Showing papers by "University of Bath published in 1969"
TL;DR: In this article, the cyclization of benzylaminoacetaldehyde dialkyl acetals has been examined and their utilization for the preparation of various isoquinoline derivatives studied.
39 citations
TL;DR: In this paper, new syntheses of tetrahydroberberine and tetrahedropalmatine are described and some other potential routes to the berbine skeleton are explored.
31 citations
01 Jun 1969
TL;DR: In this article, the authors describe theoretical and experimental work on pulse operation of inward radial flow turbines, together with certain essential steady flow data, and demonstrate the reliability, consistency and accuracy of the dynamometer.
Abstract: The paper describes theoretical and experimental work on pulse operation of inward radial flow turbines, together with certain essential steady flow data. Power measurement was by means of a specially developed high speed dynamometer, capable of speeds up to 10 000 rev/min, which is described in some detail.Steady flow tests confirmed the expected trends of mass flow and torque as functions of turbine speed and overall pressure ratio, and in addition proved the reliability, consistency and accuracy of the dynamometer. The unsteady flow analysis of Appendix 1 which is unique in incorporating a very full description of rotor geometry as well as of the complex nozzle-rotor interspace conditions, was applied to two particular experimental cases and gives good agreement with respect to pressure variation in the pipe system, turbine volute and at nozzle exit, but rather less satisfactory agreement with respect to power.Further theoretical work is summarized at the end of the paper.
29 citations
TL;DR: In this paper, the first members of the II IV V2 family of compound semiconductors were synthesized by Goodman and there has been an increasing interest in these ternary analogues of the III V compound semiconductor, particularly in the USSR.
Abstract: SINCE the first members of the II IV V2 family of compound semiconductors were synthesized by Goodman1 there has been an increasing interest in these ternary analogues of the III V compound semiconductors, particularly in the USSR2. Until recently only fourteen members of the family were known to exist with the diamond-like chalcopyrite or sphalerite structures2–4 out of a possible total of 125 (ref. 3). In particular only one compound containing magnesium, MgGeP2 (refs. 3 and 5), had been identified. As with the III V compounds, there is a general tendency for an increase of energy gap with decreasing average atomic number and, in consequence, the magnesium compounds would be expected to have higher energy gaps (in excess of 2.0 eV) than many of the other members of the family.
28 citations
27 citations
TL;DR: An examination of the length frequency distribution of ammocoetes of the Sea lamprey, Petromyzon marinus L. marinus, suggests that the duration of the larval period cannot be less than five years.
Abstract: An examination has been made of the length frequency distribution of ammocoetes of the Sea lamprey, Petromyzon marinus L. collected during April, July, August and October. A comparison of the frequency distributions for the individual collections and a study of gonadal development within certain length ranges suggests that the duration of the larval period cannot be less than five years.
26 citations
TL;DR: The technique of solution synthesis has been used to prepare large crystals of orthorhombic SiP2 from tin solutions containing magnesium as discussed by the authors, which exhibit p-type semiconduction with an optical energy gap at 1.89 eV.
16 citations
01 Jun 1969
TL;DR: In this article, three turbines, covering a range of reaction of +20 per cent to − 10 per cent at their blade roots, have been tested under both steady and "pulse flow" conditions in order to assess their degree of suitability for turbo-charger application.
Abstract: Three turbines, covering a range of reaction of +20 per cent to − 10 per cent at their blade roots, have been tested under both steady and ‘pulse flow’ conditions in order to assess their degree of suitability for turbo-charger application.The results have been analysed in a way which enables efficiencies to be plotted against a mean non-dimensional blade speed irrespective of the level of pulsation. This method of presentation enables the results to be used directly for design purposes and in matching calculations. Thus the efficiency penalty due to pulse flow, the effect of pulse flow on the choice of turbine size, and the preferred degree of reaction under pulse flow may be assessed.For the present tests the range of variation in gas speed under pulsing conditions is thought to compare in severity with that produced when a single turbocharger is connected to three cylinders of a large two-stroke marine engine. For this case the design having the highest degree of reaction is shown to give an efficiency...
16 citations
TL;DR: In this paper, the effect of shape on sieving time has been investigated, and it was concluded that Sieving time depends on the number of points on the particle, rather than on flatness or elongation.
15 citations
01 Jun 1969
TL;DR: In this paper, an extension of an earlier and very successful one-dimensional analysis by one of the authors (reference (1)) for design and off-design performance evaluation of inward radial f...
Abstract: The paper describes an extension of an earlier and very successful one-dimensional analysis by one of the authors (reference (1)) for design and off-design performance evaluation of inward radial f...
TL;DR: This chapter explains solid and solidified growth media in microbiology, and the use of cultures on solidified media for inoculum production has found favor particularly with fungi and actinomycetes in which sporulation is stimulated by the emergence of the hyphae from the submerged to the aerial condition.
