bluuebunny/crossref_metadata_2025 huggingface dataset:
Globalising or assimilating? Exploring the contemporary function of regionalised global university rankings in Latin America
Authors: Darwin Stephen , Barahona Malba
Published: February 2023

Global university rankings (GUR) have become increasingly influential as a proxy measure of higher education quality. The more recent development of regionalised forms of rankings has increased their global reach, drawing a greatly expanded range of institutions into their orbit. As a result, regionalised GUR have developed an increasing potential power to shape social perceptions, institutional actions, and everyday academic practices. In this paper, the perceived impact of regionalised forms of GUR is analysed from the perspective of Latin American higher education. Based on a critical meta-synthesis framed by a glonacal heuristic (Marginson and Rhoades, Higher Education 43:281–309, 2002), the tensions arising around the application of regionalised forms of global rankings are mapped. Specifically, the impact of rankings on conceptions of the mission of universities is foregrounded. The meta-synthesis identifies three primary tensions around the regional application of GUR in Latin American contexts: how conceptions of regional higher education quality are most effectively developed, how the local university is imagined under the weight of global expectations, and the relativised value of local agency in assessing quality outcomes. The findings suggest that GUR have created strong fissures in Latin American higher education regarding the missions of institutions, particularly in confronting the powerful hegemonies of the epistemologies of the Global North imposing themselves on Latin American higher education. The paper concludes that the stratification and social anxiety caused by the regional applications of GUR may not be necessarily productive in encouraging regional institutional diversity or in enhancing the local relevance of higher education.
Conduction system pacing: promoting the physiology to prevent heart failure
Authors: Tun Han Naung , Khan Hafiza , Chernikova Daryna , Mareev Yury , Chakrabarti Santabhanu , Thant May , Cannata Antonio
Published: February 2023

Cardiac conduction system pacing provides physiological ventricular activation by directly stimulating the conduction system. This review describes the two types of conduction system pacing: His bundle pacing (HBP) and left bundle area pacing (LBAP). The most significant advantage of HB pacing is that it can provide a regular, narrow QRS; however, the disadvantages are challenging implantation and a high risk of re-intervention due to lead dislodgement and the development of high pacing threshold. LBAP provides optimum physiological activation of the left ventricle by engaging the left bundle/fascicular fibers. LBAP is more physiological than traditional RV apical pacing and could be an attractive alternative to conventional cardiac resynchronization therapy (CRT). The advantages of LBAP are a relatively more straightforward implantation technique than HBP, better lead stability and pacing thresholds. HBP and LBAP are more physiological than right ventricular pacing and may be used instead of conventional pacemakers. Both HBP and LBBP are being investigated as alternatives to conventional CRT.
Existence of Optimal Control for Dirichlet Boundary Optimization in a Phase Field Problem
Authors: Wodecki Aleš , Balázsová Monika , Strachota Pavel , Oberhuber Tomáš
Published: February 2023

Phase field modeling finds utility in various areas. In optimization theory in particular, the distributed control and Neumann boundary control of phase field models have been investigated thoroughly. Dirichlet boundary control in parabolic equations is commonly addressed using the very weak formulation or an approximation by Robin boundary conditions. In this paper, the Dirichlet boundary control for a phase field model with a non-singular potential is investigated using the Dirichlet lift technique. The corresponding weak formulation is analyzed. Energy estimates and problem-specific embedding results are provided, leading to the existence and uniqueness of the solution for the state equation. These results together show that the control to state mapping is well defined and bounded. Based on the preceding findings, the optimization problem is shown to have a solution.
On the nonlinear dynamics of a piezoresistive based mass switch based on catastrophic bifurcation
Authors: Azizi Saber , Madinei Hadi , Khodaparast Hamed Haddad , Faroughi Shirko , Friswell Michael I.
Published: February 2023

This research investigates the feasibility of mass sensing in piezoresistive MEMS devices based on catastrophic bifurcation and sensitivity enhancement due to the orientation adjustment of the device with respect to the crystallographic orientation of the silicon wafer. The model studied is a cantilever microbeam at the end of which an electrostatically actuated tip mass is attached. The piezoresistive layers are bonded to the vicinity of the clamped end of the cantilever and the device is set to operate in the resonance regime by means of harmonic electrostatic excitation. The nonlinearities due to curvature, shortening and electrostatic excitation have been considered in the modelling process. It is shown that once the mass is deposited on the tip mass, the system undergoes a cyclic fold bifurcation in the frequency domain, which yields a sudden jump in the output voltage of the piezoresistive layers; this bifurcation is attributed to the nonlinearities governing the dynamics of the response. The partial differential equations of the motion are derived and discretized to give a finite degree of freedom model based on the Galerkin method, and the limit cycles are captured in the frequency domain by using the shooting method. The effect of the orientation of the device with respect to the crystallographic coordinates of the silicon and the effect of the orientation of the piezoresistive layers with respect to the microbeam length on the sensitivity of the device is also investigated. Thanks to the nonlinearity and the orientation adjustment of the device and piezoresistive layers, a twofold sensitivity enhancement due to the added mass was achieved. This achievement is due to the combined amplification of the sensitivity in the vicinity of the bifurcation point, which is attributed to the nonlinearity and maximizing the sensitivity by orientation adjustment of the anisotropic piezoresistive coefficients.
Extending the usability of the force-flow based topology optimization to the process of generative design
Authors: Birosz Márton Tamás , Bátorfi János György , Andó Mátyás
Published: February 2023

