bluuebunny/crossref_metadata_2025 huggingface dataset:
Penser et agir pour la paix : Célestin Bouglé, la Société des nations et la Coopération intellectuelle (1918-1940)
Authors: Marcel Jean-Christophe
Published: September 2024

Célestin Bouglé (1870-1940) est des intellectuels de son époque qui, après 1918, s’est le plus efforcé de penser des relations pacifiées entre nations, mais aussi de les « faire », en militant dans le cadre de la Société des Nations pour la paix entre les peuples, et en articulant à cet « engagement pratique » son activité de savant. Bouglé développa en effet des trésors de dialectique pour (se) persuader – en réinterprétant le schéma d’évolution des sociétés préalablement esquissé par Durkheim – que le sens de l’histoire aboutissait à une installation durable la paix. Ces arguments sociologiques étaient aussi destinés à prouver que la Société des Nations entérinait l’entrée du monde dans une nouvelle ère de « rationalisme moral », tout en étant étroitement articulée à une activité de propagande en faveur de la coopération intellectuelle. Militant infatigable de l’Institut International de Coopération intellectuelle de la SDN, Bouglé s’efforça en même temps de rassembler et de produire au Centre de Documentation sociale qu’il dirigeait, une connaissance de l’actualité de l’époque, qui avait pour finalité de faciliter la propagation, et former les étudiants à ce qu’il appelait « l’esprit international ».
Au fond des poches
Authors: Fennetaux Ariane
Published: September 2024

Poche Détachables pendant près de deux siècles, les poches féminines sont de forme oblongue, une fente verticale en constituant l’ouverture. Nouées sous les jupes autour de la taille, elles se présentent parfois en paire. Réticule Petit sac porté à la main, le réticule, parfois appelé « ridicule », fait son apparition dans la presse féminine vers 1800. Réalisé en textile, parfois en cuir, il est fait pour être montré.
L’Oréal : le fleuron français de la Tech ?
Authors: Lannuzel Stéphane
Published: September 2024

Pour devenir leader mondial de la Beauty Tech , L’Oréal a dû intégrer la Tech au cœur de son business, ses métiers, son organisation. Le Groupe investi dans les réseaux sociaux et le e-commerce, cultive un patrimoine de données inégalé, ou encore développe des services Tech innovants et des expériences clients multiples et diverses. Cela a nécessité d’apprendre à conjuguer curiosité et sens critique. Alors qu’elle n’allait pas de soi, l’alliance des produits de beauté et du digital est devenue un puissant moteur de performance.
Photographier l’œuvre d’art et son environnement : les « vues d’atelier » de Cy Twombly
Authors: Spathoni Anthi-Danaé
Published: September 2024

Cy Twombly est un artiste très secret. De son vivant, il ne laissait personne entrer dans son atelier pendant qu’il peignait et seulement quelques photographes ont pu en franchir le seuil. C’est l’artiste lui-même qui offre le meilleur accès à son univers dans ses ateliers de New York, Rome, Bassano in Taverina ou Gaeta et dans sa ville natale de Lexington : une publication récente, Cy Twombly : Homes & Studios (Nicola Del Roscio, Schirmer/Mosel, 2019), nous permet d’avoir un aperçu de ses lieux de travail par des clichés choisis avec soin par l’artiste. Face à ces photographies de Twombly, une question se pose : quel usage fait Twombly de la photographie d’atelier ? Dans cet article, nous allons explorer ce thème à travers l’étude approfondie de ces prises de vue, et analyser trois approches et regards différents de l’artiste sur son espace créatif : les vues d’ensemble, les natures mortes et les détails.
Redecoupages sectoriels a propos du rattachement de Pertuis au centre hospitalier de Montperrin
Authors: Lavergne Thierry
Published: September 2024

A partir de l’exemple du rattachement de PERTUIS au CH MONTPERRIN le 01.09.1995, l’auteur tente de déterminer les critères évaluatifs permettant de valider la réalisation des objectifs de santé publique, justifiant la nouvelle carte sanitaire de février 1995 en région PACA.
Justice, intérêt et judiciarisation : un éclairage liminaire
Authors: Sala Adrienne , Campagnolo Gilles
Published: September 2024

Cet article propose une synthèse théorique pour mieux appréhender la problématique du présent numéro de la Revue de Philosophie Économique qui, axé sur « Justice, intérêt et judiciarisation », donne une place de choix au droit. Le texte revisite quelques principes fondamentaux de l’utilitarisme, plusieurs théories de la justice et des libertés en vue d’examiner la « judiciarisation » comme processus exprimant justice et intérêt(s). En repartant de Jeremy Bentham, en passant par les options opposées de John Rawls et de Friedrich Hayek notamment, des tensions sont mises au jour au sein de la triade de concepts. En abordant le « réalisme » juridique, notamment chez Richard Posner, il apparaît combien la perspective socio-économique nourrit la judiciarisation, qui influence en retour les interactions sociales. L’enjeu du cadre civilisationnel est souligné sur le cas japonais, qui montre la pertinence de ressaisir ces concepts en contexte. Toile de fond, ce texte sert à aborder les articles subséquents du numéro, focalisés sur des applications pratiques de la philosophie économique.
Enhancing quality in Lot reception: A comparative analysis of innovative attribute acceptance sampling plans
Authors: Peña-González Darwin , Caicedo Solano Nestor E. , Torres-Peña Roberto , Chacuto-López Ellery , Ariza Edwan Anderson
Published: September 2024

