bluuebunny/crossref_metadata_2025_split huggingface dataset:
High school physics teachers’ perceptions and attitudes towards thought experiments in Indonesia
Authors: Bancong Hartono , Nurazmi  , Sirajuddin  
Published: June 2023

Abstract
Thought experiments have a crucial role in the discovery of physics theories. Yet, in order to properly use thought experiments in the classroom, teachers must have enough pedagogical knowledge and abilities. This study aims to explore the perceptions and attitudes of high school physics teachers toward thought experiments. In this study, we involved 30 physics teachers from different schools in both urban and rural schools. The data were collected through questionnaires and semi-structured interviews. The quantitative and qualitative analysis results demonstrate that physics teachers have a high awareness of the importance of thought experiments in physics learning, especially atomic theory and relativity, and perceive themselves to lack skills regarding the pedagogical aspects of thought experiments. Teachers also show positive attitudes and beliefs about teaching thought experiments. However, teachers still recognized the challenges of implementing thought experiments in the classroom. The teacher suggests that thought experiments be carried out collaboratively so that students can share ideas with each other. Furthermore, technology media such as virtual reality may be the ideal answer for assisting students in visualizing an imaginary environment when doing thought experiments in the classroom.
Motion-compensated scheme for sequential scanned statistical iterative dual-energy CT reconstruction
Authors: Ge Tao , Liao Rui , Medrano Maria , Politte David G , Whiting Bruce R , Williamson Jeffrey F , O’Sullivan Joseph A 
Published: June 2023

Abstract

Objective. Dual-energy computed tomography (DECT) has been widely used to reconstruct numerous types of images due its ability to better discriminate tissue properties. Sequential scanning is a popular dual-energy data acquisition method as it requires no specialized hardware. However, patient motion between two sequential scans may lead to severe motion artifacts in DECT statistical iterative reconstructions (SIR) images. The objective is to reduce the motion artifacts in such reconstructions. Approach. We propose a motion-compensation scheme that incorporates a deformation vector field into any DECT SIR. The deformation vector field is estimated via the multi-modality symmetric deformable registration method. The precalculated registration mapping and its inverse or adjoint are then embedded into each iteration of the iterative DECT algorithm. Main results. Results from a simulated and clinical case show that the proposed framework is capable of reducing motion artifacts in DECT SIRs. Percentage mean square errors in regions of interest in the simulated and clinical cases were reduced from 4.6% to 0.5% and 6.8% to 0.8%, respectively. A perturbation analysis was then performed to determine errors in approximating the continuous deformation by using the deformation field and interpolation. Our findings show that errors in our method are mostly propagated through the target image and amplified by the inverse matrix of the combination of the Fisher information and Hessian of the penalty term. Significance. We have proposed a novel motion-compensation scheme to incorporate a 3D registration method into the joint statistical iterative DECT algorithm in order to reduce motion artifacts caused by inter-scan motion, and successfully demonstrate that interscan motion corrections can be integrated into the DECT SIR process, enabling accurate imaging of radiological quantities on conventional SECT scanners, without significant loss of either computational efficiency or accuracy.
Minihalos as probes of the inflationary spectrum: accurate boost factor calculation and new CMB constraints
Authors: Abellán Guillermo Franco , Facchinetti Gaétan 
Published: June 2023

