bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient CO2 hydrogenation to formate with an iridium catalyst supported by a porous organic polymer containing an N-phenylpicolinamide motif
Authors: Ding Yang , Duan Yikang , Li Yang , Wang Jiasheng , Bao Ming , Himeda Yuichiro , Wang Wan-Hui
Published: December 2024

Two highly active POP-supported Ir catalysts functionalized with an N-phenylpicolinamide motif were synthesized by a straightforward method for the hydrogenation of CO2 to formate.
Electrokinetic flow instabilities in shear thinning fluids with conductivity gradients
Authors: Chen To-Lin , Raihan Mahmud Kamal , Tabarhoseini Seyed Mojtaba , Gabbard Chase T. , Islam Md Mainul , Lee Yu-Hsiang , Bostwick Joshua B. , Fu Lung-Ming , Xuan Xiangchun
Published: December 2024

Electrokinetic instabilities in a shear thinning fluid start at a smaller electric field and an earlier location than in a Newtonian fluid but with a smaller wave amplitude and frequency.
Facilitating polysulfide conversion kinetics via multifunctional solid-state electrolytes under lean electrolyte conditions for lithium–sulfur batteries
Authors: Park Hyunji , Lee Jooyoung , Yu Choongho
Published: December 2024

A Li10GeP2S12 superionic conductor provides efficient lithium-ion pathways in lean-electrolyte Li–S batteries, enhancing polysulfide affinity and conversion kinetics.
Effect of molecular size on the electrocatalytic activity of M-N4-C catalysts for ORR, OER, and HER
Authors: Xie Liang , Zhou Wei , Qu Zhibin , Meng Xiaoxiao , Huang Yuming , Zhang Xuewei , Yang Chaowei , Li Junfeng , Li Jingyu , Sun Fei , Gao Jihui , Zhao Guangbo
Published: December 2024

This study uses density functional theory to analyze the size-dependent electrocatalytic performance of M-N4-C catalysts, revealing stability and activity fluctuations, particularly for nC@FeN4 and nC@CoN4.
A flexible protective electronic skin with tunable anti-impact and thermal insulation properties for potential rescue applications
Authors: Wang Wenhui , Wang Sheng , Li Zimu , Zhou Jianyu , Liu Shuai , Xuan Tingting , Zhang Junshuo , Gong Xinglong
Published: December 2024

A flexible protective electronic skin (FPES) with excellent and adjustable impact and thermal protection has been developed. The FPES functions as a capacitive sensor, effectively monitoring both impact pressure and high temperature.
Supernova remnants on the outskirts of the Large Magellanic Cloud
Authors: Sasaki Manami , Zangrandi Federico , Filipović Miroslav , Alsaberi Rami Z. E. , Collier Jordan D. , Haberl Frank , Heywood Ian , Kavanagh Patrick , Koribalski Bärbel , Kothes Roland , Lazarević Sanja , Maggi Pierre , Maitra Chandreyee , Points Sean , Smeaton Zachary J. , Velović Velibor
Published: December 2024

When a star dies, it can explode in a supernova, causing a strong shock wave and forming an interstellar object called a supernova remnant (SNR). Observational studies of SNRs allow us to learn about the different types of progenitors, the explosion mechanisms, the physics of interstellar shocks, and the matter cycle in galaxies. We report on the first detection of SNRs located on the outskirts of a galaxy; namely, the Large Magellanic Cloud (LMC), the largest satellite galaxy of our Galaxy. The sources were discovered ∼3° outside the main stellar and gas distribution of the LMC in the recent surveys in radio with the Australian Square Kilometre Array Pathfinder (ASKAP) and in X-rays with the extended Roentgen Survey with an Imaging Telescope Array (eROSITA). We studied them in follow-up observations with the X-ray Multi-Mirror Mission-Newton telescope and MeerKAT and confirmed them to be SNRs. Their progenitors are most likely stars that had left the LMC due to tidal interaction between the Magellanic Clouds and the Milky Way. SNR J0614-7251 is located in an environment with a similar density to those of the other known SNRs in the LMC, and has similar X-ray properties. SNR J0624-6948, on the other hand, is located in a region with a lower density, n0 < 0.01 cm−3. Its radio shell shows a spectral index and polarisation typical of an SNR.
Unified multiwavelength data analysis workflow with gammapy
Authors: Nievas Rosillo M. , Acero F. , Otero-Santos J. , Vazquez Acosta M. , Terrier R. , Morcuende D. , Arbet-Engels A.
Published: December 2024

Context. The flat-spectrum radio quasar (FSRQ) OP 313 entered an enhanced activity phase in November 2023 and has undergone multiple flares since then. This activity has motivated the organization of several large multi-wavelength campaigns, including two deep observations from the hard X-ray telescope NuSTAR. We investigate the broadband emission from OP 313 during these two observations, based on a new unified analysis framework, with data in the optical to γ rays.

Aims. Traditional methods for analyzing blazar emission often rely on proprietary software tailored to specific instruments, making it challenging to integrate and interpret data from multiwavelength campaigns in a comprehensive way. This study demonstrates the feasibility of utilizing gammapy, an open-source Python package, together with common data formats originally developed for γ-ray instrumentation to perform a consistent multi-instrument analysis. This enables a forward-folding approach that fully incorporates source observations, detector responses, and various instrumental and astrophysical backgrounds. This methodology has been applied to an example set of recent data collected from the distant quasar OP 313.