Purpose: This study aims to enhance production quality by applying Quality Control (QC) principles through acceptance sampling, specifically analyzing the efficacy of attribute acceptance sampling plans in final lot receptions.Design/methodology/approach: Through a comprehensive review and critical evaluation of various sampling methodologies found in literature, this paper assesses their efficiency under distinct administrative and operational conditions. It emphasizes the comparison of different attribute acceptance sampling plans by examining variations in parameters and key performance indicators, such as Average Outgoing Quality (AOQ) and inspection time allocation percentage. Furthermore, it proposes a model for Continuous Sampling Plans (CSP) to evaluate these plans' performance in response to operational characteristic variations.Findings: The analysis reveals that the selected methodologies significantly aid in decision-making processes for lot acceptance, utilizing non-conforming rates depicted by the Average Quality Level (AQL). This provides a robust framework for improving Quality Control strategies, demonstrating the potential of these methodologies to optimize production quality through strategic lot acceptance.Practical implications: This paper outlines a practical approach for industry practitioners to enhance decision-making in lot acceptance, offering a method to balance quality control with operational efficiency effectively.Originality/value: By comparing a wide range of attribute acceptance sampling plans and introducing a novel CSP model, this research contributes valuable insights into the optimization of QC strategies. It offers a unique perspective on enhancing production quality, marking a significant advancement in the field of Quality Control and management.
Global existence of weak solutions to a class of higher-order nonlinear evolution equations
Authors: Xiao Li-ming , Luo Cao , Liu Jie
Published: September 2024

This paper deals with the initial boundary value problem for a class of n-dimensional higher-order nonlinear evolution equations that come from the viscoelastic mechanics and have no positive definite energy. Through the analysis of functionals containing higher-order energy of motion, a modified potential well with positive depth is constructed. Then, using the potential well method, and Galerkin method, it has been shown that when the initial data starts from the stable set, there exists a global weak solution to such an evolution problem.
Mathematical modeling of infectious diseases and the impact of vaccination strategies
Authors: Bolatova Diana , Kadyrov Shirali , Kashkynbayev Ardak
Published: September 2024

Mathematical modeling plays a crucial role in understanding and combating infectious diseases, offering predictive insights into disease spread and the impact of vaccination strategies. This paper explored the significance of mathematical modeling in epidemic control efforts, focusing on the interplay between vaccination strategies, disease transmission rates, and population immunity. To facilitate meaningful comparisons of vaccination strategies, we maintained a consistent framework by fixing the vaccination capacity to vary from 10 to 100% of the total population. As an example, at a 50% vaccination capacity, the pulse strategy averted approximately 45.61% of deaths, while continuous and hybrid strategies averted around 45.18 and 45.69%, respectively. Sensitivity analysis further indicated that continuous vaccination has a more direct impact on reducing the basic reproduction number $ R_0 $ compared to pulse vaccination. By analyzing key parameters such as $ R_0 $, pulse vaccination coefficients, and continuous vaccination parameters, the study underscores the value of mathematical modeling in shaping public health policies and guiding decision-making during disease outbreaks.
Participação política da mulher: um viés da condição de agente de Amartya Sen
Authors: Ferraz Miriam Olivia Knopik , Oliveira Pinto Tomazini Amanda Luiza , López Valle Vivian Lima
Published: September 2024

O presente artigo tem como objetivo demonstrar que a participação política da mulher deve ser vislumbrada como uma das formas para o alcance da condição de agente livre da mulher. Parte-se do problema de pesquisa: Como a participação política da mulher se relaciona com a condição da mulher? A metodologia utilizada é a lógico-dedutiva lastreada pela revisão bibliográfica para efetivação dos objetivos específicos: esse processo transpassa pela menção de algumas referências históricas que demonstram a luta pelo direito político da mulher e pelo patamar atual da legislação brasileira a esse respeito. Após, estuda-se a teoria de Amartya Sen sobre a condição de agente livre da mulher, enquanto referencial teórico da pesquisa, onde inicia-se o estudo da necessidade da superação dos obstáculos que restringem as liberdades das mulheres, para somente assim elas alcançarem a efetiva possibilidade de escolha em participar ou não do processo político. Como resultado elenca-se que somente após essa superação se iniciará um processo de repensar o direito, as instituições e o começo para o alcance de um entendimento de desenvolvimento como expansão de liberdades das mulheres.
E-Training in HRM Context
Authors: Kumar Sunil , Kumar Dushyanth
Published: September 2024

E-training refers to virtual, web-based training programs. Organizations are increasingly adopting e-training tools and methods for human resource management (HRM). This study aims to describe the role of e-training and its tools in the learning and development of employees across organizations. Data were collected from the SCOPUS database, identifying 80 publications on e-training through keyword searches. Performance analysis was conducted using bibliometric methods, identifying relevant sources, authors, and countries, along with thematic and factorial evolution. Various problems, challenges, tools, and technologies were identified based on the literature. This study aims to guide and assist learning and development practitioners, scholars, and HR managers in understanding the significance of e-training methods and tools in HRM.
The Effect of the Number of Precursor Spin-Coating on the Properties of Sb2(S,Se)3 Thin Film
Authors: Cui Xiao Rong , Shi Yi Yang , Bai Xiao Tong , Zhang Lin Rui
Published: September 2024