Abstract: Publisher Summary This chapter explains solid and solidified growth media in microbiology. In a liquid environment, micro-organisms may either grow as single cells and small aggregates of cells dispersed in the liquid, or as films and colonies on the interfaces bounding the liquid, including the solid-liquid interfaces and particularly the gas-liquid interface. If solid materials capable of supplying the nutrient requirements of micro-organisms contain more than a critical proportion of water, they become subject to microbial attack and may support the growth of micro-organisms on surfaces exposed to the surrounding gas phase. Solid substrates may also support the growth of anaerobic organisms mixed with or occluded by the solid. The growth rate of micro-organisms on solidified substrates may be compared by direct measurement of colony dimensions or, with fungi, the extension of individual hyphae growing on a plane surface may be measured microscopically. In the early stages of colony formation by bacteria and yeasts, growth rate may be followed by estimating numbers of cells present. The use of cultures on solidified media for inoculum production has found favor particularly with fungi and actinomycetes in which sporulation is stimulated by the emergence of the hyphae from the submerged to the aerial condition. Some microbial products have been prepared by using solid particulate substances.
TL;DR: In this paper, the diffuse reflectance and solution spectra of the HfX 6 2− (X = Cl or Br), NbX 6 − and TaX 6− anions are reported and the absorption bands associated with the halogen (π) → metal (γ 5 g ) transitions are assigned.
TL;DR: In this article, the threshold gate is used to realize all the normal basic binary logic functions, and in addition can realize more complex switching functions which would otherwise require the use of several normal logic gates.
Abstract: The familiar logic building blocks of AND, OR, NAND, and NOR functions are practical realizations of well-known basic boolean algebraic connectives, and as such enable any two-state logic system to be constructed. however, a more powerful basic logic building block than boolean gates is the `threshold gate?. such a gate has binary inputs A, B, C,?, with `weights? a, b, c,?associated with these respective inputs, and a binary output z. the output from such a gate is: Z = 1 if ?a.A + b.B + c. C +???some value t1 Z = 0 if ?a.A + b.B + c.C +?? some value t2 where normal arithmetic rules are involved in the above summations. such gates can be used to realize all the normal basic binary logic functions, and in addition can realize more complex switching functions which would otherwise require the use of several normal logic gates. thus the number of gates in a switching system may be drastically reduced by using threshold gates in place of the normal types.
TL;DR: In this paper, the action of sodium iodide in acetone on methyl 4 O -benzyl-3-deoxy-3 -iodo-2- O -tosyl-β- l -xylopyranoside was described.
TL;DR: The aim is to show the common features in the various systems, and to provide a common basis for analysing them, which are characterized by relatively low speed, low accuracy in general, and low complexity.
Abstract: Pulse-rate signals are introduced and the influence of various conventional circuits on their behaviour is considered. An introduction to more complex systems is given by considering the behaviour of certain simple feedback circuits. A survey is then made of the major applications of pulse-rate signals, including regular and stochastic rates, sampled systems, and the digital-differential-analyser.The aim is to show the common features in the various systems, and to provide a common basis for analysing them. Pulse-rate systems can carry out the normal arithmetic and integral operations. They are characterized by relatively low speed, low accuracy in general, and low complexity.
TL;DR: In this article, the platinum metals are converted into chlorides by reaction with sulphuryl chloride, in some cases the chloride isolated being dependent on reaction temperature, while the rhodium (III) chloride is only formed extremely slowly from the metal by this method.
TL;DR: The structure 4, originally suggested by W. H. Perkin, for pseudocryptopine chloride, has been corrected to 13 as mentioned in this paper, which is the correct structure.
TL;DR: Using open tube iodine vapour transport, epitaxial layers of germanium have been deposited onto crystals of the chalcopyrite structure semiconductors ZnSiP 2, ZnGeP 2 and Zn SiAs 2 as mentioned in this paper.
TL;DR: The diffusion coefficients of Ag(I) have been measured in molten mixtures of NaNO3 and KNO3 with varying molar ratios, by a linear diffusion cell of variable path length.
01 Feb 1969
TL;DR: A marked inhibition of polysaccharide synthesis by decreasing extracellular H-Ion concentration was shown and was found to be mainly associated with an inhibition of the synthesis of low molecular weight, trichloroacetic acid soluble, α1–4 linked glucose polymers.
Abstract: A marked inhibition of polysaccharide synthesis by decreasing extracellular H-Ion Concentration has been shown. The decreased synthesis was found to be mainly associated with an inhibition of the synthesis of low molecular weight, trichloroacetic acid soluble, α1–4 linked glucose polymers.
TL;DR: It was found possible to use plastic adapters marketed as disposable for more than 100 filtrations and cellulose membranes could be reused up to 10 times after boiling in 3 changes of distilled water.
TL;DR: In this article, a new parameter is suggested to specify the logarithmic series distribution and a table is constructed to provide the maximum-likelihood estimate of this parameter for different values of the mean.
Abstract: SUMMARY A new parameter is suggested to specify the logarithmic series distribution and this parameter is shown to have a number of advantages. A table is constructed to provide the maximum-likelihood estimate of this parameter for different values of the mean. The same table can also be used in estimating the negative binomial distribution by mean and zeros.
TL;DR: An increased polysaccharide synthesis at low external H-ion concentration was found to be associated with an elevated level of glucose-6-phosphate, which appeared to be regulated by the energy status of the cells.
Abstract: An increased polysaccharide synthesis at low external H-ion concentration was found to be associated with an elevated level of glucose-6-phosphate. Differences in the level of glucose-6-phosphate appeared to be due to changes in the activity of phosphofructokinase which in turn appeared to be regulated by the energy status of the cells.