bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulating phase transformation kinetics via redox reaction in ferroelectric Ge-doped HfO2
Authors: Yajima T. , Nishimura T. , Migita S. , Tanaka T. , Uchida K. , Toriumi A.
Published: November 2020

HfO2 ferroelectricity is promising due to CMOS compatibility and various exceptional properties compared to conventional ferroelectricity. However, the mechanism for stabilizing the ferroelectric phase is still controversial. In this study, it is found that the redox reaction at high temperature strongly influences the phase transformation kinetics during the cooling process of Ge-doped HfO2 and alters the ferroelectric phase ratio at room temperature. The transformation to the non-ferroelectric phase becomes so fast during cooling in the oxidized sample that the transformation is unavoidable even in fast cooling and deteriorates ferroelectricity. It is further revealed that while the high-temperature redox reaction itself is reversible, the transformation to the non-ferroelectric phase during cooling is an irreversible process, which dominates ferroelectricity. These results help understand ferroelectric phase formation in doped HfO2 and elaborate the fabrication process of advanced ferroelectric devices.
Effects of alloying elements on the Ni/Ni3Al interface strength and vacancy diffusion behavior
Authors: Wen Qiuhao , Wang Mingxu , Kong Lingti , Zhu Hong
Published: November 2020

The effects of seven alloying elements (Co, Cr, Mo, Re, Ru, Ta, and W) on the Ni-vacancy diffusion behavior and the rupture strength of γ-Ni/γ′-Ni3Al interfaces are studied using density functional theory calculations. Our results reveal that all seven solutes prefer to occupy Al sites close to or Ni sites far from the interface. These solutes except for Co could significantly increase the barrier of Ni-vacancy diffusion within the γ/γ′ interface region. The retarding effects are similar when solutes are located at their favored Al and Ni sites, which follows the sequence of Ta > W > Mo > Re > Ru > Cr > Co. Besides, it is found that the presence of solute atoms could always increase the rupture strength of their neighboring interface but reduce that of their next neighboring interface. The best strengthening effects on the neighboring interface are achieved by Re and W. In terms of the entire interface region, alloying at the favored Al site brings a better strengthening effect than that at the favored Ni site. The charge density difference analysis demonstrates that the charge accumulation level at the interface explains the variable strengthening effects among different alloying elements.
Dexterous formation of unconventional Chladni patterns using standing bulk acoustic waves
Authors: Lei Junjun , Cheng Feng , Liu Guotian , Li Kemin , Guo Zhongning
Published: November 2020

Classical Chladni patterns formed by vibrations of flat plates have been studied for centuries and are well understood. In this Letter, we show dexterous formation of unconventional Chladni patterns in a fluid using standing bulk acoustic waves. A neat acoustofluidic resonator enabling visualization of microparticles in the fluid channel both on its cross section and in its flow direction was designed. In contrast to classical Chladni patterns, which depend on resonant modes of flat plates, the Chladni patterns herein are generated by vibrations of cylindrical walls and are related to resonant modes of fluid channels. The behavior of the acoustofluidic resonator is numerically predicted by applying an acoustic-structure interaction model to calculate the acoustic pressure distribution at different modes of resonances and the Gorkov theory to obtain the potential of the acoustic radiation forces that act on suspended particles. We also demonstrate numerically and experimentally that further focusing of microparticles can be achieved if the actuation of ultrasound continues after Chladni patterns are formed on the cross section of the fluid channel.
The MscS-like channel YnaI has a gating mechanism based on flexible pore helices
Authors: Flegler Vanessa Judith , Rasmussen Akiko , Rao Shanlin , Wu Na , Zenobi Renato , Sansom Mark S. P. , Hedrich Rainer , Rasmussen Tim , Böttcher Bettina
Published: November 2020

Significance

Many biological processes are based on mechanosensitive channels which are stimulated by mechanical forces. In cell-walled organisms, the large family of MscS-like channels is extremely diverse and often several different versions of these channels are present in the same organism. However, we hardly understand the reason for this diversity because only the simplest known member of this family, MscS, has been studied in some depth. Here, we present the molecular structures of two more complex members of this family, YnaI and YbiO. While the basic architecture of the core is conserved, functional properties and the way they open vary. We ultimately will learn how evolution provides by structural variation a wider range of cellular functions.
Degenerative and regenerative pathways underlying Duchenne muscular dystrophy revealed by single-nucleus RNA sequencing
Authors: Chemello Francesco , Wang Zhaoning , Li Hui , McAnally John R. , Liu Ning , Bassel-Duby Rhonda , Olson Eric N.
Published: November 2020

Significance

Skeletal muscle is composed of multinucleated myofibers that are essential for movement and metabolism. Duchenne muscular dystrophy (DMD) is a devastating disease that is caused by the lack of the dystrophin protein, which maintains the integrity of muscle membranes. The absence of dystrophin results in myofiber degeneration followed by regeneration until muscle stem cells are depleted. We generated a new DMD mouse model lacking exon 51 and then used single-nucleus RNA sequencing to reveal the transcriptional diversity of individual myofiber nuclei in dystrophic muscle compared to normal muscle. Our findings uncover disease-associated pathways responsible for muscle degeneration and regeneration that might ultimately be manipulated therapeutically and reveal an unrecognized regenerative myonuclear population associated with dystrophic muscle.
CLIL as a balance for female–male differences?
Authors: Graham Keith M. , Kim Haemin , Choi Yunkyeong , Eslami Zohreh R.
Published: November 2020

