bound-free transitions.
The study of radiation attenuation in disordered silver nanoparticles arrays formed by dry aerosol printing
Authors: Khabarov K M , Efimov A A , Ivanov V V
Published: December 2020

The interaction processes of continuous laser radiation with wavelengths 527 and 980 nm with disordered arrays of spherical silver nanoparticles formed by dry aerosol printing are studied. The arrays were deposited on a glass substrates in the form of lines of various thickness and differed in the mean sizes of nanoparticles. It is shown that the radiation attenuation by arrays with disordered nanoparticle structure depends on the optical effects both on isolated spherical nanoparticles and on nanoparticle agglomerates.
Developing of NbN films for superconducting microstrip single-photon detector
Authors: Manova N. N. , Simonov N. O. , Korneeva Yu. P. , Korneev A. A.
Published: December 2020

We optimized NbN films on a Si substrate with a buffer SiO2 layer to produce superconducting microstrip single-photon detectors with saturated dependence of quantum efficiency (QE) versus normalized bias current. We varied thickness of films and observed the maximum QE saturation for device based on the thinner film with the lowest ratio R

S

300/R

S

20.
Features of the construction of fiber-optic communication lines with code division multiplexing
Authors: Popovskiy N I , Davydov V V , Valiullin L R
Published: December 2020

The necessity of research of the fiber-optic communication lines with code division multiplexing is justified. The structural diagrams of transmitters and signal receivers of fiber-optic communication lines with code division multiplexing is presented. The features its design are established. The investigation results are presented.
Near-infrared photoluminescence and micro-Raman study of spark discharge germanium nanoparticles
Authors: Malo D , Lizunova A A , Ramanenka A A , Masnaviev B I , Solovey V R , Ivanov V V
Published: December 2020

We report the investigation of near-infrared (NIR) photoluminescent and structural properties of aerosol germanium nanoparticles, synthesized by spark discharge method followed by sintering in a tube furnace at different temperatures varying from 25 to 750 °C. We demonstrate a growth of mean primary particle size and change in morphology from agglomerates of germanium nanocrystals in amorphous matrix to individual pure crystal germanium nanoparticles with temperature increase. Pure germanium nanoparticles were prepared at temperatures above 600 °C and distinguished by absence of near-infrared photoluminescence. According to Raman spectroscopy the presence of amorphous germanium in the samples, sintered at 25 to 450 °C, leads to appearance of the luminescence in infrared region with intensity increase from 1100 to 1550 nm.
Feature of Optical Soliton Sequence Propagation in Single-Mode Fiber
Authors: Andreeva E I , Potapov I A
Published: December 2020

Estimates of information capacity of the optical system as product of maximum data rate in single soliton channel and long span distance are considered. The linear (fiber group velocity dispersion and optical losses) and nonlinear (self-phase modulation and Raman self-frequency shift) effects, the signal/noise ratio of pulse source are included in pulse evolution description. It was shown, that maximum optical system capacity can be achieved with NZDS-fiber.
Effective absorption coefficient of a graphene atop of silicon nitride nanophotonic circuit
Authors: Komrakova S , Kovalyuk V , An P , Golikov A , Rybin M , Obraztsova E , Goltsman G
Published: December 2020

In this paper, we demonstrate the results of a study of the optical absorption properties of graphene integrated with silicon nitride O-ring resonator. We fabricated an array of O-ring resonators with different graphene coverage area atop. By measuring the transmission spectra of nanophotonic devices with and without graphene, we calculated the effective absorption coefficient of the graphene on a rib silicon nitride waveguide.
Near-electrode polarization and determination of the mobility of intrinsic charge carriers in PVDF films
Authors: Borisova M E , Kamalov A M , Jayasinghe B M D N S
Published: December 2020

The process of near-electrode polarization in a polyvinylidene fluoride (PVDF) film was studied using reverse currents Irev(t). It was proven that the maxima on the Irev(t) curves are characteristic of near-electrode polarization. The dependences of the reversal currents on time were analyzed based on various representations. The mobilities of the intrinsic charge carriers in the film and the magnitude of the charge transferred through the dielectric layer from electrode to electrode were calculated. The conductivity of PVDF was studied and analyzed in the temperature range 90°C-130°C.
Research of low noise pHEMT transistors in equipment for microwave radiometry using numerical simulation
Authors: Tikhomirov V G , Gudkov A G , Agasieva S V , Yankevich V B , Popov M K , Chizhikov S V
Published: December 2020

