bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors Impacting Students' Well-Being and Possible Intervention Strategies in Kenyan Universities
Authors: Barongo Samson , Mwau Cynthia , Omukami Howard
Published: August 2024

There has been a sharp increase in the issues affecting university students in both local and global contexts. Here, local and global contexts can be defined by considering factors within and without Kenya respectively. In this chapter, the authors shall discuss factors from the local context. Most of these factors have a direct or indirect impact on the life of university students. Transition from secondary schools to university introduces students to new life experiences, especially socially and academically. The freedom to make their own choices may lead them to acts detrimental to their wellbeing. Such acts include suicidal tendencies, homicide, crime, chemical dependency, depression, debt, stress, negligence of studies and other varied forms of addiction. The foregoing notwithstanding, peers, lecturers, university administration family, and the community are also affected. The purpose of this chapter is to empower students with the ideas, skills, and knowledge necessary for making sound decisions about their well-being. It covers stress, addictions, chemical dependency, suicide, homicide, and financial control. The students will be able to maintain a healthy balance between their social life and academic demands. Additionally, the chapter will empower them with knowledge for mental and physical well-being. It relates the comorbidity of the factors and provides vital information for students to lead stable lives even beyond their university time. Moreover, it also analyses some statistics emerging from trends and patterns depicted by past cohorts of university students. This is necessary for individual reflection and decision making. The data will also provide an insight for university managements to put in place support systems for addressing students' well-being and assisting those already affected by drugs and other chemical substances. The university management structures have been challenged to be affirmative in building strong cultures of resilience and systems of values in their quest to provide higher education. This is because of the changing needs of society and family set-ups in which the students live.
Social Support, Student Well-Being, and Academic Achievement in the Institution of Higher Learning
Authors: Omer Solomon Wachara
Published: August 2024

This chapter introduces the reader to the social support, students' well-being, and academic achievement in the university. The university students were randomly selected and divided into four focus groups, and voluntarily participated in the focus discussion. Peer- reviewed journal articles were critically reviewed. The data analysis was carried out thematically. The themes that emerged included family social support, peer social support, psychological well-being, and environmental factors.
Application of Agricultural Information Big Data Technology in Rural Economic Revitalization
Authors: Feng Liwan
Published: August 2024

The main purpose of this paper is to explore the application of big data technology in the implementation of rural revitalization strategy. From the perspective of “prosperous industry, livable ecology, civilized rural customs, effective governance, and prosperous life”, this paper expounds the collection, storage and analysis of agricultural information big data. It also expounds the key points of the follow-up audit of the implementation of the rural revitalization strategy from the perspectives of pre-, in- and post-audit. Specifically, the article first clarifies the basis of the demands and functional positioning of the core stakeholders, and then uses the principal-agent theory to explore the incentive mechanism for cooperation between local governments and big data operating enterprises and uses evolutionary game theory to explore the relationship between big data operating enterprises and agriculture-related enterprises. Finally, MATLAB software is used to simulate and analyze how key parameters affect the evolution trend of the system.
Online Monitoring Technology for Cable Insulation in Distribution Networks Based on Line Conduction Characteristics
Authors: Li Hongbo , Shao Huawei , Niu Sen
Published: August 2024

Due to the increasing load of the power grid and the rapid expansion of cable line construction, monitoring cable insulation performance has become very important. To address this challenge, this paper proposes an online monitoring system for cable insulation in distribution networks based on line conduction characteristics. The system combines advanced signal acquisition technology, data processing methods, and deep learning (DL) algorithms to enable real-time monitoring and accurate evaluation of cable insulation status. The results demonstrate that the system excels in real-time monitoring of cable insulation status. Compared to traditional methods, the system proposed in this paper shows significant advantages in key indicators such as missed detection rate, fault location accuracy, recognition speed, and recall rate. Specifically, the system effectively reduces the missed detection rate, improves the accuracy of fault location, accelerates identification speed, and enhances the recall rate, enabling more comprehensive detection of insulation faults.
A Machine Learning-Based Approach for Efficient Brain Tumour Classifications
Authors: Al-Qassab Zainab , Gharsellaoui Hamza , Bouamama Sadok
Published: August 2024

This journal paper deals with data-Mining striving as emerging technique which plays the vital role in digging out the significant appropriate information from the vast stream of data collection. The present research focusses on the diagnosis of the brain tumours and the predictions of disease distinguishing the healthy individuals and the patients. To accomplish this predictions, machine learning algorithm Multinomial-Naive-Bayes algorithm in the classification technique to prediction of the results in relevance with the brain tumors disease. The proposed research consists of Collection of dataset, pre-processing technique, Feature-selection method, and organisation of the data in the normalised form, classification implementation and in the generation of the predicted results. These depicted results were subjected to the comparative analysis of the existing previous predictive models with the present proposed work which is superior to them.
Advanced Detection of Chronic Atrophic Gastritis Using High-Resolution Endoscopy and Semantic Web
Authors: Zhao Junyi , Gao Yaxin , Li Jinbao
Published: August 2024