Preparing of Sb2S3 precursor by sol gel method and the post selenization is a simple and low-cost method for preparing Sb2(S, Se)3. In the preparation process of this method, the number of spin-coating of Sb2S3 precursor determines the film thickness, structure, and S/Se ratio. In this work, the effects of different spin-coating times (1 to 5) on the structure, optical and electrical properties of the film were studied. The results showed that when the number of spin-coating increased from 1 to 5, the thickness of the film increased from 0.24 μm to 1.17 μm. When spin-coating twice, the strongest diffraction peak of the film changed from (120) to (230); as the spin-coating frequency continued to increase, the film gradually exhibited Sb2S3 characteristics, accompanied by a small amount of Sb2O3 impurities. In addition, excessive spin-coating cycles can cause large voids to appear on the surface of the film. From the UV-visible spectrum, it can be seen that as the thickness of the film increases, the light absorption also gradually improve, and the band gap increases from 1.34 eV to 1.66 eV. The Mott-Schottky test showed that the prepared thin films were all P-type semiconductor. When spin-coated twice, the carrier concentration of the thin film reached 5.8×1015cm-3.
Free Vibration of Composite Rectangular Plates with Internal Crack
Authors: Dookhi Mundher A.
Published: September 2024

In this work, rectangular sheets of composite materials consisting of epoxy with a single layer of fiberglass were studied with the internal crack at angles (0°, 90°) with the x-axis in the presence of nanomaterial TiO2 in proportions (1 wt%, 2 wt%, and 3 wt%), the study was experimental and numerical using the ANSYS. The sample mold was made from plastic using a CNC machine. One case was studied in both the experimental and numerical parts, which is clamped-clamped-free-free (CC-FF). After conducting the test, it was found that the crack negatively affects the rectangular composite plate, as it reduces the value of the natural frequency and increases the value of damping. However, in the case of adding the nanomaterial, it was found that the natural frequency increases with the increase in the percentage of nanomaterials, and the maximum value of the natural frequency was at 3% because it works to increase hardness rectangular plate stiffens and reduces damping. The error rate between the experimental and numerical parts did not exceed (9.717%).
Numerical Simulation of the Thermal Performance of a Building Using Electrochromic Devices
Authors: Soares Netto Michele , da Silva Porto Joseane , Brum Ruth da Silva , de Quadros Régis Sperotto , Avellaneda César Oropesa
Published: September 2024

More energy-efficient buildings have a significant impact on reducing energy consumption, as they provide thermal comfort to their occupants with lower electricity usage. Aligned with the interpretation of thermal performance, this article analyzes the results of a thermo-energy performance simulation of a residential building located in different bioclimatic zones, Pelotas/RS (BZ2) and Cuiabá (BZ7). For the simulation, the EnergyPlus software was used, varying the configuration of the building's windows, including electrochromic film, double glass, and common glass. The energy consumption results were analyzed, and finally, the thermal comfort of each model was evaluated using the adaptive method of ASHRAE 55 (2017), with the aim of assisting in the design and construction of residential buildings that are truly suitable and adapted to the climate. After conducting the simulations, it was possible to conclude that the use of electrochromic film led to the greatest reduction in energy consumption in both Zones, by 1.8% in BZ2 and 13.9% in BZ7, with an increase in thermal comfort in both simulated cases, showing better results in BZ7, a region with a hot climate.
Design, Development, and Closed-loop Flight-Testing of a Single Power Plant Variable Pitch Quadrotor Unmanned Air Vehicle
Authors:   Indian Institute of Technology Kanpur, Abhishek Abhishek ,   Combat Robotics India Pvt. Ltd., Kadukar Shashikant , Gadekar Ramdas , Duhoon Ankur , Kothari Mangal , Rane Lokesh , Suryavanshi Ganesh
Published: September 2024

This paper describes the design, development and flight testing of a single power plant variable pitch quadrotor unmanned air vehicle (UAV). The use of variable pitch rotor enables replacement of four motors of the conventional quadrotor design with a single power plant, opening up the possibility of use of fuel engine. The work is carried out in two phases. In the first phase, a proof-of-concept prototype of variable pitch quadrotor powered by a single brushless DC motor is fabricated to demonstrate the variable pitch concept and to develop the control strategy required for attitude stabilization and trajectory tracking. A PID based closed loop controller is developed and implemented on PixHawk autopilot board and its performance is demonstrated through flight test of the electric quadrotor prototype. In the second phase, two stroke internal combustion engine powered prototypes are developed based on the understanding generated from the first phase. The gasoline powered quadrotor with all up weight of 10 kg is estimated to offer hovering endurance of 2.4 hours with 2 liters of fuel. This design revisits the possibility of developing helicopters without cyclic pitch control which was first explored nearly a century ago.
Bell V-280 Valor Hydraulic System Optimization for Accelerated Development
Authors:   Bell Helicopter, Reynolds Robert , Elving Carl
Published: September 2024