The numerical impact modeling of some external effects on devices based on AlGAs/InGaAs/GaAs heterostructures (pHEMT) was carried out. The mathematical model was created that allowed to predict the behavior of the drain current depending on condition changes on the heterostructure in the barrier region and to start the process of directed construction optimization of the devices based on AlGaAs/InGaAs/GaAs pHEMT with the aim of improving their noise characteristic.
dV/dt testing of high voltage 4H-SiC Schottky diodes with different types of metal-polymeric packages
Authors: Knyginin D A , Rybalka S B , Kulchenkov E A , Demidov A A , Zhemоedоv N A , Drakin A Yu
Published: December 2020

The dV/dt values for 4H-SiC Schottky type diodes with different type packages have been determined experimentally. It is determined that experimental dV/dt values for 4H-SiC Schottky type diodes in metal-polymeric packages (SOT-89, QFN, PQFN, TO-220) are varying in interval of 645¸1103 V/ns. It is established that the dV/dt dependence on maximal amplitude of reverse voltage demonstrate nonlinear character (close to parabolic dependence) for all studied SiC Schottky type diodes in different type packages.
Simulation of one-dimensional van der Waals heterojunction formed by a carbon nanotube embedded into MoS2 nanotube
Authors: Timkaeva D. A.
Published: December 2020

The concept of van der Waals (vdW) heterostructures provides a wide range of possibilities of combining two-dimensional (2D) layered materials for heterogeneous integration at atomic level without the constraint of lattice matching. The resulting structures exhibit unique physical properties and are promising for nanoelectronic and photonic applications. Recently, the concept of vdW heterostructures has been extended to 1D materials, and coaxial heteronanotubes have been synthesized. In the present work, we simulate a one-dimensional vdW heterojunction based on a carbon nanotube (semiconducting or metallic) embedded into a uniaxial MoS2 nanotube. Using first-principles methods, electron difference density and transmission spectra are calculated for two vdW junctions at room temperature. The considered systems can serve as a nanodiode with controlled width of a space charge region.
Nonradiative recombination channel of dark excitons in colloidal CdSe nanoplatelets
Authors: Golovatenko A A
Published: December 2020

Nonradiative recombination channel of spin-forbidden dark excitons in colloidal 4 ML thick CdSe nanoplatelets synthesized in argon and ambient atmosphere is revealed by theoretical analysis of time-resolved photoluminescence. The nonradiative recombination lifetime τnr ≈ 11 ns is found to be independent on nanoplatelets synthesis atmosphere. It is shown that the presence of the nonradiative recombination channel affects spin polarization of dark excitons and results in the time dependence of the circular polarization degree of photoluminescence in the external magnetic field.
Design and simulation high aspect ratio torsion suspension of MEMS z-axis accelerometer
Authors: Lysenko I E , Naumenko D V , Ezhova O A
Published: December 2020

This paper presents new design torsion suspension of MEMS z-axis accelerometer. These prototypes Z-axis accelerometer are based on pantograph lever structure is out-of-plane devices. The results of finite element analysis of the structure are presented.
Polymer-salt synthesis of Gd2O3:Nd3+ nanophosphors
Authors: Kuzmenko N K , Evstropiev S K , Aseev V A , Danilovich D P , Nikonorov N V , Ignatiev A I , Matrosova A S , Demidov V V , Emerson A V , Sevastyanova I M
Published: December 2020

The paper describes aspects of Gd2O3:Nd3+ phosphors synthesis by the liquid polymer-salt method. The double role of polyvinylpyrrolidone as an organic solvent was revealed in the process of highly-luminescent cubic nanocrystals formation. The developed technique was applied for modification of a hollow-core anti-resonant optical fiber by thin films based on the synthesized material without any structural and phase transformations of Gd2O3 nanocrystals after the fiber drawing process.
Electrical characterization of nitride silicon layers SiN:x enriched in silicon at different stoichiometry - photovoltaic application
Authors: Boudjemila L , Mahmoudi B , Khenfer Kh , Krasnoschekov V V , Rud’ V Yu , Davydov V V , Valiullin L R
Published: December 2020