Chronic atrophic gastritis is a precancerous lesion that can progress to gastric cancer. Existing deep-learning methods often downsample high-resolution images during diagnosis, leading to a loss of texture details and a reduced ability to identify pathological features of chronic atrophic gastritis. To address this limitation, we propose a novel approach for intelligently identifying chronic atrophic gastritis directly from high-resolution endoscopic images. Specifically, we design a two-stage network that emulates the diagnostic workflow of clinical experts, which first localizes the lesion area to downscale the high-resolution image and then applies a patch-based magnification technique to detect finer pathological features. On a real clinical cases dataset, our method achieves a diagnostic accuracy of 94.08%, with specificity and precision of 96.86% and 96.28%, respectively. These performance metrics outperform many state-of-the-art methods and closely match those of senior endoscopists, providing clinicians with a more objective and reliable tool for lesion assessment.
Research on Online Vocal Music Smart Classroom-Assisted Teaching Based on Wireless Network Combined With Artificial Intelligence
Authors: Zhang Tieyi
Published: August 2024

With the rapid advancement of information technology, online education based on big data and artificial intelligence is a hot research topic in education. This study focuses on applying big data and AI in online vocal wisdom classes to enhance personalized teaching and effectiveness. It aims to address issues in traditional vocal education like lack of personalized guidance and poor outcomes. The research proposes an intelligent learning system for vocal education, featuring modules for data collection, analysis, and intelligent recommendations. Functions include personalized learning paths, teaching assistance, real-time feedback, and assessment. Experiments show significant improvements in student outcomes and satisfaction. This innovative approach contributes to enhancing vocal education through personalized and intelligent teaching, offering valuable insights for future education development. Online vocal wisdom classrooms leveraging big data and AI represent a crucial direction with broad application prospects.
Mobile Payment Innovations in Ambiguously Enforced Use Contexts
Authors: de Araujo Machado Petruska , Porto-Bellini Carlo G. , de Faria Pereira Rita de Cássia , Shah Vishal , de Luna Franklin Martins
Published: August 2024

In this study, the authors discuss whether the innovation characteristics of mobile payment (m-payment) explain user attitudes and intentions in a psychologically conflictual context regarding the locus of control of use decisions. The authors present the development of an instrument that fully integrates innovation diffusion theory with the technology acceptance model and analyze data collected with it from Brazilian m-payment users during the COVID-19 pandemic. With path analysis, the authors found that the innovation factors of perceived observability and perceived relative advantage respectively explain the attitudes and the intentions toward m-payment. None of the other innovation factors had explanatory power. Moreover, two expected relationships in voluntary use settings for the formation of attitudes were not supported, leading the authors to conclude that the locus of control in use decisions was ambiguous to the user. The findings contribute to research on innovation diffusion, technology acceptance, consumer studies, usage patterns, behavioral change, and on the debate about the voluntariness or mandatoriness of technology use.
The First Optimisation of a 16 kV 4H-SiC N-Type IGCT
Authors: Cao Qinze , Gammon Peter Michael , Renz Arne Benjamin , Antoniou Marina , Mawby Philip  Andrew , Lophitis Neophytos
Published: August 2024

A challenge in the development of Silicon carbide (SiC) gate turn-off thyristors lie in an uneven transient behaviour, necessitating expensive snubbers. To address these limitations and simplify circuit topology we present an optimized 16 kV n-type SiC integrated gate commutated thyristor (IGCT) design, which utilises a novel highly doped base strip (HDBS). A particular focus is on optimizing the gate commutation of the GCT during switching, and the trade-offs in the HDBS base design were investigated. The findings reveal that compared with conventional GCT design, the HDBS design under high current conditions recorded a 11.8% reduction in turn-off power losses. When simulating the device in a high-voltage scenario, the HDBS IGCT demonstrated a 3.9% reduction in turn-off power losses and an improved turn-on power loss performance. This resulted in a reduction of power losses by 12.1% and 2.3% in high current and high voltage conditions, respectively. In summary, the novel SiC HDBS IGCT design paves the way towards a secure, high current density, and low loss switching SiC thyristor device.
High-Speed and High-Temperature Switching Operations of a SiC Power MOSFET Using a SiC CMOS Gate Driver Installed inside a Power Module
Authors: Yao Atsushi , Okamoto Mitsuo , Kato Fumiki , Hozoji Hiroshi , Sato Shinji , Yamaguchi Daiki , Ando Takashi , Harada Shinsuke , Sato Hiroshi
Published: August 2024

In this study, the simultaneous realization of high-speed and high-temperature switching operations is demonstrated using a custom-made high-speed and high-temperature power module installed with a silicon carbide (SiC) CMOS gate driver, which can reduce gate loop inductance and operate at high temperatures. Approximate switching speeds of 70 and 60 V/ns are achieved during the turn-on and turn-off operations, respectively, at 300°C, 600 V DC bus voltage, and 20 A load current using the developed module. The switching speed remained above 50 V/ns in the temperature range from room temperature to 300°C. Numerical calculations based on the static properties of the SiC power MOSFET and CMOS gate driver can predict the actual switching properties over a wide temperature range when the developed module incorporating the fabricated SiC CMOS gate driver is used.
Study of Parasitic Effects for Accurate Dynamic Characterization of SiC MOSFEFTs: Comparison between Experimental Measurements and Numerical Simulations
Authors: Arai Takamasa , Takeda Ryo , Neville Tom , Hawes Mike
Published: August 2024