AbstractAlthough the spectrum of primordial fluctuations has been accurately measured on scales above ∼ 0.1 Mpc, only upper limits exist on smaller scales. In this study, we investigate generic monochromatic enhancements to the ΛCDM spectrum that trigger the collapse of ultracompact minihalos (UCMHs) well before standard structure formation. We refine previous treatments by considering a mixed population of halos with different density profiles, that should realistically arise as a consequence of late-time accretion and mergers. Assuming that dark matter (DM) can self-annihilate, we find, as expected, that UCMHs can greatly enhance the annihilation rate around recombination, significantly imprinting the cosmic microwave background (CMB) anisotropies. However, we provide additional insight on the theoretical uncertainties that currently impact that boost and which may affect late-time probes such as the 21 cm line or γ-ray signals. We derive constraints on the primordial power spectrum on small scales using theExoCLASS/HYRECcodes and thePlanck legacy data. We account for the velocity dependence of the DM annihilation cross-section (s- orp-wave), annihilation channel, the DM particle mass and the inclusion of late-time halo mergers. Our s-wave constraints are competitive with previous literature, excluding primordial amplitudes 𝒜*≳ 10-6.5at wavenumbersk∼ 104- 107Mpc-1. For the first time, we highlight that evenp-wave processes have constraining power on the primordial spectrum for cross-sections still allowed by currently the strongest astrophysical constraints. Finally, we provide an up-to-date compilation of the most stringent limits on the primordial power spectrum across a wide range of scales.
Relaxion dark matter from stochastic misalignment
Authors: Chatrchyan Aleksandr , Servant Géraldine 
Published: June 2023

Abstract
Cosmological relaxation of the electroweak scale via Higgs-axion interplay, named as relaxion mechanism, provides a dynamical solution to the Higgs mass hierarchy. In the original proposal by Graham, Kaplan and Rajendran, the relaxion abundance today is too small to explain the dark matter of the universe because of the high suppression of the misalignment angle after inflation. It was then realised by Banerjee, Kim and Perez that reheating effects can displace the relaxion, thus enabling it to account for the dark matter abundance from the misalignment mechanism. However, this scenario is realised in a limited region of parameter space to avoid runaway. We show that in the regime where inflationary fluctuations dominate over the classical slow-roll, the “stochastic misalignment” of the field due to fluctuations can be large. We study the evolution of the relaxion after inflation, including the high-temperature scenario, in which the barriers of the potential shrink and destabilise temporarily the local minimum. We open new regions of parameter space where the relaxion can naturally explain the observed dark matter density in the universe, towards larger coupling, larger mass, larger mixing angle, smaller decay constant, as well as larger scale of inflation.
Measurement science meets the reproducibility challenge
Authors: Possolo Antonio 
Published: June 2023

Abstract
Measurement science is particularly well equipped not only to meet reproducibility challenges arising within the field of metrology, but also to suggest strategies and best practices for how such challenges can be met in other fields. This contribution illustrates three such challenges, in three different fields, and proposes ways to address them that can supplement the only way in which reproducibility challenges in science can be resolved definitively: by validated scientific advances that point toward the truth. The first example concerns a large interlaboratory, international comparison of the measurement of the mass fraction of silica in a granite reference material, using classical methods of wet analytical chemistry, carried out in the 1940s. The results delivered a shock to analysts worldwide about the state of the art at the time. The challenge was magnified by the fact that none of the measured values was qualified with an evaluation of measurement uncertainty. We offer an approach developed by Andrew Rukhin from NIST, for how to compute a meaningful consensus value in such case, and explain how the associated uncertainty can be characterized. The second example is about the currently hot topic of the Hubble tension, which refers to the mutual inconsistency of the measurement results, obtained by different methods, for the Hubble-Lemaître constant, which expresses the rate of expansion of the Universe. We suggest that such tension can be quantified in terms of the dark uncertainty that figures as a parameter in a laboratory random effects model, thus providing an objective metric whereby progress toward resolving such tension can be gauged. The third example discusses two sources of lack of reproducibility: on the one hand, the fact that different laboratories produced strikingly discrepant values for the mass fraction of arsenic in kudzu; on the other hand, that different models can be fitted to these data, each producing its own set of results. Here we use a Bayesian model selection criterion to choose one from among four models that are natural candidates to address this double reproducibility challenge. This third example also affords us the opportunity to deflate two widespread myths: that one needs at least four observations to obtain a Bayesian evaluation of standard uncertainty, and that sample standard deviations of small samples are systematically too small.
Characteristics of a real-time ensemble time scale corrected by the KRISS-PSFS using a reduced Kalman filter (Kred) algorithm
Authors: Lee Ho Seong , Kwon Taeg Yong , Park Sang Eon , Lee Young Kyu , Yang Sung-hoon , Yu Dai-Hyuk , Heo Myoung-Sun , Kim Huidong , Park Chang Yong , Lee Won-Kyu 
Published: June 2023

