Miracle-dz/UniFAR-FTUs huggingface dataset:
Corrosion Protection of Monel Alloy Coated with Graphene Quantum Dots Starts with a Surge

There has been an active interest in protecting metals and alloys using graphene coating. The mechanism by which corrosion protection occurs has not been well understood as the couple involved are both good electron conductors. In this work, we demonstrate that Monel alloy coated with graphene quantum dots (GQD) changes the corrosion rate with a surge (increase) caused by the galvanic coupling of the two materials. This surge results in the protective layer formation on Monel to inhibit the corrosion. X-ray fluorescence spectrum of Monel (400) alloy showed the composition of it as Ni (67.05%) and Cu (29.42%). The Tafel experiments carried out in NaCl and Na2SO4 electrolytes showed an initial enhancement of the corrosion rate followed by a decrease upon successive polarizations. Monel coated with graphene oxide (an insulator) shows no initial enhancement of corrosion rate; the coated samples showed a lower corrosion rate in comparison to the uncoated samples. X-ray fluorescence, Fourier Transform spectroscopy (FTIR) and Raman imaging studies have been carried out for understanding this transformation. Distinct peaks due to Ni-O stretching and Ni-O-H bending vibration were observed in the FTIR spectrum.
Stress Analysis of a Nature-Inspired Skin Adhesive Patch as a Wound Closure Technique

Skin is the outermost layer of human body that protects it from various threats. Although the human skin acts as a protective layer, when the skin is injured it can be an open inlet for bacterial and virus attacks. Staples and sutures are used to close the skin wounds but they cause some problems such as skin irritation. Utilizing adhesive patches can be considered as an appropriate alternative to the sutures and staples. In this paper, two natural mechanisms found in the gecko toe pad and housefly feet were employed in order to improve the skin adhesive patch performance. Finite element simulations were conducted in order to study the effects of different geometrical parameters of the skin adhesive patch and achieve better performance of the patch. The proposed configuration of the skin adhesive patch can completely close the wound opening and provide effective air circulation to aid cell and tissue regeneration. Therefore, it can provide better biocompatibility with the human skin in contrast with the traditional skin adhesive patches with minimal patient inconvenience.
Dielectric barrier discharge non-thermal plasma stability analysis based on temperature profiles using fiber bragg grating sensor

This study aims to determine the stability of atmospheric pressure non-thermal plasma generated in dielectric barrier discharge (DBD) based on temperature profiles measured using a fiber Bragg grating (FBG). Two sets of the DBD reactor were fabricated using two symmetrical electrodes separated by 2.31 mm and 3.74 mm discharge gap, respectively with dielectric material of alumina plates. The FBG was used as a temperature sensor by embedded directly into the plasma stream. The temperature was measured at different applied voltages within range of 0 to 7 kV. The results show that the streamer discharge was generated by the DBD reactor with the 2.31 mm discharge gap at 5.5 kV while the DBD reactor with the 3.74 mm discharge gap generated filamentary discharge at 7 kV. The temperature increases proportionally as the applied voltages increases. The stability of the DBD reactor was performed by operated at constant applied voltage for 600 seconds. The temperature profiles of the DBD reactor with the 2.31 mm discharge gap were measured in the range of 210 - 231 oC with applied voltage of 5.0 kV and in the range of 270 - 286 oC at 6 kV. For the DBD reactor with the 3.74 mm discharge gap, the temperature profiles were measured in the range of 47 - 67 oC when operated at 6 kV and in the range of 193 - 245 oC at 7 kV. A huge temperature difference was found for the DBD reactor with the 3.74 mm discharge gap which results in localized heat generation of the discharge caused by the filamentary discharge. The filamentary discharge disrupted the homogeneity of the plasma and created the instabilities in the DBD reactor. The plasma intensity of the DBD reactor measured by the optical emission spectroscopy (OES) showed more fluctuation pattern when the filamentary discharge was generated compared to the streamer discharge. From this finding, the FBG can be used for temperature profiles of the DBD reactor to determine its stability on the generation of the filamentary discharge.
Influencing Parameters on the Load‐bearing Capacity of Composite Dowels positioned close to the free Surface of Concrete Slabs

