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

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arXiv Open Access 2026
DUCTILE: Agentic LLM Orchestration of Engineering Analysis in Product Development Practice

Alejandro Pradas-Gomez, Arindam Brahma, Ola Isaksson

Engineering analysis automation in product development relies on rigid interfaces between tools, data formats and documented processes. When these interfaces change, as they routinely do as the product evolves in the engineering ecosystem, the automation support breaks. This paper presents a DUCTILE (Delegated, User-supervised Coordination of Tool- and document-Integrated LLM-Enabled) agentic orchestration, an approach for developing, executing and evaluating LLM-based agentic automation support of engineering analysis tasks. The approach separates adaptive orchestration, performed by the LLM agent, from deterministic execution, performed by verified engineering tools. The agent interprets documented design practices, inspects input data and adapts the processing path, while the engineer supervises and exercises final judgment. DUCTILE is demonstrated on an industrial structural analysis task at an aerospace manufacturer, where the agent handled input deviations in format, units, naming conventions and methodology that would break traditional scripted pipelines. Evaluation against expert-defined acceptance criteria and deployment with practicing engineers confirm that the approach produces correct, methodologically compliant results across 10 repeated independent runs. The paper discusses the paradigm shift and the practical consequences of adopting agentic automation, including unintended effects on the nature of engineering work when removing mundane tasks and creating an exhausting supervisory role.

en cs.SE, cs.AI
arXiv Open Access 2026
Round-trip Engineering for Tactical DDD: A Constraint-Based Vision for the Masses

Weixing Zhang, Mario Herb, Martin Armbruster et al.

Despite Domain-Driven Design's proven value in managing complex business logic, a fundamental semantic expressiveness gap persists between generic modeling languages and tactical DDD patterns, causing continuous divergence between design intent and implementation. We envision a constraint-based tactical modeling environment that transforms abstract architectural principles into explicit, tool-enforced engineering constraints. At its core is a DDD-native metamodel where tactical patterns are first-class modeling primitives, coupled with a real-time constraint verification engine that prevents architectural violations during modeling, and bidirectional synchronization mechanisms that maintain model-code consistency through round-trip engineering. This approach aims to democratize tactical DDD by embedding expert-level architectural knowledge directly into modeling constraints, enabling small teams and junior developers to build complex business systems without sacrificing long-term maintainability. By lowering the technical barriers to DDD adoption, we envision transforming tactical DDD from an elite practice requiring continuous expert oversight into an accessible engineering discipline with tool-supported verification.

arXiv Open Access 2025
Large Language Models in Thematic Analysis: Prompt Engineering, Evaluation, and Guidelines for Qualitative Software Engineering Research

Cristina Martinez Montes, Robert Feldt, Cristina Miguel Martos et al.

As artificial intelligence advances, large language models (LLMs) are entering qualitative research workflows, yet no reproducible methods exist for integrating them into established approaches like thematic analysis (TA), one of the most common qualitative methods in software engineering research. Moreover, existing studies lack systematic evaluation of LLM-generated qualitative outputs against established quality criteria. We designed and iteratively refined prompts for Phases 2-5 of Braun and Clarke's reflexive TA, then tested outputs from multiple LLMs against codes and themes produced by experienced researchers. Using 15 interviews on software engineers' well-being, we conducted blind evaluations with four expert evaluators who applied rubrics derived directly from Braun and Clarke's quality criteria. Evaluators preferred LLM-generated codes 61% of the time, finding them analytically useful for answering the research question. However, evaluators also identified limitations: LLMs fragmented data unnecessarily, missed latent interpretations, and sometimes produced themes with unclear boundaries. Our contributions are threefold. First, a reproducible approach integrating refined, documented prompts with an evaluation framework to operationalize Braun and Clarke's reflexive TA. Second, an empirical comparison of LLM- and human-generated codes and themes in software engineering data. Third, guidelines for integrating LLMs into qualitative analysis while preserving methodological rigour, clarifying when and how LLMs can assist effectively and when human interpretation remains essential.

en cs.SE
arXiv Open Access 2025
Teaching Simulation as a Research Method in Empirical Software Engineering

Breno Bernard Nicolau de França, Dietmar Pfahl, Valdemar Vicente Graciano Neto et al.

