bluuebunny/crossref_metadata_2025 huggingface dataset:
A reliable voltage clamping submodule based on SiC MOSFET for solid state switch
Authors: Ma Shaoxiang , Shang Wentong , Wang Dongyu , Zhang Ming , Zhu Bangyou , Yu Kexun , Pan Yuan
Published: February 2021

The electron cyclotron resonance heating system is one of the most effective plasma heating systems for controlled nuclear fusion. The key part of the system called gyrotron is driven by a high voltage power supply with a rated output power of hundreds of kilowatts. When the system is in operation, breakdowns frequently occur in the gyrotron. During breakdowns, the gyrotron will endure a large volume of energy and may be damaged. A solid-state switch is required to protect it by blocking high voltage (∼40 kV) within 10 microseconds and limiting energy within a few joules. Compared with Si IGBT/MOSFET, SiC MOSFET with higher switching speed is more suitable for the switch. However, rapid switching speed exacerbates the voltage imbalance. To solve the problems, a reliable module named Advanced Chopper Sub-Model based on SiC MOSFETs for a solid-state switch is proposed. The module adopts a voltage-clamped circuit to achieve the capabilities of rapid switching-off speed, as well as low overvoltage and good voltage balancing. In addition, modules connected in series can tolerate large driver time delay. The SPICE simulation and the double-pulse test are used to validate the effectiveness of the proposed module. The protection performance test was also conducted by using a spark gap to simulate the breakdown fault. Finally, the switch that consists of 64 series-connected modules has been tested at 30 kV/6 A. The turn-off time is ∼5 µs, and the energy during the turn-off transition is 0.283 J. The results show that the switch has good performance.
Global strong solutions for viscous radiative gas with degenerate temperature dependent heat conductivity in one-dimensional unbounded domains
Authors: Wu Yunshun , Xiao Li , Yu Rongfeng
Published: February 2021

In one-dimensional unbounded domains, we prove the global existence of strong solutions to the compressible Navier–Stokes system for a viscous radiative gas, when the viscosity μ is a constant and the heat conductivity κ is a power function of the temperature θ according to κ(θ)=κ̃θβ, with β ≥ 0 and κ̃>0. Our result generalizes Zhao and Liao’s result [Y. K. Liao and H. J. Zhao, J. Differ. Equations 265, 2076–2120 (2018)] to the degenerate and nonlinear heat conductivity. In particular, the constant coefficients’ case (μ and κ are positive constants) is also covered in our theorem.
Large eddy simulation/probability density function modeling of turbulent swirling stratified flame series
Authors: Turkeri Hasret , Zhao Xinyu , Muradoglu Metin
Published: February 2021

The large eddy simulation/probability density function (LES/PDF) method is applied to a turbulent swirling stratified flame series to systematically investigate its performance for accurate prediction of effects of stratification on turbulent flames under swirling conditions. The Cambridge/Sandia turbulent stratified flame series is selected as a target flame series. An augmented reduced mechanism is used for the methane/air combustion. The chemical calculations are accelerated by using the in situ adaptive tabulation method. The differential diffusion and heat loss from the bluff-body surface are taken into account in the simulations. The effect of stratification in fuel concentration is studied by increasing the stratification progressively from the pure premixed case to moderately and highly stratified cases. The performance of the LES/PDF modeling is evaluated by comparing the numerical results with the experimental data. The computed mean and rms of velocity, temperature, equivalence ratio, and mass fractions of species are found to be in good agreement with the measurements for all three conditions. Scatter plots and conditional means of mole fractions of species and temperature are presented and found to be in overall good consistency with those obtained from the experimental measurements. The recirculation zones are found to be about five times longer than those obtained under the non-swirling conditions. A low-equivalence-ratio high-temperature region near the bluff body is not captured in the computation, which is attributed to the insufficient entrainment of downstream mixtures into the recirculation zone. The parametric studies show that the differential diffusion has a minor effect on the mean and rms quantities, while the heat loss has a considerable effect on temperature and CO profiles close to the bluff body.
Reconstruction of depth resolved strain tensor in off-axis single crystals: Application to H+ ions implanted LiTaO3
Authors: Louiset Antonin , Schamm-Chardon Sylvie , Kononchuk Oleg , Cherkashin Nikolay
Published: February 2021

In the context of growing interest in strain engineering, we present a theoretical protocol for the reconstruction of extrinsic and intrinsic strain tensors in single-crystals attached to a template, with an arbitrary oriented coordinate system. Input data for the protocol are extrinsic deformations of lattice planes, i.e., measured with reference to a template. By combining the protocol with elasticity theory, material property modification can be elucidated. Different methods for strain measurements can take advantage of this approach. It has been applied for reconstruction of strain tensor depth distribution in off-axis LiTaO3 crystals implanted with H+ ions, which is the key step for piezoelectric thin film-on-insulator fabrication by the Smart Cut process. Modifications of composition, lattice parameters, and elastic constants are indicated and discussed.
Interfacial properties of binary mixtures of Lennard-Jones chains in planar interfaces by molecular dynamics simulation
Authors: Granados-Bazán Eder L. , Quiñones-Cisneros Sergio E. , Deiters Ulrich K.
Published: February 2021

