bluuebunny/crossref_metadata_2025 huggingface dataset:
Server Consolidation Algorithms for Cloud Computing
Authors: Mikram Hind , El Kafhali Said , Saadi Youssef
Published: October 2022

In recent years, companies and researchers have hosted and rented computer resources over ‎the ‎‎internet due to cloud computing, which led to an increase in the energy consumed by ‎data centers. This ‎‎consumption is considered one of the world's highest, ‎which pushed many ‎researchers to propose ‎several techniques such as server ‎consolidation (SC) to solve the‎‏ ‏trade‏-‏off‏ ‏‏‎between energy saving and ‎quality of service ‎‎(QoS). SC requires maintaining service level ‎agreements (SLA) violations and ‎minimizing ‎the number of active physical machines (PMs). ‎Furthermore, to achieve this balance and ‎‎avoid ‎increasing hardware costs, the SC challenge targets ‎placing new virtual machines ‎‎(VMs) in ‎suitable PMs. This work explored the existing SC algorithms ‎that include ‎CloudSim as a simulator ‎environment and PlanetLab as a dataset. The authors compared ‎the well-known optimization methods ‎and extracted the weaknesses of the main three deployed ‎‎approaches involved in the consolidation ‎process: bin-packing model, metaheuristics, ‎and machine ‎learning-based solutions.‎
Malaysian Language Teachers' ICT Competencies
Authors: Seng Thah Soon
Published: October 2022

This study was conducted to determine the level of ICT competencies among Malaysian language teachers at both primary and secondary schools. The focus of this study was on four specific domains: 1) technological concepts and operational skills; 2) pedagogical skills; 3) professional skills; and 4) social, ethics, and security skills. These skills were developed based on the guidelines provided by the International Society for Technology in Education (ISTE). The sample comprised 761 teachers. The findings of the study showed significant differences (p<.05) between primary and secondary school teachers in their ICT competencies with significant differences in the domains related to technological concepts and operational skills and social, ethical, and security skills. However, there were no significant differences (p>.05) in terms of pedagogical and professional skills between primary and secondary school teachers.
E-Marketing Mix Variables to Create Online Brand Equity in the Indian Context
Authors: Rana Arunima , Bhat Anil Kumar , Rani Leela
Published: October 2022

This paper is an attempt to investigate and empirically validate e-marketing mix framework creating online brand equity suitable for adaptation in the Indian context. Exploratory and confirmatory factor analysis are used to identify and validate the e-marketing mix variables to create online brand equity. Primary product and service offerings, website content, customer care and relationship, website interactivity, website's security and reliability, and website speed are the six e-marketing mix elements identified. Also, a conceptual categorization is used to propose and develop a typology that classifies these six variables into primary and secondary activities. The identified e-marketing mix variables will be an insightful aid to planning various marketing activities and controlling other outcome variables like online satisfaction, e-loyalty, online brand equity, etc. This is one of the first attempts to propose and verify e-marketing mix variables for a developing economy like India and classify them under a generic parsimonious dimensional framework for e-commerce.
Logistic Management in the Supply Chain Market Using Bio-Inspired Models With IoT Assistance
Authors: Liu Hongyun
Published: October 2022

The internet of things (IoT) is a modern generation of internet-associated embedded information and communication technology in an online environment to incorporate logistics and supply chain processes seamlessly. Automation in inventory monitoring, product control, storage, customer relationships, fleet tracking, etc. is a common issue faced by firms suggesting alternatives to the various problems. In this study, IoT-assisted bio-inspired framework (IoT-BIF) has been proposed for effective logistics management and supply chain processes. IoT with bio-inspired model sensors can track products via different supply chain units to address under-stocking and over-stocking issues. This modern technology allows the connection of numerous objects by gathering real-time data and sharing it; the resulting data can help automated decision-making in industries. The experimental results show that the proposed IoT-BIF method reduces the cost, memory utilization, average running time compared to other popular methods.
A Hybrid Siamese-LSTM (Long Short-Term Memory) for Classification of Alzheimer's Disease
Authors: M. Aparna , Rao Srinivasa B.
Published: October 2022

Alzheimer's disease (AD) is the most general type of dementia, which concludes in memory-related problems. For researchers, the AD diagnosis at an early stage is a complex task. Alzheimer's disease is a chronic neurodegenerative disease. The risk of further degeneration will be decreased by early diagnosis of the disease. Other than predicting the possible growth of the disease, the recent studies concentrate on disease classification state. In this research, a Siamese-LSTM (long short-term memory) model is proposed for the enhanced multiple stages of Alzheimer's disease classification. The BoG bag of visual word method is utilized in order to improve the potency of texture based features (i.e., GLCM). The dataset used in this research work is ADNI. For multi-class classification, the samples are classified into three classes such as normal, AD, and MCI. The performance of the Alzheimer's disease stage is calculated in terms of accuracy, precision, and recall. Moreover, in addition, the sensitivity and specificity are evaluated.
Mitigating Black Hole Attacks in Routing Protocols Using a Machine Learning-Based Trust Model
Authors: Shanmugam Sivagurunathan , V. Muthu Ganeshan , K. Prathapchandran , T. Janani
Published: October 2022

