Design Principles Research Articles

A Lightweight File System Design for Unikernel

Unikernels are specialized operating system (OS) kernels optimized for a single application or service, offering advantages such as rapid boot times, high performance, minimal memory usage, and enhanced security compared to general-purpose OS kernels. Unikernel applications must remain compatible with the runtime environment of general-purpose kernels, either through binary or source compatibility. As a result, many Unikernel projects have prioritized system call compatibility over performance enhancements. In this paper, we explore the design principles of Unikernel file systems and introduce a new file system tailored for Unikernels named ULFS (Ultra Lightweight File System). ULFS provides system call services akin to those of general-purpose OS kernels but achieves superior performance and security with significantly fewer system resources. Specifically, ULFS is developed as a lightweight file system embracing Unikernel design principles. It streamlines system calls, removes unnecessary locks, and omits permission checks for multiple users, utilizing a non-hypervisor architecture. This approach significantly reduces the memory footprint of the file system and enhances performance. Through measurement studies, we assess the performance and memory requirements of various file systems from major Unikernel projects. Our findings demonstrate that ULFS surpasses several existing Unikernel file systems, including Rumpvfs, Ramfs-u, Ramfs-q, 9pfs, and Hcfs.

Polymeric micelle gel with luliconazole: in vivo efficacy against cutaneous candidiasis in Wistar rats.

The objective of this research was focused on the design and development of luliconazole-loaded polymeric micelle hydrogel (LUL-PM-CHG) using quality by design (QbD) principle to improve the penetration and retention of LUL in the skin. The optimization of the formulation involved the utilization of a Box-Behnken design with three factors and three levels. The impact of specific formulation variables, namely the ratio of poloxamer P123 and F127, sonication time, and the quantity of drug, was investigated in terms of particle size, micellar incorporation efficiency, and polydispersity index. The LUL-loaded P123/F127 mixed micelles involved the thin film hydration method for thin preparation. The characteristics of optimized formulation include a particle size of 226 ± 8.52nm, a polydispersity index (PDI) of 0.153 ± 0.002, a zeta potential (ZP) of 30.15 ± 2.32mV, and a micellar incorporation efficiency (MIE) of 88.38 ± 3.84%. In vitro release studies indicated a sustained release of LUL-PM-CHG for a duration of up to 8h. The MIC, GI50, and GI90 of different formulations on Candida albicans were determined using both the microtiter broth dilution method and the plate method and showed that LUL-PM-CHG exhibited the highest antifungal activity compared to the other formulations, with MIC values of 3.25 ± 0.19ng/mL, GI50 values of 37.11 ± 2.89, and GI90 values of 94.98 ± 3.41 The study also measured the % of inhibition activity and the generation of intracellular reactive oxygen species (ROS) using flow cytometry. LUL-PM-CHG showed the highest percentage of inhibition (75.5%) and ROS production (MFI-140951), indicating its enhanced activity compared to LUL-CHG and LUL. Fungal infection was induced in Wistar rats using immunosuppressant's treatment followed by exposure to C. albicans. Finally, in vivo fungal scaling and histopathological studies indicated a reduction in fungal infection in Wistar rat skin after treatment. The obtained results suggested that LUL-PM can serve as a promising formulation to enhance luliconazole antifungal activity and increase patient compliance.

3D printable strong and tough composite organo-hydrogels inspired by natural hierarchical composite design principles.

Fabrication of composite hydrogels can effectively enhance the mechanical and functional properties of conventional hydrogels. While ceramic reinforcement is common in many hard biological tissues, ceramic-reinforced hydrogels lack a similar natural prototype for bioinspiration. This raises a key question: How can we still attain bioinspired mechanical mechanisms in composite hydrogels without mimicking a specific composition and structure? Abstracting the hierarchical composite design principles of natural materials, this study proposes a hierarchical fabrication strategy for ceramic-reinforced organo-hydrogels, featuring (1) aligned ceramic platelets through direct-ink-write printing, (2) poly(vinyl alcohol) organo-hydrogel matrix reinforced by solution substitution, and (3) silane-treated platelet-matrix interfaces. Unit filaments are further printed into a selection of bioinspired macro-architectures, leading to high stiffness, strength, and toughness (fracture energy up to 31.1 kJ/m2), achieved through synergistic multi-scale energy dissipation. The materials also exhibit wide operation tolerance and electrical conductivity for flexible electronics in mechanically demanding conditions. Hence, this study demonstrates a model strategy that extends the fundamental design principles of natural materials to fabricate composite hydrogels with synergistic mechanical and functional enhancement.