Binary mixtures of fully flexible linear tangent chains composed of bonded Lennard-Jones interaction sites (monomers) were studied using the molecular dynamics simulation in the NVT ensemble. Their interfacial properties were investigated in planar interfaces by direct simulation of an explicit liquid film in equilibrium with its vapor. A method for the calculation of long-range interactions in inhomogeneous fluids was implemented to take into account the potential truncation effects. Surface tension and the pressure tensor were calculated via the classical Irving–Kirkwood method; vapor pressure, orthobaric densities, density profiles, and Gibbs relative adsorption of the volatile component with respect to the heavy component were also obtained. The properties were studied as a function of the temperature, molar concentration of the heavy component, and the asymmetry of the mixture. According to the results of this work, the temperature loses influence on the surface tension, vapor pressure, and Gibbs relative adsorption curves as the molecular length of the heavy component increases. This suggests that the universal behavior observed in pure fluids of Lennard-Jones chains also holds for binary mixtures. The contribution of the long-range interactions turned out to account for about 60%, 20%, and 10% of the surface tension, vapor pressure, and orthobaric density final values, respectively. This contribution was even larger at high temperatures and for large molecules. Strong enrichment of the volatile component at the interface was observed in the asymmetric mixtures. One of these mixtures even showed a barotropic effect at elevated pressures and a class III phase behavior.
A new form of transcorrelated Hamiltonian inspired by range-separated DFT
Authors: Giner Emmanuel
Published: February 2021

The present work introduces a new form of explicitly correlated factor in the context of the transcorrelated methods. The new correlation factor is obtained from the r12 ≈ 0 mathematical analysis of the transcorrelated Hamiltonian, and its analytical form is obtained such that the leading order in 1/r12 of the scalar part of the effective two-electron potential reproduces the long-range interaction of the range-separated density functional theory. The resulting correlation factor exactly imposes the cusp and is tuned by a unique parameter μ, which controls both the depth of the coulomb hole and its typical range in r12. The transcorrelated Hamiltonian obtained with such a new correlation factor has a straightforward analytical expression depending on the same parameter μ, and its physical contents continuously change by varying μ: One can change from a non-divergent repulsive Hamiltonian at large μ to a purely attractive one at small μ. We investigate the convergence of the ground state eigenvalues and right eigenvectors of such a new transcorrelated Hamiltonian as a function of the basis set and as a function of μ on a series of two-electron systems. We found that the convergence toward the complete basis set is much faster for quite a wide range of values of μ. We also propose a specific value of μ, which essentially reproduces the results obtained with the frozen Gaussian geminal introduced by Ten-no [Chem. Phys. Lett. 330, 169 (2000)].
The Synthesis of a Two-Photon Fluorescence Labelling Probe and its Immunochromatographic Strip for Rapid Diagnosis of COVID-19
Authors: Huang Chibao , Kang Shuai , Yu Fuxun , Wei Zairong
Published: February 2021

A two-photon fluorescence labelling probe (LP) was synthesised, and LP-Ag was obtained by LP labelling the N-protein antigen (Ag) of COVID-19. LP-Ag was made into an immunochromatographic strip. When a blood sample was added to the sample hole of the test card, it would move forward along the nitrocellulose (NC) film. If the sample contained IgM, the IgM bound to LP-Ag and formed an M line with the coated mouse anti-human IgM antibody, giving a positive response to the presence of IgM of COVID-19. The sensitivity, specificity, and accuracy of the immunochromatographic strip based on the LP was compared with those of the nucleic acid detection method and the colloidal gold method, proving it to be much simpler than the nucleic acid detection method, which can greatly shorten the detection period, and to be much more stable than the colloidal gold method, which can overcome uncertainty. LP-Ag can be used to image lung tissue with COVID-19 by two-photon fluorescence microscopy (TFM).
Sema7A is crucial for resolution of severe inflammation
Authors: Körner Andreas , Bernard Alice , Fitzgerald Julia C. , Alarcon-Barrera Juan Carlos , Kostidis Sarantos , Kaussen Torsten , Giera Martin , Mirakaj Valbona
Published: February 2021

Significance

Nonresolving inflammation, a hallmark of sepsis and/or multi-organ failure, still poses a challenge in medicine. The mortality rate is enormous, and so far no adequate curative therapy is available. Here we identify a previously unrecognized role of the neuronal guidance protein semaphorin 7A in the transition to resolution processes in severe systematic inflammation such as sepsis.
Controls on the size distributions of shallow landslides
Authors: Bellugi Dino G. , Milledge David G. , Cuffey Kurt M. , Dietrich William E. , Larsen Laurel G.
Published: February 2021