Many application domains gain considerable advantages with the internet of things (IoT) network. It improves our lifestyle towards smartness in smart devices. IoT devices are mostly resource-constrained such as memory, battery, etc. So it is highly vulnerable to security attacks. Traditional security mechanisms can't be applied to these devices due to their restricted resources. A trust-based security mechanism plays an important role to ensure security in the IoT environment because it consumes only fewer resources. Thus, it is essential to evaluate the trustworthiness among IoT devices. The proposed model improves trusted routing in the IoT environment by detecting and isolating malicious nodes. This model uses reinforcement learning (RL) where the agent learns the behavior of the node and isolates the malicious nodes to improve the network performance. The model focuses on IoT with the routing protocol for low power and lossy network (RPL) and counters the blackhole attack.
Perceived Impediments and Anticipated Solutions to HR (Human Resource) Towards Implementing Industry 4.0 in SMEs
Authors: Sharma Nagendra Kumar , Kumar Vimal , Lai Kuei-Kuei , Chen Wen-Kuo
Published: October 2022

The study aims to evaluate perceived impediments and anticipated solutions to HR while implementing Industry 4.0 initiatives in SMEs. A group of 10 decision-makers from these SMEs was tasked with assigning ratings to a variety of parameters. To create the model for 10 perceived impediments and five anticipated solutions and subsequently rank them, the TOPSIS technique is employed. According to the data analysis, job reductions, unemployment, and job uncertainty have emerged as the top three significant hurdles, while challenges to trainers, replacement of humans, and training costs have been recognized as the bottom three. Smart HR 4.0 and AI & Data Analytics are the top and lowest-ranked solutions respectively. HR in I4.0 in SMEs parameters have been graded based on their contributing attributes. However, it is also true that there are several impediments associated with the implementation of Industry 4.0. These impediments become more challenging in the context of SMEs.
Neurologic disorders and COVID-19
Authors: Gunatilake Saman B.
Published: October 2022

SARS-CoV-2 with its wide range of disease severity ranging from asymptomatic carriers to severe respiratory compromise and death, is still with us. High rates of infection and subsequent long-term sequelae have raised significant concerns, particularly for those with underlying medical illnesses, who may be more severely affected. This includes not only those treated with immunosuppressive therapies for their neurologic disorders (e.g., myasthenia gravis or multiple sclerosis [MS]) but also those with significant functional disability from their disease and elderly patients with a history of cerebrovascular disease, Parkinson disease and dementia. As neurologic disorders are common, the effect of SARS-CoV-2 on patients with neurologic illnesses poses a substantial public health risk. Prioritizing this population is critical when considering the risks and benefits of vaccination.
Cerebral microbleeds and stroke: more questions than answers
Authors: Ranawaka Udaya K.
Published: October 2022

With the widespread availability of MRI scanning, cerebral microbleeds (CMBs) are being increasingly recognised in patients with stroke and in healthy individuals. As CMBs are commonly viewed as markers of increased risk of intracerebral haemorrhage (ICH), there are concerns regarding the use of antithrombotic agents (antiplatelets, and especially anticoagulants) in the presence of CMBs, even in patients at high risk of ischaemic events. The use of antiplatelet or anticoagulant therapy in the presence of CMBs, balancing the risk of recurrent ischaemic stroke against the risk of possible intracranial bleeding, is one of the most contentious contemporary issues in stroke medicine.
Intracerebral haemorrhage due to vaccine-induced immune thrombocytopenia and thrombosis
Authors: Gamaarachchi Dimithri , Subasinghe Shyama , Wijeratne Maheshi , Gunasekara Harsha
Published: October 2022

Introduction: Vaccine-induced Immune thrombocytopenia and thrombosis (VITT) is a rare complication following vaccination with the ChAdOx1 nCov-19 [recombinant adenoviral vector encoding the spike protein antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)]. VITT has been reported in several countries and there are no published reports of this entity from Sri Lanka. We report a case of VITT causing fatal intracerebral haemorrhage (ICH) following ChAdOx1 nCov-19 vaccination.
Answers to Neurology Quiz Vol.8(1)
Authors: Alibhoy A.T.
Published: October 2022

No abstract available.
Investigation of the Flow Fields of Coaxial Stacked and Counter-Rotating Rotors using PIV Measurements and URANS Simulations
Authors:   Technical University of Munich, Platzer Stefan ,   Georgia Institute of Technology, Rauleder Juergen ,   University of Texas at Austin, Mortimer Patrick , Hajek Manfred , Sirohi Jayant
Published: October 2022

The flow fields of a 2m-diameter two-bladed single rotor, a 22-bladed coaxial co-rotating (stacked) rotor, and a 22-bladed coaxial counter-rotating (CCR) rotor were measured using Particle Image Velocimetry, and computed using a finite-volume URANS CFD model. Phase-resolved measurements were performed on the stacked rotor at nine azimuthal locations, and time-resolved measurements were performed on the CCR rotor at 64/rev with at least 500 flow realizations per azimuth in each case. The goal of this study was to compare the flow features of these rotor configurations, and explore the interactions between the rotors. Overall, there was good correlation between the measurements and simulations. In particular, the effect of index angle on the upper and lower rotor thrust sharing for the stacked rotor was captured well by the simulation. The slipstream boundary and vortex trajectories for the CCR rotor were found to vary with azimuthal location, indicating the effect of blade passage on the wake geometry. The slipstream boundary for the stacked rotor was found to vary with the index angle. Simulations indicated a stronger dependence of the tip vortex trajectory on the index angle and thrust for the stacked rotor compared to the CCR rotor. The radial thrust distribution along the upper blades was dependent on the index angle for the stacked rotor, and showed small variation due to blade passage on the CCR rotor. A larger azimuthal dependence was seen for the radial thrust distribution on the lower rotor blades, primarily due to the proximity of upper rotor tip vortices. The lower rotor radial thrust distribution was biased towards the blade tip, outside the upper rotor slipstream.
Development of Secondary Vortex Structures in Rotor Wakes
Authors:   German Aerospace Center (DLR), Schwarz Clemens ,   Science and Technology Corporation, Bodling Andrew ,   US Army TDD, Potsdam Mark , Brinkema Robert , Gardner Anthony , Wolf Christian
Published: October 2022