The main objective of researches in the field of photovoltaic is to increase the efficiency. This work aims a new concept which is the integration of nanoparticles in the anti-reflection layerSi3N4 (silicon nitride), in order to improve the performance of solar cells. This concept is based on the up conversion, where the nanoparticles are characterized by the ability to function as a converter of infrared rays having high energies in the receptivity in the visible. The concept of conversion leads to a better exploitation of the solar spectrum, by widening the useful range of the spectrum. Firstly, we realized SiNx layers at different compositions and proved that variation by calculating the silicon excess and the gap energy. But the focus is on the analysis of photocurrent measurements for the vertical and lateral configuration to show the role of nanparticules. And we finalize with measurement of currents at the test bench I-V to find the ideal stoichiometry for nanoparticles.
The Study of Mambong Clay Properties Improvement with Calcium Carbonate Addition
Authors: Bakar Nurul Ainon , Mohamed Julie Juliewatty , Sulaiman Muhammad Azwadi , Muhammad Nik Maheran Nik
Published: December 2020

Mambong pottery is a unique heritage of Kelantan state with its own identity and features. However, the fabrication technique of this pottery can be improved to gain the product quality in terms of its properties. The additional of CaCO3 as an additive opens the opportunities to improve the properties of this pottery. Four different compositions which are 0%, 5%, 10%, and 15% of CaCO3 were used in 12 hours firing duration. The slip casting method was used in this research as the modern fabrication technique. The aim of this research is to study the Mambong clay properties improvement with different compositions of CaCO3 addition.
The Effect of Bismuth Addition on Sn-Ag-Cu Lead-Free Solder Properties: A Short Review
Authors: Muhamad M , Masri MN , Nazeri MFM , Mohamad AA
Published: December 2020

Sn-0.7Ag-0.5Cu lead-free solder is an alternative solder material suitable to replace Sn-Pb solder in electronic manufacturing. In this review, the change in the microstructure, elements, the structural and melting point of Sn-0.7Ag-0.5Cu after the addition of different compositions of bismuth were discovered. Besides, the influence of bismuth in lead-free solder alloys attracts to be studied due to its capability to improve the wettability and solder spread.
Degradation Kinetics of Humic acid in Aqueous Solution by Ozonation Treatment under Different Parameter Conditions
Authors: Mahyun Zafirah , Shoparwe Noor Fazliani , Abdullah Ahmad Zuhairi , Ahmad Abdul Latif , Mohamad Mardawani , Yusoff Abdul Hafidz
Published: December 2020

This study evaluated the kinetics of humic acid (HA) degradation in aqueous solution by ozonation process under different parameter conditions. The effect of initial HA concentration (5 to 100 mg/L), solution pH (2 – 12) and initial ozone doses (1.6– 4.9 mg/L) of HA degradation were evaluated through batch ozonation processes at ambient temperature for 2 hours. The HA degradation followed pseudo-first order kinetics where the rate constant changed based on these parameters effect. Results showed that, the HA degradation by ozonation process was more effective (98% degradation) at 20 mg/L initial HA concentration, initial pH 7 and 4.9 mg/L of ozone dose. These finding suggest that the ozonation process can be effectively used in wastewater treatment for improving the biodegradability of recalcitrant organic compounds.
Raw and acetylated Sugarcane Bagasse (Saccharum officinarum) and Rubber wood (Hevea brasiliensis) in oil spill sorption at Pantai Kuala Perlis
Authors: Anuwar Nur Aina Annisa , Ameram Nadiah
Published: December 2020

In this research, raw and modified (acetylated) sugarcane bagasse (SGB) (Saccharum officinarum) and rubber wood (RB) (Hevea brasiliensis) were used as sorbents in oil sorption to absorb the used oil in the seawater sample at Pantai Kuala Perlis. The research is done using different time which are 5, 10 and 15 minutes with different thickness of oil layer which are 10 and 20 ml, using 2 g of sorbents. In the percentage of oil removal and oil sorption capacity, 15 minutes was chosen as optimum adsorption time and 10 ml as optimum oil thickness. In term of effect of adsorption time, for overall results, the longer the adsorption time, the higher the sorption capacity and percentage removal of oil. Meanwhile, in term of effect of oil layer thickness, the lower the thickness of oil layer, the higher the sorption capacity and percentage removal. For Fourier Transform Infrared Spectroscopy (FTIR), the spectroscopic data shown that both modified SGB and RB had O-H, CH3 and C=O functional group at the range of 3000-3500, 2500-3000 and 1500-2000 cm-1 respectively. These shown that modified RGB and RB had successfully synthesized. For salinity test, there were no significance different between the initial salinity and after-adsorption salinity of the seawater sample.
Effect of Welding Process to the Porosity Formation in Carbon Steel
Authors: Ellyana Roslan Rose Alifah , Mohd Ladin Luqman Haniff , Mamat Sarizam , Teo Pao Ter , Abdullah Nor Hakimin , Arlina Ali , Mohamad Firdaus , Toshifum Yuji
Published: December 2020

