scholarly journals Design and implementation of a low-cost device for measuring sap flow in woody species

DYNA ◽  
2019 ◽  
Vol 86 (208) ◽  
pp. 214-220
Author(s):  
María Fernanda Cárdenas ◽  
Cristina López Ramírez ◽  
Juan Diego Mejía ◽  
Jhon Fredy Escobar

Transpiration is a key variable in water balance. Sap flow measurement methods allow to estimate transpiration at plant level, but scalable at the stand, river basin or ecosystem level. This requires recording data continuously, for which there are commercial devices, but they are specialized and expensive. This document shows that it is possible to integrate a data capture, management and storage system, as a counterpart to a commercial system such as Campbell's CR-100, for measuring and recording environmental variables, with a notable reduction in costs. The methodology used to develop a device for the estimation of sap flow using the heat ratio method, the design of the Arduino-based  electronic circuit and the software, with register 13-64-171 of the Dirección Nacional de Derechos de Autor, is presented.

2004 ◽  
Vol 31 (6) ◽  
pp. 645 ◽  
Author(s):  
Timothy M. Bleby ◽  
Stephen S. O. Burgess ◽  
Mark A. Adams

We validated and compared two heat-pulse methods for measuring sap flow in potted Eucalyptus marginata Donn ex. Smith (jarrah) saplings. During daylight hours and under well-watered conditions, rates of sap flow (0.1–0.5 kg h–1) measured by the established compensation heat-pulse method (CHPM) and the newly developed heat-ratio method (HRM) were similar to rates measured with a weighing lysimeter, and most of the time there was no significant difference (P<0.001) between methods. The HRM accurately described sap flow at night when rates of flow were low (< 0.1 kg h–1) or near zero, but the CHPM was unable to measure low rates of sap flow due to its inability to distinguish heat-pulse velocities below a threshold velocity of 0.1 kg h–1 (3–4 cm h–1). The greatest potential for error in the calculation of daily sap flow was associated with the misalignment of temperature sensors, the estimation of sapwood area and the method used to acquire total sap flow from point measurements of sap velocity. A direct comparison of the two heat-pulse methods (applied synchronously) revealed that the HRM had a more convincing mechanism for correcting spacing errors and was more resistant to random fluctuation in measurements than the CHPM. While we view the HRM more favourably than the CHPM in some key areas, both methods are valid and useful, within their constraints, for measuring transpiration in jarrah and other woody species.


2011 ◽  
Vol 32 (4) ◽  
pp. 976-983 ◽  
Author(s):  
Eduardo Augusto Girardi ◽  
Francisco de Assis Alves Mourão Filho ◽  
Juan Sinforiano Delgado-Rojas ◽  
João Paulo de Campos Araújo

Sap flow could be used as physiological parameter to assist irrigation of screen house citrus nursery trees by continuous water consumption estimation. Herein we report a first set of results indicating the potential use of the heat dissipation method for sap flow measurement in containerized citrus nursery trees. 'Valencia' sweet orange [Citrus sinensis (L.) Osbeck] budded on 'Rangpur' lime (Citrus limonia Osbeck) was evaluated for 30 days during summer. Heat dissipation probes and thermocouple sensors were constructed with low-cost and easily available materials in order to improve accessibility of the method. Sap flow showed high correlation to air temperature inside the screen house. However, errors due to natural thermal gradient and plant tissue injuries affected measurement precision. Transpiration estimated by sap flow measurement was four times higher than gravimetric measurement. Improved micro-probes, adequate method calibration, and non-toxic insulating materials should be further investigated.


2021 ◽  
Author(s):  
Anan Zhou ◽  
Benshun Yi ◽  
Mian Xiang ◽  
Laigan Luo

Abstract Distributed storage system (DSS) is an emerging paradigm which provides reliable storage services for various source data. As the fault-tolerance scheme for DSS, erasure codes are required to provide redundancy service with high fault-tolerance and low cost. However, the existing coding scheme cannot provide these requirements well. Thus, it becomes an important yet challenging issue to find a code for storing various source data with high fault-tolerance and low cost. In this paper, a novel construction of repairable fountain codes with unequal locality is proposed by combining with partial duplication tech- nique, namely the PD-ULRFC scheme. We construct a multi-tier heterogeneous storage network, where data core, processing units and storage nodes collaboratively store and transmit data. Moreover, the proposed PD-ULRFC scheme can reduce the repair and download cost by sacrificing a little extra storage occupation. Furthermore, the expressions of the repair cost and download cost are derived to analyze the performance of PD-ULRFC scheme. The simulation results demonstrate that the PD-ULRFC scheme significantly outperforms other redundant schemes in communication cost saving.


