Miracle-dz/UniFAR-FTUs huggingface dataset:
Ionic Seebeck Effect in Alkali Niobophosphate Glasses

Ionic Seebeck effect has been investigated in Li (Na,K)2O‐Nb2O5‐P2O5 glasses. Ionic Seebeck coefficients and heats of ion transfer have been measured. Soret coefficients have been calculated for glasses being studied. Temperature dependence and content of Nb2O5 dependence of Soret coefficients have been analyzed. Hypotheses of coefficients of self-diffusion and thermodiffusion ratio when temperature and content of Nb2O5 change have been proposed.
Ultrabroadband, Large Sensitivity Position Sensitivity Detector Based on a Bi2Te2.7Se0.3/Si Heterojunction and Its Performance Improvement by Pyro‐Phototronic Effect

Bi2Te(/Se)3, as a novel topological insulator, is a prospective candidate for next‐generation spintronic and photoelectric devices. Here, A series of Bi2Te2.7Se0. 3 films are successfully prepared on Si substrate with different thicknesses and used as a self‐powered light position sensitive detector (PSD) through the introduction of a lateral photovoltaic effect (LPE). Owing to its wide and strong absorption, the high surface mobility of the Bi2Te2.7Se0. 3 layer, and the outstanding heterojunction quality, this PSD shows an unprecedentedly broadband photoresponse from ≈350 to ≈2200 nm and exhibits very good performance with ultralarge sensitivities (283.71 mV mm−1 at 532 nm, 137.4 mV mm−1 at 1064 nm, 38.91 mV mm−1 at 1550 nm, and 16.56 mV mm−1 at 2200 nm), perfect nonlinearity (<3%), and ultrafast response times (≈52.1 µs/≈70.2 µs), all of which are among or represent the best results reported until now, especially in the infrared region. Additionally, its sensitivity can also be greatly improved though the addition of a bias voltage with an increment up to 194.6% at −1 V. More importantly, the pyro‐phototronic effect, which can be used to modulate both the LPE and the time response, is surprisingly observed in this PSD but with different working mechanisms than found in traditional photodetectors.
Ductile Failure Analysis in Metallic Materials through Computational Homogenization

Ductile Failure Analysis in Metallic Materials through Computational Homogenization Over the last years, the use of computational tools for the study of the constitutive behavior of materials has received increasing attention, particularly the modeling of heterogeneous materials by an interchange of information between the macro and micro scales. The macroscopic response is obtained by the homogenization of microscopic Representative Volume Elements (RVEs). The ductile failure of metals at low homologous temperatures is largely determined by the nucleation, growth and coalescence of microstructural voids. These phenomena are strongly dependent on the stress state, specifically on parameters such as triaxiality and Lode angle. High triaxiality stress states tend to increase the void size, whereas lower triaxialities distort them significantly. In this work, the influence of factors such as porosity, Lode parameter, triaxiality, material properties and void geometry on the overall macroscopic yield response is investigated. Using the Finite Element Method, several RVEs containing voids are analyzed, subject to different boundary conditions, with both isotropic (von Mises) and anisotropic (monoand polycrystalline FCC slip) matrix material models. A stress-driven homogenization approach is used, allowing for strict control over both triaxiality and Lode angle. Various parametric studies are conducted, and the resulting yield curves are compared with analytical models whenever possible. For vonMises matrices, the numerical results are comparedwith themodels of Gurson (1977), GTN (Tvergaard and Needleman, 1984), Madou and Leblond (2012a,b) (ML) and Danas and Aravas (2012) (MVAR). The single crystal results are compared with the models of X. Han et al. (2013) and Mbiakop, Constantinescu, et al. (2015b) (MVAR). The numerical solutions capture the same trend as the analytical models. In general, for high triaxialities, void growth up to the yield onset is not negligible. This significantly affects the yield estimates for those loadings. A corrected porosity expression is proposed to predict the porosity at yield as a function of the triaxiality. With isotropic matrices, the effect of the Lode parameter is marginal. For single crystal matrices, its influence is mostly caused by the response of the constitutive model, not by the voids. Even though the Lode parameter also affects the void distortion, the magnitude of this effect is reduced. In the studies conducted, the influence of void geometry and orientation is found to be of the same magnitude as the Lode parameter, for the void volume fractions considered. For
High-Temperature Characterization of a 1.2-kV SiC MOSFET Using Dynamic Short-Circuit Measurement Technique