Methods. We present a comprehensive data reconstruction and analysis for instruments including the Liverpool Telescope’s IO:O detector, Swift-UVOT, Swift-XRT, NuSTAR, and Fermi-LAT. The resulting spectral analysis has been validated against the native tools for each instrument. Additionally, we developed a multiwavelength phenomenological model of the source emission, encompassing the optical to γ-ray bands and incorporating absorption components across different energy regimes.

Results. We have introduced and validated a new unified framework for multiwavelength forward-folding data analysis based on gammapy and open data formats, demonstrating its application to spectral data from the quasar OP 313. This approach provides a more statistically correct treatment of the data than fitting a collection of flux points extracted from the different instruments. This study is the first to use a common event data format and analysis tool covering 11 orders of magnitude in energy, from approximately 1 eV to 100 GeV. The high-level event data, instrument response functions, and models are provided in a gammapy-compatible format, ensuring accessibility and reproducibility of scientific results. A brief discussion on the origin of the broadband emission of OP 313 is also included in this work.
High-resolution simulation of coastal flooding under extreme storm tides and sea level rise: A case study of Macau
Authors: Zhuge Wenxiao , Liu Xiaodong , Li Huajun , Liang Bingchen
Published: December 2024

In the face of climate change, coastal cities are challenged with growing risks from rising sea levels and intensified storm surges which could turn urban areas into temporary waterways. To address this, our study developed a high-resolution coastal urban flood model, OUC-CUFM (Ocean University of China – Coastal Urban Flood Model), designed to help municipal governments make precise coastal flood forecasts and reduce potential threats to people and property. This model is based on two-dimensional nonlinear Navier–Stokes shallow water equations, incorporating factors like local acceleration, convection, bottom friction, wind stress, and shallow water effects. Using the finite difference method with upwind spatial discretization and a leapfrog time scheme, it can simulate detailed street-level water flow interactions with buildings. In a case study on Macau, we used a 5-m resolution digital elevation model to simulate storm tide flooding from Typhoons Hato (2017) and Mangkhut (2018), with the former for model calibration and the later for validation. Comparisons between simulated and observed water levels showed that the model accurately captured storm water arrival, overtopping, and flood extent and depth. The model also projected flood changes under sea level rise (SLR) scenarios of 0.5 m (by 2070) and 1.0 m (by 2100) for Typhoon Hato, indicating that such SLRs would significantly increase storm-induced flood depth and extent. This model serves as a valuable tool for street-scale flood risk analysis, hazard mapping, and assessing the impact of coastal defenses, like dyke upgrades or new dyke construction, in densely built coastal cities.
Climate change could amplify weak synchrony in large marine ecosystems
Authors: Karatayev Vadim A. , Munch Stephan B. , Rogers Tanya L. , Reuman Daniel C.
Published: December 2024

Climate change is increasing the frequency of large-scale, extreme environmental events and flattening environmental gradients. Whether such changes will cause spatially synchronous, large-scale population declines depends on mechanisms that limit metapopulation synchrony, thereby promoting rescue effects and stability. Using long-term data and empirical dynamic models, we quantified spatial heterogeneity in density dependence, spatial heterogeneity in environmental responses, and environmental gradients to assess their role in inhibiting synchrony across 36 marine fish and invertebrate species. Overall, spatial heterogeneity in population dynamics was as important as environmental drivers in explaining population variation. This heterogeneity leads to weak synchrony in the California Current Ecosystem, where populations exhibit diverse responses to shared, large-scale environmental change. In contrast, in the Northeast U.S. Shelf Ecosystem, gradients in average environmental conditions among locations, filtered through nonlinear environmental response curves, limit synchrony. Simulations predict that environmental gradients and response diversity will continue to inhibit synchrony even if large-scale environmental extremes become common. However, if environmental gradients weaken, synchrony and periods of large-scale population decline may rise sharply among commercially important species on the Northeast Shelf. Our approach thus allows ecologists to 1) quantify how differences among local communities underpin landscape-scale resilience and 2) identify the kinds of future climatic changes most likely to amplify synchrony and erode species stability.
Magnetoelectric properties and Morin type spin transitions of Na-doped GaFeO3
Authors: Rahmany Zamzama , S Savitha Pillai
Published: December 2024

The effects of Na doping on the structure magnetic, electric, and magnetoelectric properties of GaFeO3 were studied. Rietveld refinement of the XRD data reveals the formation of a single-phase trigonal structure with no impurity on Na doping up to 50% and a significant increase in lattice strain with doping. FTIR and Raman analysis further supported the phase purity of the samples. The morphology of the samples was studied using FESEM, and the particle size increased with Na doping. Magnetic data shows room temperature ferrimagnetic properties. Temperature-dependent magnetization measurements revealed a noticeable change from GaFeO3, exhibiting a Morin-like transition at 182 K for the lowest Na content. This AFM transition temperature increased to 217 K with the highest Na doping levels. The temperature-dependent Raman spectra do not reveal any structural phase transition and show a distinct change in phonon modes near the spin reorientation temperature. The leakage current density of the samples at 100 volts increased from 10−8 A cm−2 to (10−4–10−5 A cm−2) with Na doping. The frequency-dependent dielectric constant increased largely with doping. The magnetoelectric coupling coefficient measured at room temperature rises for x = 0.05 to (36.2 ps m−1) and slowly decreases as Na concentration increases.
Transfer matrix in graphene-like materials: the case of silicene and transition metal dichalcogenides
Authors: Ibarra-Reyes M , Pérez-Álvarez R , Rodríguez-Vargas I
Published: December 2024

