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Showing papers by "University of Iceland published in 1982"


Journal ArticleDOI
TL;DR: In this article, a computer program is developed to calculate the composition and aqueous speciation of geothermal reservoir waters including pH, redox potential and gas partial pressures, which is specifically suited to handle geochemical data from wet-steam wells, hot-water wells and boiling hot springs, but it may also be used for non-thermal waters.

350 citations


Journal ArticleDOI
TL;DR: In this article, the authors present a survey of the state-of-the-art tools and techniques used in the development of the HOGA algorithm and its application in the field of artificial intelligence.
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231 citations


Journal ArticleDOI
01 Feb 1982-Nature
TL;DR: In this article, the authors proposed that penetration of water into hot rock is the primary reason for the intense heat release (5,000 MW thermal) of the subglacial Grimsvotn geothermal area.
Abstract: The Grimsvotn geothermal area is located within one of the most active caldera volcanoes in Iceland in the interior of the ice cap Vatnajokull at an altitude of 1,400 m (Fig. 1). Its setting oilers unique conditions for calorimetric measurement of the heat release from the subglacial geothermal system. The melting of ice due to the geothermal activity creates a depression in the surface of the ice cap. Ice and water are diverted towards the depression from a 300 km2 drainage basin. The meltwater accumulates in a 30 km2 subglacial lake. Periodic outbursts of water (jokulhlaups) drain the lake subglacially down to the Skeidararsandur plain. We propose here that penetration of water into hot rock is the primary reason for the intense heat release (5,000 MW thermal) of the subglacial Grimsvotn geothermal area. Injection of water into boundary rocks of magma should be considered as a method of heat exploitation.

79 citations


Journal ArticleDOI
TL;DR: In this paper, a six-year-old Icelandic child learning English in a naturalistic setting, with particular emphasis on fricatives and affricates, was examined with reference to two hypotheses: (1) the developmental position that second language phonology acquisition parallels first language acquisition, and (2) the transfer position that the learner's phonological knowledge in the first language directly influences acquisition of a second-language phonology.
Abstract: The acquisition of a second language phonology is examined with reference to two hypotheses: (1) the developmental position that second language phonology acquisition parallels first language acquisition versus (2) the transfer position that the learner’s phonological knowledge in the first language directly influences acquisition of a second language phonology. These two hypotheses are evaluated in light of data from a six-year-old Icelandic child learning English in a naturalistic setting, with particular emphasis on fricatives and affricates. This child’s phonological acquisition is best accounted for as a systematic interaction between transfer from the first language and developmental processes. Transfer best predicts the relative difficulty of particular segments, while the developmental hypothesis best predicts which sounds will be substituted for those difficult segments.

68 citations


Journal ArticleDOI
TL;DR: In this paper, a finite element model for calculation of stresses and deformations of beams with thin walled cross-sections is presented, which takes into account deformations due to shear.

56 citations


Journal ArticleDOI
TL;DR: In this article, the major part of the palaeomagnetic sampling is represented by 2462 lavas in five long composite sections through the lava pile, and various statistical properties of this data set are discussed.
Abstract: Summary. In 1972-78, the late N. D. Watkins and others carried out ajoint field programme of geological mapping in the Mio-Pliocene flood basalts of Iceland, including sampling for K-Ar dating and palaeomagnetic research. The major part of the palaeomagnetic sampling is represented by 2462 lavas in five long composite sections through the lava pile. This paper deals with various statistical properties of this data set. It is concluded that geomagnetic reversals occur more frequently than is assumed in the current ocean-floor polarity time-scale. There is no evidence for significant asymmetries between normal and reverse polarity states of the field, neither as regards chron lengths, secular variation, or virtual dipole moment magnitude. Intensities of remanence in these lavas are shown to be well approximated in terms of a hyperbolic distribution, The latitude distribution of virtual magnetic poles can be fitted with a Bingham function having k'* 4.5, and low-latitude poles do not occur preferentially in any particular longitude interval.

