bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of illusion device in the electro-quasi-static field
Authors: Liu Ning , Mei Zhong Lei
Published: April 2024

Illusion devices have important applications in military fields because they can change the scattering pattern of objects. In this paper, the illusion conditions in the electro-quasi-static (EQS) field when transient excitation is applied are first deduced. According to the conditions derived, the illusion in the EQS field can be realized. Three representative cases are considered, one for the invisibility situation and two for the illusion situation. Moreover, the evolution of potential with time and its relationship with the excitation is determined. The result has been verified by analytical solution and finite element simulation. Finally, the possible realization of the illusion is discussed by equating the illusion device to the resistance-capacitance network. We also discuss the potential improvement of the device by using reconfigurable components in the device.
Family behavior and Dirac bands in armchair nanoribbons with 4–8 defect lines
Authors: Gillen Roland , Maultzsch Janina
Published: April 2024

Bottom-up synthesis from molecular precursors is a powerful route for the creation of novel synthetic carbon-based low-dimensional materials, such as planar carbon lattices. The wealth of conceivable precursor molecules introduces a significant number of degrees-of-freedom for the design of materials with defined physical properties. In this context, a priori knowledge of the electronic, vibrational and optical properties provided by modern ab initio simulation methods can act as a valuable guide for the design of novel synthetic carbon-based building blocks. Using density functional theory, we performed simulations of the electronic properties of armchair-edged graphene nanoribbons (AGNR) with a bisecting 4–8 ring defect line. We show that the electronic structures of the defective nanoribbons of increasing width can be classified into three distinct families of semiconductors, similar to the case of pristine AGNR. In contrast to the latter, we find that every third nanoribbon is a zero-gap semiconductor with Dirac-type crossing of linear bands at the Fermi energy. By employing tight-binding models including interactions up to third-nearest neighbors, we show that the family behavior, the formation of direct and indirect band gaps and of linear band crossings in the defective nanoribbons is rooted in the electronic properties of the individual nanoribbon halves on either side of the defect lines, and can be effectively through introduction of additional ‘interhalf’ coupling terms.
Vibrational properties of disordered stealthy hyperuniform 1D atomic chains
Authors: Zhuang Houlong , Chen Duyu , Liu Lei , Keeney David , Zhang Ge , Jiao Yang
Published: April 2024

Disorder hyperuniformity is a recently discovered exotic state of many-body systems that possess a hidden order in between that of a perfect crystal and a completely disordered system. Recently, this novel disordered state has been observed in a number of quantum materials including amorphous 2D graphene and silica, which are endowed with unexpected electronic transport properties. Here, we numerically investigate 1D atomic chain models, including perfect crystalline, disordered stealthy hyperuniform (SHU) as well as randomly perturbed atom packing configurations to obtain a quantitative understanding of how the unique SHU disorder affects the vibrational properties of these low-dimensional materials. We find that the disordered SHU chains possess lower cohesive energies compared to the randomly perturbed chains, implying their potential reliability in experiments. Our inverse partition ratio (IPR) calculations indicate that the SHU chains can support fully delocalized states just like perfect crystalline chains over a wide range of frequencies, i.e.

ω
∈
(
0
,
100
)

cm−1, suggesting superior phonon transport behaviors within these frequencies, which was traditionally considered impossible in disordered systems. Interestingly, we observe the emergence of a group of highly localized states associated with

ω
∼
200

cm−1, which is characterized by a significant peak in the IPR and a peak in phonon density of states at the corresponding frequency, and is potentially useful for decoupling electron and phonon degrees of freedom. These unique properties of disordered SHU chains have implications in the design and engineering of novel quantum materials for thermal and phononic applications.
A novel residual global context shrinkage network based fault diagnosis method for rotating machinery under noisy conditions
Authors: Tong Jinyu , Tang Shiyu , Zheng Jinde , Zhao Hongjie , Wu Yi
Published: April 2024

In real industrial environments, vibration signals generated during the operation of rotating machinery are typically accompanied by significant noise. Existing deep learning methods often yield unsatisfactory diagnostic results when dealing with noisy signals. To address this problem, a novel residual global context shrinkage network (RGNet) is proposed in this paper. Firstly, to fully utilize the useful information in the raw vibration signal, a multi-sensor fusion strategy based on dispersion entropy is designed as the input of the deep network. Then, the RGNet is designed, which improves the long-distance modeling capability of the deep network while suppressing noise, optimizes the network gradient and computational performance. Finally, the noise suppression ability and feature extraction ability of the RGNet are intuitively revealed through an interpretability study. The advantages of the proposed method are proved through a series of comparison experiments under noisy backgrounds.
An acoustic emission identification model for train axle fatigue cracks based on deep belief network
Authors: Lin Li , Tang Xiaowen , Zhu Xiaoxiao , Yu Xinyuan , Bi Tianlong
Published: April 2024