The fundamental properties of 1D Dirac-like problems in silicene and transition metal dichalcogenides (TMDs) are derived with the use of the transfer matrix. Analytic expressions for the transmission coefficient and the bound states are obtained for these 2D materials. The continuity between states of perfect transmission and bound states is also addressed in silicene and TMDs. The similarities and differences with respect to the fundamental properties of 1D Dirac-like problems in graphene derived with the transfer matrix (Ibarra-Reyes et al 2023 J. Phys.: Condens. Matter
35 395301) are discussed.
Newly formed carbon nanotubes as counter electrodes for wire-shaped Dye-sensitized solar cells (WDSSCs)
Authors: Ahmad Arsalan , M Alshehri Badria , Kanjariya Prakash , Kumar Nitin , Sharma Rohit , Kalyani Teku , Kumari Bharti , Al-Dossari Mawaheb , EL-Gawaad N S Abd
Published: December 2024

In this study, the electrodeposition method is employed to treat carbon nanotubes (CNTs) with polythiophene (PTh), polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) (PEDOT), and polyaniline (PANI) polymers, and used them as counter electrodes (CEs) in the structure of wire-shaped dye-sensitized solar cells (WDSSCs). Photoanodes are made of Ti wires that have been anodized and surface treated to produce TiO2. We used FESEM images, FTIR, EIS, CV, and Tafel analyses for characterization. Electrochemical methods demonstrate that PEDOT and PANI CEs have higher electrocatalytic activity than that of PTh and PPy polymers, resulting in more current for the WDSSCs. Furthermore, PANI and PEDOT CEs have higher electrocatalytic activity than platinum wire, which is promising. The efficiency of the wire-shaped solar cell based on PEDOT and PANI CEs are 8.51 and 8.58%, which are improved respectively by 7 and 8% compared to the Pt sample, indicating that it could be a promising replacement for this expensive element. Furthermore, the power conversion efficiency test for wire-shaped solar cells using polymer CEs demonstrates their proper performance at various bending angles as well as their high mechanical stability. The long-term stability of wire-shaped solar cells (2000 hours) demonstrates that PANI and PEDOT solar cells have maintained respectively 94 and 88% of their initial efficiency.
TiS2 quantum dots composite carbon nanotubes aerogel with electromagnetic interference shielding effect
Authors: Kong Mengnan , Zhou Liangliang , Chao Xingbing , Chang Zhangyong , Wang Qing
Published: December 2024

Titanium disulfide quantum dots (TiS2 QDs) has garnered significant research interest due to its distinctive electronic and optical properties. However, the effectiveness of TiS2 QDs in electromagnetic interference (EMI) shielding is influenced by various factors, including their size, morphology, monodispersity, tunable bandgap, Stokes shift and interfacial effects. In this study, we propose a systematic approach for the synthesis of TiS2 QDs with small size (3.1 nm), uniform dispersion (∼1.5 nm), a transition from indirect to direct bandgap (bulk 0.09 eV-monolayer 0.69 eV), large Stokes shift (∼93 nm) and larger surface area containing multiple active interfaces, achieved through ultrasound-assisted liquid phase processing. Subsequently, these QDs are combined with carbon nanotubes (CNTs) to fabricate an aerogel with outstanding EMI shielding capabilities. The resulting TiS2 QDs composite CNTs (C-TiS2) aerogel demonstrates robust EMI shielding of 51.9 dB within the microwave X-band (8–12.4 GHz) due to its porous and lightweight structure, effectively mitigating incoming electromagnetic (EM) radiation. Overall, this study highlights the promising properties of C-TiS2 aerogel for applications in both civilian and military fields.
Synthesis of anisotropic silica nanoparticles by organic amine with diverse structures
Authors: Fan Yuanqing , Wei Lili , Kang Libin , Che Shunai
Published: December 2024

Herein, we synthesized anisotropic silica nanoparticles (AISNPs) with organic amines with different structures. Monoamines and diamines with distance between amine groups shorter than ca. 4 Å have been observed to facilitate the formation of isotropic silica nanoparticles (ISNPs). AISNPs were synthesized with diamines with distance between amine groups longer than ca. 4 Å and linear structures of triamines. Non-linear structures with amine groups positioned in a triangular configuration and the cage-like structure of tetra-amines directed the formation of ISNPs. It has been speculated that the formation of AISNPs would be due to the spherical primary particles connecting by organic amines with two or more amine groups with distances between them longer than ca. 4 Å. On the contrary, the formation of ISNPs would be attributed to the adsorption of two amine groups on the same primary particles, or to steric hindrance that prevent their connection.
The structure of the toric locus of a reaction network
Authors: Craciun Gheorghe , Jin Jiaxin , Sorea Miruna-Ştefana
Published: December 2024