Composite dowels as shear connectors between steel profiles and concrete sections have been investigated for decades. The long‐term aim is to develop consistent design approaches and implement them within Eurocode 4 covering both fields of bridge and building construction. Especially in building construction, where the concrete slabs are dimensioned increasingly slimmer in contrast to bridge construction, the composite dowels are positioned unavoidably close to free concrete surfaces (1). This causes further failure modes which have not been entirely investigated yet. At University of Kaiserslautern experimental push‐out tests were performed within a research project in cooperation with RWTH Aachen University focusing on the behaviour of these composite dowels in dependence of varying influence parameters, such as the dowel's distance to the edge, the concrete strength and the position of the reinforcement stirrups. Some results showed a significant reduction of the load‐bearing capacity and an affection of the deformability, mostly accompanied by the spalling of the concrete cover. Based on the tests, numerical simulations were calibrated and utilized to understand more about the load transfer mechanisms and to interpolate between existing experimental results. This paper will particularly show the influence of three parameters and present considerations on the load transfer model including further primary, secondary and tertiary failure mechanisms leading to the overall failure of the specimens.
A Rapid Synthesis of Mesoporous Mn2O3 Nanoparticles for Supercapacitor Applications

Mn2O3 nanomaterials have been recently composing a variety of electrochemical systems like fuel cells, supercapacitors, etc., due to their high specific capacitance, low cost, abundance and environmentally benign nature. In this work, mesoporous Mn2O3 nanoparticles (NPs) were synthesized by manganese acetate, citric acid and sodium hydroxide through a hydrothermal process at 150 °C for 3 h. The synthesized mesoporous Mn2O3 NPs were thoroughly characterized in terms of their morphology, surfaces, as well as their crystalline, electrochemical and electrochemical properties. For supercapacitor applications, the synthesized mesoporous Mn2O3 NP-based electrode accomplished an excellent specific capacitance (Csp) of 460 F·g−1 at 10 mV·s−1 with a good electrocatalytic activity by observing good electrochemical properties in a 6 M KOH electrolyte. The excellent Csp might be explained by the improvement of the surface area, porous surface and uniformity, which might favor the generation of large active sites and a fast ionic transport over the good electrocatalytic surface of the Mn2O3 electrode. The fabricated supercapacitors exhibited a good cycling stability after 5000 cycles by maintaining ~83% of Csp.
Forensic approach to predict film thickness of reacted and activated rubber (RARX) modified asphalt mixtures

The major objective of this study was to arrive at an optimum threshold asphalt binder film thickness, and develop predictive equation that includes materials and mixture properties, which could be used in all future forensic assessment of asphalt mixtures. Also, 18 field asphalt mixtures constructed as test sections were investigated for their field performance and correlated with . Furthermore, the performance criteria set by Arizona department of transportation (ADOT) in the USA to assess the field mixtures were related to established in this study. An optimum of 12 µ was selected as the threshold magnitude for asphalt mixtures that incorporates activated crumb rubber modified products, termed RARX. It was found that with increase in the overall cumulative surface area (SA) of the mix matrix, the required binder content also increased, in turn decreasing . predictive equation encompassing materials properties and associated volumetrics was established as a best-fit nonlinear regression model that had excellent statistical measures: R 2 = 99.8%; Se/Sy = 0.0447. It is noteworthy that the predictive model was established using the robust concept that introduced utilisation of SA of the whole mixture matrix, including, those that of SA of aggregate fractions not estimated by current models. Based on the methodical approach followed in this study to calculate , it is recommended that more amount of RARX be tried in other mixtures to enhance pavement performance. The current study involved only 18 field asphalt mixtures, amongst which six were without RARX. So, it is suggested that additional field sections be placed and monitored for their performance keeping in mind the volumetrics and specifically, , which can potentially be a quality control parametric assessor for field performance forensic evaluation, and that which becomes an integral characteristic in perpetual pavement design philosophy.
Multi-Band Rectangular Zig-Zag-Shaped Microstrip Patch Antenna for Wireless Applications

