bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple imputation approaches for handling incomplete three‐level data with time‐varying cluster‐memberships
Authors: Wijesuriya Rushani , Moreno‐Betancur Margarita , Carlin John , De Silva Anurika Priyanjali , Lee Katherine Jane
Published: July 2022

Three‐level data arising from repeated measures on individuals clustered within higher‐level units are common in medical research. A complexity arises when individuals change clusters over time, resulting in a cross‐classified data structure. Missing values in these studies are commonly handled via multiple imputation (MI). If the three‐level, cross‐classified structure is modeled in the analysis, it also needs to be accommodated in the imputation model to ensure valid results. While incomplete three‐level data can be handled using various approaches within MI, the performance of these in the cross‐classified data setting remains unclear. We conducted simulations under a range of scenarios to compare these approaches in the context of an acute‐effects cross‐classified random effects substantive model, which models the time‐varying cluster membership via simple additive random effects. The simulation study was based on a case study in a longitudinal cohort of students clustered within schools. We evaluated methods that ignore the time‐varying cluster memberships by taking the first or most common cluster for each individual; pragmatic extensions of single‐ and two‐level MI approaches within the joint modeling (JM) and the fully conditional specification (FCS) frameworks, using dummy indicators (DI) and/or imputing repeated measures in wide format to account for the cross‐classified structure; and a three‐level FCS MI approach developed specifically for cross‐classified data. Results indicated that the FCS implementations performed well in terms of bias and precision while JM approaches performed poorly. Under both frameworks approaches using the DI extension should be used with caution in the presence of sparse data.
Comparing the Gettering Effect of Heavily Doped Polysilicon Films and Its Implications for Tunnel Oxide‐Passivated Contact Solar Cells
Authors: Yang Zhongshu , Krügener Jan , Feldmann Frank , Polzin Jana-Isabelle , Steinhauser Bernd , Aleshin Matvei , Le Tien T. , Macdonald Daniel , Liu AnYao
Published: July 2022

In addition to excellent surface passivation and carrier selectivity, the structure based on the heavily doped polysilicon layer on an ultrathin silicon oxide interlayer also demonstrates strong impurity gettering effects. Herein, the gettering strength of a range of phosphorus‐ or boron‐doped polysilicon films from different fabrication techniques is assessed and compared. Iron, one of the most common metallic impurities in silicon, is used as a tracer impurity to quantify the gettering strength (segregation coefficient). A comparison of the experimental results to the literature, combined with measurements of the electrically active and inactive dopant concentrations, enables us to suggest the main gettering mechanisms in different polysilicon films. The differences in the segregation coefficients of the phosphorus‐doped polysilicon films for iron are within one order of magnitude, in spite of their different combinations of gettering mechanisms. On the other hand, boron‐doped polysilicon films show a large variation in their gettering effects, although the predominant gettering mechanisms are all attributed to electrically inactive boron, according to the current understanding of the gettering mechanisms from the literature. Finally, the impact of different polysilicon gettering effects on the efficiency of tunnel oxide‐passivated contact (TOPCon) cells is simulated and discussed.
Ethanol‐Processable Polyfuran Derivative for Eco‐Friendly Fabrication of Organic Solar Cells Featuring Self‐Healing Function
Authors: Shang Luwen , Zhang Wenzhi , Zhang Bo , Gao Yueyue , He Shenghua , Dong Guohua , Li Wangpeng , Bai Hairui , Yue Gentian , Chen Shanshan , Tan Furui
Published: July 2022

Eco‐friendly fabrication of organic solar cells (OSCs) via alcohol or water is highly desired for their cost‐effective feature and benign profit for derived operators and ambient environment. Herein, a simple polyfuran derivative (PFO) that exhibits good solubility in ethanol/water solvent mixture is reported. Moreover, PFO displays broad optical absorption, high‐lying electronic energy level, and large hole mobility. The air‐ and ethanol‐processed PFO‐based OSCs deliver a fine efficiency of 2.25%. Even though only 45.24% of their initial efficiency is preserved for optimized devices after continuous illumination for 200 h in ambient atmosphere, the remained efficiency value of optimized devices can increase by 19.20% when undergoing intermittent illumination yet for the same light‐soaking time of 200 h. The self‐healing efficiency of devices suffering from discontinuous illumination is associated with the partial dissolution and reconstruction of hydrogen bonds in active layer. The results provide important guidelines for designing electroactive materials for safe and environmentally benign fabrication of OSCs with self‐sealing function.
A Study on Dye Inclusion Complex, Adsorption, and Kinetic of Silk Floss Sheet Modified with β‐Cyclodextrin as a Biodegradable Adsorbent
Authors: Salimpour Abkenar Samera , Mohammad Ali Malek Reza
Published: July 2022

