Fixed Competitive Price TU-1H02 thermal wax actuator for thermostatic radiator valve for New Delhi Importers

Gardening in the modern age means making things more complicated and arduous, with electrons, bits, and bytes. Behold: the garduino. My brother got me an arduino microcontroller board for Christmas, which to me was a solution looking for a problem. I finally found the problem: fresh herbs are expensive at the grocery store. But apparently not as expensive as adding a bunch of sensors and electronics to your garden.

Build one yourself or just poke around in the code: https://github.com/gradyh/GradyHillhouseGarduino.git

Thanks to my brother, Graham, for the Arduino board and editing the narration. Thanks to Chris from YouTube channel AvE (https://www.youtube.com/user/arduinoversusevil) for the tips on soil moisture sensors and water hammer. Most of the parts in this build came from https://www.adafruit.com.

Combining microcontrollers and gardening is a really popular idea. I think that’s because gardens have very simple inputs and outputs that are easy to wrap your head around. I guess people (myself included) see a notoriously simple and relaxed hobby and can’t help but feel compelled to overcomplicate it. But just about anyone can connect the dots between “Garden needs water” and “I am not a responsible human being who is capable of remembering to water a garden every day” and realize, “Hey, I can use technology to overcome my personal shortcomings,” and more than that, “I can bend technology to my will and that will feel good to my ego and my sense of self-worth.” After all, no one’s hobby is to buy an irrigation controller off the shelf of a hardware store. Thanks for watching, and let me know what you think.

A few technical details below… If there’s anything I didn’t address, feel free to shoot me a question in the comments.

Moisture sensors that measure the resistance or conductivity across the soil matrix between two contacts are essentially junk. First of all, resistance is not a very good indicator of moisture content, because it is highly dependent on a number of factors which might vary from garden to garden including soil ph, dissolved solids in the water, and temperature. Second, most of them are of poor quality with contacts that easily corrode. For the most part you’d be lucky to get one to last through an entire season. Capacitive sensors are generally more accurate because they are just measuring the change in dialetric properties of the soil which is less sensitive to other environmental factors. They also don’t require any exposed conductive surfaces which means they can last a bit longer in the harsh environment of your backyard. My soil moisture sensor (and soil temperature sensor) came from https://www.vegetronix.com.

The arudino’s analog inputs read voltage, so to use a resistive sensor (like the photoresistor I used to measure sunlight), you have to set up a voltage divider. This is just a really simple circuit which divides the voltage drop between your sensor and a known resistor. You know the current is the same for both, so you can calculate the resistance of your sensor using ohm’s law. The only problem here is that a photoresistor’s relationship to illuminance is log-log, that is to say it spans several orders of magnitude. So if you use a big resistor (5k – 10k ohm) in your voltage divider, your sensor will be sensitive to low light levels, but you won’t be able to tell the difference between a sunny day and an overcast one. Since this thing’s going outside, I used a 100 ohm resistor, which should hopefully give me good differentiation between levels of brightness in the daylight.

Music from incompotech.com

Vidéo 1/4 sur la simulation numérique d’un écoulement électroosmotique en milieu poreux.

J’espère que ça vous aidera, et désolé pour la qualité de la vidéo et des explications, j’ai dû faire vite. Bon visionnage et bon courage pour votre travail !

Liens des tutoriaux pour Blender:

Code pour l’UDF dans Fluent:

#include “udf.h”
#include “models.h”

enum

PSI
;

real z = 1;
real F = 96485.33289; /*(C/mol) */
real R = 8.3144621 ; /* (J/mol*K) */
real T = 305; /* (K) */
real epsilon = 6.9*0.0000000001; /* (C/V*m) */
real Ex = 40000; /* (V/m) */
real c_0 = 7.5*0.001; /* (mol/m3) loin du mur */

real x[ND_ND];
real y;

Thread *t;

cell_t c;
face_t f;

