Showing papers by "University of Canterbury published in 1971"

Flexural Members with Confined Concrete

Abstract: Existing experimental evidence for the stress-strain curve for concrete confined by transverse steel hoops or spirals is examined and used to determine the moment-curvature characteristics of flexural members with confined concrete The stress-strain curve for confined concrete is represented by a parabola up to maximum stress, a linear falling branch followed by a straight horizontal portion The slope of the linear falling branch is found as a function of the volume and spacing of the hoop steel and the strength of the concrete The compressive stress block parameters for flexural members with different levels of strain at the extreme compression fiber and quantities of confining steel are found from the proposed stress-strain curve The examination of the moment-curvature characteristics of beams with confined concrete showed that the quantity of confining steel only has a significant effect on the behavior of members with a high tension steel content and a low compression steel content

Coupling Beams of Reinforced Concrete Shear Walls

Abstract: The behavior of short and relatively deep reinforced concrete beams, which occur in shear walls of multistory structures, and the damage or failure of which has been observed in recent earthquakes, is examined. Experimental and analytical studies indicate that their ultimate flexural capacity is reduced by large shearing forces, even if a diagonal tension failure is prevented by adequate web reinforcement. After diagonal cracking, the distribution of internal forces radically differs from that observed in beams of normal proportions. The flexural reinforcement is found to be in tension in areas where compression is expected, and this affects the beam's ductility. Shear deformations of diagonally cracked coupling beams greatly overshadow those causd by flexure. With the aid of a model of the cracked beam its stiffness can be approximated. This satisfactorily agrees with observations which indicate that the stiffness after cracking is less than 20% of the stiffness of uncracked coupling beams.

Inelastic behaviour of reinforced concrete members with cyclic loading

Abstract: The results of an investigation into the behaviour of reinforced concrete members subjected to cyclic loading in the inelastic range are summarized. The investigation commences with studies of the Bauschinger effect for cyclically stressed mild steel reinforcement and the influence of rectangular steel hooping on the stress-strain behaviour of concrete. Using these derived stress-strain curves the moment-curvature relation ships for reinforced concrete members under cyclic loading are studied theoretically and compared with the results of a series of tests on reinforced concrete beams under cyclic loading.

Ultrastructure of vacuolar inclusions in root tips

Abstract: Vacuoles in plant cells often contain inclusions which at early stages of development are bounded by a single membrane. The inclusion bodies (IBs) comprise a diversity of forms and various stages of differentiation are recognizable. IBs are divided into two categories: those which have a matrix without internal membranes, and those which contain cytoplasmic organelles and other membranous material. The internal membranes may be tightly coiled or in the form of vesicles. IBs develop from invaginations of the tonoplast which become detached into the vacuole. They are initiated mainly during active cell growth but may remain within the vacuole in differentiated cells. Various components contribute to the contents of IBs: endoplasmic reticulum, nuclear envelope, Golgi vesicles, extruded portions of mitochondria and plastids, ribosomes and groundplasm. In most IBs the limiting membrane and contents eventually disappear within the vacuole. Some IBs prior to their breakdown within the vacuole also function as sites for the formation of material not found elsewhere in the cell. The disappearance of IBs from vacuoles suggests that such vacuoles behave as lysosomes.

Simulated Seismic Loading of Spandrel Beams

Abstract: The most critical components of coupled shear wall structures are the short and often relatively deep spandrel beams, formed between door or window openings. These may be subject to high intensity alternating flexure in the presence of large shear forces when the structure is exposed to seismic disturbances. The behavior of these beams, when subjected to monotonic one way loading, was previously reported by the writer. In this paper the more interesting features of the performance of relatively deep spandrel beams, subjected to seismic type of alternating static loading, are presented. In the experiments the performance of the flexural reinforcement, the deterioration of the stirrups with high intensity alternating loading was observed. The principal modes of failure were identified and the stiffness degradations were evaluated from rotational measurements. Some evidence is presented with respect to the available ductilities for two types of steel arrangement and the effectiveness of beam repair.

