bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, DFT calculations and optical nonlinear properties of two derived Schiff base compounds from ethyl-4-amino benzoate
Authors: Abdullmajed Hasanain A , Sultan H A , Al-Asadi Rafid H , Hassan Qusay M A , Ali Asaad A , Emshary C A
Published: December 2021

Two Schiff base compounds viz., Ethyl (E)-4-((3-ethoxy-2-hydroxybenzylidene)amino)benzoate(EHB) and Ethyl (E)-4-(((2-hydroxynaphthalen-1-yl)methylene)amino)benzoate(ENB) are synthesized by condensation of ethyl-4-amino benzoate with 2-hydroxy-3-ethoxy benzaldehyde and 2-hydroxy-1-naphthaldehyde. The two compounds are studied and identified by FT-IR, UV-visible, Mass, 1H-NMR, and 13C-NMR spectroscopies. The nonlinear refractive index (NRI) of the two compounds are determined, for ENB compound via the diffraction ring patterns (DRPs) and the Z-scan and via Z-scan for the EHB compound, using continuous wave (CW) low power laser beam, and founds of the order of 10−7 cm2 W−1 due to the first technique and 10−8 cm2 W−1 due to the second technique. The optical limiting (OL) property of both compounds is studied too with OLg thresholds of 16.5 mW and 11 mW for the compounds EHB and ENB respectively, which makes these two compounds as candidates to be used as an optical limiter (OLr). The DRPs are numerically simulated based on the theory of Fresnel-Kirchhoff with reasonable agreement compared to the experimental findings.
Coherent perfect absorption in the one-dimensional non-magnetized plasma photonic crystals
Authors: Wu Fupei , Zhang Hao , Wan Baofei , Zhang Haifeng
Published: December 2021

Electromagnetic (EM) absorption is the basic characteristic of materials that plays an important role in many applications such as solar cells, EM radiation protection, and stealth technology. However, under normal circumstances, the traditional medium’s absorption efficiency of EM waves is limited, but the designer can operate by adjusting the structure of the medium. In this paper, the coherent perfect absorption (CPA) is introduced in the one-dimensional (1D) non-magnetized plasma photonic crystals. Under the premise that the selected material meets the conditions (appropriate thickness and dielectric constant), the absorption amplitude at the frequency point that meets the coherent absorption conditions is greatly improved. The results show that the forward and backward EM waves that meet the CPA conditions and propagate in PPCs can increase the absorption to 99.94% and change the phase difference of the two coherent beams to control the adjustment range of the absorption efficiency to 12.60%–99.94%. In addition, the effects of plasma and collision frequency on the absorption property, and the effects of the periodic constant of dielectric layers and plasma thickness on the frequency and amplitude of coherent absorption are also presented. It is foreseeable that the idea of tunability of light absorption in photovoltaic cells is proposed in this paper, and the application of absorbers in the field of optical switching and light modulation has been further expanded.
Design and simulation of a compact Ku-band RTTO with power divider extraction structure
Authors: Yang Chaochao , Meng Jin , Wang Haitao , Zhu Danni , Yuan Yuzhang , Cui Yancheng
Published: December 2021

The radial transit time oscillator (RTTO) has attracted much attention because of its high power capacity and pure mode of output microwave. To make the high power microwave (HPM) source devices more compact and to enable it to measure the output microwave mode quantitatively, this paper proposed a compact Ku-band RTTO with the power divider extraction structure (PDES). The radial decreasing magnetic field is applied to decreasing the mass of excitation system. Compared the conventional uniform solenoids, it can reduce the mass by about 30%. In the coaxial output waveguide, the PDES is used instead of the traditional support rods connecting the inner and outer conductors so as to convert TEM mode into TE10 mode efficiently. This structure can not only help shorten the axial dimension of the device, but also make it possible to measure the output microwave mode more accurately online. In particle-in-cell (PIC) simulation, the proposed Ku-band RTTO can output HPMs with the power of 3.05 GW and the frequency of 14.36 GHz, and the working efficiency is 40.3%. The maximum radial electric field intensity in the extraction cavity is 0.92 MV/cm, and the maximum electric field intensity in the PDES is 0.52 MV/cm, both of which are lower than the radio frequency (RF) breakdown threshold of metal materials.
Cosmological model with time varying deceleration parameter in F(R, G) gravity
Authors: Lohakare Santosh V , Tripathy S K , Mishra B
Published: December 2021

In this paper, we study the dynamical behaviour of the Universe in the F(R, G) theory of gravity, where R and G respectively denote the Ricci scalar and Gauss-Bonnet invariant. Our wide analysis encompasses the energy conditions, cosmographic parameters, Om(z) diagnostic, stability and the viability of reconstructing the referred model through a scalar field formalism. The model obtained here shows the quintessence like behaviour at late times.
Effect of off-stoichiometry on the thermal conductivity of amorphous GeTe
Authors: Leng M J , Wu B H , Lu A J , Wu L C , Wang C R , Song Z T
Published: December 2021

