Sample records for recirculating hydroponic system
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A recirculating hydroponic system for studying peanut (Arachis hypogaea L.)
Mackowiak, C. L.; Wheeler, R. M.; Stutte, G. W.; Yorio, N. C.; Ruffe, L. M.; Sager, J. C. (Principal Investigator)
1998-01-01
Peanut (Arachis hypogaea L.) plants were grown hydroponically, using continuously recirculating nutrient solution. Two culture tray designs were tested; one tray design used only nutrient solution, while the other used a sphagnum-filled pod development compartment just beneath the cover and above the nutrient solution. Both trays were fitted with slotted covers to allow developing gynophores to reach the root zone. Peanut seed yields averaged 350 gm-2 dry mass, regardless of tray design, suggesting that substrate is not required for hydroponic peanut production.
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DEFF Research Database (Denmark)
Trang, N.T.D.; Brix, Hans
2014-01-01
The feasibility of using planted biofilters for purification of recirculated aquaculture water in the Mekong Delta of Vietnam was assessed. The plant trenches were able to clean tilapia aquaculture water and to maintain good water quality in the fish tanks without renewal of the water. NH4-N was ...... rates of 725 kg N and 234 kg P ha-1 year-1. This research demonstrates that integrated recirculating aquaculture-hydroponics (aquaponics) systems provide significant water savings and nutrient recycling as compared with traditional fish ponds....
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Nutrient Management in Recirculating Hydroponic Culture
Bugbee, Bruce
2004-01-01
There is an increasing need to recirculate and reuse nutrient solutions in order to reduce environmental and economic costs. However, one of the weakest points in hydroponics is the lack of information on managing the nutrient solution. Many growers and research scientists dump out nutrient solutions and refill at weekly intervals. Other authors have recommended measuring the concentrations of individual nutrients in solution as a key to nutrient control and maintenance. Dumping and replacing solution is unnecessary. Monitoring ions in solution is not always necessary; in fact the rapid depletion of some nutrients often causes people to add toxic amounts of nutrients to the solution. Monitoring ions in solution is interesting, but it is not the key to effective maintenance.
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Recycling crop residues for use in recirculating hydroponic crop production
Mackowiak, C. L.; Garland, J. L.; Sager, J. C.
1996-01-01
As part of bioregenerative life support feasibility testing by NASA, crop residues are being used to resupply elemental nutrients to recirculating hydroponic crop production systems. Methods for recovering nutrients from crop residues have evolved from water soaking (leaching) to rapid aerobic bioreactor processing. Leaching residues recovered the majority of elements but it also recovered significant amounts of soluble organics. The high organic content of leachates was detrimental to plant growth. Aerobic bioreactor processing reduced the organic content ten-fold, which reduced or eliminated phytotoxic effects. Wheat and potato production studies were successful using effluents from reactors having with 8- to 1-day retention times. Aerobic bioreactor effluents supplied at least half of the crops elemental mass needs in these studies. Descriptions of leachate and effluent mineral content, biomass productivity, microbial activity, and nutrient budgets for potato and wheat are presented.
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Mackowiak, C. L.; Garland, J. L.; Strayer, R. F.; Finger, B. W.; Wheeler, R. M.
1996-01-01
This study compared the growth of potato plants on nutrients recycled from inedible potato biomass. Plants were grown for 105 days in recirculating, thin-film hydroponic systems containing four separate nutrient solution treatments: (1) modified half-strength Hoagland's (control), 2) liquid effluent from a bioreactor containing inedible potato biomass, 3) filtered (0.2 micrometer) effluent, and 4) the water soluble fraction of inedible potato biomass (leachate). Approximately 50% of the total nutrient requirement in treatments 2-4 were provided (recycled) from the potato biomass. Leachate had an inhibitory effect on leaf conductance, photosynthetic rate, and growth (50% reduction in plant height and 60% reduction in tuber yield). Plants grown on bioreactor effluent (filtered or unfiltered) were similar to the control plants. These results indicated that rapidly degraded, water soluble organic material contained in the inedible biomass, i.e., material in leachate, brought about phytotoxicity in the hydroponic culture of potato. Recalcitrant, water soluble organic material accumulated in all nutrient recycling treatments (650% increase after 105 days), but no increase in rhizosphere microbial numbers was observed.
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Hydroponic systems and water management in aquaponics: A review
Directory of Open Access Journals (Sweden)
Carmelo Maucieri
2017-09-01
Full Text Available Aquaponics (AP, the integrated multi-trophic fish and plants production in quasi-closed recirculating system, is one of the newest sustainable food production systems. The hydroponic component of the AP directly influences water quality (in turn influencing fish growth and health, and water consumption (through evapotranspiration of the entire system. In order to assess the role of the design and the management of the hydroponic component on the overall performance, and water consumption of the aquaponics, 122 papers published from 1979 to 2017 were reviewed. Although no unequivocal results were found, the nutrient film technique appears in several aspects less efficient than medium-based or floating raft hydroponics. The best system performance in terms of fish and plant growth, and the highest nutrient removal from water was achieved at water flow between 0.8 L min–1 and 8.0 L min–1. Data on water consumption of aquaponics are scarce, and no correlation between the ratio of hydroponic unit surface/fish tank volume and the system water loss was found. However, daily water loss was positively correlated with the hydroponic surface/fish tank volume ratio if the same experimental conditions and/or systems were compared. The plant species grown in hydroponics influenced the daily water loss in aquaponics, whereas no effect was exerted by the water flow (reciprocating flood/drain cycle or constant flow or type (medium-based, floating or nutrient film technique of hydroponics.
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Schuerger, Andrew C; Hammer, William
2009-05-01
Zoosporic pathogens in the genera Pythium and Phytophthora cause extensive root disease epiphytotics in recirculating hydroponic vegetable-production greenhouses. Zoospore cysts of Pythium myriotylum Drechsler were used to evaluate the effectiveness of cross-flow membrane filters to control pythiaceous pathogens in recirculating hydroponic systems. Four membrane filter brands (Honeycomb, Polypure, Polymate, and Absolife) were tested alone or in combination to determine which filters would effectively remove infective propagules of P. myriotylum from solutions and reduce disease incidence and severity. Zoospore cysts of P. myriotylum generally measured 8 to 10 microm, and it was hypothesized that filters with pore-sizespepper plants from root infection. Single-filter assays with Honeycomb and Polypure brands removed 85 to 95% of zoospore cysts when pore sizes were rated at 1, 5, 10, 20, or 30 microm. Single-filter assays of Polymate and Absolife brands were more effective, exhibiting apparently 100% removal of zoospore cysts from nutrient solutions on filters rated at 1 to 10 microm. However, plant bioassays with Honeycomb and Polymate single filters failed to give long-term protection of pepper plants. Double-filter assays with 1- and 0.5-microm Polymate filters significantly increased the protection of pepper plants grown in nutrient film technique systems but, eventually, root disease and plant wilt could be observed. Insect transmissions by shore flies were not factors in disease development. Scanning electron microscopy images of zoospore cysts entrapped on Polymate filters revealed zoospore cysts that were either fully encysted, partially encysted, or of unusually small size (3 microm in diameter). It was concluded that either the atypically small or pliable pleomorphic zoospore cysts were able to penetrate filter membranes that theoretically should have captured them.
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Continuous hydroponic wheat production using a recirculating system
Mackowiak, C. L.; Owens, L. P.; Hinkle, C. R.; Prince, R. P.
1989-01-01
Continuous crop production, where plants of various ages are growing simultaneously in a single recirculating nutrient solution, is a possible alternative to batch production in a Controlled Ecological Life Support System. A study was conducted at John F. Kennedy Space Center where 8 trays (0.24 sq m per tray) of Triticum aestivum L. Yecora Rojo were grown simultaneously in a growth chamber at 23 C, 65 percent relative humidity, 1000 ppm CO2, continuous light, with a continuous flow, thin film nutrient delivery system. The same modified Hoagland nutrient solution was recirculated through the plant trays from an 80 L reservoir throughout the study. It was maintained by periodic addition of water and nutrients based on chemical analyses of the solution. The study was conducted for 216 days, during which 24 trays of wheat were consecutively planted (one every 9 days), 16 of which were grown to maturity and harvested. The remaining 8 trays were harvested on day 216. Grain yields averaged 520 g m(exp -2), and had an average edible biomass of 32 percent. Consecutive yields were unaffected by nutrient solution age. It was concluded that continual wheat production will work in this system over an extended period of time. Certain micronutrient deficiencies and toxicities posed problems and must be addressed in future continuous production systems.
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Tyler S. Anderson; David de Villiers; Michael B. Timmons
2017-01-01
The primary objective of this research was to compare lettuce performance under conventional hydroponics at pH 5.8 (referred to as H5), hydroponics at pH 7.0 (referred to as H7), and recirculated aquaponic water at pH 7.0 (referred to as A7). Aquaponic nutrients were supplied by continuously recirculating water between a fish rearing system (recirculating aquaculture system or RAS) and the lettuce growing system (with the sole addition being chelated iron). This paper builds upon our previous...
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Directory of Open Access Journals (Sweden)
LORENA SFETCU
2008-10-01
Full Text Available Aquaponics are modern production systems, which integrate the aquaculture technology with hydroponic systems (vegetable production without soil with a goal of fructification of residual nutrients resulted from metabolic activity of fish biomass as high quality vegetable biomass sealable as ecological products. In the present study, as a first step in aquaponic recirculating systems evaluation, the authors aim to compare two types of recirculating systems: classical (hereby noted with RAS and integrated/aquaponic (RAS_A regarding water quality parameters generally, and TAN (total ammonia nitrogen production and transformation, particularly.
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DEFF Research Database (Denmark)
Trang, Ngo Thuy Diem; Schierup, Hans-Henrik; Brix, Hans
2010-01-01
In recirculating aquaculture and hydroponics systems, the waste products from fish production are used to produce vegetables or other crops of economic value, and the water is recirculated to the fish tanks. We studied growth, productivity and nutrient uptake of four leaf vegetable species (Lactuca...... sativa, Ipomoea aquatica, Brassica rapa var. chinensis and Brassica rapa var. parachinensis) in a controlled growth experiment with three root flooding treatments (drained, half-flooded and flooded) to assess their preferred hydroponic growth requirements, biomass production and nutrient removal......, respectively. The two Brassica varieties produced much less aerial biomass (50-54 g DW/m2 during a 60-day period). Both I. aquatica and L. sativa are promising species to be included in integrated hydroponic and aquaculture facilities, with I. aquatica showing the most promise because of its higher growth...
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Mackowiak, C. L.; Wheeler, R. M.; Lowery, W.; Sager, J. C.
1990-01-01
Establishing mass budgets of various crop needs, i.e. water and nutrients, in different environments is essential for the Controlled Ecological Life Support System (CELSS). The effects of CO2 (500 and 1000 umol mol (exp -1)) on water and acid use (for pH control) by soybeans in a recirculating hydroponic system were examined. Plants of cvs. McCall and Pixie were grown for 90 days using the nutrient film technique (NFT) and a nitrate based nutrient solution. System acid use for both CO2 levels peaked near 4 weeks during a phase of rapid vegetative growth, but acid use decreased more rapidly under 500 compared to 1000 umol mol (exp GR) CO2. Total system water use by 500 and 1000 umol mol (exp -1) plants was similar, leaving off at 5 weeks and declining as plants senesced (ca. 9 weeks). However, single leaf transpiration rates were consistently lower at 1000 umol mol (exp -1). The data suggest that high CO2 concentrations increase system acid (and nutrient) use because of increased vegetative growth, which in turn negates the benefit of reduced water use (lower transpiration rates) per unit leaf area.
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Wang, Qing
2015-01-01
Hydroponically grown microgreens are gaining in popularity, but there is a lack of information pertaining to their microbiological safety. The potential risks associated with virus contamination of crops within a hydroponic system have not been studied to date. Here a human norovirus (huNoV) surrogate (murine norovirus [MNV]) was evaluated for its ability to become internalized from roots to edible tissues of microgreens. Subsequently, virus survival in recirculated water without adequate disinfection was assessed. Kale and mustard seeds were grown on hydroponic pads (for 7 days with harvest at days 8 to 12), edible tissues (10 g) were cut 1 cm above the pads, and corresponding pieces (4 cm by 4 cm) of pads containing only roots were collected separately. Samples were collected from a newly contaminated system (recirculated water inoculated with ∼3 log PFU/ml MNV on day 8) and from a previously contaminated system. (A contaminated system without adequate disinfection or further inoculation was used for production of another set of microgreens.) Viral titers and RNA copies were quantified by plaque assay and real-time reverse transcription (RT)-PCR. The behaviors of MNV in kale and mustard microgreens were similar (P > 0.05). MNV was detected in edible tissues and roots after 2 h postinoculation, and the levels were generally stable during the first 12 h. Relatively low levels (∼2.5 to ∼1.5 log PFU/sample of both edible tissues and roots) of infectious viruses were found with a decreasing trend over time from harvest days 8 to 12. However, the levels of viral RNA present were higher and consistently stable (∼4.0 to ∼5.5 log copies/sample). Recirculated water maintained relatively high levels of infectious MNV over the period of harvest, from 3.54 to 2.73 log PFU/ml. Importantly, cross-contamination occurred easily; MNV remained infectious in previously contaminated hydroponic systems for up to 12 days (2.26 to 1.00 PFU/ml), and MNV was detected in both
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Wang, Qing; Kniel, Kalmia E
2016-01-15
Hydroponically grown microgreens are gaining in popularity, but there is a lack of information pertaining to their microbiological safety. The potential risks associated with virus contamination of crops within a hydroponic system have not been studied to date. Here a human norovirus (huNoV) surrogate (murine norovirus [MNV]) was evaluated for its ability to become internalized from roots to edible tissues of microgreens. Subsequently, virus survival in recirculated water without adequate disinfection was assessed. Kale and mustard seeds were grown on hydroponic pads (for 7 days with harvest at days 8 to 12), edible tissues (10 g) were cut 1 cm above the pads, and corresponding pieces (4 cm by 4 cm) of pads containing only roots were collected separately. Samples were collected from a newly contaminated system (recirculated water inoculated with ∼3 log PFU/ml MNV on day 8) and from a previously contaminated system. (A contaminated system without adequate disinfection or further inoculation was used for production of another set of microgreens.) Viral titers and RNA copies were quantified by plaque assay and real-time reverse transcription (RT)-PCR. The behaviors of MNV in kale and mustard microgreens were similar (P > 0.05). MNV was detected in edible tissues and roots after 2 h postinoculation, and the levels were generally stable during the first 12 h. Relatively low levels (∼2.5 to ∼1.5 log PFU/sample of both edible tissues and roots) of infectious viruses were found with a decreasing trend over time from harvest days 8 to 12. However, the levels of viral RNA present were higher and consistently stable (∼4.0 to ∼5.5 log copies/sample). Recirculated water maintained relatively high levels of infectious MNV over the period of harvest, from 3.54 to 2.73 log PFU/ml. Importantly, cross-contamination occurred easily; MNV remained infectious in previously contaminated hydroponic systems for up to 12 days (2.26 to 1.00 PFU/ml), and MNV was detected in both
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Steinberg, S. L.; Ming, D. W.; Henderson, K. E.; Carrier, C.; Gruener, J. E.; Barta, D. J.; Henninger, D. L.
2000-01-01
Hydroponic culture has traditionally been used for controlled environment life support systems (CELSS) because the optimal environment for roots supports high growth rates. Recent developments in zeoponic substrate and microporous tube irrigation (ZPT) also offer high control of the root environment. This study compared the effect of differences in water and nutrient status of ZPT or hydroponic culture on growth and yield of wheat (Triticum aestivum L. cv. USU-Apogee). In a side-by-side test in a controlled environment, wheat was grown in ZPT and recirculating hydroponics to maturity. Water use by plants grown in both culture systems peaked at 15 to 20 L m-2 d-1 up to Day 40, after which it declined more rapidly for plants grown in ZPT culture due to earlier senescence of leaves. No consistent differences in water status were noted between plants grown in the two culture systems. Although yield was similar, harvest index was 28% lower for plants grown in ZPT than in hydroponic culture. Sterile green tillers made up 12 and 0% of the biomass of plants grown in ZPT and hydroponic culture, respectively. Differences in biomass partitioning were attributed primarily to NH4-N nutrition of plants grown in ZPT compared with NO3-N in hydroponic nutrient solution. It is probable that NH4-N-induced Ca deficiency produced excess tillering and lower harvest index for plants grown in ZPT culture. These results suggest that further refinements in zeoponic substrate would make ZPT culture a viable alternative for achieving high productivity in a CELSS.
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AQUAPONICS: INTEGRATION BETWEEN AQUACULTURE AND HYDROPONICS
Directory of Open Access Journals (Sweden)
Guilherme Crispim Hundley2
2013-12-01
and hydroponics in recirculating systems for water and nutrients. Furthermore, Aquaponics presents itself as a real alternative for the production of food with reduced impact to the environment for its sustainability characteristics. Thus, Aquaponics is among the sustainable techniques involving fish and vegetable integrated production, capable of benefiting both. This integration allows the plant to use the nutrients from the water provided by the fish, thus improving water quality.