Topology optimization and Generative Design are two methods to create volume or stiffness optimized parts and they are used more frequently nowadays. However, the specific methods are often not well described and the connection between these two is not clearly explained. In this article, a force-flow based topology optimization process has been explained in detail and extended with a function to be able to use as a Generative Design tool. The proposed algorithm has been tested on three 2D shapes and the effectiveness was evaluated. This work clarifies the vague description of theoretical solutions by presenting in detail the operation of the algorithm and bridging the lack of information that exists between the shape or topology optimization procedure and the generative design solution.
MRI-based artificial intelligence to predict infection following total hip arthroplasty failure
Authors: Albano Domenico , Gitto Salvatore , Messina Carmelo , Serpi Francesca , Salvatore Christian , Castiglioni Isabella , Zagra Luigi , De Vecchi Elena , Sconfienza Luca Maria
Published: February 2023

Purpose

To investigate whether artificial intelligence (AI) can differentiate septic from non-septic total hip arthroplasty (THA) failure based on preoperative MRI features.

Materials and methods

We included 173 patients (98 females, age: 67 ± 12 years) subjected to first-time THA revision surgery after preoperative pelvis MRI. We divided the patients into a training/validation/internal testing cohort (n = 117) and a temporally independent external-testing cohort (n = 56). MRI features were used to train, validate and test a machine learning algorithm based on support vector machine (SVM) to predict THA infection on the training-internal validation cohort with a nested fivefold validation approach. Machine learning performance was evaluated on independent data from the external-testing cohort.

Results

MRI features were significantly more frequently observed in THA infection (P < 0.001), except bone destruction, periarticular soft-tissue mass, and fibrous membrane (P > 0.005). Considering all MRI features in the training/validation/internal-testing cohort, SVM classifier reached 92% sensitivity, 62% specificity, 79% PPV, 83% NPV, 82% accuracy, and 81% AUC in predicting THA infection, with bone edema, extracapsular edema, and synovitis having been the best predictors. After being tested on the external-testing cohort, the classifier showed 92% sensitivity, 79% specificity, 89% PPV, 83% NPV, 88% accuracy, and 89% AUC in predicting THA infection. SVM classifier showed 81% sensitivity, 76% specificity, 66% PPV, 88% NPV, 80% accuracy, and 74% AUC in predicting THA infection in the training/validation/internal-testing cohort based on the only presence of periprosthetic bone marrow edema on MRI, while it showed 68% sensitivity, 89% specificity, 93% PPV, 60% NPV, 75% accuracy, and 79% AUC in the external-testing cohort.

Conclusion

AI using SVM classifier showed promising results in predicting THA infection based on MRI features. This model might support radiologists in identifying THA infection.
An algebraic approach to symmetric linear layers in cryptographic primitives
Authors: Subroto Robert Christian
Published: February 2023

Subterranean 2.0 is a permutation-based cipher suite which works with a 257 bit-state. It is designed for lightweight cryptography, and it scores very well with respect to energy consumption. Its security has been investigated by the designers against well-known attack vectors. A possible point of concern is the relatively low order of its linear layer, which equals 256. In the past, such properties have been exploited by invariant subspace attacks. We define linear mappings with a similar structure as the linear layer of Subterranean as SC-compositions. In this work, we explore finding SC-compositions with a higher order than 256. We rely on concepts from abstract algebra and number theory to understand the relation between the order and the bit-states of SC-compositions. Using a 257 bit-state as done in Subterranean is an unfortunate choice for designing such SC-compositions with a high order. We present two examples with different bit-states, each having a significantly higher order than 256.
Methodologies to reveal young Australian Indigenous students’ mathematical proficiency
Authors: Reid O’Connor Bronwyn
Published: February 2023

A 7-month mathematics proficiency program was conducted in a primary Australian Indigenous community school. This paper focuses on outlining the specific methodologies employed to explore how students’ mathematical proficiency changed throughout the implementation of the program in Years 2 to 4 (~ 7 to 9 years old). A mixed methods research design was utilised, and findings will be presented to evidence how the combination of standardised tests, diagnostic tests, and Newman interviews were useful in capturing and making visible young Indigenous student’s mathematical proficiency. Whilst standardised tests provided a useful and comparable measure of student achievement, diagnostic tests and Newman interviews gave space for Indigenous student voice and demonstrated their strengths and areas for improvement in relation to their conceptual understanding, procedural fluency, and strategic competence. From these findings, recommendations concerning the adjustment of data collection procedures for young students in this setting are presented. The findings question the accuracy of standardised tests in revealing young students’ proficiency, and this has implications for the extent to which standardised tests are relied upon to inform educational reform particularly for Indigenous students. Striving for equitable educational outcomes is an important endeavour in Australia, and such undertakings must be driven by meaningful and accurate evidence of students’ proficiency in mathematics.
Mapping of total suspended solids using Landsat imagery and machine learning
Authors: Torres-Vera M.-A.
Published: February 2023

