bluuebunny/crossref_metadata_2025_split huggingface dataset:
Technical Note
Authors: Fejtek Ian , Nehera John 
Published: March 2023

An experimental study was undertaken to measure the instantaneous lift and propulsive forces generated by a rigid, sinusoidally flapping wing at Reynolds numbers ranging from 72 000 to 120 000. The wing was flapped about a fulcrum at the root at frequencies of 2.55 Hz and 3.30 Hz. Instrumentation and a data reduction system were developed to provide quick and reliable assessment of the effects of changes in flapping amplitude, flapping frequency, flapping plane angle, wing incidence, and windspeed. In this way it was attempted to model, however crudely, the forward flapping flight of birds.The instantaneous values of lift coefficient and thrust coefficient were plotted against position in the cycle while the average CL and CT were plotted against advance ratio (ratio of the windspeed to the maximum tip speed velocity). The experimental results were compared to the theories of Walker(e) and Hoist ' Kuchemann(4) both modified to correspond more closely to the experimental conditions.
The certification of composite airframe structures
Authors: Guyett P. R. , Cardrick A. W. 
Published: March 2023

Structural integrity is a key ingredient of aircraft design. It takes its place alongside flight performance, operational effectiveness, reliability, maintainability and economy in determining, or contributing in very large measure to, the success of a project in service.What is expected from the contractor for a new project in respect of these qualities is set down by the customer in a specification which includes reference to a set of mandatory design requirements. Thus, flight performance parameters such as speed, range and payload, are defined in the specification : there too is to be found a description of the sorties to be flown, numbers and types of manoeuvres and their severity (conventionally including the levels of normal acceleration) and the regions in which the aircraft is required to operate. Sufficient detail is given to establish, as the process of design evolves, the loading and environmental conditions to which the structure will be subjected.
Flowcharts for PADIS
Authors: Andrews David 
Published: March 2023

The discovery of the essential logic of engineering design through the development of the ‘procedure for analysing the design of interactive solutions’ (PADIS) has made it possible to prepare authoritative flowcharts for the design process. This deeper understanding has revealed that, for the design task overall, there is no unique flowchart but many. Each project study is inspired by a combination of up to five types of inspiration, and by appropriately combining the flowcharts given here, an individual flowchart can be determined for each design task undertaken.At subordinate levels of design, it is true, the design process is normally stereotyped, but if invention or new knowledge encourages redesign there may be need to adopt different procedures.
The application of computer aided techniques to project design
Authors: Howe D. 
Published: March 2023

The initial phase of the design of an aircraft is usually thought of as being glamorous and exciting since it is the part of the total exercise which determines those characteristics of the aircraft for all to see. The artistically inclined can let his imagination run away with him as he visualises an aesthetically pleasing concept. The inventor has more than ample scope to propose layout innovations which supposedly confer some advantages, often of ill defined value. Tradition has it that the renowned designers of the past with their vast experience, aesthetic flair and innovatory streak would blend all the numerous possibilities into a satisfying if not always entirely satisfactory, project.Of course such an idea is a gross over-simplification of the project design process which, as in any design activity, must consist of many configuration iterations before an acceptable solution is achieved. The large number of variables which have to be considered coupled with the extremely demanding performance and safety requirements of any advanced aeronautical system imply such complexity that every aid available must be employed.
Theoretical lower limits of forebody drag
Authors: Morel Thomas 
Published: March 2023

One of the more important objectives of research in aerodynamics is drag reduction. In this paper we consider one part of the drag problem, the forebody pressure drag, and enquire about the lower limit to which it may theoretically be reduced by elimination of flow separation. It is customary to decompose the total drag force into two parts: pressure drag and friction drag, represented by force coefficients CD and CF, respectively. The ratio of these two forces may be taken as a convenient criterion to decide whether a body is ‘streamlined’ or ‘bluff’:At high enough Reynolds numbers many bodies of interest are (according to this definition) bluff bodies, i.e. their pressure drag is much larger than the friction drag. This analysis is most relevant for bluff bodies where one needs to be concerned only with the pressure drag.
Conversion training of a qualified engineer
Authors: Godsave A. F. 
Published: March 2023

