bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimizing light absorption and emission in thermophotovoltaics: A study of tungsten–hafnium dioxide metamaterials
Authors: Fite Gemechis Mathewos , Maremi Fekadu Tolessa , Gemta Abebe Belay , Hurisa Tesfaye Feyisa , Aredo Tadese Bekele
Published: February 2025

This study presents a theoretical investigation into the spectral performance of a metamaterial structure composed of tungsten (W) and hafnium dioxide (HfO2) layers, which are specifically designed for applications in energy conversion. The proposed metamaterial, which is structured in a multilayer W/HfO2/W configuration, aims to increase light absorption and emission characteristics at targeted wavelengths, thereby improving the efficacy of thermophotovoltaic systems. By utilizing advanced simulation techniques, we analyze the optical properties of the metamaterial, focusing on its ability to achieve high spectral efficiency through tailored emission and absorption mechanisms. Our findings indicate that the designed metamaterial has an average emissivity exceeding 96% in the wavelength range of 0.3–2.2 μm, peaking at 99.9% within the 1.5–2.0 μm range, as evidenced by numerical simulations. Furthermore, significant enhancements in spectral efficiency were observed, reaching optimal values at wavelengths corresponding to the bandgap energy of the targeted InGaAsSb photovoltaic materials. Additionally, the metamaterial maintains high emissivity across a wide range of incident angles (0°–60°) and is insensitive to the polarization of incident light. This investigation underscores the potential of W/HfO2/W metamaterials in advancing energy conversion technologies, highlighting their promising role in enhancing the performance of future thermophotovoltaic devices. The results contribute to a deeper understanding of metamaterial design principles and their implications for efficient energy harvesting systems.
Lattice dynamics modeling of thermal transport in solids using machine-learned atomic cluster expansion potentials: A tutorial
Authors: Guo Liben , Liu Yuanbin , Yang Lei , Cao Bingyang
Published: February 2025

Lattice dynamics (LD) plays a crucial role in investigating thermal transport in terms of not only underlying physics but also novel properties and phenomena. Recently, machine learning interatomic potentials (MLIPs) have emerged as powerful tools in computational physics and chemistry, showing great potential in providing reliable predictions of thermal transport properties with high efficiency. This tutorial provides a comprehensive guideline for MLIPs’ development and how they are used for the computational modeling of thermal transport. Using atomic cluster expansion (ACE) as the paradigmatic potential, we introduce the essential fundamentals of MLIPs, including data construction, model training, and hyperparameter optimization. With the developed ACE potentials, we further showcase their applications in the LD modeling of thermal transport for crystalline silicon and amorphous carbon. The corresponding code implementations for MLIP applications in calculating thermal conductivity are also provided for beginners to follow.
How obstructed jets experience detrainment
Authors: De Serio F. , Mossa M.
Published: February 2025

A comprehensive understanding of turbulent jets discharged into obstructed environments remains a critical gap in the current literature. This issue holds significant importance for applications ranging from environmental fluid dynamics to industrial processes. The primary goal of this study is to theoretically investigate the dynamics of planar turbulent non-buoyant jets interacting with arrays of rigid obstacles, supported by a comparison between theoretical predictions and experimental data. Specifically, our analysis focuses on the entrainment process, revealing that obstructions in non-stratified flows impede entrainment, reversing it into detrainment. This finding is novel because (i) detrainment in natural settings is typically associated with buoyancy-driven flows, such as plumes or density currents in stratified environments, and (ii) to the best of the authors' knowledge, this is the first validation of theoretical entrainment coefficients with experimental data for obstructed non-buoyant jets. Experiments were conducted with turbulent non-buoyant jets using particle image velocimetry, providing detailed insights into flow structure and entrainment dynamics. Furthermore, the study explores jet particle dispersion and diffusivity through a Lagrangian framework. The results demonstrate significant differences in dispersion behavior between unobstructed and obstructed jets, showing that obstacle-induced blockage profoundly influences flow characteristics and jet detrainment. In particular, obstructions play a fundamental role, initially affecting the dispersion mechanism through obstacle diameter and later through the free spacing between obstacles. These findings provide valuable contributions to understanding flow physics in complex environments and have implications for engineering and environmental applications.
Illustrated Garden Glossary
Authors: Mayfield Enid
Published: February 2025

The Illustrated Garden Glossary is a comprehensive glossary of over 1000 terms related to gardening and horticulture, each supported by superb colour illustrations to aid understanding.

The topics covered include plant classification, morphology and growth; plants from seeds; propagation; soil; compost; planting systems; pruning; pests and diseases; water and more. It also explores terms relating to the history of gardens, from ancient Greece and Egypt, to gardens across Asia and the Middle East, and through to our modern-day urban farms.