Significance

Shallow landslides are destructive and widespread natural hazards, but what controls their size distribution is poorly understood. We present a generalized theory to explain landslide size distribution at specific locations by combining a mechanistic slope stability model with a spatial-statistical description of the variability in hillslope conditions. We perform numerical experiments to explore how landslide size is controlled by the spatial structure of hillslope strength variability. We find that this structure must obey particular constraints in terms of amplitude, form, and wavelength to reproduce observed size distributions. Our theory can account for the broad similarities and occasional differences in field-mapped landslide inventories; it highlights the critical need to constrain the spatial variability in material strength properties of hillslopes.
Meteorin-like/Meteorin-β protects heart against cardiac dysfunction
Authors: Rupérez Celia , Ferrer-Curriu Gemma , Cervera-Barea Aina , Florit Laura , Guitart-Mampel Mariona , Garrabou Gloria , Zamora Mònica , Crispi Fàtima , Fernandez-Solà Joaquim , Lupón Josep , Bayes-Genis Antoni , Villarroya Francesc , Planavila Anna
Published: February 2021

Meteorin-like/Meteorin-β (Metrnl/Metrnβ) is a secreted protein produced by skeletal muscle and adipose tissue that exerts metabolic actions that improve glucose metabolism. The role of Metrnβ in cardiac disease is completely unknown. Here, we show that Metrnβ-null mice exhibit asymmetrical cardiac hypertrophy, fibrosis, and enhanced signs of cardiac dysfunction in response to isoproterenol-induced cardiac hypertrophy and aging. Conversely, adeno-associated virus–mediated specific overexpression of Metrnβ in the heart prevents the development of cardiac remodeling. Furthermore, Metrnβ inhibits cardiac hypertrophy development in cardiomyocytes in vitro, indicating a direct effect on cardiac cells. Antibody-mediated blockage of Metrnβ in cardiomyocyte cell cultures indicated an autocrine action of Metrnβ on the heart, in addition to an endocrine action. Moreover, Metrnβ is highly produced in the heart, and analysis of circulating Metrnβ concentrations in a large cohort of patients reveals that it is a new biomarker of heart failure with an independent prognostic value.
The Conditioning Role of Judicial Independence in the Exercise of Judicial Review
Authors: Vande Kamp Garrett N.
Published: February 2021

Scholars recognize that judicial review depends upon judicial independence: an independent court is more likely to invalidate a statute it opposes than a nonindependent court. But scholars have lost that the previous statement is a conditional relationship, in which judicial independence moderates the relationship between a court’s ideological preferences and its decision to strike statutes. I model this conditional relationship using the US Supreme Court’s constitutional decisions on important federal statutes. The analysis reveals that judicial independence is best modeled as a conditional predictor of judicial review and that modeling judicial independence as an additive predictor risks false negative results.
Positron-induced scattering of acetone from 0.1 eV to 5 keV
Authors: Sahgal Vardaan , Bharadvaja Anand , Baluja Kasturi Lal
Published: February 2021

Positron impact scattering cross-sections (CS) like elastic differential, integral and momentum transfer of acetone are reported in the energy range from 0.1 eV to a few keV using a cc-pVTZ basis set within single centre expansion formalism. The optimized molecular wavefunction of the target was obtained from the multi-center expansion of the Gaussian-type orbitals within a Hartree–Fock self consistent field scheme. Two different models were used to account for the long-range effects arising due to the polar nature of the target. Both the models gave overlapping ‘correction’ CS. The Born corrected elastic CS exhibit a good agreement with existing experimental results and ab initio theoretical results. The inelastic CS like positron impact excitation and ionization are also computed. The total CSs obtained by summing elastic and inelastic CS are in excellent agreement with the ‘forward angle corrected’ experimental results over the majority of the energy range. The deviations in the energy range of 3–7 eV are due to the exclusion of the positronium formation channel from the computation. A brief observation is also made about the impact of the Born closure scheme.
Lead-free MCP to improve coincidence time resolution and reduce MCP direct interactions
Authors: Ota R , Nakajima K , Ogawa I , Tamagawa Y , Kwon S I , Berg E , Cherry S R , Shimoi H , Hasegawa Y , Nishizawa H , Shimano K , Hasegawa T
Published: February 2021

Achieving direct imaging of the annihilation position of a positron on an event-by-event basis using an ultrafast detector would have a great impact on the field of nuclear medicine. Cherenkov emission is the most attractive physical phenomenon for realizing such an ultrafast timing performance. Moreover, a microchannel-plate photomultiplier tube (MCP-PMT) is one of the most promising photodetectors for fully exploiting the fast timing properties of Cherenkov emission owing to its excellent single photon time resolution of 25 ps full width at half maximum (FWHM). However, as the MCP structure generally contains a lead compound, the gamma rays frequently and directly interact with the MCP, resulting in the degradation of its timing performance and generation of undesirable side peaks in its coincidence timing histogram. To overcome this problem, we have developed a new MCP-PMT based on an MCP consisting of borosilicate glass, thus drastically reducing the probability of the photoelectric effect occurring in the MCP. To evaluate its insensitivity to gamma rays and its timing performance, a coincidence experiment was performed and showed that the probability of direct interactions was reduced by a factor of 3.4. Moreover, a coincidence time resolution of 35.4 ± 0.4 ps FWHM, which is equivalent to a position resolution of 5.31 mm, was obtained without any pulse height/area cut, improving to 28.7 ± 3.0 ps when selecting on the highest amplitude events by careful optimization of the voltage divider circuit of the new MCP-PMT. The timing performance of this new MCP-PMT presents an important step toward making direct imaging possible.
Stochastic thermodynamics and fluctuation theorems for non-linear systems
Authors: Korbel Jan , Wolpert David H
Published: February 2021

