bluuebunny/crossref_metadata_2025_split huggingface dataset:
Griffith's early ideas on turbomachinery aerodynamics
Authors: Howell A. R. 
Published: July 2022

This paper is intended to supplement a part of the paper by Mr. F. W. Armstrong on ‘The aero engine and its prospects—fifty years after Griffith’. It deals in more detail with Dr. A. A. Griffith's early ideas on the aerodynamic aspects of turbomachines.Even with reasonably optimistic use of materials and operating temperatures it was essential in 1926 that very high component efficiencies were obtained to make the gas turbine competitive with the piston engine on fuel consumption. Griffith believed that efficiencies of over 90% could be obtained for the compressor and turbine components, if the correct attention was given to the aerodynamic design of the blades. His 1926 report on ‘An aerodynamic theory of turbine design’ showed how such high efficiency designs should be carried out and gave appropriate formulae for the compressor and turbine efficiencies.
Advanced materials for aircraft brakes
Authors: Weaver John V. 
Published: July 2022

The continued trend of increased weight and landing speeds of modern aircraft has strengthened the demand for improved materials for the manufacture of aircraft brakes.The aircraft brake is similar to the car disc brake since both represent a medium for the conversion of kinetic energy to heat energy by means of friction. There are, however, unique problems which confront the aircraft brake designer since he is required to provide an acceptable mechanism involving components of minimum weight. The present paper discusses some general aspects of aircraft brakes and deals in more detail with some of the materials and material requirements for aircraft brakes; in particular it is hoped to show the manner in which advanced materials can provide some answers to the problems of the most recent development in design.
Recent experience in flight testing for pilot induced oscillations (PIO) on transport aircraft
Authors: Lee B. P. 
Published: July 2022

AbstractThough the subject of pilot induced oscillations (PIO) is not new, it has garnered significant attention in the past several years. Since the mid-1990s, Boeing Commercial Airplanes has been conducting specific flight tests of its products in order to evaluate PIO tendencies. Beginning with the 777-200, a generic suite of test manoeuvres has been used to evaluate PIO tendencies on each product. The testing has been conducted on a ‘window of opportunity’ basis with the intent to gather data and evaluate each model. To date, specific evaluations have been carried out on six different aircraft models spanning a wide range of aircraft sizes, inertial characteristics, and control system implementations. Each manoeuvre in the generic suite is discussed in detail. In addition, along the way, a large number of other manoeuvres have been used at various times to evaluate PIO tendencies. These are briefly described. No single test manoeuvre or technique has been identified which provides effective discrimination of PIO tendencies. Finally, the subject of the pilot in the loop is discussed with regard to achieving consistency in conducting PIO evaluations.
Elastic–plastic buckling behaviour of shafts in torsion
Authors: Robotham W. S. , Hyde T. H. , Williams E. J. , Taylor J. W. 
Published: July 2022

AbstractThe development of more powerful and efficient aero-engines requires ways of increasing the torque transmitted by shafts, whilst also restricting their dimensions and weight. Thin-walled designs can assist this objective, but their use is limited by their torsional collapse behaviour. Of particular interest are conditions leading to buckling instability. The paper investigates the factors influencing this behaviour in order to provide the basis for an improved analysis method applicable to typical gas turbine aero-engine components.The Riks finite element algorithm has been successfully applied to both plain shafts and shafts with holes. In the former case, it is shown that the perfect cylindrical geometry must be given an initial perturbation in order to give accurate predictions. The perturbation imposed is obtained by scaling the mode shape from an eigenvalue solution so that the maximum radial deformation is a percentage of the wall thickness. The predictions for both plain and holed shafts have been validated experimentally.
The United Kingdom’s contributions to the development of aeronautics. Part 1. From antiquity to the era of the Wrights
Authors: Ackroyd J. A. D. 
Published: July 2022