Beyond Tolerance: Mitigating Human–Wildlife Conflict with Hospitality

Tolerance has become a central position in wildlife conservation thought, and a goal in and of itself. Appeals to tolerance are expected to grow as the planet becomes more crowded, species are lost, and habitat is degraded. The concept has been uncritically adopted in wildlife conservation to mitigate human–wildlife conflicts (HWCs). However, scholars have demonstrated that tolerance is burdened with limitations, paradoxes, and shortcomings. Thus, blind adherence to it is not expected to produce a coexistence design necessary to sustain wildlife populations in the long term. This paper is a conceptual scoping project that engages a summary and critique of tolerance as a design principle within wildlife conservation governance. After introducing a resultant theory of dysfunctional human–wildlife coexistence, a pathway toward hospitality as a social institution is outlined via several commitments societies can make to transition to an era of normalizing a process of sincere welcoming, care, and support. The transition from tolerance to hospitality will entail shifting responsibility to humans to modify their behavior to help keep wildlife invisible where it is essential, learning about what wildlife want and need, and ensuring wildlife are not injured for being themselves.

Use of Elements and Application of Principles of Art and Design in the Creation of Pictorial Compositions among Fine Art Students at Kenyatta University, Nairobi, Kenya

In the creation of any work of art, whether in two or three dimension, the use of elements and principles is fundamental. It has been acknowledged across ages that the purpose of the creation of any work of art is to create some form of defined meaning or express some artistic phenomenon. It has also been acknowledged that elements and principles have a symbiotic relationship. In examining the paintings and drawings presented by students, this study seeks to explore the relationship between elements and principles as they are applied in the paintings and drawings to determine the effectiveness of this synchrony in terms of visual enhancement and the eventual creation of meaning. The study features students' work at various levels where they spontaneously created their paintings and drawings with focus on the use of elements and principles. However, their usage and application were spontaneous and not geared towards specific responses, which was necessary for the outcome of the study. From preliminary enquiry, it emerged that although students had received adequate tutorials about the use of elements and principles in the creation of artwork, they did not apply them from an academic perspective but instinctively. It was therefore envisaged that focusing on the quality of their work would ultimately yield better results about their comprehension of the use of elements and principles as featured in their work. This study, therefore, used the execution and analysis of their practical work as testimony to their comprehension. The selection of 35 presentations, including black and white pencil drawings, provided a wide spectrum and depicted how students used and understood the application of both elements and principles and were deemed adequate for the study. The paintings featured the use of colour as an integral element, and the pencil drawings were strong in depicting textural effects and using value. The presentations featured different subject matter which was important for the creative essence of work

The Role of Environmentally Responsible Interior Design in Healthcare for Enhanced Patient Well-being

While the healthcare industry is struggling with environmental impacts, it is also trying to bring together holistic design practices to create sustainable, patient-centered and ecologically responsible, energy-efficient healthcare areas. With the increase in studies focusing on the positive effects of the ecological design approach on the well-being and recovery processes of patients, the integration of green elements into healthcare structures becomes even more important. Integration of environmentally responsible design (ERD) principles into hospital interior design; It contributes significantly to reducing carbon emissions, resource consumption and environmental waste. At the same time; by optimizing energy-efficient systems, adopting sustainable materials, and creating patient-centered healing spaces by utilizing natural light and natural ventilation, it can be both contributed to the treatment process and reduce carbon footprints. This study proposes a new approach that integrates ERD elements with healthcare interior design. Recognizing that the built environment and human health are interconnected, the research examines innovative design strategies to promote healing through environmentally responsible interior design (ERID). The focus of this approach is on combining ERD strategies such as healing design, patient-centered design, evidence-based design and the use of sustainable materials, daylight, natural ventilation, energy-efficient design, sustainable design, biophilic design. As a result of this integration, by drawing attention to the role that patient-centered green interior designs play in improving the health and well-being of patients and the efforts to minimize the negative effects of hospitals on the environment. Also, it is aimed to encourage the health and construction sectors in this sense and proposed a path towards a green future.

