bluuebunny/crossref_metadata_2025 huggingface dataset:
LC dynamic signal modeling and analysis of resonant frequency measurement error under rapid eye movements interference
Authors: An Hongbin , Ke Yu
Published: October 2024

LC resonant wireless passive intraocular pressure (IOP) sensors measure IOPs by mapping them to LC resonance frequencies. However, during the sweeping acquisition process of each LC signal frame, possible rapid eye movement (REM) can interfere with the wireless mutual inductance coupling, leading to the signal distortion and resulting in the error of resonance frequency measuring. Currently, there is a lack of modelling analysis of the errors generated by REM effect, resulting in an absence of guidance for reducing the impact. Therefore, here, we start from the perspective of the signal model and establish the LC dynamic signal model for sweeping acquisition. By means of the limit state analysis and Monte Carlo simulation, we analyze the influence of external REM parameters (including REM range and velocity) and internal parameters of the LC sensing system (including the quality coefficient of LC sensor, diameter, and number of turns of the reader coil, signal sweep acquisition speed and period) on the errors. We demonstrated theoretical relationship between the extreme errors with these parameters and verify it through a computer simulation. Based on the results, we propose to optimize the internal parameters of the LC sensing system to reduce the REMs effect on errors, safeguarding the quality of signal acquisition and improving the measurement accuracy.
Bridging length and time scales in predictive simulations of thermo-mechanical processes
Authors: Sun Jiaqi , Taormina Nicholas , Bilgili Emir , Li Yang , Chen Youping
Published: October 2024

This work introduces a theoretical formulation and develops numerical methods for finite element implementation of the formulation so as to extend the concurrent atomistic-continuum (CAC) method for modeling and simulation of finite-temperature materials processes. With significantly reduced degrees of freedom, the CAC simulations are shown to reproduce the results of atomically resolved molecular dynamics simulations for phonon density of states, velocity distributions, equilibrium temperature field of the underlying atomistic model, and also the density, type, and structure of dislocations formed during the kinetic processes of heteroepitaxy. This work also demonstrates the need of a mesoscale tool for simulations of heteroepitaxy, as well as the unique advantage of the CAC method in simulation of the defect formation processes during heteroepitaxy.
Effect of hydrogen sulfide concentration on two-dimensional SnS2 film by atomic layer deposition in annealing process
Authors: Yoon Heejun , Jeon Hyeongtag
Published: October 2024

Two-dimensional materials are widely studied due to its unique physical, optical, electrical properties, and good compatibility with various synthesis methods. And among the many fabrication methods, tin disulfide (SnS2) material, a two-dimensional (2D) material that can be achieved with accurate thickness control using atomic layer deposition (ALD), high uniformity and conformality even at low process temperatures is attracting attention. However, since the crystallinity of the thin film is low at a low process temperature, various post-annealing methods are being studied to compensate for film quality. In this work, we compared the crystal structures, chemical binding energies, and electrical properties of the thin films by post-annealing SnS2 thin films according to the hydrogen sulfide concentrations of 4.00% and 99.99% in the hydrogen sulfide atmospheres. The crystallinity, grain size, and carrier concentrations of the SnS2 thin film were the highest at a post-annealing temperature of 350 °C at a hydrogen sulfide concentration of 99.99%, and the chemical binding energies also corresponded with the standard Sn4+ states, forming a pure 2D-hexagonal SnS2 phase. In addition, SnS2 thin films deposited via ALD showed high uniformity and conformality in large-scale wafers and trench structure wafers.
Investigation of scalable chiral metamaterial beams for combined stiffness and supplemental energy dissipation
Authors: Liu Han , Laflamme Simon
Published: October 2024

Metamaterials have gained important interest in the research community attributable to advances in additive manufacturing enabling their fabrication at reasonable costs. The vast majority of their applications and demonstrations are at micro- and nano-scales, and challenges remained regarding the larger scale applications. In this paper, we are interested by the scalability of metamaterials, targeting structural engineering applications. To do so, we explore mechanisms capable of providing both bending stiffness and high-performance energy dissipation. Our study includes beams constructed with chiral topologies of different structural hierarchy orders, and we also explore three new topologies that we termed chiral friction, chiral-rectangular and chiral-hexagonal design to engineer the beams and the use of friction rods with tunable post-stress that inserted longitudinally through the beams to provide enhanced friction. The mechanical performance of the metamaterial beams is characterized through a series three-point bending tests. Of interest is to evaluate the bending stiffness, shape recoverability, and energy dissipation capabilities. We find that the chiral-hexagonal topology equipped with a non-stressed friction rod exhibit excellent energy dissipation capabilities, showing an improved loss factor by 11.9 times compared to the control beam using 68% of its materials density. Moreover, the use of the post-stress mechanism shows that it is possible to augment both its shape recovery and bending stiffness up to 99.3% and 47.1%, respectively. Overall, our investigation shows that it is possible to engineer scalable metamaterial beams targeting structural engineering applications, and that the use of topology optimization and strategically designed post-tensioning mechanism can allow tuning of mechanical performance.
Performance evaluation of a racetrack high temperature superconductor winding in an HTS levitation platform
Authors: Fang Xinyu , Wang Xilian , Fang Jin , Li Wenlong
Published: October 2024