Threshold voltage and channel mobility of a 1.2-kV planar-channel SiC MOSFET at high junction temperature (<inline-formula> <tex-math notation="LaTeX">$T_{j}$ </tex-math></inline-formula>) up to 700 °C have been extracted and analyzed for the first time, by virtue of a specially designed short-circuit (SC) measurement technique we developed. Under the SC condition, <inline-formula> <tex-math notation="LaTeX">$T_{j}$ </tex-math></inline-formula> of the SiC MOSFET can rise significantly within a few microseconds, which can be extracted based on the SC waveforms and thermal calculations. The planar-channel SiC MOSFET investigated in this work can maintain normally-off operation at an elevated <inline-formula> <tex-math notation="LaTeX">$T_{j}$ </tex-math></inline-formula> up to 700 °C. Furthermore, the underlying mechanisms of the temperature dependence of the threshold voltage and channel mobility are also analyzed. The threshold voltage of the SiC MOSFET exhibits a different temperature dependence over a wide range (120–700 °C) compared with that of Si counterparts, which is attributed to interface traps’ response. The channel mobility shows a non-monotonic temperature dependence, due to divergent scattering mechanisms.
Control of self-driving vehicles using deep learning

This thesis investigates the use of deep learning to control an autonomous vehicle in urban environments. A so called direct perception system was implemented, allowing for human interpretation of the output while providing a means of guaranteed safety. Moreover, the system was trained using unlabeled data, providing a cost and time efficient alternative to other approaches. The data was obtained by recording lidar and GNSS-IMU sensor readings while driving a simulated car. Together with high level directions, traffic light status and speed limit, this information captured the state of the ego-vehicle and its surroundings at every time step. Given such a state, the networks were trained to predict the future trajectory of the ego-vehicle. The predicted trajectory could then be followed by applying appropriate control signals to the vehicle, found using a model predictive controller. Four types of deep neural networks were implemented in order to explore different ways of predicting trajectories. The performance of the networks was measured using the mean squared error between the ground truth trajectories and the predicted ones. In addition, a more qualitative analysis was made by visually inspecting the trajectories. Three of the four network types obtained similar performance, while all networks failed to reach acceptable performance. The networks were able to predict acceptable trajectories in some situations, e.g., turning at crossroads and driving on straight roads. On the other hand, some situations were evidently more difficult, e.g., non-crossroad turns and stopping for traffic lights and other vehicles. Owing to these results, it is not possible to conclude whether the sensors provide sufficient information to control a vehicle or not. In conclusion, deep learning seems to be a promising technique for controlling autonomous vehicles, although the problem was harder than expected.
Simulation of aqueous humour (ah) flows and deformation of descement membrane detachment (dmd) in a three dimensional anterior chamber (ac)

This thesis strives the interaction between the aqueous humour (AH) flows and the deformation of Descemet membrane detachment (DMD) in a 3D anterior chamber (AC). Descemet membrane detachment (DMD) is an uncomman condition with a wide range of possible cause of disease. The aqueous humour flow in the anterior chamber is described as flow driven by buoyancy effects due to the existing temperature difference. The mathematical model has been developed and numerical result for finite element method are carried out using COMSOL Multiphysics software by solving the governing equations for the AH flows and the deformation of DMD. The fluid flow behavior and the deformation of the detached Descemet membrane are analysed in order to comprehend the progression of the DMD in the AC due to the AH flows and vice versa. The direction of the gravitational force acting has a great influence to the fluid flow in the AC. Thus, the position of the patient with DMD need to be concerned in order to induce the phenomena of spontaneous reattachment. The spontaneous attachment or re-detachment of the DMD could then be induced in the simulation to better understand its occurrence for a viable treatment to be devised.
Advanced interfacial properties of glass fiber/dopamine-epoxy composites using a microdroplet pull-out test and acoustic emission