The chapter supports educators and postgraduate students in understanding the role of simulation in software engineering research based on the authors' experience. This way, it includes a background positioning simulation-based studies in software engineering research, the proposition of learning objectives for teaching simulation as a research method, and presents our experience when teaching simulation concepts and practice. For educators, it further provides learning objectives when teaching simulation, considering the current state of the art in software engineering research and the necessary guidance and recommended learning activities to achieve these objectives. For students, it drives the learning path for those interested in learning this method but had no opportunity to engage in an entire course on simulation in the context of empirical research.

en cs.SE
arXiv Open Access 2025
Differences between Neurodivergent and Neurotypical Software Engineers: Analyzing the 2022 Stack Overflow Survey

Pragya Verma, Marcos Vinicius Cruz, Grischa Liebel

Neurodiversity describes variation in brain function among people, including common conditions such as Autism spectrum disorder (ASD), Attention deficit hyperactivity disorder (ADHD), and dyslexia. While Software Engineering (SE) literature has started to explore the experiences of neurodivergent software engineers, there is a lack of research that compares their challenges to those of neurotypical software engineers. To address this gap, we analyze existing data from the 2022 Stack Overflow Developer survey that collected data on neurodiversity. We quantitatively compare the answers of professional engineers with ASD (n=374), ADHD (n=1305), and dyslexia (n=363) with neurotypical engineers. Our findings indicate that neurodivergent engineers face more difficulties than neurotypical engineers. Specifically, engineers with ADHD report that they face more interruptions caused by waiting for answers, and that they less frequently interact with individuals outside their team. This study provides a baseline for future research comparing neurodivergent engineers with neurotypical ones. Several factors in the Stack Overflow survey and in our analysis are likely to lead to conservative estimates of the actual effects between neurodivergent and neurotypical engineers, e.g., the effects of the COVID-19 pandemic and our focus on employed professionals.

en cs.SE
DOAJ Open Access 2024
Performance Optimization and Analyses on Recuperative Heat Pump System Using CO2/R1233zd €

Zou Dexin, Zhao Zhen, Yang Kaiyin et al.

Air-source heat pumps, as a new, energy-saving, and environmentally friendly technology, are widely applied in various heating applications, yet their reliable operational efficiency at low ambient temperatures is a concern. In this study, a simple, low-cost, and reliable heat pump system is constructed using safety and environmentally friendly binary refrigerant CO2/R1233zd(E), and the system performances such as the coefficient of performance (COP), volumetric heating capacity, suction pressure, and exhaust pressure are obtained through optimization analyses at ambient temperatures from -30 to -10 ℃. By comparing the vapor-injection heat pump system and cascade heat pump system, it was deduced that a recuperative heat pump system using a binary refrigerant can maintain high efficiency at low ambient temperatures. At ambient temperatures ranging from -30 to -10 ℃, the COP of the recuperative heat pump system decreases by 9.8% to 20.6%, whereas the volumetric heating capacity increases by 3.5% to 56.1% compared to the R410A vapor-injection heat pump system. Moreover, the compressor pressure ratio and its variation with ambient temperature are lower than other heat pump systems. Owing to the simple structure of the recuperative system and the adoption of the safe and environmentally friendly binary refrigerant CO2/R1233zd(E), the solution proposed in this study has unique advantages in heat pump applications in regions with low ambient temperatures.

Heating and ventilation. Air conditioning, Low temperature engineering. Cryogenic engineering. Refrigeration
DOAJ Open Access 2024
Optimization on Condenser Fin in Air Conditioners with Small Tube Diameter

Li Cheng′en, Li Chaungye, Li Rixin et al.

Small-diameter heat exchangers for air conditioning can reduce cost and refrigerant charge, which is of great significance for realizing energy savings and emission reduction. In this study, the plate fins of a 5 mm single-row air-conditioning condenser are optimized to replace a 7 mm single-row air-conditioning condenser. The optimization variables are tube spacing, fin width, and fin spacing, and the objectives are to maximize heat transfer and minimize air-side pressure drop and cost. The Taguchi method was selected for the experimental design and single-objective optimization, and the grey relational analysis and comprehensive performance index method were used for multi-objective optimization. The final optimum tube spacing, fin width, and fin spacing were 16.0 mm, 16 mm, and 1.4 mm, respectively. The heat transfer was the same as that of the 7 mm tube condenser. The pressure drop was reduced by 35%, and the cost was reduced by 26%, validating the effective replacement of the 7 mm condenser.

