bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterizing the Mechanical Properties of Graphene and Single Walled Carbon Nanotubes
Authors: Tzeng S.-H. , Tsai J.-L. 
Published: December 2011

ABSTRACTIn this study, the mechanical properties of graphene and single walled carbon nanotubes (SWCNTs) were investigated based on molecular dynamics (MD) simulation. During the characterization of the mechanical properties, the atomistic interactions of the carbon atoms were described using the bonded and non-bonded energies. The bonded energy consists of four different interactions: Bond stretching, bond angle bending, dihedral angle torsion, and inversion. On the other hand, the non-bonded interaction between the carbon atoms within the cut-off ranges was regarded as the van der Waals (vdW) force. The effect of vdW force on the mechanical properties of graphene and SWCNTs would be mainly of concern. Simulation results indicated that the Young's modulus of the graphene with vdW force included is 15% higher than that without considering any vdW interaction. The same tendency also was observed in the armchair and zig-zag SWCNTs. Furthermore, it was revealed that the increment of moduli caused by the vdW force could be primarily attributed to the 1-4 vdW interaction. The influence of the vdW interactions on the mechanical properties of graphene and SWCNTs was then elucidated using the parallel spring concept.
Inverse Active Load Inputs Estimation of the 3D Spatial Truss Structure System
Authors: Lee M.-H. 
Published: December 2011

ABSTRACTThis study presents an innovative fuzzy inverse method with the finite-element scheme for estimating the unknown time-varying load inputs on a three-dimensional (3D) spatial truss structural system. The finite-element scheme is employed to discretize the problem in space, allowing multidimensional problems of various geometries to be treated. This method is based on the fuzzy Kalman Filter (FKF) technology and the fuzzy weighting recursive least square method (FWRLSM). The fuzzy Kalman filter measures the system responses at two distinct nodes in the 3D spatial truss structure. The fuzzy weighting recursive least square method is derived using the residual innovation sequence to compute the input loads. The proposed method's superiority is demonstrated using several typical simulation cases that vary with different estimator and the distinct levels of the initial process noise covariance and the measurement noise covariance. The results show that this method has great stability and accuracy.
Study of a Crossflow over a Zero-Net-Mass-Flux Synthetic Jet Driven by a Vibrating Diaphragm
Authors: Tseng L.-Y. , Yang A.-S. , Lin J.-C. 
Published: December 2011

ABSTRACTMiniature synthetic jet actuators are low operating power, zero-net-mass-flux and very compact devices which have demonstrated their capability in modifying the subsonic flow characteristics for boundary layer flow control. In order to improve the design active flow control systems, the present study aims to examine the formation and interaction of unsteady flowfield of a synthetic jet with external crossflow. In view of a single synthetic jet emitting into a turbulent boundary layer crossflow via a circular orifice, the theoretical model utilized the transient three-dimensional conservation equations of mass and momentum for compressible, turbulent flows with a negligible temperature variation over the computational domain. The motion of a movable membrane plate was also treated as the moving boundary by prescribing the displacement on the plate surface. The predictions by the computational fluid dynamics (CFD) software ACE+®were compared with the measured transient phase-averaged velocities in literature for code validation. The predictions showed the time evolution of the large vortical structure originating from the jet orifice and its successive interaction with the crossflow to change the flow structure inside the boundary layer.
Optimal Design of Side-Inlet/Side-Outlet Expansion Mufflers with Open-Ended Perforated Tubes Using Simulated Annealing
Authors: Chiu M.-C. , Chang Y.-C. 
Published: December 2011

