Assessing the vulnerability of organic matter to C mineralisation in pasture and cropping soils of New Zealand

Soil Research ◽  
2018 ◽  
Vol 56 (5) ◽  
pp. 481 ◽  
Author(s):  
Sam McNally ◽  
Mike Beare ◽  
Denis Curtin ◽  
Craig Tregurtha ◽  
Weiwen Qiu ◽  
...  
Keyword(s):  
New Zealand ◽  
Organic Carbon ◽  
Cold Water ◽  
Exponential Model ◽  
Hot Water ◽  
Environmental Perturbations ◽  
Wide Range ◽  
C Mineralisation ◽  
The Mean ◽  
The Difference

In New Zealand, pastoral soils have substantial organic carbon (OC) stocks, which may be vulnerable to loss from disturbance and environmental perturbations. We assessed OC vulnerability using two approaches. For the first approach, we postulated that the OC deficit of continuously cropped soils relative to nearby pastoral soils would provide a measure of the quantity of potentially vulnerable OC in pastures. As a test, soils were sampled to a depth of 15 cm at 149 sites and the total organic carbon (TOC) and particulate organic carbon (POC) contents were measured. The second approach involved measurement of OC mineralisation in a laboratory assay (98 day aerobic incubation at 25°C). For the pastoral soils, the mean TOC and POC was about twice that of the cropped soils. On average, 89% more OC was mineralised from the pastoral soils compared with the cropped counterparts. However, the quantity of OC mineralised in pasture soils was small relative to the potential for OC loss inferred from the difference in TOC between pastoral and cropped soils. Carbon mineralisation was explained using a two-pool exponential model with rate constants of the ‘fast’ and ‘slow’ pools equating to 0.36 ± 0.155 and 0.007 ± 0.003 day–1 respectively. The larger, slow OC pool correlated strongly with hot water extractable OC whereas the fast pool was related to OC extracted using cold water. Our results suggest that water extraction (using cold and hot water) can provide a rapid estimate of the quantity of mineralisable OC across a wide range of New Zealand soils.

Thermal Protection System for Underwater Use in Cold and Hot Water

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Joseph C. Mollendorf ◽  
David R. Pendergast
Keyword(s):  
Thermal Protection ◽  
Cold Water ◽  
Electrical Power ◽  
Thermal Protection System ◽  
Hot Water ◽  
Protection System ◽  
Working Fluid ◽  
Physiological Data ◽  
Wide Range ◽  
Body Core

Underwater workers, sport and military divers, are exposed to thermal stress since most of the waters of the world are below or above what is thermally neutral. Although divers wear insulation suits for passive thermal protection they are inadequate. Active heating is currently accomplished by resistive heating and open-flow tubes delivering hot water; however, these methods are problematic. The challenge of this project was to design, build and test an active diver thermal protection system (DTPS) to be used with wet suit insulation that is effective, user-friendly, reliable, and that could be used by a free-swimming diver. The DTPS has a minimum number of moving parts, is low maintenance, has no unsafe or toxic working fluid and uses no consumables except a safe, high density, modular electrical power source. A portable and swimmable, self-contained, electrically powered unit (DTPS) has been designed, built, and tested that produces and circulates thermally conditioned water in a closed-loop through a zoned tube suit worn by a diver under a wetsuit to maintain skin and body core temperatures within prescribed safe limits. The system has been validated by using physiological data taken on human subjects over a wide range of ambient water temperatures. Corresponding enthalpy and electrical power measurements were used as the basis of a thermodynamic analysis. The DTPS maintained skin and body core temperatures within safe and functional ranges by providing up to about 200 W of heating in cold water and up to about 330 W of cooling in hot water. The corresponding electrical power consumption was up to about 300 W in cold water and up to about 1500 W in hot water. The results of a complete audit of the power use and heat transfer are presented along with the efficiency of the thermoelectric heating/cooling modules and the duty cycle of the system for a range of water immersion temperatures from 10°C to 39°C. The DTPS proved to be an effective and reliable apparatus for diver thermal protection in water temperatures from 10°C to 39°C, which covers most of the range of the earth’s waters. The data presented here can be used to modify the design of the DTPS to meet specific needs of the diving community.

