bluuebunny/crossref_metadata_2025 huggingface dataset:
PENGARUH BERMAIN FINGER PAINTING TERHADAP KEMAMPUAN MOTORIK HALUS ANAK USIA 5-6 TAHUN DI RA. AL MUHAJIRIN BEKASI
Authors: Pujianti Yuli , Sumaryati Sumaryati , Wijaya Purwani Kusumawati Wijaya Kusumawati
Published: July 2023

ABSTRACTThe fine motor skills of children aged 5-6 years at RA Al Muhajirin Bekasi have not developed properly, so there needs to be an effort to develop these fine motor skills. This study aims to obtain empirical data regarding the significant effect of playing finger painting on the fine motor skills of children aged 5-6 years at RA Al Muhajirin Bekasi.The research method used in this thesis is a quantitative research method of experimental type. The experimental method is a research method to find the effect of certain treatments on others under controlled conditions. The research design used a true experimental design with a posttest-only control design technique. Posttest-only control design is an experimental research design in which two groups are selected randomly, the first group is given treatment and the other group is not given treatment. The data collection method used an observation sheet in the form of a checklist that measures the fine motor skills of children aged 5-6 years.The results of the post-test data analysis showed that the level of fine motor development of children treated with finger painting was higher (42.75) than the group of children who were not treated with finger painting (35.08). The results of hypothesis testing using the t-test which compares the average post-test scores obtained tcount = 5.110 and Sig. (2-tailed) = 0.000, with ttable = 2.22. Because the value of tcount is greater than ttable and the value of Sig. (2-tailed) is less than 0.05, then "Ha is accepted". The conclusion of this study is that there is a positive and significant effect of playing finger painting on the fine motor skills of children aged 5-6 years at RA Al Muhajirin Bekasi.Keywords: Fine motor, finger painting, children aged 5-6 years
Understanding Sun-as-a-Star Variability of Solar Balmer Lines
Authors: Criscuoli S. , Marchenko S. , DeLand M. , Choudhary D. , Kopp G.
Published: July 2023

Precise, high-cadence, long-term records of stellar spectral variability at different temporal scales lead to better understanding of a wide variety of phenomena including stellar atmospheres and dynamos, convective motions, and rotational periods. Here, we investigate the variability of solar Balmer lines (Hα, β, γ, δ) observed by space-borne radiometers (OSIRIS, SCIAMACHY, OMI, and GOME-2), combining these precise, long-term observations with high-resolution data from the ground-based NSO/ISS spectrograph. We relate the detected variability to the appearance of magnetic features on the solar disk. We find that on solar-rotational timescales (about 1 month), the Balmer line activity indices (defined as line-core to line-wing ratios) closely follow variations in the total solar irradiance (which is predominantly photospheric), thus frequently (specifically, during passages of sunspot groups) deviating from behavior of activity indices that track chromospheric activity levels. On longer timescales, the correlation with chromospheric indices increases, with periods of low correlation or even anticorrelation found at intermediate timescales. Comparison of these observations with estimates from semiempirical irradiance reconstructions helps quantify the contributions of different magnetic and quiet features. We conclude that both the lower sensitivity to network and in part the higher sensitivity to filaments and prominences, may result in complex, time-dependent relationships between Balmer and other chromospheric indices observed for the Sun and solar-like stars. The fact that core and wings contribute in a similar manner to the variability, and current knowledge of Balmer-lines formation in stellar atmospheres, supports the notion that Balmer line core-to-wing ratio indices behave more like photospheric rather than chromospheric indices.
Formation of Complex Organic Molecules on Interstellar CO Ices? Insights from Computational Chemistry Simulations
Authors: Ferrero Stefano , Ceccarelli Cecilia , Ugliengo Piero , Sodupe Mariona , Rimola Albert
Published: July 2023

The carbon (3P) atom is a reactive species that, according to laboratory experiments and theoretical calculations, condensates with interstellar ice components. This fact is of uttermost importance for the chemistry in the interstellar medium (ISM) because the condensation reaction is barrierless, and the subsequent species formed are still reactive given their open-shell character. Carbon condensation on CO-rich ices forms the C=C=O (3Σ−) species, which can be easily hydrogenated twice to form ketene (H2CCO). Ketene is very reactive in terrestrial conditions, usually found as an intermediate that is difficult to isolate in chemical synthesis laboratories. These characteristics suggest that ketene can be a good candidate to form interstellar complex organic molecules via a two-step process, i.e., its activation followed by a radical–radical coupling. In this work, reactions between ketene and atomic H and the OH and NH2 radicals on a CO-rich ice model have been explored by means of quantum chemical calculations complemented by kinetic calculations to evaluate if they are favorable in the ISM. Results indicate that the addition of H to ketene (helped by tunneling) to form the acetyl radical (CH3CO) is the most preferred path as the reactions with OH and NH2 possess activation energies (≥9 kJ mol−1) hard to surmount in the ISM conditions unless external processes provide energy to the system. Thus, acetaldehyde (CH3CHO) and, probably, ethanol (CH3CH2OH) formation via further hydrogenations, are the possible unique operating synthetic routes. Moreover, from the computed, relatively large binding energies of OH and NH2 on CO ice, slow diffusion is expected, hampering possible radical–radical couplings with CH3CO. The astrophysical implications of these findings are discussed considering the incoming James Webb Space Telescope observations.
Flares, Warps, Truncations, and Satellite: The Ultra-thin Galaxy UGC 11859
Authors: Ossa-Fuentes Luis , Borlaff Alejandro S. , Beckman John E. , Marcum Pamela M. , Fanelli Michael N.
Published: July 2023