The V-280 Valor is Bell Helicopter's next-generation tiltrotor, represented as the Air Vehicle Concept Demonstrator (AVCD), designed for the Joint Multi-Role Technology Demonstrator (JMR-TD) program under a Technology Investment Agreement (TIA) with the US Army. The aircraft incorporates a Fly-By-Wire flight control system with a triplex redundant hydraulic system. The hydraulic system design was developed by conducting component and system level analysis in parallel with the broader design process. The parallel effort ensured that the hydraulic system would meet technical performance requirements and program goals for cost and schedule. Hydraulic system performance was evaluated in several areas including: Hydraulic Line Sizing, Thermal Performance and the Evaluation of Integrated Subsystems. The hydraulic system sizing iterations used a combination of steady state spreadsheet based analysis and dynamic system level analysis to achieve the necessary power delivery and thermal performance for the aircraft. The completed hydraulic system architecture maximizes performance while achieving minimum weight, cost and development time.
Assessment of Ship Landing Assist System in Maritime Helicopter Operation
Authors:   Mitsubishi Heavy Industries Ltd, Takahashi Shuhei , Ishii Rie , Kono Hiroaki , Matsuda Takeshi
Published: September 2024

In maritime helicopter operation, approaching to a sailing ship and landing on a small flight deck is the most demanding task facing a pilot in a low visibility situation, such as heavy rain or snow, haze, no light at night. The ship landing assist system (SLAS) that was developed and evaluated during flight tests of XSH-60K from 2002 through 2004 is a great aid to the pilot, providing an auto approach and landing capabilities under a 100m visibility situation. The systems have been equipped by 50 or more maritime patrol helicopters SH-60K, and used for over 10 years in Japan. This paper describes an outline of SLAS and an assessment of the system in maritime helicopter operation.
Development of a Continuum Damage Mechanics Material Model of a Graphite- Kevlar Hybrid Fabric for Simulating the Impact Response of Energy Absorbing Subfloor Concepts
Authors:   NASA Langley Research Lab, Jackson Karen ,   National Institute of Aerospace, Fasanella Edwin , Littell Justin
Published: September 2024

This paper describes the development of input properties for a continuum damage mechanics based material model, Mat 58, within LS-DYNA® to simulate the response of a graphite-Kevlar® hybrid plain weave fabric. A limited set of material characterization tests were performed on the hybrid graphite-Kevlar® fabric. Simple finite element models were executed in LS-DYNA® to simulate the material characterization tests and to verify the Mat 58 material model. Once verified, the Mat 58 model was used in finite element models of two composite energy absorbers: a conical-shaped design, designated the "conusoid," fabricated of four layers of hybrid graphite-Kevlar® fabric; and, a sinusoidal-shaped foam sandwich design, designated the "sinusoid," fabricated of the same hybrid fabric face sheets with a foam core. Dynamic crush tests were performed on components of the two energy absorbers, which were designed to limit average vertical accelerations to 25- to 40-g, to minimize peak crush loads, and to generate relatively long crush stroke values under dynamic loading conditions. Finite element models of the two energy absorbers utilized the Mat 58 model that had been verified through material characterization testing. Excellent predictions of the dynamic crushing response were obtained.
Comparison of CAMRAD II and RCAS Predictions of Tiltrotor Aeroelastic Stability
Authors:   US Army ADD AvMC, Yeo Hyeonsoo ,   Bell Helicopter Textron Inc., Jr. Jeffrey ,   NASA - Ames Research Center, Acree C. ,   US Army Research Laboratory, Kreshock Andrew
Published: September 2024

Tiltrotor whirl flutter in cruise flight is investigated using comprehensive rotorcraft analysis codes CAMRAD II and RCAS. A generic tiltrotor model with a 3-bladed gimballed rotor was systematically developed starting with a simple rigid rotor mounted on a rigid pylon and a more sophisticated model was built up by adding one design variable at a time. The rotor is also coupled with a flexible wing/pylon modeled from NASTRAN for aeroelastic stability analysis. The effects of pitch-flap coupling (δ₃), blade elasticity, precone, undersling, yoke chord and flap stiffness, pitch link stiffness, rotor rotational speed, density, speed of sound, inflow modeling, unsteady aerodynamics, and realistic airfoil tables on whirl flutter speed are thoroughly examined. With careful and thorough modeling/analysis, aeroelastic stability (frequency and damping) calculated by CAMRAD II and RCAS shows consistently excellent agreement with each other for wide variations of design variables and operating conditions. For the configurations investigated in this study, blade pitch-flap coupling, rotor lag frequency, rotor rotational speed, and density play an important influence on whirl flutter speed.
Data-Driven Classification of Ch-146 Manoeuvres Using Mems-Imu Sensor System
Authors:   National Research Council Canada, Cheung Catherine , Rubio Alejandro , Valdés Julio
Published: September 2024

This paper describes the use of a low-cost standalone MEMS-IMU (micro-electromechanical system - inertial measurement unit) sensor system developed by the National Research Council Canada (NRC) for manoeuvre recognition in helicopters. The system records accelerations, angular rotation rates, magnetic flux, altitude, location and velocity through its IMU and GPS. The MEMS-IMU system was flown on the Bell 412 CH-146 Griffon helicopter in a series of scripted flights consisting of 60 manoeuvres and regimes from the helicopter's usage spectrum. A flight log recorded by passengers with detailed start and stop times and identification of the manoeuvres during flight was key information in the development of manoeuvre recognition models. Statistical tests to analyze the data diversity between each flight showed significant variability of the parameters from flight to flight. Because of this variability and because there was significant imbalance in the distribution of data for the individual manoeuvres, a pooled stratified sampling scheme was used to construct a representative training set for developing data-driven models. Different subsets of the MEMSIMU measurements were explored to exclude GPS and/or magnetometer readings. Even with the different subsets, the classifier results using stratified sampling show that very high overall classification accuracy can be obtained using the measurements from the standalone MEMS-IMU sensor system.
Thick-Walled Composite Cylinder Fabrication to Support Composite Rotor Shaft Development for CH-47 Chinook
Authors:   The Boeing Company, Darmstadt Patrick , Hendrickson Anthony , Moore Jeron , Barbato Kelli , Vitlip Robert , Hu Zhenning
Published: September 2024