ABSTRACT The evaluation of interfacial properties between fiber and epoxy resin is very important. An advanced microdroplet pull-out test was introduced to quantitatively evaluate the interfacial adhesion. To improve the interfacial property, dopamine was added in the epoxy resin whereas grease treatment was applied to the glass fiber to reduce the interfacial property. The pull-out forces of microdroplets as well as acoustic emission energy were measured by establishing a relationship between the adhesive force and acoustic emission energy per embedded length. Microdroplet fatigue tests were performed on microdroplets with the same embedded lengths. To observe the effect of interfacial properties, tensile specimens of milled glass fiber-reinforced epoxy composite were manufactured and tensile tests were conducted. During this tensile testing, the stress distribution was determined using polarized optical light. The results indicated that the dopamine conditions produced the highest degree of curing of the epoxy resin resulted in improved mechanical properties and interfacial shear strength. In addition, the studies also demonstrated that the debonding and fracture forces of the microdroplets were proportional to the acoustic emission energy accompanying fracture of specimens during microdroplet pull-out test with the associated acoustic emission test.
Optimization of the Compression-Based Piezoelectric Traffic Model (CPTM) for Road Energy Harvesting Application

This paper employs the Two-Degree-of-Freedom (2DOF) electromechanical model to show the probability of the piezoelectric approach as an option for energy scavenging devices in roadway applications. The passing vehicles are the main energy source for harvesting device. A 2DOF electromechanical model as the piezoelectric harvesting unit is applied to explain the harvester performance in a single lane road. APC piezoelectric ceramic (APC 855) is selected as the optimum piezoelectric material due to its high piezoelectric constant values and high piezoelectric charge constant. Also, in the traffic model, we employ a Cellular Automata (CA) model. The vehicle dynamics model is used to transfer information from the traffic model to the piezoelectric model. Combining both the traffic model, i.e. the piezoelectric and the vehicle dynamics model, results in the compression-based piezoelectric traffic model (CPTM). In a single-lane traffic model with different arrival rate λ, a single circle-shaped Piezoelectric Cymbal Transducer (PCT) with thickness of 0.3 mm and diameter of 32 mm is applied, in which the produced power is 14.126 W and 29.746 W and 6.47 W. Based on these outcomes, if we lay multiple PCT arrays along the highway road, a large amount of power can be produced. Hence, a great potential is shown by the proposed electromechanical-traffic model for applications related to the macro-scale roadway electric power generation systems.
Modelling ion migration and charge carrier transport in planar perovskite solar cells

Perovskite solar cells (PSCs) have significant potential for success in the global market,as both a thin-film technology and as part of perovskite-on-silicon tandem devices. The latter technology is currently in the early stages of commercialisation. The record efficiencies of some types of PSC are close to their theoretical maximum; however, their long-term stability remains an area of concern. Rapid degradation caused by the external environment can be avoided via careful encapsulation of the device. However, cells also show an unforeseen internal behaviour, the effects of which have been termed current voltage hysteresis by the research field. It is now widely accepted that ion migration via vacancies in the perovskite is the origin of hysteresis, and hence that this behaviour is intrinsic to every PSC. Modelling ion migration in PSCs, and its effect on both their transient and steady-state performance, is the topic of this project. A combination of numerical techniques and asymptotic analysis is used to investigate a three-layer driftdiffusion model for ion vacancy migration and charge carrier transport within a PSC. For realistic values of the parameters, such a model displays both temporal and spatial stiffness and hence requires tailored numerical methods of solution. In addition, a simplified surface polarisation model is derived using the method of matched asymptotic expansions.The form of this model reveals how ion vacancy migration controls the evolution of the electric field across the three layers of a PSC and that this is the key to explaining its behaviour. The influence of two important properties of the transport layers, which adjoin the perovskite layer of a PSC, on the distribution of the electric field is highlighted and explained for the first time. Simulations are used to reproduce a number of experimentally observed trends, including why PSCs with organic transport layers tend to display reduced hysteresis. Strategies for determining the dominant charge carrier recombination mechanism, and reducing the associated performance loss, are also discussed.
Rhyme and reason

