Miracle-dz/UniFAR-FTUs huggingface dataset:
A generalised P-matrix model for SAW filters

The P-matrix model, which can be seen as a discrete version of the continuous COM model, is a well established tool to analyse the electro-acoustic properties of IDTs and reflector gratings. It relates both outgoing acoustic surface waves and the electric current to both incoming acoustic surface waves and the electric voltage. If an acoustic track consists of several IDTs and reflectors, it can be described by cascading the P-matrices of its building blocks. However, this approach has its clear limitations. Let us consider, e.g., a DMS track: if a voltage is applied to one IDT it will generate electric charges not only on the fingers of this IDT but also on its neighbouring fingers. These charges cause capacitive coupling between neighbouring elements and change the electro-acoustic excitation and detection of forward and backward propagating surface waves. Both effects are ignored in the building block model. The resulting inaccuracies are most pronounced, if short elements, such as in DMS tracks, are used. In this paper, I will present a generalisation of the classical P-matrix model, which relates the outgoing acoustic surface waves and all electric currents to the incoming acoustic surface waves and all electric voltages in a general acoustic track. This track might consist of an arbitrary number of IDTs, reflectors, and delay lines. To demonstrate the advantage of this model it will be compared to the simpler building block model and to measurements for two typical filters.
Actively Lubricated Bearings Applied as Calibrated Shakers to Aid Parameter Identification in Rotordynamics

The servo valve input signal and the radial injection pressure are the two main parameters responsible for dynamically modifying the journal oil film pressure and generating active fluid film forces in controllable fluid film bearings. Such fluid film forces, resulting from a strong coupling between hydrodynamic, hydrostatic and controllable lubrication regimes, can be used either to control or to excite rotor lateral vibrations. An accurate characterization of the active oil film forces is of fundamental importance to elucidate the feasibility of applying the active lubrication as non-invasive perturbation forces, or in other words, as a “calibrated shaker”, to perform in-situ rotordynamic tests. The main original contributions of this paper are three: a) the experimental characterization of the active fluid film forces generated in an actively-lubricated tilting-pad journal bearing in the frequency domain and the application of such a controllable bearing as a calibrated shaker aiming at determining the frequency response function (FRF) of rotordynamic systems; b) experimental quantification of the influence of the supply pressure and servo valve input signal on the FRF of rotor-journal bearing systems; c) experimental indication of how small such active fluid film forces (perturbation forces) should be, in order to perturb the rotor-journal bearing system without significantly changing its dynamic characteristics. To validate the experimental procedure and results obtained via actively-lubricated bearing, similar experimental tests are carried out using an electro-magnetic shaker. Very good agreements between the two experimental approaches are found. Maximum values of the main input parameters, namely servo valve voltage and radial injection pressure, are experimentally identified/suggested with the objective of obtaining non-invasive perturbation forces.Copyright © 2013 by ASME
p-q Theory power components calculations

The "generalized theory of the instantaneous reactive power in three-phase circuits", proposed by Akagi et al., and also known as the p-q theory, is an interesting tool to apply to the control of active power filters, or even to analyze three-phase power system in order to detect problems related to harmonics, reactive power and unbalance. In this paper it will be shown that in three phase electrical systems the instantaneous power waveform presents symmetries if 1/6, 1/3, 1/2 or 1 cycle of the power system fundamental frequency, depending on the system being balanced or not, and having or not even harmonics (interharmonics and subharmonics are not considered in this analysis). These symmetries can be exploited to accelerate the calculations for active filters controllers based on the p-q theory. In the case of the conventional reactive power or zero-sequence compensation, it is shown that the theoretical control system dynamic response delay is zero.
Mathematical model of the microchannel plate single electron impulse formation

A mathematical model is proposed of the cascade electron multiplication in a channel of microchannel plate (MCP), when the effects of space charge and surface charging can be ignored. The functional equations for evaluation of the MCP single electron impulse characteristics are obtained. The results are given of the calculation of the gain, pulse-height, and time distribution of a single electron signal.
Experimental Study of Endwall Heat Transfer in a Linear Cascade

