bluuebunny/crossref_metadata_2025 huggingface dataset:
Superconductor-ferromagnet hybrids for non-reciprocal electronics and detectors
Authors: Geng Zhuoran , Hijano Alberto , Ilić Stefan , Ilyn Maxim , Maasilta Ilari , Monfardini Alessandro , Spies Maria , Strambini Elia , Virtanen Pauli , Calvo Martino , González-Orellána Carmen , Helenius Ari P , Khorshidian Sara , de Araujo Clodoaldo I Levartoski , Levy-Bertrand Florence , Rogero Celia , Giazotto Francesco , Bergeret F Sebastián , Heikkilä Tero T
Published: October 2023

We review the use of hybrid thin films composed of superconductors and ferromagnets for creating non-reciprocal electronic components and self-biased detectors of electromagnetic radiation. We begin by introducing the theory behind these effects, as well as discussing various potential materials that can be used in the fabrication of these components. We then proceed with a detailed discussion on the fabrication and characterization of Al/EuS/Cu and EuS/Al/Co-based detectors, along with their noise analysis. Additionally, we suggest some approaches for multiplexing such self-biased detectors.
Noise suppression by differential detection of simultaneous electromagnetically induced transparency and absorption in counterpropagating bichromatic light
Authors: Li Qinglin , Yun Peter , Yang Tenghui , Hao Qiang , Zhang Shougang , Gu Sihong
Published: October 2023

Well-established electromagnetically induced transparency (EIT) and absorption (EIA) have been applied to various applications including quantum computing, light storage, and precision measurement. Here, we propose and implement a differential detection scheme based on coexisting EIT and EIA signals in a double-Λ system with counterpropagating bichromatic laser fields, in which a differential coherent population trapping (diff-CPT) signal is extracted with a desired enhanced amplitude and highly suppressed common-mode noise. Compared to that of either EIT or EIA, the observed signal-to-noise ratio of the proposed method’s diff-CPT signal improved by one order of magnitude, which would benefit the implementation of high-performance CPT clocks. This technique may also be applied to magnetometers and precision spectroscopy.
Semiclassical theory of frequency combs generated by parametric modulation of optical microresonators
Authors: Sumetsky M
Published: October 2023

An optical microresonator, which parameters are periodically modulated in time, can generate optical frequency comb (OFC) spectral resonances equally spaced by the modulation frequency. Significant recent progress in realization of OFC generators based on the modulation of microresonator parameters boosted interest to their further experimental development and theoretical understanding of underlying phenomena. However, most of theoretical approaches developed to date were based on the lumped parameter models which unable to evaluate, analyse, and optimize the effect of spatial distribution of modulation inside microresonators. Here we develop the multi-quantum semiclassical theory of parametrically excited OFCs which solves these problems. As an application, we compare OFCs which are resonantly or adiabatically excited in a racetrack microresonator (RTM) and a Surface Nanoscale Axial Photonics (SNAP) bottle microresonator (SBM). The principal difference between these two types of microresonators consists in much slower propagation speed of whispering gallery modes along the SBM axis compared to the speed of modes propagating along the RTM waveguide axis. We show that, due to this difference, similar OFCs can be generated by an SBM with a much smaller size compared to that of the RTM. Based on the developed theory, we analytically express the OFC spectrum of microresonators through the spatial distribution of modulated parameters and optimize this distribution to arrive at the strongest OFCs generated with minimum power consumption.
Gauss-Bonnet Dark Energy and the speed of gravitational waves
Authors: Terente Díaz José Jaime , Dimopoulos Konstantinos , Karčiauskas Mindaugas , Racioppi Antonio
Published: October 2023

Gauss-Bonnet Dark Energy has been a popular model to explain
the accelerated expansion of the Universe. Quite generically it also
predicts the speed of gravitational waves c
GW to be different
from the speed of light. This fact alone led some authors to exclude
such models in view of the new tight observational constraints on
c
GW. However, the behaviour of c
GW depends on the choice of
the Gauss-Bonnet (GB) coupling function. It is possible to construct
models where c
GW is always equal to the speed of light. More generally,
c
GW is a time dependent function with instances where both speeds
coincide. Nevertheless, we observe that the bound on c
GW excludes
scenarios where the GB term directly affects the expansion of the
Universe, even if the constraint on the variation of the coupling
function does not appear to be strong. We perform the dynamical systems
analysis to see if the expansion of the Universe could be affected
indirectly by modulating the behaviour of the scalar field, which
modulates the GB coupling. It is shown that either the bounds on c
GW
are violated by many orders of magnitude, or it might be very difficult
to find models that are consistent with other cosmological observations.
Harvesting energy driven by Comisso-Asenjo process from Kerr-MOG black holes
Authors: Khodadi Mohsen , Mota David F. , Sheykhi Ahmad
Published: October 2023