The effect of the welding process on porosity formation in SPCC carbon steel was studied by comparing MIG, MAG, and TIG welding processes. In this work, the main consideration relates to the welding processes, which are welding current, welding speed, and heat input were investigated. Industrial x-ray observation was performed to study the distribution of porosity within the weld bead. Analysis of bead geometry shows the deepest penetration in TIG welding. The most significant size of porosity was shown in MAG welding compared to MIG and TIG welding. The result indicates that an increase in heat input affects the size of porosity distribution and depth penetration of the weld bead.
Optimization and Modelling of the Removal of Groundwater Turbidity by Nanomagnetic Adsorbent Composite
Authors: Huda A , Jayanthi B , Ariff A L Zul , Leony TYS , Siti M A , Huda Nuurul , Palsan SA
Published: December 2020

Groundwater pollution with turbidity problem is a matter of concern because at least 50 % of global population consume groundwater. The presence of suspended particles comprise of clay and silts as well as organic and inorganic particles is the main cause for the water to be turbid. A nanomagnetic adsorption composite (NMAC) was applied in this study to purify turbid polluted groundwater. A 3k full factorial design was used to investigate five factors; dosage of adsorbent (0.02, 0.04, and 0.06 g), time of agitation (15, 30, and 60 min), rate of adsorption (150, 200, and 250 rpm), size of adsorbent (<45 μm and >300 μm), and initial concentration of sample (<21.3 and < 48.8 NTU). The optimum parameters were found to be 0.02 g, 249 rpm, 46 min, <45 μm and <21.3 NTU with 94.13 % turbidity removal efficiency. The turbidity of purified groundwater complies with the Drinking Water Quality Standard.
Explore the Rural Community Understanding and Practices on Sustainable Lifestyle in Kelantan, Malaysia
Authors: Abas Muhamad Azahar , Yusoh Mohamad Pirdaus , Sibly Suzyrman , Mohamed Sulzakimin , Ta Wee Seow
Published: December 2020

This study aims to explore the understanding and practices of the rural community on sustainable living in Jeli District, Kelantan. A qualitative research approach was adopted in this study by using an in-depth interview. A total of 36 respondents from three (3) locations (Jeli, Kuala Balah, and Batu Melintang) participated in this study. This findings show the rural community of Jeli has a modest understanding of a sustainable lifestyle. Besides that, several sustainable initiatives are practiced by the Jeli community, like using energy-saving products and recycling. However, the number of people involved in any sustainable lifestyle is small as compared to the total population. However, the initiatives that have been conducted could be motivation for others to start practicing sustainable living.
Landslide Susceptibility Assessment Using Geographic Information System (GIS) Application of Putat Area, Gunungkidul, Yogyakarta, Indonesia
Authors: Mohd Shariffuddin Saidah Izzati , Sofia Udin Wani
Published: December 2020

Gunungkidul is located in Central Java Province, Indonesia which is vulnerable to geological hazard such as floods and earthquake. However, it is also susceptible to landslide in some areas of Gunungkidul which contributes to damage and loss. The study area is located in Putat Area of Gunungkidul with the area covered of 25km2 which aligned along latitude 7° 51’ 04.35”S to 7° 51’ 04.35”S and longitude 110° 30’ 58.15”E to 110° 33’ 41.72”E. This research aims to produce a landslide susceptibility map. The factors that triggered the landslide in Gunungkidul, Special Region of Yogyakarta such as rainfall intensity and earthquake were also analysed. The parameters that caused the occurrence of landslide were determined and the landslide susceptibility map was produced using Weightage Overlay Method (WOM) in ArcGIS software. Results showed that the susceptibility map was classified into three zones which is low, moderate and high zone. The factor that triggered the landslide were identified which is heavy rainfall intensity and earthquake. As a conclusion, the ability to detect landslide susceptibility lead to a better understanding of landslide mechanisms for the research area, thus leading to an enhanced identification of the most likely failure sites within a landslide-prone area.
Adsorption of COD in wastewater by Activated Carbon from Rice Husk
Authors: Pei Goh Chia , Ghazi Rozidaini Mohd , Nik Yusoff Nik Raihan , Mohd Alias Mohd Zazmiezi , Jani Musfiroh
Published: December 2020