The main objective of this work is to propose a new technique for water quality parameters monitoring by applying artificial intelligence methods to optimize remote sensing data processing. A multiple regression model was developed to create a total suspended solids (TSS) prediction model, using unsupervised machine learning. Currently, water bodies throughout the world are poorly supervised in terms of quality, so it is necessary to implement efficient mechanisms to obtain synoptic information for a good diagnosis in TSS evolution, because they are a key indicator of the biophysical state of lakes and an essential marker for continuous monitoring. Conventional methods used to monitor the physical parameters of water bodies, for example, in situ sampling, have proven impractical due to time, cost and space constraints, and remote sensing tools can help to achieve this purpose more efficiently. The proposed multiple regression model requires calibration and to that end, Lake Chapala data from the monitoring time series collected by the National Water Commission (CONAGUA) were used. Lake Chapala is the largest freshwater body in Mexico, and the human intervention that develops around the lake has caused drastic changes such as decrease in the size of the lake and increase in suspended matter and aquatic vegetation. These changes alter the balance of the system, endangering the health of the lake. This work presents a generalized semi-empirical model that uses Landsat image data and machine learning methods for estimating total suspended solids (TSS) in water bodies, with a good prediction precision (R = 0.81, RMSE = 32.52).
Avian ichnofauna from Sierra de las Cabras tracksite (late Miocene, Jumilla, SE Spain)
Authors: Herrero Cayetano , Herrero Emilio , Martín‑Chivelet Javier , Pérez‑Lorente Félix
Published: February 2023

The Sierra de las Cabras (Lat. 38° 28′ 53″N, Lon. 1° 24′ 52″W) is an exceptional ichnofossil site of late Miocene age, located in the Prebetic ranges near the town of Jumilla (Murcia Province, SE Spain). The site contains abundant vertebrate ichnofauna preserved in carbonate facies that were deposited in a semi-arid wetland system with shallow ponds and marshes. The ichnofauna includes diverse mammal footprints and trackways, which have been recently studied, as well as bird ones, which are the target of this paper. We report a total of 51 avian footprints spread over two of the three track-bearing stratigraphic surfaces of the site. The detailed study of these ichnites (footprints and trackways) allows their attribution to the ichnogenus Fuscinapeda (Sarjeant and Langston, Texas Memorial Museum Bulletin 36:1–86, 1994), as well as to infer diverse patterns of bird’s behavior consistent with shallow water wetlands avifauna. Also, we discuss about the possible trackmakers, which should correspond to walking birds characterized by long legs, with no hallux or a raised one, which could probably belong to the Gruiformes order. The study confirms the presence of Fuscinapeda in the Iberian Peninsula and completes the characterization of the vertebrate ichnofauna of Sierra de las Cabras, a site that joins the nearby Hoya de la Sima ichnofossil site to yield the largest and most diverse record of vertebrate ichnites of late Miocene age in southern Iberia.
Patient Assessment and Therapy Planning Based on Homologous Recombination Repair Deficiency
Authors: Li Wenbin , Gao Lin , Yi Xin , Shi Shuangfeng , Huang Jie , Shi Leming , Zhou Xiaoyan , Wu Lingying , Ying Jianming
Published: February 2023

Defects in genes involved in the DNA damage response cause homologous recombination repair deficiency (HRD). HRD is found in a subgroup of cancer patients for several tumor types, and it has a clinical relevance to cancer prevention and therapies. Accumulating evidence has identified HRD as a biomarker for assessing the therapeutic response of tumor cells to poly(ADP-ribose) polymerase inhibitors and platinum-based chemotherapies. Nevertheless, the biology of HRD is complex, and its applications and the benefits of different HRD biomarker assays are controversial. This is primarily due to inconsistencies in HRD assessments and definitions (gene-level tests, genomic scars, mutational signatures, or a combination of these methods) and difficulties in assessing the contribution of each genomic event. Therefore, we aim to review the biological rationale and clinical evidence of HRD as a biomarker. This review provides a blueprint for the standardization and harmonization of HRD assessments.
The International Law of the Sea
Authors: Tanaka Yoshifumi
Published: February 2023

This new edition has been revised and updated to provide current and comprehensive coverage of essential issues of the international law of the sea in a systematic manner. This book presents two paradigms of the law of the sea: the law of divided oceans and the law of our common ocean. It covers contemporary issues, such as protection of the marine biological diversity, marine plastic pollution, the Arctic, and impacts of climate change on the oceans. Following the clear and accessible approach of previous editions, with many illustrations and tables, The International Law of the Sea continues to help students to best understand the law of the sea.
Post-Wall German Cinema and National History
Authors: O'Brien Mary-Elizabeth
Published: February 2023