In this study, the silk floss sheet (SFS) modified with β‐cyclodextrin (β‐CD) is used to adsorb various dyes (anionic: Acid Red 33/ AR33, cationic: Basic Blue 9/ BB9, and non‐ionic: Disperse Yellow 26/ DY26) from colored solutions. The various analyses (fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), ultraviolet‐visible spectroscopy (UV‐Vis), and elemental analysis) are used to study the inclusion complex between β‐CD and the mentioned dyes. In addition, the influence of experimental parameters on the adsorption process (such as dye molecular size, adsorbent dosage, initial dye concentration, contact time, and pH) is assessed. The results show that the molecular size and pH have more effect on the adsorption capacity of SFS. It is found that optimum adsorption of acid and disperse dyes occurrs at pH 4, while basic dye can adsorb at around pH 10. Also, the experimental data have a good fit with the Langmuir equation and the kinetic data can correlate with the second‐order equations. Finally, the desorption studies show that this natural adsorbent can be reused many times without any change in its adsorption capacity.
Chemically Engineered Avenues: Opportunities for Attaining Desired Carrier Cooling in Perovskites
Authors: Kaur Gurpreet , Shukla Ayushi , Babu K. Justice , Ghosh Hirendra N.
Published: July 2022

Hot carrier extraction‐based devices are presently being persuaded as the most revolutionary means of surpassing the theoretical thermodynamic conversion efficiency limit (∼67 % for a model hot carrier solar cell). However, for practical realisation, there stand various hurdles that need to be surmounted, a major among all being the rapid hot carrier cooling rate. Though, the perovskite family has already demonstrated itself to exhibit slower cooling in contrast to the prototypical semiconductors. Decelerating this entire process of cooling further can prove to be a crucial stride in this regard. Quite contrarily, for the optoelectronic applications the situation is entirely conflicting where quick rate of cooling is a chief prerequisite. In the recent times, there have been various key developments that have targeted altering this cooling rate by various chemically engineered strategies. This review highlights such blueprints that can be utilized towards the advantageous alteration of the carrier cooling in accordance with the device requirements.
Ultrasonographic and haematology findings as an indicator of uterine torsion prognosis in cattle
Authors: de Carvalho Jaqueline Candido , Lainetti Patrícia de Faria , Alonso Juliana de Moura , Souza Fabiana Ferreira , Ferreira João Carlos Pinheiro
Published: July 2022

Uterine torsion is considered an obstetric emergency. In severe cases, it compromises the survival of both the fetus and the dam. The purpose of the current report is to describe uterine torsion in an 8‐year‐old full‐term pregnant Nelore cow, at 275 days of gestation, presenting physiological and behavioural changes for 12 hours. Physical examination revealed tachycardia, tachypnoea and mucoid vaginal discharge. On rectal examination, absent signs of fetal viability, increased ultrasonographic appearance of the uterine wall, separation of its layers and hyperechogenic placentomes showing rough borders were observed. Blood sample evaluation revealed biochemical changes. The postmortem examination confirmed severe uterine torsion with detachment of uterine wall layers and severe subendometrial haemorrhage. Haematology and biochemistry profiles and ultrasonographic findings were helpful in determining the severity of uterine damage. Ultrasound examination is a rapid, non‐invasive and low‐cost procedure that can be used to establish a prognosis while avoiding expensive and unsuccessful therapeutic approaches.
Internationalization of the University
Authors: Mazzara Manuel , Succi Giancarlo , Tormasov Alexander
Published: July 2022

These days, universities acquire a reputation appearing on international rankings such as THE and QS. Innopolis is in the process of entering such rankings. In this chapter, we discuss how this challenge should be attacked and how the related processes should be organized in order to achieve the result. We also present some of the early successes of the university in this area. The chapter also analyzes the role of international conferences in achieving global reputation.
Nutritional Status and the Risk of Preterm Birth
Authors: Gillespie Bronwen
Published: July 2022

A woman’s body mass index and nutritional status should be assessed in the antenatal period. The evidence indicates that maternal anemia is a risk factor for preterm birth. Ensuring adequate levels of iron and folic acid is essential for general pregnancy health and outcomes. To reduce the risk of pre-eclampsia, daily calcium supplementation for populations with low dietary calcium intake may be advised, although negative interactions between iron and calcium supplements may occur so these two nutrients should be administered several hours apart. In undernourished populations, balanced energy and protein supplementation should also be recommended for pregnant women (though not specifically linked to a reduction in preterm birth). For populations at risk of vitamin D deficiency, possible benefits for general pregnancy outcomes may be gained from vitamin D supplementation. Where dietary zinc is low, it has been suggested that zinc supplementation may reduce the risk of preterm birth. However, further research is required to clarify the benefits of supplementation. For example, vitamin D in combination with calcium may increase the risk of preterm birth. In the antenatal period, the most important focus should be on promoting a good quality diet in general, rather than a specific supplementation regime.
Video Projection on Transparent Materials
Authors: Leischner Vojtěch , Mikovec Zdenek
Published: July 2022

