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Experiencing Responsive Technology in a Mixed Work: Interactive music as embodied and situated activity
Anna Einarsson
Journal: Organised Sound / Volume 22 / Issue 3 / December 2017
How is performing with responsive technology in a mixed work experienced by performers, and how may the notion of embodied cognition further our understanding of this interaction? These questions are addressed here analysing accounts from singers performing the author's mixed work Metamorphoses (2015). Combining semi-structured interviews and inspiration from Interpretative Phenomenological Analysis, questions concerning the 'self' when listening, singing, moving and relating to fellow musicians, as well as the relationship towards the computer, are explored. The results include a notion of the computer as neither separated nor detached but both, and highlight the importance of the situation, including not only the here and now but also social and cultural dimensions. The discussion emphasises the role of sensorimotor interaction and bodily experience in human meaning-making.
Subglacial flood path development during a rapidly rising jökulhlaup from the western Skaftá cauldron, Vatnajökull, Iceland
BERGUR EINARSSON, TÓMAS JÓHANNESSON, THORSTEINN THORSTEINSSON, ERIC GAIDOS, THOMAS ZWINGER
Journal: Journal of Glaciology / Volume 63 / Issue 240 / August 2017
Print publication: August 2017
Discharge and water temperature measurements in the Skaftá river and measurements of the lowering of the ice over the subglacial lake at the western Skaftá cauldron, Vatnajökull, Iceland, were made during a rapidly rising glacial outburst flood (jökulhlaup) in September 2006. Outflow from the lake, flood discharge at the glacier terminus and the transient subglacial volume of floodwater during the jökulhlaup are derived from these data. The 40 km long initial subglacial path of the jökulhlaup was mainly formed by lifting and deformation of the overlying ice, induced by water pressure in excess of the ice overburden pressure. Melting of ice due to the heat of the floodwater from the subglacial lake and frictional heat generated by the dissipation of potential energy in the flow played a smaller role. Therefore this event, like other rapidly rising jökulhlaups, cannot be explained by the jökulhlaup theory of Nye (1976). Instead, our observations indicate that they can be explained by a coupled subglacial-sheet–conduit mechanism where essentially all of the initial flood path is formed as a sheet by the propagation of a subglacial pressure wave.
A spectrum of jökulhlaup dynamics revealed by GPS measurements of glacier surface motion
Bergur Einarsson, Eyjólfur Magnússon, Matthew J. Roberts, Finnur Pálsson, Thorsteinn Thorsteinsson, Tómas Jóhannesson
Journal: Annals of Glaciology / Volume 57 / Issue 72 / July 2016
Published online by Cambridge University Press: 12 May 2016, pp. 47-61
GPS campaigns on glaciers during jökulhlaups show how subglacial floods affect glacier motion and shed light on the dynamics of such floods. Three such campaigns have been carried out on southern and western Vatnajökull, southeast Iceland, over known jökulhlaup paths. Two slowly rising jökulhlaups from Grímsvötn and two rapidly rising jökulhlaups from the western and eastern Skaftá cauldrons were captured in these campaigns, with maximum discharge ranging from 240 to 3300 m3 s−1. Glacier surface movements measured in these campaigns are presented along with the corresponding discharge curves. The measurements are interpreted as indicating: (1) initiation of rapidly rising jökulhlaups with a propagating subglacial pressure wave, (2) decreased glacier basal friction during jökulhlaups, (3) subglacial accumulation of water in slowly rising jökulhlaups and (4) lifting of the glacier caused by subglacial water pressure exceeding overburden in both rapidly and slowly rising jökulhlaups. The latter two observations are inconsistent with assumptions that are typically made in theoretical and numerical modelling of jökulhlaups. Both viscous and elastic deformation of the glacier as well as turbulent hydraulic fracture at the ice/bedrock interface are important in the dynamics of the subglacial pressure wave at the front of rapidly rising jökulhlaups.