Organic pollution occurs due to the presence of organic compound that will causing oxygen depletion and gives potential adverse impacts on human health and the environment. Wastewater from the fish cracker industry typically has high chemical oxygen demand (COD) and it is needed to be treated before release to water bodies in order to reduce the organic pollution. The treatment of COD was done using rice husk activated carbon (RHAC) that produced from agricultural wastes that contributed to waste minimization and reduce the environmental pollution. Therefore, this study emphasized on the feasibility of rice husk activated carbon for removing the COD from fish cracker wastewater. It was also to identify the optimization factors (pH, flow rate and initial concentration of COD) that affecting adsorption by rice husk activated carbon. RHAC was produced by chemical activation using phosphoric acid, H3PO4 and a real wastewater from fish cracker industry was collected, characterized, and treated by using continuous fixed bed column adsorption method. The result shows that the adsorption of COD by RHAC was optimum at pH 2, flow rate 5 ml/min and 5 % v/v initial COD concentration with the COD removal at 31.8% (150 mg/L) which comply with Standard B. Thus, RHAC could be used to develop an alternative method and suitable carbonaceous substances that was used to treat water and wastewater.
Agriculture Management Strategies Using Simple Logistic Growth Model
Authors: Abdul Latif Nurul Syaza , Anuar Mushoddad Noor Asma’ Mohd , Mior Azmai Norin Syerina
Published: December 2020

Farm management involves the development of long-term strategies to increase the profitability and competitiveness of its agricultural business. In recent years, mathematical models have been extended to the agriculture sector as a decision-making tool to ensure continuous and optimum supply. One of the well-known mathematical functions by Pierre François Verhulst, the Logistic function, has been widely used in modelling population growth rates. Many processes in biology, ecology, and other areas follow this S-shaped logistic growth. This paper explores the application of a simple logistic growth model for agriculture management strategies. Two applications illustrated here; vegetative growth response of banana to foliar fertiliser and growth of grey mould disease infection on different drying tomato coating period. The model presented here quantitatively estimates the effectiveness of the procedure used.
The Intention of Agro Farmers towards the Application of Kitosanplus in Kelantan
Authors: Abdul Latiff Zul Ariff , Mohd Zain Nur Syazwani , Muhamad Nursalwani , Abdullah Palsan Sannasi , Ayob Mohammad Amizi
Published: December 2020

The Kitosanplus is an active molecule that finds many possible applications in agriculture to reduce or replace more environmentally damaging chemical pesticides. Thus, Kitosanplus could represent an innovative eco-friendly strategy for managing plant diseases and replacing copper. The effectiveness of Kitosanplus in protecting plants from biotic stresses by direct or indirect actions, but Kitosanplus interaction with pathogens and plants are still not fully understood. This study is to determine the agro farmer intention towards the application of Kitosanplus and the relationship between age and perceived behaviour of agro farmers towards the application of Kitosanplus. The location selected is in Kampung Bukit Jawa, Selising, Pasir Puteh. Most popular agriculture activities in this area are paddy plantation. The descriptive analysis and Pearson correlation analysis were used to analyze the data. The respondents indicated that Kitosanplus is an excellent organic fertilizer, and their application of chemical pesticides do not harm the crop. Instead, the attitude, perceived behaviour and social norm of agro farmers show they have a weak intention towards using Kitosanplus in their plantation.
Effect of Encapsulation-Dehydration Cryopreservation on Histological Analysis of Oncidium Golden Anniversary orchid PLBs
Authors: Zakaria Suhana , Subramaniam Sreeramanan , Mubbarakh Safiah Ahmad , James Antony Jessica Jeyanthi
Published: December 2020

Oncidium Golden Anniversary is a hybrid orchid that has been grown as cut flowers, potted plant and is valued for its attractive flower shapes and colours. New hybrid orchids are difficult to maintain and cultivate easily; therefore, cryopreservation technology has been applied to conserve the orchid plant genetic resources. This study aims to evaluate the impact of encapsulation-dehydration as one of the cryopreservation techniques on histological analysis of Oncidium Golden Anniversary orchid PLBs using stock, cryopreserved and non-cryopreserved PLBs. Results from the histological analysis indicated that the degree of plasmolysis due to dehydration and ruptured cells after freezing were the main factors affecting the viability of PLBs.
Effects of Fermentation on the Nutritional Composition, Mineral Content and Physical Characteristics of Banana Leaves
Authors: Mat Khairiyah , Taufik Hanani A. , Rusli Nor D. , Hasnita Che H. , Al-Amsyar Syed M. , Rahman Mohammad M. , Mahmud Mohd
Published: December 2020