The reversible phase change of Germanium Telluride (GeTe) is essential for developing advanced non-volatile devices. We investigate off-stoichiometric effect on the thermal and structural properties of amorphous Ge1−δ
Te (0 ≤ δ ≤ 0.12) via molecular dynamics. The structural optimization due to off-stoichiometry was taken into account with an empirical potential. Our simulated thermal conductivity is in the range of experimental observations. With increasing δ, the thermal conductivity tends to be slightly reduced. Analysis on the coordination number and the bond angle distribution indicates that the off-stoichiometric Ge1−δ
Te still retain its ability of rapid phase transition. These results are helpful in reliable device design and modeling.
Synthesis, optical, and electrical properties of starch/chitosan/NaTiO3 bio-nanocomposites modified with ErCl3
Authors: El Sayed Adel M , El-Gamal S
Published: December 2021

Solid polymer electrolytes (SPEs) based on nanocomposites are attracting increasing attention due to their technological and industrial applications. In the present work, a facile aqueous casting method was utilized for the preparation of a starch-chitosan blend loaded with nanosized NaTiO3 (NTO) and co-mixed with ErCl3 (EC) salt. The interactions between OH group of starch and N–H group of chitosan with NTO and EC, and the films’ crystallinity and surface morphology were studied by FTIR, XRD, and SEM. UV-Vis-NIR measurements showed the indirect (direct) optical band gaps decreased from 3.4 to 2.0 eV (4.5 to ∼2.5 eV), i.e., ∼41%–44% shrinking. At the time that the films maintained a reasonable transmittance. The optical constants of the films; extinction coefficient, refractive index, and the carrier’s concentration to the electron effective mass (N/m*) are reported. N/m* of the pure blend was 4.85 × 1039 (kg−1 m−3) increased to 1.64 times and 2.8 times after loading with 1.0% NTO and 20% EC, respectively. Various dielectric parameters (dielectric constant ε′, dielectric loss ε″, ac conductivity σ
ac, and dielectric moduli M′ & M″) were evaluated in the frequency range 5 Hz–1 MHz and temperatures of 298–353 K. The conductivity (σ
ac) of the blend increased from 1.10 × 10–3 S cm−1 to 8.17 × 10–3 S cm−1 after modifying with 20% EC, i.e., became 8 times greater. Moreover, the influence of NTO and EC on the conduction mechanism and Cole-Cole plots are discussed. The improvements in the optical and electrical properties of EC/NTO/blend illustrate the possibility of extending the applications of these smart materials to include optoelectronic devices, batteries, and supercapacitors.
Predicting the onset of nucleate boiling heat flux of one-side heated flat heat sink in sub-cooled flow conditions for fusion divertor cooling
Authors: Lim Ji Hwan , Park Minkyu
Published: December 2021

For the cooling system of the future, nuclear fusion tokamak, to operate stably and continuously, it is important to identify potential hazards that may occur in the system in advance. Among the various hazards associated with the nuclear fusion tokamak, the onset of nucleate boiling (ONB) is a point at which the heat-transfer mechanism changes dramatically and is a crucial factor that must be addressed. In particular, the equipment inside the tokamak is loaded with a heat flux of several MW m−2under single-side heating conditions, and it is important to predict the ONB under these special heating conditions. Therefore, in this study, the ONB of a flat heat sink was experimentally investigated under highly subcooled flow conditions. Based on the physical understanding of the thermo-hydraulic aspect of the ONB, the wall temperature gradient change point, which is mainly used in the subcooled flow condition, was selected as the ONB detection criterion. Trends in the ONB heat flux change were analyzed as representative system parameters that can be tuned in the cooling system, such as subcooling, mass flow rate, and pressure. In addition, the ONB correlations developed in the previous studies were evaluated for predicting the performance under one-side high heat load conditions. However, the large difference in the experimental conditions (range of system parameters and heating conditions) and the fact that the influence of system parameters was not reflected in the correlation resulted in high error rates. Therefore, the ONB correlation that can be used in the tokamak heat flux condition was newly developed through a dimensional analysis that can effectively reflect the influences in the correlation through dimensionless numbers. The developed correlation can be of great help in designing a diverter or blanket cooling system and establishing an operational strategy.
Cross-section measurements of (n, 2n) and (n, p) reactions on 124,126,128,130,131,132Xe in the 14 MeV region and theoretical calculations of their excitation functions *
Authors: Luo Junhua , Jiang Li , Liang Juncheng , Tuo Fei , He Long , Zhou Liang
Published: December 2021

The reaction cross-sections of 124Xe(n, 2n)123Xe, 126Xe(n, 2n)125Xe, 128Xe(n, 2n)127Xe, 130Xe(n, 2n)129mXe, 132Xe(n, 2n)131mXe, 130Xe(n, p)130I, 131Xe(n, p)131I, and 132Xe(n, p)132I were measured at the 13.5, 13.8, 14.1, 14.4, and 14.8 MeV neutron energies. The monoenergetic neutrons were generated via the 3H(d,n)4He reaction at the China Academy of Engineering Physics using the K-400 Neutron Generator with a solid 3H-Ti target. A high-purity germanium detector was employed to measure the activities of the product. The reactions 93Nb(n, 2n)92mNb and 27Al(n, α)24Na were adopted for neutron flux calibration. The cross sections of the (n, 2n) and (n, p) reactions of the xenon isotopes were obtained within the 13–15 MeV neutron energy range. These cross-sections were then compared with the IAEA-exchange format (EXFOR) database-derived experimental data, together with the evaluation results of the CENDL-3, ENDF/B-VIII.0, JENDL-4.0, RUSFOND, and JEFF-3.3 data libraries, as well as the theoretical excitation function obtained using the TALYS-1.95 code. The cross-sections of the reactions (except for the 124Xe(n, 2n)123Xe and 132Xe(n, p)132I) at 13.5, 13.8, and 14.1 MeV are reported for the first time in this study. The obtained results are beneficial in providing better cross-section constraints for the reactions in the 13–15 MeV region, thus improving the quality of the corresponding database. Meanwhile, these data can also be used for the verification of relevant nuclear reaction model parameters.
Detection of Gamma-Rays from the Protostellar Jet in the HH 80–81 System
Authors: Yan Da-Hai , Zhou Jia-Neng , Zhang Peng-Fei
Published: December 2021