This paper considers the conversion training of qualified engineers employed in flight simulation from the background of experience in British Airways. The title is taken to mean the conversion of engineers qualified to appropriate standards, with experience in their chosen area which is demonstrated to be generally some form of electronics, to full skill level in flight simulation.The rate of change in flight simulation is very fast. Training should keep up with these changes, but it is often hard-pressed to do so for reasons explained subsequently.I would like first of all to explain the philosophy of our operation with an eye to the future for we are in a transitional stage at present. Our primary effort is a maintenance task where the 17 flight simulators will be divided into three groups. These groups will contain six analogue simulators and eight digital simulators currently in house, with three further simulators on order or about to be (Fig. 1). Not shown in Fig. 1 is a support group providing specialist service as required.
The evolution of fly-by-wire control techniques in the UK
Authors: Hunt G. H. 
Published: March 2023

Control is a fundamental part of the aeronautical sciences playing a necessary role in the design of all air-vehicles whether they are aircraft or balloons, missiles or kites. The early years of aircraft research were characterised by the amount of effort devoted to the control of the aircraft, and the shortcomings of early aircraft designs were frequently due to instability and to poor handling characteristics. Indeed the triumph of the Wright Brothers in 1903 when their first sustained powered flight was made at Kitty Hawk was due as much to their mastery of the problems of control as to their work on aerodynamics, structure or powerplant, vital though these latter were.There are inherently two ways of obtaining an aircraft design having the desired control characteristics, either by so designing the structure and the aerodynamics of the aircraft itself or by providing some ‘artificial’ or ‘automatic’ control to change its characteristics. The latter method uses the signal from some sensor in essentially the same way that the human being uses signals from his vestibular organs to stabilise himself, and the crane fly similarly stabilises his flight using signals from his vestibular organs to stabilise himself, and the crane fly similarly stabilises his flight using signals from his halteres. The technique was tried even before 1903, and Sir Hiram Maxim in 1891 had produced a patent for an aircraft using a pendulous gyroscope for pitch stabilisation (Fig. 1). For various reasons most of these early efforts were rather unsuccessful, and in the period up to the Second World War the principal advances in the science of aircraft stability and control came largely from the refinement of the basic aerodynamics of the vehicle.
Age and petrogenesis of mafic granulites from central Madurai block, south India: implications on regional tectonics
Authors: Dev J Amal , Tomson JK , Vijaya Kumar T , Sorcar Nilanjana 
Published: March 2023

AbstractThe Precambrian Southern Granulite Terrane (SGT) of south India is well-known for the preservation of high- to ultrahigh-temperature (HT-UHT) granulites, prominently exposed in its central part forming a linear belt referred to as the Kambam UHT belt. This belt also hosts widespread occurrences of mafic granulites that are observed in close spatial association with the HT-UHT granulites. This study presents detailed petrology, geochemistry and geochronology of representative mafic granulites from the area to understand their petrogenesis and tectonic setting. The results demonstrate that mafic granulites are low- to medium-K tholeiites, with continental arc affinity, formed by the partial melting of a subduction-modified enriched mantle source. The composition of the parent mantle source is modelled with a spinel/garnet lherzolite contribution ratio between 100/0 and 70/30, suggesting the mixing of spinel and garnet bearing melts during asthenosphere upwelling. Zircon U–Pb geochronology of mafic granulites constrains their emplacement between 612 Ma and 625 Ma, that subsequently underwent metamorphism between 581 Ma and 531 Ma. This overlaps with the timing of HT-UHT metamorphism in the Kambam UHT belt bracketed between 593 and 532 Ma. Zircon Hf isotopic studies reveal parent magma generation from reworked melting sources involving Archean and Proterozoic components. These results propose an alternative heat source for the formation of HT-UHT granulites in the Kambam UHT belt which can be designated as a major terrane boundary within the SGT.
Empire in the Cottage: Welfare Capitalism and Workers’ Housing Policy in the Habsburg Monarchy, 1880–1914
Authors: Nebřenský Zdeněk , Herc Svatopluk 
Published: March 2023