High temperature superconducting (HTS) is a key technology for next generation high-speed railway systems, which guarantees high current and highly efficient traction power supplies. HTS devices can reduce system weight and thus improve loads of vehicles. In high-speed maglev trains, HTS windings wound by second-generation HTS tapes play an important role in suspension and traction. However, in complex ferromagnetic environments, the performance of windings is notably influenced by the varying magnetic fields. In this paper, a new maglev platform is designed and comprised of a winding of six racetrack HTS coils, an E-shaped iron core and a magnetic guide rail. The air core structure of the winding is modeled and tested and the electromagnetic characteristics are analyzed for three dimensional finite element analysis of the platform. An A formulation is used to calculate magnetic vectors A and infer magnetic flux densities and current densities for the structures. After the winding is installed on the iron core and the magnetic guide rail is suspended above the iron core, the air gap between the iron core and the rail is varied from 0 mm to 20 mm in models and experiments. The magnetic fields, critical currents and losses of the winding in the cases of the air core and the iron core conditions are used for analysis. The comparison between the air core and the iron core conditions confirms the reliability of the proposed models. This study provides a means for the analysis of complex superconducting maglev systems.
Criterion for vanishing valley asymmetric transmission in dual-gated bilayer graphene
Authors: Wu Xiuqiang , Meng Hao , Zhang Haiyang , Xu Ning
Published: October 2024

Realizing valley asymmetric transmission(VAT) for incoming valley unpolarized Dirac carriers across an electrostatically modulated confinement potential(ECP) step, which is located at the interface of the unipolar (

n
−

n

′

) junction in dual-gated Bernal-bilayer graphene(BBG), has caught growing attention because it provides a platform to study the valley polarizer. Such a junction, however, seems to preclude from supporting vanishing VAT. Based on the effective two-band Hamiltonian of BBG with wave matching approach, we demonstrate theoretically that VAT through the n/n′ interface vanishes in the following conditions: (i) the disappearing electrostatically modulated interlayer potential difference(EPD), or (ii) the invariance condition of the sum or difference of ECPs and EPDs, which physically corresponds to the zero band offset of the conduction or valence band in the band alignment of

n
−

n

′

junction. Guided by this, it is worth mentioning that the we can derive simple, analytical valley-independent expressions for the reflection and transmission probabilities. When the same invariant conditions occur, our calculations further show the appearance of the nearly vanishing VAT for the four-band model in bilayer graphene with ‘Mexican hat’-like band. As a byproduct, we apply these findings to suggest the best design for the valley-dependent selection of momenta based on dual-gated BBG connected to two pristine BBG electrodes in which ECPs of the two outer regions are distinguishable and show that the sign of valley polarization can be switched via varying EPD. We expect our results can provide guidance for future device applications relying on ballistic and valley-selective transport.
SU(N) magnetism with ultracold molecules
Authors: Mukherjee Bijit , Hutson Jeremy M , Hazzard Kaden R A
Published: October 2024

Quantum systems with SU(N) symmetry are paradigmatic settings for quantum many-body physics. They have been studied for the insights they provide into complex materials and their ability to stabilize exotic ground states. Ultracold alkaline-earth atoms were predicted to exhibit SU(N) symmetry for

N
=
2
I
+
1
=
1
,
2
,
…
,
10

, where I is the nuclear spin. Subsequent experiments have revealed rich many-body physics. However, alkaline-earth atoms realize this symmetry only for fermions with repulsive interactions. In this paper, we predict that ultracold molecules shielded from destructive collisions with static electric fields or microwaves exhibit SU(N) symmetry, which holds because deviations of the s-wave scattering length from the spin-free values are only about 3% for CaF with static-field shielding and are estimated to be even smaller for bialkali molecules. They open the door to N as large as 32 for bosons and 36 for fermions. They offer important features unachievable with atoms, including bosonic systems and attractive interactions.
Exploring electron-phonon coupling using quantum computing methods
Authors: Zhou Pengyu , Shang Honghui
Published: October 2024

Quantum computing in the noisy intermediate-scale quantum (NISQ) era has foregrounded the importance of Variational Quantum algorithms (VQAs). These algorithms are crucial for addressing complex quantum mechanical problems that challenge classical computers. One such problem is the electron-phonon (e-ph) interaction, which is essential for determining the zero-point renormalization (ZPR) of electronic structure properties. The calculation of ZPR of fundamental gap relies on the accurate computation of ionization potential (IP) and electron affinity (EA) energy levels in molecular systems, where the VQAs offer the promising solutions. Despite the critical importance of IP, EA energies and ZPR in quantum chemistry calculations, research into the application of quantum algorithms for these calculations remains limited. To address these challenges, we propose two quantum algorithms for ZPR of fundamental gap calculation using Variational Quantum Deflation (VQD) and Quantum equation of Motion (QEOM) algorithm for several molecular systems. This work opens up new possibilities for the accurate and efficient study of e-ph interaction in electronic structure calculations, even with NISQ-era hardware.
Dynamic magnetic properties and magnetocaloric effect of a nanotube encapsulated with X36
Authors: Xing Lu , Wang Wei , Lv Dan , Li Bo-Chen , Liu Gong-Zhao
Published: October 2024