German history films that focus on utopianism and political dissent and their effect on German identity since 1989.
Barefoot Doctors and Western Medicine in China
Authors: Fang Xiaoping
Published: February 2023

The first study in English that examines barefoot doctors in China from the perspective of the social history of medicine.
Worldmaking at the End of History: The Gulf Crisis of 1990–91 and International Law
Authors: Aber Samuel L.
Published: February 2023

This Article argues that the Gulf Crisis of 1990–91, the first major international crisis of the post-Cold War era, was a constitutive moment for international law. The Article examines the contests in the United Nations over the meaning of the Crisis and shows that these contests were also over the meaning of cooperation under international law in the “new world order.” The Article casts the Gulf Crisis itself as a moment of “worldmaking,” in which the United States refashioned foundational concepts like interdependence, sovereignty, and humanity in warfare and deployed them to suit a state-centered vision of international cooperation under hierarchy.
Structural Elements and Requirements in Forming Prehospital Health Response Teams in Response to Chemical, Biological, Radiation, and Nuclear Incidents (CBRN), a Comparative Review Study
Authors: Nazari Saeed , Sharififar Simintaj , Ahmadi Marzaleh Milad , Zargar Sanaz , Azarmi Somayeh , Akbari Shahrestanaki Yusef
Published: February 2023

One of the important indicators of increasing the capacity of the health system and the chances of survival of patients and injured immediately after chemical, biological, radiation and nuclear (CBRN) accidents is rapid access to medical services. Establishing prehospital health response teams is one of the main strategies to improve the capacity and ability to respond to unusual events. The aim of this study was to investigate the factors influencing the formation of rapid response teams in the field of health in response to chemical, biological, radiation and nuclear accidents (CBRN EDMRT). In this study, the comparative review method was used. The study period was from November 1, 2021 to March 2022. Forming and deploying rapid health response teams based on an extensive multi-step search and keywords in multiple databases such as PubMed, CINHAL, Blackwell, Iranmedex, SID, Cochrane Database of Systematic Reviews, Google Scholar, Scopus Also, the websites of the Ministry of Health and the responsible organizations in different countries and the proposed structure were done by international institutions and sites. After accessing the resources and documents, the process of analysis and comparison of different team structures was performed. After the initial search, the structure and required elements of their teams were extracted. According to published articles and texts, 10 teams from the International Atomic Energy Agency (IAEA), the US Centers for Disease Control and Prevention (CDC), the US Department of Homeland Security, and the North Atlantic Treaty Organization (NATO), Australia, the British Public Health Organization, and the Japanese Red Cross were compared. Team requirements, population distribution, type of accident, level of team activity and training, equipment required by the team after the accident, according to which, each country/organization should consider the above factors to design and establish the structure of CBRN EDMRT to take. A study should be conducted to design a comprehensive and evidence-based structure.
Deep Vein Thrombosis After Earthquake: A Systematic Review and Meta-analysis
Authors: Sahebi Ali , Nejati-Zarnaqi Bayram , Vasei Narges , Jahangiri Katayoun
Published: February 2023

Objective:

Among natural disasters, earthquake is associated with heavy fatalities and financial damages, causing considerable mortality. The complications resulting from getting trapped in rubble, secondary traumas, obligation to reside in temporary shelters, along with other factors such as limited mobility, stress, and dehydration, predispose earthquake survivors to Deep Vein Thrombosis (DVT). The aim of the present study is to investigate the rate of DVT after an earthquake using a systematic review and meta-analysis.

Methods:

To perform the present study, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was used. The protocol of this review study has been registered in the International Perspective Register of Systematic Review (PROSPERO) with the code of CRD42021290375. Credible data resources including PubMed, Scopus, Web of Science, Science Direct, Google Scholar, Magiran, SID, and Embase were used for extracting relevant studies. Random effect model was used to perform the meta-analysis. I2 was ritualized to investigate heterogeneity across the studies. Publication bias of studies was evaluated using the Begg test.

Results:

In this study, 267 primary studies were identified and extracted. After removing the duplicate ones and the screening, eventually 12 final studies were chosen for the meta-analysis. Based on the meta-analysis results, the total rate of DVT was 9.07% (95% confidence interval [CI]: 7.32-10.81; I2 = 97.9%; P = 0<0.001). Analysis of DVT in the subgroups of the general population and patient survivors were 11.43% (95% CI: 9.06-13.79; I2 = 98%; P = 0<0.001) and 2.51% (95% CI: 0.04-4.63; I2 = 77.7%; P = 0.001). Also, based on the Begg test, the publication bias in the chosen studies was not considerable.