Mental Maps of the City: Suburban Preference Patterns

Abstract: Many sets of observations have shown that intra-urban migration is generally oriented outwards, away from the City centre. Two major suggested explanations for this directional bias are Hoyt's concept of the sectoral structuring of socio-economic status residential patterns and Adams's ideas concerning the shape of the mental images of the City which its residents hold. The present paper presents an investigation of the mental maps of some sample respondents in the Christchurch urban area, New Zealand, which asks whether these images are influenced both by the perceived socioeconomic status of the various suburbs and a restricted view of the City. The results are encouraging and suggest that both Hoyt and Adams may have been correct in formulating their ideas.It is becoming commonplace within urban research to criticise the widely-used models of intra-urban residential patterns as inappropriate. Not all would agree with this, however, so further testing is required. Among the more important aspects needin...

Electron-Phonon Interaction Effects in the Spectra of Hydrogenated, Deuterated, and Tritiated Crystals of Calcium and Strontium Fluorides Containing Cerium

Abstract: Spectroscopic measurements of cerium-hydride, cerium-deuteride, and cerium-tritide ion pairs in calcium and strontium fluoride crystals are reported. The local-mode spectrum of the hydride ion shows a splitting of the doubly degenerate vibration which is attributed to electron-phonon interaction effects between the cerium $4f$ electronic states and the hydride-ion local-mode phonons. A dipole moment of $1.1e{a}_{0}$ for the hydride ion, where ${a}_{0}$ is the Bohr radius, is postulated to explain the observed local-mode spectrum. The electronic lines of the tetragonal cerium-hydride ion pairs display large isotope shifts of 23. 8 and 35. 1 ${\mathrm{cm}}^{\ensuremath{-}1}$ for hydrogen to deuterium and hydrogen to tritium, respectively. Only the nondegenerate vibration of the hydride ion appears in the vibronic spectrum of the $4f\ensuremath{\rightarrow}5d$ transition of cerium and has a higher frequency when coupled to the cerium-ion $5d$ electronic state than to the $4f$ electronic states. The intensity of these vibronics relative to their parent electronic lines is quantitatively explained on a configuration-coordinate model. Both the electronic line isotope shifts and the vibronic frequency shifts are attributed to electron---local-mode-phonon interaction effects in the cerium-ion $5d$ electronic state. A quantitative model for the electron---local-mode-phonon interaction with point-charge and dipolar interactions between the cerium ion and the hydride ion is set up and includes anharmonic effects. This model successfully explains the vibronic splitting in the local-mode spectrum, the occurrence of only one local-mode frequency in the vibronic spectrum of the cerium $4f\ensuremath{\rightarrow}5d$ transition, and the relative intensity of these lines, but is unsuccessful in explaining the magnitude or sign of the observed isotopic effects. The estimated electronic line isotope shifts are \textonequarter{} the magnitude of the observed shifts and of opposite sign.

Ecological studies on intertidal New Zealand Sphaeromatidae (Isopoda: Flabellifera)

Abstract: Ten sympatric rocky shore species and 3 brackish-water species of Sphaeromatidae were studied. Rocky shores were classified in terms of substrate and exposure to wave action. Although most of the rocky-shore species occur on all shore classes, vertical and horizontal distribution in each species, as well as densities, vary with substrate and wave action. A close relationship between distribution and breeding exists in the rocky-shore species; maximum differences in the vertical distribution of juveniles and adults occur, together with the highest reproductive capacities, in the species exposed to the greatest wave action. Tolerances to temperature, salinity and desiccation are wider in the species of brackish water and less exposed rocky shores, correlating with the greater variations in these conditions where wave action is reduced. Exoskeletons and pereopods are stouter in the species of more exposed shores, except where the microhabitat affords protection from wave action. In Isocladus armatus, geographic and seasonal variations in relative frequencies of colour forms correlate with differences in environmental temperatures. Under laboratory conditions, the colour forms show differences in tolerances to temperature and salinity.

First diagnostic Carboniferous fossils from New Zealand.

Abstract: THE first New Zealand fossils indicative of Carboniferous age have been found in rocks from the South Canterbury region of the South Island. They are conodonts, accompanied by rare fish scales, and were obtained from the marble of the Kakahu inlier in a Tertiary area 10 miles south-west of Geraldine1: fossil sample locality No. S102/607, grid ref. 627815 (latitude 44° 09′ S, longitude 171° 04′ 30″ E).