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Degradation of Surfactants in Hydroponic Wheat Root Zones
Monje, Oscar; McCoy, Lashelle; Flanagan, Aisling
Hygiene water recycling in recirculating hydroponic systems can be enhanced by plant roots by providing a substrate and root exudates for bacterial growth. However, reduced plant growth can occur during batch mode additions of high concentrations of surfactant. An analog hygiene water stream containing surfactants (Steol CS330, Mirataine CB) was added to a hydroponically-grown wheat plant root zone. The plants were grown at 700 mol mol-1 CO2, a photosynthetic photon flux of 300 mol m-2 s-1, and a planting density of 380 plants m-2. Volumetric oxygen mass transfer coefficients were determined using the fermentative/dynamic outgassing method to maintain adequate oxygen mass transfer rates in the root zone. This analysis suggested an optimal flow rate of the hydroponic solution of 5 L min-1. The hydroponic system was inoculated with biofilm from a bioreactor and rates of surfactant degradation were measured daily based on reduction in chemical oxygen demand (COD). The COD decreased from 400 to 100 mg L-1 after 2 days following batch addition of the analog hygiene water to the hydroponic system. Measurements of dissolved oxygen concentration and solution temperature suggest that the root zone was provided adequate aeration to meet both oxygen demands from plant and microbial respiration during the degradation of the surfactant. Results from this study show that hydroponic systems can be used to enhance rates of hygiene water processing.
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Directory of Open Access Journals (Sweden)
Tyler S. Anderson
2017-07-01
Full Text Available The primary objective of this research was to compare lettuce performance under conventional hydroponics at pH 5.8 (referred to as H5, hydroponics at pH 7.0 (referred to as H7, and recirculated aquaponic water at pH 7.0 (referred to as A7. Aquaponic nutrients were supplied by continuously recirculating water between a fish rearing system (recirculating aquaculture system or RAS and the lettuce growing system (with the sole addition being chelated iron. This paper builds upon our previous research where we found that H7 produced 26% less shoot fresh weight (FW growth than H5 and an 18% reduction in dry weight (DW. In this research, we also evaluated the inorganic hydroponics nutrient solution at pH 7.0 (H7 to provide continuity between experiments and to isolate the pH effect. The A7 plant biomass responses were not different from H5 in all biomass response categories. H7 was different from H5 in shoot FW, DW, and DW/FW, as well as root FW and DW. H7 was different from the A7 in shoot FW, DW/FW, and root DW. There were no tissue elemental differences between H5 and H7 except Cu. The Ca and Na contents differed between H5 and A7, while the microelements Mn, Mo, and Zn differed. Generally, the elemental tissue differences between treatments were proportional to the differences for the same elements in the nutrient solutions. Aquaponic systems are often viewed to be more complicated and more risky because two complex systems are being joined (hydroponics plus RAS. However, the aquaponics system proved to be surprisingly simple to manage in daily operations. Our data suggested that the aquaponics system (A7, which was operated at a higher pH 7.0, was able to offset any negative biomass and elemental effects that occurred in the inorganic hydroponic pH 7.0 treatment (H7 from its increased pH and less optimized nutrient solution elemental concentrations.
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Sheridan, C; Depuydt, P; De Ro, M; Petit, C; Van Gysegem, E; Delaere, P; Dixon, M; Stasiak, M; Aciksöz, S B; Frossard, E; Paradiso, R; De Pascale, S; Ventorino, V; De Meyer, T; Sas, B; Geelen, D
2017-02-01
Plant growth promoting microorganisms (PGPMs) of the plant root zone microbiome have received limited attention in hydroponic cultivation systems. In the framework of a project aimed at the development of a biological life support system for manned missions in space, we investigated the effects of PGPMs on four common food crops (durum and bread wheat, potato and soybean) cultivated in recirculating hydroponic systems for a whole life cycle. Each crop was inoculated with a commercial PGPM mixture and the composition of the microbial communities associated with their root rhizosphere, rhizoplane/endosphere and with the recirculating nutrient solution was characterised through 16S- and ITS-targeted Illumina MiSeq sequencing. PGPM addition was shown to induce changes in the composition of these communities, though these changes varied both between crops and over time. Microbial communities of PGPM-treated plants were shown to be more stable over time. Though additional development is required, this study highlights the potential benefits that PGPMs may confer to plants grown in hydroponic systems, particularly when cultivated in extreme environments such as space.
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Tomato Productivity and Quality in Aquaponics: Comparison of Three Hydroponic Methods
Directory of Open Access Journals (Sweden)
Zala Schmautz
2016-11-01
Full Text Available Aquaponics (AP is a food production system that combines hydroponic (HP crop production with recirculating aquaculture. Different types of hydroponic systems have been used for growing crops in aquaponics. However, very few studies have compared their suitability and efficiency in an aquaponic context. The study presented here compares tomato yield, morphological (external and biochemical (internal fruit quality, and overall tomato plant vitality from three different HP systems (nutrient film technique, drip irrigation system, and floating raft culture and examines the distribution of nutrients in different parts of the tomato plant. Three replicate AP systems were set up, each incorporating the three different HP systems coupled with a separate recirculating aquaculture unit growing Nile tilapia. The results showed that the choice of the cultivation system had little influence on most of the above-mentioned properties. Tomato fruit mineral content was found to be in similar range for N, P, K, Ca, Mg, Fe, and Zn as reported in the literature. Yield and fruit quality were similar in all three systems. However, the drip irrigation system did perform slightly better. The slightly higher oxygen radical absorbance capacity (ORAC of the fruits grown in AP in comparison to commercially produced and supermarket derived tomatoes might indicate a potential for producing fruits with higher health value for humans.
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Recirculation system for nuclear reactors
International Nuclear Information System (INIS)
Braun, H. E.; Dollard, W. J.; Tower, S. N.
1980-01-01
A recirculation system for use in pressurized water nuclear reactors to increase the output temperature of the reactor coolant, thereby achieving a significant improvement in plant efficiency without exceeding current core design limits. A portion of the hot outlet coolant is recirculated to the inlets of the peripheral fuel assemblies which operate at relatively low power levels. The outlet temperature from these peripheral fuel assemblies is increased to a temperature above that of the average core outlet. The recirculation system uses external pumps and introduces the hot recirculation coolant to the free space between the core barrel and the core baffle, where it flows downward and inward to the inlets of the peripheral fuel assemblies. In the unlikely event of a loss of coolant accident, the recirculation system flow path through the free space and to the inlets of the fuel assemblies is utilized for the injection of emergency coolant to the lower vessel and core. During emergency coolant injection, the emergency coolant is prevented from bypassing the core through the recirculation system by check valves inserted into the recirculation system piping
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Directory of Open Access Journals (Sweden)
Boris Delaide
2016-10-01
Full Text Available Plant growth performance is optimized under hydroponic conditions. The comparison between aquaponics and hydroponics has attracted considerable attention recently, particularly regarding plant yield. However, previous research has not focused on the potential of using aquaponic solution complemented with mineral elements to commercial hydroponic levels in order to increase yield. For this purpose, lettuce plants were put into AeroFlo installations and exposed to hydroponic (HP, aquaponic (AP, or complemented aquaponic (CAP solutions. The principal finding of this research was that AP and HP treatments exhibited similar (p > 0.05 plant growth, whereas the shoot weight of the CAP treatment showed a significant (p < 0.05 growth rate increase of 39% on average compared to the HP and AP treatments. Additionally, the root weight was similar (p > 0.05 in AP and CAP treatments, and both were significantly higher (p < 0.05 than that observed in the HP treatment. The results highlight the beneficial effect of recirculating aquaculture system (RAS water on plant growth. The findings represent a further step toward developing decoupled aquaponic systems (i.e., two- or multi-loops that have the potential to establish a more productive alternative to hydroponic systems. Microorganisms and dissolved organic matter are suspected to play an important role in RAS water for promoting plant roots and shoots growth.
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Computer model of hydroponics nutrient solution pH control using ammonium.
Pitts, M; Stutte, G
1999-01-01
A computer simulation of a hydroponics-based plant growth chamber using ammonium to control pH was constructed to determine the feasibility of such a system. In nitrate-based recirculating hydroponics systems, the pH will increase as plants release hydroxide ions into the nutrient solution to maintain plant charge balance. Ammonium is an attractive alternative to traditional pH controls in an ALSS, but requires careful monitoring and control to avoid overdosing the plants with ammonium. The primary advantage of using NH4+ for pH control is that it exploits the existing plant nutrient uptake charge balance mechanisms to maintain solution pH. The simulation models growth, nitrogen uptake, and pH of a l-m2 stand of wheat. Simulation results indicated that ammonium-based control of nutrient solution pH is feasible using a proportional integral controller. Use of a 1 mmol/L buffer (Ka = 1.6 x 10(-6)) in the nutrient solution is required.
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Nutrient Film Technique (NFT Hydroponic Monitoring System
Directory of Open Access Journals (Sweden)
Helmy Helmy
2016-10-01
Full Text Available Plant cultivation using hydroponic is very popular today. Nutrient Film Technique (NFT hydroponic system is commonly used by people. It can be applied indoor or outdoor. Plants in this systemneed nutrient solution to grow well. pH, TDS and temperature of the nutrient solution must be check to ensure plant gets sufficient nutrients. This research aims todevelop monitoring system of NFT hydroponic. Farmer will be able to monitor pH, TDS and temperature online. It will ease farmer to decide which plant is suitable to be cultivated and time to boost growth.Delay of the system will be measured to know system performance. Result shows that pH is directly proportional with TDS. Temperature value has no correlation with pH and TDS. System has highest delay during daylight and afternoon but it will decline in the night and morning. Average of delay in the morning is 11 s, 28.5 s in daylight, 32 s in the afternoon and 17.5 s in the night.
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BWR recirculation pump diagnostic expert system
International Nuclear Information System (INIS)
Chiang, S.C.; Morimoto, C.N.; Torres, M.R.
2004-01-01
At General Electric (GE), an on-line expert system to support maintenance decisions for BWR recirculation pumps for nuclear power plants has been developed. This diagnostic expert system is an interactive on-line system that furnishes diagnostic information concerning BWR recirculation pump operational problems. It effectively provides the recirculation pump diagnostic expertise in the plant control room continuously 24 hours a day. The expert system is interfaced to an on-line monitoring system, which uses existing plant sensors to acquire non-safety related data in real time. The expert system correlates and evaluates process data and vibration data by applying expert rules to determine the condition of a BWR recirculation pump system by applying knowledge based rules. Any diagnosis will be automatically displayed, indicating which pump may have a problem, the category of the problem, and the degree of concern expressed by the validity index and color hierarchy. The rules incorporate the expert knowledge from various technical sources such as plant experience, engineering principles, and published reports. These rules are installed in IF-THEN formats and the resulting truth values are also expressed in fuzzy terms and a certainty factor called a validity index. This GE Recirculation Pump Expert System uses industry-standard software, hardware, and network access to provide flexible interfaces with other possible data acquisition systems. Gensym G2 Real-Time Expert System is used for the expert shell and provides the graphical user interface, knowledge base, and inference engine capabilities. (author)
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Hydroponic system for the treatment of anaerobic liquid.
Krishnasamy, K; Nair, J; Bäuml, B
2012-01-01
The effluent from anaerobic digestion process has high concentrations of nutrients, particularly nitrogen, essential for plant growth but is not suitable for direct disposal or application due to high chemical oxygen demand (COD), low dissolved oxygen (DO), odour issues and is potentially phytotoxic. This research explored the optimum conditions of anaerobic effluent for application and dilutions of the effluent required to obtain better plant growth. A small-scale hydroponic system was constructed in a glasshouse to test different concentrations of anaerobic effluent against a commercial hydroponic medium as the control for the growth of silverbeet. It was found that the survival of silverbeet was negatively affected at 50% concentration due to low DO and NH(4) toxicity. The concentration of 20% anaerobic liquid was found to be the most efficient with highest foliage yield and plant growth. The hydroponic system with 20% concentrated effluent had better utilisation of nutrients for plant growth and a COD reduction of 95% was achieved during the 50-day growth period. This preliminary evaluation revealed that the growth and development of silverbeet was significantly lower in anaerobic effluent compared with a commercial hydroponic plant growth solution. The nutrient quality of anaerobic effluent could be highly variable with the process and the waste material used and dilution may depend on the nutrient content of the effluent. It is recommended that, a pre-treatment of the effluent to increase DO and reduce ammonium content is required before plant application, and simple dilution by itself is not suitable for optimum plant growth in a hydroponic system.
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Hydroponic systems: hype or new perspective
Vermeulen, T.; Weel, van P.A.; Ruijs, M.N.A.; Buwalda, F.; Os, van E.A.; Giacomelli, G.; Samperio Ruiz, G.
2014-01-01
Over the past five to ten years internationally a renewed interest can be observed in systems that require little or no substrate, such as deep flow technique and nutrient film technique - here dubbed hydroponic systems. Interestingly these systems have been around for over 40 years, but have only
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Stouvenakers, Gilles; Massart, Sébastien; Jijakli, Haissam
2016-01-01
Aquaponics is an integrated recirculated system that combines aquaculture and hydroponic plant production. The dissolved nutrients generated by the fish rearing after bacterial activities are used by the plants for their growth. This uptake reduces the accumulation of some molecules which allow a longer water recirculation. When comparing growth conditions between aquaponics and hydroponics, we observed much lower concentration of several key nutrients in aquaponics. Nevertheless, several exp...
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Akiyama, H; Nose, M; Ohtsuki, N; Hisaka, S; Takiguchi, H; Tada, A; Sugimoto, N; Fuchino, H; Inui, T; Kawano, N; Hayashi, S; Hishida, A; Kudo, T; Sugiyama, K; Abe, Y; Mutsuga, M; Kawahara, N; Yoshimatsu, K
2017-01-01
Glycyrrhiza uralensis roots used in this study were produced using novel cultivation systems, including artificial hydroponics and artificial hydroponic-field hybrid cultivation. The equivalency between G. uralensis root extracts produced by hydroponics and/or hybrid cultivation and a commercial Glycyrrhiza crude drug were evaluated for both safety and efficacy, and there were no significant differences in terms of mutagenicity on the Ames tests. The levels of cadmium and mercury in both hydroponic roots and crude drugs were less than the limit of quantitation. Arsenic levels were lower in all hydroponic roots than in the crude drug, whereas mean lead levels in the crude drug were not significantly different from those in the hydroponically cultivated G. uralensis roots. Both hydroponic and hybrid-cultivated root extracts showed antiallergic activities against contact hypersensitivity that were similar to those of the crude drug extracts. These study results suggest that hydroponic and hybrid-cultivated roots are equivalent in safety and efficacy to those of commercial crude drugs. Further studies are necessary before the roots are applicable as replacements for the currently available commercial crude drugs produced from wild plant resources.
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Exhaust gas recirculation system for an internal combustion engine
Wu, Ko-Jen
2013-05-21
An exhaust gas recirculation system for an internal combustion engine comprises an exhaust driven turbocharger having a low pressure turbine outlet in fluid communication with an exhaust gas conduit. The turbocharger also includes a low pressure compressor intake and a high pressure compressor outlet in communication with an intake air conduit. An exhaust gas recirculation conduit fluidly communicates with the exhaust gas conduit to divert a portion of exhaust gas to a low pressure exhaust gas recirculation branch extending between the exhaust gas recirculation conduit and an engine intake system for delivery of exhaust gas thereto. A high pressure exhaust gas recirculation branch extends between the exhaust gas recirculation conduit and the compressor intake and delivers exhaust gas to the compressor for mixing with a compressed intake charge for delivery to the intake system.
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The radon daughter radiation hazard in controlled recirculation systems
International Nuclear Information System (INIS)
Rolle, R.; Burton, R.C.
1987-01-01
In deep South African gold mines, controlled recirculation systems with air cooling are being used to an increasing extent to improve the thermal environment. Recirculation causes some air to reside in the working area for a longer time than would have occurred without recirculation. Since radon daughters grow spontaneously from radon there is some concern that, with the extended residence time, the potential radiation hazard could increase to an unacceptable level. This paper describes the results obtained from a theoretical model of a controlled recirculation system. Guidelines for the design of recirculation systems to control the radon daughter radiation, and to keep it within acceptable limits are provided. 3 refs., 5 figs
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Plant-uptake of uranium: Hydroponic and soil system studies
Ramaswami, A.; Carr, P.; Burkhardt, M.
2001-01-01
Limited information is available on screening and selection of terrestrial plants for uptake and translocation of uranium from soil. This article evaluates the removal of uranium from water and soil by selected plants, comparing plant performance in hydroponic systems with that in two soil systems (a sandy-loam soil and an organic-rich soil). Plants selected for this study were Sunflower (Helianthus giganteus), Spring Vetch (Vicia sativa), Hairy Vetch (Vicia villosa), Juniper (Juniperus monosperma), Indian Mustard (Brassica juncea), and Bush Bean (Phaseolus nanus). Plant performance was evaluated both in terms of the percent uranium extracted from the three systems, as well as the biological absorption coefficient (BAC) that normalized uranium uptake to plant biomass. Study results indicate that uranium extraction efficiency decreased sharply across hydroponic, sandy and organic soil systems, indicating that soil organic matter sequestered uranium, rendering it largely unavailable for plant uptake. These results indicate that site-specific soils must be used to screen plants for uranium extraction capability; plant behavior in hydroponic systems does not correlate well with that in soil systems. One plant species, Juniper, exhibited consistent uranium extraction efficiencies and BACs in both sandy and organic soils, suggesting unique uranium extraction capabilities.
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Soybean cultivar selection for Bioregenerative Life Support Systems (BLSSs) - Hydroponic cultivation
Paradiso, R.; Buonomo, R.; De Micco, V.; Aronne, G.; Palermo, M.; Barbieri, G.; De Pascale, S.