DEFINE_SOURCE(axial_mom_source, c, t, dS, eqn)

float S_x;
dS[eqn] = 0;
S_x = -2*z*F*c_0*sinh(z*F*C_UDSI(c, t, 0)/(R*T))*Ex;
return S_x;

DEFINE_SOURCE(psi_source, c, t, dS, eqn)

float S_psi;
dS[eqn] = -2*pow(z,2)*pow(F,2)*c_0*cosh(z*F*C_UDSI(c,t,0)/(R*T))/(epsilon*R*T);
S_psi = -2*z*F*c_0*sinh(z*F*C_UDSI(c, t, 0)/(R*T))/epsilon;
return S_psi;

Sources:

Chen, C. H., & Santiago, J. G. (2002). A planar electroosmotic micropump. Microelectromechanical Systems, Journal of microelectromechanical systems.

Ren, Y., & Stein, D. (2008). Slip-enhanced electrokinetic energy conversion in nanofluidic channels. Nanotechnology.

Berrouche, Y. (2008). Etude théorique et expérimentale de pompes électro-osmotiques et de leur utilisation dans une boucle de refroidissement de l’électronique de puissance (Doctoral dissertation, Institut National Polytechnique de Grenoble-INPG).

Shamloo, A., Merdasi, A., & Vatankhah, P. (2016). Numerical Simulation of Heat Transfer in Mixed Electroosmotic Pressure-Driven Flow in Straight Microchannels. Journal of Thermal Science and Engineering Applications.

Kim, M. M. (2006). Computational Studies of Protein and Particle Transport in Membrane System (Doctoral dissertation, The Pennsylvania State University).

Young, J. M. (2005). Microparticle Influenced Electroosmotic Flow.

Xu, Z., Miao, J., Wang, N., Wen, W., & Sheng, P. (2011). Maximum efficiency of the electro-osmotic pump. Physical Review.

Devasenathipathy, S., & Santiago, J. G. (2005). Electrokinetic flow diagnostics. In Microscale Diagnostic Techniques (pp. 113-154). Springer Berlin Heidelberg.

Tenny, J. S. (2004). Numerical Simulations in Electro-osmotic Flow.

Wang, X., Cheng, C., Wang, S., & Liu, S. (2009). Electroosmotic pumps and their applications in microfluidic systems. Microfluidics and Nanofluidics.

Joseph, P. (2005). Etude expérimentale du glissement liquide-solide sur surfaces lisses et texturées (Doctoral dissertation, Université Pierre et Marie Curie-Paris VI).

Brask, A. (2005). Electroosmotic micropumps. PhD ThesisTechnical University of Denmark, Denmark.

Yao, S., & Santiago, J. G. (2003). Porous glass electroosmotic pumps: theory. Journal of Colloid and Interface Science, 268(1), 133-142.

Patel, V., & Kassegne, S. K. (2007). Electroosmosis and thermal effects in magnetohydrodynamic (MHD) micropumps using 3D MHD equations. Sensors and Actuators B: Chemical, 122(1), 42-52.

Pieritz, R. A. (1998). Modélisation et simulation de milieux poreux par réseaux topologiques (Doctoral dissertation, Université Joseph Fourier–Grenoble).

Kang, Y., Yang, C., & Huang, X. (2002). Dynamic aspects of electroosmotic flow in a cylindrical microcapillary. International Journal of Engineering Science, 40(20), 2203-2221.

Balli, M., Mahmed, C., Duc, D., Nikkola, P., Sari, O., Hadorn, J. C., & Rahali, F. (2012). Le renouveau de la réfrigération magnétique. Revue Générale du Froid, 102(1121), 45-54

Drake, D. G., & Abu-Sitta, A. M. (1966). Magnetohydrodynamic flow in a rectangular channel at high Hartmann number. Zeitschrift für angewandte Mathematik und Physik ZAMP, 17(4), 519-528.

Müller, U., & Bühler, L. (2002). Liquid Metal Magneto-Hydraulics Flows in Ducts and Cavities. In Magnetohydrodynamics (pp. 1-67). Springer Vienna.