Acetylene reduction associated with zostera novazelandica Setch. and Spartina alterniflora Loisel., in Whangateau harbour, North Island, New Zealand

Nitrogen fixation (acetylene reduction) was investigated in Zostera novazelandica Setch. and Spartina alterniflora Loisel., in the North Island of New Zealand. Moderate rates of acetylene reduction were found in sediments in which plants were growing (means ± 95% confidence limit: 15.2 ± 2.8 |jmol C2H4 nrr2 h~l for Zostera and 24.7 ± 4.6 |amol C2H4 m~2 h"1 for Spartina). Activity was closely correlated with the dry weight of root; (r2 = 0.65, N = 15 for Zostera, and r2 = 0.85, A' =10 for Spartina). Sediment close to the plant beds, but without plants, exhibited only low rates of acetylene reduction (2.9 ± 2.2 and 4.5 ± l.OjLtmol C2H4 m~2 h"1, respectively). Sediments associated with Z. novazelandica and S. alterniflora in New Zealand exhibit moderate rates of nitrogenase activity compared to rates found in other countries. N fixation may contribute significantly to the nutrition of these plants in New Zealand estuaries

Land use, associated eel production, and abundance of fish and crayfish in streams in Waikato, New Zealand

The density and biomass of fish and crayfish, and the production of eels, was compared among streams in native forest, exotic forest, and pasture. Populations were estimated by multiple-pass electroshocking at 11 sites in hill-country streams in the Waikato region, North Island. Three sites were in native forest, four in exotic forest, and four in pasture. Length of stream sampled at each site was 46-94 m (41-246 m2 in area), and catchment areas up stream of the sites ranged from 0.44 to 2.01 km2. A total of 487 fish were caught. The species were longfinned and shortfinned eels, banded kokopu, Cran's and redfinned bullies, and common smelt. Eels were the most abundant fish in all three land-use types, and shortfinned eels were more abundant at pastoral sites (mean density 1.11 fish m-2) than longfinned eels (mean density 0.129 fish m-2). Banded kokopu were present only at forested sites. Mean fish densities were greater at pastoral sites (1.55 fish m-2) than under either native forest (0.130 fish m-2) or exotic forest (0.229 fish m-2). Mean fish biomass was also greater at pastoral sites (89.7 g m-2) than under native forest (12.8 g m-2) or exotic forest (19.3 g m-2). Longfinned eels made a greater contribution to the fish biomass at all sites than did shortfinned eels. Densities of crayfish were high (0.46-5.40 crayfish m-2), but were not significantly different between land-use types. Crayfish biomass ranged from 1.79 to 11.2 g m-2. Total eel production was greater at pastoral sites (mean 17.9 g m-2 year-1) than at forest sites (mean 2.39 g m-2 year-1)

Nitric oxide formation in gas turbine engines: A theoretical and experimental study

A modified Zeldovich kinetic scheme was used to predict nitric oxide formation in the burned gases. Nonuniformities in fuel-air ratio in the primary zone were accounted for by a distribution of fuel-air ratios. This was followed by one or more dilution zones in which a Monte Carlo calculation was employed to follow the mixing and dilution processes. Predictions of NOX emissions were compared with various available experimental data, and satisfactory agreement was achieved. In particular, the model is applied to the NASA swirl-can modular combustor. The operating characteristics of this combustor which can be inferred from the modeling predictions are described. Parametric studies are presented which examine the influence of the modeling parameters on the NOX emission level. A series of flow visualization experiments demonstrates the fuel droplet breakup and turbulent recirculation processes. A tracer experiment quantitatively follows the jets from the swirler as they move downstream and entrain surrounding gases. Techniques were developed for calculating both fuel-air ratio and degree of nonuniformity from measurements of CO2, CO, O2, and hydrocarbons. A burning experiment made use of these techniques to map out the flow field in terms of local equivalence ratio and mixture nonuniformity

Ecological and physical characteristics of the Te Awa O Katapaki Stream, Flagstaff, Waikato

1. The fish, macroinvertebrates, aquatic vegetation, and water quality indicate that the Te Awa O Katapaki Stream is an unpolluted, pastureland stream that is typical of the Waikato region. 2. The stream has very high nutrient concentrations that probably result from the dairy farming upstream. 3. The fish fauna is dominated by the native shortfinned eels. The presence of the migratory common smelt indicates that swimming fish species also have free access to the stream from the Waikato River. 4. Fish of high conservation value, such as giant or banded kokopu (Galaxias argenteus or G. fasciatus) were absent, which is predictable given the warm, unshaded nature of the stream. 5. Fish and invertebrates would soon recolonise the restored stream following any work in the streambed

Quantum Layers over Surfaces Ruled Outside a Compact Set

In this paper, we proved the quantum layer over a surface which is ruled outside a compact set, asymptotically flat but not totally geodesic admits ground states

Getting it Right: Directors’ assessment of information

Purpose: The purpose of this research is to examine a role for Information and Process scepticism in non-delegable director duties. We draw upon auditing literature to guide an understanding of scepticism. Design: This is a conceptual paper, drawing upon archival material, including statute law, case law, regulatory guidance material and media releases in Australasia. Research Implications: We present arguments that challenge us to understand the process of information, judgment and actions of directors as a neuroeconomic phenomenon