Miracle-dz/UniFAR-FTUs huggingface dataset:
Generalised mc  × nc -stage switched-capacitor-voltage-multiplier-based boost DC–AC inverter

A closed-loop scheme of a generalised -stage (multistage) switched-capacitor-voltage-multiplier inverter (SCVMI) is proposed by combining a two-phase interleaved phase generator and a sinusoidal-pulse-width-modulation (SPWM) control for low-power boost dc–ac conversion and regulation. In this SCVMI, the power unit contains two parts: SCVM booster (front) and H-bridge (rear). The SCVM booster is composed of two -stage SC cells and two -stage SC cells in series for a boost dc–dc conversion, and these cells are operated with two-phase non-overlapping clocks of phase generator for a high conversion ratio of at most (like a voltage multiplier). The H-bridge consists of four switches for a dc–ac conversion, and these switches are controlled by SPWM not only for realising full-wave operation, but also for enhancing output regulation as well as robustness to source/loading variation. Further, some aspects of theoretical analysis and design are included: SCVMI formulation, steady-state/dynamic analysis, conversion ratio, power efficiency, stability, capacitance selection, output filter and control design. Finally, the closed-loop SCVMI is simulated and the hardware implemented and tested. All the results are illustrated to show the efficacy of the proposed scheme.
Viscoelastic finite element analysis in design of potash mines

Computer simulation is playing an increasingly important role in evaluating the short and long term structural stability of underground mine openings, and in ground control studies related to mine design and layout. Such simulations are increasingly being used in the design of underground salt and potash mines. Because of the viscoelastic nature of salt rock, simulation models used in these deposits must take into consideration their time dependent properties if they are to correctly predict opening closures, ground stresses, and ground stability based on prescribed failure criteria. A number of computer codes have been developed in Canada in recent years meeting these requirements. This paper describes the use of one of these codes to predict the ground behaviour of a typical room and pillar mining section of a Western Canadian potash mine. Predicted ground behaviour, based on use of the code, was compared with actual behaviour through field measurements. The study provided good correlation between predicted and measured ground behaviour, and is an encouragement to greater use of numerical modelling in mine stability studies related to mine design.
PC‐based spinning rotor gage controller

The spinning rotor gage (SRG) is a molecular drag vacuum gage. Commercial versions are available that operate between about 10−4 and 1 Pa. In this paper we describe the design, and present performance data for a new SRG controller that uses a plug‐in peripheral board and a personal computer (PC) to perform all control, signal processing, and data analysis functions. This controller offers several advantages over those presently available, including the simultaneous operation of multiple SRGs (at least four SRGs with a single PC), complete software control of all operating parameters, and significantly improved low‐pressure performance.
An Adaptive Multiple LS Channel Estimation Method for MIMO System

Accurate channel estimation plays a key role in multiple-input and multiple-output (MIMO) communication systems. In this paper, we firstly discuss the popular linear least squares (LS) channel estimation and the multiple LS (MLS) channel estimation. Then an adaptive multiple LS (AMLS) channel estimate approach is proposed. Using numerical simulation, it is found that the proposed estimation method outperforms LS and MLS for a wide range of training SNRs.
Outcomes of Preoperative Embolization of Juvenile Nasopharyngeal Angiofibroma

Background: These are rare fibro-vascular neoplasms, out of all head and neck tumors, JNA contributing for only less than 0.5%. JNA incidence rate almost 1/150,000 and affects men and adolescents’ males Objectives: To study outcome and the role of Pre-operative Embolization of surgeries for Juvenile Nasopharyngeal Angiofibroma. Methods: A retrospective cross sectional study conducted at Al-Sader Medical City during the period 2010 through 2020 included 15 male patients who were managed for JNA, in whom embolization was performed preoperatively. Results : The study included 15 male patients with an average age of 16.4 ± 3.1 (standard deviation) (range: 11-22) years. The duration of the procedure is 126 minutes, on average and ranged 75 to 180 minutes; Average intra-operative blood loss was 300 (range: 150-750) ml. The postoperative hospitalization period was 2 days in 14 cases and a recurrence rate of 13.3% was reported. Conclusions : The use of preoperative embolization in JNA patients has been very beneficial in shortening surgery time, improve bloodless of the operative site, with a significant reduction in intraoperative blood loss, reduction in postoperative hospitalization time, and reduction in recurrent
Analytical equivalence between substrate-integrated waveguide and rectangular waveguide

