bluuebunny/crossref_metadata_2025 huggingface dataset:
Creation and validation of the anti-racism efficacy measure: factor analysis and measurement invariance
Authors: Eschmann Rob , Thompson Julian G. , Harbaugh Allen G. , Copeland Phillipe
Published: March 2023

This study develops and validates the Anti-Racism Efficacy Scale (A-RES), a 4-item measure that examines (1) competence, or self-rated ability to challenge racism and (2) impact, the degree to which an individual believes they may create change in working against racism. Drawing on a sample of 1322 college students, including 26.6% White, 20.6% Black, 17.1% Latinx, 25.3% Asian or Pacific Islander, 1.2% American Indian, and 9.3% indicating either nothing, other or more than one racial grouping, we test for measurement invariance, conduct a factor analysis, and use ANOVA to compare factor scores by racial grouping. Past literature on antiracism has either not focused explicitly on efficacy, or has not developed means to measure it. The A-RES scale assesses the extent to which individuals feel they are capable of exerting some impact on racism in society.
Circular Economy Research in the COVID-19 Era: a Review and the Road Ahead
Authors: Rejeb Abderahman , Rejeb Karim , Appolloni Andrea , Treiblmaier Horst , Iranmanesh Mohammad
Published: March 2023

The onset of the Coronavirus Disease 2019 (COVID-19) pandemic has resulted in a major crisis that has severely impacted numerous economic, environmental, and social aspects of human life. During the pandemic, the potential of the circular economy (CE) has gained increasing attention as a prospective remedy for numerous sustainability problems. This systematic literature review charts CE research in the COVID-19 era. To this end, 160 journal articles were selected from the Scopus database. The performance indicators of the literature were determined and described through a bibliometric analysis. Moreover, the conceptual structure of CE research was identified via a keyword co-occurrence network. Based on bibliographic coupling, the focus of CE research in the COVID-19 era revolves mainly around five thematic areas, including: (1) waste management; (2) digitalization and sustainable supply chain management; (3) the impact of COVID-19 on food systems; (4) sustainable development goals, smart cities, and bioeconomy; and (5) closed-loop supply chains. Overall, this review contributes to enriching the literature by determining the main thematic areas and future research directions that can help to advance the transition to the CE and reduce the impact of COVID-19 and similar disasters in the future.
Could global norms enable definition of sustainable farming systems in a transformative international trade system?
Authors: Giger Markus , Musselli Irene
Published: March 2023

This paper aims to support differentiation between sustainable and unsustainable agricultural production, with a view to enabling a transformative agricultural trade system by incentivizing sustainable agricultural production. We argue that transformative governance of corresponding global trade flows will need to provide support to the weaker participants in production systems, above all small-scale farmers in the global South, in order to support their food security and a path out of poverty as well as global environmental goals. The present article seeks to provide an overview of internationally agreed norms that can serve as basis for differentiation between sustainable and unsustainable agricultural systems. Such common objectives and benchmarks could then be used in multilateral and binational trade agreements. We propose a list of objectives, criteria, and benchmarks that could contribute to formulation of new trade agreements that strengthen producers who are currently marginalized in international trade flows. While acknowledging that sustainability cannot be easily measured and defined for all site-specific conditions, we posit that it is nevertheless possible to identify such common objectives and benchmarks, based on internationally agreed norms.
Hidden Genetic Regulation of Human Complex Traits via Brain Isoforms
Authors: Pan Lu , Zheng Chenqing , Yang Zhijian , Pawitan Yudi , Vu Trung Nghia , Shen Xia
Published: March 2023

Alternative splicing exists in most multi-exonic genes, and exploring these complex alternative splicing events and their resultant isoform expressions is essential. However, it has become conventional that RNA sequencing results have often been summarized into gene-level expression counts mainly due to the multiple ambiguous mapping of reads at highly similar regions. Transcript-level quantification and interpretation are often overlooked, and biological interpretations are often deduced based on combined transcript information at the gene level. Here, for the most variable tissue of alternative splicing, the brain, we estimate isoform expressions in 1,191 samples collected by the Genotype-Tissue Expression (GTEx) Consortium using a powerful method that we previously developed. We perform genome-wide association scans on the isoform ratios per gene and identify isoform-ratio quantitative trait loci (irQTL), which could not be detected by studying gene-level expressions alone. By analyzing the genetic architecture of the irQTL, we show that isoform ratios regulate educational attainment via multiple tissues including the frontal cortex (BA9), cortex, cervical spinal cord, and hippocampus. These tissues are also associated with different neuro-related traits, including Alzheimer’s or dementia, mood swings, sleep duration, alcohol intake, intelligence, anxiety or depression, etc. Mendelian randomization (MR) analysis revealed 1,139 pairs of isoforms and neuro-related traits with plausible causal relationships, showing much stronger causal effects than on general diseases measured in the UK Biobank (UKB). Our results highlight essential transcript-level biomarkers in the human brain for neuro-related complex traits and diseases, which could be missed by merely investigating overall gene expressions.
The rapid competitive economy of machine learning development: a discussion on the social risks and benefits
Authors: Walter Yoshija
Published: March 2023

