Fundamental Design Research Articles

Design Principle and Regulation Strategy of Noble Metal‐Based Materials for Practical Proton Exchange Membrane Water Electrolyzer

AbstractGreen hydrogen holds immense promise in combating climate change and building a sustainable future. Owing to its high power‐to‐gas conversion efficiency, compact structure, and fast response, the proton exchange membrane water electrolyzer (PEMWE) stands out as the most viable option for the widespread production of green hydrogen. However, the harsh operating conditions of PEMWE make it heavily dependent on noble metal‐based catalysts (NMCs) and incur high operational and maintenance costs, which hinder its extensive adoption. Hence, it is imperative to improve the performance and lifespan of NMCs and develop advanced components to reduce the overall costs of integrating PEMWE technology into practical applications. In light of this, the fundamental design principles of NMCs employed in acidic water electrolysis are summarized, as well as recent advancements in compositional and structural engineering to enhance intrinsic activity and active site density. Moreover, recent innovations in stack components of practical PEMWE and their impact on cost‐benefit and lifespan are presented. Finally, the current challenges are examined, and potential solutions for optimizing NMCs and PEMWE in electrocatalytic hydrogen production are discussed.

Near-Infrared Bioimaging Using Two-photon Fluorescent Probes.

Near-infrared (NIR) bioimaging has emerged as a transformative technology in biomedical research. Among many fluorescent probes that are suitable for NIR imaging studies, two-photon absorption (TPA) ones represent a particularly promising category, because TPA fluorescent probes can overcome the inherent limitations of one-photon absorption (OPA) counterparts. By leveraging the unique properties of two-photon absorption, TPA fluorescent probes achieve superior tissue penetration, significantly reduced photodamage, and enhanced spatial resolution. This perspective article delves into the fundamental principles, design strategies, and representative TPA probes for various imaging applications. In particular, a number of molecular fluorescent probes, ranging from organic, inorganic, and COF/MOF-based systems are highlighted to showcase the vast scope of possible TPA probe design and application scenarios. In addition, the employment of stimulated TPA probes that are responsive to different external factors, including pH, redox species, enzymes, and hypoxia, is also discussed. In the end, the future perspectives for the continuous advancement of TPA fluorescent probes in the NIR bioimaging field are presented. For instance, it is essential to transition from cellular to in vivo imaging studies to obtain more physiologically relevant insights. Additionally, the development of "dual-function" TPA probes for both disease diagnosis and therapeutic treatment is particularly promising.

Incorporation of Fe/FeOx Nanoparticles into Interlinked N-Doped Porous Carbon Nanofiber Networks to Realizing Sequential Catalytic Conversion of Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries (LSBs) with energy density (2600 Wh/kg) much higher than typical Li-ion batteries (150-300 Wh/kg) have received considerable attention. However, the insulation nature of solid sulfur species and the high activation barrier of lithium polysulfides (LiPSs) lead to slow sulfur redox kinetics. By the introduction of catalytic materials, the effective adsorption of LiPSs, and significantly reduced conversion, energy barriers are expected to be achieved, thereby sharpening electrochemical reaction kinetics and fundamentally addressing these challenges. In this work, a multifunctional catalyst consisting of highly dispersed heterostructure Fe-Fe2O3 nanoparticles was synthesized and introduced to the LSB. Experimental and theoretical analyses revealed that the spontaneous interfacial charge redistribution, resulting in moderate polysulfide adsorption, facilitates the transfer of polysulfides and diffusion of electrons at heterogeneous interfaces. This catalyst achieves sequential catalytic processes on polysulfides with different components. Furthermore, the reduced conversion energy barriers enhanced the catalytic activity of Fe/Fe2O3-NG for expediting LiPS conversion. Consequently, the battery exhibited long-term stability for 300 cycles with 0.03% capacity decay per cycle at 5C. This work provides in-depth insight into the fundamental design principles of effective catalysts for LSBs.

An Integrated Approach to Green and Bioclimatic Design in High-Rise Mixed-Use Buildings: A Case Study of Green Skyscrapers

Urbanization has led to challenges such as resource strain and environmental degradation, prompting the need for innovative solutions. High-rise mixed-use developments offer a way to maximize land use efficiency, but traditional designs often neglect green spaces, leading to energy inefficiency and a lack of connection with nature. This paper discusses the role of plants, integration of plants and bioclimatic design principles in addressing urban challenges. This study explores the integration of plants and bioclimatic design principles in high-rise mixed-use developments. This paper also explains the fundamental principles and design considerations for high-rise buildings, focusing on structural systems, earthquake resistance, and wind load effects. In conclusion, integrating plants and bioclimatic design principles in high-rise mixed-use developments is important for creating sustainable and livable urban environments. By prioritizing green spaces and sustainable design practices, developers can contribute to a greener skyline and a more sustainable future.