Modifications are being made to the CH-47 Drive System in order to increase power capacity and lower operating costs. In addition to designing in capacity improvements to the CH-47 Drive System, Boeing is investigating weight reduction technologies for the CH-47F Block II Program. One opportunity is focused on advancing the Manufacturing Readiness Level (MRL) and Technology Readiness Level (TRL) of a Fiber-Reinforced Polymer (Composite) Section of the Chinook's Aft Rotor Shaft. The Composite Section is calculated to save over 50 pounds in the Aft Section of the aircraft. The Hybrid Steel/Composite Aft Rotor Shaft Development was split into a phased program to advance the MRL and TRL while keeping program risk low. Early phases defined component requirements and developed a preliminary ply table to validate weight predictions. The development then moved into manufacturability studies, revising the preliminary ply table and fabricating and inspecting a Half-Length Composite Shaft (Half-Shaft). As the design matures, future phases will encompass full-scale shaft fabrication and risk-reduction and qualification tests. This paper summarizes the interim design considerations of a full-scale hybrid composite shaft and fabrication and inspection of a thick-walled composite tube to develop the technology.
Development of a Finite State Dynamic Inflow Model for Coaxial Rotor using Analytical Methods
Authors:   Georgia Institute of Technology, Kong Yong-Boon ,   Washington University, Peters David , V. J.
Published: September 2024

A finite state coaxial rotor dynamic inflow model can be developed by superposition of two single rotor pressure or velocity potentials. In the velocity potential superposition approach, time delays associated with upper rotor pressure perturbations at the lower rotor are inherently captured in the model inflow solutions. But adjoint velocity potential solutions used in the velocity potential model are computed by backward integration in time which introduces additional complexity for real-time flight simulations. Another approach which uses pressure potential superposition can be easily integrated into existing real-time flight software, but it does not predict time delays that exist in coaxial rotor systems. As such, a methodology for incorporating time delay terms associated with upper rotor inflow perturbations into the pressure potential superposition model is presented in this paper. It is shown that inclusion of time delay terms in the pressure potential superposition model captures the correct inflow phase responses at the lower rotor for different values of upper rotor thrust coefficient.
State-Space Inflow Model Identification and Flight Dynamics Coupling for an Advanced Coaxial Rotorcraft Configuration
Authors:   University of Maryland, Hersey Sean ,   Ames Research Center, Juhasz Ondrej ,   Technion, Rand Omri , Celi Roberto , Tischler Mark , Khromov Vladimir
Published: September 2024

In order to consider the stability and controllability of advanced coaxial configurations, a better understanding of the aerodynamic interactions between rotors is required. Modern aerodynamic analysis tools such as free wake models can accurately model the behavior of the inflow of a coaxial configuration, without the inclusion of theoretical limitations and approximations used by classical-simplified schemes. They are not, however, expressed in state-space form and therefore can not be readily analyzed as a linear flight dynamics problem and are often computationally expensive. The objective of this paper is to extend a system identification method, which was previously validated for single main rotor helicopters, to the extraction of state-space linearized models from computed inflow data acquired from free wake models of a coaxial rotor in hover. Also a key extension of the identified inflow systems is shown to model inflow off of the rotor plane as a output equation of the inflow system, or as its own ODE inflow system. With state-space models of inflow defined for an advanced coaxial configuration, this paper also presents a study of the fully coupled aircraft flight dynamics, showing key effects of rotor inflow on the dynamics of a coaxial rotorcraft configuration.
Simulation of Pitching Moment and Drag by a State-Space Dynamic Stall Model - Experimental Correlation
Authors:   Washington University in Saint Louis, Malick Michael , Peters David
Published: September 2024

The Peters-Modarres semi-empirical dynamic stall model is extended to the simulation of pitching moment and drag. The new model is correlated with experimental data. In particular, wind tunnel and water tunnel tests of harmonically pitching Boeing VR-12 and VR-7 airfoils are used for validation, including Mach numbers of 0.2, 0.3, and 0.4, and reduced frequencies of 0.02 - 0.25. Secondary peaks in the pitching moment stall data are modeled with an additional secondary stall model: a simple second-order equation driven by a rectangular pulse, requiring no additional states in simulation. As a state-space model, the extended model is in a form useful for design of controls and flutter analyses. An optimization routine is used to determine the empirical parameters of the stall model by comparison of the computed results with each experimental case, producing a set of 12 stall parameters and 2 static corrections. The results show good agreement for each case, and are an improvement over previous efforts by Ahaus to correlate pitching moment and drag data.
Progressive Damage in Rotorcraft Composite Structures as Random Process: Integration of Characterization, Modeling and Validation
Authors:   United Technologies, Gurvich Mark ,   US Army ADD, Robeson Mark , Kim SeungBum
Published: September 2024