Law of the wall in an unstably stratified turbulent channel flow
A. Scagliarini, H. Einarsson, Á. Gylfason, F. Toschi
Journal: Journal of Fluid Mechanics / Volume 781 / 25 October 2015
Published online by Cambridge University Press: 17 September 2015, R5
Print publication: 25 October 2015
We perform direct numerical simulations of an unstably stratified turbulent channel flow to address the effects of buoyancy on the boundary layer dynamics and mean field quantities. We systematically span a range of parameters in the space of friction Reynolds number ( $\mathit{Re}_{{\it\tau}}$ ) and Rayleigh number ( $\mathit{Ra}$ ). Our focus is on deviations from the logarithmic law of the wall due to buoyant motion. The effects of convection in the relevant ranges are discussed, providing measurements of mean profiles of velocity, temperature and Reynolds stresses as well as of the friction coefficient. A phenomenological model is proposed and shown to capture the observed deviations of the velocity profile in the log-law region from the non-convective case.
The ability of video image analysis to predict lean meat yield and EUROP score of lamb carcasses
E. Einarsson, E. Eythórsdóttir, C. R. Smith, J. V. Jónmundsson
Journal: animal / Volume 8 / Issue 7 / July 2014
Published online by Cambridge University Press: 07 May 2014, pp. 1170-1177
A total of 862 lamb carcasses that were evaluated by both the VIAscan® and the current EUROP classification system were deboned and the actual yield was measured. Models were derived for predicting lean meat yield of the legs (Leg%), loin (Loin%) and shoulder (Shldr%) using the best VIAscan® variables selected by stepwise regression analysis of a calibration data set (n=603). The equations were tested on validation data set (n=259). The results showed that the VIAscan® predicted lean meat yield in the leg, loin and shoulder with an R 2 of 0.60, 0.31 and 0.47, respectively, whereas the current EUROP system predicted lean yield with an R 2 of 0.57, 0.32 and 0.37, respectively, for the three carcass parts. The VIAscan® also predicted the EUROP score of the trial carcasses, using a model derived from an earlier trial. The EUROP classification from VIAscan® and the current system were compared for their ability to explain the variation in lean yield of the whole carcass (LMY%) and trimmed fat (FAT%). The predicted EUROP scores from the VIAscan® explained 36% of the variation in LMY% and 60% of the variation in FAT%, compared with the current EUROP system that explained 49% and 72%, respectively. The EUROP classification obtained by the VIAscan® was tested against a panel of three expert classifiers (n=696). The VIAscan® classification agreed with 82% of conformation and 73% of the fat classes assigned by a panel of expert classifiers. It was concluded that VIAscan® provides a technology that can directly predict LMY% of lamb carcasses with more accuracy than the current EUROP classification system. The VIAscan® is also capable of classifying lamb carcasses into EUROP classes with an accuracy that fulfils minimum demands for the Icelandic sheep industry. Although the VIAscan® prediction of the Loin% is low, it is comparable to the current EUROP system, and should not hinder the adoption of the technology to estimate the yield of Icelandic lambs as it delivered a more accurate prediction for the Leg%, Shldr% and overall LMY% with negligible prediction bias.
Age of the Younger Laxá Lava and Lake Mývatn, Northern Iceland, Determined by AMS Radiocarbon Dating
Ulf Hauptfleisch, Árni Einarsson
Journal: Radiocarbon / Volume 54 / Issue 2 / 2012
Lake Mývatn and several smaller lakes in northern Iceland were formed by the large Holocene lava flow of the Younger Laxá Lava (YLL). The age of the YLL was estimated by tephrochronology at 1800–2300 BP (Thorarinsson 1951). Conventional radiocarbon dating of charred vegetation beneath the YLL (Thorarinsson 1964) yielded uncalibrated ages of 1940 ± 270 14C yr BP (Yale), 2110 ± 140 14C yr BP (Copenhagen), and 1990 ± 50 14C yr BP (Winnipeg). Ongoing palcolimnological research at Lake Mývatn requires a more precise age estimation of the YLL. Charcoal samples from beneath the YLL were collected at Presthvammur in 2007 and analyzed by accelerator mass spectrometry (AMS) 14C measurements. The reliability of the conventional 14C ages of the samples Yale, Copenhagen, and Winnipeg was re-evaluated, applying criteria from Pettit et al. (2003) and Graf (2009). The result of AMS 14C measurement (2170 ± 38 cal yr BP) underpins the local tephrochronology and provides a reliable age of the YLL and Lake Mývatn.
