scholarly journals Continuous Measurement of Greenhouse Ventilation Rate in Summer and Autumn via Heat and Water Vapor Balance Methods

2021 ◽  
Vol 59 (2) ◽  
pp. 41-48
Author(s):  
Ahmad TUSI ◽  
Teruaki SHIMAZU ◽  
Masaki OCHIAI ◽  
Katsumi SUZUKI
Keyword(s):  
Water Vapor ◽  
Continuous Measurement ◽  
Ventilation Rate ◽  
Greenhouse Ventilation

scholarly journals REAL-TIME COMPARISON OF SEVERAL TRANSPIRATION METHODS FOR ESTIMATING GREENHOUSE VENTILATION RATE VIA WATER VAPOUR BALANCE METHOD

2021 ◽  
pp. 91-98
Author(s):  
Ahmad Tusi ◽  
Teruaki Shimazu
Keyword(s):  
Water Vapor ◽  
Transpiration Rate ◽  
Water Flow Rate ◽  
High Sensitivity ◽  
Ventilation Rate ◽  
Balance Method ◽  
Scattering Data ◽  
Time Interval ◽  
Short Time Interval ◽  
Level Measurement

Transpiration rate is an essential factor in the water vapor balance method for estimating the ventilation rate in a greenhouse continuously. Several methods of transpiration measurement, i.e., electronic weighing device (Control), the sap flow measurement (SF), water level measurement (WL), and water flow rate measurement (WF) tested and evaluated on tomato crops in a naturally ventilated greenhouse. The objective was to compare these methods and establish the most affordable one to be used in a greenhouse condition to determine the ventilation rate using the water vapor balance approach. Results obtained with the SF particularly have a strong correlation and are not statistically different from the Control (r=0.89). The WF method gave good results and reliable for predicting the total of transpiration in the greenhouse. However, in our conditions, this method generally had a lag time of the transpiration rate in a short time interval basis (minute and hourly). But it had an excellent predicted transpiration rate in daily evapotranspiration. The WL suffered weak agreement to the Control due to the scattering data. It was affected by the very high sensitivity of the device, and it is not recommended to use on the farm level, like in a greenhouse. It appears that measurements with the control and the SF could be considered for monitoring the ventilation rate in the greenhouse using a water vapor balance technique.

Sensor for Continuous Measurement of the Ventilation Rate in Livestock Buildings

Indoor Air ◽  
1991 ◽  
Vol 1 (3) ◽  
pp. 323-336 ◽  
Author(s):  
D. Berckmans ◽  
Ph. Vandenbroeck ◽  
V. Goedseels
Keyword(s):  
Continuous Measurement ◽  
Ventilation Rate ◽  
Livestock Buildings

Effect of wind direction on greenhouse ventilation rate, airflow patterns and temperature distributions

2008 ◽  
Vol 101 (3) ◽  
pp. 351-369 ◽  
Author(s):  
M. Teitel ◽  
G. Ziskind ◽  
O. Liran ◽  
V. Dubovsky ◽  
R. Letan
Keyword(s):  
Wind Direction ◽  
Ventilation Rate ◽  
Temperature Distributions ◽  
Greenhouse Ventilation

Continuous measurement of water vapor D/H and 18O/16O isotope ratios in the atmosphere

2008 ◽  
Vol 349 (3-4) ◽  
pp. 489-500 ◽  
Author(s):  
Xue-Fa Wen ◽  
Xiao-Min Sun ◽  
Shi-Chun Zhang ◽  
Gui-Rui Yu ◽  
Steve D. Sargent ◽  
...  
Keyword(s):  
Water Vapor ◽  
Continuous Measurement ◽  
Isotope Ratios

scholarly journals Greenhouse Ventilation Rate: Theory and Measurement with Tracer Gas Techniques

1999 ◽  
Vol 72 (4) ◽  
pp. 363-374 ◽  
Author(s):  
F.J. Baptista ◽  
B.J. Bailey ◽  
J.M. Randall ◽  
J.F. Meneses
Keyword(s):  
Ventilation Rate ◽  
Rate Theory ◽  
Tracer Gas ◽  
Greenhouse Ventilation