Using Monte Carlo simulation, the dynamic magnetic properties and magnetocaloric effect of a mixed-spin (3/2, 2) single-walled nanotube encapsulated with X36 was studied, where X denotes the magnetic atom. The effects of intrinsic parameters on dynamic order parameters, magnetic susceptibility, internal energy, and specific heat were considered. The phase diagrams were obtained. The results indicate that the critical temperature can be increased by decreasing the absolute values of the anisotropies (D

a

, D

b
), increasing the exchange couplings (|J

ab
|, J

bb
), and decreasing the amplitude h
0 and the period τ of the external magnetic field. And under the influence of these parameters, the magnetocaloric effect is generated.
Engineering of hyperentangled complex quantum networks
Authors: Ahmad Murad , Ali Liaqat , Imran Muhammad , -ul-Islam Rameez , Ikram Manzoor , Ud Din Rafi , Ahmad Ashfaq , Ahmad Iftikhar
Published: October 2024

We propose a novel scheme to engineer the atomic hyperentangled cluster and ring graph states invoking cavity-QED technique for applicative relevance to quantum biology and quantum communications utilizing the complex quantum networks. These states are engineered using both external quantized momenta states and energy levels of neutral atoms under off-resonant and resonant Atomic Bragg Diffraction (ABD) technique. The study of dynamical capacity and potential efficiency have certainly enhanced the range of usefulness of these states. In order to assess the operational behavior of such states when subjected to a realistic noise environment has also been simulated, demonstrating long enough sustainability of the proposed states. Moreover, experimental feasibility of the proposed scheme has also been elucidated under the prevailing cavity-QED research scenario.
A comparative analysis of dissipation coefficients in warm inflation
Authors: dos Santos F.B.M. , de Souza R. , Alcaniz J.S.
Published: October 2024

In the warm inflation scenario, the early cosmic acceleration is driven by the inflaton coupled to thermal fields, decaying into radiation and leaving a hot universe populated by relativistic particles after the end of inflation. The interaction
is usually modeled by a dissipation coefficient Υ that contains the microphysics of the model. In this work, we adopt a well-motivated potential V(ϕ)=λ/4ϕ
4 and constrain a variety of Υ parameterizations by using updated Cosmic Microwave Background data from the Planck and BICEP/Keck Array collaborations. We also use a Bayesian statistical criterion to compare the observational viability of these models. Our results show a significant improvement in the constraints over past results reported in the literature and also that some of these warm inflation models can be competitive compared to Starobinsky inflation.
Quasi-continuous exhaust operational space
Authors: Dunne M. , Faitsch M. , Radovanovic L. , Wolfrum E. ,   the ASDEX Upgrade Team
Published: October 2024

The IPED predictive pedestal code has been used to determine the critical gradients for the onset of 1) separatrix ballooning modes and 2) global peeling-ballooning modes as a function of plasma shaping. This results in a scaling of the onset threshold of separatrix ballooning modes as a function of elongation and triangularity

α
edge,crit

=
0.64

κ

2.2

(
1
+
δ

)

0.9

, while the critical gradient for global peeling-balloonig modes increases as

≈

α
edge,crit

1.5

. This implies that operational space for a ballooning unstable separatrix and stable peeling-ballooning modes exists at sufficiently high shaping. Applying a collisional broadnening based scaling of the separatrix gradients allows the critical separatrix density, required to drive the separatrix ballooning mode, to be derived from global plasma parameters for any operational scenario on any device. Evaluations for ASDEX Upgrade, JET, and the ITER 15 MA baseline plasma predict critical separatrix densities of 0.3–0.4

n

GW

for QCE access, making the QCE an attractive operational scenario for fusion devices.
First access to ELM-free negative triangularity at low aspect ratio
Authors: Nelson A.O. , Vincent C. , Anand H. , Lovell J. , Parisi J.F. , Wilson H.S. , Imada K. , Wehner W.P. , Kochan M. , Blackmore S. , McArdle G. , Guizzo S. , Rondini L. , Freiberger S. , Paz-Soldan C. ,   the MAST-U Team
Published: October 2024

A plasma scenario with negative triangularity (NT) shaping is achieved on MAST-U for the first time. While edge localized modes (ELMs) are eventually suppressed as the triangularity is decreased below

δ
≲
−
0.06

, an extended period of H-mode operation with Type-III ELMs is sustained at less negative δ even through access to the second stability region for ideal ballooning modes is closed. This documents a qualitative difference from the ELM-free access conditions documented in NT scenarios on conventional aspect ratio machines. The electron temperature at the pedestal top drops across the transition to ELM-free operation, but a steady rise in core temperature as δ is decreased allows for similar normalized β in the ELM-free NT and H-mode positive triangularity shapes.
The seeding of neoclassical tearing modes by resonant magnetic perturbations in the EAST tokamak
Authors: Shi Tonghui , Wei L. , Sun Y.W. , Wang H.H. , Ma Q. , Li E. , Zhang Y. , Qian J.P. , Zeng L. , Shen B. , Wang Y.M. , Zhang T. , Zhao H.L. , Liu H.Q. , Luo Z.P. , Li Y.Y. , Xu L.Q. , Zhang B. , Li M.H. , Wang Z.X. , Ling B.L. , Gong X.Z. , Wan B.N.
Published: October 2024