Railway axles are safety-critical components of the railroad rolling stock and the consequences of possible in-service failures can have a huge impact. Axle fatigue cracks are relatively common defects during train operation, but how to intelligently identify axle fatigue cracks in running trains is still a great challenge. In order to identify axle fatigue cracks more intelligently, the problem that needs to be solved is how to overcome the manual extraction of features by manual experience as well as shallow networks. Therefore, in this paper, an acoustic emission signal identification method based on deep belief networks (DBNs) for axle fatigue cracks is proposed. In this method, a DBN model is constructed. The axle fatigue crack acoustic emission signal data were obtained by our designed acquisition experimental setup, and these data were used to verify the accuracy of the constructed DBN network model identification. The experimental results show that the method of identification of axle fatigue cracks based on DBN, compared with the traditional fault diagnosis method, eliminates the operations of data feature extraction, feature screening, feature fusion, etc and makes complete use of all the information contained in the fault data. The method can not only identify fatigue crack signals but also has a high identification rate of fatigue cracks at different stages. In the axle fatigue crack acoustic emission identification field, it can be seen that the proposed method in this paper will be a promising approach.
Reference-free x-ray fluorescence analysis with a micrometer-sized incident beam
Authors: Hönicke Philipp , Wählisch André , Unterumsberger Rainer , Beckhoff Burkhard , Bogdanowicz Janusz , Charley Anne-Laure , Mertens Hans , Rochat Névine , Hartmann Jean-Michel , Giambacorti Narciso
Published: April 2024

Spatially resolved x-ray fluorescence (XRF) based analysis employing incident beam sizes in the low micrometer range (μXRF) is widely used to study lateral composition changes of various types of microstructured samples. However, up to now the quantitative analysis of such experimental datasets could only be realized employing adequate calibration or reference specimen. In this work, we extent the applicability of the so-called reference-free XRF approach to enable reference-free μXRF analysis. Here, no calibration specimen are needed in order to derive a quantitative and position sensitive composition of the sample of interest. The necessary instrumental steps to realize reference-free μXRF are explained and a validation of ref.-free μXRF against ref.-free standard XRF is performed employing laterally homogeneous samples. Finally, an application example from semiconductor research is shown, where the lateral sample features require the usage of ref.-free μXRF for quantitative analysis.
Nano-cutting mechanism of ion implantation-modified SiC: reducing subsurface damage expansion and abrasive wear
Authors: Kang Qiang , Kong Xianguang , Chang Jiantao , Fang Xudong , Kang Chengwei , Wu Chen , Li Changsheng , Maeda Ryutaro , Jiang Zhuangde
Published: April 2024

This study utilized ion implantation to modify the material properties of silicon carbide (SiC) to mitigate subsurface damage during SiC machining. The paper analyzed the mechanism of hydrogen ion implantation on the machining performance of SiC at the atomic scale. A molecular dynamics model of nanoscale cutting of an ion-implanted SiC workpiece using a non-rigid regular tetrakaidecahedral diamond abrasive grain was established. The study investigated the effects of ion implantation on crystal structure phase transformation, dislocation nucleation, and defect structure evolution. Results showed ion implantation modification decreased the extension depth of amorphous structures in the subsurface layer, thereby enhancing the surface and subsurface integrity of the SiC workpiece. Additionally, dislocation extension length and volume within the lattice structure were lower in the ion-implanted workpiece compared to non-implanted ones. Phase transformation, compressive pressure, and cutting stress of the lattice in the shear region per unit volume were lower in the ion-implanted workpiece than the non-implanted one. Taking the diamond abrasive grain as the research subject, the mechanism of grain wear under ion implantation was explored. Grain expansion, compression, and atomic volumetric strain wear rate were higher in the non-implanted workpiece versus implanted ones. Under shear extrusion of the SiC workpiece, dangling bonds of atoms in the diamond grain were unstable, resulting in graphitization of the diamond structure at elevated temperatures. This study established a solid theoretical and practical foundation for realizing non-destructive machining at the atomic scale, encompassing both theoretical principles and practical applications.
Magnetic tunnel junction random number generators applied to dynamically tuned probability trees driven by spin orbit torque
Authors: Maicke Andrew , Arzate Jared , Liu Samuel , Kwon Jaesuk , Smith J Darby , Aimone James B , Misra Shashank , Schuman Catherine , Cardwell Suma G , Incorvia Jean Anne C
Published: April 2024

Perpendicular magnetic tunnel junction (pMTJ)-based true-random number generators (RNGs) can consume orders of magnitude less energy per bit than CMOS pseudo-RNGs. Here, we numerically investigate with a macrospin Landau–Lifshitz-Gilbert equation solver the use of pMTJs driven by spin–orbit torque to directly sample numbers from arbitrary probability distributions with the help of a tunable probability tree. The tree operates by dynamically biasing sequences of pMTJ relaxation events, called ‘coinflips’, via an additional applied spin-transfer-torque current. Specifically, using a single, ideal pMTJ device we successfully draw integer samples on the interval [0, 255] from an exponential distribution based on p-value distribution analysis. In order to investigate device-to-device variations, the thermal stability of the pMTJs are varied based on manufactured device data. It is found that while repeatedly using a varied device inhibits ability to recover the probability distribution, the device variations average out when considering the entire set of devices as a ‘bucket’ to agnostically draw random numbers from. Further, it is noted that the device variations most significantly impact the highest level of the probability tree, with diminishing errors at lower levels. The devices are then used to draw both uniformly and exponentially distributed numbers for the Monte Carlo computation of a problem from particle transport, showing excellent data fit with the analytical solution. Finally, the devices are benchmarked against CMOS and memristor RNGs, showing faster bit generation and significantly lower energy use.
A piezoelectric energy harvester with parallel connection using beams of different lengths to improve output performance
Authors: Wang Liang , Su Donghao
Published: April 2024

