Miracle-dz/UniFAR-FTUs huggingface dataset:
The End-to-End Simulation of Semi-Continuous Casting and Subsequent Hot Rolling with Account of Microstructure

Basing on the developed methodology for data transfer between the ProCAST and Deform-3D software products, which allows exporting geometry, temperature, residual stresses and microstructure of the casting, it is simulated semi-continuous casting of ingots from aluminum alloy 5182 into a direct chill mold and their following hot rolling in a reversing rolling stand to with aim to study microstructure the evolution.
Micro/Nano Structured Materials for Enhanced Device Performance and Antibacterial Applications

Micro/nanostructured materials have been used extensively for various applications due to their unique chemical, physical, and mechanical properties. In this thesis we report the fabrication and characterization of micro/nanostructured materials with antibacterial properties. Plastics are used in a wide range of medical components such as prosthetics, implants, catheters, and syringes. However, contaminating bacteria can attach to plastic surfaces and grow and form biofilms that lead to healthcare associated infections. The consequences on patients and their families are serious, as infections can extend hospital stays, create long-term disability, increase healthcare costs, and even result in unnecessary deaths. Two strategies for creating antibacterial surfaces are (1) anti-biofouling surfaces that make the bacterial attachment process difficult and (2) bactericidal surfaces that kill bacteria cells that come in proximity of or contact the surface. We demonstrate that a fluorine etch chemistry may be utilized to create lotus leaf-inspired, low surface energy, hierarchical micro-structure/nanofibrils in Polypropylene (PP). Our anti-biofouling PP surfaces exhibit a 99.6% reduction of E. coli cell adhesion compared to untreated PP. We also fabricated bactericidal surfaces consisting of uniform and regular nanostructured arrays. The interest in mechanical bactericidal effect has recently increased, as the bacteria cells grow drug resistance. Nanosphere lithography and combination of reactive ion etching and deep reactive ion etching were utilized to prepare these substrates. The pitch, diameter, taper, and height of the nanostructures are controlled. The bactericidal effect of these structures is investigated and significant enhancement in killing is observed. We also report fabrication of micro/nanostructured materials to improve device performance. Our simulation results show that absorption enhancement in vertical nanowire arrays on a perfectly electric conductor can be further improved through tilting. Tilted nanowire arrays, with the same amount of material, exhibit improved performance over vertical nanowire arrays over a broad range of tilt angles. The optimum tilt of 53° has an improvement of 8.6% over that of vertical nanowire arrays and 80.4% of the ideal double pass thin film. Incorporation of these structures could improve the efficiency of solar cells.
Meta‐learning how to forecast time series

A crucial task in time series forecasting is the identification of the most suitable forecasting method. We present a general framework for forecast-model selection using meta-learning. A random forest is used to identify the best forecasting method using only time series features. The framework is evaluated using time series from the M1 and M3 competitions and is shown to yield accurate forecasts comparable to several benchmarks and other commonly used automated approaches of time series forecasting. A key advantage of our proposed framework is that the time-consuming process of building a classifier is handled in advance of the forecasting task at hand.
Microstructure and stability conditions for hot deformation of a modified iron-based superalloy

ABSTRACT A modified iron-based superalloy is studied regarding its hot formability. The microstructure contained particles of titanium carbides, carbonitrides and nitrates. Torsion tests at high strain rate at temperatures ranging from 800 to 1200°C were conducted. Results of these tests were correlated by means of the Garofalo hyperbolic sine creep relation. An optimum forming temperature of 1260°C at 10 s−1 is obtained. This temperature is strongly dependent on the strain rate. An activation energy for plastic deformation close to that for the activation energy for lattice diffusion in austenitic stainless steels and a stress exponent near 5 were obtained. These values suggest that plastic deformation is controlled by a dislocation climb mechanism.
Spatial, temporal, and spectral control towards quantitative tissue spectroscopic imaging in the spatial frequency domain