Magnetic reconnection is a process that plays a critical role in
plasma astrophysics by converting magnetic energy into plasma
particle energy. Recently, Comisso and Asenjo demonstrated that
rapid magnetic reconnection within a black hole's ergosphere can
efficiently extract energy from a rotating black hole. In this
paper, by considering a Kerr black hole in the MOdified gravity
(MOG) framework, we investigate the impact of the MOG parameter
α on the rotational energy extraction via the
Comisso-Asenjo process (CAP). To model energy extraction from supermassive black holes located in the center of galaxies, we set the value of α within the range inferred from the recent observation of Sgr A* by the Event Horizon Telescope (EHT). Our
results indicate that the Kerr-MOG black hole is a more efficient
host for CAP-based rotational energy extraction compared to the
Kerr black hole, since it amplifies the power of energy extraction
and efficiency of the plasma energization process. We show that,
from the energy extraction viewpoint, the CAP is more efficient
than the Blandford-Znajek process (BZP). The latter is another
magnetic field-based energy extraction model which is widely
believed to be an engine for powering the high-energy
astrophysics jets emerging from the supermassive black holes at
active galactic nuclei. In particular, we show that the ratio of
the energy extraction power of CAP to BZP in the presence of the
MOG parameter is greater than that of the Kerr black hole. Our
results promise this phenomenological message that the
MOG-induced correction on the Kerr black hole background plays an
important role in favor of energy extraction via the CAP.
Formation of trapped vacuum bubbles during inflation, and consequences for PBH scenarios
Authors: Escrivà Albert , Atal Vicente , Garriga Jaume
Published: October 2023

A class of inflationary scenarios for primordial black hole (PBH) formation include a small barrier in the slope of the potential. There, the inflaton slows down, generating an enhancement of primordial perturbations. Moreover, the background solution overcomes the barrier at a very low speed, and large backward quantum fluctuations can prevent certain regions from overshooting the barrier. This leads to localized bubbles where the field remains “trapped” behind the barrier. In such models, therefore, we have two distinct channels for PBH production: the standard adiabatic density perturbation channel and the bubble channel. Here, we perform numerical simulations of bubble formation, addressing the issues of initial conditions, critical amplitude and bubble expansion. Further, we explore the scaling behaviour of the co-moving size of bubbles with the initial amplitude of the field fluctuation. We find that for small to moderate non-Gaussianity f
NL ≲ 2.6, the threshold for the formation of vacuum bubbles agrees with previous analytical estimates [1] to 5% accuracy or so. We also show that the mass distribution for the two channels is different, leading to a slightly broader range of PBH masses when both contributions are comparable. The bubble channel is subdominant for small f
NL, and becomes dominant for f
NL ≳ 2.6. We find that the mass of PBHs in the bubble channel is determined by an adiabatic overdensity surrounding the bubble at the end of inflation. Remarkably, the profile of this overdensity turns out to be of type-II. This represents a first clear example showing that overdensities of type-II can be dominant in comparison with the standard type-I. We also comment on exponential tails and on the fact that in models with local type non-Gaussianity (such as the one considered here), the occurrence of alternative channels can easily be inferred from unitarity considerations.
Dam UAV Image Stitching Technology Studies Based on Weak Texture
Authors: Liu Si Min , Zhou Shuai , Jiang Kun Hong , Li Xiang , Peng Zhang Jun , Liu Zhi Gui , Li Li
Published: October 2023

Extraction of image feature point pairs is an important step in the image alignment process. In this paper, we propose a grid-based adaptive threshold feature detection method for weakly textured images using a single threshold extraction algorithm that cannot propose uniformly distributed feature points. Finally, the designed experiments show that the feature points extracted by this method have a lower dispersion than the traditional KAZE algorithm by 70% and a higher alignment accuracy than the traditional KAZE algorithm by 10%.
High-resolution remote sensing image land cover classification based on EAR-HRNetV2
Authors: Zhu Wanling , Jia Yuan
Published: October 2023

The application of land cover classification is very extensive, it can be used in land resources management, urban planning, agricultural and other fields. The multi-scale variation of targets in high-resolution remote sensing images leads to low accuracy in land cover classification tasks. In response to this problem, an improved semantic segmentation model named EAR-HRNetV2 is proposed based on HRNetV2. Firstly, the attention mechanism is added to the Bottleneck residual and Basic residual modules to obtain more efficient features. Then, the atrous spatial pyramid pooling is added to the model. And it is modified to cope with the gridding issue caused by the dilation convolution. Finally, the refinement module is used to combine features from different stages and further extract semantic features. The experiments show that on the WHDLD public dataset, compared with five semantic segmentation models, the EAR-HRNetV2 model is effective with Kappa coefficient, F1-score, overall accuracy, and mean intersection over union reaching 77.85%, 73.00%, 87.92%, and 60.28%. Compared with HRNetV2, the mean intersection over union of EAR-HRNet increases by 2.93 percentage points, the F1-score increases by 2.67 percentage points, the Kappa coefficient increases by 2.37 percentage points, and the overall accuracy increases by 1.19 percentage points. EAR-HRNetV2 network provides a feasible solution for the land cover classification.
A network traffic identification method based on AutoEncoder - a feature selection algorithm
Authors: Yang Tao , Jiang Rui , Deng HongLi , Tang XiaoMei
Published: October 2023

