bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of ecological health of Hainan Island inshore waters in the South China Sea based on preliminary fish biotic integrity index (Actinopterygii and Elasmobranchii)
Authors: Yu Peimin , Luo Zhengli , Wang Liangming , Liu Yan , Huang Yingbang , Shan Binbin , Yang Changping , Sun Dianrong
Published: October 2024

The well-being of marine ecosystems significantly influences biodiversity and ecological equilibrium amidst pressing challenges such as overfishing, water pollution, and climate change. Drawing upon data from two fishery stock surveys conducted in the inshore waters of Hainan Island in 2022, this study undertook a comprehensive evaluation of the marine ecosystem’s health status in the region. Employing the Fish Index of Biological Integrity (F-IBI) analysis method, coupled with an examination of the structural and functional aspects of the fish community, our research sheds light on the prevailing conditions. Our study revealed a spatial dichotomy within the fish communities of the study area and delineated them into two distinct groups: the northwestern and southeastern ones, with evident disparities in community structure between the two. By employing indicator screening and calculation, we segmented the fish health index in the inshore waters of Hainan Island into five tiers. Despite discernible anthropogenic influences, the ecological health of these waters remained generally robust. Notably, the mean F-IBI of fall (56.30) significantly exceeded that of spring (48.16) (P < 0.01). Furthermore, regarding spatial distribution, the ecological well-being of the southeastern waters surpassed that of the northwestern and Qionghzhou Strait waters. This study represents a pioneer endeavor to apply ecological health assessment methodologies towards informing resource management and conservation strategies for the inshore fisheries of Hainan Island. By furnishing a scientific foundation, our research contributes to the pursuit of sustainable marine ecological development within this locale.
Potentially inappropriate prescription of medications to older adults who access a community pharmacy in Peru
Authors: Bazán-Vásquez Mónica , Galliani-Huamanchumo Gladys , Campos-Bazán Alessandra , Villafana-Medina Haydee , Requejo-Torres Kelyn , Campos-Florián Julio
Published: October 2024

Polypharmacy in older adults is associated with a higher incidence of medication-related problems, such as pharmacological interactions, adverse reactions, and medication errors. This study aimed to identify and evaluate potentially inappropriate prescription of medications (PIP) using the screening tool of older persons’ prescriptions/screening tool to alert doctors to right treatment (STOPP/START) criteria in a representative community pharmacy in Trujillo, Peru. The population sample consisted of 158 subjects, with 66.5% between 65 and 69 years old, 53.8% male, and 77.9% receiving between 3 and 4 medications. Medical prescriptions were analyzed using the explicit STOPP/START version 2 criteria, revealing that 93.7% of patients presented STOPP criteria (to stop medication) and 53.8% presented START criteria (to start medication). The most frequently identified STOPP criterion was the gradual withdrawal of benzodiazepines, while the most frequently identified START criterion was the initiation of antihypertensive treatment in patients with systolic blood pressure > 160 mmHg and diastolic blood pressure > 90 mmHg. Principal component analysis showed that the high prevalence of PIP was significantly associated (p < 0.05) with the number of prescribed medications and as age decreases, the number of medical diagnoses also decreases. It is concluded that there is a high prevalence of PIP in the studied population, posing a greater challenge in older adults, highlighting the importance of addressing prescribing practices with greater involvement of community pharmacists.
Determination of non-cytotoxic antiviral concentrations of purine and indole derivatives in vitro
Authors: Sainova Iskra , Kolyovska Vera , Ilieva Iliana , Nikolov Rumen , Petrov Andrey , Hadjiolova Radka , Dimitrova-Dikanarova Dimitrina , Markova Tzvetanka
Published: October 2024

Mammalian cells from lines derived from bovine embryonic trachea (EBTr) were used in the present study. After the formation of semi-confluent monolayers, one subpopulation of cells was inoculated with the vaccine avian poxvirus strain FK (fowl) and the other with the vaccine avian poxvirus strain Dessau (pigeon) (Poxviridae family). Twenty-four hours after viral inoculation, individual subsets of infected cells were treated with the purine derivative aminophylline and the remaining subsets with the indole derivative ergotamine tartrate, respectively. The effects of the analogues thus administered on the cells were recorded at the 24th hour and 48th hour after treatment with each substance, respectively. In cells inoculated with the FK viral strain and treated with both aminophylline and ergotamine tartrate, decreased cell viability was observed at all dilutions at the 48th hour post-treatment compared to the 24th hour. In aminophylline-treated cells, these differences were not statistically significant, unlike in ergotamine tartrate-treated cells, where they were statistically significant. In the same cells infected with the Dessau strain and treated with aminophylline, although decreased cell viability was found at the 48th hour of treatment compared to the 24th hour, in most cases no statistically significant differences were found. In cells infected with the same strain but treated with ergotamine tartrate, despite the lack of statistically significant differences, increased cell viability was seen at the 48th hour post-treatment compared to the 24th hour, specifically at the higher concentrations of 10-3 and 10-4 M/mL. These results suggest a lower cytotoxicity of aminophylline compared to ergotamine tartrate, but on the other hand, a higher anti-viral activity of ergotamine tartrate against the Dessau virus strain compared to aminophylline in in vitro conditions. Further studies need to be conducted in this regard.
Miconia garagoana - Melastomataceae: A new rheophytic species from the eastern Andes of Colombia
Authors: Mendoza-Cifuentes Humberto , Ariza-Cortés William , Carvajal Rojas Lyndon
Published: October 2024

