Phenology of the Cladophora-Stigeoclonium community in Two Urban Creeks of Melbourne

1989 ◽  
Vol 40 (5) ◽  
pp. 471 ◽  
Author(s):  
TJ Entwisle
Keyword(s):  
Standing Crop ◽  
Cladophora Glomerata ◽  
Mean Flow ◽  
Complete Darkness ◽  
Flow Rates ◽  
Central Victoria ◽  
South Central ◽  
Air Temperatures ◽  
Macroalgal Biomass ◽  
Urban Creeks

Cladophora glomerata and Stigeoclonium tenue dominate lowland urban creeks in the Yarra River basin of south-central Victoria. In Darebin and Merri Creeks, Cladophora produces extensive mats in summer and autumn, and is mostly replaced by Stigeoclonium in winter and spring. Although Stigeoclonium can grow all year round, it only outcompetes Cladophora in winter and spring, when air temperatures range between a maximum of < 15� C and a nightly minimum of < 10� C (water temperature < 15� C, usually about 10� C). The seasonal composition and abundance of these macroalgae depend on temperature and on the severity of, and time since, the last floods, and the effect that these factors have on interspecific competition. Features of the microhabitat (e.g. photon irradiance, substratum stability and composition, and mean flow rates) determine the range of these variations. The biomass of both macroalgae fluctuates widely; this is due mainly to floods, which can remove almost the entire standing crop. In off-seasons, both species are maintained by small resilient plants or protected populations (in culture, plants remain viable after up to 6 months in complete darkness). Filaments of Cladophora readily produce zoospores and new vegetative growth following dormancy. The prostrate thallus of Stigeoclonium initiates new erect filaments before zoospores are produced. An understanding of the large local and seasonal variations in macroalgal biomass is essential for biological monitoring programmes.

scholarly journals Increased take-off level in automatic milking systems – effects on milk flow, milk yield and milking efficiency at the quarter level

2018 ◽  
Vol 86 (1) ◽  
pp. 85-87 ◽  
Author(s):  
Sabine Ferneborg ◽  
Måns Thulin ◽  
Sigrid Agenäs ◽  
Kerstin Svennersten-Sjaunja ◽  
Peter Krawczel ◽  
...  
Keyword(s):  
Flow Rate ◽  
The Other ◽  
Mean Flow ◽  
Flow Rates ◽  
Decline Phase ◽  
Flow Profiles ◽  
Milk Flow ◽  
Automatic Milking ◽  
Automatic Milking Systems ◽  
Time Required

AbstractThis research communication describes how different detachment levels (0.48, 0.3 and 0.06 kg milk/min) at the quarter-level affect milk flow profiles and overall milking efficiency in automatic milking systems. We hypothesized a higher detachment level would result in greater mean flow rates without affecting the volume of harvested milk per cow during 24 h compared to lower detachment levels. The data suggest milk flow decreased to a rate below the overmilking limit within the 6-s delay time required for termination in all treatments, but the duration of overmilking was shorter for the greatest detachment level compared to the other treatments. We conclude that setting a detachment level at a greater milk flow rate reduces the duration of overmilking without affecting the amount of milk harvested when applied to cows in mid-lactation during quarter-level milking. We also suggest that the steepness of the decline phase of the milk flow curve might have a larger effect than the actual detachment level on the duration of overmilking.

P4379Pathophysiology of left atrial filling in mitral regurgitation. A new volumetric flow rate index describing disturbed left atrial filling behavior in mitral regurgitation by 3D TTE

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
D Frumkin ◽  
K Stangl ◽  
A Muegge ◽  
T Buck ◽  
B Plicht
Keyword(s):  
Mitral Regurgitation ◽  
Left Atrium ◽  
Flow Rate ◽  
Left Atrial ◽  
Volume Overload ◽  
Volumetric Flow Rate ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Mean Flow ◽  
Flow Rates

