•Fault detection and isolation of a dual spool gas turbine engine is investigated by using dynamic neural networks.•Banks of dynamic neural nets and time-delay neural nets are developed for solving ...the fault detection problem.•Results show certain engine variables have better detection capabilities as compared to others.•Fault detection performance was shown to be improved by monitoring several engine variables simultaneously.•Fault isolation uses multilayer perceptions as pattern classifier of residual signals that are generated from the fault detection phase.
The main goal of this paper is to design and develop a fault detection and isolation (FDI) scheme for aircraft gas turbine engines by using neural networks. Towards this end, first for the fault detection task two types of dynamic neural networks are used and compared to learn the engine dynamics. Specially, the dynamic neural model (DNM) and the time delay neural network (TDNN) are utilized. For both architectures a bank of neural networks is trained separately to capture the dynamic relationships among the engine measurable variables. The results show that certain engine parameters have better detection capabilities as compared to the others. Finally, the fault isolation task is accomplished by using a multilayer perception (MLP) network functioning as a pattern classifier applied to the residual signals that are generated by the two dynamic neural networks used for the purpose of the fault detection task. The simulation results do indeed substantiate and verify that our proposed FDI scheme represents a promising tool for aircraft engine diagnostics and health monitoring.
The rapid expansion of mobile technology is transforming the biomedical landscape. By 2016 there will be 260 M active smartphones in the US and millions of health accessories and software "apps" ...running off them. In parallel with this have come major technical achievements in lab-on-a-chip technology leading to incredible new biochemical sensors and molecular diagnostic devices. Despite these advancements, the uptake of lab-on-a-chip technologies at the consumer level has been somewhat limited. We believe that the widespread availability of smartphone technology and the capabilities they offer in terms of computation, communication, social networking, and imaging will be transformative to the deployment of lab-on-a-chip type technology both in the developed and developing world. In this paper we outline why we believe this is the case, the new business models that may emerge, and detail some specific application areas in which this synergy will have long term impact, namely: nutrition monitoring and disease diagnostics in limited resource settings.
The rapid expansion of mobile technology is transforming the biomedical landscape.
DNA-protein conjugates are important in bioanalytical chemistry, molecular diagnostics and bionanotechnology, as the DNA provides a unique handle to identify, functionalize or otherwise manipulate ...proteins. To maintain protein activity, conjugation of a single DNA handle to a specific location on the protein is often needed. However, preparing such high-quality site-specific conjugates often requires genetically engineered proteins, which is a laborious and technically challenging approach. Here we demonstrate a simpler method to create site-selective DNA-protein conjugates. Using a guiding DNA strand modified with a metal-binding functionality, we directed a second DNA strand to the vicinity of a metal-binding site of His6-tagged or wild-type metal-binding proteins, such as serotransferrin, where it subsequently reacted with lysine residues at that site. This method, DNA-templated protein conjugation, facilitates the production of site-selective protein conjugates, and also conjugation to IgG1 antibodies via a histidine cluster in the constant domain.
During the past decade, gadolinium zirconate (Gd2Zr2O7, GZO) has attracted interest as an alternative material to partially yttria‐stabilized zirconia (YSZ) for thermal barrier coatings (TBCs). ...Despite the well‐known benefits of GZO, such as lower thermal conductivity and superior temperature capability compared to YSZ, processing of GZO via atmospheric plasma spraying (APS) still remains a challenge. Here, we report on APS experiments which were performed to investigate the influence of processing on GZO microstructure and lifetime of GZO/YSZ double‐layer TBCs. Different microstructures of GZO were produced and characterized in terms of porosity, stoichiometry, Young′s modulus, and their effects on the lifetime of YSZ/GZO double‐layer TBCs were discussed. Particle diagnostics were utilized for the optimization of the process parameters with respect to different microstructures of GZO and stoichiometry. It was found that both cumulative porosity of GZO and pore size distribution, which alter the Young′s modulus significantly, govern the lifetime of double layers. In addition, it was shown that the deviation in GZO stoichiometry due to gadolinia evaporation in the investigated range does not display any critical effect on lifetime.
As gas-phase methods for the synthesis of tailored nanomaterials become increasingly sophisticated, the need for in situ diagnostics of reaction conditions and particle properties grows ...correspondingly. Laser-based methods provide a wide range of capabilities which are reviewed in this article.
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•Laser-based diagnostics provide unique insight in gas-phase nanoparticle synthesis.•Spatially-resolved in situ information provides input for modeling reaction conditions.•We give an overview over a rapidly expanding research field.
•A prognosis scheme for predicting the performance of gas turbine components is presented.•The proposed prognosis scheme takes into consideration flexible and dynamic operating conditions of gas ...turbines.•The performance of the scheme is tested under transient conditions of gas turbines.•The proposed scheme is utilized to detect and forecast compressor fouling and turbine erosion.