A new species, Miconia garagoana, from riparian environments of the northern Cordillera Oriental of Colombia, is described. This is the second species exclusive to rheophytic conditions that grows in the Andean forest in Colombia and is characterized by the presence of stellate-lepidote trichomes on young structures and inflorescences, terminal inflorescences, 4-merous (rarely 5-merous) flowers, oblong-subulate anthers with an apical pore and 2-locular ovary. The differences with other rheophytic species occurring in Colombia are noted and it is argued that it is related to other Andean species with bluish-green ripe fruits such as M. squamulosa and M. symplocoidea. This new species is so far known only from Colombia and its threat category is suggested as Critically Endangered” (CR).
De l’impact de l’innovation à l’investissement à impact
Authors: Rousselet Evelyne , Dubocage Emmanuelle , Sattin Jean-François
Published: October 2024

Les innovations sociales et environnementales (ISE) constituent un enjeu majeur face aux défis contemporains et leur développement ne pourra se faire sans celui de l’investissement à impact (II). Nous proposons une réflexion approfondie sur la portée effective et les principales perspectives qui sont associées aux concepts d’ISE et d’II. Cet article associé aux autres contributions qui composent le cahier spécial montre comment l’opérationnalisation du concept d’II conduit, d’une part, à questionner la nature même de l’ISE et de la mesurabilité de l’impact qui lui est associé, et, d’autre part, soulève des problèmes concrets de mise en œuvre. Nous mettons également en évidence l’importance de l’intervention publique visant à soutenir l’II. Codes JEL : A13, O31, G23, G24
Contribution de l’investissement à impact pour le développement humain de l’économie ? Approche énantiologique
Authors: Bonnet Daniel
Published: October 2024

Cet article propose une analyse critique de la notion « d’investissement à impact », envers la transformation des comportements : comment cette transformation peut favoriser ce type d’investissement en entreprise, quels sont les enjeux, défis et limites ? L’investissement à impact qualifie les investissements contribuant au développement de stratégies innovantes, d’essence socio-économique. Ils incorporent des exigences sociales, environnementales et sociétales. Il est stipulé par son intentionnalité, l’additionnalité des attributs, et sa mesurabilité. Notamment, il doit convertir des externalités négatives et produire des externalités positives. Il doit également générer une performance financière additionnelle, car il est aussi une épargne qui finance un investissement vertueux. La recherche est réalisée dans le cadre de la théorie socio-économique des organisations. Elle mobilise des incorporats d’investigation. Sont notamment mobilisés les incorporats définissant une approche énantiologique, à savoir une approche examinant les transformations envers leur impact sur la transformation des comportements. Codes JEL : O31, D21, D24, G4
Entre la horde et l’État, le réseau
Authors: Bouilloud Jean-Philippe
Published: October 2024

Le but de cet article est de repenser, à partir de De la horde à l’État d’Enriquez, les phénomènes contemporains que sont les réseaux technologiques et sociaux, qui établissent de nouvelles relations entre « horde » et « État ». Les réseaux sont des organisations qui ne remplissent pas les fonctions des institutions, mais vivent en symbiose avec elles et influent sur leur fonctionnement. Ils sont le lieu d’émergence de sous-groupes sociaux, comme les Gilets jaunes, dont toute la dynamique reposait sur l’utilisation de Facebook. Loin de réguler le fonctionnement du social, les réseaux sont le canal des pulsions d’individus qui se coalisent dans des convergences d’opposition par rapport aux institutions existantes, dans un processus d’illusion groupale et de sentiment de puissance. Étant aussi les lieux par où transitent les formes modernes de l’argent, les réseaux participent au développement d’une fétichisation généralisée de la modernité.
Entre malaise et destruction : des enjeux de civilisation
Authors: Carreteiro Teresa Cristina , Rochael Nasciutti Jacyara
Published: October 2024

Ce texte est consacré à une lecture du chapitre « Malaise dans la civilisation » du livre d’Eugène Enriquez De la horde à l’État . Les auteures, fidèles à l’écrit d’Enriquez, retracent ses idées centrales qu’elles reprennent à la lumière des évolutions des sociétés contemporaines. Le fil conducteur de l’analyse est la prévalence de la pulsion de mort au sein de la civilisation comme signe de la tragédie humaine et destin inexorable. Les auteures s’attachent à passer en revue différents thèmes, comme le sentiment de culpabilité, le refoulement, à travers lesquels il est montré combien le surmoi collectif, bien qu’ayant subi des transformations, continue de générer un malaise qui rend le bonheur difficile, et posent la question du passage entre un avenir idéalisé et un avenir possible.
Violence et sublimation : essai sur le cinéma de Paul Schrader à partir de la pensée d’Eugène Enriquez
Authors: Lomellini Gabriel
Published: October 2024