2012-12-01
Four soybean cultivars ('Atlantic', 'Cresir', 'Pr91m10' and 'Regir'), selected through a theoretical procedure as suitable for cultivation in BLSS, were evaluated in terms of growth and production. Germination percentage and Mean Germination Time (MGT) were measured. Plants were cultivated in a growth chamber equipped with a recirculating hydroponic system (Nutrient Film Technique). Cultivation was performed under controlled environmental conditions (12 h photoperiod, light intensity 350 μmol m-2 s-1, temperature regime 26/20 °C light/dark, relative humidity 65-75%). Fertigation was performed with a standard Hoagland solution, modified for soybean specific requirements, and EC and pH were kept at 2.0 dS m-1 and 5.5 respectively. The percentage of germination was high (from 86.9% in 'Cresir' to 96.8% in 'Regir')and the MGT was similar for all the cultivars (4.3 days). The growing cycle lasted from 114 in 'Cresir' to 133 days on average in the other cultivars. Differences in plant size were recorded, with 'Pr91m10' plants being the shortest (58 vs 106 cm). Cultivars did not differ significantly in seed yield (12 g plant-1) and in non edible biomass (waste), water consumption and biomass conversion efficiency (water, radiation and acid use indexes). 'Pr91m10' showed the highest protein content in the seeds (35.6% vs 33.3% on average in the other cultivars). Results from the cultivation experiment showed good performances of the four cultivars in hydroponics. The overall analysis suggests that 'Pr91m10' could be the best candidate for the cultivation in a BLSS, coupling the small plant size and the good yield with high resource use efficiency and good seed quality.
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Automated Liquid-Level Control of a Nutrient Reservoir for a Hydroponic System
Smith, Boris; Asumadu, Johnson A.; Dogan, Numan S.
1997-01-01
A microprocessor-based system for control of the liquid level of a nutrient reservoir for a plant hydroponic growing system has been developed. The system uses an ultrasonic transducer to sense the liquid level or height. A National Instruments' Multifunction Analog and Digital Input/Output PC Kit includes NI-DAQ DOS/Windows driver software for an IBM 486 personal computer. A Labview Full Development system for Windows is the graphical programming system being used. The system allows liquid level control to within 0.1 cm for all levels tried between 8 and 36 cm in the hydroponic system application. The detailed algorithms have been developed and a fully automated microprocessor based nutrient replenishment system has been described for this hydroponic system.
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Engineering systems designs for a recirculating heavy ion induction accelerator
International Nuclear Information System (INIS)
Newton, M.A.; Barnard, J.J.; Reginato, L.L.; Yu, S.S.
1991-05-01
Recirculating heavy ion induction accelerators are being investigated as possible drivers for heavy ion fusion. Part of this investigation has included the generation of a conceptual design for a recirculator system. This paper will describe the overall engineering conceptual design of this recirculator, including discussions of the dipole magnet system, the superconducting quadrupole system and the beam acceleration system. Major engineering issues, evaluation of feasibility, and cost tradeoffs of the complete recirculator system will be presented and discussed. 5 refs., 4 figs
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Tripathi, Prateek; Rabara, Roel C; Shulaev, Vladimir; Shen, Qingxi J; Rushton, Paul J
2015-01-01
The deleterious changes in environmental conditions such as water stress bring physiological and biochemical changes in plants, which results in crop loss. Thus, combating water stress is important for crop improvement to manage the needs of growing population. Utilization of hydroponics system in growing plants is questionable to some researchers, as it does not represent an actual field condition. However, trying to address a complex problem like water stress we have to utilize a simpler growing condition like the hydroponics system wherein every input given to the plants can be controlled. With the advent of high-throughput technologies, it is still challenging to address all levels of the genetic machinery whether a gene, protein, metabolite, and promoter. Thus, using a system of reduced complexity like hydroponics can certainly direct us toward the right candidates, if not completely help us to resolve the issue.
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A thin film hydroponic system for plant studies
Hines, Robert; Prince, Ralph; Muller, Eldon; Schuerger, Andrew
1990-01-01
The Land Pavillion, EPCOT Center, houses a hydroponic, thin film growing system identical to that residing in NASA's Biomass Production Chamber at Kennedy Space Center. The system is targeted for plant disease and nutrition studies. The system is described.
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A Reliable Wireless Control System for Tomato Hydroponics.
Ibayashi, Hirofumi; Kaneda, Yukimasa; Imahara, Jungo; Oishi, Naoki; Kuroda, Masahiro; Mineno, Hiroshi
2016-05-05
Agricultural systems using advanced information and communication (ICT) technology can produce high-quality crops in a stable environment while decreasing the need for manual labor. The system collects a wide variety of environmental data and provides the precise cultivation control needed to produce high value-added crops; however, there are the problems of packet transmission errors in wireless sensor networks or system failure due to having the equipment in a hot and humid environment. In this paper, we propose a reliable wireless control system for hydroponic tomato cultivation using the 400 MHz wireless band and the IEEE 802.15.6 standard. The 400 MHz band, which is lower than the 2.4 GHz band, has good obstacle diffraction, and zero-data-loss communication is realized using the guaranteed time-slot method supported by the IEEE 802.15.6 standard. In addition, this system has fault tolerance and a self-healing function to recover from faults such as packet transmission failures due to deterioration of the wireless communication quality. In our basic experiments, the 400 MHz band wireless communication was not affected by the plants' growth, and the packet error rate was less than that of the 2.4 GHz band. In summary, we achieved a real-time hydroponic liquid supply control with no data loss by applying a 400 MHz band WSN to hydroponic tomato cultivation.
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A Reliable Wireless Control System for Tomato Hydroponics
Ibayashi, Hirofumi; Kaneda, Yukimasa; Imahara, Jungo; Oishi, Naoki; Kuroda, Masahiro; Mineno, Hiroshi
2016-01-01
Agricultural systems using advanced information and communication (ICT) technology can produce high-quality crops in a stable environment while decreasing the need for manual labor. The system collects a wide variety of environmental data and provides the precise cultivation control needed to produce high value-added crops; however, there are the problems of packet transmission errors in wireless sensor networks or system failure due to having the equipment in a hot and humid environment. In this paper, we propose a reliable wireless control system for hydroponic tomato cultivation using the 400 MHz wireless band and the IEEE 802.15.6 standard. The 400 MHz band, which is lower than the 2.4 GHz band, has good obstacle diffraction, and zero-data-loss communication is realized using the guaranteed time-slot method supported by the IEEE 802.15.6 standard. In addition, this system has fault tolerance and a self-healing function to recover from faults such as packet transmission failures due to deterioration of the wireless communication quality. In our basic experiments, the 400 MHz band wireless communication was not affected by the plants’ growth, and the packet error rate was less than that of the 2.4 GHz band. In summary, we achieved a real-time hydroponic liquid supply control with no data loss by applying a 400 MHz band WSN to hydroponic tomato cultivation. PMID:27164105
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Aquaponics: integrating fish feeding rates and ion waste production for strawberry hydroponics
International Nuclear Information System (INIS)
Villarroel, M.; Alvarino, J. M. R.; Duran, J. M.
2011-01-01
Aquaponics is the science of integrating intensive fish aquaculture with plant production in recirculating water systems. Although ion waste production by f ish cannot satisfy all plant requirements, less is known about the relationship between total feed provided for f ish and the production of milliequivalents (mEq) of different macronutrients for plants, especially for nutrient flow hydroponics used for strawberry production in Spain. That knowledge is essential to consider the amount of macronutrients available in aquaculture systems so that farmers can estimate how much nutrient needs to be supplemented in the waste water from fish, to produce viable plant growth. In the present experiment, tilapia (Oreochromis niloticus L.) were grown in a small-scale recirculating system at two different densities while growth and feed consumption were noted every week for five weeks. At the same time points, water samples were taken to measure pH, EC 2 5, HCO3 - , Cl - , NH + 4 , NO 2 - , NO 3 - , H 2 PO 4 - , SO 4 2 -, Na + , K + , Ca 2 + and Mg 2 + build up. The total increase in mEq of each ion per kg of feed provided to the fish was highest for NO 3 - , followed, in decreasing order, by Ca 2 +, H 2 PO 4 - , K + , Mg 2 + and SO 4 2 -. The total amount of feed required per mEq ranged from 1.61- 13.1 kg for the four most abundant ions (NO 3 - , Ca 2 +, H 2 PO 4 - and K + ) at a density of 2 kg fish m3, suggesting that it would be rather easy to maintain small populations of fish to reduce the cost of hydroponic solution supplementation for strawberries. (Author) 16 refs.
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Siswanto, Dian; Widoretno, Wahyu
2017-11-01
Problems due to the increase in agricultural land use change can be solved by hydroponic system applications. Many hydroponic studies have been conducted in several countries while their applications in Indonesia requires modification and adjustment. This research was conducted to design and construct a hydroponic system with semi-continuous and continuous nutrition systems. The hydroponic system which was used adapts the ebb and flow system, and the nutrient film technique (NFT). This hydroponic system was made from polyvinyl chloride (PVC) pipes with a length of 197 cm, a diameter of 16 cm, and a slope of 4°. It was constructed from four PVC pipes. In semi-continuous irrigation treatment, nutrients flow four to six times for each of ten minutes depending on plant development and the estimated evapotranspiration occurring, while in a continuous nutrient system the nutrients are streamed for twenty-four hours without stopping at a maximum flow rate of 13.7 L per second.
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Alatorre-Cobos, Fulgencio; Calderón-Vázquez, Carlos; Ibarra-Laclette, Enrique; Yong-Villalobos, Lenin; Pérez-Torres, Claudia-Anahí; Oropeza-Aburto, Araceli; Méndez-Bravo, Alfonso; González-Morales, Sandra-Isabel; Gutiérrez-Alanís, Dolores; Chacón-López, Alejandra; Peña-Ocaña, Betsy-Anaid; Herrera-Estrella, Luis
2014-03-21
Hydroponics is a plant growth system that provides a more precise control of growth media composition. Several hydroponic systems have been reported for Arabidopsis and other model plants. The ease of system set up, cost of the growth system and flexibility to characterize and harvest plant material are features continually improved in new hydroponic system reported. We developed a hydroponic culture system for Arabidopsis and other model plants. This low cost, proficient, and novel system is based on recyclable and sterilizable plastic containers, which are readily available from local suppliers. Our system allows a large-scale manipulation of seedlings. It adapts to different growing treatments and has an extended growth window until adult plants are established. The novel seed-holder also facilitates the transfer and harvest of seedlings. Here we report the use of our hydroponic system to analyze transcriptomic responses of Arabidopsis to nutriment availability and plant/pathogen interactions. The efficiency and functionality of our proposed hydroponic system is demonstrated in nutrient deficiency and pathogenesis experiments. Hydroponically grown Arabidopsis seedlings under long-time inorganic phosphate (Pi) deficiency showed typical changes in root architecture and high expression of marker genes involved in signaling and Pi recycling. Genome-wide transcriptional analysis of gene expression of Arabidopsis roots depleted of Pi by short time periods indicates that genes related to general stress are up-regulated before those specific to Pi signaling and metabolism. Our hydroponic system also proved useful for conducting pathogenesis essays, revealing early transcriptional activation of pathogenesis-related genes.
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Sell, Merran
1997-01-01
Summarizes the benefits of using hydroponics in school for investigational work. Lists requirements and includes advice on suitable plant choices. Outlines the various growing systems and growing media and provides suggestions for science investigations using hydroponics. (DDR)
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Closed-Cycle Nutrient Supply For Hydroponics
Schwartzkopf, Steven H.
1991-01-01
Hydroponic system controls composition and feed rate of nutrient solution and recovers and recycles excess solution. Uses air pressure on bladders to transfer aqueous nutrient solution. Measures and adjusts composition of solution before it goes to hydroponic chamber. Eventually returns excess solution to one of tanks. Designed to operate in microgravity, also adaptable to hydroponic plant-growing systems on Earth.
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Investigation of induced recirculation during planned ventilation system maintenance
Pritchard, C.J.; Scott, D.F.; Noll, J.D.; Voss, B.; Leonis, D.
2015-01-01
The Office of Mine Safety and Health Research (OMSHR) investigated ways to increase mine airflow to underground metal/nonmetal (M/NM) mine working areas to improve miners’ health and safety. One of those areas is controlled recirculation. Because the quantity of mine air often cannot be increased, reusing part of the ventilating air can be an effective alternative, if implemented properly, until the capacity of the present system is improved. The additional airflow can be used to provide effective dilution of contaminants and higher flow velocities in the underground mine environment. Most applications of controlled recirculation involve taking a portion of the return air and passing it back into the intake to increase the air volume delivered to the desired work areas. OMSHR investigated a Nevada gold mine where shaft rehabilitation was in progress and one of the two main fans was shut down to allow reduced air velocity for safe shaft work. Underground booster fan operating pressures were kept constant to maintain airflow to work areas, inducing controlled recirculation in one work zone. Investigation into system behavior and the effects of recirculation on the working area during times of reduced primary ventilation system airflow would provide additional information on implementation of controlled recirculation into the system and how these events affect M/NM ventilation systems. The National Institute for Occupational Safety and Health monitored the ventilation district when both main fans were operating and another scenario with one of the units turned off for maintenance. Airflow and contaminants were measured to determine the exposure effects of induced recirculation on miner health. Surveys showed that 19% controlled recirculation created no change in the overall district airflow distribution and a small reduction in district fresh air intake. Total dust levels increased only modestly and respirable dust levels were also low. Diesel particulate matter
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Shaw, Angela; Helterbran, Kara; Evans, Michael R; Currey, Christopher
2016-12-01
The desire for local, fresh produce year round is driving the growth of hydroponic growing systems in the United States. Many food crops, such as leafy greens and culinary herbs, grown within hydroponics systems have their root systems submerged in recirculating nutrient-dense fertilizer solutions from planting through harvest. If a foodborne pathogen were introduced into this water system, the risk of contamination to the entire crop would be high. Hence, this study was designed to determine whether Escherichia coli O157:H7, non-O157 Shiga toxin-producing E. coli , and Salmonella were able to survive and reproduce in two common hydroponic fertilizer solutions and in water or whether the bacteria would be killed or suppressed by the fertilizer solutions. All the pathogens grew by 1 to 6 log CFU/ml over a 24-h period, depending on the solution. E. coli O157:H7 reached higher levels in the fertilizer solution with plants (3.12 log CFU/ml), whereas non-O157 Shiga toxin-producing E. coli and Salmonella reached higher levels in the fertilizer solution without plants (1.36 to 3.77 log CFU/ml). The foodborne pathogens evaluated here survived for 24 h in the fertilizer solution, and populations grew more rapidly in these solutions than in plain water. Therefore, human pathogens entering the fertilizer solution tanks in hydroponic systems would be expected to rapidly propagate and spread throughout the system and potentially contaminate the entire crop.
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Preoperational test report, recirculation condenser cooling systems
Energy Technology Data Exchange (ETDEWEB)
Clifton, F.T.
1997-11-04
This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.
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Preoperational test report, recirculation condenser cooling systems
International Nuclear Information System (INIS)
Clifton, F.T.
1997-01-01
This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System
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Aquaponics: integrating fish feeding rates and ion waste production for strawberry hydroponics
Energy Technology Data Exchange (ETDEWEB)
Villarroel, M; Alvarino, J M. R.; Duran, J M
2011-07-01
Aquaponics is the science of integrating intensive fish aquaculture with plant production in recirculating water systems. Although ion waste production by fish cannot satisfy all plant requirements, less is known about the relationship between total feed provided for fish and the production of milliequivalents (mEq) of different macronutrients for plants, especially for nutrient flow hydroponics used for strawberry production in Spain. That knowledge is essential to consider the amount of macronutrients available in aquaculture systems so that farmers can estimate how much nutrient needs to be supplemented in the waste water from fish, to produce viable plant growth. In the present experiment, tilapia (Oreochromis niloticus L.) were grown in a small-scale recirculating system at two different densities while growth and feed consumption were noted every week for five weeks. At the same time points, water samples were taken to measure pH, EC25, HCO3{sup -}, Cl{sup -}, NH{sup +}{sub 4}, NO{sub 2}{sup -}, NO{sub 3}{sup -}, H{sub 2}PO{sub 4}{sup -}, SO{sub 4}{sup 2}-, Na{sup +}, K{sup +}, Ca{sup 2}+ and Mg{sup 2}+ build up. The total increase in mEq of each ion per kg of feed provided to the fish was highest for NO{sub 3}{sup -}, followed, in decreasing order, by Ca{sup 2}+, H{sub 2}PO{sub 4}{sup -}, K{sup +}, Mg{sup 2}+ and SO{sub 4}{sup 2}-. The total amount of feed required per mEq ranged from 1.61 - 13.1 kg for the four most abundant ions (NO{sub 3}{sup -}, Ca{sup 2}+, H{sub 2}PO{sub 4}{sup -} and K{sup +}) at a density of 2 kg fish m{sup -3}, suggesting that it would be rather easy to maintain small populations of fish to reduce the cost of hydroponic solution supplementation for strawberries. (Author) 16 refs.
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Hydroponic system design with real time OS based on ARM Cortex-M microcontroller
Atmadja, Wiedjaja; Liawatimena, Suryadiputra; Lukas, Jonathan; Nata, Eka Putra Leo; Alexander, Ivan
2017-12-01
Hydroponic is the process of growing plants without soil, plant root flooded or moist with nutrient-rich solutions in inert material. Hydroponics has become a reality for greenhouse growers in virtually all climates. Large hydroponic installations exist throughout the world for growing flowers, vegetables and some short period fruit like tomato and cucumber. In soilless culture, we must maintain stable pH and conductivity level of nutrient solution to make plant grow well, large variation of pH of certain time will poisoned plant. This paper describes development complete automation hydroponic system, from maintaining stable nutrient composition (conductivity and pH), grow light, and monitor plant environment such as CO2, temperature and humidity. The heart of our automation is ARM Cortex-M4 from ST Microelectronic running ARM mbed OS, the official Real Time Operating System (RTOS) for ARM Cortex-M microcontroller. Using RTOS gives us flexibility to have multithreaded process. Results show that system capable to control desired concentration level with variation of less than 3%, pH sensor show good accuracy 5.83% from pH value 3.23-10. Growing light intensity measurement show result 105 μmol/m2/s therefore we need turn on the light at least 17 hours/day to fulfil plant light requirement. RTOS give good performance with latency and jitter less than 15 us, system overall show good performance and accuracy for automating hydroponic plant in vegetative phase of growth.