We extend stochastic thermodynamics by relaxing the two assumptions that the Markovian dynamics must be linear and that the equilibrium distribution must be a Boltzmann distribution. We show that if we require the second law to hold when those assumptions are relaxed, then it cannot be formulated in terms of Shannon entropy. However, thermodynamic consistency is salvaged if we reformulate the second law in terms of generalized entropy; our first result is an equation relating the precise form of the non-linear master equation to the precise associated generalized entropy which results in thermodynamic consistency. We then build on this result to extend the usual trajectory-level definitions of thermodynamic quantities that are appropriate even when the two assumptions are relaxed. We end by using these trajectory-level definitions to derive extended versions of the Crooks fluctuation theorem and Jarzynski equality which apply when the two assumptions are relaxed.
Numerical study of energy transmission through copper-based nanofluid contained in a partially heated isosceles triangular cavity in the presence of heat source/sink
Authors: Siddiqui Muhammad Arshad , Mehmood Ziafat , Riaz Arshad , Lu Dianchen
Published: February 2021

This study reports computational simulation of natural convective energy transport through copper-based nanofluid contained in partially heated isosceles triangular conduit in the presence of invariable magnetic field under the influence of energy source/sink. Inclined sides of the enclosure are retained cold and horizontal boundary is supposed thermally insulated. Heat source of a particular length is placed on the horizontal wall. Relations expressing the energy transport and fluid flow are first dealt by penalty scheme and then composed expressions are assembled through Galerkin approximation scheme. Pertinent physical parameters governing the flow are the solid volume increment of nanoparticles (0.0 < 

ϕ

 < 0.06), Hartmann number (0 < Ha < 100), Rayleigh number (105 < Ra < 108) and coefficient of heat source/sink (−10 < Q < 10). It has been noted through this investigation that in consequence of magnetic force, reduction in heat transport occurs. Conduction and convection regimes are dominant for small and large Rayleigh numbers respectively. Energy transport rate is found zero on corners of the cold inclined walls. Obtained computational results reveal that the flow pattern relies considerably on the concentration of nanoparticles, coefficient of energy source/sink, Rayleigh and Hartmann numbers. Computed solutions are expressed through plots of streamlines, isothermal lines, and rate of local and overall energy flow. The current results are also validated through graphical comparison with the existing literature.
Vector kink-dark complex solitons in a three-component Bose–Einstein condensate
Authors: Li Yan , Qin Yan-Hong , Zhao Li-Chen , Yang Zhan-Ying , Yang Wen-Li
Published: February 2021

We investigate kink-dark complex solitons (KDCSs) in a three-component Bose–Einstein condensate (BEC) with repulsive interactions and pair-transition (PT) effects. Soliton profiles critically depend on the phase differences between dark solitons excitation elements. We report a type of kink-dark soliton profile which shows a droplet-bubble-droplet with a density dip, in sharp contrast to previously studied bubble-droplets. The interaction between two KDCSs is further investigated. It demonstrates some striking particle transition behaviours during their collision processes, while soliton profiles survive after the collision. Additionally, we exhibit the state transition dynamics between a kink soliton and a dark soliton. These results suggest that PT effects can induce more abundant complex solitons dynamics in multi-component BEC.
Breather solutions of modified Benjamin–Bona–Mahony equation
Authors: Adamashvili G T
Published: February 2021

New two-component vector breather solution of the modified Benjamin–Bona–Mahony (MBBM) equation is considered. Using the generalized perturbation reduction method, the MBBM equation is reduced to the coupled nonlinear Schrödinger equations for auxiliary functions. Explicit analytical expressions for the profile and parameters of the vector breather oscillating with the sum and difference of the frequencies and wavenumbers are presented. The two-component vector breather and single-component scalar breather of the MBBM equation is compared.
A novel consciousness emotion recognition method using ERP components and MMSE
Authors: Zheng Xiangwei , Zhang Min , Li Tiantian , Ji Cun , Hu Bin
Published: February 2021

Objective. Electroencephalogram (EEG) based emotion recognition mainly extracts traditional features from time domain and frequency domain, and the classification accuracy is often low for the complex nature of EEG signals. However, to the best of our knowledge, the fusion of event-related potential (ERP) components and traditional features is not employed in emotion recognition, and the ERP components are only identified and analyzed by the psychology professionals, which is time-consuming and laborious. Approach. In order to recognize the consciousness and unconsciousness emotions, we propose a novel consciousness emotion recognition method using ERP components and modified multi-scale sample entropy (MMSE). Firstly, ERP components such as N200, P300 and N300 are automatically identified and extracted based on shapelet technique. Secondly, variational mode decomposition and wavelet packet decomposition are utilized to process EEG signals for obtaining different levels of emotional variational mode function (VMF), namely