Heating and ventilation. Air conditioning, Low temperature engineering. Cryogenic engineering. Refrigeration
arXiv Open Access 2024
Transforming Information Systems Management: A Reference Model for Digital Engineering Integration

John Bonar, John Hastings

Digital engineering practices offer significant yet underutilized potential for improving information assurance and system lifecycle management. This paper examines how capabilities like model-based engineering, digital threads, and integrated product lifecycles can address gaps in prevailing frameworks. A reference model demonstrates applying digital engineering techniques to a reference information system, exhibiting enhanced traceability, risk visibility, accuracy, and integration. The model links strategic needs to requirements and architecture while reusing authoritative elements across views. Analysis of the model shows digital engineering closes gaps in compliance, monitoring, change management, and risk assessment. Findings indicate purposeful digital engineering adoption could transform cybersecurity, operations, service delivery, and system governance through comprehensive digital system representations. This research provides a foundation for maturing application of digital engineering for information systems as organizations modernize infrastructure and pursue digital transformation.

en cs.CR, cs.SE
arXiv Open Access 2024
Teaching Research Design in Software Engineering

Jefferson Seide Molleri, Kai Petersen

In the dynamic field of Software Engineering (SE), where practice is constantly evolving and adapting to new technologies, conducting research is a daunting quest. This poses a challenge for researchers: how to stay relevant and effective in their studies? Empirical Software Engineering (ESE) has emerged as a contending force aiming to critically evaluate and provide knowledge that informs practice in adopting new technologies. Empirical research requires a rigorous process of collecting and analyzing data to obtain evidence-based findings. Challenges to this process are numerous, and many researchers, novice and experienced, found difficulties due to many complexities involved in designing their research. The core of this chapter is to teach foundational skills in research design, essential for educating software engineers and researchers in ESE. It focuses on developing a well-structured research design, which includes defining a clear area of investigation, formulating relevant research questions, and choosing appropriate methodologies. While the primary focus is on research design, this chapter also covers aspects of research scoping and selecting research methods. This approach prepares students to handle the complexities of the ever-changing technological landscape in SE, making it a critical component of their educational curriculum.

en cs.SE
arXiv Open Access 2023
Treat societally impactful scientific insights as open-source software artifacts

Cynthia C. S. Liem, Andrew M. Demetriou

So far, the relationship between open science and software engineering expertise has largely focused on the open release of software engineering research insights and reproducible artifacts, in the form of open-access papers, open data, and open-source tools and libraries. In this position paper, we draw attention to another perspective: scientific insight itself is a complex and collaborative artifact under continuous development and in need of continuous quality assurance, and as such, has many parallels to software artifacts. Considering current calls for more open, collaborative and reproducible science; increasing demands for public accountability on matters of scientific integrity and credibility; methodological challenges coming with transdisciplinary science; political and communication tensions when scientific insight on societally relevant topics is to be translated to policy; and struggles to incentivize and reward academics who truly want to move into these directions beyond traditional publishing habits and cultures, we make the parallels between the emerging open science requirements and concepts already well-known in (open-source) software engineering research more explicit. We argue that the societal impact of software engineering expertise can reach far beyond the software engineering research community, and call upon the community members to pro-actively help driving the necessary systems and cultural changes towards more open and accountable research.

arXiv Open Access 2022
Thermodynamic engine powered by anisotropic fluctuations

Olga Movilla Miangolarra, Amirhossein Taghvaei, Yongxin Chen et al.