scholarly journals Response Variability in Balanced Cortical Networks

2006 ◽  
Vol 18 (3) ◽  
pp. 634-659 ◽  
Author(s):  
Alexander Lerchner ◽  
Cristina Ursta ◽  
John Hertz ◽  
Mandana Ahmadi ◽  
Pauline Ruffiot ◽  
...  
Keyword(s):  
Mean Field ◽  
Excitatory Input ◽  
Response Variability ◽  
Cortical Column ◽  
Single Model ◽  
Wide Range ◽  
High Connectivity ◽  
The Mean ◽  
The Difference ◽  
External Population

We study the spike statistics of neurons in a network with dynamically balanced excitation and inhibition. Our model, intended to represent a generic cortical column, comprises randomly connected excitatory and inhibitory leaky integrate-and-fire neurons, driven by excitatory input from an external population. The high connectivity permits a mean field description in which synaptic currents can be treated as gaussian noise, the mean and autocorrelation function of which are calculated self-consistently from the firing statistics of single model neurons. Within this description, a wide range of Fano factors is possible. We find that the irregularity of spike trains is controlled mainly by the strength of the synapses relative to the difference between the firing threshold and the postfiring reset level of the membrane potential. For moderately strong synapses, we find spike statistics very similar to those observed in primary visual cortex.

scholarly journals Correcting Positional Errors in Shore-Based Theodolite Measurements of Animals at Sea

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ophélie Sagnol ◽  
Femke Reitsma ◽  
Christoph Richter ◽  
Laurence H. Field
Keyword(s):  
New Zealand ◽  
Habitat Use ◽  
Marine Mammal ◽  
Positional Information ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Vertical Angle ◽  
Position Accuracy ◽  
Wide Range ◽  
The Difference

Determining the position of animals at sea can be particularly difficult and yet, accurate range and position of animals at sea are essential to answer a wide range of biological questions. Shore-based theodolite techniques have been used in a number of studies to examine marine mammal movement patterns and habitat use, offering reliable position measurements. In this study we explored the accuracy of theodolite measurements by comparing positional information of the same objects using two independent techniques: a shore-based theodolite station and an onboard GPS over a range of 25 km from the shore-based station. The technique was developed to study the habitat use of sperm whales (Physeter macrocephalus) off Kaikoura, New Zealand. We observed that the position accuracy fell rapidly with an increase in range from the shore-based station. Results showed that the horizontal angle was accurately determined, but this was not the case for the vertical angle. We calibrated the position of objects at sea with a regression-based correction to fit the difference in distance between simultaneously recorded theodolite fixes and GPS positions. This approach revealed the necessity to calibrate theodolite measurements with objects at sea of known position.

A new approach to the measurement of the quantitative effects of inherent and environmental factors on the composition of the milk of individual cows and of herds, with particular reference to lactose content

1968 ◽  
Vol 35 (1) ◽  
pp. 91-105 ◽  
Author(s):  
J. P. Walsh ◽  
J. A. F. Rook ◽  
F. H. Dodd
Keyword(s):  
Quantitative Estimation ◽  
Relative Importance ◽  
New Approach ◽  
Mean Values ◽  
Stage Of Lactation ◽  
Bulk Milk ◽  
Wide Range ◽  
The Mean ◽  
The Difference ◽  
Effect Of Age