We propose a new coating for light projection on transparent materials that can open new possibilities for design. What we often struggle with is the lighting of clear glass. By definition, clear glass lets most of the light pass through. We have found a way to turn glass surfaces opaque or transparent by using ultraviolet (UV) fluorescence coating. In combination with a UVA light source, we can project the dynamic content onto a glass surface treated with a special coating that transforms the UVA light into visible light. The added benefit of such a coating is that it can be applied to any organically shaped surface using a spray gun, not just flat surfaces. Another advantage is that the light source is nearly invisible to the human eye, especially with a UV light pass-through filter. We have created a prototype with a modified overhead projector to measure the light characteristics and documented the steps to reproduce our results.
Remote Scientific Conferences After the COVID-19 Pandemic: The Need for Socialization Drives Preferences for Virtual Reality Meetings
Authors: Kopacz Agata , Knapińska Anna , Müller Adam , Banerski Grzegorz , Bohdanowicz Zbigniew
Published: July 2022

The COVID-19 pandemic continues to exert influence on the scientific community: circumstances have forced academics to engage more frequently in technology-mediated activities, including their participation in remote and virtual conferences. In this article, we contemplate immersive virtual environments: we verify researchers’ motivations and constraints in the context of online conferences, and discover in what elements of such conferences researchers wish to participate in virtual reality (VR). A survey was administered using a computer-assisted web interview (CAWI) questionnaire among the sample of 1,575 academics with the POL-on database as the sampling frame. The results indicate that individuals’ contrasting needs and attitudes toward technology determine the degree to which they look favourably upon both remote conferencing and VR. Immersive virtual environments appear to satisfy the need for socialization; ordinary remote conferences fulfil the need for security and the achievement of fundamental conference goals, such as establishing collaboration and publishing research results. Conferences that are hosted remotely must be relevant to the needs of researchers and meet their discrete expectations; only then will such events prove valuable enough that researchers are willing to continue participating in them after the pandemic subsides.
Participatory Action for Citizens’ Engagement to Develop a Pro-environmental Research Application
Authors: Jaskulska Anna , Skorupska Kinga , Bubrowska Zuzanna , Kwiatkowska Kinga , Stawski Wiktor , Krzywicki Maciej , Kornacka Monika , Kopeć Wiesław
Published: July 2022

To understand and begin to address the challenge of air pollution in Europe we conducted participatory research, art and design activities with the residents of one of the areas most affected by smog in Poland. The participatory research events, described in detail in this article, centered around the theme of ecology and served to design an application that would allow us to conduct field research on pro-environmental behaviours at a larger scale. As a result we developed a research application, rooted in local culture and history and place attachment, which makes use of gamification techniques. The application gathers air quality data from the densest network of air pollution sensors in Europe, thereby aligning the visible signs of pollution in the app with the local sensor data. At the same time it reinforces the users’ pro-environmental habits and exposes them to educational messages about air quality and the environment. The data gathered with this application will validate the efficacy of this kind of an intervention in addressing residents’ smog-causing behaviours.
Multisensory Representation of Air Pollution in Virtual Reality: Lessons from Visual Representation
Authors: Pochwatko Grzegorz , Świdrak Justyna , Kopeć Wiesław , Jȩdrzejewski Zbigniew , Feledyn Agata , Vogt Matthias , Castell Nuria , Zagórska Katarzyna
Published: July 2022

The world is facing the problem of anthropogenic climate change and air pollution. Despite many years of development, already established methods of influencing behaviour remain ineffective. The effect of such interventions is very often a declaration of behaviour change that is not followed by actual action. Moreover, despite intensive information campaigns, many people still do not have adequate knowledge on the subject, are not aware of the problem or, worse, deny its existence. Previous attempts to introduce real change were based on providing information, persuasion or visualisation. We propose the use of multi-sensory virtual reality to investigate the problem more thoroughly and then design appropriate solutions. In this paper, we introduce a new immersive virtual environment that combines free exploration with a high level of experimental control, physiological and behavioural measures. It was created on the basis of transdisciplinary scientific cooperation, participatory design and research. We used the unique features of virtual environments to reverse and expand the idea of pollution pods by Pinsky. Instead of closing participants in small domes filled with chemical substances imitating pollution, we made it possible for them to freely explore an open environment - admiring the panorama of a small town from the observation deck located on a nearby hill. Virtual reality technology enables the manipulation of representations of air pollution, the sensory modalities with which they are transmitted (visual, auditory, tactile and smell stimuli) and their intensity. Participants’ reactions from the initial tests of the application showed that it is a promising solution. We present the possibilities of applying the new solution in psychological research and its further design and development opportunities in collaboration with communities and other stakeholders in the spirit of citizen science.
Folk Plant Names Are Condensed Forms of Traditional Knowledge: Case Study with the Urang Kanekes of Banten, Indonesia
Authors: Hidayati Syafitri , Franco F. Merlin , Suhaimi Aznah
Published: July 2022

