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The Australasian sea cucumber (Australostichopus mollis) has attracted commercial attention for aquaculture development, partly due to its potential for co-culture with shellfish and finfish species. However, minimal attention has been given to the possibility of co-culturing this species with oysters. In this study we evaluated the growth of juvenile sea cucumbers (36.7 ± 0.9 g, wet weight) caged underneath Pacific oyster farms in northern New Zealand. Co-culture started at the end of the summer, and after 304 days the juveniles had doubled in size (79.8 ± 3.3 g, wet weight), but their subsequent growth appeared to be constrained by overstocking of the cages and summer water temperatures, reaching a carrying capacity of 720 g m−2. Overall, the results of this study indicate that the co-culture of juvenile sea cucumbers with Pacific oysters is feasible, if sea cucumber losses are reduced (between 33% and 52% lost in this study) and careful attention is given to stocking rates and the water temperature reg...

Isothermal decomposition of coal compacts was carried out in nitrogen between 200–700°, and weight loss was recorded against time. Surface area changes, measured by nitrogen adsorption, were determined at 300° and 500°. The porous structure of the coal disappeared for a while during the decomposition owing to blocking of the pores by tarry matter. The surface area then increased when this tarry matter was driven off.

In this study a relationship between the surface and textural properties of carbon blacks and the gasification process induced thermally in air is noted. A temperature jump method was used to follow the gasification in air and to establish the relevant Arrhenius parameters. This can be associated with the activity of ‘basal’ plane carbon atoms as well as ‘edge’ carbon atoms at the surface. This is based on a model of carbon black structure consisting of the irregular packing of small graphite carbon structures. The carbon black surface was measured using a single measurement of adsorption based essentially on the BET volumetric method. The carbon black surface had a rate of oxidation per unit are which clearly indicated that the lower area carbon blacks had a predominately active area of ‘edge’ atoms at the surface while the surface of the higher area carbon blacks had a predominate amount of ‘basal’ plane graphite carbon atoms.

The thermal decomposition of copper(II) oxalate has been studied under vacuum using a constant-volume apparatus and a microbalance; and under dynamic atmospheres of air, nitrogen and oxygen using thermogravimetry and differential scanning calorimetry. The decomposition was found to proceed to copper metal under an inert atmosphere and vacuum; while in air and oxygen, copper(II) oxide was found to be the decomposition product. In each case the decomposition was found to be exothermic with an enthalpy change of –9 ± 2 kJ mol–1 in nitrogen and –134 ± 5 kJ mol–1 in air. Isothermal kinetic analysis showed the data to fit an Avrami–Erofeev relationship with n= 3 in each case. Arrhenius parameters are reported for each decomposition atmosphere and are compared to those of other transition-metal oxalates which appear in the literature.The presence of a preparation effect is noted, as seen with other oxysalts; however, no evidence for the formation of copper(I) oxlate has been found which has previously been speculated to be an intermediate in the decomposition.

In this paper we describe an abstract model for the development of object-oriented software in a context where several programmers work together as a team. We introduce the different levels that compose our model, mapping its concepts and tools to existing systems whenever possible. The goal of this work is to design an environment for co-operative programming that deals specifically with the needs of developers using object-oriented technology. Our model is based on existing software engineering tools for the development of medium and large software projects, and also on a survey of user requirements for object-oriented programming. We explain the reasons why existing software engineering tools for team programming are not suited to object-oriented technology. We also briefly describe our prototype and the tools necessary to support our co-operative object-oriented programming model.

Serum levels of the four main immunoglobulins, IgA, IgM, IgG and IgD were estimated in a sample of 54 subjects with tuberous sclerosis and the data compared with similar findings in a sample of 100 mentally retarded subjects chosen at random. Normal levels of IgA and IgD were found in the T.S. group, but elevated levels of IgM significant at P equals 0.001 was found in 49 of the 54 cases. A reduction in IgG levels (significant at P equals 0.001) was a much less constant feature being found in 29 of the 54 subjects. The significance of these results in the light of the observation that one of the principal causes of death in T.S. is from recurrent infection is discussed.