Research in artificial intelligence (AI) has started in the twentieth century but it was not until 2012 that modern models of artificial neural networks aided the machine learning process considerably so that in the past ten years, both computer vision as well as natural language processing have become increasingly better. AI developments have accelerated rapidly, leaving open questions about the potential benefits and risks of these dynamics and how the latter might be managed. This paper discusses three major risks, all lying in the domain of AI safety engineering: the problem of AI alignment, the problem of AI abuse, and the problem of information control. The discussion goes through a short history of AI development, briefly touching on the benefits and risks, and eventually making the case that the risks might potentially be mitigated through strong collaborations and awareness concerning trustworthy AI. Implications for the (digital) humanities are discussed.
AHHO: Arithmetic Harris Hawks Optimization algorithm for demand side management in smart grids
Authors: Manzoor Awais , Judge Malik Ali , Islam Saif ul , Neggaz Nabil , Abulaigh Laith , Ahmad Ishfaq
Published: March 2023

Energy management strategies are crucial to efficiently scheduling appliances and preventing peak generation due to increased energy demand. It is essential to manage the demand and supply of energy based on the consumer’s consumption patterns using various heuristic optimization techniques. Additionally, the end-user is more concerned with minimizing electricity costs and reducing peak-to-average ratios (PARs). This work proposes an arithmetic Harris hawks optimization (AHHO) as a new approach for improving the Harris hawks algorithm to optimize residential demand response (DR) load management in a smart grid. Our method employs arithmetic and lightweight flight operators based on the Lévy flight distribution to generate diverse design solutions and improve the HHO’s exploration capabilities. We consider 15 smart appliances and categorize them based on how much energy they use, computing the electricity price using real-time pricing (RTP) and critical peak pricing (CPP). While maintaining user satisfaction within operational and power limits, the objective is to decrease energy costs and PAR. We evaluate the effectiveness of our proposed AHHO approach against nine cutting-edge algorithms using both RTP and CPP schemes. The findings demonstrate that our suggested approach performs better than the other algorithms because it achieved cost savings of 42.10% and 30% under RTP and CPP schemes, respectively. Meanwhile, it also reduced PAR by 55.17% and 50% under RTP and CPP schemes, respectively.
DeepDual-SD: Deep Dual Attribute-Aware Embedding for Binary Code Similarity Detection
Authors: Guo Jiabao , Zhao Bo , Liu Hui , Leng Dongdong , An Yang , Shu Gangli
Published: March 2023

Binary code similarity detection (BCSD) is a task of detecting similarity of binary functions which are not available to the corresponding source code. It has been widely utilized to facilitate various kinds of crucial security analysis in software engineering. Because of the complexity of the program compilation process, identifying binary code similarity presents tough challenges. The most sensible binary similarity detector relies on a robust vector representation of binary code. However, few BCSD approaches are suitable to form vector representations for analyzing similarities between binaries, which may not only diverge in semantics but also in structures. And the existing solutions which only depend on hands-on feature engineering to form feature vectors, fail to take into consideration the relationships between instructions. To resolve these problems, we propose a novel and unified approach called DeepDual-SD that aims to combine the dual attributes (semantic and structural attribute). More specifically, DeepDual-SD consists of two branches, in which one text-based feature representation is driven by semantic attribute learning to exploit instruction semantics, another graph-based feature representation for structural attribute learning to investigate structural differences. Meanwhile deep embedding (DE) technology is utilized to map this information into low-dimensional vector representation. In addition, to get together the dual attributes, a fusion mechanism based on gate architecture is designed for learning to pay proper attention between the two attribute-aware embeddings. Experimental verifications are conducted on Openssl and Debian datasets for several tasks, including cross-compiler, cross-architecture and cross-version scenarios. The results demonstrate that our method outperforms the state-of-the-art BCSD methods in different scenarios in terms of detection accuracy.
Addiction to medical websites post COVID-19 pandemic: a predictor of illness anxiety disorder among Arabian youth
Authors: Hamid Mohamed S. , Abo Hamza Eid , Rivera Rita M. , Carballea Denise , Mohamed Nagwa Ibrahim A.
Published: March 2023

Background

The coronavirus (COVID-19) pandemic has significantly impacted every region of the world. During these unprecedented times, college students have been experiencing severe mental health issues concerning excessive internet usage. On average, 42.9% of students in Egypt utilized the internet (Anwar et al. in J Public Health 30:1753–1762, 2022). Arabs quickly diagnose themselves online using medical websites. The issue is exacerbated by drugs bought without a prescription (Alghadeer et al. in Saudi Pharm J 26:719–724, 2018).

Methods

This study examined he relationship between addiction to medical websites and behaviors related to Illness Anxiety Disorder among a population of Arabic university students. A sample consisting of N = 368 youths was examined.