The purpose of this work is to present the concept of an autonomous Stirling-like engine powered by anisotropy of thermodynamic fluctuations. Specifically, simultaneous contact of a thermodynamic system with two heat baths along coupled degrees of freedom generates torque and circulatory currents -- an arrangement referred to as a Brownian gyrator. The embodiment that constitutes the engine includes an inertial wheel to sustain rotary motion and average out the generated fluctuating torque, ultimately delivering power to an external load. We detail an electrical model for such an engine that consists of two resistors in different temperatures and three reactive elements in the form of variable capacitors. The resistors generate Johnson-Nyquist current fluctuations that power the engine, while the capacitors generate driving forces via a coupling of their dielectric material with the inertial wheel. A proof-of-concept is established via stability analysis to ensure the existence of a stable periodic orbit generating sustained power output. We conclude by drawing a connection to the dynamics of a damped pendulum with constant torque and to those of a macroscopic Stirling engine. The sought insights aim at nano-engines and biological processes that are similarly powered by anisotropy in temperature and chemical potentials.

en cond-mat.stat-mech, eess.SY
DOAJ Open Access 2021
Study on the Characteristics of Air Side Heat Transfer for Finned Tube Condenser in Low-pressure Environment

Zhang Ruhang, Liu Jianhua, Zhang Liang

In this study, a pressure-adjustable closed environment chamber was built, and the effect of different tube rows and circulating hot water temperatures on the characteristics of air-side convective heat transfer for a finned tube condenser at a low-pressure environment of 40–101 kPa were studied. The results show that under the same Reynolds number, the reduction in ambient pressure leads to a reduction in air-side convective heat transfer. When the air-side Reynolds number is 400, the ambient pressure decreases from 101 kPa to 40 kPa, and the convective heat transfer coefficient decreases by 44.1%. As the ambient pressure decreases, the number of tubes has a weaker effect on the air-side convective heat transfer. In a low-pressure environment, changing the heating temperature of the circulating water does not have a significant impact on the heat transfer coefficient. As the ambient pressure decreases, the air-side convective heat transfer coefficient deviates from the calculation results of the normal atmospheric pressure model. As the ambient pressure decreases from 101 kPa to 40 kPa, the average deviation increases from 17.3% to 77.5%. Based on the experiment results, the air-side heat transfer model of the finned tube is modified at normal pressure according to the influence of the ambient pressure and the tube rows on the air-side convective heat transfer.

Heating and ventilation. Air conditioning, Low temperature engineering. Cryogenic engineering. Refrigeration
arXiv Open Access 2021
Changing Software Engineers' Self-Efficacy with Bootcamps:A Research Proposal

Danilo Monteiro Ribeiro, Alberto Souza, Victor Santiago et al.

In several areas of knowledge, self-efficacy is related to the perfomance of individuals, including in Software Engineering. However,it is not clear how self-efficacy can be modified in training conducted by the industry. Furthermore, we still do not understand how self-efficacy can impact an individual's team and career in the industry. This lack of understanding can negatively impact how companies and individuals perceive the importance of self-efficacy in the field. Therefore, We present a research proposal that aims to understand the relationship between self-efficacy and training in Software Engineering. Moreover, we look to understand the role of self-efficacy at Software Development industry. We propose a longitudinal case study with software engineers at Zup Innovation that participating of our bootcamp training. We expect to collect data to support our assumptions that self-efficacy can be related to training in Software Engineering. The other assumption is that self-efficacy at the beginning of training is higher than the middle, and that self-efficacy at the end of training is higher than the middle. We expect that the study proposed in this article will motivate a discussion about self-efficacy and the importance of training employers in the industry of software development.

en cs.SE
S2 Open Access 2020
Overview of Selected Natural Gas Drying Methods

Natalia Generowicz

Abstract The gas produced from the deposit usually contains various types of pollution. They are the reason for limiting its use, often making its use impossible. Therefore, it requires appropriate treatment. One of the main pollutants in gas is water. Its occurrence causes a lot of problems, especially at the stage of gas transport, such as the formation of hydrates blocking pipelines and apparatus, causes the phenomenon of condensation and corrosion of pipelines, especially if there is carbon dioxide or hydrogen sulphide in the gas. The paper presents a number of methods that enable drying of gas after extraction. Each of them has different parameters that will be achieved for the gas after it is dried. Depending on the required degree of drying, the economics of the process and compatibility with other dependent processes, the individual methods are more or less used in gas engineering. The paper discusses methods of absorption in ethylene glycol solutions, adsorption methods using silica gel, molecular sieves or calcium chloride and low-temperature processes such as Twister® supersonic separator, IFPEX-1® process and DexProTM process.