Summary(1) A tentative scheme is proposed for the quantitative estimation of the effects of various factors on one major milk constituent, lactose, from analyses of the milk of individual cows within herds. The potential lactose content in the milk of individual cows is predicted from the observed potassium-to-lactose ratio in the milk, and the difference between the predicted potential and the actual lactose content is partitioned into fractions that are attributed to effects due to age, inter-quarter difference and changes with stage of lactation. The scheme was applied to 2 commercial herds, one (herd A) producing milk of low and the other (herd B) milk of normal SNF content.(2) Lactation mean values for fat, SNF and lactose contents of the milk of individual cows showed a wide range of the same order in each of the 2 herds. Of the mean difference in SNF percentage of 0·30 between the herds, 0·14, or 47%, was due to a difference in lactose content.(3) The predicted potential milk lactose content of the cows in the 2 herds ranged from 5·04 to 5·66 (g/100 g milk water). Herd mean values were 5·394 for herd A and 5·244 for herd B.(4) Herd mean values for the effect on the lactose content (g/100 g milk water) of age, of changes with stage of lactation and of inter-quarter difference were −0·127, −0·080, and 0·073 respectively in herd A, and −0·197, −0·058 and −0·078, respectively, in herd B.(5) The relative importance of the various factors in accounting for differences between the herds in the lactose content of their bulk milk were: predicted potential lactose content 61%, effect of age 28%, effect of changes with stage of lactation 9% and effect of inter-quarter difference 2%.(6) The errors attached to the estimation of potential milk lactose content and the effects of age, of changes with stage of lactation and of inter-quarter difference are discussed.

scholarly journals Sustainable Economic Solution to Prevent the Wasted Cold Water in the Start of Shower Time Using Low Cost In-Line Electrical Heater with MISO Fuzzy Logic Controller

2021 ◽  
Author(s):  
Muhammad M. A. S. Mahmoud
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Greenhouse Gas Emission ◽  
Cold Water ◽  
Economic Benefits ◽  
Hot Water ◽  
Electric Heater ◽  
Operating Voltage ◽  
Control Input ◽  
Wide Range

This paper discusses domestic problem of waiting hot water for the shower use till it reaches satisfactory temperature, which result a lot of wastage in fresh water. The outcome from research survey shows that there is no satisfactory solution till now as all solutions were either expensive or with no effective results. Local small inline electric heater equipped with fuzzy logic controller is proposed in this paper to be installed just before the showerhead to measure the water temperature and flow before the showerhead, as control input-variables, and decide the operating voltage of the heater, as control output-variable. Matlab Simulink is used to model the proposed system. Different test cases are simulated to prove the performance and the safe operation of the system. Techno-economic study is carried out to determine the “Direct Benefits” and “Indirect Benefits” that can be achieved if such system is implemented in wide range. Azerbaijan data is taken as an example to calculate the economic benefits. The results show important benefits not only for economy but also for climate and the reduction of greenhouse gas emission. Different economic indices are provided to be an easy reference for decision makers and project managers.

scholarly journals Cold water, ultra-high pressure cleaning of abattoirs

1977 ◽  
Vol 78 (1) ◽  
pp. 11-16 ◽  
Author(s):  
J. F. Dempster
Keyword(s):  
High Pressure ◽  
Sodium Silicate ◽  
Cold Water ◽  
Low Pressure ◽  
Hot Water ◽  
Ultra High Pressure ◽  
The Mean ◽  
Effect Of Surface

SUMMARYCold water (10° C) at ultra-high pressure (38·5–49 kg/cm2) was compared with (a) hot water (65·6–82·2° C) at low pressure (4·2–5·6 kg/cm2) and (b) hot water containing a detergent (2% (w/v) sodium silicate). Seven sites were examined in a beef abattoir and six in a bacon factory.Three surfaces in the beef abattoir had lower residual colony counts (higher reductions) after hot water/low pressure than after cold water/high pressure. However, the differences were not significant (P> 0·05). The range of the mean log10count/cm2before cleaning was 4·02–5·15, and after cleaning 1·73–2·32 (hot water) and 1·9–2·85 (cold water).On three of the remaining sites, the three methods were compared. The total differences between treatments were not significant (P> 0.05), although there was an effect of surface and an interaction between surface and treatment. The cold water produced lower residual counts on three sites in the bacon factory than the hot water (45–54°C). However, the differences were not significant on the remaining surfaces.