50 citations


Journal ArticleDOI
TL;DR: Two Icelandic sheep with clinical signs of visna appearing 6-7 years after intracerebral infection with visna virus were killed, fixed by perfusion and the central nervous system lesions examined by light and electron microscopy as mentioned in this paper.
Abstract: Two Icelandic sheep with clinical signs of visna appearing 6–7 years after intracerebral infection with visna virus were killed, fixed by perfusion and the central nervous system lesions examined by light and electron microscopy. Both sheep showed similar pathological changes. In the brain there was a severe periventricular inflammatory process with small foci of liquefaction necrosis and scattered small granulomas. In some areas of inflammation there was evidence of primary demyelination but it was not prominent. In the spinal cord there were focal plaques of primary demyelination. At the ultrastructural level the spinal cord lesions showed unambiguous primary demyelination with many naked axons; various stages of remyelination with peripheral type of myelin were also common.

47 citations


Journal ArticleDOI
TL;DR: Comparison of the mean ages at emergence of primary teeth in Icelandic, Finnish, Swedish, US, and Hungarian children disclosed a significantly earlier emergence in the Icelandic children, except that in Finnish children it was similar.
Abstract: This study was undertaken to elucidate the mean ages at emergence of primary teeth and at the onset of dental stages DS 01 and DS 02 in Icelandic children. The material comprised 927 children (498 boys and 429 girls) aged 0-83 months who were presented for regular examinations in two Health Centers and children in three kindergartens in Reykjavik. Comparison of the mean ages at emergence of primary teeth in Icelandic, Finnish, Swedish, US, and Hungarian children disclosed a significantly earlier emergence in the Icelandic children, except that in Finnish children it was similar.

43 citations


Journal ArticleDOI
TL;DR: The results are consistent with the view that the same model of metabolism of activator calcium as previously proposed for rabbit papillary muscles is also applicable to the rat heart.
Abstract: The experiments were performed on isometrically contracting rat papillary muscles paced at 1.0 Hz and at a temperature of 37 degrees C. The contractile response of a test contraction continuously rose when the duration of the preceding stimulus interval was gradually increased from 0.2 s. A maximum value was seen at intervals of 60--120 s. This phenomenon was called mechanical restitution of the papillary muscle. The insertion of a priming beat before the test contraction in order to increase the amount of contractile calcium elevated the mechanical restitution curve but it did not change the maximum contractile force seen after 60--120 s intervals. Lowering the extracellular calcium concentration from 2.0 mM to 1.0 mM, however, depressed this maximum contractile force to about 50%. The mechanical restitution is thought to reflect inflow of activator calcium to a cellular store, from which it is later released in response to the action potential. By using two test contractions a simple method is described to estimate the recirculating fraction of activator calcium between beats in this preparation. In 11 preparations the recirculating fraction of activator calcium was 0.72 +/- 0.03 (mean +/- SE). The results are consistent with the view that the same model of metabolism of activator calcium as previously proposed for rabbit papillary muscles is also applicable to the rat heart.

37 citations


Journal ArticleDOI
TL;DR: In this paper, the authors presented maps for the glacier surface and the bedrock of two areas on Vatnajokull -Tungnarjokull and Sylgjujokaull in the western ice cap and Eyjabakkajokool in the northeast.
Abstract: Maps are presented for the glacier surface and the bedrock of two areas on Vatnajokull - Tungnarjokull and Sylgjujokull in the western ice cap and Eyjabakkajokull in the northeast. The ice surface maps are obtained by precision barometric altimeter. They form the basis for delimitation of ice drainage basins. The bedrock maps are the results of radio echo soundings. Both maps are used for defining the water drainage basin which is estimated 121 km 2 for the river Tungna, 85 km 2 for the rivers from Sylgjujokull and 117 km 2 for the rivers from Eyjabakkajokull.

35 citations


Journal ArticleDOI
TL;DR: The concentration of iron in Icelandic geothermal waters lies in the range of about 0.004-0.3 ppm as mentioned in this paper and the concentration of H2S shows a very good correlation with the temperature of the geothermal water.

Journal ArticleDOI
TL;DR: In this article, the production of I( 2 P 1 2 ) in the photolysis of CH 2 I 2 has been studied optoacoustically at excitation wavelengths between 365.5 and 247.5 nm.

Journal ArticleDOI
TL;DR: In this article, the use of earthquake studies in the field of geothermal exploration is reviewed and the utility of the method cannot yet be assessed because of its undeveloped methodology and the paucity of case histories.