V
M
F

β
+
γ

, and then nonlinear feature MMSE of each

V
M
F

β
+
γ

are extracted. At last, ERP components and nonlinear feature MMSE are fused to generate a new feature vector, which is fed into random forest to classify the consciousness and unconsciousness emotions. Main results. Experimental results demonstrate that the average classification accuracy of our proposed method reach 94.42%, 94.88%, and 94.95% for happiness, horror and anger, respectively. Significance. Our study indicates that the fusion of ERP components and nonlinear feature MMSE is more effective for the consciousness and unconsciousness emotions recognition, which provides a new research direction and method for the study of nonlinear time series.
Natural partial order on semigroup partial linear transformation with restricted range
Authors: Himayati A I A , Prasetyanto M A
Published: February 2021

The set with assosiative binary operations is semigroup. Of all set partial linear transformations with a composition function is semigroup which is called a partial linear transformation semigroup that is denoted by (PT (X), o). If Y is a subspace of X, with all images of PT (X) a subset of Y, so the semigroup which is formed is a semigroup of partial linear transformation with restricted range that is denoted by (PT(X,Y),o). A natural partial order is a relation which defined by a ≤ b if only if a = xb = by, xa = a for some x,y ∈PT(X,Y) in a semigroup partial linear transformation with restricted range. In this article using the literature study method, it discusses the characterization of natural partial order on partial linear transformations semigroups with restricted range resulting neccesary and sufficient condition for a natural partial order in semigroup partial linear transformation with restricted range.
The Role of Electronic Customer Relationship Management (E-CRM) In Improving Service Quality
Authors: Adnan Ahmad Zaelani , Rahayu Agus , Hendrayati Heny , Yusuf Ramayani
Published: February 2021

Electronic Customer Relationship Management(E-CRM) is one of business concepts and technology that supported by information systems to integrate all of business proccess that customer interacted. The most common E-CRM implementation in hotel industry is website. This research is to know the role of E-CRM to improve service quality, describe the implementation of E-CRM, understand the guest service procedure in, and to know the service quality through E-CRM in Prama Grand Preanger Bandung. The role of E-CRM by giving understandable information quality through two languages, ease of navigation, consumer service quality, fulfilling guests request, integrated marketing channels, online community through social media, giving guests rewards, personalization levels, and site security. Prama Grand Preanger Bandungs ECRM applies compatible with common information, alternative contact, membership, automatic e-mail, and instructions for new guest. Service is done by giving informations about room reservation, payment method, and transaction security. Service quality through E-CRM is generaly acceptable by hotel guests because of the ease in getting information and room reservation.
Analysis of the Impact of using Syariah Bonds (Sukuk) and Conventional Bonds on Stock Returns for Investors in Indonesia: Study of Manufacturing Companies Listed on the IDX in the year 2015-2017
Authors: Dian Rahmawati I. , Qudus.SN N. , Dian Pertiwi R
Published: February 2021

The stock market is an integral part of economic activity in many countries. One of the stock market types is financial obligations. In Indonesia has developed two types of financial obligations are Sharia-based obligations called Sukuk, and non-Sharia ones called conventional obligation. This study aims to analyze the impact of Sukuk and conventional obligation issuance on stock returns. The company under review is a company that issues obligation. The study uses event studies to see the reaction of the stock market to the event of issuance of Sukuk and conventional obligation. The results of the study show that Sukuk and conventional obligation affect stock returns.
Learning Materials Based On Digital Art Student Creativity in Universitas Muhammadiyah Tapanuli Selatan
Authors: Ariaji Rizky , Nasution Ahmad Husein , Dharma Harahap Andes Fuady , Abubakar  , Tuah Sahlan , Darwis  , Hilda Lelya
Published: February 2021

In fact, the teaching materials are still using teaching books, so in the learning media courses will be developed based on digital art teaching materials at Universitas Muhammadiyah Tapanuli Selatan. In the development of the teaching materials contain teaching materials tailored to the curriculum that applies with the tools and materials contained in the environment. Research objectives to know the expert opinion on the feasibility test and influence of the development of digital art-based teaching materials. Research and Development (R&D) method of ADDIE model (Analyze, Design, Development, Implementation, and Evaluation). For the average result of expert validator assessments on this study covers aspects of feasibility standards based on BSNP by 3.27, then the validity criteria is quite good (quite valid and need revision). The result of student learning creativity Assessment was obtained at 3.18, hence the creativity category is creative.
Teacher’s Efforts to Enhance Students’ Competence in Madrasah Ibtidaiyah in Science Skills and Academic Achievement
Authors: Saepuloh Aep , Rosfiani Okta , Hermawan CecepMaman , Sutiawati  , Apriyana Mita
Published: February 2021

