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Hierarchical engineering of modular tissues
No full textTissue engineering, aimed at engineering organs, is a compelling and growing field of science with yearly improvements and progress. New technological advancements in material science, stem cell engineering, and fabrication techniques push the field forward with a shared determination to improve human health and well-being. However, the real challenge is the complex architecture of native tissues and its reciprocation in engineered tissues, which hinders the engineering of fully functional tissues. Despite conventional tissue engineering approaches utilizing the combination of modern biomaterials and advanced properties of stem cells, they are still less successful in reciprocating the full functionality of engineered tissues. Hence, this thesis aims to engineer tissues with near-architectural resemblance to native tissues, with hierarchical emergent properties from the single-cell to tissue level. A single-cell pericellular environment is developed using droplet microfluidics, and the mechanics from the matrix are transmitted to the cell by anchoring the matrix directly onto the cell membrane. The established mechanotransduction route determines stem cell fate via intracellular biophysical programming of the cytoplasm and nucleus. The pericellular environment matches the native tissue’s pericellular matrix properties, enabling a functional, living micro building block. These micro building blocks are then used to create an engineered modular tissue by embedding them in a strong and tough interterritorial matrix, compensating for the tissue-level mechanical properties. The interterritorial matrix, is achieved using the properties of immiscible biomaterials in aqueous states (phase separation), forms various architectures that dictate the overall mechanics of the interterritorial matrix. The engineered modular tissue matches native tissue architecture by being soft at the cellular level and strong and tough at the tissue level. This emergent property, achieved via modular design, includes selective diffusion properties between the pericellular and interterritorial matrices. Thus, this modular design favors the concentration of cell-produced factors in the pericellular environment that the cells can use for cellular function. Moreover, it also inhibits the entry of catabolic paracrine factors from the external environment that could induce inflammatory stimulation in the cells. Collectively, this thesis engineered a modular tissue with emergent properties that compensate for the presence of cell- and tissue-level hierarchy present in native tissues
Fostering university students’ entrepreneurial opportunity identification capability:A systematic literature review
Full text linkFostering university students’ Opportunity Identification (OI) capability has received much attention from entrepreneurship scholars. There is, however, a lack of comprehensive understanding of “why” some students can better identify business opportunities and “how” their OI capability can be improved. This systematic review aims to synthesize the research findings on university students’ OI capability to answer the above questions and propose evidence-informed guidance for entrepreneurship educators when developing programs designed to enhance this key entrepreneurial capability. In this regard, 44 empirical studies (out of 945 peer-reviewed articles) on OI, dating from 2000 through 2022, were reviewed. The findings were categorized by answering five essential questions raised by the adopted teaching model framework, i.e., “why?”, “for whom?”, “for which results?”, “what?”, and “how?”. The findings indicate that students’ prior knowledge, entrepreneurial alertness, and creativity are the most influential factors in the OI process. The research found that developing students’ opportunity identification capability requires guiding them through three distinct stages, namely, triggering, idea generation, and idea evaluation, within a constructively aligned learning environment. The paper concludes by presenting several suggestions and directions for future research.<br/
The SPACE4ALL Project: Accounting for the hazard exposure of the urban poor:Combining remote sensing and citizen science
No full textSlums and informal settlements are among the most common forms of urban development in Africa. These areas often lack essential infrastructure and services, face socioeconomic disparities, and are increasingly vulnerable to climate risks such as floods. The Space4All project aims to promote sustainable urban development by integrating advanced geospatial technologies with locally grounded approaches to analyze the intersection of livability and flood exposure in pilot cities in Ghana, Kenya, and Mozambique. To develop a scalable approach, we use open data such as Sentinel-2 satellite imagery. The methodology combines state-of-the-art AI models, Earth Observation data with Citizen-generated data collected via a custom app. The results highlight deprivation hotspots, revealing the intersection of spatial inequalities and flood exposure. Flood exposure is assessed through a comprehensive approach that integrates local knowledge gathered from workshops in informal settlements with flood models and historical rainfall data. This research provides actionable insights for urban planners, policymakers, and NGOs to prioritize targeted interventions and investments, fostering resilience through community-driven approaches
Mapping causes and consequences of decision-making challenges with systems engineering experts
No full textIn high-tech systems design there is tension between the aim for short time to market and high performance. Systems engineers therefore have to ensure high quality decision-making in the design process. In previous work we showed that systems engineering experts from the industrial partner in our research project saw pre-decision alignment as one of the most important factors for decision quality. Alignment was at the same time also seen as challenging. To work towards better quality decision-making in a systems engineering context, we developed a DRM impact model in this work for a consistent picture, together with our industrial partner. We use this model to identify root causes for alignment challenges and give a possible solution direction. Our model shows how the effort required for alignment for design decisions is increased by the large number of stakeholders and knowledge fragmentation resulting from the size and complexity of an organization. The consequences of this extra required effort is a longer time to market for new products and potentially lower decision quality, which lead to lower value for the customers and lower profitability of the organization. The model shows how a potential support can impact the effort required for alignment and thereby lead to better decision-making. We end with a concept description of a support that will be further developed in our project
