MRC Laboratory of Molecular Biology
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The effect of CO on CO<inf>2</inf>-char gasification
No full textThe effect of CO on the gasification of a Polish coal-derived char was studied in a fluidized bed from 1123 K to 1248 K. Rate expressions developed from Ergun’s mechanism or a modified three-step reaction mechanism, coupled with Cylindrical Pore Interpolation Model to account for the intra-particle mass transfer, were developed to predict gasification and the effect of CO. Compared to the Ergun’s rate expression, the three-step expression had an extra term for pco , making the inhibition effect of CO more pronounced. The agreement between experimental and numerical results was satisfactory for both models simulating gasification by CO2/N2. When CO (1% or 3%) was intentionally introduced in the feed gas (CO2/N2), the gasification rates significantly decreased. The model based on Ergun’s mechanism over-estimated the gasification rate, while the results from the model with the three-step mechanism agreed with the experimental data
Evaluation of the formal risk assessment practice in hospitals in England
No full textIn England, hospitals routinely conduct a formal risk assessment practice to ensure the safety of patients and staff. However, although specific criticisms have been made on the practice, few investigated the formal risk assessment practice in the literature. This study investigates the risk assessment policies and procedures of one hundred hospitals in the English National Health Service (NHS) through content analysis. Findings revealed that hospitals provided varied descriptions of the terms risk and risk assessment. The concept of risk was often defined to be an undesired event, and risk assessment was often explained with the involvement of risk control step. Despite the variety in the descriptions of the risk terms, all hospitals recommended following similar steps to undertake risk assessments. Risk matrices- and therefore risk scoring–are at the heart of the formal practice, which increases the possibility of wrong risk prioritisation. This study provides several recommendations for the improvement of current guidelines by considering both Safety-I and Safety-II approaches
Blockchain at the Edge: Performance of Resource-Constrained IoT Networks
No full textThe proliferation of IoT in various technological realms has resulted in the massive spurt of unsecured data. The use of complex security mechanisms for securing these data is highly restricted owing to the low-power and low-resource nature of most of the IoT devices, especially at the Edge. In this article, we propose to use blockchains for extending security to such IoT implementations. We deploy a Ethereum blockchain consisting of both regular and constrained devices connecting to the blockchain through wired and wireless heterogeneous networks. We additionally implement a secure and encrypted networked clock mechanism to synchronize the non-real-time IoT Edge nodes within the blockchain. Further, we experimentally study the feasibility of such a deployment and the bottlenecks associated with it by running necessary cryptographic operations for blockchains in IoT devices. We study the effects of network latency, increase in constrained blockchain nodes, data size, Ether, and blockchain node mobility during transaction and mining of data within our deployed blockchain. This study serves as a guideline for designing secured solutions for IoT implementations under various operating conditions such as those encountered for static IoT nodes and mobile IoT devices
Wp-5 external flows—wing
No full textStudy of transition location effect (from natural transition to fully turbulent) on separation size, shock structure and unsteadiness was the focus of this WP. Boundary layer tripping (by wire or roughness) and flow control devices (VG) were used for boundary layer transition induction. Although this type of flow field had been studied widely in the past, there remains considerable uncertainty on the effects of transition on transonic aerofoil performance. In particular it is not known how close to the shock location transition has to occur to avoid detrimental effects associated with laminar shock-induced separation. Furthermore, it was unclear how best to provoke transition on an airfoil featuring significant laminar flow and how close to the shock this needs to be performed. Finally, current CFD methods are particularly challenged by such transitional flows. In this work package some of the findings from the basic research performed in other WPs was applied. Specialized large-scale transonic wind tunnels running cost is very high therefore using such facilities is not appropriate for upstream research programs such as TFAST. Therefore we have used existing wind tunnels within our consortium. One of these is a transonic test section at UCAM where laminar and transitional profiles were studied previously at Reynolds numbers up to 2 million (based on chord length). This wind tunnel allowed basic investigations of the transition location effects on a shock induced separation and unsteadiness for a relatively large number of parameters. A larger wind tunnel at Institute of Aviation in Warsaw was used, which enabled the investigation of a much larger aspect ratio profile. In this facility it was possible to measure a whole force polar up to and including the buffet boundary. The research was carried out for the natural b/l transition location as well as different methods of tripping
Reality-assisted evolution of soft robots through large-scale physical experimentation: A review
No full textWe introduce the framework of reality-assisted evolution to summarize a growing trend towards combining model-based and model-free approaches to improve the design of physically embodied soft robots. In silico, data-driven models build, adapt, and improve representations of the target system using real-world experimental data. By simulating huge numbers of virtual robots using these data-driven models, optimization algorithms can illuminate multiple design candidates for transference to the real world. In reality, large-scale physical experimentation facilitates the fabrication, testing, and analysis of multiple candidate designs. Automated assembly and reconfigurable modular systems enable significantly higher numbers of real-world design evaluations than previously possible. Large volumes of ground-truth data gathered via physical experimentation can be returned to the virtual environment to improve data-driven models and guide optimization. Grounding the design process in physical experimentation ensures that the complexity of virtual robot designs does not outpace the model limitations or available fabrication technologies. We outline key developments in the design of physically embodied soft robots in the framework of reality-assisted evolution
