Hasil untuk "Low temperature engineering. Cryogenic engineering. Refrigeration"

Cheng Zhang, Q. Yu, Yuanbo T. Tang et al.

: The highly tunable properties of multi-principal element alloys, commonly known as high-entropy alloys (HEAs), provide a remarkable potential for the development of superior materials for critical structural applications that involve extreme conditions. However, the optimization of the properties of HEAs has been primarily limited to behavior either low or high temperatures. Here, we report on a non-equiatomic, heterostructured, high-entropy alloy FeNiCoAlTaB which possesses remarkable combinations of mechanical properties across a wide range of temperatures from 77 K to 1073 K. The current metastable alloy presents good ductility and superior engineering tensile strengths of 2.2 GPa, 1.4 GPa, 800 MPa, and 500 MPa at 77 K, 298 K, 873 K, and 1073 K, respectively. This behavior is achieved by a synergic sequence of individual mechanisms that are activated at different temperatures. The alloy even displays pseudoelasticity at 77 K with an applied load up to 2 GPa. This work provides a methodology for tailoring structural heterogeneity and metastability in the design and fabrication of multifunctional HEAs that will outperform known metals and alloys over a wide range of temperatures.

Daniel Rodriguez-Cardenas, Xiaochang Li, Marcos Macedo et al.

Large language models for code are advancing fast, yet our ability to evaluate them lags behind. Current benchmarks focus on narrow tasks and single metrics, which hide critical gaps in robustness, interpretability, fairness, efficiency, and real-world usability. They also suffer from inconsistent data engineering practices, limited software engineering context, and widespread contamination issues. To understand these problems and chart a path forward, we combined an in-depth survey of existing benchmarks with insights gathered from a dedicated community workshop. We identified three core barriers to reliable evaluation: the absence of software-engineering-rich datasets, overreliance on ML-centric metrics, and the lack of standardized, reproducible data pipelines. Building on these findings, we introduce BEHELM, a holistic benchmarking infrastructure that unifies software-scenario specification with multi-metric evaluation. BEHELM provides a structured way to assess models across tasks, languages, input and output granularities, and key quality dimensions. Our goal is to reduce the overhead currently required to construct benchmarks while enabling a fair, realistic, and future-proof assessment of LLMs in software engineering.

Paloma Guenes, Rafael Tomaz, Maria Teresa Baldassarre et al.

The Impostor Phenomenon (IP) impacts a significant portion of the Software Engineering workforce, yet it is often viewed primarily through an internal individual lens. In this position paper, we propose framing the prevalence of IP as a form of Human Debt and discuss the relation with the ICSE2026 Pre Survey on the Future of Software Engineering results. Similar to technical debt, which arises when short-term goals are prioritized over long-term structural integrity, Human Debt accumulates due to gaps in psychological safety and inclusive support within socio-technical ecosystems. We observe that this debt is not distributed equally, it weighs heavier on underrepresented engineers and researchers, who face compounded challenges within traditional hierarchical structures and academic environments. We propose cultural refactoring, transparency and active maintenance through allyship, suggesting that leaders and institutions must address the environmental factors that exacerbate these feelings, ensuring a sustainable ecosystem for all professionals.

Yixuan Liu, Yulou Fan, Yixin Zhou et al.

ABSTRACT The application of recycled asphalt materials in pavement engineering has been significantly hindered by excessive stiffness and susceptibility to cracking. SBS-modified epoxy asphalt has demonstrated a remarkable ability to enhance material toughness. This study aims to investigate the influence of varying aged asphalt content and epoxy resin content on the low-temperature performance of SBS-modified asphalt. Through the tensile test and bending beam rheometer (BBR) analysis, the low-temperature cracking resistance was evaluated. The viscoelastic constitutive relation was established based on the Burgers model. The results indicate that increasing epoxy content enhances material strength, reduces elongation at break and improves anti-crack performance. The toughening effect of epoxy enhances the asphalt's resistance to deformation and stress relaxation. Differential scanning calorimetry (DSC) was employed to study the curing behaviour, and nonisothermal curing kinetic equations were established. Frequency sweep tests were conducted to construct complex modulus and phase angle master curves, revealing that the maximum complex modulus and optimal low-temperature performance were achieved at 40% epoxy content. The glass transition temperatures of all materials were below 15°C, confirming their superior toughness at ambient temperatures. It lays the foundation for optimising the material design and facilitating the widespread application of epoxy-modified recycled asphalt.

