Showing papers by "Queen's University Belfast published in 1981"

Transport processes in the sorption of colored ions by peat particles

Abstract: A three-step model has been proposed for the adsorption of Astrazone Blue dye (Basic Blue 69) on peat. The initial rate of uptake of dye ions due to physical adsorption and chemisorption (ion exchange) has been correlated using a surface mass transfer coefficient. These coefficients have been determined and expressed in the dimensionless mass transfer form, Sh Sc 0.33 , as a function of agitation, initial dye concentration, peat particle size range, dye solution temperature, and mass of peat.

Use of di-isopropyl phenol as main agent for short procedures

Abstract: The use of di-isopropyl phenol (Diprivan) for induction of anaesthesia was assessed in doses ranging from 1 to 3 mg kg−1. With less than 1.75 mg kg−1 not all patients were anaesthetized; 2.0 mg kg−1 appeared to be a satisfactory induction dose. Involuntary muscle movement, cough and hiccup at induction were rare with any dose studied. However, the frequency of hypotension and respiratory depression were related to the dose given. Pain on injection was uncommon when the drug was given into an antecubital vein, but occurred in 39% of patients when injected to the back of the hand or wrist. Recovery was rapid, and characterized by lack of emetic sequelac. Di-isopropyl phenol 1.5–2.0 mg kg−1 given rapidly during reactive hyperaemia can produce anaesthesia in one arm—brain circulation time. A reaction involving flush, hypotension, cough, laryngospasm and bronchospasm occurred in one patient receiving 2.5 mg kg−1 given over 20 s.

Experimental study of the ionisation of atomic hydrogen by fast H+ and He2+ ions

Abstract: Cross sections for the ionisation of ground state hydrogen atoms by 38-1500 keV H+ and 125-2200 keV He2+ ions have been determined using a crossed-beam technique. Collision products produced in the intersection of the primary ion beam with a highly dissociated thermal energy beam of hydrogen are identified by time-of-flight spectroscopy and counted using a coincidence technique. Cross sections sigma (H+) for proton impact, which involve much smaller uncertainties and cover a wider energy range than previous measurements, now permit an accurate assessment of the validity of the various theoretical predictions. Cross sections sigma (He2+) for He2+ impact, the first such measurements, are also compared with theory and measured cross section ratios sigma (He2+)/ sigma (H+) are considered in terms of the Z2 scaling predicted by the Born approximation.

Allozyme evidence for reproductively isolated sympatric populations of brown trout Salmo trutta L. in Lough Melvin, Ireland

Abstract: Electrophoretic studies of five polymorphic enzyme loci (G-3-PDH-2, LDH-I, LDH-5, PGI-2, PGI-3) in brown trout from Lough Melvin in northwestern Ireland have demonstrated that the morphotypes known by the vernacular names of ‘ferox’, ‘gillaroo’ and ‘sonaghen’, are not merely ecophenotypes but represent genetically distinct and reproductively isolated populations. The results suggest that the long life and higher growth potential of ferox trout of this lake, and possibly others, has a genetic basis. These separate demes of brown trout are probably the result of multiple invasions in post-glacial times of allopatrically derived stocks. Lough Melvin's isolated position and absence of pike, Esox lucius, and large cyprinids have probably contributed to its pristine condition. As such it is one of the few remaining examples of what may once have been a widespread situation in Britain and Ireland.

Chromatic adaptation of photosynthesis in benthic marine algae: An examination of its ecological significance using a theoretical model

Abstract: All available action spectra of photosynthesis for benthic marine algae have been multiplied by the spectral distribution of the light at different depths in all Jerlov water types to predict the photosynthesis per unit quantum irradiance of each species in each habitat. Comparison of the predictions indicates that red algae are best adapted chromatically to photosynthesize at all depths (including 0 m) in all except the clearest oceanic waters. The results show little correlation with the patterns of vertical distribution of green, brown, and red algae in benthic marine habitats, and suggest, therefore, that light quality is not a major factor in the control of that distribution. A review of physiological evidence supports the hypothesis that the changes in pigment composition that are observed with increasing depth in marine algae are largely adaptations to low irradiance, and not to the spectral composition of underwater light.

A Simultaneous Iteration Algorithm for Real Matrices

Abstract: Simultaneous iteration methods are extensions of the power method whereby iteration is carried out with a number of trial vectors tha t converge onto the eigenvectors corresponding to the dominant eigenvalues. T h e y are particularly suitable where the matrix requiring eigensolution is large and sparse, or where approximations to the required dominant eigenvectors are already available. The first s imultaneous iteration methods are due to Bauer [1] and have been discussed by Wilkinson [10]. Subsequent methods are related to Bauer ' s bi-iteration technique but improve the convergence rate by including an interaction analysis into the iteration cycle. These methods have been most highly developed for the real syrmnetric eigenvalue problem where the left and right eigenvectors coincide. A previous paper by the authors [4] describes two possible pro~cedures for real unsymmetr ic eigenvalue problems. One procedure is a bi-iteration technique in which left and right eigenvector sets are simultaneously predicted, while the