A new wave of research emerging in the last two decades has turned the focus of linguistic ethnobiology on folk names used by local communities to denote biota. Studies have used traditional knowledge or linguistic approaches to unravel the elaborate body of knowledge used to generate folk names and link them to their appropriate denotatum. In this chapter, we present the folk food plant names of the Kanekes community of Banten Indonesia, classifying them into barefaced or cryptic based on apparency of Traditional Knowledge (TK) encoded in them. Barefaced folk names are self-explanatory names where the TK on the salient feature of the respective taxa is apparent. Cryptic names are those with TK either not readily comprehensible, or those containing TK on multiple taxa/entities. We found the 294 food plant names recorded by us encoding traditional knowledge related to morphology (161), ecology (45), utility (39), and quality (49) of the taxa. The majority of the names documented (172 names) are cryptic (111 metaphors, 53 metonyms, and 08 portmanteaus), while the rest are barefaced (122 names). Our study shows that cryptic names possess a remarkable ability to encode traditional knowledge on multiple taxa/entities. When folk names are lost or replaced, the traditional knowledge encoded by them is also lost. Researchers and practitioners working with local communities should therefore consider the potential of folk names as condensed forms of traditional knowledge.
Cluster analysis of extracellular matrix biomarkers predicts the development of impaired systolic function within 1 year of acute myocardial infarction
Authors: Brunton-O’Sullivan Morgane M. , Holley Ana S. , Shi Bijia , Harding Scott A. , Larsen Peter D.
Published: July 2022

The clinical utility of combining extracellular matrix (ECM) biomarkers to predict the development of impaired systolic function following acute myocardial infarction (AMI) remains largely undetermined. A combination of ELISA and multiplexing assays were performed to measure matrix metalloproteinase (MMP)-2, MMP-3, MMP-8, MMP-9, periostin, N-terminal type I procollagen (PINP) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in plasma samples from 120 AMI patients. All patients had an echocardiogram within 1 year of AMI, and were divided into impaired (n = 37, LVEF < 50%) and preserved (n = 83, LVEF ≥ 50%) systolic function groups. Exploratory factor analysis was performed on log-transformed biomarkers using principle axis analysis with Oblimin rotation. Cluster analysis was performed on log-transformed and normalised biomarkers using Ward’s method of minimum variance and the squared Euclidean distance metric. Upon univariate analysis, current smoking, prescription of ACE inhibitors at discharge, peak hsTnT > 610 ng/L (median), MMP-8 levels, Factor 1 scores and Cluster One assignment were predictive of impaired systolic function. Upon multivariate analysis, Cluster One assignment (odds ratio [95% CI], 2.74 [1.04–7.23], p = 0.04) remained an independent predictor of systolic dysfunction in combination with clinical variables. These observations support the usefulness of combining ECM biomarkers using cluster analysis for predicting the development of impaired systolic function in AMI patients.
A Formalization of SQL with Nulls
Authors: Ricciotti Wilmer , Cheney James
Published: July 2022

SQL is the world’s most popular declarative language, forming the basis of the multi-billion-dollar database industry. Although SQL has been standardized, the full standard is based on ambiguous natural language rather than formal specification. Commercial SQL implementations interpret the standard in different ways, so that, given the same input data, the same query can yield different results depending on the SQL system it is run on. Even for a particular system, mechanically checked formalization of all widely-used features of SQL remains an open problem. The lack of a well-understood formal semantics makes it very difficult to validate the soundness of database implementations. Although formal semantics for fragments of SQL were designed in the past, they usually did not support set and bag operations, lateral joins, nested subqueries, and, crucially, null values. Null values complicate SQL’s semantics in profound ways analogous to null pointers or side-effects in other programming languages. Since certain SQL queries are equivalent in the absence of null values, but produce different results when applied to tables containing incomplete data, semantics which ignore null values are able to prove query equivalences that are unsound in realistic databases. A formal semantics of SQL supporting all the aforementioned features was only proposed recently. In this paper, we report about our mechanization of SQL semantics covering set/bag operations, lateral joins, nested subqueries, and nulls, written in the Coq proof assistant, and describe the validation of key metatheoretic properties. Additionally, we are able to use the same framework to formalize the semantics of a flat relational calculus (with null values), and show a certified translation of its normal forms into SQL.
Molecular Circuit Discovery for Mechanobiology of Cardiovascular Disease
Authors: Yu Xinren , Doyle Adele
Published: July 2022

Purpose

Cardiovascular diseases, the world’s leading cause of death, are linked to changes in tissue mechanical and material properties that affect the signaling of cells in the damaged tissue. It is hard to predict the effect of altered physical cues on cell signaling though, due to the large number of molecules potentially involved. Our goal is to identify genes and molecular networks that mediate cellular response to cardiovascular disease and cardiovascular-related forces.