The Millennium now being upon us, it is perhaps appropriate to pause a while and take stock before leaping into an ever more problematic future. But why pause? Indeed, why bother with the past? Surely our newest, ever more sophisticated computer packages provide all the necessary paths to that next commercial edge, that future, unassailable military superiority? To this the German polymath, Gottfried Wilhelm von Leibniz, provides an apt, timely and, indeed, timeless corrective:“It is an extremely useful thing to have knowledge of the true origins of memorable discoveries, especially those that have been found not by accident but by dint of meditation. It is not so much that thereby history may attribute to each man his own discoveries and others should be encouraged to earn like commendation, as that the art of making discoveries should be extended by considering noteworthy examples of it.”
The role of aero engineering in the sustainable development of the aviation industry
Authors: Thomas C. , Raper D. 
Published: July 2022

SummaryThe aviation industry plays a critical role in modern society, supporting global, regional and local economies and facilitating long distance travel for business and leisure. However the environmental impact of the industry is significant and this threatens the sustainability of future growth and the consequential benefits which could arise from it. Technological, operational and infrastructure improvements designed to reduce emissions and noise from aircraft are continually being eroded by the rapid growth of the industry, with the result that the environmental impact of air travel is increasing. Consequently, the sustainable development of the aviation industry will require that in future, technological innovation and fleet replacement continues at a rapid pace and that the highest priority is given to achieving a ‘step change’ in aircraft technology.
Stress analysis of door and window of a passenger aircraft
Authors: Ukadgaonker V. G. , Awasare P. J. , Gade S. V. 
Published: July 2022

AbstractThe stresses around the passenger door, emergency door and window of an aircraft, Airbus A300B, are considered in this paper. By idealising these opening as rectangular holes with rounded corners in an infinite plate subjected to inplane loads and considering the presence of adjacent holes the stresses are determined using the complex variable method along with Schwarz Alternating Method. The results of the analytical solution are found to be in good agreement with those of the finite element analysis using ANSYS 5.0 software within 5%.
ACFD applications to store separation — status report
Authors: Cenko A. , Lutton M. 
Published: July 2022

During the past decade, the Navy has considerably improved its capabilities in aircraft-weapon integration. In 1989 it took more than 400 hours of wind-tunnel testing, which cost $1,5000,000, and 20 flights to clear the JSOW from the F-18 to Mach 0·95. This year the Mk-83 JDAM was cleared after only 60 hours of wind-tunnel testing and five flights to the full F-18 aircraft envelope of Mach 1·3. This reduction occurred because the Navy not only learned to test smarter, but also developed an integrated approach to modelling and simulation (M&S), wind-tunnel and flight testing which allowed lessons learned on previous programmes to be applied to new ones. However, the present approach still requires a fairly large commitment of time and financial resources to accomplish the mission.The present approach has optimised the use of available resources; any further gains will have to come not by improving existing techniques, but by bringing new resources into the process.
Calculation of compressible indicial response
Authors: Shaw S. T. , Qin N. 
Published: July 2022

AbstractThe present paper addresses the problem of extracting indicial response functions from solutions of the Navier-Stokes equations. Two approaches are considered.In the first, the indicial response is computed directly by modifying the local grid velocity to reflect the step change in plunge velocity. The computed data are then fitted using an assumed form for the response function and numerical optimisation techniques.In the second (indirect) approach, the general form of the lift transfer operator is determined analytically from the functional form of the assumed response. Using the lift transfer operator explicit solutions of the in-phase and quadrature components of the normal force time history can be obtained. The unknown coefficients in the response function are then extracted from computed data for harmonic motion by fitting the time history using the explicit solution.Computed response functions are presented for a range of Mach numbers and are compared with analytical results and indicial models currently used within the rotorcraft community. For the cases considered there is no significant difference between the response functions determined using the direct or indirect approach. Comparison of the computed results with existing models suggests that generalisation of the response to step changes in incidence using a two-pole approximation of the circulatory response together with the Prandtl-Glauert factor is not possible. However, comparison with higher order semi-empirical models is much improved, providing some justification for the use of such models. In addition to these observations, the extracted response functions suggest improvements to piston theory to account for thickness effects. The proposed modification of piston theory is based upon properties of the static pressure distribution and so can be used in conjunction with both CFD and experimental data.
Aircraft Development and World Aviation Growth
Authors: Steiner J. E. 
Published: July 2022