The Illustrated Garden Glossary is a must-have reference for gardeners, plant scientists, horticulturalists, students, libraries, ecologists and urban farmers.
Ancient genomes reveal trans-Eurasian connections between the European Huns and the Xiongnu Empire
Authors: Gnecchi-Ruscone Guido Alberto , Rácz Zsófia , Liccardo Salvatore , Lee Juhyeon , Huang Yilei , Traverso Luca , Radzevičiūtė Rita , Hajnal Zsuzsanna , Szécsényi-Nagy Anna , Gyuris Balázs , Mateovics-László Orsolya , Bernert Zsolt , Szeniczey Tamás , Hajdu Tamás , Mészáros Boglárka , Bálint Marianna , Mende Balázs Gusztáv , Miller Bryan , Samashev Zainolla , Childebayeva Ainash , Djansugurova Leyla , Geary Patrick , Ringbauer Harald , Vida Tivadar , Jeong Choongwon , Pohl Walter , Krause Johannes , Hofmanová Zuzana
Published: February 2025

The Huns appeared in Europe in the 370s, establishing an Empire that reshaped West Eurasian history. Yet until today their origins remain a matter of extensive debate. Traditional theories link them to the Xiongnu, the founders of the first nomadic empire of the Mongolian steppe. The Xiongnu empire dissolved, however, ~300 y before the Huns appeared in Europe, and there is little archaeological and historical evidence of Huns in the steppe during this time gap. Furthermore, despite the rich 5th to 6th centuries current era (CE) archaeological record of the Carpathian Basin, the cultural elements of connections with the steppe are limited to few findings and even fewer solitary eastern-type burials. In this study, we coanalyze archaeological evidence with 35 newly sequenced and published genomic data for a total of 370 individuals—from 5th to 6th century CE contexts in the Carpathian Basin including 10 Hun-period eastern-type burials, 2nd to 5th century sites across Central Asia and 2nd c. before current era (BCE) to 1st c. CE Xiongnu period sites across the Mongolian steppe. We find no evidence for the presence of a large eastern/steppe descent community among the Hun- and post-Hun-period Carpathian Basin population. We also observe a high genetic diversity among the eastern-type burials that recapitulates the variability observed across the Eurasian Steppe. This suggests a mixed origin of the incoming steppe conquerors. Nevertheless, long-shared genomic tracts provide compelling evidence of genetic lineages directly connecting some individuals of the highest Xiongnu-period elite with 5th to 6th century CE Carpathian Basin individuals, showing that some European Huns descended from them.
Ancient ocean coastal deposits imaged on Mars
Authors: Li Jianhui , Liu Hai , Meng Xu , Duan Diwen , Lu Haijing , Zhang Jinhai , Zhang Fengshou , Elsworth Derek , Cardenas Benjamin T. , Manga Michael , Zhou Bin , Fang Guangyou
Published: February 2025

The northern lowlands of early Mars could have contained a significant quantity of liquid water. However, the ocean hypothesis remains controversial due to the lack of conclusive evidence from the Martian subsurface. We use data from the Zhurong Rover Penetrating Radar on the southern Utopia Planitia to identify subsurface dipping reflectors indicative of an ancient prograding shoreline. The reflectors dip unidirectionally with inclinations in the range 6° to 20° and are imaged to a thickness of 10 to 35 m along an uninterrupted 1.3 km northward shoreline-perpendicular traverse. The consistent dip inclinations, absence of dissection by fluvial channels along the extended traverse, and low permittivity of the sediments are consistent with terrestrial coastal deposits—and discount fluvial, aeolian, or magmatic origins favored elsewhere on Mars. The structure, thickness, and length of the section support voluminous supply of onshore sediments into a large body of water, rather than a merely localized and short-lived melt event. Our findings not only provide support for the existence of an ancient Martian ocean in the northern plains but also offer crucial insights into the evolution of the ancient Martian environment.
Boosted recovery of rare earth elements from mining wastes and discarded NdFeB magnets by tributyl phosphate–grafted ZIF-8
Authors: Wan Shun , Liu Wu-Jun , Tan Guangcai , Yu Han-Qing
Published: February 2025

The escalating demand for rare earth elements (REEs) highlights the necessity for their sustainable recovery from waste streams and secondary resources. However, this process requires materials with exceptional selectivity and capacity for REEs due to their low concentration and high presence of interfering ions. Herein, we synthesized zeolitic imidazolate framework-8 (ZIF-8) and subsequently modified it with tributyl phosphate (TBP) to enhance its affinity and selectivity for the recovery of REEs. The distribution coefficients (
K
d
) of ZIF-8-TBP for REEs (neodymium, Nd, and dysprosium, Dy) were orders of magnitude higher than the
K
d
of main interfering ions (e.g., Mg, Ni Al, and Fe). Particularly, the maximum sorption capacities (

q
m

) for Nd and Dy were 475 and 529 mg g
−1
, respectively. In addition, the separation factor between Dy (a representative of heavy REE) and Nd (a representative of light REE) reached 24, greatly exceeding the figures reported previously. Importantly, the outstanding ability of ZIF-8-TBP for selective separation and recovery of REEs was demonstrated via its application to real samples including mining wastewater, and leaching solutions from REE filter cakes and discarded NdFeB magnets. Multiscale simulations reveal that ZIF-8-TBP possessed a stronger binding strength and greater sorption energy for REE ions. These results indicate that ZIF-8-TBP could effectively harvest REEs from wastes and offers an efficient alternative for industrial applications in REE recovery.
The form and force of Kirundi exclamatives
Authors: Myers Willie
Published: February 2025

