bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of multi-attribute task battery in mental workload studies: A scoping review
Authors: Prasetyo Ridwan Aji Budi
Published: April 2024

Multi-Attribute Task Battery (MATB) is a software that has been arguably utilized in many ergonomics/human factors studies, including in the topic of mental workload. However, the use of this well-known program in diverse investigations has not yet been systematically tracked. Furthermore, it may be argued that a critical appraisal of MATB is urgently needed so that future researchers and users can take several crucial factors into account when planning a study or experiment using MATB. The aim of this paper is to comprehensively identify and review the use of MATB software in published studies. This aim might be accomplished by achieving two goals: (1) systematic discovery of published papers in literature databases and (2) categorization of research according to pertinent topics. In this paper, thirty-one articles were included for analysis after carefully screening for their eligibility. Our scoping review finds that MATB is a beneficial program for creating multitasking environments in general, with aviation being the area where it has been used the most. The program was also extensively used for studies on mental workload, especially by producing various stimuli that ultimately result in varying degrees of task demand or difficulty. Moreover, to successfully use MATB, researchers must be aware of a few operational issues and criticisms.
The Carpal Tunnel Syndrome and Ergonomic Risk Factor Profile in Online Motorcycle Taxi Drivers (ojol) in Jakarta
Authors: Mariyamah Titis , Handoko Yusuf , Eliana Maria , Winata Susanty Dewi
Published: April 2024

Introduction: The increasing need for online motorcycle taxi driver (ojol) transportation continues to increase in Jakarta. This increases the activity of motorcycle taxi drivers, which can cause Carpal tunnel syndrome risks due to the awkward posture of the wrist while riding the motorcycle (the wrist posture is too long on the motorcycle handlebars with repetitive motion), which will affect the nerves and blood supply to the wrist and hand. This study aims to determine the risk of the motorcycle taxi driver’s upper limb using Rapid Upper Limb Assessment (RULA) and Carpal tunnel syndrome risk factor using the Boston Carpal Tunnel Syndrome Questionnaire (BTCSQ).

Method: This research used a cross-sectional study approach with 97 respondents online motorcycle taxi drivers. The respondents were collected based on the activity of online motorcycle taxi drivers who were in or passing through the data collection location and willing to take part in the Rapid Upper Limb Assessment (RULA) and the Boston Carpal Tunnel Syndrome Questionnaire (BTCSQ). The RULA assessment and analysis were performed and supported by video (recording from a cycle of the activity while the respondents were riding the motorcycles). The respondents’ criteria were an online motorcycle taxi driver with a minimum of 1 year of working experience, at least 3 hours working duration per day, and not clinically suffering from rheumatoid arthritis and wrist problems. This study has been approved by Universitas Kristen Krida Wacana ethical committee.

Result: The results of BCTSQ and RULA in online motorcycle taxi drivers have found that there’s mild–moderate risk respectively in Jakarta. In RULA, it was found that there were 87.6% of respondents were reported at moderate risk which had an impact on musculoskeletal problems, especially the upper limb. In the BCTSQ, the result showed that there were mild complaints in 38.1% of respondents regarding the wrist which was at risk of developing carpal tunnel syndrome.

Discussion: With RULA results, in the form of moderate risk, Further ergonomics investigation and assessment are needed to find out further risk factors, mitigation plans, and best improvements to reduce the risks. The occurrence of mild complaints in the wrist based on BCTSQ requires further clinical examination of carpal tunnel syndrome to reduce the incidence of CTS cases in online motorcycle taxi drivers.

Conclusion: This research’s result has found mild-moderate risk factors from the activity and working posture among online motorcycle taxi drivers in Jakarta. Further investigation and research ergonomically are needed.
Stepwise Carbene Transfer Reaction with Alkenes beyond Cyclopropanation
Authors: Xu Xinfang , Yao Minghan , Dong Shanliang , Yusuf Abdulla
Published: April 2024

Metal carbene transfer reactions have been well-established as an indispensable tool in modern organic synthesis, especially in the construction of C–C and C–X bonds with high efficiency and selectivity. Among these, stepwise carbene transfer reaction with alkenes beyond classical cyclopropanation reaction has been demonstrated as a practical method for the effective olefinic C–H/C–C bond functionalization. This review highlights the recent achievements in this area for the direct C–C bond formation involving metal carbene species with alkenes through a through stepwise reaction pathway. The content of this review is organized into three general categories according to the types of the reactions, including (i) direct nucleophilic addition of alkenes with metal carbene species, (ii) cross-coupling reaction via an alkenylic C–H bond activation and migration insertion sequence, and (iii) catalytic coupling reaction involving radical intermediate. Considering this rapidly evolving field, detailed reaction mechanism, current limitations, and future research directions are discussed.