Jiadong Wang, Mingliang Ma, Qing Ma et al.

Abstract In the move away from fossil fuels, methanol is viewed as a viable alternative engine fuel and hydrogen carrier, while serving as a key component in the chemical industry. In responding to the environmental impact caused by excessive CO2 emissions and the drive to promote green H2 technology, CO2 hydrogenation to produce methanol has received increasing attention, which has addressed H2 storage and transport. The reaction is thermodynamically feasible at low temperatures with a high conversion in a single pass, but there is significant scope to enhance reaction kinetics. This article reviews the progress that has been made in engineering catalytic active sites for the heterogeneous hydrogenation of CO2 to methanol at temperatures below 200 °C, including considerations of alloying effects, doping, defect formation, active site size and dispersion, coordination effects, and surface modification. The active site valence state and size in tandem with electron transfer, hydrogen spillover, and surface alkalinity/hydrophobicity can affect catalytic performance and the prevailing reaction pathway to varying degrees. The low-temperature reaction process is briefly discussed and future research directions required to further enhance catalytic efficiency are proposed.

Bin Chen, Qiang Sun, Jingjing Nan et al.

Xinhua Wang, Shi Lin, Yong Kang et al.

Fei Liu, Shibing Huang, Yongshui Kang et al.

Marvin Wyrich, Lloyd Montgomery

A well-rounded software engineer is often defined by technical prowess and the ability to deliver on complex projects. However, the narrative around the ideal Software Engineering (SE) candidate is evolving, suggesting that there is more to the story. This article explores the non-technical aspects emphasized in SE job postings, revealing the sociotechnical and organizational expectations of employers. Our Thematic Analysis of 100 job postings shows that employers seek candidates who align with their sense of purpose, fit within company culture, pursue personal and career growth, and excel in interpersonal interactions. This study contributes to ongoing discussions in the SE community about the evolving role and workplace context of software engineers beyond technical skills. By highlighting these expectations, we provide relevant insights for researchers, educators, practitioners, and recruiters. Additionally, our analysis offers a valuable snapshot of SE job postings in 2023, providing a scientific record of prevailing trends and expectations.

Timo Kehrer, Robert Haines, Guido Juckeland et al.

Anecdotal evidence suggests that Research Software Engineers (RSEs) and Software Engineering Researchers (SERs) often use different terminologies for similar concepts, creating communication challenges. To better understand these divergences, we have started investigating how SE fundamentals from the SER community are interpreted within the RSE community, identifying aligned concepts, knowledge gaps, and areas for potential adaptation. Our preliminary findings reveal opportunities for mutual learning and collaboration, and our systematic methodology for terminology mapping provides a foundation for a crowd-sourced extension and validation in the future.

Lekshmi Murali Rani, Richard Berntsson Svensson, Robert Feldt

The integration of AI for Requirements Engineering (RE) presents significant benefits but also poses real challenges. Although RE is fundamental to software engineering, limited research has examined AI adoption in RE. We surveyed 55 software practitioners to map AI usage across four RE phases: Elicitation, Analysis, Specification, and Validation, and four approaches for decision making: human-only decisions, AI validation, Human AI Collaboration (HAIC), and full AI automation. Participants also shared their perceptions, challenges, and opportunities when applying AI for RE tasks. Our data show that 58.2% of respondents already use AI in RE, and 69.1% view its impact as positive or very positive. HAIC dominates practice, accounting for 54.4% of all RE techniques, while full AI automation remains minimal at 5.4%. Passive AI validation (4.4 to 6.2%) lags even further behind, indicating that practitioners value AI's active support over passive oversight. These findings suggest that AI is most effective when positioned as a collaborative partner rather than a replacement for human expertise. It also highlights the need for RE-specific HAIC frameworks along with robust and responsible AI governance as AI adoption in RE grows.

Kun Zhang, Congwei Wang, Xinglin Luo et al.