The thermal decomposition of magnesium hydroxide is correlated with the effect of the temperature treatment on the strength of compacted discs of the material. The alteradon in the strength of the magnesium hydroxide which had been subjected to various temperatures between 450° and 800°C was obtained as well as by altering degassing conditions between ambient and 300°C. Up to twenty samples were broken at each of these conditions and the results show a skewed distribution of data points. The experiments on powders heat treated up to 800°C showed an increase in strength beyond 400°C. The TG data showed decomposition in the range 350°C to 500°C although farther weight loss was shown to be due to the presence of about 2–3% carbonate. The most useful correlation between the heat treatment and the strength is seen in the linear relationship between the surface area and the modules of rupture.

During carbonization, graphitizable aromatic organic compounds such as naphthalene, anthracene, phenanthrene and chrysene pass through a liquid or plastic-state mesophase of optical anisotropy, the lifetime of which is limited by its hardening to a semi-coke. Reflected polarized-light micrography, using cross polarizers with a gypsum plate, has been employed to characterize the carbonaceous mesophases of the different samples.

SYSNOPSISThis report is concerned with a simple statistical model of the way the brain may function, suggested by the analysis of intelligence test results in two groups of children. The model describes the statistical behaviour of an ideal array of elements, representing the brain, during tests of cognitive ability. Predictions from the model indicate that comparison of the EEC recording taken from groups of children who were good or poor readers would show amplitude differences. These were found between the groups when the eyes were open but not when the eyes were closed–a result explained by the model.

A system for investigating the energetic nature of catalyst surfaces has been developed from thermal desorption experiments. By applying an incremental isothermal heating program to the studies, the desorption kinetics have been analyzed to yield the variation in activation energy of desorption with coverage. The technique has been used to study a supported cobalt catalyst and, by following the desorption of hydrogen, the nature of the surface has been studied during reduction, and after a series of hydrogenolysis reactions had been conducted on the surface.

The heat of wetting of a graphite has been determined in four different liquids, methyl alcohol, isopropyl alcohol, benzene and toluene. The surface area of the material has been calculated from vapour adsorption isotherms determined gravimetrically using the same liquids and the B.E.T. theory. From the two sets of results the heat of wetting per square centimetre of the graphite surface has been obtained. The surface area calculated from the vapour adsorption isotherms show reasonable agreement with the surface area determined by low temperature nitrogen adsorption, indicating that pores which are accessible at room temperatures are also accessible at the lower temperature. The isotherms are type II with slight hysteresis and both adsorption and desorption branches of the hysteresis loops are sloping. It is thought that this could result from particle-particle adhesion under the influence of the adsorbed film and need not necessarily be a reflection of a porous character in the graphite particles themselves. This suggests that it is reasonable to accept the graphite sample as a suitable material for correlating adsorption and heat of wetting data, leading to the determination mentioned previously of the heat of wetting per square centimetre for each of the liquids used. The heat of wetting calculated in this way for methyl alcohol is then compared with other published data.

A versatile partial-pressure mass spectrometer system is described for measuring gaseous species thermally desorbed from solid surfaces. The system evaluates not only the ratio of masses present in the gaseous phase but also the specific mass (mg/g of solid) desorbed or decomposed during thermal treatment. The extension of the method to oxidation studies is also described. A study has been made of the evolution of gases from graphitic and nongraphitic carbons. These range in properties from a non-graphitic carbon, a PVDC charcoal of molecular sieve type, through a ground graphite of specific surface 102 m 2 /g to a nuclear type graphite of 0.6 m 2 /g. The formation of surface oxide on a clean surface at pressures of the order 0.2 mm Hg is evaluated along with the subsequent thermal decomposition of the surface oxide. The data from this paper together with other published work on graphites is used to illustrate the application of the thermal-desorption results to oxidation studies on carbons and graphites.

A preliminary investigation has been made into the behaviour of the surface oxygen complex during its formation and thermal desorption from the cleaned surface of a non-graphitic carbon (a rapidly pyrolised 720°C polyvinylidene chloride carbon). Using a direct sampling mass spectrometric technique a reasonable agreement was obtained between the amount of oxygen chemisorbed as surface oxide (by material balance of oxygen) and that obtained from analysis of the thermal desorption products CO and CO 2 . The extent of the surface oxygen complex coverage was shown to be of the order of 3 per cent of the total surface. The thermal desorption products CO and CO 2 were found to obey separately the Elovich equation for desorption in the temperature range 400°–900°C. As a consequence of the mechanism by which thermal desorption occurred, a linear plot of increasing activation energy of desorption of CO vs. decreasing coverage θ of the active sites was obtained. A comparison is made between the observed behaviour of surface oxide on a non-graphitic carbon and that obtained by other workers on graphitic carbons.

