This enquiry sets out to explore the hypothesis that students at Colleges of Education undergo a potentially stressful experience, with certain predictable areas of special difficulty. The study is based theoretically on findings from developmental and analytical psychology, with special reference to ego-development, and to the self-concept. Field-work evidence was collected from 3 major sources: (a) a written Questionnaire answered by students from 6 Colleges; (b) taped records of individual and small-group work done in a College of Education course over a 2 year period; (c) a study of 10 years work in psychological counselling -with manifestly disturbed students. Ensuing analysis, both statistical and clinical, of this material gave results which appeared to support both the general hypothesis and the underlying theoretical formulations. Suggestions were also outlined for constructive future action, designed to increase students' professional effectiveness and personal welfare.

The doubly fed machine is similar to the slip ring induction motor except that both the stator and the rotor are simultaneously supplied with polyphase a.c. The machine develops a synchronous torque at a certain speed (called the 'speed of synchronous operation'), which is proportional to the sum or the difference of the frequencies of the two supplies (depending on the relative phase sequence). When operating synchronously, the machine exhibits several attributes, the most important of which is its ability to act as a variable speed drive (speed variation is caused by variation of one of the supply frequencies) wiith a speed-independent-of-load characteristic. It is, however, unstable at certain speeds. This work uses methods similar to that of Prescott and Raju (Proc. I.E.E. 1958) to analyse the doubly fed machine. An equation is produced relating the speed of synchronous operation of the machine to its supply frequencies and the machine is assumed to operate at (or about) this speed. Equations are also produced, using the method of superimposition, relating the various currents, emf's and torques in the machine to the machine parameters and to the supply voltages and frequencies. This is done in such a way that studies of the dynamic behaviour of the machine could be made. Workers in the past have either defined the ratio of the rotor voltage to the stator voltage in an arbitrary manner or just tried several values. In seeking an equation to define this ratio is it sensible to stipulate the condition that the minimum current (for that load-speed combination) should be drawn from the supplies. This stipulation resolves into two criteria: one of unity power factor in the stator supply and one of unity power factor in the rotor supply, which can be expressed mathematically as two equations. Only one of these criteria may be used at any one time (the choice of which one to use depends on practial rather than theoretical considerations). The machine is now completely specified. To verify the validity of the various expressions, a series of experiments and computer simulations were executed. (The latter being based on the expressions with the parameters of the test machine, used in the former, as data.) The results of these experiments and computer simulations did not only show good agreement between practice and theory but also showed that several advantages ensued from the use of a unity power factor criterion. These advantages are: an increase in the stable speed range of the machine, an increase in efficiency, a possible increase in the usable torque range (at any particular speed), a reduction in the currents drawn from the supplies. These advantages are suggested by qualitative arguments, which use the similarities between the doubly fed machine and its, more well known, special cases. The analysis mentioned above was required to quantify them. The performance of the doubly fed machine under conditions of unity power factor (both stator and rotor power factor conditions), and the variation OF the rotor voltage (for a fixed stator voltage) to maintain these conditions, form the latter part of the work. Comparisons are also made between unity power factor conditions and non unity power factor conditions. The final part of the project was the building and testing of a simple feedback device designed to automatically adjust the rotor voltage to maintain unity stator power factor for all speeds and torques. Many practical difficulties were overcome by using this device including those associated with the starting and synchronising of the machine.

No description available.

Purified samples of sixteen compounds of the type RCOCHR'COR2 have been prepared by standard synthetic procedures. Twelve correspond to R = R2 = CH3 with R' representing the substituent groups -H,-CH3,-C2H5, -nC3H7,-iC3H7,O2N-, -OCOC2H5,-OCCH3,-Br,-Cl,allyl, butylidene, and a second series of four in which R = CH3, R' = H, R2 = C2H5; R = R' = CH3, R2 = C2H5; R = R2 C2H5, R' = H; R = R2 = C2H5, R' = CH3. Using a potentiometric technique, acid dissociation constants (pKa) in water and 50 per cent aqueous dioxan at 25 have been obtained for a number of these compounds. Variation of pKa with temperature has been studied for the second series, together with pentane-2,4-dione, its 3-methyl derivative, l-phenylbutane-l,3-dione and 1,3-diphenylpropane-l,3-dione. The stability constants (logK1, logK2) of their chelates with divalent cobalt, copper, magnesium, manganese, nickel and zinc have been determined at 25 , and also at 5 degrees, 15 degrees, 35 degrees and 45 degrees in the case of cobalt (II). This variation of pKa and logK with temperature has enabled enthalpies ([delta]H) and entropies ([delta]S) of protonation and chelation to be obtained for these ligands and their cobalt (II) chelates. Nearly forty metal chelates have been prepared for the divalent metals cobalt, nickel and copper, and the trivalent metals iron, chromium and cobalt, and infra-red studies carried out from 400-4000cm-1. Diffuse reflectance measurements have been made on the nickel (II) chelates. The transmission spectra of five ligands and several metal chelates have been measured in chloroform solution. During spectroscopic pKa studies, a number of the 3-substituted pentane-2,4-diones have been found to decompose, the decomposition appearing to be dependent upon the acidity (pH) of the solution. The decomposition of 3-methylpentane-2,4-dione has been studied in some detail.