L’un des axes majeurs de la pensée d’Eugène Enriquez, du moins tel que développé dans son maître-ouvrage De la horde à l’État (1983), se situe dans la mise au jour de ce fonds pulsionnel psychosocial qu’il nomme, par référence à Freud, la « horde » : vestige pulsionnel archaïque qui, loin d’avoir été conjuré ou définitivement refoulé, continue de hanter la vie de la civilisation. Cet essai, en forme de rencontre, vise à rapprocher l’anthropologie civilisationnelle d’Eugène Enriquez du cinéma pulsionnel de Paul Schrader. Si les trois derniers films du réalisateur américain – First Reformed (2017), The Card Counter (2021) et Master Gardener (2023) – déploient une sorte de sismographe ou d’« analyseur » des pathologies sociales occidentales contemporaines, son cinéma invite avant tout le spectateur à un véritable exercice de contemplation, incarnant sous une forme sensible cette « éthique de la finitude » appelée par Enriquez et n’omettant en rien les fondements pulsionnels de la culture et de la civilisation.
« Le plus irremplaçable des êtres »
Authors: de Gaulejac Vincent
Published: October 2024

L’article décrit l’importance du compagnonnage de son auteur avec Eugène Enriquez, tant sur le plan théorique que dans les registres institutionnels et existentiels. Dans un contexte géopolitique qui voit l’émergence de régimes autoritaires au sein de démocraties que l’on pensait solides, la montée du populisme et de l’obscurantisme, la radicalisation du débat politique, la contestation de la raison, il est bon de se rappeler que Thanatos est toujours à l’œuvre dans la société. Eugène Enriquez, dans De la horde à l’État , en a exploré les différentes facettes. Le refus d’intégrer l’analyse du psychisme individuel et collectif dans l’explication des phénomènes sociaux est une erreur majeure d’une certaine sociologie. Dans la filiation de Freud et d’Enriquez, la démarche clinique cultivée par l’auteur s’inscrit dans une sociologie du vivant qui part de l’expérience vécue pour analyser les processus sociopsychiques, comme la permanence du passé en soi, le « besoin de transmettre », l’ordre généalogique au fondement même de l’ordre social.
Migration, mémoire, muséification. Du « musée » à « mime »
Authors: Savarese Éric , Zoïa Geneviève
Published: October 2024

Cet article interroge, à partir d’une série d’entretiens réalisés dans le cadre du projet MIME (Migrations et mémoires plurielles, MSH Sud, 2022-2022), dans quelle mesure le projet de réalisation d’un musée de l’Histoire de France et de l’Algérie, à Montpellier, est susceptible de susciter l’approbation des Français d’origine algérienne, et au-delà – et cela indépendamment des générations et des positions sociales. Préconisé par le rapport Stora, nul ne sait aujourd’hui si le projet, plusieurs fois reporté, est susceptible de voir le jour à Montpellier.
La politique étrangère de l’Allemagne : une transformation inachevée
Authors: Stark Hans
Published: October 2024

Dans un discours du 27 février 2022 devant le Bundestag, le chancelier Olaf Scholz a qualifié la rupture provoquée par l’intervention russe en Ukraine de « changement d’époque » ( Zeitenwende ). Ces mots puissants marquent la fin de la retenue et d’une certaine forme de naïveté allemande. Tiraillé entre la nécessité de conserver les bonnes grâces de l’allié américain et celle de ménager le partenaire commercial chinois, Berlin est mis face à ses propres contradictions .
Existence and blow up for viscoelastic hyperbolic equations with variable exponents
Authors: Chu Ying , Wen Bo , Cheng Libo
Published: October 2024

In this article, we consider a nonlinear viscoelastic hyperbolic problem with variable exponents. By using the Faedo$ - $Galerkin method and the contraction mapping principle, we obtain the existence of weak solutions under suitable assumptions on the variable exponents $ m(x) $ and $ p(x) $. Then we prove that a solution blows up in finite time with positive initial energy as well as nonpositive initial energy.
The effect of feedstock densification on the process and product properties of sugarcane leaves pyrolysis
Authors: Setiawan Adi , Fringki Ananda , Iqbal Hifzi M. , Riskina Shafira , Jalaluddin  , Kurniawan Eddy , Burhanuddin
Published: October 2024

Sugarcane leaves are the main residue constitute approximately 14% of the total weight of the remaining sugarcane after harvesting. An effective method for processing sugarcane leaves residues is needed at low cost without causing any environmental problem. This research aims to disclose the effect of sugarcane leaves densification method applied prior to pyrolysis process in a pilot scale reactor. To evaluate the process and its product, the experiments were carried out into two types: (i) pyrolysis of sugarcane leaves without densification at 320 ℃ with a variation of pyrolysis time for 100,120, and 130 minutes and (ii) pyrolysis of densified sugarcane leaves with the variation of pyrolysis temperature 320 ℃ and 420 ℃. The investigated conditions showed that the effect of sugarcane leaves densification prolong the pyrolysis time up to 240 minutes at a pyrolysis temperature of 320 ℃, and increased the yield of biochar and bio-oil products up to 41% and 38%, respectively. However, in term of the physical properties of biochar products, the fixed carbon content decreased by 7% when the sugarcane leaves were compacted. While other parameters found no significant difference in pyrolysis at 320 ℃, the effect of sugarcane leaves densification is very beneficial especially when the pyrolysis was performed at 420 ℃.
Astrágalos en La Bastida de les Alcusses (Moixent, València): ritualidad, riqueza ganadera y azar en época ibérica
Authors: Blasco Martín Marta , Iborra Eres Maria Pilar , Vives-Ferrándiz Sánchez Jaime
Published: October 2024