Dark patterns: Can criminal law remedy the shortcomings of antitrust law?

Antitrust laws' remedies to address Big Tech's anticompetitive business models have often been questionable. Since the fundamental design choices of business models pose significant challenges, due to dark patterns, Austrian criminal law may compensate for antitrust laws' enforcement limits. It is argued that Amazon's Prime and BuyBox, Google's Search and its AI Bard, Activision Blizzard's lootboxes, and Engagement Optimised Matchmaking (EOMM) algorithms contain dark patterns that may constitute (commercial) fraud within the meaning of §§ 146, 148 StGB. This is because these business models are designed to deceive consumers to unlawfully enrich Big Tech and video game publishers.

Developing Practical Catalysts for High‐Current‐Density Water Electrolysis

AbstractHigh‐current‐density water electrolysis is considered a promising technology for industrial‐scale green hydrogen production, which is of significant value to energy decarbonization and numerous sustainable industrial applications. To date, substantial research advancements are achieved in catalyst design for laboratory‐based water electrolysis. While the designed catalysts demonstrate remarkable performance at laboratory‐based low current densities, they suffer from marked deteriorations in both activity and long‐term stability under industrial‐level high‐current‐density operations. To provide a timely assessment that helps bridge the gap between laboratory‐scale fundamental research and industrial‐scale practical water electrolysis technology, here the current advancements in various commercial water electrolyzers are first systematically analyzed, then the key parameters including work temperature, current density, lifetime of stacks, cell efficiency, and capital cost of stacks are critically evaluated. In addition, the impact of high current density on the electrocatalytic behavior of catalysts, including intrinsic activity, long‐term stability, and mass transfer, is discussed to advance the catalyst design. Therefore, by covering a range of critical issues from fundamental material design principles to industrial‐scale performance parameters, here the future research directions in the development of highly efficient and low‐cost catalysts are presented and a procedure for screening laboratory‐designed catalysts for industrial‐scale water electrolysis is outlined.

Design for Circular Manufacturing and Assembly (DfCMA): Synergising Circularity and Modularity in the Building Construction Industry

Modular construction is emerging into the limelight in the construction industry as one of the front-running modern methods of construction, facilitating multiple benefits, including improved productivity. Meanwhile, Circular Economy (CE) principles are also becoming prominent in the Building Construction Industry (BCI), which is infamous for its prodigious resource consumption and waste generation. In essence, the basic concepts of modular construction and CE share some commonalities in their fundamental design principles, such as standardisation, simplification, prefabrication, and mobility. Hence, exploring ways of synergising circularity and modularity in the design stage with a Whole Life Cycle (WLC) of value creation and retention is beneficial. By conducting a thorough literature review, supported by expert interviews and brainstorming sessions, followed by a case study, the concept of Design for Circular Manufacturing and Assembly (DfCMA) was proposed to deliver circularity and modularity synergistically in circularity-oriented modular construction. This novel conceptualisation of DfCMA is envisaged to be a value-adding original theoretical contribution of this paper. Furthermore, the findings are expected to add value to the BCI by proposing a way forward to synergise circularity and modularity to contribute substantially towards an efficient circular built environment.

Breathable and Stretchable Epidermal Electronics for Health Management: Recent Advances and Challenges.

Advanced epidermal electronic devices, capable of real-time monitoring of physical, physiological, and biochemical signals and administering appropriate therapeutics, are revolutionizing personalized healthcare technology. However, conventional portable electronic devices are predominantly constructed from impermeable and rigid materials, which thus leads to the mechanical and biochemical disparities between the devices and human tissues, resulting in skin irritation, tissue damage, compromised signal-to-noise ratio (SNR), and limited operational lifespans. To address these limitations, a new generation of wearable on-skin electronics built on stretchable and porous substrates has emerged. These substrates offer significant advantages including breathability, conformability, biocompatibility, and mechanical robustness, thus providing solutions for the aforementioned challenges. However, given their diverse nature and varying application scenarios, the careful selection and engineering of suitable substrates is paramount when developing high-performance on-skin electronics tailored to specific applications. This comprehensive review begins with an overview of various stretchable porous substrates, specifically focusing on their fundamental design principles, fabrication processes, and practical applications. Subsequently, a concise comparison of various methods is offered to fabricate epidermal electronics by applying these porous substrates. Following these, the latest advancements and applications of these electronics are highlighted. Finally, the current challenges are summarized and potential future directions in this dynamic field are explored.