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Recirculation nursery systems for bivalves
Kamermans, P.; Blanco Garcia, A.; Joaquim, Sandra; Matias, Domitilia; Magnesen, Thorolf; Nicolas, J.; Petten, Bruno; Robert, Rene
2016-01-01
n order to increase production of bivalves in hatcheries and nurseries, the development of new technology and its integration into commercial bivalve hatcheries is important. Recirculation aquaculture systems (RASs) have several advantages: high densities of the species can be cultured resulting in
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Computer-operated analytical platform for the determination of nutrients in hydroponic systems.
Rius-Ruiz, F Xavier; Andrade, Francisco J; Riu, Jordi; Rius, F Xavier
2014-03-15
Hydroponics is a water, energy, space, and cost efficient system for growing plants in constrained spaces or land exhausted areas. Precise control of hydroponic nutrients is essential for growing healthy plants and producing high yields. In this article we report for the first time on a new computer-operated analytical platform which can be readily used for the determination of essential nutrients in hydroponic growing systems. The liquid-handling system uses inexpensive components (i.e., peristaltic pump and solenoid valves), which are discretely computer-operated to automatically condition, calibrate and clean a multi-probe of solid-contact ion-selective electrodes (ISEs). These ISEs, which are based on carbon nanotubes, offer high portability, robustness and easy maintenance and storage. With this new computer-operated analytical platform we performed automatic measurements of K(+), Ca(2+), NO3(-) and Cl(-) during tomato plants growth in order to assure optimal nutritional uptake and tomato production. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Hydroponics--Studies in Plant Culture With Historical Roots.
Lopez, Luz Maria
1981-01-01
Presents methods for demonstrating and applying scientific principles by growing plants through water culture (hydroponics), including a review of the history of hydroponics, re-creating some early experiments, and setting up a modern hydroponic system. (CS)
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Microbial ecosystem constructed in water for successful organic hydroponics
Makoto Shinohara; Hiromi Ohmori; Yoichi Uehara
2008-01-01
Conventional hydroponics systems generally use only chemical fertilisers, not organic ones, since there are no microbial ecosystems present in such systems to mineralise organic compounds to inorganic nutrients. Addition of organic compounds to the hydroponic solution generally has phytotoxic effects and causes poor plant growth. We developed a novel hydroponic culture method using organic fertiliser. A microbial ecosystem was constructed in hydroponic solution by regulating the amounts of or...
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Lettuce seeds production in hydroponic system
Menezes, Nilson Lemos de; Santos, Osmar Souza dos; Schmidt, Denise
2001-01-01
Sementes de alface das cultivares Deyse e Regina foram produzidas em estufa, no sistema hidropônico, com elevados rendimentos por planta e boa qualidade de sementes, quando comparados a resultados de sistema convencional, de canteiros em campo. Esses dados sugerem estudos de produção de sementes de alface em cultivo protegido.Lettuce seeds of Deyse and Regina cultivars were produced in greenhouse, in hydroponic system, with excelents rendiments per plant and seed quality, when compared to con...
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Tripathi, Prateek; Rabara, Roel C.; Shulaev, Vladimir; Shen, Qingxi J.; Rushton, Paul J.
2015-01-01
The deleterious changes in environmental conditions such as water stress bring physiological and biochemical changes in plants, which results in crop loss. Thus, combating water stress is important for crop improvement to manage the needs of growing population. Utilization of hydroponics system in growing plants is questionable to some researchers, as it does not represent an actual field condition. However, trying to address a complex problem like water stress we have to utilize a simpler growing condition like the hydroponics system wherein every input given to the plants can be controlled. With the advent of high-throughput technologies, it is still challenging to address all levels of the genetic machinery whether a gene, protein, metabolite, and promoter. Thus, using a system of reduced complexity like hydroponics can certainly direct us toward the right candidates, if not completely help us to resolve the issue. PMID:26734044
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Removal of micro-organisms in a small-scale hydroponics wastewater treatment system.
Ottoson, J; Norström, A; Dalhammar, G
2005-01-01
To measure the microbial removal capacity of a small-scale hydroponics wastewater treatment plant. Paired samples were taken from untreated, partly-treated and treated wastewater and analysed for faecal microbial indicators, i.e. coliforms, Escherichia coli, enterococci, Clostridium perfringens spores and somatic coliphages, by culture based methods. Escherichia coli was never detected in effluent water after >5.8-log removal. Enterococci, coliforms, spores and coliphages were removed by 4.5, 4.1, 2.3 and 2.5 log respectively. Most of the removal (60-87%) took place in the latter part of the system because of settling, normal inactivation (retention time 12.7 d) and sand filtration. Time-dependent log-linear removal was shown for spores (k = -0.17 log d(-1), r(2) = 0.99). Hydroponics wastewater treatment removed micro-organisms satisfactorily. Investigations on the microbial removal capacity of hydroponics have only been performed for bacterial indicators. In this study it has been shown that virus and (oo)cyst process indicators were removed and that hydroponics can be an alternative to conventional wastewater treatment.
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A hydroponic system for growing gnotobiotic vs. sterile plants to study phytoremediation processes.
Kurzbaum, E; Kirzhner, F; Armon, R
2014-01-01
In some phytoremediation studies it is desirable to separate and define the specific contribution of plants and root-colonizing bacteria towards contaminant removal. Separating the influence of plants and associated bacteria is a difficult task for soil root environments. Growing plants hydroponically provides more control over the biological factors in contaminant removal. In this study, a hydroponic system was designed to evaluate the role of sterile plant roots, rhizodeposition, and root-associated bacteria in the removal of a model contaminant, phenol. A strain of Pseudomonas pseudoalcaligenes that grows on phenol was inoculated onto plant roots. The introduced biofilm persisted in the root zone and promoted phenol removal over non-augmented controls. These findings indicate that this hydroponic system can be a valuable tool for phytoremediation studies that investigate the effects of biotic and abiotic factors on pollution remediation.
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Nguyen, Nga T; McInturf, Samuel A; Mendoza-Cózatl, David G
2016-07-13
Hydroponic systems have been utilized as one of the standard methods for plant biology research and are also used in commercial production for several crops, including lettuce and tomato. Within the plant research community, numerous hydroponic systems have been designed to study plant responses to biotic and abiotic stresses. Here we present a hydroponic protocol that can be easily implemented in laboratories interested in pursuing studies on plant mineral nutrition. This protocol describes the hydroponic system set up in detail and the preparation of plant material for successful experiments. Most of the materials described in this protocol can be found outside scientific supply companies, making the set up for hydroponic experiments less expensive and convenient. The use of a hydroponic growth system is most advantageous in situations where the nutrient media need to be well controlled and when intact roots need to be harvested for downstream applications. We also demonstrate how nutrient concentrations can be modified to induce plant responses to both essential nutrients and toxic non-essential elements.
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Production of cobia in recirculating systems
Only limited information exists with respect to rearing juvenile cobia Rachycentron canadum to stocker and marketable sizes using recirculating aquaculture systems (RAS). To investigate this topic, two rearing trials were conducted using commercial scale RAS. In Trial 1, juvenile cobia (29 g) we...
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Hydroponic production systems grow plants without soil, relying on a circulating solution to provide the necessary nutrients. Maintaining an optimum nutrient balance in this solution is important for maximizing crop growth and yield. Particularly in closed hydroponic systems it is important to monit...
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Re-circulating linac vacuum system
International Nuclear Information System (INIS)
Wells, Russell P.; Corlett, John N.; Zholents, Alexander A.
2003-01-01
The vacuum system for a proposed 2.5 GeV, 10ΜA recirculating linac synchrotron light source [1] is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads directly to relatively high limits on the background gas pressure through much of the facility. The 10ΜA average beam current produces very little synchrotron radiation induced gas desorption and thus the need for an ante-chamber in the vacuum chamber is eliminated. In the arc bend magnets, and the insertion devices, the vacuum chamber dimensions can be selected to balance the coherent synchrotron radiation and resistive wall wakefield effects, while maintaining the modest limits on the gas pressure and minimal outgassing
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Root-Contact/Pressure-Plate Assembly For Hydroponic System
Morris, Carlton E.; Loretan, Philip A.; Bonsi, Conrad K.; Hill, Walter A.
1994-01-01
Hydroponic system includes growth channels equipped with rootcontact/pressure-plate assemblies. Pump and associated plumbing circulate nutrient liquid from reservoir, along bottom of growth channels, and back to reservoir. Root-contact/pressure-plate assembly in each growth channel stimulates growth of roots by applying mild contact pressure. Flat plate and plate connectors, together constitute pressure plate, free to move upward to accommodate growth of roots. System used for growing sweetpotatoes and possibly other tuber and root crops.
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Steucek, G. L.; Yurkiewicz, W. J.
1973-01-01
Describes a hydroponic culture technique suitable for student exercises in biology. This technique of growing plants in nutrient solutions enhances plant growth, and is an excellent way to obtain intact plants with root systems free of soil or other particulate matter. (JR)
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Prediction system of hydroponic plant growth and development using algorithm Fuzzy Mamdani method
Sudana, I. Made; Purnawirawan, Okta; Arief, Ulfa Mediaty
2017-03-01
Hydroponics is a method of farming without soil. One of the Hydroponic plants is Watercress (Nasturtium Officinale). The development and growth process of hydroponic Watercress was influenced by levels of nutrients, acidity and temperature. The independent variables can be used as input variable system to predict the value level of plants growth and development. The prediction system is using Fuzzy Algorithm Mamdani method. This system was built to implement the function of Fuzzy Inference System (Fuzzy Inference System/FIS) as a part of the Fuzzy Logic Toolbox (FLT) by using MATLAB R2007b. FIS is a computing system that works on the principle of fuzzy reasoning which is similar to humans' reasoning. Basically FIS consists of four units which are fuzzification unit, fuzzy logic reasoning unit, base knowledge unit and defuzzification unit. In addition to know the effect of independent variables on the plants growth and development that can be visualized with the function diagram of FIS output surface that is shaped three-dimensional, and statistical tests based on the data from the prediction system using multiple linear regression method, which includes multiple linear regression analysis, T test, F test, the coefficient of determination and donations predictor that are calculated using SPSS (Statistical Product and Service Solutions) software applications.
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KE basin recirculation/skimmer/IX systems restart acceptance test report
International Nuclear Information System (INIS)
Derosa, D.C.
1996-01-01
The 105 KE Basin Recirculation System and Skimmer Loop have been upgraded to provide the flexibility to run the Ion Exchange Modules on either system to support spent fuel removal for the Spent Nuclear Fuel Project. This Acceptance Test Report Provides the documentation of the leak Testing for the construction work associated with the IXM inlet and outlet piping, places the cartridge filters back in service and provides the functional testing of the IXM's on the recirculation and skimmer systems
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Hydroponic cultivation of Oncidium baueri
Directory of Open Access Journals (Sweden)
Daniele Brandstetter Rodrigues
2017-08-01
Full Text Available In Brazil, orchid cultivation has been increasing steadily over the last few years and contributing significantly to the economy. It has been reported that several vegetable crops and ornamentals have been successfully grown by soilless cultivation. The orchid Oncidium baueri Lindl. is grown on pot substrates. Nevertheless, hydroponics is an excellent alternative, especially for the production of cut flowers and bare root plants. The objective of this study was to evaluate the development of Oncidium baueri on two soilless systems: (a pots containing Amafibra® coconut fiber, carbonized rice husk, and pine bark (1:1:1 irrigated with nutrient solution every 15 d; and (b a nutrient film technique (NFT hydroponic system irrigated with nutrient solution daily. Shoot height, pseudobulb diameter, and number of sprouts were evaluated monthly. The number of flowering plants, number of flowers, dry mass of shoots, and dry mass of roots were evaluated 11 months after onset of experiment. The pot cultivation system yielded more flowers and higher values for all vegetative parameters than the NFT hydroponic system.
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Hydroponic cultivation of soybean for Bioregenerative Life Support Systems (BLSSs)
De Pascale, Stefania; De Micco, Veronica; Aronne, Giovanna; Paradiso, Roberta
For long time our research group has been involved in experiments aiming to evaluate the possibility to cultivate plants in Space to regenerate resources and produce food. Apart from investigating the response of specific growth processes (at morpho-functional levels) to space factors (namely microgravity and ionising radiation), wide attention has been dedicated to agro-technologies applied to ecologically closed systems. Based on technical and human dietary requirements, soybean [Glycine max (L.) Merr.] is studied as one of the candidate species for hydroponic (soilless) cultivation in the research program MELiSSA (Micro-Ecological Life Support System Alternative) of the European Space Agency (ESA). Soybean seeds show high nutritional value, due to the relevant content of protein, lipids, dietary fiber and biologically active substances such as isoflavones. They can produce fresh sprouts or be transformed in several edible products (soymilk and okara or soy pulp). Soybean is traditionally grown in open field where specific interactions with soil microrganisms occur. Most available information on plant growth, seed productivity and nutrient composition relate to cultivated varieties (cultivars) selected for soil cultivation. However, in a space outpost, plant cultivation would rely on soilless systems. Given that plant growth, seed yield and quality strictly depend on the environmental conditions, to make successful the cultivation of soybean in space, it was necessary to screen all agronomic information according to space constraints. Indeed, selected cultivars have to comply with the space growth environment while providing a suitable nutritional quality to fulfill the astronauts needs. We proposed an objective criterion for the preliminary theoretical selection of the most suitable cultivars for seed production, which were subsequently evaluated in bench tests in hydroponics. Several Space-oriented experiments were carried out in a closed growth chamber to
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Particle surface area and bacterial activity in recirculating aquaculture systems
DEFF Research Database (Denmark)
Pedersen, Per Bovbjerg; von Ahnen, Mathis; Fernandes, Paulo
2017-01-01
Suspended particles in recirculating aquaculture systems (RAS) provide surface area that can be colonized by bacteria. More particles accumulate as the intensity of recirculation increases thus potentially increasing the bacterial carrying capacity of the systems. Applying a recent, rapid, culture...... but may provide significant surface area. Hence, the study substantiates that particles in RAS provide surface area supporting bacterial activity, and that particles play a key role in controlling the bacterial carrying capacity at least in less intensive RAS. Applying fast, culture-independent techniques......-independent fluorometric detection method (Bactiquant®) for measuring bacterial activity, the current study explored the relationship between total particle surface area (TSA, derived from the size distribution of particles >5 μm) and bacterial activity in freshwater RAS operated at increasing intensity of recirculation...
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Hydroponics reducing effluent's heavy metals discharge.
Rababah, Abdellah; Al-Shuha, Ahmad
2009-01-01
This paper investigates the capacity of Nutrient Film Technique (NFT) to control effluent's heavy metals discharge. A commercial hydroponic system was adapted to irrigate lettuces with primary treated wastewater for studying the potential heavy metals removal. A second commercial hydroponic system was used to irrigate the same type of lettuces with nutrient solution and this system was used as a control. Results showed that lettuces grew well when irrigated with primary treated effluent in the commercial hydroponic system. The NFT-plant system heavy metals removal efficiency varied amongst the different elements, The system's removal efficiency for Cr was more than 92%, Ni more than 85%, in addition to more than 60% reduction of B, Pb, and Zn. Nonetheless, the NFT-plants system removal efficiencies for As, Cd and Cu were lower than 30%. Results show that lettuces accumulated heavy metals in leaves at concentrations higher than the maximum acceptable European and Australian levels. Therefore, non-edible plants such as flowers or pyrethrum are recommended as value added crops for the proposed NFT.
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Evaluation of a rainbow trout (Oncorhynchus mikyss culture water recirculating system
Directory of Open Access Journals (Sweden)
Iván Sánchez O.
2014-09-01
Full Text Available Objective. To evaluate a water recirculation system for rainbow trout fish cultures at the recirculating laboratory of the Aquaculture Engineering Production Program of University of Nariño. Materials and Methods. 324 rainbow trout (Oncorhynchus mikyss fries were cultured in 12 plastic tanks with a capacity of 250 L in an aquaculture recirculating system the treatment system of which was made up by a conventional sedimentation tank, a fixed stand upflow biofilter with recycled PVC tube pieces and a natural degassing system; the sedimentation unit effluent was pumped up to a reservoir tank using a 2 HP centrifugal pump after being subject to gravity through the biofilter and to be then distributed to the 12 culture units to which a constant amount of air from a blower was injected. Results. The water treatment system removed 31% of total suspended solids, 9.5% of total ammonia nitrogen, and increased dissolved oxygen to the final effluent in 6.5%. An increase of 305% in biomass was calculated during 75 days, the mortality percentage registered throughout the study period was 4.9%. Conclusions. The water treatment system maintained the physicochemical water quality parameters within the values recommended for the species. The increase in weight and size, food conversion, mortality and biomass production reported normal values for rainbow trout fish culture in recirculating systems.
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Seismic proving test of BWR primary loop recirculation system
International Nuclear Information System (INIS)
Sato, H.; Shigeta, M.; Karasawa, Y.
1987-01-01
The seismic proving test of BWR Primary Loop Recirculation system is the second test to use the large-scale, high-performance vibration table of Tadotsu Engineering Laboratory. The purpose of this test is to prove the seismic reliability of the primary loop recirculation system (PLR), one of the most important safety components in the BWR nuclear plants, and also to confirm the adequacy of seismic analysis method used in the current seismic design. To achieve the purpose, the test was conducted under conditions and scale as near as possible to actual systems. The strength proving test was carried out with the test model mounted on the vibration table in consideration of basic design earthquake ground motions and other conditions to confirm the soundness of structure and the strength against earthquakes. Detailed analysis and analytic evaluation of the data obtained from the test was conducted to confirm the adequacy of the seismic analysis method and earthquake response analysis method used in the current seismic design. Then, on the basis of the results obtained, the seismic safety and reliability of BWR primary loop recirculation of the actual plants was fully evaluated
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Preoperational test report, recirculation ventilation systems
Energy Technology Data Exchange (ETDEWEB)
Clifton, F.T.