This work presents a robust methodology for effectively distinguishing between the seed island and the onset of the neoclassical tearing mode (NTM) in the EAST tokamak. Unlike previously employed methods, the width of the seed island is carefully regulated by gradually ramping up the currents in the resonant magnetic perturbation (RMP) coils. Remarkably, the seed island phase can be sustained for several hundred milliseconds, providing ample time to examine the nonlinear dynamics of NTM threshold physics. This study investigates the plasma response in terms of various factors, including the plasma rotation, the electron density, and the electron temperature, from the initial formation of the seed island to the saturation of the NTM island. Through extensive statistical analysis of NTM triggering events, it is revealed that both the critical width of the seed island and the critical RMP currents are positively correlated with β

p
. Moreover, the relationship of the transition time associated with mode penetration to β

p
differs from the dependence of the transition time for NTM triggering on β

p
. The growth rates associated with these two nonlinear phenomena show similar characteristics. Finally, reduced magnetohydrodynamic (MHD) modeling replicates the two nonlinear bifurcation states observed in the experiment. It is noteworthy that the RMP-induced NTM islands are locked to the static magnetic perturbation. This scenario differs from the natural excitation of NTMs, which occurs due to transient MHD phenomena, such as sawtooth crashes, where the triggering source is a rotating magnetic perturbation. This leads to the formation of rapidly rotating islands at a natural frequency. Furthermore, the stability of these islands is expected to be related to the polarization current effect. Nevertheless, this experiment sets a new course for the comprehensive investigation and understanding of NTM threshold physics, providing valuable insights for future tokamak design and operational strategies.
Bridging the Gap between Policy and Net-Zero Realization in Indonesia: An Outlook of Available Approaches
Authors: Ardiansyah Harun , Wahyuni Elisa , Ekadewi Putty
Published: October 2024

Indonesia has been ambitious with its efforts to tackle climate change and achieve net zero carbon emission. This is reflected by the Nationally Determined Contribution (NDC) that has been defined by the Government and presented during the Copenhagen Accord, Paris Agreement, and Glasgow Climate Pact. In realization, Indonesia has also pledged to achieve net-zero carbon emission by 2060, especially in the energy sector. The Ministry of Energy and Mineral Resources (MEMR/KESDM) of Indonesia has published its plan to achieve said targets through diversification and intensification of new and renewable energy resources. New and renewable energy bill is also currently being discussed in Indonesia’s House of Representative (DPR-RI). However, the reality is that the country is facing several challenges in meeting its targets, and the plans and targets set by the government in the energy sector are not being achieved. In this paper, we analyze the factors that have hindered the implementation of Indonesia’s energy transition plan and suggest potential solutions for filling the gaps. To achieve the NDC, we suggest that Indonesia must identify new resources and intensify the use of existing resources. Additionally, the paper provides recommendations on energy market policy that can help to accelerate the transition to sustainable energy. This paper would provide a future outlook on Indonesia’s energy policy and energy market. by adopting new energy technologies, increasing investment in renewable energy, and developing policies that support the transition to a low-carbon economy. Our analysis highlights the importance of addressing the challenges faced by Indonesia’s energy sector and the need for a comprehensive strategy that takes into account the complex interplay of factors that affect the energy transition process.
Logistic transportation role for sustainable ecotourism industry
Authors: Subkhan Muhamad Fajar , Taali Muhammad , Puspitasari Dyah Ayu Kunthi , Ainul Amri Lala Hucadinota
Published: October 2024

Transportation plays a pivotal role in the industrial landscape, and the ecotourism sector, particularly sustainable ecotourism, is no exception. Sustainable ecotourism places emphasis on the responsible management of natural resources, aiming to foster comprehension, appreciation, and the conservation of both the environment and cultural heritage. The purpose of this research is to examine how the emergence of logistics transportation studies is driven by the transportation needs of island communities and tourists to increase sustainable ecotourism industry activities. Logistics transportation services that support ecotourism is a relatively new study of existing logistics resources in Indonesia. This study chooses sea transportation routes for the Karimunjawa Islands and Jepara. The logistics services for tourism transportation provided by the government and third parties pay little attention to sea transportation routes that pass-through conservation areas, namely the Panjang Island Conservation Area and Karimun Jawa National Park. Indeed, there has been a sea route provided, but several obstacles arose when passing through the conservation area. The establishment of novel transportation routes emerges as a viable solution for bolstering the sustainable ecotourism sector and addressing the transportation requisites of the local community. Additionally, these new transportation routes can yield positive outcomes for the safeguarding of conservation areas.
Validation of MCNPX Calculational Model for Kartini Reactor Outer Core Neutron Flux
Authors: Karsono W , Agung A , Antariksawan A R , Sadewo P H
Published: October 2024

Kartini reactor in Yogyakarta is a nuclear reactor with a low thermal power of 100 kW that is mainly used for education, training, and research. For that purpose, measuring neutron flux and controlling the power are important operational parameters. The Fission Chamber (FC) type of detector is the main component in the reactor operation and safety system that measures the neutron flux in the outer reactor core. As the FC detector is placed in a fixed location, a numerical calculation model is needed to know the neutron flux in all outer core regions. In this study, the MCNPX code is used. The first step is to validate the model with experimental measurement. The objective of the present study is to obtain a validated model by comparing calculations using MCNPX with measurements using gold foil activation (Neutron Activation Analysis technique). The computational model tested showed promising results with an average difference compared to the gold foil activation method of about 23%. Further research can be done using more gold foil samples or foils from other materials to see the consistency of measurements or minimize the measurement difference.
A Comparative Study of the Effect of Weather Conditions on Solar Irradiance Forecasting Using Various Methods in Yogyakarta, Indonesia
Authors: Nugroho M V , Mardiansah F , Pratama T O , Fikriyadi Z A , Dianti D V , Prastawa Andhika
Published: October 2024

