bluuebunny/crossref_metadata_2025 huggingface dataset:
The Scots in Java, 1811-1816. An Episode from the History of the 78th Regiment of Foot (Ross-shire Buffs): The Storming of the Yogyakarta Court, 20 June 1812, and its aftermath
Authors: (†) E. Edwards McKinnon , Carey Peter
Published: October 2024

During the short-lived British interregnum regime in Java (1811-1816), a battalion (1,000 soldiers) of the 78th Highland (Scottish) Regiment of Foot (Ross-shire Buffs) took part in the British invasion force. They participated in nearly all the major military engagements of this period, including the 20 June 1812 storming of the Yogyakarta kraton. The events of that bloody operation and the contribution of the 78th Highland Regiment to its success form the core of this article. This describes how sharpshooters of the regiment’s two rifle companies overwhelmed the Javanese gunners on the kraton battlements, and how a junior officer, Lieutenant Henry N. Douglas (1787-1860), secured the person of the Sultan (Hamengku Buwono II) and escorted him to the Dutch fort, Vredeburg. The role of the Scots Assistant-Resident of Yogyakarta, John Deans (1786-1868), and his disfigurement of the body of the slain Yogyakarta army commander, Sumodiningrat (c. 1760-1812), in his private mosque in his residence to the south of the court is also mentioned. Following the close of hostilities, the Scots troops were the last to leave Yogyakarta (13 July 1812) and used the time to teach local Javanese troops the Scottish broadsword dance, later adopted into the repertoire of the two minor courts (Pakualaman and Mangkunegaran). During their subsequent garrison duties in East Java, the regiment lost its commanding officer, Lieutenant-Colonel James Fraser (1766-1813), during a local uprising in Besuki in the Oosthoek (Eastern Salient), and later participated in the campaigns against Bali Buleleng (May 1814) and Bone in South Sulawesi (June 1814). By the time the regiment eventually returned to Scotland in late 1817, only 400 out of the 1,062 troops which had sailed from Madras (Chennai) in early May 1811 were still alive, most having succumbed to tropical diseases in their unhealthy barracks in Surabaya, Batavia (Weltevreden) and Cimanggis (Depok).
On ‘hanging meaning’ and its transmission. Tracing a didactic poem from Aceh
Authors: Iankovskaia Aglaia
Published: October 2024

Drawing on a case study of an Arabic poem and two versions of its interlinear Malay translation, the paper speculates on the involvement of oral practices in the transmission of interlinear texts. The translations are found in two manuscripts from Aceh (EAP329/1/11, Endangered Archives, 18th c., and ML 341, Jakarta, late 19th c.), between the lines of a didactic verse dealing with the duties of a good Muslim student. While the Arabic text of the poem seems to have been reproduced through copying from a written source, the transmission history of its Malay translations appears to be more complicated. Juxtaposing the two versions of interlinear translation reveals that they are too similar to be unrelated and, at the same time, too different for the differences to result from corruption in the process of recopying. The paper argues that the interlinear text in the manuscripts under discussion has gone through both written and oral transmission—likely in the classroom settings, with a teacher dictating the translation looking into a written copy, but feeling free to slightly modify or complement it during the dictation.
Disseminated Views During the Digitalization Process
Authors: İdacıtürk Emre
Published: October 2024

With digitalization and the development of the internet, copyrighted and royalty-free images are accessible from all over the world, and these images are often used in promotional materials; It can be used in outdoor advertising, on billboards at stops, on buses and subways, on websites, in short, in every field. In particular, the use of relevant images obtained from stock image sites in promotional materials belonging to different sectors may lead to negative consequences on the quality of their works. Regardless of the visual type, this can sometimes be the case even for template pages used in an illustration, a logo or presentation sheets. Considering that the design must be unique and have an original value, such copies can create a kind of metastasis effect and lead to a negative picture in terms of art and design.
Decentralized Aesthetics
Authors: Bakan Ufuk , Üstündağ Emine Nilüfer , Bakan Uğur
Published: October 2024

The comprehensive paper, grounded in a rigorous methodology that draws upon theoretical frameworks from diverse disciplines, explores the transformative impact of Non-Fungible Tokens (NFTs) on artistic collaboration and patronage within the creative industry, coined as decentralized aesthetics. It delineates the technical intricacies of NFTs, highlighting their role in empowering artists through ownership and control over their digital creations. Case studies and analysis illustrate how NFTs democratize access to the art market, enabling emerging talents to gain recognition and support without traditional gatekeepers. While acknowledging challenges such as legal ambiguity and environmental concerns, it emphasizes the opportunities for innovation and inclusivity presented by NFTs. It provides valuable insights for stakeholders interested in navigating the intersection of blockchain technology and artistic expression.
The Artist's Statement of Gülsün Erbil
Authors: Erbil Gülsün
Published: October 2024