Considering that the existence of relativistic particles in the protostellar jet has been confirmed by the detection of linearly polarized radio emission from the HH 80–81 jet, we search for gamma-rays from the HH 80–81 system using ten-year Fermi-LAT observations. A significant point-like γ-ray excess is found in the direction of the HH 80–81 system with the Test-Statistic value >100, which is likely produced in the HH 80–81 jet. The γ-ray spectrum extends only to 1 GeV with a photon index of 3.5. No significant variability is found in the gamma-ray emission. It is discussed that the properties of HH 80–81 jet suffice for producing the observed γ-rays.
Structured large-pore foams improve thermal performance of LiMIT-style liquid lithium PFC
Authors: Szott M. , Stemmley S. , Moynihan C. , de Castro A. , Ruzic D.N.
Published: December 2021

As magnetically confined fusion devices improve, the conditions at the walls become increasingly intense. Plasma facing components (PFCs) must withstand these extreme heat and particle loads without damage or degradation. Liquid lithium PFCs are known to be quite resilient, and the presence of lithium also serves to improve plasma properties. The liquid metal infused trench (LiMIT) concept is an open surface liquid lithium PFC design that has been tested extensively at the University of Illinois and in fusion devices around the world. LiMIT utilizes thermoelectric magnetohydrodynamics (TEMHD) to passively drive liquid lithium flow. This work demonstrates an extension of the LiMIT trench geometry to three dimensions. Additively manufactured large pore metallic foams maintain TEMHD drive while drastically improving heat flux handling and resistance to lithium dryout, a phenomenon where locally high TEMHD forces depresses the lithium level and exposes underlying solid structure. COMSOL multiphysics modeling of the system yields insight into the forces at play in dryout development, and shows the 3D structures can eliminate dryout. Low heat proof-of-concept experimental testing of the system matches computational results, and high heat flux electron beam tests more than double the proven operational range of a LiMIT-style PFC, to 6.8 MW m−2, with no indications of dryout or impending damage.
SOLPS-ITER simulations of high power exhaust for CFETR divertor with full drifts
Authors: Si Hang , Ding Rui , Senichenkov Ilya , Rozhansky Vladimir , Molchanov Pavel , Liu Xiaoju , Jia Guozhang , Sang Chaofeng , Mao Shifeng , Chan Vincent , the CFETR Team
Published: December 2021

One of the major challenges for the Gigawatt-class Chinese Fusion Engineering Testing Reactor (CFETR) is to efficiently handle huge power fluxes on plasma-facing components , especially the divertor targets. This work investigates the effects of two candidate radiation impurity species, argon (Ar) and neon (Ne), with two different divertor geometries (baseline and long leg divertor geometry) on the reduction of steady-state power load to divertor targets in CFETR by using the SOLPS-ITER code package with full drifts and kinetic description of neutrals. The modeling results show clearly that increasing the seeding rate of Ar or Ne with fixed fueling gas D2 injection rate reduces the target electron temperature and heat flux density for the baseline divertor geometry, which can be reduced further by higher D2 injection rate. With a high impurity seeding rate, partial detachment with steady-state power load at the divertor target below the engineering limit of 10 MW m−2 is demonstrated. In addition, the radiation efficiency for Ar is better than that for Ne. Increasing the divertor leg length reduces the electron temperature and heat load at the targets. This modeling, therefore, suggests that a long leg divertor design with Ar seeding impurity is appropriate to meet the CFETR divertor requirements.
Hybrid simulations of beta-induced Alfvén eigenmode with reversed safety factor profile
Authors: Duan Sizhe , Fu G.Y. , Cai Huishan , Li Ding
Published: December 2021