This study examines female–male differences in English writing outcomes for Taiwanese primary school learners
enrolled in a Content and Language Integrated Learning (CLIL) program. Narrative and expository writing samples of 212 primary
school students (Male = 103, Female = 109) in Taiwan were collected and scored using several measures including spelling accuracy,
correct word sequences, lexical diversity, total t-units, and a holistic rubric for ideas. Students’ topic interest was also
measured through a Likert-scale survey. The findings revealed differences between females and males and the two genres of writing.
While there were statistical differences attributed to gender and topic interest variables for some writing measures, further
analysis revealed that these effects were minimal in terms of practical significance. The paper raises questions about the
relationship between female–male writing differences and CLIL and provides suggestions for future research to broaden our
understanding and support diversity in the CLIL classroom.
Exploring the relationships between fundamental movement skills and health related fitness components in children
Authors: Behan Stephen , Belton Sarahjane , Peers Cameron , O'connor Noel E. , Issartel Johann
Published: November 2020

This study examined the relationship between fundamental movement skills (FMS) and health related fitness (HRF) components in children. A cross section of Irish primary school children across all age groups participated in this study (n=2098, 47% girls, age 5–12 years of age, mean age 9.2 ± 2.04). FMS were measured using the Test of Gross Motor Development (TGMD‐3), along with two additional assessments of vertical jump and balance. All HRF components were also assessed: body composition through BMI and waist circumference, muscular strength (MS) using a hand dynamometer, muscular endurance (ME) through the plank test, flexibility with back‐saver sit‐and‐reach, and cardiovascular endurance (CVE) using the 20 m PACER test. Hierarchal multiple regressions were used to measure associations between the HRF components and overall FMS and the FMS subtests: locomotor, object control and balance skills. Results show significant positive relationships between FMS and MS (R 2 = 0.25, β= −0.19), ME (R 2 = 0.11, β = 0.34), flexibility (R 2 = 0.13, β = 0.14) and CVE (R 2 = 0.17, β = 0.39), and an inverse relationship between FMS and body composition (R 2 = 0.25, β= −0.19). The data presented reinforces the position that the relationship between FMS and HRF is dynamic, and predominantly strengthens with age through the course of childhood. Findings suggest that developing FMS as a child may be important to developing HRF across childhood and into adolescence.
Deep synthesis network for regularizing inverse problems
Authors: Obmann Daniel , Schwab Johannes , Haltmeier Markus
Published: November 2020

Recently, a large number of efficient deep learning methods for solving inverse problems have been developed and show outstanding numerical performance. For these deep learning methods, however, a solid theoretical foundation in the form of reconstruction guarantees is missing. In contrast, for classical reconstruction methods, such as convex variational and frame-based regularization, theoretical convergence and convergence rate results are well established. In this paper, we introduce deep synthesis networks for regularizing inverse problems (DESYRE) using neural networks as nonlinear synthesis operator bridging the gap between these two worlds. The proposed method allows to exploit the deep learning benefits of being well adjustable to available training data and on the other hand comes with a solid mathematical foundation. We present a complete convergence analysis with convergence rates for the proposed deep synthesis regularization. We present a strategy for constructing a synthesis network as part of an analysis–synthesis sequence together with an appropriate training strategy. Numerical results show the plausibility of our approach.
Joint reconstruction of initial pressure distribution and spatial distribution of acoustic properties of elastic media with application to transcranial photoacoustic tomography
Authors: Poudel Joemini , Anastasio Mark A
Published: November 2020

Photoacoustic computed tomography (PACT) is an emerging computed imaging modality that exploits optical contrast and ultrasonic detection principles to form images of the photoacoustically induced initial pressure distribution within tissue. The PACT reconstruction problem corresponds to a time-domain inverse source problem, where the initial pressure distribution is recovered from the measurements recorded on an aperture outside the support of the source. A major challenge in transcranial PACT brain imaging is to compensate for aberrations in the measured acoustic data that are induced by propagation of the photoacoustic wavefields through the skull. To properly account for these effects, previously proposed image reconstruction methods for transcranial PACT require knowledge of the spatial distribution of the elastic parameters of the skull. However, estimating the spatial distribution of these parameters prior to the PACT experiment remains challenging. To circumvent this issue, in this work a method to jointly reconstruct the initial pressure distribution and a low-dimensional representation of the elastic parameters of the skull is developed and investigated. The joint reconstruction (JR) problem is solved by use of a proximal optimization method that allows constraints and non-smooth regularization terms. The proposed method is evaluated by use of large-scale three-dimensional (3D) computer-simulation studies that mimic transcranial PACT experiments.
Plasma dynamics at the preionization stage in discharge-based EUV lasers
Authors: Eliseev S , Timshina M , Samokhvalov A , Zhao Y , Burtsev V
Published: November 2020

