Miracle-dz/UniFAR-FTUs huggingface dataset:
Control surfaces in confined spaces :the optimisation of trailing edge tabs to reduce control surface hingemoments

This thesis describes the first project relating to the Control Surfaces in Confined Spaces (CoSICS) project at Stellenbosch University. The aim of CoSICS project is to reduce the size of control surface actuators, and this thesis considers the aileron system of commercial aircraft such as the Airbus A320 and A330. Specifically the project aims to reduce the aileron hinge moment, as this will result in smaller actuators. Possible methods are discussed where aerodynamic forces are used to reduce the aileron hinge moment through the use of a wing-aileron-tab configuration. In order to examine the use of the configuration, first order aerodynamic modelling is performed using two-dimensional thin-aerofoil theory, which is also extended to a basic three-dimensional approximation. To determine the maximum reduction in hinge moment several optimisations are performed where only the tab chord length is varied, both tab and aileron chord lengths are varied, and finally the tab chord length and aileron span are varied. The optimisation methods used, namely the gradient-based sequential quadratic programming (SQP) and a real-encoded genetic algorithm (REGA) are discussed in detail and include general implementations which are then applied to the problem. The optimisations performed are dual-layered where optimal deflection angles are determined as well as the optimal geometry. The results of the optimisation are tested using a roll manoeuvre in a specially developed Simulink simulation environment for this purpose. The study produces results where new hinge moment values are an order of magnitude smaller than those of the old configuration, while maintaining suitable lift and rolling moment coefficients. The optimisation and simulation infrastructure developed in this thesis provides a platform for higher-fidelity models and components being developed in future work to provide higher fidelity results.
Detection of Singularities and Subsurface Defects in Wood by Infrared Thermography

Infrared thermography (IRT) is a technique that allows the visualization of the surface temperature of objects from the radiation that they emit without any kind of contact. This non-destructive technique (NDT) is used worldwide for locating and identifying internal defects in materials from the thermal anomalies that these defects generate on the surface of the materials, among other applications. Two types of irregularities are found in wood: singularities and defects, which are regions of disorder that affect the quality of the wood and decrease its resistance capacity. Based on the local density variations caused by these irregularities that alter the thermodynamic behavior of the wood, the present investigation analyzed the capacity and performance of IRT for the exploration and detection of these subsurface singularities and defects in wood. The results establish the true scope of this technique in detecting subsurface defects in wood and verifying the complexity inherent in the analysis.
New generation high-speed high-resolution hemispherical scatterometer

A new instrument has been developed that takes hundreds of thousands of points of scattered light data at 0.1 degree(s) resolution over a three dimensional segment of the hemisphere. The data can be acquired and displayed in 0.5 to 20 seconds depending on the amount of data desired. The instrument is the size of a 'shoe box' and provides solid state operation. With the instrument's high resolution three dimensional capability, well-defined three dimensional interference patterns, speckle, and diffraction can be seen in near-real-time. Much of these patterns are out of the plane of incidence and sometimes add significantly to the scatter, and may allow a scattering surface to be characterized through methods not available before. The high speed capability makes this instrument ideal for scattered light measurements to be used for high resolution surface defect quality control on high volume assembly lines.
Instruction for Military Air Intercept Control

Two experiments were conducted using a microcomputer simulation to teach military air-intercept control skills. In Experiment I, three experimental training methods were compared to the normal method in which students identify the bearing of the enemy fighter from a friendly fighter and then calculate an intercept heading. Part training was employed to provide intensive training in critical component skills. Time compression was used to speed the simulation after the student provided a solution, so that many more practice trials could be given in each training session. A spatial visualization method of determining the intercept heading was contrasted to the normal method of mathematical calculation. After training, all subjects were tested with the same whole, real-time scenario. Part training with time compression and the spatial visualization method of determining intercepts was more effective than whole, real-time training with the calculation method of determining intercepts. The results suggest a substantial benefit from time compression. The possible benefits of part-task training were not as clear. In the second experiment, two part-task training methods were compared to a whole-task method. One part-task group received long blocks of each component while the second part-task group received a series of short blocks. Time compression and spatial visualization were used in all conditions. The results suggest that part-task training does not improve the effectiveness of training air intercept control skills.
An Optical Acoustic Detection System Based on Fabry Pérot Etalon Stability Structure