Results

Bivariate linear regression, Z score, R2, t-test, ANOVA, mean, and standard deviation were used for statistical analysis. The findings of the study revealed a linear equation that predicts illness anxiety in adolescents. The correlation between medical website addiction and hypochondria was found to be 0.69. Furthermore, male participants were more addicted to medical websites than female participants.

Conclusions

Findings supported the notion that addiction to medical websites significantly predicts hypochondria.
Demonstration and experimental characteristics of a water-vapor Hall thruster
Authors: Shirasu Kento , Kuwabara Hiroki , Matsuura Masayuki , Koizumi Hiroyuki , Nakagawa Yuichi , Watanabe Hiroki , Sekine Hokuto , Komurasaki Kimiya
Published: March 2023

Water is an attractive candidate for condensable propellants owing to its availability, handleability, and sustainability. This study proposes the use of water vapor as a propellant for a low-power Hall thruster, and experimentally demonstrates the feasibility of this proposal. Based on the performance estimation from the plume diagnostics, a thrust-to-power ratio of 19 mN/kW, specific impulse of 550–860 s, and anode efficiency of 5–8 % were obtained at an anode power of 233–358 W. From further efficiency analysis, the mass utilization efficiency of water was found to be the most deteriorated among the internal efficiencies compared to the conventional xenon propellant, which was consistent with the expectations from a small discharge current oscillation, large beam divergence, and increase in low-energy ions. Moreover, additional power loss via reactions unique to polyatomic molecules was indicated by evaluation of the ionization cost. In this experiment, the mass utilization efficiency was improved with an increase in the anode voltage from 200 to 240 V without degradation of the power utilization. This suggests that operating at a higher voltage is more suitable for a water-vapor Hall thruster.
Behaviour and welfare of African lion (Panthera leo) cubs used in contact wildlife tourism
Authors: Wilson Ann , Phillips Clive JC
Published: March 2023

Lion (Panthera leo) cubs are used in wildlife interaction tourism but the effects on cub welfare are unknown. We assessed the behaviour of three cohorts of lion cubs, twelve animals in total, at three different interaction facilities, using continuous and scan-sampling methodologies for the entire duration of cub utilisation for human interactions. Cubs spent most time inactive (62%), particularly sleeping (38%), but also spent a substantial amount of time playing (13%) and being alert (12%). A generalised linear mixed model revealed that cub behaviour was similar in two facilities but different from cubs in the third. In these two similar facilities, as human interactions increased, the time spent resting, sleeping and playing with other cubs decreased, and alert behaviour, grooming of humans and flight responses increased. In the third facility, cubs had an abnormal activity budget, with high levels of inactivity (80%) accompanied by a lack of response to human interactions. We conclude that in some facilities normal cub behaviour cannot be achieved and may be compromised by a high frequency of human interactions, which therefore needs to be controlled to limit adverse effects on cub behaviour.
The first report of Chelonioidea cf. Ctenochelys from the Late Cretaceous of the Maastrichtian type area
Authors: Heere Jelle J.A. , Wallaard Jonathan J.W. , Mulder Eric W.A. , Ponstein Jasper , Schulp Anne S.
Published: March 2023

A mandible of a Late Cretaceous sea turtle with affinities to Ctenochelys is reported from the Maastrichtian type area of the Netherlands. The triangular mandible has a well-developed symphyseal ridge surrounded on both sides by large, concave areas on the triturating surface. It represents the first potential occurrence of Ctenochelys from the Maastrichtian type area. This finding increases the diversity of the turtle fauna known from the Maastrichtian type area.
Genuine Domestic Change or Fake Compliance? Political Pervasiveness in the Serbian Media
Authors: Dragojlov Aleksandra
Published: March 2023

Since the election of Aleksandar Vučić and the Progressives, Serbia has witnessed a slow decline in media freedom, which scholars such as Subotić (2017) argue has been worse than in the 1990s. Although the government had adopted a package of three laws in August 2014 to bring the media landscape up to European standards, the implementation of the laws has been limited and marginal, with the Progressives engaging in fake compliance. The adoption of the new media strategy 2020–2025 in 2020 has not led to genuine domestic reform and compliance to EU conditionality. In fact, the EU Commission and journalists’ associations in Serbia have criticized the decline in Serbia’s media freedom, citing continued attacks on journalists and indirect political and economic control through advertising and project co-financing, which continue to be features of the Serbian media landscape. In the absence of clear and credible EU conditionality, the decline of media freedom is in the eye of the beholder, where the gap between public engagements with Serbian politicians and the critical stance of progress reports regarding the degradation of the media have enabled Serbian elites to exploit this ambiguity to continue their strategy of fake compliance vis-à-vis rule of law.
Velocity scales for constrained flows
Authors: Ramamurthy A. S. , Lee P. M. , Ng G. P.
Published: March 2023

Two-dimensional flow past a bluff body can be constrained under two important circumstances. For single models, the side walls of a testing facility can impose a constraint on the flow past the model. On the other hand, for single row configurations the adjacent members impose a constraint on the flow past an intermediate member of the row. Both these effects are a consequence of boundary interference.