The government’s plan to build utility-scale solar power plants for the next decade will impact the high penetration of solar energy into the grid. This problem is associated with the intermittent nature of solar electricity, which can disrupt the grid system’s stability and reliability if it is not tackled. Furthermore, the complicated weather conditions in Indonesia make this variable challenging to predict. Therefore, one of the solutions offered is the solar irradiance forecasting technique that helps the operator during planning. This paper will look at the differences in these weather characteristics in predicting solar irradiance using three forecasting methods: LSTM, RNN, and ARIMA. The data is taken from direct measurements installed in the center of the island of Java, namely Yogyakarta. The result of this work shows that among LSTM, RNN, and ARIMA forecasting models, the highest forecast accuracy has been performed by LSTM with RMSE, MAPE, MAE, and R2 are 33.01 W/m2, 7.72%, 24.51 W/m2 and 0.96 respectively. Subsequently, partially cloudy, cloudy, or rainy weather has a worse predicting performance than weather with a sunny or clear sky. However, they are still regarded as reasonable forecasts.
Characterization of Municipal Solid Waste Based on Seasonal Diversity as Energy Potential Materials
Authors: Mariatunnikmah Khusnul , Ain Lubis M Faisal , Wintoko Joko , Budiman Arief
Published: October 2024

Interrelated problems related to resource availability and population growth rates, such as energy demand and waste generation, have become pressing global concerns. Municipal Solid Waste (MSW) poses a significant challenge due to its impact on society and the environment, including the associated hazards and threats. This study was conducted at the Piyungan Integrated Santary Landfill (TPST Piyungan) in Yogyakarta, Indonesia, from June to November 2022. The annual waste generation in the city is 586,267.37 tons per year in 2021, with a daily per capita waste generation rate of 0.43 kg/person. Two types of MSW samples were collected during the dry and rainy season to assess their composition. The collected samples were sorted, sun-dried, quartered, and reduced to 1mm particles for proximate analysis. The results of MSW characterization revealed that non-organic combustible materials accounted for a higher percentage during the dry season (62.7%) compared to the rainy season (53.1%). Conversely, organic matter constituted a higher proportion during the rainy season (36.7%) compared to the dry season (30.4%). The moisture content ranged from 4 to 11%, volatile matter content varied between 60% and 66%, and fixed carbon content ranged from 19 to 31%. The energy content of MSW during the dry season was measured at 20.67 MJ/kg, while in the rainy season, it yielded 14.99 MJ/kg. These findings indicate that due to the substantial energy content and waste generation rates, waste-to-energy (WtE) technologies can be effectively applied to manage MSW in Yogyakarta, simultaneously reducing waste volumes and recovering energy.
Study of [Cu3(C6H3(COO)3)2(H2O)3]n (HKUST-1) Resistance to Gamma Radiation at Dose of 125 kGy to 200 kGy
Authors: Fernanda V F E , Ferdiansjah  , Kambali I , Muharini A
Published: October 2024

Adsorption is one of the methods for processing gas and liquid radioactive waste to prevent the dispersion of substances into the environment. The metal-organic framework (MOF) material HKUST-1, known for its porous structure, exhibits impressive adsorption capacity and efficiency. These characteristics make it highly suitable as a radioactive waste adsorbent. This study aims to assess its resilience to gamma radiation by exposing it to doses ranging from 125 to 200 kGy, with a 25 kGy interval. The samples used in this research were produced using the solvothermal method at 100°C. Subsequently, the irradiated samples underwent evaluation using XRD, SEM, and isothermal adsorption with nitrogen gas. As the dose increased, the crystal grain size decreased, resulting in sharper crystal corners. Additionally, the crystallinity value rose from 15.49% to 17.70%. However, at a dose of 175 kGy, the crystalline corners became obtuse, and the degree of crystallinity decreased to 16.21%. Based on the isothermal adsorption results, the adsorbed gas volume increased from 212.186 cm3/g to 340.335 cm3/g, the surface area expanded from 520.379 m2/g to 917.048 m2/g, and the pore volume grew from 0.424 cm3/g to 0.615 cm3/g. In contrast, the pore radius decreased from 1.631 nm to 1.341 nm, except at 175 kGy, where it measured 1.399 nm. This result surpassed the sample irradiated at 150 kGy, which had a pore radius value of 1.352 nm.
Experimental study of hydrothermal treatment for reducing potassium content on palm oil empty fruit bunch (EFB)
Authors: Arnif I , Ahda Y , Pansawati I S , Saputra T F , Agustin Y , Chaeruni W
Published: October 2024