8 sitasi en Environmental Science
arXiv Open Access 2020
Exploration in Algorithm Engineering: Modeling Algorithms

Sabah Al-Fedaghi

According to some algorithmicists, algorithmics traditionally uses algorithm theory, which stems from mathematics. The growing need for innovative algorithms has caused increasing gaps between theory and practice. Originally, this motivated the development of algorithm engineering, which is viewed as experimental techniques related to software engineering. Currently, algorithm engineering is a methodology for algorithmic research that combines theory with implementation and experimentation in order to produce better algorithms with high practical impact. Still, researchers have questioned whether the notion of algorithms can be defined in a fully generable way and discussed what kinds of entities algorithms actually are. They have also struggled to maintain a view that formulates algorithms mathematically (e.g., Turing machines and finite-state machines [FSMs]) while adapting a more applied view. Answering the question of what algorithms have practical applications in software specifications in particular, this paper proposes a diagrammatical definition of an algorithm based on a new modeling machine called a thinging machine (TM). The machine has five actions (e.g., create, process, release, transfer, and receive) that can form a network of machines. The paper explores the application of the definition in Turing machines and FSMs. The results point to the fact that the proposed definition can serve as a middle-ground representation of algorithms, a definition which is between formal specification and the commonly used informal definition (e.g., set of instructions).

en cs.SE
S2 Open Access 2019
Phonon spectra and vibrational heat capacity of quasi-one-dimensional structures formed by rare gas atoms on the surface of carbon nanotube bundles

E. Manzhelii, S. Feodosyev, I. N. K. I. O. Physics et al.

The features of phonon spectra and their effect on the vibrational heat capacity of linear chains of inert gas atoms adsorbed onto a substrate, which is the surface of nanotubes bound to a nanobundle. The influence of the substrate results both in a shift of the lower limit of the chain spectrum from zero, and in mechanical stress in the chain (its extension or compression) also. It is shown that in the case of a compressed chain, the non-central interaction between atoms is negative (repulsive), it results in a shift of the lower boundary of the spectrum of transverse vibrations to low frequencies and to a shortening of the part of the specific heat temperature dependence in which this dependence is close to exponential. Heterogeneity of the nanobundle structure can cause a change in the distances between atoms of the chain. It is shown both and analytically and numerically, that as a result of it, discrete levels with frequencies both above and below the quasi-continuous spectrum band can appear in the phonon spectrum of the chain. The discrete levels with frequencies below the quasi-continuous spectrum band lead to a further shortening of the temperature interval at which the temperature dependence of the specific heat is close to the exponential one.The features of phonon spectra and their effect on the vibrational heat capacity of linear chains of inert gas atoms adsorbed onto a substrate, which is the surface of nanotubes bound to a nanobundle. The influence of the substrate results both in a shift of the lower limit of the chain spectrum from zero, and in mechanical stress in the chain (its extension or compression) also. It is shown that in the case of a compressed chain, the non-central interaction between atoms is negative (repulsive), it results in a shift of the lower boundary of the spectrum of transverse vibrations to low frequencies and to a shortening of the part of the specific heat temperature dependence in which this dependence is close to exponential. Heterogeneity of the nanobundle structure can cause a change in the distances between atoms of the chain. It is shown both and analytically and numerically, that as a result of it, discrete levels with frequencies both above and below the quasi-continuous spectrum band can appear in the ...

6 sitasi en Materials Science, Physics
S2 Open Access 2019
Evaluation of Lychee Fruits and Effect of Osmotic Treatments on Flesh Quality