Temporal and Spatial Variations in Freshwater 14C Reservoir Effects: Lake Mývatn, Northern Iceland
P L Ascough, G T Cook, M J Church, E Dunbar, Á Einarsson, T H McGovern, A J Dugmore, S Perdikaris, H Hastie, A Friðriksson, H Gestsdóttir
Published online by Cambridge University Press: 18 July 2016, pp. 1098-1112
Lake Mývatn is an interior highland lake in northern Iceland that forms a unique ecosystem of international scientific importance and is surrounded by a landscape rich in archaeological and paleoenvironmental sites. A significant freshwater reservoir effect (FRE) has been identified in carbon from the lake at some Viking (about AD 870–1000) archaeological sites in the wider region (Mývatnssveit). Previous accelerator mass spectrometry (AMS) measurements indicated this FRE was about 1500–1900 14C yr. Here, we present the results of a study using stable isotope and 14C measurements to quantify the Mývatn FRE for both the Viking and modern periods. This work has identified a temporally variable FRE that is greatly in excess of previous assessments. New, paired samples of contemporaneous bone from terrestrial herbivores and omnivores (including humans) from Viking sites demonstrate at least some omnivore diets incorporated sufficient freshwater resources to result in a herbivore-omnivore age offset of up to 400 14C yr. Modern samples of benthic detritus, aquatic plants, zooplankton, invertebrates, and freshwater fish indicate an FRE in excess of 5000 14C yr in some species. Likely geothermal mechanisms for this large FRE are discussed, along with implications for both chronological reconstruction and integrated investigation of stable and radioactive isotopes.
Interrogative suggestibility, compliance and false confessions among prisoners and their relationship with attention deficit hyperactivity disorder (ADHD) symptoms
G. H. Gudjonsson, J. F. Sigurdsson, O. O. Bragason, A. K. Newton, E. Einarsson
Journal: Psychological Medicine / Volume 38 / Issue 7 / July 2008
Published online by Cambridge University Press: 14 February 2008, pp. 1037-1044
Interrogative suggestibility and compliance are important psychological vulnerabilities during interrogation. The aim of the study was to investigate the relationship of suggestibility and compliance with childhood and current symptoms of attention deficit hyperactivity disorder (ADHD). Compliance has not been studied previously in relation to ADHD. A further aim was to investigate the relationship between ADHD and the reporting of having made a false confession to the police.
The participants were 90 male prisoners, all of whom had completed the Gudjonsson Suggestibility and Compliance Scales (GSS and GCS) within 10 days of admission to the prison. Childhood ADHD symptoms were screened by the Wender Utah Rating Scale (WURS) and current adult symptoms by the DSM-IV Checklist criteria for ADHD.
Half of the prisoners (50%) were found on screening to meet criteria for ADHD in childhood and, of those, over half (60%) were either fully symptomatic or in partial remission of their symptoms. ADHD symptoms were found to be significantly associated with compliance, but not with suggestibility. The relationship with compliance was stronger (effect size) in relation to current than childhood symptoms. The ADHD symptomatic groups were significantly more likely to claim that they had made a false confession to the police in the past.
The findings raise important questions about the potential vulnerability of adults with ADHD symptoms in terms of their ability to cope with interrogation.
