JUNIA

In traditional quantum computing, e.g. in the quantum circuit model, the size of the data structure describing basis elements is well known, because the dimensionality is fixed. General quantum systems, however, exhibit basis elements of variable size, and state spaces having dynamically unbounded, possibly infinite dimensionality, e.g. for quantum Turing machines or quantum field theories. When seeking to simulate them classically, this imposes an irregularity on both the memory representation of basis elements and the sparsity of the quantum transformations they undergo. Moreover, the high dimensionality of these problems often makes them memory intensive, potentially requiring truncation methods during the simulation. One prototypical example of this would be quantum causal graph dynamics (QCGD), which feature superpositions of colored graphs of different shapes and sizes, driven by the application of local quantum transformations. Numerical observations show that their reversible counterparts typically grow in size; understanding how this is affected in the quantum regime is an arduous computational challenge requiring a particular HPC expertise. In this work, we address this challenge by developing a computational framework for a scalable simulation of such general irregular quantum systems in distributed-memory parallel environments. We lay out the computational challenges arising from the nature of such simulations and then propose effective parallelization, load balancing, memory management, and parallel sampling strategies to accelerate them. We report parallel scalability and accuracy results for up to 1548 MPI processes on a parallel cluster using our framework for the QCGD simulation.

Abstract This study conducts a detailed thermal and economic analysis of a heat recovery concentric tube heat exchanger (HR-CTHE) designed to utilize diesel engine exhaust waste heat for domestic water heating. Using a counter-flow configuration, we systematically vary hot exhaust inlet temperatures (500–900 K), Reynolds numbers on both hot and cold sides (1,000–20,000), and geometric parameters (inner tube diameters from 0.03 to 0.15 m and diameter ratios of 1.25–3) to assess their impact on system performance. The results indicate that higher exhaust inlet temperatures and increased hot-side turbulence (e.g., Re h = 20,000) dramatically enhance the heat recovery rate, surpassing 25,000 W, and raise the preheated water temperature above 310 K under optimal conditions. From an economic perspective, these thermal improvements translate into significantly shortened discounted payback periods, reaching as low as a few months. Furthermore, the baseline energy source—electricity or natural gas—profoundly influences the payback period, with systems displacing more expensive electricity achieving notably quicker returns. These findings highlight the HR-CTHE’s potential as a cost-effective and efficient option for integrating waste heat recovery into residential hot water systems.

In this paper, we investigate the capabilities of analog quantum computers in solving well-known optimisation problems, with a specific focus on the Max-Cut and Capacitated Vehicle Routing Problem (CVRP). Our aim is to evaluate the performance of the D-Wave Advantage machine in addressing these complex challenges. We selected instances from the literature for these two problems based on the machine's capacity, specifically considering its number of qubits and the topology of its qubit network. For the Max-Cut problem, we utilise a fully quantum approach, employing an Ising model to find optimal solutions. For the CVRP, we adopt a hybrid quantum-classical methodology, following a cluster first-route second scheme. Our findings suggest that quantum computers are a promising tool for rapidly solving optimisation problems, although we observed limitations in terms of scalability.

Pancreatic islets play a major role in glucose homeostasis as well as in diabetes, and islets-on-chip devices have been mainly developed using optical means for on-line monitoring. In contrast, no well-characterized electrophysiological platform for on-line analysis with unrivalled temporal resolution has been reported. Extracellular electrophysiology monitors two crucial parameters, islet β-cell activity and β-to-β-cell coupling, does not require chemical or genetic probes with inherent potential bias, is non-invasive and permits repetitive long-term monitoring. We have now developed and characterized a microfluidic islets-on-chip for combined electrophysiology (on-line) and hormone monitoring (off-line) with two chambers for concomitant monitoring. Fabrication of the device, based on commercial or easily manufacturable components, is within the reach of non-specialized laboratories. The chip permits convenient loading as well as long-term culture with comparable glucose kinetics and low shear stress in both chambers. An optimized flow rate did not alter islet β-cell electrical activity or coupling in response to glucose. Culturing for up to 8 days did not change islet survival as well as glucose-induced electrical or secretory kinetics of islet β-cells. The addition of a physiological amino acid mix, in the presence of elevated glucose, made a considerable change in the functional organisation of islet β-cell activity in terms of frequency and coupling, which explains the ensuing strong increase in insulin secretion. This device thus allows reliable long-term multiparametric on-line monitoring in two islet populations. The ease of fabrication, assembly and handling should permit widespread long-term on-line monitoring of islet activity in native micro-organs (e.g. controls/mutants), pseudo-islets or stem-cell-derived islet-like organoids.