This work is aimed to address the random nature of the progressive damage process (PDP) in laminated composite structures for enhancement of engineering solutions and decision-making based on damage tolerance assessment (DTA). A general approach integrating input characterization, output validation, and corresponding modeling solutions is suggested for understanding and quantification of inevitable randomness of multi-step PDP in laminated composites and components. A general modeling approach of probabilistic PDP is developed based on system definition of laminated composites consisting of elements with random properties and random load distribution between them. The approach is implemented in form of a parametric model based on Finite Element Analysis (FEA) coupled with statistical simulations. Damage initiation and damage growth are captured through cohesive-element FEA. FEA/probabilistic coupling is performed through developed Python/MATLAB software. Robust demonstration of developed modeling capabilities is shown on examples of thick laminated composite beam with a network of multiple potential interlaminar damages. Quick convergence with respect to number of statistical simulations is shown. Preliminary qualitative comparison with similar available experimental results indicates good match between observed and predicted damage processes. Challenges of probabilistic characterization and validation are listed and discussed. Finally, directions of follow-up expansions of the developed capabilities are proposed for future efforts.
Very High Altitude Flight Testing of the H145 Helicopter
Authors:   Airbus, Ockier Carl , Kolb Christian , Berthe Adeline
Published: September 2024

The H145 is a multipurpose twin-engine helicopter with a maximum gross weight of 3700 kg (8160 lbs). The H145 entered service in 2014 and was originally certified for Cat B take-off and landing up to 16000 ft density altitude and Cat A operations up to 12000 ft density altitude. Because of its excellent high altitude performance, several operators requested an increase of the maximum certified altitude of the H145. Flight testing for this altitude extension was conducted in May 2015 near La Paz, Bolivia, at density altitudes between 15000 and 18200 ft. Although testing at such extremely high altitudes was very demanding, the results were as or better than expected. Analysis of the performance and controllability showed that the aircraft could comfortably and safely operate up to a maximum pressure/density altitude of 20000 ft for Cat B operations, and up to a pressure/density altitude of 15000/16000 ft for Cat A operations. EASA certification for these operations was obtained in March 2017.
Kalman Filter Estimation of Rotor-State Flapping: An Optimization-based Approach with UH-60 Flight Test Data
Authors:   Santa Clara University and San Jose State University Research Foundation, Knapp Marit ,   US Army ADD - AMRDEC, Ivler Christina , Berrios Marcos , Berger Tom , Tischler Mark
Published: September 2024

Flight testing of explicit rotor-state feedback (RSF) fly-by-wire control laws showed that measuring rotor tip-path-plane (TPP) flapping, via a laser measurement system, provided additional lead to the control system. This resulted in superior handling qualities in turbulence and heavy winds and improved stability margins. However, a significant impediment to the adoption of explicitly measured RSF has been the difficulty in extracting reliable rotor measurements. Therefore, this paper describes the development of a Kalman filter that was designed to estimate rotor TPP coordinates, and remove noise from the flapping signals while retaining the useful information without introducing large time delay, as would be the case for conventional low pass filtering. A new method for the design of the process noise covariance matrix using optimization of frequency domain specifications was implemented using flight test data from the UH-60 Black Hawk. The design was integrated into an explicit rotor-state feedback control algorithm, where it was tested for robustness to sensor faults and effectiveness based on improvements to stability margins. The results showed that the Kalman filter was robust to rotor blade sensor spike and drop-out faults and resulted in improved stability margins and handling qualities.
MH-60M Directional Control Margin Investigation
Authors:   US Army Redstone Test Center, Hor Jeffrey , Guess Allan
Published: September 2024

A directional control margin investigation of the MH-60M Black Hawk helicopter was conducted to address the loss of directional control when operating at high density altitudes and high gross weights. This paper will discuss the flight test techniques used to assess directional control margin, the process for determining gross weight for flight testing at high density altitude, and resolution of the loss of directional control on the MH-60M. Additionally, low density altitude, low gross weight, and low power flight tests were performed to ensure adequate right directional control margin remained after implementation of changes to improve the loss of directional control at high density altitudes and high gross weights. A relationship between power required and directional control margin was established. Based on that relationship, a flight test methodology was developed to successfully quantify the directional control margin (DCM) of the MH-60M in stabilized hover and in the low airspeed flight regimes.
Attributes of Pathological Fractures in a Nigerian myeloma cohort
Authors: Duru Augustine Nwakuche , Nonyelu Charles Emeka , Madu Anazoeze Jude , Okoye Helen Chioma , Ugwu Angela Ogechukwu , Anigbogu Ikechukwu Okwudili , Muoghalu Ebele Adaobi
Published: September 2024

