bluuebunny/crossref_metadata_2025 huggingface dataset:
Architecture research in urban heritage resilience: a systematic literature review
Authors: Walidonna A R , Soemardiono B , Antaryama I G N
Published: May 2024

The conservation of urban heritage is an important process in maintaining the sustainability of urban areas. Sustainability in the context of urban heritage includes the management and conservation of cultural and physical heritage, as well as its harmonious integration with the development of existing social and economic dynamics. Historic cities and urban heritage areas are threatened from both internal and external sources, ranging from over-development of tourism, lack of support for cultural management, and preservation threatened by development projects that are not in line with the characteristics of the area. The objective of this paper is to conduct a literature review pertaining to urban resilience research within the field of architecture, and to provide an analysis of the factors that contribute to the resilience of urban heritage areas. This study applied the systematic literature review method, using the PRISMA 2020 statement as a reference. The methodology involved searching for articles in the DOAJ and Scopus databases with a time limit of 2010 to 2023. Based on this research, it was found that there are a number of factors that contribute to urban resilience and urban heritage, including cultural, economic, social, heritage, environmental and institutional. It also proved that the conservation and enhancement of urban heritage, such as historic buildings, cultural landmarks and other elements that make up a city’s identity, is strongly influenced by architecture. In addition, the findings highlight the importance of a multi-dimensional and collaborative approach to the conservation process. This study shows that the conservation of urban heritage plays an important role in achieving holistic urban resilience. However, there are several challenges and knowledge gaps that need to be addressed in future research, such as the integration of sustainability with urban heritage conservation, participatory management to engage local communities, and the development of effective methods to identify and mitigate risks to urban heritage.
Slope failure lines analysis to determine landslide potential based on standard penetration test method
Authors: Agung P A M , Hasan M F R , Dwiyasa A P , Susilo A , Suryo E A , Pradiptiya A
Published: May 2024

Landslide events cause road access to be cut off, such as in the Payung area of Batu City, which connects Malang and Kediri. Analysis and evaluation of landslide disasters need to be carried out in this area to anticipate the next landslides and reduce economic losses. This study aims to determine landslide potential in the Payung Area, Batu City, using the SPT method. The test is carried out at 2 points of the slope on the provincial roads and the slope above the road so that the two measurement points can be correlated. The data needed to analyze slope stability include the internal shear angle, cohesion, and soil unit weight; analysis and modeling of slope stability using Geostudio SLOPE/W software. The results of the slope stability analysis at point 1 show that the average failure line is at a depth of 6.00 m with the smallest Safety Factor (SF) value of 0.710 in scenario 2. While the slope at point 2, the failure line is at a depth of 1.50 m with the smallest FK value of 0.840 in scenario 2. Significant changes in the N-SPT value indicate differences in soil mechanical properties, such as shear angle and cohesion that affect the stability of the slope and cause landslides.
Feasibility of the tower crane jib made of composite material
Authors: Solazzi L
Published: May 2024

The main purpose of this research is to design a jib of a tower crane using composite material and to compare the effects/performance on the whole machine due to this lightweight process. The research starts by sizing the jib with steel material. Many different load conditions were involved and different criteria were assumed; those are: stress safety factor, stiffness, dynamic performance (modal) and buckling phenomenon which is the most important parameter. Then other non-standard load conditions were applied to the tower crane: moving load and jib (rotation and elevating) and adopting wind variable in time. The results of these load conditions were assumed to design a new jib made of pultruded composite material. The next step involves the design of additional elements of the crane: ropes, counter boom, counterweight, electric motor, etc. The last step concerns the economic feasibility of the new solution. The results show that the weight of the jib made by composite material is about 25% of the one made by steel and the economic payout for making the composite arm can be equalized in about a year and a half of machine operation, making the proposed solution very worthwhile.
Optimization and validation of a finite element methodology for thermo-structural analysis of polyhuretane wheels for roller coaster application
Authors: Palmieri Massimiliano , Ferri Alberto , Cianetti Filippo , Braccesi Claudio
Published: May 2024

Polymeric materials are widely used in several engineering sectors. Among these, a particularly critical sector for this type of material is that of roller coasters. The wheels are indeed made with an aluminum hub and a compact polyurethane coating, which, being in contact with the track, is subject to high speeds dynamic loads. Due to the viscoelastic behavior typical of these materials, such loads induce overheating of the coating and therefore a rapid degradation of the wheel. This results in machine downtime and, consequently, significant waste of time and money. In this context, the authors have developed a methodology for finite element thermo-structural analysis capable of quickly evaluating the temperature reached during work cycles and proving very useful in selecting the type of wheels to use. In this work, this methodology was firstly computationally developed and then validated by comparing the analysis results with data obtained from experimental tests conducted by the manifacturer. The comparison demonstrated the effectiveness of the proposed method, highlighting, however, a constant error in terms of maximum temperature reached attributable to a non-exact material characterization.
Biomechanical evaluation of a custom-made mandibular plate
Authors: Mineo R , La Rosa G , Cocomero T , Barbagallo R , Battaglia S , Crimi S
Published: May 2024