The structure of the outskirts of galaxies provides valuable information about their past and evolution. Due to their projected orientation, edge-on isolated galaxies effectively serve as test labs in which to study the three-dimensional structures of galaxies, including warps and flares, and to explore the possible sources of such distortions. We analyzed the structure of the apparently isolated edge-on ultra-thin galaxy UGC 11859 to look for the presence of distortions. The deep optical imaging observations (

μ

lim

=
30.6

and 30.0

mag

arcsec

−
2

in the g- and r-bands, respectively) we acquired with the 10.4 m Gran Telescopio Canarias are used to derive the radial and vertical surface brightness profiles and g − r color radial profile. We find that UGC 11859’s disk displays a significant gravitational distortion. A warp is clearly detected on one side of the disk, and the galactic plane on both sides of the center shows increasing scale height with an increasing galactocentric radius, indicating the presence of a flare in the stellar distribution. The surface brightness profile of the disk shows a sharp break at 24 kpc galactocentric radius, and a steep decline to larger radii, an “edge-on truncation,” which we associate with the presence of the flare. The present study is the first observational support for a connection between truncations and flares. Just beyond the warped side of the disk, a faint galaxy is observed within a small angular distance, identified as a potential interacting companion. Based on ultradeep g and r photometry we estimate that if the potential companion is at the same distance as UGC 11859, the stellar mass of the satellite galaxy is log10(M
⊙) =

6.33

−
0.02

+
0.02

.
Richard Siddoway Bagnall (1884-1962), Entomologist
Authors: Berridge Louise
Published: July 2023

This biography describes the life and professional work of entomologist and industrialist Richard Siddoway Bagnall (1884-1962). This work significantly expands on the biographical notes of Laurence Mound in his paper “A review of R. S. Bagnall’s Thysanoptera Collections”.

Bagnall’s life and entomological career is described in detail, including a clarification of his birth date. This biography was written to complement the recent digitisation of Bagnall’s Thysanoptera slides at The Natural History Museum, London, and it is hoped that this biography will be of benefit to future workers upon his material. In addition to Thysanoptera, Bagnall also worked on Collembola, Coleoptera, Myriapoda and other groups.
Application of Improved Jellyfish Search algorithm in Rotate Vector reducer fault diagnosis
Authors: Wu Xiaoyan , Ye Guowen , Liu Yongming , Zhao Zhuanzhe , Liu Zhibo , Chen Yu
Published: July 2023

In order to overcome the low accuracy of traditional Extreme Learning Machine (ELM) network in the performance evaluation of Rotate Vector (RV) reducer, a pattern recognition model of ELM based on Ensemble Empirical Mode Decomposition (EEMD) fusion and Improved artificial Jellyfish Search (IJS) algorithm was proposed for RV reducer fault diagnosis. Firstly, it is theoretically proved that the torque transmission of RV reducer has periodicity during normal operation. The characteristics of data periodicity can be effectively reflected by using the test signal periodicity characteristics of rotating machinery and EEMD. Secondly, the Logistic chaotic mapping of population initialization in JS algorithm is replaced by tent mapping. At the same time, the competition mechanism is introduced to form a new IJS. The simulation results of standard test function show that the new algorithm has the characteristics of faster convergence and higher accuracy. The new algorithm was used to optimize the input layer weight of the ELM, and the pattern recognition model of IJS-ELM was established. The model performance was tested by XJTU-SY bearing experimental data set of Xi'an Jiaotong University. The results show that the new model is superior to JS-ELM and ELM in multi-classification performance. Finally, the new model is applied to the fault diagnosis of RV reducer. The results show that the proposed EEMD-IJS-ELM fault diagnosis model has higher accuracy and stability than other models.
Journal update
Authors: Talanow Roland
Published: July 2023

As of 1st of September, 2021 the submission process is now again available without going first through the priority pass process.
Nueva población de pico mediano (Dendrocoptes medius) en el Pirineo aragonés
Authors: Lorente Luis , Palacio Luis
Published: July 2023

El pico mediano fue citado en el Pirineo aragonés por primera vez en 2019, y se confirmó la reproducción de una pareja en 2021. En primavera de 2022, y adicionalmente en el otoño e invierno posteriores, se realizaron muestreos específicos en bosques con robles en la comarca de Ribagorza. Se detectaron 11 individuos territoriales en bosques dominados por el roble cerrioide Quercus cerrioides, repartidos en un tramo superior del valle del río Ésera. Se desconoce el origen de esta población, pero se podría relacionar por la existencia de una población relicta que hubiera pasado desapercibida, aunque parece más probable que se originara por la llegada de individuos de alguna población fuente. La más cercana se encuentra en la vertiente norte del Pirineo, a unos 30 km, separada por una barrera montañosa de más de 2.300 m, mientras que la más cercana conocida en la vertiente sur se sitúa en el Pirineo navarro, a más de 100 km. El pico mediano se caracteriza por ser una especie sedentaria, con movimientos dispersivos muy limitados. El establecimiento de esta nueva población, aparentemente aislada, podría sugerir que la especie podría tener una mayor capacidad dispersiva y colonizadora de la que se le atribuye.
Les associations du secteur social et médico-social : une analyse par les médiations institutionnelles
Authors: Gallois Florence
Published: July 2023