Traffic identification methods consider a large number of traffic features, resulting in low identification efficiency. To address the efficiency problem of traffic recognition, this paper proposes an efficient network traffic recognition method, AutoEncoder-based traffic recognition (AE-NTI). The method first preprocesses the original dataset and converts it into a two-dimensional grayscale image. Then, feature selection is performed by an improved feature selection algorithm based on AutoEncoder. The algorithm consists of a feature scorer, which globally scores all features, and a feature selector, which selects the highest scoring features to reconstruct the original data. Finally, the convolutional neural network structure is adjusted so that the network traffic can be identified. The experimental results show that the method has significantly improved in recognition accuracy and model fitting speed.
Nozzle diameter and expansion ratio of compressed air foam system
Authors: Farida F M , Kusumohadi C S , Fikri M F
Published: October 2023

Variations of nozzles are studied for Compressed Air Foam Systems (CAFS). The CAFS is a self-contained fire suppression system with the capability of injecting compressed air into the foam solution to create a dense mist. Even though this type of foam has a tighter, denser bubble structure that allows it to adhere to vertical and horizontal surfaces and penetrate the fire more deeply before the bubbles burst, thereby making it more effective, the nozzle of CAFS is weak. The experimental study has been done in order to find the expansion ratio of the nozzle. Four sizes of diameter nozzles are 5 mm, 10 mm, and 20 mm, and three holes are 20 mm. Nozzle diameter size has a correlation with bubble size. The highest expansion ratio is found in the nozzle with three holes 20 mm in diameter. It is followed by a nozzle with a 20 mm diameter, then a 10 mm diameter. The last finding is a nozzle with five diameters. The other founding is the linear correlation between nozzle diameter size and bubble size. But it is on the other way than the correlation between nozzle diameter and bubble size. The shorter the nozzle diameter, the faster the fire extinguishing time.
Comparison of phenol formaldehyde with polyvinyl chloride resin as binder bonded NdFeB magnet for axial flux generator
Authors: Sudrajat N , Dedi D , Rusmana A
Published: October 2023

Bonded permanent magnets are made by mixing a magnetic powder material Neodymium Iron Boron (NdFeB) commercial MQP type 16-7 with a polymer material powders phenol formaldehyde (Bakelite) and polyvinyl chloride (PVC) resin. Comparison between the composition of NdFeB powder and the polymer powders were varied at 80:20, 90:10, and 95:5 wt%, respectively. This mixture is then pressed with a hot press system and then carried out magnetic alignment axial flux using a magnetizer machine, Magnet Phisyk-Germany, with an impulse system. Magnetic properties were characterized by permagraph Magnet Phisyk-Germany. The best value obtained for the composition of 95: 5% NdFeB-pvc resin powder to the value of remanence magnet (Br) = 0.604 Tesla (T), the value of coercivity (Hc) = 480 kA/m and maximum energy product (BH)max = 50.05 kJ/m3. Fabrication is done by the size of the magnetic 50 mm diameter, 8 mm thick and was applied to the axial flux generator. The output voltage of the generator has been tested with variations of 50 to 300 rotations per minute (rpm) using a Hantek 6022BE oscilloscope, and the measurement results obtained values of 1.9 to 12.2 Volts.
Simulation of temperature distribution in 3D printing heated chamber on orientation and temperature variations with ABS material
Authors: Kholil A , Syaefudin E A , Juniar A , Rohim M K , Dwiyati S T
Published: October 2023

Currently, the use of 3D printing is growing rapidly. Uneven temperature distribution in the printing chamber causes problems such as warpage, shrinkage, geometric accuracy, and decreased mechanical properties. The proper environmental temperature is needed to produce a good part. The heated chamber is needed to regulate the temperature during the printing process. Simulation of CFD is carried out, knowing the temperature distribution inside the heated chamber. Simulations and experiments were carried out with variations in temperature of 70 °C, 80 °C, 90 °C, and 100 °C with an airflow rate of 3 m/s. The correlation of temperature distribution in a chamber between simulation and experiment was investigated. Experiments on FDM 3D Printing with 70 × 30 × 30 mm3 ABS material dimensions. Meanwhile, variations in printing orientation on the x, y, and z-axes. The results show a fit correlation between simulation and experiment. The temperature in a heated chamber has increased and the temperature distribution is even during the printing process, along with increasing temperature variations from the heater. The heat flux distribution shows different temperature variations in each part build orientation. Therefore, the orientation and temperature rise of the chamber play a pivotal role in quality.
Nickel layers properties produced by electroplating were influenced by spinning permanent magnet
Authors: Syamsuir S , Susetyo F B , Soegijono B , Yudanto S D , Basori  , Nanto D
Published: October 2023