Gülsün Erbil is considered a remarkable figure in the field of art. She draws attention with both artist identity and academic background. At the heart of her art lie such deep thoughts as the philosophy of Mevlana, and this mystical approach is evident in her works. By skillfully blending abstract and minimalist elements, she has opened a new path in Turkish painting art. She also adopted the mission of building a cultural bridge, combining traditional motifs with modern interpretations. She exhibited her art in both Turkey and international platforms, contributing to intercultural communication and emphasizing the universal language of art. She is also known for her humanistic attitude and aims to touch the depths of man in her works. With this work, it aims to convey the understanding of art of Gülsün Erbil.
Transhumanism and Ethics
Authors: Bansal Ankita , Vyas Anjali , Singh Raj Kumar
Published: October 2024

The primary objective of this study is to conduct a detailed bibliometric analysis to gain an in-depth and detailed analysis of Transhumanism, specifically focusing on ethical dimensions of human enhancement. This research will elucidate all the aspects of transhumanism including keyword trends, thematic trends, and cluster analysis to provide an understanding of the concept in the last two decades. This research will also make a significant contribution in listing the emerging themes, prominent articles, authors, institutions, and countries. A bibliometric methodology has been adapted. This study includes the usage of the Vos Viewer and R studio- Biblioshiny tools to visualize the results of performance analysis and knowledge foundations which include co- citation, co-occurrence, co-authorship, and keyword trend analysis. This multi-faceted approach also follows a critical examination and exploration of the present literature facilitating insights into the concept and evolution of Transhumanism and ethics in navigating the future of human enhancement. The study highlights the ethical implications of AI and technology associated with human enhancement.
Cyborgs in the Workplace
Authors: Preet Noble
Published: October 2024

Cyborg employees – people with augmented body parts – are expected to become part of the workforce and their HRM has not yet been addressed in the literature. This chapter discusses the issues of how the organisation's processes of human resource management must adapt to the implications of the existence of cyborgs within an organisation's payroll. It also considers the ramifications of cyborg workers for recruitment, training motivational appraisal, and performance, especially with reference to ethical issues and the fact that new measures and policies will be necessary to cover cyborg staff. Moreover, it presents the need of technology in allowing this transition and the resulting implications that can arise on the organizational culture and concerning the employees. The chapter will conclude with a look into the future of HRM with enhanced technologies that are emerging with ever-nearing speed of erasing the difference between man and a robot.
Aeroacoustic Simulation of an EC145-T2 Rotor in Descent Flight
Authors:   University of Stuttgart, Kowarsch Ulrich ,   Airbus Helicopters Deutschland GmbH, Schneider Sascha ,   University of Stuttgart, Keßler Manuel , Lippert Daniel , Krämer Ewald
Published: October 2024

In recent years a growing ecological awareness in society can be observed and more and more attention has been drawn to low noise concepts for instance. Hence, an improved aeroacoustic predictive capability in the early helicopter design phase is mandatory. For this purpose, IAG enhanced the DLR CFD Code FLOWer with a higher orderWENO method which is now investigated for its industrial applicability for helicopter noise predictions at Airbus Helicopters Deutschland GmbH. By means of a CFD (aerodynamics) - CAA (acoustics) simulation, the EC145-T2 helicopter is investigated in descent flight condition. Subsequently the simulation results are assessed on the basis of flight test data, measured during the EC145-T2 noise certification campaign. In a first step, the isolated rotor only is considered to reduce the computational effort to a complexity realistic for industrial applications. Results show the good capability of the higher order CFD code to resolve the aeroacoustic noise emission within the confidence interval.
Navier-Stokes Assessment of Test Facility Effects on Hover Performance
Authors:   NASA Ames Research Center, Chaderjian Neal , Ahmad Jasim
Published: October 2024

Recent advances in computational fluid dynamics (CFD) flow simulation has resulted in the accurate prediction of hover performance and vortex wake resolution that significantly exceeds the accuracy and scope provided by many legacy experiments. New experiments are needed to further validate these CFD codes, including the measurement of figure of merit within a few tenths percent error, detailed sectional loads, surface pressures, and wake surveys. This study is part of an exploratory exercise for a proposed NASA hover experiment to meet these modern objectives. Navier-Stokes simulations have been carried out for a 5ft radius rotor within the Rotor Test Cell (RTC) and the National Full-scale Aerodynamics Complex (NFAC). CFD is used to assess and understand facility effects on hover performance by comparing facility simulations with free-air conditions. Recommendations are provided to help select a facility.
Comparing Numerical and Experimental Results for Drag Reduction by Active Flow Control Applied to a Generic Rotorcraft Fuselage
Authors:   ONERA, Lienard Caroline ,   NASA Langley Research Center, Allan Brian , Pape Arnaud , Schaeffler Norman
Published: October 2024

Helicopter fuselage drag reduction using active flow control is a topic that has been addressed both by NASA and ONERA over recent years. Some common investigations were performed under the framework of the US/France Memorandum of Agreement on Helicopter Aeromechanics with both entities conducting independent research on generic rotorcraft fuselages. In particular, the ONERA ASF2 fuselage has undergone a comprehensive experimental study, with two successive wind-tunnel campaigns, that has resulted in a large experimental database. The experimental work demonstrated significant drag reduction over a wide range of angles of attack was possible through the use of two different flow control strategies. A portion of this experimental database was used in a collaborative investigation between ONERA and NASA to evaluative the effectiveness of Reynolds-Averaged Navier-Stokes solvers to predict these types of flows. This investigation demonstrates that the NASA and ONERA flow solver codes were able to predict the major trends observed in the experiment, however they were not able to quantitatively predict the fuselage forces or performance of the flow control.
Boundary Layer Transition Determination for Periodic and Static Flows using Phase-Averaged Pressure Data
Authors:   DLR, Gardner A.D. , Richter K.
Published: October 2024