Rectangular waveguide (RW) with sidewalls of vertical conducting cylinders (i.e. SIW, substrate-integrated waveguide) becomes popular with the advent of low-temperature co-fired ceramic structure; its analysis is usually numerical, or modal, leading to empirical design formulas. However, its analytical equivalence to the common RW of the solidwall is identified; in other words, analytical design formulas of the SIW and the equivalent RW of solid sidewalls are the same. The equivalence is established on comparing the surface impedances along the side walls, of the SIW and of an RW through analytical continuation. The equivalence formulas, propagation and cut off frequency show very good agreement with the results from both numerical simulations and measurements of hardware experiments, and over wide frequencies. The good agreements are easily understood on the basis of the conformal maps and the variational principle.
Role of Viscosity in Dynamic Creep Tests in Conventional, Oxidized, and Polymer-Modified Asphalts

A dynamic creep test was proposed as a new method for evaluating the ability of modified asphalt binders to maintain their elastic response. The test was readily proposed to evaluate the resistance to rutting of asphalt pavements. The authors are reporting the analysis of results of the dynamic creep test on several conventional and oxidized asphalts and blends of conventional asphalts with two polymers. The used polymers were styrene-butadiene-styrene and styrene-(ethylene-co-butylene)-styrene. The effects of temperature, material (base asphalt and polymer modifier), applied stress level, and oxidation were investigated. The possibility of using linear viscoelastic models for the description of the dynamic creep test was also studied.
Real-time integrity monitoring of composite laminates with magnetostrictive sensory layer

Fundamental research and development in smart materials and structures have shown great potential for enhancing the functionality, serviceability and increased life span of civil and mechanical infrastructure systems. Researchers from diverse disciplines have been drawn into vigorous efforts to develop smart and intelligent structures that can monitor their own conditions, detect impending failure, control damage and adapt to changing environments. Smart structures are generally created through synthesis by combining sensing, processing and actuating elements integrated with conventional structural materials. The conventional non-destructive evaluation techniques are not very effective in monitoring the structural integrity of composite structures due to their micro-mechanical complexities. With the commercial availability of the magnetostrictive (MS) material Terfenol-D in particulate form, it is now feasible to develop particulate sensors to detect damage with minimum effect on structural integrity. In present investigation, the electromagnetic response in the MS layer at the onset of delamination in one of the weakest ply of the composite laminate has been analyzed. For the numerical analysis symmetric and asymmetric carbon epoxy laminates with one of its layers embedded with Terfenol-D particles have been taken. Terfenol-D layer experiences a change in stress due to onset of delamination causing a change in its magnetic state, which can be sensed as induced open circuit voltage in the sensing coil enclosing the laminate beam. The effect of material properties, lamination schemes and placement of MS layer on the sensing capabilities has been analyzed.
Characterising the electrothermal properties of microstrip-coupled TES detectors

Microstrip-coupled Transition Edge Sensors (TESs) are important because they can be combined with waveguide-horn technology to produce sensitive bolometric detectors with well-defined, single-mode beam patterns and polarisation characteristics. They also allow superconducting RF filters to be included on the detector chips. Our own design of TES uses a finline taper to transform between waveguide and superconducting Nb microstrip. The microstrip transports the signal to a matched Au-Cu resistor, which is deposited on a thermally isolated SiN membrane. The dissipated RF power causes the resistance of a Mo-Cu TES bilayer to increase, and the resulting reduction in bias current is read out by a SQUID. We have fabricated TES bilayers with critical temperatures of 400 to 600mK, and deduced dark NEPs as low as 3x10-17W/√Hz at 150GHz. In this paper we describe a number of experiments that were carried out in order to investigate the electrothermal behaviour of microstrip-coupled TESs. We show that the electrothermal behaviour of microstrip-coupled TESs can be as good as that of free-space TESs, and therefore that they are suitable for high-performance astronomical applications.
Advances in performance and miniaturization of a FT-IR spectrometer system based on a large stroke MOEMS piston mirror

Standard FT-IR spectrometers are large, usually static, and expensive and require operation by qualified personnel. The presented development involves achievements in MEMS technologies and electronics design to address size, speed and power requirements and develop a fully integrated miniaturized FT-IR spectrometer. A suitably matched interaction of multiple new components - source, interferometer, detector and control and data processing - develops unique MEMS based spectrometers capable of reliable operation and finally results in compact, robust and economical analyzers. The presented system now aims at a high performance level to measure in the range between 5000-750 cm-1 at a spectral resolution better than 10 cm-1. The Michelson interferometer design and the desired performance put several demands on the MOEMS device. Amongst these, a mirror travel of ± 500 μm and a minimal dynamic deformation of < λ/10 peak-to peak in combination with a large mirror aperture of 5 mm were the most challenging goals. However, a signal-to-noise ratio of 1000 is required to qualify a FT-IR system as a sensor for industrial applications e.g. process control. The purpose of the system, presented in this work, is to proof that this is feasible on the basis of MEMS technology and it is demonstrated that most of these specifications could be already met.
A New Mode Changable Asymmetric Full Bridge DC/DC Converter having 0 ~ 100 % Duty Ratio

