scholarly journals Sap Flow and Water Consumption of Captain Cook Tree [Cascabela thevetia (l.) Lippold].

2021 ◽  
Vol 4 (4) ◽  
Keyword(s):  
Flow Rate ◽  
Water Consumption ◽  
Sap Flow ◽  
Black Tea ◽  
Flow Measurements ◽  
Flow Rates ◽  
Tea Tree ◽  
Late Night ◽  
Moreton Bay ◽  
Native Trees

A two-year field study documented the diurnal and nocturnal sap flow rates and water consumption of young (YCC), adult (ACC) and mature (MCC) Captain Cook trees [Cascabela thevetia (L.) Lippold] that were invading a riparian habitat in northern Queensland. For comparison, two native trees [black tea tree (Melaleuca bracteata F. Muell.) and Moreton Bay ash (Corymbia tessellaris (F.Muell.) K.D.Hill & L.A.S.Johnson)] growing in association with Captain Cook tree were also monitored. Sap flow measurements were grouped into eight timeframes per day (early morning, late morning, early afternoon, late afternoon, early night, late night, early dawn and late dawn). Significant interactions in sap flow rate occurred between plant types, timeframes, and months. The magnitude of sap flow rate was Moreton Bay ash>YCC>ACC>black tea tree>MCC. Maximum sap flow rates tended to occur during early (1-3 pm) to mid-afternoon (4-6 pm) for all age groups of Captain Cook tree and the two native trees. Diurnal sap flow rates were significantly greater than nocturnal, and on a monthly basis sap flow rates were highest over the spring to autumn period (September-May) and lowest during winter (June–August). Significant differences in water consumption also occurred between species and months. Water consumption peak time varied between plant types with most plants peaking in January except for MCC and Moreton Bay ash trees for which peak water consumption occurred in June and July respectively. Water consumption was high across all seasons except winter. The magnitude of water consumption was Moreton Bay ash>black tea tree>YCC>ACC>MCC trees. Moreton Bay ash registered maximal monthly water consumption (4700 L) compared with minimal consumption by MCC trees (55 L). On average, Captain Cook trees used 99% and 72% less water than Moreton Bay ash and black tea trees respectively. The significantly lower water consumption by Captain Cook trees compared with Moreton Bay ash and black tea trees may be offset by high population densities. Results also suggest that knowledge of optimal sap flow timeframes may be advantageous in exploring optimal timing for application of control operations related to management of Captain Cook trees.

Off-Design Flow Measurements in a Centrifugal Compressor Vaneless Diffuser

1995 ◽  
Vol 117 (4) ◽  
pp. 602-608 ◽  
Author(s):  
A. Pinarbasi ◽  
M. W. Johnson
Keyword(s):  
Flow Rate ◽  
Centrifugal Compressor ◽  
Secondary Flows ◽  
Design Flow ◽  
Vaneless Diffuser ◽  
Flow Measurements ◽  
Vaned Diffuser ◽  
Flow Angle ◽  
Flow Rates ◽  
Study Results

Detailed measurements have been taken of the three-dimensional velocity field within the vaneless diffuser of a backswept low speed centrifugal compressor using hot-wire anemometry. A 16 percent below and an 11 percent above design flow rate were used in the present study. Results at both flow rates show how the blade wake mixes out more rapidly than the passage wake. Strong secondary flows inherited from the impeller at the higher flow rate delay the mixing out of the circumferential velocity variations, but at both flow rates these circumferential variations are negligible at the last measurement station. The measured tangential/radial flow angle is used to recommend optimum values for the vaneless space and vane angle for design of a vaned diffuser.

scholarly journals Non-Invasive Estimation of Domestic Hot Water Usage with Temperature and Vibration Sensors

2019 ◽  
Author(s):  
MJ Booysen
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Consumption ◽  
Flow Measurement ◽  
Hot Water ◽  
Water Usage ◽  
Flow Rates ◽  
Domestic Hot Water ◽  
Non Invasive ◽  
Water Heaters

Electric water heaters are responsible for a large portion of electricity consumption and water usage in the domestic sector. Smart water heaters alleviate the strain on the electricity supply grid and reduce water consumption through behavioural change, but the installation of in-line flow meters is inconvenient and expensive. A non-invasive water flow meter is proposed as an alternative. Non-invasive flow measurement is more common for high flow rates in the industrial sector than for domestic applications. Various non-invasive water measurement methods are investigated in the context of domestic hot water, and a combination of thermal- and vibration-sensing is proposed. The proposed solution uses inexpensive, easily installable, non-invasive sensors and a novel algorithm to provide the same flow measurement accuracy as existing in-line meters. The algorithm detects the beginning and end of water consumption events with an accuracy of 95.6%. Quantitative flow rate estimation was possible for flow rates greater than 5 L min⁻¹ with an accuracy of 89%, while volumetric usage estimation had an accuracy of more than 93%. The algorithm limitations were applied to field data, revealing that water consumption could be detected with an error of less than 12% within the limitations of the proposed algorithm. The paper presents a successful proof of concept for a non-invasive alternative to domestic hot water flow rate measurement.