Evaluation of midazolam as an intravenous induction agent

Abstract: Midazolam, a new water-soluble benzodiazepine, was investigated as an intravenous anaesthetic agent in 260 adult patients in doses ranging from 0.15 to 0.5 mg/kg using a variety of premedications. Its onset of action was generally slow, taking up to 3 minutes to exert its maximum effect. A wide variability in response was found in that some unpremedicated patients were satisfactorily anaesthetised with 0.15 mg/kg while other were only moderately sedated following doses of 0.5 mg/kg. Less variability was found in the elderly who also required smaller doses. Narcotic premedication potentiated the sedative effect of midazolam. Few respiratory or cardiovascular effects were noted apart from hiccough following the larger doses. The incidence of venous sequelae was much lower than that found following diazepam.

Electron-atom scattering at intermediate energies

Abstract: Over the last few years there has been much interest, both theoretically and experimentally, in electron-atom scattering at intermediate energies. The theoretical work has been driven mainly by the many applications in astronomy, laser physics and plasma physics which require accurate data for their interpretation and by experimental advances which provide an important stimulus to theory. The increasing availabililty of more powerful computers has enabled the development of more sophisticated theoretical methods to study electron scattering in the intermediate energy regime, which faces particular difficulties owing to the infinite number of open channels which occur in this energy region. In order to obtain accurate results in the intermediate energy region, the theoretical approaches used must be able, in some way, to allow for loss of flux into these highly excited states and continuum states of the target atom or ion. Recent theoretical approaches which have been proposed include extensions of low-energy methods, the use of optical potentials and extensions of the Born approximation by the inclusion of higher-order terms.

Ambiguities and Insecurities in Pascal.

Abstract: Ambiguities and insecurities in the programming language Pascal are discussed.

Genetic variation in Irish populations of brown trout (Salmo trutta L.): electrophoretic analysis of allozymes

Abstract: 1. 1. Starch gel electrophoresis and isoelectric focusing of skeletal muscle, eye, brain, liver and heart extracts of Irish brown trout populations revealed extensive genetic heterogeneity. 2. 2. Twenty-three enzyme systems, comprising a putative 63 loci, were examined. Polymorphism was observed at 13 loci of which four, PGI-2, 5AAT-4, 2IDH-1 and 2IDH-2, have not previously been reported as polymorphic in brown trout. 3. 3. The value of the relatively high level of polymorphism, (22%) is discussed with respect to salmonid genetic research and management programmes.

The energy balance in coronal holes and average quiet-sun regions

Abstract: Emission measure curves are presented for average coronal hole and quiet-sun spectra taken during the Skylab mission by Vernazza and Reeves (1978), and the curves are used to discuss the energy balance in each region. Close-coupling calculations are used for the Be sequence, assuming a 10 level ion; for B sequence ions mainly distorted wave calculations in an 11 level ion are used, but close-coupling cross sections are used for some ions; for C and Mg sequence ions, distorted wave calculations are used with 15 and 10 level ions, respectively, and close-coupling results are used for Li-like ions with two levels. Results are presented and include the following: the coronal hole spectrum shows a smaller slope in the emission measure distribution, consistent with the expected outflow effects. It is concluded that the simple constant pressure models of static coronal loops of constant cross section are basically able to match the observed emission measure distribution of the average quiet sun between 1,000,000 and 10,000,000 K. However, the cell center and network distributions are respectively steeper and shallower than predicted by the detailed cooling curve.

Dating of post‐glacial landforms in the central howgills

Abstract: Little is known of Holocene landform development in Upland Britain. This paper describes a site at Middle Langdale in the Howgill Fells of Cumbria where large, but now stabilized and inactive gullies cut through periglacial material. At the base of the gullies large debris cones have buried earlier alluvial sediments on the valley floor. On these sediments and buried by the debris cones is a well-developed organic soil from which two 14C dates have been obtained in an attempt to estimate the age range of the soil. These dates range from 2580±55 years BP for the fine particulate fraction from the base of the organic horizon to 940±95 years BP for fossil rootlets from the uppermost organic layer, immediately below the overlying debris cones. The pollen evidence suggests that the valley floor site was initially dominated by alder carr and later by a Juncus marsh with birch, alder and hazel nearby. The pollen, from the surrounding upland area suggests woodland on the valley sides, dominated by oak and elm that was later replaced by a more open environment rich in heath species and in which disturbed ground species were present. The magnetic evidence indicates a stable local environment during soil formation but shows a sudden inwash of unweathered debris at the top of the buried soil. The evidence suggests that the valley floor was geomorphologically stable throughout the period of soil formation, although there was a local change in valley floor vegetation and a reduction of woodland cover on the valley sides at sometime during the period. The evidence then points to major geomorphological changes; a wave of soil erosion, gully development and debris cone deposition, perhaps following the Scandinavian introduction of sheep farming in the tenth century A.D.