Automatic detection of avalanches and debris flows by seismic methods
Bjarni Bessason, Gísli Eiríksson, Óðinn Thorarinsson, Andrés Thórarinsson, Sigurður Einarsson
Journal: Journal of Glaciology / Volume 53 / Issue 182 / 2007
Published online by Cambridge University Press: 08 September 2017, pp. 461-472
The road along the Óshlíð hillside in the West Fjords region of Iceland is one of the most hazardous roads in Iceland due to avalanches, rockfalls and debris flows. The road has little traffic, but nevertheless traffic accidents caused by the severe conditions at the site are common. A number of avalanche tracks are found on the hillside. In some of these tracks, avalanches occur more frequently than in others. When there is an avalanche threat, avalanches generally flow over many tracks in a short time. Monitoring vibrations in the tracks with the highest avalanche frequency can indicate when avalanches start flowing down the hillside in a snowstorm, and avalanche hazard can then be declared with the specific site indicated. The same methodology can be used for rockfalls and debris flows, which are strongly affected by weather conditions and typically occur in clusters. Based on this knowledge, a research project was initiated in February 1996 with the objective of developing an automatic system based on seismic measurements to detect and analyze avalanches on the Óshlíð hillside and to instantly send a warning to a control station.
Investigating the Growth Process of Vertically Aligned Single-Walled Carbon Nanotubes Synthesized from Alcohol
Erik Einarsson, Rong Xiang, Kazuaki Ogura, Jun Okawa, Zhengyi Zhang, Shigeo Maruyama
Journal: MRS Online Proceedings Library Archive / Volume 1057 / 2007
Published online by Cambridge University Press: 01 February 2011, 1057-II14-04
We have performed a systematic investigation of the influence of the growth parameters on the synthesis of vertically aligned single-walled carbon nanotubes (VA-SWNTs) by the alcohol catalytic chemical vapor deposition (ACCVD) method. The growth process of the VA-SWNTs was monitored using an in situ optical absorbance technique and the effects of CVD temperature and ethanol pressure on the initial growth rate and the catalyst lifetime were investigated. We found that for a given CVD temperature, there is an optimum pressure at which the VA-SWNT film height is maximized, and this pressure increases with temperature. Below this optimum pressure the growth reaction is first-order, with the arrival of ethanol to the catalyst being the rate-limiting step. The activation energy of the growth was also determined to be approximately 1.5 eV.
The root-growth mechanism of VA-SWNTs by the alcohol CVD method was also confirmed by a two-stage growth process. Following a short growth period using normal ethanol, isotope labeled 13C ethanol was introduced to continue the growth. The location of the 13C was confirmed by resonance Raman spectroscopy, confirming the root-growth mechanism.
Reservoirs and Radiocarbon: 14C Dating Problems in Mývatnssveit, Northern Iceland
Philippa L Ascough, Gordon T Cook, Mike J Church, Andrew J Dugmore, Thomas H McGovern, Elaine Dunbar, árni Einarsson, Adolf Frioriksson, Hildur Gestsdóttir
This paper examines 2 potential sources of the radiocarbon offset between human and terrestrial mammal (horse) bones recovered from Norse (∼AD 870–1000) pagan graves in Mývatnssveit, north Iceland. These are the marine and freshwater 14C reservoir effects that may be incorporated into human bones from dietary sources. The size of the marine 14C reservoir effect (MRE) during the Norse period was investigated by measurement of multiple paired samples (terrestrial mammal and marine mollusk shell) at 2 archaeological sites in Mývatnssveit and 1 site on the north Icelandic coast. These produced 3 new δR values for the north coast of Iceland, indicating a δR of 106 ± 10 14C yr at AD 868–985, and of 144 ± 28 14C yr at AD 1280–1400. These values are statistically comparable and give an overall weighted mean δR of 111 ± 10 14C yr.
The freshwater reservoir effect was similarly quantified using freshwater fish bones from a site in Mývatnssveit. These show an offset of between 1285 and 1830 14C yr, where the fish are depleted in 14C relative to the terrestrial mammals. This is attributed to the input of geothermally derived CO2 into the groundwater and subsequently into Lake Mývatn. We conclude the following: i) some of the Norse inhabitants of Mývatnssveit incorporated non-terrestrial resources into their diet that may be identified from the stable isotope composition of their bone collagen; ii) the MRE off the north Icelandic coast during the Norse period fits a spatial gradient of wider North Atlantic MRE values with increasing values to the northwest; and iii) it is important to consider the effect that geothermal activity could have on the 14C activity of samples influenced by groundwater at Icelandic archaeological sites.