A spinning magnet is an alternative engineering approach to produce the Ni layer. In the present research, the Ni layer was plated on Cu alloy substrates influenced by a spinning magnet. Various rotating speeds (0, 500, and 800 rpm) were used to influence the Ni layer’s properties were formed. A digital scale was used to measure the deposition rate and cathodic current efficiency. XRD, SEM-EDS, potentiostat, and hardness tests were performed to determine the properties of the Ni layers. A rotating magnetic field can reduce the deposition rate and cathodic current efficiency by reducing the ionic movement from the anode to the cathode. The XRD and SEM results revealed a distinct crystallite size and surface morphology. Exhibiting a spinning could result in a decrease in oxygen in the Ni layer and a slight change in the corrosion rates. Different hardness is also seen in the various sample due to crystallite size.
Effect of temperature on the creep properties of polycrystalline Cu-Ni alloy: insight from molecular dynamics simulation
Authors: Ekardi M L , Zaenudin M , Saleh Y K P , Hidayat N C , Gamayel A , Mulyana F , Mohammed M N
Published: October 2023

Creep is a phenomenon where a particular material tends to deform due to highly subjected parameters, such as temperature and pressure. This deformation is promoted by the diffusion of the material across the grain boundary, as critically assessed by Coble in 1963. This phenomenon is primarily crucial since the most critical application of materials is subjected to high temperature and pressure. This study intends to assess the effect of temperature of polycrystalline Cu-Ni alloy by utilizing molecular dynamics simulation. The simulation is run with different temperatures, thus allowing studying the critical differences between the applied parameters. The results show that the temperature affects the creep rate at every creep stage, primary and secondary, by a significant value. This is due to the deformation promoted by the diffusion of atoms across the grain boundary, decreasing the crystallinity of polycrystalline Cu-Ni alloy. Although the effect of temperature on the creep mechanism of polycrystalline Cu-Ni alloy seems straightforward, it is necessary to assess whether it increases the creep rate at a low temperature in further detail.
Synthesis and microwave absorption properties of Ca-substituted barium hexaferrite nano-crystalline synthesized via ceramic and mechanical milling method
Authors: Handoko E , Aulia T B , Marpaung M A , Taufiq A , Iriani Y , Umaisaroh U , Alaydrus M
Published: October 2023

To broaden the scope of a novel microwave absorbing material inside the x-band frequency range (8.2–12.4 GHz), Ca-substituted barium hexaferrite nano-crystalline were successfully synthesized prepared via standard ceramic route and mechanical milling method. The sintered BaFe12O19 (x=0) and Ba0.9Ca0.1Fe12O19 (x=1) at 1100°C for three hours were obtained the formation of magnetic phase and hysteresis behaviour and indicative of ferromagnetism. The analysis of x-ray diffraction was resulted to investigate the composition and magnetic phase. The dependence of complex permeability on frequency (μ = μ′ – jμ″) and the permittivity (ε = ε′ – jε″) were obtained. The reflection loss, RL-values were calculated and resulted multi–broadband with a thickness of 9.7 mm. It proved that Ca-substituted barium hexaferrite nano-crystalline material has a great potential for microwave absorption and electromagnetic applications.
Implementation of active noise cancelling for sound isolation box
Authors: Putri C C , Hermawanto D , Prajitno P
Published: October 2023

A quiet room is essential for acoustical instrument calibration, such as the sound level meter. A small acoustic chamber can be utilized to create an environment that is free from noise. Commonly, it is built with a passive noise-blocking system using high-density absorber material such as rock wool or glass wool. However, this approach results in a room that is both heavy and costly. This paper proposes a mini acoustic chamber that utilizes an active noise cancelling (ANC) system to block the noise. A filtered-x least mean square (FxLMS) algorithm was implemented for the ANC system. A simulation of the system with the recorded actual noise data was conducted to find the optimum filter parameter. The results show that the ANC system could reduce the noise up to 2 dB for certain types of noises. The sound outside the chamber was recorded and processed offline to tune the filter parameter. Evaluation of the effectiveness of the proposed noise reduction system was performed by measuring the sound inside the chamber.
Prediction of organic molecular optical absorption energy based on deep learning using mordred descriptor features
Authors: Suhendar H , Windiyanti A , Asriani A
Published: October 2023

Organic molecules have several characteristics based on optical absorption. A molecule absorbs a specific light wavelength that represents electronic energy in the material. The absorption wavelength is also related to atomic binding of molecules that interact with material during light exposure producing electronic instability in the material. Molecular absorption can be measured using several optical spectrometer configurations that contain a light source, optical path, and light detector. The measurements of molecular optical absorption have been reported in several research and have been collected into a material database. In this paper, we developed a model for predicting organic molecular optical absorption using deep learning. The model can predict molecular absorption energy based on extracted features of molecular structure using Mordred descriptor features extraction. Our model used 1625 molecules of absorption in several solvent datasets that split into 80% training and 20% testing dataset. The result show that our model has a good agreement with experimental data with correlation coefficient 0.96 and mean average error 0.172 eV.
The Power-Normalized Cepstral Coefficient (PNCC) for convolutional neural networks-based robust speech command recognition
Authors: Iswanto B H , Hafizhahullah H , Pardede H F , Zahra A
Published: October 2023