Multiple Myeloma (MM) is a plasma cell tumor usually characterized by lytic bone lesions. Pathological Fracture (PF) is a debilitating condition that usually affects a patient’s psychomotor functions, treatment modality, morbidity, and outcome.
We evaluated the associations, characteristics, and impact of PF on survival in a group of Nigerian myeloma cohort.             
A 10-year (2011-2021) retrospective review of MM data from Nigerian tertiary hospital haemato-oncology unit to evaluate attributes of PFs in myeloma cohort.
Sixty-six patients had MM of which 23 had PF while forty-three had no fractures. Of the number with PF, 18 had lytic bone lesions, while 20 had bone pains. Monoclonal Immunoglobulin G was predominant followed by Immunoglobulin A. Significant correlations existed between hemoglobin level (r=0.446, p=0.002); platelet count (r=-0.347, p=0.041), serum calcium (r=0.471, p=0.006) and bone pains; as well as between urea level (r=-0.787, p=001), creatinine level (r=-0.853, p=0.001) and renal impairment respectively. PFs are associated with diabetes, peptic ulcer disease, hypertension, nephropathy, and arthritis. Bortezomib-based regimen was the choice treatment. Overall survival was 16 (69.6%) with 7 (30.4%) mortality.
PF is common amongst the myeloma cohort with the spine being the most common site. It is associated with significant comorbidities like hypertension, diabetes, peptic ulcer disease, and paraplegia and is characterized by severe debilitating bone pains, anemia, hypercalcemia, raised plasma monoclonal immunoglobulin, renal impairment, loss of man-hour at work, and psychosocial imbalance. The impact of the fracture has increased morbidity and mortality and has reduced the median survival duration to as low as 4 years.
Rossby waves impact on persistent oxic and suboxic chlorophyll maxima in the Eastern Tropical North Pacific
Authors: Márquez-Artavia Amaru , Márquez-Artavia Xiomara , Salazar-Ceciliano Juan Pablo , Sánchez-Velasco Laura , Beier Emilio , Paulmier Aurelien
Published: September 2024

This study aims to describe the response of two persistent chlorophyll-a maxima to physical processes that affect the po- sition of the thermocline/nitracline in the Eastern Tropical North Pacific (ETNP). We focused on Long Rossby Waves (LRWs) due to their relevance to the ETNP circulation and their potential role in introducing nutrients into the euphotic zone. We found that the shallower chlorophyll-a maximum in oxygenated waters became more intense when denser waters (containing more nu- trients) moved toward the surface. This suggests that changes in isopycnals and nitracline displacements modify nutrient supply in the euphotic zone, leading to changes in phytoplankton growth. The suboxic and deeper chlorophyll-a maximum showed a strong association with the 26 kg m-3 isopycnal, which was only mechanically displaced, and its chlorophyll-a content did not seem to covary with irradiance or nutrients. The decor- related responses of the chlorophyll-a maxima could be ex- plained if different phytoplankton groups are associated with them. LRWs can affect the position of the thermocline/nitracline and isopycnals in an annual cycle, but it seems to be a “back- ground” signal modulated by higher frequency processes such as mesoscale eddies and other Rossby waves. The co-occurrence of processes can control the nitracline depth, and thus the input of nutrients into the euphotic zone, leading to sporadic enhance- ments in chlorophyll-a concentration in one maximum.
Experiences of occupational nurses regarding non-adherent mineworkers with chronic illnesses
Authors: Manyeneng Lorato G. , Pilusa Mogale L.
Published: September 2024

Background: Occupational nurses continue to provide service to mineworkers diagnosed with chronic illnesses, however, non-adherence to medication is prevalent, cause overcrowding, long queues and admission at hospitals as they become sick.Aim: This study aimed to describe the experience of occupational nurses (ONs) regarding non-adherence to medication among mineworkers diagnosed with chronic illnesses.Setting: The study was conducted at a selected mine in Gauteng province, South Africa.Methods: A qualitative, exploratory, descriptive design that is contextual in nature, was used with a phenomenological approach. Thirteen ONs were purposively sampled and individual face-to-face interviews were conducted until data saturation was reached. Thematic analysis using ATLAS.ti 24 software was applied to analyse the data collected. The researcher and the independent coder held a consensus discussion and agreed on the themes and the sub-themes.Results: Two themes and various sub-themes emerged along with Care-related challenges linked to the mineworkers and challenges related to the provision of service to mineworkers. Data analysed indicated that the ONs had varying but often similar perspectives regarding non-adherence to medication among mineworkers diagnosed with chronic illnesses.Conclusion: Non-adherence to medication is prevalent among mineworkers diagnosed with chronic illnesses and improving the mineworkers’ outcomes requires addressing the issue of non-adherence to primary medication.Contribution: This study highlights the importance of adhering to prescribed medication among mineworkers diagnosed with chronic illnesses to ensure quality of life.
Clinical Comparison of Stain Removal Efficacy between Glycine Powder Air Polishing System and Ultrasonic Scaling in Removing Dental Plaque and Stains: A Split-mouth Randomized Clinical Trial
Authors: Mohta Ruhi , Thorat Vinayak , Rao Prajakta , Sharma Udita , Joshi Shivangi , Shreya Somya
Published: September 2024

Introduction:

Glycine powder air polishing (GPAP) has emerged as a less invasive option for periodontal maintenance therapy. This study aims at comparing the efficacy of GPAP in removing plaque and stains as compared to conventional ultrasonic scaling (USS).

Materials and Methods:

The present split-mouth randomised clinical trial recruited 20 adults with healthy gingiva or mild gingivitis. Removal of plaque and stains was performed by USS in one maxillary quadrant and by GPAP in the other. Clinical parameters assessed included stain scores by Lobene Stain Index, plaque level by Silness-Loe plaque Index, and pain scores using the Visual Analog Scale. The assessments were performed before and after the treatment and at a 15-day follow-up visit.