Conclusions:

DVT rate in earthquake survivors is higher compared with other disasters, and over time it finds a growing trend. After earthquake, the focus of rescue and health-care teams is on individuals with observable injuries and damages. Because DVT is first asymptomatic but has fatal consequences, including pulmonary embolism and sudden death, it should be incorporated in health’s status assessment of earthquake-stricken people as well as screening and diagnostic programs of health-care providers.
Geoff Harcourt, Political Economist, 1931–2021
Authors: Harcourt Tim
Published: February 2023

This personal biography by the son of GC Harcourt focuses mainly on the political aspects of the life and work of this important Australian and Cambridge economist.
Characterisation of fully developed and equilibrium states of non-electrolyte diffusiophoretic systems via numerical simulations
Authors: da Cunha Sergio , Shcherbakova Nataliya , Gerbaud Vincent , Bacchin Patrice
Published: February 2023

Diffusiophoresis takes place when a particle in solution moves due to the presence of a solute concentration gradient. This phenomenon is often studied under some simplifying assumptions, such as negligible diffusive layer thickness or infinite diffusion coefficient. In this work we simulate diffusiophoresis without these simplifications. The goal of this numerical study is to investigate equilibrium and fully developed states of non-electrolyte phoretic systems. Simulation results show that equilibrium states depend on solute diffusivity and on a reference solute concentration far from the particle. An expression is regressed that gives the (equilibrium) diffusiophoretic velocity as a function of solute concentration gradient, solute diffusion coefficient and the reference solute concentration far from the particle. A different set of results reveals that the state of phoretic systems does not depend on the initial conditions when time goes to infinity. This motivates the definition of fully developed states, designating those systems whose properties no longer depend on initial conditions. Apart from these findings, this work also depicts the effect of solute–interface interactions on diffusiophoresis. Simulation results for two solid particles with different interaction potentials are used to illustrate particle separation via diffusiophoresis. Finally, values of particle mobility are calculated for different solute–interface attraction strengths. These results are compared with another work in the literature, which studies polymer diffusiophoresis via molecular simulations (Ramírez-Hinestrosa et al., J. Chem. Phys., vol. 152, 2020, p. 164901).
Thirty Years of Nation-Building in the Post-Soviet States
Authors: Rutland Peter
Published: February 2023

This introduction to the special issue looks back at 30 years of nation-building in the post-Soviet states. Initial hopes that national self-determination would reinforce democratization proved misplaced. While that synergy worked well in the Baltic states, elsewhere authoritarian leaders embraced nationalism, while democracies like Georgia, Moldova, and Ukraine lost control of parts of their territory to secessionist movements backed by Russia. Each of the post-Soviet states promoted a national language (except for Belarus) and forged a new historical narrative for their “imagined community,” but in most cases they remained multi-ethnic and multi-lingual communities. In recognition of this persisting ethnic diversity, nation-building was accompanied by policies of ethnicity management. The international economic environment was rapidly changing due to globalization, posing new challenges for nation-builders. The gender dimension is important to the new national identities being forged in the post-Soviet space: the categories of race and class, less so. The article concludes with a review of the salient features of each of the newly-independent states.
Climate-driven mid- to late Holocene hydrologic evolution of arid wetlands documented by strontium, uranium, and oxygen isotopes from Lower Pahranagat Lake, southern Nevada, USA
Authors: Theissen Kevin M. , Paces James B.
Published: February 2023

Lacustrine carbonates in a 12.4-m-long core from Lower Pahranagat Lake (LPAH), southern Nevada, indicate that radiogenic isotopes of Sr and U (87Sr/86Sr and 234U/238U) preserve evidence of past variations in water sources and evolving hydrologic conditions. Sr and U isotope compositions in LPAH carbonates fall within the range defined by the three primary groundwater sources in Pahranagat Valley and reflect variable mixtures of those sources since the mid-Holocene. Compositions in the oldest sample (5.78 ka) closely match modern compositions of modern discharge from nearby springs, indicating that LPAH water was derived almost exclusively from the local volcanic aquifer. By ca. 5.3–5.2 ka, LPAH water compositions shifted sharply towards isotopic compositions observed in groundwater from the regional carbonate aquifer, indicating a marked increase in surface flow from high-volume springs discharging from the carbonate aquifer to the north. Sediments deposited between 3.08–1.06 ka indicate reduced contributions from the regional aquifer. A comparison of uranium- and oxygen-isotope values in LPAH carbonates suggests that wetter climate conditions favor increased supply from deeper, regional carbonate aquifers compared to drier conditions when contributions from shallower, local volcanic aquifers were more important.
Non-linear flight dynamics at high angles-of-attack
Authors: Gránásy P. , Thomasson P. G. , Sørensen C. B. , Mosekilde E.
Published: February 2023

The methods of non-linear dynamics are applied to the longitudinal motion of a vectored thrust aircraft, in particular the behaviour at high angles-of-attack. The model contains analytic non-linear aerodynamic coefficients based on Nasa windtunnel tests on the F-18 high alpha research vehicle (Harv). The equilibrium surfaces are plotted against thrust magnitude and thrust deflection and are used to explain the behaviour. When the aircraft is forced with small thrust deflections whilst in poststall equilibrium, chaotic motion is observed at certain frequencies. At other frequencies, several limiting states coexist, e.g. a chaotic attractor and a limit cycle, or two limit cycles. The steady state behaviour then depends on the initial conditions. The non-linear pitching moments are shown to have a significant effect upon the model. Omitting these terms, the region of chaos shrinks, this is not observed for lift.
The making of helicopter flying qualities: a requirements perspective
Authors: Padfield Gareth D.
Published: February 2023