The high-speed switching capabilities of wide bandgap (WBG) power devices have posed challenges in accurately evaluating their dynamic characteristics, primarily due to the increasing influence of parasitic components in switching test circuits. To address this issue, we investigated the impact of parasitics by conducting dynamic tests and schematic-level transient simulation on a half-bridge switching circuit incorporating SiC MOSFETs. This comparative analysis identified specific parasitic components responsible for undesirable behaviors such as spikes and ringing in the switching waveform. Our findings provide insights into which parasitic components in the test circuit are critical for the accurate dynamic characterization of SiC MOSFETs.
Power Cycling Performance of 3.3 kV SiC-MOSFETs and the Impact of the Thermo-Mechanical Stress on Humidity Induced Degradation
Authors: Hanf Michael , Hoffmann Felix , Brunko Alexander , Peters Jan Hendrik , Clausner Sven , Kaminski Nando
Published: August 2024

Recently, silicon carbide (SiC) power modules of the 3.3 kV voltage class became available and are a promising candidate to replace silicon power modules in traction applications. However, the more than three times higher Young’s Modulus compared to silicon leads to a reduced lifetime under thermo-mechanical stress. This could pose a significant obstacle in their implementation, since traction applications are particularly demanding in their mission profiles with respect to load cycling, but also to environmental conditions. Thus, the thermo-mechanical stress is not just limiting the lifetime itself, but might also promote the humidity induced degradation due to delamination or micro-cracks. In this work, multiple power cycling tests at different temperature swings on 3.3 kV SiC MOSFET chips in a power module were performed, to assess their ruggedness under thermo-mechanical stress. Before or afterwards, these modules were tested under standard HV-H3TRB conditions to verify the interaction between thermo-mechanical and humidity stress on the robustness of the modules.
Junction-Controlled-Diode-Embedded SiC-MOSFET for Improving Third Quadrant and Turn-On Characteristics
Authors: Lou Qian , Li Xuan , Yang Zheng Yu , Li Ling Feng , Li Song Jun , Deng Xiao Chuan , Zhang Bo
Published: August 2024

In this paper, we propose a novel 1200V SiC MOSFET featuring the embedded junction-controlled-diode (JCD-MOSFET) and demonstrate its static and dynamic characteristics through TCAD simulations. Without sacrificing blocking and conduction performance, the adoption of JCD can effectively reduce knee voltage to 1.7V based on unipolar carrier conduction mode. Due to the reduced peak reverse recovery current and reverse recovery charge, the JCD-MOSFET achieves 30.8% lower turn-on losses than conventional MOSFET. Meanwhile, the fabrication process for the JCD-MOSFET is the same as conventional MOSFET without an extra mask. This proposed JCD-MOSFET prototype shows great potential in target applications in the near future.
Excellent Avalanche Capability in SiC Power Device with Positively Beveled Mesa Termination
Authors: Liu Yan Cong , Tang Xiao Yan , Zhou Yu , Yuan Hao , Sun Le Jia , Song Qing Wen , Zhang Yu Ming
Published: August 2024

In this work, 4H-SiC p-i-n diodes with excellent single-pulse avalanche energy density (EAS) with positively beveled mesa termination have been demonstrated. The fabrication of this junction termination extension (JTE) obviates ion implantation and requires only etching process. With its uniform electric field and temperature distribution, the fabricated 4H-SiC p-i-n diodes show breakdown voltage (BV) of 886V (98.4% of the parallel-plane limit) and the inductive avalanche energy density of ~10.4J/cm2@1mH. Meanwhile, ruggedness of the avalanche breakdown has also been evidently promoted. The results confirm that this structure exhibits great capability potential in power applications.
Investigation of the Trapping and Detrapping Behavior by the On-State Resistance at Low Off-State Drain Bias in Schottky p-GaN Gate HEMTs
Authors: Goller Maximilian , Franke Jörg , Lutz Josef , Mouhoubi Samir , Curatola Gilberto , Basler Thomas
Published: August 2024

GaN power HEMTs enable the design of power electronic systems with highest efficiencies and reduced size. Despite strong advancements in device reliability, charge carrier trapping is still an important challenge. The applied methodology allows to characterize defects that cause the dynamic RDS,on in GaN power devices at product level with flexibility in duty cycle, number of pulses and mission profile. A pronounced trapping is observed for lateral GaN-on-Si HEMTs with Schottky p-GaN gate structure at low drain bias and long off-state pulses (> 100 ms). The effect is investigated by fast determination of the on-state resistance RDS,on under different trap capturing conditions: a) different drain bias b) off-state time and number of cycles c) variation of temperature. The trapping and detrapping effects are characterized and the activation energy is extracted from time constants. An elevated on-state resistance was present for up to 3 hours. The threshold voltage modification due to high drain bias does explain the significant RDS,on increase.
Experimental Demonstration and Analysis of 3.3kV 4H-SiC Common-Drain Bidirectional Charge-Balanced Power MOSFETs
Authors: Torky Mohamed , He Zhaowen , Hitchcock Collin , Ghandi Reza , Kennerly Stacey , Chow T. Paul
Published: August 2024