We consider toric dynamical systems, which are also called complex-balanced mass-action systems. These are remarkably stable polynomial dynamical systems that arise from the analysis of mathematical models of reaction networks when, under the assumption of mass-action kinetics, they can give rise to complex-balanced equilibria. Given a reaction network, we study the set of parameter values for which the network gives rise to toric dynamical systems, also called the toric locus of the network. The toric locus is an algebraic variety, and we are especially interested in its topological properties. We show that complex-balanced equilibria depend continuously on the parameter values in the toric locus, and, using this result, we prove that the toric locus has a remarkable product structure: it is homeomorphic to the product of the set of complex-balanced flux vectors and the affine invariant polyhedron of the network. In particular, it follows that the toric locus is a contractible manifold. Finally, we show that the toric locus is invariant with respect to bijective affine transformations of the generating reaction network.
Birkhoff normal form in low regularity for the nonlinear quantum harmonic oscillator
Authors: Abou Khalil Charbella
Published: December 2024

Given small initial solutions of the nonlinear quantum harmonic oscillator on

R

, we are interested in their long time behaviour in the energy space which is an adapted Sobolev space. We perturbate the linear part by V taken as multiplicative potentials, in a way that the linear frequencies satisfy a non-resonance condition. More precisely, we prove that for almost all potentials

V
,

the low modes of the solution are almost preserved for very long times.
Global well-posedness, ill-posedness and long time behavior of solutions of the surface electromigration equation
Authors: Zhou Deqin
Published: December 2024

This paper is concerned with the Cauchy problem and the long time behavior of the two-dimensional surface electromigration (SEM) equation. Firstly, we prove that the SEM equation is locally well-posed in

H
s

(

R

2

)

with

s
>
−

1
4

, and globally well-posed in

L
2

(

R

2

)

without smallness assumption. Secondly, we prove that the SEM equation is ill-posed in

H
s

(

R

2

)

with

s
<
−

1
4

in the sense that the solution map is not C
2. Finally, we get a local energy decay result of the global solution in a growing unbounded in time region but not containing the soliton region. Our well-posedness results extend the latest findings in Linares et al (2021 Nonlinearity
34 5213–33), where the authors proved that the SEM equation is locally well-posed in

H
s

(

R

2

)

with

s
>

1
2

. The key ingredient in this paper is to rewrite the linear and nonlinear part in the SEM equation into symmetric separate dispersive terms on the two space variables and some divergence form, respectively. After this invertible process, we use two bilinear estimates in the modified Fourier restriction space introduced in Kinoshita (2021 Ann. Inst. Henri Poincare C 38 451–505) to relax the local well-posedness index from

s
>

1
2

to

s
>
−

1
4

.
Impact of applied voltage, air gap, and ground arrangement on discharge power and dielectric capacitance in a volume DBD plasma
Authors: Gohain Reetesh Borpatra , Biswas Subir
Published: December 2024

Electrical parameters such as total equivalent capacitance, dielectric capacitance, and average discharge power of a dielectric barrier discharge (DBD)-cold atmospheric plasma (CAP) setup have been determined and their dependency on the applied voltage, air gap, and ground arrangement have been investigated. Considering a more practical scenario of DBD-CAP application in material processing and biomedical fields, three different ground arrangements: (i) bare ground, (ii) glass slide covered ground and (iii) water in a petri dish on the ground electrode have been considered in this study. The electrical parameters are determined by interpreting the charge-voltage (Q-V) plot of the DBD-CAP obtained experimentally. The value of effective dielectric capacitance (ζ

d
) determined from Q-V plot at a lower applied voltage is less, and approaches the geometrically calculated value (C

d
) at higher applied voltage which signifies the DBD discharge occurs from the partial area of the electrode surface. Discharge power and discharge efficiency increase with the applied voltage (V

a
). Empirical fit of the obtained discharge power shows the increase is proportional to

(

V

a

−
B
)

2

, where the value of constant B is close to the value of threshold voltage for the discharge.
Size-Dependent Effects in the Modified Green–Lindsay Thermoelasticity Model: Analysis of Ultrashort Pulse Interactions in the Presence of Electromagnetic Fields
Authors: Mirparizi Mina , Mohammadian Masoud
Published: December 2024

This study provides a more detailed model for wave transmission and reflection in a complex thermodynamic framework. The governing equations are developed from multiphase electromagnetic size-dependent thermoelasticity models. The main focus here is on the development of the Modified-Green Lindsay nonlocal generalized thermoelasticity model that improves previous nonlocal approaches by incorporating additional strain and temperature rate terms. This study also examines how materials react to very short pulses and the effect of external electric and magnetic fields. The highly developed nonlinear equations in this study are solved using advanced programming techniques, including an iterative approach that combines finite element methods with a Newmark time-marching scheme. The results of this work established the nonlocal heat conduction theory of generalized thermoelasticity along with nonlocal continuum theory as a new improvement and progress in the field of thermoelasticity. This model shows that without considering thermal nonlocality interactions, predictions may miss essential aspects of wave behavior. The results show that the materials experience changes in mechanical properties, particularly an increase in hardness, when exposed to stronger magnetic fields. In addition, the results show that as the duration of laser pulses decreases, the speed of wave propagation increases. Shortening the pulse duration increases the wave propagation speed, which can create steep thermal gradients. In the case of pure metals heated by ultra-short pulse lasers, the fast electron heat conduction prevents the formation of significant thermal waves, while these pulses induce more intense and localized thermal stresses. Analysis of wave propagation also shows that the return time can exceed the forward time as the waves react to applied electric and magnetic fields.
Influence of chromium doping on structural, microstructure, optical and electrical properties of zinc ferrite.
Authors: Wani S. M. , Kotkar M. T. , Vidhate R. G. , Bhandari J. M. , Jadhav K. M.
Published: December 2024