This study investigated the effects of the potassium content of EFB biochars after hydrothermal treatment (HT). The experiments were carried out in a 3000 mL reactor and treated for 60 min. Two parameters were studied in detail: water (liquid) to EFB (solid) ratio or L/S (5:1 and 10:1) and varied temperature (150, 180, 210, and 230°C). The ash content of biochars decreased gradually due to the increasing temperature, with values varying from 6.55% to 12.79%. The sodium of the treated biochars was removed entirely for each HT process, while the potassium notably reduced with the removal efficiency reached 75.34-93.79%. HT at temperature 230°C was the optimum condition to reduce the Agglomeration Index (AI), which 230H5 and 230H10 resulted in 0.26 and 0.31, respectively. Although the mass yield significantly reduced, the 230H5 was highly recommended when used for co-combustion fuel because it had the highest HHV (21.36 MJ/kg), the lowest AI (0.26), and the high removal efficiency of potassium (93.76%).
Synthesis of Activated Carbon from Banana Peel Biomass Using NaCl and Gamma Co-60 Irradiation
Authors: Ariyanti D , Christian A I , Swantomo D , Permana S , Pramutadi A
Published: October 2024

Indonesian Institute of Sciences (LIPI) stated that the potential for biomass resources in Indonesia is estimated at 49,810 MW originating from plants and waste in 2013 and of course it continues to grow, considering that the source of biomass is from nature. An example of biomass is banana peel. This banana peel can be used as activated carbon. Known from several journals that activated carbon can be applied in various ways such as being a hydrogen storage material, water purification, etc. There are three steps to synthesis activated carbon that divided into initial steps, the first is synthesis of activated carbon, which begins with drying banana peels and then cutting them, then drying them below the sun. Then it is carbonized at 400°C and immersed chemically activated with a salt activator, NaCl. The second step is combining or modifying activated carbon via gamma irradiation and the last step is characterization using BET to know surface area and FTIR to analyze the functional group. The result shows that as an effect of the modification of gamma irradiation doses by 10 kGy, 30 kGy and 50 kGy on activated carbon banana peel, the FTIR spectra increased markedly by the widening of the last stretch. Modification the banana peel with gamma irradiaton Co-60 is the surface area is increase than those without irradiation, but not significantly. It occurred due to the process of carbon degrade due to gamma irradiation of Co-60 can degrade cellulose structures.
Analysis of the Influence of Variation in Medical Waste Heating Value on the Electrical Energy Output of Generator in Medical Waste Cogeneration Incinerator System using Gatecycle Solver
Authors: Kusnanto  , Harto Andang Widi , Wallitu Hafizh , Facius Maria Josephine , Afifah Nuha Amiratul , Tenggara Ayodya Pradhipta
Published: October 2024

Medical waste incinerator is a technology capable of processing and exterminating hazardous medical waste through combustion at temperatures exceeding 800°C. Medical waste exhibits a range of heating values depending on its material composition. The heating value represents the potential heat energy released when a substance undergoes complete combustion. A cogeneration incinerator is designed to treat medical waste while also harnessing the heat of the flue gas that emanates from the combustion process. The flue gas acts as a hot fluid that transfers its heat, causing the water temperature inside the boiler to increase and transform into high-temperature steam. This steam drives a steam turbine connected to a generator to generate electrical energy. The amount of electrical energy generated is influenced by the steam quality produced through the boiler’s water-heating process. This study aims to investigate the influence of variation in the heating value in medical waste on the electrical energy output of the generator in a medical waste cogeneration incinerator system. The range of heating value variations used in the testing varies from 25 MJ/kg to 35 MJ/kg. The variation is tested through thorough simulations using GateCycle software to obtain data on the electrical energy generated. To achieve a maximum electrical energy output of 200 kW, fuel with a total heating value of 32.25 MJ/kg is required. This study is beneficial to be implemented as renewable energy sources based on biomass powerplant systems.
Microwave absorption studies in X-band of magnetized barium hexaferrite
Authors: Handoko Erfan , Marpaung Mangasi Alion , Jalil Zulkarnain , Rahwanto Adi , Aulia Teuku Budi , Iriani Yofentina , Mutiara Adayila Muda , Utami Ghania Ayu , Fernando Juwanda , Tarihoran Lily Amanda , Tua Munthe Sahat Maruli , Umaisaroh Umaisaroh , Alaydrus Mudrik
Published: October 2024

To enhance the magnetic and microwave absorbing properties, barium hexaferrite, BaFe12O19, was studied in the x-band (7–13 GHz) frequency range. The BaFe12O19 was prepared as non-magnetized and magnetized samples. The crystal structure, surface morphology, magnetic and microwave absorption of BaFe12O19 were studied with X-ray diffraction (XRD), optical microscope, permagraph and vector network analyzer (VNA), respectively. XRD result showed the formation of M-type hexagonal polycrystalline structure. The hysteresis loop results verified the formation of permanent magnet with high saturation magnetization. The VNA results showed that reflection loss and absorption were − 71.07 dB and 67.96% for magnetized barium hexaferrite, respectively.
Middle-Level Fusion YOLO on Multispectral Image to Detect Unhealthy Oil Palm Trees
Authors: Rista  , Rumata Panggabean Prima Ria , Saputro Adhi Harmoko , Handayani Windri
Published: October 2024

