Gene A Giacomelli

Abstract:

NASA scientists have previously researched biomass production units for the purpose of bioregenerative life support systems (BLSS). The University of Arizona, Controlled Environment Agriculture Center (UA-CEAC) in cooperation with Sadler Machine Company (SMC) designed, constructed and assisted real-time operations of the South Pole Food Growth Chamber (SPFGC). The SPFGC is a semi-automated, hydroponic, multiple salad crop production chamber located within the U.S. National Science Foundation New Amundsen-Scott South Pole Station. Fresh vegetables are grown for the Station crew during the annual eight-month period of isolation in one of the most extreme and remote environments on Earth. An empirical mathematical model was developed from data monitored onsite and remotely by Internet and telecommunications during the winter of 2006. The SPFGC model was based on a mass balance, whereby all carbon dioxide and water were monitored within the system and biomass generated by the crops was recorded. Edible production yields within the 21.90 m² SPFGC Plant Production Room averaged 2.8 kg day^-1 (± 1.0 kg day^-1) with 12 kW of installed high intensity discharge lighting and a 17-hour photoperiod. Other operational resources were monitored including labor, energy, and plant nutrients. The data generated from the remote and isolated location of the SPFGC includes information for future BLSS applications. Copyright © 2008 SAE International.

Abstract:

An 11 by 15 meter free span, gutter connected, double polyethylene clad greenhouse was equipped with a porous concrete warm floor heating system. The warm floor heating system consisted of a 30 cm deep, vinyl swimming pool liner, filled with 20 cm of bluestone and capped with a 10 cm layer of porous concrete. It was filled with water to a depth of 20 cm and heated by a hot water boiler through a network of 1. 3 cm diameter pipes embedded within the bluestone. Supplemental heating was supplied by a water to air heat exchanger connected to the boiler. Cooling was achieved by forced air ventilation. There were three stages of ventilation with a maximum capacity of one air change per minute. This paper discusses tests conducted in the greenhouse, along with instrumentation hardware, the software program, and system operation.

Abstract:

An animated computer model has been developed using a simulation language SIMAN/CINEMA to simulate greenhouse internal transport systems. The model can be used as a tool to study the performance of materials handling operations within a greenhouse. The potential bottleneck of a transport system can be visually detected on the computer monitor. Statistical analyses on the system parameters, such as the status and utilization of machines, workers and waiting lines, and throughput time of an operation, are performed during the simulation. From these data, the interaction between machines and workers within a greenhouse system can be studied.

Abstract:

Cooling must be supplied for greenhouses located in semiarid climates most of the year to provide desired climate conditions for year-round crop production. High-pressure fogging systems have shown promising results for cooling, however the lack of effective control strategies, especially under passive ventilation, have limited their use. In this study, a new proposed climate control strategy, which considers the contribution on cooling and humidification from plants, is tested through simulation. The developed strategy using variable pressure fogging (VPF) and variable vent configurations was compared to a constant pressure fogging (CPF), fixed vents cooling strategy. In both cases, the control of fog was based on vapor pressure deficit (VPD) set points. Results showed that on average, VPF based system was able to save 15.2% of water and consumed 10.1% less energy. Pump cycling was reduced by 78.5% and lower temperature and relative humidity fluctuations were achieved by adjusting fog rates through manipulating the system working pressure. Finally, simulations also showed that by reducing the number of nozzles, a smaller fogging rate was achieved and the system performance and savings on water and energy were enhanced during morning hours of operation.

Abstract:

Water availability is a common concern in semi-arid regions, such as Southern Arizona, USA, where greenhouse crop production is popular due to high solar radiation. Hydroponic greenhouse crop production greatly reduces irrigation water use; however, water use by evaporative cooling systems has never been quantified. This project investigated water use by two evaporative cooling systems: pad-and-fan (P&F) and high-pressure-fog (HPF) with fan ventilation and a central overhead line. Water use data were collected from a double-layer polyethylene film-covered greenhouse (28 × 9.8 × 6.3 m) with mature tomato plants (1.7 plants m ^-2) from 08:00-17:00 for each ventilation rate tested under semi-arid climate conditions (T Out,Avg=35°C, RH Out,Avg=10%, Solar Avg=900 W m ^-2). Total daily water use by P&F was 3.2, 6.4, 8.5, and 10.3 L m ^-2 for ventilation rates of 0.016, 0.034, 0.047, 0.061 m ³ m ^-2 s ^-1 respectively. Total daily water use by the HPF system was 7.9, 7.4, and 9.3 L m ^-2 for fan ventilation rates of 0.01, 0.016, 0.034 m ³ m ^-2 s ^-1, respectively. Total greenhouse WUE (water use efficiency) was calculated using hydroponie irrigation (4.5 L m ^-2) and evaporative cooling water use. Total WUE values were comparable to sprinkler-irrigated WUE (15-19 L m ^-2) and flood-irrigated WUE (12L m ^-2). Using a "closed" hydroponic irrigation system would increase the WUE greatly and should be implemented to conserve water. Furthermore, HPF water use should decrease under natural ventilation.