Coiled-Coil Protein Hydrogels Engineered with Minimized Fiber Diameters for Sustained Release of Doxorubicin in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) lacks expressed protein targets, making therapy development challenging. Hydrogels offer a promising new route in this regard by improving the chemotherapeutic efficacy through increased solubility and sustained release. Moreover, subcutaneous hydrogel administration reduces patient burden by requiring less therapy and shorter treatment times. We recently established the design principles for the supramolecular assembly of single-domain coiled-coils into hydrogels. Using a modified computational design algorithm, we designed Q8, a hydrogel with rapid assembly for faster therapeutic hydrogel preparation. Q8 encapsulates and releases doxorubicin (Dox), enabling localized sustained release via subcutaneous injection. Remarkably, a single subcutaneous injection of Dox-laden Q8 (Q8•Dox) significantly suppresses tumors within just 1 week. This work showcases the bottom-up engineering of a fully protein-based drug delivery vehicle for improved TBNC treatment via noninvasive localized therapy.

Exploring the Influence of Dynamic Indicators in Urban Spaces on Residents’ Environmental Behavior: A Case Study in Shanghai Utilizing Mixed-Methods Approach and Artificial Neural Network (ANN) Modeling

The main aim of this article is to evaluate the impact of dynamic indicators associated with urban spaces on the environmental behavior of residents in Shanghai, China. With the city experiencing rapid urbanization and increasing environmental concerns, it is crucial to understand how the design and management of urban spaces can encourage pro-environmental attitudes and actions among the population. The study specifically focuses on dynamic indicators, namely vitality, accessibility, quality, and walkability, to develop a comprehensive understanding of the utilization and experience of urban spaces. The research outcomes will make valuable contributions towards Shanghai’s objectives of achieving environmental sustainability, while also providing insights that have broader relevance to sustainable urban development globally. As the built environment significantly influences energy consumption, resource utilization, pollution generation, and overall human wellbeing, attaining urban sustainability is of paramount importance. The findings of this study will aid in informing strategies and policies that promote sustainable practices, not only benefiting Shanghai but also serving as a valuable resource for urban development initiatives worldwide. Sustainable urban design principles, including compactness, density, mixed land use, greening, and walkability, have been associated with pro-environmental behaviors, including reduced reliance on automobiles, increased walking and cycling, and heightened environmental consciousness. Nevertheless, the relationship between the built environment and sustainability behaviors is intricate and is influenced by multiple factors. Consequently, further research is necessary to comprehend how specific spatial and temporal dynamics impact environmental behaviors within urban settings. In this study, an artificial neural network (ANN) was developed to estimate the quality and walkability of an area and environmental behaviors by considering the augmented vitality and accessibility factors. The ANN’s predictions demonstrate that higher levels of vitality and accessibility positively contribute to improved walkability and environmental behaviors. The accuracy of the ANN’s predictions was assessed using linear regression, which yielded acceptable error rates when compared with experimental results.

Enabling Logistics Automation in Nanofactory: Cobalt Phosphide Embedded Metal-Organic Frameworks for Efficient Electrocatalytic Nitrate Reduction to Ammonia.

Electrocatalytic nitrate reduction reaction (NitRR) in neutral condition offers a promising strategy for green ammonia synthesis and wastewater treatment, the rational design of electrocatalysts is the cornerstone. Inspired by modern factory design where both machines and logistics matter for manufacturing, we report that cobalt phosphide (CoP) nanoparticles embedded in zinc-based zeolite imidazole frameworks (Zn-ZIF) function as a nanofactory with high performance. By selective phosphorization of bimetallic ZnCo-ZIF, the generated CoP nanoparticles act as "machines" (active sites) for molecular manufacturing (NO3 - to NH4 + conversion). The purposely retained framework (Zn-ZIFs) with positive charge promotes logistics automation, i.e., the automatic delivery of NO3 - reactants and timely discharge of NH4 + products in-and-out the nanofactory due to electrostatic interaction. Moreover, the interaction between Zn-ZIF and CoP modulates the Co sites into electron insufficient state with upshifted d-band center, facilitating the reduction/hydrogenation of NO3 - to ammonia and restricting the competitive hydrogen evolution. Consequently, the assembled CoP/Zn-ZIF nanofactory exhibits superior NitRR performances with a high Faraday efficiency of ≈97% and a high ammonia yield of 0.89mmol cm-1 h-1 in neutral condition, among the best of reported electrocatalysts. Our work provides new insights into the design principles of efficient NitRR electrocatalysts. This article is protected by copyright. All rights reserved.

