bluuebunny/crossref_metadata_2025 huggingface dataset:
MENTAL MODELS AND CREATIVE THINKING SKILLS IN STUDENTS’ PHYSICS LEARNING
Authors: Batlolona John Rafafy , Diantoro Markus
Published: June 2023

The study of mental models and creative thinking skills in students’ physics learning with the problem-based learning model has been scarce. This study aimed to analyze the relationship between mental models and creative thinking skills in high school students. Many previous research findings explain a relationship between mental models and creative thinking skills among students at the university level and workers. This mixed-methods study was conducted on high school students in Malang, East Java, Indonesia, aged between 14 and 15 years. The instrument used is in the form of mental models and creative thinking skills test questions. This finding explains no relationship between mental models and creative thinking skills because learning has not fully empowered mental models and creative thinking skills. On the other hand, learning at the previous level, students’ knowledge is still fragmented, so that is incomplete. Therefore, at the high school level, they need help to improve their mental models and creative thinking skills. This finding implies that teachers in developing learning materials, tools, and instruments must pay attention to the level of student knowledge so that learning can be more optimal.
Precise Age for the Binary Star System 12 Com in the Coma Berenices Cluster
Authors: Lam Rex , Sandquist Eric L. , Schaefer Gail H. , Farrington Christopher D. , Monnier John D. , Anugu Narsireddy , Lanthermann Cyprien , Klement Robert , Ennis Jacob , Setterholm Benjamin R. , Gardner Tyler , Kraus Stefan , Davies Claire L. , Orosz Jerome A.
Published: June 2023

We present measurements of the interferometrically resolved binary star system 12 Com and the single giant star 31 Com in the cluster Coma Berenices. 12 Com is a double-lined spectroscopic binary system consisting of a G7 giant and an A3 dwarf at the cluster turnoff. Using an extensive radial velocity data set and interferometric measurements from the Palomar Testbed Interferometer and the Center for High Angular Resolution Astronomy array, we measured masses M
1 = 2.64 ± 0.07M
⊙ and M
2 = 2.10 ± 0.03M
⊙. Interferometry also allows us to resolve the giant and measure its size as R
1 = 9.12 ± 0.12 ± 0.01R
⊙. With the measured masses and radii, we find an age of 533 ± 41 ± 42 Myr. For comparison, we measure the radius of 31 Com to be 8.36 ± 0.15 R
⊙. Based on the photometry and radius measurements, 12 Com A is likely the most evolved bright star in the cluster, large enough to be in the red giant phase, but too small to have core helium burning. Simultaneous knowledge of 12 Com A’s mass and photometry puts strong constraints on convective core overshooting during the main-sequence phase, which in turn reduces systematic uncertainties in the age. Increased precision in measuring this system also improves our knowledge of the progenitor of the cluster white dwarf WD1216+260.
The 14 Her Planetary System: Companion Masses and Architecture from Radial Velocities and Astrometry
Authors: Benedict G. F. , McArthur B. E. , Nelan E. P. , Bean J. L.
Published: June 2023

We combine Hubble Space Telescope (HST) Fine Guidance Sensor, Hipparcos, and Gaia DR3 astrometric observations of the K0 V star 14 Her with the results of an analysis of extensive ground-based radial velocity data to determine perturbation orbits and masses for two previously known companions, 14 Her b and c. Radial velocities obtained with the Hobby–Eberly Telescope and from the literature now span over 25 years. With these data we obtain improved radial velocity (RV) orbital elements for both the inner companion, 14 Her b and the long-period outer companion, 14 Her c. We also find evidence of an additional RV signal with P ∼ 3789d. We then model astrometry from Hipparcos, HST, and Gaia with RV results to obtain system parallax and proper motion, perturbation periods, inclinations, and sizes due to 14 Her b and c. We find P
b = 1767.6 ± 0.2 days, perturbation semimajor axis α
b = 1.3 ± 0.1 mas, and inclination i
b = 36° ± 3°, P
c = 52160 ± 1028 days, perturbation semimajor axis α
c = 10.3 ± 0.7 mas, and inclination i
c = 82° ± 14°. In agreement with a past investigation, the 14 Her b, c orbits exhibit significant mutual inclination. Assuming a primary mass M
* = 0.98 ± 0.04M
☉, we obtain companion masses



b

=

8.5

−
0.8

+
1.0



Jup

and



c

=

7.1

−
0.6

+
1.0



Jup

.
Confinedness of an X3.1-class Solar Flare Occurred in NOAA 12192: Analysis from Multi-instrument Observations
Authors: Vasantharaju N. , Zuccarello F. , Ferrente F. , Guglielmino S. L.
Published: June 2023