In the era of fifth generation communication system, multi-band patch antenna is the key element of this system. Most of the wireless communication devices work in the range of 1 to 6 GHz such as wireless fidelity (Wi-Fi), Wi-Max, and wireless local area network. In this research work, a modified zig-zagshaped multiband patch antenna with cross-cut set that covers 1 to 6 GHz range is designed. Proposed patch antenna shows five different bands at Multi-Band Rectangular Zig-Zag-Shaped Microstrip Patch Antenna for Wireless Applications
Teaching machine learning in robotics interactively: the case of reinforcement learning with Lego® Mindstorms

ABSTRACT Preparing students for dealing with a world more and more densely populated with physical machines that possess learning capabilities, e.g. intelligent robots, is of the utmost importance in engineering. In this paper, we describe and analyse a design of interactive sessions devoted to the application of some machine learning (ML) methods within a master degree subject named “Cognitive Robotics”, in particular, reinforcement learning (RL), a technique that allows the machine to autonomously learn decision-making in a physical environment. The paper contains a complete depiction of the interactive teaching sessions, implemented with reasonable cost and resources thanks to a suitable mixture of the constructivist and instructivist paradigms. It also gathers the experiences of students and teachers through both qualitative and quantitatively indicators. GRAPHICAL ABSTRACT Video abstract Watch the video on Vimeo
A Fully Printed Flexible MoS2 Memristive Artificial Synapse with Femtojoule Switching Energy

Realization of memristors capable of storing and processing data on flexible substrates is a key enabling technology toward “system‐on‐plastics”. Recent advancements in printing techniques show enormous potential to overcome the major challenges of the current manufacturing processes that require high temperature and planar topography, which may radically change the system integration approach on flexible substrates. However, fully printed memristors are yet to be successfully demonstrated due to the lack of a robust printable switching medium and a reliable printing process. An aerosol‐jet‐printed Ag/MoS2/Ag memristor is realized in a cross‐bar structure by developing a scalable and low temperature printing technique utilizing a functional molybdenum disulfide (MoS2) ink platform. The fully printed devices exhibit an ultra‐low switching voltage (0.18 V), a high switching ratio (107), a wide range of tuneable resistance states (10–1010 Ω) for multi‐bit data storage, and a low standby power consumption of 1 fW and a switching energy of 4.5 fJ per transition set. Moreover, the MoS2 memristor exhibits both volatile and non‐volatile resistive switching behavior by controlling the current compliance levels, which efficiently mimic the short‐term and long‐term plasticity of biological synapses, demonstrating its potential to enable energy‐efficient artificial neuromorphic computing.
3D Printing of Magnetoresponsive Polymeric Materials with Tunable Mechanical and Magnetic Properties by Digital Light Processing

Digital light processing is used for printing magnetoresponsive polymeric materials with tunable mechanical and magnetic properties. Mechanical properties are tailored, from stiff to soft, by combining urethane‐acrylate resins with butyl acrylate as the reactive diluent. The magnetic response of the printed samples is tuned by changing the Fe3O4 nanoparticle loading up to 6 wt%. Following this strategy, magnetoresponsive active components are fabricated with programmable complex functions using external magnetic fields. Different objects are printed exhibiting varying stiffness and magnetic responses, probing different kinds of movements, such as rolling, translation, stretching, shape‐shifting, and folding/unfolding.
ReClass: An Application of Deep Learning for Real-time Reading Detection Using an Eye Tracking Device