ABSTRACTResearch on new techniques of multi-chamber mufflers equipped with a side inlet and internal nonperforated intruding tubes has been discussed in recent literature; however, the research work of multichamber mufflers in conjunction with side inlet and open-ended perforated intruding tubes which may efficiently increase the acoustical performance has been neglected. Therefore, the main purpose of this paper is to optimize the best design shape of multi-chamber side mufflers with open-ended perforated intruding tubes within a limited space.In this paper, the four-pole system matrix in evaluating the acoustic performance is also deduced in conjunction with a simulated algorithm (SA). Results reveal that the maximum sound transmission loss (STL) is precisely located at the desired target tone. In addition, the acoustical performance of mufflers conjugated with perforated intruding tubes is superior to those equipped with non-perforated tubes. Additionally, the noise reduction ability for a three-chamber side muffler with a non-perforated intruding tube and a two-chamber side muffler with perforated intruding tubes are equivalent. Moreover, mufflers with more chambers will increase the acoustic performance for both pure tone and broadband noise.
Simulation Methodology on Analyzing Clamping Mode for Single Proton Exchange Membrane Fuel Cell
Authors: Wen C.-Y. , Chang H.-T. , Luo T.-W. 
Published: December 2011

ABSTRACTIn proton exchange membrane fuel cells (PEMFCs), a low interfacial pressure between the bipolar plates and the membrane exchange assembly (MEA) results in a high contact resistance. Conversely, an excessive interfacial pressure reduces the porosity of the gas diffusion layer (GDLs) and may damage the proton exchange membrane (PEM). Consequently, the performance of a PEMFC is critically dependent upon the clamping method. Accordingly, this study emphasizes the development of a numerical methodology for analyzing clamping of a PEMFC and constructs a detailed three-dimensional (3D) full-scale finite element (FE) model of a PEMFC with the traditional and most popular point-load design as an example. The numerical method is first validated by experiments. A series of simulations are then performed on the example cases (i.e. 2-bolt, 4-bolt or 6-bolt) to analyze their behaviors on the contact pressure between the bipolar plates and the MEA and the corresponding effects on the GDL porosity and the contact resistance, under the constraints that the membrane and gaskets remain within their respective elastic limits and the porosity of the GDL has a value higher than 0.5. Overall, to complete the analysis procedures proposed in this paper, the results show that the six-bolt clamping mode with a tightening torque of 16 N-m achieves a uniform pressure distribution and a high interfacial pressure, and therefore represents the optimal clamping mode for the performed example cases.
An Analytical Method for the Inverse Cauchy Problem of Laplace Equation in a Rectangular Plate
Authors: Liu C.-S. 
Published: December 2011

ABSTRACTThe present paper reveals an analytically computational method for the inverse Cauchy problem of Laplace equation. For the sake of analyticity, and also for the frequent use of rectangular plate in engineering structure, we only consider the analytical solution in a two-dimensional rectangular domain, wherein a missing boundary condition is recovered from a partial measurement of the Neumann data on an accessible boundary. The Fourier series is used to formulate a first-kind Fredholm integral equation for the unknown function of data. Then, we consider a Lavrentiev regularization amended to a second-kind Fredholm integral equation. The termwise separable property of kernel function allows us to obtain a closed-form solution of the regularization type. The uniform convergence and error estimation of the regularization solution are proven. The numerical examples show the effectiveness and robustness of the new method.
The International Institute of African Languages and Cultures: A memory of its Beginnings
Authors: Ward W. E. F. 
Published: December 2011

I went out to the Gold Coast as a teacher on the staff of the newly established Achimota College in October 1924, and a few weeks before I came back for my first leave, in April 1926, there came to the college a distinguished visitor, Major Hanns Vischer (later Sir Harms), the educational adviser to the Colonial Office in London. It was Major Vischer who told me about the project to establish an International African Institute.Vischer was a remarkable and delightful character. I was told that he was of Swedish descent, which was why he spelt his name Harms instead of in the German form Hans. He had served in the British army through the First World War, but before the war he had served in Nigeria as a missionary for the Church Missionary Society. He spoke fluent Hausa, and (I was told) some other languages. He was certainly a skilled linguist, for he seemed equally at home in English, French and German. He spoke English with a slight foreign accent, which made it easy to believe in his Scandinavian origin; it was not a German accent. He stayed at Achimota for a week or so, and went on from the Gold Coast to visit Sierra Leone. He joined my homeward-bound steamer at Freetown; he remembered having met me at Accra, and told me about the projected institute. Whoever may have been responsible for starting the scheme, it was Vischer who was the driving force in organising its inaugural meeting.
Madness, Suicide and the Victorian Asylum: Attempted Self-Murder in the Age of Non-Restraint
Authors: Shepherd Anne , Wright David 
Published: December 2011