The slip flow permeability of a low rank powdered coal in the form of compacted disks has been investigated. A flow porosity is calculated based on the assumption of a fixed value for the slip flow coefficient. Mean pore radius values are calculated and it is suggested that the discontinuity in these values when plotted against compacting pressure is due to a change in the mechanism of compaction. Initially, the flow takes place mainly through the interparticulate pores. At higher compacting pressure the pores can be regarded as the macropore structure of coal.

SummaryFour channels of EEG (T4-T6, P4-02, T3-T5, P3-01) were recorded from several groups of control subjects and schizophrenia patients on analogue tape. They were later digitized and analysed by computer; power spectra were computed for 30 second epochs of EEG per channel; eyes closed, eyes open. No difference between normal controls and neurotic in-patients was apparent. An acute schizophrenic group had less alpha power, this change being confined largely to the temporal areas. A chronic outpatient sample showed less alpha and beta power, while chronic long-stay schizophrenic patients had an excess of delta power. The changes in both chronic patient groups were diffuse rather than local.

A calibrated constant volume reaction system is described for the measurement of evolved gas during thermal decomposition, or the measurement of a gas — solid thermal reaction. The system is calibrated to give specific weight changes from gas evolution and gas depletion data. An AEI MSIO mass spectrometer is used to monitor the gas phase. The standardisation of data is discussed for the carbon — oxygen reac tion. This particular reaction shows a transient formation of surface oxygen complex along with apparent first order reaction that is a function of temperature and pressure.

The initial degassing of a high-surface-area graphite is characterized using mass spectrometric and thermogravimetric weight-loss measurements. It will be indicated how far the combination of these allied techniques can be used to define the graphitic nature of the material in terms of the extent of the basal and edge planes of the graphite crystallite. The active surface area of the graphite was measured by the formation of surface oxide during low-pressure oxygen chemisorption onto the clean surface of the material. By subsequent thermal desorption of surface oxide an additional value for the active surface area was obtained from the weight-loss data and the known ratios of the desorbed gaseous species CO and CO2. The utility of a mass spectrometer — microbalance system for the study of gas — surface reactions is discussed.

A method of fitting an autoregressive series to the EEG is described. Some results from this method of analysis relating to the statistical properties of the EEG are mentioned which show the EEG ‘generators’ to be changing every 20 seconds, and which suggest the optimum length of an epoch for analysis is from 20 to 30 seconds. Some evidence that the EEG generators and the generators of the evoked potential have certain features in common is presented and that a model set up to the spontaneous ongoing activity of the EEG is able to specify within limits the form of the evoked potential at that point. Finally, a simple model of the cortico-thalamic action seen from the point of view of the autoregressive series is described.

A sample of borstal boys was selected (56). All had an assessment of mental state and ratings of sociopathy and aggressiveness performed, using structured interview techniques. A group of RAMC apprentices matched for age, sex and social class, was also examined (56). Eight-channel bipolar scalp EEG recordings were taken, 4 channels (T4–T6, P4–O2, T3–T5, P3–O1) being recorded on analogue tape. The tape-recorded signals were filtered off line through a low pass filter, multiplexed and digitized on to magnetic tape. Power spectral analysis was carried out on this data, using the University of London CDC 60 600 computer. Three 30-second epochs were analysed: eyes closed, eyes open, and eyes closed. No significant EEG differences were found between the borstal boys and the control sample. Neither visual inspection nor power spectral analysis revealed any EEG differences between the borstal boys and controls. Correlation coefficients between the power at each frequency from all four channels, the violence and sociopathy ratings and the time spent in institutional care in months for each boy were computed. These showed that violence contributes not more than 1 per cent and sociopathy not more than 5 per cent to the variance of the EEG power. Duration of stay in the institution accounted for as much as 20 per cent of the variance of the EEG power with significant correlations at 7 Hz (positive) and 11 Hz (negative). Duration of stay is thus a variable that must be controlled for during the investigation of subjects in penal institutions and long-stay hospitals.