Abstract Background In chronic mitral regurgitation (MR) the left atrium (LA) is one of the first cardiac structures involved in remodeling by progressive volume overload. Real-time three-dimensional echocardiography is able to monitor volumetric changes of the left atrium during the heart cycle. Purpose We hypothesized that chronic volume overload due to MR leads to detectable changes in the LA filling behavior described by mean and maximum filling flow rates and their relation called volumetric flow rate index. Methods We prospectively analyzed data of 36 patients in different stages of chronic MR and 13 patients without MR. Transthoracic echocardiography was conducted using the Epiq 7G Ultrasound System. Standard 2D- and 3D apical 4-chamber views were recorded and stored for offline analysis. We generated volume-time-curves by 3D volume analysis to derive mean and maximum volumetric flow rates during LA reservoir, conduit and pump phase. Volumetric flow rate index was calculated as the quotient of mean flow rate/maximum flow rate. Results Average MR severity, calculated with the MR Scoring system introduced from Buck et al. and implicated in the ESC Guidelines, was 6.2 points (±2.5) according to Grade I-II. We included 13 patients without MR, 18 with mild MR, 12 patients with moderate MR, 6 patients with severe MR. Left ventricular ejection fraction was similar in the different groups (51,2±12,3%). Maximum and mean flow rate showed no significant correlation with MR severity. Correlation of MR severity with LA dilation (ml/m2 BSA) was r=0.41; p<0.001. Flow rate index showed strong significant correlation with MR severity in left atrial reservoir phase (r=−0.75; p<0.001). There was no statistically relevant difference of volumetric flow rate parameters in left atrial pump and conduit phase. Line chart Conclusions We observed a significant correlation of the volumetric flow rate index to MR severity in the left atrial reservoir phase with stronger correlation than MR severity to left atrial dilation. The results of this work encourage further investigations to establish the presented volumetric flow rate index as a progression marker of MR and to evaluate its prognostic value.

Performance of the Directly-Irradiated Annular Pressurized Receiver (DIAPR) Operating at 20 Bar and 1,200°C

2000 ◽  
Vol 123 (1) ◽  
pp. 10-17 ◽  
Author(s):  
A. Kribus ◽  
P. Doron ◽  
R. Rubin ◽  
R. Reuven ◽  
E. Taragan ◽  
...  
Keyword(s):  
Radiation Flux ◽  
Test Results ◽  
Gas Temperature ◽  
Flow Rates ◽  
Air Temperatures

The Directly Irradiated Annular Pressurized Receiver (DIAPR) is a volumetric (directly-irradiated) windowed cavity receiver, designed for operation at a pressure of 10–30 bar, exit gas temperature of up to 1,300°C, and aperture radiation flux of up to 10 MW/m2. This paper presents test results obtained under various irradiation conditions and flow rates. Inlet aperture flux was up to 5 MW/m2; exit air temperatures of up to 1,200°C were obtained, while operating at pressures of 17–20 bar. Estimated receiver efficiency in these tests was in the range of 0.7–0.9. The absorber and window temperatures were 200-400°C below the permitted maximum, indicating that higher air exit temperatures are possible.

Geographical Elements in the Flora of Victoria

1976 ◽  
Vol 24 (2) ◽  
pp. 249 ◽  
Author(s):  
PB Bridgewater
Keyword(s):  
Plant Communities ◽  
Vascular Plants ◽  
Distribution Data ◽  
Inverse Association ◽  
Central Victoria ◽  
South Central ◽  
Southern Half ◽  
Species Groups ◽  
Geographical Elements ◽  
Very High

Distribution data for vascular plants in Victoria were recorded on grid squares of 1° latitude by 1.5° longitude. Data for six angiosperm families (Cyperaceae, Liliaceae, Chenopodiaceae, Rhamnaceae, Rutaceae and Myrtaceae) were analysed by the techniques of normal and inverse association analysis. Analyses of the data produced a series of species groups with similar geographical ranges (elements). These elements may be broadly divided into eastern and western groups, with two exceptions-one extending over the southern half of the State and the other occupying the coastal fringe. Geographical elements are helpful in defining the range of plant communities, as well as suggesting hypotheses as to the origins of floras. South central Victoria is seen to be a junction for species of both the eastern and western groups of elements, which may explain the very high number of species recorded from the Melbourne region.

LDV Measurements and Investigation of Flow Field Through Radial Turbine Guide Vanes

1991 ◽  
Vol 113 (4) ◽  
pp. 660-667
Author(s):  
Hasan Eroglu ◽  
Widen Tabakoff
Keyword(s):  
Flow Field ◽  
Flow Direction ◽  
Mean Flow ◽  
Flow Rates ◽  
Radial Turbine ◽  
Contour Plots ◽  
Mass Flow Rates ◽  
Flow Turbulence ◽  
Downstream Flow ◽  
Nozzle Blade

The results of LDV measurements and investigation of the detailed flow field in a radial inflow turbine nozzle are presented. The flow velocities were measured at upstream, inside and downstream of the nozzle blades for two different mass flow rates, using a three-component LDV system. Results are presented as contour plots of mean velocities, flow angles, and turbulence intensities. The flow field inside the nozzle blade passages was found to be influenced by the upstream scroll geometry. The flow turbulence increased in the downstream flow direction. The LDV mean flow results on the blade-to-blade midspan plane which is parallel to the end walls were also compared with an inviscid, “panel method” solution.