1 Introduction

2 Nucleophilic Addition of Alkenes to Metal Carbene Species

2.1 Using Polarized Alkenes

2.2 Using Unactivated Alkenes

2.3 Cascade Reactions

3 Cross-Coupling Reaction Involving Metal Carbene Migratory Insertion Process

4 Coupling Reaction Involving Radical Intermediate

5 Conclusions and Perspectives
Photoredox-Enabled Synthesis of α-Alkylated Alkenylammonium Salts
Authors: Sakakibara Yota , Murakami Kei , Tonedachi Rina , Yoshita Aoi
Published: April 2024

The development of novel synthetic methods for quaternary ammonium salts is highly demanded since the current synthesis heavily relies on the conventional Menshutkin reaction. Herein, we report photoredox-catalyzed alkylation of α-brominated alkenylammonium salts. Mechanistically, the generation of a highly reactive α-ammoniovinyl radical is the key to our method. This reaction enables the synthesis of various unprecedented α-alkylated alkenylammonium salts.
Validation of Novel Microsurgical Vessel Anastomosis Techniques: A Systematic Review
Authors: Sadigh Yasmin , Mechri Imen , Jain Anamika , Gautam Amata Thongphetsavong , Seh Hadil , Volovici Victor
Published: April 2024

Background Thorough validation of novel microsurgical techniques is deemed essential before their integration into clinical practice. To achieve proper validation, the design of randomized controlled trials (RCTs) should be undertaken, accompanied by the execution of comprehensive statistical analyses, including confounder adjustment and power analysis. This systematic review aims to provide an encompassing overview of the validation methodologies employed in microsurgical studies, with a specific focus on innovative vessel anastomosis techniques.

Methods A literature search was conducted in PubMed for articles describing the validation of novel microsurgical vessel anastomosis techniques in animal or human subjects.

Results The literature search yielded 6,658 articles. A total of 6,564 articles were excluded based on title and abstract. Ninety-four articles were assessed for full-text eligibility. Forty-eight articles were included in this systematic review. Out of 30 comparative studies, 9 studies validated novel modified interrupted suture techniques, 6 studies modified continuous techniques, 6 studies modified sleeve anastomosis techniques, 1 study a modified vesselotomy technique, 7 studies sutureless techniques, and 1 study a modified lymphaticovenular anastomosis technique. Twenty-eight studies contained animals (n = 1,998). Fifteen animal studies were RCTs. Two studies contained human/cadaveric subjects (n = 29). Statistical power analysis and confounder adjustment were performed in one animal study. Out of 18 noncomparative studies, 5 studies validated novel modified interrupted suture techniques, 1 study a modified continuous technique, 2 studies modified sleeve anastomosis techniques, 4 studies modified vesselotomy techniques, 4 studies sutureless techniques, and 2 studies modified lymphaticovenular anastomosis techniques. Ten studies contained animal subjects (n = 320), with two RCTs. Eight studies contained human subjects (n = 173). Statistical power analysis and confounder adjustment were performed in none of the animal or human studies.

Conclusion The current methods of microsurgical technique validation should be reconsidered due to poor study design. Statistical analysis including confounder adjustment and power analysis should be performed as a standard method of novel technique validation.
Perceptions and attitudes toward COVID-19 vaccination among health professional students in Australia: a qualitative study
Authors: Chen Yingyan , Tower Marion , Zimmerman Peta-Anne , Layh Janice , Sparke Vanessa , Prichard Roslyn , Mason Matt , Lin Frances Fengzhi
Published: April 2024

Using two qualitative data sources: free-text responses to an open-ended question of an online survey and subsequent interviews and focus groups, we explored perceptions and attitudes toward COVID-19 vaccination among health professional students enrolled in Australian universities during the pandemic with data collected from October 2021 to April 2022. Students provided free-text responses to the open-ended question (n = 313) in the online survey and participated in interviews or focus groups (n = 17). Data analysis revealed three themes, including perceptions of COVID-19 seriousness and the risk of contracting the virus, information dissemination, and attitudes toward the vaccine mandate. The study identified evolving perceptions of COVID-19 seriousness among Australian health professional students and their sentiments toward the vaccine mandate. There is a need to ensure the quality of information dissemination related to the vaccine mandate. This may not only support students’ uptake of mandatory vaccination but also provide a means for them to address vaccination with healthcare consumers and patients.
Bound state energies and critical bound region in the semiclassical dense hydrogen plasmas
Authors: Yan Tong , Jiao Li Guang , Liu Aihua , Wang Yuan Cheng , Montgomery Henry E. , Ho Yew Kam , Fritzsche Stephan
Published: April 2024

We calculate the bound state energies of the hydrogen atom in semiclassical dense hydrogen plasmas modeled by the effective screened interaction potential developed by Ramazanov et al. [Phys. Rev. E 92, 023104 (2015)]. It is shown that the quantum degenerate and exchange-correlation effects of plasma electrons do not play significant roles in the region where the system exhibits bound states. The bound-continuum critical transition lines and the distribution of the ground state energies in the plasma density-temperature phase diagrams are obtained, both with and without taking into account the screening effect of the plasma ions. The dipole transition oscillator strengths and static dipole polarizabilities of the electron-ion subsystems in semiclassical dense hydrogen plasmas are calculated in a wide range of plasma parameters.
Buried junction and efficient carrier separation in CdSexTe1−x/CdTe solar cells
Authors: Jiang Hongxu , Cai Yanbo , Wang Guangwei , Yi Kai , Liu Fei , Tian Juan , Shen Kai , Wang Deliang
Published: April 2024