Abstract
An ensemble time, which is indicated by TA (temps atomique, in French), was generated every minute by combining four active hydrogen masers with the reduced Kalman filter (Kred) algorithm. The TA frequency was averaged over 12 h and then the mean frequency was steered to the primary and secondary frequency standards developed by KRISS with a micro-phase stepper (MPS). The steered and physically realized TA frequency is called KRISS ensemble time (KET). We investigated the frequency-state estimate outputted from the Kred algorithm and the control signal applied to the MPS, according to the abnormal temperature change of the room where the hydrogen masers were placed. When the frequency of the TA was corrected by the KRISS-F1, the Allan deviation of KET was 1.72 × 10−15 at the average time τ = 1 d, and the variation of [UTC–KET] was stable within 2 ns for 75 d.
Measurements and modeling of type-I and type-II ELMs heat flux to the DIII-D divertor
Authors: Perillo R. , Boedo J.A. , Lasnier C.J. , Pitts R.A. , Brank M. , Bykov I. , Coburn J.D. , Glass F. , Marini C. , Osborne T. , Riding M. , Rudakov D.L. , Watkins J.G. , Zeng L. 
Published: June 2023

Abstract
Type-I and type-II edge-localized-modes (ELMs) heat flux profiles measured at the DIII-D divertor feature a peak in the vicinity of the strike-point and a plateau in the scrape-off-layer (SOL), which extends to the first wall. The plateau is present in attached and detached divertors and it is found to originate with plasma bursts upstream in the SOL. The integrated ELM heat flux is distributed at ∼65% in the peak and ∼35% in this plateau. The parallel loss model, currently used at ITER to predict power loads to the walls, is benchmarked using these results in the primary and secondary divertors with unprecedented constraints using experimental input data for ELM size, radial velocity, energy, electron temperature and density, heat flux footprints and number of filaments. The model can reproduce the experimental near-SOL peak within ∼20%, but cannot match the SOL plateau. Employing a two-component approach for the ELM radial velocity, as guided by intermittent data, the full radial heat flux profile can be well matched. The ELM-averaged radial velocity at the separatrix, which explains profile widening, increases from ∼0.2 km s−1 in attached to ∼0.8 km s−1 in detached scenarios, as the ELM filaments’ path becomes electrically disconnected from the sheath at the target. The results presented here indicate filaments fragmentation as a possible mechanism for ELM transport to the far-SOL and provide evidence on the beneficial role of detachment to mitigate ELM flux in the divertor far-SOL. However, these findings imply that wall regions far from the strike points in future machines should be designed to withstand significant heat flux, even for small-ELM regimes.
Potential of Ultra-High-Performance Concrete (UHPC) for Refurbishment of Bridges
Authors: Fehling Ekkehard , Thiemicke Jenny 
Published: June 2023

Abstract
In many countries, the bridge infrastructure suffers from damaged bridges that need to be rehabilitated or replaced. This means that the state or the institutions responsible for this must make extensive investments. Are there other ways to address the problems caused by the damaging effects of de-icing agents, by fatigue due to high vehicle loads and frequencies on the load side or by lack of fatigue strength of, for example, orthotropic bridge decks? Yes, UHPC surface courses can be used as a protective barrier against aggressive substances such as chlorides. They can also be load-bearing and contribute to improved bearing capacity while providing durability. In addition, a single layer can replace the foundation of multiple layers required for sealing and trafficability. The following article shows the potential of such UHPC layers for improving existing bridges, be they concrete or steel bridges.
Nonlinear finite element analyses of reinforced concrete beam-column joints subjected to cyclic loading
Authors: Handoko J , Gunawan A , Chandra J , Wibowo H 
Published: June 2023