A method of boundary layer transition measurement is presented for wind tunnel models instrumented with surface pressure taps. The measurement relies on taking a number of theoretically identical measurements at different times and then analysing the standard deviation of the pressures. Due to the slight unsteady movement of the transition position, a peak in the standard deviation of pressure σCPpeak is found at the transition position, and this is correlated with measurements of the transition position with an infrared camera and hot film anemometers. In contrast to microphone measurements, it is shown that the transition detection works for data which has been low-pass filtered with a cutoff of 1 Hz. The application to static and dynamic transition measurements on static and periodically pitching helicopter rotor blade airfoils at Mach 0.3-0.5 is demonstrated.
Dynamic Stall with Circulation Pulse and Hysteresis for NACA 0012 and VR-12 Airfoils
Authors:   Washington University in St. Louis, Modarres Ramin , Peters David , Gaskill Jacob
Published: October 2024

Airfoils undergoing dynamic stall often display a secondary lift peak after the lift has begun to decrease. A study of this phenomenon for the NACA 0012 and VR-12 airfoils shows that the secondary peak is followed by a damped oscillation in lift. It is found that this under-damped lift can be modeled by an ONERA type equation for secondary lift that is driven by a simple pulse. It is speculated that the physical basis of this pulse is the attaching of a secondary vortex to the airfoil. The onset and duration of this pulse can be predicted in terms of angle of attack in a general time-domain simulation. When added to the present Ahaus-Peters stall equations, this new stall equation gives a total finite-state model for dynamic stall simulation that can include the secondary stall peak.
Computations of Dynamic Stall Control with Combustion-Powered Actuation
Authors:   United Technologies Research Center, Jee Solkeun ,   Georgia Institute of Technology, Crittenden Thomas , Matalanis Claude , Min Byung-Young , Bowles Patrick , Wake Brian , Glezer Ari
Published: October 2024

A computational investigation on the dynamic stall control capabilities of combustion-powered actuation (COMPACT) is presented. Major geometry parameters for the actuator slot are investigated at high-speed conditions relevant to rotor dynamic stall. Optimal chordwise location, slot angle, and slot thickness are determined through 2D computations. It was discovered that the gap between slots in the span significantly reduced COMPACT effectiveness compared to the promising results shown in the 2D computations. Unique designs were developed to overcome these problems. The final 3D slot design, called the "vanishing gap," produces the most 2D-like behavior. The vanishing gap concept was carried forward to high-speed experiments.
Effects of Advance Ratio and Radial Location on the Vortex Structure on a Rotating Blade in Reverse Flow
Authors:   Georgia Institute of Technology, Hiremath Nandeesh , Shukla Dhwanil , Raghav Vrishank , Pirau Sorin , Komerath Narayanan
Published: October 2024

At high advance ratio, rotor blades encounter reversed flow over substantial portions of the retreating blade side. Prior approaches have modeled these using quasi-static separation with airfoil data modified for yaw, vortex shedding, dynamic pitch oscillations, and reverse dynamic stall of an airfoil. We pursue the hypothesis that development of a sharp-edge vortex (SEV) on a highly swept edge at angle of attack, modified with rotation effects, is a more viable model. Stereo Particle Image Velocimetry (SPIV) is used under a reversing blade of a 2-bladed rotor with cyclic pitch at advance ratios from 0.7 to 1.0 in a low speed wind tunnel. A sharp-edged vortex (SEV) develops and grows, starting in the forward-yaw region between 180° and 270° azimuth, with a significant inboard-directed core flow and outboard-directed surface layer flow. As yaw decreases, the vortex stops growing, and bursts. By 270° this vortex detaches at some locations and convects. In the backward-yaw region beyond 270°, the vortex again grows outboard, with the pressure gradient due to the vortex causing an inboard-directed surface pressure gradient that overcomes centrifugal effects. The occurrence of the vortex ahead of the sharp edge at some stations negates models based on sharp-edge shedding. Dynamic lift is not observed prior to stall. There is no evidence of unsteady shedding from the sharp edge.
Lifting Surface Blade Model for Comprehensive Rotorcraft Analysis
Authors:   Continuum Dynamics Inc., Wachspress Daniel , Yu Michael
Published: October 2024