The optical acoustic detection system based on the Fabry Pérot Etalon (FPE) with high quality–factor (High Q) and stability structure is described and tested. The FPE contains two high–reflectivity Plano–Concave lenses, achieving high fineness and stability. The protective structure of the confocal stabilized FPE is composed of an invar tube, copper sheath, Bakelite sheath and aluminum housing to protect the sensor from the effects of ambient temperature and vibration. The audio signal is injected into the cavity through the sound hole located in the center of the cavity. Acoustic waves induce the vibration of the medium in the cavity, which leads to a simultaneous change in the FPE optical path and a shift of the interference spectrum. The acoustic detection system is built, and the frequency of the laser is locked on the resonant frequency points of the FPE by using phase modulation technology, so as to detect acoustic signals of different frequencies and amplitudes. In addition, the sensitivity of the proposed sensor exceeds 34.49 mV/Pa in the range of 20 Hz–20 kHz. A Signal-to-Noise Ratio (SNR) of 37 dB can be achieved at 20 Hz. Acoustic signal detection technology based on the FPE stability model is used to test the theoretical feasibility of the future high sensitivity Fabry Pérot Interferometric (FPI) acoustic sensors.
A Study on Scaling Laws for Thermal Parameters of Permanent Magnet Synchronous Machines

Right-sizing of electric machines can optimize the efficiency of electric vehicles and improve the driving range. Conventional scaling laws are based on magnetics without considering the thermal impacts. Therefore, the objective of this contribution is to find the scaling laws for the parameters in the low-order lumped parameter thermal model, which enable to evaluate the thermal overload of the permanent magnet synchronous machine in the electric powertrain optimization in an early development stage. By using the scaling laws the average temperature of the components can be well estimated. The average temperature deviation between scaling law and Motor-CAD yields less than 9 °C. In the sensitivity analysis, the thermal behaviors of the stator, the end winding and the rotor are demonstrated. The temperature development of the stator with different scaling factors is operating point dependent due to the different losses distribution. The length and the diameter of the PMSM has almost the same impact on the rotor temperature, while the end winding temperature is more sensitive to the radial scaling.
Assuring the information flow from accident sites to decision makers – a Finnish case study

In spite of the huge amount of information regarding natural and man-made accidents, rescue forces are not able to use information efficiently in their decision-making. From a rescue services point of view, the main challenge is not only to get authentic and real data, but to get ready analysed data. This paper discusses the Finnish way to create an emergency management system that collects reasonable data from an emergency situation, merges the data to get a better overall picture, and sends the analysed assessment of the situation to the rescue services and decision-makers. Two pilot tests were made to define how the information would flow from accident sites to rescue authorities and decision-makers in the best way. The results show that a network has to be established for supplying and analysing the information into a suitable form to be used in real-time management of crisis situations. The authorities also have to ensure that there are no technical limits which obstruct the real-time information flow from accident sites to the decision-makers’ monitors.
Reduction of blood group A antigen on erythrocytes in a patient with myelodysplastic syndrome harboring somatic mutations in RUNX1 and GATA2

Reduction of blood group ABO antigens on red blood cells (RBCs) is well known in patients with leukemias, and this reduction of ABO expression is strongly associated with DNA methylation of the ABO promoter. Previously, we reported a two‐nucleotide deletion in RUNX1 encoding an abnormally elongated protein lacking the trans‐activation domain in a patient with myelodysplastic syndrome (MDS) showing A‐antigen loss on RBCs. This prompted us to investigate the underlying mechanism responsible for A‐antigen reduction on RBCs in another patient with MDS.
Implementation of Improved Z-Source Inverter with Reduced Z-Source Capacitor Voltage Stress and Soft-Start Capability

This paper proposes an improved Z-source inverter topology. Compared to the traditional Z-source inverter, it can reduce the Z-source capacitor voltage stress significantly to perform the same voltage boost and has inherent limitation to inrush current at startup. The control strategy of the proposed Z-source inverter is exactly the same as the traditional one, so all the existing control strategy can be used directly. A soft-start strategy is also proposed to suppress the inrush surge and the resonance of Z-source capacitors and inductors. The operation principle of the proposed topology and comparison with the traditional topology are analyzed in detail. Simulation and experimental results are given to demonstrate the new features of the improved topology.
Design considerations and signal processing algorithms for laser-induced fluorescence airborne pathogen sensors

Sensors based on laser-induced fluorescence (LIF) enable the rapid detection of micron-size airborne pathogens. As with any sensor, the central design issue is the trade between sensitivity and selectivity. In the case of a LIF bio-particle sensor, the objective is to best distinguish a small concentration of “threat” particles against a potentially much larger concentration of harmless “background” particles, without an excessive rate of falsely alarming when threat particles are absent. In this paper, we characterize sensor performance using four inter-related metrics -- sensitivity, probability of detection, false positive rate (FPR) and response time. We develop several sensor design principles and present a new approach to signal processing called the “degree of threat” algorithm. We describe a recent experiment quantifying the performance of a BioLert testbed in distinguishing a biological agent (Bacillus globigii spores) from a mineral dust (kaolin), using a receiver operating characteristic (ROC) curve to show the trade between sensitivity and FPR.
Performance Analysis of an IRS-Aided Wireless Communication System With Spatially Correlated Channels