The purpose of this paper is to design an energy harvester to improve output performance. The theoretical analysis of the piezoelectric energy harvester has been performed. Reducing the length of one cantilever beam, thereby changing the relative impact position, causing the amplitude of the two cantilever beams to be different, and making the waveform of two beams different. Some experiments have been tested to verify the feasibility of the device and compare the differences with Plan A. Based on the experiment, it can be concluded that the output voltage is higher at both high and low speeds. When the rotation speed is 255 r min−1, Plan B arrives at the optimum speed, and the maximum output voltage is 166.2 V, which significantly increases from 97.2 V of Plan A. The maximum output power is 0.966 W under the load resistance of 10 kΩ. The maximum voltage is 157.7 V under the load resistance of 120 kΩ. Nevertheless, the maximum voltage and maximum power of Plan A are 92.62 V and 0.52 W. Besides, the prototype has fewer materials and nearly 1.5 times the energy conversion rate compares to Plan A. It can light up 42 LEDs easily and can adapt to environmental vibration frequency changes, so it has an intensely adaptable and outstanding performance in practical applications.
Electromagnetic lensing using the Aharonov–Bohm effect
Authors: Tokoro Schreiber Makoto , Cassidy Cathal , Saidani Menour , Wolf Matthias
Published: April 2024

We demonstrate theoretically and experimentally an electromagnetic lensing concept using the magnetic vector potential—in a region free of classical electromagnetic fields—via the Aharonov–Bohm (AB) effect. This toroid-shaped lens with poloidal current flow allows for electromagnetic lensing which can be tuned to be convex or concave with a spherical aberration coefficient of opposite polarity to its focal length. This field-free lens combines the advantages of traditional electromagnetic and electrostatic field-based lenses and opens up additional possibilities for the optical design of charged-particle systems. More generally, these results demonstrate that the AB effect can shape charged particle wavefronts beyond simple step shifts if topologies beyond simple flux lines are considered and further supports the physical significance of the magnetic vector potential.
Interpretative 3D MHD modelling of deuterium SPI into a JET H-mode plasma
Authors: Kong M. , Nardon E. , Hoelzl M. , Bonfiglio D. , Hu D. , Lee S.-J. , Samulyak R. , Sheikh U. , Silburn S. , Artola F.J. , Boboc A. , Bodner G. , Carvalho P. , Delabie E. , Fontdecaba J.M. , Gerasimov S.N. , Hender T.C. , Jachmich S. , Kos D. , Lawson K.D. , Pamela S. , Sommariva C. , S̆tancar Z̆. , Stein-Lubrano B. , Sun H.J. , Sweeney R. , Szepesi G. ,   the JOREK Team,   JET Contributors
Published: April 2024

The pre-thermal quench (pre-TQ) dynamics of a pure deuterium (D2) shattered pellet injection (SPI) into a3MA/7MJJET H-mode plasma is studied via 3D non-linear MHD modelling with the JOREK code. The interpretative modelling captures the overall evolution of the measured density and radiated power. The simulations also identify the importance of the drifts of ablation plasmoids towards the tokamak low field side (LFS) and the impurities in the background plasma in fragment penetration, assimilation, radiative cooling and MHD activity inD2SPI experiments. It is found that plasmoid drifts lead to an about 70% reduction of the central line-integrated density (compared to a simulation without drifts) in the JETD2SPI discharge considered. Impurities that pre-exist before the SPI as well as those from possible impurity influxes related to the SPI are shown to dominate the radiation in the considered discharge. With inputs from JOREK simulations, modelling with the Lagrangian particle-based pellet code PELOTON reproduces the deviation of the SPI fragments in the direction of the major radius as observed by the fast camera. This confirms the role of rocket effects and plasmoid drifts in the considered discharge and reinforces the validity of the JOREK modelling. The limited core density rise due to plasmoid drifts and the strong radiative cooling and MHD activity with impurities (depending on their species and concentration) could limit the effectiveness of LFSD2SPI in runaway electron avoidance and are worth considering in the design of the ITER disruption mitigation system.
Overview of the KSTAR experiments toward fusion reactor
Authors: Ko Won-Ha , Yoon S.W. , Kim W.C. , Kwak J.G. , Park K.L. , Nam Y.U. , Wang S.J. , Chung J. , Park B.H. , Park G.Y. , Lee H.H. , Han H.S. , Choi M.J. , Na Y.S. , In Y. , Lee C.Y. , Kim M. , Yun G.S. , Ghim Y.-C. , Choe W.H. , Kwon J.M. , Lee J.P. , Lee W.C. , Jeon Y.M. , Kim K. , Lee J.H. , Shin G.W. , Kim J. , Lee J. , Hahn S.H. , Lee J.W. , Kim H.S. , Bak J.G. , Lee S.G. , Lee Y.H. , Jeong J.H. , Woo M.H. , Kim J.H. , Juhn J.W. , Ko J.S. , Sung C. , Shin H.W. , Park J.M. , Kim S.K. , Park J.K. , Logan N.C. , Yang S.M. , Kolemen E. , Hu Q.M. , Shousha R. , Barr J. , Paz-Soldan C. , Park Y.S. , Sabbagh S.A. , Ida K. , Kim S. , Loarte A. , Gilson E. , Eldon D. , Nakano T. , Tala T. ,   KSTAR Team
Published: April 2024