Alloying CdTe absorbers with Se is a critical advancement for the fabrication of highly efficient CdTe thin-film solar cells. Herein, the role of the Se concentration gradient in CdSexTe1−x/CdTe solar cells is stressed in addition to the decreased bandgap and passivation effect of Se. The buried graded CdSexTe1−x at the front interface of the device was stripped and analyzed by quasi in situ x-ray photoelectron spectroscopy depth profiling. A serial shift of Fermi level toward the valence band was probed as the Se concentration decreased in the graded CdSexTe1−x absorber, revealing the presence of n-type CdSexTe1−x region near the front contact. Kelvin probe force microscopy characterizations and voltage-dependent photocurrent collection analysis further confirmed the existence of a buried junction in the graded CdSexTe1−x absorber. The CdS-free CdTe solar cell with a graded CdSexTe1−x/CdTe absorber fabricated in this study showed an efficiency of 17.6%. These results indicated that the non-uniform distribution of Se introduced a built-in field in the graded CdSexTe1−x absorber and enabled efficient separation of photogenerated carriers, yielding high-performance CdTe solar cells in the absence of a conventional n-type CdS window layer. This study deepened the understanding of the performance enhancement in Se-containing CdTe solar cells and provided new ideas for further performance optimization.
Managing photon flux in a miniaturized photoionization detector
Authors: Meyer Mackenzie , Huang Xiaheng , Fan Xudong , Kushner Mark J.
Published: April 2024

Miniaturized photoionization detectors (PIDs) are used in conjunction with gas chromatography systems to detect volatile compounds in gases by collecting the current from the photoionized gas analytes. PIDs should be inexpensive and compatible with a wide range of analyte species. One such PID is based on the formation of a He plasma in a dielectric barrier discharge (DBD), which generates vacuum UV (VUV) photons from excited states of He to photoionize gas analytes. There are several design parameters that can be leveraged to increase the ionizing photon flux to gas analytes to increase the sensitivity of the PID. To that end, the methods to maximize the photon flux from a pulsed He plasma in a DBD-PID were investigated using a two-dimensional plasma hydrodynamics model. The ionizing photon flux originated from the resonance states of helium, He(3P) and He(21P), and from the dimer excimer He2*. While the photon flux from the resonant states was modulated over the voltage pulse, the photon flux from He2* persisted long after the voltage pulse passed. Several geometrical optimizations were investigated, such as using an array of pointed electrodes. However, increasing the capacitance of the dielectric enclosing the plasma chamber had the largest effect on increasing the VUV photon fluence to gas analytes.
Using Kondo entanglement to induce spin correlations between disconnected quantum dots
Authors: Büsser C. A.
Published: April 2024

We investigate the entanglement between the spins of two quantum dots that are not simultaneously connected to the same system. Quantum entanglement among localized spins is a crucial property for the advancement of quantum computing and quantum information. Generating and controlling an entangled state between quantum dots have garnered significant attention in recent years for this reason. In this study, we demonstrate that information about the spin orientation of a quantum dot can be preserved, utilizing Kondo entanglement, within a reservoir of electrons. Subsequently, this information can be transmitted to another dot after the initial dot has been decoupled from the reservoirs. We employ a double quantum dot system in a parallel geometry to establish the initial state, where each dot interacts with reservoirs of different symmetries. A specific phase in the couplings is chosen to induce antiferromagnetic spin correlation between the dots. The time evolution of the initial state is analyzed using the time-dependent density matrix renormalization group method. Our findings reveal that a partially entangled state between the dots can be achieved, even when they are not simultaneously connected. This entangled state arises transiently and dissipates in the stationary state. The stability of the state observed during the transient phase is demonstrated. To comprehend the details of these phenomena, we employ a canonical transformation of real space.
Spatiotemporal reshaping of femtosecond laser pulses on interaction with gas sheath at ionization saturation intensity regime
Authors: Ansari A. , Kumar M. , Singhal H. , Chakera J. A.
Published: April 2024

Interaction of intense ultrashort laser pulse with gases generates a transient spatiotemporal electron density distribution via field ionization, which may lead to the spatiotemporal reshaping of the pulse, viz., its beam profile, pulse width, etc. Here, we present an experimental study on ultrashort laser pulse interaction with argon gas sheath in an ionization saturation intensity regime (∼1015–1017 W/cm2). The present investigation has been performed using a 6 mJ, 1 kHz, and 55−60 fs Ti:Sapphire laser pulse interaction with a ∼2.5 mm long argon sheath. After the laser gas interaction, the laser spatial profile exhibits a multi-ring structure around a central maximum spot. Laser gas interaction parameters, such as laser intensity, gas pressure, etc., affect the ring pattern significantly. Under optimum parameter conditions, the laser pulse has two rings in spatial profile, and the pulse width of the central spot is self-compressed to ∼35 fs. A theoretical calculation reveals that the laser beam’s spatiotemporal profile evolves as it propagates inside the gas sheath. The calculation also demonstrates that the gas ionization profile plays a crucial role in the spatiotemporal reshaping and self-compression of the laser beam. The calculation also shows that the generation of concentric ring patterns in the spatial profile is mainly due to the ionization of argon atoms into Ar+, Ar2+, and Ar3+ species in the interaction region. Such self-compressed laser pulses with concentric ring beam profiles may be useful for high-harmonic generation and shorter attosecond pulse trains.
A computational screening of Ta–Sb intermetallics at high pressure
Authors: Shi Diwei , Song Jiexi , Qin Yanqing , Chen Xinyu , Du Shiyu
Published: April 2024