A simple sampler for subglacial water bodies
Eric Gaidos, Brian Glazer, David Harris, Zensho Heshiki, Nina Jeppsson, Mary Miller, Thorsteinn Thorsteinsson, Bergur Einarsson, Vilhjálmur Kjartansson, Andri Stefánsson, Luiz Gabriel, Quinn De Camargo, Tomas Johannesson, Matthew Roberts, Mark Skidmore, Brian Lanoil
High-yield synthesis of carbon coils on tungsten substrates and their behavior in the presence of an electric field
Jun Jiao, Erik Einarsson, David W. Tuggle, Logan Love, Josie Prado, George M. Coia
Journal: Journal of Materials Research / Volume 18 / Issue 11 / November 2003
We report an effective procedure for fabricating carbon microcoils and nanocoils with three-dimensional spiral structures in high yield by nickel (Ni)-catalyzed thermal decomposition of acetylene. The Ni catalyst particles used in this preparation were electrochemically deposited onto tungsten substrates. Springlike coils having low pitch and micrometer-scale diameters and ropelike coils having higher pitch and nanometer-scale diameters were observed. Electrical and optical properties were investigated by employing a field-emission probe system equipped with an optical spectrometer. In an applied field above 1.5 V/μm, significant electron emission was observed from individual ropelike nanocoils. The approximately linear slope of the corresponding Fowler-Nordheim plot denotes predominately field-emission behavior. During measurement, individual carbon coils aligned themselves along the electric field, exhibiting a natural resonance on some occasions. As the field strength increased above 2.5 V/μm, the emission-current density for a single nanocoil was measured to be on the order of 104 A/cm2. This high-current density caused Joule heating, resulting in strong photon emission by incandescence.
Synthesis of Carbon Microcoils and Nanocoils on Various Substrates
Erik Einarsson, Jun Jiao, Josie Prado, George M. Coia, Logan Love
Published online by Cambridge University Press: 10 February 2011, P9.21
This research investigates the role of the substrate in the synthesis of carbon coils. Coils were produced on tungsten, titanium, and glassy carbon substrates via chemical vapor deposition (CVD) of acetylene (C2H2) on electrochemically deposited nickel at 800°C, but the growth varied among the samples. Coils were also produced on pure nickel by the same CVD method. Using tungsten as a substrate, carbon coils intermixed with thin carbon nanotubes were produced in high-yield from nickel particle clusters. On the titanium substrate, carbon coils were synthesized in small, high-yield patches with few co-produced carbon nanotubes. Synthesis from nickel clusters on glassy carbon usually resulted in amorphous carbon, but sparse, low-yield coil growth was observed. Carbon coils were also synthesized when pure nickel wire was used without a separate substrate. These results indicate the nickel catalyst controls the production of carbon coils, but the substrate has some effect on the yield. Carbon coils synthesized were either microcoils, which have diameters of a few microns, or nanocoils, which have diameters of one or two hundred nanometers.
Electrodeposition of Ni Catalyst on Tungsten Substrates and Its Effect on the Formation of Carbon Nano- and Micro-coils
Erik Einarsson, Jun Jiao, Josie Prado, George M. Coia, Jeremy Petty, Logan Love
Published online by Cambridge University Press: 11 February 2011, I3.20
Carbon micro-coils and nano-coils were produced in high yield from nickel catalyst particles electrochemically deposited onto tungsten substrates. Various electrochemical deposition techniques were used to produce the nickel catalyst particles. These particles catalyzed the chemical vapor deposition (CVD) of acetylene at 800°C, resulting in growth of carbon microand nano-coils. Linear-sweep (cyclic) voltammetry produced catalyst particles which resulted in single- filament coils intermixed with thin nanotubes over most of the substrate surface. Passing the same amount of charge by constant current electrolysis produced nickel particles that decomposed carbon but did not grow coils. Catalyst particles deposited by constant current electrolysis grew nanocoils similar to linear-sweep voltammetry but in small, localized, high-yield patches. The coils produced were either spring- like micro-coils of low pitch and large diameter or rope- like nano-coils of higher pitch and smaller diameter. High-resolution transmission electron microscopy (HRTEM) showed typical graphite fringes in the filaments, but did not reveal an internal tubular structure. Catalyst particles were often detected at the ends of the coils.