H. Suo, Jiaying Zhang, Mingen Xu et al.

Three-dimensional (3D) printing is a promising method to prepare scaffolds for tissue regeneration. Collagen and chitosan composites are superior materials for tissue engineering scaffold but rarely printed due to their poor printability. Here, we prepared a series of tunable hybrid collagen/chitosan bioinks with significantly improved printability through hydrogen bond interaction and printed them into scaffolds by carefully controlling the temperature. Rheological tests proved the printable bioinks had sound shear thinning behavior, dramatical viscosity variation with temperature, and the gelation temperature from 7 to 10 °C. Chitosan could decrease the swelling ratio of the printed scaffolds, while their degradation rate increased with collagen proportion and the values of Young's modulus and tensile strength increased with chitosan proportion. Moreover, the scaffolds containing 2% (m/v) collagen and 2% (m/v) chitosan had a homogeneous and compact honeycomb-like structure, demonstrating the strengthening effect of chitosan. Cell viability assay presented vigorous cell growth on the surface of scaffolds, meanwhile, live cells were also found inside and at the bottom of the scaffolds, indicating the migration of cells. Therefore, chitosan can improve the printability of collagen and the hybrid collagen/chitosan bioinks can be printed into scaffolds with regulated properties, thus can fit different applications in tissue engineering.

J. V. Sontia Metekong, C. R. Kaze, E. Kamseu et al.

The present project deals with the production of lateritic soil based bricks under different curing temperatures (28°C–150°C). A fraction of 10–30 wt% amount alkaline solution was added to improve the reactive phase content. The raw materials and hardened products were characterized using X‐ray diffraction (XRD), fourrier transform infrared spectroscopy (FTIR), mechanical properties and scanning electron microscope analysis. The results show that the addition of alkaline solution (30%) and the curing temperature (150°C) have a beneficial influence on physical properties (bulk density: 1.77 g/cm3, water absorption: 16.98%, and porosity: 30.13%) and mechanical performances (flexural: 6.61 MPa and compressive: 13.57 MPa). Compared with the code requirements for stabilized earth blocks, the compressive strength was higher than the minimum required. Microstructural investigations were also carried out to confirm the macrostructural properties. The above‐mentioned process appears to be a suitable candidate for engineering applications such as the stabilization of earth roads.

Proc IMechE, Aftab Anjum, R. S. Mishra

Among the various solar technologies, solar power tower (SPT) technology is being widely used for large-scale energy generation. Therefore, this work developed a trigeneration system for SPT plant that produces power, heating and cooling at low temperature efficiently from a high temperature SPT heat source. In order to create heating and low temperature (at −20°C) cooling benefits for food preservation, this trigeneration unit integrates a cascaded vapor compression-absorption refrigeration system combined with a helium Brayton cycle for power generation. The exergy-energy analysis was performed by the numerical technique using engineering equation solver software to evaluate the performance of the proposed SPT plant. The power output, exergy and energy efficiency of the SPT plant were found as 14,865 kW, 39.53% and 28.82%, respectively. The coefficient of performances values for cooling and heating were observed as 0.5391 and 1.539, respectively. Exergy evaluation revealed that approximately 78.18% of the total energy destruction of the entire plant is attributed to the solar subsystem only. Furthermore, a parametric investigation shows that the temperature of the evaporator, generator and helium turbine inlet, and the efficiency of the heliostat and receiver all have a significant impact on the plant performance. Furthermore, a comparative analysis with relevant previous studies has shown that the proposed system outperforms systems based on supercritical CO2 cycles and the Rankine cycles.

Johan Cederbladh, Antonio Cicchetti

In this paper we discuss the growing need for system behaviour to be validated and verified (V&V'ed) early in model-based systems engineering. Several aspects push companies towards integration of techniques, methods, and processes that promote specific and general V&V activities earlier to support more effective decision-making. As a result, there are incentives to introduce new technologies to remain competitive with the recently drastic changes in system complexity and heterogeneity. Performing V&V early on in development is a means of reducing risk for later error detection while moving key activities earlier in a process. We present a summary of the literature on early V&V and position existing challenges regarding potential solutions and future investigations. In particular, we reason that the software engineering community can act as a source for inspiration as many emerging technologies in the software domain are showing promise in the wider systems domain, and there already exist well formed methods for early V&V of software behaviour in the software modelling community. We conclude the paper with a road-map for future research and development for both researchers and practitioners to further develop the concepts discussed in the paper.

Oleksandr Kosenkov, Michael Unterkalmsteiner, Jannik Fischbach et al.