The binary high-pressure phase diagram of the Ta–Sb system was constructed for the first time in this study, utilizing the evolutionary algorithm USPEX and density functional theory (DFT). Ten pressurized dynamically and mechanically stable or metastable novel phases of Ta–Sb were discovered, including I4/mmm-TaSb2, P4/nmm-TaSb, P-3-Ta2Sb7, I4/mmm-Ta2Sb3, P-4m2-Ta7Sb, Pm-3-Ta7Sb, Pmm2-Ta15Sb, P4/nmm-TaSb3, I4/mmm-Ta3Sb4, and I4/mmm-Ta2Sb5. The compounds P-4m2-Ta7Sb and Pmm2-Ta15Sb exhibit promising characteristics as non-centrosymmetric superconductors (NCSs), with their superconducting critical temperature (TC) being 3.831 and 3.221 K, respectively. The application of pressure tuning is predicted to transform the topological characteristics of P4/nmm-TaSb, causing it to transition from a topological insulator state to a Dirac semimetal state and ultimately reverting back to a topological insulator state. Therefore, the P4/nmm-TaSb compound is considered a promising candidate to investigate topological and superconducting excitations. Moreover, the mechanical and thermal properties of Ta–Sb binary phases were also investigated. The thermal conductivity of I4/mmm-TaSb2, P4/nmm-TaSb, and P4/nmm-TaSb3 all surpasses 20 W m−1 K−1 at 1000 K, showcasing their excellent thermal conductivity properties. The present study addresses the research gap concerning high-pressure structures in the Ta–Sb binary system, thereby offering valuable insights for the design and development of intermetallic compounds within this binary system.
Parametric learning of time-advancement operators for unstable flame evolution
Authors: Yu Rixin , Hodzic Erdzan
Published: April 2024

This study investigates the application of machine learning, specifically Fourier neural operator (FNO) and convolutional neural network (CNN), to learn time-advancement operators for parametric partial differential equations (PDEs). Our focus is on extending existing operator learning methods to handle additional inputs representing PDE parameters. The goal is to create a unified learning approach that accurately predicts short-term solutions and provides robust long-term statistics under diverse parameter conditions, facilitating computational cost savings and accelerating development in engineering simulations. We develop and compare parametric learning methods based on FNO and CNN, evaluating their effectiveness in learning parametric-dependent solution time-advancement operators for one-dimensional PDEs and realistic flame front evolution data obtained from direct numerical simulations of the Navier–Stokes equations.
Childhood maltreatment influences adult brain structure through its effects on immune, metabolic, and psychosocial factors
Authors: Orellana Sofia C. , Bethlehem Richard A. I. , Simpson-Kent Ivan L. , van Harmelen Anne-Laura , Vértes Petra E. , Bullmore Edward T.
Published: April 2024

Childhood maltreatment (CM) leads to a lifelong susceptibility to mental ill-health which might be reflected by its effects on adult brain structure, perhaps indirectly mediated by its effects on adult metabolic, immune, and psychosocial systems. Indexing these systemic factors via body mass index (BMI), C-reactive protein (CRP), and rates of adult trauma (AT), respectively, we tested three hypotheses: (H1) CM has direct or indirect effects on adult trauma, BMI, and CRP; (H2) adult trauma, BMI, and CRP are all independently related to adult brain structure; and (H3) childhood maltreatment has indirect effects on adult brain structure mediated in parallel by BMI, CRP, and AT. Using path analysis and data from
N
= 116,887 participants in UK Biobank, we find that CM is related to greater BMI and AT levels, and that these two variables mediate CM’s effects on CRP [H1]. Regression analyses on the UKB MRI subsample (
N
= 21,738) revealed that greater CRP and BMI were both independently related to a spatially convergent pattern of cortical effects (Spearman’s ρ = 0.87) characterized by fronto-occipital increases and temporo-parietal reductions in thickness. Subcortically, BMI was associated with greater volume, AT with lower volume and CPR with effects in both directions [H2]. Finally, path models indicated that CM has indirect effects in a subset of brain regions mediated through its direct effects on BMI and AT and indirect effects on CRP [H3]. Results provide evidence that childhood maltreatment can influence brain structure decades after exposure by increasing individual risk toward adult trauma, obesity, and inflammation.
Harmonic resonance and entrainment of propagating chemical waves by external mechanical stimulation in BZ self-oscillating hydrogels
Authors: Geher-Herczegh Tunde , Wang Zuowei , Masuda Tsukuru , Vasudevan Nandini , Yoshida Ryo , Hayashi Yoshikatsu
Published: April 2024