scholarly journals SUPRAOPTIMAL ROOT-ZONE TEMPERATURE EFFECTS ON WATER USE OF THREE CERCIS SPP.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 635c-635
Author(s):  
Beth Jez Lawrence ◽  
Jayne M. Zajicek
Keyword(s):  
Sap Flow ◽  
Root Zone ◽  
Time Intervals ◽  
Flow Measurements ◽  
Root Zone Temperature ◽  
Flow Rates ◽  
Plant Transpiration ◽  
Whole Plant ◽  
Environment Chamber ◽  
Sap Flow Measurements

Sap flow rates of three Cercis spp. exposed to supraoptimal root-zone temperatures were characterized in a controlled environment chamber using a water bath to control temperatures. Flow rates of sap in the xylem were measured every 15 sec. and averaged over 15 min. intervals. Sap flow measurements were correlated to root-zone temperatures recorded during the same time intervals. Whole plant transpiration was measured gravimetrically. Root-zone temperatures were maintained at 22C for three consecutive 24-hr cycles and then increased to 45C for an additional three 24-hr periods. All plants, regardless of species, had reduced sap flow patterns when exposed to high root-zone temperatures. Plants maintained at a constant temperature of 22C showed no extreme fluctuations in sap flow rate. Stomatal conductance rates and leaf water potentials showed similar trends to whole plant transpiration.

scholarly journals Prediction of Grape Sap Flow in a Greenhouse Based on Random Forest and Partial Least Squares Models

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3078
Author(s):  
Xuelian Peng ◽  
Xiaotao Hu ◽  
Dianyu Chen ◽  
Zhenjiang Zhou ◽  
Yinyin Guo ◽  
...  
Keyword(s):  
Random Forest ◽  
Least Squares ◽  
Partial Least Squares ◽  
Flow Rate ◽  
Sap Flow ◽  
Deficit Irrigation ◽  
Coefficient Of Determination ◽  
Growth Stages ◽  
Irrigation Amount ◽  
Flow Rates

Understanding variations in sap flow rates and the environmental factors that influence sap flow is important for exploring grape water consumption patterns and developing reasonable greenhouse irrigation schedules. Three irrigation levels were established in this study: adequate irrigation (W1), moderate deficit irrigation (W2) and deficit irrigation (W3). Grape sap flow estimation models were constructed using partial least squares (PLS) and random forest (RF) algorithms, and the simulation accuracy and stability of these models were evaluated. The results showed that the daily mean sap flow rates in the W2 and W3 treatments were 14.65 and 46.94% lower, respectively, than those in the W1 treatment, indicating that the average daily sap flow rate increased gradually with an increase in the irrigation amount within a certain range. Based on model error and uncertainty analyses, the RF model had better simulation results in the different grape growth stages than the PLS model did. The coefficient of determination and Willmott’s index of agreement for RF model exceeded 0.78 and 0.90, respectively, and this model had smaller root mean square error and d-factor (evaluation index of model uncertainty) values than the PLS model did, indicating that the RF model had higher prediction accuracy and was more stable. The relative importance of the model predictors was determined. Moreover, the RF model more comprehensively reflected the influence of meteorological factors and the moisture content in different soil layers on the sap flow rate than the PLS model did. In summary, the RF model accurately simulated sap flow rates, which is important for greenhouse grape irrigation.

Numerical and Experimental Analysis of the Flow in a Centrifugal Pump at Nominal and Partial Flow Rate

1992 ◽  
Author(s):  
J. F. Combes ◽  
E. Rieutord
Keyword(s):  
Turbulent Flow ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Suction Side ◽  
Design Flow ◽  
Low Flow ◽  
Laser Doppler Velocimeter ◽  
Finite Element Code ◽  
Flow Measurements ◽  
Flow Rates

Detailed flow measurements in the impeller and the diffuser of an industrial centrifugal pump have been performed with a 2-component laser Doppler velocimeter. Measurements were made at 8 radial positions for flow rates ranging from 50% to 100% of design flow. The experimental results were compared to 3D turbulent flow calculations performed with a finite element code. At nominal flow rate, both measurements and calculations show a wake pattern along the suction side at the shroud. The flow is separated in the diffuser on the hub, and on the shroud at low flow rate. The inlet recirculation, occurring at 0.65 Qn is well predicted by the turbulent flow calculation.