Effect of Water Temperature on the Performance of Gas Turbine Inlet Air-Fogging Systems

2013 ◽  
Author(s):  
Mustapha A. Chaker ◽  
Cyrus B. Meher-Homji
Keyword(s):  
Water Temperature ◽  
Gas Turbine ◽  
Droplet Size ◽  
Gas Turbines ◽  
Cold Water ◽  
Hot Water ◽  
Initial Water ◽  
Effect Of Water ◽  
Turbine Inlet ◽  
Wide Range

With more than 1000 fogging systems installed worldwide on a wide range of gas turbines of different types, gas turbine inlet air fogging systems have become a well-established technology used to increase gas turbines power output. The major benefit of spraying fog droplets in the inlet airflow of the gas turbines is to increase the density of the air entering the gas turbine by evaporative cooling in the inlet air stream. Significant amount of research has been carried out to improve the efficiency of fogging systems. However, the effect of water temperature on the overall efficiency of a fogging system has yet to be addressed. In this paper, a detailed analysis of this effect will be presented, both from an experimental and a theoretical view point. Due to the small size of the droplets used in this application, the temperature of the droplet converges quickly to the wet bulb temperature, regardless of the initial water temperature. The rapidity at which this convergence occurs depends on the initial droplet size, the water temperature, the air mass flow to mass of injected water ratio, and the ambient psychrometric conditions of the surrounding air. The present study was carried out using water temperatures between 1 °C and 60 °C. Results showed that the water temperature has no significant effect on the droplet size. However, within the range of droplet sizes atomized from nozzles installed in the fogging system, using cold water provides a marginal benefit on the cooling efficiency; using hot water, on the other hand, slightly increases the evaporation efficiency.

Impact of mortality, possibly due to herpesvirus, on pilchard Sardinops sagax stocks along the south coast of Western Australia in 1998-99

2000 ◽  
Vol 51 (6) ◽  
pp. 601 ◽  
Author(s):  
D. J. Gaughan ◽  
R. W. Mitchell ◽  
S. J. Blight
Keyword(s):  
Western Australia ◽  
Total Mortality ◽  
Simulation Models ◽  
Mortality Rates ◽  
Sea Surface ◽  
Sea Floor ◽  
Wide Range ◽  
The Mean ◽  
The Difference ◽  
The Impact

During progression of a mass mortality of Australian pilchards in late 1998 and early 1999, quantities of dead pilchards on the sea-surface, sea-floor and along beaches were estimated in three regions along southern Western Australia (WA) by use of transects. Total mortality was estimated at 17 590, 11193 and 144.4 t for Esperance, Bremer Bay and Albany respectively. Mortality rates at Esperance and Bremer Bay were similar at 74.5% and 64.7% respectively, with a mean of 69.6%. In contrast, estimated mortality at Albany was only 2.4%. Although the difference in total mortality between regions is probably related to differences in stock size, as determined by simulation models, the much lower estimate for Albany is probably an artefact of an over-estimated pilchard biomass and not due to large differences in actual mortality rates. Variability in estimates of both pilchard biomass and quantities killed resulted in a wide range of estimated mortality rates, with lower estimates for Esperance and Bremer Bay of 28.0% and 22.9% respectively. This represents a significant decline in the breeding stock of WA pilchards. If the impact was closer to the mean (69.6%), then pilchard stocks in WA are severely depressed.

scholarly journals Advances and limitations of atmospheric boundary layer observations with GPS occultation over southeast Pacific Ocean

2012 ◽  
Vol 12 (2) ◽  
pp. 903-918 ◽  
Author(s):  
F. Xie ◽  
D. L. Wu ◽  
C. O. Ao ◽  
A. J. Mannucci ◽  
E. R. Kursinski
Keyword(s):  
Boundary Layer ◽  
Pacific Ocean ◽  
Atmospheric Boundary Layer ◽  
Temperature Inversion ◽  
Lower Percentage ◽  
Trade Wind ◽  
Sampling Errors ◽  
Wide Range ◽  
The Mean ◽  
The Difference