This paper examines the syntax and semantics of two types of exclamatives in Kirundi: property exclamatives, which
express surprise at the extreme degree of some property of an entity, and proposition exclamatives, which express surprise at a
proposition’s truth. Though most languages have canonical clause types for declaratives, interrogatives, and imperatives, only
some further distinguish exclamatives (Sadock & Zwicky 1985). Drawing on fieldwork,
I argue that the form and force of Kirundi exclamatives motivates their recognition as a true clause type. Notably, Kirundi
exclamatives satisfy semantic criteria for exclamativity but take a unique form, lacking overt wh- and/or degree
morphology. I propose a constructional account, in the spirit of Zanuttini & Portner
2003, in which exclamativity arises as the result of interaction between syntactic elements linked to factivity,
general interrogative force, and focus. This paper has implications for exclamative typology and the analysis of illocutionary
force at the syntax-semantics interface.
The acquisition of locative inversion at the syntax-pragmatics interface by Chinese learners of English
Authors: Jiang Shan , Zhang Huiping
Published: February 2025

This study investigated the acquisition of English locative inversion at the syntax-pragmatics interface by
Chinese learners, and explored the factors for non-native performance within the framework of the Interface Hypothesis. A picture
description test and a context-matching test were administered through an online questionnaire to 300 Chinese learners of English
and twenty native speakers of English at a university in China. Follow-up interviews were conducted with thirty Chinese learners.
Results showed that (1) compared with English natives, Chinese learners under-produced locative inversion, achieving native-like
attainment until the advanced stage; (2) they also displayed a different preference pattern for locative inversion, converging to
a native-like pattern by the advanced stage; (3) non-native performance in production was attributed to processing limitations and
input frequency, while that in interpretation resulted from underspecification of form-function mapping, input frequency and
contexts. The paper offers implications for syntax-pragmatics teaching and proposes future directions for L2 interface
studies.
A novel approach to crack refinement measurement under impact loading based on OFDR technique
Authors: li jin , Yang Liyun , zuo jinjing , Yang Renshu , Zhang Xiang , You Yuanyuan , wang bo
Published: February 2025

The dynamic crack propagation characteristics of brittle materials are a crucial focus in impact dynamics. The randomness of crack growth under impact loading poses significant challenges to accurately monitoring crack behavior during experiments. In this study, two novel crack refinement measurement techniques based on Optical Frequency Domain Reflectometry (OFDR) technology were developed to provide more comprehensive strain distribution data under impact loading and to capture detailed crack propagation behavior. Additionally, a trending algorithm was introduced to process large datasets and accurately pinpoint crack locations. The study begins by presenting the two innovative deployment methods and the fabrication process of custom specimens. After conducting impact tests on the specimens, the resulting strain distribution data were compared with actual crack propagation. The results demonstrated precise crack location identification down to the millimeter level, and the crack extension path was accurately mapped using strain profiles from fiber-optic measurements. These findings validate the effectiveness of the proposed approach, which shows great potential for accurately monitoring, locating, and quantifying cracks using distributed optical fibers.
Fully autonomous anti-interference flight control of vertical takeoff and landing unmanned aerial vehicles in satellite positioning rejection environment
Authors: Yang Liben , Li Yu , Tian Jianwen , Wang Dong
Published: February 2025

This paper proposes an autonomous anti-disturbance control algorithm for vertical takeoff and landing unmanned aerial vehicle (VTOL-UAV) in satellite positioning rejection environment. In this kind of environment, the external satellite information is unavailable. This paper proposes a VTOL-UAV environment perception and precise positioning algorithm based on tightly coupled LiDAR and inertial navigation, on the basis of environment perception and precise positioning, the autonomous motion planning algorithm for VTOL-UAV is proposed. Motion planning is carried out according to the environmental information and the dynamic characteristics of the UAV, and the planning results include the spatial path information, the velocity information, the acceleration information and the JERK information of the UAV. Finally, the path tracking method of the VTOL-UAV with an extended state observer is proposed. Based on accurate estimation and feed-forward suppression of the external disturbances of the complex environment, the motion planning results can be accurately tracked, so as to realize the autonomous control of VTOL-UAV in complex environment of ultra-low altitude and improve the intelligence level of UAV.
Dose measurement of ophthalmic Ru-106/Rh-106 applicators with a diamond detector calibrated in a clinical megavoltage electron beam
Authors: Valve Assi , Reijonen Vappu , Rintala Anna , Strengell Satu , Nousiainen Katri , Tenhunen Mikko
Published: February 2025