While implementations of speech recognition grow rapidly in recent years and are slowly being integrated into our daily devices, the problem of noise robustness is still a challenging task, even with the recent advancement of deep learning technologies for speech recognition. The presence of noise may cause a mismatch between training, which is performed in clean conditions, and noisy testing conditions. This paper proposes a method to extract features for speech recognition by employing features derived under the power law scale, i.e., the Power-Normalized Cepstral Coefficient (PNCC). The power-law can provide better compression in low-energy regions so that it is not sensitive when the speech signal is distorted by noise. The features are implemented on speech recognition based on Convolutional Neural Networks (CNNs). The experiments were carried out by TensorFlow’s Speech Command Dataset mixed with various signal-to-noise ratio to evaluate the method. The experimental findings indicate that the accuracy ranges from 81% to 86%.
The effect of Coulomb repulsion on Seebeck coefficient of NiCl2 monolayer
Authors: Prayitno T B , Sarwono Y P , Budi E , Riyanto F A , Jaelani A
Published: October 2023

The Seebeck effect of NiCl2 has been explored by using first-principles calculations under the LDA+U to include the Coulomb repulsion. The exploration was conducted for two cases, namely, close to the critical temperature and room temperature. We found the slight difference of the peaks of Seebeck coefficients, i.e., the highest peak has been observed near the critical temperature. As the Coulomb repulsion was considered, the peak was shifted both two cases. It suggested that the Seebeck effect was influenced by the Coulomb repulsion.
Investigation on Seebeck coefficient of FeCl2 monolayer with LDA+U approach
Authors: Prayitno T B , Sarwono Y P , Abdillah M A , Kartika M C
Published: October 2023

Implementation of LDA+U approach has been employed to investigate the Seebeck effect of FeCl2 monolayer. The calculation was carried out by keeping the out of plane magnetism in the primitive cell. After obtaining the convergence calculation, we then used the semi classical Boltzmann transport to calculate the Seebeck coefficient. To see the effect of magnetism, we plotted two Seebeck coefficients near the critical temperature and room temperature. The peak of Seebeck coefficient near the critical temperature was higher than that at room temperature. This implies the magnetism may influence the Seebeck effect in thermoelectric material.
Development of mobile biosensor reader for wearable sweat glucose biosensor application
Authors: Busono P , Febryarto R , Ma’arif R A , Astawa I M , Yogiswara I P A , Karim S , Majid F A , Amrullah A , Rahayu S , Rahmah M
Published: October 2023

Sweat contains numerous biomarkers, including glucose, which can provide valuable insights into an individual’s metabolic state. Noninvasive glucose monitoring eliminates the need for frequent finger pricks or blood samples, offering greater convenience and reducing discomfort for individuals with diabetes. These biosensors are designed to detect and quantify glucose levels through various sensing mechanisms, such as enzymatic reactions or electrochemical measurements. The integration of biosensors into wearable devices, such as smartwatches, patches, or flexible electronics, allows for mobile glucose monitoring in sweat. Accurate glucose measurements require calibration and validation against reference measurements, such as blood glucose levels. Research focuses on developing calibration algorithms and improving the accuracy and reliability of mobile glucose biosensors in sweat.
Preliminary analysis of crustal anisotropy in the southernmost part of Simeulue Island
Authors: Syuhada S , Muttaqy F , Puspito N T , Pranata B , Anggono T , Ramdhan M , Mukti M M , Febriani F , Dewi C N , Prasetio A D , Hasib M , Aulia A N
Published: October 2023

The study location is in the southernmost region of Simeulue Island near the Indo-Australian subduction margin. The deformation and geodynamic evolution around the island have been studied through some geophysical and geological studies. However, information regarding crustal seismic anisotropy around this region is less investigated, which may be very useful in delineating the deformation process in this area. In this work, we conducted an initial crustal anisotropy study using shear wave splitting analysis for two seismic stations from two datasets. One seismic station is from temporary deployment data recording data between December 2005 and March 2006, and the other one is from IA permanent network data. The objective of using these two different datasets is to assess the splitting analysis’s consistency and constrain the dominant cause of crustal anisotropy around the study area. The anisotropy orientations at all seismic stations are parallel to the regional stress direction. This situation may imply that anisotropy around the study area is mainly due to stress-induced anisotropy. Furthermore, the delay time distribution with depth suggests that the anisotropic source is concentrated around 15-20 km depth of the crust. This indicates a strong influence from the interaction between the lower crust and the upper part of the subducting slab.
Analysis of vertical seismic deformation of the 2018 Palu earthquake using Global Navigation Satellite System (GNSS) data
Authors: Nurdin N , Pujiastuti D , Marzuki M
Published: October 2023