Cet article discute du rôle occupé dans le système de protection sociale par les associations du champ social et médico-social (aide à domicile, établissement pour l’accueil de personnes handicapées, etc.). Sous l’impulsion de politiques de marchandisation, les associations du secteur social et médico-social sont de façon croissante mises en invisibilité et considérées comme un simple prestataire de service, restreignant leur rôle dans la protection sociale. En développant une analyse des médiations institutionnelles à partir de la caractérisation de la protection sociale de Théret (1997), nous montrons que les dispositifs du secteur social et médico-social au sein de la protection sociale ne confèrent pas de rôle particulier aux associations. Pourtant, les travaux relatifs aux associations permettent de mettre en évidence d’autres médiations institutionnelles, qui reposent sur l’exercice de la fonction tribunitienne des associations. Ces médiations portent une futurité structurante du secteur et du système de protection sociale. Elles différencient les associations des autres acteurs et portent des mécanismes de régulation méso.
La relation d’emploi à l’aune du multi-sociétariat
Authors: Cartellier Jean , Ferraton Cyrille , Magne Nathalie , Vallade Delphine
Published: July 2023

Créé en 2001, le statut de Société coopérative d’intérêt collectif (SCIC) introduit le multi-sociétariat dans le droit français. Ce texte, qui s’appuie sur une étude empirique au sein de la région Occitanie, s’intéresse aux implications du multi-sociétariat sur la relation d’emploi. Celui-ci conduit les acteurs à chercher à atténuer les divergences d’intérêts inhérentes à cette relation, bien qu’ils ne puissent complètement les effacer. Les SCIC portent ainsi une critique de la subordination salariale. Cependant, des tensions sur les contrats de travail, le nombre d’heures travaillées et/ou payées demeurent, en particulier lorsque salariés, bénévoles et consommateurs sont amenés à se côtoyer au travail et au sein du sociétariat.
A Deep Dive Analysis of Online Food Delivery With 6 Ps of The Digital Marketing Mix-Based Framework
Authors: Wathanakom Narubodee , Juicharoen Nhatphaphat
Published: July 2023

Online Food Delivery (“OFD”) experienced substantial double-digit growth worldwide, before and during the global COVID-19 pandemic. This paper presents a holistic analysis of OFD by utilizing the 6 Ps of the digital marketing mix to portray how each platform employs strategic marketing to drive sustainable growth. The article utilizes extensive reviews of previous literature, as well as up-to-date news and observations. It was found that each of the market players focused on the product by expanding from only OFD to become lifestyle-driven “everyday apps” by enhancing the UX/UI experiences of the application, which supported and coordinated profound experiences, personalized offerings, and precise data analytics. Price played a role but was not the primary focus since it is controlled by the government to protect consumers. It can be concluded that if an OFD platform would like to grow sustainably, it should place a strong emphasis on product service, quality, and user-friendly technology on the application. Most of the previous studies regarding online food delivery discuss factors in driving adoptions, consumer attitudes and satisfaction towards the application and OFD landscape. There are the gaps in the holistic analyses of OFD from the digital marketing mix framework. Therefore, this academic article is the first to focus on uncovering how each of the top three OFD players in Thailand adopted the digital marketing mix to optimize opportunity.
Soluble Enolase 1 of Candida albicans and Aspergillus fumigatus Stimulates Human and Mouse B Cells and Monocytes
Authors: Langenhorst Daniela , Fürst Anna-Lisa , Alberter Karl , Vilhena Cláudia , Dasari Prasad , Daud Muhammad , Heilig Linda , Luther Christian H , Dittrich Marcus , Reiher Nadine , Wich Melissa , Elmowafy Mohammed , Jacobsen Ilse D , Jungnickel Berit , Zipfel Peter F , Beyersdorf Niklas
Published: July 2023

Because of the growing numbers of immunocompromised patients, the incidence of life-threatening fungal infections caused by Candida albicans and Aspergillus fumigatus is increasing. We have recently identified enolase 1 (Eno1) from A. fumigatus as an immune evasion protein. Eno1 is a fungal moonlighting protein that mediates adhesion and invasion of human cells and also immune evasion through complement inactivation. We now show that soluble Eno1 has immunostimulatory activity. We observed that Eno1 from both C. albicans and A. fumigatus directly binds to the surface of lymphocytes, preferentially human and mouse B cells. Functionally, Eno1 upregulated CD86 expression on B cells and induced proliferation. Although the receptor for fungal Eno1 on B lymphocytes is still unknown, the comparison of B cells from wild-type and MyD88-deficient mice showed that B cell activation by Eno1 required MyD88 signaling. With respect to infection biology, we noted that mouse B cells stimulated by Eno1 secreted IgM and IgG2b. These Igs bound C. albicans hyphae in vitro, suggesting that Eno1-induced Ab secretion might contribute to protection from invasive fungal disease in vivo. Eno1 also triggered the release of proinflammatory cytokines from monocytes, particularly IL-6, which is a potent activator of B cells. Together, our data shed new light on the role of secreted Eno1 in infections with C. albicans and A. fumigatus. Eno1 secretion by these pathogenic microbes appears to be a double-edged sword by supporting fungal pathogenicity while triggering (antifungal) immunity.
Filter-Based Detection of the Proximity to Loss of Tail Rotor Effectiveness within Helicopter Flight Data Monitoring
Authors:   Georgia Institute of Technology, Zanella Paola ,   FAA William J. Hughes Technical Center, Johnson Charles , Collins Kyle , Mavris Dimitri
Published: July 2023