In this paper, a new mode changeable asymmetric full bridge dc/dc converter is proposed to solve the freewheeling current problem of the conventional zero voltage switching(ZVS) phase shift full bridge(PSFB) dc/dc converter of low output voltage and high output current applications. The proposed converter is operated as an asymmetric full bridge converter when the duty cycle is less than 50% and active clamp full bridge converter when the duty cycle is greater than 50%. As a result, since its freewheeling current is eliminated, the conduction loss is lower than that of the conventional ZVS PSFB dc/dc converter. Moreover, ZVS of all power switches can be ensured along a wide load ranges and output current ripple is very small. Therefore, high efficiency of the proposed converter can be achieved. Especially since its operation mode is changed to the active clamp full bridge converter during hold up time and can be operated with 50~100% duty ratio, it can produce the stable output voltage along wide input voltage range. The operational principles, theoretical analysis and design considerations are presented. To confirm the operation, validity and features of the proposed converter, experimental results from a 1.2kW() prototype are presented.
Protocol for a systematic review on classification, outcomes and follow-up of patients undergoing reconstructive surgery after Noma disease-

Background: NOMA is a significant yet neglected disease which affects children in some of the least developed countries in the world. Surgical reconstructive missions for patients affected by NOMA are undertaken regularly by surgeons from more developed countries. However, the long-term benefit and safety of these missions have recently been criticized due to a perceived lack of measurable outcomes and appropriate follow-up. We are conducting a systematic review to critically evaluate the classification systems, outcome measurement tools, and follow-up periods reported in the literature for NOMA disease. Methods: This systematic review is undertaken following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (“PRISMA”) guidelines. The databases MEDLINE, Embase and Web of Science are searched from infinity to 24th of April 2019. All original publications of studies undertaken on reconstructive surgery for NOMA disease, reporting data on outcome after surgery, follow-up time and complications are eligible for inclusion. The primary outcome of interest are the outcome measurement methods used for assessing successful reconstructive surgery after NOMA disease. Other outcomes we are assessing are methods for classification of disease severity and time to last follow-up. The quality of evidence for each summary outcome measure is assessed using the MINORS criteria. Discussion: Given the precarious situations in the countries where mission surgeons often undertake reconstructive surgery, time pressure and the lack of infrastructure on site prevent them from being able to measure the effect of their surgical outcomes. Our goal is to express the key points of debate and make recommendations for how future surgical missions can be improved. We aim to do so by comparing the current best standards of practice Publishing this protocol will help future NOMA surgeons plan their missions in a standardised and reproducible way, striving towards a future of worldwide high-quality research.Systematic review registrations: This protocol was submitted to PROSPERO on the 02.10. 2020 and is currently under assessment. (ID 181931)
Nonlinear HBT table-based model including low-frequency noise effects

A nonlinear HBT table-based model is presented in which low-frequency (LF) noise effects are incorporated, thus allowing for precise oscillator design. The model uses four table-based nonlinear functions: Ic, Qc, Vbe and Qb, and takes into account temperature and noise behaviour. This approach is able to predict the LF noise behaviour under both static and dynamic conditions by using cyclostationary noise sources. HBT-based oscillators have been designed using this model, and very good predictions have been obtained for the oscillation frequency, the output power and the phase noise.
High-speed thermography of fast dynamic processes on electronic switching devices

Electro technical machines and systems have to provide a permanent operational safety in every phase of their lifecycle. An interruption or failure, e.g. of the DC24V energy supply, must not cause any dangerous situation for man or machine. A selective protective function is achieved by using electronic or mechanical circuit breakers mainly consisting of an integrated printed circuit board (pcb) with a number of conductive paths and components. PCBs and components respond to current variations respectively overcurrent with partly punctual thermal changes which can be tolerated up to a certain limit. A thermally and geometrically high-resolution real-time thermography system monitors fast electrical changes in loadings on electronic circuit breakers which immediately result in thermal effects on the electronic system. The infrared thermography visualises the thermal loadings occurring in conductive paths and electronic components. The data determined by this innovative medium will be put into relation to the electrical loadings. Conclusions to the component and pcb-layout efficiency are drawn from the temporally high-resolved heating processes in the millisecond range. Due to these data, the electronic circuit breaker will be miniaturised. The high-speed thermography compares variously dimensioned devices during electrical loads with regard to their thermal management. As proof of feasibility, the heating processes are displayed in quick movies depending on pcb dimensions and electrical loads.
Impact of Ethical Behavior on Financial Performance of Firms Listed on Ghana Stock Exchange.