Ealier investigations related to the interference effects of side walls on the vortex shedding frequency and drag coefficient of single bluff bodies were limited to weakly constrained flows. Recently, side wall interference effects have been reported for severely constrained two-dimensional flows past normal plates, inclined plates, triangular prisms and circular cylinders Constraint or blockage for two-dimensional flow is defined as the ratio of the model width to the test section width. While defining blockage for single rows of bodies, the width of the test section has to be replaced by the spacing between adjacent rows of bodies.
Fly-by-wire and control configured vehicles—rewards and risks
Authors: Burns B. R. A.
Published: March 2023

Many thousands of words have already been spoken and numerous papers written extolling the virtues of fly-by-wire and the control configured vehicle. Most of these issue from control system specialists and avionics engineers anxious to sell their new technology. Aircraft designers and development teams, including test pilots, must adopt a cautious approach to these new developments and ask the questions “What has it to offer?” and “What's the catch?”.

We must always balance performance rewards against development risks, ensuring that the risks are carefully evaluated and that we do not suffer from what the Americans call “Second Degree Ignorance” (we don't know what we don't know). If we can define the development problems, we are well on the way to solving them; if they remain obscure then the benefits will elude us. If the risk outweighs the reward a conservative solution must be adopted; it is this consideration that so often makes us, like Hamlet, “rather bear those ills we have, than fly to others that we know not of”.
An experimental investigation of axisymmetrically loaded, plate-reinforced, circular holes
Authors: Terry G.
Published: March 2023

The reinforcement for holes in tensile stress fields sometimes takes the form of an extensive thin plate attached to the sheet, especially if the reinforced region is of integrally machined or bonded construction. Such reinforcements are often placed eccentrically, that is on one side of the sheet only. It has been shown both experimentally and analytically that such an eccentrically placed reinforcement can promote considerable bending stresses.

Wittrick gives curves showing the effect of eccentricity in the case of the circular hole with an eccentrically located annular plate reinforcement in a plane, axially symmetric stress field. High, but only local, bending stresses exist which simple theory will not predict. The stresses are markedly higher than those given with the corresponding symmetric reinforcement. For example, under axisymmetric loading it is possible to design an optimum plate-reinforced neutral hole (i.e. the stress concentration factor is 1·0 in both sheet and reinforcement) if the reinforcement is deposed symmetrically about the plane of the sheet. If however it is placed totally eccentrically then for realistic sheet stresses bending raises the sheet concentration factor 2·0.
Royal Air Force search and rescue facilities
Authors: Price H. T.
Published: March 2023

I would like to begin by suggesting a small but important correction to the title of this Symposium. We must not refer to “the UK”, which infers the islands and surrounding coastal waters, but to the entire area for which the United Kingdom has search and rescue responsibilities.

The ICAO Convention, to which we were signatories in Chicago 1947, laid down that “Contracting States, separately or jointly, shall delineate Search and Rescue Areas for which they will be responsible, and establish one Rescue Co-ordination Centre in each”.

This Agreement went on to recommend that the areas might extend beyond national boundaries, by agreement with neighbouring States, and, as the Search and Rescue Services were to operate in close conjunction with the Air Traffic Services, there would be mutual operational advantages in having the Flight Information Regions and Search and Rescue Areas co-extensive.
Royal Navy search and rescue facilities
Authors: Sirett V. G.
Published: March 2023

The very nature of Naval flying and carrier operations in the maritime environment has always given rise to a requirement for an efficient rescue facility during both peace and war. When safety at sea was solely dependent on surface units it was perhaps natural that a faster aerial vehicle with some form of rescue capability would eventually arrive and as we now know the ubiquitous helicopter became that vehicle.

The military requirement to save people from the sea has been with the Navy for a very long time and that lonely feeling of being by oneself in the water has raised many a heartfelt cry.

Helicopter SAR was conceived in the Royal Navy with the advent of the S51 Dragonfly in 1951. This was the first service helicopter to have a winch. During the time that helicopters were proving their worth in Korea we formed 705 Squadron at Lee-on-Solent with the primary task of developing the SAR role. Initially none of the equipment was standardised and improvisation was the keyword.
Cost effectiveness of systems
Authors: Howlett D. P. , Howard R. W.
Published: March 2023

Modern aircraft, both combat and civil, are representative of the most complex “man-machine” devices ever produced and they have now been developed to the stage where, relatively speaking, little more will be achieved by the normal evolutionary processes. Increasing attention is, therefore, now being paid to new configurations, new materials and new uses of technologies such as safe automatic controls in an attempt to break through the present limits of performance, safety and cost.