In the field of maxillofacial surgery, mandibular reconstruction with plates is one of the operations that is performed when resection of part of the jaw is unavoidable in patients suffering from pathologies such as, for example, neoplasms and osteonecrosis. Through the use of standard prostheses, which are commercially available in various models, mandibular reconstruction is possible. However, in the presence of particularly serious and complex clinical pictures, in which it is necessary to resect large parts of the mandibular bone, such as in some oncological cases, the use of serial prostheses is not always resolving. In these cases, a customized implant, designed specifically for the patient, is preferable.

Aim of this work is the mechanical evaluation of a custom-made mandibular plate with an innovative bone-implant interface geometry through a finite element analysis. Three physiological loading conditions were analysed: RUC (right unilateral canine) bite, RGF (right group functional) bite and maximum opening. Finally, the maximum pull-out force acting on the fixation screws was evaluated through an experimental fatigue test.
Design And Optimization Of Aeronautical Components And Digital Twins Development
Authors: Lopez A , Cella U , Groth C , Biancolini M E
Published: May 2024

In this work, the feasibility of using reduced models (ROMs) for optimizing a scoop air intake for aeronautical applications was evaluated. Since the air intake is exposed to aerodynamic loads, a two-way fluid-structure interaction workflow was used to characterize the component. The goal is to create an optimization dashboard that allows both scalar quantities (the parameters that are intended to be monitored during the design and optimization of the air intake) and field quantities to be evaluated in real time. In this way, the designer can have a full understanding of the physics of the problem and make more informed design choices. In addition, in this way it is possible to visualize results from different physics in a single dashboard, linking different components, interacting with models in real time. A mesh morphing technique based on Radial Basis Functions (RBFs) was used. The result was very interesting both from a structural point of view (mass reduction over 90% and maximum strain reduction of 36%) and from a fluid dynamic point of view (outlet pressure 86% higher and drag 32% lower) and the generated ROMs proved to be a very accurate (ROM relative error in the order of 7%) and flexible tool.
Smart design of a high-performance seat frame for a luxury car
Authors: Milone D , Dusini L , Nicoletta A , Santonocito D , Risitano G
Published: May 2024

The design of mechanical components in recent years has been experiencing a series of innovative processes which, in addition to the classic methodologies, also support topological and structural optimization considering the product life cycle (LCA). These innovative aspects make it possible to reduce the weight of the components and the impact on the environment, both during production and during operation. The purpose of this work is to create a tool for the “intelligent design” of automotive components through optimization algorithms called “Smart Design”. The final intent is to create a multidisciplinary methodology for mechanical design that combines topological optimization techniques and product life cycle analysis. The single studies, from the creation of the CAD and the finite element analysis, up to the topological optimization and the LCA analysis, are managed by a single code generated in the Matlab® environment. The work is carried out in collaboration with Ferrari S.p.a.
Retrofitting pedestrian and cyclist collision warning for improved safety of heavy trucks employed in urban areas: a case study in Florence and Pistoia, Italy
Authors: Lucci Cosimo , Pierini Marco , Savino Giovanni
Published: May 2024

The increasing use of heavy vehicles for services such as public transport, waste collection and logistics in densely populated urban areas causes numerous collisions with serious consequences every year, particularly for pedestrians, cyclists and motorcyclists. Advanced Driver Assistance Systems (ADAS) have proven to be a solution because they can significantly reduce the occurrence and consequences of road crashes. Although many ADAS technologies will be mandatory on new trucks in 2024, it will take more than a decade before the benefits are realised due to the average fleet renewal time. To accelerate this process, the most promising solution is therefore the introduction of aftermarket ADAS (also referred to as ‘retrofit’ ADAS) on the circulating fleet. This study aims to identify a tailored solution for retrofitting ADAS capable of providing pedestrian collision warnings on heavy vehicle fleets currently circulating in urban areas. The study involves a sample of vehicles and drivers operating in the metropolitan areas of Florence and Pistoia for waste collection services. The company owner of the vehicles integrated a commercial camera-based ADAS system with three additional cameras installed on the frontal bumper and edges of the vehicle, linked with three screens positioned in the vehicle cabin. In this study, a field test campaign was performed integrating trials in a proving ground closed to traffic with testing and monitoring in urban areas. This allowed to define a set of recommended parameters depending on vehicle speed that represent a good balance between alert frequency, minimizing false positives and ensuring that the alerts indicate real potential hazards to the driver. The recommendations provided in this study can also be extended to other vehicle fleets so that rapid and substantial improvements in the safety of heavy vehicles operating in cities can be achieved.
Advancing Structural Optimization of an Electric Motor Rotor through Mesh Morphing Techniques
Authors: Porziani S , Groth C , Zhang H , Biancolini M E
Published: May 2024