Se presenta un conjunto de astrágalos recuperado en un depósito extramuros de La Bastida de les Alcusses (Moixent, València). Está integrado por 644 tabas de caprinos y suidos, 207 de ellas con modificaciones antrópicas y otras 5 realizadas en plomo. También se realiza una valoración de los astrágalos procedentes de otros espacios del asentamiento, tanto en hueso como en otros materiales y se reflexiona sobre su presencia en el mundo ibérico, en contextos de hábitat y funerarios, así como sobre los distintos valores y usos económicos, cotidianos y rituales de estos objetos.
A Comprehensive Review of the Safety of Dietary Supplements Used to Enhance Athletic Performance
Authors: Banerjee Swapan , Reyed Reyed M. , Sharma Urvashi , Srivastava Saroj
Published: October 2024

Dietary supplements are popular for maintaining well-being and enhancing athletic performance. These are believed to be safe and effective but also carry health risks. To avoid adverse health consequences, professional athletes and parents of under-18 athletes must be educated about dietary supplement safety, especially sports supplements that they consume regularly. Understanding the advantages and disadvantages of dietary supplements is crucial for safe and effective use. The study emphasized the positive and negative effects of the most consumed amino acids such as branch chain amino acids (BCAA), leucine, creatine, glutamine, β-hydroxy-β-methylbutyrate, tryptophan, citrulline, etc. Besides the adverse effects of excess consumption of amino acids, increasing risks of toxicity, mutagenicity, carcinogenicity, and impact on renal and gastrointestinal performance were also reviewed.
An In-Depth Assessment of Dietary Methods and Nutritional Treatments to Improve Female Athletes
Authors: Reyed Reyed M. , Prabhakar Pranav Kumar
Published: October 2024

A female athlete needs to plan her diet properly in order to provide the necessary support for her body and help her perform optimally. A more systematic assessment of different dietary and nutrient approaches is required to successfully enhance nutrition, health conditions, and iron status, besides optimizing physical functions. This includes evaluating several effective nutritional approaches to determine the right way to implement the necessary nutritional changes. Therefore, studying such approaches will help identify effective ways to enhance female athletes' health and performance, ensuring the possibility of achieving the best outcomes.
Assessment of Sports-Specific Dietary Methods
Authors: Mathur Srishti , Chandel Mamta
Published: October 2024

The relentless pursuit of peak performance in athletes has driven the exploration of diverse dietary interventions. However, a universal approach often fails to account for the unique physiological demands of various sports disciplines. This chapter critically assesses sports-specific dietary methods, integrating cutting-edge research and advancements while offering a forward-looking perspective on the field's future. Traditional methods like 24-hour recalls and food diaries have evolved with technology. Mobile apps allow real-time food logging and nutrient analysis, while wearables provide continuous activity and energy data, synced with dietary logs. Biomarker analysis offers objective insights into nutrient status. Athlete nutrition varies by sport; endurance athletes need high carbohydrates for sustained energy, while strength athletes prioritize protein for muscle growth. Dietary assessments tailor plans to optimize endurance glycogen and hydration, and strength protein intake and recovery. The future holds promise with wearable tech, AI, and ML.
Construction of Evaluation Index System of Specialized Teaching Effect of Physical Education in Universities
Authors: Zhang Limeng
Published: October 2024

In the field of physical education, the specialized teaching of physical education in colleges and universities is gradually becoming the focus. This study aims to build an evaluation index system of specialized physical education teaching effect in colleges and universities, so as to accurately reflect the current actual situation of physical education teaching in colleges and universities. By clarifying the principles that should be followed in the construction of an evaluation index system and listening to experts' opinions, it is ensured that the constructed evaluation system can not only fully reflect the teaching effect, but also objectively evaluate the teaching quality. Finally, a comprehensive evaluation system is put forward and implemented, so that colleges and universities can more clearly understand the advantages and disadvantages of physical education, and then formulate targeted improvement measures. This will not only help to improve the quality of physical education in colleges and universities, but also improve students' physical literacy and physical and mental health.
English Learning Strategies Supported by Wireless Communication Modules and Their Application in 5G
Authors: Li Lemin
Published: October 2024

In this study, a simplified strategy for the English assistance model was provided to overcome the limitations of current school English display settings and increase the scope of 5G innovation. This study uses a learning strategy based convolutional neural network (LS-CNN) to determine the execution of college English learning strategies. This article breaks traditional school English learning strategies by integrating 5G, which significantly improves classroom communication. In addition, this development approach may improve the standards of English performance in various methods, while strictly and purposefully adhering to the display guidance of “displaying substitute actors based on their skills”. The early findings of the review revealed that the proposed method focuses on the weaknesses of the standard English display model used in universities, while improving the mental abilities of substitute actors in various fields, including listening, talking, reading, and composing.
Organizational Factors Influencing Data Analytics Adoption in SMEs
Authors: Alsulami Abdulaziz , Hamid Suraya , Ghani Norjihan Abdul
Published: October 2024

