bluuebunny/crossref_metadata_2025 huggingface dataset:
Automated Optimum Extrusion Die Design and Profile Quality Control Based on Simulation
Authors: Kniazkin Ivan , Biba Nikolay , Kulakov Ivan , Duzhev Alexey , Stebunov Sergei
Published: September 2024

The paper presents the experience of development and implementation of an integrated approach of extrusion simulation with the automated design of the dies as a new way to speed up the technology development and its optimisation based on the QForm UK Extrusion simulation program and QForm Extrusion Die Designer (QExDD) design system. Bearing and prechamber optimisation types are considered for the porthole design. Welding quality and possible streaking lines in the profile are analysed for the tool construction with optimised prechamber contour.
Automatic Lung Nodules Detection Using a Modified YOLOv5
Authors: Bhatt Shital D. , Astik Mitesh B. , Soni Himanshu B.
Published: September 2024

Lung cancer diagnosis involves a detection strategy to determine the specific location of the abnormality and its likelihood whether cancerous or non-cancerous. In existing methods such as Endobronchial ultrasound-guided transbronchial needle extraction (EBUS-TBNA) method requires specific equipment and trained operators. The limits in biomarker discovery begin with sample collection, transportation, representative tissue processing, reference standards, assay sensitivity and specificity. Liquid biopsy method requires tissue biopsy for initial diagnosis and may increase the likelihood of false negatives and false positives. To overcome these challenges, initially in this paper, three detectors are trained for nodule detection i.e. You Only Look Once version 3 (YOLOv3), YOLOv4 and YOLOv5. YOLOv3 achieved precision of 72%, recall of 75%, mean Average Precision (mAP) of 70%, F1 Score of 0.73 and Giga Floating-Point Operations (GFLOPs) of 30. In contrast, YOLOv4 achieved 85% precision, 70% recall, 80% mAP, F1 score of 0.76 and 65 GFLOPs. On the other hand, YOLOv5 achieved precision of 90%, recall of 80%, mAP of 85%, F1 Score of 0.85 and FLOPs of 217. These three detectors also faced few challenges like complexity, have high computation time and low performance. So, to overcome the problems of YOLO based methods, a modified YOLOv5 model has been proposed for the automatic detection of lung nodules in CT scans. Key modifications include enhanced feature extraction layers and customized anchor boxes tailored for small nodule detection. These modifications demonstrate the model's potential for reliable and efficient lung cancer screening, aligning with the manuscript's focus on advancing detection techniques through customized YOLOv5 enhancements. The modified model achieves a 90% precision, 85% recall, 88% mAP, 0.87 F1 score and 35.2 GFLOPs. These results represent an improvement in accuracy and increase in sensitivity compared to the standard YOLOv5 model. Also, GFLOPs have been reduced which demonstrates low computing requirement for the proposed model. The proposed model could be further used as clinical tool for lung cancer diagnosis.
Enhancing Deaf Athletes' Performance: Vibrating Wristband for Referee Whistle Detection on Recreational Sports Using Wi-Fi
Authors: Rubio Molina Diana Aurora , Martínez Zapata María José
Published: September 2024

This project arises in response to the to the various investigations found that have pointed out the difficulties that Deaf people have faced in the sports field due to the communication barriers they have with referees. The ASH board of directors has confirmed this fact and this is the problem identified. In addition, several studies support the difficulty of concentration among athletes. The proposal consists of a device for athletes placed on a wristband, which emits vibrations when the referee's whistle is blown. It seeks to improve the performance of the Deaf player by obtaining instant communication with the referees. For this project, a qualitative approach has been used to collect data on the experience of Deaf players in sport. For its construction, materials were needed such as the ESP8266-01 modules, a vibrating motor, a push button, transistor and batteries. In this case, each of the modules, connected to the transmitter or receiver, used the Wi-Fi network as a means of wireless communication between them. In addition, tools such as SolidWorks, Fusion 360 and Arduino IDE were used for programming, since HTTP was used as a communication protocol between the modules. Finally, the prototype obtained has been validated by comparing it with a previously developed device and performing maximum range and instantaneous response tests. As a result, it has been improved compared to the existing ones, the design was adjusted to improve and change the components used, size and ergonomics. Furthermore, the tests were successful, and the device functioned correctly.
Assessment of Semi-Flexible Pavement Using Styrene-Butadiene Emulsion Modified Cement Grout
Authors: Do Thi My Chinh , Nguyen Manh Tuan
Published: September 2024

Semi-flexible pavement (SFP) is a type of road surface that combines open-graded asphalt concrete with cement grout for wearing courses containing 18 to 28% air voids. This study investigates the effectiveness of two types of cement grouts using modified styrene-butadiene emulsions, Sika Latex and Sika Latex TH, with varying amounts ranging from 4.5% to 7.5% and 7.5% to 9%, respectively. The goal of the paper is to determine the appropriated type of styrene-butadiene emulsion type for SFP. To create the SFP, the selected grout and Vinkems Asphalsol grout with a water-cement ratio of 0.45 were poured into the asphalt structure, resulting in an SFP with 22.8% air voids. Additionally, several experiments were conducted to evaluate the effectiveness of SFP. These experiments included the Marshall stability test, indirect tensile strength test, and resilient modulus test. The study results showed that Sika Latex 6.5% and Sika Latex TH 9% had good properties for use in SFP.
Study of Direct Metal Extrusion by the Upper-Bound and Finite Volume Methods
Authors: Bressan José Divo , Martins Marcelo Matos
Published: September 2024