Current comprehensive rotorcraft analyses typically use lifting line theory coupled with 2D look-up tables to determine section lift, drag and pitching moment along the rotor blade. These methods cannot directly capture important 3D flow effects that influence chordwise loading and unsteady aerodynamics. Computational fluid dynamics (CFD) codes have been coupled to comprehensive rotorcraft analyses to provide this capability, but these coupled solutions are too computationally intensive for daily design work. This paper describes work performed to investigate the effectiveness of using a vortex lattice lifting surface blade model in comprehensive rotorcraft analyses to bridge the gap between current lifting line models and full CFD blade airload solutions. A vortex lattice blade model was used to directly compute section lift and pitching moment, including both circulatory and noncirculatory unsteady airloads, within the 3D rotating environment. The method was coupled with a free-vortex wake model and predictions were compared with experimental data, model problems and other methods. It was observed that with a modest increase in computation time, a comprehensive rotorcraft analysis using a vortex lattice blade model can obtain significantly improved predictions of blade pitching moment over a lifting line model, particularly in flight conditions that involve blade vortex interactions.
Validation of Rotorcraft Comprehensive Analysis Performance Predictions for Coaxial Rotors in Hover
Authors:   Science and Technology Corporation - Ames Research Center, Ho Jimmy ,   US Army Aviation Development Directorate - AFDD, Yeo Hyeonsoo , Bhagwat Mahendra
Published: October 2024

Comparisons of rotor aerodynamic performance parameters in hover, between rotorcraft comprehensive analysis predictions using a free vortex wake model and measured data, for two model–scale and two full–scale coaxial rotors are provided. Predictions from a computational fluid dynamics analysis are also included for one of the full–scale rotors to provide additional insights. Test points evaluated form sweeps in both the coaxial rotor system thrust and the axial separation distance between the two rotors. The comprehensive analysis predictions are mostly in good agreement with measured data, which includes reflecting the same trends from all sweeps. While the comprehensive analysis predictions are mostly in good agreement with measured data and computational fluid dynamics predictions for individual rotor thrust, good agreement for individual rotor torque is more elusive. The comprehensive analysis predictions also show that even though the coaxial rotor figure of merit is not strongly dependent on the thrust sharing ratio between the two rotors, the figure of merit of the two individual rotors are highly sensitive to the thrust sharing ratio.
A Higher-Order, Free-Wake Method Applied to the Problem of Hovering Rotors
Authors:   The Pennsylvania State University, Choephel Tenzin , Schmitz Sven , Maughmer Mark
Published: October 2024

In this paper, the results of a correlation study using a new higher-order, free-wake method, applied to the problem of hovering rotors, are presented. The predictions of the free-wake method are compared with the experimental data from three different studies focusing on sectional force distributions, aggregate performance parameters such as figures of merit and downwash distributions. The correlations provide a good amount of confidence as to the ability of the new free-wake method in predicting the challenging aerodynamics of a helicopter rotor in hover.
Investigation of Centrifugal Pumping Rotor Blades as a Means of Vortex Diffusion
Authors:   US Naval Academy, Kuerbitz Daniel , Milluzzo Joseph
Published: October 2024

High-resolution flow visualization (FV) and particle image velocimetry (PIV) measurements were taken to document the development and evolution of a rotor wake in ground effect. In particular, the current work focuses on diffusing the tip vortices, through the use of centrifugal pumping, before they can fully form and reach the ground. A baseline non-pumping blade set and four different pumping blade designs were tested. All the pumping blade designs utilized the same centrifugal air flow mechanism, but the internal flow exited the blade at angles of 0°, 30°, 45°, and 60° above the horizontal axis. Detailed flow field measurements were performed for regions of interest near the rotor and in the near-wall region to understand the development and evolution of the trailed tip vortices in ground effect. All the blades sets were tested in a hovering state in ground effect at a blade loading coefficient, CT/σ, of 0.080. Additional measurements were also performed on the baseline and 0° pumping blade design at a reduced blade loading coefficient of CT/σ = 0.053 to examine the effect mass flow rate had on tip vortex diffusion. All the pumping blade designs were found to incur a power penalty, which resulted from the exit slots at the tip increasing the profile losses. The 30°, 45°, and 60° pumping blade designs were found to have a degraded performance as compared to that of the 0° pumping blade, which is believed to result from negative thrust effects associated with the mass flow of the air out the exit slots. When operating at the higher thrust condition, the pumping blade designs were found to merely prolong the initial formation of the tip vortices as opposed to completely diffusing them. However, when the 0° pumping blade was operated at the lower thrust condition the tip vortices were found to be more diffused, with significant reduction in the upwash velocity near the ground.
Systematic Analysis of Rotor Blade Effective Twist Due to Planform Variation
Authors:   Central Connecticut State University, Wei Fu-Shang ,   Washington University in St Louis, Peters David
Published: October 2024

In a highly twisted blade combined with a variable chord, the effective thrust-weighted twist angle often differs from that of a rectangular blade under the same thrust conditions. Very few articles directly analyze the thrust-weighted effective twist angle as a function of blade planform changes. This paper introduces a design process to systematically predict rotor blade effective solidity and twist angle due to planform changes. Several planforms have been investigated, including blades with servo-flap, taper, dihedral, sweep and peddle tip. Interesting results are presented in the paper: i) With a servo-flap located at the outboard of 80%R, the blade flap-weighted effective twist angle (θFW) is increased in the design and the θFW is decreased if a servo-flap is placed at the inboard of 70%R; ii) For a 20% increase of the mid-span blade chord size design and a 3:1 tip taper ratio with the blade taper starting from 85%R to the tip, the maximum change of the effective blade twist angle is around 7.07%; iii)The blade dihedral-weighted effective solidity (θDW) has an 11.6% reduction when a rotor blade has a 30° dihedral starting from 70%R to the tip. In addition, the dihedral-weighted blade effective twist angle (σDW) has a 3.99% reduction; iv) The blade thrust-weighted effective solidity is reduced by 13.6% when a blade has an outboard 30% blade swept aft with a 30° angle. The blade effective twist angle has been reduced by 9.79% under the same outboard blade sweep condition.
Development of Conceptual Design Framework with Rotor Structural Design Optimization for Compound Rotorcraft with a Lift Offset
Authors:   Samsung Heavy Industry, Lim JaeHoon ,   Seoul National University, Shin SangJoon ,   Korea Aerospace Research Institute, Kee YoungJung , Kang YooJin
Published: October 2024