Small and medium-sized enterprises (SMEs) can use analytics tools to use data for strategic decision-making, but their adoption remains limited because of several issues. This study conducts a systematic literature review spanning the years 2018 to 2024 to investigate how the adoption of data analytics factors influences the widespread utilization of Technology-Organization-Environment (TOE) and Diffusion of Innovation (DOI) frameworks within SMEs. After a rigorous selection procedure, 25 relevant publications were found on Web of Science and Google Scholar, providing insight into significant factors impacting adoption initiatives. The study highlights the significance of top management support, organizational readiness, rivalry, and relative advantage in fostering successful adoption campaigns within SMEs. By arranging and categorizing these variables, this study offers important perspectives to scholars and industry professionals, empowering them to formulate informed choices and tactical plans for the implementation of data analytics in SMEs.
Hepatitis B Virus Increases SphK1–S1P Synthesis by Promoting the Availability of the Transcription Factor USF1
Authors: Zhang Lu , Song Ya-Hui , Liu Juan , Zhao Yin-Xia , Zhou Ruo-Ran , Xu Jun-Chi , He Jun , Lu You-Li , Gan Wen-Juan , Lu Xing-Sheng , Li Min , Zhou Peng , Wang Lin , Han Qing-Zhen
Published: October 2024

Hepatitis B virus (HBV) is the most common chronic viral infection globally, affecting ∼360 million people and causing about 1 million deaths annually due to end-stage liver disease or hepatocellular carcinoma. Current antiviral treatments rarely achieve a functional cure for chronic hepatitis B, highlighting the need for improved monitoring and intervention strategies. This study explores the role of the sphingosine kinase 1 (SphK1)–sphingosine-1-phosphate (S1P) axis in HBV-related liver injury. We investigated the association between serum S1P concentration and HBV DNA levels in chronic hepatitis B patients, finding a significant positive correlation. Additionally, SphK1 was elevated in liver tissues of HBV-positive hepatocellular carcinoma patients, particularly in HBsAg-positive regions. HBV infection models in HepG2–sodium taurocholate cotransporting polypeptide cells confirmed that HBV enhances SphK1 expression and S1P production. Inhibition of HBV replication through antiviral agents and the CRISPR-Cas9 system reduced SphK1 and S1P levels. Further, we identified the transcription factor USF1 as a key regulator of SphK1 expression during HBV infection. USF1 binds to the SphK1 promoter, increasing its transcriptional activity, and is upregulated in response to HBV infection. In vivo studies in mice demonstrated that HBV exposure promotes the expression of USF1 and SphK1–S1P. These findings suggest that the SphK1–S1P axis, regulated by HBV-induced USF1, could serve as a potential biomarker and therapeutic target for HBV-related liver injury.
IDO2 Drives Autoantibody Production and Joint Inflammation in a Preclinical Model of Arthritis by Repressing Runx1 Function in B Cells
Authors: Peng Weidan , Merlo Lauren M F , Grabler Samantha , Montgomery James D , Mandik-Nayak Laura
Published: October 2024

The immunomodulatory enzyme IDO2 is an essential mediator of autoantibody production and joint inflammation in preclinical models of autoimmune arthritis. Although originally identified as a tryptophan-catabolizing enzyme, we recently discovered a previously unknown nonenzymatic pathway is essential for the proarthritic function of IDO2. We subsequently identified Runx1 (Runt-related transcription factor 1) as a potential component of the nonenzymatic pathway IDO2 uses to drive arthritis. In this study, we find that IDO2 directly binds Runx1 and inhibits its localization to the nucleus, implicating Runx1 as a downstream component of IDO2 function. To directly test whether Runx1 mediates the downstream pathway driving B cell activation in arthritis, we bred B cell conditional Runx1-deficient (CD19cre Runx1flox/flox) mice onto the KRN.g7 arthritis model in the presence or absence of IDO2. Runx1 loss did not affect arthritis in the presence of IDO2; however, deleting Runx1 reversed the antiarthritic effect of IDO2 loss in this model. Further studies demonstrated that the IDO2-Runx1 interaction could be blocked with a therapeutic anti-IDO2 mAb in vitro and that Runx1 was required for IDO2 Ig’s therapeutic effect in vivo. Taken together, these data demonstrate that IDO2 mediates autoantibody production and joint inflammation by acting as a repressor of Runx1 function in B cells and implicate therapeutic targeting of IDO2-Runx1 binding as a strategy to inhibit autoimmune arthritis and other autoantibody-mediated diseases.
Quantification of Rotor Surface Roughness due to Ice Accretion via Broadband Noise Measurement
Authors:   The Pennsylvania State University, Cheng Baofeng , Brentner Kenneth , Han Yiqiang , Palacios Jose , Morris Philip
Published: October 2024