Zinc ferrite with crystalline nature with the formula ZnFe2-xCrxO4, (x =0.0 to 0.4, in the step of 0.1) were produced utilizing a sol-gel auto-combustion approach taking Glycine (C2H5NO2) as a chelating agent and annealed at 800°C for 5h. XRD analysis revealed the presence of α-Fe2O3 as an extra peak. The lattice parameter reduces from 8.4423 Å to 8.4191 Å as the chromium content increases. The FTIR spectroscopy results exhibit two significant absorption bands approximately at 400 cm⁻¹ and 600 cm⁻¹ Indicating the successful formation of the spinel crystal structure in the synthesized sample. Debye temperature elevated from 670.95 K to 696.15 K with Cr3+ doping. Elastic constants also increase with Cr3+ doping. The band gap energy, determined using Tauc plots, varies between 2.05 eV to 2.25 eV. The DC resistivity plot exhibited semiconducting behavior. Resistivity increases with Cr3+ doping concentration. A linear inverse correlation was observed between the Curie temperature and the concentration of Cr3+ ions. With increasing chromium content, the activation energy (ΔE) exhibited a positive trend from 0.26 eV to 0.39 eV, while the charge carrier concentration (n), drift mobility (µd), and diffusion coefficient (D) demonstrated inverse relationships. The obtained structural, elastic, optical and DC electrical data is useful for high-frequency device applications.
Optimization of indium concentration and compositional grading in InGaN heterojunction solar cells by SCAPS-1D simulation
Authors: Omar Mohammed Kakasur , Manzoor Habib Ullah , Ng Sha Shiong , Mohd Rashid Mohd Marzaini , Pakhuruddin Mohd Zamir
Published: December 2024

Indium gallium nitride (InGaN) thin-film solar cells exhibit exceptional potential for photovoltaic (PV) applications due to their tunable bandgap (0.7–3.4 eV) and high absorption coefficient (>105 cm−1). Using SCAPS-1D simulation, this study demonstrates that incorporating compositional grading in the InGaN absorber layer significantly enhances the solar cells performance. Graded InGaN solar cells with optimized Indium (In) concentration achieve superior power conversion efficiency (PCE) compared to ungraded cells. The optimal graded structure, with an In concentration of 0.7, achieves PCE of 36.08%, current density (Jsc) of 23.52 mA cm−2, open-circuit voltage (Voc) of 1.66 V, and fill factor (FF) of 92.1%. In contrast, the ungraded cell exhibits PCE of 34.83%, Jsc of 22.8 mA cm−2, Voc of 1.66 V, and FF of 91.87%. These findings underscore the efficacy of compositional grading in advancing high-efficiency InGaN solar cells.
Molecular dynamics study on the influence of loading mode on deformation behavior of Ni/Al nano-laminated composite
Authors: Pang Weiwei , Yang Kai , Han Fangyuan , Wei Chenao , Liu Aosong
Published: December 2024

Molecular dynamics investigated the influence of loading mode on deformation behavior of Ni/Al nano-laminated composite. Mechanical properties are significantly dependent on the angles between loading axis and heterogeneous interface. Yield strength of inclined sample is the lowest, but yield strain is the highest. Tensile strength of parallel sample with lowest angle is the highest, and that of samples with higher angle is significantly lower. Inclined sample has moderate tensile strength and the highest tensile ductility. In samples with higher angle, lattice dislocations explosively nucleate in softer layer around interface, while in samples with lower angle, they nucleate at interface nodes. Interface in samples with higher angle has stronger hindering effect on continuous sliding of dislocation through interface than that in samples with lower angle. Stress component along sliding direction on slip plane and the angle between sliding direction of activated dislocation and the direction interfacial misfit dislocation line well quantify the activation of slip system and damage of heterogeneous interface, respectively. Total dislocation density in sample with higher angle is higher among all samples. Furthermore, density peak value of stair-rod dislocation in samples with higher angle is the highest, density peak values of Frank and Hirth dislocations in samples with lower angle are the highest. In samples with higher angle, voids first appear in the slice of Al layer below interface, voids originate from the junction point among three activated slip planes, and void morphologies present sphere-like. In samples with lower angle, voids first appear in the slice of interface, voids originate from the interaction position between lattice dislocations and interfacial misfit dislocations, and void morphology presents strip-like.
CAMO-S: A Meteor-tracking Spectrograph at the Canadian Automated Meteor Observatory
Authors: Mazur Michael J. , Campbell-Brown Margaret , Brown Peter G. , Vida Denis , Gural Pete , Yang Zhangqing
Published: December 2024

