MRC Laboratory of Molecular Biology
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Clustering Information Types for Semantic Enrichment of Building Information Models to Support Automated Code Compliance Checking
No full textMissing, incomplete, implicit, and/or incorrect information are major obstacles to automated code compliance checking in the construction industry. All existing platforms for automated code checking require users to extensively preprocess their input models to supplement missing information before checking can begin. Semantic enrichment using artificial intelligence (AI) can automate much of this normalization process. Progress in the field of semantic enrichment, in turn, requires identification and specification of the information types that must be made explicit, and of the procedures appropriate for each type. After characterizing a broad set of clauses from five diverse building codes, a two-stage clustering process with the k-means algorithm was used to derive a hierarchical classification of semantic enrichment task types. The resulting classification defines 10 tasks that are typically needed for automated code compliance checking. Future research can build on the classification to formalize a knowledge base to inform selection of appropriate approaches for semantic enrichment tasks
Reconfigure and Reuse: Interoperable Wearables for Healthcare IoT
No full textIn this work, we propose Over-The-Air (OTA)-based reconfigurable IoT health-monitoring wearables, which tether wirelessly to a low-power and portable central processing and communication hub (CPH). This hub is responsible for the proper packetization and transmission of the physiological data received from the individual sensors connected to each wearable to a remote server. Each wearable consists of a sensor, a communication adapter, and its power module. We introduce low-power adapters with each sensor, which facilitates the sensor-CPH linkups and on-demand network parameter reconfigurations. The newly introduced adapter supports the interoperability of heterogeneous sensors by eradicating the need for sensor-specific modules through OTA-based reconfiguration. The reconfiguration feature allows for new sensors to connect to an existing adapter, without changing the hardware units or any external interface. The proposed system is scalable and enables multiple sensors to connect in a network and work in synchronization with the CPH to achieve semantic and device interoperability among the sensors. We test the implementation in real-time using three different health-monitoring sensor types - temperature, pulse oximeter, and ECG. The results of our real-time system evaluation depict that the proposed system is reliable and responsive in terms of the achieved packet delivery ratio, received signal strength, and energy consumption
Highly value-added utilization of H<inf>2</inf>S in Na<inf>2</inf>SO<inf>3</inf>solution over Ca-CdS nanocrystal photocatalysts
No full textAlkaline-earth metal Ca2+ modified CdS nanocrystals have been designed for the first time for highly efficient H2 evolution from hydrogen sulfide (H2S) with Na2SO3 as a favourable reaction medium. The advantage of Na2SO3 was revealed by an electrochemical test, and the conversion of Na2SO3 during the reaction was carefully studied. Particularly, most of Na2SO3 was converted into Na2S2O3. Highly value-added utilization of waste H2S is therefore achieved via photocatalysis. This journal i
Optical and electronic properties of colloidal CdSe quantum rings
No full textLuminescent colloidal CdSe nanorings are a recently developed type of semiconductor structure that have attracted interest due to the potential for rich physics arising from their nontrivial toroidal shape. However, the exciton properties and dynamics of these materials with complex topology are not yet well understood. Here, we use a combination of femtosecond vibrational spectroscopy, temperature-resolved photoluminescence (PL), and single-particle measurements to study these materials. We find that on transformation of CdSe nanoplatelets to nanorings, by perforating the center of platelets, the emission lifetime decreases and the emission spectrum broadens due to ensemble variations in the ring size and thickness. The reduced PL quantum yield of nanorings (∼10%) compared to platelets (∼30%) is attributed to an enhanced coupling between (i) excitons and CdSe LO-phonons at 200 cm-1 and (ii) negatively charged selenium-rich traps, which give nanorings a high surface charge (∼-50 mV). Population of these weakly emissive trap sites dominates the emission properties with an increased trap emission at low temperatures relative to excitonic emission. Our results provide a detailed picture of the nature of excitons in nanorings and the influence of phonons and surface charge in explaining the broad shape of the PL spectrum and the origin of PL quantum yield losses. Furthermore, they suggest that the excitonic properties of nanorings are not solely a consequence of the toroidal shape but also a result of traps introduced by puncturing the platelet center
Impact of the interface vacancy on Schottky barrier height for Au/AlN polar interfaces
No full textSchottky barrier heights (SBHs) at the Au/AlN interface are systemically studied by density functional calculations. Two types of interfaces, including Al- and N-polar interfaces, are constructed to examine the relationship between the SBH and the interfacial atom species. An in-depth exploration is conducted by introducing interfacial aluminum vacancy or nitride vacancy. The results show that the calculated p-type SBH of the Al-polar interface (2.30 eV) is higher than that of the N-polar interface (1.23 eV). Results also show that the SBH of the interface with Al or N vacancies would be higher. More obvious metal-induced gap states (MIGS) can be observed after the introduction of interfacial vacancy site, leading to a stronger Fermi-level pinning at the contact. The derived SBHs are within the reported measurement range. The findings provide an insightful hint for AlN-based devices where Schottky contact matters
Strain-tunable III-nitride/ZnO heterostructures for photocatalytic water-splitting: A hybrid functional calculation