How unemployment benefit duration shapes startup motivation and growth

AbstractBusiness creation is economically important, and unemployment precedes the creation of a substantial share of new firms. Yet, most research has focused on analyzing the effects of unemployment insurance policies on re-employment outcomes, ignoring self-employment. In this paper, we analyze how the potential duration of unemployment benefits, a fundamental design choice of unemployment insurance systems, affects whether new firms are founded out of opportunity or necessity and their growth potential. To this end, we construct a comprehensive dataset on German firm founders that links administrative social insurance information with business survey data. Exploiting reform and age-related exogenous variation in the potential duration of unemployment benefits, we find that longer potential benefit duration implies longer actual unemployment and, as a consequence, more necessity entrepreneurship and worse startup outcomes in terms of sales and employment growth. We explain this overall effect of potential benefit duration through a mix of compositional and individual-level duration effects. Our findings underline that new firms started out of unemployment are a highly heterogeneous group and suggest that the (optimal) design of unemployment insurance systems has important externalities on whether innovation- and growth-oriented firms are started out of unemployment.

Reduction of N2 to NH3 using FeP(101)/TiO2 catalysts: A First-principles study

The electrochemical nitrogen reduction reaction offers an eco-friendly and sustainable way for synthesizing ammonia at room temperature, in contrast to the energy-intensive Haber-Bosch process. In this study, we demonstrate that FeP (101) is stabilized by anatase TiO2(101), resulting in the formation of a FeP/TiO2 composite. This composite shows promising potential as a catalyst for N2 electroreduction. All hydrogenation reactions are feasible and occur spontaneously, with the ∗N2-∗N2H step serving as the potential determining step (PDS) with a value of 0.59 V. In comparison to the Ru (0001) surface (1.08 V), which exhibits superior catalytic activity in nitrogen reduction reactions (NRR), the obtained value is significantly lower. FeP/TiO2 exhibits ∼100% selectivity towards ammonia synthesis as compared to the competitive hydrogen evolution process (HER). This study demonstrates that the correlation between N2 activation and the electronic structure will aid in the fundamental comprehension, design, and alteration of NRR catalysts.

Design and Implementation of a Desorption Electro-flow Focusing Sprayer on an Orbitrap Mass Spectrometer for DESI Mass Spectrometry Imaging at High Spatial Resolution and at High Speed.

Since desorption electrospray ionization mass spectrometry (DESI-MS) was first presented in 2004, the fundamental design of the sprayer has undergone relatively minor modifications. This changed in 2022 when Takats and co-workers implemented the desorption electro-flow focusing (DEFFI) sprayer design by modifying the sprayer from a commercial DESI system, leading to significantly improved spatial resolution and robustness compared with the traditional DESI-MSI sprayer design. Here, we present the design of a new DEFFI sprayer that can be built from standard fittings and connectors in combination with an aluminum spray head that can be machined in most mechanic workshops. The new design represents a cost-efficient approach to improved DESI-MSI on mass spectrometers from all vendors, including high-resolution instruments such as Orbitraps and FT-ICR. The new DEFFI sprayer is demonstrated on a QExactive Orbitrap mass spectrometer, resulting in a massively improved ion yield compared with the classic DESI sprayer. The improved ion yield enables DESI-MSI at ion injection times down to 5 ms, allowing for DESI-MSI at a potentially very high speed. More importantly, the DEFFI sprayer delivers a more robust and focused spray, which is easier to use and requires less optimization. It provides high spatial resolution with limited effort compared with previous modifications of the traditional DESI design. Imaging of rat testis was performed at pixel sizes down to 12 μm, suggesting a spatial resolution of approximately 30 μm, which may have potential for further improvement.

A radar array expansion design method based on modular subarray layout

Abstract This paper introduces a design method for expandable subarray structures used in phased array radar arrays. Based on the structural characteristics of modular subarray layout for large radar arrays, this paper analyzes the assembly dimension chain tolerance based on subarray expansion. One third of the allowable deviation of the radar array is used as the subarray design tolerance, and the size tolerance of each installation surface of the subarray is designed according to the design tolerance. Finally, the subarray array is assembled into any size of radar array, and the probability of the radar array assembly accuracy meeting the allowable deviation is 99.73%. For large radar arrays, adopting this design method can significantly reduce the tolerance span between the sub array and the area array, greatly reducing the difficulty of design and processing. This paper provides a fundamental design method for the expansion design of radar arrays with similar systems, which has universal applicability.