Journal ArticleDOI
TL;DR: In this paper, the 350-400 nm oscillatory continuum, observed in emission when I 2 is excited to the D 1 Σ + u state (λ = 193 nm, u′ ≈ 134), has been analyzed.

Journal ArticleDOI
TL;DR: Serum/CSF IgG1 ratios indicated that the blood-brain barrier was apparently intact in long-term visna infection, consistent with intrathecal synthesis of IgM and of antiviral antibody.

Journal ArticleDOI
Peter Thy1
01 Jan 1982-Lithos
TL;DR: In this article, it is suggested that the contents of certain minor elements in both ilmenite and titanomagnetite can be related to changing composition and crystallization conditions during fractional differentiation in the parent magma.

Journal ArticleDOI
TL;DR: In this article, the authors deal with stochastic theory of nonlinear wave forces emphasizing their effects on the structural response of offshore towers and analyze forces and response using second-order statistics expressed in terms of power spectral densities.

Journal ArticleDOI
TL;DR: The present paper gives the complete data of the study of Iceland and extends the sample size for most of the genetic systems to over 1500 individuals, approximately 1/130 of the population.
Abstract: SummaryBjarnason, Bjarnason, Edwards, Fridriksson, Magnusson, Mourant and Tills (1973) published preliminary data on a study of Iceland. The present paper gives the complete data of the study and extends the sample size for most of the genetic systems to over 1500 individuals, approximately 1/130 of the population. The sample was divided into seven subpopulations and these were compared using a genetic distance matrix. Considerable internal variation was revealed with two groups appearing very different. The seven regions were then compared with possible founding populations and no close relationships were found. The possible mechanism for the internal variation and the differences between Icelandic gene frequencies and those from other N.W. European populations are discussed.

Journal ArticleDOI
TL;DR: It is concluded that the changes in the psychiatric services are associated with an increase in the rate of suicide and that this increase may to some extent be a side effect of therapeutic methods introduced after 1965.
Abstract: The purpose of the study is to discover whether there is an association between changes in the psychiatric services offered by the largest psychiatric hospital in Iceland during the period 1955–1978 and changes in the rate of suicide. Marked changes occurred in the services after 1965. The rate of suicide in the patient population was significantly higher during 1965–1978 than during 1955–1964. It is concluded that the changes in the psychiatric services are associated with an increase in the rate of suicide and that this increase may to some extent be a side effect of therapeutic methods introduced after 1965. The conclusion is thought to imply the necessity for further evaluation of those therapeutic methods as applied in the hospital and increasing the application of measures for the prevention of suicide.

Journal ArticleDOI
TL;DR: In this paper, the establishment and direction of sociology as a discipline in Iceland are considered in ways that are pertinent to national conditions and the influence of such general characteristics of Icelandic society as nationalism, the rapid industrialization, and the size of the population, on the definition and development of Icelandic sociology are also considered.
Abstract: The establishment and direction of sociology as a discipline in Iceland are considered in ways that are pertinent to national conditions The discussion emphasizes. (a) the institutional structure of the educational system, (b) the availability of an appropriate terminology, and (c) the placement of sociology among the existing disciplines. The influence of such general characteristics of Icelandic society as nationalism, the rapid industrialization, and the size of the population, on the definition and development of Icelandic sociology are also considered.

Journal ArticleDOI
TL;DR: In this paper, a critical survey of Nordic umlaut research during the last thirty years is presented, and an attempt is made to evaluate the various contributions to this research which have been based, alternately, on structural generative phonological theory.
Abstract: The article contains a critical survey of Nordic umlaut research during the last thirty years. An attempt is made to evaluate the various contributions to this research which have been based, alternately, on structural generative phonological theory; in contrast to the earlier heavily datae-based research, recent work in this field has indeed been more exclusively theory- oriented. that the results of these ene deavors have on the whole not been commensurate with the effort; in spite of the evident optimism which, at certain times at any rate, has dominated this research, it apperars indeed that some of the traditional or classical problems of Nordic umlaut research tend to persist, or continually toreappear, in one guise or another, and thus to continue to defy a convincing solution.