Conceptual design optimization framework with rotor structural design was developed and validated for a compound rotorcraft with a lift offset. The power estimation algorithm in HCDO (Helicopter Conceptual Design Optimization) program was upgraded to consider the compound rotorcraft with a lift offset. For validation purposes, conceptual design of an existing stiff-in-plane rotor in XH-59A compound rotorcraft was conducted upon the present procedure. The hover and forward flight rotor performance maps of the XH-59A aircraft were obtained by using CAMRAD II. By using the resulting rotor performance maps, conceptual design of the aircraft was conducted. In addition to the conceptual design, optimization for the structural construction of a rotor system in XH-59A aircraft was conducted by applying the present two-level procedure. Verification of the influence by the optimization efforts on the conceptual design was conducted.
Optimization of a Lift-Offset Compound Helicopter in a Multidisciplinary Analysis Environment
Authors:   US Army, Sinsay Jeff ,   Stanford University, Alonso Juan
Published: October 2024

A multidisciplinary analysis environment is described which enables easy tailoring of analysis fidelity to the problem of interest. A description of the important aspects of this multidisciplinary analysis environment, including a method for estimating the impact of the design variables on rotor airfoil and structural properties suitable for use in rotor comprehensive analysis, are provided. A method for generalizing and storing the description of the rotor in python to support multiple analyses is also described. The optimization of a lift-offset compound is examined as a test problem, highlighting the environment’s ability to enable the use of additional rotor design variables not typically considered in conceptual design.
Twin Engine Pack System: A Twin Piston Engine Propulsion Unit For Very Light Rotorcraft
Authors:   Politecnico di Milano, Alicino Roberto ,   Robby Moto Engineering, Albertoni Andrea , Cirrottola Luca , Quaranta Giuseppe , Massera Marta , Papetti Roberto
Published: October 2024

The paper presents the conceptual design of a new class of very light rotorcraft: a twin piston-engine helicopter. Exploiting the Twin Engine Pack System developed by Robby Moto Engineering, a a lo-cost Class-A VTOL aircraft that can potentially fly over densely populated areas can be developed filling a gap in the current rotorcraft market.
Future Avionic System Hybrid Processor Pooled Architectures
Authors:   Lockheed Martin MST, Gaska Thomas ,   Binghamton University, Carpenter Aaron , Chen Yu
Published: October 2024

Next generation avionics Size Weight and Power (SWaP) can benefit from transformational improvements and flexibility in processing brought on by Moore's Law with proper heterogeneous pooled processor solutions. It is no longer feasible to simply use a modest number of network-connected single-core processors in isolated subsystems; instead, multicore processing is the norm. By 2016-2018, there will be on-chip multicore processors with 16 or more cores on each die integrated with on-chip transformational multi-Teraflop General Purpose Graphics Processing Units (GPGPUs). Heterogeneous reprogrammable System-on-Chip (SoC) devices will include multicore processors mixed with 5 billion transistor Field Programmable Gate Arrays (FPGAs). At this time, many avionics subsystems are just beginning the integration of multicore into safe and secure systems. Similarly, sensor critical avionics systems are still adjusting their heterogeneous processing mix in multicore, FPGA, and GPGPU processing solutions. Pooled processing across subsystems is still very limited in deployment. Subsystem level partitioning and security/safety considerations often still limit the potential SWAP improvement for pooled processing if not properly planned and managed. Legacy software migration also continues to make pooled processing in tech refresh a challenge.
This paper presents results of an initial investigation into relevant dual use parallels from adjacent markets with similar challenges. One of the adjacent markets that can be used for open discussion of the heterogeneous pooled processor challenge is the driverless car processor architecture. There are already developments with Teraflop computing in the glove compartment, modular multi-sensor data fusion sensor software, integrated information and infrastructure hardware security, and standards for on-platform/off-platform cloud integration. Future cars will have hardware that runs up to 100 Million lines of code. What can the avionics industry leverage from this adjacent market as it moves forward in hybrid pooled processor architectures?
New Developments in the Manufacture of Invar Tooling for Composite Components
Authors:   Monmet, Durham Simon ,   Ferry Capitain, Duquenne Christian
Published: October 2024