One of the most rapidly advancing technologies at the present time is microelectronics and its particular application in miniature digital computers. Professor Gosling of the University of Bath recently described microelectronics as a “technology which makes negligible demands on materials and energy and yet is already changing the rules for future social evolution by making possible intelligent machines, which achieve biological orders of complexity at trivial cost”.
The proper symbiosis of the human pilot and automatic flight control
Authors: Doetsch K. H.
Published: March 2023

It is indeed a great honour and a particularly pleasing experience for me to have been invited to give the 18th Lanchester Memorial Lecture. Pleasing because it enables me to recall before such a distinguished audience, one of Lanchester's outstanding achievements in the field of aircraft stability, his phugoid theory. This slow oscillation problem has often been neglected but its implications can be vital as the Vulcan crash in 1956 emphasises, and the development of STOL with high lift has forced designers to turn again to a serious consideration of the phugoid as I will show presently in the first part of this lecture.
Payload without penalty—a suggestion for improving the take-off performance of fixed-wing V/STOL aircraft
Authors: Taylor D. R.
Published: March 2023

The ideal of high speed centre-to-centre inter-city air transport remains unrealised with the problems of poor economics and excessive noise dominant and still largely unsolved.

Economics hit particularly hard at VTOL aircraft. Thrust/weight ratios in the order 1·15:1 are necessary with the result that total installed thrust is much larger than is required for the cruise condition and payload and range suffer. It is therefore tempting to compromise and go for a STOL solution and current trends are in this direction.
Aero and underwater engineering
Authors: Henson G. S.
Published: March 2023

The first item in this paper is a comparative review of the history of air and underwater achievements. We shall see that commercial underwater vehicles are a recent development and offer today a magnificent challenge to engineers with many opportunities and pitfalls. Small multi-disciplinary teams of engineers are able to advance rapidly, and the calibre of a few men matters, rather than vast organisations. In some ways this resembles the aeronautical world of the 1920s and 30s, during which period R. J. Mitchell contributed so greatly. Certainly it is closer to that period of aeronautics than to aerospace today, as I shall try to show.
Technology research at Boeing Vertol Company
Authors: Euan Hooper W.
Published: March 2023

Occasionally, in the midst of satisfying customer requirements, we have to assess whether or not we are really making progress in terms of achieving more effective helicopters. We should identify both the areas which offer the greatest potential for improvement and those in which improvement is the most required. Then, we must decide on the amount of effort we will put into improving these areas.
The removal of wind tunnel panels to prevent flow breakdown at low speeds
Authors: Hansford R. E.
Published: March 2023

The testing of model rotors in closed throat wind tunnels is known to present major problems in the form of tunnel wall interference when operating at low speed. However, it is precisely this region of the aircraft's flight envelope which is of prime importance when investigating areas such as transitional flight, hovering in winds and tail rotor performance and handling qualities. Although much work has been carried out in the past to determine wall interference factors for various model and tunnel configurations, there still exists a problem of flow breakdown due to the presence of tunnel boundaries, for which no corrections are possible. The aim of this experiment was to conduct a short and simple investigation, first to identify the flow breakdown condition for a finite sized rotor in a closed tunnel, then to assess the feasibility of at least delaying the onset of this limiting condition by selectively removing panels from the walls of the working section. Since the experiment was designed only to study gross flow effects, no attempt was made to include wall interference factors.
A digital state observer for the attitude control of a flexible space vehicle
Authors: Smith E. H. , Gill K. F.
Published: March 2023

A space vehicle is usually required to maintain a specific orientation with respect to Earth. If flexible appendages (such as panels of solar cells) are associated with the vehicle, the problem of controlling the attitude of the spacecraft becomes more complex. In this paper, attention will be directed towards the control of this class of vehicle when the control law suggested by Hughes is employed. This approach requires that the attitude and its rate of change with time are available in satisfactorily noise-free forms. The measurement of attitude is physically possible, but the measurement of rate is not. Consequently a Luenberger state observer was employed by the authors to reconstruct the rate information. A similar approach was adopted earlier where an analogue model of the observer was employed. It was found that in some situations the design procedure for the observer stipulated that very large amplifier gains should be incorporated into the model, and great care was needed to avoid this problem.
The effect of secondary flow velocity profile on the static performance of low speed ejector thrust augmenters
Authors: Jones C. N.
Published: March 2023

Jet thrust at low speeds is notoriously inefficient, and ejectors have often been proposed as thrust augmenters in the hope of increasing the mass flow and momentum flux for a given expenditure of energy. Henri Coanda reported the development of a successful thrust augmenter (the Coanda nozzle) for the propulsion of ambulance sledges in Russia during the Second World War, and useful thrust augmentations with this were reported by Sproule and Robinson and Reba. These reports raised interest in the technical press, and large scale experimental programmes have been mounted by Lockheed Aircraft, Cornell Aeronautical Laboratory, Hiller Aircraft and others. However, no clear conclusions seem to have resulted. Although recent published analyses of the performance of ideal ejector thrust augmenters stress the importance of size and energy input, no detailed analysis of the many different definitions of thrust augmentation which appear in the literature, or of their practical implications, seems to be available.
The development of the WG-13
Authors: Smith A. H.
Published: March 2023

This paper deals with the conception of the initial programme, the management and development of this programme up to its present philosophy and how this programme is now being managed to meet the future of the Lynx in relation to the current development knowledge. Some aspects of the development manufacture are also covered.