1997-11-11
This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.
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Preoperational test report, recirculation ventilation systems
International Nuclear Information System (INIS)
Clifton, F.T.
1997-01-01
This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System
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Phytoaccumulation of antimicrobials by hydroponic Cucurbita pepo.
Aryal, Niroj; Reinhold, Dawn
2013-01-01
Consumer use of antimicrobial-containing products continuously introduces triclocarban and triclosan into the environment. Triclocarban and triclosan adversely affect plants and animals and have the potential to affect human health. Research examined the phytoaccumulation of triclocarban and triclosan by pumpkin (Cucurbita pepo cultivar Howden) and zucchini (Cucurbita pepo cultivar Gold Rush) grown hydroponically. Pumpkin and zucchini were grown in nutrient solution spiked with 0.315 microg/mL triclocarban and 0.289 microg/mL triclosan for two months. Concentrations of triclocarban and triclosan in nutrient solutions were monitored weekly. At the end of the trial, roots and shoots were analyzed for triclocarban and triclosan. Research demonstrated that pumpkin and zucchini accumulated triclocarban and triclosan. Root accumulation factors were 1.78 and 0.64 and translocation factors were 0.001 and 0.082 for triclocarban and triclosan, respectively. The results of this experiment were compared with a previous soil column study that represented environmentally relevant exposure of antimicrobials from biosolids and had similar root mass. Plants were not as efficient in removing triclocarban and triclosan in hydroponic systems as in soil systems. Shoot concentrations of antimicrobials were the same or lower in hydroponic systems than in soil columns, indicating that hydroponic system does not overpredict the concentrations of antimicrobials.
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Carver, Jeffrey; Wasserman, Bradley
2012-01-01
Hydroponics is a process in which plants are grown using nutrient-rich water instead of soil. Because this process maximizes the use of water and nutrients--providing only what the plant uses in controlled and easily maintained systems--it is a viable alternative to traditional farming methods. The amount of control in these systems also ensures…
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Cs phytoremediation by Sorghum bicolor cultivated in soil and in hydroponic system.
Wang, Xu; Chen, Can; Wang, Jianlong
2017-04-03
Cs accumulation characteristics by Sorghum bicolor were investigated in hydroponic system (Cs level at 50-1000 μmol/L) and in soil (Cs-spiked concentration was 100 and 400 mg/kg soil). Two varieties of S. bicolor Cowly and Nengsi 2# grown on pot soil during the entire growth period (100 days) did not show significant differences on the height, dry weight (DW), and Cs accumulation. S. bicolor showed the potential phytoextraction ability for Cs-contaminated soil with the bioaccumulation factor (BCF) and the translocation factor (TF) values usually higher than 1 in soil system and in hydroponic system. The aerial parts of S. bicolor contributed to 86-92% of the total removed amounts of Cs from soil. Cs level in solution at 100 μmol/L gave the highest BCF and TF values of S. bicolor. Cs at low level tended to transfer to the aerial parts, whereas Cs at high level decreased the transfer ratio from root to shoot. In soil, the plant grew well when Cs spiked level was 100 mg/kg soil, but was inhibited by Cs at 400 mg/kg soil with Cs content in sorghum reaching 1147 mg/kg (roots), 2473 mg/kg (stems), and 2939 mg/kg (leaves). In hydroponic system, average Cs level in sorghum reached 5270 mg/kg (roots) and 4513 mg/kg (aerial parts), without significant damages to its biomass at 30 days after starting Cs treatment. Cs accumulation in sorghum tissues was positively correlated with the metal concentration in medium.
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Dedicated exhaust gas recirculation control systems and methods
Sczomak, David P.; Narayanaswamy, Kushal; Keating, Edward J.
2018-05-01
An engine control system of a vehicle includes a fuel control module that controls fuel injection of a first cylinder of an engine based on a first target air/fuel ratio that is fuel lean relative to a stoichiometric air/fuel ratio and that controls fuel injection of a second cylinder of the engine based on a second target air/fuel ratio that is fuel rich relative to stoichiometry. The first cylinder outputs exhaust to a first three way catalyst (TWC), and the second cylinder outputs exhaust to an exhaust gas recirculation (EGR) valve. An EGR control module controls opening of the EGR valve to: (i) a second TWC that reacts with nitrogen oxides (NOx) in the exhaust and outputs ammonia to a selective catalytic reduction (SCR) catalyst; and (ii) a conduit that recirculates exhaust back to an intake system of the engine.
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Optimization of recirculating laminar air flow in operating room air conditioning systems
Directory of Open Access Journals (Sweden)
Enver Yalcin
2016-04-01
Full Text Available The laminar flow air-conditioning system with 100% fresh air is used in almost all operating rooms without discrimination in Turkey. The laminar flow device which is working with 100% fresh air should be absolutely used in Type 1A operating rooms. However, there is not mandatory to use of 100% fresh air for Type 1B defined as places performed simpler operation. Compared with recirculating laminar flow, energy needs of the laminar flow with 100 % fresh air has been emerged about 40% more than re-circulated air flow. Therefore, when a recirculating laminar flow device is operated instead of laminar flow system with 100% fresh air in the Type 1B operating room, annual energy consumption will be reduced. In this study, in an operating room with recirculating laminar flow, optimal conditions have been investigated in order to obtain laminar flow form by analyzing velocity distributions at various supply velocities by using computational fluid dynamics method (CFD.
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Os, van Erik; Waked, Laith; Blok, Chris
2016-01-01
From January 25-29 2016 Wageningen UR Greenhouse Horticulture organized a Hydroponic Training for Jordan researcher and consultants. The order was supplied by Ecoconsult (Hydroponic Green Farming Initiative) from Jordan and funded by USAID. Presentations were delivered in the field of growing
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Directory of Open Access Journals (Sweden)
I Ketut Budaraga
2017-05-01
Full Text Available Current conditions especially in urban agricultural land is getting narrower due to the rapid development. If left untreated it can lead to food security and environmental problems. One solution to allow the fulfillment of foodstuffs such as vegetables can be fulfilled for the people to exploit the potential of the narrow yard with continuous production of hydroponic systems. Interest dedication to the community to find ways to introduce a hydroponic vegetable crops that can supplement the family income of farmers. Benefits of the service is expected to increase peoples income and the public generally in Community Economic Zone KEM Kanagarian Tikalak in particular and can provide lucrative benefits for the environment. Devotion execution method implemented by a lecture and demonstration. The materials used such as husks seeds of vegetables kale collards caisin hydroponic media such as slug biogas rope bamboo to place the plants grow. The results of this activity the community has been able to make a hydroponic vegetable cultivation system and has been applied to plant vegetables such as kale collards and caisin.
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Vessey, J. K.; York, E. K.; Henry, L. T.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)
1988-01-01
A portable system of hydroponic culture was developed that maintained temperature, pH, and nutrient concentrations of circulating nutrient solutions. The hydroponic system is used within a controlled-environment room (CER) for control of aerial environment. The CER was equipped with an auto-calibrating system for atmospheric CO2 control. The control systems for the hydroponic chambers were able to maintain acidity within +/- 0.2 pH units and the temperature with +/- 0.5 degree C. Mixing time for the 200-liter volume of solution within a hydroponic chamber was less than 12 min. The CO2 control system was able to maintain aerial concentrations within +/- 10 ppm CO2 during the light period. The only gradient found to occur within the hydroponic chambers or CER was a slight gradient in aerial temperature along the length of hydroponic chambers. Growth of soybeans [Glycine max (L.) Merr.] was characterized during a 3-week period of vegetative development by leaf number and area, plant dry weight, total N content of plants, and N depletion from the nutrient solution. The growth characteristics among populations for three hydroponic chambers within the CER were not significantly different, and the percent standard errors of means of the measurements within populations from each chamber were nearly all less than 10%. Thus, the uniformity of plant growth reflected the uniformity of environmental conditions.
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Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy; Shaffer, Jason Brian; York, William David
2014-05-13
A power plant is provided and includes a gas turbine engine having a combustor in which compressed gas and fuel are mixed and combusted, first and second supply lines respectively coupled to the combustor and respectively configured to supply the compressed gas and the fuel to the combustor and an exhaust gas recirculation (EGR) system to re-circulate exhaust gas produced by the gas turbine engine toward the combustor. The EGR system is coupled to the first and second supply lines and configured to combine first and second portions of the re-circulated exhaust gas with the compressed gas and the fuel at the first and second supply lines, respectively.
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A Simplified Integrated Fish Culture Hydroponics System.
Emberger, Gary
1991-01-01
Investigations that facilitate experimental design, the concept of replication, data analysis, and other aspects of scientific study are described. A list of materials, the recommended plants, and the directions for building the hydroponics unit are included. (KR)
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Reuse of hydroponic waste solution.
Kumar, Ramasamy Rajesh; Cho, Jae Young
2014-01-01
Attaining sustainable agriculture is a key goal in many parts of the world. The increased environmental awareness and the ongoing attempts to execute agricultural practices that are economically feasible and environmentally safe promote the use of hydroponic cultivation. Hydroponics is a technology for growing plants in nutrient solutions with or without the use of artificial medium to provide mechanical support. Major problems for hydroponic cultivation are higher operational cost and the causing of pollution due to discharge of waste nutrient solution. The nutrient effluent released into the environment can have negative impacts on the surrounding ecosystems as well as the potential to contaminate the groundwater utilized by humans for drinking purposes. The reuse of non-recycled, nutrient-rich hydroponic waste solution for growing plants in greenhouses is the possible way to control environmental pollution. Many researchers have successfully grown several plant species in hydroponic waste solution with high yield. Hence, this review addresses the problems associated with the release of hydroponic waste solution into the environment and possible reuse of hydroponic waste solution as an alternative resource for agriculture development and to control environmental pollution.
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Mo, Qianzhen; Mai, Rongjia; Yang, Zhixiao; Chen, Minfang; Yang, Tiezhao; Lai, Huafang; Yang, Peiliang; Chen, Qiang; Zhou, Xiaohong
2012-06-01
To develop a hydroponic Nicotiana cultivation system for rapid and high-yield transient expression of recombinant proteins under laboratory conditions. To establish the hydroponic cultivation system, several parameters were examined to define the optimal conditions for the expression of recombinant proteins in plants. We used the green fluorescent protein (GFP) and the geminiviral plant transient expression vector as the model protein/expression vector. We examined the impact of Nicotiana species, the density and time of Agrobacterium infiltration, and the post-infiltration growth period on the accumulation of GFP. The expression levels of GFP in Nicotiana leaves were then examined by Western blotting and ELISA. Our data indicated that a hydroponic Nicotiana cultivation system with a light intensity of 9000 LX/layer, a light cycle of 16 h day/8 h night, a temperature regime of 28 degrees celsius; day/21 degrees celsius; night, and a relative humidity of 80% could support the optimal plant growth and protein expression. After agroinfiltration with pBYGFPDsRed.R/LBA4404, high levels of GFP expression were observed in both N. benthamiana and N. tobaccum (cv. Yuyan No.5) plants cultured with this hydroponic cultivation system. An optimal GFP expression was achieved in both Nicotiana species leaves 4 days after infiltration by Agrobacterium with an OD(600) of 0.8. At a given time point, the average biomass of N. tobaccum (cv. Yuyan No.5) was significantly higher than that of N. benthamiana. The leaves from 6-week-old N. benthamiana plants and 5-week-old N. tobaccum (cv. Yuyan No.5) plants could be the optimal material for agroinfiltration. We have established a hydroponic cultivation system that allows robust growth of N. benthamiana and N. tobaccum (cv. Yuyan No.5) plants and the optimal GFP expression in the artificial climate box.
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Closed recirculation-Water treatment
International Nuclear Information System (INIS)
Hamza, Hamza B.; Ben Ali, Salah; Saad, Mohamed A.; Traish, Massud R.
2005-01-01
This water treatment is a practical work applied in the center, for a closed recirculation-water system. The system had experienced a serious corrosion problem, due to the use of inadequate water. This work includes chemical preparation for the system. Water treatment, special additives, and follow-up, which resulted in the stability of the case. This work can be applied specially for closed recirculation warm, normal, and chilled water. (author)
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Recycling of treated domestic effluent from an on-site wastewater treatment system for hydroponics.
Oyama, N; Nair, J; Ho, G E
2005-01-01
An alternative method to conserve water and produce crops in arid regions is through hydroponics. Application of treated wastewater for hydroponics will help in stripping off nutrients from wastewater, maximising reuse through reduced evaporation losses, increasing control on quality of water and reducing risk of pathogen contamination. This study focuses on the efficiency of treated wastewater from an on-site aerobic wastewater treatment unit. The experiment aimed to investigate 1) nutrient reduction 2) microbial reduction and 3) growth rate of plants fed on wastewater compared to a commercial hydroponics medium. The study revealed that the chemical and microbial quality of wastewater after hydroponics was safe and satisfactory for irrigation and plant growth rate in wastewater hydroponics was similar to those grown in a commercial medium.
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Evaluating irrigation scheduling of hydroponic tomato in Navarra, Spain
Lizarraga, H.J.; Boesveld, H.; Huibers, F.P.; Robles, H.
2003-01-01
The correct supply of water and nutrients is important in hydroponic growing systems in order to use water efficiently, avoid stress situations, and control production. The present study was conducted to evaluate two irrigation scheduling techniques for hydroponic tomato production in Navarra,
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Automated pH Control of Nutrient Solution in a Hydroponic Plant Growth System
Smith, B.; Dogan, N.; Aglan, H.; Mortley, D.; Loretan, P.
1998-01-01
Over, the years, NASA has played an important role in providing to and the development of automated nutrient delivery and monitoring, systems for growing crops hydroponically for long term space missions. One example are the systems used in the Biomass Production Chamber (BPC) at Kennedy Space Center (KSC). The current KSC monitoring system is based on an engineering workstation using standard analog/digital input/output hardware and custom written software. The monitoring system uses completely separate sensors to provide a check of control sensor accuracy and has the ability to graphically display and store data form past experiment so that they are available for data analysis [Fortson, 1992]. In many cases, growing systems have not been fitted with the kind of automated control systems as used at KSC. The Center for Food and Environmental Systems for Human Exploration of Space (CFESH) located on the campus of Tuskegee University, has effectively grown sweetpotatoes and peanuts hydroponically for the past five years. However they have adjusted the pH electrical conductivity and volume of the hydroponic nutrient solution only manually at times when the solution was to be replenished or changed out according to its protocol (e.g. one-week, two-week, or two-day cycle). But the pH of the nutrient solution flowing through the channel is neither known nor controlled between the update, change out, or replenishment period. Thus, the pH of the nutrient solution is not held at an optimum level over the span of the plant's growth cycle. To solve this dilemma, an automated system for the control and data logging of pH data relative to sweetpotato production using the nutrient film technique (NFT) has been developed, This paper discusses a microprocessor-based system, which was designed to monitor, control, and record the pH of a nutrient solution used for growing sweetpotatoes using NFT.
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Wang, Minjuan; Fu, Yuming; Liu, Hong
2015-08-01
Hydroponic culture has traditionally been used for Bioregenerative Life Support Systems (BLSS) because the optimal environment for roots supports high growth rates. Recent developments in Porous-tube Nutrient Delivery System (PTNDS) also offer high control of the root environment which is designed to provide a means for accurate environmental control and to allow for two-phase flow separation in microgravity. This study compared the effects of PTNDS and traditional hydroponic cultures on biomass yield, nutritional composition and antioxidant defense system (T-AOC, GSH, H2O2 and MDA) of G. bicolor, and ionic concentration (NH4+, K+, Mg2+, Ca2+, NO3-, H2 PO4-, SO42-) of nutrient solution during planting period in controlled environment chambers. The results indicated that the biomass production and yield of G. bicolor grown in PTNDS were higher than in hydroponic culture, although Relative water content (RWC), leaf length and shoot height were not significantly different. PTNDS cultivation enhanced calories from 139.5 to 182.3 kJ/100 g dry matter, and carbohydrate from 4.8 to 7.3 g/100 g dry matter and reduced the amount of protein from 7.3 to 4.8 g/100 g dry matter and ash from 1.4 to1.0 g/100 g dry matter, compared with hydroponic culture. PTNDS cultivation accumulated the nutrition elements of Ca, Cu, Fe and Zn, and reduced Na concentration. T-AOC and GSH contents were significantly lower in PTNDS than in hydroponic culture in the first harvest. After the first harvest, the contents of MDA and H2O2 were significantly higher in PTNDS than in hydroponic culture. However, the activity of T-AOC and GSH and H2O2 and MDA contents had no significant differences under both cultures after the second and third harvest. Higher concentrations of K+, Mg2+ and Ca2+ were found in nutrient solution of plants grown in hydroponics culture compared to PTNDS, wherein lower concentrations of NO3-, H2 PO4- and SO42- occurred. Our results demonstrate that PTNDS culture has more
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The Effect of Effluent Recirculation in a Semi-Continuous Two-Stage Anaerobic Digestion System
Directory of Open Access Journals (Sweden)
Karthik Rajendran
2013-06-01
Full Text Available The effect of recirculation in increasing organic loading rate (OLR and decreasing hydraulic retention time (HRT in a semi-continuous two-stage anaerobic digestion system using stirred tank reactor (CSTR and an upflow anaerobic sludge bed (UASB was evaluated. Two-parallel processes were in operation for 100 days, one with recirculation (closed system and the other without recirculation (open system. For this purpose, two structurally different carbohydrate-based substrates were used; starch and cotton. The digestion of starch and cotton in the closed system resulted in production of 91% and 80% of the theoretical methane yield during the first 60 days. In contrast, in the open system the methane yield was decreased to 82% and 56% of the theoretical value, for starch and cotton, respectively. The OLR could successfully be increased to 4 gVS/L/day for cotton and 10 gVS/L/day for starch. It is concluded that the recirculation supports the microorganisms for effective hydrolysis of polyhydrocarbons in CSTR and to preserve the nutrients in the system at higher OLRs, thereby improving the overall performance and stability of the process.