An intelligent reflecting surface (IRS) assisted wireless communication system, with statistically correlated channels between the transmitter and the IRS pair and between the IRS and the receiver pair, is studied in the absence of channel state information (CSI). Assuming the phases added by IRS elements to be deterministic, the closed-form analytical expression for the symbol error probability (SEP) and the upper bound on the channel capacity are derived, with the transmitter employing binary phase-shift keying (BPSK) modulation for data transmission. The asymptotic SEP expression is derived and the achievable diversity order of the system is shown to be independent of the number of IRS elements. A search based algorithm is proposed to obtain the optimal phase at IRS minimizing the average SEP, as a equal phase configuration. The optimal equal phase is also found to maximize the average channel capacity. Numerical results are presented for the case of channels following a practical IRS correlation model.
Possible Complication Pneumothorax of in COVID-19

Two male patients, 57 and 58 years old, were evaluated in our emergency department. The complaints of cough that had been continuing for 1 week was at the forefront in their histories. Diarrhea and fever accompanied. In both patients, the complaint of shortness of breath increased significantly in the last 6 hours. Although 20lt/min oxygen was given to hypoxemic patients, SpO2 values were in the range of 80% to 84%. Despite oxygen supplementation, the current sinus tachycardia (140bpm) did not improve. In the thorax x-ray evaluations which were performed immediately, it was seen that both patients had pneumothorax covering the entire left hemithorax. The patients were connected to the underwater drainage system by inserting a chest tube. In clinical radiological follow-up, pneumothorax regressed and lung parenchyma was re-expanded in both cases. A contralateral pneumothorax occurred in the second patient. Conditions observed in these cases show that pneumothorax can be caused by Covid-19 and may be mortal. Pneumothorax should be kept in mind in the presence of severe dyspnea, hypoxia and tachycardia when suddenly added to the clinic. Both patients died in their second week of intensive care unit treatment.
Ultra-wideband MMIC active power splitters with arbitrary phase relationships

Novel MMIC active power splitters, which allow arbitrary phase division over wide frequency ranges exceeding an octave in bandwidth, are proposed. An FET's inherent phase inversion properties together with phase adjustment circuits, e.g., common drain FETs followed by phase-shift transmission lines, can be successfully combined for broadband, arbitrary phase division. As an example of this technique, an MMIC active quadrature splitter has been designed and fabricated in a 1.1 mm*0.7 mm chip area. A phase error of less than 5 degrees with a magnitude imbalance of less than 1 dB has been demonstrated over a double-octave frequency range of 7.2-21.6 GHz. The MMIC active power splitter promises to make possible miniaturized, full MMIC signal processing components. >
A Survey of Different Software Fault Prediction Using Data Mining Techniques Methods

Software fault prediction method used to improve the quality of software. Defective module leads to decrease the customer satisfaction and improve cost. Software fault prediction technique implies a good investment in better design in future systems to avoid building an error prone modules. Faulty modules are predicted using data mining techniques. Various classifiers are used to classify faulty or non-faulty modules. The goal of software fault prediction is to help the software manager to increase the software system quality. There are many software fault prediction techniques are available. This paper presents the survey on software fault prediction models.
Relationship between Biofilm and the Presence of Drug Resistance Genes in Clinical Isolates of Klebsiella Pneumoniae in Qom Hospitals

Background & Objectives: Klebsiella pneumoniae is a significant cause of nosocomial infections. This bacterium survives in difficult conditions by forming biofilms in hospital equipment and causes severe infections. On the other hand, the emergence and spread of carbapenem resistance among bacteria and biofilm production is a current health concern. There are controversial findings about the relevance of this issue. This study aimed to evaluate the relationship between biofilm formation and carbapenem resistance among clinical isolates. Materials & Methods: A total of 160 isolates of Klebsiella pneumoniae were collected. Molecular methods were used to detect resistance genes. Subsequently, the ability to produce biofilms in isolates with resistance genes was assessed. Finally, the correlation of biofilm formation among resistant isolates was calculated using χ2 test. Results: 79 imipenem-resistant isolates were obtained. 46 isolates (66.66%) containing VIM gene, 36 isolates (52.17%) containing OXA-48 gene, five isolates (7.24%) containing NDM gene, Six isolates (8.69%) containing gene IMP and five isolates (7.24%) also had KPC gene. The results showed a significant correlation between the ability to form biofilms and the presence of carbapenem-resistant genes. Conclusion: Increased carbapenem resistance in Klebsiella pneumoniae isolates and its association with biofilm formation is severe warning for basic measures to combat this phenomenon.
Fretting Corrosion of Solder-Coated Electrical Contacts