On 20 July 1870, Catherine Tyrrell found herself transferred to another asylum. The 32-year-old nurse suffering from melancholia had previously been a private patient in Bethlem Hospital; but, having had her twelve months expire at that institution, she was conveyed across the metropolis and into the bucolic countryside and county asylum of Buckinghamshire. Up to this point, Catherine had had a long and sad history of suicide attempts and food refusal. Indeed, when she was transferred the following year, this time from Buckinghamshire to the Surrey County Asylum at Wandsworth, she was listed as “very suicidally disposed”. Now diagnosed as suffering from “mania”, she managed only three months before arriving at her fourth institution in as many years—the Surrey County Asylum at Brookwood. On admission, the medical superintendent described, with transparent disapproval, the precautionary clothing that held her suicidal impulses in check:She was brought in a canvas garment which fitted her person even down to her ankles, the arms however not going through the sleeves, but being folded across her chest close to her skin, the hands being locked in leather gloves. The jacket or whatever it is called being [fastened] at the back by 5 locks. All this complicated arrangement was immediately removed. There was no clothing of ordinary kind under it.
The Outer Hebrides: where genes and geography meet
Authors: Berry R. J. 
Published: December 2011

SynopsisThe Outer Hebridean fauna is almost entirely the result of the chance characteristics of opportunist colonizers modified by subsequent adaptation and sometimes later immigrants. A few primitive relicts may persist (e.g. possibly, the mothNyssia zonarid), but the fauna is certainly not largely composed of early post-glacial invaders. These, traditional theory argues, are likely to have been eliminated on the mainland by later arrivals but to have been able to persist on the islands by the timely breaking of hypothetical land-bridges.The influence of the original island colonizers is discernible through the persistence of similar traits in both ancestral and descendant populations despite massive genetical differences produced by stochastic sampling, and often by an apparently random pattern of differentiation between islands (e.g. field mice, cats, men, wrens). Adaptation is difficult to detect in the presence of unmeasurable founder effects, but is shown by large-scale clines (such as bridling in guillemots or colour phase frequencies in arctic skuas), by the existence of similar local races in different species (notably by melanism in Lepidoptera, especiallyTriphaena comes; but also possibly in bumble-bees and dragonflies), and by evidence of local selection (e.g.Cochlicella acuta).In the light of these many pressures, simple equilibrium theories of island biogeography are woefully inadequate; every species has to be considered on its merits. This can be done for terrestrial vertebrates, and virtually all but the Pygmy Shrew prove to have been introduced by man.
Some oceanographic features of Hebridean waters
Authors: Ellett D. J. 
Published: December 2011

SynopsisSouth of St Kilda, Atlantic water reaches the edge of the Continental Shelf west of the Hebrides from the eastern side of the Rockall Channel, whereas the main north-east going current from the western side of the channel probably lies close to the shelf-edge to the north of St Kilda. On the shelf, Atlantic water mixes with Clyde and Irish Sea water to the south-west of the Small Isles, and the mixed water so formed diverges to flow partly northward through the Little Minch and partly southward to Barra Head, then northward along the western coasts of the Outer Hebrides. On the outer shelf, dense winter-formed bottom water persists into the autumn, implying that advection is weak in this region in summer.Data of temperature and salinity are sparse around the Outer Hebrides. Annual temperature cycles at depth on the shelf can be explained in terms of the cycle of wind mixing. A non-divergent Continental Shelf wave gives rise to strong diurnal components in the tidal streams upon the outer shelf and in the Sound of Harris, but causes no perceptible disturbance to the semi-diurnal rise and fall.
A statistical approach to the geomorphology of the Outer Hebrides
Authors: Halstead Cyril A. 
Published: December 2011