The electric motor has been one of the most important inventions of the last two centuries and has become increasingly important in the last 10 years thanks to its efficiency and its ability to reduce pollution. Given this increasing importance of electrical motors, an interest in design and optimization approaches for motor components is arising. Given the different physics involved in the transformation from electrical to mechanical energy, a valuable and reliable approach has to be applied in the optimization process. In past years, Mesh Morphing based on Radial Basis Functions (RBF) has largely proved its validity in generating shape modification for Finite Element Method (FEM) models. In this work, authors will demonstrate the advantages in applying two opposite approaches for shape optimization using RBF Mesh Morphing applied to electrical motors rotors. These components need to be accurately designed in order to guarantee an adequate life duration by reducing stresses in the rotating components. The two approaches that will be described are the parameter based one, in which a set of design parameters will be varied to generate shape modification used to feed a meta-model that will be used to identify an optimal configuration, and a parameter-less approach, in which the shape modification will be driven by FEM analysis results, with the aim to reduce stress hot-spots.
Influence of car front-end designs on motorcyclists’ trajectory in head-on and side-on-head crashes
Authors: Perticone A , Nardomarino V , Baldanzini N
Published: May 2024

Motorcyclists are highly vulnerable road users, and cars are one of their primary crash opponents. This study investigates the influence of car front-end designs on motorcyclist trajectory in head-on and side-on-head crashes. The analysis is based on a dataset of 120 multi-body crash simulations conducted using MADYMO and post-processed with MATLAB. An analysis of 1412 real-world Powered Two-Wheeler (PTW) to car accidents was conducted to determine the most common crash configurations and the associated ranges of the variables, such as vehicle speeds and contact points. Three PTW styles (sport-touring, scooter, and sport) and four car front-end designs (Sport utility vehicle (SUV), Family Car/Sedan (FCR), Roadster (RDS), and Multi-purpose vehicle (MPV)) were considered.

The study examined the riders’ thrown distance in both collision types. It was observed that, regardless of the collision type, the head was identified overall as the primary body region coming into contact with the opposing vehicle, followed by the chest and neck. In frontal collisions, an augmented bonnet height corresponded to an increased incidence of head contact, whereas a lower bonnet height resulted in a higher frequency of chest contact. Moreover, the thrown distance depended also on PTW speed, particularly for sport and sport-touring motorcycles. Notably, contact with the car windscreen was only observed at velocities exceeding 60 km/h, whereas impact with the bonnet leading edge occurred exclusively below this threshold. Due to the shielding effect of their PTW’s fairing, scooter riders predominantly experienced no contact with the opposing vehicle. Sport-touring motorcycles exhibited a more vertical trajectory upon ejection, leading to a greater likelihood of overturning and subsequent rearward head impact with the vehicle. In contrast, sport motorcycles tended to forward projections with a high likelihood of chest contact. In the case of lateral impacts, it was observed that vehicles with a more prominent profile, such as SUVs and MPVs, equipped with protruding bumpers, effectively restrained riders. In this case, vehicle speed did not exert a significant influence on the thrown distance. Additionally, the presence of a conspicuous fuel tank and the initial posture of the rider on the PTW played a crucial role in determining the final thrown distance. Due to their upright postures and the absence of a pronounced fuel tank, scooter dummies were thrown further than others, thus causing head contact with the windscreen.

These findings highlight the importance of car front-end design and PTW fairings in mitigating riders’ injuries and provide valuable insights to vehicle manufacturers for developing tailored safety measures for riders.
Approaching the re-design of reusable packaging from an environmental perspective: a case study in the railway sector
Authors: Berzi L. , Cocci M , Barbieri R. , Pierini M. , Delogu M.
Published: May 2024

The production of railway vehicles determines the handling of a large amount of materials which are transferred from suppliers to production site using industrial packaging. The activity here described is part of the MORIMB project, which dealt with the reduction of waste related to railway sector; wood, plastic, cardboard and metal fasteners are the typical materials which are adopted for such packaging.