The velocity fields of axisymmetric direct extrusion of metals was analysed by the upper-bound method and compared with the results from the finite-volume method, FVM. The upper-bound technique proposed by Avitzur and by Zhao et al. together with the streamline functions were employed to calculate the analytical velocity fields, which consider the friction at die wall. Moreover, the components of strain-rate are also presented. Additionally, the axisymmetric extrusion process was modelled by the FVM method to calculate the velocity fields and compared with the Avitzur’s and by Zhao’s solutions. The FVM velocity fields were calculated by using the Eulerian approach of fixed grid, the governing equations of metal plastic flow and conservation laws discretized by the FVM and the Explicit MacCormack method in structured and collocated mesh were also employed. Friction at die wall was modelled by the friction factor model, using the tangential shear stress boundary conditions. The examined material experimental parameters were obtained from the Al 6351 aluminium alloy in the direct extrusion process at 450o C. Velocity fields of the longitudinal and radial velocity distributions by the upper-bound and FVM methods are presented and compared. Good agreement is shown between the radial velocity component Vr from the Avitzur´s and FVM results, but poor for the longitudinal velocity Vz. From the analysis of velocity fields, the most severe condition of wear on the inner wall of the die and material surface damage occurs in the area near the exit corner of the die. However, the predicted location of the severe wear region in the die wall by the FVM method is located prior to the point predicted by the Avitzur model.
Marble-Looking Fired Clay Tiles Produced by Utilizing Local Clay and Glass Cullet
Authors: Loetchantharangkun Witsanu , Pitipoomsuksan Chonlathit , Wangrakdiskul Ubolrat
Published: September 2024

This research is aim at developing marble-looking fired clay tile by utilizing waste glass cullet (CGC) mixed up with local plastic clay, sediment soil, and laterite clay. Boric oxide is also used as sintering aid. The experimental formulation is divided into 3 groups (A, B, and C) with 27 formulas. Test samples are moulded at 100 bar by Uni-axial pressing in dimension 50 x 100 x 7 mm and fried at temperature 850 °C. The initial results show that all formulas can develop marble texture and achieve Thai Industrial Standard TIS 2508-2555. Reducing firing temperature to 800 °C is the further investigation. However, formulas consisting 90% glass cullet are not selected, due to difficulty of molding workpieces. The final results of firing 800o C show that formula A6 containing 15% Plastic clay, 85% glass cullet, 2% boric oxide has the highest bending strength and lowest water absorption (<1%). Its properties are similar to formula C6 containing 15% laterite soil 85% glass cullet, 2% boric oxide. They can pass Thai Industrial Standard TIS 2508-2555 Floor Tiles BIb. Analyzing microstructure the fired specimens of these formulas by Scanning Electron Microscope has found glassy phases and dense matrix structures. Furthermore, Nepheline, Quartz, Cristobalite, Wollastonite, Devitrite, and Albite are identified by X-Ray Diffractometer. It can be summarized that marble texture surface fired clay tile can be developed by utilizing waste glass and low cost local materials.
Characterization of Cocoa Waste Husks Charcoal from Suratthani Thailand as Potential Sources of High Valued Products
Authors: Srirachya Nuttida , Theuput Seksit , Yasun Anurak , Saguansakbaramee Nattapan , Thongnueaha Sarawut , Nuchuay Peerapong
Published: September 2024

Cocoa husks, usually discarded as waste, possess valuable biomass that can be utilized. The objective of this research is to study the properties of charcoal obtained from the carbonization of leftover cocoa husks in the Suratthani province, Thailand. The discarded cocoa husks were carbonized in a designed charcoal kiln, and the carbonization temperature was investigated. It was found that the carbonization process had four phases, with a total duration of approximately 3.5 hours. The maximum temperature reached during carbonization was around 470 °C, and the average ignition temperature of the charcoal from cocoa husks in this research was approximately 261.1 °C. Heat analysis of the charcoal revealed a thermal conductivity of about 4678 kcal/kg. Additionally, a morphological analysis of the charcoal from cocoa husks showed higher porosity compared to dried cocoa husks. Therefore, charcoal from cocoa husks has the potential to be used in value-added products such as charcoal briquettes and odor-absorbing materials.
Beyond the Spirometry: New Diagnostic Modalities in Chronic Obstructive Pulmonary Disease
Authors: Song Jin Hwa , Kim Youlim
Published: September 2024

Spirometry can play a critical role as a gold standard in the diagnosis and treatment of patients with chronic obstructive pulmonary disease (COPD). While the criteria for diagnosis have advanced over time, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) standard of the forced expiratory volume in 1 second/forced vital capacity ratio <0.7 remains the most universally employed metric. However, spirometry cannot be utilized in all situations, and test execution can be difficult for some patients, often showing normal values in the early diagnosis of COPD. Therefore, research on new diagnostic methods is underway. Techniques include whole-body plethysmography for measurement of residual volume and inspiratory capacity and airway resistance, diffusing capacity of carbon monoxide or nitric oxide, impulse oscillometry, infrared time-offlight depth image sensor, diaphragm ultrasonography, which can enable early diagnosis and multifaceted assessment of patients with COPD.
Intravenous Bacillus Calmette–Guérin (BCG) Induces a More Potent Airway and Lung Immune Response than Intradermal BCG in Simian Immunodeficiency Virus–infected Macaques
Authors: Jauro Solomon , Larson Erica C , Gleim Janelle L , Wahlberg Brendon M , Rodgers Mark A , Chehab Julia C , Lopez-Velazques Alondra E , Ameel Cassaundra L , Tomko Jaime A , Sakal Jennifer L , DeMarco Todd , Borish H Jacob , Maiello Pauline , Potter E Lake , Roederer Mario , Ling Lin Philana , Flynn JoAnne L , Scanga Charles A
Published: September 2024