E. El-Hadidy

The lychee (Litchi chinensis Sonn.) fruits (a species of the Sapindaceae family) is of Chinese origin and is perfectly adapted to Egyptian climatic conditions. This study included the evaluation of fresh lychee flesh, seeds and pericarps, also fresh lychee flesh treated with sugar solution (sucrose 20 °Brix) in refrigerator (4±1°C) during storage for 12 months, also fresh lychee flesh treated with sucrose 40 °Brix (as an osmotic agent) was dehydrated in air oven drier (60°C) and oven drier under vacuum (50°C) at ambient temperature (25±2°C) during storage for 12 months. The obtained results showed that, fresh flesh lychee was higher in weight percentage (73.22%) than lychee seeds and pericarps (17.58 and 9.20%, respectively) of the total weight of fruits. There were also, no significant variance in crude oil content between fresh flesh lychee and flesh lychee in sugar solution (0.68 and 0.63%), respectively. While, lychee seeds were possessing high content of crude oil (3.72%) followed by lychee flesh dried under vacuum and oven dry (3.62 and 3.53%, respectively) after dipping in sugar agent, then crude oil in pericarps were the lowest content of crude oil (2.98%). While, protein and crude fiber contents were higher in pericarps (9.25 and 28.34%) respectively, than seeds (8.73 and 21.42%), also the content of protein and crude fiber were nearly in dried lychee under two treatments of dehydration (6.94, 7.02 and 6.84 and 6.88%), respectively. Furthermore, dried flesh lychee in oven or under vacuum gave high calories (374.45 and 375.22 kcal./100g), respectively, followed by lychee seeds then pericarps (317.78 and 287.26 kcal./100g). Results, also indicated that, lychee seeds were having the highest contents of  6 and  9 (2226.65 and 1144.56 mg/100g, on dry weight basis), respectively. While, fresh lychee flesh treated with osmotic solution was decrease in  9, 6 and 3 contents (79.25, 95.87 and 29.61 mg/100g, on fresh weight basis, respectively) compared to fresh lychee flesh without any treatment (98.94, 117.16 and 39.92 mg/100g, on fresh weight basis), respectively. Also, lychee flesh dried under vacuum was higher contents in  6 and  3 (924.84 and 393.48 mg/100g, on dry weight basis, respectively) than dried by oven dryer, while the same treatment had highest content in  3 than other treatment and other parts of lychee fruit (seeds and pericarps). The results also indicated that, lychee seeds had highest content of total polyphenols, total flavonoids, total carotenoids, L-ascorbic acid and anthocyanins followed by lychee pericarps then fresh lychee flesh except vitamin C, fresh lychee flesh had higher contents then pericarps. These results reflected to antioxidant activity, whereas, seeds had higher antioxidant activity (87.00%) than fresh lychee flesh and pericarps (81.00 and 78.00%), respectively. The results showed that, the total soluble solids, pH and acidity were ranged from 16.50, 4.42 and 0.38 to 15.95, 4.36 and 0.45, respectively in fresh osmotic lychee flesh during refrigeration storage. The contents of total polyphenols, total flavonoids and total carotenoids had not significant changes during storage for 12 months. While, vitamin C content was decrease 1.46% in after storage 12 months, but this decrement is not statistical significance. The results total polyphenols, total flavonoids, total carotenoids and anthocyanins contents in oven dried (60°C) on osmotic lychee flesh during storage for 12 months at room temperature (25±2°C) had no significantly decrease changes till 8 months. Also, vitamin C contents in osmotic lychee flesh affected by oven dry treatment till 6 months, in addition, vitamin C contents was decreased significant till the end of experiment (7.10%). While, total polyphenols, carotenoids, anthocyanins contents had no significant decrease till 10 months in dried osmotic lychee flesh at 50°C under vacuum (Osmovac) treatment. But, it’s observed the content of vitamin C was gradually significant decreased (from 360.38 to 350.00 mg/100g on dry weight), the percentage of decrement was 2.88% at the end of storage in osmovac treatment. Advances in Food Science and Engineering, Vol. 3, No. 3, September 2019 https://dx.doi.org/10.22606/afse.2019.33002 37 Copyright © 2019 Isaac Scientific Publishing AFSE The results confirmed that, the fresh lychee flesh treated with osmatic agent and dried lychee flesh at 50°C under vacuum (Osmovac) were the most suitable treatments for storing and keeping the antioxidant contents, especially vitamin C. Also, osmovac treatments can retain their high quality of lychee flesh for 1 year at room temperature compared to osmotic oven dried at 60°C flesh lychee fruits (8 months). While, seeds and pericarps were rich in bioactive components as omega fatty acids, anthocyanins and others, may use in food and pharmaceutical products for their value for sustainable development in future studies.

1 sitasi en Biology

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