The vertical seismic deformation of the Palu earthquake magnitude of 7.4 on the Richter Scale, which occurred on September 28, 2018, has been analyzed using InaCORS (Indonesian Continuously Operating Reference Stations) stations. The stations used are CBAL, PALP, CTOL, CMLI, CPAL, and CBIT. The analysis was conducted using GAMIT, GLBOK, and GMT software. The analysis focused on the period of 100 days, starting from August 6, 2018 (DoY 218) to November 28, 2018 (DoY 318), encompassing the preseismic, coseismic, and post-seismic phases. During the preseismic phase (DoY 218-270), the InaCORS stations experienced a slight deformation ranging from -10.9353 mm to 6.5525 mm. Tectonic manifestations influenced the direction of movement in Sulawesi. The deformation significantly increased in the coseismic phase (DoY 271-272). The InaCORS stations experienced deformations ranging from -169.8 mm to 8.755 mm, which differed in the direction from the preseismic phase. The stations in the northern region predominantly moved towards the north, while those in the southern region moved towards the south. During the post-seismic phase (DoY 273-318), the movement of the InaCORS stations followed the direction of deformation observed in the coseismic phase. However, the displacement was relatively smaller, ranging from 11.5909 mm to 17.23733 mm.
Analysis of peak ground acceleration based on microtremor data in Rejang Lebong, Bengkulu
Authors: Siburian B I , Lubis A M , Marzuki M
Published: October 2023

Rejang Lebong is a regency in the province of Bengkulu, located in the Bukit Barisan mountainous region. The area is dominated by fault earthquakes due to its proximity to the Musi and Ketaun faults. This article presents the results of a study on earthquake hazard analysis through microtremor measurement using the HVSR method to determine the value of Peak Ground Acceleration (PGA). Measurements were taken at 10 points for 60 minutes with a 2 km interval. The HVSR method was used to obtain the dominant period value. The determination of PGA value was based on historical fault earthquakes in RejangLebong in 1943 with a magnitude of Mw 7.4. The largest PGA value obtained was 627.34 gal, which was in the western part of the study area. This is significantly correlated with the earthquake hazard in 1943, which caused the highest damage in the Tes village located in the western part of the study area. This research is useful for pre-disaster earthquake mitigation plans through risk management to reduce the impact of earthquake hazards.
Integration of Electrical Resistivity Tomography (ERT) and Induced Polarization (IP) methods to observe seawater intrusion in Sungai Nipah Village, Mempawah Regency
Authors: Muhardi M , Perdhana R , Kusuma I
Published: October 2023

Sungai Nipah Village is one of the coastal areas of Mempawah Regency, where most people utilize dug wells to meet their clean water needs. The problem faced by the community is that the clean water from the drilled well still has a brackish to salty taste. This study aims to observe seawater intrusion that is estimated to cause the problem based on the distribution of resistivity and chargeability values in the subsurface. The methods used are electrical resistivity tomography (ERT) and induced polarization (IP). The field measurements used a Wenner-Schlumberger configuration with three lines that have a length of 200 m each. The resulting research showed that the study area in Sungai Nipah village is prone to seawater intrusion. The seawater intruding the shallow unconfined aquifer is indicated by resistivity and chargeability values of less than 1 Ωm and 5 ms – 25 ms, respectively. The aquifer layer is composed of sand and clay at a depth of about 13 to 17 m. The seawater intrusion extended from the southern part of the study area to the north and covered about half of the study area.
The Fourth-Order KN potential Matrix-Element in 3D basis
Authors: Nugraha A , Fadhlurahman H , Fachruddin I , Salam A
Published: October 2023

The aim of this study is to derive the fourth-order KN potential matrix-element. The matrix element is derived in 3D basis. Previous study about the-second order KN interaction shows that the result need to be improved, so we continue the study to the fourth-order. Potential matrix-element is derived from KN Interaction potential which is developed by Büttgen (Nucl. Phys. A506) dan Müller (Nucl. Phys. A513). The meson being exchanged in the fourth-order KN interaction is pion with intermediate state are NK* and ΔK*. Potential matrix-element is formulated from potential on 3D basis. We apply 3D technique in this study as a good alternative to Partial wave technique. That technique does not expand the free state in partial wave so it is useful in high energy scattering. Potential matrix-element derived from this study can be used to calculate differential cross section which can be used to calculate the contribution of pion exchange in KN scattering.
Design of S-Band accelerator structure utilizing 2.45 GHz magnetron
Authors: Rezon K , Satmoko A , Kasmudin K
Published: October 2023

This work presents the design of a side-coupled standing wave accelerator structure operating in S-band resonant frequency. It consists of cavity cells, side coupling cells, a power coupling cavity cell, a waveguide structure, and a magnetron operating in an S-band frequency regime. It was designed to use a more commercially available magnetron (a frequency range of 2445 to 2465 MHz). Electromagnetic analysis was performed using CST Microwave Studio’s electromagnetic field eigenmode, time domain, and PIC solvers. A cavity cell design was obtained with Q
0 of 20288 and a shunt impedance of 96.247 MΩ. The multi-cavity structure is side coupled and operates in