The change of rotor broadband noise due to different surface roughness heights is investigated. The goal of the present work is to quantify the surface roughness at the early stage of helicopter rotor ice accretion through acoustic measurement. Proof-of-concept measurements have been performed in the Adverse Environment Rotor Test Stand (AERTS) facility at The Pennsylvania State University to explore the effect of different surface roughness heights on rotor broadband noise. First, sand paper with different grit sizes is applied to the leading edge of the blade to represent different surface roughness at different ice accretion times. The measured broadband noise, in the frequency bandwidth region ranging from 10 kHz to 24 kHz, is separated by at least 2dB due to due to different sand paper grit sizes. This demonstrates the feasibility of quantifying surface roughness through acoustic measurements. Comprehensive broadband noise measurements based on different accreted ice roughness are then conducted to form the data base from which a correlation between the ice-induced surface roughness and the broadband noise level is developed. Two parameters, the arithmetic average roughness height, Ra , and the averaged roughness height, based on the integrated ice thickness at the blade tip, are introduced to describe the ice-induced surface roughness at the early stage of the ice accretion. The ice roughness measurements are correlated to the measured broadband noise level. Strong correlations (absolute mean deviations of 9.3% and 11.2% for correlation using Ra and the averaged roughness height separately) between the ice roughness and the broadband noise level are obtained, which can be used as an early ice accretion detection tool for helicopters, as well as to quantify the ice-induced roughness at the early stage of rotor ice accretion.
Development of Control Strategies and Flight Testing of a Twin-Cyclocopter in Forward Flight
Authors:   University of Maryland, Shrestha Elena , Benedict Moble , Hrishikeshavan Vikram , Chopra Inderjit , Yeo Derrick
Published: October 2024

This paper describes the control strategies, avionics system development, and wind tunnel testing that enabled the first successful stable forward flight of a cycloidal-rotor aircraft (cyclocopter) purely using thrust vectoring. The present 550-gram vehicle has a hybrid configuration utilizing two optimized cycloidal rotors and a conventional propeller which counteracts the pitching moment generated by the cyclorotors and also provides pitch control. Stable free flight is achieved through independent rotational speed control of the three rotors and thrust vectoring of the cyclorotors through onboard closed-loop control. Since the cyclorotors spin in the same direction, there is a net angular momentum that induces a strong gyroscopic coupling between the roll and yaw degrees of freedom. The gyroscopic couplings are eliminated by implementing a careful mixing of roll and yaw inputs onboard. Unlike a conventional helicopter, a cyclocopter is propelled in forward flight purely by vectored thrust from the cyclorotors. Even though such a strategy could facilitate efficient, high-speed steady level forward flight, it is accompanied by a strong yaw-roll control cross couplings, which is in addition to the inherent gyroscopic coupling. To understand these challenges, a flight dynamics model of the vehicle derived from first principles clearly demonstrates that these couplings arise because the resultant force vector is tilted forward during forward flight. The control mixing obtained from the simulation showed good agreement with the values obtained experimentally from the wind tunnel. This mixing ratio between roll and yaw control formed the basis of the control strategy for forward flight along with aggressive closed-loop control implemented on a custom-built processor sensor board. The wind tunnel studies showed that mixing ratio was a function of phasing of blade cyclic pitch especially at high phase angles. Therefore, these mixing ratios needed to be actively changed during flight depending on phase angle. Based on these studies, steady level forward flight up to 5 m/s was successfully achieved.
Aerodynamic Performance Modeling of Ducted Fans and Shrouded Propellers for Preliminary Design
Authors:   The Boeing Company, Stahlhut Conor
Published: October 2024

A new methodology has been formulated for the prediction of the aerodynamic loads on the rotor blades of a ducted fan or shrouded propeller. The method, implemented in Boeing's BEARPAD code, uses combined blade element momentum theory (BEMT) to model ducted fan performance both in hover and high-speed axial flight. Included in the model are adjustments to open rotor BEMT theory that allow solutions to be generated for the ducted fan configuration, including modifications for cascade theory and tip corrections near a wall. The accuracy of the model was confirmed in validations against wind-tunnel test data. The methodology is computationally cheap and suitably accurate, making it ideal for trade studies and preliminary design work. The main objectives of the study are the inclusion of ducted fan theory into a BEMT model, the validation of said model, and an application of the theory to examine ducted fan/shrouded propeller performance, particularly in comparison to open rotors.
Boundary Layer Transition Measurements on Hovering Helicopter Rotors by Infrared Thermography
Authors:   German Aerospace Center (DLR), Richter Kai , Schülein Erich
Published: October 2024

High speed infrared thermography was applied for boundary layer transition measurements on the upper side of helicopter rotors. The transition detection is based on the analysis of a single instantaneous thermal image of the rotating blade and allows the determination of both the locations of the onset and of the end of the transition region. Measurements were performed on a Mach scaled BO105 model rotor for different rotation frequencies. The transition characteristics are presented and compared to two-dimensional numerical simulations, and the measurement scatter is discussed. Additional transition measurements were performed on the main rotors of the DLR research helicopters Eurocopter BO105 and EC135. The transition behavior of the EC135 rotor blade is presented for different cases and the effect of the contamination of the rotor blade leading edge on the laminar flow is discussed.
Time-depedent Adjoint-based Aerodynamic Shape Optimization Applied to Helicopter Rotors
Authors:   University of Wyoming, Mani Karthik , Mavriplis Dimitri , Mishra Asitav , Sitaraman Jay
Published: October 2024