Based on the experimental parameters in the HL-2A tokamak, hybrid simulations have been carried out to investigate the linear stability and nonlinear dynamics of the beta-induced Alfvén eigenmode (BAE). It is found that the (m/n = 3/2) BAE is excited by co-passing energetic ions with q
min = 1.5 in linear simulation, and the mode frequency is consistent with the experimental measurement. The simulation results show that the energetic ions β
h, the injection velocity v
0, and orbit width parameter ρ
h of energetic ions are important parameters determining the drive of BAE. Furthermore, the effect of q
min (with the fixed shape of the q profile) is studied, and it is found that when q
min ⩽ 1.5, the excited modes are BAEs, which are located near q = 1.5 rational surfaces; when q
min > 1.5, the excited modes are similar to the reversed-shear Alfvén eigenmodes, which are mainly localized around q = q
min surfaces. Nonlinear simulation results show that the nonlinear dynamics of BAE are sensitive to the EP drive. For the strongly driven case, firstly, redistribution and transport of energetic ions are trigged by 3/2 BAE, which raised the radial gradient of the distibution function of energetic ions near the q = 2 rational surface, and then an energetic particle mode (EPM) (m/n = 4/2) is driven in the nonlinear phase. Finally, these two instabilities triggered a significant redistribution of energetic ions, which results in the twice-repeated and mostlydownward frequency chirping of 3/2 BAE. For the weakly driven case, there are no 4/2 EPM being driven nor twice-repeated chirping in the nonlinear phase, since the radial gradient near q = 2 rational surface is small and almost unchanged.
The role of B
T-dependent flows on W accumulation at the edge of the confined plasma
Authors: Zamperini S.A. , Nichols J.H. , Stangeby P.C. , Donovan D.C. , Duran J.D. , Elder J.D. , Unterberg E.A. , Rudakov D.L.
Published: December 2021

Near-separatrix impurity accumulation between the crown and the outer midplane of tokamaks is a common feature in results from codes such as SOLPS-ITER and DIVIMP; however, experimental evidence of accumulation has only recently been obtained and is reported here. The codes find that the poloidal distribution of impurity ions in the scrape-off layer (SOL) depends primarily on toroidal field (B
T)-dependent parallel flow patterns of the background plasma and the parallel ion temperature gradient (∇‖
T
ion) force. Experimentally, Mach probes used in L-mode plasmas with favorable (for H-mode access) B
T measure fast (M ∼ 0.3–0.5) inner-target-directed (ITD) background plasma flows at the crown of single-null discharges. This study reports a set of DIVIMP simulations for two similar H-mode discharges from the DIII-D W metal rings campaign differing primarily in B
T-direction to assess the effect that fast ITD flows have on the distribution of W ions in the SOL. It is found that for imposed ITD flows of M = 0.3, W ions that otherwise accumulate due to the ∇‖
T
ion-force are largely flushed out. It is also found that doubling the radial diffusion coefficient from 0.3 to 0.6 m2 s−1 prevents accumulation due to rapid cross-field transport into the far-SOL, where background plasma flows drain W ions to the divertors. Far-SOL W distributions from DIVIMP are then used to specify input to the impurity transport code 3DLIM, which is used to interpretively model collector probe (CP) deposition patterns measured in the ‘wall-SOL’. It is demonstrated that the deposition patterns are consistent with the DIVIMP predictions of near-SOL accumulation for the unfavorable-B
T direction, and little/no accumulation for the favorable-B
T direction. The wall-SOL CPs have thus provided the first experimental evidence, albeit indirect, of near-SOL W accumulation—finding it occurs for the unfavorable-B
T direction only. For the favorable-B
T direction, fast flows can largely prevent accumulation from occurring.
Models and scalings for the disruption forces in tokamaks
Authors: Pustovitov V.D.
Published: December 2021

The study is devoted to theoretical analysis of some models for calculating the disruption forces in tokamaks and scalings for these forces which can be proposed for ITER. It is motivated by the necessity of reliable predictions for ITER. The task includes the evaluation of the existing models, resolution of the conflicts between them, elimination of contradictions by proper improvements, elaboration of recommendations for dedicated studies. Better qualities of the modelling and higher accuracy are the ultimate theoretical goals. In recent years, there was a steady progress in developing a physics basis for calculating the forces, which gave rise to new trends and ideas. It was discovered, in particular, that the wall resistivity, penetration of the magnetic perturbation through the wall, the poloidal current induced in the wall, the kink-mode coupling, plasma position in the vacuum vessel must be the elements essentially affecting the disruption forces. These and related predictions along with earlier less sophisticated concepts and results are analysed here.
Toward full simulations for a liquid metal blanket: part 2. Computations of MHD flows with volumetric heating for a PbLi blanket prototype at Ha ∼ 104 and Gr ∼ 1012
Authors: Chen L. , Smolentsev S. , Ni M.-J.
Published: December 2021

On the pathway toward full simulations for a liquid metal (LM) blanket, this part 2 extends a previous study of purely magnetohydrodynamic (MHD) flows in a DCLL blanket in reference Chen et al (2020 Nucl. Fusion
60 076003) to more general conditions when the MHD flow is coupled with heat transfer. The simulated prototypic blanket module includes all components of a real LM blanket system, such as supply ducts, inlet and outlet manifolds, multiple poloidal ducts and a U-turn zone. Volumetric heating generated by fusion neutrons is added to simulate thermal effects in the flowing lead–lithium (PbLi) breeder. The MHD flow equations and the energy equation are solved with a DNS-type finite-volume code ‘MHD-UCAS’ on a very fine mesh of 470 × 106 cells. The applied magnetic field is 5 T (Hartmann number Ha ∼ 104), the PbLi velocity in the poloidal ducts is 10 cm s−1 (Reynolds number Re ∼ 105), whereas the maximum volumetric heating is 30 MW m−3 (Grashof number Gr ∼ 1012). Four cases have been simulated, including forced- and mixed-convection flows, and either an electrically conducting or insulating blanket structure. Various comparisons are made between the four computed cases and also against the purely MHD flows computed earlier in reference Chen et al (2020 Nucl. Fusion
60 076003) with regards to the (1) MHD pressure drop, (2) flow balancing, (3) temperature field, (4) flows in particular blanket components, and (5) 3D and turbulent flow effects. The strongest buoyancy effects were found in the poloidal ducts. In the electrically non-conducting blanket, the buoyancy forces lead to significant modifications of the flow structure, such as formation of reverse flows, whereas their effect on the MHD pressure drop is relatively small. In the electrically conducting blanket case, the buoyancy effects on the flow and MHD pressure drop are almost negligible.
Recent progress in the assessment of irradiation effects for in-vessel fusion materials: tungsten and copper alloys
Authors: Terentyev D. , Rieth M. , Pintsuk G. , Riesch J. , von Müller A. , Antusch S. , Mergia K. , Gaganidze E. , Schneider H.-C. , Wirtz M. , Nogami S. , Coenen J. , You J.H. , Zinovev A. , Van Renterghem W.
Published: December 2021