The endwall heat transfer characteristics of forced flow past outlet guide vanes (OGVs) in a linear cascade have been investigated by using a liquid crystal thermography (LCT) method. Due to the special design of an OGV profile, the focus of this study is emphasized on the heat transfer patterns around the leading part of a vane. The Reynolds number is kept constant at 260,000. Two attack angles of the vane are considered. For α = 0°, the vane obstructs the incident flow like a bluff body and a remarkable flow separation phenomenon was noticed. For α = 30°, the vane is more "streamlined" with respect to the incoming flow and no obvious flow separation was observed. In general, the endwall heat transfer for α = 0° is higher than that for α = 30°.
Easier Implant Restoration: CAD/CAM Generated Implant Abutments

Computer-designed and -generated implant abutments offer restorative dentists alternative ways of restoring implants compared to present restorative techniques. Standard implant prosthetic techniques rely on implant level impressions and casting technology for component fabrication. Other techniques have included shaping or reduction of a stock component by either lab or dentist. Speaking to dental providers at my seminars and lectures, I have found that many dentists are looking for alternative ways to restore implants in a fast, easy, and predictable manner. In fact, some dentists I have spoken to avoid restoring implants because they feel too overwhelmed with the selection, technique, and protocol for restoring implants. Because of this, some of these providers do not offer implants as a treatment alternative. I have found that implant abutments generated by computer-aided design and computer-aided manufacturing (CAD/CAM) can be more precise than those created using traditional casting technology. This increased accuracy has specific application to implant dentistry, where precision of components may affect implant longevity, prosthetic success, and ease of restoration. After reading this article, the reader should be able to recognize and understand the CAD/CAM application in the dental field when restoring implants.
Different Combinations of Butchery and Vegetable Wastes on Growth Performance, Chemical-Nutritional Characteristics and Oxidative Status of Black Soldier Fly Growing Larvae

Simple Summary Due to the high sustainability of insect farming, the possibility to farm insects as a food and feed source seems to be very promising. Reusing and enhancing food waste is possible by using it as a substrate for the growth of insects. In this context, black soldier flies (BSF) can grow on a wide range of substrates, transforming them into valuable biomass. In this trial, four different substrates were used and were evaluated for their suitability for larvae rearing: broiler feed as standard diet, a vegetable diet, a diet with 50% of vegetables and 50% of butchery wastes, and a diet composed by 75% of vegetables and 25% of butchery wastes. Butchery wastes can be suitable, but they must be well combined with other ingredients to balance the high level of lipid and the low content of protein, and vegetable wastes can be an appropriate candidate. Vegetable and butchery wastes are easy to find and collect, and in the present trial, they showed interesting potential for BSF larvae growth producing, at 22 days of age, insects with interesting chemical characteristics. The use of vegetable wastes reduced the level of the reactive oxygen species in insect hemolymph, suggesting a positive effect of larvae welfare. Abstract Hermetia illucens larvae (five days old) were farmed on broiler feed (control diet), a vegetable diet (V100), a 50% of vegetable diet + 50% of butchery wastes (V50 + B50), and a 75% of vegetable diet + 25% of butchery wastes (V75 + B25) to evaluate their suitability. Ten kilograms of substrate and 6000 larvae composed each replicate (nine per group). Larvae were weighed and measured every two days until the 25% developed into prepupae. Larval mortality and growing indexes were calculated. Substrates, larvae, and frass chemical composition were analyzed. Larvae oxidative status and stability were measured in hemolymph and body. The V100 larvae showed the lowest live weight, length, thickness, and growth rate but had low mortality rate and high substrate reduction index and protein conversion ratio. The V100 larvae had similar protein to and lower lipids than the control ones, while the V50 + B50 and V75 + B25 larvae contained higher lipids and lower protein than the others. Despite the vegetable wastes, at different levels, the reactive oxygen species content decreased in hemolymph, and the V100 diet depressed growth performance and should be avoided. The use of butchery wastes combined with vegetable ingredients can be a suitable alternative to balance the high level of lipid and the low content of protein.
‘Dynamic’ transverse mechanical properties of rat skeletal muscle under in vivo compression