In this series of five questionnaire studies, an investigation was made into the kinds of fears and other feelings that adults had about dying, death, and grief. In the first two studies this was looked at in a general sense; then in the three subsequent studies the adult's loss of parents was specifically considered. In the first two studies it was found that subjects most feared the physical deterioration and pain of dying, particularly in relation to cancer; female subjects were more anxious than males about the death of others, and expected to feel a deeper sense of loss. When the next two studies were carried out, a fairly close parallel emerged between the ways in which the non-bereaved subjects anticipated feeling when their parents died, and the ways in which those who had already lost parents reported having felt; both at the time of the loss and later. Both sexes anticipated and experienced feeling more intense grief when the first parent died than when the second one did, whichever parent had been the first to die. The timeliness or untimeliness of the parental death was examined in the final questionnaire study. It was found that if the parent had died an untimely, early, death, while the subject was still in early adulthood, the grief reactions were initially more intense, and continued to be experienced at a higher intensity two or more years after the loss than was the case where a more timely death had occurred. These studies have put forward some evidence to show that the loss of parents in adult life constitutes a more important bereavement than was previously realised.

Seven experiments were conducted in a mobile laboratory on location in schools. Seven year-old children were tested alone, or in like-sex dyads or triads which were based on the audience and coation paradigms of social facilitation. Subjects listened, once only, to tape-recorded humorous material on headphones. They were unaware that (a) they were participating in a laughter experiment; (b) their nine year-old companions (after experiment one) were models complying with pre-recorded directions; (c) they were observed through a screen. In naturalistic conditions, coactors lauded and smiled more than audience condition subjects who laughed and smiled more than alone subjects. The companion's behaviour was varied systematically in subsequent experiments. The principal statistically significant findings were: (i) Increments in subjects' laughter, smiling and "looking" resulted from increments in coactors' laughter and "mirth" (laughter plus smiling). (ii) Subjects smiled more as coactors smiled and "looked" more. (iii) Increments in audiences' "mirth" led to an inverted-U effect for subjects' laughter but to regular increases in "looking". (iv) Subjects looked more at coactors than audiences; they looked most at coactors who looked most at them. (v) Even when audiences and coactors were totally unresponsive, subjects generally laughed and smiled more than alone subjects. (vi) The more "shared" coaction conditions, as defined firstly by seating arrangements and then by interaction between pairs of companions, were associated with higher response levels. (vii) Girls sometimes smiled more than boys. (viii) Humour-ratings were often, but not always, related to overt expressive behaviours. It was found convenient in analyzing results to divide facilitative factors into "first order" and "second order" categories, and to develop the interrelated concepts of "psychological presence" and "cognitive sharing". Other mechanisms were considered briefly. The concept of "mirth" and the distinction between "social" and "mirthful" smiling were discussed. The thesis includes reviews of the social facilitation and the humour and laughter literatures.

A number of previous authors have investigated individual differences in the tempi at which people perform everyday activities such as walking, speaking and writing. The present work consists of seven studies of the tempi which subjects spontaneously adopt when performing simple laboratory tasks, particularly repetitive motor activities such as tapping. In the first experiment, intercorrelational data were reported which contradicted the view that there is a unitary "personal tempo", though clusters of inter- correlated activities were obtained. In the second study, "spontaneous" and "maximum" tempi were compared, previous work on this question being considered methodologically unsound. It was concluded that there is little or no common variance between speeds elicited by "spontaneous" and "maximum" tempo instructions. Later experiments were concerned with the question as to whether there might exist a "preferred rhythm" --- a rhythm of performance which the subject adopts whenever the conditions of the task permit him to do so. Evidence in favour of this suggestion was obtained in the first experiment, but the third and fourth experiments, which were designed to test a prediction derived from it, failed to support the hypothesis. This negative conclusion was further supported in a study in which subjects were paced at rates other than that which they spontaneously adopted, and in which they displayed no tendency to depart from the imposed ("non-preferred") rate when presented with an opportunity to do so. Finally, an experiment was performed which demonstrated no significant difference between the test-retest reliabilities of the speed which the subject spontaneously adopts and speeds arbitrarily imposed by the experimenter. It was concluded that there was no need for the hypothesis of a "special" or "preferred" rhythm with these tasks.