In this review paper, a recurring theme is the interplay between flying qualities as a technical discipline and flying qualities as an operational attribute. This interplay provides the setting for a presentation on the status of helicopter flying quahties, using maritime helicopter operations as the focus, particularly the recovery phase and the helicopter-ship dynamic interface. Poor weather, inducing high sea states and ship motion, along with complex, invisible and disturbing airflow and degraded visibility, make the dynamic interface a particularly demanding environment for both pilot and helicopter.

Flying qualities are a product of four elements — the aircraft, the pilot, the task and the environment — and the maritime application serves to give this viewpoint its full perspective. Mission-oriented flying quahties engineering is described within the systems framework of Aeronautical Design Standard 33 (ADS-33), utilising concepts like the mission task element, usable cue environment, response type and dynamic response criteria. The innovative constructs introduced by ADS-33 for flying qualities in degraded visual conditions are given special attention. The paper argues that the requirements for what constitutes safe and easy, or Level 1, flying qualities now exist and are well substantiated. New aircraft can now be designed to achieve these performance and safety standards while existing aircraft can be upgraded with integrated flight management systems featuring advanced control/flying qualities technologies.

In this context, the paper also promotes the concept of concurrent requirements capture and preliminary design, to maximise the likelihood that user requirements are achieved and that designs are robust and work first time. The multidisciplinary nature of flying qualities is emphasised, embracing aeromechanics and flight dynamics, controls and displays and human factors. Similarly, the importance of high-fidelity design tools and comprehensive evaluation methods in the concurrent process is stressed.

Handling deficiencies can increase the risk of helicopter accidents, particularly in degraded visual conditions or in emergencies where excursions beyond the operational flight envelope can lead to piloting difficulties. These situations are the new challenges for flying qualities engineers, and two areas are discussed here in some detail. First, flight in severely degraded visual conditions, highlighting the importance of understanding the fundamentals of human visual perception in the development of integrated control and display augmentation. Second, handling qualities following tail rotor failures are discussed and results from current research to develop new advice for aircrew are presented. The author takes the view that much more can and needs to be done to assist the pilot in the management of the tension between performance and safety in helicopter operations, through the provision of improved flying qualities.
Experimental and numerical failure analysis of bolted joints in CFRP woven laminates
Authors: Andréasson N. , Mackinlay C. P. , Soutis C.
Published: February 2023

The purpose of a joint is to transfer load between the two parts being joined. As a result of this load transfer there will be a stress variation in the components in the joint region, as well as stresses in the joining medium (fasteners or adhesive). In fhjs work, the stress results of a two-dimensional finite element (FE) analysis are used to understand failure modes of a bolted joint in low-temperature cure carbon fibre reinforced plastic (CFRP) woven laminates loaded in tension, and to predict the bearing strength. Good agreement with experimentally observed damage modes and strengths is achieved with, in some cases, a difference of less than 10%.
Multi-sensor data fusion in defence and aerospace
Authors: Harris C. J. , Bailey A. , Dodd T.J.
Published: February 2023

The UK OST Technology Foresight for defence and aerospace identified multi-sensor data fusion as a future critical enabling technology for the UK, requiring a coordinated research agenda. This review paper provides an overview of past research and applications of data fusion. The process of data fusion and sensor integration is formally introduced together with a variety of implementation architectures, that recognise data fusion as a critical element in overall systems integration. The various benefits and attributes of data fusion are discussed together with a brief review of potentially fruitful areas of future research.
The effect of trailing edge geometry on cavity flow oscillation driven by a supersonic shear layer
Authors: Zhang X. , Rona A. , Edwards J. A.
Published: February 2023

A computational analysis is performed of self-sustained oscillatory flow over a cavity driven by a shear layer at Mach 1·5. The unsteady flow is studied through solutions of the Reynolds-averaged Navier-Stokes equations with turbulence modelled by a two-equation k-ω model. The trailing edge (face) of a baseline rectangular cavity is modified using wedge and ramp shapes to investigate means for the suppression and attenuation of the self-sustained oscillation. Through modification of the shear layer impingement, both wedge and ramp are effective in reducing the level of oscillation. The time-averaged pressure (form) drag coefficient of the cavity is also reduced significantly. The main cause of the drag reduction is the elimination or reduction of the high pressure area near the downstream corner of the cavity due to the presence of a vortex. Two types of unsteady flow exist when a curved ramp is employed: ‘regular’ and ‘random’. The use of a h= 0·6D ramp generates a random type pressure fluctuation with lower rms pressure compared with the h= 0·2D and 0·4D ramps.
The effect of skewing on the vorticity produced by an airjet vortex generator
Authors: Barberopoulos A. A. , Garry K. P.
Published: February 2023