When designing tooling for autoclave curing of close tolerance composite components there is always the tradeoff between the cost and durability of the tooling. Composite tooling can be easily constructed but is not very durable, whereas metal tooling made from low expansion alloy - Invar - is extremely durable but more costly to fabricate. The expense of Invar tooling is greatly affected by the complexity of the part, particularly for large components, which may have to be fabricated from welded and machined assemblies. Recent developments in the casting industry have lead to significant improvements in the design and fabrication of Invar tooling. Simulation systems for mold design and pattern-less mold preparation technologies have greatly reduced the mold design time, enhanced first-time yield and design change flexibility. It is now possible to incorporate last minute design changes shortly before the casting is poured. Thus it is possible to produce a complex near net-shape thin walled casting with all of the stiffening features that would otherwise be welded, machined and heat treated fabricated assembly. The presentation will give examples of the size and complexity of aerospace grade Invar tooling that is being used for the production of composite helicopter and aircraft components.
Simulation of Helicopter Shipboard Operations with Spatial Velocity Gradients in the Ship's Airwake
Authors:   Virginia Tech, Ngo Tri , Sultan Cornel
Published: October 2024

A mathematical model of a generic helicopter that captures essential helicopter-ship's airwake dynamics (e.g. fuselage dynamics, blade flapping and lead/lagging, interactional aerodynamic effects of the ship's airwake) has been developed in the implicit nonlinear ODE form for control design and evaluation. A procedure in which the ship's airwake characteristics with spatial velocity gradients are integrated into the rotor blade dynamics is described using polynomial interpolations from available CFD data. A simulation of the automatic lateral reposition toward the ship in 30-deg wind-over-deck condition is performed using model predictive control. Comparisons between different assumptions about the uniform/spatial gradient airwake velocities over the main rotor disk of the helicopter are also presented. It is ascertained that severe spatial velocity gradients from the ship's airwake can increase the rotor blade loading and vibration, as well as the control workload to accomplish the mission.
Design and Testing of the Bell FARDS Tail Rotor Driveshaft
Authors:   AATD, Baker Treven ,   Bell Helicopter, Chavez Andrea , Fetty Jason , Spears Steven
Published: October 2024

Testing was recently performed on a new tail rotor drive shaft (TRDS) technology developed under the Future Advanced Rotorcraft Drive System (FARDS) program. The FARDS TRDS operates above its third critical speed, has a curved shaft centerline, and utilizes a novel damper design, advanced materials, and advanced manufacturing technologies. This TRDS design allows for a reduction from seven shaft segments to only two, which reduces system weight and cost. The endurance, low cycle fatigue, and high cycle fatigue testing performed on this drive shaft design was successful, and demonstrated a Technology Readiness Level (TRL) 6.
Design, Development and Flight-Testing of a Robotic Hummingbird
Authors:   Texas A&M University, Coleman David ,   University of Maryland, Hrishikeshavan Vikram , Benedict Moble , Chopra Inderjit
Published: October 2024

This paper details the design, development and flight testing of a 62-gram hummingbird-inspired flapping wing micro air vehicle with hovering capability. The key barriers in the development of this vehicle included optimizing the wing design at high flap frequencies by utilizing aeroelastic tailoring to produce the required lift for hover, designing insect-based wing kinematic modulation mechanisms for control and stabilization, utilizing a kinematic autopilot for attitude sensing and vehicle control, and system integration. To achieve the required large flap-stroke amplitudes necessary to generate lift for hover at moderate flap frequencies (∼25Hz), a novel mechanical linkage system called a "modified 5-bar" mechanism was developed, which amplifies the output of a standard 4-bar crank-rocker mechanism. Systematic experimental studies were utilized to design lightweight (∼0.8 grams) flexible wings and to optimize their performance for a specific operational frequency range. Additionally, a fabrication technique was developed, which ensured the wings could be reproduced with consistency. Control of the vehicle is achieved through the use of wing kinematic modulations, which change two key kinematic parameters: the tilt of the flapping planes relative to the vehicle, and the flapping amplitude. This effectively alters the magnitude and direction of the lift vector of each wing to achieve motion or trim equilibrium in a particular direction. Innovative mechanisms were developed to implement this modulation technique, and these mechanisms are controlled via a kinematic autopilot, which senses the vehicle attitude and, using an on-board closed-loop proportional-derivative controller, transmits corrective signals to the servos to stabilize the vehicle. A systematic approach to tuning the vehicle trim and controller gain values has been implemented, leading to several stable controlled flight experiments. One such flight test lasted ∼5.0 seconds in which the vehicle ascended and sustained an altitude of ∼1 meter with minimal drift. The final vehicle weighs 62 grams and flaps at about 22Hz during hover.
Design Space Exploration of an Electric-Powered Reconfigurable Rotor VTOL Concept
Authors:   Georgia Institute of Technology, Bouchard Etienne , Rancourt David , Mavris Dimitri
Published: October 2024