It is an honour and a privilege to commemorate the memory of Sir Charles Kingsford-Smith. It is 41 years since he linked by air the United States and Australian nations. Those 41 years have been years of phenomenal progress and growth from the infant industry of that time to the monumental industry of today.Forty-one years ago the flying time from San Francisco to Australia was 83½ hours and the elapsed time was 10 days.
Pilot modelling and inverse simulation for initial handling qualities assessment
Authors: Cameron N. , Thomson D. G. , Murray-Smith D. J. 
Published: July 2022

AbstractThis paper describes the development of an approach to handling qualities investigation that can be applied at an early stage in t he design of the vehicle. It makes use of inverse simulation techniques, together with a pilot model to provide an integrated description of the man-machine control system. In order to incorporate pilot effects into data generated by inverse simulation, the output from an inverse simulation run is applied as input to a closed-loop system model that includes the vehicle dynamics and a simple parametric model of the pilot. Parameters of the pilot model are determined by optimisation and the pilot effect is added to the system output. Validation of the approach is achieved through a case study involving a predefined mission task involving a lateral manoeuvre. Equalisation characteristics estimated for each pilot are compared with those found by inverse simulation for the same manoeuvre. This approach may be applied using a simple real-time simulation on a desk-top computer and could be of value in identifying any potential deficiencies in a helicopter flight control system at an early stage in its development
Singular elliptic equations with nonlinearities of subcritical and critical growth
Authors: Stapenhorst Matheus F. 
Published: July 2022

AbstractIn this paper, we consider the problem $-\Delta u =-u^{-\beta }\chi _{\{u>0\}} + f(u)$ in $\Omega$ with $u=0$ on $\partial \Omega$, where $0<\beta <1$ and $\Omega$ is a smooth bounded domain in $\mathbb {R}^{N}$, $N\geq 2$. We are able to solve this problem provided $f$ has subcritical growth and satisfy certain hypothesis. We also consider this problem with $f(s)=\lambda s+s^{\frac {N+2}{N-2}}$ and $N\geq 3$. In this case, we are able to obtain a solution for large values of $\lambda$. We replace the singular function $u^{-\beta }$ by a function $g_\epsilon (u)$ which pointwisely converges to $u^{-\beta }$ as $\epsilon \rightarrow 0$. The corresponding energy functional to the perturbed equation $-\Delta u + g_\epsilon (u) = f(u)$ has a critical point $u_\epsilon$ in $H_0^{1}(\Omega )$, which converges to a non-trivial non-negative solution of the original problem as $\epsilon \rightarrow 0$.
On the rationality of semi-secular simultaneity: a non-doxastic interpretation of the seemingly inconsistent worldviews of some Swedish ‘nones’
Authors: Palmqvist Carl-Johan , Jonbäck Francis 
Published: July 2022

AbstractProponents of religious non-doxasticism standardly aim to show how a commitment to traditional religion can be rational in the absence of religious belief. We demonstrate how the non-doxastic framework can be given a much wider application. In a study on Swedish semi-secularity, sociologist Ann af Burén has discovered a pattern where subjects simultaneously entertain naturalistic and supernatural explanations of extraordinary events. We reject Burén's interpretation of these people as irrational and compartmentalized and offer a contrasting non-doxastic reading in which the subjects involved are fully rational in their belief-less engagement with significant supernatural possibilities.
Cost-utility of a web-based intervention to promote maternal mental health among postpartum women presenting low risk for postpartum depression
Authors: Monteiro Fabiana , Antunes Patrícia , Pereira Marco , Canavarro Maria C. , Fonseca Ana 
Published: July 2022

Abstract

Objectives
Web-based interventions for the promotion of maternal mental health could represent a cost-effective strategy to reduce the burden associated with perinatal mental illness. This study aimed to evaluate the cost-utility of Be a Mom, a self-guided web-based cognitive behavioral therapy intervention, compared with a waiting-list control.