New Design for a Differentially Pumped Hydration Chamber for a Siemens IA

1971 ◽  
Vol 29 ◽  
pp. 44-45
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Electron Diffraction ◽  
Water Vapor Pressure ◽  
Biological Materials ◽  
Thin Membrane ◽  
Reliable System ◽  
System A ◽  
Water Films ◽  
Aperture Opening

Electron microscopy and diffraction of biological materials in the hydrated state requires the construction of a chamber in which the water vapor pressure can be maintained at saturation for a given specimen temperature, while minimally affecting the normal vacuum of the remainder of the microscope column. Initial studies with chambers closed by thin membrane windows showed that at the film thicknesses required for electron diffraction at 100 KV the window failure rate was too high to give a reliable system. A single stage, differentially pumped specimen hydration chamber was constructed, consisting of two apertures (70-100μ), which eliminated the necessity of thin membrane windows. This system was used to obtain electron diffraction and electron microscopy of water droplets and thin water films. However, a period of dehydration occurred during initial pumping of the microscope column. Although rehydration occurred within five minutes, biological materials were irreversibly damaged. Another limitation of this system was that the specimen grid was clamped between the apertures, thus limiting the yield of view to the aperture opening.

Hydration Chamber for Jeolco 200 Kv Microscope

1970 ◽  
Vol 28 ◽  
pp. 542-543
Author(s):  
V. R. Matricardi ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Electron Microscope ◽  
Water Vapor ◽  
Vapor Pressure ◽  
Pressure Gradient ◽  
Room Temperature ◽  
List Type ◽  
Type Number ◽  
Equilibrium Vapor Pressure

In order to observe room temperature hydrated specimens in an electron microscope, the following conditions should be satisfied: The specimen should be surrounded by water vapor as close as possible to the equilibrium vapor pressure corresponding to the temperature of the specimen.The specimen grid should be inserted, focused and photo graphed in the shortest possible time in order to minimize dehydration.The full area of the specimen grid should be visible in order to minimize the number of changes of specimen required.There should be no pressure gradient across the grid so that specimens can be straddled across holes.Leakage of water vapor to the column should be minimized.

Warm and freeze-fracture of cotton seed radicles

1987 ◽  
Vol 45 ◽  
pp. 984-985
Author(s):  
E. L. Vigil ◽  
E. F. Erbe
Keyword(s):  
Thin Film ◽  
Water Vapor ◽  
Fracture Surface ◽  
Membrane Structure ◽  
Room Temperature ◽  
Freeze Fracture ◽  
Longitudinal Axis ◽  
Fracture Plane ◽  
Cotton Seeds ◽  
Condensed Water

In cotton seeds the radicle has 12% moisture content which makes it possible to prepare freeze-fracture replicas without fixation or cryoprotection. For this study we have examined replicas of unfixed radicle tissue fractured at room temperature to obtain data on organelle and membrane structure.Excised radicles from seeds of cotton (Gossyplum hirsutum L. M-8) were fractured at room temperature along the longitudinal axis. The fracture was initiated by spliting the basal end of the excised radicle with a razor. This procedure produced a fracture through the tissue along an unknown fracture plane. The warm fractured radicle halves were placed on a thin film of 100% glycerol on a flat brass cap with fracture surface up. The cap was rapidly plunged into liquid nitrogen and transferred to a freeze- etch unit. The sample was etched for 3 min at -95°C to remove any condensed water vapor and then cooled to -150°C for platinum/carbon evaporation.

Direct Measurement of the Listening of Hearing-Impaired Children

1970 ◽  
Vol 13 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Mary Mira
Keyword(s):  
Direct Measurement ◽  
Continuous Measurement ◽  
Hearing Impaired ◽  
Reinforcement System ◽  
School Aged Children ◽  
Conjugate Reinforcement ◽  
Impaired Children ◽  
Hearing Impaired Children

Listening, a significant dimension of the behavior of hearing-impaired children, may be measured directly by recording childrens' responses to obtain audio narrations programmed via a conjugate reinforcement system. Twelve hearing-impaired, school-aged children responded in varying ways to the opportunity to listen. Direct and continuous measurement of listening has relevance for evaluation of remediation methods and for discovery of variables potentially related to listening.

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