In this paper we present the results of a detailed numerical investigation of plasma formed at the preionization stage of extreme ultraviolet (EUV) lasers based on nanosecond capillary discharges. Despite the general consensus that preliminary ionization is one of the features that have originally allowed creating stable and efficient lasers operated in argon-filled capillaries, little attention has been paid to the observed sensitivity of their performance to the properties of the preionizing current pulse. The goal of present studies was to obtain basic description of preliminary plasma state that could be used for interpretation of available experimental data on the subject. The numerical model was based on the hydrodynamic ‘fluid’ approach coupled with the heat transfer, the continuity and the Navier–Stokes equations. Preliminary discharge dynamics for conditions typical of an argon EUV laser is illustrated in detail, starting from the initial breakdown, taking the form of a fast ionization wave, to formation of a self-sustaining nonequilibrium plasma column. It is shown that a few microseconds after application of the prepulse a concave gas density profile is formed that can potentially be a factor influencing plasma compression and emission during the main stage of a capillary discharge.
Mixed temperature-dependent order parameters in the extended Hubbard model
Authors: Hutchinson Joel , Marsiglio Frank
Published: November 2020

The extended Hubbard model can host s-wave, d-wave and p-wave superconducting phases depending on the values of the on-site and nearest-neighbour interactions. Upon detailed examination of the free energy functional of the gap in this model, we show that these symmetries are often dependent on temperature. The critical points of this functional are constrained by symmetry and allow us to formulate stringent conditions on the temperature profile of the gap function, applicable to other models as well. We discuss the finite temperature phase diagram of the extended Hubbard model, and point out the existence of symmetry transitions below T
c. Understanding the nature of these transitions is crucial to assessing the symmetry of unconventional superconductors.
Molecular magnetism in the multi-configurational self-consistent field method
Authors: Georgiev M , Chamati H
Published: November 2020

We develop a structured theoretical framework used in our recent articles (2019 Eur. Phys. J. B
92 93 and 2020 Phys. Rev. B
101 094427) to characterize the unusual behavior of the magnetic spectrum, magnetization and magnetic susceptibility of the molecular magnet Ni4Mo12. The theoretical background is based on the molecular orbital theory in conjunction with the multi-configurational self-consistent field method and results in a post-Hartree–Fock scheme for constructing the corresponding energy spectrum. Furthermore, we construct a bilinear spin-like Hamiltonian involving discrete coupling parameters accounting for the relevant spectroscopic magnetic excitations, magnetization and magnetic susceptibility. The explicit expressions of the eigenenergies of the ensuing Hamiltonian are determined and the physical origin of broadening and splitting of experimentally observed peaks in the magnetic spectra is discussed. To demonstrate the efficiency of our method we compute the spectral properties of a spin-one magnetic dimer. The present approach may be applied to a variety of magnetic units based on transition metals and rare Earth elements.
Influence of nonlocal dielectric response on the Au tip-enhanced fluorescence effect
Authors: Pei Huan , Wei Yong , Dai Qiyuan
Published: November 2020

Tip-enhanced fluorescence (TEF) with ultra-high detection sensitivity and spatial resolution has been a powerful characterization technique in the study of surface science and life science. Herein, a systematically theoretical investigation in the visible range had been performed to study TEF properties of a single molecule located inside a nanogap formed by Au tip and substrate. In the strong localized surface plasmon coupling effect, the contribution of nonlocal dielectric response to the fluorescence quantum yield as well as radiative and energy dissipated decay rates were calculated. It is found that the nonlocal dielectric effects become comparable to the radiative and energy dissipated decay rates with the increasing of the tip-molecule distance, as a result, the nonlocal dielectric effect significantly suppresses the fluorescence process. The huge excitation enhancement at the shorter tip-molecule distance can efficiently compensate the low quantum yield, leading to the great fluorescence enhancement. The results show that the maximum enhancement obtained from the calculations can reach as high as four orders of magnitude by optimizing the tip-molecule distance. These results are not only helpful to our understanding of the TEF mechanism but also valuable for its further applications.
Meissner to ferromagnetic phase transition in La-decorated functionalized Nb2C MXene: an experimental and computational analysis
Authors: Fatheema Jameela , Khan Saleem Ayaz , Arif Nimrah , Iqbal Mudassir , Ullah Hamid , Rizwan Syed
Published: November 2020