Methods

We used custom computer code, statistics, and bioinformatics tools to meta-analyze PubMed-indexed citations for mentions of genes and proteins.

Results

We identified the names and frequencies of genes studied in the context of mechanical cues (shear, strain, stiffness, and pressure) and major diseases (stroke, myocardial infarction, peripheral arterial disease, deep vein thrombosis). Using statistical and bioinformatics analyses of these biomolecules, we identified the cellular functions and molecular gene sets linked to cardiovascular diseases, biophysical cues, and the overlap between these topics. These gene sets formed independent molecular circuits that each related to different biological processes, including inflammation and extracellular matrix remodeling.

Conclusion

Computational analysis of cardiovascular and mechanobiology publication data can be used for discovery of evidence-based, data-rich gene networks suitable for future systems biology modeling of mechanosignaling.
Constraints on Future Analysis Metadata Systems in High Energy Physics
Authors: Khoo T. J. , Reinsvold Hall A. , Skidmore N. , Alderweireldt S. , Anders J. , Burr C. , Buttinger W. , David P. , Gouskos L. , Gray L. , Hageböck S. , Krasznahorkay A. , Laycock P. , Lister A. , Marshall Z. , Meyer A. B. , Novak T. , Rappoccio S. , Ritter M. , Rodrigues E. , Rumsevicius J. , Sexton-Kennedy L. , Smith N. , Stewart G. A. , Wertz S.
Published: July 2022

In high energy physics (HEP), analysis metadata comes in many forms—from theoretical cross-sections, to calibration corrections, to details about file processing. Correctly applying metadata is a crucial and often time-consuming step in an analysis, but designing analysis metadata systems has historically received little direct attention. Among other considerations, an ideal metadata tool should be easy to use by new analysers, should scale to large data volumes and diverse processing paradigms, and should enable future analysis reinterpretation. This document, which is the product of community discussions organised by the HEP Software Foundation, categorises types of metadata by scope and format and gives examples of current metadata solutions. Important design considerations for metadata systems, including sociological factors, analysis preservation efforts, and technical factors, are discussed. A list of best practices and technical requirements for future analysis metadata systems is presented. These best practices could guide the development of a future cross-experimental effort for analysis metadata tools.
Cabinet Reshuffles and Parliamentary No-Confidence Motions
Authors: Fleming Thomas G. , González-Bustamante Bastián , Schleiter Petra
Published: July 2022

How do cabinet reshuffles affect the parliamentary opposition's use of no-confidence motions in the government? Opposition parties employ no-confidence motions as electoral signals to highlight government incompetence and to position themselves as a government in waiting. We argue that cabinet reshuffles – which prime ministers use to respond to policy failures, scandals, poor ministerial performance and disloyalty – present an opportunity for the opposition to deploy no-confidence motions to this end. The incentives to deploy this strategy, however, are contingent on the nature of the party system and are greatest where party-system concentration positions a single opposition party as the alternative to the government and sole beneficiary of a no-confidence vote. We test this expectation using a multilevel modelling approach applied to data on reshuffles in 316 governments and 16 parliamentary democracies, and find support for our expectation: cabinet reshuffles raise the probability of no-confidence motions conditional on party-system concentration.
INTRODUCTION Commercial Speech and the Commercial Determinants of Health
Authors: Garde Amandine , Cabrera Oscar A.
Published: July 2022

This article introduces a symposium that aims to identify and critically assess the legal strategies of the tobacco, alcohol, and food and beverage industries which rest on freedom of expression arguments.
Commercial Speech and Unhealthy Food Products: Conceptual Foundations
Authors: Constantin Andrés , Hevia Martín , Cabrera Oscar A.
Published: July 2022

This article provides a critical and philosophical assessment of arguments invoked for and against the constitutional protection of commercial expression and the regulation of commercial speech with a focus on the commercialization of unhealthy food products.
Economic Perspectives on Food Choices, Marketing, and Consumer Welfare
Authors: Etilé Fabrice
Published: July 2022

This contribution reviews the main normative and positive arguments that can used in the assessment of the costs and benefits of food marketing restrictions, focusing specifically on theoretical and empirical developments in the economics of advertising, consumer behaviour and industrial organization since the 70s.
United States: Protecting Commercial Speech under the First Amendment
Authors: Pomeranz Jennifer L.
Published: July 2022

The First Amendment to the US Constitution protects commercial speech from government interference. Commercial speech has been defined by the US Supreme Court as speech that proposes a commercial transaction, such as marketing and labeling. Companies that produce products associated with public health harms, such as alcohol, tobacco, and food, thus have a constitutional right to market these products to consumers. This article will examine the evolution of US law related to the protection of commercial speech, often at the expense of public health. It will then identify outstanding questions related to the commercial speech doctrine and the few remaining avenues available in the United States to regulate commercial speech including the use of government speech and addressing deceptive and misleading commercial speech.
Public Health Protection vs. Freedom of Commercial Expression in the Commonwealth Caribbean: The Case of Barbados and Jamaica
Authors: Lake Shajoe J. , Benjamin Kimberley E. , Foster Nicole D.
Published: July 2022