SynopsisThe results of measurements of contour areas at 1:63,360 scale allow a quantitative elaboration of the geomorphoiogical regions identified by Professor Alain Godard. Appropriate graphical techniques clearly indicate the sharp altitudinal breaks between the elements of these regions and show how they vary from island to island. Sample slope measurements are compared with clinographic estimates from the contour areas and suggestions made about relative rates of erosive processes in the different regions. It is hoped that some light is thrown on the relative importance of rock type, differential uplift and of Tertiary and glacial processes in the geomorphoiogical differentiation of the area.
Machair development and chronology in the Uists and adjacent islands
Authors: Ritchie W. 
Published: December 2011

SynopsisSeveral types of machair landforms are found in the Uists (Outer Hebrides) but the most distinctive are low altitude plains. Morphological and stratigraphical evidence suggests that both erosional and depositional processes, operating over a long period of time, have produced these sand plains and other landforms. A vast but relatively finite (partly shell-derived) sand supply was swept landwards across the gentle offshore rock platform assisted by a rising sea level to provide the initial pre-machair coastal accumulation. Phases of development can be dated using archaeological evidence, and 14C dating of offshore peat suggests that initiation probably took place before 5700 BP. Although the evidence is fragmentary, machair development appears to have consisted of long periods of stability, interrupted by episodes of major environmental disturbances. There is also evidence of coastal erosion and associated physiographic changes.
The macrofauna of intertidal sand in the Outer Hebrides
Authors: Angus I. Stewart 
Published: December 2011

SynopsisThe abundance and composition of the macrofauna of Outer Hebridean beaches is determined mainly by the degree of exposure to wave action. Most of the beaches are on the western seaboard, many without any form of shelter, and thus receive the full force of the Atlantic swell.Twenty principal sites in Lewis and Harris were sampled for intertidal macrofauna.Beaches of open aspect are populated by amphipods and Eurydice pulchra with very low densities of polychaetes. The sands of the Minch coast and some of the western beaches which are sheltered by islands or headlands usually have a Tellina–Nephtys association, with a tendency for Tellina tenuis to be replaced by Donax vittatus with increasing shelter. Very sheltered inlets and the fords of the Uists have a well-developed Cerastoderma-Macoma association, while Traigh Mhor in Barra, dominated by Cerastoderma edule, has the richest fauna of any beach in the Outer Hebrides.
Mollusca of rocky shores: Lewis and Harris, Outer Hebrides
Authors: Smith Shelagh M. 
Published: December 2011

SynopsisThe history of previous molluscan work in the Outer Hebrides shows that most work has been done offshore, and that the littoral zone of Lewis and Harris has been neglected. In the present paper mollusc populations of different macro- and micro-habitats are examined empirically, and compared and contrasted with each other. Habitats have been chosen to exhibit as wide a variety of environment as possible, from the wave-lashed exposed rocks facing the Atlantic to the very sheltered sea lochs opening into the Minch. The richness and diversity of the fauna is noted.
The vegetation of the Outer Hebrides
Authors: Currie Andrew 
Published: December 2011

SynopsisThe paper reviews four topics in relation to the vegetation of the Outer Hebrides: (a)history and flora, (b) environment and habitat, (c) geographical relationship, and (d) conservation. The preliminary flora edited by J. W. Heslop Harrison in 1941 remains the best published list, and there is need for a modern flora. A provisional checklist is presented, based upon recently published data, especially theAtlas of the Bristish Flora(Perring and Walters 1962) and theCritical Supplement(Perring 1968) Miss M. S. Campbell has been responsible for a great deal of recent recording. Geology and climate are critical factors, and soils are mainly peat, except in the extensive machair areas. Significant habitals are coastland, wetland, peatland, moorland and upland. woodland is scarce, though there are good amenity woodlands. Each habitat is reviewed in relation to the floristic lists in theNature Conservation Review(Ratcliffe 1977b). There has been no phytosociological study of the vegetation overall, though particular localities such as St Kilda have been described. The geographical elements are listed, and related to those of Skye, Shetland and Faeroe. The flora is more restricted than that of the mainland. Important categories recognized are (a) species of localized distribution, (b) southern species reaching their northern limits and (c) ‘Atlantic’ species. The origin of the flora is discussed, and it is concluded that the facts have not yet been clearly demonstrated. Eight potential threats are identified as fire, changing agricultural practice including drainage, large-scale peat, sand and gravel extraction, the oil industry, wave-energy generation and tourism.
The macrofauna of brackish and fresh waters of the Loch Druidibeg National Nature Reserve and its neighbourhood, South Uist
Authors: Waterston A. R. , Lyster I. H. J. 
Published: December 2011