A formulation for sensitivity analysis of fully coupled time-dependent aeroelastic problems is given in this paper. Both forward sensitivity and adjoint sensitivity formulations are derived that correspond to analogues of the non-linear aeroelastic analysis problem. Both sensitivity analysis formulations make use of the same iterative disciplinary solution techniques used for analysis, and make use of an analogous coupling strategy. The information passed between fluid and structural solvers is dimensionally equivalent in all cases, enabling the use of the same data structures for analysis, forward and adjoint problems. The fully coupled adjoint formulation is then used to perform rotor blade design optimization for a four bladed HART2 rotor in hover conditions started impulsively from rest. The effect of time step size and mesh resolution on optimization results is investigated. Results indicate that good optimization results can be obtained using time steps as large as 2 degrees, and that optimizations obtained on the coarse mesh level can be used to initialize fine mesh optimization problems in order to reduce overall computational effort. Future work will focus on aeroelastic optimizations for forward flight cases.
Investigation of Three-dimensional Dynamic Stall on an Airfoil using Fast Response Pressure Sensitive Paint
Authors:   DLR, Gardner Anthony , Klein Christian , Sachs Werner , Henne Ulrich , Mai Holger , Richter Kai
Published: October 2024

Dynamic stall on a pitching OA209 airfoil in a wind tunnel is investigated at Mach 0.3 and 0.5 using high-speed pressure sensitive paint (PSP) and pressure measurements. At Mach 0.3 the dynamic stall vortex was observed to propagate faster at the airfoil midline than at the wind tunnel wall, resulting in a "bowed" vortex shape. At Mach 0.5 shock-induced stall was observed, with initial separation under the shock foot and subsequent expansion of the separated region upstream, downstream and along the breadth of the airfoil. No dynamic stall vortex could be observed at Mach 0.5. The investigation of flow control by blowing showed the potential advantages of PSP over pressure transducers for a complex three-dimensional flow.
Numerical Investigation of Three-dimensional Dynamic Stall on an Oscillating Finite Wing
Authors:   German Aerospace Center (DLR), Kaufmann Kurt ,   ONERA - The French Aerospace Lab, Costes Michel , Gardner Anthony , Richez François , Pape Arnaud
Published: October 2024

Three-dimensional numerical computations using ONERA's structured elsA code and the unstructured DLR-TAU code are compared with the OA209 finite wing experiments in static stall and dynamic stall conditions at a Mach number of 0.16 and a Reynolds number of 1 x 10⁶. The DLR-TAU computations were run with the Spalart-Allmaras and Menter SST turbulence models, and the elsA computations were carried out using the Spalart-Allmaras and the k-ω Kok + SST turbulence models. Although comparable grids were used the static simulations show large discrepancies in the stall region between the structured and unstructured approaches. Large differences for the three-dimensional dynamic stall case are obtained with the computations using the Spalart-Allmaras turbulence model showing no flow separation in contrast to the experiment. The three-dimensional dynamic stall computations with the two-equation turbulence models are in good agreement with the unsteady pressure measurements and flow field visualizations of the experiment, but also show a shift in the stall angle compared to the experiment. The analysis of the flow field around the finite wing using the numerical simulations reveals the evolution of the Ω-shaped vortex, generated by the interaction of the blade tip vortex.
Design and Development of the Atlas HPH
Authors:   AeroVelo Inc., Robertson Cameron , Reichert Todd
Published: October 2024

AeroVelo initiated the Atlas Human-Powered Helicopter Project in August 2011 to capture the AHS Sikorsky Prize, which despite prior attempts had remained unclaimed for over 30 years. A configuration study was undertaken using low-fidelity aerodynamic analysis and estimated mass figures. The authors developed an aero-structural optimization scheme for rotor design, including a novel vortex-ring aerodynamic model with included ground effect prediction, finite-element analysis and integrated composite failure analysis, and a detailed weight estimation scheme. The airframe was comprised of a wire-braced truss structure, and innovative designs were developed for many of the aircraft's lightweight-focused subsystems. After initial flight-testing in August 2012, experimental optimization and performance improvement led to a second testing program beginning in January 2013. Testing in 2013 led to a reduction in required power, improved understanding of structural dynamics and control strategy. The project culminated in a successful AHS Sikorsky Prize flight on June 13th, 2013.
Integrated Optimization Analyses on Aerodynamic/Stealth Characteristics of Helicopter Rotor Based on Surrogate Model
Authors:   Nanjing University of Aeronautics and Astronautics, Li Peng , Jiang Xiang-Wen , Zhao Qi-Jun , Zhao Guo-Qing
Published: October 2024

Based on Computational Fluid Dynamics (CFD) method, electromagnetic high-frequency method and surrogate model optimization techniques, an integration design method about aerodynamic/stealth has been established for helicopter rotor. The developed integration design method is composed of three modules: 1) integrated grids generation: the moving-embedded grids for CFD solver and the blade grids for Radar Cross Section (RCS) solver are generated by solving Poisson equations and folding approach. 2) aerodynamic/stealth solver: the aerodynamic characteristics are simulated by CFD method based upon Navier-Stokes(N-S) equations and Spalart-Allmaras(S-A) turbulence model, and the stealth characteristics are calculated by using a panel edge method combining the method of Physical Optics(PO), Equivalent Currents(MEC) and Quasi-Stationary (MQS), and 3) integrated optimization analysis: based upon the surrogate model optimization technique with Full Factorial Design (FFD) and Radial Basis Function (RBF), an integrated optimization analyses on aerodynamic/stealth characteristics of rotor are conducted. It has been demonstrated that CFD and RCS method are effective by comparing the calculated pressure distributions of UH-60A rotor and scattering distributions of cone with the experimental data. Then scattering characteristics of the rotor with different blade-tip swept and twist angles have been carried out. Considering the modulation of rotor, time-frequency domain grayscale with strong scattering regions of rotor have been given. Simultaneously, the effects of swept-tip and twist angles on the aerodynamic characteristic of rotor have been performed. Furthermore, by choosing suitable object function and constraint condition, the compromised design about swept and twist combinations of rotor with high aerodynamic performances and low scattering characteristics has been given at last.
A Physics-Based Approach to Trim Optimization of an Articulated Slowed-Rotor Compound Helicopter in High-Speed Flight
Authors:   Rensselaer Polytechnic Institute, Reddinger Jean-Paul , Gandhi Farhan
Published: October 2024