The present contribution highlights results of the recent irradiation campaigns applied to screen mechanical properties of advanced tungsten and copper-based materials—main candidates for the application in the plasma-facing components (PFC) in the European DEMO, which has also been presented at 28th IAEA fusion energy conference. The main challenges in the formulated irradiation programme were linked to: (I) assessment of the ductile-to-brittle transition temperature of newly developed tungsten-based materials; (ii) investigation of an industrial pure tungsten grade under high temperature irradiation, reflecting operational conditions in the high flux divertor region; (iii) assessment of the high temperature strength of CuCrZr-based alloys and composites developed to enable the extension of the operational window for the heat sink materials. The development and choice of the advanced materials is driven naturally by the need to extend the operation temperature/fluence window thereby enlarging the design space for PFCs. The obtained results helped identifying the prospective tungsten and copper-based material grades as well as yielded a number of unexpected results pointing at severe degradation of the mechanical properties due to the irradiation. The results are discussed along with the highlights of the microstructural examination. An outlook for near future investigations involving in-depth post-irradiation examination and further irradiation campaigns is provided.
A Mathematical Modelling of The Dynamics of Voters Model of Two Political Fanaticism Figures with The Interaction Between Voters in Indonesian Presidential Elections
Authors: Yong B.
Published: December 2021

In this study, we present a dynamical analysis of the NS1S2A mathematical model that describe votes movement of voters in presidential elections. The NS1S2A deterministic voters model of two political fanaticism figures is described by ordinary differential equations. We considering the interaction between voters in the supportive voters compartment. We investigate the existence and the stability of four equilibrium solutions; free of supportive voters, supportive voters to first political figure, supportive voters to second political figure, and supportive voters to all political figures. Then we demonstrate this model by estimating the number of votes of two presidential candidates in Indonesian presidential elections. A numerical simulation is given to verify our analytical results. The result shows that the difference in the number of votes between the model with the interaction between voters and survey conducted by Litbang KOMPAS is smaller than the model without the interaction between voters.
Comparing the Performance of Several Multivariate Control Charts Based on Residual of Multioutput Least Square SVR (MLS-SVR) Model in Monitoring Water Production Process
Authors: Ahsan M , Aulia T R
Published: December 2021

Water that is used as the basic human need, requires a processing process to get it. Water quality control in Tirtanadi Water Treatment Plant is still univariate, while theoretically the quality characteristics of water quality are correlated and there is also an autocorrelation due to the continuous process. In this study, quality control is performed on three main variables of water quality characteristics, namely acidity (pH), chlorine residual (ppm), and turbidity (NTU) using several multivariate control charts based on Multioutput Least Square Support Vector Regression (MLS-SVR) residuals. MLS-SVR modelling is used to overcome and get rid of autocorrelation. The input results of the MLS-SVR model are specified from the significant lag of the Partial Autocorrelation Function (PACF), which in this study, is the first lag. The results of the MLS-SVR input model and the optimal combination of hyper-parameters produce residual values that have no autocorrelation anymore. The residuals are used to develop the Hotelling’s T
2, Multivariate Exponentially Weighted Moving Average (MEWMA), and Multivariate Cumulative Sum (MCUSUM) control charts. In phase I, we found that the processes are statically controlled. Meanwhile, in phase II, the monitoring results show that there are several out-of-control observations.
Students’ Error on Proof of The Group with “Satisfy Axioms Proof” based on Newman Error Analysis
Authors: Suradi  , Djam’an Nurwati
Published: December 2021

This study aims to analyze students’ errors in solving proof problems on group theory, focus on proofs with satisfying axioms proof. The analysis used refers to the Newman Error Analysis, namely: reading, understanding, transformation, process skills, and coding. The participants in this study consisted of students at the Mathematics Department that enrolled in the group theory course during the odd semester of the 2021/2022 academic year in Universitas Negeri Makassar. Research data was obtained through tests, followed by interviews based on student answers from the test. Based on the results of the error analysis conducted in this study, it can be concluded that: (1) There were no reading errors; (2) Comprehension error was incorrectly write down the meaning of what is known from the problem in symbolic form; (3) Transformation error was error determining the type of proof, mistake write down a formula to show an axiom in the group; (4) Process skill error was an error using arithmetic operations for the validity of an axiom; and (5) Encoding error was an error in writing the final answer, wrong evaluation to conclude.
Application of Nonparametric Geographically Weighted Spline Regression Model for Spatial Mapping of Open Unemployment Rate in Kalimantan
Authors: Sifriyani  , Ilmi Hillidatul , Mar’ah Zakiyah
Published: December 2021