By using 4H-SiC packaged Charge-Balanced (CB) MOSFET, we have experimentally demonstrated a 3.3kV 4H-SiC common-drain bidirectional (BD) CB power MOSFET and measured its static and dynamic characteristics compared to its unidirectional counterpart. We show that the BD CB MOSFET conducts and blocks at the first and third quadrants with the appropriate gate bias with an on-state resistance double its unidirectional counterpart, while its switching energies are 12 (19) and 34 (12) mJ/cm2for BD CB MOSFET (UD CB MOSFET).
Influence of Material Properties on Ruggedness Evaluation of Package Architectures for SiC Power Devices
Authors: Funke Hans-Juergen , Li Zh. , Fan H. , Dong O. , Garete A J. , Birkoben Tom , Liguda Christian , Habenicht Soenke
Published: August 2024

Button shear tests at different temperatures between different mold compounds and Cu-leadframes have been performed to evaluate the adhesion of mold compounds to the inner surfaces of SiC-power devices. The results at different temperatures show the behavior of different material and layer stack combinations under storage at room temperatures as well as under operating conditions with elevated temperatures, where adhesion and thus the hermeticity of the device against moisture is significantly lowered. It has been shown that different thermomechanical properties of the mold compounds as well as the usage of different adhesion promoter materials have a significant effect on the adhesion properties of the mold compound to the leadframe surface of the SiC power devices, which have direct impact on the ruggedness and lifetime stability. Furthermore, these results have been correlated to thermomechanical simulations of the package architecture of SiC power devices under stress. Different wire bond architectures have been evaluated in simulations with and without die top delamination taken into account, showing that EMC delamination may play a major role in the lifetime stability of SiC power devices under thermomechanical stress like simulated in TCT- , IOL- and PTC-testing.
Ohmic Contact Resistance in SiC Diodes with Ti and NiSi P+ Contacts
Authors: Mazzillo Massimo , Momeni Davood , Yu Zhe , Stache Joachim , Urresti Jesus , Liguda Christian , Habenicht Soenke
Published: August 2024

Ohmic contacts play a major role in the signal transfer between the semiconductor device and the external circuitry. One of the main technological issues to develop high-performance SiC-based devices is the control of metal/SiC contact properties to fabricate low resistance and high stability SiC Ohmic contacts to p-type SiC. This is mostly due to intrinsic SiC characteristics like large work function, low dopant activation for p-type materials and low hole mobility. These limits are even more emphasized in SiC JBS or MPS diodes, where Schottky and Ohmic contacts on the P doped regions embedded in the active area to improve surge ruggedness are usually formed by using the same metallization process. This naturally results either in a high Schottky barrier height in the Schottky contact with consequent increase of the conduction loss at low currents or in a poorly conductive Ohmic contact, leading to reduced IFSM capability. Therefore, the optimization and control of the process parameters like for example the P+ doping concentration peak underneath the metallization layer and the annealing process temperatures is crucial to obtain a good Ohmic contact and enhance the device´s robustness against surge current.
1.2 kV SiC MOSFET with Low Specific ON-Resistance and High Immunity to Parasitic Turn-On
Authors: Pham Thanh Toan , Franchi Jimmy , Kang Soo Hyun , Park Kyeong Seok , Choi Doo Jin , Domeij Martin
Published: August 2024

With the capability to switch at high speed, there are important concerns about Parasitic Turn-On (PTO) when using SiC MOSFETs in switching applications with fundamental half-bridge configuration [1]. In this work, we present 1200V SiC planar MOSFETs with low specific ON-resistance (Rsp), fast switching characteristics and high immunity to PTO. The PTO immunity is verified by experimental comparison to several commercially available SiC MOSFETs.
Influence of Channel Length and Gate Oxide Thickness Variations in 3300 V 4H-SiC VDMOSFET
Authors: Rathi Servin , Macdonald David , Murphy Aled , Bell Martin , Young Robert , Clark David T.
Published: August 2024

In this work, variations in the channel length and gate oxide thickness are studied for the design optimization of 3300 V 4H-SiC based VDMOSFETs. For this, a batch of 3 wafers was processed and tested for key device characteristics. The results indicate shorter channel length of 0.5 μm leads to an increase in the drain leakage current, thus affecting the breakdown voltage as well. The thinner gate oxide at 50 nm demonstrates better control of threshold voltage with no variations in the gate leakage current distribution as compared to 65 nm.
SiC GAA MOSFET Concept for High Power Electronics Performance Evaluation through Advanced TCAD Simulations
Authors: Maresca Luca , Terracciano Vincenzo , Borghese Alessandro , Boccarossa Marco , Riccio Michele , Breglio Giovanni , Mihaila Andrei , Romano Gianpaolo , Wirths Stephan , Knoll Lars , Irace Andrea
Published: August 2024