AbstractThis study focuses on welfare capitalism and workers’ housing policy in the Habsburg Empire on the eve of the Great War. It deals with the concessions for buildings containing healthy and affordable workers’ flats. The study argues that the existing research on welfare capitalism concentrated mostly on the entrepreneurs and industrialists as key actors in the building of workers’ flats. As the concessions for the building of workers’ houses suggest, the imperial authorities also maintained welfare capitalism and played a certain role in supporting the construction of workers’ housing. Through the concessions, authorities tried to regulate the company construction and to intervene into places of the everyday. They sought to enforce an appropriate lifestyle and to separate spaces for people of workers’ background, male and female workers, single workers, and workers’ families.
The Diffusion of Knowledge during the British Industrial Revolution
Authors: Galofré-Vilà Gregori 
Published: March 2023

AbstractWhile technological progress played a central role in the British Industrial Revolution, statistical evidence on how inventors and entrepreneurs engaged in the process of technological innovation has typically received minor attention. In this paper I use quantitative methods to show that counties with a relatively high number of informal networks −in the form of Freemasonry, friendly societies, libraries, and booksellers− experienced more innovation as measured by new patents and exhibits at the 1851 Crystal Palace World’s Fair. Qualitative evidence and propensity score matching suggest that the mechanisms highlighted here were an important part of British technological leadership. Economic factors cannot account for these patterns.
Development of the Miniature Robotic Electrodialysis (MR ED) System for Small‐Scale Desalting of Liquid Samples With Recovery of Organics
Authors: Bryson F. E. , Ingall E. D. , Hanna A. M. , Cardelino M. , Plattner T. , Meister M. R. , Lawrence J. D. , Mullen A. D. , Dichek D. , Schmidt B. E. 
Published: March 2023

AbstractWhile liquid environments with high salt content are of broad interest to the Earth and Planetary Science communities, instruments face challenges in detecting organics in hypersaline samples due to the effects of salts. Therefore, technology to desalt samples before analysis by these instruments would be enabling for liquid sampling on missions to Mars or ocean worlds. Electrodialysis (ED) removes salt from aqueous solutions by applying an electric potential across a series of ion‐selective membranes, and is demonstrated to retain a significant percentage of dissolved organic molecules (DOM) in marine samples. However, current electrodialysis systems used for DOM recovery are too large for deployment on missions or for use in terrestrial fieldwork. Here, we present the design and evaluation of the Miniature Robotic Electrodialysis (MR ED) system, which is approximately 1/20th the size of heritage instruments and processes as little as 50 mL of sample at a time. We present tests of the instrument efficiency and DOM recovery using lab‐created solutions as well as natural samples taken from an estuary of the Skidaway River (Savannah, GA) (Verity, 2002) and from South Bay Saltworks (San Diego, CA) (Roseman & Watry, 2008; Survey, 2011). Our results show that the MR ED system removed 97%–99% of the salts in most samples, with an average DOC recovery range from 53% to 77%, achieving similar capability to tabletop instruments. This work both demonstrates MR ED as a possible field instrument and increases the technology readiness level of miniaturized electrodialysis systems for future missions.
Variation of Fault Creep Along the Overdue Istanbul‐Marmara Seismic Gap in NW Türkiye
Authors: Becker D. , Martínez‐Garzón P. , Wollin C. , Kılıç T. , Bohnhoff M. 
Published: March 2023

AbstractStrain energy from tectonic loading can be partly released through aseismic creep. Earthquake repeaters, repeatedly activated brittle fault patches surrounded by creep, indicate steady‐state creep that affects the amount of seismic energy available for the next large earthquake along a plate contact. The offshore Main Marmara Fault (MMF) of the North Anatolian Fault Zone represents a seismic gap capable of generating a M > 7 earthquake in direct vicinity to the mega‐city Istanbul. Based on a newly compiled seismicity catalog, we identify repeating earthquakes to resolve the spatial creep variability along the MMF during a 15‐year period. We observe a maximum of seismic repeaters indicating creep along the central and western MMF segments tapering off toward the locked onshore Ganos fault in the west, and the locked offshore Princes Islands segment immediately south of Istanbul in the east. This indicates a high degree of spatial creep variability along the Istanbul‐Marmara seismic gap.
On the Temperature Dependence of the Cloud Ice Particle Effective Radius—A Satellite Perspective
Authors: Stengel Martin , Meirink Jan Fokke , Eliasson Salomon 
Published: March 2023