Thermogravimetry and differential thermal analysis studies are reported for potassium titanyl oxalate, potassium aluminium oxalate and the related oxalates, potassium, titanyl and aluminium oxalates. The thermal decomposition of these materials in dynamic atmospheres of air, nitrogen and carbon dioxide has been studied. The oxalates and their decomposition products have been characterised by chemical and X-ray analysis. The thermal decomposition results for the complex oxalates show distinct reaction stages, but the aluminium and titanyl oxalates are not clearly characterised under the conditions used in the present work.The dehydration of the potassium titanyl oxalate starts at 70° C and proceeds in several stages until completion at 200° C. The anhydrous oxalate is not stable although only 1 per cent. of the original weight is lost between 200° and 275° C, but the decomposition is rapid above 275° C. The titanate formed as the final product is the result of the initial decomposition of the anhydrous complex. Potassium aluminium oxalate gives a stable anhydrous complex over the range 150° to 375° C, followed by a two-stage decomposition, with the bulk of the reaction complete at 575° C, and the end product is potassium aluminate, formed as a result of the initial decomposition.

A partial-pressure mass-spectrometer system is described for measuring thermally desorbed species from solid surfaces. The system evaluates not only the ratio of masses present in the gaseous phase but also relates the specific mass (mg g–1 of solid) desorbed or decomposed during thermal treatment. The extension of the method to include oxidation studies is also described.A study has been made of the initial evolution of gases from graphitic and non-graphitic carbons. These range in properties from a ground graphite of specific surface 103 m2 g–1 to a nuclear-type graphite of 0·6 m2 g–1. A study of a non-graphitic carbon, saran charcoal, of molecular-sieve type is also included.The formation of surface oxide on a clean surface at low pressures is evaluated together with the resultant thermal decomposition of the surface oxide. The results from this paper together with other published work on graphites are reviewed and used to illustrate the application of the results of thermal desorption to oxidation studies on carbons and graphites.

The thermal decomposition of basic aluminium oxalate has been studied by thermogravimetric and X-ray powder diffraction methods. It is suggested that the decomposition is similar to that of gibbsite, and that the original structure is a three-dimensional array of aluminium, oxalate, and hydroxyl ions in a distorted gibbsite lattice.

Cobalt oxalate dihydrate dehydrated at 150° is porous, and the subsequent isothermal decomposition in a vacuum to cobalt differs considerably from the isothermal decomposition of the anhydrous oxalate prepared at a higher temperature. The characteristic feature of the decomposition of the porous anhydrous cobalt oxalate is the retention of a constant rate of reaction up to the last 10% of the decomposition. A possible explanation of this is offered in terms of a reaction interface advancing simultaneously from interior and exterior surfaces.

The surface areas of the solid residues from the isothermal heat treatment of manganese(II) oxalate dihydrate are determined. The dehydration reaction kinetics between 100–200° are described by a contracting envelope equation and an activation energy (18·3 kcal. mole–1) lower than previously reported. This could be due to the presence of defects similar to those caused by irradiation of the hydrated salt. The anhydrous oxalate produced under these conditions was crystalline and this influences the subsequent decomposition to the oxide. The energy of activation is 33·8 kcal. mole–1 which is lower than previously reported for the decomposition of amorphous anhydrous manganese(II) oxalate. The adsorption data indicates that the oxide produced at 310° is in the form of plates but that these sinter extensively at higher temperatures.

The intermediate and final products of the isothermal decomposition of nickel oxalate dihydrate in air and nitrogen have been characterised by physical adsorption, X-ray diffraction, and electron micrography, and their properties related to possible reaction kinetics.

The kinetics of desorption of surface oxide as CO and CO2 from graphite have been followed, using a mass spectrometer system, allowing their activation energies of desorption to be measured as a function of the amount desorbed. After the initial degassing of the graphite, surface oxide was reformed by chemisorption at 298 K and 573 K, and oxygen pressures of 760 Torr and 0.2 Torr respectively. Similar analysis of the desorption kinetics of these oxides, formed under controlled conditions, has allowed a comparison of their desorption energetics to be made.

The thermal and X-ray analysis has been made of the decomposition of the trisoxalato-complexes potassium ferric oxalate, sodium ferric oxalate, and ammonium ferric oxalate. The reaction stoicheiometry is described, and the thermal properties of the ammonium complex have been compared with those of ferrous oxalate and ferric oxalate where the end-product in each case is the same.