Author(s): Torabzadeh, Mohammad | Advisor(s): Tromberg, Bruce J | Abstract: Spatial Frequency Domain Imaging (SFDI) is a non-contact wide-field spectroscopy technique that employs sinusoidal patterns of spatially modulated light as the excitation source. By obtaining the effective modulation transfer function of the diffusively reflected light from a turbid medium, it considers the contribution of reduced scattering and absorption coefficient to this function allowing for decoupling of the optical properties. The extracted optical properties at several wavelengths can provide quantitative information on concentration of tissue chromophores such as hemoglobin, fat, and water. It also delivers information on the arrangement of tissue structural components, mainly cells and extracellular matrix proteins. The technique has been utilized to investigate many phenomena in brain, kidney, and skin tissues.Enhancing spatial, temporal, and spectral information content in SFDI can give insight to tissue constituents, their dynamics, and distribution. In this work, we developed and validated three variations of SFDI instruments with design considerations to match specific applications:1. High Speed SFDI instrument that detects rat cortex dynamic optical and physiological properties at 17 frames per second following cardiac arrest and resuscitation.2. Hyperspectral SFDI instrument which measures tissue optical properties at 1000 spectral bins over a broad range, 580-950 nm, and can spatially resolve concentrations of oxy- deoxy- and met- hemoglobin as well as water and fat fractions. It utilizes principles of spatial scanning of the spectrally dispersed output of a supercontinuum laser.3. Single pixel SFDI instrument which takes advantage of high bandwidth available for spectral encoding using a single-element detector and sparse sampling based on compressed sensing to characterize tissue optical properties over a wide field of view, 35 mm × 35 mm.
Study of the electric and magnetic properties in doped pyrochlore iridate Bi2-xCuxIr2O7

ABSTRACT In this study, we examined the magnetic and electric properties of the Cu-doped Bi2-xCuxIr2O7 (x = 0,0.2,0.4,0.6). The X-ray diffraction confirmed that the Bi2-xCuxIr2O7 had a cubic structure. The electric transport properties indicate that the samples were in a metallic state when x < 0.4, and the metal-insulator transition occurred in the sample at x = 0.6. The behaviour of the resistivity in the composite material was produced by the electron-electron scattering process. The grain boundary effect played a dominant role in the conduction process. It was also found that the antiferromagnetic interactions enhanced with increasing Cu doping at first, but they weakened with further increases in Cu doping. These findings are explained based on the competition among the ferromagnetic Cu–Cu, antiferromagnetic Ir–Ir and antiferromagnetic Ir–Cu interactions.
Dynamic simulation of a full vehicle system featuring magnetorheological dampers with bypass holes

This study suggests a relationship between two different types of magnetorheological dampers and the driving performance of the passenger vehicles such as ride quality and stability. One of the magnetorheological dampers has the two different bypass holes in the piston bobbin to achieve a relatively low damping force slope in the low piston velocity region. Without bypass holes, two cylindrical-type magnetorheological dampers have same dimensions (pole lengths, piston radius, and coil size). To enhance the ride quality of the passenger vehicle, the damping force slope of the magnetorheological damper with bypass holes is more gradual than that of the magnetorheological damper without bypass holes. On the basis of the damping force model, three vehicle types with two working modes (soft and hard) are formulated. Driving performance indexes, such as vertical acceleration of the sprung mass and tire deflection, are evaluated in frequency domains under two random road conditions. A comparative study is conducted to prove the effectiveness of the magnetorheological damper with bypass holes through simulation.
Experimental determination of fracture toughness of epoxy toughened with nano-block copolymers