The contact resistance of fretting solder-plated contacts may rise quickly due to the accelerated formation of insulating oxides on their surfaces. This condition becomes worse with increase in length of wipe and with reduction in normal load. The solder-plated versus gold-plated system shows a more rapid rise in contact resistance which can be explained by differences in the mechanics of oxide film fracture compared to that of all-solder-coated contacts. Many fluid lubricants are able to maintain low, stable contact resistance when applied to surfaces in thick (about 20 000 A) layers, particularly on both contacts of a mated pair. The contact resistance of solder versus gold is more difficult to stabilize with lubricants than that of solder against itself, although lubricants may be useful provided that fretting distances are small. The effectiveness of coatings is due to their ability to greatly reduce oxygen arrival at the surface. When it is impractical to employ finishes other than solder on the contacts of separable connectors and when fretting can occur, it is recommended that coatings of viscous oils or greases be used to prolong contact life. An example of a useful coating is one which is obtained by immersion and withdrawal of the contacts from a mixture by weight of 20 percent polyphenylether fluid and 1 percent of microcrystalline wax in 1,1,1- trichloroethane.
Assessment of the Effect of Different Isolation Systems on Seismic Response of a Nuclear Power Plant

Seismic isolation is utilized in both traditional and industrial structures for its ability to reduce structural responses while effectively protecting sensitive building contents. Although this mature technology has been studied extensively, there is limited research on its application to Nuclear Power Plants (NPPs). Studies have yet to address topics such as sensitivity of equipment and the effects of seismic isolation on floor response spectra (FRS) caused by high frequencies and the inclusion of vertical motion. This paper's studies investigate the relationship between structural response and isolator mechanics, ground motion sensitivity, and the effectiveness of various isolator types, especially nonlinear isolators. Overall trends are identified that provide insight into the interaction between the isolation system and the response at various levels of the NPP. By understanding these relationships and connections, a set of valid recommendations for the selection and design of isolation systems is provided. This work is pursued through analyzing the performance of an APR1400 plant considering regulatory guidelines and utilizing a variety of ground motions, isolator types, and isolator models.
Occlusion-Aware Self-Supervised Monocular 6D Object Pose Estimation

6D object pose estimation is a fundamental yet challenging problem in computer vision. Convolutional Neural Networks (CNNs) have recently proven to be capable of predicting reliable 6D pose estimates even under monocular settings. Nonetheless, CNNs are identified as being extremely data-driven, and acquiring adequate annotations is oftentimes very time-consuming and labor intensive. To overcome this limitation, we propose a novel monocular 6D pose estimation approach by means of self-supervised learning, removing the need for real annotations. After training our proposed network fully supervised with synthetic RGB data, we leverage current trends in noisy student training and differentiable rendering to further self-supervise the model on these unsupervised real RGB(-D) samples, seeking for a visually and geometrically optimal alignment. Moreover, employing both visible and amodal mask information, our self-supervision becomes very robust towards challenging scenarios such as occlusion. Extensive evaluations demonstrate that our proposed self-supervision outperforms all other methods relying on synthetic data or employing elaborate techniques from the domain adaptation realm. Noteworthy, our self-supervised approach consistently improves over its synthetically trained baseline and often almost closes the gap towards its fully supervised counterpart.
Preparation and Properties Research of PA6/PLA Blends Toughening Modified by TPU

Polyamide 6/Poly(lactic acid) (PA6/PLA) blends introduce the degradability of PLA to high performance PA6, but the bad toughness of both PA6 and PLA limits the application of blends. Aiming at this deficiency, thermoplastic polyurethane (TPU) was used as an additive for modifying the toughness of PA6/PLA blends. PA6/PLA/TPU blends at various compositions were prepared by melt blending, the effects of blend compositions on the morphology, thermal and mechanical properties of blends were investigated. The results showed that the addition of TPU improves the compatibilization between PA6 and PLA and makes the blends show more obvious plastic fracture behavior than PA6/PLA.When the content of PLA in PA6/PLA increases, the impact and tensile strength of blends decrease slightly with the intense decrease of the elongation at break, adding TPU into PA6/PLA blends strengthens the toughness of blends, but the tensile strength of blends decreases. Moreover, the crystallinity of PA6 /PLA blend is hampered by TPU.
First operational results of the 3rd harmonic superconducting cavities in SLS and ELETTRA

In both ELETTRA and the Swiss Light Source (SLS), a complementary 3rd harmonic (1.5 GHz) idle superconducting RF system has been recently implemented and commissioned, in order to lengthen the bunches and therefore improve the Touschek dominated beam lifetime. Here below we report on the commissioning results.