Objective: Uveal melanomas and retinoblastomas can be treated with ophthalmic beta-emitting ruthenium-106/rhodium-106 applicators. The applicator manufacturer provides a datasheet of the dosimetric properties of each applicator set, but the source strengths and 3D dose distributions should be verified by the end user with independent measurements. Approach: The purpose of this work was to calibrate diamond detector against low energy electron beam and determine necessary correction factors in the geometry of ophthalmic applicators to be able to perform quality assurance (QA) measurements for the applicators. Two separate sets of applicators were evaluated. Main results: The results showed good agreement with manufacturers' specifications. An average agreement of 3 % to the manufacturer's reference data was observed: measured dose rate / reference = 0.97 +/- 0.04 (mean +/- SD), range 0.90 - 1.05. Significance: It can be concluded that megavoltage electron beam is suitable for calibration of a diamond detector. After calibration, detector can be used for an absolute dose measurement of a ruthenium-106/rhodium-106 applicator with sufficient performance to detect deviations larger than 10 % in the QA before clinical use.
Anticipating potential bottlenecks in adaptive proton FLASH therapy: a ridge filter reuse strategy
Authors: Roberfroid Benjamin , Vera Macarena Chocan , Draguet Camille , Lee John Aldo , Barragan Montero Ana Maria , Sterpin Edmond
Published: February 2025

ObjectiveAchieving FLASH dose rate with Pencil Beam Scanning intensity modulated proton therapy is challenging. However, utilizing a single energy layer with a ridge filter (RF) can maintain dose rate and conformality. Yet, changes in patient anatomy over the treatment course can render the RF obsolete. Unfortunately, creating a new RF is time-consuming, thus, incompatible with online adaptation. To address this, we propose to re-optimize the spot weights while keeping the same initial RF.ApproachData from six head and neck cancer patients with a repeated computed tomography (CT2) were used. FLASH treatment plans were generated with three methods on CT2: "full-adaptation" (FA), optimized from scratch with a new RF; "spot-adaptation only” (SAO), re-using initial RF but adjusting plan spot weights; and “no adaptation” (NoA) where the dose from initial plans on initial CT (CT1) was recomputed on CT2. The prescribed dose per fraction was 9 Gy. Different beam angles were tested for each CT2 (1 beam per fraction). The FA, SAO and NoA plans were then compared on CT2. Main resultsFractions with SAO showed a mean decrease of 0.08Gy for D98% of and a mean increase of 0.03Gy for D2% of CTV when compared to their homologous FA plans on nominal case. Median conformity number decreased by 0.02. Mean max dose to spinal cord increased by 0.2Gy. The largest average increase in mean dose to organs was 0.1Gy to the right parotid. The largest observed mean difference in organs receiving a minimal dose rate of 40Gy/s was 1.4% for the mandible. Up to 16 of the 20 evaluated SAO fractions were thus deemed clinically acceptable, with up to 8 NoA plans already acceptable before adaptation.SignificanceProposed SAO workflow showed that for most of our evaluated plans, daily reprinting of RF was not necessary. 
Selective reagent ion – time-of-flight – mass spectrometric studies of cocaine: investigations of charge and proton transfer reaction processes
Authors: Chawaguta Anesu , Olivenza-León David , Sulzer Philipp , Mayhew Chris A , Petralia Lorenzo Salvatore
Published: February 2025

Investigations are reported for the reactions of H3O+.(H2O)n (n = 0 and 1), NO+ and O2+• with cocaine (C17H21NO4) using a Selective Reagent Ion-Time-of-Flight-Mass Spectrometer (SRI-ToF-MS) covering a range of DC reduced electric field values (from approximately 60 Td up to about 230 Td), with the electric field strength being determined from the total DC voltage drop across the drift tube. In addition to examining the influence of the reduced electric field value on the reagent ion-cocaine product ion types and distributions, the effects of applying a radio frequency (RF) electric field in the ion funnel region of the drift tube are also reported. Observed reaction pathways without (DC mode) and with (DC + RF mode) the ion funnel operating include non-dissociative and dissociative proton transfer for the reactions involving H3O+.(H2O)n (n = 0 and 1), and non-dissociative and dissociative charge transfer for the reactions involving NO+ and O2+•. Although the dissociative proton transfer pathways leading to product ions with m/z values of 272.129 (C16H18NO3+), 182.118 (C10H16NO2+) and 123045 (C7H7O2+) are highly exoergic, as determined from density functional theory calculations, non-dissociative proton transfer dominates resulting in C17H21NO4.H+ at m/z 304.155. The significance of the lack of dissociative proton transfer is discussed. Non dissociative charge transfer, leading to C17H22NO4+ at m/z 303.155, dominates up to DC drift tube electric field strengths of about 80 V/cm, after which the product ion C5H8N+ becomes the dominant product ion. Other product ions resulting from dissociative charge transfer processes that are common to both NO+ and O2+• reactions with cocaine are C10H16NO2+ and C7H5O+ at m/z 182.118 and 105.036, respectively. The reactions with O2+• lead to a fourth observed fragment ion at m/z 272.129 corresponding to C16H18NO3+.
1.7 μm all-fiber Tm-doped mode-locked laser with narrow bandwidth filtering based on the nonlinear multimode interference effect
Authors: Zhang Peng , Ning Yuzhu , Wu Tong , Fan Yunlong , Liu Yang , Li Xiaoyan , Han Kexuan , Tong Shoufeng
Published: February 2025