A lack of resistance to crack growth and initiation limits the application of epoxy in fields requiring high fracture toughness. Means to improve the fracture toughness of epoxy are commonly achieved through the addition of a secondary phase. The study of increasing levels of Nanostrength® M52N nano-block copolymers with a bisphenol A epoxy resin has been investigated due to low agglomeration of the nanophase, and retention of mechanical and thermal properties signature to epoxy. Mode I fracture toughness has been determined using double cantilever beam testing. A modified simple beam theory for brittle, linear elastic behaviour, has accounted for bond line properties and non-symmetrical crack propagation of the adherend. Experimental investigation has shown improvements of stress intensity factor for Mode I failure, KIc, of 173% for 10% volume fracture nanophase.
Enhanced C-V2X Mode-4 Subchannel Selection

In Release 14, the 3rd Generation Partnership Project (3GPP) introduced Cellular Vehicle-to-Everything (C-V2X) mode-4 as a novel disruptive technology to support sidelink vehicular communications in out-of-coverage scenarios. C-V2X mode-4 has been engineered to operate in a distributed manner, wherein vehicles autonomously monitor the received power across sidelink subchannels before selecting one for utilization. By means of such an strategy, vehicles attempt to (i) discover and (ii) reserve subchannels with low interference that may have the potential to maximize the reception likelihood of their own broadcasted safety messages. However, due to dynamicity of the vehicular environment, the subchannels optimality may fluctuate rapidly over time. As a consequence, vehicles are required to make a new selection every few hundreds of milliseconds. In consonance with 3GPP, the subchannel selection phase relies on the linear average of the perceived power intensities on each of the subchannels during a monitoring window. However, in this paper we propose a nonlinear power averaging phase, where the most up-to-date measurements are assigned higher priority via exponential weighting. We show through simulations that the overall system performance can be leveraged in both urban and freeway scenarios. Furthermore, the linear averaging can be considered as a special case of the exponentially-weighted moving average, ensuring backward compatibility with the standardized method. Finally, the 3GPP mode-4 scheduling approach is described in detail.
History of Digital Detectors in Intraoral Radiography

The first digital sensor used in intraoral radiography, RadioVisioGraphy was introduced in 1987. It was based on the activity of a charged-Coupled Device (CCD) sensor. Later on, other digital sensors became commercially available, including the Digora featuring an imaging plate coated with photostimulable phosphor (PSP) in 1994 and the complementary metal-oxide semiconductorbased sensor, CDR active pixel sensor, in 1998. These technologies have recently undergone considerable improvement, and several dental clinics have switched from film-based systems to digital imaging. In the early days, digital sensors were considered inferior to film in clinical diagnostics, but according to recent research results, there is no longer any significant difference because of the improvement in performance. However, our latest research using a new evaluation method and a precise phantom model indicated some differences between the performance of CCD and PSP systems and further differences between PSP systems of different function and performance.
Interacting Bilayer Electron System

This thesis summarizes the explorations of interacting bilayer electron systems which provide a versatile, extended platform to study electron-electron interaction beyond single layers. By setting each layer at a different density, the bilayer electron system hosts different electronic phases in each layer; moreover, we can study the role of interaction between these phases when the two layers are closely spaced. We first present a new technique and experimental results directly probing the magnetic-field-induced Wigner crystal (WC) through its interaction with another many-body phase which is comprised of composite fermions (CFs). We measure the magnetoresistance of a bilayer electron system where one layer has a very low density and is in the WC regime, while the other (probe) layer is near half Landau level filling and hosts a sea of CFs. The data exhibit commensurability oscillations in the magnetoresistance of the CF layer, induced by the periodic potential of WC electrons in the other layer, and provide a unique, direct glimpse at the symmetry of the WC, its lattice constant, and melting. They also demonstrate a striking example of how one can probe the many-body state of two-dimensional electrons using another many-body state with exotic quasiparticles. We also report experiments demonstrating that the layer densities of an asymmetric bilayer electron system oscillate as a function of perpendicular magnetic field that quantizes the energy levels. At intermediate fields, this interlayer charge transfer can be well explained by the alignment of the Landau levels in the two layers. At the highest fields where both layers reach the extreme quantum limit, however, there is an anomalous, enhanced charge transfer to the majority layer. Surprisingly, when the minority layer becomes extremely dilute, this charge transfer slows down as the electrons in the minority layer condense into a WC. Furthermore, by examining the quantum capacitance of the dilute layer at high fields, the screening induced by the CFs in an adjacent layer is unveiled. The results highlight the influence of strong iniii teraction in interlayer charge transfer in the regime of very high fields and low Landau level filling factors. By further scrutinizing the details of the interlayer charge transfer as a function of magnetic field and its termination as mentioned above, we are able to measure the critical filling factor (νC) below which a magnetic-field-induced, quantum WC forms in a dilute, two-dimensional electron layer when a second, high-density electron layer is present in close proximity. The data reveal that the WC forms at a significantly smaller νC compared to the νC (≃ 0.20) in single-layer two-dimensional electron systems. The measured νC exhibits a strong dependence on the interlayer distance, reflecting the interaction and screening from the adjacent, high-density layer.
Magnetic core–shell nanocatalysts: promising versatile catalysts for organic and photocatalytic reactions