The blade tip vortex system is a crucial feature in the wake of helicopter rotors, and its correct prediction represents a major challenge in the numerical simulation of rotor flows. A common phenomenon in modern high-fidelity CFD simulations is the breakdown of the primary vortex system in hover due to secondary vortex braids. Since they are strongly influenced by the numerical settings, the degree to which these secondary vortex structures actually physically occur is still discussed and needs experimental validation. In the current work, the development of secondary vortex structures in the wake of a two-bladed rotor was investigated by combining stereoscopic particle image velocimetry measurements in different measurement planes and high-fidelity simulations. Secondary vortex structures were detected and quantified at different axial locations in the wake by applying an identical scheme to the measured and simulated velocity data. In agreement, it was found that the number of secondary vortices is maximum at a distance of 0:8R below the rotor. The more intense secondary vortex structures were quantitatively well captured in the simulation, whereas in the experiment a larger number of weaker vortices was detected. No distinct preferential direction of rotation was found for the secondary vortices, but they tended to develop in vortex pairs with alternating sense of rotation. A clustered occurrence of secondary vortices was observed close to the primary tip vortices, where the rolled-up blade shear layer breaks down into coherent vortex structures.
A Computational Investigation of Side-by-Side Rotors in Ground Effect
Authors:   Rensselaer Polytechnic Institute, Healy Richard , Gandhi Farhan , McCauley Joseph , Sahni Onkar
Published: October 2022

This study investigates the interactional aerodynamics of hovering side-by-side rotors in ground effect. The 5.5 ft diameter, 3-bladed fixed-pitched rotors are simulated using CFD at a targeted 5 lb/ft2 disk loading. Simulations are performed using the commercial Navier Stokes solver, AcuSolve, with a detached eddy simulation (DES) model. Side-by-side rotors are simulated at two heights above the ground (H/D = 0.5 and H/D = 1), and with two hub-hub separation distances (3R and 2.5R). The performance of side-by-side rotors in ground effect are compared to isolated rotors out of ground effect. Between the side-by-side rotors in ground effect, a highly turbulent mixing region is identified where the wakes of each rotor collide. The flow fountains upwards, as well as exits outwards (along a direction normal to a plane connecting the two rotor hubs). The fountaining between rotors reaches up to 1.5R above the ground, and as blades at H/D = 0.5 traverse the highly turbulent flow, strong vibratory loading is induced, and a larger thrust loss is observed outboard between the rotors. Side-by-side rotors at H/D = 0.5 with 2.5R hub-hub spacing produce peak-to-peak thrust oscillations up to 16% the steady thrust. Rotors positioned higher, at H/D = 1 are above the turbulent mixing flow, and produce significantly lower vibratory loads. The spacing between rotors at H/D = 0.5 and 3R hub-hub separation allows strong vortical structures to develop between the rotors which move from side-to-side over multiple revolutions. When the vorticity is positioned closer to one of the rotors, it produces a greater lift deficit over the outboard region and higher vibratory loading. For rotors closer together, at H/D = 0.5 and 2.5R separation, the vortical structures between rotors are constrained to a more concentrated area, and show less side-to-side drift.
Time-Resolved Stereo PIV Measurements of a Cyclorotor in Hover
Authors:   CycloTech GmbH, Rooij Anouk
Published: October 2022

A cyclorotor is a thrust generating device that can produce thrust in any direction. CycloTech develops cyclorotors which can be used on drones or air taxis. To improve the understanding of a cyclorotor in hover, time-resolved stereo PIV measurements have been performed at an in-house test bench. Part of the flow field on the cyclorotor’s mid-plane has been visualised. In this work the instantaneous velocity vector fields and the spanwise velocity contours were studied for two different RPMs and two maximum pitch amplitudes. In addition, the centers and sizes of the vortices were detected and analysed for a single cycle of the cyclorotor. From the flow fields a very large influence of the pitch amplitude on the results was observed; at large pitch amplitude vortices developed much earlier and more vortices existed. The flow direction inside the cyclorotor also changed. The RPM mainly influences the velocity magnitude outside and inside of the cyclorotor.
Physics of BVI-Induced Dynamic Stall on Equivalent One-Bladed and Four-Bladed Rotors
Authors:   Geogia Institute of Technology, Grubb Amanda ,   US Army CCDC AvMC, Jain Rohit , Smith Marilyn
Published: October 2022

