ALBERT

Description: The coagulation of hydrosols was investigated theoretically and experimentally. A reduced form of the particle size distribution function, designated “self-preserving,” was found to satisfy Smoluchowski's equations of coagulation by Brownian motion and shear flow. Brownian motion coagulation experiments with two heterogeneous hydrosols showed that the distributions were self-preserving. The rate of coagulation for heterogeneous systems was found to be second order in total particle concentration, consistent with the self-preserving form of the distribution function. Coagulation experiments were carried out in a simple laminar shear field using a homogeneous Dow polystyrene latex dispersion. Smoluchowski's shear flow theory was confirmed for shear rates ranging from 1 to 80 sec.−1 The shear coagulation of a heterogeneous emulsion was studied at several shear rates, and the size distributions were self-preserving.

Description: Two case studies of the application of geoscientific maps for planning in semi-arid regions are presented, one for the Mediterranean province of Valencia and another for the island of Gran Canaria (Canaries). Both regions are very dynamic from the point of view of population growth and urban-touristic-industrial development, and they suffer from a serious degree of environmental degradation. The provincial/ island governments have undertaken programmes of geoscientific mapping and assessment to serve as a basis for the establishment of guidelines for future planning. Two map sets have been made (1:200,000 in Valencia and 1:50,000 in Gran Canaria), based on initial maps of homogeneous integrated units. These represent a series of hierarchical land subdivisions, progressively smaller and more detailed (morphodynamic environments, systems, units, elements), defined on the basis of morphostructure, climate, lithology, surficial deposits, landforms, topography, active processes, soils, vegetation and human influence. Each individual map unit is described by means of a form which includes 114 items, summarising its environmental features. Morphodynamic units have been evaluated in terms of qualities significant for planning, and a series of derivative maps has been developed (geologic hazards, soil capability, present degree of erosion, potential erodibility, quality for conservation). A final map shows the most advisable types of uses and the main limitations for human activities, mainly due to engineering geological factors. This is a synthesis document which can be used directly by planners.

Description: Middle Pleistocene strata of the Kidnappers Group consist of a conformable sequence of alternating fluvio-lacustrine and shallow marine sediments exposed along coastal cliffs near Cape Kidnappers, southern Hawkes Bay, New Zealand. Three major paleomagnetic polarity intervals are recognised and interpreted as Jaramillo Normal Subchron, upper Matuyama Reversed Chron and Brunhes Normal Chron. This and biostratigraphy indicates an age range of 0.97 to 0.54 Ma for the group, compared to 0.85 to 〈 0.33 Ma previously suggested by fission track ages of tuffs. The new age control and facies interpretations suggest that the upper part of the group represents oxygen isotope stages 22 to 15. The duration and magnitude of isotope stages is reflected in the relative thicknesses of lithological units. Glacial periods are recorded as alluvial aggradation in the form of braidplain conglomerates, while estuarine and subaerial sands and muds with temperate climate pollens represent interglacial periods. This contrasts with many coastal and shelf sequences where glacial periods are represented by unconformities. Chemical and paleomagnetic characterisation of silicic tuffs in the Kidnappers Group establishes correlation to other sections and cores in New Zealand, the Tasman Sea and the western Pacific Ocean, thus providing temporal correlation for a range of sedimentary environments.

Description: Fecal excretion of calcium of endogenous origin has been measured in 52 studies in 33 adult human subjects, under full metabolic balance conditions. Endogenous fecal calcium averaged .130 ± .047 Gm. per day, was positively correlated with both fecal calcium and dietary calcium and was inversely correlated with fractional calcium absorption. The regression line relating endogenous fecal calcium with fractional absorption allowed estimates for total intestinal calcium secretion at both zero and 100 per cent absorption; from these estimates it was calculated that approximately 15 per cent of the total intestinal calcium secretion was nonabsorbable even under conditions when dietary calcium was completely absorbed (presumably because it enters the gut caudad of the absorption sites). Total intestinal calcium secretion, calculated so as to allow for this nonabsorbable fraction, averaged .194 ± .073 Gm. per day, and could not be correlated with age, sex, dietary calcium intake, caloric intake, urine calcium, or plasma calcium. A weak correlation with body size (weight, surface area) was observed. The conditions studied were principally disorders of bone, calcium, and parathyroid metabolism, and in most of them total intestinal calcium secretion appeared identical. The sole exception was seen in two studies on a patient with acromegaly, in which total intestinal calcium secretion was over twice the mean value for the remainder of the group.

Description: We studied the distribution and abundance of marine birds in Bransfield Strait and southern Drake Passage during January and February 1985. We identified clusters of bird species, “communities” with similar distributions, and examined the extent to which the distributions of these seabird communities reflected the underlying physical oceanography of the region. Based on temperature, salinity and silicon data, we identified 11 water masses which resulted from varying degrees of mixing of water from the Pacific Basin, the Bellingshausen Sea, the Weddell Sea and terrestrial runoff. Seabird species assemblages were associated with contiguous clusters of water masses, suggesting a response by the birds to apparently subtle differences in their marine habitat.

Description: The Hg concentration in horned octopus was studied in relation to its biological cycle. The metal was measured in the muscle tissue of specimens of different size, sex and maturity. This species proved to be a strong accumulator of mercury, whose concentration was found to be correlated with length independently of the sex. The relationship with size was found also for the organic form. Consideration was given to the danger of frequent consumption of this cephalopod and to its use as a biomonitor of environmental mercury impact.

Description: Eco-friendly, cost efficient and effective extraction methods have become significant for the industries applying zero waste principles. The two main objectives of this study were; to examine fucoxanthin extraction from wet Phaeodactylum tricornutum using subcritical fluid extraction and to characterize the residual biomass in order to determine the potential application areas. The highest fucoxanthin yield of 0.69 ± 0.05 mg/g wet cell weight was achieved using methanol with solvent-to-solid ratio of 200:1 at 120 rpm, 20 MPa pressure and at 35 °C for 60 min by subcritical extraction. Microscopy images showed that most of the cells were disrupted and intracellular components were effectively released. Based on the results of energy dispersive spectroscopy, biomass contained a mixture of organic molecules including mainly carbon (57–72%), oxygen (26–41%), magnesium (0.6–1.4%) and silica (0.4–1%) (wt%). These results make the residual biomass a potential candidate for various areas such as bioenergy, material sciences and sensor technologies.