Context: Regulatory acts are a challenging source when eliciting, interpreting, and analyzing requirements. Requirements engineers often need to involve legal experts who, however, may often not be available. This raises the need for approaches to regulatory Requirements Engineering (RE) covering and integrating both legal and engineering perspectives. Problem: Regulatory RE approaches need to capture and reflect both the elementary concepts and relationships from a legal perspective and their seamless transition to concepts used to specify software requirements. No existing approach considers explicating and managing legal domain knowledge and engineering-legal coordination. Method: We conducted focus group sessions with legal researchers to identify the core challenges to establishing a regulatory RE approach. Based on our findings, we developed a candidate solution and conducted a first conceptual validation to assess its feasibility. Results: We introduce the first version of our Artifact Model for Regulatory Requirements Engineering (AM4RRE) and its conceptual foundation. It provides a blueprint for applying legal (modelling) concepts and well-established RE concepts. Our initial results suggest that artifact-centric RE can be applied to managing legal domain knowledge and engineering-legal coordination. Conclusions: The focus groups that served as a basis for building our model and the results from the expert validation both strengthen our confidence that we already provide a valuable basis for systematically integrating legal concepts into RE. This overcomes contemporary challenges to regulatory RE and serves as a basis for exposure to critical discussions in the community before continuing with the development of tool-supported extensions and large-scale empirical evaluations in practice.

Jukka Ruohonen, Kalle Hjerppe

Participatory citizen platforms are innovative solutions to digitally better engage citizens in policy-making and deliberative democracy in general. Although these platforms have been used also in an engineering context, thus far, there is no existing work for connecting the platforms to requirements engineering. The present paper fills this notable gap. In addition to discussing the platforms in conjunction with requirements engineering, the paper elaborates potential advantages and disadvantages, thus paving the way for a future pilot study in a software engineering context. With these engineering tenets, the paper also contributes to the research of large socio-technical software systems in a public sector context, including their implementation and governance.

Eiji Miyazaki, Hiroki Kimura, Hiroyuki Kukita et al.

Japan Aerospace Exploration Agency, JAXA, and Nihon Dempa Kogyo Co., Ltd., NDK, developed an original QCM sensor system under wide temperature range named “Twin-QCM” for ground use since 2015, put on the market in 2017. Twin-QCM series has “Twin-CQCM” with built-in heater and “Twin-TQCM” with built-in peltier element. Twin-TQCM has an operational temperature limitation at low temperature caused by use of built-in peltier element. Since 2021, we have proceeded to initiate the development of advanced Twin-QCM aiming for flight and exploration. Then, we decided to develop a new version of Twin-TQCM which can be used under cryogenic temperature, i.e., lower than -80 degrees C, named “cryo-use Twin-TQCM (Engineering Model).” Then, we have planned to evaluate the performance of the Engineering Model in terms of deposition sensing. In this presentation, we will report the test results of the experiment for performance evaluation of cryo-use Twin-TQCM Engineering Model.

Sergey Kravchenko, Natalia Kravchenko, N. Kuleshov et al.

Producers and processors of agricultural raw materials are faced with the task of increasing the competitiveness of their products and added value. One of the solutions to these problems is to increase the depth of processing raw materials by agricultural producers or primary processors to obtain valuable products with high added value that are in demand in the markets for the production of final products (in pharmaceuticals, perfume and cosmetics industry, ready-made food production, etc.). In the process of obtaining valuable products of agricultural raw materials there is a need for low-temperature condensation and/or low-temperature adsorption of useful products or intermediate technological substances. Low temperature refrigerated vapour traps with an operating temperature range of -70 °C to -110 °C and below are used for such process operations. In many technological applications, these traps are used in combination with vacuum processes, e.g. in the deposition of vacuum distillation products, which predetermines the requirements for hermetic tightness of the flowing part of such a trap. In recent years, in connection with the struggle to reduce emissions of gases that destroy the ozone layer and contribute to the greenhouse effect, the EU has banned the use of the cheapest and most efficient refrigerants, e.g. R13, which allows to obtain temperatures of about -100 °C using single-stage refrigeration machines. Modern refrigerants on the market, having an order of magnitude higher price, require 2-3 times higher design pressure from the equipment and have a lower cycle efficiency. In this regard, the creation of a low-temperature trap is a complex engineering task associated not only with the design of a multi-stage refrigeration machine, but also with the creation of a control system for the cascades of the refrigeration machine and vacuum pumping equipment, ensuring the safe and reliable operation of the trap and the achievement of the desired low temperature range during its long-term operation. SIA Cryogenic and vacuum systems have created a prototype of this low-temperature trap and is working on creating of processing complexes, included such traps for industrial quantities of processed biomaterials. The article highlights our engineering approaches, calculations and experience in creating a prototype of a low-temperature trap.