No full textSolar to fuel energy conversion is one of the momentous topics nowadays considering the urgent demand for clean energy supplies. In this work, the tunable electronic and optical properties of III-nitride/ZnO 2D/2D heterostructures (including GaN/ZnO, AlN/ZnO, and GaN/AlN) by strain engineering were investigated by first-principles calculations. The studied heterostructures feature a small interlayer distance, with the cation of one layer directly above the anion of the other layer, and vice versa. This leads to a strong binding energy and interlayer coupling across the heterostructure. The built-in field induced by the charge redistribution facilitates the photoexcited carrier migration, which is beneficial to the photocatalytic water splitting application. The stable III-nitride/ZnO heterostructures exhibit decent band edge positions with biaxial strain engineering and feature an enhancement of optical absorption under tensile strain. Our results indicate that the III-nitride/ZnO 2D/2D heterostructures are promising photocatalysts for solar to hydrogen generation by water splitting
Numerical Study on the Influence of Superconductor Layer Thickness on AC losses in Conductor on Round Core Cable
No full textIt is a promising cable structure methodology to use conductor on round core (CORC) cables for large current density applications. In this study, a three-dimensional (3-D) CORC model was built from different thicknesses of the superconductor layers using finite element method. The AC losses exposed to a sinusoidal external magnetic field were calculated. Furthermore, we provide a recommendation to simulate a thicker model instead of the real physical thickness to save computation resources while maintaining a high accuracy
From Thermal Energy to Kinetic Energy: Droplet Motion Triggered by the Leidenfrost Effect
No full text© 2020 Wiley-VCH GmbH When a liquid is dropped on a surface significantly hotter than the liquid's boiling point, a vapor film forms beneath the droplet creating an insulation layer sufficient enough to prevent the droplet from rapidly boiling. This phenomenon is known as the Leidenfrost effect, and enables droplets to survive for up to several minutes before fully evaporating. Solids are similarly able to levitate due to sublimation. Furthermore, a liquid droplet placed on a heated flat surface moves randomly, but on a ratcheted substrate, will self-propel and move unidirectionally along the ratchets. Such a system with no other external energy fields applied is designated a Leidenfrost self-propulsion device, first introduced by Linke et al. Given the ability of such an arrangement to effectively convert thermal energy into kinetic energy, numerous studies have subsequently attempted to understand and refine the control of motion of the levitated droplets/solids. This review addresses the fundamental understanding of this “heat-to-motion” mechanism, where the main focus is conversion of thermal energy into kinetic energy through the unique Leidenfrost self-propulsion mechanism. Potential applications of Leidenfrost self-propulsion devices are also discussed, including a brief outlook for the future of this research field
SLow Onset Disaster Events Factors in Italian Built Environment Archetypes
No full textResilience of the built environment is a primary issue to provide the citizens users a high-quality environment and livable cities. The aim of this research is to identify the Built Environment (BE) typologies prone to the Slow Onset Disasters (SLODs), in Italian cities. A SLOD can be defined as an uninterrupted, gradual or variable, low intensity and high frequency event that generates a negative effect on population, which on the long term can generate significant health and environmental decay. The results of the research have demonstrated that some SLODs type are more impacting within the built environment: the air pollution concentration and the increasing temperatures. Moreover, it has been demonstrated that some urban archetypes: the piazza, piazzale and the urban canyon are more prone to produce negative effects on the population through amplification of the consequences of the exposure to the SLODs. The article concludes with some insights (solar radiation and wind tunneling analysis) on the most critical architypes, for understanding better how they perform under specific conditions. This research, within the context of the Italian research project (PRIN) BE S ECURe, is to be intended as the first step towards the definition of a method for assessment of the effects of the SLODs risk on a specific part of the city.
Behind the scenes: Addressing dual pressures for product standardization and adaptation in new product development in multinational corporations
No full textPurpose: Prior studies on product standardization–adaptation in multinational corporations (MNCs) have revealed environmental factors that can influence the choices of MNCs. However, these studies have not shown how these choices are made behind the scenes in new product development (NPD). In many industries, MNCs face the dual pressures for product standardization and adaptation from the environment. This study aims to explore how MNCs facing dual pressures can make choices of product standardization–adaptation in NPD. Design/methodology/approach: A qualitative case study of four high-performing MNCs was conducted. The four MNCs were selected using the theoretical sampling approach. Data were collected, mainly through 74 semi-structured interviews. Coding was conducted and four aggregate dimensions were generated. Findings: This study reveals that choices of product standardization–adaptation are made through a process in MNCs’ NPD, including four steps – organizing for NPD, organizational diversity, cross-unit integration and combination of design practices. In addition, MNCs adopt different process variants to address different environmental pressures. Research limitations/implications: This research focuses on high-performing MNCs in manufacturing industries. Future research can explore different types of firms. Practical implications: Managers in MNCs should focus more on the process of choices for product standardization–adaptation, than on the level of product standardization–adaptation. They should also keep monitoring the environmental pressure and employ experienced engineers. Originality/value: By focusing on NPD, the authors shift the attention from product standardization–adaptation to product feature standardization–adaptation in MNCs, which is a fresh and refined perspective. The authors show a process in NPD composed of activities and mechanisms that managers might use for handling product standardization–adaptation challenges in MNCs. The authors contribute to the area of cross-unit integration in MNCs’ NPD by revealing mental mechanisms for mitigating tensions in cross-unit interactions