This chapter explores the tension between public health protection and the freedom of commercial expression from a Commonwealth Caribbean perspective, using Barbados and Jamaica as case studies. First, it assesses the scope of the right to freedom of expression. Second, it discusses the extent to which public health protection may be invoked to restrict the right. The authors conclude that Commonwealth Caribbean states can justifiably restrict commercial speech about tobacco products and unhealthy food and beverages.
Robustness of the subsonic doublet lattice method
Authors: Zyl L. H. van
Published: July 2022

The subsonic doublet lattice method (DLM) has been the industry standard method for the calculation of unsteady air loads for the past three decades. A recent comparison between the DLM and the subsonic constant pressure panel code ZONA6 suggested that the DLM lacked robustness. However, the DLM code used in the comparison was flawed and not representative of the DLM as such. Results from a contemporary DLM code are presented for the same test cases that were used in the misleading comparison. These new results show that the DLM can produce valid results for all the test cases considered. Where feasible, a comparison is made between results from the present DLM code and the published ZONA6 results.
The broad delta airliner
Authors: Denning R. M. , Allen J. E. , Armstrong F. W.
Published: July 2022

Aeronautics faces new and increased challenges in the 21st century. These include climate change, long-term fuel supply, traffic congestion, and noise pollution. Radical technological steps will be demanded of the industry in order to maintain a sustainable transportation system.

In setting out its ideas for a Sonic Cruiser, Boeing has recently acknowledged that there is a need to look beyond the high-aspect-ratio wing with separate fuselage and podded engine configuration, which it pioneered at the start of the Jet era.

This paper sets out the case for the broad delta including its advantages as a basis for achieving higher transonic cruising speeds, with very long range and large payloads, while providing progressive and significantly improved environmental impact. The work is based on concept designs drawing on flight and weight data from the Vulcan bomber and the Concorde aircraft – both pioneering designs, by no means at the end of their technical potential.

A broad delta is taken to mean an aircraft of aspect ratio in the range 2 to 4. Not only does such a planform have application to many sizes of airliner, cruising at various high subsonic speeds, but also it is inherently well suited to later application of laminar flow. Wing surfaces undisturbed by flaps and slots and unhampered by very thick wing skins, together with favourable engine inlet locations, could be a basis for improved overall aerodynamic efficiency.

Airliners designed for operation in the region of Mach 1 are likely to pose more difficult problems for the aerodynamicist. Designs must cater for both cruise and maximum design speeds, which may encompass the Mach 1 condition.
The birth of flight control: An engineering analysis of the Wright brothers’ 1902 glider
Authors: Padfield G. D. , Lawrence B.
Published: July 2022

In the autumn of 1902 the Wright brothers spent just over eight weeks at their test site in the Kill Devil Hills near Kitty Hawk, North Carolina, testing their third Glider design. During the trial period they implemented an inter-linked roll-yaw control system. Together with the forward canard surface, this gave them control over vertical and horizontal components of the flight path. They were also able to hone and perfect their piloting skills. In just two days in the final week, they made about 250 glides. The success of the trials instilled the confidence in the Wright brothers to proceed rapidly to the construction of a powered aircraft. Within a month of returning to Dayton, they were writing to engine manufacturers with their specification – an engine that would develop eight to nine brake horse power, weigh no more than 180lb and be free from vibration; they would not find a suitable powerplant and had to design and build their own. The invention of the powered aeroplane in 1903 somewhat overshadows the earlier critical flight control developments, but the birth of flight control in 1902 opened the way for aviation to flourish. With the aid of modern flight science techniques – wind-tunnel testing, computational flight dynamics and piloted simulation, this paper examines the technology of the Wrights' 1902 glider. The research forms a part of the Liverpool Wright Project, aiming to bring to life the Wright brothers' achievements in this centenary period. Wilbur and Orville Wright are recognised by many as the first aeronautical engineers and test pilots. In so many ways they set standards that today's engineers and organisations benefit from. Their work in the period 1901 to 1902 reflects their genius and the paper reviews this work in detail, examining the design, aerodynamic characteristics and flying qualities of the aircraft that first featured a practical three-axis control system.
Aerospace applications of luminescent paint
Authors: Kingsley-Rowe J. R. , Lock G. D. , Davies A. G.
Published: July 2022