Numeracy Education for Adult Learners: A Scan of the Field and Principles for Course and Materials Design

Additional research is needed to improve adult numeracy instruction, training for instructors, and our understanding of the feasibility and impact of innovations in these areas. The Adult Numeracy in the Digital Era (ANDE) project, funded by the Institute of Education Sciences (IES) at the U.S. Department of Education, seeks to develop and test an innovative, technology-enabled approach for improving adult numeracy and digital literacy instruction. We began this project guided by principles of user-centered design, specifically the principle of knowing the user’s wants and needs. We conducted a “field scan” of adult numeracy and digital literacy, by interviewing researchers, instructors, students; conducting classroom observations; and reviewing literature. We detail our key findings within two emergent themes: (1) extensive variability in learner backgrounds and readiness, instructors’ experiences, standards alignment, course structures, and classroom contexts; and (2) diversity of learner goals and the actions they and their instructors took as they worked together within the course and local policy contexts. We also identify three design principles to guide course development, suggesting that adult numeracy courses should be: aligned and relevant; interactive and participatory; and relationship-centered. These principles guided the design of our adult numeracy course, and we offer questions that current instructors can consider as they design their own adult numeracy lessons.

Design and experiment of an innovative rotational two-level friction damper

In this paper, a novel rotational two-level friction damper (RTFD) was proposed and its cyclic behavior was experimentally validated. The RTFD realizes the two-level working behavior through the gap mechanism between the rotary plates and the inner plates, which is optimized to mitigate the structural vibrations in various magnitudes of excitations. In particular, the RTFD amplifies the bearing force and deformation of the friction materials through the lever mechanism, achieving higher energy consumption efficiency. The working mechanism of the RTFD is discussed and the analytical design principles are presented to quantify the performance of the developed dampers. Moreover, a full-size prototype specimen was designed, manufactured, and tested with a repeated general loading scheme and cyclic loading scheme with a constant amplitude to investigate the seismic performance of the proposed damper. The experimental phenomena indicate the feasibility of the two-level working mechanism of the proposed RTFD and the ignorable wear of the friction subs. The experimental results confirm that the innovation damper is characterized by stable hysteresis behavior and favorable two-level energy dissipation capacity. Moreover, the remarkable recoverability of the developed RTFD is demonstrated by the narrow variation of 10.51% in the bearing force and 7.93% in the accumulative dissipated energy between repeated loadings.

Design principles for integrating science practices with conceptual understanding: an example from a digital learning environment on microbial resistance to antibiotics

We aim to illustrate the use of generic design principles to attain the integrated promotion of conceptual understanding and science competences in online enquiry-oriented learning environments. Engaging students in the development of competences related to science practices in unison with nurturing rigorous understanding of the mechanisms underpinning phenomena is thought to be valuable both for making science education more relevant to students’ interests and for attaining meaningful learning outcomes. We describe the design and development of a learning environment on the socio-scientific issue of microbial resistance to antibiotics. Our effort is situated in reflective enquiry, a framework for teaching and learning in science. The learning environment seeks to promote argumentation skills and conceptual understanding of evolutionary adaptation, in unison. On the basis of theoretical grounds, we have chosen to work with five design principles, integration of epistemic practices, making evidence-based inferences, competence-oriented design, authentic and relevant context and scaffolding. The first part of the study presents the design principles that have been embedded in the learning environment and the second part provides a description of the learning environment linking the various features to the corresponding design principles. Finally, we discuss the implications of this study for research and teaching practice.