The nonassociation of coronal mass ejections with high energetic flares is sparse. For this reason, the magnetic conditions required for the confinedness of major flares is a topic of active research. Using multi-instrument observations, we investigated the evolution and effects of confinedness in an X3.1 flare, which occurred in active region (AR) 12192. The decrease of net fluxes in the brightening regions near the footpoints of the multisigmoidal AR in the photosphere and chromosphere, indicative of flux cancellation favoring tether-cutting reconnection (TCR), is observed using the magnetic field observations of HMI/SDO and SOT/Hinode, respectively. The analysis of spectropolarimetric data obtained by the Interferometric Bidimensional Spectrometer over the brightening regions suggests untwisting of field lines, which further supports TCR. Filaments near the polarity inversion line region, resulting from TCR of low-lying sheared loops, undergo merging and form an elongated filament. The temperature and density differences between the footpoints of the merged filament, revealed by DEM analysis, cause streaming and counterstreaming of the plasma flow along the filament and unload at its footpoints with an average velocity of ≈40 km s−1. This results in a decrease of the mass of the filament (density decreased by >50%), leading to its rise and expansion outward. However, due to strong strapping flux, the filament separates itself instead of erupting. Further, the evolution of nonpotential parameters describes the characteristics of confinedness of the flare. Our study suggests that the sigmoid–filament system exhibits upward catastrophe due to mass unloading but gets suppressed by strong confinement of the external poloidal field.
Semi-analytical Expression of G-mode Period Spacing: The Case of Brunt–Väisälä Frequency with Not a Jump but a Ramp
Authors: Hatta Yoshiki
Published: June 2023

To decipher complex patterns of gravity-mode period spacings observed for intermediate-mass main-sequence stars is an important step toward a better understanding of the structure and dynamics in the deep radiative region of the stars. In this study, we apply the JWKB approximation to derive a semi-analytical expression of the g-mode period spacing pattern, for which the gradient in the Brunt–Väisälä frequency is taken into account. The formulation includes the term P
−1
B
⋆, where P and B
⋆ represent the g-mode period and degree of the structural variation, the latter of which especially is related to the steepness of the gradient of the Brunt–Väisälä frequency. Tests with one-dimensional stellar models show that the semi-analytical expression derived in this study is useful for inferring the degree of the structural variation B
⋆ with an accuracy of ∼10 % in the case of relatively massive intermediate-mass models with the mass M larger than 3 M
⊙. The newly formulated expression will possibly allow us to put further constraints on, e.g., mixing processes inside intermediate-mass main-sequence g-mode pulsators such as β Cep, SPB, and γ Dor stars that have been principal targets in asteroseismology.
2023 Recovery Observations and Characterization of the Active Centaur P/2010 TO20 (LINEAR-Grauer)
Authors: Schambeau Charles A. , Lilly Eva , Micheli Marco , Fernandez Yanga R. , Jevčák Peter , Samarasinha Nalin
Published: June 2023

We report the recovery of the Centaur P/2010 TO20 (LINEAR-Grauer) on CCD imaging data from three separate dates in 2023 April, May, and June from the 8.1 m Gemini South Telescope, representing its first known detections since 2012. The recovery observations display a compact coma and tail, consistent with ongoing activity after its recent 2022 November 27 perihelion passage. We estimate a nucleus radius upper-limit of r

n
 ≤ 2.7 km. Due to the current uncertainty inherent in the nucleus’ true size, we report a plausible range for the dust production of 2.7 cm ≤ Af
ρ ≤ 14.5 cm after subtraction of an assumed nucleus flux based on radii of 2.7 km and 0.5 km, respectively. P/2010 TO20 experienced a recent and well-defined orbital change and associated change in thermal environment, making it an exciting target through which to study Centaur activity drivers and their evolution as their orbits change in real-time.
A RESILIENT SOLDIER, A RESILIENT STATE
Authors: DIVIŠOVÁ Vendula , FRANK Libor , BÍZIK Vladimír , NOVOTNÝ Karel
Published: June 2023

This paper introduces a questionnaire as a measurement tool that will help evaluate the armed forces’ resilience to hybrid interference. It is based on the previously developed conceptualisation of resilience as consisting of the national, social, institutional, and psychological dimensions and guides the reader through the operationalisation of the corresponding variables in the form of a questionnaire to be distributed within different groups of the Czech Armed Forces.
The effects of low-dose radiation therapy in patients with mild-to-moderate Alzheimer's dementia: an interim analysis of a pilot study
Authors: Kim Aryun , Lee Jeonghwan , Moon Hansol , Kim Chulhan , Yoo Min Young , Park Woo Yoon , Kim Won Dong , Seo Young-Seok
Published: June 2023

Purpose: We aimed to determine whether low-dose radiotherapy (LDRT) is effective in patients with Alzheimer disease (AD).Materials and Methods: We included patients according to the following criteria: probable Alzheimer's dementia according to the New Diagnostic Criteria for Alzheimer’s Disease; confirmation of amyloid plaque deposits on baseline amyloid positron emission tomography (PET); a Korean Mini-Mental State Examination 2nd edition (K-MMSE-2) score of 13–26; and a Global Clinical Dementia Rating (CDR) score of 0.5–2 points. LDRT was performed six times at 0.5 Gy each. Post-treatment cognitive function tests and PET-CT examinations were performed to evaluate efficacy. The medication for AD treatment was maintained throughout the study period.Results: At 6 months after LDRT, neurological improvement was seen in 20% of patients. Patient #2 showed improvement in all domains of the Seoul Neuropsychological Screening Battery II (SNSB-II). Moreover, the K-MMSE-2 and Geriatric Depression Score-Short Form scores improved from 20 to 23 and from 8 to 2, respectively. For patient #3, the CDR score (sum of box score) improved from 1 (4.0) to 1 (3.5) at 3 months follow-up. Moreover, the Z scores for language and related functions, memory, and frontal executive function improved to -2.56, -1.86, and -1.32, respectively at the 6-month follow-up. Two patients complained of mild nausea and mild hair loss during LDRT, which improved after treatment.Conclusion: One of the five patients with AD treated with LDRT experienced a temporary improvement in SNSB-II. LDRT is tolerable in patients with AD. We are currently under follow-up and will conduct cognitive function tests after 12 months after LDRT. A large-scale randomized controlled trial with a longer follow-up period is warranted to determine the effect of LDRT on patients with AD.
Europe. Critères de Barcelone et accueil des jeunes enfants : des disparités croissantes entre les pays
Authors: Collombet Catherine , Math Antoine
Published: June 2023