Unravelling the relationship between stem temperature and air temperature to correct for errors in sap-flow calculations using stem heat balance sensors

2005 ◽  
Vol 32 (7) ◽  
pp. 599 ◽  
Author(s):  
Kathy Steppe ◽  
Raoul Lemeur ◽  
Diego Dierick
Keyword(s):  
Air Temperature ◽  
Flow Rate ◽  
Heat Balance ◽  
Sap Flow ◽  
Heat Storage ◽  
Flow Rates ◽  
Storage Effects ◽  
Stem Temperature ◽  
Oak Tree ◽  
Set Up

Results from measurement of sap flow by heat balance sensors on the stem of a young oak tree (Quercus robur L.) revealed that thermal disequilibrium (i.e. heat storage) within the heated stem segment can introduce considerable errors in the measured sap-flow rates. The magnitude, sign and significance of these errors depend on the sap-flow rate and on the relationship between stem temperature and air temperature. Sap-flow rates were found to be more prone to errors caused by heat storage effects under low flow conditions than at higher rates of sap flow. Furthermore, daytime fluctuations of air temperature and stem temperature inside the heat balance sensor were either in phase when a low, or in opposite phase when a high sap-flow rate was passing through the stem of the young tree. To investigate this relationship, we developed an experimental set-up with cut stem segments through which tap water could be pressed. This set-up allowed the effects of air temperature and sap-flow rates on stem temperatures within heat balance sensors to be clearly separated. Good mathematical relationships were obtained and were successfully used to assess the relative importance of air temperature and sap-flow rate with respect to the fluctuations in stem temperature of the young oak tree. Based on the established relationships, a novel approach was put forward to correct for errors introduced into sap-flow calculations caused by heat storage effects if no measured data on stem temperature are available.

scholarly journals An experimental analysis on accuracy of customer water meters under various flow rates and water pressures

2019 ◽  
Vol 69 (1) ◽  
pp. 18-27 ◽  
Author(s):  
I. Ethem Karadirek
Keyword(s):  
Flow Rate ◽  
Water Consumption ◽  
End Users ◽  
Consumption Patterns ◽  
Water Supply Systems ◽  
Domestic Water ◽  
Flow Rates ◽  
Starting Flow ◽  
Water Meters ◽  
Water Meter

Abstract Apparent losses are mainly due to metering errors in well-managed water supply systems. There are many types of water meters based on mechanisms to measure flow passing through. Therefore, selection of water meter type is important as meter type effects measurement accuracy. In this study, a total of 50 domestic water meters were tested under varying flow rates and different water pressures. Water consumptions of end-users show temporal changes depending on the life style of consumers. Flow rates passing through the water meter and water consumption profiles affect water meter accuracy. Water consumption of a couple of end-users was monitored and consumption patterns were extracted and obtained water consumption patterns were used to determine water meter errors. The collection method was applied for determination of water meter errors. Starting flow rates, error curves and weighted error of water meters were measured in a laboratory setup. Tested volumetric-type water meters have the lowest starting flow rate and the highest accuracy whereas single-jet water meters have the lowest accuracy and the highest starting flow rate. This study aimed to provide insights on the accuracy of water meters under varying flow rates and water pressures, and advantageous information for water meter-type selection.

scholarly journals Water yield and consumption of cauliflower plants grown in a hydroponic system using brackish waters and different flow rates

2021 ◽  
Vol 25 (6) ◽  
pp. 422-428
Author(s):  
Ruana I. F. Cruz ◽  
Gerônimo F. da Silva ◽  
Ênio F. de F. e Silva ◽  
Hammady R. e Soares ◽  
José A. Santos Júnior ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Nutrient Solution ◽  
Flow Rate ◽  
Water Consumption ◽  
Brackish Water ◽  
Water Yield ◽  
Flow Rates ◽  
Hydroponic System ◽  
Brackish Waters ◽  
Electrical Conductivities

HIGHLIGHTS Raising the flow rate of the nutrient solution with brackish water results in less water consumption in cauliflower. The water yield in cultivation of cauliflower depends on the chemical composition of the water used in the nutrient solution. The cauliflower production is viable in hydroponics using waters with electrical conductivities of up to 5.88 dS m-1.

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