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High ratio recirculating gas compressor
Weinbrecht, J.F.
1989-08-22
A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor. 10 figs.
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Control methodologies based on geothermal recirculating aquaculture system
International Nuclear Information System (INIS)
Farghally, Hanaa M.; Atia, Doaa M.; El-madany, Hanaa T.; Fahmy, Faten H.
2014-01-01
One of the most common uses of geothermal heat is in RAS (recirculation aquaculture systems) where the water temperature is accurately controlled for optimum growing conditions for sustainable and intensive rearing of marine and freshwater fish. This paper presents a design for RAS rearing tank and plate type heat exchanger to be used with geothermal energy as a source of heating water. A well at Umm Huweitat on the Red Sea is used as a source of geothermal energy. The heat losses from the RAS tank are calculated using Geo Heat Center Software. Then a plate type heat exchanger is designed using the epsilon–NTU (number of transfer units) analysis method. For optimal growth and abundance of production, a different techniques of control system are applied to control the water temperature. The total system is built in MATLAB/SIMULINK to study the overall performance of control unit. Finally, a comparison between PI, Fuzzy-PID, and Fuzzy Logic Control has been done. - Highlights: • Design recirculating aquaculture system using geothermal energy. • Design a PI controller for water temperature control. • Design a Fuzzy logic controller for water temperature control. • Design a Fuzzy-PID controller for water temperature control. • Comparison between different control systems
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Freshwater Institute: Focused on improving recirculating aquaculture system technology
Recirculating aquaculture system (RAS) technologies help to overcome barriers to domestic aquaculture expansion and enhance the sustainability of the modern fish farming industry through reduction in environmental impacts. With RAS, fish farm expansion is no longer highly constrained by competition ...
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Economic Feasibility of Recirculating Aquaculture Systems in Pangasius Farming
Pham, T.A.N.; Gielen-Meuwissen, M.P.M.; Le, T.C.; Verreth, J.A.J.; Bosma, R.H.; Oude Lansink, A.G.J.M.
2016-01-01
This study aims to analyze the economic feasibility of recirculating aquaculture systems (RAS) in pangasius farming in Vietnam. The study uses a capital budgeting approach and accounts for uncertainty in key parameters. Stochastic simulation is used to simulate the economic performance of medium and
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I Ketut Budaraga; Ramaiyulis; Ellyza nurdin
2017-01-01
Current conditions especially in urban agricultural land is getting narrower due to the rapid development. If left untreated it can lead to food security and environmental problems. One solution to allow the fulfillment of foodstuffs such as vegetables can be fulfilled for the people to exploit the potential of the narrow yard with continuous production of hydroponic systems. Interest dedication to the community to find ways to introduce a hydroponic vegetable crops that can supplement the fa...
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Daily micro particle distribution of an experimental recirculating aquaculture system – A case study
DEFF Research Database (Denmark)
Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg
2014-01-01
The particle size distribution (PSD) in a recirculating aquaculture system (RAS) was investigated duringa 24-h cycle. PSD was analyzed in water sampled at several locations in a recirculation loop containing a60-m drum filter, a submerged fixed-bed biofilter and a trickling filter.In relation...
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Control oriented modeling of ejector in anode gas recirculation solid oxygen fuel cell systems
International Nuclear Information System (INIS)
Zhu Yinhai; Li Yanzhong; Cai Wenjian
2011-01-01
A one-equation model is proposed for fuel ejector in anode gas recirculation solid oxide fuel cell (SOFC) system. Firstly, the fundamental governing equations are established by employing the thermodynamic, fluid dynamic principles and chemical constraints inside the ejector; secondly, the one-equation model is derived by using the parameter analysis and lumped-parameter method. Finally, the computational fluid dynamics (CFD) technique is employed to obtain the source data for determining the model parameters. The effectiveness of the model is studied under a wide range of operation conditions. The effect of ejector performance on the anode gas recirculation SOFC system is also discussed. The presented model, which only contains four constant parameters, is useful in real-time control and optimization of fuel ejector in the anode gas recirculation SOFC system.
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Directory of Open Access Journals (Sweden)
ANGELICA DOCAN
2008-10-01
Full Text Available Recirculating aquaculture offers good potential for successful fish farming since is often independent of environmental conditions. Maintaining healthy fish in a recirculating system involves establishing adequate dissolved oxygen levels, removal of solid wastes, and sufficient ammonia nitrification to assure optimal rearing conditions. Neglecting these, the fish immune system will depress, the facultative pathogen germs will be able to provoke important disease outbreaks into cultured biomass, as was happened in our recirculating pilot system. In this study are presented the pathological aspects registered to the beluga sturgeon of 1 year, reared into our recirculating pilot system, pathological aspects generated by a haemorrhagic bacterial septicaemia which was manifested in the conditions of low concentrations of DO. The disease was diagnosed to the affected fish through anatomopathological and clinical exam, haematological exam and microbiological exam.
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Production of strawberry cultivars in closed hydroponic systems and coconut fibre substrate
Directory of Open Access Journals (Sweden)
Fabio Rodrigues de Miranda
Full Text Available The objective of this work was to evaluate yield and average fruit weight of strawberry cultivars Albion, Camarosa, Festival and Oso Grande, in two closed hydroponic systems (gutters and grow bags, using coconut fibre as substrate. The experimental design was of randomised blocks, divided into strips, with five replications. The hydroponic systems did not differ significantly as to yield, with advantages, such as savings in water and fertilizer and reduced environmental impact, over open systems. The most productive cultivar was Festival, followed by Oso Grande, with average yields of 6.99 kg m-2 and 5.56 kg m-2 respectively. The cultivars with the greatest fruit weight were Oso Grande and Albion, having averages of 11.8 and 11.1 g respectively, with the former being significantly superior to the latter. The highest yield (7.4 kg m-2 was obtained from the cultivar Festival under the gutter system. The Ibiapaba region has conditions which are favourable to strawberry production in relation to precocity (harvesting starts in the 6th week of growth and production continues throughout the year; however there is a need to test new cultivars and to improve the cultivation techniques with an aim to producing larger-sized fruit.
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Biocompatibility of sweetpotato and peanut in a hydroponic system
Mortley, D. G.; Loretan, P. A.; Hill, W. A.; Bonsi, C. K.; Morris, C. E.; Hall, R.; Sullen, D.
1998-01-01
'Georgia Red' peanut (Arachis hypogaea L.) and TU-82-155 sweetpotato [Ipomoea batatas (L.) Lam] were grown in monocultured or intercropped recirculating hydroponic systems in a greenhouse using the nutrient film technique (NFT). The objective was to determine whether growth and subsequent yield would be affected by intercropping. Treatments were sweetpotato monoculture (SP), peanut monoculture (PN), and sweetpotato and peanut grown in separate NFT channels but sharing a common nutrient solution (SP-PN). Greenhouse conditions ranged from 24 to 33 degrees C, 60% to 90% relative humidity (RH), and photosynthetic photon flux (PPF) of 200 to 1700 micromoles m-2 s-1. Sweetpotato cuttings (15 cm long) and 14-day-old seedlings of peanuts were planted into growth channels (0.15 x 0.15 x 1.2 m). Plants were spaced 25 cm apart within and 25 cm apart between growing channels. A modified half-Hoagland solution with a 1 N: 2.4 K ratio was used. Solution pH was maintained between 5.5 and 6.0 for treatments involving SP and 6.4 and 6.7 for PN. Electrical conductivity (EC) ranged between 1100 and 1200 microS cm-1. The number of storage roots per sweetpotato plant was similar for both SP and SP-PN. Storage root fresh and dry mass were 29% and 36% greater, respectively, for plants in the SP-PN treatment than for plants in the SP treatment. The percent dry mass of the storage roots, dry mass of fibrous and pencil roots, and the length-to-diameter ratio of storage roots were similar for SP and SP-PN sweetpotato plants. Likewise, foliage fresh and dry mass and harvest index were not significantly influenced by treatment. Total dry mass was 37% greater for PN than for SP-PN peanut plants, and pod dry mass was 82% higher. Mature and total seed dry mass and fibrous root dry mass were significantly greater for PN than for SP-PN plants. Harvest index (HI) was similar for both treatments. Root length tended to be lower for seedlings grown in the nutrient solution from the SP-PN treatment.
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DEFF Research Database (Denmark)
Hambly, Adam; Arvin, Erik; Pedersen, Lars-Flemming
2015-01-01
The potential of recirculating aquaculture systems (RAS) in the aquaculture industry is increasingly being acknowledged. Along with intensified application, the need to better characterise and understand the accumulated dissolved organic matter (DOM) within these systems increases. Mature RASs...
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Steroids accumulate in the rearing water of commercial recirculating aquaculture systems
Mota, V.C.; Martins, C.I.; Eding, E.H.; Canário, A.V.M.; Verreth, J.A.J.
2014-01-01
Little information is available on steroid concentrations in the rearing water of aquaculture systems and whether they accumulate in recirculating aquaculture systems (RAS). Therefore this study aimed at determining (1) the concentrations and variation of cortisol and sex steroids in RAS, (2) the
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Xiao, Zhenlei; Bauchan, Gary; Nichols-Russell, Lydia; Luo, Yaguang; Wang, Qin; Nou, Xiangwu
2015-10-01
Radish (Raphanus sativus var. longipinnatus) microgreens were produced from seeds inoculated with Escherichia coli O157:H7 by using peat moss-based soil-substitute and hydroponic production systems. E. coli populations on the edible and inedible parts of harvested microgreen plants (7 days postseeding) and in growth medium were examined. E. coli O157:H7 was shown to survive and proliferate significantly during microgreen growth in both production systems, with a higher level in the hydroponic production system. At the initial seed inoculation level of 3.7 log CFU/g, E. coli O157:H7 populations on the edible part of microgreen plants reached 2.3 and 2.1 log CFU/g (overhead irrigation and bottom irrigation, respectively) for microgreens from the soil-substitute production system and reached 5.7 log CFU/g for those hydroponically grown. At a higher initial inoculation of 5.6 log CFU/g seeds, the corresponding E. coli O157:H7 populations on the edible parts of microgreens grown in these production systems were 3.4, 3.6, and 5.3 log CFU/g, respectively. Examination of the spatial distribution of bacterial cells on different parts of microgreen plants showed that contaminated seeds led to systematic contamination of whole plants, including both edible and inedible parts, and seed coats remained the focal point of E. coli O157:H7 survival and growth throughout the period of microgreen production.
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Hoffmann, Astrid; Maurer, Andreas; Pillen, Klaus
2012-10-20
In this report we studied the genetic regulation of juvenile development of wild barley introgression lines (S42ILs) under two contrasting hydroponic nitrogen (N) supplies. Ten shoot and root related traits were examined among 42 S42ILs and the recurrent parent 'Scarlett'. The traits included tiller number, leaf number, plant height, leaf and root length, leaf to root length ratio, shoots and root dry weight, shoot to root weight ratio, and chlorophyll content. Our aims were (1) to test the suitability of a hydroponic system for early detection of favourable S42ILs, (2) to locate quantitative trait loci (QTL) that control the examined traits, (3) to identify favourable wild barley alleles that improve trait performances in regard to N treatment and, finally, (4) to validate the identified QTL through comparison with previously reported QTL originating from the same parental cross. The phenotypic data were analysed in a mixed model association study to detect QTL. The post-hoc Dunnett test identified 28 S42ILs that revealed significant (P hydroponic N study corresponded to QTL that were also detected in field trials with adult plants of a similar S42IL set or of the original S42 population. For instance, S42IL-135, -136 and -137, revealed increasing Hsp effects for tiller number, leaf number, leaf length, plant height and leaf to root ratio on the long arm of chromosome 7H. These QTL correspond to QTL for ears per plant and plant height that were previously detected in field trials conducted with the same S42ILs or with the S42 population. Our results suggest that the QTL we identified under hydroponic N cultivation partly correspond to QTL detected in field experiments. Due to this finding, screening of plants in early developmental stages grown in a hydroponic system may be a fast and cost effective method for early QTL detection and marker-assisted allelic selection, potentially speeding up elite barley breeding programs.
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Technology development for recirculating heavy-ion accelerators
International Nuclear Information System (INIS)
Newton, M.A.; Kirbie, H.C.
1993-01-01
The open-quotes recirculator,close quotes a recirculating heavy-ion accelerator has been identified as a promising approach for an inertial fusion driver. System studies have been conducted to evaluate the recirculator on the basis of feasibility and cost. The recirculator has been shown to have significant cost advantages over other potential driver schemes, but some of the performance requirements exceed the capabilities of present technology. The system studies identified the high leverage areas where advances in technology will significantly impact the cost and performance of a recirculator. One of the high leverage areas is the modulator system which generates the acceleration potentials in the induction cells. The modulator system must be capable of generating the acceleration potentials at peak repetition rates in excess of 100 kHz with variable pulse widths. LLNL is developing a modulator technology capable of driving induction cells using the latest in solid state MOSFET technology. A small scale modulator has been built and tested to prove the concept and the next version is presently being designed. The objective is to demonstrate a modulator operating at 5 kV, 1 kA, with 0.2--1 μs pulse widths while driving an induction cell at >100 kHz within the next year. This paper describes the recirculator, the technology requirements necessary to implement it and the modulator system development that is being pursued to meet these requirements
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Engine with exhaust gas recirculation system and variable geometry turbocharger
Keating, Edward J.
2015-11-03
An engine assembly includes an intake assembly, an internal combustion engine defining a plurality of cylinders and configured to combust a fuel and produce exhaust gas, and an exhaust assembly in fluid communication with a first subset of the plurality of cylinders. Each of the plurality of cylinders are provided in fluid communication with the intake assembly. The exhaust assembly is provided in fluid communication with a first subset of the plurality of cylinders, and a dedicated exhaust gas recirculation system in fluid communication with both a second subset of the plurality of cylinders and with the intake assembly. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the second subset of the plurality of cylinders to the intake assembly. Finally, the engine assembly includes a turbocharger having a variable geometry turbine in fluid communication with the exhaust assembly.
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Kanjanamaneesathian, Mana
2015-01-01
In Thailand, yield loss due to plant diseases in vegetables grown hydroponically is very high as a result of the growers` lack of knowledge for controlling diseases and their un- willingness to invest in setting-up the proper hydroponic system from the beginning. Severe root rot disease caused by Pythium spp. is frequent and can be anticipated in the hot climate in Thailand. This review focuses on the diseases in temperate lettuces which have been produced hydroponically and have been attacked by plant pathogens, particularly Pythium spp. Biological control of vegetable diseases grown hydroponically has been investigated in Thailand. Research is being carried out to identify effective strains of the antagonists, formulating the applicable products and delivering them appropriately to control the disease. Products of Bacillus subtilis, Chaetomium globosom and Trichoderma harzianum have been recommended for use to control diseases in vegetables grown hydroponically. Control efficacy of these products is varied as the biological products have been used by the growers in the paradigm of using chemical fungicide for disease control in hydroponic production system, overlooking the intrinsic characteristics of the biological control products. The recent patent, which minimizes the effects of sunlight and heat on the nutrient solution without the use of an external energy for cooling the nutrient, should be applied in producing hydroponic vegetables to mitigate poor plant growth and root rot disease outbreak in Thailand.
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National Research Council Canada - National Science Library
Resh, Howard M
2013-01-01
Hydroponic Food Production: A Definitive Guidebook for the Advanced Home Gardener and the Commercial Hydroponic Grower details advances that have taken place in this field since the publication of the previous edition in 2001...
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2013-01-01
Background Hydroponic growth systems are a convenient platform for studying whole plant physiology. However, we found through trialling systems as they are described in the literature that our experiments were frequently confounded by factors that affected plant growth, including algal contamination and hypoxia. We also found the way in which the plants were grown made them poorly amenable to a number of common physiological assays. Results The drivers for the development of this hydroponic system were: 1) the exclusion of light from the growth solution; 2) to simplify the handling of individual plants, and 3) the growth of the plant to allow easy implementation of multiple assays. These aims were all met by the use of pierced lids of black microcentrifuge tubes. Seed was germinated on a lid filled with an agar-containing germination media immersed in the same solution. Following germination, the liquid growth media was exchanged with the experimental solution, and after 14-21 days seedlings were transferred to larger tanks with aerated solution where they remained until experimentation. We provide details of the protocol including composition of the basal growth solution, and separate solutions with altered calcium, magnesium, potassium or sodium supply whilst maintaining the activity of the majority of other ions. We demonstrate the adaptability of this system for: gas exchange measurement on single leaves and whole plants; qRT-PCR to probe the transcriptional response of roots or shoots to altered nutrient composition in the growth solution (we demonstrate this using high and low calcium supply); producing highly competent mesophyll protoplasts; and, accelerating the screening of Arabidopsis transformants. This system is also ideal for manipulating plants for micropipette techniques such as electrophysiology or SiCSA. Conclusions We present an optimised plant hydroponic culture system that can be quickly and cheaply constructed, and produces plants with similar
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Björn Baßmann; Matthias Brenner; Harry W. Palm
2017-01-01
African catfish (Clarias gariepinus) were investigated for physiological stress parameters to assess the influence of different cultivation techniques on fish welfare. The fish were reared in two conceptually identical recirculating aquaculture systems (RAS) constructed in a greenhouse. One system was combined with a floating raft hydroponic unit to culture cucumbers (Cucumis sativus) only using the process water. The second system remained without the plant cultivation unit and functioned as...