Tuberculosis (TB), caused by Mycobacterium tuberculosis, is one of the leading causes of death due to an infectious agent. Coinfection with HIV exacerbates M. tuberculosis infection outcomes in people living with HIV. Bacillus Calmette–Guérin (BCG), the only approved TB vaccine, is effective in infants, but its efficacy in adolescents and adults is limited. In this study, we investigated the immune responses elicited by BCG administered via i.v. or intradermal (i.d.) routes in SIV-infected Mauritian cynomolgus macaques (MCM) without the confounding effects of M. tuberculosis challenge. We assessed the impact of vaccination on T cell responses in the airway, blood, and tissues (lung, thoracic lymph nodes, and spleen), as well as the expression of cytokines, cytotoxic effectors, and key transcription factors. Our results showed that i.v. BCG induces a robust and sustained immune response, including tissue-resident memory T cells in lungs, polyfunctional CD4+ and CD8αβ+ T cells expressing multiple cytokines, and CD8αβ+ T cells and NK cells expressing cytotoxic effectors in airways. We also detected higher levels of mycobacteria-specific IgG and IgM in the airways of i.v. BCG-vaccinated MCM. Although i.v. BCG vaccination resulted in an influx of tissue-resident memory T cells in lungs of MCM with controlled SIV replication, MCM with high plasma SIV RNA (>105 copies/ml) typically displayed reduced T cell responses, suggesting that uncontrolled SIV or HIV replication would have a detrimental effect on i.v. BCG-induced protection against M. tuberculosis.
Design, Development and Flight Testing of a Novel Quadrotor Convertiplane Unmanned Air Vehicle
Authors:   Indian Institute of Technology Kanpur, Abhishek Abhishek , Krishna M. , Sinha Sourav , Bhowmik Joydeep , Das Debopam
Published: September 2024

This paper describes the design, development and flight testing of a small novel quadrotor convertiplane Unmanned Air Vehicle (UAV) which has four propellers driven by individual brushless DC motors mounted at the tip of tandem wings. The segment of the wing under the propeller downwash is tilted with the propeller to improve the hovering efficiency of the UAV. Tandem low and high wing design is chosen to mitigate the interference losses due to the influence of fore wing and propeller downwash on the aft wing and the propellers. The motor and propeller suitable for the design are chosen through systematic performance measurements carried out using a hover test stand and wind tunnel tests. The effect of tilting the wing segment below the rotor is studied by modifying the hover stand and including the wing in the setup. A PID controller is developed, first in simulation and then implemented on a PixHawk autopilot board to stabilize the prototype during hover. The performance of the controller is demonstrated through flight test of the prototype. For the current configuration and size, the current design, with the wing in propeller downwash tilting with the rotor, offers 50% higher power loading in hover in comparison to a conventional quad tiltrotor with no wing tilting. It is observed that the propeller looses 40% of its thrust due to the download penalty on the wing when no part of the wing is tilted with the propeller. The tilting of the wing portion equal to the radius of the propeller increases the power loading of the propeller making it nearly same as the isolated rotor. The current design is estimated to consume 50% less power during airplane mode in comparison to the quadrotor mode thereby establishing the advantage of the proposed convertiplane vehicle over regular quadrotor UAVs.
Performance and Flowfield Measurements of a Meso-Scale Cycloidal Rotor in Hover
Authors:   Texas A&M University, Runco Carl , Himmelberg Brett , Benedict Moble
Published: September 2024

This paper details the performance and flowfield measurements on a meso-scale cycloidal rotor. Owing to the small size (rotor radius of 1 inch), the cycloidal rotor investigated in the present study operates at ultralow Reynolds numbers (Re∼11,000) and also utilizes a blade design completely different from the previous studies. The meso-scale rotor utilizes a low aspect ratio cantilevered blade design with flat plate airfoil and elliptical blade planform, which means that 3-dimensional effects will be more prominent. A highly sensitive, miniature 3-component balance was developed to measure the vertical and sideward thrust, torque, and rpm with varying number of blades, pitch amplitude, and blade aspect ratio (with constant blade area). The studies showed the highest efficiency was achieved with higher number of blades (4 – 6 blades), high pitch amplitude (40° – 45°) and moderate aspect ratios. Phase-locked flowfield measurements were conducted using Particle Image Velocimetry (PIV) technique in two different orientations, chordwise and spanwise measurements. The chordwise measurements had the laser plane normal to the rotational-axis/blade-span and examined the evolution of leading edge vortices and the trailing wake at 60% blade span location. The spanwise measurements had the laser plane parallel to the axis of rotation, bisecting the rotor vertically to examine the evolution of blade tip and root vortices. PIV measurements show that the flowfield on the present meso-scale cycloidal rotor is highly 3-dimensional and unsteady, characterized by the growth and shedding of leading edge vortices (LEVs) and trailing vortex sheet similar to the ones seen on flapping wings, strong root and tip vortices that interact with each other to create an undulating wake, skewed inflow and the strong interaction of the slip stream from the upper blade on the lower blade.
The Tip Vortex-System of a Four-Bladed Rotor in Dynamic Stall Conditions
Authors:   German Aerospace Center - DLR, Wolf C. , Braukmann Johannes , Stauber Wolfgang , Schwermer Till , Raffel Markus
Published: September 2024