Abstract
Interaction of forces and moments in a beam-column joint is complex and most of the time nonlinear. Thus, a simple, global model is insufficient to estimate the performance and behavior of the joint. Results from several nonlinear finite element analyses of beam-column joints using VecTor2 are presented herein. Four interior and two exterior beam-column joint models with three different types of failure were studied. The analysis results in terms of force-drift ratio curves and crack patterns were then compared to the experimental results. In general, the results obtained from VecTor2 were satisfactory, but in some cases the program could not accurately capture the strength degradation observed in the specimen with joint shear failure. Moreover, the crack patterns were not accurately captured. Nevertheless, VecTor2 can still estimate the peak forces well for all specimens in this study.
Mechanical behaviours of cellular lightweight concrete using finite element analysis
Authors: Suryanita Reni , Maizir Harnedi , Saputra Hari 
Published: June 2023

Abstract
Cellular Lightweight Concrete (CLC) is a concrete brick with a density lighter than concrete bricks. The efficiency of the use and quality of CLC can be determined by analysing mechanical behaviour using the finite element method. The purpose of this study is to analyse the mechanical behaviour of lightweight concrete using the finite element method. Analysis of mechanical behaviour using LUSAS finite element software. The CLC model used admixture materials of silica foam, palm oil fly ash (POFA) and lime (CaCO3). The study resulted in the difference between the numeric and experimental analysis being less than 10%. The most considerable deformation occurred at the top of the CLC model based on the deformation contour distribution. The most significant stress and strain contours distribution occurred at the CLC model’s bottom. The controlled load of 6 kN to 60 kN causes an increase in the mechanical behaviour of CLC. The most considerable deformation occurred when the maximum load on the CLC model with a silica fume mixture was 9.239 mm. The stress of the CLC model is 1.148 N/mm2, and the most significant strain occurred in CLC with silica fume admixture with a CLC weight of 0.038. Thus, the finite element method can be used as a comparison of laboratory test results to determine the mechanical behaviour of CLC.
Accident prevention in a highly occupied building through safety audit: a readiness perspective in university buildings
Authors: Hermawan F , Pratiwi A N , Susanto T , Hatmoko J U D 
Published: June 2023

Abstract
Potential accidents can occur at any time, including educational activities at a university. Twenty-four cases of accidents at universities in Indonesia, in the form of collapsing building components and fires, have been recorded in the last decade. There is a need for colleges to be ready to implement a Construction Safety Management System in the buildings where educational activities take place. There are two aspects to construction safety in public buildings: the engineering aspect and the aspect of safety management and occupational health. This research aims to assess and analyse the readiness to apply construction safety in a building with large occupancy. The research method uses a case study of a building in the civil engineering department of a university in Indonesia. Data collection comprised field surveys, semi-structured interviews and the collection of drawings and documents regarding the management of occupational safety and health in 2020-2021. The results show that the site studied was mediocre, in terms of implementing a construction safety management system. Although the physical condition of the building is good, other indicators, such as building documents and the application of occupational health and safety, fall into the ‘lack of application’ category.
Corrosivity of water for concrete and metal water resources infrastructure with modification of the DIN Method and Langelier Saturation Index of Metcalf and Eddy
Authors: Lestari Devita Satya , Sukamta  , Sari Yunitta Chandra 
Published: June 2023

Abstract
Corrosion or rust is an endless problem, both in Indonesia and in the world. This is so because corrosion or rust is very detrimental, especially if it occurs in water infrastructure, particularly one built from concrete and metal. Corrosion is a decrease in material quality due to a reaction with the environment. The kinds of losses incurred if corrosion occurs in the infrastructure of water resources include reservoir collapse due to the acceleration of corrosion in the dam, damage to the turbine, and damage to the irrigation gates. This research was conducted to determine level of corrosivity water to water infrastructure built from concrete and metal in 9 (nine) reservoirs. The primary data consist of water quality parameters, determined by sampling the water. The storage and preservation methods of the water samples were done in accordance with Indonesian National Standard Number 6989.57:2008. Water quality was tested by an accredited laboratory. Corrosivity of water for metal and concrete infrastructure was calculated using Metcalf and Eddy formula (2003) and the modification of the DIN 4030 method (2008), respectively. The results of the calculation with Metcalf and Eddy’s LSI (2003) show that the water corrosivity in the 9 (nine) reservoirs had the potential to damage the metal infrastructure, ranging from mild to severe corrosion and lime/crust formation. Based on the modification of the DIN 4030 method (2008), the water in 7 (seven) reservoirs did not have the potential to damage concrete infrastructure, but the water in 2 (two) reservoirs had the potential to damage the concrete infrastructure from mild to moderate level.
Liquefaction severity assessment for the Anutapura Medical Center Area of Palu-Indonesia
Authors: Simatupang Minson , Edwin Romy Suryaningrat , Sulha  
Published: June 2023