This work reports experimental and computational magnetic phase transition from superconducting-diamagnet to ferromagnet in lanthanum (La)-doped functionalized Nb2C MXene. Co-precipitation method is used to synthesize La-doped Nb2C MXene. Structure and morphology of the compound are studied through x-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy and energy dispersion spectroscopy, confirming the successful doping of La while retaining the two-dimensional (2D) structure of MXene. The magnetic properties of doped sample are studied using field-cooled and zero-field-cooled curves as well as from magnetization (M) versus applied magnetic field (H) graphs. Contrary to the superconductivity-like diamagnetic behavior in pristine Nb2C MXene, the La-doped MXene converts the diamagnetism into the ferromagnetic (FM) phases at all temperatures. The ferromagnetism arises due to the pinning of magnetic spins pinned by Lanthanum itself. The computational analysis of pristine Nb2C MXene confirms its diamagnetic behavior and further clarifies the role of La and functional groups (O and F) in the reduction of diamagnetic behavior in La-doped Nb2C MXene while inducing FM nature. This work provides an interesting superconducting-diamagnetic to FM transition with a possibility of its implementation in 2D spintronics.
Development of self-powered bubble velocity sensor for gas–liquid two-phase flow based on triboelectric nanogenerator
Authors: Fan Chenxing , Wu Chuan , Wen Guojun , Wang Aiyan , Zhou Qing
Published: November 2020

Bubble velocity of gas–liquid two-phase flow in coalbed methane well is an key parameter for formulating coalbed methane drainage technology. In this paper, a self-powered bubble velocity sensor (GLT-TENG) of two-phase flow, which is composed of distributed copper electrodes and low-density polyethylene wrapped in an outer layer, is proposed and analyzed based on triboelectric nanogenerator. Test results show that the measurement range is 0–0.49 m s−1 with a measurement error less than 6% when the GLT-TENG is used to measure a single bubble, but the measurement errors are inversely proportional to the time interval (the ratio of distance to speed difference) between the two bubbles when the GLT-TENG is used to measure continuous bubbles, and the measurement accuracy can reach 100% when the bubble time interval is greater than 0.3 s. The maximum output can be achieved when the bubble velocity impulse is 6200 cm3 · cm s−1, that is, the maximum output voltage and current are 0.38 V and 6.3 nA, respectively, and the maximum output power is 0.64 pW when the external load is 50 MΩ. In addition, the temperature and pulverized coal tests show that GLT-TENG has a good signal-to-noise ratio in the coalbed methane well environment, which can meet the actual working conditions.
A reaction mechanism for vibrationally-cold low-pressure CO2 plasmas
Authors: Silva A F , Morillo-Candás A S , Tejero-del-Caz A , Alves L L , Guaitella O , Guerra V
Published: November 2020

The use of plasmas for CO2 utilization has been under investigation in recent years following a wave of environmental awareness. In this work, previously published experimental results on vibrationally cold CO2 plasmas are modelled to define a reaction mechanism, i.e. a set of reactions and rate coefficients validated against benchmark experiments. The model couples self-consistently the electron and heavy particle kinetics. In turn, the simulated results are validated against measurements taken in CO2 DC glow discharges in a relatively large range of experimental conditions: at pressures from 0.4 to 5 Torr, reduced electric fields ranging from 50 to 100 Td and gas flowing from 2 to 8 sccm. The model predicts the measured values of product formation (CO and O) as well as discharge power and electric field. After validation, a thorough analysis of the model’s results is presented, including: electron properties, species densities, power distribution into different excitation channels and main creation and destruction mechanisms of the main species. It is shown that, although vibrational populations are low, they have a significant effect on the electron properties and thus on the electric field and conversion. Moreover, the shape of the EEDF is significantly dependent on the dissociation degree. The role of electronically excited states on CO2 dissociation is also analyzed, showing that the first electronic excited state of CO can have a beneficial or detrimental effect in further producing CO and O in the discharge.
Analytical modeling and simulation of a multifunctional segmented lithium ion battery unimorph actuator
Authors: Gonzalez Cody , Ma Jun , Frecker Mary , Rahn Christopher
Published: November 2020

Lithium-ion batteries (LIBs) are able to achieve large deformation and high actuation force when using a unimorph configuration and a silicon composite anode. Distribution of charge to different segments allows for shape change with only small parasitic losses due to internal resistance. A unique attribute of LIB actuators are their ability to maintain actuation shape. The actuation mechanism also requires no power to be consumed to maintain the deformed shape. Segmenting the unimorph improves the customizability and allows for spatial variation of the unimorph parameters. Spatially varying the charge and thickness of the unimorph along the length improves the range of motion and complex shapes achievable by this design. Spatially varying the thickness of the unimorph specifically allows for improved blocked force and actuation force per volume. An analytical model is developed to predict several key actuator metrics. Free deflection is found for a variety of example cases. Blocked deflection and blocked force are also found using a novel modified equivalent end moment method. Actuation force is found using a combination of both the free deflection and blocked force equations herein developed. Euler–Bernoulli beam theory is used, including the effects of beam segmentation and curvature shortening. This model and a commercial finite element analysis simulation are compared and experimentally verified.
Nonequilibrium thermodynamics of turbulence and stochastic fluid systems
Authors: Wu Wei , Wang Jin
Published: November 2020