The vorticity production by a single vortex generator jet in a turbulent boundary layer at high speed and zero pressure gradient was studied by analysing surface-flow patterns. The investigation involved a range of jet mass flow rates and skew angles while the freestream Mach number and jet pitch angle were held constant. A qualitative analysis of the skin friction patterns demonstrated the effective role of the skew angle as a bifurcation parameter. The vortex production is classified into three main regimes as the skew angle increases from zero (fully downstream) to 180° (fully upstream). Better understanding of the physical mechanism behind the transition from the first regime to the second is crucial in the design of the airjet vortex generator.
Autonomous control for on-orbit assembly using potential function methods
Authors: McQuade F. , McInnes C. R.
Published: February 2023

Potential function methods have been applied extensively to many terrestrial and space robot control problems. This paper extends these methods to multiple robot problems for on-orbit assembly. By considering a population of free-flying robotic vehicles in orbit, capable of both rotation and translation, the potential function method reduces complex assembly problems to sets of simple translation and rotational commands. This is achieved using a potential function incorporating both collision avoidance between the free-flyers and connection constraints in the assembled structure. The method also allows a subsumptive type control architecture with the flexibility to carry out many different assembly tasks simultaneously.
A cartesian cut cell method for compressible flows Part A: static body problems
Authors: Yang G. , Causon D. M. , Ingram D. M. , Saunders R. , Battent P.
Published: February 2023

A method for the calculation of steady or unsteady compressible flows is presented. The procedure, based on a cartesian cut cell approach and multi-dimensional high resolution upwind finite volume scheme, can cope with static or moving body problems having arbitrarily complex geometries. The method is described in two parts. In Part A, we discuss the cartesian cut cell approach and upwind finite volume scheme for static body problems. The method is validated on test problems involving both steady and unsteady compressible flows and then applied to some practical problems. The extension of the method to moving body problems is presented in Part B (pp 57-65).
A cartesian cut cell method for compressible flows Part B: moving body problems
Authors: Yang G. , Causon D. M. , Ingram D. M. , Saunders R. , Battent P.
Published: February 2023

A cartesian cut cell method for static body problems was presented in Part A (pp 47-56). Here, we extend the method to unsteady compressible flows involving arbitrarily moving bodies. The moving bodies are allowed to cross a stationary background cartesian mesh. So problems such as mesh distortion and/or restrictions on body motion which may affect other mesh approaches do not occur.

A MUSCL-Hancock finite volume scheme has been modified for moving boundary problems. The upwind fluxes on the interfaces of static cells are updated using an HLLC approximate Riemann solver and an exact Riemann solution for a moving piston is used to update moving solid boundaries (faces). A cell merging technique has been developed to maintain numerical stability in the presence of arbitrarily small cut cells and to retain strict conservation at moving boundaries.

The method has been validated against some well-known two dimensional test problems and applied to practical examples involving an exploding pressure vessel and a store release into a Mach 1.5 stream.
Modelling dynamic stall vortex inception at low Mach numbers
Authors: Niven A. J. , Galbraith R. A. McD.
Published: February 2023

Results of a comparison of dynamic stall onset are presented, as assessed from low Mach number windtunnel data contained in the University of Glasgow's database and that from the well established Beddoes’ model. The model, which was originally developed to reconstruct higher Mach number dynamic stall characteristics, exhibited a lower stall onset incidence than that assessed from the windtunnel data. The differences and speculations on the physical reasoning underlying the two assessments are discussed. An addition to the Beddoes model is proposed which yields an improved reconstruction of the Glasgow windtunnel data.
Aeroelastic optimisation of composite wings using the dynamic stiffness method
Authors: Lillico M. , Butler R. , Guo S. , Banerjee J.R.
Published: February 2023

A computer program for use in the conceptual stage of aircraft design has been developed. The program obtains minimum mass designs for high aspect ratio, composite wings, subject to constraints on flutter speed, divergence speed and material stress. The wing is modelled as a series of composite beam elements and both flutter speed and divergence speed are calculated using a normal mode approach. Modal analysis is carried out by applying the Wittrick-Williams algorithm to the dynamic stiffness method, whereas unsteady aerodynamic loads are calculated from strip theory, although an option which uses lifting-surface theory is also presented. A previously published example is given to validate the analysis. Single level optimisation is carried out using a sequential quadratic programming strategy combined with the modified methods of feasible directions optimizer, for which flutter sensitivities are obtained by an efficient determinant interpolation technique. Design variables include topological variables such as spar and engine positions as well as layer thicknesses, which are modelled using quadratic functions. The wing of a regional turboprop aircraft is optimized to illustrate the use of the program. The problem was modelled using 10 elements and had 43 design variables, 162 constraints and required just over 20 minutes of CPU time on a workstation. This, coupled with the fact that a full three-dimensional FE model of the same wing would require over 1000 elements, illustrates the suitability of the dynamic stiffness method to the conceptual design stage.
Technical Note
Authors: Traub L. W.
Published: February 2023