In a general purpose, studies about effects of external mechanical strains on muscle aimed to investigate sores formation, rise of muscle pathologies by long term pressure application, impact damage, muscle fatigue (1). Few studies concerning mammalian muscles have investigated twitch contraction under in vivo compression either on rat muscle fibre bundles using high hydrostatic pressure (2) or on human biceps using a compressive cuff (3). Our purpose was to study the effect of in vivo compression on twitch contraction with a particular interest to the transverse force developed by compressed muscle.
Correction procedures for the numerical parasitic elements associated with lumped elements in global electromagnetic simulators

This paper presents a comparative study of the treatment of lumped elements in two different full-wave electromagnetic formulations: the finite-difference time-domain (FDTD) technique and the technique of integral equations. Although these two approaches are basically different, they are seen to exhibit the same kind of numerical troubles when lumped elements are involved. More precisely, lumped elements are systematically associated with numerical parasitic elements that can seriously alter the calculated results. As a solution, this paper proposes a general alternative formulation, which permits one to suppress these numerical parasites. This formulation is successfully applied to the FDTD technique. A simpler numerical deembedding procedure, which does not fundamentally transform the original formulation, is preferred for the integral-equation technique.
Perspectives of Students With Disabilities and Their Parents on Influences and Barriers to Joining and Staying in Extracurricular STEM Activities

Students with disabilities (SWDs) are less likely to establish themselves successfully in science, technology, engineering, and mathematics (STEM) careers. Researchers have identified barriers to participation in STEM, including deficits in mathematics and science, executive functioning skills, and self-efficacy, and lack of exposure to STEM experiences. Researchers found students who participate in STEM clubs have higher grades in STEM content areas, have better attitudes toward school, and are more likely to graduate. This study aimed to understand student and parent perceptions about the influences and challenges to participation in STEM clubs. We used a sequential explanatory mixed-methods design that began with a survey, followed by focus groups and interviews with parents and SWDs. We identified four salient meta-themes regarding what influences students to join and stay in a STEM club: fun and the subject matter, social and peer interactions, parent and teacher initiative, and a “semblance of normal. ” In addition, we identified meta-themes on the barriers for SWDs to join and stay in STEM clubs. These include being a good fit, having no student interest, others not making accommodations, and overwhelmed parents. This article concludes with recommendations for educators to make STEM clubs more inclusive.
LASER CLADDING PROCESS AND IMAGE PROCESSING

The laser cladding process involves many processing parameters. We present in this paper a low cost system based on two CCD cameras, a standard acquisition card and a Personal Computer which enables the operator to interact with the process and processing parameters. Geometrical information can be extracted such as the height or the width of the track. Moreover, one of the camera is used to carry out temperature measurements. In addition we present three different methods of measuring the speed of the particles in the powder spray.
Machine learning prediction of novel pectinolytic enzymes in Aspergillus niger through integrating heterogeneous (post-) genomics data