The effects of agronomy on the carbon and nitrogen contained in the soil biomass

Abstract: Soils of various agronomic histories were fumigated with chloroform, and the resultant increased production of CO2 and mineral-N measured and expressed as biomass C and the flush of mineral-N production (FN), respectively. Biomass C and FN contents of grassland soils were greater than those of arable soils, and significant correlations with macro organic-matter content were found. Biomass C contents varied from 7 to mg C/100 g soil in arable soil and from 31 to 222 mg C/100 g soil in grassland or woodland. The proportion of soil organic C that was contained within the biomass ranged from 0·3 to 4·0%, whilst FN comprised from 1·0 to 11·7% of total soil N. FNcontents ranged from 1·1 to 13·2mg N/1OOg soil for arable soils, and from 2·5 to 31·7 mg N/100 g soil for grassland and woodland. Application of organic manures increased biomass C and FN contents in grassland soil.

Some perspectives on frost shattering

Abstract: Luckman, 1976). Grawe (1936), however, placed limiting conditions on this mechanism, and proposed that ’the force exerted when water freezes in rock cannot be stated as a definite value unless the conditions under which the process takes place are also stated’ (Grawe, 1936, 182). These remarks have gone largely unheeded and his paper may be read profitably to this day. There is a very real lack of knowledge concerning the operation of freezing processes in high latitude and high altitude areas. For example, in spite of an emphasis on the relevance of freeze-thaw cycles to frost processes (Jenness, 1952; Rapp, 1960; Bjerrum and Jorstad, 1968), there is a paucity of detailed field measurements of such phenomena. Additionally, there is a lack of theoretical knowledge of the process of frost shattering. Experiments which have been conducted

Master equation derivation of quantum regression theorem

Abstract: The master equation approach is used to relate the calculation of correlation functions to the calculation of single-time expectation values. The quantum regression theorem is shown to result on neglecting a certain term. The properties of this neglected term are briefly discussed.

Meaning through metaphor: analogy as epistemology

Abstract: The role of imagination in geographical philosophy and theory is demonstrated by an examination of the function of analogical thinking in scientific investigation. Specifically, the interrelationships between metaphorical usage and mythic understanding and the development of models is elucidated through an analysis of the metaphor-myth-model nexus. The contribution of organicistic models of society to geographical investigation is shown to rely upon metaphor and to generate myth. Erected on this foundation, the Turnerian frontier hypothesis, itself premised on and creating myth, has been reconceptualized to fit both the space-time continuum, in the analysis of nighttime urban society, and the experience of the black inner city. Since the investigation of the unknown can only be conducted with open-ended concepts, the “flight of imagination'’is an indispensable element in geographical epistemology.

The pathology of multiple sclerosis--fact, fiction and hypothesis.

Abstract: The present state of our pathological knowledge of multiple sclerosis is reviewed emphasizing the ‘hard facts’ while highlighting subjects of disputed interpretation and of ignorance.

Swimming against the tide

Abstract: The Politics of Self-Sufficiency. By Michael Allaby and Peter Bunyard. Pp.242. Publised by (Oxford University Press: 1980.) Hbk 7.95, 24.95; pbk 3.95.

Developmental mechanisms in normal and abnormal palate formation with particular reference to the aetiology, pathogenesis and prevention of cleft palate.

Abstract: Palatal development was studied macroscopically, microscopically and ultrastructurally in foetuses of inbred Wistar rats and Alligator mississippiensis. In the rat, elevation of the palatal shelves from a vertical position lateral to the tongue to a horizontal position above the tongue, occurs very rapidly. This reorientation is postulated to be caused by an intrinsic turgor shelf force generated by the hydration of mesenchymal mucopolysaccharides (predominantly hyaluronic acid). Cleft palate was induced in rat foetuses using 5-fluoro-2-desoxyuridine and was associated with greatly decreased mucopolysaccharide synthesis. The alligator is the only animal which develops in an external egg and which possesses a true mammal-like secondary palate: it is therefore a useful animal model system because longitudinal studies and direct surgical and pharmacological manipulations can be performed. The palatal shelves of alligators grow horizontally above the dorsum of the tongue from their first appearance. This de novo horizontal shelf growth is associated with an increase amount of space in the alligator oronasal cavity due to the small, fatty, alligator tongue. It is postulated that the evolution of the large muscular mammalian tongue constrains the palatal shelves to grow vertically until sufficient space can be created to form the common nasal passage simultaneous with shelf elevation.

The placental transfer of cimetidine.

Abstract: Summary The placental transfer of cimetidine 200 mg intravenously was investigated in 16 patients in normal labour and 40 patients undergoing elective Caesarean section. Cimetidine crosses the placental barrier, blood levels at delivery in mothers and infants being lower with increasing time from injection. Umbilical cord blood cimetidine levels are markedly lower than those of the mother during the first hour following administration but thereafter levels are similar. The mean fetal–maternal ratio at delivery was highest (0.84) at 1 1/2–2 hours following administration. Postdelivery infant and maternal blood samples showed that cimetidine could not be detected, in most cases, 19 hours following administration. The relevance of these findings is discussed.