π
2

mode at 2453.835 MHz with a quality factor of 13376. A power coupler with a width of 1.3 cm and length of 2.9 cm transfers the RF power through a WR340 waveguide into the cavity with minimal loss. The total structure length was 52.17 cm. We achieved a peak accelerating gradient of about 22.1 MV/m at 1 Joule of stored energy and calculated a beam peak energy of 4.535 MeV.
Analysis of faculty of electrical engineering and informatics building energy use intensity in pardubice, czech
Authors: Rahardjo I A , Pidanic J , Rolecek J , Garniwa I , Suhartanto H , Soeprijanto  , Putro P A W , Imandeka E , Dung N Q , Tuan D H
Published: October 2023

The investigation focused on analyzing the energy usage patterns of the Faculty of Electrical Engineering and Informatics in Pardubice. The recorded energy consumption data were examined and discussed. The average heating energy consumption in the Faculty of Electrical Engineering and Informatics building in 2020, 2021, and 2022 is 686.45 MWh or 57% of the total energy equivalent value. Meanwhile, the average electricity consumption in the building during the same period is 518.97 MWh or 43% of the total energy equivalent value. The average fluctuation in heating energy consumption used in the Faculty of Electrical Engineering and Informatics building tends to increase by 2.9% per year, while the average fluctuation in electricity consumption tends to increase by 3.3% per year. According to the findings, the average comprehensive energy consumption per unit area in the building was 146,03kWh/m2. It was the sum of the energy use intensity for heating and the energy use intensity for electricity. The average energy use intensity value for heating in the building was 83.16 kWh/m2, while the average energy use intensity value for electricity was 62.78 kWh/m2.
The effect of baseline establishment on energy savings estimate in green building certification
Authors: Najed F , Djunaedy E , Utami A R I , Sari I P , Rithwan F , Sofyan S
Published: October 2023

Recently, increasing energy consumption and CO2 emissions buildings and construction together are accounted globally for 36% and 37%, respectively. This situation implies that buildings consume over one-third of energy demand and emitter CO2 globally. Hence, energy-efficient practices were applied in green building certification to reduce energy consumption and CO2 emission. Each green building certification follows the energy baseline created to take a step further for better future equipped energy end-use. This research objective explains the comparison of different energy baselines referring to GBCI (Green Building Council Indonesia) and ASHRAE standards. Eight buildings using different energy baselines were observed in this research. By integrating energy-efficient practices in green building certification, three energy savings methods were used to calculate different energy baselines, specifically EnergyPlus simulation, worksheet calculation, and EDGE simulation. Through the energy savings method, thus outcome energy savings estimate was obtained. The energy savings estimate in the boxplot graph showed GBCI baseline results in huge savings compared to ASHRAE baseline.
Measurement and analysis of the variation of albedo and surface temperature at Pondok Betung, South Tangerang
Authors: Arif M , Sunaryo S , Nahas A C
Published: October 2023

In 2021, the IPCC reported that the rate of global warming has reached 1.1°C. The BMKG also states that many regions in Indonesia are experiencing warming. Two indicators of global warming are surface air temperature (SAT) and albedo. Changes in these two variables contribute to an urban heat island (UHI). Recent research reveals an increase in the UHI index in Pondok Betung area. Variations in SAT and albedo values can be obtained through the Automatic Solar Radiation System, and Automatic Weather Station provided at the Pondok Betung BMKG Station. The data obtained are SAT and two types of albedos, namely the albedo of direct radiation and the albedo of diffuse radiation on a grass surface. The results obtained show a small increase in SAT and a small decrease in the two albedos. Such a result is to be expected in January 2021-June 2022. The lowest SAT was 26.16°C in January 2021, and the highest was 27.92°C in March 2021. The lowest direct albedo was 0.158 in July 2021, and the highest was 0.178 in October 2021. The lowest diffuse albedo was 0.173 in June 2021, and the highest was 0.183 in October 2021.
Analysis of estimated age of distribution transformer against loading at ULP Panakkukang with the montsinger method
Authors: Sofyan S , Faraby M D , Naim K , Idris A R , Akhmad S S , Firmansyah H
Published: October 2023

Distribution transformers are electric power equipment that plays a role in distributing electricity to consumers from medium voltage to low voltage through transmission lines. Factors affecting the life of the transformer are overloading and ambient temperature are the main factors affecting the life of the transformer. This study aims to analyze the increase in transformer load, the age losses that occur in the transformer, and the age of the transformer. The time series method is used to calculate the load forecast that occurs each year, and the Montsinger Method is used to obtain the relative speed values of the transformer. In this study, the data used were ten types of transformers at ULP Panakukang. The results are in the form of a yearly increase with different increases. Calculation of the remaining service life of the transformer obtained from each substation is 13 years for GT PHB016, six years for GT PHB021, two years for GT PHB031, 14 years for GT PHB 095, 18 years for GT PKS073, seven years for GT PKS075, six years for GT PTP024, nine years for GT PTP034, 16 years for GT PRC024 and six years for GT PBG002.
“Philipp Lenard and Cathode Rays” - the development of comics for Physics learning
Authors: Muliyati D , Nurcholisah A , Purwahida R , Rahmadini D , Sari N L K , Sumardani D
Published: October 2023

