Two light fixture designs and corresponding circuitry are presented. Results: In this technical report we describe the practical construction of tunable red-green-blue LED arrays to support research in plant growth and development.
Raymond m. wheeler nasa kennedy space center series#
However, there is a need for a versatile and inexpensive LED array platform where individual wavebands can be specifically tuned to produce a series of light combinations consisting of various quantities and qualities of individual wavelengths. These factors render LED-based light strategies particularly appropriate for space-biology as well as terrestrial applications. LEDs are particularly well suited for plant growth chambers, as they have an extraordinary life (about 100,000 hours), require little maintenance, and use negligible energy. Light emitting diodes (LEDs) has been used for decades to test plant responses to narrow-bandwidth light. Many studies over the last several decades, primarily in Arabidopsis thaliana, have clearly shown that variation in light quantity, quality and photoperiod can be manipulated to affect growth and control developmental transitions. Plant growth chambers are typically outfitted with fluorescent and/or incandescent fixtures that provide a general spectrum that is accommodating to the human eye and not necessarily supportive to plant development. Abstract: Background: Although specific light attributes, such as color and fluence rate, influence plant growth and development, researchers generally cannot control the fine spectral conditions of artificial plant-growth environments.To reflect viable cells found in the samples, RNA was also detectable using a modified, single-step reverse transcription reaction. Total heterotrophic counts could also be detected using a 16S gene marker that can identify up to 98% of all bacteria. Escherichia coli, Salmonella enterica Typhimurium, and Pseudomonas aeruginosa were detected at low levels using real-time DNA amplification. The RAZOR EX, a ruggedized, commercial off the shelf, real-time PCR field instrument was tested for its ability to detect microorganisms at low concentrations within one hour. Therefore, a more expedient, low-cost, in-flight method of microbial detection, identification, and enumeration is warranted. To identify and enumerate ISS microbes requires that samples be returned to Earth for complete analysis. The culture based method detects approximately 1-10% of the total organisms present and provides no identification. This increases the microbial load while detecting only a limited number of the total microorganisms. Current microbial characterization methods require enrichment of microorganisms and at least a 48-hour incubation time. ECLSS, environmental control and life support systems). Microorganisms introduced to the ISS are readily transferred between crew and subsystems (i.e. The likelihood of introducing new microorganisms occurs with every exchange of crew or addition of equipment or supplies. Previous research has shown that potentially destructive microorganisms and human pathogens have been detected on the International Space Station (ISS). The 45th International Conference on Environmental Systems was held in Bellevue, Washington, USA on 12 July 2015 through 16 July 2015. Hummerick, Vencore, Inc., Kennedy Space Center, USAĭavid J. Birmele, Sierra Lobo, Inc, Kennedy Space Center, USA
Khodadad, Sierra Lobo, Inc, Kennedy Space Center, USA
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