The study is motivated from the evidence that, due to the peculiarities of the transported components, most of the packaging units were different from standardized formats therefore they were frequently used for a single transport and subsequently scrapped. An applicative methodology for the analysis, redesign, and evaluation of environmental and economic impacts was defined, with particular attention to packaging reusability. An adaptation of the DMAIC approach was used to analyze the various components and find solutions reusability and performance improvement, especially in terms of volume efficiency and component protection. Depending on the item to be transported, specific crates have been designed and structurally verified according to existing technical regulation, and their sustainability has been analyzed considering environmental and economic impact during production, transport and storage phase; appropriate scenarios regarding distance travelled and volume occupancy were defined. The case study presented in detail in this work concerns the concept of special crates for the transport of passenger seats – a key component for train production - for which an increase in packaging density and a reduction of transportation costs was achieved. Other case studies were also considered.
3D bioprinting platform development for high-throughput cancer organoid models construction and drug evaluation
Authors: Dai Rui , Chen Wei , Chen You , Jin Jinlong , Zhang Shiwei , Zhang Changhua , Liu Jie
Published: May 2024

The evaluation of anti-tumor drugs is critical for their development and clinical guidance. Tumor organoid models are gaining increased attention due to their ability to better mimic real tumor tissues, as well as lower time and economic costs, which makes up for the shortcomings of cell lines and xenograft models. However, current tumor organoid cultures based on the Matrigel have limitations in matching with high-throughput engineering methods due to slow gelation and low mechanical strength. Here, we present a novel composite bioink for culturing colorectal cancer organoids that provides an environment close to real tissue growth conditions and exhibits excellent photocrosslinking properties for rapid gel formation. Most importantly, the tumor organoids viability in the composite bioink after printing was as high as 97%, which also kept multicellular polar structures consistent with traditional culture methods in the Matrigel. Using 3D bioprinting with this composite bioink loaded with organoids, we demonstrated the feasibility of this drug evaluation model by validating it with clinically used colorectal cancer treatment drugs. Our results suggested that the composite bioink could effectively cultivate tumor organoids using 3D bioprinting, which had the potential to replace less reliable manual operations in promoting the application of tumor organoids in drug development and clinical guidance.
Interfacial dynamics of two immiscible second-grade and couple stress fluids in rotating and counter-rotating scenarios
Authors: Bashir Sammar , Sajid Muhammad
Published: May 2024

This article aims to examine the dynamics of interfacial flow that occurs when a layer of second-grade fluid rotates over another layer of uniformly rotating immiscible couple stress fluid. Fluid models with different densities, pressures, velocities, and viscosities exhibit intriguing flow properties. Under the restriction of parameter

σ
2

ρ
=
1

, where

σ
=

ω
2

/

ω
1

(angular velocities ratio) and

ρ
=

ρ
2

/

ρ
1

(densities ratio), the occurrence of similarity solutions under coupling and viscoelastic effects across the interface for both cases of co-and-counter rotation is investigated. In contrast to the rotation of upper fluid, the couple stress fluid layer can counter-rotate. An advanced numerical method known as the Keller box is employed to thoroughly analyze the multiple aspects of the flow. The dominance of the couple stress fluid has been observed in shaping the dynamics of interfacial flow, significantly impacting phenomena such as the generation of inward/outward jets, Ekman pumping/suction, and the development of recirculation regions. Lower-layer far-field flow demonstrates transitions, oscillating between inflow and outflow, depending on parameters

μ

and

σ

. These findings illustrate an interesting interplay between rheological parameters, providing perspectives into the complicated behaviors of immiscible rotating fluids under different characteristics and useful implications for a variety of practical applications.
Effect of dopant loading and calcination conditions on structural and optical properties of ZrO2 nanopowders doped with copper and yttrium
Authors: Khomenkova L , Marchylo O , Polishchuk Yu , Ponomaryov S , Isaieva O , Vorona I , Melnichuk L , Portier X , Melnichuk O , Korsunska N
Published: May 2024

Undoped, Cu and/or Y doped ZrO2 nanopowders were synthesized with Zr, Y, and Cu nitrates using a co-precipitation approach. Their structural and optical properties were examined regarding dopant content (0.1–8.0 mol.% of CuO and 3–15 mol.% of Y2O3) and calcination conditions (400 °C–1000 °C and, 1,2 or 5 h) through Raman scattering, XRD, TEM, EDS, AES, EPR, UV–vis and FTIR diffused reflectance methods. The results showed that both Cu and Y dopants promoted the appearance of additional oxygen vacancies in ZrO2 host, while the formation of tetragonal and cubic ZrO2 phases was primarily influenced by the Y content, regardless of Cu loading. The bandgap of most of the powders was observed within the 5.45–5.65 eV spectral range, while for those with high Y content it exceeded 5.8 eV. The (Cu,Y)-ZrO2 powders with 0.2 mol.% CuO and 3 mol.% Y2O3 calcined at 600 °C for 2 h demonstrated nanoscaled tetragonal grains (8–12 nm) and a significant surface area covered with dispersed CuxO species. For higher calcination temperatures, the formation of CuZr
2+ EPR centers, accompanied by tetragonal-to-monoclinic phase transformation, was found. For fitting of experimental FTIR reflection spectra, theoretical models with one, five, and seven oscillators were constructed for cubic, tetragonal, and monoclinic ZrO2 phases, respectively. Comparing experimental and theoretical spectra, the parameters of various phonons were determined. It was found that the distinct position of the high-frequency FTIR reflection minimum is a unique feature for each crystalline phase. It was centered at 700–720 cm−1, 790–800 cm−1, and 820–840 cm−1 for cubic, tetragonal, and monoclinic phases, respectively, showing minimal dependence on phonon damping coefficients. Based on the complementary nature of results obtained from structural and optical methods, an approach for monitoring powder properties and predicting catalytic activity can be proposed for ZrO2–based nanopowders.
PdCu nanoparticles with multienzymatic activity to treat tumors through the synergistic photothermal and chemodynamic therapy
Authors: Fan Wende , Xie Yulin , Zhang Yinyuan , Li Xiaoju , Li Chunxia
Published: May 2024