Harmony as an Aesthetic Approach for Meditation Centers

In recent years, meditation centres have become increasingly popular among individuals seeking solace, tranquillity, and respite from the pressures of contemporary life. This research paper seeks to explore the significance of harmony as an aesthetic approach in designing and organizing meditation centres, with the aim of enhancing the overall meditative experience for practitioners. By conducting an interdisciplinary examination of architecture, interior design, and psychological well-being, this study aims to investigate the role of harmonious aesthetics in facilitating a more effective and fulfilling meditation experience. The study emphasizes the importance of harmonious aesthetics in shaping the design of meditation centres. The pursuit of visual appeal extends beyond mere aesthetics to encompass a multisensory experience that evokes a sense of calmness and promotes mindfulness. The interplay of colours, textures, and spatial arrangements come together to create a serene atmosphere that guides practitioners on a journey inward. The paper underscores the significance of interior design in fostering harmony in meditation centres. Interior spaces that incorporate calming colour palettes, natural materials, and minimalist aesthetics create an environment that is conducive to meditation. Researchers examine the psychological impact of these design choices on practitioners, exploring how a harmonious interior can facilitate a deeper sense of mindfulness and focus during meditation sessions. Furthermore, the study analyses case studies of existing meditation centres that are renowned for their aesthetic excellence. By identifying commonalities in their design philosophies and best practices, the paper aims to inform architects, designers, and meditation practitioners alike. The goal is to foster a deeper understanding of the role of intentional aesthetics in enhancing the meditative journey and contributing to holistic well-being. In conclusion, this research paper emphasizes the significance of harmony as a key aesthetic principle in meditation centre design. By focusing on harmonious aesthetics, architects, designers, and meditation practitioners can create an environment that promotes inner peace, mindfulness, and overall well-being. The findings of this study contribute to the evolving discourse on meditation centre design and have practical implications for those involved in the design and construction of such spaces. Keywords: harmonious aesthetics, design of meditation centres, multisensory experience, harmony principle

Ether-Based High-Voltage Lithium Metal Batteries: The Road to Commercialization.

Ether-based high-voltage lithium metal batteries (HV-LMBs) are drawing growing interest due to their high compatibility with the Li metal anode. However, the commercialization of ether-based HV-LMBs still faces many challenges, including short cycle life, limited safety, and complex failure mechanisms. In this Review, we discuss recent progress achieved in ether-based electrolytes for HV-LMBs and propose a systematic design principle for the electrolyte based on three important parameters: electrochemical performance, safety, and industrial scalability. Finally, we summarize the challenges for the commercial application of ether-based HV-LMBs and suggest a roadmap for future development.

Design Principles of Voltage Controlled DC-DC Boost Converters through the integration of PID and Model Predictive Control

Abstract This paper presents the design of the transfer function between the control and output variable of a DC-DC boost converter using a combination of Proportional Integral Derivative (PID) and output-based Model Predictive Control (MPC) mechanisms for eradicating the effect of the non-minimum phase (NMP) behavior on the system. This is made possible due to the existence of a right half plane (RHP) zero. It is observed that the MPC outperformed the conventionally designed PID approach by a significant margin. Based on the computed results, it can be emphasized that the combination of output-based MPC and PID controller demonstrated a strong alignment with optimal designs, exhibiting a fast convergence rate than PID and PID-IMC. Simulation results are presented to showcase the fast transient response and a high level of robustness of the proposed control methodology.

Identifying the Active Sites in MoSi2@MoO3 Heterojunctions for Enhanced Hydrogen Evolution.

Developing Two-dimensional (2D) Mo-based heterogeneous nanomaterials is of great significance for energy conversion, especially in alkaline hydrogen evolution reaction (HER), however, it remains a challenge to identify the active sites at the interface due to the structure complexity. Herein, the real active sites are systematically explored during the HER process in varied Mo-based 2D materials by theoretical computational and magnetron sputtering approaches first to filtrate the candidates, then successfully combined the MoSi2 and MoO3 together through Oxygen doping to construct heterojunctions. Benefiting from the synergistic effects between the MoSi2 and MoO3, the obtained MoSi2@MoO3 exhibits an unprecedented overpotential of 72mV at a current density of 10mA cm-2. Density functional theory calculations uncover the different Gibbs free energy of hydrogen adsorption (ΔGH*) values achieved at the interfaces with different sites as adsorption sites. The results can facilitate the optimization of heterojunction electrocatalyst design principles for the Mo-based 2D materials.