Cet article propose une analyse comparative de la situation en matière d’accueil des jeunes enfants au regard des indicateurs retenus par l’Union européenne pour les enfants de moins de 3 ans et pour ceux de 3 ans jusqu’à l’âge de la scolarité élémentaire obligatoire, ainsi qu’au regard des dépenses qui sont consacrées aux dispositifs d’accueil. Il montre que les fortes disparités entre les pays se sont accrues depuis la fixation des objectifs de Barcelone en 2002. Ce panorama permet de mesurer le chemin parcouru et restant à parcourir pour un certain nombre de pays afin d’atteindre les objectifs fixés pour 2030 par la nouvelle recommandation sur les modes de garde.
La dette publique peut-elle rester indolore?
Authors: Levy-Garboua Vivien , Maarek Gérard
Published: June 2023

Les grands pays industrialisés semblent s’accommoder d’un niveau de dette publique sans cesse croissant. Une fois revenue au plein-emploi, une économie peut-elle sans dommage supporter un endettement public de plus en plus élevé ? Les modalités de financement de la dépense publique, impôt vs endettement, obligations d’État vs émission monétaire, sont-elles sans incidence sur la dynamique de long terme de l’économie ? Les modèles décrivant l’évolution de la dette donnent les conditions de sa soutenabilité, en fonction du taux d’intérêt et du taux de croissance de l’économie. La spécificité de notre modèle réside dans la prise en compte du comportement des prêteurs, qui n’acceptent de détenir une quantité croissante de titres publics, qu’à condition de percevoir une rémunération plus élevée au regard du rendement du capital productif. L’équilibre macroéconomique s’en trouve affecté. À persister dans une séquence de déficits publics croissants, on risque des déboires, (i) l’éviction de la dépense publique par les charges d’intérêt (ii) le retour à la rigueur budgétaire (iii) ou le réveil de l’inflation.
The sixth power mean of one kind generalized two-term exponential sums and their asymptotic properties
Authors: Zhang Jin , Li Xiaoxue
Published: June 2023

The main aim of this article is using the elementary method and the number of the solutions of some congruence equations modulo an odd prime $ p $, to study the calculating problem of the sixth power mean of one kind generalized two-term exponential sums, and give a sharp asymptotic formula for it.
Existence and stability results for impulsive $ (k, \psi) $-Hilfer fractional double integro-differential equation with mixed nonlocal conditions
Authors: Sudsutad Weerawat , Lewkeeratiyutkul Wicharn , Thaiprayoon Chatthai , Kongson Jutarat
Published: June 2023

This paper investigates a class of nonlinear impulsive fractional integro-differential equations with mixed nonlocal boundary conditions (multi-point and multi-term) that involves $ (\rho_{k}, \psi_{k}) $-Hilfer fractional derivative. The main objective is to prove the existence and uniqueness of the solution for the considered problem by means of fixed point theory of Banach's and O'Regan's types, respectively. In this contribution, the transformation of the considered problem into an equivalent integral equation is necessary for our main results. Furthermore, the nonlinear functional analysis technique is used to investigate various types of Ulam's stability results. The applications of main results are guaranteed with three numerical examples.
The index of strong rotundity
Authors: García-Pacheco Francisco Javier
Published: June 2023

The index of strong rotundity is introduced. This index is used to determine how far an element of the unit sphere of a real Banach space is from being a strongly exposed point of the unit ball. This index is computed for Hilbert spaces. Characterizations of the set of rotund points and the set of smooth points are provided for a better understanding of the construction of the index of strong rotundity. Finally, applications to the stereographic projection are provided.
A novel event-triggered constrained control for nonlinear discrete-time systems
Authors: Cheng Yuanyuan , Li Yuan
Published: June 2023

In this paper, a novel event-triggered optimal control method is developed for nonlinear discrete-time systems with constrained inputs. First, a non-quadratic utility function is constructed to overcome the challenge caused by saturating actuators. Second, a novel triggering condition is designed to reduce computational burden. Difference from other triggering conditions, fewer assumptions are required to guarantee asymptotic stability. Then, the optimal cost function and control law are obtained by constructing the action-critic network. Convergence analysis of the system is provided in the consideration of the system state and neural network weight estimation errors. Finally, the effectiveness and correctness of the proposed method are verified by two numerical examples.
Association of Infant Feeding Characteristics With Dietary Patterns and Obesity in Korean Childhood
Authors: Kim Kyoung-Nam , Shin Moon-Kyung
Published: June 2023

