Showing papers by "University of Bedfordshire published in 1978"

Field studies of rainsplash erosion

Abstract: Studies on sandy soils of the Cottenham Series in mid-Bedfordshire confirm in the field the relationships between splash erosion, rainfall energy and ground slope obtained in the laboratory experiments of other workers. Only 0·06 per cent of the rainfall energy contributes to splash erosion and rates are low, attaining a maximum of 0·082 kg m−2 y−1 on a slope of 11°. The major role of splash action is in the detachment of soil particles prior to their removal by overland flow.

Connection means for structures

Abstract: In connection means comprising a hook projecting from one structure member and shaped for engagement with an elongated hole having a portion of downwardly tapered shape in another structure member, the hook is complemented by a boss which projects from the same face of the said one member, but spaced from the hook in the vertical direction, and which engages in a said hole in the other member. In a preferred embodiment, the boss is of a shape, for example a truncated pyramid with a trapezium base, engageable by its sides with the sides of the same hole with which the hook is engaged. The hook and boss are integral with the said one member, the boss being disposed closely above the hook from which it is separated by a transverse web. The sides of the boss are undercut. A spring-loaded locking device may be provided in conjunction with the boss.

Spontaneous skeletal deformities in the Zebra Danio (Brachydanio rerio) bred for fish toxicity tests

Abstract: Zebra Danio (Brachydanio rerio, Hamilton-Buchanan) tropical fish are easily maintained and bred under laboratory conditions; procedures for maintenance and breeding are described. Intensive inbreeding of this fish gave rise to a high incidence of spontaneous skeletal deformities which appear to reflect a genetic defect rather than an environmental stimulus. This finding casts doubt on the suitability of the Zebra Danio for fish toxicity testing.

Digital measurement of impedance ratios

Abstract: A circuit arrangement for measuring the ratio of first and second capacitances of a capacitance displacement transducer. An alternating signal is developed the amplitude of which is proportional to the values of the first and second capacitances during respective first and second timing periods, the alternating signal being synchronously demodulated in one phase in the first period and in the opposite phase in the second period. The demodulated signal is integrated so that the integrator is charged and discharged during the first and second periods respectively, and the ratio of the discharge time to the charge time is equal to the ratio of the two capacitances. A digitized output is provided by means of a clock pulse generator and counter.

Method of treating inorganic oxide pigments

Abstract: Inorganic oxides pigments, coated with alumina are treated with water soluble hydroxy acids or salts for example sodium citrate, and with water soluble di- or polyhydric alcohols, for example pentaerythritol, or with a water soluble reaction product of excess di- or polybasic organic hydroxy acids with di- or polyhydric alcohol. Titanium dioxide pigment so treated may be used in both emulsion paint and in organic based paint systems.

Breeding the convict cichlid (Cichlasoma nigrofasciatum) for use in laboratory fish toxicity tests

Abstract: A procedure is described for breeding Convict Cichlid (Cichlasoma nigrofasciatum) tropical fish under laboratory conditions. Three generations of Convict Cichlids were bred successfully using this procedure and there was no significant incidence of deformities from in–breeding to the F3, which contrasts with a high incidence of skeletal deformities observed when Zebra Danio tropical fish were inbred to the F3 generation. The Convict Cichlid is a suitable species for laboratory toxicity testing, particularly studies to assess effects on breeding performance.

Condition monitoring by thermography

Abstract: Thermography techniques are used to monitor both the temperature and the temperature pattern of equipment in operation. This information, together with data on the physical construction of the component and the thermodynamic state of the equipment is used to evaluate the degree of deterioration of an item of process plant. Three successful applications of thermography to different industries are described.

Medical and scientific investigations of an exhumation in unhallowed ground.

Abstract: INTRODUCTION One may be considerably handicapped in carrying out an investigation of a person who has been buried in a shallow grave for a number °f years, because of the erosion or disappearance °f vital evidence with the passage of time. It is a task, therefore which must be performed with scrupulous thoroughness by a team of forensic experts each with his own speciality hut working in close liaison at all times. The case described illustrates the problems encountered and the various disciplines employed which enabled satisfactory conclusions to be drawn from evidence as it became available during the course of the investigation and study.

Comparative serological and clinical findings in subjects exposed to environmental allergens

Abstract: Summary Serological tests of healthy atopic and non-atopic subjects were carried out during medical surveillance of 288 workers in detergent and food manufacturing factories in the same highly industrialized area. Correlations between the serological parameters and various aspects of the clinical history were compared for subgroups in these and control populations. The value of serological tests as aids in the diagnosis of allergic reactivity to the detergent enzyme Alcalase was given particular attention. There was no indication that employment in the detergent factory significantly increased the amount of serum total IgG, IgA or IgM. There was a positive correlation between the amount of serum total IgE and atopy as defined. The need for new standards of normality in the amount of serum total α1-antitrypsin in women receiving oral contraceptives was confirmed. No subjects had a homozygous deficiency of α1-antitrypsin. There was a statistically significant correlation between the level of allergen-specific antibody measured by the RAST and skin prick test weals of 3·0 mm diameter or greater, which were obtained using standardized skin prick test procedure and reagents. The significance of small skin prick test reactions has been evaluated critically. The results of various tests for allergen-specific precipitating antibodies indicated the need for caution in interpreting the results of such tests with allergens such as Alcalase, which contain several antigenic components. Alcalase-specific IgG antibodies were only detected in the sera of persons exposed to enzyme dusts in factories. They were evidence of exposure to the antigens, not of a clinical allergic response, and probably reflect the natural formation of antibody shown to occur with numerous environmental antigens.