Combined chemodynamic/photothermal therapy has great potential in tumor treatment. However, the presence of excessive glutathione (GSH) in the tumor microenvironment (TME) can attenuate its therapeutic effect, and other components in the TME have not been fully utilized as well. In this article, we designed a noble metal nanozyme called PdCu@BSA, which can be used for the combined chemodynamic therapy (CDT) and photothermal therapy (PTT) of tumor. In detail, PdCu@BSA has three different types of enzyme-like activities. Its catalase (CAT)-like activity can degrade extra H2O2 in the TME to create O2 and relieve the hypoxic situation. The glutathione oxidase (GSHox)-like activity can consume high level of GSH in the TME to reduce the consumption of reactive oxygen species (ROS). Peroxidase (POD)-like activity catalyzes H2O2 to form strong oxidized ·OH. The above enzyme-like activities enhance the effectiveness of CDT. Besides, PdCu@BSA has good photothermal effect and can be used for PTT when exposed to 1064 nm laser. Therefore, based on multiple enzyme-like activities and photothermal effects, PdCu@BSA can be employed for synergistic tumor therapy, resulting in good therapeutic outcome.
Progress of the bolometer diagnostic system on EAST
Authors: WEN 文 Wen 雯 , DUAN 段 Yanmin 艳敏 , PAN 潘 Shanshan 姗姗 , CHAO 晁 Yan 燕 , MAO 毛 Songtao 松涛 , QIAN 钱 Jing 静 , MENG 孟 Lingyi 令义 , TANG 汤 Panjun 潘君 , LIN 林 Shiyao 士耀
Published: May 2024

Measurements of the total radiated power and its spatial distribution are crucial for fusion research. On the experimental advanced superconducting tokamak (EAST), both the metal foil resistive bolometer and the absolute extreme ultraviolet (AXUV) photodiodes have been used to quantify the radiated power. This article introduces the latest improvement of the bolometer diagnostic system on EAST. It also details the successful design and installation of new divertor AXUV cameras, which are dedicated to the investigation of divertor physics. The shielding components of the bolometer detector have been refined, and the article provides a detailed exposition of the double shielding structures that have been verified as effective in microwave shielding. Additionally, the changes in the radiated power distribution in the divertor region during the plasma detachment process are measured using the divertor AXUV camera. Finally, the radiated power measured by the AXUV detector and metal foil resistive bolometer are compared, and different detector performances are presented.
Improving durability and electrical performance of flexible printed e-textile conductors via domestic ironing
Authors: Komolafe Abiodun , Beeby Steve , Torah Russel
Published: May 2024

The electrical performance of printed conductors often degrades over time due to recurrent or infrequent exposure to practical stresses such as bending and washing. To avoid this, a repair mechanism is required to return the conductor to prime condition, enhancing lifetime and durability during extended stress cycles. In this study, domestic ironing is used to repair and restore the electrical resistance of printed conductors damaged by prolonged bending and washing cycles at standard ironing temperatures. The results of reliability tests on screen-printed conductors on two polyurethane-coated fabrics and six different laminate sheets adhered to the fabrics revealed that ironing significantly enhances the electrical performance of the conductors, limiting the change in electrical resistance to less than 20% after 400 000 bending cycles and to less than 1 Ω after 50 wash cycles. Although laminated conductors are more durable and generally outperformed conductors on the printed primer layer, in both cases, the results showed that the sample could be left for 24 h for ‘self-relaxation’ and would also return to the original value, implying that for future wear, either immediate ironing or leaving the garment for a period between uses could effectively ‘fix’ any bending or washing damage.
Disturbance rejection based consensus controller for swarm system
Authors: Dixit Abhishek , Agrawal Pooja , Misra Ajay
Published: May 2024