Objectives: Young children’s feeding characteristics can play an important role in eating habits and health during later childhood. This study was conducted to examine the associations of feeding characteristics with dietary patterns and obesity in children.Methods: This study utilized data from the Korea National Health and Nutrition Examination Survey conducted between 2013 and 2017. In total, 802 toddlers were included, with information on their demographic characteristics, feeding practices and duration, and 24-hour recall obtained from their parents. Feeding characteristics were categorized into feeding type, duration of total breastfeeding, duration of total formula feeding, duration of exclusive breastfeeding, and age when starting formula feeding. Dietary patterns were identified based on factor loadings for the food groups for 3 major factors, with “vegetables & traditional,” “fish & carbohydrates,” and “sweet & fat” patterns. Overweight/obesity was defined as ≥85th percentile in body mass index based on the 2017 Korean National Growth charts for children and adolescents. Multiple regression analysis was conducted to examine associations between feeding characteristics and dietary patterns. The association between dietary patterns and obesity was analyzed using multivariable logistic regression analysis.Results: The early introduction of formula feeding was inversely associated with the “vegetables & traditional” pattern (β=-0.18; 95% confidence interval [CI], -0.34 to -0.02). A higher “vegetables & traditional” intake was associated with a lower risk of obesity (odds ratio, 0.48; 95% CI, 0.24 to 0.95).Conclusions: Feeding characteristics are associated with dietary patterns in later childhood, and dietary patterns were shown to have a potential protective association against obesity.
An Innovative Approach to Knowledge Management
Authors: Kiernan Ferrigno Beth A.
Published: June 2023

This chapter summarizes a case study of the Harborwoods Central School District's successful implementation of a knowledge management system to improve social emotional learning for students and teachers. The case study highlights the challenges faced by K12 education in the realm of EdTech, including high costs, wasted instructional time, and tools that do not align with district goals. The COVID-19 pandemic has led to an increase in the adoption of EdTech solutions without proper professional development. The case study explores how Harborwoods transformed resistant teachers into tech-savvy experts and how they supported their school community through social emotional learning, AI, and collaboration. The analysis identifies an autonomous approach, adopting AI and technology tools, structured project management, and continuous collaboration and innovation as the main drivers behind Harborwoods' success. The findings can help school leaders to develop effective strategies for improving EdTech usage, saving time and money for school systems, and enhancing learning outcomes.
Innovative and Knowledge Developments for Sustainability in Salmon-Based Aquaculture
Authors: Westeren Knut Ingar
Published: June 2023

Coastal marine salmon-based aquaculture has grown considerably in produced volumes in recent years, and projections from FAO lay out possibilities for further increases. This can only be done by introducing stronger restrictions on sustainability, including fish health and environmental regulations. To solve environmental problems, the Norwegian aquaculture company Midt-Norsk Havbruk (now Salmonor AS) received development permits in 2017 for a project based on Aquatraz semi-closed steel cages. The study is based on documentation from the Aquatraz project and interviews with employees at Midt-Norsk Havbruk. The project has mainly been successful, as in the fourth generation of the Aquatraz cage put in operation in 2021/22 delousing was not required and escape did not take place. The projects also showed how knowledge management (KM) procedures were successfully changed during implementation of new innovative technologies, the main reason for this being a flat organizational structure and focus on training and upgrading of knowledge levels and dissemination.
Enhancing DevOps Using Intelligent Techniques
Authors: Shankar Sahana P. , Varadam Deepak , Bharadwaj Aryan , Dayananda Shraddha , Agrawal Sarthak , Jha Ayush , V. Surya Tejas
Published: June 2023

Change is an inevitable part of any business. Customer satisfaction and building good will is the primary goal. The real success lies in the above two factors rather than money. Different businesses operate in different ways. Each one focuses on a different set of criteria and thus follows a different set of models. There are various models in the software development life cycle, such as the waterfall model, spiral model, V-model, and so on. These models have advantages and disadvantages and aid in the improvement of a company's workforce. They overcome the disadvantages of the previous model with each model. DevOps is the most recent model that is widely used. This chapter deals with DevOps, including the need, working, and how it differs from other models. This also looks into how intelligent techniques can be used to enhance the DevOps process for better productivity in the businesses (i.e., AIOps). It summarizes the different phases in DevOps, the corresponding machine learning or artificial algorithms that can be applied in the phases.
Digitalization of the Marketing Strategy as SMEs' Sustainable Development Guarantee
Authors: Surmanidze Natia , Tskhadadze Keti , Tabagari Khatuna , Tevdoradze Sopiko , Mushkudiani Zurab
Published: June 2023

The chapter reviews and analyzes in depth the role and importance of marketing digitalization strategies in small companies, using the example of Georgian handmade accessories (bag manufacturer), where the problematic aspects of access to finance are considered vital for developing countries' entrepreneurship. Qualitative research was conducted on 90 respondents, the results of which and the comparative analysis of desk research confirmed the hypothesis that digital marketing strategy is a significant factor for SMEs to reach sustainable development. Besides, if the strategy is long-term, the company gets a guarantee to grow its size and obtain high competitiveness. The research solved the most critical problem, how small companies can implement marketing activities cheaply and qualitatively, and effectively, forming a brand and a loyal customer.
Assessing the Effect of Lift Position on Helicopter Recovery to a Twin-Island Aircraft Carrier using Piloted Flight Simulation
Authors:   University of Liverpool, Watson Neal , Owen Ieuan , White Mark
Published: June 2023