Abstract. The typical atmospheric boundary layer (ABL) over the southeast (SE) Pacific Ocean is featured with a strong temperature inversion and a sharp moisture gradient across the ABL top. The strong moisture and temperature gradients result in a sharp refractivity gradient that can be precisely detected by the Global Positioning System (GPS) radio occultation (RO) measurements. In this paper, the Constellation Observing System for Meteorology, Ionosphere & Climate (COSMIC) GPS RO soundings, radiosondes and the high-resolution ECMWF analysis over the SE Pacific are analyzed. COSMIC RO is able to detect a wide range of ABL height variations (1–2 km) as observed from the radiosondes. However, the ECMWF analysis systematically underestimates the ABL heights. The sharp refractivity gradient at the ABL top frequently exceeds the critical refraction (e.g., −157 N-unit km−1) and becomes the so-called ducting condition, which results in a systematic RO refractivity bias (or called N-bias) inside the ABL. Simulation study based on radiosonde profiles reveals the magnitudes of the N-biases are vertical resolution dependent. The $N$-bias is also the primary cause of the systematically smaller refractivity gradient (rarely exceeding −110 N-unit km−1) at the ABL top from RO measurement. However, the N-bias seems not affect the ABL height detection. Instead, the very large RO bending angle and the sharp refractivity gradient due to ducting allow reliable detection of the ABL height from GPS RO. The seasonal mean climatology of ABL heights derived from a nine-month composite of COSMIC RO soundings over the SE Pacific reveals significant differences from the ECMWF analysis. Both show an increase of ABL height from the shallow stratocumulus near the coast to a much higher trade wind inversion further off the coast. However, COSMIC RO shows an overall deeper ABL and reveals different locations of the minimum and maximum ABL heights as compared to the ECMWF analysis. At low latitudes, despite the decreasing number of COSMIC RO soundings and the lower percentage of soundings that penetrate into the lowest 500-m above the mean-sea-level, there are small sampling errors in the mean ABL height climatology. The difference of ABL height climatology between COSMIC RO and ECMWF analysis over SE Pacific is significant and requires further studies.

scholarly journals Attenuation of Modified Mercalli intensity in New Zealand earthquakes

1999 ◽  
Vol 32 (2) ◽  
pp. 55-89 ◽  
Author(s):  
D. J. Dowrick ◽  
D. A. Rhoades
Keyword(s):  
New Zealand ◽  
Distance Measures ◽  
Fault Rupture ◽  
Ground Acceleration ◽  
Seismic Region ◽  
Source Distance ◽  
The Mean ◽  
The Difference ◽  
Attenuation Models ◽  
Saturation Effects

The main result of this study is the development of attenuation expressions for Modified Mercalli intensity isoseismals in New Zealand earthquakes, in terms of magnitude Mw and source distance. Attenuation of isoseismal intensities has been modelled in a new 2-dimensional manner, i.e. in terms of three distance measures, i.e. radius a along the strike of the fault rupture, radius b normal to strike, and the mean radius c. Other factors which are included in the modelling are depth, focal mechanism, tectonic type (i.e. crustal, interface or dipping slab), and regional variations. As well as being implied in the source distance, the moderate effect of depth (to increase intensities) is modelled well with a separate linear depth term. Shallow (hc ≤ 60 km) Reverse mechanism events were found to give stronger intensities than Strike-Slip events which in tum were stronger than Normal mechanism events, the difference near source between Reverse and Normal events of Mw 7+ events being about 0.4 intensity units. Attenuation for the Central Volcanic Region and Deep events differs markedly from the Main Seismic Region. No magnitude saturation effects were found. Comparisons are made with some earlier New Zealand intensity models, and local and international peak ground acceleration attenuation models.

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