Recent developments in high-fidelity CFD analyses of dynamic stall on three-dimensional, rotating systems has disrupted the classic view of dynamic stall. Visual inspection of rich flowfields generated from these studies lead research and academia subject matter experts to observe that in addition to rigid and elastic blade motion, dynamic stall may be triggered by other mechanisms, such as blade-vortex interactions, tip shocks, fluid structure coupling, and other complex phenomena associated with rotorcraft aeromechanics. The UH-60A four-bladed, articulated rotor was studied at various test points from the 2010 National FullScale Aerodynamics Complex (NFAC) 40-by-80 foot wind tunnel test. Four-bladed, loosely-coupled CFDCSD predictions were compared to one-bladed predictions using prescribed motion to isolate the effects of blade motion from the effects of complex aerodynamics associated with blade-vortex interactions (BVI) associated with dynamic stall. From these, further insights into the role of BVI on rotor blade separation and the onset of dynamic stall.
CFD Turbulence Transition Models Validation for Rotors in Unsteady Axial and Forward-flight Conditions using CREATETM-AV Helios
Authors:   U.S. Army DEVCOM AvMC, Jain Rohit
Published: October 2022

Computational Fluid Dynamics (CFD) turbulence transition models are evaluated for rotors in unsteady axial and in forward flight conditions. The study is carried out using CREATETM -AV Helios with NASA codes, Overflow and FUN3D, as the near-body solvers. Three transition models are considered, Amplification Factor Transport (AFT), Langtry-Menter γ-Reθt (LM), and the LM with a crossflow transition model. The LM model is modified to allow for Galilean invariance. The validation study utilizes the data from two recent rotor tests where unsteady transition measurements were obtained on the upper (suction) surface of rotor blades using a novel application of the Differential Infrared Thermography (DIT) technique. The first configuration, the DLR RTG rotor, is a four-blade, 2.13-foot radius rotor in axial flow with pitching blades, operating at Reynolds numbers of 3.2 x 10-5 and 1.7 x 10-5> at three quarter radius, for the two test cases studied. The second configuration, the PSP rotor, is a model-scale, 5.58-foot radius, three-blade rotor in a high-advance-ratio, high-thrust forward flight condition, mounted on a ROBIN-Mod7 fuselage, and operating at a hover Reynolds number of 1.25 x 10-6 at three quarter radius. For this rotor, the validation study also included the DIT measurements on the lower (pressure) surface. Both configurations exhibit large unsteadiness in transition locations. CFD predictions are obtained using consistent grid resolution and numerical settings across the three models and the two rotor configurations. The computed results are analyzed in terms of the rotor transition maps, separation maps, and surface streamlines on the blade upper and lower surfaces. The agreement with the test data is good, in general, including the rapid, unsteady movement of the transition locations.
High-fidelity Simulation of the Volocopter-2X in Cruise Flight
Authors:   University of Stuttgart, Miesner Sebastian ,   Volocopter GmbH, Schäferlein Ulrich , Keßler Manuel , Krämer Ewald
Published: October 2022

A comparison between high-fidelity simulations of a half and a full model approach of the Volocopter-2X (VC2X) in cruise flight is conducted. To ensure an identical flight condition for both cases a flight mechanics trim is performed. Therefore, the computational fluid dynamic (CFD) code FLOWer is loosely coupled to the flight mechanics tool VFAST. The half model simulation setup can save up to half of the cells and therefore also computational time. However, it is only valid for a center of gravity lying on the geometric symmetry plane and a coordinated flight with a zero sideslip angle and no roll rate. The comparison between the half and full model shows no visible difference in the mean rotor revolution speed and only small difference in the pitch attitude. The Volocopter flow is characterized by a high density of small-scale vortex structures. These result, on the one hand, from the rotor wake and rotor-rotor interactions and, on the other hand, from rotor-airframe interactions. A vortex tube developes near the symmetry plane above the rotor disc of the VC2X, which is more prominent in for the half model. The differences on the level of the individual rotors is for most rotors small, only the front outer rotors show bigger deviations.
Solving the Ship-Rotorcraft Dynamic Interface Problem Using Lattice-Boltzmann Aerodynamics Two-Way Coupled with Blade Element Based Flight Dynamics
Authors:   Technical University of Munich, Bludau Jakob ,   Georgia Institute of Technology, Rauleder Jürgen , Hajek Manfred
Published: October 2022

A dynamic interface model based on a Lattice-Boltzmann fluid solver two-way coupled with flight dynamics is introduced. The model is neither limited to helicopters, nor by the number of rotors or their size. Although applied to a landing approach of a MBB Bo105 helicopter on a SFS2 ship in the current work, the introduced dynamic interface model is applicable to any situation with interactions between random solid objects, their wakes, and rotor wakes. The model uses a pre-computed airwake solution of the ship, which can be computed by any CFD solver or method. In this work, the SFS2 airwake was simulated for three different resolutions using the sameLattice-Boltzmann solver that was used for the dynamic interface model. The computed airwake was validated using PIV and higher-fidelity URANS data. Furthermore, an analysis of the frequency spectra of the velocity fluctuations in the ship airwake was related to frequency ranges that are of particular importance to the pilot. Using this ship airwake, the dynamic interface model was convergent with a resolution that was real-time computable for the simulated approach. The effects of the two-way aerodynamic interactions of the ship deck, walls and the ship airwake with the rotor wake on the rotor airloads was captured. In its current model development stage, data import from hard disk drive was identified as bottleneck for a piloted evaluation in flight simulators.
High-fidelity Numerical Investigation of Ducted Propeller Aerodynamics/Acoustics and Adjoint-based Design Optimisation
Authors:   University of Glasgow, Zhang Tao , Barakos George
Published: October 2022