Banana leaves are one of the most abundant agriculture wastes in Malaysia. However, it is not suitable to be given directly to ruminant as feed and need to be pre-treated. Therefore, the objectives of this study were to evaluate the nutritional composition of banana leaves fermented with different additives including molasses, effective microorganisms (EM) and urea on the nutritional composition, mineral content and physical characteristics. Samples of banana leaves were divided into three treatment groups; control (no additives), treatment 1 (3% of molasses + 3% EM + 0.5% urea) and treatment 2 (5% of molasses + 4% EM + 1% urea). Samples were fermented for 21 and 35 days. The pH value, nutritional composition, mineral content and physical characteristics were determined and subjected to analysis of variance. There is significance different (P<0.05) in pH value for treated samples fermented for 35 days. Moisture and crude protein content were significantly higher (P<0.05) for both treatment groups, fermented for 21 and 35 days. The aroma for treated samples were pleasantly acidic compared to the control. In conclusion, fermentation for 21 days with molasses, EM and urea improves the nutritional composition of banana leaves, therefore it can be considered as an appropriate pre-treatment method to produce an alternative material for animal feed.
Antibacterial properties of natural tropical fruit vinegars against Propionibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus bacteria
Authors: Mokhtar Seri Intan , Pahirulzaman KAK
Published: December 2020

Various researchers have found that vinegar has antibacterial effect on different types of pathogenic bacteria which make it useful for a varieties of application in medical, food preservation and as cosmetic ingredient. Many new emerging tropical fruits vinegars were not tested for antibacterial properties especially for skin and acne causing treatment. Therefore, this study aim is to test several tropical fruits vinegar in order to determine their ability against skin and acne causing bacteria ultimately could lead to application of effective vinegars in personal care and cosmetic products. Tropical fruit vinegars such as pineapple, mango, coconut, dokong and rambutan vinegars were tested for the presence of acetic acid, titratable acid, pH and anti-microbial properties against acne causing bacteria Propionibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus. The presence of acetic acid content in the vinegar samples was determined using HPLC analysis against 100% glacial acetic acid standard and shown to be between 6.444, 6.959, 5.832, 6.484 and 6.373 min. Titratable acidity range lied between 1.14 ± 0.06% to 3.26 ± 0.09% of which rambutan vinegar showing highest acetic acid content while pineapple vinegar giving the lowest value. The pH value among five vinegar samples fell within the range of 3.06 to 3.65 of which pineapple vinegar has the lowest value and coconut vinegar had the highest pH. Antimicrobial properties of different tropical fruit vinegar samples with different percentage of acetic acid content in samples comprised of 0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0% were determined by antimicrobial disk diffusion assay on Propionibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus. Clear zone of inhibition could be observed at 1% acetic acid in all samples, ranging from 7.8 mm to 8.6 mm against main acne causative bacteria, Propionibacterium acnes indicating that the vinegars has antibacterial properties against the bacterium
Antioxidant, Antibacterial and Anti-Diabetic Activities of Stingless Bee Honey from Selected Areas in Peninsular Malaysia
Authors: Zakaria N.N.A , Mohd Jaafar N.N , N. N Mad Desa , Zolkopli Mohamad A.
Published: December 2020