This article introduces a robust controller designed to facilitate consensus among leader-follower agents in a swarm system. The method employs algebraic graph theory to establish a consensus framework and incorporates a sliding surface-based uncertainty and disturbance estimator (SUDE) to mitigate the effects of nonlinearities, external disturbances, and parametric uncertainty inherent in swarm systems. The stability of the SUDE controller is examined using Lyapunov theory. Importantly, this approach operates without prior knowledge of disturbance bounds, relying instead on the dynamics of disturbance error. Simulation studies demonstrate the effectiveness of the proposed control methodology, showing that the SUDE controller expedites consensus achievement while ensuring smooth and non-chattering control behavior. The proposed SUDE controller demonstrates a notable improvement in achieving position and velocity consensus in both the X and Y directions, with a 75% and 66% faster convergence rate, respectively, when compared to the conventional sliding mode controller (SMC). Additionally, the performance of the proposed controller is assessed under various external disturbances and parametric uncertainty conditions. Comparative analyses using root mean square error (RMSE) and integral absolute time error (IATE), both based on consensus error, confirm the effectiveness of the proposed SUDE consensus controller.
A low-cost simple lysimeter soil retriever design for retrieving soil from small lysimeters
Authors: Gunaratnam Abhiram , McCurdy Murray , Grafton Miles , Jeyakumar Paramsothy , Davies Clive E , Bishop Peter
Published: May 2024

A lysimeter-soil retriever (LSR) is a device used to retrieve the soil with minimum disturbance from lysimeters. This device makes the process of sampling intact soil layers from lysimeters easier and faster, especially when a large number of lysimeters are being sampled. In this study, mini lysimeters (200 mm diameter and 25 kg weight) were used to test fertilizers. A low-cost LSR was designed to aid the accurate removal of the soil from these lysimeters. This paper describes the design and testing of the suitability of a linear actuator for this application. This study investigates the influence of soil moisture on the retrieval and structural stability of lysimeter and LSR. The results revealed that soil with a high moisture level was more suitable as it showed lower disturbance for the retrieved block, lower soil losses, minimal disturbance for roots and lower variation of soil block height and weight. The retrieval time was influenced by soil moisture level and were 48 and 52 s for low and high-moisture soils, respectively. The finite element model showed that the stress applied by the linear actuator on the lysimeter body and top-wood plate were 2.18 and 0.32 MPa, respectively. These stress values were within the safe limit of the corresponding materials. It was found that the selected linear actuator is suitable for soil retrieving from lysimeters packed with sandy-clay loam and sand. It showed consistent performance (stroke time and maximum force) after retrieval of 400 soil blocks. The suitability of this design for various soil types needs to be tested to determine its applicability in a broader range of scenarios.
Effects of bio-inspired infill design on the mechanical properties of ultrasonic vibration assisted 3D printed samples
Authors: Rajendran Thavinnesh Kumar , Shahrum Mohd Afiq , Maidin Shajahan , Ismail Shafinaz
Published: May 2024

This paper study the tensile strength and microstructure of the 3D bio-inspired printed samples by comparing the ultrasonic vibration assisted test samples with standard ABS and PLA samples with three different bio-inspired infill designs namely elephant trunk, bamboo and leaf. The test samples were printed with optimal printing process parameters and 0 kHz and 20 kHz frequency of ultrasonic vibration. SolidWorks software was used to design the bio-inspired infill designs and create the 3D-printed test samples. Tests to evaluate mechanical properties and microstructure were carried out after printing the test samples. The investigation primarily focuses on the impact of ultrasonic vibration assisted 3D bio-inspired printed samples of ABS and PLA materials. This research explores using ultrasonic vibration assistance to enhance the tensile strength of 3D-printed infills. The elephant trunk inspired infill design with ABS at 20 kHz achieved the best results, suggesting that ultrasonic vibration strengthens intermolecular bonding. The bamboo inspired infill performed poorly due to its design, while PLA deformed due to lower heat resistance. Overall, ultrasonic frequency improved layer bonding, especially for the elephant trunk infill, indicating potential for further optimization. These results demonstrate the effectiveness of bio-inspired infill solutions, mainly the ABS elephant trunks with ultrasonic 20 kHz of vibration.
GPU optimization techniques to accelerate optiGAN—a particle simulation GAN
Authors: Srikanth Anirudh , Trigila Carlotta , Roncali Emilie
Published: May 2024

The demand for specialized hardware to train AI models has increased in tandem with the increase in the model complexity over the recent years. Graphics processing unit (GPU) is one such hardware that is capable of parallelizing operations performed on a large chunk of data. Companies like Nvidia, AMD, and Google have been constantly scaling-up the hardware performance as fast as they can. Nevertheless, there is still a gap between the required processing power and processing capacity of the hardware. To increase the hardware utilization, the software has to be optimized too. In this paper, we present some general GPU optimization techniques we used to efficiently train the optiGAN model, a Generative Adversarial Network that is capable of generating multidimensional probability distributions of optical photons at the photodetector face in radiation detectors, on an 8GB Nvidia Quadro RTX 4000 GPU. We analyze and compare the performances of all the optimizations based on the execution time and the memory consumed using the Nvidia Nsight Systems profiler tool. The optimizations gave approximately a 4.5x increase in the runtime performance when compared to a naive training on the GPU, without compromising the model performance. Finally we discuss optiGANs future work and how we are planning to scale the model on GPUs.
Investigating the ability of PINNs to solve Burgers’ PDE near finite-time blowup
Authors: Kumar Dibyakanti , Mukherjee Anirbit
Published: May 2024