The increase in energy demand has led to expansion of renewable energy sources and their integration into a more diverse energy mix. Consequently the operation of thermal power plants, which are spearheaded by the gas turbine technology, has been affected. Gas turbines are now required to operate more flexible in grid supporting modes that include part-load and transient operations. Therefore, condition based maintenance should encapsulate this recent shift in the gas turbine’s role by taking into account dynamic operating conditions for diagnostic and prognostic purposes. In this paper, a novel scheme for performance-based prognostics of industrial gas turbines operating under dynamic conditions is proposed and developed. The concept of performance adaptation is introduced and implemented through a dynamic engine model that is developed in Matlab/Simulink environment for diagnosing and prognosing the health of gas turbine components. Our proposed scheme is tested under variable ambient conditions corresponding to dynamic operational modes of the gas turbine for estimating and predicting multiple component degradations. The diagnosis task developed is based on an adaptive method and is performed in a sliding window-based manner. A regression-based method is then implemented to locally represent the diagnostic information for subsequently forecasting the performance behavior of the engine. The accuracy of the proposed prognosis scheme is evaluated through the Probability Density Function (PDF) and the Remaining Useful Life (RUL) metrics. The results demonstrate a promising prospect of our proposed methodology for detecting and predicting accurately and efficiently the performance of gas turbine components as they degrade over time.
Suitable pumping methods for flow control remain a major technical hurdle in the path of biomedical microfluidic systems for point-of-care (POC) diagnostics. A vacuum-driven power-free micropumping ...method provides a promising solution to such a challenge. In this review, we focus on vacuum-driven power-free microfluidics based on the gas solubility or permeability of polydimethylsiloxane (PDMS); degassed PDMS can restore air inside itself due to its high gas solubility or gas permeable nature. PDMS allows the transfer of air into a vacuum through it due to its high gas permeability. Therefore, it is possible to store or transfer air into or through the gas soluble or permeable PDMS in order to withdraw liquids into the embedded dead-end microfluidic channels. This article provides a comprehensive look at the physics of the gas solubility and permeability of PDMS, a systematic review of different types of vacuum-driven power-free microfluidics, and guidelines for designing solubility-based or permeability-based PDMS devices, alongside existing applications. Advanced topics and the outlook in using micropumping that utilizes the gas solubility or permeability of PDMS will be also discussed. We strongly recommend that microfluidics and lab-on-chip (LOC) communities harness vacuum energy to develop smart vacuum-driven microfluidic systems.
This article provides a comprehensive overview of the physics of the gas solubility and permeability of PDMS, a systematic review of different types of vacuum-driven power-free microfluidics, design guidelines, existing applications, and the outlook.
Highlights • Breathomics is an upcoming bioanalytical area transforming point-of-care diagnostics. • Volatile organic compounds (VOCs) are an important source of potential diagnostic information. • ...Current technologies bridge the gap from large analytical systems to portable sensor platforms.
Ob koncu lanskega leta je Zdravstveni svet Republike Slovenije potrdil program preprečevanja zgodnjih invazivnih okužb novorojenčkov, povzročenih s streptokokom skupine B, ki vključuje univerzalno ...presejanje nosečnic v 35.–37. tednu nosečnosti. V prispevku smo pregledali različne diagnostične metode presejanja in dejavnike, ki pomembno vplivajo na njihovo uspešnost tako v ginekološki ambulanti kakor tudi v mikrobiološkem laboratoriju. Bralca opozarjamo na pravilnost odvzema kužnine, mu predstavimo izbrano strategijo testiranja s kombinacijo obogatene kulture in molekularnega testiranja ter mu ponujamo seznam registriranih molekularnih testov, primernih za testiranje. V zadnjem delu prispevka razpravljamo o pomenu hipervirulentnega klona CC-17, ki povzroča večino invazivnih okužb novorojenčkov v Sloveniji, in o metodah, s katerimi ga prepoznamo.
In the past decade, responsive polymers exhibiting reversible or irreversible changes in physical properties and/or chemical structures in response to external stimuli have been extensively ...investigated. Among them, tertiary amine methacrylate-based block copolymers represent a unique category considering their responsiveness to multiple external stimuli (e.g., pH, temperature and salts), which are essentially relevant to the biological milieu. These intriguing properties allow for their applications in a variety of fields ranging from drug or gene delivery, imaging, diagnostics, antibacterial coatings, catalysis, and bio-separations. This review article highlights tertiary amine methacrylate-based block copolymers, focusing on recent advances in the synthesis of tertiary amine methacrylate-based block copolymers with varying chemical structures and chain topologies, their supramolecular self-assembly in aqueous media as well as in the bulk state, and the emerging functional applications.
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