Locating the unhealthy oil palm trees is one of the essential things in precision agriculture. In several countries such as Indonesia, Malaysia, and Thailand, Ganoderma disease often attacks oil palm trees. Detection techniques using leaf sample pieces, the possibility of biological changes in the leaf, and the collection process are too tricky. Detection techniques using image samples captured by the drone can be more accessible, but they need to provide complete information related to plant vegetation. This research proposes detecting unhealthy oil palms by capturing top-view images using drone. The drone has dual cameras (RGB and OCN bands) to get more information on plant vegetation. Middle-level fusion YOLO is used to recognize the unhealthy oil palm trees. The data was collected at the Oil Palm Plantation in Bogor, which contains over 100 unhealthy objects. Using multispectral images can improve performance compared to using only RGB images. The proposed method provides better performance than using only RGB images and OCN images with mAP (mean Average Precision) is 0.919. The proposed method provides better performance in detecting unhealthy oil palm trees.
Investigation of Aquifer Zone using Central Loop Time-domain Electromagnetic in Institut Teknologi Bandung
Authors: Chaerul V A , Salsabila D P , Djaja I G P F S , Pratomo P M , Supriyadi  , Mahardika H , Agustine E , Srigutomo W
Published: October 2024

Time-domain electromagnetic (TDEM) has been widely used to investigate the subsurface aquifer. In this research, the TDEM method with a central loop configuration was employed to define the aquifer zone in the southern area of the Institut Teknologi Bandung (ITB) campus in Bandung, Indonesia. Moreover, TDEM is effective for mapping aquifers due to its sensitivity to subsurface conductivity. The acquisition consists of five sounding points spaced 20 meters apart, along with a W-E profile in the southern area of ITB. The data were interpreted using 1D inversion software (1X1D, Interpex, USA), utilizing weights from a smoothing constraint scheme (Occam) to obtain the resistivity distribution of the subsurface structure. The interpretation results indicate three layers from top to bottom: (a) the topsoil was interpreted as a sand layer with resistivity of 100 to 350 Ωm; (b) beneath it lies a shale layer with resistivity ranging from 5 to 100 Ωm that has good porosity to allow water from the surface to flow into the ground; and (c) further down, there is a clay layer with low resistivity of 1 to 5 Ωm which act as impermeable layer.
Integrated Magnetic and Geochemical Assessment of the Soil from the Steam Power Plant Area of South Kalimantan Province
Authors: Sudarningsih S , Fahruddin F , Astuti P , Wahyono S C , Ibrahim I , Siregar S S , Zulaikah S , Rifai H , Hamdan A M
Published: October 2024

The magnetic proxy approach has proven to be efficient in the assessment of pollution by potentially toxic elements when targeting soils or areas with a homogeneous background where anthropogenic magnetic signals can be easily distinguished. It’s crucial to conduct research on the impact of fly ash on the vicinity of the PLTU in this particular area, as it’s a previously unexplored area. The unique thing about this research is that this PLTU uses coal containing Fe, Pb, and Mg as fuel and has a fairly high susceptibility value for fly ash and bottom ash. This study is due to an analysis of the magnetic susceptibility and heavy metal content in the soil of the area around the Asam-Asam steam power plant (PLTU) of South Kalimantan Province, where geogenic input and fly ash can influence it. Heavy metals that have passed the threshold at all locations are Ti, Cr, Mn, Fe, Ni, Cu, V, and Al. Most of the correlation coefficients are strong and significant between magnetic susceptibility values and heavy metal concentrations at each location. The correspondence between magnetic susceptibility values and heavy metal content reflects the potential of magnetic proxy methods at polluted spots, provided that the lithological conditions are carefully considered.
Optimization of a Smart Greenhouse with a Solar Energy System for Floating Raft Hydroponic Cultivation: Implementation and Performance Evaluation
Authors: Wahyu S , Purwalaksana A Z , Ritonga A F , Suharmanto P , Kusumadjati A , Akbar A M , Sujadi T
Published: October 2024

The rapid growth of the global population has increased food demand, posing challenges for traditional agriculture due to limited natural resources. Hydroponic systems offer a sustainable solution by optimizing the growing environment. This study evaluates the performance of a floating-raft hydroponic smart greenhouse powered by solar energy. The system integrates advanced technologies and renewable energy sources, including three 120 Wp and 130 Wp solar panels arranged in a series-parallel configuration, a solar charge controller, two parallel 12V 65Ah and 12V 200Ah batteries, a microcontroller, DHT22 sensors, and actuators such as LED lights and a mist-type DC pump sprayer. These components effectively regulate humidity, temperature, lighting, and spraying, with data transmission to the Antares platform via a monitoring system utilizing NodeMCU ESP8266. The greenhouse maintained optimal environmental conditions, reducing the temperature from 38°C to 32°C within 30 minutes. The system’s daily electrical load was 1006.36 Wh, leaving an energy reserve of 68.35%. The plants cultivated in the greenhouse responded favorably to the system. This study highlights the potential of combining renewable energy with smart agricultural technologies to address the limitations of traditional farming practices and enhance sustainability.
The Effect of Using Worksheet Based on a Scientific Approach Assisted by Scaffolding on High School Student’s Cognitive Learning Outcomes on Temperature and Heat Material
Authors: Made Astra I , Suganda Yoga
Published: October 2024