The Canadian Automated Meteor Observatory (CAMO) mirror tracking system has been in operation since 2009 and has, to date, produced more than 20,000 two-station meteor observations at meter-level spatial and 10 ms temporal resolution. In 2020, a spectral tracking camera was added in parallel at one of the CAMO stations. To date, it has recorded the spectra of hundreds of faint meteors. Engineering testing from 2020 to 2023 resulted in the selection of a 150 lpmm grating and an EMCCD camera to achieve a spectral resolution of about 1 nm pixel−1 in the final configuration. The CAMO spectral system can resolve spectra from individual meteoroid fragments, record spectra for meteors of +2 peak magnitude to as faint as +4 in parts of the lightcurve and produce relative abundance estimates for Mg, Fe and Na. Our preliminary results also show identification of the H and K lines of CA(II). Meteors with strong iron lines were found to have unusual fragmentation behaviour, involving gross fragmentation rather than continuously shedding small particles. The spectra of individual fragments can be resolved in some cases, showing that these Fe-rich objects do not differ in composition among fragments. Our calibration procedure and hardware configuration are discussed together with preliminary results.
O’Connell Effect and Period Variations on Solar-like Contact Binary EF Boo
Authors: Wang Jing-Jing , Guo Meng , Tian Xiao-Man , Zhang Bin
Published: December 2024

Using ground-based telescopes, the multi-color photometric observations of the contact binary EF Boo were obtained in 2020, 2023, and 2024. Combining these with 7-sectors of light curves from TESS data, the variations of the O'Connell effect in continuous time and shapes of light curves over several years were identified. Three sets of typical light curves were analyzed to determine the photometric solutions via the Wilson–Devinney program. Considering the spectroscopic mass ratio of q = 0.53, these photometric solutions suggest that EF Boo is a W-type W UMa contact binary with the averaged filling factor of f = 22.26%, a small temperature difference, and a cool spot on the primary component. If the variations of the O'Connell effect are due to the magnetic activity of this cool spot, the longitudinal location varied from 50

.

°

4 to 302

.

°

7 over the time interval of 1434 days. Based on all CCD minimum times from ground-based telescope and TESS data, the O − C curve was also analyzed. A cyclic oscillation (A
3 = 0.00575 days, T
3 = 27.8 yr) superimposed on a secular increase (dP/dt = 6.74 × 10−8 day yr−1) was discovered for the first time. The successive increase is possibly a result of mass transfer from the less massive star to the more massive one. The cyclic oscillations were possibly explained by the light-travel time effect via a third body or the magnetic activities. From the short cadence observations from TESS, we also calculated the value of the O'Connell effect and O − C value for each cycle and found no correlation between the O'Connell effect and O − C over nearly 30 days across different sectors.
Effect of Styrene Concentration on Tensile Properties of Styrene-Acrylate Films
Authors: Eyann L. , Rashid S. M. , Musa M. S.
Published: December 2024

Due to an increasing awareness of environmental protection, waterborne coatings have replaced solvent-borne ones. The waterborne styrene-acrylate dispersion was successfully synthesized using emulsion polymerization. In this work, the emulsion was composed of Butyl Acrylate (BA) and Styrene (Sty) at different ratios. FTIR spectra confirmed the successful copolymerization of BA and Sty. Additionally, it was observed that all emulsions exhibited a consistent hydrodynamic diameter (120 nm to 140 nm), polydispersity index (between 0.030 and 0.050), and zeta potential (-40 mV to -60 mV). Thus, the BA/St ratio did not impact particle growth during emulsion polymerization. Furthermore, an increase in Sty concentration raised the glass transition temperature (Tg) of the films from 10.8 °C to 30.8 °C. This is attributed to Sty being a high Tg polymer, contributing to a rigid monomer that could enhance rigidity and restrict the movement of polymer chains. Additionally, the tensile strength of the dispersion films increased with the increase in Sty concentration, from 3.01 MPa to 5.88 MPa. Interestingly, the elongation at break did not significantly change as the St concentration increased, dropping by 15%. The investigation to aid in establishing relationships between the monomer concentration and mechanical properties of styrene-acrylate films.
Preliminary Investigation of Dust Generation in Granite Quarry
Authors: Saka Mumini Babatunde , Hashim Mohd Hazizan Mohd
Published: December 2024

Dust dispersion from granite surface quarries substantially influences the health of workers and nearby neighbourhoods. A preliminary study was conducted at a granite quarry to investigate the factors that contribute to the emission of dust in granite surface quarries and to develop effective dust control measures. The particulate matter from areas within the site was measured using a Handheld Laser Particle Counter Model 3887. The preliminary results revealed the presence of PM0.3, PM0.5, and PM5.0 at their least value of 4.85×107µm/m3, 1.18×107µm/m3, and 2.83×104µm/m3 respectively. While, the highest value ranges of 6.22×107µm/m3, 7.68×106µm/m3, and 9.89×103µm/m3 respectively, and is considered to be beyond hazardous. The preliminary readings indicate that the air quality is extremely poor and that there is a high risk of health problems, even for healthy people. The initial results of this study suggest that dust generation in granite surface quarries is a complex process influenced by various factors, including the type of rock being quarried, the blasting methods used, and the prevailing meteorological conditions. To better understand the factors that contribute to dust generation and to devise effective dust control measures, additional research is required.
Adsorption of Acetaminophen onto activated carbon derived from corn cobs: Optimizations by using response surface methodology
Authors: Ramli M.R.M. , Shoparwe N.F. , Ahmad M.A.
Published: December 2024