In this work a groundbreaking SiC power MOSFET based on innovative vertical Gate All Around (GAA) concept is presented. Extensive TCAD simulations are performed to analyze the performance in forward as well as in reverse conditions for this new device concept. The proposed design has a target rating voltage of 1200V, suitable for e-mobility applications.
Effect Evaluation and Modeling of p-Type Contact and p-Well Sheet Resistance of SiC MOSFET with Respect to Switching Characteristics
Authors: Nagase Yui , Nakata Shuhei , Tominaga Takaaki
Published: August 2024

SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) exhibit excellent high-speed switching characteristics. However, the sheet resistance of the p-body region and the contact resistance between the p-body region and source electrode significantly degrade the switching performance. In this study, to clarify the effect of resistance on switching speed, which has not been sufficiently explored before, we used the temperature dependence of sheet and contact resistance and conducted switching tests under different temperature conditions. Furthermore, we created a circuit model that considered body effects and compared the results of the models with the measurements. We were able to reproduce the same temperature and resistance dependences as those exhibited by the experimental results, thus confirming the effectiveness of the model.
Frequency Investigation of SiC MOSFETs C-V Curves with Biased Drain
Authors: Matacena Ilaria , Maresca Luca , Riccio Michele , Irace Andrea , Breglio Giovanni , Daliento Santolo
Published: August 2024

SiC MOSFETs still suffers from some open issues, such as the high density of defects existing at the SiC/ SiO2 interface. In order to characterize such interface, a non-destructive investigation technique should be employed. In this work, we investigate the measurement of Gate capacitance with biased Drain. More in detail, the effect of frequency on such curves is considered. The analysis is performed using both in experimental setup and numerical framework. Experimental and numerical results both exhibit a sharp capacitance peak in the inversion region which reduces its height as frequency increases.
Quantification of the Aerodynamic Interference for Counter-Rotating Coaxial Rotors In-Ground Effect
Authors:   Auburn University, Moore Zachary , Silwal Lokesh , Vijayaraj Aditya , Raghav Vrishank
Published: August 2024

The performance of a coaxial rotor hovering in-ground effect (IGE) is compared against the out-of-ground effect (OGE) condition to quantify the rotor-ground interaction and against an isolated rotor IGE at equivalent blade loading to quantify the rotor-rotor interaction. It is observed that the performance of the coaxial rotor improves when it hovers IGE. However, the rotor-rotor and rotor-ground interactions compete, which affects the performance of the coaxial rotor. This paper aims to quantitatively measure the aerodynamic interactions of the CCR in IGE by developing a theoretical framework based on momentum theory. This formulation introduced induced power factors to understand the aerodynamic interactions of a CCR operating IGE. The performance measurements show that the rotor-ground interaction in the CCR system behaved similarly to a single rotor operating in IGE conditions. The interactional effects significantly influence the individual rotors as the rotor-rotor interactions get modified in the presence of ground. At the extreme ground height, the rotor-rotor interaction on the upper rotor decreased, while that for the lower rotor increased when the ground height was reduced. However, with an increase in the inter-rotor spacing, the performance of the lower rotor degrades while that of the upper rotor improves. At the (z/R)l = 0.4, the performance of the upper rotor in IGE improves by ∼ 8%, whereas the lower rotor performance degrades by 8% when compared to their respective OGE conditions.
Full Vehicle Simulations of a Helicopter in Steady Autorotation
Authors:   NASA Ames Research Center, Tran Steven , J. Mark
Published: August 2024

In this paper a full vehicle UH-60A helicopter with and without stub wings is simulated in steady autorotation using both the flight dynamics (FD) code HeliUM-A and the computational fluid dynamics/computational structural dynamics (CFD/CSD) solver CREATE-AVTM Helios. Significant effort was put into trimming the CFD/CSD simulations to an autorotative state that is representative to how the aircraft flies in practice, and the method for doing so is described. For the baseline aircraft, both FD and CFD/CSD predictions of the vehicle's autorotational descent rate were in excellent agreement with available flight test data. CFD/CSD analysis showed that the presence of the fuselage led to a significant positive pitching moment on the rotor as well as a sudden loss of loading as the rotor blades pass through the fuselage wake. When External Stores Support System (ESSS) stub wings were added to the model, both solvers show both quantitative and qualitative agreement in their predictions of the increase in autorotational descent rate due to the additional ESSS drag. CFD/CSD analysis showed that the stub wings had minimal effect on the interactional aerodynamics between the airframe and rotor.
A Quasi-Prescribed Vortex Wake Method Capturing Rotor Wake Distortion
Authors:   Stanford University, Erhard Racheal , Alonso Juan
Published: August 2024