Any duplication from the preceding papers given by Messrs. Austin and Rogers is considered to be given as reiteration of points necessary for completeness of this paper in its own right.
Certification of helicopters for flight in instrument meteorological conditions
Authors: Le Sueur H. E.
Published: March 2023

In determining the airworthiness of a helicopter to fly in all weather conditions it is necessary to examine all the effects of such flying on the safety of the passengers, flight crew and third parties involved in such flying. Rule 24 of the Rules of the Air defines that “for VFR outside controlled airspace that an aircraft shall fly at least one nautical mile horizontally and 1000 ft vertically away from a cloud with a visibility range of five nautical miles, except that below 3000 ft the aircraft must be flown clear of cloud and in sight of the surface”. Inside controlled airspace the same rule applies except that the aircraft on Special VFR shall be flown in accordance with the specific instructions given by ATC.
Requirements for the helicopter instrument rating
Authors: Perry W. H.
Published: March 2023

Most of you will be familiar with the disclaimer which some people make before giving talks in these circumstances. Whilst what I have to say to you may not by any means be taken as an official statement of the policy of the Civil Aviation Authority it may be taken as an indication of the way the Authority is thinking about the introduction and operation of ratings for instrument flight in helicopters.
Some compressible jet flow and reattachment effects in fluid control valves
Authors: Begg R. D.
Published: March 2023

In an early investigation of gas flow through a spool valve model Stenning discovered the same bi-stable flow patterns as had been established for oil flow, but reported no measurement of quantitative similarity or of other compressibility effects which would be of importance if such valves were to be used in pneumatic systems. Since then there have been no reports of comparisons between compressible and incompressible flow patterns in control valves, and the present investigation has been carried out to determine the characteristics of compressible flow through a two-dimensional model of a control valve port and to try to derive these characteristics from established compressible flow behaviour.
Glass windshields for wide bodied aircraft
Authors: Roberts W. G.
Published: March 2023

For many years most transport aircraft throughout the world have used a common form of windshield construction with a single ply of tempered glass for pressure resistance, combined with a thick polyvinyl butyral interlayer. This interlayer is usually reinforced at the edges with a metal insert and acts as a diaphragm to provide bird impact resistance, and also serves as a secondary load path to contain pressurisation in the event of failure of the primary glass ply.
An analytical approach to attitude determination of a spinning satellite
Authors: Dasarathy Belur V.
Published: March 2023

The attitude of a spinning satellite, specified in terms of the three Eulerian angles, is related to the angular velocity components in body-fixed co-ordinates by three coupled first-order non-linear differential equations. In general, these equations, being complex, are not amenable to analytical techniques. This study presents a new analytical approach to the analysis of these equations by first reducing the problem to the study of a single second-order non-linear differential equation and then establishing its equivalence with a second-order linear differential equation for the case of the satellite spinning with constant angular velocity components. The solution of this equivalent linear equation is then used to obtain the Eulerian angles.
Drone/RPV systems
Authors: Hemenway Ward W.
Published: March 2023

The Remotely Piloted Vehicle, or RPV, is here as a viable element in the arsenal of aerospace power. The astute student of air power, the United States Air Force planner, and we in the research and development community are well aware of the current and potential applications of the RPV in fulfilling aerospace missions.
Fatigue properties of the Alclad Al-Cu-Mg-Si-Mn alloy
Authors: Sova J. A. , Williams T. R. G.
Published: March 2023

Despite the wide use of Alclad aluminium alloy sheets in the aircraft industry, information on the effect of cladding on the mechanical strength of the strong alloy core is mainly limited to comparative fatigue testing of clad and unclad sheets, tested as plain specimens and subjected to constant-amplitude loadings. S/N curves obtained under such conditions were published by Smith, Brueggeman and Harwell for 24S-T3 material and by Shabalin for the D16T alloy (Russian specification). Both sets of data show that the soft cladding had a detrimental effect upon the fatigue strength of the strong alloy. Forrest has presented several comparative S/N curves which also show a reduction in the fatigue strength of the Alclad unnotched specimens compared with the bare alloy. Karlashov and Batov investigated the behaviour of cyclically-strained D16AT alloy (Russian specification), with particular reference to the nature of the mechanism of protection offered by pure aluminium. Although the core was electrochemi-cally protected against corrosion, intense damage occurred in the cladding layer.
The Lockheed TriStar—an operational overview
Authors: Frisbee L. E.
Published: March 2023