Methods
The economic evaluation alongside a randomized controlled trial was conducted from a societal perspective over a 14-month time frame. Postpartum women presenting low risk for postpartum depression were randomized to the intervention (n = 191) or control (n = 176) group and assessed at baseline, postintervention and 4 and 12 months after postintervention. Data regarding healthcare use, productive losses and quality-adjusted life years (QALYs) were collected and used to calculate incremental cost-effectiveness ratios (ICERs). Uncertainty was accounted for with nonparametric bootstrapping and sensitivity analyses.

Results
At 14 months, and after accounting for a 3.5 percent discount rate, the intervention resulted in a yearly cost-saving of EUR 165.47 (−361.77, 28.51) and a QALY gain of 0.0064 (−0.0116, 0.0244). Bootstrapping results revealed a dominant ICER for the intervention group. Although results were statistically nonsignificant, cost-effectiveness acceptability curves showed that at a EUR 0 willingness to pay threshold, there is a 96 percent probability that the intervention is cost-effective when compared with the control group. The sensitivity analyses generally supported the acceptable likelihood of the intervention being more cost-effective than the control group.

Conclusions
From a societal perspective, the implementation of Be a Mom among low-risk postpartum women could be a cost-effective way to improve perinatal mental health.
“Wow, I Didn’t Know These Options Existed”: Understanding Tenure-Track Start-Up Packages
Authors: Farris Emily M. , Key Ellen M. , Sumner Jane L. 
Published: July 2022

ABSTRACTStart-up packages vary enormously, particularly across institutions, and not all faculty know what items they may negotiate for to support their probationary period. To demystify this part of the hidden curriculum, we discuss the components of start-up packages and other benefits that may be provided to new faculty at the time of hire. We focus on five broad topics: compensation and personal support, general support, research support, teaching support, and service and professional development. Drawing on the results of a survey of tenure-track assistant political science professors in the United States, we also provide an overview of the prevalence of a variety of items at different types of institutions and discuss other considerations in the negotiation process to close the knowledge gap for candidates during negotiations.
High gain and circularly polarized beam-switching 8 × 8 Vivaldi antenna array for X-band application
Authors: Aribi Tohid , Sedghi Tohid , Khajeh Mohammad Lou Reza 
Published: July 2022

AbstractAn 8 × 8 butler Vivaldi beam-steering antenna array is introduced for X-band application. Circularly polarized array is made of eight Vivaldi elements with 1×8 platform and an 8×8 beam feeding network. Vivaldi radiating element is used in array form to enhance impedance bandwidth and overall efficiency such as gain. Using microwave passive components, for instance, 3 dB branch line couplers and crossover help to have orthogonal modes for feeding each of the elements, hence circular polarization property is achieved. Extracted results show that the array has an impedance bandwidth over 7–12.7 GHz (~58%) for VSWR≤2 and an axial-ratio bandwidth of 3.15 GHz that is between 8.15 and 11.3 GHz (~33%). The peak gain of antenna array is 18 dBi at 10 GHz. The proposed beam-steering antenna with compact size and good operation is capable to cover an angle range from −42 to 55 degree in whole operation frequency.
Comparative characterization of antibody responses induced by Ad5-vectored spike proteins of emerging SARS-CoV-2 VOCs
Authors: Wang Busen , Xu Jinghan , Wu Shipo , Zhang Zhe , Zhao Zhenghao , Zhang Jun , Fu Ling , Zai Xiaodong , Wang Yudong , Zhang Guanying , Chen ZhengShan , Chen Yi , Sun Hancong , Song Xiaohong , Zhang Jinlong , Zhu Lianhui , Hou Lihua , Chen Wei 
Published: July 2022