Luminescent paints allow non-intrusive measurement of pressure and temperature at high spatial resolution without prior knowledge of the flow-field. Experiments have demonstrated that a ‘standard’ luminescent paint technique, developed by BAE Systems, can simultaneously measure steady pressure and temperature. This is achieved through knowledge of the paint phosphorescence lifetime rather than the absolute intensity, which increases the measurement accuracy. In addition, a new ‘fast’ paint has been calibrated at the University of Bath for the measurement of unsteady pressure using a variable frequency pulsing air jet. Pressure measurements were made with both paints in the wake of various excrescences, sized to produce vortex shedding in the frequency range 500–4,200Hz, in a transonic tunnel. The extent of the wakes was determined from a flow visualisation technique. Time-averaged measurements, using both luminescent paints, and transient measurements of the unsteady pressure field, made with the fast paint, were compared with transducer data. For all cases the luminescent paint data compared well with the conventional measurements and the Strouhal number agreed well with data from the literature. The use of luminescent paint for the simultaneous measurement of pressure and temperature over a NACA 0012 aerofoil, as well as the quantification of convective heat transfer is examined in Part 2.
Aircraft airworthiness certification standards for civil UAVs
Authors: Haddon D. R. , Whittaker C. J.
Published: July 2022

The CAA has recognised the need to develop civil standards for unmanned aerial vehicles (UAVs). Accordingly the CAA Directorate of Airspace Policy has published the document ‘CAP 722 – Unmanned Air Vehicle Operation in UK Airspace – Guidance’, (which can be accessed via the CAA website — http://www.caa.co.uk/docs/33/CAP722.pdf). The document itemises the top-level military and civil regulations which impact upon the operation of UAVs in the UK. One of the items listed within the document is ‘Civil Certification’ of UAVs. This particular aspect is the responsibility of the Design and Production Standards Division, (D&PSD), of the CAA Safety Regulation Group. The purpose of this paper is to present and explain the current position of D&PSD regarding the appropriate design standards to be applied for the civil certification of the airworthiness of UAVs.

This paper presents the CAA position that UAVs should be granted permission to fly by qualifying for certificates of airworthiness, by demonstration of compliance with defined airworthiness standards comparable to, and derived from, those applied to manned aircraft. The paper also presents a method for determining, to a first approximation, the level of airworthiness standards which should be applied to any particular design of UAV by reference to the existing codes of airworthiness requirements for manned aircraft.
Effects of sweep on the dynamics of active separation control
Authors: Pack L. G. , Seifert A.
Published: July 2022

A series of active flow control experiments were recently conducted at high Reynolds numbers on a wall mounted ‘Hump’. The model simulates the upper surface of a 20% thick Glauert-Goldschmied type airfoil at zero incidence. The flow over the model is turbulent since the tunnel sidewall boundary-layer flows over it, eliminating laminar-turbulent transition from the problem. The main motivation for the experiments was to generate a comprehensive data base for validation of unsteady numerical simulation as a first step in the development of a design tool, without which it would not be possible to effectively utilise the great potential of unsteady flow control. This paper focuses on the dynamics of several key features of the baseline as well as the controlled two- and three-dimensional flows.

It was found that the two-dimensional separated flow contains unsteady waves centered on a reduced frequency (Strouhal number based on the length of the separated region and free-stream velocity) of 0·8, while in the three-dimensional separated flow, reduced frequencies of 0·3 and 1·0 are active. Several scenarios of resonant wave interaction take place over the separated shear-layer and in the pressure recovery regions. The unstable reduced frequency bands for periodic excitation are centered on 1·5 and 5, but these reduced frequencies are based on the length of the baseline bubble that shortens due to the excitation. The conventional swept wing-scaling works well for the coherent wave features. Reproduction of these dynamic effects by a numerical simulation would provide benchmark validation.
A comparison of turning radii for four Battle
of Britain fighter aircraft
Authors: Ackroyd J. A. D. , Lamont P. J.
Published: July 2022

Prompted by claims made in the popular aviation literature, analysis is used in an attempt to estimate the turning performance of certain fighter aircraft flown during the Battle of Britain. In this it is necessary to provide values for such aerodynamic quantities as the drag coefficient at zero lift and these are estimated from published flight data.
Computing the motion of spinning finned projectiles
Authors: Thomasson P. G.
Published: July 2022

The inertia characteristics of symmetrically finned projectiles are shown to be invariant of roll angle. This special property is used to derive ‘despun’ equations of motion so avoiding the rapid rates of change associated with the use of body fixed axes. By exploiting the special inertia and aerodynamic characteristics of symmetrically finned spinning projectiles it is possible to reduce the computer solution time required for long down range calculations. By combining the system with the use of quaternions for attitude determination, firings at high elevation can also be accommodated. A speed up by an order of magnitude is observed for the example of a 40mm shell.
The aerodynamic interaction at the junction between a forward-swept wing and a plate
Authors: Arnottt A. D. , Bernstein L.
Published: July 2022

A study has been carried out of the aerodynamic interference flow arising at the junction of a cambered, swept-forward wing and a flat plate on which a fully-developed turbulent boundary layer approached the junction. CFD predictions of the pressure field in the junction region were carried out. Flow visualisation tests and surface pressure measurements over a wind-tunnel model were conducted at incidences from -3° to +9°. With the wing at zero incidence, a single-tube yawmeter was used to explore the flow around the leading edge of the junction arid an X-wire anemometer to examine the mean velocity and turbulence fields in the streamwise corners and at the trailing edge. The Reynolds number of the tests, based on the streamwise chord and a free-stream velocity of 30ms-1, was 1·03 x 106.

