WYOMING-EASTERN COLORADO Silicic Acid Affects Growth, Productivity, and Quality of Alfalfa: Greenhouse and Field Study

Overview

Alfalfa is the most important perennial forage crop. Application of silicic acid can impact growth, yield, and quality of alfalfa. The experiment was conducted at greenhouse and field environments. There were five treatments: 0, 1, 2, 3, and 4 ml silicic acid L-1. Treatments were foliar sprayed biweekly. Growth data was measured monthly before harvest (four harvests). Results showed that silicic acid had significant effect on plant growth and dry matter (DM) yield of alfalfa. In greenhouse, control treatment produced lowest plant height, leaf length, leaf color, and DM. Leaf color increased with increasing silicic acid application with darkest green color at 4 ml silicic acid L-1 treatment. The 3 ml silicic acid L-1 treatment produced highest plant height, leaf length, and DM. Similar results were also observed in field study except for plant height and plant count in which there were no differences among treatments. In greenhouse, silicic acid application affected forage quality parameters of neutral detergent fiber, in vitro dry matter digestibility, and relative feed value. Silicic acid application had no effect on forage quality in field study. Overall, the results clearly indicate that foliar application of silicic acid can improve growth, yield, and quality of alfalfa. The Development of an Electrothermal Ion Thruster Matthew Murphy SkyView Academy, Highlands Ranch, CO This year we have endeavored to modify the traditional system of an ion thruster and determine the effectiveness of this modification. In short, we have experimented with a new way of generating plasma and have significantly reduced the size of a typical thruster. Specifically, we have decided to replace the discharge cathodes found in most ion thrusters with an electrothermal accelerator as a new method of supplying the plasma. This allowed us to reduce the size of the thruster which is an important result to note since cargo space is a salient concern in designing rockets. Because we were able to construct a compact and functional ion thruster, it shows the potential to continue reducing the size of these key mechanical components of spacecraft allowing for the possibility of reducing rocket size for bigger craft. Another reason for using ion thrusters is that they are better for the mobility of spacecraft. They have a lower thrust, but a high specific impulse, ideal for mobility in space. When comparing the fuel efficiencies between chemical and ion propulsion, ion thrusters display efficiencies up to 90% while chemical thrusters only reach efficiencies of 35%. Ion thrusters also allow for spacecraft to travel at higher speeds, capable of accelerating them up to 90,000 m/s allowing journeys throughout space to be significantly less time-consuming. Ion Thrusters typically utilize the process of electron bombardment where a neutral gas is injected into the ionization chamber and bombarded with electrons generated by a discharge cathode. The free electrons in the propellant are knocked loose resulting in a plasma. These electrons are then pulled away by magnets creating a cation which is accelerated out the thruster via the electrostatic force generated by the electrodes. We took inspiration in our final ion thruster from a prototype that runs on a similar voltage input, but ionizes the oxygen gas in the air to produce thrust, rather than the plasma from the electrothermal accelerator. Our thruster incorporates the copper couplings as the electrodes similar to what their function was in the prototype. Our model takes the plasma supplied by the electrothermal accelerator and uses neodymium magnets to remove the free electrons creating cations which are accelerated by the electrostatic force coming from the electrodes out the thruster. We found that the Electrothermal Ion Thruster was able to fit in a cubic foot area and could be condensed to 3 key mechanical components: the electrodes, electrothermal accelerator, and the neodymium magnets. This thruster still proved to be effective as it showed capability to displace an object with a mass of 2.3 grams about 7.3 cm.

Competition history

• JSHS 2022 Category not listed

Resources

• National JSHS abstract book ↗

Related projects

Closest projects by meaning, across every fair and year in the corpus.