The mode-locked (ML) all-fiber lasers with a linear cavity, using a single-mode-graded-index multimode-single-mode (SMS) device or a single-mode-few-mode-single-mode (SFS) device, are proposed and experimentally demonstrated. The homemade SMS or SFS devices work on the principle of nonlinear multimode interference. The linear cavity was constructed with two fiber Bragg gratings. By inserting an optimized length SMS into a Thulium-doped cavity, we achieved a 1724.9 nm Q-switched ML pulsed laser at the pump threshold of 29.9 dBm. A ML laser was observed when the multimode fiber in the SMS was stretched with a pump power of 31 dBm. The pulse width was about 326.3 ps, and the repetition rate was 16.5 MHz. The SMS was replaced with the SFS for comparison, and it was observed that the ML laser could be obtained with a better tolerance of the few-mode fiber length. Additionally, the SFS device offered a lower pump threshold and higher slope efficiency.
Enhancement of four-wave mixing due to coherent holes burning in a degenerate two-level system
Authors: Zhi-Yuan Liu , Yi-Fan Yao , Sun Yue , Han Jia-Yu , Du Ying-Jie
Published: February 2025

We present a theoretical study of four-wave mixing (FWM) in a degenerate two-level atomic system subject to a magnetic field whose Zeeman sublevels constitute a tripod-type atomic system, which is driven by a linearly polarized field, and coupled and probed by two sets of left and right circularly polarized fields. The optical effects of coherent hole burning (CHB) and electromagnetically induced transparency (EIT) are involved in the coherent system, among which the CHB has much larger response for the FWM than the EITs. Three situations of CHB are involved, and they are the solitary CHB, overlapped CHBs, and overlap between CHB and EIT. For the overlapped CHBs, there is the greatest magnitude of the FWM signal among the three situations. However, for the overlapped CHB and EIT, there is the smallest FWM magnitude among them, which is not more than one tenth of the former. While for the single CHB, the FWM magnitude has half of that for the overlapped CHBs. It is noted that in the overlap between CHB and EIT the dual EIAs can be obtained, whose FWM signal also has an enhancement in comparison to no EIA.
Extension of the visibility concept for EEG signal processing
Authors: Debenay Valentin , Turbelin Grégory , Issartel Jean-Pierre , Courmontagne Philippe , Chellali Amine , Ferrer Marie-Hélène
Published: February 2025

Objective. Visibility is an intrinsic property of any network of sensors that describes the regions in which its measurement sensitivity is concentrated. Initially introduced to describe the global spatial sensitivity of air pollution monitoring networks, we propose to extend the concept of visibility to characterize the detection capabilities of electroencephalography (EEG) systems utilized to measure brain electrical activity. Approach. In this paper, we represent visibility within the brain as a field of symmetric 3×3 matrices, satisfying the so-called “renormalizing conditions”, and interpreted as second-order tensors. A compact and computationally efficient iterative algorithm is proposed for computing this tensor field. In addition, we explain how to visualize and present the visibility information in an intuitive and easily understandable way. Main results. The visibility concept is exploited to evaluate and compare the ability of three consumer-grade EEG headsets to detect and localize an arbitrary current distribution in the brain. Additionally, visibility is applied to derive an inverse solution that can solve the Neuroelectromagnetic Inverse Problem (NIP) by reconstructing focal brain sources from EEG data. Significance. Although the lead field function approach can be employed to describe the sensitivity of individual electrodes from an EEG headset, this paper extends the sensor network’s visibility concept to characterize the sensing capabilities of a complete EEG system. The comparison between three consumer-grade EEG headsets shows that the size of the low-visibility brain area decreases when the number of electrodes used increases. In addition, we show that the source parameters are best estimated by the inverse solution when they are oriented towards the maximum visibility direction.
Sparse Knowledge Sharing (SKS) for privacy-preserving domain incremental seizure detection
Authors: An Jiayu , Peng Ruimin , Du Zhenbang , Liu Heng , Hu Feng , Shu Kai , Wu Dongrui
Published: February 2025

Objective: Epilepsy is a neurological disorder that affects millions of patients worldwide. Electroencephalogram-based seizure detection plays a crucial role in its timely diagnosis and effective monitoring. However, due to distribution shifts in patient data, existing seizure detection approaches are often patient-speciﬁc, which requires customized models for different patients. This paper considers privacy-preserving domain incremental learning (PP-DIL), where the model learns sequentially from each domain (patient) while only accessing the current domain data and previously trained models. This scenario has three main challenges: 1) catastrophic forgetting of previous domains, 2) privacy protection of previous domains, and 3) distribution shifts among domains. Approach: We propose a Sparse Knowledge Sharing (SKS) approach. First, Euclidean Alignment is employed to align data from different domains. Then, we propose an Adaptive Pruning approach for SKS to allocate subnet for each domain adaptively, allowing speciﬁc parameters to learn domain-speciﬁc knowledge while shared parameters to preserve knowledge from previous domains. Additionally, Supervised Contrastive Learning is employed to enhance the model’s ability to distinguish relevant features. Main Results: Experiments on two public seizure datasets demonstrated that SKS achieved superior performance in PP-DIL. Signiﬁcance: SKS is a rehearsal-free privacy-preserving approach that effectively learns new domains while minimizing the impact on previously learned domains, achieving a better balance between plasticity and stability.
Experimental study on the impact of viscosity index and contaminant concentration on the vibration characteristics of a Dual-Disc flexible rotor
Authors: Sun Ming , Cai Xin , Gao Bingpeng
Published: February 2025