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Hydroponic cultivation techniques: good results with Eg system
Energy Technology Data Exchange (ETDEWEB)
Mimiola, G; Sigliuzzo, C [Tecnagro, Valenzano (Italy)
1988-12-01
This report describes results obtained at the Tecnagro agronomic institute (Valenzano, Italy) in which research is being carried out on the use of the Eg hydroponic system developed in Israel. The research program examined the following: composition of nutritive solutions for ornamental plants and vegetables, methods of application of nutritive substances, breeding densities for ornamental plants and vegetables. Successful nutritive formulas were obtained which resulted, in the case of ornamental plants, in increases in plant height (from 30 to 50%), foliage area (50%), as well as, in shortened growth cycles. For vegetables, shortened growth cycles were developed along with a greater and more consistant production. From the economics point of view, tomatoes proved to be the best choice of vegetable for cultivation with the Eg technique.
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National Research Council Canada - National Science Library
Resh, Howard M
2013-01-01
.... Meant for hobby and commercial growers, the book shows readers how to set up a hydroponic operation with the options of using any of the many hydroponic cultures presently used in the industry to grow vegetable crops...
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Exploring Classroom Hydroponics. Growing Ideas.
National Gardening Association, Burlington, VT.
Growing Ideas, the National Gardening Association's series for elementary, middle, and junior high school educators, helps teachers engage students in using plants and gardens as contexts for developing a deeper, richer understanding of the world around them. This volume's focus is on hydroponics. It presents basic hydroponics information along…
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Carotenoid composition of hydroponic leafy vegetables.
Kimura, Mieko; Rodriguez-Amaya, Delia B
2003-04-23
Because hydroponic production of vegetables is becoming more common, the carotenoid composition of hydroponic leafy vegetables commercialized in Campinas, Brazil, was determined. All samples were collected and analyzed in winter. Lactucaxanthin was quantified for the first time and was found to have concentrations similar to that of neoxanthin in the four types of lettuce analyzed. Lutein predominated in cress, chicory, and roquette (75.4 +/- 10.2, 57.0 +/- 10.3, and 52.2 +/- 12.6 microg/g, respectively). In the lactucaxanthin-containing lettuces, beta-carotene and lutein were the principal carotenoids (ranging from 9.9 +/- 1.5 to 24.6 +/- 3.1 microg/g and from 10.2 +/- 1.0 to 22.9 +/- 2.6 microg/g, respectively). Comparison of hydroponic and field-produced curly lettuce, taken from neighboring farms, showed that the hydroponic lettuce had significantly lower lutein, beta-carotene, violaxanthin, and neoxanthin contents than the conventionally produced lettuce. Because the hydroponic farm had a polyethylene covering, less exposure to sunlight and lower temperatures may have decreased carotenogenesis.
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Energy Technology Data Exchange (ETDEWEB)
Mayrapetyan, Khachatur; Hovsepyan, Albert; Daryadar, Mahsa; Alexanyan, Julietta; Tovmasyan, Anahit; Ghalachyan, Laura; Tadevosyan, Anna; Mayrapetyan, Stepan [Institute of Hydroponics Problems, NAS, Noragyugh 108, 0082, Yerevan (Armenia)
2014-07-01
Natural and artificial radionuclides (RN) dangerous for health are emitted into ecosystems because of human anthropogenic activities in the field of nuclear energetics. Biologically artificial RN {sup 90}Sr(T{sub 1/2}=28,6 years) and {sup 137}Cs (T{sub 1/2}=30,1 years)are very dangerous. Therefore obtaining radio-ecologically safe raw material of high quality is a very urgent problem now. Taking into account the above mentioned, in order to obtain ecologically safe raw material we carried out comparative radiochemical investigations on essential oil and medicinal plants peppermint(Mentha piperita L.) and sweet basil (Ocimum basilicum L.) grown in new water-stream (continuous, gully, cylindrical) and classical hydroponics, with the aim of revealing accumulation peculiarities of {sup 90}Sr and {sup 137}Cs. The results of experiments have shown that in classical hydroponics peppermint and sweet basil exceeded the same indices of water-stream hydroponics with {sup 90}Sr and {sup 137}Cs content 1,1-1,2; 1,2-1,3 and 1,5-1,8; 1,4-1,8 times, respectively. Moreover, sweet basil exceeded peppermint in water-stream hydroponics {sup 90}Sr 1,3-1,6; {sup 137}Cs 1,2-1,4 times and in classical hydroponics {sup 90}Sr 1,6; {sup 137}Cs 1,2 times. The content of controlled artificial RN in raw material did not exceed the allowed concentration limit (ACL). New water-stream hydroponics system worked out in Institute of Hydroponics Problems is a radio-ecologically more profitable method for producing raw material than classical hydroponics. At the same time water-stream hydroponics system in comparison with classical hydroponics promoted productivity (dry raw material) increase of peppermint and sweet basil 1,1-1,4 times. (authors)
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Tubtong, Cheevanuch; Towprayoon, Sirintornthep; Connor, Michael Anthony; Chaiprasert, Pawinee; Nopharatana, Annop
2010-09-01
A project was undertaken to examine the feasibility of treating organic wastes from Thai fruit and vegetable markets using the sequential batch anaerobic digester (SEBAR) approach. A key feature of the SEBAR system is the regular interchanging, or recirculation, of portions of leachate between each freshly filled digester and a support digester to which it is coupled until it is ready to operate independently. Leachate transfer from this support digester to the fresh waste digester provides additional alkalinity to help counteract the effects of early high acid release rates; it also helps build a balanced microbial population in the fresh waste digester. To optimize the leachate recirculation process, the effect of varying the quantities of leachate interchanged between freshly filled waste digesters and the still highly active support digesters to which they were coupled was studied. It was found that increasing the recirculation rate accelerated the onset of both waste degradation and methane production. The increasing of recirculation rate from 10% to 20% and 10% to 30% could reduce the SEBAR cycle period by approximately 7% and 22% without significant reduction in the amount of methane obtained from the systems. The methane yields were 0.0063, 0.0068 and 0.0077 l g(-1) VS added in the NEW digester per day using leachate recirculation rates of 10%, 20% and 30%, respectively. This finding has potentially important practical and economic implications for those using the SEBAR system to add value to market waste.
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BWR series pump recirculation system
International Nuclear Information System (INIS)
Dillmann, C.W.
1992-01-01
This patent describes a recirculation system for driving reactor coolant water contained in an annular downcomer defined between a boiling water reactor vessel and a reactor core spaced radially inwardly therefrom. It comprises a plurality of circumferentially spaced second pumps disposed in the downcomer, each including an inlet for receiving from the downcomer a portion of the coolant water as pump inlet flow, and an outlet for discharging the pump inlet flow pressurized in the second pump as pump outlet flow; and means for increasing pressure of the pump inlet flow at the pump inlet including a first pump disposed in series flow with the second pump for first receiving the pump inlet flow from the downcomer and discharging to the second pump inlet flow pressurized in the first pump
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Xydis, George A; Liaros, Stelios; Botsis, Konstantinos
2017-09-01
The study is a qualitative approach and looks into new ways for the effective energy management of a wind farm (WF) operation in a suburban or near-urban environment in order the generated electricity to be utilised for hydroponic farming purposes as well. Since soilless hydroponic indoor systems gain more and more attention one basic goal, among others, is to take advantage of this not typical electricity demand and by managing it, offering to the grid a less fluctuating electricity generation signal. In this paper, a hybrid business model is presented where the Distributed Energy Resources (DER) producer is participating in the electricity markets under competitive processes (spot market, real-time markets etc.) and at the same time acts as a retailer offering - based on the demand - to the hydroponic units for their mass deployment in an area, putting forward an integrated energy-food nexus approach. Copyright © 2017 Elsevier B.V. All rights reserved.
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Engineering development for a small-scale recirculator experiment
International Nuclear Information System (INIS)
Newton, M.A.; Deadrick, F.J.; Hanks, R.L.; Hawkins, S.A.; Holm, K.A.; Kirbie, H.C.; Karpenko, V.P.; Nattrass, L.A.; Longinotti, D.B.
1995-01-01
Lawrence Livermore National Laboratory (LLNL) is evaluating the physics and technology of recirculating induction accelerators for heavy-ion inertial-fusion drivers. As part of this evaluation, the authors are building a small-scale recirculator to demonstrate the concept and to use as a test bed for the development of recirculator technologies. System designs have been completed and components are presently being designed and developed for the small-scale recirculator. This paper discusses results of the design and development activities that are presently being conducted to implement the small-scale recirculator experiments. An, overview of the system design is presented along with a discussion of the implications of this design on the mechanical and electrical hardware. The paper focuses primarily on discussions of the development and design of the half-lattice period hardware and the advanced solid-state modulator
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Proliferation of Escherichia coli O157:H7 in soil and hydroponic microgreen production systems
Radish (Raphanus sativus var. longipinnatus) microgreens were produced from seeds inoculated with Escherichia coli O157: H7 using soil substitute and hydroponic production systems. E. coli populations on the edible and inedible parts of harvested microgreen plants and in growth medium were examined....
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Off-gas recirculation system for nuclear reactors
International Nuclear Information System (INIS)
Eppler, M.; Lade, H.J.
1975-01-01
According to the invention, it is suggested to provide a buffer vessel in the ring main of the off-gas recirculation system for off-gases of a nuclear reactor to which all chambers or vessels which may contain radioactively contaminated gases are connected, within the connection line to outside air. This is to prevent the immediate release of an appreciable amount of gas to the outside air due to pressure variations conditioned by the sequence of operations - e.g. on the filling of the coolant storage. After the improvement, the released gas may be reduced to the amount of gas corresponding to the leakage gas flow entering the ring mains system. (TK) [de
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Directory of Open Access Journals (Sweden)
Hoffmann Astrid
2012-10-01
Full Text Available Abstract Background In this report we studied the genetic regulation of juvenile development of wild barley introgression lines (S42ILs under two contrasting hydroponic nitrogen (N supplies. Ten shoot and root related traits were examined among 42 S42ILs and the recurrent parent ‘Scarlett’. The traits included tiller number, leaf number, plant height, leaf and root length, leaf to root length ratio, shoots and root dry weight, shoot to root weight ratio, and chlorophyll content. Our aims were (1 to test the suitability of a hydroponic system for early detection of favourable S42ILs, (2 to locate quantitative trait loci (QTL that control the examined traits, (3 to identify favourable wild barley alleles that improve trait performances in regard to N treatment and, finally, (4 to validate the identified QTL through comparison with previously reported QTL originating from the same parental cross. Results The phenotypic data were analysed in a mixed model association study to detect QTL. The post-hoc Dunnett test identified 28 S42ILs that revealed significant (P Hsp effects for tiller number, leaf number, leaf length, plant height and leaf to root ratio on the long arm of chromosome 7H. These QTL correspond to QTL for ears per plant and plant height that were previously detected in field trials conducted with the same S42ILs or with the S42 population. Conclusion Our results suggest that the QTL we identified under hydroponic N cultivation partly correspond to QTL detected in field experiments. Due to this finding, screening of plants in early developmental stages grown in a hydroponic system may be a fast and cost effective method for early QTL detection and marker-assisted allelic selection, potentially speeding up elite barley breeding programs.
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Hormonal regulation of wheat growth during hydroponic culture
Wetherell, Donald
1988-01-01
Hormonal control of root growth has been explored as one means to alleviate the crowding of plant root systems experienced in prototype hydroponic biomass production chambers being developed by the CELSS Breadboard Project. Four plant hormones, or their chemical analogs, which have been reported to selectively inhibit root growth, were tested by adding them to the nutrient solutions on day 10 of a 25 day growth test using spring wheat in hydroponic cultures. Growth and morphological changes is both shoot and root systems were evaluated. In no case was it possible to inhibit root growth without a comparable inhibition of shoot growth. It was concluded that this approach is unlikely to prove useful for wheat.
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Application of Open Garden Sensor on Hydroponic Maintenance Management
Nasution, S.; Siregar, B.; Kurniawan, M.; Pranoto, H.; Andayani, U.; Fahmi, F.
2018-03-01
Hydroponic farming system is an agricultural system that uses direct water as a nutrient without using soil as a planting medium. This system allows smallholder farmers to have the opportunity to develop their crop production with less capital. In addition, hydroponic planting has also been widely adapted by individuals as a personal hobby. Application of technology has penetrated various fields including agricultural fields. One of the technologies that can be applied in a hydroponic farming system is the sensor. Sensors are devices that used to convert a physical quantity into a quantity of electricity so that it can be analyse with a certain electrical circuit. In this study, the technology to be applied is wireless sensor technology applied in human life to help get information quickly and accurately. Sensors to be used in this study are pH sensors, conductivity sensors, temperature sensors and humidity. In addition to sensors, the study also involved Arduino technology. Arduino is a microcontroller board that is used to interact with the environment based on programs that have been made. The final results of the application testing show that the system success to display diagram in real-time in an environment from Arduino board to database and web server.
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Recirculating ventilation system for radioactive laboratories
International Nuclear Information System (INIS)
Kotrappa, P.; Menon, V.B.; Dingankar, M.V.; Chandramoleshwar, K.; Bhargava, B.L.
1980-01-01
Radioactive laboratories designed to handle toxic substances such as plutonium are required to have ''once through'' ventilation scheme. This is an expensive proposition particularly when conditioned air is required. A recent approach is to have recirculatory system with exhausted air passing through absolute (HEPA) filters. This scheme not only drastically reduces capital costs but also substantially cuts down maintenance and running costs. Experiments emplyoing aerosol clearance techniques were conducted to specifically establish that this new scheme meets all the health physics safety stipulations laid down for such installations. It is shown that the ''once through'' system is three times more expensive compared to the recirculation system adopted in Purnima Laboratories. Further a saving of 70% is also achieved in running and operating costs. Therefore the new approach deserves serious consideration in future planning of similar projects, particularly in view of the fact that the considerable savings achievable both in terms of money and energy are without in any way compromising on safety. (auth.)
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Garlic exerts allelopathic effects on pepper physiology in a hydroponic co-culture system
Directory of Open Access Journals (Sweden)
Haiyan Ding
2016-05-01
Full Text Available A hydroponic co-culture system was adopted to determine the allelopathic potential of garlic on the growth of pepper plants. Different numbers of garlic plants (0, 2, 4, 8 and 12 were hydroponically co-cultured with two pepper plants to investigate allelopathic effects on the growth attributes and antioxidative defense system of the test pepper plants. The responses of the pepper plants depended on the number of garlic plants included in the co-culture system, indicating an association of pepper growth with the garlic root exudate concentration. When grown at a pepper/garlic ratio of 1:1 or 1:2, the pepper plant height, chlorophyll content, and peroxidase (POD, catalase (CAT and phenylalanine ammonia-lyase (PAL activities were significantly increased after 30 days of co-culture; in contrast, reduction in methane dicarboxylic aldehyde (MDA content was observed. However, when the pepper/garlic ratio was 1:4 or higher, these morphological indices and protective enzyme activities were significantly inhibited, whereas MDA levels in the pepper leaves were significantly increased due to severe membrane lipid peroxidation. The results indicate that although low concentrations of garlic root exudates appear to induce protective enzyme systems and promote pepper growth, high concentrations have deleterious effects. These findings suggest that further investigations should optimize the co-culture pepper/garlic ratio to reduce continuous cropping obstacles in pepper production.
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Adoption of Recirculating Aquaculture Systems in Pangasius Farms: A Choice Experiment
Pham, T.A.N.; Gielen-Meuwissen, M.P.M.; Le, T.T.; Bosma, R.H.; Oude Lansink, A.G.J.M.
2015-01-01
A growing number of European customers’ demands certified pangasius such as ASC in order to ensure sustainable production. Implementing Recirculating Aquaculture Systems (RAS) contributes to an improved water quality, a key issue in achieving ASC certification. This study uses a choice experiment to
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Nathoo, Naeem; Bernards, Mark A; MacDonald, Jacqueline; Yuan, Ze-Chun
2017-07-22
An experimental design mimicking natural plant-microbe interactions is very important to delineate the complex plant-microbe signaling processes. Arabidopsis thaliana-Agrobacterium tumefaciens provides an excellent model system to study bacterial pathogenesis and plant interactions. Previous studies of plant-Agrobacterium interactions have largely relied on plant cell suspension cultures, the artificial wounding of plants, or the artificial induction of microbial virulence factors or plant defenses by synthetic chemicals. However, these methods are distinct from the natural signaling in planta, where plants and microbes recognize and respond in spatial and temporal manners. This work presents a hydroponic cocultivation system where intact plants are supported by metal mesh screens and cocultivated with Agrobacterium. In this cocultivation system, no synthetic phytohormone or chemical that induces microbial virulence or plant defense is supplemented. The hydroponic cocultivation system closely resembles natural plant-microbe interactions and signaling homeostasis in planta. Plant roots can be separated from the medium containing Agrobacterium, and the signaling and responses of both the plant hosts and the interacting microbes can be investigated simultaneously and systematically. At any given timepoint/interval, plant tissues or bacteria can be harvested separately for various "omics" analyses, demonstrating the power and efficacy of this system. The hydroponic cocultivation system can be easily adapted to study: 1) the reciprocal signaling of diverse plant-microbe systems, 2) signaling between a plant host and multiple microbial species (i.e. microbial consortia or microbiomes), 3) how nutrients and chemicals are implicated in plant-microbe signaling, and 4) how microbes interact with plant hosts and contribute to plant tolerance to biotic or abiotic stresses.