SynopsisThree main types of Hebridean freshwater lochs occur in the Loch Druidibeg National Nature Reserve; eutrophic calcareous machair lochs near the Atlantic coast, mesotrophic lochs on the edge of the moor and oligotrophic lochs on the peatlands. Chloride/calcium concentrations, highest in lochs near the sea, fall away rapidly inland and are lowest in the moor lochs. The fauna of eutrophic and mesotrophic lochs includes a few euryhaline brackish-water species Potamopyrgus jenkinsi, Diaptomus wierzejskii, Neomysis integer and Gammarus duebeni. G. duebeni alone penetrates the oligotrophic lochs. Freshwater sponges are widespread but are absent from the machair lochs and there are no triclad planarians. The fauna of fast and slow stream segments is described. Loch Bee, a man-made lagoon, unlike the open brackish lochs of North Uist, is an unstable habitat and its fauna has changed considerably since it was investigated in 1933. The fauna consists mainly of brackish-water species and a few stenohaline marine species which are confined to its seaward ends. The sequence of faunistic change in the Howmore estuary, Lochs Roag and Fada, a Site of Special Scientific Interest (SSSI), is described; the brackish-water fauna is reduced by the volume of fresh water passing through the system. A brief account is given of the unusual dominance of Hyalinella punctata and Potamopyrgus jenkinsi in Loch Ardvule (SSSI), South Uist.
The fishes of inland waters in the Outer Hebrides
Authors: Campbell R. N. , Williamson R. B. 
Published: December 2011

SynopsisOnly euryhaline fishes were able to recolonize Outer Hebridean fresh waters after the last glaciation so that inland waters now contain only six indigenous, truly freshwater species; salmon, trout, charr, three- and ten-spined stickleback and the freshwater eel. Parts of some lochs are invaded by the sea at stages in the tidal cycle and some 20 species of marine fish may be found at times in inland waters.Both salmon and sea trout occur in all the larger freshwater systems and sea trout are also found in many of the minor ones.The original sea trout gave rise to sedentary brown trout populations similar to those of the mainland.Fluctuations in the Hebridean salmon catch suggest that the stock is affected by the same factors as those affecting Scottish west coast stocks generally: the vast-majority return to fresh water as grilse, while sea trout stocks have been declining over the last 25 years.Brown trout and eels are almost ubiquitous. Charr occur in Lewis and parts of North Uist but have not been reported from Harris or South Uist and are now only present as sedentary forms. The three-spined stickleback is more widely distributed than the ten-spined.Outer Hebridean lochs in general have special scientific value because, unlike many Scottish mainland lochs, they have not been affected by the introduction of alien species and some are still in an unexploited state.
Survey of the invertebrate fauna of sand dune and machair sites in the Outer Hebrides during 1976
Authors: Welch R. C. 
Published: December 2011

SynopsisDuring June and July 1976 the Institute of Terrestrial Ecology carried out a limited invertebrate survey on 18 sites in the Outer Hebrides.Portable battery-operated UV light traps were installed at each site and left to operate for eight nights. Bad weather in June greatly reduced the numbers of Lepidoptera caught. During July moths were trapped at 16 of the sites. Details of the combined catches are given. Pitfall traps were also installed at all sites and all beetles, spiders, harvestmen, snails, millipedes, centipedes and woodlice have been identified. In addition a list of species of littoral Coleoptera recorded from 24 Hebridean localities is given.This survey was part of a much wider project around the coasts of Scotland, commissioned by the Nature Conservancy Council, to whom a full report will be submitted when identification and analysis of the results has been completed.