Loss of Tail rotor Effectiveness (LTE) is a critical low-speed aerodynamic flight characteristic that causes an unanticipated rapid yaw rate that will not subside on its own. Multiple factors influence this aerodynamic condition, like environmental conditions, helicopter model specifications and phases of flight. However, predictions of which of those elements cause a higher risk for LTE has not been determined as of yet. Because of this knowledge gap, pilots are often not trained well enough to proactively recognize the proximity to LTE, leading to several accidents in which the pilot fails to maintain directional control. This study begins to characterize the factors that contribute to LTE and the importance of this to helicopter safety. An LTE bowtie diagram is proposed to support hazard risk assessment and mitigation. The diagram is built through accident reviews and aims to give pilots a schematic summary of all the scenarios that may lead to LTE. Further, a new systematic filter-based framework able to detect proximity to LTE events within Helicopter Flight Data Monitoring (HFDM) is proposed. Safety-events detection is the main method of analysis used within HFDM. This method compares flight data to a large safety-event database, which includes predefined hazardous flight conditions and different levels of proximity to events. Through this framework, participating operators will be able to easily analyze data from multiple flights, visualize the results, and provide feedback to the pilots. This will promote pilots' awareness on the proximity to LTE during flight and educate them on conducting proactive LTE risk evaluations.
An Alternative Probabilistic Approach for Reliability Assessment of Rotorcraft Structures
Authors:   United Technologies Research Center, Frewen Thomas , Gurvich Mark , LaBarre Bob
Published: July 2023

An alternative probabilistic approach is proposed to assess the reliability of rotorcraft structures. According to the approach, safe boundaries of reliability predictions (i.e., conservative ones with additional safety margins) are calculated instead of exact values of the reliability as usually estimated in conventional analysis. Due to additional safety margins, these boundaries are suggested for practical engineering applications. The proposed approach is based on two main ideas, namely a) prediction of a relatively small population of independent coarse estimations of reliability and b) application of sampling methods to predict reliability for each individual coarse estimation. Robustness and convenience of the developed approach and its computational implementation is demonstrated for four scenarios considering two problems (simplified analytical and realistic FEA-based ones) under two sets of input data providing probability of failure (POF) close to 1e-6 and 1e-9, respectively. High accuracy of predictions according to the developed approach is independently verified by comparison with known "exact" references: closed-form solutions for the analytical problem and by direct MCS for the numerical one. The proposed approach can be recommended as an efficient practical solution for a broad range of reliability assessments of rotorcraft structures requiring both i) low POF (e.g., below 1e-6) and ii) relatively complex time-consuming structural definitions (e.g., compute times in hours for each quasi-deterministic simulation).
Machine Learning based Digital Twin Simulation and Prediction of Structural Component's Fatigue Life
Authors:   Global Engineering & Materials Inc., Ren Xiang , Sadeghirad Alireza , Pham D. , Lua Jim
Published: July 2023

A key component for implementing the digital twin approach is to apply a validated high fidelity simulation tool to generate a mapping between the virtual test and structural performance. Due to the high computational intensity of physical simulation tools, their application for a complex system along with its error estimation can be time consuming. In addition, given the limited data gathered from sensors, onsite inspection, and tests at different configurations, it is imperative to create a high fidelity and efficient model based on the previously gathered information and enhance the model when more data points are gathered. Motivated by this, we develop a machine learning based digital twin simulation framework to predict fatigue life of a structural component from available information gathered. Different from a conventional physical simulation approach, the prediction error from the physical simulation and machine learning are explicitly obtained, in addition to the improvement of the computational efficiency at the prediction stage via the trained machine learning model. To illustrate the idea of this modeling strategy, we applied our developed 3D extended finite element toolkit for Abaqus (XFA3D) as a virtual testing tool for fatigue crack path and life prediction of a welded metallic component in conjunction with the observed testing data. Using machine learning techniques, we first estimate prediction error from the physical model based on previous cross validation results, and then predict the fatigue life in the presence of uncertainties associated with fabrication induced imperfection, welding induced residual stress, and the machine learning errors. It is found that the inclusion of as-manufactured characteristics and uncertainties are essential for the application of a digital twin approach for the total life management of aging structures.
Development of a Comprehensive Rotorcraft Model to Study the Susceptibility of Teetering Rotors to Mast Bumping Accidents
Authors:   Georgia Institute of Technology, Robinson Joseph , Collins Kyle , Mavris Dimitri
Published: July 2023