Smart polymer materials that are nonliving yet exhibit complex “life-like” or biomimetic behaviors have been the focus of intensive research over the past decades, in the quest to broaden our understanding of how living systems function under nonequilibrium conditions. Identification of how chemical and mechanical coupling can generate resonance and entrainment with other cells or external environment is an important research question. We prepared Belousov–Zhabotinsky (BZ) self-oscillating hydrogels which convert chemical energy to mechanical oscillation. By cyclically applying external mechanical stimulation to the BZ hydrogels, we found that when the oscillation of a gel sample entered into harmonic resonance with the applied oscillation during stimulation, the system kept a “memory” of the resonant oscillation period and maintained it post stimulation, demonstrating an entrainment effect. More surprisingly, by systematically varying the cycle length of the external stimulation, we revealed the discrete nature of the stimulation-induced resonance and entrainment behaviors in chemical oscillations of BZ hydrogels, i.e., the hydrogels slow down their oscillation periods to the harmonics of the cycle length of the external mechanical stimulation. Our theoretical model calculations suggest the important roles of the delayed mechanical response caused by reactant diffusion and solvent migration in affecting the chemomechanical coupling in active hydrogels and consequently synchronizing their chemical oscillations with external mechanical oscillations.
Molecular mechanism underlying SNARE-mediated membrane fusion enlightened by all-atom molecular dynamics simulations
Authors: Rizo Josep , Sari Levent , Jaczynska Klaudia , Rosenmund Christian , Lin Milo M.
Published: April 2024

The SNAP receptor (SNARE) proteins syntaxin-1, SNAP-25, and synaptobrevin mediate neurotransmitter release by forming tight SNARE complexes that fuse synaptic vesicles with the plasma membranes in microseconds. Membrane fusion is generally explained by the action of proteins on macroscopic membrane properties such as curvature, elastic modulus, and tension, and a widespread model envisions that the SNARE motifs, juxtamembrane linkers, and C-terminal transmembrane regions of synaptobrevin and syntaxin-1 form continuous helices that act mechanically as semirigid rods, squeezing the membranes together as they assemble (“zipper”) from the N to the C termini. However, the mechanism underlying fast SNARE-induced membrane fusion remains unknown. We have used all-atom molecular dynamics simulations to investigate this mechanism. Our results need to be interpreted with caution because of the limited number and length of the simulations, but they suggest a model of membrane fusion that has a natural physicochemical basis, emphasizes local molecular events over general membrane properties, and explains extensive experimental data. In this model, the central event that initiates fast (microsecond scale) membrane fusion occurs when the SNARE helices zipper into the juxtamembrane linkers which, together with the adjacent transmembrane regions, promote encounters of acyl chains from both bilayers at the polar interface. The resulting hydrophobic nucleus rapidly expands into stalk-like structures that gradually progress to form a fusion pore, aided by the SNARE transmembrane regions and without clearly discernible intermediates. The propensity of polyunsaturated lipids to participate in encounters that initiate fusion suggests that these lipids may be important for the high speed of neurotransmitter release.
Unlocking the performance evolution of GdBCO coated conductors irradiated by deuterium plasma
Authors: Wang Meiqi , Huang Daxing , Wang Tongxin , Dong Hao , Zhang Wenjie , Jiang Zhenyu , Gu Hongwei , Zhu Kaigui , Ding Fazhu
Published: April 2024

REBa2Cu3O7-δ
(REBCO, RE: rare earth) coated conductors (CCs) can generate a powerful magnetic field and are optimal for sustaining the reaction in fusion devices. However, the REBCO CCs will inevitably be exposed to neutron radiation during device operation. Transmutation produces gas atoms such as hydrogen will affect their properties. In this paper, GdBCO CCs were irradiated by 20 eV deuterium plasma. It was found that the irradiation introduced smaller (2–4 nm) pinning sites that formed a mixed pinning landscape with rare earth oxides (tens of nanometres) in the pristine samples, leading to an improved vortex pinning. At an irradiation fluence of 5.0 × 1018 D cm−2, the J
c values of the samples irradiated by deuterium can maintain the best enhancement of in-field performance at 4.2 K. Excess irradiation results in a decrease in J
c, a broadening of the superconducting transition width, and an enhanced disorder in GdBCO. This study provides some valuable insights for potential changes in the properties of REBCO CCs irradiated in fusion devices.
Soliton molecules, breather molecules and stability analysis of the three-coupled nonlinear Schrödinger equation
Authors: Xiong Zuoxin , Ren Bo
Published: April 2024

We investigate the three-coupled nonlinear Schrödinger (NLS) equation, which holds a significant physical implications in optical communications and biophysics. The multi-soliton solutions are derived utilizing the Hirota bilinear method. Multi-breather solutions are presented by assuming certain relationship for the parameters of the multi-solitons. By introducing the velocity resonance mechanism to multiple soliton/breather solutions, it is found that the three-coupled NLS model possesses abundant soliton molecule, breather molecule and breather-soliton molecule structures. The interactions among different types of soliton molecules which can be observed in marine and oceanic waters are investigated through numerical simulation. Ultimately, baseband modulation instability of the three-coupled NLS equation is analyzed. It is highly significance for the study of soliton formation and rogue waves in the three-coupled NLS equation.
Magnetic modes for enhancing second harmonic generation at ultraviolet frequencies
Authors: He Yonglin , Wang Jingyu , Yang Weimin , Jiang Shengjie
Published: April 2024