In its initial version, the L-1011 TriStar (the Dash One) is designed for short/medium-haul routes—typically carrying 250/270 mixed-class passengers distances of from 300 to more than 3000 nm. A general arrangement is shown in Fig. 1. As indicated in Fig. 2, the L-1011-1 payload/range curve is placed between those of the DC-8-61 and the Boeing 747. It should be noted that both these aircraft are designed for long ranges and are suited only for operation from major airports. On the other hand, the TriStar has airport performance, in terms of field length, comparable to that of the much smaller short-range types, typified by the Boeing 727. This, in broad terms, illustrates the primary design objective of the Dash One. The dashed line on Fig. 2 shows the payload/range curve of the L-1011-2 which will, of course, have an airport performance at the heavier gross weights more in keeping with long-haul requirements.
The Stiletto project
Authors: Youens F. P.
Published: March 2023

The Stiletto is an air launched supersonic target developed for UK ranges. It is based on the American AQM 37A target which was designed and manufactured by Beech Aircraft.

The development programme has entailed a number of changes, both in equipment fit and control, on the target and the design and incorporation of a launching system into a Canberra aircraft. The programme has been a joint one between MoD as the customer and Shorts as co-ordinating design authority with collaboration from Beech and from the UK companies who developed and supplied the required equipment. The AQM 37A Target is purchased by Shorts from Beech, the necessary changes and additions made at Belfast and the resulting Stiletto target is delivered to RAE, Llanbedr. The development contract was placed late in 1966 and the first Stiletto was launched on programme on 1st August 1968.
Adrift on the air ocean—the future of air commerce
Authors: Browne Secor D.
Published: March 2023

It is a special honour and privilege to be asked to give the Wilbur and Orville Wright Lecture this year. My good friend, John Seekings, has reminded me that 1972 marks the 100th anniversary of the publication of Around the World in 80 Days. That celebrated voyage by Phineas Fogg is particularly appropriate to our contemporary world of air transport. Many of the problems he faced are still with us—and we will probably have them 100 years from now.

It was also just about a 100 years ago that the Russian scientist, Mendeleyev, described the skies as “air oceans”. That description seems particularly apt today. And it is the basis for my thesis that we are now adrift on the “air ocean”. We are adrift because we have the technical means to tie the world together aeronautically but we cannot seem to agree on a heading to follow.

Technology has compressed a trip around the world from the 80 days of Phineas Fogg to a matter of hours. When we consider that it has only been 45 years since Lindbergh's historic flight across the Atlantic, the advances of technology seem even more staggering. But, while we have performed some technological miracles, we have also engendered some of the most difficult and complex problems since man rolled the first wheel downhill.
Selling high cost capital equipment
Authors: Cundall H. B
Published: March 2023

Little has so far been written to specifically cover this subject*. Many papers and books make passing reference to it; many management courses touch lightly upon it. However, most writings and teachings on “salesmanship” deal with the conventional salesman with a detergent packet in hand, a foot in the door, and a “management objective” of umpteen calls per week. Nowhere have I found a reasoned analysis and exposition of the problems faced by those of our select band who try to sell high cost capital equipment, mostly in the export market.

Selling aero engines is unusual in that the aero engine is only an accessory to the aircraft —yet an accessory whose performance can often dictate the size and shape of the aircraft, as well as its profitability in operation. Nevertheless much of the techniques of selling this equipment is common to other prime movers and also reads across both to the aircraft manufacturer and to the smaller accessory supplier; many of the general principles apply across a wide field of capital goods.
The financing of aircraft procurement
Authors: Sowter Robert S.
Published: March 2023

It is a prerequisite that by investigating the financing of aircraft procurement in relation to transport systems, we first accept the predominance of the defence budgets on all aircraft projects. However, because the penalty of democracy is public accountability, defence procurement is supposedly in one ledger and civil projects in another. Whereas budgets, accounting and technical errors in the defence category cause only domestic problems with the electorate, similar mistakes in the civil field can have far more disastrous effects on overseas clients and world trade. How short this paper would be in the USSR. Just a case of debiting the manufacturer with research, development, raw materials, labour and overhead—if that exists—and then, when each aircraft is ready for delivery, credit the manufacturer with total cost—surely profit is unthinkable—and debit the USSR Air Force and Aeroflot.
Flight procedures into and out of heliports
Authors: Wood H.E.
Published: March 2023

This paper concentrates on helicopter operations in the London area. There are of course, other fields of helicopter operations—most topically those to and from oil rigs in the North Sea—but times does not permit consideration of them on this occasion. I shall first then, attempt to set the scene by describing the layout of the controlled airspace which contains the helicopter route system for the London area.