Part 1 The first day - the minimalist viewpoint: the mystery of language acquisition the mystery of language variation knowledge of language simple learning methods simple universal minds economy language and form. Part 2 The second day - notation and reality: levels of representation words (repeat thrice) systems of features the inclusive nature of LF the invariant parts of the computational system representational alternatives optimality theory. Part 3 The third day - phrases and linearity: (virtually) necessary properties phrasal representations precendence by hierarchy some interesting predictions further intriguing predictions empty categories are not empty further consequences of linearization. Part 4 The fourth day - cyclic transformations: movement in languages "without movement" extending structures noncyclic mergers? adjunction the array as a numeration clockwork some open questions to exercise with. Part 5 The fifth day - chains and their checking domain: the minimal link condition well-formedness conditions versus ranking criteria further conditions pertaining to chains the overall shape of grammatical chains (and where it may come from) desperately seeking features there! heads and tails. Part 6 The sixth day - words and their internal domain: internal domains much ado about word formation the subcase principle departures from optimality on the origins of uninterpretable features evolution strikes back an abrupt and unexpected coda. Part 7 And on the seventh day.
Finite Element Simulation of Multiple Slip Effects on MHD Unsteady Maxwell Nanofluid Flow over a Permeable Stretching Sheet with Radiation and Thermo-Diffusion in the Presence of Chemical Reaction

The aim of the present study is to investigate the multiple slip effects on magnetohydrodynamic unsteady Maxwell nanofluid flow over a permeable stretching sheet with thermal radiation and thermo-diffusion in the presence of chemical reaction. The governing nonlinear partial differential equations are transformed into a system of coupled nonlinear ordinary differential equations with the aid of appropriate similarity variables, and the transformed equations are then solved numerically by using a variational finite element method. The effects of various physical parameters on the velocity, temperature, solutal concentration, and nanoparticle concentration profiles as well as on the skin friction coefficient, rate of heat transfer, and Sherwood number for solutal concentration are discussed by the aid of graphs and tables. An exact solution of flow velocity, skin friction coefficient, and Nusselt number is compared with the numerical solution obtained by FEM and also with numerical results available in the literature. A good agreement between the exact and numerical solution is observed. Also, to justify the convergence of the finite element numerical solution, the calculations are carried out by reducing the mesh size. The present investigation is relevant to high-temperature nanomaterial processing technology.
A Comparative ex-vivo Study of Effects of Different Irrigation Protocols with/without Laser Activation on the Root Dentine’s Micro-Hardness

Objective: To compare the effects of different irrigation protocols, with/without laser activation, on the radicular dentine’s micro-hardness. Methods: Eighty-two human extracted premolars were decoronated and divided into 7 groups. Roots were longitudinally split into two halves. The micro-hardness was measured for one half before and after irrigation protocols. The groups were; G1: MTAD without laser-activation, G2: MTAD with laser-activation, G3: sodium-hypochlorite (SH) with laser-activation, G4: SH then EDTA with laser-activation, G5: SH then MTAD with laser-activation, G6: SH without laser-activation. G7: distilled water (control). In the two-irrigants groups G4 and G5), samples were irrigated first with SH then with MTAD or EDTA irrigants, which were activated by the laser. The difference between the before- and after-irrigation micro-hardness was calculated to obtain the micro-hardness difference. Data were analyzed using the Paired Sample-t and Two-ways ANOVA tests at P=0.05. Results: Overall, the mean dentine’s micro-hardness after-irrigation (103.1) was lower than before-irrigation (116.1) (P<0.001); except for the distilled-water group, (116.6 and 112.9, respectively) (P=0.075). The micro-hardness reduction of SH without laser-activation group (32.5) was the greatest (P<0.001). The single-irrigant or laser-activation irrigation protocols caused significantly less micro-hardness reduction compared to the two-irrigants or no laser-activation protocols. The mean micro-hardness reduction of SH and MTAD groups (both with laser-activation) (5.8 and 9.3, respectively) were significantly lower than other groups, but not from that of the control group (3.7). Conclusion: Using irrigants significantly reduced the root-dentine’s micro-hardness. Although irrigants agitation by an Er: Yag laser significantly minimized micro-hardness reduction, it did not suppress the adverse effects on dentine micro-hardness when two-irrigants were used.
Phase transformations at heating of Sn–Ni–Zn powders obtained by cementation from solutions