The vibration of rotor systems is significantly affected by solid particle contaminants, leading to reduced system performance and, in some cases, failure. In this paper, the influence of lubricant viscosity index and solid particle contaminants on the vibration characteristics of a dual-disc flexible rotor was examined. A dual-disc flexible rotor test rig was established. Extensive experiments were carried out by mixing various concentrations of contaminants with four types of lubricants, each with a different viscosity index. The results indicated that nonlinear vibration phenomena were induced by the presence of contaminants. Significant changes in the rotor’s vibration characteristics were observed when contaminants were introduced into lubricants of varying viscosity indices, altering the system’s maximum amplitude and critical speed. These alterations included abrupt amplitude shifts and periodic variations in critical speed. This study provides important experimental evidence for the operation of dual-disc flexible rotor systems in complex environments and supports the further optimization of rotor design and safe operational strategies under contamination conditions.
Clam Shell Powder as Cement Substitution in Concrete Production
Authors: Abdul Malek A S , Jakaria S Z , Wan Putera Shah W M F I , Mohd Zuki S S , Mohammad Azmi M A , Shahidan S , Mohd Yusof N
Published: February 2025

In this era of rapid development, cement is used extensively in the building sector, resulting in a growing need for cement. This also causes the cost of cement to rise over time, and as a result, the cost of building construction also rises. In addition, the cement production industry is one of the most significant contributors to greenhouse gases. Clamshells are a kind of food waste whose breakdown requires a lengthy time. As a result, one of the methods to limit the disposal of this food waste is by substituting this material for cement in the production of concrete, due to the silica concentration of this clamshell being identical to that of cement. The research objective is to evaluate the compressive strength of concrete mixed with different percentages (5%, 10%, and 15%) of Clam Shell Powder as cement replacement. In addition, OPC and CSP’s chemical composition and microstructure are determined using X-ray fluorescence and Scanning Electronic Microscopy. This research aims to determine if clam shell powder is a suitable substitute for cement. It can be concluded that substituting 5% of cement with CSP gave concrete with similar design strength at 28 days due to CaO content found in CSP is comparable to that found in cement. It was observed that concrete with CSP increases the durability of concrete.
Utilizing mode shape curvature and artificial neural networks for structural damage assessment in beam-like structures
Authors: Hakim S J S , Mhaya A M , Noh M S M , Paknahad M , Tami H , Alshalif A F
Published: February 2025

Damage within a structure refers to changes in both its geometric and material characteristics, resulting in a drop in the stiffness that impacts the structure’s performance adversely. This decrease in stiffness causes alterations in modal parameters, including natural frequencies and mode shapes. Utilizing modal analysis allows for the extraction of modal frequencies and mode shapes, facilitating the analysis of mode shape curvature to detect structural damage. In recent years, artificial neural networks (ANNs) have achieved significant application, mainly for their exceptional capability in pattern recognition, which proves invaluable for identifying structural damage. This article proposes a novel method based on mode shape curvature and ANNs for detecting damage in beam-like structures. Experimental study is conducted to analysis damaged and undamaged structural modal behaviours. A feed-forward neural network with two hidden layers, trained on damage indices from mode shape data, is used to accurately pinpoint damage locations within the structure. The proposed approach for damage detection is validated and proves its ability to precisely pinpoint the location of damage. The results of this study demonstrate that ANNs trained with modal curvatures hold significant promise for identifying structural damage, enabling early detection in beam-like structures and contributing to ensuring their safe operation.
Evaluation of arch bridges using Finite element model updating
Authors: Kurniawan M , Syarif F , Setiawan P R , Ahmadi H , Putri C R
Published: February 2025

The arch bridge at the Islamic University of Riau is the main transportation access to the Faculty of Communication Sciences. Initially, the bridge was designed with a 16-meter span, but it’s currently only 13 meters long due to unexpected changes. Additionally, the bridge’s placement has shifted, affecting its load distribution and foundation due to soil accumulation. This study aims to evaluate the arch bridge’s Finite element (FE) model after updating it. To achieve this, Structural health monitoring systems (SHMS) will be used to assess the structural elements’ durability. One method being utilized is Finite element model updating (FEMU), which aims to improve the accuracy of the model by comparing field measurement data with numerical simulation results. The data obtained from the G-Link 200 USB accelerometer is processed using the ARTeMIS, FEMtools, and MATLAB programs to display the structural modal parameters. The results and discussions of this study indicate that the updated parameters mainly relate to the elastic modulus of the bridge structure. It’s concluded that the updated model, based on natural frequency and mode shape, illustrates that the bridge is still capable of operating normally. This is evidenced by a difference of 0.5885 Hz between the actual and theoretical frequency, indicating that the bridge has not diminished in its capacity.
Evaluating Productivity, Safety and Barriers in Modular Construction System Implementation
Authors: Sarbini N N , Wee Z Y , Thong J W
Published: February 2025