Physics Informed Neural Networks (PINNs) have been achieving ever newer feats of solving complicated Partial Differential Equations (PDEs) numerically while offering an attractive trade-off between accuracy and speed of inference. A particularly challenging aspect of PDEs is that there exist simple PDEs which can evolve into singular solutions in finite time starting from smooth initial conditions. In recent times some striking experiments have suggested that PINNs might be good at even detecting such finite-time blow-ups. In this work, we embark on a program to investigate this stability of PINNs from a rigorous theoretical viewpoint. Firstly, we derive error bounds for PINNs for Burgers’ PDE, in arbitrary dimensions, under conditions that allow for a finite-time blow-up. Our bounds give a theoretical justification for the functional regularization terms that have been reported to be useful for training PINNs near finite-time blow-up. Then we demonstrate via experiments that our bounds are significantly correlated to the

ℓ
2

-distance of the neurally found surrogate from the true blow-up solution, when computed on sequences of PDEs that are getting increasingly close to a blow-up.
Emulating inconsistencies in stratospheric aerosol injection
Authors: Farley Jared , MacMartin Douglas G , Visioni Daniele , Kravitz Ben
Published: May 2024

Stratospheric aerosol injection (SAI) would involve the addition of sulfate aerosols in the stratosphere to reflect part of the incoming solar radiation, thereby cooling the climate. Studies trying to explore the impacts of SAI have often focused on idealized scenarios without explicitly introducing what we call ‘inconsistencies’ in a deployment. A concern often discussed is what would happen to the climate system after an abrupt termination of its deployment, whether inadvertent or deliberate. However, there is a much wider range of plausible inconsistencies in deployment than termination that should be evaluated to better understand associated risks. In this work, we simulate a few representative inconsistencies in a pre-existing SAI scenario: an abrupt termination, a decade-long gradual phase-out, and 1 year and 2 year temporary interruptions of deployment. After examining their climate impacts, we use these simulations to train an emulator, and use this to project global mean temperature response for a broader set of inconsistencies in deployment. Our work highlights the capacity of a finite set of explicitly simulated scenarios that include inconsistencies to inform an emulator that is capable of expanding the space of scenarios that one might want to explore far more quickly and efficiently.
Increasing fluctuations in the Arctic summer sea ice cover are expected with future global warming
Authors: Poltronieri Anna , Bochow Nils , Boers Niklas , Rypdal Martin
Published: May 2024

The loss of Arctic sea ice (ASI) represents a major transformation in the Arctic region, impacting regional and global climate, ecosystems, and socio-economic structures. Observational and reanalysis data have consistently shown a notable shift in polar environmental conditions over recent decades, marked by a substantial reduction in the ASI area and a rise in the variability in its coverage and distribution. Utilizing data from the latest Coupled Model Intercomparison Project phase, our study reveals a consistent pattern highlighting a fundamental shift in ASI dynamics preceding total loss. We observe increasing fluctuations in the September ASI area as the threshold for an ice-free Arctic is approached across various scenarios and models. This pattern is particularly concentrated in the Central Arctic (CA) sub-region. Spatial analyses reveal increasing variance along the CA’s northern coastlines, accompanied by a substantial increase in open water coverage, underscoring the shift from stable to highly variable ice conditions in this region. Additionally, our findings suggest a potential link between increased ASI fluctuations and variability in surface wind speeds. These specific results underscore the urgency of multidisciplinary approaches in addressing the challenges posed by ASI variability, with implications for marine ecosystems, Indigenous communities, and navigational safety.
Western Europe’s extreme July 2019 heatwave in a warmer world
Authors: de Vries Hylke , Lenderink Geert , van Meijgaard Erik , van Ulft Bert , de Rooy Wim
Published: May 2024

Summertime heatwaves are extreme events with a large societal impact. Intensity, duration and spatial extent, all heatwave properties are projected to increase in a warming world, implying that summers that qualified as extreme in the past will become increasingly normal. In this paper we quantify how the changes play out for the July 2019 European heatwave that shattered temperature records throughout Western Europe. We combine a storyline approach with ensemble Pseudo Global Warming (PGW) and high-resolution dynamical downscaling. The downscaling is done with a regional climate model (RACMO2, 12 km resolution) and a convection-permitting model (HCLIM-AROME, 2.5 km resolution). Under PGW the maximum temperature during the heatwave rises 1.5 to 2.5 times faster than the global mean, implying that even at moderate warming levels the heatwave impact changes are tangible. Moreover, there is no sign that the increase in the maximum temperature levels off at higher warming levels, implying that at +4K above present-day temperatures could reach 50 ∘C. During heatwaves cities become islands of heat where daily maxima and night-time minima are up to 5 ∘C higher than in rural areas as we show in ultra-high resolution HCLIM-AROME simulations at 150 m resolution.
Sampling-based methods for multi-block optimization problems over transport polytopes
Authors: Hu Yukuan , Li Mengyu , Liu Xin , Meng Cheng
Published: May 2024