Enhancing nonlinear frequency conversions at ultraviolet (UV) frequencies holds immense significance in contemporary physics and nanophotonics. In this work, we have theoretically demonstrated a highly efficient UV second-harmonic generation (SHG) in the Al nanorod−LiNbO3 (LN)−Al film nanostructure by two orders of magnitude higher compared to the conventional LiNbO3 nanostructure in this range. This result is acquired by designing a simple Al nanoparticle-Al film plasmonic system that generates magnetic resonances at near-UV frequencies to confine light to the LN, which can highly enhance the electromagnetic field and lead to strong interactions with the large nonlinear susceptibility. Our research provides profound insights into the pivotal role of plasmon-induced magnetic resonance (PIMR) modes in UV-SHG processes, thereby opening up new avenues for the development of nanoscale UV nanosources and nonlinear metasurface applications at subwavelength scale.
Compressive Property of Biomass Briquettes Made of Hazelnut Shell and Peanut Shell
Authors: Gusnia Yessi , Aditya Irfan Dwi , Widayani
Published: April 2024

In Indonesia, energy consumption increases as with its population, while fossil energy sources keep running out. This condition forces the development of non-fossil energy sources. One promising alternative is biomass briquette. In this study a biomass briquette was made using hazelnut shell (limbah cangkang kemiri CK) and peanut shell waste (kulit kacang tanah KT) with various CK concentrations: 0/24, 4/24, 8/24, 12/24, 16/24, 20/24, and 24/24 (w/w). Initially, dried CK and KT waste were processed into charcoal powder with a particle size of ~ 0,25 mm. The briquette was prepared by densification of the two charcoal mixtures at a pressure of 29778,99 N/m2 for 15 min, followed by heating at 60 °C for 4 h. Due to storage and delivery process in the application, briquettes must have good compressive properties. In this study, compressive property of the produced briquette was characterized using a universal testing machine (UTM). The results showed that the values of ultimate strength, modulus of elasticity, and elongation at break of the CK-KT briquette increased with increasing CK concentration, with highest values of 5.69 MPa, 80 MPa and 0.146, respectively.
Accuracy and Characteristic of Electrocardiographic Signal from Mobile Biomedical Sensor
Authors: Rahmansyah Praditya Rizky , Khotimah Siti Nurul , Haryanto Freddy , Sofyansyah Ridwan
Published: April 2024

Based on the Global Burden of Disease and the Institute for Health Metrics and Evaluation 2014-2019, heart disease is the highest cause of death in Indonesia. One way to deal with this disease is through early detection by reading the electrical signals of the heart. Therefore, the technology for recording the electrocardiographic signal is developing rapidly. Recently, there have been many uses of biomedical sensors to record the electrical activity of the heart by utilizing internet facilities and without cables. This study discusses the accuracy and characterization of cardiac signals recorded by the portable KardiaMobile 6L against the Fukuda M.E Cardisuny type C100 clinical electrocardiograph (ECG). The data are taken from 9 patients using both devices simultaneously. ECG signals from the two devices are digitized using web plot digitizer to obtain the RR interval values. The clinical ECG produces 6 ECG signals (as short data). Meanwhile, the KardiaMobile produces ECG signals for 30 seconds (as long data- and five sequential ECG signals can be sampled as short data). Accuracy is done through linear regression, percent difference, and root mean squared error for the heart rate in two devices and RR interval from ECG signals. They provide excellent goodness of fit measures for the linear regression. The percent difference is still in the reliability of the devices. The value of RMSE is very low. Characterization of ECG signals is done by t-test between two array RR interval data from two leads for the same device. Using KardiaMobile, the RR interval value of short data is not significantly different from long data for a subject with normal sinus rhythm. The RR interval value of long data and short data between two leads is not significantly different. Using clinical ECG, the RR interval value of short data between two leads is not significantly different. Therefore, KardiaMobile has an accuracy similar with a clinical electrocardiograph in determining HR and is effective for analyzing dynamic changes based on RR intervals.
The Effect of Porous Media Grain Size on non-Darcy Flow Behavior using Pore Scale Simulation
Authors: Feriadi Yusron , Fauzi Umar , Rizqie Arbie M , Fariduzzaman
Published: April 2024

The impact of grain size of the porous media of the 3D images of a beadpack on the permeability values and non-Darcy flow behaviour is analyzed using pore-scale flow modelling utilizing the finite volume method. In this study, the sample used was a 3D image from random tight packing of spheres (beadpack) with a size of 250×250×250 voxels and a porosity of 0.36. Variation in grain size is carried out by upscaling the 3D image sample, so that this treatment affects the specific surface area value but does not change the porosity and tortuosity of the sample. Several variations of grain diameter include 100 μm, 125 μm, 150 μm, 175 μm, and 200 μm. In this study, we adopted PIMPLE algorithm, which combines SIMPLE and PISO algorithms to accomplish the Navier-Stokes equations of fluid dynamics in such porous media. The simulation results show that the permeability value exhibits an inverse relationship with the specific surface area. This correlation is in accordance with the Kozeny-Carman equation. In addition, the initiation of non-Darcy flow occurs at the reference length-based Reynolds number of 2.06 and the permeability-based Reynolds number of 0.049.
Time Lapse Measurement of Reservoir’s Parameters Change due to CO2 Injection in Parigi Carbonate West Java
Authors: Nurhandoko Bagus Endar B. , Wibowo Satryo Agung , Chandra Rufidi , Apriansyah Boma , Handietri Zerlinda , Pratiwi Ratih , Cindrawati Maria , Manullang Tri Agatha , Susilowati  , Abdillah Fathur Rijal , Nefrizal  , Nurani Amalia , Endaryanto Aris , Supriyanto Eko Bambang
Published: April 2024