Rotorcraft with a teetering rotor design are susceptible to a phenomenon known as "mast bumping" or "excessive flapping" which can lead to severe shaft structural damage followed by total separation of the rotor from the vehicle and a potential incursion of the rotor blade into the fuselage. Mast bumping accidents are nearly always fatal and are generally unavoidable once specific flight conditions are met. Certain teetering rotor vehicles are prohibited from specific maneuvers that may lead to mast bumping events. However, specific incidents indicate that certain causes of mast bumping may have not yet been determined, and the extreme danger of the phenomenon makes studies using flight testing impossible. This research uses the Rotorcraft Comprehensive Analysis System (RCAS) to create a physics-based, parameterized model of a nominal teetering rotor helicopter to simulate and assess the mast bumping risk of various level flight conditions and specific maneuvers. This data is used to develop a metric to quantify the mast bumping risk of any maneuver. This model is also used to study the sensitivity of a vehicles mast bumping tendency to conceptual rotor design parameters. Preliminary analyses show a relationship between mast bumping risk and high airspeed, as well as low g-force. Studies on variations in blade mass properties indicate that increasing the blade mass or placing the blade CG farther towards the tip increases mast bumping risk in low speed flight regimes.
Structural Optimization of Composite Rotor Blade for Unmanned Helicopter using Variational Asymptotic Beam Sectional Analysis and Multi-Objective Bat Algorithm
Authors:   Indian Institute of Science Bangalore, Dandinasivara Abhiram , Ganguli Ranjan , Harursampath Dineshkumar
Published: July 2023

This work presents a structural design optimization of composite rotor blades for a typical unmanned helicopter. Multiple parameters that influence the stiffness and weight of the rotor blade are considered as design variables. These include the number of composite plies, the thickness of composite plies, and the web location as a fraction of the rotor blade airfoil chord. To further improve the stiffness, carbon nano-tubes are doped into the composite material and the percentage of doped carbon nano-tubes are considered as an additional design variable. The structural analysis of the rotor blade is carried out using principle of the Variational Asymptotic Method (VAM). Using VAM, the 3D elastic rotor blade problem is decoupled into two reduced-dimension sequential problems of 2D cross-sectional analysis and 1D beam analysis. Variational Asymptotic Beam Sectional Analysis (VABS) tool is used for the 2D cross-section analysis to obtain the blade stiffness. Orthogonal array based design of experiments approach is followed to efficiently explore the design space. A novel orthogonal array, named MGB-4P OA which has 18 sample design points, is used to construct the design of experiments. VABS is used for cross-sectional analysis at the 18 sample design points of the MGB-4P orthogonal array. Second order polynomial nonlinear response surface models are generated for the blade stiffness and blade weight using their respective values from the orthogonal array. The response surface models predict the output of the structural analysis from VABS and the estimated blade weights accurately, and are therefore, considered as surrogate models for the objective functions during optimization. A recently developed nature inspired meta-heuristic Multi-Objective Bat-Algorithm (MOBA) optimization routine is employed in conjunction with Pareto analysis for optimizing the design variables for the mutually conflicting objectives of maximizing the rotor blade stiffness and minimizing the blade weight.
Autonomous Camber Morphing of a Helicopter Rotor Blade with Temperature Change using Integrated Shape Memory Alloys
Authors:   Rensselaer Polytechnic Institute, DiPalma Matthew , Gandhi Farhan
Published: July 2023

The present study proposes and explores a new autonomous morphing concept, whereby an increase in helicopter rotor blade camber of the order of 12-13° is realized over the inboard section of the blade with increase in ambient temperature. The camber change is achieved through a proper integration of Shape Memory Alloys (SMAs) on the lower surface of the blade aft of the leading-edge spar. For a reference rotor (no-SMA) generating 21,000 lbs thrust, operation in hot conditions resulted in a 2,590lb loss in lift. When the SMA camber morphing section extends from the blade root to 50% span, the rotor recovered up to 43% of the lift loss at high temperature. If the camber-morphing section is further extended to 75% span, up to 82% of the lost lift can be recovered.
Taking a Systems Engineering Approach to Address Sustainability
Authors:   Sikorsky a Lockheed Martin Co., Yu Xiaomei
Published: July 2023

Sustainability is a key element of Lockheed Martin's business model for innovation and growth and a commonly concerned attribute during product design and improvement. One of the sustainability concerned areas is environmental sustainability. This work summarizes the recent practices of taking a systems engineering approach to ensure technical excellence and develop customer centric solutions on the journey of pursuing environmental sustainability of product and manufacturing process. Continued improvement by leveraging Model Based Systems Engineering approach is recommended.
High-Speed Wind Tunnel Tests of a Full-Scale Proprotor on the Tiltrotor Test Rig
Authors:   NASA Ames Research Center, W. C. , Sheikman Alex , Norman Thomas
Published: July 2023

The Tiltrotor Test Rig (TTR) is a NASA project, joint with the U.S. Army and Air Force, to develop a new, largescale proprotor test system for the National Full-Scale Aerodynamics Complex (NFAC). The first wind-tunnel entry was completed in November 2018 with a modern, 26-ft diameter proprotor. The primary purpose was to complete the development of the TTR, including systems integration with the NFAC. The TTR and rotor were tested up to 273 knots in axial flow. This is the highest airspeed ever achieved by a full-scale proprotor in any wind tunnel. Extensive conversion-mode data were also acquired, and hover/climb conditions were explored. Additional testing included aerodynamic tares, motor tests, thermal tests, modal vibration tests, and other checkout activities. This paper summarizes the results of the test, including examples of the most significant data.
Flight Dynamic Modeling and Control of an Unmanned Helicopter During Autonomous Autorotation
Authors:   Indian Institute of Technology Kanpur, Setu Sagar , Abhishek Abhishek
Published: July 2023