The present study considers a compound helicopter with an articulated main rotor and uses a physics-based approach to arrive at, and understand, the optimal trim states at high-speeds in the 225-250 kts range. Simulations are based on a compound derivative of a modified UH-60A helicopter with a 20,110 lbs gross weight operating at sea level. The study shows that it is critical to use ailerons on the wing to counteract the propulsor torque and reduce rotor lateral cyclic pitch requirement and lateral cyclic flapping. Also, the stabilator needs to be used to fly the aircraft at a nose-level pitch attitude and bring the wing-lift fraction in the range of 75% and upward. With the ailerons and stabilator used to counteract propulsor torque and adjust aircraft pitch attitude, rotor RPM and propulsor thrust can be used to seek low power states. At both 225 and 250 kts the lowest power states correspond to high wing-lift fraction, low rotor RPM (advance ratio greater than 1), negative longitudinal cyclic flapping (blowback) producing an upwash through the rotor disk and putting the rotor in a near-autogyro, or even a windmill state. The high advance ratios increase the prominence of the reverse flow region, which can account for 30-40% of the total rotor drag.
A Redundant Aircraft Attitude System Based on Fuzzy Logic Data Fusion of the Miniaturized Inertial Sensors
Authors:   In Flight Research and Test Center Craiova, Sandu Dragos ,   Ecole de Technologie Superieure, Botez Ruxandra ,   University of Craiova, Grigorie Teodor
Published: October 2024

A redundant strap-down attitude system using three miniaturized gyro sensors linear clusters in the detection unit are here presented. For each of the three clusters the inertial sensors' data are fused by using a fuzzy logic method, in order to improve the angular speed signal measured by the detection unit and delivered to the attitude algorithm. After a short introduction the data fusion algorithm and the theoretical background of the attitude system are shown in the sections two and three. In the fourth section, the software implementation and experimental validation of the redundant inertial attitude system are exposed. To perform the experimental validation of the developed redundant attitude system some data were simultaneously acquired from a three-dimensional redundant gyro sensors unit and from an integrated INS/GPS navigator; the INS/GPS system was used as reference system to perform an evaluation of the attitude angles errors. The three-dimensional redundant gyro sensors unit was built with twelve gyros disposed in three clusters of four sensors each, along the x, y and z axes of the body frame.
An Investigation into the Effects of Body-borne Equipment on Occupant Injury Under Simulated Vertical Impact with Seat 'Bottom-out'
Authors:   Monash University, Aggromito Daniel ,   Defence Science and Technology Organisation, Wang John ,   Cooperative Research Centre for Advanced Composite Structures, Thomson Rodney , Chen Bernard , Yan Wenyi
Published: October 2024

Over recent years, military personnel have been required to carry increasing amounts of equipment, raising the overall mass of the occupant. A crashworthy seat is designed to a specified mass range, including equipment; and only provides energy absorption protection to the occupant within its designed mass and velocity range. If the increased mass causes the impact energy to be excessive, a phenomenon called bottoming out will occur when the seat stroking mechansim is exhausted and the occupant is exposed to excessive and likely injurous loads. In this study, an 8-degree-of-freedom mass-spring-damper system was modelled to represent an occupant with body-borne equipment and simulated under a crash test. Equations to represent a fixed load energy absorption device on a seat and a spring stiffness to characterize bottoming out were developed. The model was solved using the fourth-order-Runge-Kutta method in Matlab and the results indicate that with increased equipment mass, bottoming out will occur and the accelerations experienced by the occupant will increase significantly. This model can be used to analyse the loading affects at a number of locations on the occupant when experiencing bottoming out.
Eliminating Avoidable Helicopter Seating-Related Injuries to Improve Combat Readiness and Mission Effectiveness
Authors:   R3Consulting LLC, Healing Richard ,   IHSolutions. LLC, Hamon Kristin
Published: October 2024

For decades, helicopter crews have reported suffering back, neck and leg pain they believe is related to service in helicopters. This presentation reviews testimony from nearly 10,000 helicopter crew members who have described their experiences with pain and injuries suffered during and after their military careers. The study quantifies, for the first time, the scope of this problem across the very large community of present and former military helicopter crewmembers, links the problem to associated direct and indirect costs, and discusses remedial designs or actions to reduce or eliminate the problem. Sponsored by the Department of Defense, Office of the Under Secretary (Acquisition, Technology and Logistics), the study discusses impact of this problem on combat readiness, mission effectiveness and safety. The report from this study was reviewed and approved by a Blue Ribbon Panel comprised of flag and general officers from all five military Services and a DoD civilian who leads medical science and technology efforts.