Utilisation of the metabolisable energy of ewe's milk by the lamb

Abstract: Efficiency of utilisation of ewe's milk by the lamb was studied. The comparative slaughter method was used to determine gain or loss in body fat, protein, and energy. Of 24 crossbred lambs used, 12 comprised an initial slaughter group|the remaining 12 were given ewe's milk for 21 days at four different levels of energy intake ranging from sub-maintenance to ad libitum. Lambs fed at the lowest plane of nutrition mobilised body fat and were in negative energy balance; all the others were in positive energy balance. The mean digestibility of ewe's milk was 98.4% and was unaffected by the plane of nutrition. The mean metabolisability of the diet was 95.6% for lambs in positive energy balance and 91.8% for those in negative energy balance. The metabolisable energy requirement for zero energy gain was 145.2 kcal/kg0.75 24 hr, and the efficiency of utilisation of metabolisable energy for maintenance and growth was 76.9%.

The effect of different types of pasture on the organoleptic qualities of lambs

Abstract: The palatability characteristics of carcasses of lambs grazed on either pure perennial ryegrass or Pure lucerne were studied in three experiments. Consumer preferences were ascertained in two experiments with untrained members of the public who scored the meat for flavour, tenderness and juiciness. The type of pasture had no significant effect on the palatability characteristics examined but the shoulder joints were significantly more juicy than the legs. In a third experiment, members of a trained taste punel were able to detect a significantly more intense flavour and odour from the casseroled twelfth rib chop of lucerne-grazed lambs than that from lambs grazed on perennial ryegrass. Since the results from the consumer acceptance tests and the trained taste panel were inconsistent, it is concluded that both methods of assessing palatability should be carried out concurrently in any evaluation of meat quality.

Measurements of tagged pups and a population estimate of New Zealand fur seals on Taumaka, open bay Islands, Westland

Abstract: In January 1970, 309 pups of the New Zealand fur seal, Arctocephalus forsteri (Lesson, 1828), were tagged on Taumaka Island, one of the Open Bay Islands, Westland, New Zealand (43°52’ S, 168°53’ E) At about 6 weeks old, male pups have longer flippers and are longer and heavier than female pups A population estimate of seals on Taumaka Island is based on a count of pups of the year, to which data from related species of fur seals were applied (incidence of pregnancy and age at first pupping from Arctocephalus pusillus, immature mortality from Callorhinus ursinus), and on the assumptions that the sex ratio and sexual mortalities are equal There were at that time 2,000–3,000 seals, including pups, on the island

Simplified ab-initio calculations on hydrogen-containing molecules

Abstract: The simplified ab-initio method described in an earlier paper is tested on some hydrogen-containing molecules. The performance is slightly below that found previously for molecules composed entirely of first-row atoms but should be suitable for applications where limited numerical accuracy is sufficient. The hope of improved performance through limited expansion of the basis, especially on hydrogen, is not realised and so alternative treatments of the two-electron many-centre integrals should be sought if greater numerical accuracy is required.

Pycnogonida of the Antipodes Islands

Abstract: Pycnogonida collected at the Antipodes Islands (49° 45’ S, 178° 45’ E) by the University of Canterbury Antipodes Islands Expedition 1969 and during New Zealand Oceanographic Institute cruises are reported on here, and constitute all material known for this group of animals from these islands. To date eight species are known; two are endemic, (Pallenopsis antipoda n.sp. and Ammothea antipodensis n.sp.); two constitute a circum‐polar element (Tanystylum cayi‐dorsum Stock and Austrodecus breviceps Gordon); the remaining four species are known also from New Zealand mainland waters (Pallenopsis obliqua (Thomson), P. kupei n.sp., Achelia dohrni (Thomson) and Ammothea magniceps Thomson), as is T. cavidorsum. An attempt is made to indicate the range of variation in Achelia dohrni, and Pallenopsis mauii Clark, 1958 is redescribed although not a part of the Antipodes Islands fauna.