The Korean Superconducting Tokamak Advanced Research has been focused on exploring the key physics and engineering issues for future fusion reactors by demonstrating the long pulse operation of high beta steady-state discharge. Advanced scenarios are being developed with the goal for steady-state operation, and significant progress has been made in high ℓ
i, hybrid and high beta scenarios with β
N of 3. In the new operation scenario called fast ion regulated enhanced (FIRE), fast ions play an essential role in confinement enhancement. GK simulations show a significant reduction of the thermal energy flux when the thermal ion fraction decreases and the main ion density gradient is reversed by the fast ions in FIRE mode. Optimization of 3D magnetic field techniques, including adaptive control and real-time machine learning control algorithm, enabled long-pulse operation and high-performance ELM-suppressed discharge. Symmetric multiple shattered pellet injections (SPIs) and real-time disruption event characterization and forecasting are being performed to mitigate and avoid the disruptions associated with high-performance, long-pulse ITER-like scenarios. Finally, the near-term research plan will be addressed with the actively cooled tungsten divertor, a major upgrade of the NBI and helicon current drive heating, and transition to a full metallic wall.
Scintillating sampling ECAL technology for the LHCb ECAL Upgrade II
Authors: Picatoste E. ,   the LHCb ECAL Upgrade II R&D group
Published: April 2024

The aim of the LHCb Upgrade II is to be able to operate at a luminosity of 1.5×1034 cm-2 s-1 to collect a data set of 300 fb-1. The required substantial modifications of the current LHCb electromagnetic calorimeter due to high radiation doses in the central region and increased particle densities are referred to as LHCb ECAL Upgrade II. A consolidation of the ECAL already during the long shutdown 3 will reduce the occupancy and mitigate the effects of substantial ageing in the central region after Run 3.

Several scintillating sampling ECAL technologies are being investigated in an ongoing R&D campaign: Spaghetti Calorimeter (SpaCal) with garnet scintillating crystals and tungsten absorber, SpaCal with scintillating plastic fibres and tungsten or lead absorber, and Shashlik with polystyrene tiles, lead absorber and fast WLS fibres.

Timing capabilities with tens of picoseconds precision for neutral electromagnetic particles and increased granularity with a denser absorber in the central region are needed for pile-up mitigation. Time resolutions of better than 20 ps at high energy were observed in test beam measurements of prototype SpaCal and Shashlik modules. Energy resolutions with sampling contributions of about 10%/√E, in line with the requirements, were observed.
A decomposition algorithm for streak camera data
Authors: Oguzhan Kaan , Ranc Lucas , Verra Livio , Caldwell Allen
Published: April 2024

We describe a novel reconstruction algorithm for
time-resolved images obtained using a streak camera. This algorithm
operates by decomposing a recorded image into a set of individual
photoelectron-induced signals, thereby providing a powerful method
for streak camera image reconstruction. This deconstruction allows
for a standard statistical analysis of the resulting image. We
demonstrate the effectiveness of this technique by analyzing the
temporal spacing between the emitted fs-long laser pulse and its
succeeding first, second, and third reflections within a thick glass
captured by a streak image.
Utilizing CO2 as a strategy to scale up direct air capture may face fewer short-term barriers than directly storing CO2
Authors: Brazzola Nicoletta , Moretti Christian , Sievert Katrin , Patt Anthony , Lilliestam Johan
Published: April 2024

Direct air capture (DAC) is increasingly recognized as a necessary puzzle piece to achieve the Paris climate targets. However, the current high cost and energy intensity of DAC act as a barrier. Short-term strategies for initial deployment, technology improvement, and cost reduction are needed to enable large-scale deployment. We assess and compare two near-term pathways leading to the same installed DAC capacity and thus yielding the same cost reductions: its combination with CO2 storage as direct air carbon capture and storage, or its deployment for CO2 utilization as direct air carbon capture and utilization e.g. for synthetic fuels, chemicals, and materials; we characterize these as Direct and Spillover pathways. Drawing on the Multi-level Perspective on Technological Transition as a heuristic, we examine both technical and immaterial factors needed to scale up DAC under the two pathways, in order to assess the pathways’ relative advantages and to identify possible short-term bottlenecks. We find neither pathway to be clearly better: the Direct pathway offers technical advantages but faces regulatory barriers that need to be resolved before deployment, while the Spillover pathway offers market and governance advantages but faces challenges related to hydrogen production and increasing resource needs as it scales up. There may be reasons for policymakers to therefore pursue both approaches in a dynamic manner. This could involve prioritizing the Spillover pathway in the short term due to possibly fewer short-term regulatory barriers and its ability to produce net-zero emission products for existing and accessible markets. Once short-term governance obstacles have been addressed, however, the Direct pathway may allow for more efficient scaling of DAC capacity and cost reductions, especially if by then the needed infrastructure and institutions are in place.
A multivariate probabilistic framework for tracking the regional tropical edges: analysis of inter-annual variations and long-term trends
Authors: Feng Xinxian , Tao Weichen , Huang Gang , Hu Yongyun , Lau William K M , Qu Xia , Hu Kaiming , Wang Ya
Published: April 2024