This study was conducted specifically to GIS mapping based on Nonparametric-Geographically Weighted Spline Regression (NGWSR) Estimation Model for the factors that affect the open unemployment rate (OUR) in Kalimantan. Observational data in this study were categorized into 56 regions based on the Regency/City scale in Kalimantan. The variables used in this study consisted of the open unemployment rate, the labor force participation rate, population density, human development index, expected years of schooling, and regional minimum wage. This study utilized the spatial analysis of the NGWSR model with the geographic weighting of the Gaussian and Bisquare kernel functions. The NGWSR model was considered capable of providing a solution to the geographically weighted spatial regression for the unknown regression curve. Regarding to the result of this study, NGWSR with geographic weighting of the Bisquare kernel function was considered as the best model. The model criteria were based on the coefficient of determination and RMSE. The results of the significance test of model parameters for 56 Regencies/Cities data in Kalimantan had succeeded in mapping the area into 14 categories based on the significant variables of each region.
Application of Modified Generalized–Gamma Mixture Cure Model in the Analysis of Ovarian Cancer Data
Authors: Folorunso Serifat A. , Oluwasola Timothy A.O. , Chukwu Angela U. , Odukogbe Akintunde A.
Published: December 2021

The modeling and analysis of lifetime for terminal diseases such as cancer is a significant aspect of statistical work. This study considered data from thirty-seven women diagnosed with Ovarian Cancer and hospitalized for care at theDepartment of Obstetrics and Gynecology, University of Ibadan, Nigeria. Focus was on the application of a parametric mixture cure model that can handle skewness associated with survival data – a modified generalized-gamma mixture cure model (MGGMCM). The effectiveness of MGGMCM was compared with existing parametric mixture cure models using Akaike Information Criterion, median time-to-cure and variance of the cure rate. It was observed that the MGGMCM is an improved parametric model for the mixture cure model.
Rainfall Forecasting Model Using ARIMA and Kalman Filter in Makassar, Indonesia
Authors: Sukarna  , Ananda Elma Yulia Putri , Wahyuni Maya Sari
Published: December 2021

Many forecasting methods have been used for forecasting rainfall data. Kalman Filter is one of the forecasting methods that could give better forecasts. To our knowledge, the Kalman Filter method has not been used to forecast rainfall data in Makassar, Indonesia. This study aims to provide more precise forecasts for rainfall data in Makassar, Indonesia by using Autoregressive Integrated Moving Average (ARIMA) and Kalman Filter methods. Rainfall data from January 2010 to December 2020 were used. The best model selection is based on the smallest Mean Absolute Percentage Error (MAPE) value. The results showed that the best ARIMA model is ARIMA(0,1,1)(0,1,1)12 with MAPE is 111.48, while MAPE value by using the Kalman Filter algorithm is 47.00 indicating that Kalman Filter has better prediction than ARIMA model.
Seemingly Unrelated Regression Spatial Autoregressive Bayesian Modeling on Heteroscedasticity Case
Authors: Adiatma
Published: December 2021

The phenomenon encountered occasionally on complications involving spatial data, is that there is a tendency of heteroscedasticity since every region has distinct characteristics. Thus, it requires the approach which is more appropriate with the problem by using the Bayesian method. Bayesian method on spatial autoregressive model to contend the heteroscedasticity by applying prior distribution on variance parameter of error. To detect heteroscedasticity, it is shown from several responses correlating with the predictors. The method abled to estimate some responses is Seemingly Unrelated Regression (SUR). SUR is an econometrics model that used to be being utilized in solving some regression equations in which of them has their own parameter and appears to be uncorrelated. However, by correlation of error in differential equations, the correlation would occur among them. With the condition of the Bayesian SUR spatial autoregressive model, it is able to overcome heteroscedasticity cases from the vision of spatial. Further, the model involves four kinds of parameter priors’ distributions estimated by using the process of MCMC.
Collinear acousto-optical filtration of polychromatic Bessel light beams in lithium niobate crystals
Authors: Kulak G V , Ropot P I , Shakin O V
Published: December 2021

The features of collinear acousto - optical filtration of quasi - diffractive Bessel light beams of o- and e-type in uniaxial crystals are investigated. Using the method of overlap integrals, an expression is found for the diffraction efficiency depending on the parameters of the acousto-optical interaction, as well as on the values of the overlap integrals. It is shown that for the zero-order mode of a Bessel light beam for a lithium niobate crystal under conditions of transverse phase synchronism and in the optical spectrum range of 0.4-0.7 μm, the filter bandwidth of ∼0.2 nm is achievable; with an increase in the order of the mode m≥1, the increase in the bandwidth is insignificant and is ∼0.23 -0.24 nm.
Acousto-optic modulators/frequency shifters with single-mode optic fibers
Authors: Epikhin V M , Mazur M M , Ryabinin A V , Kamaushkin P V , Mazur L I
Published: December 2021