Fluid systems are found in the Universe at various scales. Turbulence as a complex form of fluid motion far from thermodynamic equilibrium remains one of the most challenging problems in physics. In this work, we study the nonequilibrium thermodynamics of stochastic fluid systems in general and turbulence in particular. Our approach is based on a reinterpretation of the stochastic fluid system as an interacting many-body system in contact with multiple heat baths. A set of nonequilibrium thermodynamic equations for general stochastic fluid systems, applicable to turbulence in the far-from-equilibrium regime, is constructed using the potential landscape and flux field theory. In addition to the energy and entropy balance equations that represent the first and second laws of thermodynamics, a new thermodynamic equation is found to be crucial for relating the first law with the second law and connecting violation of detailed balance to entropy flow and entropy production at the steady state. It is demonstrated that steady-state entropy production and energy flow are manifestations of the nonequilibrium irreversible nature of fluid systems characterized by the nonequilibrium trinity construct that originates from temperature nonuniformity. We propose an intuitive thermodynamic picture of the turbulence energy cascade process as heat conduction in the scale domain, where energy flow across scales is conducted by nonlinear convection and driven by the temperature difference between the large and small scales. Nonequilibrium irreversibility of turbulence energy cascade is quantified by the steady-state entropy production rate. This work is rooted in both fluid dynamics and nonequilibrium statistical physics, fostering a deeper level of communication between these fields. Further extensions of this work have the potential to grow into a more complete nonequilibrium statistical theory, with a much wider range of applications encompassing general physical, chemical and biological nonequilibrium systems.
Controlling multiple optomechanically induced transparency in the distant cavity-optomechanical system*
Authors: Xiao Rui-Jie , Pan Gui-Xia , Xiu Xiao-Ming
Published: November 2020

We theoretically investigate a two-cavity optomechanical system in which each optical cavity couples to a mechanical resonator via radiation pressure force, and the two optical cavities couple to each other via a distant waveguide. Our study shows that the multiple optomechanically induced transparency can be observed from the output field at the probe frequency. The number and width of the transparent windows can be tuned by the classical driving power Pl
. We also analyze the distance of the two outermost transparency windows, which shows a linear relation with the parameters Pl
and λ. Our approach is feasible for controlling multipartite induced transparency, which represents a valuable step towards quantum networks with photonic and phononic circuits.
Probing time delay of strong-field resonant above-threshold ionization*
Authors: Xu Shengliang , Zhang Qingbin , Ran Cheng , Huang Xiang , Cao Wei , Lu Peixiang
Published: November 2020

The high-resolution three-dimensional photoelectron momentum distributions via above-threshold ionization (ATI) of Xe atoms are measured in an intense near circularly polarized laser field using velocity map imaging and tomography reconstruction. Compared to the linearly polarized laser field, the employed near circularly polarized laser field imposes a more strict selection rule for the transition via resonant excitation, and therefore we can selectively enhance the resonant ATI through certain atomic Rydberg states. Our results show the self-reference ionization delay, which is determined from the difference between the measured streaking angles for nonadiabatic ATI via the 4f and 5f Rydberg states, is 45.6 as. Our method provides an accessible route to highlight the role of resonant transition between selected states, which will pave the way for fully understanding the ionization dynamics toward manipulating electron motion as well as reaction in an ultrafast time scale.
The Influence of Milling Ball Size on the Structural, Morphological and Catalytic Properties of Magnetite (Fe3O4) Nanoparticles toward Methylene Blue Degradation
Authors: Amiruddin Erwin , Awaluddin Amir , Hariani Innike , Sihombing Ribka , Angraini Riska
Published: November 2020

Structural, morphological properties and the catalytic activity of magnetite (Fe3O4) nanoparticles for degradation of methylene blue have been studied. The magnetite nanoparticles were synthesised from Padang beach sand West Sumatera by 2 steps ball milling method. Structures and morphologies of the synthesized magnetite nanoparticles were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was shown that the particle size of the magnetite nanoparticles can be controlled by milling ball size. The average grain size of magnetite particles milled for milling ball size of 0.7 cm and 1.5 cm was found to be 81.25 nm and 30.75 nm, respectively. Scanning electron microscopy (SEM) images show that the particle size of samples decreases as milling ball size increases and the grains exhibit irregular form. The effect of milling ball size on the degradation efficiency of catalytic reaction exhibited a good ability to degrade methylene blue from aqueous solutions with a maximum methylene blue removal rate of 86.79% for 10 hours reaction time.
The Physical and Electrochemical Properties of Activated Carbon Electrode Derived from Pineapple Leaf Waste for Supercapacitor Applications
Authors: Agustino  , Awitdrus  , Amri Amun , Taslim Rika , Taer Erman
Published: November 2020

This study aims to the physical and electrochemical properties of the supercapacitor carbon electrodes derived from pineapple leaf waste. The production of carbon electrodes was conducted using combinations of chemical activation, carbonization, and physical activation. The chemical activation was carried out using a 0.9 M KOH activator. The carbonization and physical activation were conducted using a one-step process. The PAL-AC electrode was obtained showed porosity in the mesoporous range, large pore volume, and high specific surface area. The surface morphology of the PAL-AC electrode is dominated by carbon and nanofibers particles. The nanofibers diameter based on the SEM micrograph is in the range of 44-137 nm. Elemental contents of the PAL-AC electrode are dominated by carbon and oxygen with an atomic percentage of 86.03% and 9.49%, respectively. The XRD pattern of the PAL-AC electrode shows the presence of two wide peaks at scattering angle of 23° and 45°. The specific capacitance of the PAL-AC electrode as high as 127 F g−1 in 6 M KOH electrolyte solution using two-electrode configuration. The pineapple leaf waste based-carbon electrodes show promising potential for use as supercapacitor electrodes.
Development of Interactive Learning Media Based on HOTS Material Temperature and Heat
Authors: Puspita Amelia Dwi , Islami Nur , Nasir Muhammad , Fakhruddin
Published: November 2020