CO2 injection is a process that involves injecting carbon dioxide gas into various substances or environments for different purposes. This technique, also called Carbon Capture and Storage (CCS) or Carbon Capture, Utilization, and Storage (CCUS), aims to prevent or reduce carbon dioxide emissions from reaching the atmosphere as they would affect climate change and also global warming. CCUS can also use the captured carbon dioxide for various purposes, such as enhancing oil recovery, producing fuels, chemicals, or building materials, or storing it underground or underwater. In this study, we investigated the phenomena of CO2 injection in Parigi carbonate rock from West Java. Our study involved various laboratory measurements of Parigi carbonate rock, focusing on changes in porosity due to CO2 injection. The porosity changes were observed using micro images analysis from microscope time-lapse analysis, CT-Scan, and laboratory helium porosity meter. The laboratory measurements of CO2 injection in brine water showed that the pH of the water can decrease to below 5, creating an acidic environment that induces dissolution of the pore structure. We measure the effect of CO2 injection to the Parigi carbonate samples by time lapse measurement strategy. Results of the laboratory measurements showed that the porosity increased during CO2 injection and the mass of the samples decreased during the CO2 injection process. These phenomena suggest that CO2 may induce dissolution of carbonate rock. Furthermore, the changes in porosity confirm that there is a chemical reaction during CO2 injection processes in Parigi carbonate.
Performance of 3D quantum Otto engine with partial thermalization
Authors: Sutantyo T E P , Zettira Z , Fahriza A , Abdullah Z
Published: April 2024

We investigate the phenomenon of partial thermalization in the context of the efficiency at maximum power (EMP) for a quantum Otto engine. This engine utilizes Bose-Einstein Condensation in a cubic potential. The occurrence of partial thermalization is observed during a finite-time isochoric process, preventing the system from reaching an equilibrium state with the reservoirs and leaving it in a state of residual coherence. The engine’s performance can be evaluated based on its power output and EMP. The cubic potential is employed to induce energy excitation during the expansion and compression phases. The total energy is determined by the work done over a complete cycle. Utilizing Fourier’s law for heat conduction, we have determined that the power output is explicitly influenced by the duration of the heating and cooling strokes as well as the engine’s efficiency. Specifically, a longer stroke time and higher efficiency result in reduced power output. To calculate EMP, we optimize power by varying the compression ratio (κ), and we have found that EMP is also influenced by the isochoric heating and cooling processes. When varying the duration of the isochoric process, EMP shows a slight decrease as isochoric time increases due to entropy production. However, significant improvements in the EMP of the Otto Engine can be achieved by extending the cooling stroke time beyond the heating stroke time.
Optimizing Neural Networks for Enhanced Material Property Predictions: Insights from Bulk Modulus Analysis
Authors: Syamsul Andi M. N. F. , Pradipto Abdul-Muizz , Soehianie Agoes
Published: April 2024

This research presents a deep learning model designed to accurately compute material properties, with a specific focus on the bulk modulus. This study places significant emphasis on hyperparameter optimization, involving adjustments to batch size, learning rate, hidden layer, and neuron count. The dataset, comprising 7107 diverse materials, undergoes thorough preprocessing, which includes outlier removal and the extraction of elemental property descriptors using the matminer library and the Magpie dataset. The core model utilized in this research is an Artificial Neural Network (ANN), with the descriptors serving as crucial input features. Model performance assessment is conducted by using the Mean Absolute Error (MAE) as a quantitative metric, providing insights into predictive accuracy. This research also employs sensitivity analysis to scrutinize the significance of 132 features in predicting the bulk modulus property, contributing to an understanding of material behavior dynamics and facilitating model optimization. The results highlight the impact of neuron count, layer depth, learning rate, and batch size on prediction accuracy. Furthermore, feature importance analysis underscores the critical role of specific material properties, with mean covalent radius emerging as the most influential factor in predicting the bulk modulus. These discoveries provide guidelines for optimizing neural network configurations and material property descriptors for predicting material elasticity.
Computation and Modelling of Seismic Refraction Tomography for Anisotropic Medium Based on Pseudo Bending Method
Authors: Hamimu La , Haraty Syamsul Razak , Rubaiyn Al , Juarzan La Ode Ihksan , Indrawati
Published: April 2024