Six polysaccharide-based chiral stationary phases were screened to separate the enantiomers of six chloro-containing derivatives and one derivative bearing electron donating mesomeric substituents, chosen for comparison. These compounds are expected to be P2X7 receptor antagonists with potential anti-inflammatory activity. The study was carried out with four different mobile phases composed of n-heptane and ethanol or isopropanol. Thus, a total of 168 experiments were implemented to find the best conditions aimed at scaling-up the separation of these anti-inflammatory compounds. Chiralpak AD-H separated half of them, i.e., 1, 2, and 6; Chiralpak AS separated also three out of the six compounds, i.e., 1, 2, and 3; Lux Cellulose-5 separated 2, 4, and 6; Lux Cellulose-2 separated 1, 2, and 4; Chiralcel OD-H separated compounds 2 and 5; and finally Chiralcel OJ separated only 3, thus having the lowest rate of success. Additionally, the influence of (i) the stationary and mobile phases and (ii) the chemical structure of the analytes on retention and resolution was investigated.

Thermal comfort is essential for human well-being, influencing our perception of surrounding thermal conditions. Achieving thermal comfort typically requires energy for cooling or heating, prompting researchers to advocate for personal technologies due to their lower energy consumption (active on-body systems) compared to traditional methods (off-body systems). Advanced textiles are promoted as a sustainable solution, providing thermal comfort over a wider temperature range without additional energy consumption (passive on-body systems). This comprehensive review examines various types of comfort, with a focus on thermal comfort, exploring influencing factors and standards for assessing advanced textile performance. Additionally, the study emphasizes the importance of developing infrared (IR) emission control technologies to enhance thermal comfort, as radiant heat significantly contributes to body heat loss. Recent advancements in passive radiative cooling/heating layer fabrication are discussed. Among the technologies utilized for creating layers with radiant heat control properties, electrospinning technology is emphasized in this study. Electrospinning technology, renowned for its simplicity, compatibility with other methods, controllability, repeatability, and burgeoning industrial applications, is of particular interest to researchers. This article explores how passive design of electrospun layers can enhance radiant heat reflection and absorption for heating and cooling purposes. These layers are passive smart textiles that adapt to weather conditions using particles added during fabrication. The article discusses the advantages and challenges of this approach, highlighting the potential of electrospinning technology in creating smart textiles with improved thermal properties. The overarching goal is to aid ongoing research in achieving thermal comfort across diverse environments.

Individual differences in free-range chicken systems are important factors influencing how birds use the range (or not), even if individuals are reared in the same environmental conditions. Here, we investigated how various aspects of the birds' behavioral and cognitive tendencies, including their optimism/pessimism, cognitive flexibility, sociability, and exploration levels, are associated with range use and how they may change over time (before and after range access). To achieve this, 100 White Leghorn laying hen chicks underwent three distinct behavioral/cognitive tests—the cognitive bias test, the detour test, and the multivariate test—prior to gaining access to the range, between 9 and 39 days of age. After range access was allowed (from day 71), birds' range use was evaluated over 7 nonconsecutive days (from 74–91 days of age). Subsequently, a subset of birds, classified as high rangers (n = 15) and low rangers (n = 15) based on their range use, underwent retesting on the same three previous tests between 94 and 108 days of age. Our results unveiled a negative correlation trend between birds' evaluation of the ambiguous cue and their subsequent range use (rho = -0.19, p = 0.07). Furthermore, low rangers were faster to learn the detour task (χ2 = 7.34, df = 1, p = 0.006), coupled with increased sociability during the multivariate test (rho = -0.23, p = 0.02), contrasting with their high-ranging counterparts, who displayed more exploratory behaviors (F[1,27] = 3.64, p = 0.06). These behavioral patterns fluctuated over time (before and after range access); however, conclusively attributing these changes to birds' aging and development or the access to the range remains challenging. Overall, our results corroborate that behavioral and cognitive individual differences may be linked to range use and offer novel perspectives on the early behavioral and cognitive traits that may be linked to range use. These findings may serve as a foundation for adapting environments to meet individual needs and improve animal welfare in the future.

A new concept of on-demand automatic electric vehicles able to circulate on roads and tracks is under development to revitalize secondary railway lines: the FLEXMOVE project. The operation of this new system requires a dynamic, flexible, and safe supervision system. Such a supervision system will be based on an information exchange between vehicles, level crossing, infrastructure and hubs. ITS-G5, LoRa, LTE, and 5G NR are potential wireless technologies that could be deployed to guarantee connectivity. In these conditions, it is important to evaluate the foreseen key performance indicators to support the different services. This paper presents an in-lab experimental evaluation of Vehicle-to-Everything (V2X) connectivity technologies with V2X channel models.

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