The focus of this study was to assess the effect of organizational ethical behavior on the financial performance of firms in Ghana. Researchers have expressed concerns about the ethical behavior of firms in Ghana with regards to its effect on financial performance. The findings of this study will add to the literature, from which those in the field of academia can continually refer. The return on assets, as an indicator for the financial performance of firms, was adopted as the dependent variable. Independent variables were good ethical behavior (GEB), corruption reduction (C), and nepotism reduction (N). A cross-sectional survey design was followed for primary data and firms’ financial records were sources of secondary data. Thirty (30) corporate firms registered on the stock market were selected for the study. A multiple regression analysis was conducted and findings presented in Tables and Figures. Results showed that firms’ adherence to ethical principles of conducting business stand the chance of increasing their financial performance up to 45.0, 38.4, and 43.7 % by unit increases in GEB, and decreases in C, and N respectively. All independent variables had positive correlations with the financial performance of firms studied (GEB, 0.349; C, -0.503; N, -0.680). On firms’ financial performance, the ROA of firms, according to findings is positively and strongly correlated to their adherence to ethical business standards. Based on these findings, the study recommends that corporate firms pay more attention to practices that enhance good ethical behavior through the implementation of ethics policies, and reduce or eradicate nepotism to increase their chances of performing better financially. In addition, firms should ensure gender equality and equity, employee training on ethical standards of work, and encouragement of ethical leadership.
A 19-Way Isolated Power Divider Via the TE/sub 01/ Circular Waveguide Mode Transition

A 19-way waveguide isolated power divider has been developed with broad bandwidth, low insertion loss and high isolation. Its design allows a flexible number of output ports and uneven power distribution. It can be used as a feed network for an antenna array and, due to this power divider's high isolation characteristics, it can be used as a power combiner for a high power amplifier.
Optimized garment pattern generation based on three‐dimensional anthropometric measurement

An automatic garment pattern generation system has been developed for the three‐dimensional apparel CAD system. To substitute the garment fitting process, which requires lots of trial and error in the traditional pattern generation methods, we developed a new direct pattern generation method using body‐garment shape matching process. In this method, we first generated a body model using three‐dimensionally measured anthropometric data and transformed it to have a convex shape similar to that of a commonly used dummy model in garment design process. Then a typical garment model has been defined by measuring the surface information of a dummy model using stereoscopy and adjusting its shape considering the geometrical constraints of the underlying body model to obtain the optimum fit garment patterns. Finally, we developed a pattern flattening algorithm that flattens the three‐dimensionally adjusted garment model into two‐dimensional patterns considering the anisotropic properties of the fabric to be used.
Automatic Control Chart for Micropipet

Abstract The control chart is defined and exemplified, and the importance of controlling the volume delivered by a micropipet is discussed. A LabVIEW VI is described, which automates control chart generation and routine use based on the gravimetric calibration of a micropipette, using a Sartorius balance. A user selects between creating a new control chart and adding a data point to the control chart. File storage and retrieval, and construction of the control chart are automated. A sample control chart for a micropipet is presented.
Analysis of unbalanced polyphase networks by the method of phase co-ordinates. Part 1: System representation in phase frame of reference

The analysis of unbalanced-power-system problems depends usually on transformation methods by which the primary or phase quantities are substituted by, for example, symmetrical-component quantities. These transformations have had computational advantages in the past, but with the use of the digital computer, they no longer appear to be necessary. Investigations into system-unbalance problems and their solution using only the actual system phase voltages, currents and impedances show that a major difficulty concerns the representation of transformers. In this paper the principles of transformer models in phase co-ordinates are derived and applied to the development of the phase equivalent circuits of a number of balanced and unbalanced polyphase multiwinding transformers. The basic element of these equivalent circuits is shown to be a symmetrical lattice network that is bilinear in all cases except for quadrature boosting transformers. With these equivalent circuits and with the phase representations of the transmission lines, generators and other system components it is then possible to solve unbalanced polyphase network problems entirely in phase co-ordinates, retaining symmetrical components only as measures of system unbalance.
MPPT of Doubly-Fed Induction Generator in Wind Farm Using SPSA Algorithm

In order to make wind power generation system be free from outside interference, and make doubly-fed induction generator (DFIG) easily operate at maximum power point under variable wind speed, simultaneous perturbation stochastic approximation (SPSA) algorithm for tracking maximum power of wind power generation system is proposed in this paper. SPSA algorithm indirectly controls DFIG speed through adjusting duty cycle of power converter, makes system operate at maximum power point under any wind speed, thus the maximum power output is transmitted to the load. SPSA algorithm not only does not need to set up PID three parameter values, but also does not anemometer and tachometer in practical applications. Simulation results show no matter how wind speed changes, SPSA algorithm can effectively improve power output of wind power generation system, and make tip speed ratio and power coefficient be near optimum value, reduce system cost.