Ultra-Wideband Information Throughput Attained via Launch Power Allocation
No full textMaximised information rates of ultra-wideband (typically, beyond 100 nm) lumped-amplified fibre-optic communication systems have been thoroughly examined accounting for the wavelength dependencies of fibre parameters as well as the impact of the inter-channel stimulated Raman scattering (SRS). If the tilted signal spectral profile due to SRS is supposed to be completely undone at every fibre span, the obtained results demonstrate the possibility to approach nearly optimal system performance by launching sub-optimal but practically relevant uniform power profiles
Ion Pair Uptake in Ion Gel Devices Based on Organic Mixed Ionic–Electronic Conductors
No full textIn organic mixed ionic–electronic conductors (OMIECs), it is critical to understand the motion of ions in the electrolyte and OMIEC. Generally, the focus is on the movement of net charge during gating, and the motion of neutral anion–cation pairs is seldom considered. Uptake of mobile ion pairs by the semiconductor before electrochemical gating (passive uptake) can be advantageous as this can improve device speed, and both ions can participate in charge compensation during gating. Here, such passive ion pair uptake in high-speed solid-state devices is demonstrated using an ion gel electrolyte. This is compared to a polymerized ionic liquid (PIL) electrolyte to understand how ion pair uptake affects device characteristics. Using X-ray photoelectron spectroscopy, the passive uptake of ion pairs from the ion gel into the OMIEC is detected, whereas no uptake is observed with a PIL electrolyte. This is corroborated by X-ray scattering, which reveals morphological changes to the OMIEC from the uptake of ion pairs. With in situ Raman, a reorganization of both anions and cations is then observed during gating. Finally, the speed and retention of OMIEC-based neuromorphic devices are tuned by controlling the freedom of charge motion in the electrolyte
Research on the allocation efficiency and influencing factors of scientific and technological resources in the yangtze river delta city group
No full textThrough the establishment of a comprehensive evaluation index system, this paper analyzes the allocation of science and technology resources in the Yangtze River Delta urban agglomeration from 2014 to 2020, evaluates the allocation efficiency of science and technology resources from the perspective of multi input and output, and understands the advantages and disadvantages of regional resource allocation. The research results show that: (1) under the guidance of the national strategic policy of actively promoting the development of world-class urban agglomerations, the allocation efficiency of science and technology resources in various provinces and cities of the Yangtze River Delta continues to optimize, and the allocation level of some regions shows a rapid development trend; (2) R&D personnel and R&D funds are the core factors that affect the efficiency of science and technology resource allocation; (3) the marketization of resource allocation is helpful to improve its allocation efficiency; and (4) improving the transformation rate of scientific and technological achievements, opening up the channel for innovative products, technologies, and services to enter the market, and enabling innovative enterprises to make profits can provide strong and lasting incentives for the improvement of scientific and technological resource allocation efficiency. Based on the research conclusions, this paper puts forward countermeasures and suggestions to improve the allocation efficiency of scientific and technological resources in the Yangtze River Delta urban agglomeration from the aspects of human resources and material resources, and provides a theoretical reference for the coordinated and sustainable development of the Yangtze River Delta City Group under the background of the implementation of the urban agglomeration strategy and the construction of a scientific and technological infrastructure platform
LIBS2ML: A library for scalable second order machine learning algorithms
No full textLIBS2ML is a library based on scalable second order learning algorithms for solving large-scale problems, i.e., big data problems in machine learning. LIBS2ML has been developed using MEX files, i.e., C++ with MATLAB/Octave interface to take the advantage of both the worlds, i.e., faster learning using C++ and easy I/O using MATLAB. Most of the available libraries are either in MATLAB/Python/R which are very slow and not suitable for large-scale learning, or are in C/C++ which does not have easy ways to take input and display results. So LIBS2ML is completely unique due to its focus on the scalable second order methods, the hot research topic, and being based on MEX files. Thus it provides researchers a comprehensive environment to evaluate their ideas and it also provides machine learning practitioners an effective tool to deal with the large-scale learning problems. LIBS2ML is an open-source, highly efficient, extensible, scalable, readable, portable and easy to use library. The library can be downloaded from the URL: \url{https://github.com/jmdvinodjmd/LIBS2ML}
Experimental Investigation of Soot Production and Oxidation in a Lab-Scale Rich–Quench–Lean (RQL) Burner
No full textSwirl-stabilized, turbulent, non-premixed ethylene–air flames at atmospheric pressure with downstream radially-injected dilution air were investigated from the perspective of soot emissions. The velocity and location of the dilution air jets were systematically varied while the global equivalence ratio was kept constant at 0.3. The employed laser diagnostics included 5 kHz planar laser-induced fluorescence (PLIF) of OH, 10 Hz PAH-PLIF, and 10 Hz laser-induced incandescence (LII) imaging of soot particles. OH-PLIF images showed that the reaction zone widens with dilution, and that regions with high OH-LIF signal shift from the shear layer to the axis of the burner as dilution increases. Dilution is effective at mitigating soot formation within the central recirculation zone (CRZ), as evident by the smaller PAH-containing regions and the much weaker LII signal. Dilution is also effective at halting PAH and soot propagation downstream of the dilution air injection point. The high momentum dilution air circulates upstream to the root of the flame and reduces fuel penetration lengths, induces fast mixing, and increases velocities within the CRZ. Soot intermittency increased with high dilution velocities and dilution jet distances up to two bluff body diameters from the burner inlet, with detection probabilities of < 5% compared to 50% without dilution. These results reveal that soot formation and oxidation within the RQL are dependant on the amount and location of dilution air injected. This data can be used to validate turbulent combustion models for soot