Mechanics of machine milking: II. The flow-rate pattern within single pulsation cycles

1966 ◽  
Vol 33 (2) ◽  
pp. 177-191 ◽  
Author(s):  
C. C. Thiel ◽  
P. A. Clough ◽  
D. R. Westgarth ◽  
D. N. Akam
Keyword(s):  
Flow Rate ◽  
Response Rate ◽  
Sphincter Muscle ◽  
Mean Flow ◽  
Considerable Time ◽  
Flow Rates ◽  
Machine Milking ◽  
Closing Force ◽  
The Mean ◽  
Pulsation Cycle

SummaryThe milk flowing during a single pulsation cycle was collected in a circle of contiguous cups which rotated in a chamber at 1 rev/pulsation cycle just below the end of the teatcup liner. The mean flow rate during the time taken for each collecting cup to pass under the milk stream was calculated and the flow-rate curve for the milkflow period of the pulsation cycle plotted. Flow rates were measured at 130, 97, 65, 32 and 16 c/min, and also after the pulsator had been stopped with the liner open for 0·5 min (0 pulsation).It was concluded from the series of flow-rate curves at the different pulsation rates that flow rate from the teat increased in about 0·05 sec to a steady value which continued for 0·5 sec or so, and then declined over a period of about 1·5 sec to a new constant value approximately equal to that shown after milk had flowed continuously from the teat for 0·5 min.These results suggest that once the pressure difference across the streak canal during milking forces the teat sphincter open a considerable time elapses before the muscle control system responds, and that a further much longer period elapses before the full closing force of the sphincter is exerted. Thus, it would appear that at pulsation rates of about 50 c/min and above, the streak canal is closed by pressure exerted on the teat by the closing liner, the sphincter muscle playing no active part because its response rate is slow compared with the pulsation rate. At lower pulsation rates the flow rate declines during each cycle because the sphincter muscle has time to exert a closing force to a greater or lesser extent depending on the duration of the milkflow period.

scholarly journals 099 LIGHT AND TEMPERATURE AFFECT SPIKING AND FLOWERING OF THE PHALAENOPSIS ORCHID

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 442d-442
Author(s):  
Yin-Tune Wane
Keyword(s):  
Regression Analysis ◽  
Night Temperature ◽  
Complete Darkness ◽  
Air Temperatures ◽  
The Impact

To determine the impact of light on spiking during forcing, mature pot-grown Phalaenopsis Joseph Hampton `Diane' plants were exposed to 0, 8, 60, or 160 μmol·m-2·s-1 of PPF while being subjected to 20C day/15C night (12 hr each) air temperatures for six weeks. Flower spikes emerged in an average of 27 and 33 days for plants exposed to 160 and 60 μmol·m-2·s-1 PPF, respectively. Those exposed to 8 μmol*·m-2·s-1 of PPF or kept in darkness did not spike after six weeks. In a second experiment, plants were kept in complete darkness for 2, 4, or 6 weeks at 20C day/15C night before exposed to 160 μmol·m-2·s-1 of PPF for six weeks. The average days to spiking for those kept in darkness for 2, 4, and 6 weeks were 30, 31, and 35, respectively, after lighting began. Therefore, light exceeding a certain level is required during the induction of spiking. Regression analysis of the results from a third experiment shows that, at a common day temperature of 25C, anthesis was delayed by one day for each 1C decrease in night temperature between 25C and 15C. Night temperature had no effect on flower count or size.

scholarly journals In vitro estimation of the energy loss through turbulence in a porcine aortic valve stenosis model and silicone ascending aorta phantom using backlight particle tracking velocimetry

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
M Chiarelli ◽  
S F De Marchi ◽  
D Obrist ◽  
E Buffle
Keyword(s):  
Left Ventricle ◽  
Aortic Stenosis ◽  
Energy Loss ◽  
Particle Tracking Velocimetry ◽  
Ascending Aorta ◽  
Low Flow ◽  
Mean Flow ◽  
Flow Rates ◽  
Stenosis Severity