At low incidence, a very weak separation occurred in the plate boundary layer, a very short distance upstream of the junction. However the oncoming stream converges into the junction, appearing to confine any vortical motion at the leading edge to within a very thin layer below the closest point of measurement to the plate. Rudimentary vortical flow developed slightly downstream of the leading edge, but dissipated further downstream. Although weak vortices were measured in the trailing-edge cross-flow plane, these were attributed to separations just upstream. The turbulence activity in the streamwise corners was found to be surprisingly low, especially on the compression side of the junction. Estimates of the skin-friction showed that it was lower over the majority of the trailing-edge crossplane than in the plate boundary layer upstream of the junction. At higher incidences, flow visualisations revealed severe stall in the junction, with large three-dimensional recirculating regions forming.
Some observations on the relaminarisation of a supersonic turbulent boundary layer
Authors: Cohen G. S. , Motallebi F. , Horton H. P.
Published: July 2022

In a number of applications, turbulent boundary layers are exposed to a gradual or rapid acceleration. As a result of this, the flow may change to a laminarised state before retransitions again to a turbulent flow. This change of state (turbulent-laminar-turbulent) can have drastic effects on a variety of engineering problems. For example it has significant effects on the heat transfer rate at a boundary over which it is flowing, the mixing of fuel and air in the scramjet combustors, the mixing process in the wake of a transonic turbine blade and hence the base drag, etc.
On the aerodynamic characteristics of thin slab delta wings at hypersonic speeds — part 1: interference of lee side bodies
Authors: Ramesh R. , Ramaswamy M. A. , Vasudevan B. , Prabhu A.
Published: July 2022

An experimental investigation on the interference effect of lee-side balance housing bodies on the longitudinal aerodynamic characteristics of thin slab delta wings has been made using a special and novel thin three-component balance. This study has been conducted using wings with a t/c of 0.053 and sweep of 76°, 70° and 65° for three different lee-side bodies viz:Body (A), Body (B) and Body (C) of which Body (C) is the smallest. The testing was carried out at Mach number of 8·2, Reynolds number of 2·13 ˘ 106 and incidence of –4° to 12°. For the smallest body (Body (C)) tested, at the incidence at which this body first goes into the aerodynamic shadow of the wing (α = 6·5°), the difference in CN, CA, CM and L/D between the wing-body and the plain wing is around by 22%, 12%, 75% and 35% respectively. This difference decreases with increase in incidence and at the highest angle-of-attack up to which testing was done (α = 12°), the. corresponding values of CN, CA, CM and L/D are around 9%, 12%, 15% and 4% respectively. Contrary to the assumption in the literature pertinent to force measurements on thin slab delta wings, the interference of the lee-side bodies are found to be appreciable even after they come into the aerodynamic shadow of the wing.
50 years of turbomachinery research at Pyestock — part one: compressors
Authors: Dunham J.
Published: July 2022

The two parts of this paper summarise the turbomachinery research
undertaken at Pyestock during the 50 years since the National Gas Turbine Establishment was formed in 1946. The theoretical and experimental activities are described, and their influence on UK military and civil aero engines is assessed. The way in which NGTE supported non-aeronautical gas turbines is also explained. Part one provides a general introduction and then covers compressors.
Aerodynamic characteristics of lambda wings
Authors: Woods M. I. , Wood N. J.
Published: July 2022

The results of wind tunnel tests carried out on a semi-span ‘lambda’ planform model with leading and trailing edges swept at 40° are presented. The planform investigated has been specified as having features likely to be encountered on future ‘ow observable’ aircraft. Balance data has been acquired to angles of attack beyond stall for both forward and reverse flow orientations. Dynamic calibration of surface pressure tappings has allowed both time-averaged and unsteady pressures to be measured over the entire upper surface of the wing. Unsteady pressure time histories have been analysed in the frequency domain to identify their spatial resolution, dominant frequencies and associated magnitudes.

In forward flow conditions, maximum buffet is observed between the primary attachment of the leading edge vortex system and the vortex core. The dominant buffet frequency is shown to be dependant on the chordwise location, incidence and free stream velocity as expected. A second coherent buffet frequency has been identified in the region of high buffet over a wide range of operating conditions. Inboard of this region a third dominant frequency has been observed. This is of an intermediate frequency and varies in a similar manner. A simple mechanism has been proposed to explain both the spanwise RMS distribution and the presence of a number of coherent buffet frequencies.