The implementation of modular construction systems in Malaysia is still low as compared to other countries, although it has proven to speed up the construction process. In this matter, this study focused on the productivity and safety that modular construction could offer. Besides, the barrier on the modular construction system implementation in Malaysia is also evaluated. This study employs a mixed research technique, combining a comprehensive literature review and a questionnaire distributed to the respondents via online forms. The analysis utilizes the Fuzzy Delphi method to reach consensus among respondents on the productivity and safety of the modular construction system. The barriers are also evaluated for consensus among the respondents. The findings indicate that modular construction systems have indeed improved site management, reduced construction time, and offered significant advantages in mitigating the risk of accidents and injuries, as supported by consensus. The main barriers to the adoption of modular construction systems include technical challenges and regulatory factors. Conversely, aspects such as supply, demand, industrial attitude, and process are not considered significant barriers. This research contributes to improve the modular construction system implementation in the Malaysian construction industry.
Sustainable Concrete Solution: Utilizing Palm Oil Fuel Ash and Metakaolin in Coconut Shell Aggregate Lightweight Concrete
Authors: Abu Bakar M N R , Ismail M H , Che Rahim N A N , George A F
Published: February 2025

The adoption of sustainable materials in the manufacturing of concrete has received considerable attention in recent years due to the environmental issues linked to conventional cement production. The objective of this study is to examine how the inclusion of palm oil fuel ash (POFA) and metakaolin (MK) as substitutes for cement affects the mechanical characteristics of lightweight concrete (LWC) that incorporates coconut shell as a partial substitute for coarse aggregate. The proportion utilised for MK and coconut shell remained constant, with 10% and 50% substitution, respectively. However, the proportion of POFA varied, ranging from 5% to 20% with increments of 5%. The study concluded that including 5% of POFA in coconut shell LWC resulted in the highest compressive strength with an increase of 68.55%, flexural strength with an increase of 39.29% while the split tensile strength was 32.18% and the lastly, was the lowest water absorption which 3.75% at 28 days of concrete age. Nevertheless, the slump value decreases as the percentage of POFA substance increases.
Site Selection Study of Siren Early Warning System for Community Preparedness due to Potential Dam Calamity: Case Study of Kg Batu Melintang, Jeli, Kelantan
Authors: Mamat Ahmad Fadhli , Amin Mohammad Faiq Md , Mahmood Jaini , Hamid Mohamad Amirul Hafiz Abd , Hussain Mohd. Ramzi Mohd. , Tukiman Izawati , Muda Rahsidi Sabri
Published: February 2025

Effective early warning systems (EWS) for dam disasters rely heavily on the strategic placement of sirens to ensure comprehensive coverage and timely alerts. This study investigates the criteria and methodologies for optimizing siren placement, utilizing Geographic Information System (GIS) technology and multi-criteria decision analysis. By integrating data on population density, geographic features, and flood hydrodynamics, the study identifies optimal siren locations to maximize effectiveness. Population data from recent census reports, geographic data from topographic maps and satellite imagery, and disaster simulation data were analysed to determine high-risk areas and prioritize siren placement. The results demonstrate that strategic placement of sirens with standard coverage radius of up to 1 kilometre can significantly enhance early warning capabilities, even in areas prone to flooding, provided they are strategically placed in densely populated zones. The findings highlight the importance of data-driven site selection in improving disaster preparedness and risk management strategies, ultimately contributing to more effective early warning systems that safeguard lives and property in vulnerable communities.
Effect of organic amendments based on date palm residues on barley crop (Hordeum vulgare L.) in an oasian environment: case of the Oued Righ region, Algeria.
Authors: Tirichine A , Abid A , Hafouda L , Sbih M , Gommeaux M , Boumaraf B , Moussa M , Marin B , Le Guyader E , Kavvadias V , Morvan X
Published: February 2025

The Saharan soils are known to be poor in organic matter and mineral elements essential to plants. In this context, the field trial has been conducted in the experimental station of the National Institute of Agronomic Research of Algeria (INRAA) of Sidi Mehdi Touggourt in order to improve soil agronomic suitability of the region’s palm groves and increase yields. The trial examined the effect of five treatments, including an unamended control and four combinations of organic amendments and/or chemical fertilizer (compost, biochar + compost, biochar + fertilizer and fertilizer alone) on some growth and yield parameters of the barley crop (number of tillers per plant, plant height, and grain yield). A randomized experimental design with three repetitions was used. For all studied parameters, the biochar + fertilizer treatment ranked first compared to the other treatments. In terms of grain yields, it exceeded 51 qt/ha followed by fertilizer treatment (49.9 qt/ha). The compost amendment gave a yield of 36.6 qt/ha. The biochar + compost treatment and the control (cultivated without amendment) were the last with yields of 30.8qt/ha and 27.7 qt/ha, respectively. The statistical study revealed significant to very highly significant differences between treatments depending on the parameters.
Repeat gravity observation using CG5 relative gravimeter since 2014 measurements of A10 absolute gravimeter in Bandung and Blora, Indonesia
Authors: Wahyudi E J , Setianingsih
Published: February 2025