Abstract Introduction Patients suffering from low-flow, low-gradient aortic stenosis present a decreased stroke volume due to decreased contraction or relaxation function of the left ventricle. As a low stroke volume tends to cause a low transvalvular flow, transvalvular pressure gradient (TVPG) and effective orifice area, the clinician cannot rely on those parameters with confidence for the evaluation of aortic stenosis severity. Hence new diagnostic parameters have to be developed. Energy loss through turbulence associated with aortic stenosis represented the wasted left ventricle work. Currently, echocardiographic measurement of the turbulence intensity is not validated for clinical evaluations of aortic stenosis. Methods Two porcine aortic valves were harvested and inserted in a flow loop that replicates the pulsatile flow of the heart. A stiffening of the valves was achieved by treating them with formaldehyde. The stiffening was externally confirmed by a custom-made force-displacement device quantifying the rigidity of the leaflet yielding two stiffness grades per valve. Each valve was tested under three different mean flow rates (1, 2.5, and 4 l/min) at each of the two stiffness grades. Moreover the pressure in the left ventricle chamber and in the aortic chamber was recorded to calculate the TVPG. Particle tracking velocimetry measurements into the transparent silicone ascending aorta phantom allowed the computation of the turbulent kinetic energy (TKE), to evaluate the energy loss due to turbulence. Results We could confirm the enhanced rigidity of the valve leaflets with our custom device (data not shown) and measure a consistent increase in TVPG across all mean flow rates between the two stiffness grades. Moreover, an explicit increase of the TKE in the aortic phantom could be measured after the stiffening process (73.1% under 1 l/min, and 43% under both 2.5 and 4 l/min). In addition, a good correlation (R = 0.86) between the mean TVPG and the TKE was found. Conclusions This project demonstrated the possibility of quantifying the energy loss attributed to turbulence for porcine valves in vitro for native and added stiffness grade. This project lays the foundation for the development of a new diagnostic tool for the assessment of stenosis severity in patients with low-flow, low-gradient aortic stenosis in cardiac imaging tool such as echocardiography. FUNDunding Acknowledgement Type of funding sources: None. TVPG and its correlation with TKE Intensity graphs of the TKE

scholarly journals Areal and Temporal Variation of Percolation of Water Through a Snow-Pack

1977 ◽  
Vol 19 (81) ◽  
pp. 668
Author(s):  
E. J. Langham
Keyword(s):  
Temporal Variation ◽  
Flow Rate ◽  
Lower Surface ◽  
Snow Melt ◽  
Snow Pack ◽  
Mean Flow ◽  
Flow Rates ◽  
Melt Water ◽  
Temporal And Spatial ◽  
True Measure

Abstract Snow melt water that is uniformly generated over the upper surface of the snow-pack does not percolate homogeneously through the snow. Consequently, the rate of arrival of melt water at a single collector at the lower surface does not give a true measure of the melt rate. The experiment described here measures the spatial variability of flow rate and the temporal variation of this two-dimensional pattern. Data are collected from an array of 64 sensors under control of a microprocessor. The microprocessor checks the consistency of the data, calculates the flow rate for each sensor and transfers the results to a recorder. These mean flow rates are calculated at regular intervals for the duration of the experiment. In this way the temporal and spatial variations of flow rate may be related to variations in meteorological conditions and the evolution of the structure snow-pack as the melting progresses.

The Litoria ewingi Complex (Anura:Hylidae) in South-Eastern Australia VIII.* Hybridization between L. ewingi and L. verreauxi alpina in the Mount Baw Baw Area, South Central Victoria

1985 ◽  
Vol 33 (2) ◽  
pp. 143 ◽  
Author(s):  
GF Watson ◽  
MJ Littlejohn ◽  
DF Gartside ◽  
JJ Loftus-Hills
Keyword(s):  
Northern Slope ◽  
Blood Proteins ◽  
Genetic Compatibility ◽  
Hybrid Swarm ◽  
Geographic Ranges ◽  
Central Victoria ◽  
South Central ◽  
Eastern Australia ◽  
High Level

Contacts between the geographic ranges of the widely distributed species, Litoria ewingi, and the montane-adapted taxon, L. verreauxi alpina, occur at about 1200 m on the Great Dividing Range in south central Victoria. Data for adult morphology, genetic compatibility, blood proteins (haemoglobins and transferrins), and structure of male advertisement calls, were obtained from seven populations at altitudes between 640 m and 1450 m in the region of the Mount Baw Baw Plateau. The results indicate that hybrids are present at intermediate altitudes (1140-1270 m), but that the nature of the interaction differs between overlap of parental taxa together with recombination products on the south-westem slope (the Baw Baw transect), and a hybrid swarm on the northern slope of the Mount Baw Baw plateau. Results of in vitro crosses (female L, ewingi by male L. v. alpina) indicate that there is a high level of genetic compatibility between the taxa. Estimates of the width of the hybrid zone on the Baw Baw transect vary from less than 4 km for morphology and calls, to between 10 and 24 km for blood proteins.

Sign in / Sign up

Export Citation Format

Share Document