ABSTRACT During the past decades, there have been enormous developments in catalysis in the form of great innovations such as precise structure characterization, surface functionalization, and effective utilization of active sites. In both academic and industrial sectors, the development of efficient nanosized catalysts has received considerable attention because it can improve the efficiency of the catalytic process and the selectivity of products, which can minimize the overall production cost and the amount of chemical wastes generated by improving the atomic efficiency. However, bulk-scale synthesis and utilization of nanocatalysts are hindered by the high synthetic cost, tedious synthesis procedure, and difficulty in the separation and recovery of the catalysts after the reactions. In this context, superparamagnetic nanoparticles have attracted much attention as a catalyst and as a support owing to their robust structure, low cost, environmental benignity, and easy separation under an external magnetic response. In this review, we focused on organic catalysis and photocatalysis using magnetically retrievable core–shell nanocatalysts with various functionalities. This review presents a comprehensive overview of the synthesis of magnetic core–shell nanocatalysts with suitable functionalities for catalysis, recent developments in organic and photocatalytic reactions using core–shell catalysts, and challenges to be addressed as part of future research activities. The first part summarizes the various synthetic methods of magnetic nanocores, and the second part overviews the detailed functionalization methods for the growth of shells on the surface of the magnetic nanocores, along with the merits and challenges to-date. In the last section, the efficiency, recoverability, and reusability of magnetic core–shell nanocatalysts are reviewed for a variety of organic and photocatalytic reactions.
Nanoindentation and scratch behaviour of Ni–P electroless coatings

In the present paper, the mechanical properties and the scratch failure mechanisms of Ni–P electroless coatings are described. The material microstructure was studied in as-deposited and annealed conditions through SEM and EDS analyses. Nanoindentation measurements on the coatings showed a remarkable hardening due to the crystallization and precipitation behaviour produced by annealing. The scratch tests, conducted by increasing the load during scratch, revealed the coating failure mechanisms in a broad range of applied stresses up to delamination.
An evaluation of a psychoacoustic model of the changing-state hypothesis

The effect of irrelevant sounds on short-term memory was investigated in two experiments using noise-vocoded speech (NVS) stimuli. Speech samples were systematically modified by a noise-vocoder and a set of stimuli varying from amplitude-modulated white noise to intelligible speech was created. Eight NVS conditions, composed of 1, 2, 4, 6, 9, 12, 15 and 18-bands, were used as the irrelevant sound stimuli in a digit-recall task next to the speech and silence conditions. The results showed that performance decreased with the number of frequency bands up to the 6-band condition but there was no influence of number of bands on performance beyond 6 bands. The results were analyzed using four acoustic metrics proposed in the literature: the frequency domain correlation coefficient, the fluctuation strength, the speech transmission index and the normalized covariance measure. None of the metrics successfully predicted the results. However, the parameter values of the frequency domain correlation coefficient, the speech transmission index and the normalized covariance measure indicated that a prediction model for irrelevant sound effect should account for both temporal and spectral features of the irrelevant sounds. 1This chapter is a modified version of: Senan, T. U. , Jelfs, S. , and Kohlrausch, A. (2018). “Cognitive disruption by noise-vocoded speech stimuli: Effects of spectral variation,” J. Acoust. Soc. Am. 143(3), 1407-1416.
Seismic evaluation and partial retrofitting of concrete bridge bents with defect details