Prescribed vortex wake methods have historically provided rapid analysis for modeling rotor performance with reasonable accuracy suitable to conceptual and preliminary design. However, determining an appropriate wake geometry requires accurate prescription functions, often relying on empirical data. For distributed electric propulsion (DEP) and electric vertical takeoff and landing (eVTOL) aircraft, interaction effects of installed multi-rotor and rotor-wing systems can introduce significant wake distortion and deflection, which is not captured by a rigid or prescribed wake model. Force-free wake methods can capture these wake interactions, but at significant computational cost. To maintain rapid analysis capabilities while capturing external wake interactions, we develop an approach for an adaptive quasi-prescribed vortex wake method. The proposed approach is developed using principles of potential flow theory and a relaxation procedure to include the mutual wake interaction between aircraft components. Applications to rotor-wing systems with coupling between the rotor wake and a vortex lattice method representation of the wing is explored. Results are compared with two additional methods that have been developed, a prescribed vortex wake and a free vortex wake. Validation against experimental measurements for a blown wing configuration is conducted, and the method's ability to more closely predict wake distortion of a tilt-rotor and wing system is also explored.
Full-Body Haptic and Spatial Audio Cueing Algorithms for Augmented Pilot Perception
Authors:   University of Maryland, Morcos Michael ,   San Jose University, Bachelder Edward ,   Independent Scholar, Godfroy-Cooper Martine , Fishman Spencer , Saetti Umberto
Published: August 2024

This paper illustrates the development, implementation, and testing of full-body haptic and spatial audio cueing algorithms for augmented pilot perception. Cueing algorithms are developed for roll-axis compensatory tracking tasks where the pilot acts on the displayed error between a desired input and the comparable vehicle output motion to produce a control action. The error is displayed to the pilot using multiple cueing modalities: visual, haptic, audio, and combinations of these. For the visual and combined visual haptic/audio modalities, visual cues are also considered in degraded visual environments (DVE). Full-body haptic and spatial audio algorithms that are based on a proportional derivative (PD) compensation strategy on the tracking error are found to provide satisfactory pilot vehicle system (PVS) performance for the task in consideration in absence of visual cueing, and to improve PVS performance in DVE when used in combination with visual feedback. These results are consistent with previous studies on the use of secondary perceptual cues for augmentation of human perception. The combination of these results indicate that the use of secondary sensory cues such as full-body haptics and spatial audio to augment the pilot perception can lead to improved/partially-restored PVS performance when primary sensory cues like vision are impaired or denied.
Development and Demonstration of a Critical Rotorcraft Safety System: Advanced Helicopter Seating System
Authors:   The Protective group, Minton Tyrone ,   Safe - A Point Blank Company, Richards Marv ,   DEVCOM AvMC, Crocco John
Published: August 2024

The Advanced Helicopter Seating System (AHSS) was started as an effort to evaluate and improve the current state of military rotorcraft seating. The overall goal of the program has been to improve pilot ergonomics and safety through the integration of advanced energy absorption and vibration reduction mechanisms as well as a broad approach to system integration based around updated occupant anthropometrics. An entirely new seating solution has been developed, with intent to integrate with the AH-64 Apache platform for demonstration purposes. The AH-64 development culminated with a series of static tests and dynamic test events to measure the effectiveness of the safety systems integrated on the seat as compared to the legacy AH-64 seating system. While lumbar load data and seat stroke data was obtained, issues with the anthropomorphic test device (ATD) configuration at the 95th male configuration caused some data to be suspect, and premature failure of several components also caused loss of capturing accurate data. Lessons learned are documented in the conclusions. Data and lessons learned from this effort are being used to support a follow-on effort to develop a pilot seat for the UH-60 Black Hawk Platform.
Rotor Blade Design Optimization with Airfoil Consideration Using Advanced Reduced Order Models
Authors:   German Aerospace Center - DLR, Hong Yoonpyo ,   Agency for Defense Development, Lee Dawoon ,   Seoul National University, Kang Yu-Eop , Yee Kwanjung
Published: August 2024

This paper introduces ABC2, an advanced framework for rotor blade design optimization that can effectively consider the airfoil shape variations during optimization process. A major component of this framework is an reduced-order model (ROM) that leverages deep-neural-network techniques both for airfoil parameterization and performance prediction. Utilizing the UIUC airfoil database and a two-dimensional unsteady Reynolds-averaged Navier-Stokes (URANS) solver, the ROM can effectively control the airfoil shapes and predict the resulting aerodynamic performance across the wide range of flow conditions. A comprehensive aerodynamic solver is incorporated for blade design optimization. Enhancement of the fidelity of the comprehensive solver is achieved through the integration of a three-dimensional URANS solver, which also plays a crucial role in analyzing the aerodynamics of the optimized blade and uncovering its underlying physics. The competence of the present framework is demonstrated by a hovering optimization problem, yielding satisfactorily optimized blades and identifying the underlying physics.
That purplish huge hole on the chest wall
Authors: Rienzo Paola , Poggiali Erika
Published: August 2024