Development of instructional media is very important in learning physics which requires high-level skills to master the concepts. The purpose of this study is to develop interactive multimedia based on HOTS on temperature and heat material. This media is made with Macromedia Flash 8 which consists of 4 main menus namely competence, material, training, and evaluation. This media features several creative animations related to temperature and heat material. The results of this development can be used as an alternative for students and teachers to understand the concepts of physics in fostering low to high level thinking
Anti-Reflecting Coating to Improve the Performance of Polycrystalline Photovoltaic Module
Authors: Putri Mella Septia , Wati Agustina , Rini Ari Sulistyo , Umar Lazuardi
Published: November 2020

Photovoltaic performance module (PV) is affected by surface temperature panel, which can reduce output efficiency represented by output power and internal parasitic resistance. Series resistance (Rs) and shunt resistance (Rsh) are needed to determine the characteristics and performance of PV modules for long-term operations. In this work, an anti-reflecting coating (AR layer) has been used to improve the efficiency of solar cells and to determine the stability of the parasitic resistance Rs and Rsh. A 10Watt Visero Polycrystalline PV module coated with AR layer is irradiated using direct sunlight, and using an artificial light of 500W halogen lamp at various temperature ranges from 30 °C to 60 °C. Rs and Rsh are determined based on the current-voltage curve using three parameters; short circuit current, open-circuit voltage, and the maximum power point generated for the Lambert-W calculation. Results show an increase of 11% output power using AR coated module, while the internal resistance Rs increases for 13% and Rsh decreases by 0.54%. For non-coated PV, Rs increased significantly for 165% and Rsh decreased by 7.4%. Furthermore, the temperature also affects the open-circuit voltage for 8.6% lower and increase the output power for 6.7%. The results show the series Rs and shunt resistance Rsh values depend on the PV module temperature.
Test on Several Concentrations Metarhizium anisopliae (Metsch) Sorokin in Palm oil Empty Fruit Bunch Compost (metankos) to Infecting Oryctes Rhinoceros Larvae.
Authors: Fauzana Hafiz , Arda Febriliani , Nelvia  , Rustam Rusli , puspita Fifi
Published: November 2020

Oil palm is a very important plant because it is one of the world's vegetable oil producing plants. Oryctes rhinoceros is one of the important pests that attack oil palm plants. The recommended control of Oryctes rhinoceros is used integrate pest control, one of which can use the biological agent of the fungus Metarhizium anisopliae. The composition of oil palm empty fruit bunches can be a medium rich in organic matter for the breeding of Fungus Metarhizium anisopliae. This research aims to study the best concentration of Metarhizium anisopliae in oil palm empty fruit bunch compost (metankos) to infect Oryctes rhinoceros larvae. This research was conducted in Laboratory of Plant Pests, Faculty of Agriculture, University of Riau, from April to October 2019. This study is experimental with Complete Randomized Design with 6 treatments and 5 replications. The treatment of Metarhizium anisopliae concentration on metankos consisted of : 0 g.l−1, 10 g.l−1, 20 g.l−1, 30 g.l−1, 40 g.l−1, and 50 g.l−1
Metarhizium anisopliae. The results show is concentration of Metarhizium anisopliae 50 g.l−1 water with a total mortality of 56% larvae.
Antioxidant activity of an Epiphyte Fern in Palm Oil Tree
Authors: Hendra Rudi , Gurning Siska Novalina , Norwahyuni  , Panjaitan Uci Putri Ayunda , Teruna Hilwan Yuda
Published: November 2020

Vitaria elongata is an epiphytic plant in the Pteridaceae family, which usually grows on palms and wetlands. Other species of this genus have been reported to have cytotoxic and antioxidant activity, but their biological activity was not reported in this species. Therefore, the research aimed at antioxidant activity from V. elongata extracts. The extract of methanol was obtained by maceration (3 x 24 h). The sample was subsequently brought with partition containing various organic solvents (n-hexane, dichloromethane and ethyl acetate). The n-hexane, dichloromethane, ethylacetate, and water extracts tested for antioxidant activity were performed using 1.1-diphenyl-2-picrylhidrazil (DPPH) methods. The IC50 value of dichloromethan, ethyl acetate and water extract was 472,35 μg / mL, 94,72 μg / mL, and 13,63 μg / mL, while there was no antioxidant activity of the n-hexane extract and component VE-DCM-01, IC50 > 1,00 μg / mL.
Antidiabetic Activity of Some Extracts from Anisophyllea disticha Leaves
Authors: Almurdani Muhammad , Fikriyah Miftahul , Zamri Adel , Nugroho Titania T. , Jasril Jasril , Eryanti Yum , Teruna Hilwan Yuda
Published: November 2020