This paper describes an investigation of the air flow over the flight deck of a twin-island aircraft carrier with the ship's lifts in a raised and lowered position, and the subsequent effect on the helicopter and on pilot workload. Computational Fluid Dynamics was used to model the unsteady flow over the flight deck in a 40 kt wind approaching from 60°starboard. The turbulence intensity and velocity flow field produced over the flight deck for each lift configuration was analyzed and compared. The unsteady air flow computed for each lift position was combined with a flight dynamics model of a helicopter configured to represent a SH-60B Seahawk an integrated with a full-motion flight simulator. To analyze the effect of the two airwakes on the helicopter and on pilot workload, a series of simulated flight trials were conducted in which the pilot performed landings to the flight deck of the aircraft carrier. The results show that while the lift configuration does affect the air flow over the flight deck, the effect on pilot workload is dependent on the location on the flight deck the pilot is landing to.
Identification of Nonlinear Corrections to Multicopter Flight Simulation Model Using Machine Learning
Authors:   Rensselaer Polytechnic Institute, Makkar Gaurav , Niemiec Robert , Gandhi Farhan
Published: June 2023

This study presents a novel methodology for identifying nonlinear corrections to improve the accuracy of a physics-based simulation model of a hexacopter using flight test data. Two distinct models are employed to capture the dynamics of the hexacopter in hover: one model is identified from flight data, and the other utilizes a physics-based blade element model with a 10-state Peter-He inflow. An input filter is extracted based on the difference between the flight test data and frequency response from the physics-based model to make corrections. This improves the predictions over the entire frequency range. For time domain analysis, the nonlinear corrections are identified by analyzing correlations between different flight variables and utilizing a filtered dataset with high normalized correlation. Regularized version of partial least squares is applied for identifying the correction terms. The performance of the updated linearized model is compared with the physics-based model and system ID model in the time domain for all four axes. It was observed that for low amplitude maneuvers, the corrected model is comparable to the model identified from flight test data and sometimes slightly better (2-5%). Predictions obtained using the corrected model exhibit superior performance to those generated by the physics-based model, particularly in the vicinity of peak values (8%-14%). For large amplitude maneuvers, the distinction is even more pronounced, with the model with nonlinear corrections surpassing all other models in terms of accuracy. Notably, while the physics-based model predictions exhibit an average error of 32% when compared to the flight test data, and the model identified using flight test data generated predictions with an average error of 22%, the model with nonlinear corrections yielded predictions with an average error of less than 10%.
Active Twist and Passive Rotors in Hover and Level Flight
Authors:   University of Liverpool, Steininger Rinaldo , Barakos George
Published: June 2023

The effect of blade twist on rotor performance is investigated using the Hover Validation Acoustic Baseline (HVAB) and Smart Twisting Active Rotor (STAR) rotors. This is a numerical study conducted using computational fluid dynamics and aeroelastic simulations. The main tool is the Helicopter Multi Block 3 CFD solver of Glasgow. Hover loads are analysed for rigid and elastic cases using a nominal and a higher twist rate. The increased twist did not affect the rotor thrust but increased the hover efficiency. In forward flight, at high-advance ratio, the effect of blade twist was also investigated using aeroelastic computations. A 2-per-rev active twist input was also investigated. Higher blade twist increased vibration in all cases, and reduced performance at high disk loading. The active twist system could achieve increased rotor efficiency and reduced vibration at the studied conditions.
NATO Generic Destroyer Moving-Ship Airwake Validation and Rotor-Ship Dynamic Interface Computations using Immersed Boundary Lattice-Boltzmann Method
Authors:   Georgia Institute of Technology, Ashok Shreyas , Rauleder Juergen
Published: June 2023

During rotorcraft ship-deck landing operations, complex interactional aerodynamic phenomena occur between the rotor and ship airwakes, and these phenomena are not fully understood. Many traditional ship - rotorcraft interactional simulation approaches use a one-way coupling, where the ship airwake is superimposed on the rotor, modifying its inflow. However, because the rotor wake does not alter the ship airwake in such a simulation, one-way coupling may not capture all relevant phenomena, especially when ship motion is accounted for; two-way fully-coupled simulations may be needed. In this study, the NATO Generic Destroyer, a shared, representative ship geometry created for collaborative studies, was investigated numerically, and the ship airwake results validated by wind tunnel measurements using discrete velocity probes on the landing deck. Lattice-Boltzmann Method (LBM) simulations of the standalone ship airwake and one- and two-way coupled ship-rotorcraft interactional simulations were conducted using a Graphics Processing Unit (GPU) accelerated solver. The ship surface was represented using a novel Grad immersed boundary approach. Using this boundary condition, effects of ship motion were included in the simulations. Ship airwake results showed good agreement with the experiment and excellent computational performance; simulations took less than four hours to run on a single GPU node. Through ship-rotorcraft interactional simulations, it was determined that one-way and two-way coupling strategies resulted in different frequency profiles of unsteady induced inflow velocity variations, with considerable differences in the closed-loop pilot response range.
Flowfield Effects on the Flight Dynamics and Control Response of Rotorcraft Operating in Close Proximity
Authors:   US Naval Academy, Juhasz Ondrej
Published: June 2023