In the present study, a multivariate probabilistic framework is used to identify the meridional positions of regional tropical edges (RTEs), which are based on two variables: sea level pressure and precipitation minus evaporation. This new defined metric effectively captures inter-annual variability and long-term trend of the commonly adopted zonal mean tropical edge based on meridional mass stream function and near-surface winds. Besides, pronounced RTE trends are primarily located over the oceanic regions, and the terrestrial areas exhibit substantial inter-annual variability. These results are consistent among three modern reanalysis datasets. Moreover, the impacts of climate modes on RTE are investigated. The El Niño-Southern Oscillation, the Atlantic multi-decadal oscillation, and the Southern Annular Mode are important both on the inter-annual variations and long-term trends of RTE. The Pacific Decadal Oscillation is more inclined to affect long-term contribution rather than inter-annual relationship, and the Pacific–North American teleconnection, the North Atlantic Oscillation, and the Arctic oscillation highlight the inter-annual relationship with RTE in the specific regions, such as North Pacific, North Atlantic, and North Africa, respectively.
Daylight Diagram – A Method to Map and Analyse the Temporal Conditions of Daylight Intensity
Authors: Foged I W
Published: April 2024

This study proposes and examines a new method and diagram for revealing and analysing temporal and transitional daylight conditions based on computational modelling and simulations. For a human to experience and decipher the world, daylight is a predominant resource to engage with the surroundings. With humans spending the prevalent time inside buildings, it is important to understand and design the daylight environments in the early phases of design processes. The aim is to retain and reveal the information of high-resolution simulations and to explore, test and verify the capacities of the method in comparison to Illuminance, Daylight Factor and Daylight Autonomy values. The research design uses digital modelling and representation techniques combined with computational simulation methods for daylight analysis, evaluation and communication. Eight digital test cases show that the proposed Daylight Diagram enables the observation of temporal daylight dynamics. The proposed method and diagram employ existing simulation systems, allowing a fast integration and use in early-phase design processes as a key instrument to design advanced daylight phenomena and conditions focusing on transitional and temporal daylight intensities.
Urban Illuminations – Light Art Activating The Public Realm
Authors: Erel Yael , Kyriakidou Foteini , Avendano Rodrigo Eduardo Muro
Published: April 2024

How can contemporary light art installations impact the sensorial perception of the urban context to modify and reinterpret urban space? In Robert Irwin’s words, how can they provide “…an extended way of looking at the world”? In this paper, we examine how temporary light installations may impact the public realm by modifying citizens’ perceptions of moments in the city: a habitual urban passage is interrupted with a temporal experience, changing the way the urban space is experienced. We explore how site-specific light installations create unique intersections of audience and spatial perception through the artists’ intent of creating new urban atmospheres through an experiential layer added onto the urban fabric during light festivals. To do so we analyze and discuss two light installations that we designed and executed, which were shortlisted for the 2022 [d]arc awards. Both projects took part in larger urban light festivals and were located within urban passages. “Reflecting on Troy” [Author 1 - Troy Glow Light Festival] created a temporal light graffiti in an urban alley, while “Riddle 102” [Authors 2,3 - Nobel Week Lights], a dynamic lighting installation in a 231m pedestrian tunnel, created an immersive environment that alters the perception of the tunnel’s physical dimensions. Through reflections, as well as visitor and curator reviews, we unpack the intent and impact of the works on the perception of the urban context. We discuss and analyze the similarities and differences between the two urban settings, identify the design processes and principles pertinent to site-specific light installations [materials, lighting fixtures, testing] and address the impact darkness and over-lit spaces have over spatial perception. Lastly we discuss the impact a temporary light installation may have on the collective memory of the city, perceived in person or online.
How to illuminate indoor plants sustainably? Tips and tricks to bridge the gap between research and design.
Authors: Hartmann J , Feltrin F
Published: April 2024

The increasing popularity of biophilic design in architecture and interior design has led to a widespread integration of indoor ornamental plants and green walls. While numerous studies have demonstrated the benefits of such integration for people, only a few have focused on the well-being of the plants themselves. Our latest research project aims to address this gap by exploring suitable lighting conditions for indoor plants, seeking an optimal spectral composition that ensures their well-being, robust growth, and visual appeal, while also optimizing maintenance. Building upon previous applied research, we conducted experiments to analyze the lighting requirements of four species of ornamental plants commonly used indoors. Seven identical room boxes were employed, each illuminated with different light spectra falling within the CCT range of 2800K-5000K. The specific light spectra were meticulously tuned with a focus on the red/blue and red/green ratios, while keeping the photosynthetic photon flux (PPFD) and average illuminance consistent. As a result of this research project, practical guidelines were developed to help lighting designers navigating the intricate world of indoor ornamental plants effectively. By carefully considering the lighting spectrum in the suggested ranges, architects and interior designers can create spaces that not only benefit human occupants but also provide an optimal environment for the well-being and flourishing of indoor plants.
Role of lighting and color in microeconomics: preference and purchase intent
Authors: Durmus D , Wang T , Gonzalez C , Kore R
Published: April 2024