Anisophyllea disticha has been being used as a traditional medicine by Talang Mamak tribe in Indragiri Hulu district, Riau province, Indonesia. The aim of this study was to evaluate antidiabetic properties of A.disticha leaves. The methanol extract was obtained by maceration, followed by successive partition process and yielded n-hexane, dichloromethane, and ethyl acetate fractions. Antidiabetic activity was determined by inhibiting the α-glucosidase activity method. The methanol extract showed high antidibetic activity followed by ethyl acetate fraction with IC50 value of 47.765 ± 0.127 and 50.883 ± 0.803 μg/mL, respectively. It could be concluded that leaves of A.disticha had antidiabetic properties.
Developing an Interactive Chemistry E-Module for Salt Hydrolysis Material to Face the Covid-19 Pandemic
Authors: Mazidah  , Erna Maria , Anwar Lenny
Published: November 2020

This study aimed to develop an interactive chemistry e-module for learning chemistry for salt hydrolysis material at senior high school (SMA/MA). The research method utilized in this study was Research and Development (R&D) by using Plomp model. This study was divided into three phases: (a) preliminary research phase; (b) the development or prototype phase; and (c) assessment phase. E-module product was developed by using Kvisoft flipbook maker application. The results of this study revealed that the chemical e-module for salt hydrolysis material was declared to be very valid. The analysis results of the responses from teachers and students showed that e-module for salt hydrolysis material included in the criteria of attractive and this e-module received positive responses from teachers and students. This implies that this interactive e-module product is recommended to be used for online chemistry learning for salt hydrolysis material during the period of Covid-19 pandemic.
Validity and Reliability of Assessment Instruments for Analytical Thinking Ability and Chemical Literacy in the Colligative Properties
Authors: Yandriani  , Rery R U , Erna Maria
Published: November 2020

This study aimed to develop and determine the construct validity, reliability, and items analysis of the instruments for assessing analytical thinking abilities and chemical literacy in the colligative properties materials. This study was a research and development (R&D) utilizing the ADDIE model. The subjects of this study were 30 students of class XII at senior high school (SMA) in Bengkalis. The results revealed that of the 15 items on the analytical thinking skills and chemical literacy, 10 items had good construct validity and had very high reliability test values, with the Cronbach alpha of 0.887. The results of item analysis of the instrument which was developed for assessing the analytical thinking skills and chemical literacy showed that for the difficulty indices, 80% of the items were classified as moderate items and 20% of them were classified as easy items. Then, the analysis results for the discrimination indices revealed that 80% of the items were good while 20% of the items were categorized as satisfactory. In addition, based on the analysis of construct validity, reliability, and items analysis, the assessment instrument for analytical thinking ability and chemical literacy was valid and feasible to be used to measure the students’ analytical thinking skills and chemical literacy on the material of colligative properties on a broad scale test.
An Analysis and Design of Web-Based Learning GoProfTeach as Interactive Learning Tools
Authors: Suryawati E , Rahmi F O , Rizki M , Arnan R H
Published: November 2020

This study aims to analyze the need for:1) analyzing resources availability 2) analysing the TPACK (Technological, Pedagogical, and Content Knowledge) profile of preservice biology teachers 3) designing GoProfTeach as a web-based learning tool for in-service and pre-service teachers. In doing so, it followed ADDIE development model. The instrument for data collection was a validated TPACK test. This article, in particular, discusses the results of the study in the first year of the analysis and design phase. The instrument for data collection included documents checking sheets, questions validation sheets and a Technological Pedagogical Content Knowledge (TPACK) test. The results of resources availability analysis and TPACK tests indicate that there is a need for the development of web-based learning resources as a means of increasing the ability of TPACK of pre-service and high school Biology teachers. The contents that have been designed include; 4 sets of practice exercises, 4 modules, and 2 virtual lab topics. Following the research findings, the website contents will be further developed to make sure that they be used as an independent and interactive learning source for undergraduate students and pre-service Biology teachers who will take the Teacher Professional Education Program (PPG) and PPG Student Competency Test.
Characteristics of CPS-Based Assessment Instrument for Critical Thinking Ability in Stoichiometry
Authors: Agustini  , Rery Usman , Anwar Lenny
Published: November 2020

The purpose of this study was to determine the characteristics (validity, reliability, difficulty indices and discrimination indices) of the items in the developed assessment instruments. Subjects in the study were 30 students of class X Science 1 SMA Negeri 2 Bantan. The samples in this study were chosen by purposive sampling technique, in which the samples were selected based on the researchers’ consideration. Then, the approach used to develop the assessment instrument was Research and Development (R&D) adapting Borg & Gall Model. In this study, the feasibility test was carried out to see the construct validity, reliability, difficulty indices, and discrimination indices of the instrument. The CPS-based assessment instrument for critical thinking ability on Stoichiometry was developed in the form of essay questions. This instrument produced 10 items that were declared valid and reliable with a reliability value of 0.749. Thus, this study concluded that CPS-based assessment instrument for critical thinking ability provided more comprehensive information about the characteristics of the instruments that have been developed.
The Development of Schoology as Media to Supporting Blended Learning on Stoichiometry Topic
Authors: Linda Roza , Anggraini Citra , Abdullah
Published: November 2020