The tip vortex-system downstream of a four-bladed instrumented rotor was investigated experimentally through the application of stereoscopic particle image velocimetry (PIV). A dynamic stall test case was facilitated by a high cyclic pitch setting of the swashplate, with additional attached-flow and constant-pitch test cases for comparison reasons. The phase-locked PIV system and a rotation of the swashplate assembly allowed for an acquisition of the tip vortex system over the entire dynamic stall cycle and vortex ages up to at least 235°. The vortex structure and its relation to the blade shear layers were studied by means of both phase-averaged flow fields and the identification of vortex properties such as circulation and swirl velocity distributions. When approaching dynamic stall, a break-down of the vortex structure started at high vortex ages, accompanied by the entrainment of turbulent structures from the passing blade shear layers into the tip vortices. After the flow over the blade is fully separated and during large parts of the downstroke, the wake of the rotor tips appeared as a highly turbulent area with no individual tip vortices traceable, before reestablishing an ordered tip vortex structure shortly before the minimum blade pitch angle.
CFD Pressure/Airload Correlation with Experimental Data on a Slowed Mach-Scaled Rotor at High Advance Ratios
Authors:   University of Maryland, Wang Xing , Jung Yong , Baeder James , Chopra Inderjit
Published: September 2024

Slowing down the rotor RPM is a viable method to alleviate the compressibility effect at the advancing side of a rotor in forward flight, which is proved effective in raising the cruise speed limitation of a compound helicopter. A series of wind tunnel tests were conducted in the Glenn L. Martin Wind Tunnel, and some basic understandings were gained on the high advance ratio aerodynamic phenomena, such as thrust reversal and dynamic stall in reverse flow region. In one of the wind tunnel tests, the rotor blades were instrumented with pressure sensors and strain gauges at 30% radius, and enough pressure data was acquired to calculate the integrated sectional airloads. Further, the experimental results of rotor performance, control angles, blade airloads and structural loads were correlated with the predictions of comprehensive analysis as well as CFD/CSD coupled analysis. Furthermore, the paper focuses on the comparison between experimental surface pressure and airload data and the CFD/CSD results for cases with various collective and shaft tilt settings. Overall, the data correlation was found satisfactory for these cases, and this study provided some insights into the aerodynamic mechanisms that affect the rotor airload and performance.
Wake characterization of a free-flying model helicopter in ground effect
Authors:   German Aerospace Center (DLR), Schwarz Clemens ,   University of Stuttgart, Mailänder Stephan , Bauknecht André , Raffel Markus
Published: September 2024

Measurements of the flow field around a free-flying model helicopter in ground effect for both quasi-steady and unsteady maneuvering flights were performed using stereoscopic particle image velocimetry (PIV). The wake features for hover and forward flight at low advance ratios were characterized and changing flow patterns like recirculation and ground vortex flow were observed to be in good agreement with existing wind tunnel data. Parameters describing both general flow patterns and single blade tip vortices were extracted and showed significant dependence on the forward flight velocity. Landing approaches were performed and large vortical structures were observed close to the rotor disk, which contained high amounts of vorticity due to entrained blade tip vortices. The vortex structures developing for unsteady landing approaches contained distinctly higher velocities and momentum fluxes than expected from quasisteady conditions at the same advance ratios. For a vertical takeoff maneuver with a rapid increase of collective pitch, the bundling of blade tip vortices into a "starting vortex" with circulation values up to 6 times higher than for a single blade tip vortex was observed. These results show the significance of experimental data on free-flying helicopters in unsteady maneuvering flight because the resulting flow fields cannot be predicted using steady-state experiments or simulations.
RACER high-speed demonstrator: Rotor and rotor-head wake interactions with tail unit
Authors:   ONERA - The French Aerospace Lab, Lienard Caroline ,   Airbus Helicopters, Fukari Raphaël , Salah Itham , Renaud Thomas
Published: September 2024

Within the framework of NACOR project in CleanSky 2 AIRFRAME ITD, ONERA and DLR performed parallel investigations dealing with the RACER high-speed demonstrator, and especially with its tail parts, each partner respectively focusing on vertical fins (ONERA) and horizontal stabilizer (DLR). During this design phase, most of the CFD simulations were steady-state and neglected the effect of the rotor (or rotor-head) and of the propellers. It however turned out that the rotor-head had a significant effect on the vertical fins and that it was essential to take into account its rotation in time-accurate simulations: the wake from the rotor-head, the upper deck and the engine cowlings indeed strongly impacts the left vertical fin because of the clockwise rotation of the rotor-head. It induces strong oscillations on the tail unit loads, and the mean tail unit lateral thrust is also significantly increased. Moreover the main conclusions of this 'aerodynamic interactions' investigation are almost identical, no matter what the computed configuration: rotating rotor-head, rotating rotor-head with actuator-disk, rotating full-rotor or rotating full-rotor with propellers effect.
CFD Predictions of Rotor-Fuselage Interactions Using Laminar-Turbulent Transition Modeling
Authors:   University of Tennessee, Parwanim Ashwin , Coder James
Published: September 2024