The active courtship, bright colouring and polymorphism of males, and the cryptic colouring and passive behaviour of females bear witness to the combined effects of selection for survival and sexual selection pressures on the morphology and behaviour of the guppy. The aim of this study was to investigate guppy sexual behaviour in the light of these pressures during its evolution. Without knowledge of the sensory modalities involved, a study of the mechanisms by which selection acts on sexual behaviour cannot be complete. In particular, there is evidence that olfaction plays a significant part in signals from the female to the male. The role of different sensory modalities in the development of normal courtship was studied by rearing individuals of both sexes in conditions of restricted access to conspecifics from birth until maturity, and then observing their behaviour during courtship. Inexperienced virgin females are highly receptive at first exposure to courtship, while males reared apart from females tend to court other males as well as females. By systematically varying the type of access (visual, olfactory etc.) allowed during development, it was hoped to assess in which modalities stimuli ensuring normal courtship were important. In neither the experiments on the development of courtship, nor on the execution of courtship (in which quantitative and qualitative variation in male courtship with and without olfactory stimuli from the female was investigated) could the role of pheromonal communication be ascertained. However, two findings emerged from the studies of the development of courtship, which were investigated in greater depth: 1) The highly receptive virgin females actively sought out males. This finding was substantiated by additional experiments in which the virgin females were found to choose to be near males rather than females, and this choice appears to be based on both the morphology and the greater activity of males than females. In normal circumstances, male guppies court females a large amount of the time, including when females are not receptive. It is possible that males are able to detect a metabolic by-product from non-receptive females and use this to locate them. The receptive females' seeking out of males may be a mechanism by which females ensure fertilisation at the optimum point of their receptivity cycle - i.e. when conditions for successful fertilisation and gestation are best. 2) Even males which had been totally isolated from conspecifics were found to be able to recognise females, although the pattern of their sexual behaviour was abnormal. The explanation of this discrepancy with the finding that males reared apart from females later courted only males (Liley, 1966) probably lies in the manner of rearing. Liley's fish were reared in a group of males, while those in the present were reared in total isolation. It seems that although males do recognise females innately, there also exists some sort of critical period in which recognition of females is substantiated or, if no females are present, imprinting on other males occurs. Bateson (1966) notes that existing unlearned preferences may be affected by imprinting. It is suggested that the imprinting process provides the optimum balance between the costs associated with inflexible recognition of conspecific males in a polymorphic species, and the costs of energy and sperm wastage associated with an indiscriminate direction of sexual behaviour. The sexual behaviour of isolated males was abnormal both in intensity and form. This was shown to be due to a motivational change, rather than a developmental pathology. Isolated males perform an exceptionally large number of Thrusts, which Liley has shown are less efficient per single act than is copulation during normal courtship. However if Thrusting takes less time than courting, and males have a finite amount of time available for sexual behaviour, then a highly motivated (and therefore sexually energetic) male can achieve a greater number of inseminations by Thrusting than by courting. The predictions of a speculative model taking these constraints into account were largely borne out. Observations of an established group of normal adult guppies indicate that mating is not random, and that some males are more successful than others at gaining access to popular females. It may be that the hierarchy of males arises from females' preferences for particular males. The form of individual males' courtship varies according to their rank in the hierarchy, and also which female they are courting. Males which are able to gain access to popular females tend to court, while lower hierarchy males perform relatively more Thrusts. This may represent a type of conditional strategy in which preferred males tend to monopolise the courtship of females, but low-ranking males can 'make the best of a bad job' by using a less profitable means of insemination which does not require female co-operation.

Any form of timing involves a rhythmic process as interval timer. It is useful to postulate a 'physiological clock' in the explanation of time estimation behaviour, provided that environmental factors are not forgotten, that the 'clock' is conceptualized in functional rather than anatomical terms, and that it is stressed that there may be many such 'clocks' within the organism, divided both in terms of physiological and behavioural system, and in terms of range of durations measured. Some such 'clock' must underlie the estimation by human beings of intervals ranging up to about 60 seconds, and wherever this 'clock' may be located one may expect it to be subject to the same effects of inheritance as other biological mechanisms. This hypothesis was investigated using the intra-pair comparison of MZ and DZ same-sex co-twins of above average intelligence, and intervals ranging from 3 to 5 seconds presented under a variety of modal and methodological conditions. No significant inter-zygosity difference in time estimation was found for pre-pubertal subjects. With post-pubertal twins (totalling 56 pairs) considerable evidence was found with reproduction and overwhelming evidence with opevative estimation that the intra-pair similarity for short interval time judgment is significantly greater for MZ co-twins than for same-sex DZ co-twins. It was also discovered that the MZ twins were somewhat more aoourate in their estimations. Sex difference does not appear to be of any significance in the judgment of duration. With verbal estimation of times ranging from 28 to 60 minutes, the intrapair similarity in judgment is considerably greater for MZ than for DZ cotwins, but with no inter-zygosity differences in accuracy. It is suggested that more attention should be paid to the method of retrieval of timing information.

No description available.