This paper presents the design space exploration of a novel concept capable of lifting tethered payloads. The system uses unmanned electric tethered aircraft capable of vertical takeoff, which then transition to a circular flight to lift the payload, and even to a horizontal flight to travel at a greater speed. The system takes advantages of the tether to transfer power from the payload or the ground station to the aircraft, which allows the aircraft to be light and takeoff vertically. A thorough description of the concept and details on the operating phases are given. A physical breakdown of the system is performed and four physics-based models are constructed: propeller efficiency, wing aerodynamics, tether and electric power production unit. An optimizer is then used to maximize the payload for a given available power. It is shown that a 40 kW, two 8 m span aircraft system can lift a 770 kg payload, and that a 1,200 kW, two 28 m span aircraft system can lift a 18,700 kg payload. Finally, a sensitivity analysis showed that the assumptions involved in the modeling of the rotor and the tether drag have significant impact on the payload capability, while the vehicle mass does not.
Flight Dynamics Modeling and System Identification of a Cyclocopter in Forward Flight
Authors:   University of Maryland, Shrestha Elena , Hrishikeshavan Vikram , Yeo Derrick , Benedict Moble , Chopra Inderjit
Published: October 2024

This paper describes the system identification methodology and the identified flight dynamics model of a cyclocopter micro air vehicle (MAV) in forward flight. The cyclocoper utilizes two cycloidal rotors (cyclorotors), a novel horizontal-axis propulsion system with rotating wings. The forward flight control strategy employs independent rpm control of all three rotors and thrust vectoring of two cyclorotors. Unlike a conventional helicopter, a cyclocopter is propelled in forward flight purely by thrust vectoring. This allows the vehicle to maintain a steady, level attitude in forward flight. Even though such a strategy could facilitate power-efficient forward flight, it is accompanied by a strong yaw-roll cross coupling, which is in addition to the inherent gyroscopic coupling that is also observed in hover. To understand these couplings and characterize the bare airframe dynamics, a 6-DOF flight dynamics model of the cyclocopter was extracted using time domain system identification techniques. The existence of a control derivative in the longitudinal translation mode showed that thrust vectoring by phasing the cyclic pitch commands forward speed. After a phasing input, the vehicle achieves steady state within two seconds. The model was able to validate the existence of the inherent roll-yaw coupling in forward flight, which was identified by contributions of roll-yaw coupling stability and control derivatives. The gyroscopic coupling is caused by unbalanced angular momentum and the controls coupling arises from increased propulsive forces at high phase angles. Decoupling methods involve simultaneously mixing roll and yaw inputs in the controller. With onboard feedback stabilization and roll-yaw mixing strategy, the cyclocopter is able to achieve decoupled dynamics in forward flight.
Performance Validation of CFD/CSD for Active and Passive Rotor Systems
Authors:   United Technologies Research Center, Wake Brian ,   Sikorsky Aircraft Corp., Egolf T. , Min Byung-Young , Matalanis Claude , Makinen Stephen
Published: October 2024

With the recent dramatic increase of computing power, first principal based CFD/CSD tools are becoming more routinely used in the rotorcraft industry. This study performed validation of current CFD/CSD tools in terms of rotor performance to assess its prediction capability for various rotor concepts using a consistent simulation approach. Correlated experimental data include UH-60A NFAC test, UH-60A slowed rotor, UH-60A individual blade control, S-434 with active trailing-edge flap, and flight test data of UH-60M with advanced blade tip design. The root shank impact was added as the post-processing step using a relevant drag coefficient. It was found that the current tools could predict performance within 10% in most cases. The peak L/De and stall boundary of UH-60A rotor were well predicted. The performance benefits from active control rotors using individual blade control and active flap were captured very well with good agreement in active control phase and magnitude. The high advance ratio flight condition was also well predicted even though highly unsteady flow features are present. Error increased at the high-thrust high-speed condition, but the absolute error was still within a reasonable range considering uncertainty in measurements and the root-shank effect. Good correlation was obtained for the UH-60M at low and moderate speeds. However, predictions showed earlier gradual stall at high-thrust and high-speed conditions. The impact of different flight conditions and grid resolution was studied, but only limited improvement was obtained. Further investigation is suggested to address the discrepancy.
Inauguration speech for the 1983-84 Academic Year at the ‘A. Gemelli’ Faculty of Medicine and Surgery
Authors: Bausola Adriano
Published: October 2024

Not available.
Human sexuality: anthropological, ethical and pedagogical perspectives
Authors: Tettamanzi Dionigi
Published: October 2024

Not available.
Medical ethics and internal medicine
Authors: Maiorano Giuseppe , Albano Ottavio
Published: October 2024

Recent scientific and technological advances in medicine have raised a number of ethical and regulatory problems, to which medicine alone can no longer provide adequate answers. Bioethics, as an interdisciplinary reflection, essentially deals with the ethical and regulatory aspects posed by biology in general; medical ethics, on the other hand, deals with the more specific aspects of medicine.
Prenatal diagnosis of genetic diseases
Authors: Serra Angelo
Published: October 2024

For the last fifteen years or so, the application of new techniques has entered medical practice, and has become widespread, that make it possible to establish the existence of particular conditions in the foetus, capable of causing alterations in its development or giving rise to serious pathologies later or later after birth. Techniques therefore offering the possibility of making prenatal genetic ‘diagnoses’ and ‘prognoses’.
Ethical indications for prenatal diagnostics
Authors: Leuzzi Lorenzo
Published: October 2024