Pressure Sensitive Paint (PSP) rotor hover predictions are obtained using computational fluid dynamics simulations. Laminar-turbulent transitional modeling predictions are made with the OVERFLOW 2.2 compressible flow solver on structured, overset grids. Solutions are generated based on a tip Mach number of 0.58 for varying collective pitch angles. In addition to isolated rotor predictions, results are generated for rotor-fuselage interactions using the PSP rotor and Rotor Body Interaction (ROBIN) fuselage. Hover performance is assessed and compared to available measurements obtained in the NASA Langley Research Center Rotor Test Cell (RTC). Grid generation techniques and computational methods for both cases are described. Rotor flow field behavior and transition locations are discussed for both cases along with the impact of transition modeling.
The Physics behind BVI Noise Reduction in Descent Flight through the Use of Dynamic Active Twist Control
Authors:   German Aerospace Center (DLR), Hoffmann Frauke , G. Berend , Yin Jianping
Published: September 2024

The paper investigates the influence of a dynamic active twist control on BVI noise in descent flight for a Mach-scaled Bo 105 model rotor. Therefore, a numerical study has been carried out with DLR's aeromechanics rotor code S4. In addition, sound pressure levels have been computed with DLR's acoustic code APSIM. The intensity of BVI noise is determined by different vortex parameters as well as the blade-vortex miss-distance and the BVI location. In this paper, all parameters that influence the intensity of the radiated BVI noise are analyzed. The analysis is carried out for a rotor shaft angle of attack of αᴿₒ = 4° for which the most intensive BVI noise was identified for the passive rotor blade. The study lays emphasis on the effect of different control amplitudes and phases but concentrates on a control frequency of the third multiple of the rotor rotational frequency for which highest reductions in BVI noise were identified.
A Computational Study on Rotor Interactional Effects for a Quadcopter in Edgewise Flight
Authors:   Rensselaer Polytechnic Institute, Misiorowski Matthew ,   University of Southern California, Oberai Assad , Gandhi Farhan
Published: September 2024

This study examines the performance of a quadcopter in edgewise flight conditions with flow simulated using the commercial Navier-Stokes solver, AcuSolve, with a Detached Eddy Simulation (DES) model. The rotating volume around each rotor interfaces with the remainder of the computational domain using a sliding mesh. Simulations were conducted for an AeroQuad Cyclone quadcopter at 10 m/s forward speed, 5 deg nose-down pitch attitude, operating in both cross and plus configurations. From the results it was observed that in the cross configuration, the aft (South) rotors showed a 19% reduction in lift (relative to an isolated rotor at the same forward speed, pitch attitude and RPM), with an associated 3% reduction in torque. The loss in lift was primarily at the front of the aft rotors due to the downwash induced by the forward rotors, therefore reducing the aft rotor nose-up pitching moments by 54% (relative to operation in isolation). In the plus configuration, sections of the East and West rotors close to the aircraft center-body operate in upwash induced by the North rotor, increasing the lift generated by 5.5% and 7.6% respectively, relative to operation in isolation. The South rotor sees both upwash (and increased lift) along the advancing and retreating edges induced by the East and West rotors, as well as downwash at the front (and reduced lift) induced by the North rotor, but no significant overall changes in thrust or torque.
Coupling of Rotorcraft Elastic Fuselage with CFD
Authors:   Advanced Rotorcraft Technology Inc., Saberi Hossein , Hasbun Matthew , Blumenstein Ryan , Kim Jeewoong
Published: September 2024

Accurate prediction of aeroelastic coupling between rotor wake and structure remains a key challenge to the development of advanced rotorcraft. Limitations of existing analysis tools to predict such aeroelastic interactions, notably empennage buffeting effects, have resulted in costly late-cycle design changes in multiple rotorcraft development programs, including the UH-60A and AH-64A. Aeromechanical phenomena involving interactions of the fuselage and rotor wake are complex, interdisciplinary, and three-dimensional in nature. For this reason, full vehicle CFD/CSD coupled analysis is essential to accurately capture the mutually dependent interactions between the aerodynamic loads and the aeroelastic response associated with these phenomena. The current state-of-the-art in rotorcraft analysis involves CFD/CSD coupled analysis of aeroelastic rotors and wings, but rigid representations of the fuselage and empennage structures (Ref. 1). To address this limitation, an elastic fuselage coupling capability was developed using RCAS and FUN3D. The elastic fuselage CFD/CSD interface has been successfully tested for several demonstration cases and one validation case.
Aerodynamic Performance of Morphing Blades and Rotor Systems
Authors:   Technical University of Munich, Rauleder Jürgen ,   German Aerospace Center (DLR), G. Berend ,   Technical University of Munich, Abdelmoula Amine ,   University of Bristol, Ondra Vaclav , Komp Dominik , Kumar Sumeet , Titurus Brano , Woods Benjamin
Published: September 2024