From Microservice to Monolith: A Multivocal Literature Review

Recently, the phenomenon of switching back from microservice to monolith has increased in frequency, leading to intense debate in the industry. In this paper, we conduct a multivocal literature review to investigate reasoning and key aspects to pay attention to when switching back and analyze other practitioners’ opinions. The results show four cases of switching back from microservice to monolith: Istio control plane, Amazon Prime Video monitoring service, Segment, and InVision. The five main reasons that led to switching back are cost, complexity, scalability, performance, and organization. During the switching back process, six key aspects need to be addressed: (1) stopping the development of more services, (2) consolidating and testing paths, (3) unifying data storage, (4) implementing the message bus principle, (5) giving up diverse techniques, and (6) learning to use modular design principles. As to the practitioners’ opinions, they had mixed views about the switching back phenomenon. However, most thought that switching back required consideration of the actual system situation and principles. These results pave the way for further research and guide researchers and companies through the process of switching back from microservice to monolith.

System-level time computation and representation in the suprachiasmatic nucleus revealed by large-scale calcium imaging and machine learning.

The suprachiasmatic nucleus (SCN) is the mammalian central circadian pacemaker with heterogeneous neurons acting in concert while each neuron harbors a self-sustained molecular clockwork. Nevertheless, how system-level SCN signals encode time of the day remains enigmatic. Here we show that population-level Ca2+ signals predict hourly time, via a group decision-making mechanism coupled with a spatially modular time feature representation in the SCN. Specifically, we developed a high-speed dual-view two-photon microscope for volumetric Ca2+ imaging of up to 9000 GABAergic neurons in adult SCN slices, and leveraged machine learning methods to capture emergent properties from multiscale Ca2+ signals as a whole. We achieved hourly time prediction by polling random cohorts of SCN neurons, reaching 99.0% accuracy at a cohort size of 900. Further, we revealed that functional neuron subtypes identified by contrastive learning tend to aggregate separately in the SCN space, giving rise to bilaterally symmetrical ripple-like modular patterns. Individual modules represent distinctive time features, such that a module-specifically learned time predictor can also accurately decode hourly time from random polling of the same module. These findings open a new paradigm in deciphering the design principle of the biological clock at the system level.

Study of operation mode and breakdown characteristics for multi-stage gas switch

Abstract Multi-stage gas switches (MSGS) are widely used in megavolt pulsed power systems due to their advantages of high withstand voltage, fast establishing time and relatively high operating frequency. Multiple operation modes, which are induced by the different breakdown sequence of each stage, are found to affect the breakdown characteristics of the gas switch. Based on the theoretical analysis of working principle, the classification of the operation mode and the factors determining the operation mode of the MSGS are proposed. Methods for investigating the output waveform for MSGS are established by simulating lumped parameters and studying the breakdown time sequence of individual stages. In comparison with the intended mode of operation, the disadvantages of the unintended modes of operation for MSGS, including error-breakdown and non-triggering mode, are revealed. For unintended modes, the distortion of the output waveform, which determines the efficiency of energy transmission through the switch, and the increased delay time jitter, which determines the synchronisation of the gas switch, are further investigated. The possibility of non-trigger and its mechanism on surface flashovers induced by drifting electrons are also analysed. Based on this study, design principles and methods are proposed to ensure the intended operation of the multi-stage gas switch.

Designing impact due diligence for startups

This paper explores the challenges impact investors face in assessing the social and environmental impact of startups, as traditional venture investing tools cannot fully capture their unique characteristics. Following a design science approach, we identify three startup-specific design requirements in the literature and propose five design principles. Building on this, we present a conceptual impact due diligence that takes into account the specific criteria for evaluating impact-driven startups. We conduct alpha tests with expert interviews that confirm the overall practical relevance and applicability of the framework. The study makes a theoretical and practical contribution to research in sustainable entrepreneurship and sustainability accounting by identifying solutions to the specific challenges of valuing such startups. Practitioners can use the resulting conceptual artifact to adapt their impact evaluation practices.