AbstractCloud ice particle effective radius in atmospheric models is usually parametrized. A widely‐used parametrization comprises a strong dependence on the temperature. Utilizing available satellite‐based estimates of both cloud ice particle effective radius and cloud‐top temperature we evaluate if a similar temperature‐dependence exists in these observations. We find that for very low cloud‐top temperatures the modeled cloud ice particle effective radius generally agrees on average with satellite observations. For high sub‐zero temperatures however, the modeled cloud ice particle effective radius becomes very large, which is not seen in the satellite observations. We conclude that the investigated parametrization for the cloud ice particle effective radius, and parametrizations with a similar temperature dependence, likely produce systematic biases at the cloud top. Supporting previous studies, our findings suggest that the vertical structure of clouds should be taken into account as factor in potential future updates of the parametrizations for cloud ice particle effective radius.
Global Spatial Distribution of Hack's Law Exponent on Mars Consistent With Early Arid Climate
Authors: Luo W. , Howard A. D. , Craddock R. A. , Oliveira E. A. , Pires R. S. 
Published: March 2023

AbstractWidespread valley networks (VNs) on Mars and other evidence point to an early warm and wet climate. However, ongoing debates still exist about VN's formation processes and associated climatic conditions. The power law relationship between basin length and area (Hack's Law) can be diagnostic of different fluvial processes related to climatic conditions. Past studies of Hack's Law on Mars at local sites have produced inconclusive results. Here we used a parameter‐free method to delineate watersheds globally on Mars based on mapped VNs and extracted their Hack's Law exponent (h). The majority of h values on Mars are similar to those in arid areas on Earth, suggesting similar runoff processes and arid conditions for VN formation on early Mars. Statistical analyses show that the spatial distribution of h on Mars is not random, but with a few clustered high and low values, likely controlled by local conditions (e.g., regional topographic slope).
Fourier Analysis of Magnetic Fields in the Ionosphere of Mars
Authors: Cravens T. E. , Hamil O. , Renzaglia A. , Ledvina S. A. , Howard S. K. 
Published: March 2023

AbstractThe two main sources of the magnetic field in the Martian ionosphere are the solar wind interaction with the planet, and, mainly in the southern hemisphere, remnant crustal magnetization. The magnetic fields measured by the Mars Atmosphere and Volatile EvolutioN (MAVEN) and Mars Global Surveyor spacecraft displayed a wide range of spatial scales, from the global (i.e., L ≈ 103 km) to mesoscale (L ≈ 102 km) to small‐scale (L < 10 km). Hamil et al. (2022) used MAVEN magnetometer and Langmuir Probe data to study these structures and suggested that they might be advected into the ionosphere from the solar wind and magnetosheath. In the current study, we apply a Fourier analysis to the fields and interpret the resulting power spectral density profiles versus frequency. The power spectral density function found from MAVEN data resembles that of the solar wind magnetic field (or interplanetary magnetic field) (i.e., power law with an index of about −2), but shifted upward in frequency by a factor of about 100. From a comparison of ionospheric power spectra with solar wind power spectra, we deduce that plasma, carrying a magnetic field with it moves from the magnetic pile‐up region downward into the ionosphere with speeds of roughly tens of meters per second. The derived power spectra in the ionosphere, in addition to the basic power law shape, show hints of extra power at a spatial scale of about 10 km, and this might be due to the creation of a magnetic structure within the ionosphere itself.
Association Between Injection and Microseismicity in Geothermal Fields With Multiple Wells: Data‐Driven Modeling of Rotokawa, New Zealand, and Húsmúli, Iceland
Authors: Yu Pengliang , Dempsey David , Rinaldi Antonio Pio , Calibugan Aimee , Ritz Vanille A. , Archer Rosalind 
Published: March 2023