This paper introduces the Shape Adaptive Blades for Rotorcraft Efficiency (SABRE) Horizon 2020 research program and presents initial comprehensive analysis results on the efficacy of adapting blade shapes as a means of reducing rotorcraft power requirements and emissions. The aims of the research program are introduced, followed by discussion of the six different morphing concepts that will be explored. The morphing mechanisms are based on active camber, chord extension, twist, and active tendon morphing technologies. SABRE will explore the use of these concepts individually and in combination, for rotor quasi-steady configuration-type morphing and up to 2/rev actuation of some of the mechanisms, with the objective being to find the best balance between emissions reductions versus complexity and added weight. Initial investigations into the potential power reductions compared to the baseline full-scale BO-105 main rotor achievable with the morphing concepts were performed using Blade Element Momentum Theory and a comprehensive analysis model that was developed using CAMRAD II. The analytical model was validated by full-scale rotor wind tunnel measurements. A combination of active twist and active chord extension achieved up to 11% performance gain in hover. Active camber morphing performance was very sensitive to the combination of deflection, morphing section radial length and placement on the blade, as well as the actuation phasing and blade loading coefficient. The active camber morphing showed power reductions of up to 5.5% in hover and 5% at an advance ratio of 0.313 with a 2/rev actuation, while the active tendon concept showed the capability to change the dynamic response of the rotor blade.
CFD/CSD Aeroelastic Predictions of a Semi-Span Tiltrotor
Authors:   Pennsylvania State University, Corle Ethan ,   US Army Research Laboratory, Floros Matt , Schmitz Sven
Published: September 2024

This work focuses on steps towards the ability to use tight coupling between computation fluid dynamics (CFD) and rotorcraft comprehensive analysis (CSD) to predict aeroelastic stability of a rotor. First, the Rotorcraft Comprehensive Analysis System (RCAS) analysis is used to carry out traditional linear stability analysis. Next, a method of using trim springs to artificially increase the stability of the wing so that a periodic solution during the RCAS trim procedure is presented. RCAS is then used to complete time-integrated transient analysis using a lifting-line aerodynamic model following a system perturbation through a vertical force located at the wing tip. CFD/CSD coupling is used for the first time to simulate a fully-elastic semi-span tiltrotor model. Loose coupling is used to achieve a trimmed solution for a sweep of airspeeds. Tight coupling is used to observe the transient behavior of the system following a perturbation. Low-speed results are promising and clearly demonstrate differences between the higher-fidelity method and comprehensive analysis indicating Helios is capturing previously missed aerodynamic effects. At higher speeds, the perturbation used here is found to be inadequate for activating the wing beam bending mode. Finally, the tight coupling procedure predicts an unstable rotor mode that is not predicted by comprehensive analysis. The primary objective of this work is to demonstrate new capabilities introduced to the CREATE-AV software Helios and RCAS which allow for a first fully-elastic semi-span simulation of a tiltrotor using high-fidelity analysis through both loose and tight coupling methodologies.
Performance Measurement of a Novel Dissimilar Coaxial Rotor System
Authors:   Indian Institute of Technology Kanpur, Aggarwal Diksha , Ramanujam Rahul , A. Abhishek , Das Debopam
Published: September 2024

This paper presents the preliminary results from the experimental study of the aerodynamic characterization of a novel dissimilar coaxial rotor concept with reduced rotor-rotor interaction. The performance of dissimilar coaxial rotor concept is compared with existing rotor configurations such as conventional single main-rotor tail-rotor and regular coaxial rotor. The performance measurement is carried out using a small scale coaxial hover test stand facility setup for this purpose. The hover performance of different rotor concepts namely conventional, regular coaxial and dissimilar coaxial rotors are compared as anti-torque mechanisms with same baseline rotor by comparing their power loading. The inter-rotor spacing between coaxial rotors is kept constant at 15% of the rotor radius. The dissimilar coaxial rotor appears to be a promising solution for development of high efficiency hovering rotor system for high thrust condition. From the tests conducted on a main rotor of 0.415 m radius operated at 1000 RPM, it is established that the dissimilar coaxial rotor system consistently shows higher power loading than the conventional rotor (especially at high thrust condition) as well as the coaxial rotor system. To achieve maximum benefits from the dissimilar coaxial rotor system, the anti-torque rotor in the dissimilar rotor pair must be spun at 50% or 40% of the main rotor RPM. The effect of the cross-section shape of the blade-hub attachment (root cutout) plays a significant role in reducing the profile power loss of the anti-torque rotor of the dissimilar coaxial rotor. In the current study, three different shapes were compared and the elliptical cross-section shape was observed to give best performance.
A case of a huge aortic pseudo-aneurysm following aortic bioprosthetic endocarditis: the key role of 3D echocardiography
Authors: Sordelli Chiara , Verde Raffaele , Fele Nunzia , Weisz Sara Hana , Severino Laura , Perrella Alessandro , Guarino Angela , Di Lorenzo Emilio , Severino Sergio
Published: September 2024

Infective endocarditis (IE) is a life-threatening condition with high morbidity and mortality rates, making early diagnosis and intervention crucial. This report details the case of a 47-year-old male with a history of mechanical prosthetic aortic valve replacement, presenting with pyrexia and diagnosed with aortic bioprosthetic endocarditis leading to a massive aortic pseudoaneurysm. This shows that 3D transesophageal echocardiography is much more useful than regular 2D imaging for finding problems with IE, which makes surgical planning and intervention more precise.
A Retrospective Study of Pattern of Abnormal Findings in Routine Screening Investigations Done of Psychiatry Inpatients in Tertiary Care Teaching Hospital
Authors: Patel Disha R , Desai Nimisha D , Shah Sandip H
Published: September 2024

Introduction:

Physical comorbidity in persons with mental illness is a rule rather than exception. Hence, regular screening investigations in psychiatry inpatients help to detect physical illness at early stage.