Teaching using the demonstration model shows that we are ready to take risks by encouraging teachers and students to be, and this adds credibility and a foundation for various things in professional learning sessions. This research aims to improve academic achievement and student skills in science. This research uses an action research method with a cycle system, which consists of planning, implementation, observation, reflection, and revision. This practical action research was conducted on fourth grade MI students in elementary school in South Tangerang. The results show a gradual increase in student learning outcomes. Where pre-cycle shows only 59.25% of students who have completed mastery of learning outcomes, cycle 1 of student mastery learning increases to 74.07%, in cycle 2 student mastery of learning increases rapidly to 92.59%. This paper argues that the application of the demonstration model has been shown to improve student learning outcomes on science subjects. This research also shows that the direct teaching model is proven to be able to transfer science skills to students better.
The Advantages of Pleco and Google Translate Applications in Assisting Mandarin Language Learning
Authors: Ying Yi , Theresia  , Febriana Vivi
Published: February 2021

As technology develops, dictionaries have changed from paper to electronic. Electronic dictionaries can be an alternative medium for language learning because they combine sound, visuals and text that make learning foreign languages easier. One example of using an electronic dictionary is in reading subjects. Users can learn about how to pronounce a vocabulary and sound tones correctly by utilizing the audio feature in an electronic dictionary. Vocabulary recall through mobile device applications is far more effective than through other media. The electronic dictionary application that is widely used by Chinese Literature students in learning Mandarin is the Pleco and Google Translate application. Therefore, the authors are interested in making comparisons of the similarities and differences between the two applications for the recommendation of Mandarin learning aids. This study uses a comparison method by comparing the functions of the two e-dictionaries. From the results of the comparison, both applications have keyboard features, handwriting features, voice record features and scanning features for translating words. The difference is in the radical features, stroke, number words and sentences sample
Symbol Sense of Mathematics Students in Solving Algebra Problems
Authors: Prasetya Rini Ariati Dwi , Hussen Saddam , Hidayati Herlina , Muttaqien Anwar
Published: February 2021

Symbol sense is a sensibility or mastery of someone against the use of symbols and an understanding of the situation when symbols can be used. This study attempts to describe the extent to which the use of symbol sense students STKIP Muhammadiyah Sampit to solve the algebra problem based on the steps of Polya’s problem-solving. The results showed that understanding the problem step of students in the first semester was still less able to relate the symbol to the problem that given, and the students still used words instead of symbols in understanding the problem. Then the third-semester students have fulfilled all the indicators of symbol sense. Furthermore, fifth-semester students are less precise in writing symbols according to their meaning in the problem. Steps of planning the problem solving all students can use the symbol sense properly. Then in the step of implementing the problem-solving plan, students in the third and fifth semesters can fulfill all the indicators symbol sense to the maximum. However, first semester students bring up or make some new symbols to solve problems. Steps of looking back at the problem solving has been obtained, all students meet all the symbol indicators well. So, the first semester students are still lacking in using their symbol sense in solving algebra problems.
Analysis The Ability of Thinking Abstractly of Mathematics And Self-Efficacy Through Tpack
Authors: Nurhadi Moh. , Darhim
Published: February 2021

The purpose of this study is to analyze the ability of thinking abstractly of mathematics and self-efficacy through TPACK learning. This research is quantitative with survey method and conducted on 7th grade studens. The Data were collected using interview, questionnaire sheets and the ability thinking abstractly of mathematics tests. The results of this study are several indicators of the ability of thinking abstractly of mathematics, found indicators that have been achieved but some of them have not yet been reached as making generalizations. The results of the questionnaire and interview it was concluded that most students still assume that mathematics is difficult to learn and the ability
Analysis of Scour Depth Around Bridge Piers With Round Nose Shape by HEC-RAS 5.0.7 Software
Authors: Silvia C S , Ikhsan M , Wirayuda A , Mastiar
Published: February 2021

Local scour of bridge piers is the main reason for the failure of a hydraulic structure like abutment, bridge piers, etc. Local scours is a complex phenomenon that depends on the discharge, depth of flow, shapes of the pier and distribution of sediment particle. The problems of local scours occurred in Krueng Ineng river, Nagan Raya Regency will cause a structural collapse which has the impact of decreasing the stability of the bridge structure. In this study, the software of Hydrologic Engineering Center River Analysis System (HEC-RAS) 5.0.7 is used to evaluate local scour around the bridge pier which employs the Colorado State University method as a default equation. Flow conditions were simulated using HEC-RAS flow modeling software estimated for 100-year flood. The Results of the analysis with used the peak discharge (Qp100) that occurs in the Krueng Seunagan watershed is 1513m3/sec, pier width of Round Nose shape is 4m, and average grain size analysis D50 and D95 is 0.91mm and 4.35mm, show a maximum scour depth obtained is 5.04m. The results of this study will be a reference for the local government to planning appropriate handling for minimalizing local scours in the study area.
Additionalto Synthetic Fiber On Materials Plastic Injection To Minimize Product Defects
Authors: Azharul Firmansyah , Rahmawati  , Harno  , Wilarso  , Mujiarto
Published: February 2021