This paper presents numerical analyses and optimisation of aerodynamics and aeroacoustics of ducted/un-ducted propellers, based on high-fidelity CFD methods with adjoint formulations. Ducted propeller experiments by NASA are chosen for validation and used as baseline designs. High-fidelity CFD simulations are performed using the in-house solver HMB3. The aeroacoustics is analysed using the high-fidelity CFD solutions and in-house codes based on FW-H equations. Analyses of the baseline design highlight the superior performance of the ducted propeller at the same RPM and pitch settings at lower advance ratios, in terms of both aerodynamics and near-/far-field acoustics. An adjointbased aerodynamic optimisation framework is proposed and applied to studies of the duct shape and the blade twist distribution for the ducted propeller. Performance of the ducted propeller is improved at higher advance ratios through the optimisation. The far-field acoustics of the optimised designs are also examined and are found to be good.
S-97 RAIDER® Wake-Empennage Interaction Fight Data and Correlation
Authors:   Sikorsky a Lockheed Martin Co., Lorber Peter , Bowles Patrick , Xin Hong , Zhao Jinggen
Published: October 2022

A combination of experimental and analytical methods has been applied to study the aerodynamic interaction of the S97 RAIDER® coaxial main rotor and its wake on an empennage. The primary goal was to characterize the periodic aerodynamic forcing from the rotor on the horizontal stabilizer over a wide range of flight conditions, and use those data to develop and validate computational fluid dynamics (CFD) methods that can then be applied to optimize future designs. The flight test aircraft was instrumented with 29 unsteady pressure sensors and flown for speed sweeps from 20 to 180 kts as well as a range of maneuvers. The data were processed to provide both unsteady and time-averaged aerodynamic forces and moments. Two CFD codes were then applied: HELIOS/RCAS using discrete main rotor and propulsor blades and STARCCM+ using a recently developed unsteady virtual blade model. Both codes captured the trends of the flight test data and agreed that the vibratory aerodynamic forcing on the empennage was not particularly large. The flight data were also compared with previously acquired powered wind tunnel model data, and showed good agreement. Finally, the Sikorsky GenHel flight dynamics model was applied to level flight and maneuver conditions, and the match was also acceptable. This study has that current state-of-the-art methodology, carefully applied, can capture complex aerodynamic interactions with sufficient accuracy for aircraft design, and that this implementation of X2 Technology(TM) does not result in unacceptable rotor on empennage interactions.
Optimisation of the AH-64A Blade Planform Based on High-Fidelity CFD Methods
Authors:   University of Glasgow, Fitzgibbon Thomas , Barakos George , Woodgate Mark
Published: October 2022

This paper presents the demonstration of a high-fidelity optimisation framework applied to the AH-64A rotor blade planform. The framework implementation includes an adjoint-harmonic balance method, which allows for efficient performance predictions and evaluation of the design sensitivities for unsteady rotor flows, whilst maintaining the f idelity of the Navier-Stokes equations. A re-design of the AH-64A blade is performed, leading to significant performance benefits, and showing the great potential of high-fidelity CFD coupled with optimisation methods. The key design features that lead to performance improvements in hover and forward flight are discussed, including the advantages and disadvantages of blades with an offloaded blade tip. The influence of the optimisation setup, including the impact of the blade surface parameterisation, treatment of trim and number of harmonic balance modes within the CFDsolution on the final optimised shape is analysed throughout the paper.
Fault Tolerant Individual Blade Control Actuation System
Authors:   Moog Inc., Kopp John
Published: October 2022

Various improvements to rotorcraft performance and operational environment with the application of Individual Blade Control (IBC) and High Harmonic Control (HHC) has been demonstrated via analytical methods and test. The need for IBC (swashplate-less actuation) as well as HHC (vibration and acoustic level reduction) is well understood and a driving force in the rotorcraft world. However, to date the level of fault tolerant, flight worthy and certifiable electric or hydraulic actuation systems capable of IBC-HHC technology has not been established to levels necessary for safe and mission critical systems. In this paper, an actuation system will be offered that utilizes a very simple mechanism connected to a direct-drive electric Brush-Less Direct Current (BLDC) motor that is capable of providing HHC frequency and amplitude control without the need of slip-ring, or rotating hub-mounted power generation system. The intent is to show in detail, the concept of control, fault tolerance and synchronization of a redundant system as well as the flight worthy (weight and envelope) attributes for a notional blade operational requirement.
Preliminary Design of Several New Kinds of Martian Aircrafts
Authors:   Zhejiang Lab, Lou Bin
Published: October 2022

The low-altitude Martian aircraft has become an important research direction in the field of Mars exploration recently. The traditional Martian aircrafts including floating balloons, fixed-wing aircrafts, rotorcrafts, flapping-wing aircrafts and tilt-rotor aircrafts, have been proposed and studied for decades. In this paper, several new kinds of Martian aircraft were proposed, maybe enlightening other researchers. Compressed-air jet aircraft makes use of the CO2 for airjet to control the flight. Coaxial tri-rotor autogyro is designed with three rotors, modified from "Ingenuity" with light weight and simple structure. Jumping-flying aircraft gets the utmost out of elastic potential energy to work in high energy efficiency.
Multi-Fidelity Surrogate Model for Interactional Aerodynamics of a Multicopter
Authors:   University of Southern California, Pinti Orazio ,   Rensselaer Polytechnic Institute, Gandhi Farhan , Oberai Assad , Healy Richard , Niemiec Robert
Published: October 2022