The need for seismic retrofitting of bridges after severe earthquakes has become important in recent years. This study examines the seismic evaluation of concrete bents of highway bridges designed and implemented according to the 1990s regulations. Compared with the older codes, 1990s codes have more complex details for connections which are evaluated by experimental and numerical methods in this research. Significant improvement was observed in the behavior of the specimens designed with 1990s codes; however, this improvement is not enough as strength degradation was also reported in the inner cycles of the hysteresis curves. Therefore, seismic improvement was performed using performance levels. Results showed that in the connection zone, the longitudinal bar slippage occurs and the performance of connection is weak. In experimental phase, a specimen was constructed with external pre-stressing in a transverse direction for retrofitting. The level of improvement in behavior was also evaluated using parameters such as energy dissipation, performance levels and force-displacement curves.
Message Passing Aided Least Square Recovery for Compressive Sensing

Compressive sensing (CS) have got attention as a promising signal processing technique to reduce information rate of sparse signals [1]. One line of CS related researches are to devise low complexity recovery algorithms since the conventional L1-norm based recovery algorithms still have high computational complexity for practical applications. Recently, a few researchers have made an attempt to apply probabilistic message passing (PMP) ideas to CS recovery [2], [3] since PMP has provided a successful solution for low complexity decoding while showing suboptimal performance in channel coding problems, such as low-density parity check codes [4]. Motivated by such previous works, in this paper, we propose a new least square estimation (LSE) based CS recovery algorithm by applying PMP, called PMP-LSE. It is well known that CS recovery is basically an underdetermined system and it can be reformed as an overdetermined system with the support set information (SI). Therefore, in the proposed algorithm, PMP undertakes to find the SI of the signal to reform the recovery to an overdetermined case, and then LSE completes the recovery using the SI. Mainly, PMPLSE has two strong benefits. First, PMP-LSE shows outstanding performance with noisy measurements by removing the noise effect from elements belonging to the non-support set. Second, PMP-LSE prevents the recovery from diverging. Under certain conditions, PMP based algorithms fails in the recovery due to divergence caused by a large number of iterations. In the algorithm, however, the possibility of the divergence highly decreases since PMP is only used to search the SI with a few iterations.
Evaluation of four different climate sources on pavement mechanistic-empirical design and impact of surface shortwave radiation

ABSTRACT This paper compares the predicted distresses (via in the AASHTOWare Pavement ME Design software (PMED)) of asphalt concrete (AC) and jointed plain concrete pavement (JPCP) using four different climate data sources. These sources also include the Modern Era Retrospective Analysis for Research and Application (MERRA) Versions 1.0 and 2.0 (MERRA-1 and MERRA-2). Pavement performance predictions generated using these data showed disagreement among some of the climate data sources, especially for MERRA-2. Comprehensive diurnal and other time-series analyses of the raw climate data found significant disagreements in the percent sunshine estimates. Percent sunshine is used in the PMED environmental effects model to semi-empirically estimate the downwelling shortwave radiation reaching the pavement surface. Both MERRA data (MERRA -1 and MERRA-2) independently provide direct predictions of downwelling surface shortwave radiation (SSR). The direct model predictions of SSR were used to back calculate ‘synthetic’ per cent sunshine for input into the PMED. The use of the synthetic per cent sunshine derived from the predicted SSR eliminated nearly all discrepancies in the predicted pavement performance using MERRA-1 versus MERRA-2 data. Based on these results, the authors recommend that SSR rather than per cent sunshine be used as a direct input to the PMED.