Stingless bee honey is one of the Malaysian honeys that has many benefits especially medically, due to the presence of enormous active phytochemical compounds. The active compounds in the honey vary depending on its geographical origin, especially the environmental conditions of the plant nectar. This study aims to analyze and compare the antioxidant, antibacterial and antidiabetic activities of stingless bee honey from different areas in Malaysia. The sample stingless bees’ honeys were obtained from Kulim, Kedah (honey sample 1), Tanjung Malim, Perak (honey sample 2) and Kuala Selangor, Selangor (honey sample 3). The methods used for the analysis were DPPH free radical scavenging, Kirby-Bauer disc diffusion assay and alpha-amylase inhibition assay for the respective activities. An analysis of gallic acid content of the stingless bee’s honeys were also performed using high-performance-liquid-chromatography (HPLC). Tukey’s multiple comparison test was used for statistical analysis. The results indicated that honey sample 2 exhibited the highest antioxidant activity with IC50 values of 89.04 ± 0.83 mg/mL, whilst honey sample 3 showed the highest inhibition capability on both E. coli and S. aureus at 16.33 ± 3.06 mm and 22.67 ± 0.58 mm respectively as compared to the other honey samples. Honey sample 3 also showed the highest inhibition against alpha amylase with an IC50 value of at 15.80 ug/mL. The gallic acid content of honey sample 3 also the highest at 39.79 ug/mL. As a conclusion, honey sample 3 originated from Kuala Selangor, Selangor has better antibacterial and anti-alpha amylase activities. Meanwhile, honey sample 2 originated from Tanjung Malim, Perak has better antioxidant properties.
Research on life prediction technology of wind turbine gearbox based on virtual simulation
Authors: Zhou Jiwei , Kong Weibing
Published: December 2020

As the core component of wind turbine energy conversion, the gearbox has been operating under variable frequency and variable load condition for a long time. The repair time is long after its fault, which leads to a large loss of power generation. This paper proposes a gearbox life prediction method. By collecting the design and manufacturing process parameters of gearbox, the gearbox virtual simulation model is established, the gearbox observable damage can be predicted accurately by inputting the actual operation load. According to the results, the maintenance and repair time of the gearbox can be arranged scientifically, which can effectively avoid the occurrence of serious faults, greatly reduce the gearbox replacement rate and unscheduled downtime, the economic benefits are obvious. After field application, the accuracy of this method can be 93.5%, which has a good prospect of application.
Application of TETSP in advance prediction of water and mud inrush in karst tunnel
Authors: Li Wei , Wang Wei , Li Jun jie , Ouyang mingming
Published: December 2020

Water and mud inrush are easy to occur in the process of karst tunnel driving, in order to reduce the risk of tunnel construction, TETSP is used in the prediction of karst cave, water gushing and mud gushing in a karst area of Longxing tunnel. The characteristics of TETSP geophone, detection principle and arrangement of observation system are introduced. The signal-to-noise ratio of TETSP data under blasting and hammering is compared. The corresponding unfavorable geology abnormal law of TETSP is summarized. Several conclusions are drawn as follow. Firstly, the TETSP geophone with direct coupling method has high installation efficiency and can obtain the original waveform with high signal-to-noise ratio. Secondly, the seismic reflection data collected by blasting is higher quality than that by hammering excitation. Thirdly, the abnormal law of the corresponding TETSP of large-scale karst cave and dissolution fracture zone present as that the P-wave velocity and S-wave velocity are low but Poisson’s ratio is high. The prediction results of TETSP are consistent with the actual excavation of the tunnel which provide an important reference for the safe construction of the tunnel.
Research on Diagnosis and Evaluation of Physical Assets of Power Grid Enterprises Based on Combined Weight TOPSIS Theory
Authors: Fuyan Liu , Yang Xiaoyong , Yu Min , Shen Jie , Shi Jianfeng , Chen Chao
Published: December 2020

Under the new reform requirements, the transmission and distribution price pricing model changes, the sales side is liberalized and competition is introduced, the incremental power distribution business investment is liberalized, and the company’s permitted income is approved on the basis of effective assets. In this paper, the combination weight TOPSIS theory is used to diagnose and evaluate the physical assets of power grid companies, and the accuracy of the model is verified through analysis, and the system’s asset status diagnostic analysis and evaluation research is carried out, and the optimization strategy and evaluation calculation are scientifically proposed to provide a research and analysis basis.
Research on the Control Strategy of dual Boost bridgeless PFC based on Lyapunov stability
Authors: Yang Shuang , Wu Lihua , Wang Wu
Published: December 2020

In order to prevent power electronic devices from causing harmonic pollution to the power grid, PFC technology is widely used between power electronic devices and the power grid. Therefore, the improvement of system power factor and robust performance has become a research focus today. This paper is aimed at dual Boost bridgeless PFC (power factor correction) converters, establishes a mathematical model in virtual dq mode, and a new nonlinear control strategy based on Lyapunov stability is proposed. The MATLAB simulation results show that the input current can better track the input voltage in the steady state, and when the load or output voltage changes, the system can quickly enter stability, and the system has strong anti-disturbance ability.