The growing interest in large electric multicopters (eVTOL aircraft) has prompted the search for methods that can accurately and efficiently predict their aerodynamic performance under different designs and operating conditions. The challenge is modeling the complex interactional effects of rotors operating in close proximity. This can be tackled with high-fidelity computational fluid dynamics (CFD) models, which capture the physics of rotor interaction from first principles. However, they are computationally demanding for performing studies over a range of parameters. On the other hand, lower-fidelity models are computationally inexpensive, but approximate the underlying physics and can be imprecise in predicting the fields of interest. In this study we present a multi-fidelity approach that inherits the accuracy of a high-fidelity model, while retaining most of the computational efficiency of a low-fidelity model. In this approach, the low-fidelity model is used to investigate the entire space of parameters and identify key parameter values to perform high-fidelity simulations. Thereafter, these high-fidelity simulations are used in a lifting procedure to determine multi-fidelity solutions at desired parameter values. We apply this strategy to determine the rotors' lift and drag distributions of a 2-rotor assembly in forward flight. The parameters considered are design variables, namely the longitudinal and vertical rotor-to-rotor separation, and operating conditions variables: forward speed and disk loading (DL). We conclude that over a large of parameters this approach yields results that retain the accuracy of the high-fidelity predictions at the computational cost of the low-fidelity model.
Simulation of Lift Plus Cruise Vehicle Models to Define a Full-Scale Crash Test Campaign
Authors:   NASA Langley Research Center, Littell Justin ,   Massachusetts Institute of Technology, Cooper Megan , Putnam Jacob
Published: October 2022

A series of dynamic simulations were completed on the National Aeronautics and Space Administration (NASA) Lift plus Cruise (LPC) concept electric Vertical Take-off and Landing (eVTOL) vehicle in preparation for an anticipated future full-scale crash-test campaign. The crash test campaign is envisioned as a data gathering exercise with an intent generating full-scale test data to inform eVTOL crashworthiness regulations, evaluate the use of energy absorbing concepts within vehicle design, and validate finite element modeling techniques used in crashworthiness predictions. This report discusses the two main objectives for the simulation efforts: the development of a structural cabin section, and a series of analyses utilized to determine the sensitivities of impact variables.

A structural cabin section was created based from previous research efforts involving the LPC vehicle utilized for occupant response. To refine for the structural modifications, the wing and tail sections of the vehicle were removed. The tail was replaced with a representative mass at the aft of the fuselage. The overhead wing was replaced with a beam structure sized to approximate the bending response of the wing under crash loading conditions. The beam structure was fixed to the fuselage similar to the original Wingbox design in order to properly capture effects of this overhead mass on survivable volume within the vehicle. The fidelity of the fuselage frame structure within the FEM was increased to quantify the effect of frame sizing on structural response. From this an eVTOL test article design was developed, which satisfied basic crashworthiness requirements, was reconfigurable to assess the effect of various design avenues on structural response and optimized to improve manufacturability.

The impact variable sensitivity results primarily show the orientation of the impact vector played a major role in types of injuries sustained, along with their severity. The vehicle was largely insensitive to small variations in pitch attitude but highly sensitive to both impact surface at certain angles and landing gear location.
Pharmacoeconomic Aspects of Pharmaceutical Ethics
Authors: Ruslanivna Huk Karina , Yaroslavivna Bespalova Olena
Published: October 2022

Nowadays, ethical standards of marketing, pricing, and safety strategies conducted by pharmaceutical manufacturers have declined significantly, which raises the question of health-care quality. The company's main objective has become to maximize profit and it is often done by unethical and deceptive marketing, implementation of direct-to-consumer ads, and educational meetings with a promotional character. One of the modern health-care areas, which aims to solve the ethical issues of the drug market, is pharmacoeconomics. The goal of pharmacoeconomics is not only the economic evaluation of various medical programs and pharmacological drugs but also the development of recommendations for the most efficient use of health resources and determining the right pricing and reimbursement strategy. Moreover, the use of the formulary system, which is the functioning tool of the evidence-based medicine (EBM), aims to provide an access to a wide range of certified and high-quality medicines that are recognized on the world market. Generics are considered a great substitutional option to the “ordinary” drugs due to their affordable price as the cost of prescription drugs in the world continues to be a source of concern. Another tool for providing affordable drug's prices is the reimbursement system, which offers a range of essential medicines at the reduced cost and can be product, disease, population, or consumption specific.
In silico Study of the Interaction of Fucoidan with Thrombolytic Agents
Authors: Suprunchuk Victoria Evgenievna
Published: October 2022

Background:

Tissue plasminogen activator (tPA) is one of the most widely used drugs in thrombolytic therapy. However, due to the inactivation of tPA in the bloodstream and increased risk of bleeding with increasing tPA dosages, the development of targeted delivery systems of tPA is required. For these purposes, it is possible to use fucoidan. The aim of the work was to study the possibility of forming of tPA-fucoidan conjugates and maintaining the activity of the enzyme using molecular docking.