Lenard conducted a study on the photoelectron-emitted energy that varies with the intensity of the light. Lenard observed that the maximal energy of the emitted electron was independent of the light color but noted that shorter wavelength light with higher frequency resulted in increased energy of the ejected electron. Lenard received the Nobel Prize in 1905 in recognition of his contributions to the field of cathode rays. Lenard’s research on cathode rays is a historical plot that is rarely presented on the photoelectric effect material in schools. Because of these conditions, students are less interested in studying concepts and phenomena in physics. The essential criterion for captivating visual learning media is the effective and enjoyable delivery of information. One of the strategies to enhance educational outcomes is the provision of captivating alternative learning resources, such as comics. This is because comics possess the unique ability to amalgamate information, creativity, and enjoyment, so fostering an engaging learning experience. This study resulted in comics about Philip Lenard and his research on cathode rays presented as simple cartoon images. The results of user’s perceptions show that the comics produced are worthy of being an alternative learning media in schools.
Designing of virtual laboratory on elasticity for Physics learning
Authors: Darman D R , Suhandi A , Kaniawati I , Samsudin A
Published: October 2023

Elasticity is one of the materials that students learn through laboratory experiments. In general, real and virtual laboratory conditions are still limited to spring elasticity experiments where the elasticity properties can be observed directly to determine the material’s elastic modulus. While on other objects and materials, elasticity experiments are still problematic to do because of the limitations of measuring instruments and microscopic observation scales. This study aims to produce a virtual laboratory of the Elasticity of various materials using wire for physics learning in universities. This study chose the Development Research (DDR) design with the ADDIE model for its development. The feasibility of the virtual laboratory is seen based on the results of the expert validation test. This research produced a Virtual Laboratory on Elasticity using aluminum, steel, iron, brass, nickel, copper, and tin wire. This virtual laboratory has four variables that can be varied, namely the type of wire material, the mass of the object, the diameter of the wire, and the initial length of the wire. The validation results with expert input show that the Elasticity virtual laboratory is valid and can be used for learning physics in universities.
Analysis of Creative Thinking Skill Instrument Test (CreaTSIT) on renewable energy topic for senior high school student using Rasch model
Authors: Rosha J M , Hidayat A
Published: October 2023

This study aims to analyze an instrument that measures the creative thinking abilities of high school students regarding renewable energy. The research model used is the ADDIE model, which consists of analysis, design, development, implementation, and evaluation. CreaTSIT was tested on 27 high school students in Bandung using a targeted sampling technique. Analysis of the Rasch model shows that the overall component of creative thinking skill is reliable and valid in the “very good” category, with a Cronbach alpha score of 0.83. A personal credibility score of 0.82 is in the “good” category. An item reliability score of 0.81 is included in the “good” category. Students’ creative thinking skills must be enhanced through models, methods, and media supporting them. CreaTSIT can be used to assess students’ creative thinking skills. We hope this research can contribute to the Indonesian educational community, especially physics teachers and educational researchers.
Revitalizing circular motion topic learning through android application based on transformative learning
Authors: Nasbey H , Kurniawan A F , Kusumadianti A R
Published: October 2023

The primary objective of this study is to create an innovative Android app that serves as an interactive educational tool, utilizing transformative learning principles, to facilitate the understanding of circular motion. The Research and Development (R&D) method is employed in this study using the ADDIE development model. The research instrument used is a Likert scale questionnaire. The Android application has undergone validation with a percentage of 89% by subject matter experts, 82% by media experts, and 80% by learning experts. Additionally, the Android application incorporates the stages of transformative learning, namely the first stage of “becoming aware of initial understanding,” the second stage of “questioning existing understanding,” the third stage of “constructing new knowledge,” and the fourth stage of “applying new understanding in everyday life.” The application has been tested with 30 tenth-grade science students and physics teachers in a secondary school in Jakarta, with a satisfaction percentage of 81.67% according to students and 76% according to teachers. Based on the research findings, it can be concluded that the Android application, as a transformative learning-based learning medium for the circular motion topic, is suitable for physics education.
Measuring the refractive index of sugar solution through the stage of science process skills
Authors: Fitri U R , Nisa S K , Zetra M F , Ziveria M , Muhara I
Published: October 2023

Refractive index practicum in sugar solution medium is carried out with the limitation of measuring the refractive angle of light using one type of solution, namely laboratory-scale sugar solution. The purpose of this study was to test the development of refractive index practicum tools for limited use with specifications of 10-watt lamps, 0°-90° arc scale, laser arc arm with a wavelength of 589 nm, laser chamber, vertical regulator position, limiting media in the form of glass and parallelogram-shaped solution cross-section. The variables used were solution concentrations in the 15% - 75% range and with incidence angles of 15°, 25°, and 35°, respectively. The results showed that the refractive index practicum tool has the advantage that it can be used more precisely both in light and darkness. The light used uses a laser with a wavelength of 549 nm and can measure the refractive index of a solution. The measurement results obtained the refractive index gradient value of the sugar solution at each concentration. The use of tools based on the processes science skills students in implementing activities practicum bias index in sugar solution.