Plastic injection molding process in the manufacture of air gun components, namely butt stock gun, and pump handles, product defects are still often found, some of the causes include: burning (burning), lack of material (short shots), and cracking products (cracking), this resulting in not achieving production targets and sales targets. The purpose of this research is to find out the root cause of failure of air gun component products. The method in this problem, plastic injection materials need to be added synthetic fibers to get the visual appearance, tensile strength, modulus of elasticity, and the desired hardness, by utilizing recycled material products. The results showed visually the addition of recycled materials and synthetic fibers did not affect appearance, in economic terms the more recycled materials added the cheaper the cost of material procurement. The addition of recycled material weighing 50% of the original material and 2.5% synthetic fiber from the total amount of material to be processed, is expected to increase the tensile strength, modulus of elasticity and desired hardness. Therefore, this addition of fiber obtains a more accurate comparison of product quality and quantity with a lower product defect rate, and is able to reduce production costs.
Roles Of Quisionary Data To Assess The Vco (Virgin Coconut Oil) Micro Business Performance In The Bojong 3 State, Bojong Village, Panjatan Sub-District, Kulons Progo Regency
Authors: Nur Suhascaryo KRT , Yudiantoro Alp
Published: February 2021

Indonesia is a country that has the largest area of coconut plantations in the world, reaching 3.7 million ha. This is an opportunity for the development of coconuts into various useful products. The Coconut tree is one of the important plantation commodities in the development of plantation sub-sector, among others, to meet domestic needs, as well as export commodities that produce foreign exchange. Virgin coconut oil is a processed product of coconut meat that has many benefits in the form of clear-colored liquid, does not taste with the distinctive smell of coconut. Making this VCO does not require expensive costs, because raw materials are easily obtained at low prices and simple processing. This was made an opportunity by residents of Bojong 3 to earn income by selling processed VCO products. To maximize this VCO micro-enterprise, a questionnaire role is needed to determine how far the readiness of citizens to start a VCO business and develop it becomes larger and has stronger economic resilience.
Growth Analysis of Escherichia coli and Salmonella typhi on MacConkey Agar Modification
Authors: Supriatin Y , Sumirat V A , Herdiani M
Published: February 2021

MacConkey Agar (MCA) is a selective and differential media that is used to isolate and differentiate easily growing Gram-negative bacteria, especially members of the Enterobacteriaceae family. This study aims to obtain MCA modified media. Research has been conducted by inoculating Escherichia coli and Salmonella typhi on MCA media as control and modification of MCA from Nutrient Agar added by bile salts, violet crystals as inhibitors of Gram-positive bacteria, lactose addition to distinguish the properties of bacteria that can ferment lactose and bacteria that cannot ferment lactose, using phenol red as an indicator, the test bacteria were incubated for 24 hours at 37°C and then counted the number of CFU/mL colonies and their lactose fermentation properties were observed. Research results were calculated by the t-test. T-test results showed that there were no differences in the average number of colonies of Escherichia coli and Salmonella typhi in the two media. So it can be concluded that the modified MCA media can be used as a substitute for MCA and show the nature of Lactose Fermenter with a color change from orange to bright yellow because the indicator used is phenol red. So it can be concluded that the MCA modification media can be used as a substitute for MCA.
Antifouling Activity of Cymodecea rotundata and Halodule pinifolia at Pulau Morotai
Authors: Nurafni  , Nur R M , Koroy K , Alwi D , Muhammad S , Eso N
Published: February 2021

Biofouling is the attachment of the organism to the surface of the submerged in water. The presence of a fouling organism causes losses in the form of accelerating damage and adding to the burden of the ship/ boat. The activity of biofouling can be avoided by using environmentally friendly antifouling paint. Some marine organisms, such as mangroves and seagrass, are reported to have antifouling activity. The purpose of this study was to determine the antifouling activity of seagrass C. rotundata and H. pinifolia and to identify bioactive compounds contained in C. rotundata and H. pinifolia. Based on the result of the research, the yield of C. rotundata extract was 5.96% and H. Pinifolia 19.23%. The activity of antifouling H. pinifolia has a minimum concentration of 1000 ppm, while C. rotundata extract is 250 ppm. The results of the identification of bioactive compounds showed that H. pinifolia contains alkaloids, saponins, and steroids, while C. rotundata contains alkaloids.
Power Grid Surveillance and Control Based on Wireless Sensor Network Technologies: Review and Future Directions
Authors: Abdulwahid Ali Hadi
Published: February 2021

In this paper, the concept of the smart grid and the emerging challenges of wireless communication technology for use on the smart grid (SG)is reviewed. One modern-day technology of great significance is wireless sensor networks (WSNs), which has the potential to ensure the smooth operation of smart grid management and increase its energy efficiency, reliability and cost-effectiveness. The advanced electric power grid infrastructure known as smart grid takes advantage of automated control and cutting-edge communication strategies to achieve greater efficiency, reliability and safety, whilst seamlessly combining renewable and alternative sources of energy. Unlike conventional communication technologies, WSNs are more beneficial to modern electric power systems because they are affordable and operate on a cooperative basis. For this reason, WSNs are considered to have good potential for improving the way electric power is produced, distributed and used. Therefore, they are a key element of the smart grid. Nevertheless, the implementation of WSNs in smart grid settings may be inadequately reliable due to the complexity and unfavourable aspects of electric power system environments. The purpose of the current work is to review WSN uses in electric power systems and the opportunities and difficulties offered by this technology, as well as to delineate possible facets of smart grid applications and wireless technologies that future research could explore. Therefore, this work is significant.
The Role of Contemporary Requirements in Shaping Iraqi Buildings Identity, (1960-1980)
Authors: Adnan Haidar , Fadhil Anwar , Jawad Ibrahim
Published: February 2021