Methods:

Docking simulations between tPA and fucoidan were performed by use of a docking software AutoDock tools version 1.5.7 and AutoDock 4.2.6. Using “blind docking” to identify the centers of molecular docking approaches of the enzyme (tPA) with the ligand (the active part of the fucoidan structure), as well as to establish the influence of the ligand on the active site of the enzyme.

Results:

Two “hot spots” of fucoidan binding to the enzyme were found: the region containing SER85-CYS97 residues and the region containing PHE217-TYR223 residues. This interaction can lead to the successful binding of the enzyme and polysaccharide to form a protein-polysaccharide complex. In this case, there may be a lack of suppression of the action of tPA. The interaction with the ligand was found to occur on the surface of the protein molecule.

Conclusions:

In this study, coupling simulations of interactions of tPA with fucoidan were conducted. The resulting conjugate can be used in the development of systems for the targeted delivery of a thrombolytic agent. This study predicts that the formation of tPA-fucoidan conjugate is a promising approach for optimizing treatment strategies for thrombosis.
Determination of In vitro Antimicrobial Activity of Copper on the Clinical Isolates of Acinetobacter spp
Authors: Begum Nila , Kabir Md Shahidul
Published: October 2022

Background:

Acinetobacter spp., emerging pathogens equipped with the competence to establish multitudinous severe infections in immunocompromised hosts, are grievous threats to human health. To tackle the enormous burden of disease caused by Acinetobacter spp., the headlong discovery and the advancement of novel therapies are of the essence at this juncture. The present study attempted to determine the antimicrobial effects of copper on the clinical isolates of Acinetobacter spp. (Iso-03 and Iso-04).

Methods:

The potential deployment of copper-based antibacterial strategies against Acinetobacter spp. was assessed by exposing the isolates to the increasing concentrations of CuSO4 (from 2.5 to 1.5 mM) in liquid culture (M9 minimal medium) for 6 h and also through the exposure of them on solid metal surfaces (stainless steel and copper coupons) for 75 min, wherein the copper sensitivity and resistance of the clinical isolates of Acinetobacter spp. were determined.

Results:

There was no interference with the growth of the isolates at the low concentrations, whereas the bacterial growth was affected by the high concentrations of CuSO4 at different levels. During the exposure on the solid metal coupons, no loss of viability of isolates was observed on stainless steel, however, the rapid death of isolates was discernible on copper surface, leading to a dramatic decrease in the number of colony-forming units (CFUs), eventually to the limit of detection (3 CFUs per coupon).

Conclusion:

This study substantiated that copper possesses antimicrobial properties which can be deployed in novel therapies for the prevention of the infections caused by Acinetobacter spp. and other emerging pathogens. Further studies on the sensitivity and resistance of Acinetobacter spp. to copper at the molecular genetics levels can open the door to better exploitation of this metal for the inhibition of the vigorous growth of drug-resistant Acinetobacter spp.
Antibacterial Activity of Some Medicinal Plants and Antibiotics Against Staphylococcus aureus and Mammaliicoccus sciuri Isolated from Acne
Authors: Goswami Meghali
Published: October 2022

Background:

Acne vulgaris is a distressing condition that affects most adolescents, causing scarring and reducing the quality of life. Among all the available therapeutic options, antibiotics are routinely used to treat moderate acne. In some cases, the clinical symptoms temporarily disappear after applying the prescribed medications, but its reoccurrence along with the misuse and overuse of the prescribed antibiotics may result in the emergence of multidrug-resistant strains.

Methods:

The present study aims to isolate and identify acne-causing bacteria from two individuals, who developed chronic or recurrent papules or pustules on their face and neck. The effect of different physiological factors on the growth of these bacteria was evaluated, followed by an evaluation of microbial adhesion, biofilm formation, hemolytic activity, extracellular enzyme production, and antibacterial activity of some medicinal plants and antibiotics.

Results:

The predominant bacteria in acne samples were Gram-positive cocci, which were identified as Staphylococcus aureus strain GCC20_MS and Mammaliicoccus
sciuri strain GCC20_MS. Both the isolates showed maximum viability at pH 7.0 and significant growth up to 10% NaCl concentration. A decreased viable count with the increase in Lysozyme concentration was also observed. The cell-surface hydrophobicity and auto-aggregation of both the tested isolates were very low; however, the strains were moderate biofilm producers. S.
aureus strain GCC_20MS exhibited β-hemolysis, whereas M.
sciuri strain GCC_20RS showed γ-hemolytic activity (no-hemolysis). Antibiotic-sensitivity test showed resistance of both the strains toward penicillin and sensitivity toward tetracycline, chloramphenicol, ciprofloxacin, levofloxacin, co-Trimoxazole, gentamicin, and ofloxacin. The aqueous extracts of Citrus
limon and Psidium
guajava significantly inhibit the growth of the isolated strains. Moderate growth inhibition was observed by the aqueous extracts of Mentha
sachalinensis and Punica
granatum.

Conclusion:

The study suggests the efficacy of topical anti-acne formulations using plant extracts that may target the early processes of acne development and combat the emergence of multidrug-resistant strains.
Anti-Oxidant and Anti-Cancer Activities of Biogenic Synthesized Copper Oxide Nanoparticles
Authors: Agila Aranganathan , Vimala Joseph Devaraj Rosaline , Bharathy Moses Stella , Dayana Jeyaleela Gnanasekar , Sheela Sagaya Adaikalaraj Margrat
Published: October 2022

Background:

The nature acts like a large “bio-laboratory” comprising plants, algae, fungi, yeast, etc., which are composed of biomolecules. These naturally occurring biomolecules have been identified to play an active role in the formation of nanoparticles.