We demonstrate the ReClass system, a real time reading detection classifier. ReClass detects if a user is reading text or not solely based on the user’s eye movements, without considering the content of the screen. We examined two machine learning approaches. In the first approach, we pre-processed the data using feature engineering and trained a Linear Support Vector Machine classifier. The second approach used a Deep Learning Neural Network; instead of feature engineering, we allowed the neural network to extract features from the raw data. The second approach outperformed the first by about 25%, achieving 96% accuracy. Our tool illustrates how Deep Learning can be a new innovative method for teaching machines to understand human behaviour. We discuss the potential applications of ReClass for educational assessment, medical diagnosis and training.
Automatic question generation using natural language processing techniques

AUTOMATIC QUESTION GENERATION USING NATURAL LANGUAGE PROCESSING TECHNIQUES This thesis proposes a new rule based approach to automatic question generation. The proposed approach focuses on analysis of both syntactic and semantic structure of a sentence. The design and implementation of the proposed approach are also explained in detail. Although the primary objective of the designed system is question generation from sentences, automatic evaluation results shows that, it also achieves great performance on reading comprehension datasets, which focus on question generation from paragraphs. With respect to human evaluations, the designed system significantly outperforms all other systems and generated the most natural (human-like) questions.
Homotopy Semi-Numerical Modeling of Non-Newtonian Nanofluid Transport External to Multiple Geometries Using a Revised Buongiorno Model

A semi-analytical solution for the convection of a power-law nanofluid external to three different geometries (i.e., cone, wedge and plate), subject to convective boundary condition is presented. A revised Buongiorno model is employed for the nanofluid transport over the various geometries with variable wall temperature and nanoparticle concentration conditions (non-isothermal and non-iso-solutal). Wall transpiration is included. The dimensional governing equations comprising the conservation of mass, momentum, energy and nanoparticle volume fraction are transformed to dimensionless form using appropriate transformations. The transformed equations are solved using a robust semi-analytical power series method known as the Homotopy analysis method (HAM). The convergence and validation of the series solutions is considered in detail. The variation of order of the approximation and computational time with respect to residual errors for temperature for the different geometries is also elaborated. The influence of thermophysical parameters such as wall temperature parameter, wall concentration parameter for nanofluid, Biot number, thermophoresis parameter, Brownian motion parameter and suction/blowing parameter on the velocity, temperature and nanoparticle volume fraction is visualized graphically and tabulated. The impact of these parameters on the engineering design functions, e.g., coefficient of skin fraction factor, Nusselt number and Sherwood number is also shown in tabular form. The outcomes are compared with the existing results from the literature to validate the study. It is found that thermal and solute Grashof numbers both significantly enhance the flow velocity whereas they suppress the temperature and nanoparticle volume fraction for the three different configurations, i.e., cone, wedge and plate. Furthermore, the thermal and concentration boundary layers are more dramatically modified for the wedge case, as compared to the plate and cone. This study has substantial applications in polymer engineering coating processes, fiber technology and nanoscale materials processing systems.
Homogenization of Structured Metasurfaces and Uniaxial Wire Medium Metamaterials for Microwave Applications