Acousto-optic modulators/frequency shifters based on TeO2 crystals with single-mode optical fibers supporting and not supporting polarization for collimated and focused light beams at radiation wavelengths of 785, 1064, 1550 nm have been developed, produced and experimentally investigated. The mechanisms of formation and methods of expanding the working band of the modulator are determined. A double-crystal acousto-optic laser emission frequency shifter with an working bandwidth of ≈40 MHz has been created. Single-crystal modulators based on collimated beams with a frequency band of ≈10 MHz are considered. A single-crystal modulator with a focused light beam with a switching time of ≈ 18 ns and an extended reception band of ≈ 40 MHz is investigated. It is shown that a light beam focusing makes it possible to implement a modulator with a minimum switching time of ≈ (2-3) ns. This value is limited by electrical breakdown of the ultrasonic wave transmitter.
Digital analysis of colposcopic images in papillomavirus infection
Authors: Dushkin A , Afanasiev M , Afanasiev S , Grishacheva T
Published: December 2021

Acetowhite epithelium (AWE) is one of the main clinical indicator of papillomavirus infection in squamous cell lesions. AWE has a different intensity in various degree of the cervix papillomavirus infection. The digital approach gives the opportunity to estimate AWE intensity by numeric values. The investigation aim is a quantitative assessment of cervical surface changes in papillomavirus infection with digital analysis and computer technologies. The spread of AWE on the cervical surface area has a value of the cervix papillomavirus infection in squamous cell lesions. These two features provide to create the index intensity (IndInt) and index grey value (IndGV). Open-source software ImageJ was used to analysis of colposcopic images. The 8-bit mode was used for the estimation of the AWE grey value. The algorithm of digital analysis detected indicators that provide the severity of papillomavirus infection. The outcomes of an algorithm were the identification of the cervix surface condition severity by an objective quantification.
Orthogonal ray interferometer: modification for testing convex and concave mirror surfaces
Authors: Askerko M V , Gavlina A E , Batshev V I , Novikov D A
Published: December 2021

A non-contact optical method for testing of large concave and convex mirrors both spherical and aspheric is presented. It is based on the orthogonal ray interferometer modification. The point source is placed near the testing mirror and the chief ray propagates normally to its axis. The information about a tangential profile of testing mirror is contained in an interference pattern that is a result of superposition between two wavefronts, the first is reflected from the mirror, the second bypasses the mirror. Testing of the entire surface is carried out by rotating the mirror. Interferogram decoding method and algorithm for determination of an error of the testing surface are presented. The proposed method does not require bulky additional optical components what differs it from existing methods and makes promising primary for testing large astronomical mirrors. Furthermore, the method is universal and suited for surfaces with various geometrical parameters. The scheme with some modification of the present method is applied for surfaces without axis of rotational symmetry or freeform surfaces.
Field curvature correction in video endoscope lenses through the parameters of air meniscus
Authors: Kryukov A V , Yakubovskiy S V
Published: December 2021

The research presents a method to synthesize lens data of an air meniscus built into the optical layout and acting as a correction element that fixes the field curvature of the entire optical system. The practical application of the proposed method is relevant when creating miniature lenses for medical video endoscopes when a small number of lenses and a flat image field for a CCD/CMOS sensor are important. Analytical dependencies for the lens data of the air meniscus are obtained and significant conditions for the field curvature correction are formed. A numerical example of a front stop lens design is demonstrated and confirms the correctness of the formulated conditions. A comparison of the aberration values of the original lens and an upgraded system is carried out. It is shown that, the values of the field curvature and astigmatism have been compensated as a result of introducing the synthesized parameters of the air meniscus into the optical layout. The correction is achieved while keeping the values of coma, distortion, focal length, and optical system total length at the level of the initial values.
Stress-strain state of the earth’s crust of the Central Asian mountain belt: distant effect of the tectonic impact of the Indo-Eurasian collision
Authors: Buslov M M
Published: December 2021

In recent decades, extensive geological, geophysical and geochronological data have been obtained that characterize in detail the results of the distant tectonic impact of the Indo-Eurasian collision on the lithosphere of Central Asia, which led to the formation of the mountain systems of the Pamirs, Tien Shan, Altai-Sayan region and Transbaikalia from the Late Paleogene (about 25 million years ago). It has been established that the formation of the structure of Central Asia occurred as a result of the transmission of deformations from the Indo-Eurasian collision over long distances according to the “domino principle” through the rigid structures of Precambrian microcontinents located among the Paleozoic-Mesozoic folded belts. The study of peneplain surfaces deformed into simple folds on high-mountain plateaus surrounded by rugged mountain ranges made it possible to reveal the parameters of the deformations of the earth’s crust, the interrelationship of the formation of relief and sedimentary basins. Apatite track dating data, structural and stratigraphic analyses of Late Cenozoic sediments in the basins prove a period of intense tectonic activation the entire lithosphere of Central Asia from the Indian continent to the Siberian platform starting from the Pliocene (about 3.5 million years). As a result of reactivation of the heterogeneous basement of Central Asia, high seismicity was manifested, which is concentrated mainly along the border of the microcontinents (Central Tianshan, Junggar and Tuva-Mongolian) and the Siberian craton, as well as in the zones of articulation of regional faults.
Contemporary earth crust strain rate tensor computed across Pamir region based on triplets of GPS velocities
Authors: Mansurov A N
Published: December 2021