Lighting and color are key factors under the control of lighting designers that can significantly impact shoppers’ perceptions and actions in the context of culinary and retail environments. Previous studies have examined the effects of color and lighting on preference and purchase intent, but results are often conflicting due to confounding variables, and a strong connection between these phenomena remains unexplored. To bridge this gap, two visual experiments were conducted, revealing that lighting can indeed influence consumers’ perception of products. Participants perceived the changes in objects under different color gamut and illuminance levels. Further research is needed to better understand the mechanisms of purchase intent, particularly across different price and product types.
Light across Disciplines and Times: A Walking Seminar at the Stockholm Public Library
Authors: Alenius Malin
Published: April 2024

Lighting in buildings today is a multi-disciplinary task. Increased complexity and specialization have led to a split process where coordination between disciplines is lacking. Despite extensive technical development, daylight and electric light are still planned in separate processes, often resulting in over-lit environments where energy savings, health and spatial potentials of daylight are not fully utilized. To address these problems, this paper introduces the walking seminar as a method to bridge and increase knowledge across disciplines in the field of lighting. The seminar was held at the Stockholm Public Library, and included invited participants with different professions and expertise: an architect, an electrical consultant, a lighting designer, a librarian, a caretaker, and an architectural historian who shared their perspectives on light. Based on the seminar, findings relevant for today’s practice are presented, both for the specific case in itself, a listed building and an active library, and at a more general level concerning lighting standards and the interaction of daylight and electric light. The main future task for the building sector is to preserve and develop our existing building stock, which includes lighting. Sustainable and long-term solutions require that daylight, electric light and spatial lighting design are planned as an integrated whole, based on the characteristics of the specific building. Findings from the walking seminar presented in this paper point at the importance and potential in transdisciplinary dialogue to enable the development of long-term lighting solutions in our existing and future buildings.
Different aspects regarding slope stability improvement using piles
Authors: Praporgescu A , Popa A
Published: April 2024

The problem of slope stability is a common one in the field of geotechnical engineering. There is more than one method that can be adopted in order to improve the stability of a slope. During the last decade, using piles for improving the mechanical behaviour of slopes has become the main approach of dealing with unstable slopes. In the current paper, the stability of a slope was analysed by using the tridimensional finite elements method using different scenarios of consolidation with timber piles. A parametric analysis was carried out for two different slopes: sand slope and soft soil slope. There were also analysed two different constitutive models: Mohr-Coulomb and Hardening Soil Small with different location of the consolidation system. The stability analyses employed both timber piles and concrete piles which were modelled in Plaxis 3D software by using two different approaches: embedded piles and volume piles. In the end, the most favourable position for the pile consolidation system is highlighted in order to attain the maximum stability of the slope. Also, different aspects of the constitutive models, modelling the piles and pile material are discussed from the point of view of slope stability improvement.
Digital applications for preserving archaeological sites and tourism management
Authors: Andrieş D I , Şeitan T , Grămescu A M , Gemănaru A
Published: April 2024

Cultural heritage is an important part of our life, a resource for the identity and the cohesion of communities. The paper aims to identify possible solutions for cultural heritage management of the archaeological sites and monuments from Dobrogea. The authors documented and researched above-ground archaeological structures, analysing their characteristics and suggesting solutions for conservation and promoting of archaeological heritage. The rapid development of digital technologies like augmented reality can help us finding cost-effective solutions for archaeology and cultural heritage tourism.
Computational assessment regarding structural rehabilitation of a reinforced concrete decanter tank
Authors: Covatariu D , Filip A , Covatariu G
Published: April 2024

The article describes the analysis of an industrial structure (reinforced concrete decanter tank for the drinking water’s storage in the Iasi – Romania area) in order to justify the proposals for structural rehabilitation to ensure structural stability. In this regard, a computational model was created in Graitec Advanced Design, using the physico-mechanical characteristics of the materials (concrete, reinforcement) from the initial design. Subsequently, using the data obtained from the technical assessment report and the non-destructive tests carried out on the structural elements, it was found a depreciation of the concrete grade (C25/30 → C16/20), at the current stage. At this stage (the structure’s service state) a modelling of the degraded structure was achieved by comparing the results obtained by Graitec Advanced Design and Axis VM, in order to realise an extended structural analysis between initial and current state. A solution for the rehabilitation of degraded elements using polymeric composite materials reinforced with carbon fibers was proposed, which was validated by the Sika CarboDur Composite systems (software program for the design of consolidation solutions).
Topographic Monitoring of the Operational Behaviour of the Longest Cantilever Viaduct in Romania
Authors: Boacă Gh. , Scutaru M.C.
Published: April 2024