AbstractUnderstanding injection‐induced microseismicity in geothermal systems can provide insight into reservoir connectedness. However, fault and reservoir complexity are difficult to represent in simple analytical models, which makes it difficult to discern clear relationships from incidental associations. Here, we have used data‐driven models to study how fluid injection and microseismicity are related in the Rotokawa (New Zealand) and Hellisheiði (Iceland) geothermal fields. We tested two classes of model: (a) lagged linear regression of seismicity rate as a function of well injection rates; and (b) systematic extraction of injection time series features that are then evaluated for associations with the seismicity. These models allowed us to determine which wells had the greatest correlation with microseismicity and to explain this association in a reservoir context. Finally, exploring different data types and transformations, we were unable to establish a link between rapid changes in injection rate and seismicity spikes, as suggested by some theoretical models.
Biogeochemical Argo Floats Reveal the Evolution of Subsurface Chlorophyll and Particulate Organic Carbon in Southeast Indian Ocean Eddies
Authors: Strutton Peter G. , Trull Thomas W. , Phillips Helen E. , Duran Earl R. , Pump Sylvia 
Published: March 2023

AbstractEddies modulate open ocean productivity, and this influence depends on both eddy source and evolution. Southeast Indian Ocean eddies are important pathways for the westward transport of biogeochemical anomalies from the Leeuwin current into the central oligotrophic South Indian Ocean (SIO). Eddy processes at the base of the mixed layer may stimulate and sustain phytoplankton, allowing these eddy impacts to persist over thousands of kilometers. We present 4 months of high‐frequency profiles from autonomous floats in one anticyclonic and one cyclonic eddy in the SIO. At the start of observations, from September to October, particulate organic carbon (POC) and especially chlorophyll were higher in the cyclone, and evenly distributed throughout the mixed layers in both eddies. As spring progressed and the eddies were transported westward, chlorophyll and POC concentrated at the base of the mixed layer at depths invisible to satellites, likely reflecting nutrient depletion in overlying waters. In the anticyclone, the increased chlorophyll at depth occurred as POC decreased, suggesting photo‐acclimation and thus both light and nutrient stress. In contrast, in the cyclone chlorophyll to POC ratios remained close to constant as their subsurface maxima formed. In both eddies, the subsurface biomass maxima exhibited no significant change in oxygen saturation state over several months suggesting these communities are sustained by low ongoing productivity in balance with community respiration. Thus, deep biomass layers may represent a mechanism for long‐distance transfer of eddy plankton communities which is not reflected in satellite remote sensing.
Chemical Characteristics and Source Apportionment of Biogenic Primary and Secondary Organic Aerosols in an Alpine Ecosystem of Tibetan Plateau
Authors: Cui Lulu , Gao Yining , Chen Yubao , Li Rui , Bing Haijian , Wu Yanhong , Wang Gehui 
Published: March 2023

AbstractThe knowledge about the chemical characteristics of organic aerosols in alpines were still limited. Fifty samples were collected in an alpine site in Tibetan Plateau during May 2015 and April 2016 to measure the concentrations of sugar and biogenic secondary organic aerosol (BSOA) compounds. The annual mean concentrations of anhydrosugar, primary sugars, and sugar alcohols in Mt. Gongga were 86.6 ± 43.1, 168 ± 40.0 and 204 ± 62.9 ng/m3, respectively. All of the anhydrosugars displayed the highest concentrations in winter, followed by spring, autumn, and the lowest ones in summer, which was contributed by dense biomass burning (BB) in winter. In contrast, nearly all of the primary sugar and sugar alcohol levels peaked in summer, which might be associated with the higher rates of vegetation growth and microbial metabolic activities during the warming season. The levels of BSOA tracers also suffered from markedly seasonal variations. The sesquiterpene SOA displayed the highest level in winter (27.3 ± 16.8 ng/m3), which might be associated with the biomass burning in the surrounding regions. However, most of the species of isoprene and monoterpene SOA tracers suffered from the higher levels in summer, which was contributed by the higher biogenic volatile organic compounds (BVOC) emission and reaction rates. Based on source apportionment result, BB (26%) was the dominant contributor to sugar and BSOA species in Mt. Gongga, followed by airborne pollen (24%), plant release (19%), soil emission (13%), fungal spore (9%), and isoprene oxidation (8%). The result of this study reveals mixed contributions of BB and vegetation emission promote the formation of biogenic organic aerosols in Tibetan Plateau.