A 54-year-old woman presented to our emergency department two months after the removal by Video-Assisted Thoracoscopic Surgery (VATS) of her middle lung lobe affected by severe inflammation and fibrosis. She was experiencing pain from a large ulcer (diameter 13 cm) starting from the surgical scar. She suffered from Calcinosis, Raynaud phenomenon, Esophageal dysmotility, Sclerodactyly, and Telangiectasia (CREST) syndrome, and hypothyroidism. The laboratory results showed White Blood Cell count (WBC) 13,600/mm3 (N 76%), C-Reactive Protein (CRP) 12 mg/L (nv<6), and Erythrocyte Sedimentation Rate (ESR) 86 mm/h (nv<20). Repeat skin swabs were always negative. Skin biopsy documented granulocyte infiltration in the dermis-hypodermis with tissue necrosis. For three weeks, the patient was treated with methylprednisolone 1 mg/Kg IV and colchicine 0.5 mg q12h orally. In the absence of a good response, oral cyclosporine 75 mg q12h was added. The ulcer gradually improved within a week. The pain was successfully treated with paracetamol 1 gr q8h IV.
Mastopexy under local anesthesia: A case series and systematic review
Authors: Bernard Cambier , Axelle Stockmans , Maxim Blanckaert , Sebastiaan Maes
Published: August 2024

Background:

Mastopexies are most frequently executed under general anesthesia. Local anesthesia (LA) on the breast tissue could make it possible to perform this type of operation without the need for (intravenous [IV]) sedation. This case series analyzes the procedure, operative pain scores, and postoperative outcomes of mastopexies performed under LA. The aim of this articles is to determine the feasibility of a mastopexy procedure under LA without the need for IV sedation.

Methods:

All patients, who underwent a mastopexy under LA, were retrospectively contacted and asked to fill in a questionnaire after informed consent. A systematic review was performed to identify all research available on this procedure.

Results:

A total of 51 patients, with an average age of 40.7 years, filled in the questionnaire. The mean Numeric Rating Scale (NRS) scores during the operation ranged from 3.47 (first intradermal injections) to 3.05 (subcutaneous injections) to 1.07 during the operation itself. Forty-five patients confirmed they would undergo the operation under LA again. Six patients did not want to undergo the same operation under LA anymore. Four patients had minor postoperative complications. Articles on mastopexy under LA without any type of IV sedation could not be found.

Conclusions:

This case series illustrates that mastopexies can be safely performed under LA. The peroperative and postoperative pain scores were low and patient satisfaction was high. This first-ever case series on mastopexy under LA without sedation shows promising results, which need to be confirmed in future studies.

Level of Evidence: Level IV, case series.
A Case Report of Tricuspid Valve Endocarditis in a 15-month-old Child Following COVID-19 Infection
Authors: Ghadimi Maryam , Ferasatkish Rasool , Givtaj Nader , Aghdaei Nahid , Chaibakhsh Yasmin
Published: August 2024

The novel SARS-CoV-2 virus, also known as COVID-19, has started a global pandemic since late December 2019. The infection is primarily manifested with fever, coughing, and myalgia, and in more severe cases causes acute respiratory distress syndrome. Older people and patients with underlying conditions such as diabetes and those who are immune compromised are more susceptible for developing COVID-19 infection and more severe complications. Several cases have reported other uncommon and rare complications in young or adult cases with COVID-19 infection. Several studies have reported bacterial co-infection with COVID-19 which caused infective endocarditis. However, there has been no report of bacterial endocarditis in infants following COVID-19 infection. In this report, we present a case of bacterial endocarditis with advanced progression in a 15-month-old child following COVID-19 infection.
The role of netrin G1-netrin-G-ligand-1 in schizophrenia
Authors: Ibiayo Ayooluwa Gabriel , Yang Luo-Zhu , Liu Ingrid Y.
Published: August 2024

ABSTRACT

Schizophrenia (SCZ) is a chronic psychotic disorder that profoundly alters an individual’s perception of reality, resulting in abnormal behavior, cognitive deficits, thought distortions, and disorientation in emotions. Many complicated factors can lead to SCZ, and investigations are ongoing to understand the neurobiological underpinnings of this condition. Presynaptic Netrin G1 and its cognate partner postsynaptic Netrin-G-Ligand-1 (NGL-1) have been implicated in SCZ. This review article emphasized the structure and expression of Netrin G1/NGL-1 in the brain, its dysregulation in SCZ patients, and its role in synaptic plasticity, synaptic interaction, learning and memory, microglia neurotrophic activity, and possible signaling between Netrin G1/NGL-1, postsynaptic density protein 95, and cyclin-dependent kinase-like 5 in synaptic morphogenesis. Pharmaceutical targets and the potential use of Netrin G1/NGL-1 as treatment targets or biomarkers for SCZ were also discussed.
Seventh Annual Research Meeting of the Noguchi Memorial Institute for Medical Research: Viral Infections
Authors: K. Odoom John , Lartey Belinda , Kyei-Baafour Eric , H.K. Bonney Joseph , Kwadwo Kwadwo , Ofori Michael , K. de Souza Dziedzom , Armah George , Yeboah-Manu Dorothy
Published: August 2024