Requirements in future rotorcraft operations will likely place several aircraft in close-proximity to one another. Flowfield interference impacts on a secondary rotorcraft operating in the wake of a primary helicopter are investigated. Of primary concern is the degradation in the flight dynamics and control performance of the secondary helicopter. A free-vortex based wake is used to trim a primary helicopter and generate a flowfield. The secondary helicopter uses a finite-state inflow model, with one way coupling to the flowfield of the primary. The trim swashplate deflections and linear responses are compared at various positions of the secondary helicopter with respect to the primary. The results show that while the trim swashplate positions vary greatly between the different cases, the linear response remains unchanged. Next, a flapping controller is developed and a time marching simulation of the secondary rotorcraft traversing the wake of the primary shows actuator usage requirements for various air speeds. The faster the secondary helicopter traverses the wake, the larger the swashplate displacement required. The swashplate limits were not reached for either scenario evaluated.
Vertiport Passenger Security Standard (VPSS)
Authors:   IDentity Management Consulting, Saleh Isam ,   Rival Air Inc., Young Grant
Published: June 2023

This technical paper will propose solutions for developing and implementing biometric driven screening processes for both passengers and employees utilizing or working in Vertiport secured areas. We will explore how biometric-based Vertiport Passenger Security can overcome the limitations of existing airport screening processes by improving accuracy, reducing wait times, and enhancing the overall passenger experience. No definitive policies or procedures have been developed to date by regulators.
Feasibility Study on the Tender eVTOL Vehicle (TeV) for Range Extension
Authors:   Yamato Transport, Ito Yu ,   Yamato Holdings, Adachi Takaaki
Published: June 2023

his study examines the utility of introducing an air-to-air power transfer (AAPT) tender vehicle (TeV) to recharge the main mission eVTOL (MeV) aircraft and extend its range without reducing the payload. After discussing how to conduct AAPT and setting numerical models of the aircrafts through referring to preceding studies, a simple simulation from the perspective of power (kW) and energy (kWh) is made to find the desirable configuration to be applied to the TeV. The result shows that by adopting slowed rotor helicopter configuration, the TeV may extend the range of the MeV for another 150+% by consuming only 70% of the energy the MeV requires. It is also found that the effect of the TeV is higher when the MeV requires more power at hovering than at cruise, so that energy available while at cruise can result in more range, compared to those recharged on ground. Future evolution in increasing the power battery will enhance the utility of the TeV.
Main Rotor Gearbox Oil Cooling System Design
Authors:   Ametek Airtechnology Group Ltd, Gore David , Kerr John
Published: June 2023

This paper details the design process for a Main Rotor Gearbox Oil Cooling System and recommends techniques to optimise future designs. It covers the drive methods which must be considered in the design, along with the optimum heat exchanger and airflow path arrangements to meet the design requirements. This paper also describes the different type of fan which can be used, and the relative merits. The cooling system design is dictated by the specification, and the impact of certain requirements - temperature, fan seizure performance, containment, bearing selection and lubrication - are covered in detail. The typical qualification testing suite for a Main Rotor Gearbox Oil Cooling System is also provided, along with predicted areas of future developments in this sector of the aerospace industry.
CH-53K® Supplemental Engine Feed System
Authors:   Lockheed Martin Sikorsky, Foti Christopher ,   NAVAIR, Eby Robert , Shields Daniel , Morrissette Robert , Lee Esther
Published: June 2023

The CH-53K® fuel system employs a unique on-demand Supplemental Engine Feed System (SEFS), which provides regulated pressure to the engine without the use of software or electronic controls. The system balances the engines' need for intermittent fuel boost with the survivability restrictions of a positively pressurized fuel system. Under normal aircraft maneuvering and loading, SEFS provides boost equivalent to a full tank of fuel such that the engine pumps can provide a consistent level of suction even when fuel levels are low. However, with higher airframe g-loading created by certain maneuvers, a second stage activates and further increases pressure boost to prevent any interruption of fuel flow. Upon completion of a high-g maneuver, the SEFS automatically returns to its constant boost mode. SEFS underwent the full developmental lifecycle, beginning as an analytical exercise before progressing through ground testing and in-flight verification.
Using Intelligent Design to Increase Redundancy Without Sacrificing Efficiency Through Adoption of Passive Lubrication in Reduction Drives
Authors:   Drive System Design, Peacey Robert , Rogers Lee
Published: June 2023

The eVTOL world is generally sceptical of using a transmission in their designs, this is largely due to the misconception that vertical flight requires a complex helicopter-style gearbox. Various styles of reduction drives have been used since the dawn of powered flight and are a viable and reliable option for an eVTOL system. Transmissions will be a key component of eVTOL propulsion systems moving forward. Their ability to match power dense motors to efficient propellers in a compact package space are unparalleled. A key aspect to the reliability and efficient operation is a robust and suitable lubrication system. Gears and bearings cannot operate effectively without this lubrication, which does not have to be complicated or inefficient. DSD will cover the process required to intelligently design a reduction gearbox lubrication system to remain passive, be efficient and robust, eliminating unnecessary complexity for improved reliability.
L’altro 1992. Quando l’Italia scoprì le riforme
Authors: Cazzola Giuliano
Published: June 2023

Non disponibile.
Scritti e discorsi politici. Il libero scambio per la pace tra le nazioni
Authors: Cobden Richard
Published: June 2023

Non disponibile.
Effects of curing time and intensity and polishing technique on color stability of bleach-shade composite resins
Authors: HashemiKamangar Sedighe Sadat , Jafari Soheil , Rouhaninasab Marzieh
Published: June 2023

Background:

Despite the improvements in optical properties of composite resins, their color stability is still a matter of concern. This study aimed to assess the curing time and intensity and polishing technique on color stability of bleach-shade composite resins.