An expression is derived to predict the effect of taper ratio on the vortex drag of high aspect ratio, unswept, planar wings. The expression was formulated by assuming that imposing an elliptic spanwise load distribution on the tapered planform, would result in a leading edge thrust excess, which relates to the increase in vortex drag above the theoretical minimum. Comparisons of this expression with results from lifting line theory show encouraging agreement.
Analysis of radiometric, lifetime and fluorescent lifetime imaging for pressure sensitive paint
Authors: Holmes J. W.
Published: February 2023

Optical pressure measurement using fluorescent techniques is being widely researched for use in windtunnels. The technique offers global coverage of model surface pressures. A paint, the fluorescence of which is dependent on air pressure, is applied to the surface of a windtunnel model and the pressure distribution is obtained from the intensities measured. There are three principle techniques used to produce the surface pressure distributions: radiometric imaging, lifetime measurement and fluorescent lifetime imaging.

Radiometric imaging produces global images. A constant illumination is used to excite the paint. The fluorescent intensity distribution is dependent on the surface pressure. Error analysis reveals that the technique has the highest precision at low absolute pressures. However, wind-off reference images are required to compensate for illumination and paint non-uniformity. Experimental investigation found that although this is able to compensate for rigid structures, model movement introduces registration and geometric errors. These errors can be corrected by processing at the expense of accuracy.

Lifetime measurement is a technique that uses pulsed illumination. The fluorescent lifetime is dependent on the pressure. A wind-off reference image is not required and error analysis predicts that the technique holds an advantage at high absolute pressures.

Fluorescent lifetime imaging produces global images using a modulated light source to excite the paint. The phase and modulation depth of the fluorescent signal are proportional to the pressure. A wind-off reference image is not required and error analysis predicts that the technique has the same advantages as lifetime imaging. Preliminary results from fluorescent lifetime imaging indicate that this technique can be implemented using robust, solid-state technology.
Weak and intermittent anoxia during the mid-Tournaisian (Mississippian) anoxic event in the Montagne Noire, France
Authors: Rakociński Michał , Książak Daria , Pisarzowska Agnieszka , Zatoń Michał , Aretz Markus
Published: February 2023

The mid-Tournaisian black radiolarian cherts of the Lydiennes Formation are exposed in deep-shelf successions of the Puech de la Suque and Col des Tribes sections of the Mont Peyroux Nappe area in the Montagne Noire, southern France. This interval represents the mid-Tournaisian anoxic event that is also termed the Lower Alum Shale Event. This event is associated with a global marine transgression that was characterized by increased productivity and drastic facies changes from pelagic carbonate sedimentation to the widespread deposition of black organic-rich siliceous shales and radiolarites in many parts of the world. In the present study, high-resolution inorganic geochemistry and framboidal pyrite analyses were employed to decipher changes in depositional conditions during the mid-Tournaisian anoxic event in the Montagne Noire. The results show that the total organic carbon contents of sediments associated with the Lower Alum Shale Event vary from 0.09 to 1.9 wt %. These low to moderate total organic carbon contents, high U/Th, low Corg/P and intermediate V/Cr ratios, enrichment in redox-sensitive trace elements, such as U, Mo and V, as well as varying sizes of pyrite framboids, indicate periodic dysoxic to anoxic bottom-water conditions during deposition of the studied sediments. Anomalous Hg spikes (>500 ppb) are also reported in the mid-Tournaisian deep-water marine succession of the Montagne Noire in the present study, which confirm a possible influence of increased regional volcanic activity during this environmental turnover.
The Information in Industry-Neutral Self-Financed Trades
Authors: Barardehi Yashar H. , Da Zhi , Warachka Mitch
Published: February 2023

We identify Industry-Neutral Self-Financed Informed Trading (INSFIT) as stock trades financed by offsetting, equivalent dollar-denominated stock trades in the same industry. Approximately 37% of short-term mutual fund trading profits can be attributed to these trade pairs. Consistent with informed trading, INSFIT precedes unusually high media coverage for the underlying stocks. The trades underlying INSFIT are also larger as the release of stock-level news becomes more imminent. Both relative valuation and the hedging of industry exposure motivate INSFIT’s industry neutrality. While INSFIT positively impacts fund performance, active fund managers who execute INSFIT more aggressively obtain smaller trading profits per execution.
Heterogeneity of Beliefs and Trading Behavior: A Reexamination
Authors: Füllbrunn Sascha , Huber Christoph , Eckel Catherine , Weitzel Utz
Published: February 2023

Combining experimental data sets from seven individual studies, including 255 asset markets with 2,031 participants, and 36,326 short-term price forecasts, we analyze the role of heterogeneity of beliefs in the organization of trading behavior by reproducing and reconsidering earlier experimental findings. Our results confirm prior evidence that price expectations affect trading behavior. However, heterogeneity in beliefs does not seem to drive overpricing and asset market bubbles, as suggested by earlier studies, and we find no indication of short-term beliefs being better determinants of trading behavior than longer-term beliefs.