Results:

Significantly lower (P < 0.05) levels of plaque and stains were achieved by both interventions as compared to those before the treatment. While immediate postoperative plaque levels were significantly (P < 0.05) lower following USS, the difference failed to reach statistical significance (P > 0.05) 1 week after the treatment. On the contrary, the stain scores were significantly lower after treatment and at the 7th-day follow-up after GPAP as compared to USS. A significantly greater number of patients (P < 0.05) reported pain to be absent or only mild following GPAP, while those treated with USS experienced pain of severe intensity.

Conclusion:

Both GPAP and USS are effective in stain and plaque removal. However, GPAP achieved superior stain removal outcomes and was associated with significantly lower pain scores, suggesting it was more comfortable for patients compared to USS.
The intersection of ophthalmology and neurology: Diagnosing acute strokes through visual symptoms
Authors: Chacko Ruhel Kurudamannil , Krishna Devu , Kumar Karthik , Shah Virna M
Published: September 2024

Purpose:

To document how acute cerebrovascular accidents (CVAs) present first to an ophthalmologist.

Methods:

Retrospective, observational, unicentric hospital-based study. The electronic medical records of new patients who presented to the Neuro-ophthalmology department of a tertiary eye hospital in the month of August 2022 were reviewed. Those with symptoms suggestive of an acute stroke requiring urgent neuroimaging were chosen for further study.

Results:

Out of the 710 new patients, 31 had a known CVA and presented with field defects (4.3%). We recognized nine new patients, subsequently diagnosed to have a CVA, initially presenting with ocular symptoms such as homonymous hemianopia in seven cases and two others as transient obscuration of vision and internuclear ophthalmoplegia.

Conclusion:

Posterior circulation strokes commonly present first to an ophthalmologist, the early recognition of which is of utmost importance.
A Technique for Retrieval of Screw for Missed Screw Head
Authors: Singh Pankaj Kumar , Singla Ajay , Garg Niket Raj , Goyal Vachan , Bansal Pahul
Published: September 2024

Background:

Orthopaedic implants are medical devices used to replace or fix bones or to replace the articulating surfaces of joints. Once fracture healing is complete, these implants may no longer serve a functional purpose and can be removed. During implant removal surgeries, surgeons may encounter various challenges, such as stripped screw heads. While several methods for addressing this issue have been previously described, this study introduces a novel technique for retrieving stripped screw heads.

Methods:

Between May 2021 and September 2023, 21 patients underwent implant removal surgeries where stripped screw heads were encountered intraoperatively. The technique involved cutting the screw head with a metal-cutting drill bit, which proved to be effective in facilitating retrieval.

Results:

All the screws with stripped screw head could be extracted using our technique.

Conclusion:

Compared to traditional methods, this new approach requires less specialized skill and equipment and is more cost-effective.
An Underrated Performer in Repair of Rotator Cuff Tears: Single-row Suture Anchor Technique
Authors: Pilaka Ravi Sharma , Paka Varun Kumar , Paka Lavanya , Shaik Jameer , Talluri Srivatsava S. Dakshina Murthy
Published: September 2024

Background:

Single-row suture anchor technique is a well-established, economical, and relatively easier method of arthroscopic rotator cuff repair that has been recently tripped over by double-row technique which is proven to be biomechanically superior. However, this advantage is not reflected in the functional outcome scores which are reported to be identical with both single- and double-row techniques.

Materials and Methods:

A prospective cohort study was performed on 67 patients with degenerative rotator cuff tear, diagnosis was confirmed on radiological magnetic resonance imaging, treated surgically by single-row suture anchor method, and evaluated for functional outcome at minimum 1-year follow-up. Pre- and postoperative Visual Analog Scale (VAS) and American Shoulder and Elbow Surgeons (ASES) scores were calculated at initial evaluation and the end of 1-year follow-up.

Results:

Eighty-six percentage of the patients showed a clinically significant improvement in VAS and ASES scores.

Conclusion:

Consistent acceptable success rates in terms of outcome functional scores, including patient reported outcomes, depict single-row suture anchor technique as a reliable option for the management of degenerative rotator cuff tears 3 cm or less.
An enhanced companding algorithm for universal filtered multicarrier system
Authors: Chintala Vijaya Durga , Kondamuri Shri Ramtej , Suddapalli Subba Rao , Sundru Anuradha
Published: September 2024

This paper proposes a new companding scheme called three ‐law companding to reduce the peak‐to‐average power ratio (PAPR) in a universal filtered multicarrier system. The proposed scheme is more flexible and provides better PAPR reduction and bit error rate (BER) through the selection of the three companding parameters. However, the proposed scheme suffers from high side lobes and increases the power of the companded signal. Hence, an enhanced three ‐law, which overcomes these limitations, is proposed. Unlike the first scheme, the enhanced scheme does not change the mean power of the companding signal because it incorporates power‐level normalization. Simulation results show that, compared with other companding transforms, the proposed enhanced three ‐law scheme offers better BER characteristics and side‐lobe level suppression. It also provides better PAPR reduction of 7.4 dB and net gain of 6.3 dB. The proposed enhanced three ‐law was evaluated over a multipath fading channel and was more robust than other companding techniques. Finally, the proposed enhanced algorithm was verified in real time using the Wireless Open‐Access Research Platform.