This paper discusses the development of flight dynamic model and control law to enable autonomous autorotative landing for small unmanned helicopters. For this, a novel modeling and system identification approach based on acceleration prediction model is proposed for accurate simulation of the plant dynamics during the unpowered descent f light of the unmanned helicopter. The flight dynamics model identified using the flight test data obtained through manual autorotation flights of the unmanned helicopter is implemented on a real-time computer to create a hardware-in-the-loop simulation (HILS) setup to design and tune a PID controller in the HILS environment to facilitate safe landing of the helicopter in the event of unpowered flight. This controller is then validated on a small unmanned helicopter using open source PixHawk 2.0 flight controller board to demonstrate autonomous autorotative landing starting from different height and velocity conditions. For vertical autorotation experiments performed, the controller is observed to maintain steady autorotative descent through application of suitable negative collective to maintain rotor RPM and then arrests the rate of descent by flaring at the appropriate height, which is defined as a function of descent rate, to ensure landing at near zero vertical speed.
Hover/Low Speed Dynamics Model Identification of a Coaxial Tricopter in Hover using Joint Input-Output Technique
Authors:   California State Polytechnic University - Pomona, Cho Sung ,   US Army CCDC AvMC, Tischler Mark ,   Universities Space Research Association, Cheung Kenny , Bhandari Subodh , Gonzalez Vanessa
Published: July 2023

This paper presents the identification and verification of the hover/low speed dynamics model of a 3DR Y6 tricopter, a coaxial tricopter, using Joint Input-Output (JIO) frequency-domain identification technique. Dynamics models for both the Y6A and Y6B configurations, which have differing rotational directions for the rear propellers, were identified. Flight data showed highly coupled dynamics and required use of JIO technique to eliminate the effect of the highly cross-correlated inputs. The identified models were verified using doublet flight data. Identification results showed that both the Y6A and Y6B configurations had highly coupled hover dynamics, different from conventional multirotor and coaxial quadrotor dynamics.
Mission Based Design Optimization of Fixed Pitch Coaxial Propeller System for VTOL UAV
Authors:   Indian Institue of Technology Kanpur, Patil Pankaj , Abhishek Abhishek
Published: July 2023

This paper investigates the mission based propeller design optimization methodology for coaxial rotors for vertical take-off and landing (VTOL) vehicles. The modified blade element momentum theory is used for blade performance prediction, which is first validated using the experimental data available in literature. Each segment has to be bound by some lower and upper bounds and it has to satisfy the design constraints specified according to the requirements for the mission. The mission considered in this paper involves a standard package delivery mission involving, vertical take-off, cruise in forward flight, drop-off in hover mode and return to origin in cruise mode. The optimization is carried out by a genetic algorithm, which is a variant of Nondominated Sorting Genetic Algorithm (NSGA -II). The performance of the optimal blade designed for a specific mission is evaluated for a range of different missions to evaluate whether the design generalizes well over a range of missions. The optimized blade profile is curve fitted and smoothened out using splines and polynomial curves. Then the performance of optimal blade is evaluated against available off-the-shelf propellers. The results indicate that the power required by using off the shelf propellers for a mission involving 100 s of hover and 500 s of cruise to be as high as 41% greater than the power required by the optimized coaxial rotor system. The optimal coaxial propeller system is observed to have different geometries for both upper and lower rotors.
Management of Infrarenal Aortic Aneurysm Rupture Postendovascular Stenting
Authors: Al Sharqi Ali , Stephen Edwin , Abdelhady Ibrahim , Al Wahaibi Khalifa
Published: July 2023

An elderly woman presented a year after undergoing endovascular repair of her infrarenal aortic aneurysm (IRAA) with abdominal pain and hypotension. Imaging revealed a ruptured IRAA, and this was managed with banding of the aorta to correct the Type-1a endoleak and tranexamic acid postoperative. We share details and a brief review of the literature.
Popliteal Vein Aneurysm: A Rare Cause of Knee Pain in a Young Male
Authors: Singh Devender , Kottilliyil Aruna Sree , Praveena Madavan , Aryala Shalini
Published: July 2023

Popliteal venous aneurysms are a rare disease of uncertain etiology that can present with serious complications, such as deep-vein thrombosis and pulmonary embolism. Ultrasound, computed tomography, and magnetic resonance imaging can be used as diagnostic tools for this condition. Early surgical repair in the form of tangential aneurysmectomy and lateral venorrhaphy of both symptomatic and asymptomatic popliteal venous aneurysms is advised since they are associated with an ill-defined possibility of pulmonary embolism and mortality, if left untreated. Herein, we present a case report of a popliteal vein aneurysm in a previously healthy 26-year-old male, presenting with pain in left knee, increased during physical activities and was successfully managed surgically.
Comparison of Various Clinical Scoring Systems in Assessing the Probability of Pulmonary Thromboembolism in Adults in a Tertiary Care Hospital in South India
Authors: Gogulakrishnan Ramalingam , Ramakrishnan Gayathri Aur
Published: July 2023

Aim:

The aim of the study was to compare various clinical scoring systems used in detecting pulmonary embolism (PE) in adults in Tertiary Care Hospital in South India.

Materials and Methods:

Prospective study was done in Apollo Hospital, Greams Road, Chennai, from January 2016 to December 2017. Sixty-five patients with suspected PE were included in the study. Details such as age, sex, pulse rate, and blood pressure were collected. Probability of PE was calculated with all four clinical scoring systems (Wells score, simplified Wells score, revised Geneva score, and simplified revised Geneva score) and compared with computed tomography–pulmonary angiography which was considered the gold standard.