The RAS Paradigm in Mainframe Systems: A Comprehensive Analysis of Design Principles and Operational Benefits

This article examines the critical role of Reliability, Availability, and Serviceability (RAS) in mainframe computing systems. We explore how RAS principles have become fundamental design features in modern mainframes, enhancing their ability to meet the demanding requirements of enterprise-level data processing. The article provides an in-depth analysis of each RAS component, detailing how reliability is achieved through robust hardware self-checking and extensive software testing, availability is maintained via seamless component failover and layered error recovery, and serviceability is ensured through advanced diagnostic capabilities and modular replacement units. We argue that the holistic integration of RAS principles in mainframe architecture not only maximizes system uptime and operational continuity but also significantly impacts application design and overall system efficiency. Through a comprehensive review of current mainframe technologies and industry practices, this article highlights the enduring importance of RAS in an era of increasing computational complexity and datadriven decision making. Our findings suggest that RAS principles will continue to evolve, playing a crucial role in shaping the future of high-performance, mission-critical computing systems.

Microwave biosensors utilizing metamaterial enhancement: Design and application

Microwave sensing technology has become increasingly widely applied in the biomedical field, playing a significant role in medical diagnosis, biological monitoring, and environmental warning. In recent years, the introduction of metamaterials has brought new possibilities and opportunities to microwave biosensors. This paper aims to explore the applications of microwave sensors in biosensing, with a particular emphasis on analyzing the crucial role of metamaterials in enhancing sensor performance and sensitivity. It provides a thorough examination of the fundamental principles, design strategies, fabrication techniques, and applications of microwave biosensors leveraging metamaterial enhancement. Moreover, it meticulously explores the latest applications spanning biomedical diagnostics, environmental monitoring, and food safety, shedding light on their transformative potential in healthcare, environmental sustainability, and food quality assurance. By delving into future research directions and confronting present challenges such as standardization and validation protocols, cost-effectiveness and scalability considerations and exploration of emerging applications, the paper provides a roadmap for advancing microwave biosensors with metamaterial enhancement, promising breakthroughs in multifaceted bioanalytical realms.

Rational Construction of Cyanide-Functionalized D-A-π-D Covalent Organic Framework for Highly Efficient Overall H2O2 Photosynthesis from Air and Water.

Sacrificial-agent-free overall photosynthesis of H2O2 from water and air represents currently a promising route to reform the industrial anthraquinone production manner, but, still blocks by the requirement of pure O2 feedstock, due to the insufficient oxygen supply from water under air. Herein, we report a rational molecule design on COFs (covalent organic frameworks) equiped with cyanide-functionalized D-A-π-D system for highly efficient overall H2O2 production from air and water through photocatalytic oxygen reduction reactions (ORR) and water oxidation reaction (WOR). Without using any sacrificial agent, the as-synthesized D-A-π-D COF is found to enable a H2O2 production rate as high as 4742 μmol h-1 g-1 from water and air and an O2 utilization and conversion rate up to 88 %, exceeding the other D-A-π-A COF by respectively 1.9- and 1.3-fold. Such high performance is attributed to the tuned electronic structure and prolonged charge lifetime facilitated by the unique D-A-π-D structure and cyanide groups. This work highlights a fundamental molecule design on advanced photocatalytic COFs with complicated D-A system for low-cost and massive H2O2 production.

Rational Construction of Cyanide‐Functionalized D‐A‐π‐D Covalent Organic Framework for Highly Efficient Overall H2O2 Photosynthesis from Air and Water

Sacrificial‐agent‐free overall photosynthesis of H2O2 from water and air represents currently a promising route to reform the industrial anthraquinone production manner, but, still blocks by the requirement of pure O2 feedstock, due to the insufficient oxygen supply from water under air. Herein, we report a rational molecule design on COFs (covalent organic frameworks) equiped with cyanide‐functionalized D‐A‐π‐D system for highly efficient overall H2O2 production from air and water through photocatalytic oxygen reduction reactions (ORR) and water oxidation reaction (WOR). Without using any sacrificial agent, the as‐synthesized D‐A‐π‐D COF is found to enable a H2O2 production rate as high as 4742 μmol h‐1 g‐1 from water and air and an O2 utilization and conversion rate up to 88%, exceeding the other D‐A‐π‐A COF by respectively 1.9‐ and 1.3‐fold. Such high performance is attributed to the tuned electronic structure and prolonged charge lifetime facilitated by the unique D‐A‐π‐D structure and cyanide groups. This work highlights a fundamental molecule design on advanced photocatalytic COFs with complicated D‐A system for low‐cost and massive H2O2 production.