Over time, bridges have been built to fulfil different roles. With the development of industry came the need to build new transit routes linking industrial areas to cities or freight routes. The peak period of industrial development in Romania was in the 1960s, when a large number of bridges were built and put into operation. One of these bridges is the Sidex viaduct, located in Galaţi. The construction has a total length of 1,070 m, with 15 spans of different lengths (47.40 m + 13 * 75.00 m + 47.40 m). The resistance structure is made of 7 prestressed concrete frames linked together by joints located at the level of the cantilevers, the structure being the largest cantilever viaduct in operation in our country. The present article focuses on the presentation of the implementation of a special monitoring program of the viaduct’s in-service performance. For this purpose, special technologies have been used, such as topographic monitoring of the evolution of structural displacements at the most representative points of the structure, an implementation that we develop in detail.
Impact of the infrared properties of the backsheet on the efficiency of an encapsulated photovoltaic silicon cell
Authors: Khouzam A. , Logerais P.O.
Published: April 2024

The efficiency of an encapsulated photovoltaic (PV) silicon cell is studied by modeling the radiative exchanges between its layers, focusing on the influence of the radiative properties of the backsheet on the cell temperature. The model uses the Monte-Carlo method to solve the radiative transfer equation. Two-dimensional simulations were performed, showing how the radiative properties of the backsheet affected the silicon cell temperature, which was then used to calculate the current-voltage characteristic and the efficiency of two PV modules. The results revealed a significant sensitivity of the model to the emissivity of the top-side backsheet, with a 19.4°C temperature difference for the silicon cell and, a 9.5% and 13.3% increase in the maximum power between a fully reflective and a fully absorptive backsheet for the two PV modules. Overall, the study highlights the importance of considering radiative properties in the design and optimization of PV panels, as they can have a substantial impact on their performances.
Digital solutions in the determination of bearing capacity for straight and stepped mat foundations on sloping ground
Authors: Bejan F , Aniculăesi M , Gafincu C V , Lungu I
Published: April 2024

On sloped sites where a mat foundation is to be used, because of the limited bearing capacity of the ground, it is necessary to cut into the sloped surface to provide a level base for the mat foundation. To reduce the amount of excavation and backfill a stepped mat may be used down the slope. Traditionally, determining the bearing capacity values for spread foundations on sloping ground has been a complex and time-consuming process. Several factors must be considered, including various variables (soil type, soil profile, slope angle and geometrical configuration of the infrastructure). The digital solution used in this study involves the use of advanced software that takes into account various input parameters and performs complex calculations to determine the bearing capacity of the foundation on horizontal and sloped ground. For this research, the analyses were done for three different slope angles (β = 5°, 10°, 15°) and a comparison is made between the bearing capacity of the ground for straight and stepped mat foundations using both analytical methods and finite element method.
Vortex position detection using a scanning triangular aperture in a digital micromirror device
Authors: Banguilan Dina Grace C , Hermosa Nathaniel
Published: April 2024

Optical vortices, as solutions to the wave equation, remain stable under ideal theoretical conditions. However, in experiments where beams produced with holograms and spatial light modulators introduce perturbations, their phase structures can be disrupted, leading to instability. Specifically, higher-order optical vortices (with topological charge

|
ℓ

|

>
1

) are inherently unstable in that they tend to separate in a series of optical vortices with unit topological charge

(

|

ℓ

|

=
1
)

even with small perturbations. In this work, we demonstrate a technique to detect the positions of optical vortices using a scanning triangular aperture in a digital micromirror device and a digital pinhole. We observe the diffraction patterns of a vortex through the triangular aperture, and we show that we can determine the center of an optical vortex (OV) by measuring the intensity at the center of a pattern using a digital pinhole. We investigate the changes in the measured signal for different triangular apertures and pinhole sizes. We observe that while smaller pinholes lead to a decrease in light intensity, the detected position of a single OV with unit topological charge is similar for all pinhole sizes. We also find that the triangular aperture size becomes important when locating vortex pairs. Using a triangular aperture with a radius R = 0.52 mm, we can resolve OV pairs at least

86.4

μ

m apart in our experiments. Our methods help pave the way to understanding the fundamental behavior of multiple vortex interactions in optical beams and also can be used when determining the position of an OV in metrology.
A carbon nanotube-based thermoelectric generator integrated into a smart composite for structural health monitoring
Authors: Koutsotolis Lampros , Karalis George , Voudouris Itskaras Angelos , Tsirka Kyriaki , Paipetis Alkiviadis S
Published: April 2024