Pectinolytic enzymes are a variety of enzymes involved in breaking down pectin, a complex and abundant plant cell-wall polysaccharide. In nature, pectinolytic enzymes play an essential role in allowing bacteria and fungi to depolymerize and utilize pectin. In addition, pectinases have been widely applied in various industries, such as the food, wine, textile, paper and pulp industries. Due to their important biological function and increasing industrial potential, discovery of novel pectinolytic enzymes has received global interest. However, traditional enzyme characterization relies heavily on biochemical experiments, which are time consuming, laborious and expensive. To accelerate identification of novel pectinolytic enzymes, an automatic approach is needed. We developed a machine learning (ML) approach for predicting pectinases in the industrial workhorse fungus, Aspergillus niger. The prediction integrated a diverse range of features, including evolutionary profile, gene expression, transcriptional regulation and biochemical characteristics. Results on both the training and the independent testing dataset showed that our method achieved over 90 % accuracy, and recalled over 60 % of pectinolytic genes. Application of the ML model on the A. niger genome led to the identification of 83 pectinases, covering both previously described pectinases and novel pectinases that do not belong to any known pectinolytic enzyme family. Our study demonstrated the tremendous potential of ML in discovery of new industrial enzymes through integrating heterogeneous (post-) genomimcs data.
The Centaurea parlatoris complex (Asteraceae): taxonomic checklist and typifications

A taxonomic account of the Centaurea parlatoris complex (Asteraceae), endemic to Sicily, is presented. This complex includes six taxa, three described in the 19th century (C. parlatoris, C. parlatoris var. tomentosa and C. parlatoris var. virescens) and three recently described (C. sicana, C. giardinae and C. heywoodiana). Starting from the designation of the types for the oldest plant names that have not been typified yet, taxonomic considerations are formulated and C. parlatoris var. virescens is elevated to the rank of species. An identification key and a distribution map complete this account.
First principles study on the structures and properties of aluminum under high pressures

The structural, electronic, elastic and thermodynamic properties of aluminum were investigated using the first principles method based on density functional calculations in the region of 0GPa~100GPa. The unit cell volume and atomic positions were optimized with generalized gradient approximation (GGA), all calculated properties are in excellent agreement with the available experimental results, which imply the reliability of the present calculation method. The results show that aluminum is structural, mechanically and dynamically stable in the region of 0GPa~100GPa. With the increase of pressures, the cell parameter and cell volume of aluminum decrease, charge density between atoms increase. The bulk modulus, shear modulus, Young’s modulus and Poisson ratio are estimated by Voigt-Reuss-Hill approach. The B/G values and Cauchy pressures indicate aluminum possesses ductility, the ductility properties of aluminum enhance with increasing pressures. The heat capacity of aluminum increases with temperature at constant pressure while decreasing with pressure at constant temperature.
Single-Voltage-Supply Operation of Ga In P/In Ga As Insulated-Gate FET's for Power Application

Single-voltage-supply operation of insulated-gate FET's using Ga In P/In Ga As heterostructures for power application was demonstrated for the first time. It is found that the device can be operated with gate voltage up to 2 V without significant drain current compression. Because of this high gate operating voltage, single-voltage-supply operation of Ga In P/In Ga As insulated-gate FET's was achieved. Preliminary results show that for a 1- m gate length device operated at 1.8 GHz under class A-bias condition, this power FET showed a 14.5-dBm (140 mW/mm) saturated power with a power added efficiency of 30% when drain voltage is 4.8 V.
TEC Depletion Generated by the Total Solar Eclipse of 2 July 2019

A total solar eclipse occurred at the ascending node of the Moon's orbit on 2 July 2019, with an eclipse magnitude of 1.0459. The totality was visible from the southern Pacific Ocean east of New Zealand to the Coquimbo Region (Chile) and Central Argentina at sunset, with the maximum of 4 min 32 s visible from the Pacific Ocean. The recent Great American Eclipse, 21 August 2017, clearly showed that the ionosphere is strongly affected by the totality. In order to explore the ionospheric signature of the 2019 eclipse, we use data of ∼110 GNSS stations seeing multiple GPS and GLONASS satellites to visualize the eclipse signature on the total electron content (TEC) in the southern hemisphere. The location of the South American GNSS stations, at the end of the path of totality, right before sunset, makes the eclipse signature in the ionospheric TEC act like an early sunset with 15 TEC‐Unit variations, corresponding to 40% of background ionization. The effect reaches only four TEC‐Units, corresponding to 25%–40% of background ionization, for the more westerly observations, where we clearly highlight the effect of the eclipse in the ionosphere and the following recovery to normality. By applying the omega‐k analysis, we can find TIDs with wavelengths of around 100 km and larger than 200 km and with periods of 20–50 min, which supports the results of the Great American Eclipse. Using different grids, we can also prove the robustness of the omega‐k analysis.
On the Interface Between Management Accounting and Modern Information Technology - A Literature Review and Some Empirical Evidence