Not available.
Withaferin A: A potential anticancer candidate drug and its challenges for the clinical trial
Authors: Alagar Yadav Sangilimuthu , Ponattil Ranjusha V.
Published: October 2024

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Depression, anxiety and coping mechanisms among mental healthcare practitioners during COVID-19
Authors: Stals Yolandi , Du Plessis Edwin , Pretorius Paul J. , Nel Mariette , Boateng Alexander
Published: October 2024

Background: The coronavirus disease 2019 (COVID-19) pandemic has placed the psychological functioning of mental healthcare practitioners under severe strain. Coping methods may affect mental health outcomes.Aim: The study examined the relationship between depression, anxiety, stress, and coping styles utilised by mental healthcare practitioners during the COVID-19 pandemic.Setting: Three private and one public mental healthcare facility in Bloemfontein, South Africa.Methods: Respondents completed the Depression, Anxiety and Stress Scale (DASS-21) and Brief Coping Orientation to Problems Experienced (Brief-COPE) inventories. An ordinal regression model was used to assess the relationship between coping styles, anxiety and depression.Results: A total of 212 practitioners were included in the analysis. According to DASS-21 measures, approximately 41% and 28% of respondents had moderate to severe depressive and anxiety symptoms, respectively, with the highest prevalence among younger female respondents and nurses. The association between stress severity, anxiety and depression was significant. Avoidant coping methods and two approach coping strategies (planning and acceptance) were associated with depression and anxiety. Anxiety was linked to an increased likelihood of transitioning to higher avoidant categories, while participants with depression were less likely to move to higher avoidant or approach categories.Conclusion: Mental healthcare practitioners, especially nurses, experienced significant COVID-19-related psychological distress during the pandemic. Avoidant coping mechanisms may increase the risk of poor mental health outcomes.Contribution: This study added data on the mental health effects of COVID-19 on mental healthcare practitioners, as well as psychological methods used to cope during the pandemic.
Left Ventricular Mass, Geometric Patterns, and Diastolic Myocardial Performance in Children with Obstructive Sleep Apnea
Authors: Ahmadu Ibrahim , Aliyu Ibrahim , Ahmed Abdulazeez , Asani Mustafa O.
Published: October 2024

Background:

Obstructive sleep apnea (OSA), characterized by recurrent partial or complete upper airway obstructions during sleep, is an established risk factor for cardiovascular diseases in children. This study aims to determine the prevalence of left ventricular hypertrophy (LVH), abnormal left ventricular (LV) geometric patterns, and diastolic dysfunction in children with OSA and compare them with healthy controls.

Materials and Methods:

This was a cross-sectional comparative study conducted on 75 eligible children with OSA aged 2–14 years and 75 age- and sex-matched healthy children. Transthoracic echocardiography was used to assess the LV structures and diastolic function in all the subjects.

Results:

The mean LV mass index was significantly higher in the patients with OSA (36.53 ± 9.1 g/m2.7) as compared to the control group (32.82 ± 7.9 g/m2.7) (P = 0.008), and it showed a significant correlation with decreasing peripheral oxygen saturation (r = −0.35, P = 0.002). LVH was present in 8.0% of the patients with OSA and none (0%) of the controls. 29.3% of the patients with OSA and 1.3% of the healthy controls had abnormal LV geometry. LV diastolic dysfunction was present in 6.7% of the patients with OSA and 0% of the controls. LV diastolic dysfunction was significantly higher among the patients with OSA who have abnormal LV geometry compared to those with normal LV geometry (P = 0.002).

Conclusion:

LVH, abnormal LV geometry, and diastolic dysfunction are more common in children with OSA than in healthy controls. Children with OSA and abnormal LV geometry are more likely to have LV diastolic dysfunction.
Association between Adverse Childhood Experiences and Internalizing Symptoms in Adults at a Wellness Centre in India
Authors: Trivedi Riri G. , Kumar Anita , Soundappan Kathirvel , Trivedi Gunjan Y. , Ramani Hemalatha , Kumar Saurabh
Published: October 2024

Background:

Adverse childhood experiences (ACE or childhood trauma) include very stressful and potentially traumatic events linked to a higher risk of mental health challenges and chronic conditions. India has an opportunity to study the association between ACE exposure and internalizing symptoms (depression and anxiety). To evaluate the association between exposure to ACE and internalizing symptoms (depression and anxiety) at a wellness centre in India.

Methods and Material:

This cross-sectional study studied a convenience sample of 909 individuals who self-assessed ACE exposure, depression (Major Depression Inventory: MDI), and anxiety levels (Generalized Anxiety Disorder: GAD-7). Logistic regression models evaluated the association between ACE and depression and anxiety levels.

Results:

The results show a strong association between ACE levels and depression as well as anxiety. Individuals with medium (1-3 ACEs), high (4-6 ACEs), and very high (> =7 ACEs) exposure to childhood trauma are at 2–7 odds of having major depression and 1–3 odds of having anxiety. Moreover, both Gen Z and Gen Y are at a higher risk of depression and anxiety compared with Gen X.

Conclusions:

The research extends the findings from global research on ACE and mental health (depression, anxiety) in India, highlighting the strong association. Future work should expand the samples across the geography to enhance the insights.