Digital Twins for Bridge Assessment and Maintenance
No full textThe increasing number of aging bridges underscores the need for efficient maintenance to enhance safety and reduce costs. This paper explores integrating digital twin technologies into bridge management to improve maintenance efficiency and accuracy. A 15-year-long simulation demonstrates improved inspection accuracy and efficiency, while a case study on a steel bridge illustrates a prototype implementation. This study advances infrastructure management and guides future digital transformation efforts, promoting interoperability and integration with artificial intelligence (AI) and extended reality (XR)
Unearthing Stakeholder Behavior Patterns to Enhance Sustainable Product Design
No full textSustainable product design (SPD) is a critical approach for mitigating environmental impacts and promoting socioeconomic welfare. This paper explores stakeholder behavior patterns throughout the life cycle of sustainable design, emphasizing their role in shaping product sustainability. Combining natural and cognitive resources within design methodologies elevates SPD beyond mere functionality, ensuring environmental stewardship and user satisfaction. Leveraging the TASKS framework illuminates stakeholder behavior complexities, optimizing cognitive resources for sustainable outcomes. Addressing implementation barriers and leveraging facilitators unlock the driving force behind stakeholder engagement, fostering active participation in sustainable design practices. The study envisions a future where informed stakeholder behaviors inherently promote sustainability, emphasizing the pivotal role of stakeholder behavior in achieving sustainable product design excellence. Through comprehensive analysis and strategic interventions, this research seeks to bridge the gap between sustainability objectives and practical implementation in product design, ultimately fostering a more sustainable future
Cascaded Periodically Poled Thin-Film Lithium Niobate for Compact Frequency Conversion
No full textWe present a single-pass, quasi-phase-matched parametric frequency conversion with reconfigurable phase-matching functionality, in a 1-cm linear footprint device in thin-film lithium niobate, featuring an effective interaction length of 1.5 cm.</p
Bloom Filters for Soft Error Detection: Neutron and Fault Injection Validation
No full textAs memory cells continue to shrink in modern semiconductor technologies, radiation-induced Single Event Effects, such as single- and multi-bit upsets, pose growing challenges to system reliability. While effective and efficient for single and double-bit errors, traditional error detection and correction approaches, such as Error Correcting Codes (ECC), incur substantial overhead and complexity when designed to detect and correct multiple-bit errors. This study investigates the use of probabilistic data structures (PDS) as lightweight detectors for multiple-bit soft errors in memories. Leveraging the space-efficient and low-latency properties of Bloom filters, we implement a lightweight error detector (checker) within a representative memory subsystem on a flash-based FPGA. The checker's performance is validated through extensive neutron beam irradiation and fault-injection campaigns, demonstrating effective detection of multiple-bit errors with a tunable false-positive rate
Straw mulching enhances rainfed maize yield under climate change scenarios
No full textMaize cropping systems dominate crop land use in Sub-Saharan Africa (SSA), where rainfed agriculture is highly vulnerable to climate variability, exacerbating hunger and poverty. Effective soil water management practices (SWMPs), such as straw mulching, are known to improve water availability and enhance maize productivity. However, limited research studies have focused on straw mulch thicknesses and depth impact on maize rainfed production systems of SSA. This study evaluates the effects of different straw mulch thicknesses (2 cm, 4 cm, and 6 cm) on maize yield simulated using the AquaCrop model under the low (SSP1–2.6) and the high (SSP3–7.0) emission climate change scenarios from the IPCC's selected CMIP6 climate models. Field experiments with varying straw mulch thicknesses (2 cm, 4 cm, and 6 cm) were used to calibrate the AquaCrop model, which was then applied to simulate maize yields across current (2018 – 2019) and future (2020 – 2099) periods. Results showed that, straw mulch thickness significantly influences maize yields, with 4 cm and 6 cm treatments increasing maize yield by up to 40 %. The 2 cm mulch, under the high emission scenario, led to a 53 % yield increase, with the 4 cm mulch being identified as the optimal thickness for maximizing yield and water use efficiency (WUE). These findings suggest that straw mulch thickness should be adjusted to regional climatic conditions for optimal effectiveness. This study highlights the importance of integrating SWMPs with climate adaptation strategies to sustain maize productivity and improve food security in the context of climate change.</p
Valorization of a Power Quality Sensor for Decentralized Energy Access
No full textThis study examines the valorization potential of a novel power quality sensor designed to address a market gap in decentralized energy access. By aligning the device’s features with the specific needs of energy access context, this study identifies potential users and investigates the value proposition of the device. A case study of the Indonesian market was conducted using surveys and interviews with potential users to understand the current challenges and expectations related to power quality measurement in remote microgrid systems. The findings suggest that the device offers a cost-effective solution with key features for improved power quality monitoring, demonstrating strong potential for successful market adoption. This work proposes a pathway to translate technological innovation into practical application, emphasizing its relevance for decentralized energy systems