Based on a review of earlier research and empirical data this study suggests that the accounting academia has in general a limited understanding of the current developments in the accounting - information technology (IT) interfaces. This knowledge gap has important implications for as regards what should be studied in the area and how, as well as for the usefulness of knowledge we want to hold out to various stakeholders. The purpose of the study is to critically evaluate the status of research on the interface between accounting and IT. The focus of the paper is on the interface between IT and management accounting/control. The analysis demonstrates beneficial/enabling as well as problematic/constraining effects IT developments have had on accounting and control practice. The study particularly discusses the transforming potential of modern IT vis-a-vis the domains of accounting, the complex intertwining of integrated IT with accounting and control, and the paradox of IT complexity and its manifestations in the management accounting domain. The analysis gives reason to be concerned about the current state of Accounting Information Systems research in certain respects.
Evaluation of analytical methodologies used to derive vulnerability functions

The recognition of fragility and vulnerability functions as a fundamental tool in seismic risk assessment has led to the development of more and more complex and elaborate procedures for their computation. Although these functions have been traditionally produced using observed damage and loss data, more recent studies propose the employment of analytical methodologies as a way to overcome the frequent lack of post‐earthquake data. The variation of the structural modelling approach on the estimation of building capacity has been the target of many studies in the past; however, its influence on the resulting vulnerability model for classes of buildings, the impact in loss estimations or propagation of the uncertainty to the seismic risk calculations has so far been the object of limited scrutiny. In this paper, an extensive study of static and dynamic procedures for estimating the nonlinear response of buildings has been carried out to evaluate the impact of the chosen methodology on the resulting capacity, fragility, vulnerability and risk outputs. Moreover, the computational effort and numerical stability provided by each approach have been evaluated and conclusions drawn regarding the optimal balance between accuracy and complexity. Copyright © 2013 John Wiley & Sons, Ltd.
Effect of Doping Element and Electrolyte’s pH on the Properties of Hydroxyapatite Coatings Obtained by Pulsed Galvanostatic Technique

Hydroxyapatite (HAp) is the most widely used calcium phosphate as a coating on metal implants due to its biocompatibility and bioactivity. The aim of this research is to evaluate the effect of the pH’s electrolyte and doping element on the morphology, roughness, chemical, and phasic composition of hydroxyapatite-based coatings obtained by pulsed galvanostatic electrochemical deposition. As doping elements, both Sr and Ag were selected due to their good osseoinductive character and antibacterial effect, respectively. The electrolytes were prepared at pH 4 and 5, in which specific concentrations of Sr, Ag, and Sr + Ag were added. In terms of morphology, all coatings consist in ribbon-like crystals, which at pH 5 appear to be a little larger. Addition of Sr did not affect the morphology of HAp, while Ag addition has led to the formation of flower-like crystals agglomeration. When both doping elements were added, the flowers like agglomerations caused by the Ag have diminished, indicating the competition between Sr and Ag. X-Ray Diffraction analysis has highlighted that Sr and/or Ag have successfully substituted the Ca in the HAp structure. Moreover, at higher pH, the crystallinity of all HAp coatings was enhanced. Thus, it can be said that the electrolyte’s pH enhances to some extent the properties of HAp-based coatings, while the addition of Sr and/or Ag does not negatively impact the obtained features of HAp, indicating that by using pulsed galvanostatic electrochemical deposition, materials with tunable features dictated by the function of the coated medical device can be designed.