Protecting the Arctic: indigenous peoples and cultural survival. Mark Nuttall. 1999. Amsterdam: Harwood Academic Publishers, viii + 195 p, soft cover. ISBN 90-5702-355-5. £13.95; US$22.00.
Niels Einarsson
Journal: Polar Record / Volume 37 / Issue 201 / April 2001
Distribution, abundance, population structure and meat yield of the ocean quahog, Arctica islandica, in icelandic waters
Gudrún G. Thórarinsdóttir, Sólmundur T. Einarsson
Journal: Journal of the Marine Biological Association of the United Kingdom / Volume 76 / Issue 4 / November 1996
A hydraulic dredge survey was conducted during January – June 1994 in north-west, north and east Iceland, to provide a first assessment of ocean quahog, Arctica islandica (Mollusca: Pelecypoda) resources in these areas. Ocean quahog was found in significant concentrations and high density. The combined high-density areas were 91.7 km2 with a minimum biomass (live weight) of 304.80 tonnes. Information on population structure and meat yield were also provided. The population in the areas was characterized by unimodal size distributions comprised of mostly larger-sized individuals. Most quahogs were between 70 and 90 mm with no individuals <17 mm which might be due to the selectivity of the dredge or because of poor recruitment in the population. Little difference was observed when comparing the mean shell length for the quahogs from the three areas. The mean shell length in the north-west area was 75.4 mm and 74.8 mm in the north and east areas. The shell length frequency distribution for the north-west area was different in shape from the two others which were not significantly different from each other. Mean quahog meat yields in the areas were from 30.1 to 33%. The meat yield was highest in the 50.55 mm size class in all areas.
Stability of a New, Multichannel, Low-Level Liquid Scintillation Counter System, Kvartett
Sigurđur Einarsson, Páll Theodórsson
Kvartett is a new liquid scintillation counting (LSC) system for radiocarbon dating that takes a radical departure from conventional systems to obtain a compact, low-level counting system measuring four samples simultaneously. Each sample vial, inside the well of a large NaI(Tl) guard-counter crystal (facing down), sits on top of a vertical PMT. The fourfold counting capacity can be used to increase the number of samples being dated or to get higher precision. The increased throughput helps to keep a rigid quality-control standard. We monitored the background count rate almost continuously for 7 months, and measured the count rate of a standard repeatedly for 2 months. The results show the background and system reproducibility to be stable.
Evaluation of a Prototype Low-Level Liquid Scintillation Multisample Counter
Sigurđur A. Einarsson
A new, improved photomultiplier has been incorporated and a more efficient active guard installed in a single photomultiplier liquid scintillation counter. A special quartz vial was designed to improve the photoelectron cathode index (photoelectrons/keV), and thus, to reduce background. Four photomultipliers were installed so that four samples can be counted simultaneously. The measurements presented here cover background spectra and counting efficiency obtained under various conditions in the laboratory. These measurements and derived parameters, such as the figure of merit (E2/B) and the factor of merit (S/√B), are used to evaluate the system performance. Also presented are the results of measurements on the cathode index and further background spectra, obtained at an underground site.
Study of Background Pulse Spectrum of an LSC System
Sigurđur A Einarsson, Páll Theodórsson
Important advances have been made in reducing the background counting rate of gas proportional counters for 14C dating through detailed and systematic study of the background components. Until recently, limited work has been reported on the study of the background of liquid scintillation counters (LSC). During the last few years, commercial systems with greatly reduced background have been introduced. It is shown that the best gas proportional counters and LSC have similar backgrounds for the same amount of sample material. Similar results with less effort may be expected with more detailed and fundamental knowledge of the components of the background of LSC. We report the results of a study of one photomultiplier LSC system where we research all parameters of importance: light collection efficiency, absorbed energy per photo-electron, pulse height spectrum and background counting rate.