This paper focuses on multi-block optimization problems over transport polytopes, which underlie various applications including strongly correlated quantum physics and machine learning. Conventional block coordinate descent-type methods for the general multi-block problems store and operate on the matrix variables directly, resulting in formidable expenditure for large-scale settings. On the other hand, optimal transport problems, as a special case, have attracted extensive attention and numerical techniques that waive the use of the full matrices have recently emerged. However, it remains nontrivial to apply these techniques to the multi-block, possibly nonconvex problems with theoretical guarantees. In this work, we leverage the benefits of both sides and develop novel sampling-based block coordinate descent-type methods, which are equipped with either entropy regularization or Kullback-Leibler divergence. Each iteration of these methods solves subproblems restricted on the sampled degrees of freedom. Consequently, they involve only sparse matrices, which amounts to considerable complexity reductions. We explicitly characterize the sampling-induced errors and establish convergence and asymptotic properties for the methods equipped with the entropy regularization. Numerical experiments on typical strongly correlated electron systems corroborate their superior scalability over the methods utilizing full matrices. The advantage also enables the first visualization of approximate optimal transport maps between electron positions in three-dimensional contexts.
On Weil-Stark elements, II: Refined Stark conjectures
Authors: Burns David , Macias Castillo Daniel , Seo Soogil
Published: May 2024

The theory of Weil-Stark elements is used to develop an axiomatic approach to the formulation of refined versions of Stark’s Conjecture. This gives concrete new results concerning leading terms of Artin

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-series and arithmetic properties of Stark elements.
Detecting changes in population trends in infection surveillance using community SARS-CoV-2 prevalence as an exemplar
Authors: Pritchard Emma , Vihta Karina-Doris , Eyre David W , Hopkins Susan , Peto Tim E A , Matthews Philippa C , Stoesser Nicole , Studley Ruth , Rourke Emma , Diamond Ian , Pouwels Koen B , Walker Ann Sarah , Infection Survey Team COVID-19
Published: May 2024

Detecting and quantifying changes in the growth rates of infectious diseases is vital to informing public health strategy and can inform policymakers’ rationale for implementing or continuing interventions aimed at reducing their impact. Substantial changes in SARS-CoV-2 prevalence with the emergence of variants have provided an opportunity to investigate different methods for doing this. We collected polymerase chain reaction (PCR) results from all participants in the United Kingdom’s COVID-19 Infection Survey between August 1, 2020, and June 30, 2022. Change points for growth rates were identified using iterative sequential regression (ISR) and second derivatives of generalized additive models (GAMs). Consistency between methods and timeliness of detection were compared. Of 8 799 079 study visits, 147 278 (1.7%) were PCR-positive. Change points associated with the emergence of major variants were estimated to occur a median of 4 days earlier (IQR, 0-8) when using GAMs versus ISR. When estimating recent change points using successive data periods, 4 change points (4/96) identified by GAMs were not found when adding later data or by ISR. Change points were detected 3-5 weeks after they occurred under both methods but could be detected earlier within specific subgroups. Change points in growth rates of SARS-CoV-2 can be detected in near real time using ISR and second derivatives of GAMs. To increase certainty about changes in epidemic trajectories, both methods could be used in parallel.
Invited commentary: raising a high-pressure alarm about pediatric hypertension
Authors: Weiss Scott L
Published: May 2024

Hypertension is a common “silent killer” in adult medicine, but epidemiologic estimates of elevated blood pressure in children and adolescents are challenged by under-diagnosis and resultant low utilization of relevant administrative or billing codes. In the article by Horgan et al (Am J Epidemiol 2024), children and adolescents with hypertension and elevated blood pressure were identified using direct assessment of blood pressure measurements available in the electronic health record from both inpatient and outpatient visits (“clinical cohort”) in comparison to diagnosis codes (“claims-based cohort”). The study population included 3.75 million pediatric healthcare visits available in the US Food and Drug Administration’s Sentinel System. While the study applied a relatively novel methodology to interrogate available clinical data within the EHR to better understand the prevalence of pediatric hypertension and raised concern for a higher occurrence of hypertension among children and adolescents than previously realized using claims codes, the utility of the prevalence estimates may be limited by the potential for misclassification bias inherent in electronic health records data. However, these data raise important concerns about relaying solely on ICD-9-CM/ICD-10-CM codes to quantify the epidemiology of pediatric hypertension and highlight opportunities to address elevated blood pressure in children that could improve long-term cardiovascular health.