Abstract
A liquefaction hazard assessment for a particular location is important to reduce disasters that may occur in the future. The liquefaction severity assessment for the Anutapura Medical Centre region of Palu-Indonesia was carried out on various pairs between peak ground surface acceleration and earthquake magnitude. It was conducted by first determining the factor of safety for each existing soil layer and applying the formulation prepared by Iwasaki to measure Liquefaction Potential for the entire soil column. The possible severity of liquefaction at these locations was compared based on the limits set by the respective theories of Iwasaki and Papathanassiou. The results showed that the Anutapura Medical Centre location was very susceptible to liquefaction events with a very high potential level of ground surface damage based on the Iwasaki boundary line. The above-mentioned severity by Papathanassiou limits ranges from high to very high.
Additional Lateral Soil Pressure on Soil due to The Vehicle at a Constant Speed
Authors: Handiman Iman , Redana I Wayan , Hidayanti Anisa Maria , Sudarsana I Ketut 
Published: June 2023

Abstract
On roads that cross the slope is often required evaluation of the need for retaining slope construction (road). In the design of the construction, one of the main factors that must be known is the amount of horizontal ground pressure that occurs. The amount of ground pressure consists of the ground pressure it self and the pressure due to other loads such as vehicles passing on it. The horizontal pressure due to constant and stationary loads is different from the horizontal pressure due to a running vehicle. This study was conducted to determine how the additional influence of horizontal pressure that occurs due to the vehicle through on it. A model (vehicle) is simulated to move at a constant speed along a sensor-Fed trajectory at a predetermined position. Instrumentation results show that the additional pressure that occurs in the form of pressure bubbles is similar to the pressure due to stationary and constant vertical loads. Test results for low-speed loads below 10 km/hrs showed the greatest horizontal pressure that occurs at a depth of 0.5 m and a distance of 0.5 m from the instrumentation. A comparison using the Boussinesq equation using the same load, shows that the maximum horizontal pressure that occurs is still relatively smaller than the additional lateral pressure due to static load.
Photon statistics and quantum phase distribution for coherent optical links in the presence of phase noise from both the laser source and the RF oscillator, and dispersion
Authors: Pratap Rana , Ramachandran Harishankar 
Published: June 2023

Abstract
A model of photon statistics and quantum phase distribution is analyzed for coherent optical communication links in the presence of quantum phase noise, dispersion and phase noise of the radio-frequency (RF) oscillator using an in-line optical amplifier. The quantum analysis of a dual drive Mach–Zehnder modulator and the quantum transfer function for an optical field mode across an in-line amplifier is performed by taking into account both the quantum and the classical phase noises. The resulting photon statistics are compared with the semiclassical model. We analyze the quantum phase distribution by considering the Wigner quasiprobability distribution for a coherent optical link. Here, we investigate the broadening of the quantum phase distribution due to quantum phase noise of the laser, the dispersive optical fiber, the phase noise of the RF oscillator and the inevitable noise coefficient of the optical amplifier for arbitrary amplified spontaneous emission (ASE) field modes. We analytically investigate the quantum analog to the bit error rate (BER) as a function of the laser’s linewidth, the linewidth of the RF oscillator and chromatic dispersion. The results of quantum models are compared with the semiclassical model. Quantum treatment of both the BER and variance is found to agree with prior results for a single-mode ASE field in the absence of phase noise but deviate when the effect of phase noise is considered. Including phase noise effects in the amplitude in the semiclassical treatment of the BER yields a new semiclassical expression that agrees with quantum expressions of machine precision for single-mode ASE fields.