Materials and Methods:

In this in vitro, experimental study, 128 discs (1 mm × 8 mm) were fabricated from two composite resins. The specimens fabricated from each composite were assigned to 8 subgroups (n = 8) based on the curing time and intensity and polishing with polishing points or discs. After polishing, the color parameters of specimens were measured by EasyShade spectrophotometer according to the CIEL* a*b* color system. The specimens were then immersed in tea solution, and their color parameters were measured again. Color change (ΔE) was calculated and analyzed at 0.05 level of significance. SPSS 25 was used for data analysis. Univariate four-way ANOVA was applied to assess the effects of composite type, curing time, curing intensity, and technique of polishing on ΔE of composite resins. Since the interaction effects were significant, subgroup analysis was performed by t-test. The level of significance for this test was set at 0.05.

Results:

The effects of curing intensity and polishing technique were significant on ΔE (P < 0.05). Filtek Z350 XBW composite specimens polished by polishing points experienced lower color change than those polished with discs. The minimum ΔE of Gradia XBW composite was recorded in specimens that underwent high-intensity curing for 20 s and were polished with polishing points while the maximum ΔE was recorded in specimens that underwent high-intensity curing for 20 s and were polished with discs.

Conclusion:

In all groups except on (Filtek, polishing with Disk, curing time = 20 s), high-intensity curing and polishing with polishing points were more effective and caused lower color change compared with low-intensity curing and polishing with discs.
A comparative evaluation of the antimicrobial effect of chamomile, Aloe vera-green tea, and chlorhexidine mouthwashes on some oral bacterial species
Authors: Naghsh Narges , Moghareabed Ahmad , Nematnejad Mahsa , Yaghini Jaber , Sadeghi Sayed Mohsen
Published: June 2023

Background:

Plant compounds such as Aloe vera, green tea, and chamomile have been increasingly used in recent years to achieve oral health. This study aimed to determine the antimicrobial effect of chamomile (Matrika), A. vera-green tea, and chlorhexidine (CHX) mouthwashes on some oral bacterial species.

Materials and Methods:

This prospective experimental study investigated the antimicrobial properties of three mouthwashes, including chamomile (Matrika), A. vera -green tea, and CHX as well as distilled water as control on five bacterial species, including Streptococcus Oralis, Streptococcus sanguis, and Streptococcus mutans as primary colonizers and Porphyromonas gingivalis and Eikenella corrodens as secondary colonizers. Colony-forming unit was used to count the colonies and disc diffusion and well diffusion methods were used to measure the diameter of zone of inhibition. Data were analyzed by SPSS (version 22) software using descriptive statistics, ANOVA, Tukey, Kruskal–Wallis, and Mann–Whitney tests (α = 0.05).

Results:

CHX had a significantly higher antibacterial effect than the other two mouthwashes in all three methods (P < 0.001). Further, the herbal mouthwashes in all three methods had a statistically significant effect on the bacterial species (P < 0.001). A. vera-green tea mouthwash had a significantly higher effect than chamomile mouthwash (Matrika) on all bacterial species except for S. sanguis (P < 0.05).

Conclusion:

The findings showed that herbal mouthwashes had potentially antibacterial effects, but these effects were significantly lower than that of CHX. However, more clinical studies are needed to prove the current findings.
Mechanisms of medicinal plants in the treatment of diabetic wound
Authors: Adeleke Oluwakemi V. , Adefegha Stephen A. , Oboh Ganiyu
Published: June 2023

Wound repair is noticeably prolonged in a diabetic state due to a faulty inflammatory process and an underlying neuropathy. Several medicinal plants and their products have been of prime importance for the management of wounds over the years. Various mechanisms whereby medicinal plants elicit their action in wound repair are revealed and some plants are proven to be experimentally effective in enhancing wound closure and achieving healing. The mechanisms identified include hyperglycemic control, alleviation of physiological inflammation, controlled oxidative stress, infection control, and influence on gene expression. Information in this review was sourced from research and review articles in electronic databases such as Web of Science, Scopus, PubMed, and Google Scholar.
Green synthesis, characterization, acaricidal, larvacidal, and repellent activities of copper nanoparticles of Astragalus sinicus against Hyalomma anatolicum
Authors: Gattan Hattan S. , Al-Ahmadi Bassam M. , Shater Abdullah F. , Majeed Qais A. H. , Alazemi Maha S. , Alanazi Abdullah D
Published: June 2023

Objective:

To green synthesize and characterize copper nanoparticles (CuNPs) using Astragalus sinicus, as well as evaluate the acaricidal, larvacidal, and repellent activities of CuNPs against Hyalomma anatolicum (H. anatolicum), one of the most prevalent ticks infesting cattle in Saudi Arabia.

Methods:

CuNPs were green synthesized by adding the Astragalus sinicus extract to a copper sulfate solution. The acaricidal, larvicidal, and repellent activities of CuNPs against H. anatolicum were assessed via the adult immersion test, the larval packet test, and the vertical movement behavior of tick larvae, respectively. The effects of CuNPs on acetylcholinesterase as well as oxidative enzyme activities were examined.