We present detailed pictures of contemporary earth crust strain rate tensor values for territories of Pamir and its surroundings computed by triplets of GPS observations’ points. We characterize directions and intensity of contemporary tectonic activity at some fault zones.
Determination Of Lunar-Solar Deformation Processes In The Geomedium Volume In The Conditions Of Megapolis
Authors: Bazhenova E A , Beloglazova N A , Vdovin A G
Published: December 2021

The paper describes a new borehole hardware-software complex designed for synchronous registration of geoacoustic emission signals, electromagnetic radiation, temperature and borehole device rotation angle. The results of regime measurements with the new equipment in megapolis conditions are shown. The analysis of the obtained data is performed. The spectral-time analysis of regime measurements of geoacoustic emission and electromagnetic radiation signals registered in the borehole at a depth of 274 m was carried out. In the spectra of signals of electromagnetic radiation and geoacoustic emission the main diurnal and semidiurnal deformation tidal processes of known physical nature were identified.
Energy characteristics of acoustic emission under various modes of uniaxial loading
Authors: Sychev V N , Kulkov D S
Published: December 2021

Acoustic emissions were recorded in the process of uniaxial compression of samples of various geomaterials. The experiments were carried out on a low-noise lever setup with water leakage; the maximum load on the sample did not exceed 250 kN. Some of the samples were tested at a continuously increasing load, the other at its stepwise change. The energy distribution of acoustic emission signals was investigated. The energy characteristic of acoustic emission was the square of the maximum signal amplitude. The flow of AE events is considered from the standpoint of nonequilibrium thermodynamics and Tsallis statistics. A decrease in the steepness of the linear part of the repeatability plots for a particular geomaterial was revealed when changing the loading mode from linear to stepwise, which means an increase in the proportion of higher-energy events with a stepwise change in load.
Mechanism of anomalous manifestations δ13C CO2 underground water on Tashkent geodynamic range
Authors: Yusupov Sh S , Yu Shin L
Published: December 2021

The results of long-term isotope and gas measurements of various groundwater sources in the Tashkent artesian basin are presented. In addition to areal studies, the results of regime observations of selected wells at the Tashkent geodynamic test site are also presented to identify prognostic features as a precursor to strong earthquakes. The first results were obtained related to the manifestation of the Nazarbek earthquake on December 11, 1980, with a magnitude of 5.3, a source depth of 10 km. On the basis of this earthquake, the behavior of isotopic and gas precursors at the Ulugbek well, Tashkent geodynamic test site, was analyzed. A quantitative analysis was made of the anomalous manifestation of the gas and isotopic composition of groundwater in the Ulugbek borehole during the preparation and execution of the Nazarbek earthquake. Determination of CO2 release from rock samples recovered from deep wells of the landfill made it possible to quantify the ratio of “background” CO2 mixing from carbonate decomposition to anomalous. Judging by the obtained ratio, the rocks during the preparation of the earthquake should emit 2 times more carbon dioxide than the background CO2. This was confirmed by observations of the CO2 content in the well, when an increase in its relative concentration of 250% was recorded. The analysis of the δ13C time series, obtained as a result of long-term regime observations of the carbon isotopic composition of CO2 in the groundwater of the Tashkent geodynamic test site, made it possible to identify significant anomalies in the carbon content.
Geopolymers based on plasma incineration waste as a material for circular economy
Authors: Plawecka K , Figiela B , Grela A , Buczkowska K E
Published: December 2021

Plasma waste treatment technology is one of the promising methods of reducing problematic waste, but the technology itself create other kind of waste that must be effectively used to recognize this technology as a suitable for circular economy. The aim of the article is to show the possibility of using waste materials from a plasma incineration plant as a raw material for the production of geopolymeric materials. The samples were made based on waste from plasma incineration plant in Liberec (Czech Republic), fly ash from thermal power plants in Skawina (Poland) and sand mixed with an aqueous chemical solution. Next they mechanical properties, microstructure and mineralogical composition have been investigated. The results show the combination of these raw materials can increase the strength of the material and, consequently find applications in the utilization of plasma incineration waste. The article show the geopolymerization could be effective process for using waste materials from a plasma incineration plant as a raw material for creating the products for construction industry.
Dynamics control of powered hydraulic roof supports in the underground longwall mining complex
Authors: Rudzki P , Krot P
Published: December 2021

The study presents the dynamic analysis of the hydraulic cylinders operated in the powered roof support sections as an important part of the longwall underground mining complexes. This type of hydraulic unit is subjected to frequent shock impacts from the significant rock masses released on the top of mined caverns. Hydraulic props are equipped with safety valves with steel helical springs, which intend to reduce peak loads by the relief of internal pressure. These valves respond to shock with a time delay due to the limited velocity of the pressure wave inside the cylinder and an additional pipe of a small section, which restricts fluid flow in outer space. The new approach represented in this paper is based on mathematical modelling of the interaction of the hydraulic and mechanical parts and using additional signals to control safety valves. Detection of shock in advance (0.02-0.05 s) allows reducing pressure peaks by 30% and avoid failures. The challenges are the development of a “smart valve” with optimised control functions by the signals from additional sensors (vibration, deformation, piston position) and providing fast reaction time with a high flow rate under pressures up to 100 MPa.