Journal ArticleDOI
TL;DR: In this article, the authors use the direct method of the calculus of variations to prove the existence of solutions to some degenerate two point boundary value problems, and estimate the behaviour of solutions at the endpoints in special cases.

Posted Content
TL;DR: The authors presented a simple synthesis of Keynesian, monetary, and portfolio approaches to macroeconomic theory under flexible exchange rates, and showed that some of the important contrasts that have been drawn between the approaches are due to a neglect of repercussions elsewhere in the economy.
Abstract: This paper presents a simple synthesis of Keynesian, monetary, and portfolio approaches to macroeconomic theory under flexible exchange rates. By including the key features of all the partial approaches in a general model, we show that some of the important contrasts that have been drawn between the approaches are due to a neglect of repercussions elsewhere in the economy. After reconciling these false contrasts, we show how some of the approaches still give different predictions about the effects of monetary and fiscal policy using differing assumptions about the international mobility of goods and financial assets.

Journal ArticleDOI
TL;DR: In this paper, the authors discuss changes in the control of access and their implications for the management of information among skippers and argue that territorial claims should be seen as pragmatic attempts to manage the conduct of fishing.
Abstract: The article discusses the nature and significance of strategies of managing access to fishing territories. The data relate to the indigenous and private strategies used by Icelandic fishermen Such strategies vary with time and with fishing technology. The article discusses changes in the control of access and their implications for the management of information among skippers. Several scholars have reported claims of territoriality among fishermen and have referred to them as manifestations of property rights and ownership. It is argued here that territorial claims should be seen as pragmatic attempts to manage the conduct of fishing


Journal ArticleDOI
TL;DR: In this paper, the authors carried out precision resistance measurements on two Fe-Ni-based amorphous alloys (Fe15Ni60P16B6Al3 and Fe11Ni69P14B6) around Tc. The analysis of data give α = -0.37 ± 0.05, in fair agreement with the value calculated via scaling relations.
Abstract: For almost all amorphous magnetic systems studied so far, the critical indices for the phase transition at the Curie point are non-Heisenberg like (β 0.4, γ 1.6). Via scaling relations this gives the specific heat index α - 0.4, indicating that the singularity at Tc is considerably reduced. To confirm this α value, a direct measurement of α would be valuable. This is possible via resistance measurements, since dρ/dT has the same critical behaviour as CP. We have carried out precision resistance measurements on two Fe-Ni-based amorphous alloys (Fe15Ni60P16B6Al3 and Fe11Ni69P14B6) around Tc. The shape of the dR/dT vs. T curves shows the typical cusp above Tc, but straight line below Tc, indicating suppression of the critical behaviour, and the presence of a T2 term. The analysis of data give α = -0.37 ± 0.05, in fair agreement with the value calculated via scaling relations. The suppression of the critical behaviour below Tc is reflected in an anomalous value for the amplitude ratio.

Journal ArticleDOI
TL;DR: In this paper, the authors argue that to understand fishing in modern Iceland, it must be contexualized in terms of a system which includes three subsystems: (1) catching and processing, (2) distribution, and (3) policy.
Abstract: We argue that to understand fishing in modern Iceland, it must be contexualized in terms of a system which includes three subsystems: (1) production–catching and processing, (2) distribution–selling processed fish internationally, (3) policy–establishing fishing areas, gear, periods, prices, quotas, and attempts to influence policy. We briefly outline the components of this system in contemporary Iceland. We conclude that if comparative studies of fishing are to be useful, they must go beyond comparisons of fishing boats to comparisons of fishing systems.

Journal ArticleDOI

Journal ArticleDOI
TL;DR: In this paper, the authors discuss the question of whether the 1953 integration of Greenland into Denmark excludes the future application of this right by the Greenlanders, and they conclude that there is general agreement that at least overseas colonial and territorial entities are entitled to exercise this right.
Abstract: There may be uncertainty and difference of opinion about the extent and scope of the right to self-determination in international law, but I believe there is general agreement that at least overseas colonial and territorial entities are entitled to exercise this right. The name of the rule of law may be either external self-determination or decolonization, but the results are the same: that peoples in colonial countries have the right to decide on their own constitutional future and international status. It is in his context that I will discuss the question of whether the 1953 integration of Greenland into Denmark excludes the future application of this right by the Greenlanders.