2020 ◽  
pp. 102-109
Author(s):  
D.KH. DOMULLODZHANOV ◽  
◽  
R. RAHMATILLOEV

The article presents the results of the field studies and observations that carried out on the territory of the hilly, low-mountain and foothill agro landscapes of the Kyzylsu-yuzhnaya (Kyzylsu-Southern) River Basin of Tajikistan. Taking into account the high-altitude location of households and the amount of precipitation in the river basin, the annual volumes of water accumulated with the use of low-cost systems of collection and storage of precipitation have been clarified. The amount of water accumulated in the precipitation collection and storage systems has been established, the volume of water used for communal and domestic needs,the watering of livestock and the amount of water that can be used to irrigate crops in the have been determined. Possible areas of irrigation of household plots depending on the different availability of precipitation have been determined. It has been established that in wet years (with precipitation of about 10%) the amount of water collected using drip irrigation will be sufficient for irrigation of 0.13 hectares, and in dry years (with 90% of precipitation) it will be possible to irrigate only 0.03 ha of the household plot. On the basis of the basin, the total area of irrigation in wet years can be 4497 ha, and in dry years only 1087 ha. Taking into account the forecasts of population growth by 2030 and an increase in the number of households, the total area of irrigation of farmlands in wet years may reach 5703 hectares,and in dry years – 1379 hectares. Growing crops on household plots under irrigation contributes to a significant increase in land productivity and increases the efficiency of water use of the Kyzylsu-yuzhnaya basin.


2003 ◽  
Vol 3 (4) ◽  
pp. 169-175 ◽  
Author(s):  
S. Barbagallo ◽  
F. Brissaud ◽  
G.L. Cirelli ◽  
S. Consoli ◽  
P. Xu

In arid and semiarid regions the reclamation and reuse of municipal wastewater can play a strategic role in alleviating water resources shortages. Public awareness is growing about the need to recycle and reuse water for increasing supply availability. Many wastewater reuse projects have been put in operation in European and Mediterranean countries adopting extensive treatment systems such as aquifer recharge, lagooning, constructed wetlands, and storage reservoirs, mainly for landscape and agricultural irrigation. In agricultural reuse systems, there is an increasing interest in extensive technologies because of their high reliability, and easy and low cost operation and maintenance. Wastewater storage reservoirs have become the option selected in many countries because of the advantages they present in comparison with other treatment alternatives, namely the coupling of two purposes, stabilization and seasonal regulation. This paper describes an example of a wastewater storage system, built in Caltagirone (Sicily, Italy). The storage results in a tertiary treatment of a continuous inlet flow of activated sludge effluents. The prediction of the microbiological water quality has been evaluated by means of a non-steady-state first-order kinetic model. Single and multiple regressions were applied to determine the main variables that most significantly affected die-off coefficients. The proposed model has been calibrated using the results of a field monitoring carried out during a period from March to October 2000.


Author(s):  
Fabian Burmann ◽  
Jerome Noir ◽  
Stefan Beetschen ◽  
Andrew Jackson

AbstractMany common techniques for flow measurement, such as Particle Image Velocimetry (PIV) or Ultrasonic Doppler Velocimetry (UDV), rely on the presence of reflectors in the fluid. These methods fail to operate when e.g centrifugal or gravitational acceleration leads to a rarefaction of scatterers in the fluid, as for instance in rapidly rotating experiments. In this article we present two low-cost implementations for flow measurement based on the transit time (or Time of Flight) of acoustic waves, that do not require the presence of scatterers in the fluid. We compare our two implementations against UDV in a well controlled experiment with a simple oscillating flow and show we can achieve measurements in the sub-centimeter per second velocity range with an accuracy of $\sim 5-10\%$ ∼ 5 − 10 % . We also perform measurements in a rotating experiment with a complex flow structure from which we extract the mean zonal flow, which is in good agreement with theoretical predictions.


Author(s):  
Murat Fidan ◽  
Alper Bayrak ◽  
Umid Karli

In this study, a low-cost and adaptable isometric strength measurement and exercise development system are described. The implemented system consists of mechanical structure, force measurement sensor, electronic circuit, and computer software. Isometric-isotonic (via spring resistance) strength analysis and various exercise programs can be applied with the system. The developed system has a lower cost compared to its counterparts in the literature and has a structure that can be adapted to different machines and measuring methods. The operability and reliability of the isometric strength measurement and exercise development system have been proven by calibration tests.


Sign in / Sign up

Export Citation Format

Share Document