Aims and Objectives:

The aim of this study was to evaluate the results of various screening investigations, referral patterns, and physical comorbidities in psychiatric inpatient records.

Methodology:

This was a descriptive, analytical, record-based study conducted in the psychiatry department of a tertiary care teaching hospital, wherein case notes of all inpatients admitted to the psychiatry unit during 6 months (January–June 2023) were studied. Inpatient records were evaluated for sociodemographic details, indication for admission, investigations as needed, any physical comorbidity, treatment history, referral patterns, and their outcomes. Records with incomplete details and known physical illnesses mentioned were excluded.

Results:

Total 100 patients’ records (63 males; mean age = 35 years, 37 females; mean age = 41 years) were included in the study. The common diagnosis was mood disorder 36% (n = 36), followed by substance use disorder 30% (n = 30) and schizophrenia 22% (n = 22). On evaluating investigations, abnormalities found were anemia, diabetes mellitus, hypertension, and thyroid disease (42% [n = 42/100], 24% [n = 24/100], 22% [n = 22/100], and 22% [n = 22/100], respectively). Magnetic resonance imaging (MRI) brain changes were seen in 75% of patients with acute behavior disturbances (n = 4) and MRI spine changes in all major depressive disorder patients presented with backache (n = 4). Ultrasonography abdomen findings were abnormal in 68% (n = 26/38), of which 80% (n = 21/26) had substance use disorder. For the management of abnormal findings, the referral consultation rate was 76% (n = 76/100); 86% (n = 66/76) of patients required more than one consultation with total 154 referrals.

Conclusions:

The investigations as indicated help in early detection and management of physical illness which mostly remains out of sight due to psychiatry illness.
Restarting Neuroleptics in Neuroleptic Malignant Syndrome – A Case Series
Authors: Rao Aishwarya , Sreedaran Priya
Published: September 2024

Neuroleptic malignant syndrome (NMS) is a rare but life-threatening side effect of antipsychotic agents. Although the incidence of NMS is rare, it is essential to recognize it at an early stage and take the necessary precautions to prevent mortality and morbidity. Along with the treatment of NMS, the challenge is to treat the concomitant psychiatric symptoms, which become difficult to manage. There are no fixed guidelines or any data available regarding restarting of neuroleptics in a patient who has recovered from NMS. This case series is a set of three cases that reviews the differences in sociodemographic data, clinical presentation, management, and trial of rechallenge of psychotropics in patients with symptoms suggestive of NMS in a tertiary care hospital.
Study of Knowledge, Attitude, and Practices of Use of Masks among Health-care Workers at a Tertiary Care Center in Mumbai
Authors: Kadamba Sharan Sadashiva , Suryavanshi Kalpana Tikaram , Bhatia Khushi P.
Published: September 2024

ABSTRACT

Introduction:

Airborne transmission of infectious diseases poses a significant public health challenge. Nosocomial outbreaks of airborne infections such as influenza H1N1, H5N1, and drug-resistant tuberculosis (TB) variants have been documented, with substantial morbidity and mortality attributed to inadequate airborne infection control strategies. N-95 respirators and surgical masks (face masks) are the examples of personal protective equipment that are used to protect the wearer from airborne particles and liquid contamination of the face.

Aim and Objectives:

The aim of this study was to assess the knowledge, practices, and attitude of health-care workers (HCWs) regarding the use of mask, especially N-95 mask.

Materials and Methods:

A prospective, was conducted over a period of 6 months at a tertiary care hospital. This study was carried out in the department of microbiology of a tertiary care hospital over a period of 6 months. A total of 500 HCWs from various departments of the hospital were included in the study. HCWs were given a questionnaire based on N-95 respirator usage, and participation was voluntary.

Results:

The analysis of survey data provides insightful perspectives on respondents’ comprehension and attitudes toward airborne infection transmission and the usage of N-95 masks. 68.6% of respondents recognized that all listed diseases (measles, TB, and chickenpox) were spread by the airborne route. 55.6% of respondents correctly acknowledged that all masks, including surgical masks, N-95 masks, and cotton masks, do not offer airborne protection. 76.0% of respondents acknowledged that N-95 masks possess a high filtration efficiency against 0.3-micron particles, 58.3% correctly identified that “N” in N-95 stands for “not resistant to oil,” and 90.8% acknowledged that the N-95 respirator as the most common type of respirators. 41.7% correctly acknowledged that N-95 masks with an exhalation valve are not recommended for use. 22.2% of respondents incorrectly believe that wearing a face mask can lead to carbon dioxide poisoning, and 52.1% of respondents correctly identified that pulmonary TB patients need not be provided with N-95 masks in isolation rooms. 76.8% of respondents understood that fit testing is required every time one dons an N-95 mask. 95.5% of respondents recognized the necessity of hand hygiene before donning and after doffing N-95 masks. 82.7% of respondents agreed regarding the necessity for consultation before N-95 mask usage for chronic lung disease and asthma patients. 93.7% are aware that there is a protocol for donning and doffing N-95 masks. 71.3% of respondents understood that extended use involves wearing the same N-95 respirator for repeated close contact encounters without removing the mask between patient encounters, while 64.4% correctly define reuse as using the same N-95 respirator for multiple encounters but removing it after each encounter.
Study of the DNA Extraction from the Nail by Spin Column-based Nucleic Acid Purification
Authors: Sujirachato Kanchana , Wongyanin Piya , Ramadjai Pilaiwan , Ladsuk Alisa , Pokkasap Kingkan , Worasuwannarak Wisarn
Published: September 2024

Background:

Nails are one of the objects that are more durable than other witness objects. This study was interested in whether the Spin column-based nucleic acid purification technique could extract DNA from nails to give satisfactory results.