AbstractHighly divergent SARS-CoV-2 variants have continuously emerged and spread around the world, and updated vaccines and innovative vaccination strategies are urgently needed to address the global SARS-COV2 pandemic. Here, we established a series of Ad5-vectored SARS-CoV-2 variant vaccines encoding multiple spike proteins derived from the Alpha, Beta, Gamma, Epsilon, Kappa, Delta and Omicron lineages and analyzed the antibody immune responses induced by single-dose and prime-boost vaccination strategies against emerging SARS-CoV-2 variants of concern (VOCs). Single-dose vaccination with SARS-CoV-2 variant vaccines tended to elicit the optimal self-matched neutralizing effects, and Ad5-B.1.351 produced more broad-spectrum cross-neutralizing antibodies against diverse variants. In contrast, prime-boost vaccination further strengthened and broadened the neutralizing antibody responses against highly divergent SARS-CoV-2 variants. The heterologous administration of Ad5-B.1.617.2 and Ad5-B.1.429 to Ad5-WT-primed mice resulted in superior antibody responses against most VOCs. In particular, the Omicron spike could only stimulate self-matched neutralizing antibodies with infrequent cross-reactivities to other variants used in single-dose vaccination strategies; moreover, with prime-boost regimens, this vaccine elicited an optimal specific neutralizing antibody response to Omicron, and prompted cross-antibody responses against other VOCs that were very similar to those obtained with Ad5-WT booster. Overall, this study delineated the unique characteristics of antibody responses to the SARS-CoV-2 VOC spikes with the single-dose or prime-boost vaccination strategies and provided insight into the vaccine development of next SARS-CoV-2 VOCs.
Whispering-gallery-mode full-color laser textiles and their anticounterfeiting applications
Authors: Ruan Jun , Guo Dan , Niu Ben , Ge Kun , Zhai Tianrui 
Published: July 2022

AbstractLight-emitting fabric can facilitate the innovation of wearable display applications. Electronic and luminescent textiles capable of communicating, sensing, and supplying energy have been achieved. However, a facile strategy for fabricating large-area flexible lasing textiles has not yet been reported. In this work, we propose a gravity-assisted rotatory drawing method for fabricating flexible lasing microfibers, which can be woven into multicolor lasing textiles. By regulating the doped dyes and solution viscosity, we achieve the mass manufacturing of lasing microfibers with different emission colors and modes and further weave them into full-color textiles with a wide color gamut, approximately 79.1% larger than that of standard RGB space. For application, we print nanoparticle patterns on the lasing textile and encode it with programmable lasing signal distribution, which can supply an anticounterfeiting label for efficient authentication. This work unifies the fabrication and application of lasing textiles, and we expect that this will provide a new platform for flexible lasing devices.
A heterozygous GRID2 mutation in autosomal dominant cerebellar ataxia
Authors: Koh Kishin , Shimazaki Haruo , Ogawa Matsuo , Takiyama Yoshihisa 
Published: July 2022

AbstractA heterozygous mutation in GRID2 that causes SCAR18 was first reported in an Algerian family with autosomal dominant cerebellar ataxia (ADCA). We identified the second ADCA family with a heterozygous GRID2 mutation. The Algerian family had cognitive impairment and hearing loss associated with cerebellar ataxia. However, the Japanese family presented here showed pure cerebellar ataxia. Therefore, we should also screen for the GRID2 mutation in ADCA families with pure cerebellar ataxia.
Bayesian tomography of high-dimensional on-chip biphoton frequency combs with randomized measurements
Authors: Lu Hsuan-Hao , Myilswamy Karthik V. , Bennink Ryan S. , Seshadri Suparna , Alshaykh Mohammed S. , Liu Junqiu , Kippenberg Tobias J. , Leaird Daniel E. , Weiner Andrew M. , Lukens Joseph M. 
Published: July 2022

AbstractOwing in large part to the advent of integrated biphoton frequency combs, recent years have witnessed increased attention to quantum information processing in the frequency domain for its inherent high dimensionality and entanglement compatible with fiber-optic networks. Quantum state tomography of such states, however, has required complex and precise engineering of active frequency mixing operations, which are difficult to scale. To address these limitations, we propose a solution that employs a pulse shaper and electro-optic phase modulator to perform random operations instead of mixing in a prescribed manner. We successfully verify the entanglement and reconstruct the full density matrix of biphoton frequency combs generated from an on-chip Si3N4 microring resonator in up to an 8 × 8-dimensional two-qudit Hilbert space, the highest dimension to date for frequency bins. More generally, our employed Bayesian statistical model can be tailored to a variety of quantum systems with restricted measurement capabilities, forming an opportunistic tomographic framework that utilizes all available data in an optimal way.