Acetaminophen (ACN) is widely used for analgesic with antipyretic and analgesics applications. The presence of ACN in the aquatic environment contributes towards the degradation of the aromatic ring of carbon, which harms human health and the ecosystem. This research aims to optimize the preparation condition of corn cob based activated carbon (CCAC) for adsorption of acetaminophen (ACN) by employing response surface methodology (RSM). The faced centered central composite design (CCD) was used to study the correlation between CCAC preparation conditions and ACN removal, and CCAC’s yield. The preparation conditions of CCAC are radiation power (X1), activation time (X2) and impregnation ratio, IR (X3). The optimal preparation conditions for CCAC were 264 W, 2 minutes, and 2.5 g/g for X1, X2, and X3, respectively.
Determination of Depositional Environment and Coal Rank of Seam C Sawahlunto Formation, Ombilin Basin, West Sumatera, Indonesia
Authors: Rahman HA , Aminuddin MIKA , Puspita R , Novendra MP
Published: December 2024

The Sawahlunto Formation is a coal-rich geological formation in the Ombilin Basin, located in central Sumatera. It contains three main coal seams, designated as Seams A, B, and C, with Seam C known for its high-quality coal. The study involved analyzing coal samples from Seam C using petrographic and proximate analysis methods. Petrographic analysis assessed the macroscopic composition and vitrinite reflectance, which are essential for determining the depositional environment and coal rating. Proximate analysis provided additional data necessary for evaluating the coal’s quality. The coal was predominantly composed of vitrinite (79.2%-80.6%) and inertinite (19.2%-20.8%). Plots of the Tissue Preservation Index (TPI) and Gelification Index (GI) indicated a limno-telmatic depositional environment. Vitrinite reflectance ranged from 0.45%-0.51%, classifying the coal as sub-bituminous. The calorific values were 15,117.2 btu/lb and 14,815.94 btu/lb, categorizing the coal as highly volatile bituminous.
Comparative Analysis of Image Processing Technique in Determining the New Crescent Moon Visibility
Authors: Nasir Ahmad Lutfi Afifi Mohd , Umar Roslan , Yussof Wan Nural Jawahir Wan , Ahmad Nazhatulshima , Sabri Nor Hazmin , Zulkeflee Ahmad Najmuddin , Kamarulzaman Amirul Hazim , Mahiddin Nor Aida
Published: December 2024

This research presents a comparative analysis of advanced image processing techniques to enhance the visibility of the new crescent moon, a crucial element in astronomy and the lunar calendar. The primary objective is to assess the effectiveness of Contrast Adjustment (CA), Histogram Equalization (HE), Contrast Limited Adaptive Histogram Equalization (CLAHE), and Gamma Correction (GC) in improving new crescent moon visibility. The study utilized a comprehensive dataset of new crescent moon images captured on various dates and times, with each image undergoing a specific image processing technique. The findings revealed that CLAHE markedly outperforms the other methods, offering superior contrast enhancement and detailed visibility. This suggests that CLAHE is the most proficient technique for augmenting new crescent moon visibility, thereby providing critical insights for future astronomical observations and practical applications. The research significantly advances the refinement of new crescent moon observation techniques, contributing to both scientific understanding and the enhancement of practical implementation in the field.
The Impact of Light Pollution on Night Sky at the Potential Astrotourism Site in Johor Bahru: A Feasibility Study
Authors: Hailmy Nur Amy Syahira Mohd , Musa Aimi
Published: December 2024

Astrotourism represents a substantial trend in sustainable tourism, where the primary resource is a starry sky with minimal light pollution. However, the escalating issue of light pollution currently undermines astronomers’ observations and the experience of astrotourists seeking clear views of the sky. Hence, this study aims to assess the impact of light pollution in one of the potential astrotourism sites at SIREH Park, Johor Bahru, by measuring the night sky’s brightness. The Sky Quality Metre-LE measures the sky’s brightness at five stations in Zone 1. The results of this study indicate that the magnitude of night sky brightness varied between 16.23 mag/arcsec2 (Station 4) and 17.24 mag/arcsec2 (Station 1). However, astronomical activities can still be conducted in SIREH Park and can be a platform to educate the public and tourists about the sky brightness and light pollution. Overall, the study provides value as it demonstrates the complex dynamics of light pollution and highlights the importance of considering multiple factors when making analyses.
Gated Recurrent Unit (GRU)-Based GIC Prediction Using dB/dt as a Proxy
Authors: Zainuddin Aznilinda , Hairuddin Muhammad Asraf , Latiff Zatul Iffah Abd , Benavides Felipe , Jusoh Mohamad Huzaimy , Yassin Ahmad Ihsan Mohd
Published: December 2024

Geomagnetically induced currents (GICs) pose a significant threat to power systems during geomagnetic storms. This work introduces a GRU approach for GICs forecasting based on the rate of change of the geomagnetic field, dB/dt at two low-latitude stations, Muntinlupa (MUT) and Guam (GUA). The performances of the model were evaluated based on the data collected from the Solar Cycle 23 (SC23) as training data, and Solar Cycle 24 (SC24) at the validation stage. The GRU model demonstrated good predictive accuracy with low RMSE values, particularly for MUT model (RMSE = 0.00917). MUT shows higher predictive accuracy and generalizability across MUT station itself and GUA station. This work underlines the potential of GRU models for GIC prediction, providing a foundation for more robust forecasting tools to mitigate the impacts of geomagnetic disturbances on power systems.
Reassessing hourly precipitation–temperature scaling: the diurnal cycle in a warming China
Authors: Lei Miao , Wang Shanshan , Huang Jianping , Wang Zhiyang , Li Xiaoping
Published: December 2024