Since 2014 micro-gravity measurements using portable absolute gravimeter A10 and relative gravimeter Scintrex CG-5 at Bandung and Blora, we continue to monitor gravity value at several cities in Java Island, Indonesia. Repeat observation from 2014 to 2024 activities conducted by team from FTTM Geophysics Exploration Laboratory. From this activities, several studies (such as: field camp geophysics, undergraduate final projects, and magister thesis) that using gravity data can be conducted. The studies mainly used to monitor hidrology variation and structural modeling in the subsurface. Repeat gravity observation during ten years (2014 to 2024) cover several cities such as: Bandung, Kebumen, Yogyakarta, Klaten, Blora, Ngawi, Madiun, and Ponorogo. Next study in several cities can be proposed to repeat the observation in several area such as: Nganjuk, Magetan, Pacitan, Sragen, Karanganyar, Wates, Purworejo, Banyumas, Cilacap, Banjar, Ciamis, and Garut. Time-lapse microgravity studies already cover the area in the several vilages in Blora, three Kecamatan of Kota Madiun, several Kecamatan of Ngawi (baseline-survey), and Bandung (since 2010 to 2021). From this work, several gravity values from reference benchmark (BM) shows small changes with standard deviation less then 20 microGal (16 refference stations), while 8 stations provide standard deviation in the range 20 to 82 microGal, and 2 other stations shows higher standard deviation up to 126 microGal.
Interception of Meratus and Java Trends Structures as Controlling the Emergence of the Purwodadi Mud Volcano Complex
Authors: Novianto Ardian , Hidayat Wahyu , Bintarto Bambang
Published: February 2025

The geological phenomena of mud volcano and eternal flame in Purwodadi and its surroundings are geological events that are often the subject of research. The concept of disaster (geohazard) is one of the concerns, especially related to infrastructure development for regional development, especially in Grobogan District (Purwodadi). The distribution pattern of mud volcano on the surface such as Bledug Kuwu, Bledug Ramesan Medang, Bledug Cangkring, Bledug Banjar Lor, Bledug Krewek, Bledug Kesonggo needs to be interpreted to predict the possibility of mudflow occurrence in other places due to infrastructure development. The pattern of mud volcano occurrence is interpreted to be controlled by the geological structure affecting the area. The confluence of structures between the stresses that produce the Meratus pattern and the Java Pattern is interpreted as a weak zone that serves as a mud release path to the surface. This research aims to identify the pattern and development of structures in the study area based on gravity data to reduce potential geohazard in infrastructure development on the surface. Structural analysis was conducted using the gravity method and enhancement data processing using the derivative method. Analysis of subsurface structural patterns based on gravity processing will be validated with seismic data and geological structures on the surface. This combination of analysis is used to interpret the pattern and development of structures that control the emergence of mud volcanoes or mud diapirs that can cause geohazards in infrastructure development. The analysis results based on several methods show that the emergence of the mud volcano phenomenon in the study area is interpreted to occur at the intersection between two major structural patterns, namely the Meratus pattern and the Java pattern. This intersection produces a weak zone that serves as a pathway for mud to escape from the underlying ellisonal basin to the surface as a mud volcano. The distribution pattern of this structural intersection zone becomes a geohazard-prone area so that it can be used in planning infrastructure development on the surface.
Assessment of Seismic Vulnerability and Shear Wave Velocity Estimation Using the Horizontal-to-Vertical Spectral Ratio (HVSR) Method in Umbul Niti Geothermal Manifestations, Jatimulyo Village, South Lampung
Authors: Prabowo Satria Bagus , Wulandari Rizki , Putri Intan Andriani , Nathania Edlyn Yoadan , Nugraha Purwaditya , Sitio Yogi Y. Ch.
Published: February 2025

The discovery of geothermal manifestations in 2021 in Umbul Niti, Jatimulyo Village, South Lampung Regency, reveals significant potential for geotourism development, which can help reduce poverty. However, this potential is accompanied by an unstable zone due to a fault, increasing earthquake risks. Additionally, population growth and the presence of the Sumatera Institute of Technology (ITERA) pose development challenges related to population density and potential losses. Therefore, investigating soil characteristics based on natural frequency (f
0), amplification (A
0), and shear wave velocity at depths of 0-30 meters (

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) is crucial for development planning and earthquake risk evaluation through seismic vulnerability values (Kg
). The Horizontal to Vertical Spectral Ratio (HVSR) method was used, revealing f
0 values from 3.876 Hz to 23.695 Hz, indicating sediment thickness variations from thick to very thin, dominated by very thin layers with very low amplification. The f
0 results, correlating with geothermal areas, show the same anomaly contrast as previous studies with 3D gravity model results and residual magnetic anomalies. Additionally, the Particle Swarm Optimization (PSO) method was used to obtain

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variations, ranging from hard to soft soil, with the lowest

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values near the manifestation. The seismic vulnerability index was generally low, indicating a low earthquake disaster risk in the study area. The cross-section results identified three faults in cross-section A-A’ and two faults in cross-section B-B’, corresponding with the forward modeling in the magnetic method. This research is expected to contribute positively to geotourism development, particularly in planning and disaster risk mitigation. These findings highlight the need for careful planning and risk mitigation to leverage geotourism potential while managing seismic risks. Although the seismic vulnerability index is generally low, some medium risk zones were detected, emphasizing the importance of integrating geotourism development with comprehensive risk management strategies to ensure sustainable geotourism development and community resilience.