Suppressed concentration quenching and tunable photoluminescence in Eu2+-activated Rb3Y(PO4)2 phosphors for full-spectrum lighting

Highly efficient inorganic phosphors are desirable for lighting-emitting diode light sources, and increasing the doping concentration of activators is a common approach for enhancing the photoluminescence quantum yield (PLQY). However, the constraint of concentration quenching poses a great challenge for improving the PLQY. Herein, we propose a fundamental design principle by separating activators and prolonging their distance in Eu2+-activated Rb3Y(PO4)2 phosphors to inhibit concentration quenching, in which different quenching rates are controlled by the Eu distribution at various crystallographic sites. The blue-violet-emitting Rb3Y(PO4)2:xEu (x = 0.1%–15%) phosphors, with the occupation of Rb1, Rb2 and Y sites by Eu2+, exhibit rapid luminescence quenching with optimum external PLQY of 10% due to multi-channel energy migration. Interestingly, as the Eu concentration increases above 20%, Eu2+ prefer to occupy the Rb1 and Y sites with separated polyhedra and large interionic distances, resulting in green emission with suppressed concentration quenching, achieving an improved external PLQY of 41%. Our study provides a unique design perspective for elevating the efficiency of Eu2+-activated phosphors toward high-performance inorganic luminescent materials for full-spectrum lighting.

Impact of geometric variables on the functionality of downdraft biomass gasifiers across diverse dimensions

This study offers an extensive examination of the fundamental design parameters that influence the performance of biomass downdraft gasifiers. The impact of design parameters such as reactor dimensions, throat diameter, length of converging and diverging section and ratio of maximum to minimum diameter (dmax/dmin) were analysed using FORTRAN code, which was initially developed for 4 kW Imbert gasifier. Simulation results highlight that the optimal range of hearth loads for gasifier operation is influenced by both the gasifier’s size and the particle size of the feedstock. Increasing gasifier size from 20 mm to 100 mm throat diameter, while maintaining the same superficial air velocity (SAV), escalates hearth load and superficial velocity due to heightened biomass consumption, leading to higher hearth temperature and improved gas calorific value. Similar trends are observed across varying SAV values (0.35 m/s to 1.8 m/s), suggesting a need for lower SAV values in larger gasifiers, possibly with larger particle sizes. Additionally, altering the length of the converging and diverging sections impacts gas quality, with deviations from recommended values affecting ignition and overall performance, while dmax/dmin variations show no significant impact.

On the Fundamental Tracking Performance and Design Considerations of Radio Navigation

On the Fundamental Tracking Performance and Design Considerations of Radio Navigation

Designing activities and tools to support university students' creative and collaborative exploration of physical computing

Today’s digital world requires students to gain skills in collaborative problem solving and digital literacy. One approach is to teach people how to design computational artefacts that require both electronics and programming. Physical computing platforms offer an endless amount of possible opportunities for people to design and develop technological artefacts. However, many times students are overwhelmed when trying to learn both software and hardware simultaneously. The students struggle to be innovative and creative in their projects. Also, they focus on mastering the tool and following instructions for existing projects rather than being able to creatively explore the tool and understand the process of designing and developing new artefacts. For that reason, we aimed to answer the question: What type of tools and activities can be developed to support university students creative exploration of physical computing? Programming and electronics are fundamental design disciplines in today's digital world, and therefore they should be taught through design activities rather than limiting education to textbook readings and laboratory exercises. We introduce our process of designing activities combined with a supportive tool to ease these challenges. The activities and tools were developed iteratively in three phases with a series of workshops with 126 students and teachers. The tool consists of a set of paper cards that provide necessary details (hints) about the electronics and software and help provide structure for the students to conceptualise how their artefact interacts. We additionally, introduced a learning Jigsaw pattern (orchestration script) for the later intervention that enabled individual students in the groups to focus on design, hardware, or software. For evaluation, we used the Creativity Support Index (CSI), which is a psychometric survey designed to assess the support of the creative process. The instrument investigates collaboration, efforts worth the result, exploration, immersion, enjoyment, and expressiveness. The results between the phases showed improvement with the use of the refined versions of the cards and orchestration of the learning activity. This study has demonstrated that design activities can provide a more accessible approach for the introduction of physical computing to students from various majors. Moreover, learning physical computing through design activities allows the learner to develop computational and design thinking skills for collaboratively solving problems.