Results:

This study included 65 patients with suspected PE. Among 65 patients, 39 (60%) were male and 26 (40%) were female. PE was present in 23 (35.4%) patients, of which 14 (60.9%) were male and 9 (39.1%) were female, but the difference was not statistically significant (P = 0.916). Wells score had a sensitivity of 87%, specificity of 67%, positive predictive value (PPV) of 59%, and negative predictive value of 90%. Simplified Wells score had a sensitivity of 91%, specificity of 50%, PPV of 50%, and negative predictive value of 91%. The revised Geneva score had a sensitivity of 70%, specificity of 52%, PPV of 44%, and negative predictive value of 76%. Simplified revised Geneva score had a sensitivity of 65%, specificity of 57%, PPV of 45%, and negative predictive value of 75%.

Conclusion:

From this study, we were able to infer that the simplified Wells score had high sensitivity and Wells score had high specificity in the diagnosis of PE. Simplified revised Geneva score had the least negative predictive value. It is very important to have a high index of suspicion for the diagnosis of PE and the clinical predictability scores are valuable tools in this regard.
Factors Associated with Poor Ovarian Reserve in Young Infertile Women: A Hospital-based Cohort Study
Authors: Hazarika Sanghamitra , Dasari Paapa , Chanu Sairem Mangolnganbi , Basu Sharbari
Published: July 2023

Background:

In practice, we encounter many young infertile women with poor ovarian reserve though ovarian reserve starts to decline after 35 years of age. One of the established risk factors for poor ovarian reserve in young women is endometriosis. There are other conditions that are reported to be associated which require further research.

Aims:

We aimed to study the prevalence of poor ovarian reserve and to find out the associated factors in women who are <35 years of age.

Settings and Design:

This was a prospective observational cohort study conducted in a tertiary care setting.

Materials and Methods:

Women aged more than 21 years and <35 years without Polycystic Ovarian Syndrome (PCOS) or ovarian dysgenesis with normal male factor were included after ethical approval. The sample size was 166 and serum anti-Mullerian hormone (AMH) was estimated by immunoenzymatic assay and expressed in ng/ml. AMH ≤0.99 ng/ml was considered poor ovarian reserve. Apart from established risk factors, the proposed risk factors studied were age 31–35 years, presence of medical disorders, gynaecological pathology and history of repeated ovulation induction (OI).

Statistical Analysis Used:

Data were analysed by SPSS version 25. Chi-square test and Fisher's exact test were used to compare the variables between normal ovarian reserve and poor ovarian reserve. Risk estimation was done by logistic regression and was expressed in odds ratio (OR).

Results:

Poor ovarian reserve was diagnosed in 40% of this cohort, and 62% were between 31 and 35 years. After adjusting for age >30 years, women with endometrioma, hypothyroidism and prior history of ≥3 cycles of OI were found to be having poor ovarian reserve (OR was 5.7, 2.5 and 2.3, respectively).

Conclusion:

Poor ovarian reserve was present in 40% of young women, and significantly associated factors were hypothyroidism and history of repeated multiple OI. This could be a confounder for other underlying mechanisms driving early exhaustion of ovarian reserve in certain young women. Hence, along with established risk factors, these women should undergo AMH testing irrespective of age.
Improving Fertility Treatment Documentation – A Survey
Authors: Koshy Aby Kottal
Published: July 2023

Background:

Many couples do not have adequate documentation following fertility treatments.

Aims:

To conduct a survey to understand the information needs of assisted reproductive technology physicians when assessing the reasons affecting treatment outcomes after intrauterine insemination (IUI) and in vitro fertilisation (IVF).

Settings and Design:

Online survey.

Materials and Methods:

Anonymous online survey of 14 parameters related to IUI treatment and 21 parameters related to IVF treatment, followed by recommendation of selected parameters for routine documentation.

Statistical Analysis Used:

Frequency distribution calculation of responses.

Results:

For IUI, total motile sperm count and post-wash sperm count and motility and for IVF, the quality and number of gametes, embryo number and morphology were the most important parameters.

Conclusion:

The study creates recommendations for the minimum information desirable in the fertility treatment documentation given to the couple undergoing treatment.
Impact of Interleukin-10 Promoter Region Polymorphisms on Recurrent Miscarriage: A Case–Control Approach
Authors: Sudhir Neha , Kaur Mandeep , Singh Sukhjashanpreet , Beri Archana , Kaur Tajinder , Kaur Anupam
Published: July 2023

Background:

Recurrent miscarriage (RM), defined as two or more consecutive miscarriages prior to the 20th week of gestation is characterised by multifactorial aetiology. The prevalence of RM varies from 0.8% to 13.5% amongst women of reproductive age. The aetiological basis of RM has been traced to chromosomal, anatomic, hormonal and immunologic factors while half of the cases remain idiopathic.

Aims:

This study aimed to investigate the association of interleukin-10 (IL-10) polymorphisms with RM amongst the Indian population.

Settings and Design:

The present study included a total of 414 individuals including RM women (n = 199) with two or more pregnancy losses and healthy women (n = 215) without any previous history of pregnancy loss were taken as the control group.