Methods:

This research work mainly aims to investigate the anti-oxidant (diphenylpicrylhydrazyl assay) and anti-cancer (Michigan cancer foundation-7 cell line) capacities of biologically prepared copper oxide mediated from the hydroalcoholic extract of Justicia
glauca by simple precipitation and also to identify the phytochemicals in the extract by qualitatively.

Results:

On screening test, the extract shows the presence of carbohydrate, phenolics, alkaloids, and terpenoids saponins which are chiefly act as a reducing, stabilizing, and capping agents in nanomaterial preparations. The medicinal plant Justicia
glauca extract-mediated copper oxide materials were synthesized by lost cost, simple, effective, and eco-friendly precipitation method. The prepared copper nanomaterials were characterized by ultraviolet–visible, Fourier-transform infrared spectroscopy, energy dispersive X-ray analysis, X-ray diffraction, and scanning electron microscope. The obtained spectral results reveal that the prepared particles were found to be elliptical flat shapes of copper oxide with the average size of 19.72 nm with 51.11% of copper and 48.89% of oxygen elements. Especially, on anti-oxidant and anti-cancer activities the prepared Justicia
glauca extract-mediated copper oxide revealed excellent potent while comparing the other green synthesized copper oxide particles.

Conclusion:

Overall results evidenced that the aqueous extract of Justicia
glauca is a very good bioreductant for the synthesis of copper oxide nanoparticles.
Inhibitory Effect of Basella alba-Mediated Zinc Oxide Nanoparticles Against the Infection-Causing Bacteria
Authors: Agila Aranganathan , Dayana Jeyaleela Gnanasekar , Vimala Joseph Devaraj Rosaline , Bharathy Moses Stella , Sheela Sagaya Adaikalaraj Margrat
Published: October 2022

Background:

Naturally occurring biomolecules from the plant extract have been identified to play an active role in the formation of any nanoparticles.

Methods:

This work aimed to synthesize the nano-sized zinc oxide material (zinc oxide nanoparticles [ZnONPs]) using the 70% ethanolic leaf extract of Basella
alba by precipitation method and also studied the antibacterial activity of green-synthesized ZnONPs on infection-causing five bacteria. Synthesized nanomaterials were characterized by the aid of ultraviolet (UV)-visible, Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffraction, and Energy Dispersive X-ray Analysis (EDAX).

Results:

Qualitative analysis and UV results of extract reveal the occurrence of some medicinally important phytomolecules such as flavonoids, terpenoids, phenolic acids, and ascorbic acid. The spherical nature of ZnONPs was observed with an average crystalline size of 28.64 nm. EDAX analysis revealed the elemental compositions in the B. alba-mediated ZnONPs (BA-ZnONPs) which showed zinc in 70.04% and oxygen in 29.96%. BA-ZnONPs were tested against the bacteria (an infection causing) such as Pseudomonas
aeruginosa,
Escherichia
coli,
Enterobacter aerogenes,
Staphylococcus
aureus, and Proteus
vulgaris, which results that, against all the pathogens, ZnONPs showed noticeable inhibition effects compared with zinc acetate and B. alba extract. Especially against the E. coli, ZnONPs performed well with inhibitory effect and least on S. aureus.

Conclusion:

Antibacterial activities of BA-ZnONPs were studied which can act as the new antimicrobial-resistant agents.
Relationship between the Hematological Indices and COVID-19
Authors: Khalil Noon Ahmed , Almugadam Babiker Saad , Elkhider Abdalkhalig
Published: October 2022

Background:

Recently, the novel coronavirus disease-2019 (COVID-19) has a wide spread around the world. Clinically, it was responsible for respiratory illness ranged from mild to life-threatening infection. The study aimed to investigate the link of gender, age, ABO blood groups, and hematological indices with COVID-19 infection.

Methods:

One hindered COVID-19 cases, as confirmed using reverse transcription–polymerase chain reaction test, were checked for some sociodemographic features, blood group, and hematology parameters. A blood sample was collected from each person in an EDTA container and immediately tested for blood group using commercial antisera, in addition to complete blood count parameters using of a semiautomated hematology analyzer (Mindray BC-3200).

Results:

Of 100 COVID-19 patients, 52% were male and 48% were female. About 33% and 31% of the study participants were of age group 15–31 and 32–49 years, respectively. The majority (37%) of COVID-19 patients carried blood group O+ve, followed by A+ve (24%). A+ve blood group was significantly more reported in males (32.7%) than females (14.6%). Notably, 61% of participants showed low Hb level. Erythropenia was detected in 41% of the participants, while thrombocytopenia was observed only in 19% of the patients. Moreover, lymphocytopenia was detected in 82%, low packed cell volume in 66%, decreased mean corpuscular volume in 20%, and declined mean corpuscular hemoglobin concentration in 8% of the participants. In contrast, leukocytosis and neutrophilia were found in 69% and 73% of the participants, respectively.

Conclusion:

Taken together, the study findings highlighted the link of COVID-19 with age, gender, blood groups, and hematology parameters, which is important in diagnosis, prognosis, and management of illness.