Results: The green synthesized CuNPs displayed a spherical form with a size range of 15-75 nm. After exposure of adult H. anatolicum to different concentrations of CuNPs, the viability rate of adult H. anatolicum and the mean number, weight, and hatchability of eggs were noticeably reduced, in comparison to the control group (P<0.001). In addition, the viability rate of larvae considerably declined (P<0.001) with the LC50 and LC90 values of 11.30 and 20.34 μg/mL, respectively. The maximum repellent activity of CuNPs was observed at 50, 100, and 200 μg/mL with complete repellent activity after 60, 120, and 180 min of exposure, respectively. CuNPs, mainly at ½LC50 and LC50 concentrations, markedly suppressed the acetylcholinesterase activity of the larval stage of H. anatolicum (P<0.001). Moreover, CuNPs, mainly at LC50 dose, significantly elevated malondialdehyde level while declining glutathione-S-transferase level in H. anatolicum larvae (P<0.001).

Conclusions:

CuNPs show potent acaricidal, larvicidal, and repellent activities against adults and larvae of H. anatolicum. However, further studies must be performed to clarify the precise mechanisms and the efficacy of CuNPs in practical use.
Evaluating the Global Strategy and Plan of Action on Public Health, Innovation, and Intellectual Property
Authors: Shrivastava Saurabh RamBihariLal , Shrivastava Prateek Saurabh
Published: June 2023

Acknowledging the dearth in the research arena and deficiencies in the technology sector to promote public health standards, the World Health Assembly and the other member states adopted a global strategy and plan of action on public health, innovation, and intellectual property in 2008. Since the adoption of the policy, some progress has been observed in minimizing the caseload resulting because of diseases that predominantly affect disadvantaged or vulnerable sections of the community. Realizing the prevailing gap on different fronts of the global strategy, the World Health Organization has authorized an external agency to perform a holistic and exhaustive evaluation of the implementation of different aspects. To conclude, the health sector has many shortcomings in the area of improving the health indicators of the masses, and it becomes even more important in cases of developing nations. Owing to the presence of numerous public health challenges in the region, it is extremely important to prioritize the issues and deal with them in a systematic manner to improve the quality of life of the general population.
Need for a diagnostic algorithm for acute encephalitis syndrome: An approach to changing paradigm
Authors: Amrutha D , Chandran Priya , Rahim Asma Ayesha , Bindu V , Aswathy Raj S. V
Published: June 2023

Introduction:

Acute encephalitis syndrome (AES) refers to a symptom complex that may be caused due to a wide range of etiologies. Outbreaks of AES have occurred in the recent past contributing to significant morbidity and mortality. Identification of the etiology of AES will help in early treatment and containment of outbreaks.

Objective:

To assess the need for a diagnostic algorithm for AES and to develop a prototype algorithm for AES to be used in the region.

Materials and Methods:

Secondary data regarding AES from the surveillance unit of our institution was used. In addition, focus group discussion with stakeholders involved in the diagnosis, treatment, and surveillance of AES was done to identify the challenges in diagnosis and develop an algorithm for AES to be used in the region.

Results and Discussion:

Of the 767 AES cases reported during the study period, only 38% had a confirmatory diagnosis. Common viral etiologies included herpes simplex virus and adenovirus. Rare etiologies viz Nipah and West Nile were also documented. The varied etiologies pose challenges in diagnosis as multiple tests are required. A diagnostic algorithm was developed, taking into consideration the facilities available. Challenges in diagnosis are due to infrastructural shortcomings like lack of point-of-care tests and the nonavailability of viral panels for simultaneous testing for pathogens.

Conclusion:

Region-specific diagnostic algorithm may be developed taking into consideration of the common etiological agents in the region, which will help in the early identification of outbreaks and help in the institution of containment measures.
Aarey conservation: A multifaceted opportunity for climate mitigation in an urban setting
Authors: Pendharkar Anand , Bhagwat Pranav , Sardesai Aradhya
Published: June 2023

Citizens of the world are bracing themselves to combat and mitigate cataclysmic climate crisis. Recurrent climate accidents are leaving behind millions of climate refugees, who flock to urban centers in search of safety and security. Overcrowded metropolitan cities are highly vulnerable due to their high human densities and absolute numbers of residents and migrants. A well-connected network of urban green zones (UGZs) provides multiple values that enable sustainable climate mitigation and adaptation. The metropolis of Mumbai, with over 24 million humans (Mumbaikars), is fortunate to also have a network of large UGZs and protected areas (PAs), viz. Sanjay Gandhi National Park, Aarey Milk Colony (AMC), Tungareshwar, Thane, Tansa, and Karnala Wildlife Sanctuaries, along with mangrove forests and public parks. However, most PAs restrict entry and climate mitigation actions. AMC, spread over 12.5 km2 provides a unique “mosaic” landscape, inhabited by indigenous communities (Warli and Mahadev Koli), locals, and migrants. The hills, farms, artificial meadows, and built-up complexes, with a good road network and proximity to Mumbai’s suburbs, provide numerous opportunities to achieve the 17 sustainable development goals set out by members of the United Nations Conference of the Parties. The path to achieve climate and resource stability, in the economic capital of the nation, is a precarious one and needs planning and engagement of all stakeholders. Long-term protection of AMC will provide socioeconomic equity as well as ecological and health security to current and future generations of Mumbaikars.