Materials and Methods:

Demographic features and reproductive history of women with RM and healthy women were taken. Genotype analysis of IL-10 polymorphisms rs1800872 and rs1800896 was performed using the polymerase chain reaction (PCR) restriction fragment length polymorphism and amplification mutation refractory system PCR, respectively.

Statistical Analysis Used:

Student's t-test was used to compare the demographic features and reproductive history amongst both groups. Pearson's Chi-square was used to calculate the Hardy–Weinberg equilibrium, allelic and genotypic frequencies. All the statistical analyses were performed using the SPSS (version 21, IBM SPSS, NY, USA).

Results:

Our results suggested that the genotypic and allelic frequency of rs1800872 polymorphism did not differ significantly between RM cases and control women (P = 0.07 and P = 0.23, respectively). The GG genotype (P = 0.007) and G allele (P = 0.003) of rs1800896 were significantly associated with an increased risk of RM. A statistically significant difference was also found for the distribution of genetic models (dominant and co-dominant model) between both groups for rs1800896. However, haplotype analysis revealed that none of the haplotypes provides a risk for the progression of RM.

Conclusion:

The study is the first of its kind from our region and provides baseline data on the genetics of RM.
Variation in Clinical Presentation, Metabolic Profile, Hormonal Parameters and Inflammatory Markers in Polycystic Ovary Syndrome Women with and without Polycystic Ovary Morphology Appearance
Authors: Jena Sweekruti , Mishra Ipsita , Baliarsinha Anoj Kumar , Jena Debarchan , Debata Madhumita
Published: July 2023

Background:

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder with a spectrum of presentation. Studies have reported considerably different rates in terms of the incidence of polycystic ovary morphology (PCOM) in patients with PCOS with inconsistent results regarding the effects of PCOM in them.

Aims:

The aim of this study was to determine the differences in clinical presentation, metabolic profile, hormonal parameters and inflammatory markers in PCOS women with and without PCOM on ultrasonography (USG).

Settings and Design:

A total of 70 PCOS women were recruited. To analyse the differences between various parameters, the patients were divided into two groups based on the presence or absence of PCOM on USG of the pelvis as per the Rotterdam criteria.

Materials and Methods:

A total of 37 patients had PCOM as per the diagnostic criteria for PCOS (Group 1), while 33 patients did not have PCOM on USG and were designated as Group 2. All participants underwent a detailed clinical evaluation and biochemical investigations, including high-sensitivity C-reactive protein, serum adiponectin, luteinising hormone, follicle-stimulating hormone, total testosterone and serum anti-Mullerian hormone. The homeostasis model assessment of IR (HOMA-IR) was calculated using standard equations.

Statistical Analysis Used:

The mean and Standard deviation were computed for all continuous variables. Frequencies and proportions were calculated for categorical variables. Comparisons of the mean scores between the study groups were assessed using the Unpaired Student's t-test. The mean score of the subgroups was also compared using the unpaired Student's t-test. P < 0.05 was considered significant for all statistical inferences.

Results:

The mean LDL and mean triglyceride were higher in Group 2, which was statistically significant (P = 0.004 and P ≤ 0.001, respectively). The mean hs-CRP was found to be higher in Group 2, which was statistically significant (P = 0.005). The mean AMH was higher in Group 1, which was statistically significant (P = 0.002). Group 1 had higher adiponectin levels, which was statistically significant (P = 0.04).

Conclusion:

The above findings suggest that patients without diagnostic PCO morphology have a worse metabolic profile compared to those with PCO morphology on USG. Obese patients without PCO morphology probably have a higher cardiovascular risk compared to obese patients with PCO morphology.
Comparative Evaluation of Effectiveness of Nisin, Amoxicillin/Clavulanic Acid (Augmentin) and Chlorhexidine on E. Faecalis as an Intracanal Irrigant: An In-vitro Study
Authors: Khan Mariyam , Samant Praveen S. , Chauhan Raju , Khan Raazia , Siddiqui Shazia , Sachan Saraswati
Published: July 2023

ABSTRACT

Aim:

The present study evaluated the antimicrobial efficacy of chlorhexidine gluconate (CHX), Nisin, and Amoxicillin/Clavulanic Acid (Augmentin) as an intracanal irrigant against Enterococcus faecalis (EF).

Materials and Methods:

Minimum Inhibitory Concentration (MIC) for EF against Nisin and Augmentin was determined by microbroth dilution technique. Time kill cycle (TKC) analysis was done for 0 MIC, ½ MIC, 1 MIC, and 2 MIC at 0 hour, 15 minutes, 30 minutes, and 45 minutes. At the end of each time period, dilutions were pipetted and swabs of agar plates were done. Incubation of agar plates was done at 37C for 24 hours. Colonies formed were counted.

Results:

The time kill curve analysis of EF for CHX, Nisin, and Augmentin at different concentrations and time periods showed a gradual decline in mean bacterial count between 0 and 45 minutes for CHX; this decline increases with increase in concentrations and time. Whereas in group Nisin, not much decline in bacterial count is noted for ½ MIC concentrations but a signification reduction of P < 0.001 after exposure to Nisin at 1 MIC ant 2 MIC concentrations. Group Augmentin showed not much reduction in bacterial count with increase in concentration and time.

Conclusion:

From this study, Nisin is found to be a promising agent in eliminating EF in comparison to other irrigants tested. However, the systemic effect of this irrigant, its biocompatibility, allergic potential, and bacterial resistance needs further investigation.