The next generation of advanced composite materials needs to simultaneously address issues such as energy harvesting and structural health monitoring (SHM). The objective of this study is to explore, for the first time, the possibility of utilizing a build-in thermoelectric generator (TEG) to fulfil self-sensing purposes. To this end, carbon nanotube-based (CNT) inks are employed to print TEGs onto a glass fiber substrate, which is then incorporated into a glass fiber reinforced polymer (GFRP) laminate. The output characteristics of the TEG-enabled specimens are measured, displaying an exceptional performance. The specimens are subjected to static, quasi static cyclic and dynamic loading. Adopting a novel idea, the conductive, fully integrated printed path is then exploited to serve as a strain/damage sensor. For this reason, its resistance is monitored online during mechanical loading. To corroborate the findings, acoustic emission (AE) is simultaneously applied. Results reveal that the self-sensing multifunctional composite can successfully monitor its structural integrity. In fact, it demonstrates high sensitivity with a gauge factor approximately equal to 3. Moreover, when the TEG operates as a piezoresistive sensor, it is characterized by reliability. We thus believe that the herein suggested approach unveils new prospects regarding the efficiency and the sustainability of composite structures.
Valleytronics in two-dimensional magnetic materials
Authors: Luo Chaobo , Huang Zongyu , Qiao Hui , Qi Xiang , Peng Xiangyang
Published: April 2024

Valleytronics uses valleys, a novel quantum degree of freedom, to encode information. It combines other degrees of freedom, such as charge and spin, to produce a more comprehensive, stable, and efficient information processing system. Valleytronics has become an intriguing field in condensed matter physics due to the emergence of new two-dimensional materials in recent years. However, in nonmagnetic valleytronic materials, the valley polarization is transient and the depolarization occurs once the external excitation is withdrawn. Introduction of magnetic field is an effective approach to realizing the spontaneous valley polarization by breaking the time-reversal symmetry. In hexagonal magnetic valleytronic materials, the inequivalent valleys at the K and –K(K′) Dirac cones have asymmetric energy gaps and Berry curvatures. The time-reversal symmetry in nonmagnetic materials can be broken by applying an external magnetic field, adding a magnetic substrate or doping magnetic atoms. Recent theoretical studies have demonstrated that valleytronic materials with intrinsic ferromagnetism, now termed as ferrovalley materials, exhibit spontaneous valley polarization without the need for external fields to maintain the polarization. The coupling of the valley and spin degrees of freedom enables stable and unequal distribution of electrons in the two valleys and thus facilitating nonvolatile information storage. Hence, ferrovalley materials are promising materials for valleytronic devices. In this review, we first briefly overview valleytronics and its related properties, the ways to realize valley polarization in nonmagnetic valleytronic materials. Then we focus on the recent developments in two-dimensional ferrovalley materials, which can be classified according to their molecular formula and crystal structure: MX2; M(XY)2, M(XY2) and M(XYZ)2; M2X3, M3X8 and MNX6; MNX2Y2, M2X2Y6 and MNX2Y6; and the Janus structure ferrovalley materials. In the inequivalent valleys, the Berry curvatures have opposite signs with unequal absolute values, leading to anomalous valley Hall effect. When the valley polarization is large, the ferrovalleys can be selectively excited even with unpolarized light. Intrinsic valley polarization in two-dimensional ferrovalley materials is of great importance. It opens a new avenue for information-related applications and hence is under rapid development.
Antipsychotic drugs in first-episode psychosis: a target trial emulation in the FEP-CAUSAL Collaboration
Authors: Szmulewicz Alejandro G , Martínez-Alés Gonzalo , Logan Roger , Ferrara Maria , Kelly Christian , Fredrikson Diane , Gago Juan , Conderino Sarah , Díaz-Caneja Covadonga M , Galvañ Joaquín , Thorpe Lorna , Srihari Vinod , Yatham Lakshmi , Sarpal Deepak K , Shinn Ann K , Arango Celso , Öngür Dost , Hernán Miguel A , FEP-CAUSAL Collaboration on behalf of the
Published: April 2024

Good adherence to antipsychotic therapy helps prevent relapses in first-episode psychosis (FEP). We used data from the FEP-CAUSAL Collaboration, an international consortium of observational cohorts, to emulate a target trial comparing antipsychotics, with treatment discontinuation as the primary outcome. Other outcomes included all-cause hospitalization. We benchmarked our results to estimates from the European First Episode Schizophrenia Trial, a randomized trial conducted in the 2000s. We included 1097 patients with a psychotic disorder and less than 2 years since psychosis onset. Inverse-probability weighting was used to control for confounding. The estimated 12-month risks of discontinuation for aripiprazole, first-generation agents, olanzapine, paliperidone, quetiapine, and risperidone were 61.5% (95% CI, 52.5-70.6), 73.5% (95% CI, 60.5-84.9), 76.8% (95% CI, 67.2-85.3), 58.4% (95% CI, 40.4-77.4), 76.5% (95% CI, 62.1-88.5), and 74.4% (95% CI, 67.0-81.2), respectively. Compared with aripiprazole, the 12-month risk differences were -15.3% (95% CI, -30.0 to 0.0) for olanzapine, -12.8% (95% CI, -25.7 to -1.0) for risperidone, and 3.0% (95% CI, -21.5 to 30.8) for paliperidone. The 12-month risks of hospitalization were similar between agents. Our estimates support use of aripiprazole and paliperidone as first-line therapies for FEP. Benchmarking yielded similar results for discontinuation and absolute risks of hospitalization as in the original trial, suggesting that data from the FEP-CAUSAL Collaboration sufficed to remove confounding for these clinical questions.

This article is part of a Special Collection on Mental Health.