This study aims to develop Schoology media as a support for Blended Learning on the subject of Stoichiometry. This research used a Research and Development (R&D) design with the Plomp model. The Plomp models have four steps faces (investigation, Design, construction and validation). The data was collected used an instruments in the form of validation sheets given to four validators and response sheets to two chemistry subject teachers and 20 students in Senior High school. The data was analyzed by calculating the percentage of the validation score and the user's response. The results obtained that the Schoology learning media are valid with an average score 93.98%, while, the teachers responded when they used the media learning was very good with the percentage of response scores 94.32% and the average student response score of 85.15 %. Based on the results of the study, it can be concluded that the Schoology media as a support for Blended Learning on the subject of developed stoichiometry is declared valid.
Readiness in Teaching Science: Early Childhood Education Teacher’s Online Experience
Authors: Novianti Ria , Puspitasari Enda , Solfiah Yeni , Febrialismanto  , Maria Ilga , Garzia Meyke
Published: November 2020

This research provides an overview of early childhood education teacher’s readiness in teaching science online during Covid-19 pandemic. This research uses descriptive quantitative method with 159 early childhood education teachers as the subject. Questionnaire designed based on holistic model of learning readiness that consist of three indicators, emotive-attitudinal readiness, cognitive readiness, and behavior readiness. The sampling technique used is simple random sampling. Data analysis techniques are present in a percentage form. The overall of early childhood education teacher’ readiness in designing science online learning in ready category.
Application of Soil Resistivity Testing using Geoelectrical Method For Landslide Identification
Authors: Ervianto Edy , Marpaung Noveri Lysbetti , Amri Rahyul , Azzmi Amirul Latief
Published: November 2020

Vulnerable area is an area whereas landslide materials move. One of avalanche causes is slip surface or shear surface. Geoelectrical Method is measuring potential different of voltage and current caused with electrical current injection into ground through a pair of current electrodes. Potential different is measured through a pair of potential electrodes.This study aims to calculate Resistivity-Values from underground soil layer, so it is used to get soil resistivity map and determine whether an area/road is susceptible for landslide by using Dipole-Dipole Configuration in Geoelectrical Method and Res2Dinv-Software. This research is conducted in Muara Lembu Village, Riau Province as far as 80 meters from both sides of road. Each value of Soil Resistivity can be represented with certain colour of Natural Material. Resistivity-Values from Top Soil at 0.854m–4.62m depths upto Lowest Layer at 11.8m–17.9m depths are smaller. Resistivity-Value from Trajectory-I Top Soil is H>328.5Ωm, whereas A<15.85Ωm Lowest Soil Layer, whereas Trajectory-II Top Soil is H>350.5Ωm and A<21.05Ωm Lowest Layer. Resistivity-Values from both sides of road can be different but Natural Material form them are same. As conclusion, Top Layer upto Lowest Layer of Trajectory-I and Trajectory-II are in Middle-Conductor Range, means these areas are susceptible for landslide.
Simulating of Microbial Growth Scale Up in a Stirred Tank Bioreactor for Aerobic Processes using Computational Fluid Dynamics
Authors: Hernandez S , Niño L , Gelves G
Published: November 2020

In this paper, the effects of some empirical scale up criteria (Reynold's number and Impeller power per bioreactor volume) on gas-liquid mass transfer and microbial growth rates are analyzed using computational fluid dynamics simulations in a stirred tank bioreactor. The effects of turbulence, fluid flow and bubbles dynamics were simulated by using a two equation turbulence model, a multiple reference frame and a population balance, respectively. The impeller power per bioreactor volume scale up criterion showed better microbial growth rates than Reynold's number scale up criterion. However, high cellular damage due to turbulence in animal cell culturing are still challenges in large scale up bioreactor prototyping.
Tempeh Extract Protects HepG2 Cells Against Oxidative Stress-Induced Cell Death
Authors: Surya Reggie , Romulo Andreas
Published: November 2020

Tempeh is an Indonesian fermented traditional food made from soybeans inoculated withRhizopus oryzaeand/orRhizopus oligosporus.It exerts antioxidant activities mainly due to the presence of bioactive compounds known as isoflavones. We previously observed that tempeh ethanol extract increased the basal expression of some cellular antioxidant enzymes including catalase and superoxide dismutases in HepG2 cellsin vitro.In this study, we showed that pretreament with tempeh extract protected HepG2 cells from oxidative stress triggered by TBHP (tert-butyl hydroperoxide) by reducing cellular ROS (reactive oxygen species) generation, TBARS (thiobarbituric acid reactive species) levels, caspase-3 activity and eventually cell death. We hypothesize that the resistance of cells pretreated with tempeh extract towards the toxicity of TBHP was in part due to the upregulation of cellular antioxidant enzymes. Taken together, our findings highlight the antioxidative potentials of tempeh, particularly in an attempt to develop tempeh as a functional food offering health-related benefits to humans.