This consists of the London Control Zone (Fig. 1), centered on London (Heathrow) Airport and it measures approximately 26 nm east to west and 16nm north to south. Its vertical extent is from ground level to FL 110 (11 000 ft approximately). This Zone is surrounded by the London Terminal Control Area, the base of which varies between 1500 ft and 2500 ft with a top limit of FL 250 (25 000 ft).
The military customer's point of view
Authors: Wheeler Neil
Published: March 2023

I have chosen to speak on what I would term the military customer's point of view. You may rightly fee] that a more appropriate audience for such a talk would be the SBAC, but the country, and indeed the world, only benefits from the original and imaginative ideas and the ingenuity of aeronautical scientists and engineers by the production of aircraft and the equipment associated with their operation. It occurred to me, therefore, that this lecture presented me with an admirable opportunity for setting out some personal—and I emphasise that word—views as a representative of the largest customer of the British Aerospace Industry.
Stiffened panels with varying stiffener sizes
Authors: Williams F. W.
Published: March 2023

Stiffened panels usually consist of a skin of uniform thickness with several identical equally spaced longitudinal stiffeners. This paper demonstrates that the weight of a panel which is designed to have a specified initial buckling load, in uniform longitudinal compression, can be reduced by using more than one size of stiffener.

Initial buckling stresses quoted were all obtained using the computer program VIPAL, which is based on a recent “exact” method which allows for coupling between all possible modes. In this method the panel is considered as an assembly of thin uniform flat rectangular plates which are rigidly connected together along their longitudinal edges and are simply supported at their ends. The in-plane destabilising effects of the longitudinal compressive stress on the behaviour of these plates are included.
The Civil Aviation Authority and safety —the regulatory framework
Authors: Veal J. B.
Published: March 2023

In his general review of the Civil Aviation Act 1971 and its implications for the regulation of civil aviation in the 1970s, Mr. Colegate has mentioned the general functions of the Civil Aviation Authority. In my contribution I will describe the safety function in greater detail and the pattern of legislation and direction within which the Authority will work.
Attitude stabilisation of the Geos-C spacecraft
Authors: Pisacane V. L. , Whisnant J. M.
Published: March 2023

GEOS-C will be the third of a series of spacecraft designed for the National Geodetic Satellite Programme. The two earlier and successful spacecraft were designated GEOS-I and II. In these, geocentric stabilisation was acheived to optimise the usage of the radiated and reflected radio and optical power of the geodetic observations. It was the atmospheric attenuation of the optical beacons, by which the spacecraft could be photographed against a star background, which imposed the accuracy requirement of earth pointing to within 5°. Descriptions as well as performance analyses of these attitude control systems have been published. In each, the proper mass distribution was obtained through an end mass on a de Havilland extendible boom. Since initial misorientation and perturbing torques induce motion about the equilibrium orientation in a gravity-gradient system, a mechanism for energy dissipation is necessary. A Magnetically Anchored Eddy Current Damper was used for this purpose. It consists of a magnet assembly that is free to lock onto the geomagnetic field and rotate freely within a conducting spherical shell. Relative motion of the two produces eddy currents in the conductor which in turn impede the relative motion.
Digital computer simulation of the dynamic response of a twin-spool turbofan with mixed exhausts
Authors: Fawke A. J. , Saravanamuttoo H. I. H.
Published: March 2023

The dynamic behaviour of gas turbines is of great practical importance, but unfortunately it cannot be investigated experimentally until late in the development programme when the mechanical integrity of the engine has been established. In the case of aero engines there is a requirement for fast engine accelerations and all engine transients must be achieved with complete safety. Thrust response rates must be guaranteed by the engine manufacturer at a very early stage and clearly it would be of great value to study engine transient behaviour at the design stage; this should lead to a significant saving in development time and cost by decreasing the amount of test bed running required.
Design for safety
Authors: Keith-Lucas D.
Published: March 2023

Flying is now an acceptably safe form of transport. This is obviously so because if it were not so people would not fly. Nevertheless it is a remarkable thing to be able to say. Consider for a moment what it means in terms of engineeering achievement. If you were to start from scratch to design a safe transport system would you for example

1.

Design a vehicle with such a light structure and such minimal factors of safety.

2.

Make it so that it cannot stop in a fog but has a minimum speed of over 100 mph.

3.

Make it so that it can cross oceans and mountain ranges but cannot stop until it gets to the other side.

4.

Make it reliant on complex electronic and electro mechanical devices for navigation, collision avoidance and even for control.

5.

Use a fuel which, according to type, has a flash point little above and sometimes actually below atmospheric temperature and which is carried in very large quantities.

One could go on listing such absurdities but these are sufficient to establish that, by all the rules, flying has no right to be safe. The fact, however, is different. Flying is many times safer than travelling by road and is, by any reasonable criterion, one of the safest of all the available modes of travel.
The present and future technology of agricultural and forestry aviation, with particular reference to Canada
Authors: Southwell P. H.
Published: March 2023

Agricultural and forestry aviation is a service industry to the food and fibre production industries, and to public health hazard control systems. The wide range of conditions which obtain in Canada is such that a review of the state of the art and of priority problems will also serve to illustrate the current situation in many other areas of the world.