Viral infections, ranging from the common cold to severe illnesses like HIV/AIDS, Ebola, and SARS-CoV-2, are a major public health concern. The Noguchi Memorial Institute for Medical Research (NMIMR) has a comprehensive research program on viral diseases. During the seventh annual research meeting (ARM), presentations highlighted NMIMR's role in Ghana's preparedness for epidemic-prone diseases, national surveillance, and policy support. NMIMR hosts several key centres, including the National Influenza Centre and the Regional Reference Laboratories for Polio and Rotavirus. During the COVID-19 pandemic, NMIMR established Ghana's first testing facility and expanded testing capacity through training and novel methodologies like sample pooling. The Institute has tested hundreds of thousands of samples and conducted genomic sequencing to track SARS-CoV-2 variants. NMIMR's polio laboratory, the WHO Regional Reference Lab for Africa, processes samples from several West African countries. The lab's genomic sequencing has been crucial for tracking poliovirus and informing immunisation strategies. The institute also plays a key role in monitoring viral hemorrhagic fevers (VHF), and diagnosing diseases like Lassa fever, yellow fever, and Marburg. NMIMR's research and surveillance efforts have been pivotal in shaping Ghana's response to viral diseases, ensuring timely diagnosis, effective outbreak management, and informed policy-making.
Control of Aflatoxin-Producing Moulds in Melon Paste (Ogiri) Sold in Ogun State Using African Star Apple Oil and Cucumber Oil
Authors: Oni E.O. , Badmos A.O. , Ariom T.O. , Shoyinka Z.O. , Parakoyi G.O. , Adeleke A.J. , Sanusi J.O. , Sirajudeen A.O. , Obuotor T.M. , Omemu A.M.
Published: August 2024

The deleterious effects of aflatoxin-producing moulds cannot be over-emphasized in traditionally fermented food condiments like 'Ogiri'  (melon paste), irrespective of their nutritional properties. Therefore, the use of essential oils as a biocontrol agent to control aflatoxin- producing moulds in food condiments like 'Ogiri' is a potential approach worth exploring. This study aimed to evaluate the antifungal  properties of African Star Apple Oil and Cucumber Oil against aflatoxin-producing moulds. A total number of five samples of the ogiri (melon paste) were purchased from five different markets (Ijebu Igbo, Ijebu Awa, Ago-Iwoye, Kuto, and Osiele) in Ogun State, Nigeria.  Fungal isolation and identification were carried out on the melon pastes using standard microbiological procedures. Aflatoxigenicity  screening of the suspected fungal isolates was carried out using Neutral Red Dessicated Coconut Agar and viewed under an ultra-violet  (UV) spectrophotometer at 365nm. The phytochemical properties and the anti-fungal potentials of the oils on the aflatoxin-producing  moulds were determined using Gas Chromatography-Mass Spectrometry (GCMS) and disc well diffusion method respectively. Aspergillus  flavus, Aspergillus niger, Neurospora spp., and Saccharomyces cerevisiae were the fungi isolated from the ogiri samples, with Aspergillus    flavus, Saccharomyces cerevisiae and Neurospora spp. having the least percentage occurrence of 21.0%, 16.0%, and 5.0% respectively while  Aspergillus niger had the highest percentage occurrence of 58.0%. The screening for aflatoxin-producing potential among the isolates indicated that only the melon samples from Osiele exhibited positive aflatoxigenicity. The result showed that fermented melon paste  were highly contaminated with aflatoxigenic fungi and its consumption could pose aflatoxicosis risk to man. The antifungal efficacy of  African star apple and cucumber oil against aflatoxin-producing mould displayed minimal zones of inhibition around the well, signifying  limited antimicrobial activity of the oils.
Use of Biological Stress as a Novel Strategy to Control the Rice Blast Disease
Authors: Dayaso N.A. , Kogi M.P. , Adamu R. , Aliyu M. , Abubakar Y.S.
Published: August 2024

Magnaporthe oryzae, a hemibiotropic fungus, causes the devastating blast disease of rice, which results in an annual loss of about 15% of  the rice produced globally, enough to feed more than 60 million people for a year. Different approached have been adopted to manage the infection, including the use of chemical fungicides. In this study, we analyzed the potentials of using biological stress to hinder the  development and pathogenicity of the fungus, thereby controlling its spread and host infection. We induced cell wall/plasma membrane, oxidative and osmotic stresses in the fungus by growing it on media supplemented with 20% w/v SDS, 10 mM H2O2 and 1M NaCl,  respectively. Under these stresses, we evaluated the vegetative growth, pathogenicity, conidiation and conidia morphology of the blast  fungus. Our results revealed that the fungal vegetative growth was seriously hindered by the various biological stresses, with SDS  exerting the most pronounced growth inhibition. Conidiation was completely abolished under osmotic stress while oxidative stress  significantly reduced conidia production, compared to the unstressed group. However, no significant difference was observed in  conidiation following treatment with SDS. We also found that the various stresses have no effect on the physical morphology of the  fungal conidia, with the exception of NaClinduced stress that completely blocked conidiation. In the presence of the biological stress, the  pathogenicity of M. oryzae has been dramatically affected. No development of disease lesion was observed on rice leaves infected with  SDS- and H2O2-stressed fungi. A weak lesion was however observed on NaCl-treated fungus. These findings have revealed the crucial potential of biological stress in the control and management of the rice blast disease, which hold a great promise to sustaining the global  food security.