Seismic refraction tomography is one of the imaging techniques in geophysical methods used to remodel the near-surface velocity layer structure of the Earth. In this study, we carried out a new computational approach and modelling of seismic refraction tomography using the pseudo-bending method. The true model of the near-surface is designed to be anisotropic medium which is having a low velocity anomaly distribution. This anomaly is constructed in such a way as to be similar to a model of liquid waste away spreading, which exhibits seismic velocities ranging from 1600 m/s to 1800 m/s. Based on our computations and numerical modelling results, it was found that the ray tracing path using pseudo-bending method displays an asymmetrical trajectory when the positions of the source and geophone are exchanged. Altering the shooting configuration from direct shoot (DS) to reversed shoot (RS) also reveals a significant difference in travel time values. The results of delay time tomography inversion, which represents the difference between travel times in the true model and the initial model using the SIRT method, indicate the presence of a low velocity anomaly that can be interpreted as the distribution of liquid waste.
The Two-Dimensional Conduction Heat Transfer Equation on a Square Plate: Explicit vs. Crank-Nicolson Method in MS Excel Spreadsheet
Authors: Eso Rosliana , Napirah Mardiana , Usman Ida , Safiuddin La Ode , Arman  , Tahir  , Aba La , Alfat Sayahdin , Husein  , Hamimu La , Sahara La
Published: April 2024

In this paper, the two-dimensional conduction heat transfer equation on a square plate is analyzed using a finite difference method. We have developed both the forward time-centered space (FTCS) and Crank-Nicolson (CN) finite difference schemes for the two-dimensional heat equation, employing Taylor series. Subsequently, these schemes were employed to solve the governing equations. The primary objective of this study is to compare the efficiency of the two methods in solving the conduction heat transfer equation. This was accomplished by implementing Spreadsheet Excel instructions. The results are presented, highlighting a comparison between the exact and approximate solutions. Furthermore, to demonstrate the convergence of the numerical schemes, we estimated the error between the actual and approximate solutions for a specific numerical problem and presented the results graphically. The data utilized in this research included the thermal conductivity of the medium of the square plate concerning width, grid, and compliance with initial and boundary conditions. The findings indicate that the Crank-Nicolson method is more accurate than the forward time-centered space method, as it approaches the exact solution more effectively. Furthermore, this study confirms that the solution and simulation of the heat transfer equation on a square plate can be accurately performed using an Excel spreadsheet as well as other numerical software.
Correlation between lithium-ion diffusion and coordination environment in solid polymer electrolytes: a molecular dynamics study
Authors: Sundari C D D , Fitriani P , Arcana I M , Iskandar F
Published: April 2024

Lithium-ion diffusion in solid polymer electrolytes (SPEs) is a pivotal characteristic that significantly influences overall lithium-ion battery performance. This characteristic can be affected by the coordination environment of lithium ions within the polymer matrix. However, the correlation between lithium-ion diffusion and its coordination environment in biopolymer-based SPEs such as carboxymethyl chitosan (CMCS) remains understudied. In this study, we used molecular dynamics (MD) simulations to investigate this correlation. Lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) was used as the lithium salt in the simulated systems. All MD simulations were conducted using the GROMACS package with the general AMBER force field (GAFF). The coordination structures around Li+ were successfully estimated using the radial distribution function obtained from the MD simulations. These results indicate a preference for Li+ coordination with oxygen atoms, both from the CMCS polymer chains (OCMCS) and TFSI− ions (OTFSI-). The coordination number between Li+ and OCMCS decreases as the concentration of LiTFSI increases. The diffusion coefficients of Li+ varied depending on the concentration of LiTFSI and demonstrated a sensitivity to the coordination structure of Li+. A high diffusion coefficient of Li+ ions was observed at low LiTFSI concentrations, where Li+ was primarily coordinated with oxygen atoms from the CMCS polymer chains.
A Simulation of Hydrazine Molecule’s Potential Energy Surface using Variational Quantum Eigensolver Algorithm
Authors: Gomosma Godwin , Agusta Mohammad Kemal , Dipojono Hermawan Kresno
Published: April 2024

Quantum computing is a technology that utilizes the principles of quantum mechanics to perform complex computational processes. In this work, we use Qiskit Module from IBM to do quantum computational calculation using Variational Quantum Eigensolver (VQE) algorithm. VQE is a hybrid quantum-classical method that combines a quantum computer to measure energies and a classical computer to process the measurement results and update the parameters of the quantum computer. The purpose of VQE is to find the ground state energy of a chemical system. In the previous study, many of the VQE calculations have been done on simple molecules. So, in this study, we would like to use Hydrazine molecule as our object of VQE calculation. Furthermore, these results will be compared with the results from the classical calculation (MP2, CCSD(T), QCISD(T), and CASSCF) methods for testing the effectiveness of VQE using Unitary Coupled-Cluster Single and Double excitations (UCCSD) Ansatz. The quantum algorithm based on the UCCSD Ansatz led to a simplification of the algorithm by reducing the circuit depth. Then, the possibility to use active space approximation, can be used to reduce the quantum gates while trying to keep a good level of accuracy. In this study, we chose (2,2) and (4,4) active spaces. Based on the results, as we increase the size of the active space during the evaluation of the single-point energy, the estimated ground states obtained from the VQE algorithm yield nearly identical values. Conversely, in CASSCF calculations, expanding the active space introduces more energy corrections, thus making it more sensitive. Additionally, when examining potential energy surfaces, VQE demonstrates results that gradually align with CCSD(T) and QCISD(T) methods.