This paper aims to find out the influence of worksheets based on a scientific approach assisted by scaffolding on temperature and heat material on students’ learning outcomes. This research aims to give a guided student a scientific approach to understanding temperature and heat using worksheet-assisted scaffolding as a teacher’s guidance. It uses a five-step guided scientific approach. This research employs a quantitative approach using a quasi-experimental method. The sample includes 70 students, who are split into two groups: an experimental class and a control class. The results of the increasing cognitive outcomes test were analyzed using two samples assuming equal variance, sample independent t-test, and N-gain to show the influence category. The test results with two samples assuming equal variance got t score 3,47 > 1,99 which is there have the different cognitive learning outcomes and increase shown by sample independent t-test with a significance level of 5% = 0.001 < 0.05, the N-gain two group class is 0.72 and 0.6 show that the experiment class more effective. As such it might be established that using worksheets based on a scientific approach assisted by scaffolding could increase student learning outcomes on temperature heat material.
Validation of Student Project Based Learning Worksheets with a Non-Parametric Statistical Approach on Greenhouse Effect Material
Authors: Akhsan H , Muslim M , Ariska M , Sapitri CL , Sari DK
Published: October 2024

So that can to produce a PjBL-based Student Worksheet with a valid and practical statistical approach to the Greenhouse Effect material in the Environmental Physics course, this research was conducted. Through the stages of planning, development procedures and Tessmer’s formative evaluation model with expert review stages in order to validate the language, content and design which is the definition of the Rowntree research model used in conducting this research. The use of the Likert scale by questionnaire techniques and walkthroughs is used to design validity data analysis for student worksheet products. As for the data analysis carried out, very valid results were obtained from a maximum score of 5 with a value of 4.3 for validation of the greenhouse effect context using a statistical approach, 4.9 for validation of working width design and 5 for linguistic validation. Tests for practical use are carried out on students. At the one-to-one evaluation stage, test results were obtained which showed the average score and for testing in small groups, it reached 93.7% and 97.5% in the very practical category.
Measuring Lens Focal Length in Lens Characteristics Experiments through Science Process Skills
Authors: Fitri U R , Budiawan M A , Nurhasanah G , Ziveria M , Muhara I
Published: October 2024

This research aims to measure the focal distance of a lens using practical lens properties. The specifications of this practical tool are made from durable acrylic material, light and easy to use. The lens nature practice equipment consists of a light source in the form of an incandescent lamp, lens path, image capture screen, arrow diaphragm, power supply, strong positive lens (+100), weak positive lens (+50) and negative lens (-50). In this practical, the light source, object, lens and screen are placed parallel. Measurements are carried out through scientific process skills including observation, classification, measurement, prediction, communication and drawing conclusions which begin with observing the image produced by the lens using three different object-to-screen distances, namely 40 cm, 60 cm and 80 cm. In addition to determining the focal distance, experiments with positive lenses produce real, inverted and magnified images. Meanwhile, in a negative lens, the image is virtual and upright. In the positive strong lens experiment, the focal distances measured at distances L = 80 cm, 60 cm, and 40 cm respectively produced average focus values of 10.53 cm, 10.49 cm, and 9.95 cm with values The standard error is 0.123 and the R square value is 0.928, indicating a fairly accurate model. In the weak positive lens experiment, the focal distances measured at distances L = 80 cm, 60 cm, and 40 cm respectively produced average values of 4.42 cm, 4.58 cm, and 4.34 cm with standard values The error is 0.0018 and the R square value is 0.9423, indicating a very precise model. In the negative lens experiment, the focal distances measured at distances L = 80 cm, 60 cm, and 40 cm respectively produced average values of 9.57 cm, 9.47 cm, and 8.95 cm with standard error values of 0.08 and an R square value of 0.967, indicating a very strong model in explaining data variations. This is in accordance with the theory of lens properties, namely that converging lenses generally have the ability to form real images, while diverging lenses often produce virtual images
Digital Physics Module for 21st Century Education on New and Renewable Energy Based on the Dilemma-STEAM Learning Model
Authors: Nasbey H , Sirait R A , Kurniawan A F , Samsudin A , Fadlan A
Published: October 2024

This study aims to develop a Dilemma-STEAM electronic module on renewable energy materials to be used as a physics teaching resource for 10th-grade high school students using the ADDIE (Analyze, Design, Development, Implementation, and Evaluation) development model. The Dilemma-STEAM based e-module is a digital physics module based on the Dilemma-STEAM (Science, Technology, Engineering, Arts, Mathematics) model of teaching. In the context of 21st-century education, the application of technology and interdisciplinary approaches is emphasized to prepare students for future challenges. This module is designed to encourage critical thinking, collaboration, communication, and creativity in students through real dilemmas story integrated with STEAM. The product is a digital module design presented through the website, it easily accessible to students using compatible electronic devices. Based on the validation results conducted by experts, an overall percentage of 87.50% was obtained from material experts, 84.44% from media experts, and 89.41% from learning experts. Additionally, the product trial by physics teachers showed a final percentage of 95.63% with an interpretation of “Very Good,” while students who had studied the material on physical quantities and measurements gave a percentage of 87.51% with an interpretation of “Very Good.” From this research, it can be concluded that the Dilemma-STEAM electronic module on renewable energy materials is deemed valid and suitable for use as a physics learning medium for 10th-grade high school students.