The low-temperature method of Sn–Ni–Zn powders synthesis by cementation of tin and nickel with zinc powder from acidic solutions with the formation of “zinc core – porous nickel shell – external tin layer” structures has been proposed. The method provides metals ratio control in wide ranges (7–41 at. % of tin, 38–86 at. % of nickel and 7–24 at. % of zinc) by variation of the process duration. X-ray phase analysis data give evidence on the presence of β-Sn and Zn phases as well as NiZn3 and NiSn intermetallics in the powders obtained. Differential scanning calorimetry data show the availability of Sn–Zn eutectic with the melting point at 171.2 °C in the powders with high tin content (30–40 at. %). The formation of the ternary intermetallic τ1 phase (Ni3+xSn4Zn) has been established to occur as a result of the powders heating at 260 °C. The discovered low-temperature phase transformation in Sn–Ni–Zn system at 260 °C is of interest for electronic equipment assembly processes that include consecutive stages of soldering and resoldering.
A Combined Finite-Element-Finite-Volume Method for Thermal Arc Numerical Simulation

Most of the numerical methods used for thermal arc simulation, are often based either on finite volume or finite element approaches but very seldom on both of them. In this paper, we present a new combined finite-element finite-volume method for stationary and unsteady cases. The flow, energy and species equations are solved using a classical finite-volume (FV) method which is conservative and bears a robust physical meaning. The electromagnetic equations (EM) are solved using finite-element (FE) analysis which has the ability to easily deal with their mathematical formulation without transforming the equations or doing any extra manipulation. We propose two separate approaches for the FE-method: one that is only suitable for a steady-state scheme and another that could be applicable for both steady and unsteady cases. Some illustrative numerical examples are also presented in this paper.
A numerical Study of Single Column Adsorber for Optimal Design of Pressure Swing Adsorption

Four different configurations of pressure swing adsorption (PSA) were designed numerically using Matlab software. The PSA system was applied to separate oxygen from air. The software was used first to validate previous experimental results of single bed adsorber. The results showed that the breakthrough time with product pressurizing is about 1000 s and mass transfer zone (MTZ) is steeper, while with the air pressurizing happened within 60s and MTZ was very wide. High purity of oxygen (>90%) was observed with the first and fourth configuration. Purity of about 88% was achieved with the third configuration, and low purity (75%) with the second configuration. In addition, high power consumption was indicated by the first, and second configurations. However, the third and fourth configurations consumed low power due to the pressure equalization step. Based on the results, the more economic and effective design is the fourth configuration.
Impact of nano-perovskite La2CuO4 on dc-conduction, opto-electrical sensing and thermal behavior of PVA nanocomposite films

ABSTRACT Nanocomposite (NC) films of poly vinyl alcohol (PVA) incorporated with varying amounts of perovskite lanthanum cuprate (La2CuO4) nanoparticles (NPs) have been fabricated by solution intercalation technique. TEM result showed the size of NPs between 91-134nm. The effects of NPs content on structural and morphological behaviors of PVA have been established by XRD, FTIR and SEM methods. Electrical properties of NC films were performed using LCR-meter. Current (I)–voltage (V) data displayed dc-conductivity increased with increasing NPs content and trends of I–V indicate the dominant Ohmic behavior at voltage <5V and above that Poole–Frenkel emission is the dominant conduction mechanism. Ac-conductivity increases with increase in frequency and dosage of NPs. The maximum ac-conductivity obtained in this investigation is 2.43X10−5S/cm for PVA/2wt% La2CuO4 with lowest activation energy of 0.147 eV at 25°C. Cyclic voltammetry (CV) revealed the specific capacitance of PVA-NC improved compared to pristine PVA. The reduction in Tg with increment NPs contents was observed. The optical behaviors of NCs were deduced by UV-visible spectroscopy where the result showed band gap energy was reduced from 5.23eV to 3.25eV whereas refractive index increased from 1.71 to 2.44 for pure PVA and PVA/2wt%La2CuO4, respectively. Graphical abstract