Aims and Objectives:

This study aimed to evaluate the yield and quality of DNA extracted from the nail.

Materials and Methods:

Nail samples from 15 males and 15 females over 18 were extracted using GeneAll® Exgene™ Cell SV Mini Kit. The DNA concentration and purity were measured using a NanoDrop Spectrophotometer, and the quality of DNA was assessed by polymerase chain reaction (PCR) using primers specific for human growth hormone (HGH).

Results:

The average yield of DNA was 0.816 μg (0.141–2.706 μg) obtained from the average nail weight of 30.2 mg (22.2–40.0 mg). The average DNA concentration was 27.2 ng/μL (4.7–90.2 ng/μL), corresponding to 30 μL in volume. Almost all DNA samples (96.7%) had high purity (A260/A280 ≥1.80) and gave a band of PCR product of the HGH gene on agarose gel electrophoresis.

Conclusion:

Spin column-based nucleic acid purification is recommended for nail DNA extraction due to its simplicity and high quality.
Impact Assessment of Systemic Geometric Distortion in 1.5T Magnetic Resonance Imaging Simulation through Three-dimensional Geometric Distortion Phantom on Dosimetric Accuracy for Magnetic Resonance Imaging-only Prostate Treatment Planning
Authors: Chaknam Korawig , Worapruekjaru Ladawan , Suphaphong Sithiphong , Stansook Nualjun , Sodkokkruad Prapa , Asavaphatiboon Sawwanee
Published: September 2024

Aims:

Magnetic resonance imaging (MRI)-only radiotherapy has emerged as a solution to address registration errors that can lead to missed dose delivery. However, the presence of systemic geometric distortion (SGD) stemming from gradient nonlinearity (GNL) and inhomogeneity of the main magnetic field (B0) necessitates consideration. This study aimed to quantitatively assess residual SGD in 1.5T MRI simulation using a three-dimensional (3D) geometric distortion phantom and evaluate its impact on dosimetric accuracy for retrospective prostate cancer patients.

Materials and Methods:

Ten retrospective cases of prostate cancer patients treated with volumetric modulated arc radiotherapy (VMAT) were randomly selected. A geometric distortion phantom was scanned on a 1.5T MRI simulation using a 3D T1 volumetric interpolated breath-hold examination sequence, varying bandwidth (BW), and two-phase-encoding directions. Distortion maps were generated and applied to the original computed tomography (oriCT) plan to create a distorted computed tomography plan (dCT), and a dice similarity coefficient (DSC) was observed. Dosimetric accuracy was evaluated by recalculating radiation dose for dCT plans using identical beam parameters as oriCT.

Results:

The SGD increased with distance from the isocenter in all series. DSC exceeded 0.95 for all plans except the rectum. Regarding GNL’s impact on dosimetric accuracy, most mean percentage errors for clinical target volume, planning target volume, and both femurs were under 2% in all plans, except for the bladder and rectum.

Conclusion:

SGD pre-evaluation is crucial and should be incorporated into a quality assurance program to ensure effective MRI-simulation performance before MRI-only treatment planning for prostate cancer.
Tumor Control and Normal Tissue Complications in High-dose-rate Brachytherapy for Cervical Cancer Patients Using Ir-192 Radioactive Source
Authors: Kaur Gurpreet , Garg Pardeep , Dangwal Vinod Kumar , Singh Baltej , Gaur Garima , Grover Romikant , Singh Simrandeep , Sharma Rachana
Published: September 2024

Introduction:

The purpose of the study was to calculate, tumor control probability (TCP) and normal tissue complication probability (NTCP) in cervical cancer patients and to clinically correlate the outcomes with a follow-up period of 24 months.

Materials and Methods:

One hundred and fifty patients were included in the present study who received 46 Gy/23 fractions/4½ weeks of external beam radiotherapy with concurrent cisplatin chemotherapy, followed by intracavitary brachytherapy of 3 different fractionations regimens, i.e., 9.5 Gy per fraction of two fractions (50 patients in Arm1), 7.5 Gy per fraction of three fractions (50 patients in Arm2), and 6.0 Gy per fraction of four fractions (50 patients in Arm3).

Results:

The median TCP value for Arm1, Arm2, and Arm3 was 99.6%, 94%, and 98.1%, respectively, (P < 0.01). The median NTCP value for bladder in Arm1, Arm2, and Arm3 was 0.17%, 0.04%, and 0.07%, respectively, (P = 0.05). The median NTCP value for rectum in Arm1, Arm2, and Arm3 was 4.73%, 4.35%, and 3.17%, respectively, (P = 0.052). The overall survival (OS) of 90%, 86%, and 84% was found for Arm1, Arm2, and Arm3, respectively, at 24 months of follow-up.

Conclusion:

TCP, NTCP, and OS rates were found higher in Arm1 as compared to the other two arms. The complications found in all arms were less, low grade, and manageable. Hence, Arm1, i.e., 9.5 Gy per fraction of two fractions can be concluded as the optimum fractionation regime in terms of radiobiological parameters as well as overall patient comfort.