Hourly extreme precipitation is expected to intensify with global warming following a Clausius–Clapeyron (CC) relationship. While extensive research has investigated the relationship between hourly precipitation and temperature, inconsistencies in this relationship across the diurnal cycle affect all-hours scaling. This study uses hourly gauge observations and reanalysis data from mainland China to analyze the scaling and explore its diurnal cycle for the first time. Our results reveal that 88.7% of the stations exhibit super-CC scaling, which is significantly underestimated by reanalysis data. Notably, the scaling shows a pronounced diurnal cycle and exceeds all-hour scaling, indicating that the mix of precipitation from different hours ultimately affects the overall scaling results. Over a 39 year period, changes in extreme precipitation intensity were closely aligned with dew-point temperatures throughout the diurnal cycle in inland regions. The above results provide a valuable insight into the shift of extreme precipitation to morning/night in some regions under climate change.
The impact of a weakened AMOC on European heatwaves
Authors: Meccia Virna L , Simolo Claudia , Bellomo Katinka , Corti Susanna
Published: December 2024

In our changing climate we expect an increase in the frequency of heatwaves, which are extreme events that can have severe consequences for human health, ecosystems, and economies. In this study, we examine how the weakening of the atlantic meridional overturning circulation (AMOC) may influence the occurrence of extreme warm events in Europe. Our analysis is based on a series of numerical experiments conducted using the EC-Earth3 climate model, which includes three ensembles of 20 Atmospheric Model Intercomparison Project-like members. The large ensemble size makes these simulations well-suited to studying rare extreme events. Our findings reveal that during boreal summer, the Northern hemisphere (NH) experiences overall mean cooling, most pronounced in the North Atlantic region. Therefore, the extreme warm events in Europe identified by using a fixed threshold tend to be less frequent. However, the cooling pattern reduces the meridional gradient of near-surface air temperature at high latitudes of the NH. As a result, the speed of the summer jet stream decreases, while the frequency of Ural atmospheric blocking events increases. Atmospheric blocking in summer is closely linked to heatwaves, primarily through subsidence warming and enhanced downward shortwave radiation under clear sky conditions. Consequently, the weakening of the AMOC leads to an increased frequency of heatwaves in Eastern Europe, the only region that presents this opposite trend. This study highlights the significant role that three-dimensional ocean circulation plays in shaping weather patterns, including extreme events such as heatwaves in Europe. These findings have important implications for future climate projections, as the AMOC is expected to weaken by the end of this century. Thus, as the Earth continues to warm, we may face an increased risk of heatwaves due to the combined effects of global warming and a weakening AMOC.
Strategizing for the Climate Change Impact on Aspiring Geopark Ranau at Geosite Gua Kelambit
Authors: Setiawan Budhi , Idarwati  , Harnani
Published: December 2024

The management of geopark, from individual geosites to entire landscapes, faces issues due to climate change, which impacts all regions of the world. The primary direct impacts will occur due to climate changes affecting geomorphological processes and vegetation cover. Meanwhile, the indirect impacts will originate from implementing complicated engineering solutions to reduce risks posed by natural catastrophes. We applied a comprehensive framework that outlines essential procedures for stakeholders interested in the geosite, especially at Gua Kelambit, one of the proposed geosite at Aspiring Geopark Ranau. The foundation of our method lies in evaluating the risk of degradation of geosites and their characteristics and processes due to the probability of climate change inAluencing them and the projected magnitude of consequences. Three factors determine the likelihood of degradation of a geosite, feature, or process:(i) its geographic location and proximity to geomorphological systems that are prone to dynamic responses to climate changes;(ii) the extent, speed, and duration of these changes; and (iii) inherent factors such as the geological and physical properties of the site and its features and processes. The range of management choices varies from non-intervention to planned actions guided by the degradation risk assessment.
Geodiversity and Geotourism in the Krayan Highlands: Exploring Connate Water Salt Formation and Sustainable Development Opportunities
Authors: Sapari Dwi Hadian Mohamad , Nursiyam Barkah Mochmad , Yandri Sunarie Cecep , Fahlevi Setiawan Iwan , Krishna Yuliawati Ayu
Published: December 2024

Krayan Plateau in North Kalimantan has an unique geological wealth and high scientific value, which offer the potential study for its geodiversity. The purpose of the study is to identify the process of salt formation from connate water that has been going on for millions of years in the Krayan Highlands as well as identify the geodiversity potential that can be developed into a geotourism destination. The study uses descriptive-analytical methods with phenomenological approaches and field studies, including observations, and literature studies, to collect and qualify geological data. The main results of the study showed that the salt formation process in the Krayan Plateau involved the evaporation of connate water which eventually crystallized into salt. In addition, it was found that eight major geodiversities in the Krayan Region as well as 16 types of geosites in 10 geological frameworks in the Krayan and Sangkulirang- Mangkarang regions have great potential to be developed into geotourism destinations and can support those regions as geopark candidate in Kalimantan. In conclusion, the Krayan and Sangkulirang-Mangkarang areas have high scientific, aesthetic, and conservation value, and require appropriate conservation efforts to maintain their sustainability. The contribution of this research is to support sustainable development through geoconservation and geotourism development in the region.