The era spirit is witnessing continuous intellectual transformations in the international architectural field, influenced by the contemporary requirements. Various design trends have emerged about dealing with these contemporaries. Some designers focused on presentation importance of Iraqi contemporary identity, while others try to employ it in other directions that are not consistent with the local character. The research problem is knowledge lack in clarifying the role of contemporary requirements in shaping the identity of Iraqi buildings for the period (1960-1980) and how to employ the architectural act of its designers. The aim to determine how the architect responds to these contemporary requirements through the architectural act that distinguishes each designer from others. The theoretical framework is embodied by establishing Dealing Levels with local identity and reading it in a specific time and place within the levels of Explanation, Interpretation, and Disassembly, which were linked to the concept of an integrated response in achieving it through three strategies of revival, renewal, and reform. Then the elements are applied to a sample of the most prominent Iraqi architects in the period above to obtain results and conclusions, which emerged in achieving an integrated response case in dealing with contemporary requirements.
Evaluation of acid leaching process and calcination temperature on the silica extraction efficiency from the sustainable sources
Authors: Ajeel Sami Abualnoun , Sukkar Khalid A. , Zedin Naser Korde
Published: February 2021

In the present work, amorphous silica (SiO2) is prepared from agricultural waste (rice husks) as a sustainable source by acid leaching process followed with the calcination process. RH treated with 3N HCl, then burned at (500, 600, 700, and 800°C) for 4 hrs. The final product of silica was characterized by X-ray fluorescence (XRF), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and thermogravimetric analysis (TGA). The results by XRD and XRF indicate that the obtained white powder was amorphous silica at calcination temperature less than 700°C with a purity of 96.976% but at 800°C the purity was 96.983%. SEM and visual inspection analyses show that RHA morphologies with acid pre-treatment at 700°C and 800°C surfaces of un-leached rice husk have a greater degree of roughness than those that have been leached with dilute acids.
Thermal Performance Optimization for Residential Buildings in Basra City
Authors: Ibrahim F A , Abdulwahid S M , Abdulrahman R S , Mosa M A
Published: February 2021

The present study investigates many parameters in the design of a residential building consisted of 6 floors with a construction area 240m2located in Basra city. This study aims to reduce electric energy consumption utilized for cooling and heating of the building. The parameters which studied included: the effect of building façade, the exterior color of the external walls, the glazing distribution and the shape of the building. eQuest energy simulation program is used to simulate the annual building energy consumption, the program uses the hourly annual collected weather data. The results show that orientation the building façade toward the north direction is the best in the design of the building. The saving in annual electric energy consumption is about 11%. Moreover, the external color of the building has a strong effect on building cooling and heating energy consumption. By utilizing white exterior wall color, the annual electric energy consumption reduced by about 12%. The results also showed that by utilizing proper glazing distribution the electric energy consumption could be reduced by 3%. When all enhancements were combined an optimum building case were found. For the optimum case, the annual electric energy consumption was reduced by 35% compared to the base building case.
CFD analysis of the classroom thermal conditions built from the sandwich panel
Authors: Laubi R N , Abbood N K
Published: February 2021

Based on the daily source energy radiation on hot summer zone like Iraq, lecture room built from sandwich wall panel (SWP) is analysed by using Computational Fluid Dynamics (CFD) technique. An air conditioning unit is operated inside a lecture room. The two targets of this study were to realize the influence of air condition location - Four cases for lecture room utilized with the same dimensions at a different position for the air conditioner unit. A thermal condition of the lecture room was optimized with ANSYS FLUENT. Numerical analyses have shown that there is a relationship between the position of air-conditioner and the distribution of convection currents in the room. However, the mass-weighted average temperature in the room almost looks like they are identical in all the cases, but differences in static temperature are observed at the different zone for the same case w.r.t the position of the air-conditioner.
Energy and exergy study of Shatt Al-Basra gas turbine power plant
Authors: Faisal S H , Naeem N K , Jassim A A
Published: February 2021

Energy and exergy analyses have been carried out on General Electric (GE) gas turbine unit in Shatt Al-Basra power plant located in Basra-Iraq. The analysis is based on both full-load and part-load actual operating data during the year 2017. An obvious drop off for plant performance characteristics is observed during the hot season. Energy and exergy analyses show that maximum thermal and exergy efficiencies were in February. Minimum exergy destruction in the unit is predicted in March. Improvement of the unit performance is recommended by installing intake air cooling as well as utilizing the discharged heat power that contains considerable work potential.