In recent years, the study of electromagnetic wave interaction with artificial media has been the subject of intense research interest due to their extraordinary properties such as negative refraction, partial focusing, enhanced transmission, and spatial filtering, among others. Artificial media are crystals of various periodic metallic inclusions with dimensions of the order of λ/10 λ/4. When compared to natural materials, the inclusions are, thus, not as small in terms of the wavelength, even in the optical band. Therefore, one should expect the electrodynamics of these media to be inherently non-local, characterized by strong spatial dispersion effects. The dissertation includes two parts and focuses on the electromagnetic wave propagation in metamaterials formed by stacked metasurfaces and structured wire media. In the first part, we propose physical systems that mimic the observed behavior of stacked metal-dielectric layers at optical frequencies, but in the microwave region of the spectrum using stacked metascreens, and at low-THz using graphene-dielectric stack. The analysis is carried out using simple analytical circuit model or transfer matrix method with the homogenized impedance for the metasurfaces. The physical mechanisms of the observed behavior is clearly explained in terms of the open/coupled Fabry-Pérot resonators. The methodology can be useful in the design of wideband planar filters based on these metasurfaces with a specific response. The second part focuses on the development of homogenization models for wire medium loaded with arbitrary impedance insertions and metallic patches, to characterize negative refraction, partial focusing, and subwavelength imaging. We propose a new concept of suppressing the spatial dispersion effects in the wire media by employing lumped inductive loads. Based on the proposed concept, we demonstrate an ultra-thin structure which exhibits indefinite dielectric response, all-angle negative refraction and high transmission. Also compact electromagnetic band-gap structure with a huge stopband for surface-wave propagation is presented, which finds application in antenna technology. Partial focusing of electromagnetic radiation at microwave frequencies from a thick wire medium slab with periodic impedance loadings is detailed. Numerical simulation and homogenization results are presented in good agreement. Finally, the subwavelength imaging using wire
Adaptive control and dynamic demand response for the stabilization of grid frequency

Over the past few years, there has been a marked increase in the output from wind and solar generation in many countries. High levels of distributed generation provide variable energy and the increasing share of converter-connected plant results in a reduction in system inertia. Consequently, the rate of change of frequency, especially during and after severe faults, becomes more rapid. This thesis describes the use of heat pumps and fridges to provide ancillary services of frequency response so that to continuously balance the supply with demand. A decentralized digital controller namely: Adaptive DeadBeat (ADB) is designed to improve the frequency behaviour in an interconnected power system during and after faults. Simulation results show that the ADB controller can be considered as a contribution of digital control application to improve the frequency behaviour in an interconnected power system with reduced system inertia. The thermal performance of domestic buildings using heat pumps, and of fridges using thermostat temperature control is modelled. A dynamic frequency control (DFC) algorithm is developed to control the power consumption of the load in response to the grid frequency without affecting the overall performance of the load. Then, the dynamic frequency control algorithm is applied to a population of over 10 million aggregated units that represent the availability of load to provide frequency response. A dynamic relationship between the temperature and pre-defined trigger frequencies is given to ensure smooth and gradual load switching. A simulation is undertaken by connecting the controllable heat pumps to the reduced dynamic model of the Great Britain power system. Following a loss of 1,800 MW of generation, it is shown that the DFC reduces 1,000 MW of heat pumps demand and hence the frequency deviation is maintained within acceptable limits. In addition, a population of heat pumps and fridges are connected to the electrodynamic master model of the GB power system that is at present used by the ii GB transmission system operator, National Grid plc. Results show that the aggregated domestic heat pumps and fridges controlled by the DFC algorithm can participate in the Firm Frequency Response (FFR) service and provide rapid frequency response to the GB power system, mimicking the behaviour of the frequency-sensitive generators.
Prediction of Bake Hardening Behavior of Selected Advanced High Strength Automotive Steels and Hailstone Failure Discussion

The purpose of the present study is three-fold. Firstly, it attempts to describe the bake hardening (BH) behavior of selected interstitial free (IF) and dual phase (DP) steels. Secondly, it predicts the BH behavior of the IF DX 51D and DP 500 HCT 590X plates of steel, and thirdly studies material failure prevention in scholarly sources. The research is aimed at investigating the increasing steel strength during the BH of these two high-strength sheets of steel used for outer vehicle body parts. Samples of steel were pre-strained to 1%, 2%, and 5% and then baked at 140–220 °C for 10 to 30 min. The BH effect was determined from three factors: pre-strain, baking temperature, and baking time. Research has shown that increasing the yield strength by the BH effect is predictable. Therefore, the number of experiments could be reduced for the investigation of BH effect for other kinds of IF and DP steels. The literature study of the hailstone failure reveals that the knowledge of BH steels behavior helps to calculate the steel supplier´s failure mode effect analysis (FMEA) risk priority number.