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Energy Technology Data Exchange (ETDEWEB)
Toever, W V
1979-01-01
Rainbow and Speckled Trout have been successfully hatched and reared in a recirculating aquaculture system. The system is integrated into the Ark greenhouse providing thermal mass for temperature regulation and supplying nutrient-rich water for plants. The system incorporates bacterial, algal and hydroponic water filtration. Various vegetable crops have been raised in the hydroponic troughs. A scaled-down system suitable for domestic solar greenhouse application is also under development.
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Hydroponics or soilless culture
Chapman, H. D.
1963-01-01
Historically, hydroponics is not a new field; plant physiologists have known and used it for some 100 years. Inevitably, some enthusiasts got carried away.Claims were made of enormous potential yields; skyscraper tops were said to be capable of producing enough food for all of their occupants; and closets, basements, garages, etc. were wishfully converted into fields for hydroponic culture. Numerous publications on the subject appeared during this period. Basic requirements for hydropinc techniques are given along with examples of where soilless culture has been used commercially.
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Gerth, Hans U; Pohlen, Michele; Thölking, Gerold; Pavenstädt, Hermann; Brand, Marcus; Hüsing-Kabar, Anna; Wilms, Christian; Maschmeier, Miriam; Kabar, Iyad; Torner, Josep; Pavesi, Marco; Arroyo, Vicente; Banares, Rafael; Schmidt, Hartmut H J
2017-10-01
Acute-on-chronic liver failure is associated with numerous consecutive organ failures and a high short-term mortality rate. Molecular adsorbent recirculating system therapy has demonstrated beneficial effects on the distinct symptoms, but the associated mortality data remain controversial. Retrospective analysis of acute-on-chronic liver failure patients receiving either standard medical treatment or standard medical treatment and molecular adsorbent recirculating system. Secondary analysis of data from the prospective randomized Recompensation of Exacerbated Liver Insufficiency with Hyperbilirubinemia and/or Encephalopathy and/or Renal Failure trial by applying the recently introduced Chronic Liver Failure-criteria. Medical Departments of University Hospital Muenster (Germany). This analysis was conducted in two parts. First, 101 patients with acute-on-chronic liver failure grades 1-3 and Chronic Liver Failure-C-Organ Failure liver subscore equals to 3 but stable pulmonary function were identified and received either standard medical treatment (standard medical treatment, n = 54) or standard medical treatment and molecular adsorbent recirculating system (n = 47) at the University Hospital Muenster. Second, the results of this retrospective analysis were tested against the Recompensation of Exacerbated Liver Insufficiency with Hyperbilirubinemia and/or Encephalopathy and/or Renal Failure trial. Standard medical treatment and molecular adsorbent recirculating system. Additionally to improved laboratory variables (bilirubin and creatinine), the short-term mortality (up to day 14) of the molecular adsorbent recirculating system group was significantly reduced compared with standard medical treatment. A reduced 14-day mortality rate was observed in the molecular adsorbent recirculating system group (9.5% vs 50.0% with standard medical treatment; p = 0.004), especially in patients with multiple organ failure (acute-on-chronic liver failure grade 2-3). Concerning the
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Kårelid, Victor; Larsson, Gen; Björlenius, Berndt
2017-05-15
The removal of pharmaceutically active compounds by powdered activated carbon (PAC) in municipal wastewater is a promising solution to the problem of polluted recipient waters. Today, an efficient design strategy is however lacking with regard to high-level overall, and specific, substance removal in the large scale. The performance of PAC-based removal of pharmaceuticals was studied in pilot-scale with respect to the critical parameters; contact time and PAC dose using one PAC product selected by screening in bench-scale. The goal was a minimum of 95% removal of the pharmaceuticals present in the evaluated municipal wastewater. A set of 21 pharmaceuticals was selected from an initial 100 due to their high occurrence in the effluent water of two selected wastewater treatment plants (WWTPs) in Sweden, whereof candidates discussed for future EU regulation directives were included. By using recirculation of PAC over a treatment system using three sequential contact tanks, a combination of the benefits of powdered and granular carbon performance was achieved. The treatment system was designed so that recirculation could be introduced to any of the three tanks to investigate the effect of recirculation on the adsorption performance. This was compared to use of the setup, but without recirculation. A higher degree of pharmaceutical removal was achieved in all recirculation setups, both overall and with respect to specific substances, as compared to without recirculation. Recirculation was tested with nominal contact times of 30, 60 and 120 min and the goal of 95% removal could be achieved already at the shortest contact times at a PAC dose of 10-15 mg/L. In particular, the overall removal could be increased even to 97% and 99%, at 60 and 120 min, respectively, when the recirculation point was the first tank. Recirculation of PAC to either the first or the second contact tank proved to be comparable, while a slightly lower performance was observed with recirculation to
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Production of deuterated switchgrass by hydroponic cultivation.
Evans, Barbara R; Bali, Garima; Foston, Marcus; Ragauskas, Arthur J; O'Neill, Hugh M; Shah, Riddhi; McGaughey, Joseph; Reeves, David; Rempe, Caroline S; Davison, Brian H
2015-07-01
The bioenergy crop switchgrass was grown hydroponically from tiller cuttings in 50 % D 2 O to obtain biomass with 34 % deuterium substitution and physicochemical properties similar to those of H 2 O-grown switchgrass controls. Deuterium enrichment of biological materials can potentially enable expanded experimental use of small angle neutron scattering (SANS) to investigate molecular structural transitions of complex systems such as plant cell walls. Two key advances have been made that facilitate cultivation of switchgrass, an important forage and biofuel crop, for controlled isotopic enrichment: (1) perfusion system with individual chambers and (2) hydroponic growth from tiller cuttings. Plants were grown and maintained for several months with periodic harvest. Photosynthetic activity was monitored by measurement of CO2 in outflow from the growth chambers. Plant morphology and composition appeared normal compared to matched controls grown with H2O. Using this improved method, gram quantities of switchgrass leaves and stems were produced by continuous hydroponic cultivation using growth medium consisting of basal mineral salts in 50 % D2O. Deuterium incorporation was confirmed by detection of the O-D and C-D stretching peaks with FTIR and quantified by (1)H- and (2)H-NMR. This capability to produce deuterated lignocellulosic biomass under controlled conditions will enhance investigation of cell wall structure and its deconstruction by neutron scattering and NMR techniques.
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Engine with pulse-suppressed dedicated exhaust gas recirculation
Keating, Edward J.; Baker, Rodney E.
2016-06-07
An engine assembly includes an intake assembly, a spark-ignited internal combustion engine, and an exhaust assembly. The intake assembly includes a charge air cooler disposed between an exhaust gas recirculation (EGR) mixer and a backpressure valve. The charge air cooler has both an inlet and an outlet, and the back pressure valve is configured to maintain a minimum pressure difference between the inlet of the charge air cooler and an outlet of the backpressure valve. A dedicated exhaust gas recirculation system is provided in fluid communication with at least one cylinder and with the EGR mixer. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the at least one cylinder to the EGR mixer for recirculation back to the engine.
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Paradiso, Roberta; Buonomo, Roberta; Dixon, Mike A; Barbieri, Giancarlo; De Pascale, Stefania
2015-01-01
Soybean is traditionally grown in soil, where root symbiosis with Bradyrhizobium japonicum can supply nitrogen (N), by means of bacterial fixation of atmospheric N2. Nitrogen fertilizers inhibit N-fixing bacteria. However, urea is profitably used in soybean cultivation in soil, where urease enzymes of telluric microbes catalyze the hydrolysis to ammonium, which has a lighter inhibitory effect compared to nitrate. Previous researches demonstrated that soybean can be grown hydroponically with recirculating complete nitrate-based nutrient solutions. In Space, urea derived from crew urine could be used as N source, with positive effects in resource procurement and waste recycling. However, whether the plants are able to use urea as the sole source of N and its effect on root symbiosis with B. japonicum is still unclear in hydroponics. We compared the effect of two N sources, nitrate and urea, on plant growth and physiology, and seed yield and quality of soybean grown in closed-loop Nutrient Film Technique (NFT) in growth chamber, with or without inoculation with B. japonicum. Urea limited plant growth and seed yield compared to nitrate by determining nutrient deficiency, due to its low utilization efficiency in the early developmental stages, and reduced nutrients uptake (K, Ca, and Mg) throughout the whole growing cycle. Root inoculation with B. japonicum did not improve plant performance, regardless of the N source. Specifically, nodulation increased under fertigation with urea compared to nitrate, but this effect did not result in higher leaf N content and better biomass and seed production. Urea was not suitable as sole N source for soybean in closed-loop NFT. However, the ability to use urea increased from young to adult plants, suggesting the possibility to apply it during reproductive phase or in combination with nitrate in earlier developmental stages. Root symbiosis did not contribute significantly to N nutrition and did not enhance the plant ability to use
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Martins, C.I.; Pristin, M.G.; Ende, S.S.W.; Eding, E.H.; Verreth, J.A.J.
2009-01-01
The accumulation of substances in Recirculating Aquaculture Systems (RAS) may impair the growth and welfare of fish. To test the severity of contaminants accumulated in RAS, early-life stages of fish were used. Ultrafiltered water from two Recirculating Aquaculture Systems (RAS), one RAS with a high
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The potential use of constructed wetlands in a recirculating aquaculture system for shrimp culture
International Nuclear Information System (INIS)
Lin, Y.-F.; Jing, S.-R.; Lee, D.-Y.
2003-01-01
Constructed wetlands improved water qualities and consequently increased the shrimp growth and survival in a recirculating system. - A pilot-scale constructed wetland unit, consisting of free water surface (FWS) and subsurface flow (SF) constructed wetlands arranged in series, was integrated into an outdoor recirculating aquaculture system (RAS) for culturing Pacific white shrimp (Litopenaeus vannamei). This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of improvement in water quality of the culture tank on the growth and survival of shrimp postlarvae. During an 80-day culture period, the wetland unit operated at a mean hydraulic loading rate of 0.3 m/day and effectively reduced the influent concentrations of 5-day biochemical oxygen demand (BOD 5 , 24%), suspended solids (SS, 71%), chlorophyll a (chl-a, 88%), total ammonium (TAN, 57%), nitrite nitrogen (NO 2 -N, 90%) and nitrate nitrogen (NO 3 -N, 68%). Phosphate (PO 4 -P) reduction was the least efficient (5.4%). The concentrations of SS, Chl-a, turbidity and NO 3 -N in the culture tank water in RAS were significantly (P≤0.05) lower than those in a control aquaculture system (CAS) that simulated static pond culture without wetland treatment. However, no significant difference (P≤0.05) in BOD 5 , TAN and NO 2 -N was found between the two systems. At the end of the study, the harvest results showed that shrimp weight and survival rate in the RAS (3.8±1.8 g/shrimp and 90%) significantly (P≤0.01) exceeded those in the CAS (2.3±1.5 g/shrimp and 71%). This study concludes that constructed wetlands can improve the water quality and provide a good culture environment, consequently increasing the shrimp growth and survival without water exchange, in a recirculating system
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The potential use of constructed wetlands in a recirculating aquaculture system for shrimp culture
Energy Technology Data Exchange (ETDEWEB)
Lin, Y.-F.; Jing, S.-R.; Lee, D.-Y
2003-05-01
Constructed wetlands improved water qualities and consequently increased the shrimp growth and survival in a recirculating system. - A pilot-scale constructed wetland unit, consisting of free water surface (FWS) and subsurface flow (SF) constructed wetlands arranged in series, was integrated into an outdoor recirculating aquaculture system (RAS) for culturing Pacific white shrimp (Litopenaeus vannamei). This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of improvement in water quality of the culture tank on the growth and survival of shrimp postlarvae. During an 80-day culture period, the wetland unit operated at a mean hydraulic loading rate of 0.3 m/day and effectively reduced the influent concentrations of 5-day biochemical oxygen demand (BOD{sub 5}, 24%), suspended solids (SS, 71%), chlorophyll a (chl-a, 88%), total ammonium (TAN, 57%), nitrite nitrogen (NO{sub 2}-N, 90%) and nitrate nitrogen (NO{sub 3}-N, 68%). Phosphate (PO{sub 4}-P) reduction was the least efficient (5.4%). The concentrations of SS, Chl-a, turbidity and NO{sub 3}-N in the culture tank water in RAS were significantly (P{<=}0.05) lower than those in a control aquaculture system (CAS) that simulated static pond culture without wetland treatment. However, no significant difference (P{<=}0.05) in BOD{sub 5}, TAN and NO{sub 2}-N was found between the two systems. At the end of the study, the harvest results showed that shrimp weight and survival rate in the RAS (3.8{+-}1.8 g/shrimp and 90%) significantly (P{<=}0.01) exceeded those in the CAS (2.3{+-}1.5 g/shrimp and 71%). This study concludes that constructed wetlands can improve the water quality and provide a good culture environment, consequently increasing the shrimp growth and survival without water exchange, in a recirculating system.
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Solution Culture Hydroponics: History and Inexpensive Equipment.
Hershey, David R.
1994-01-01
Describes historical accounts dating back to as early as 604-562 BC of the various uses of hydroponics. Throughout the article, diagrams and simple instructions are provided to aid in classroom use of hydroponics. (ZWH)
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Automated sensing of macronutrients in hydroponic solution would allow more efficient management of nutrients for crop growth in closed hydroponic systems. Ion-selective microelectrode technology requires an ion-selective membrane or a solid metal material that responds selectively to one analyte in...
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Martins, C.I.; Eding, E.H.; Verdegem, M.C.J.; Heinsbroek, L.T.N.; Schneider, O.; Blancheton, J.P.; Roque dÓrbcastel, E.; Verreth, J.A.J.
2010-01-01
The dual objective of sustainable aquaculture, i.e., to produce food while sustaining natural resources is achieved only when production systems with a minimum ecological impact are used. Recirculating aquaculture systems (RASs) provide opportunities to reduce water usage and to improve waste
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Blok, Chris; Os, van Erik; Daoud, Raed; Waked, Laith; Hasan, A.
2017-01-01
Hydroponic Green Farming Initiative was executed in Jordan. Wageningen UR Greenhouse Horticultureanalysed the present situation at hydroponic farmers with the aim to adapt and to improve where possibleand to disseminate results and knowledge to other farmers in training sessions. With large amounts
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Nichols, M.; Os, van E.A.
2011-01-01
Hydroponic and greenhouse technologies offer the promise of growing many crops traditionally grown in soil. A comparative study in The Netherlands has demonstrated that it is now possible to grow leeks in soilless culture using protected cropping technologies with increased production and yields and
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Mota, Vasco C.; Martins, Catarina I.M.; Eding, Ep H.; Canário, Adelino V.M.; Verreth, Johan A.J.
2017-01-01
The accumulation of steroids released by fish in recirculating aquaculture systems (RAS) may potentially influence their physiology and behavior. The present study examined the release rate of cortisol and testosterone by Nile tilapia, Oreochromis niloticus, and their accumulation in six identical
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Spectral Quantitation Of Hydroponic Nutrients
Schlager, Kenneth J.; Kahle, Scott J.; Wilson, Monica A.; Boehlen, Michelle
1996-01-01
Instrument continuously monitors hydroponic solution by use of absorption and emission spectrometry to determine concentrations of principal nutrients, including nitrate, iron, potassium, calcium, magnesium, phosphorus, sodium, and others. Does not depend on extraction and processing of samples, use of such surrograte parameters as pH or electrical conductivity for control, or addition of analytical reagents to solution. Solution not chemically altered by analysis and can be returned to hydroponic process stream after analysis.
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Investigation of a combined gas-steam system with flue gas recirculation
Directory of Open Access Journals (Sweden)
Chmielniak Tadeusz
2016-06-01
Full Text Available This article presents changes in the operating parameters of a combined gas-steam cycle with a CO2 capture installation and flue gas recirculation. Parametric equations are solved in a purpose-built mathematical model of the system using the Ebsilon Professional code. Recirculated flue gases from the heat recovery boiler outlet, after being cooled and dried, are fed together with primary air into the mixer and then into the gas turbine compressor. This leads to an increase in carbon dioxide concentration in the flue gases fed into the CO2 capture installation from 7.12 to 15.7%. As a consequence, there is a reduction in the demand for heat in the form of steam extracted from the turbine for the amine solution regeneration in the CO2 capture reactor. In addition, the flue gas recirculation involves a rise in the flue gas temperature (by 18 K at the heat recovery boiler inlet and makes it possible to produce more steam. These changes contribute to an increase in net electricity generation efficiency by 1%. The proposed model and the obtained results of numerical simulations are useful in the analysis of combined gas-steam cycles integrated with carbon dioxide separation from flue gases.
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Process for producing vegetative and tuber growth regulator
Stutte, Gary W. (Inventor); Yorio, Neil C. (Inventor)
1999-01-01
A process of making a vegetative and tuber growth regulator. The vegetative and tuber growth regulator is made by growing potato plants in a recirculating hydroponic system for a sufficient time to produce the growth regulator. Also, the use of the vegetative and growth regulator on solanaceous plants, tuber forming plants and ornamental seedlings by contacting the roots or shoots of the plant with a sufficient amount of the growth regulator to regulate the growth of the plant and one more of canopy size, plant height, stem length, internode number and presence of tubers in fresh mass. Finally, a method for regulating the growth of potato plants using a recirculating hydroponic system is described.
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International Nuclear Information System (INIS)
BERG, J.S.; GARREN, A.A.; JOHNSTONE, C.
2000-01-01
This paper compares various types of recirculating accelerators, outlining the advantages and disadvantages of various approaches. The accelerators are characterized according to the types of arcs they use: whether there is a single arc for the entire recirculator or there are multiple arcs, and whether the arc(s) are isochronous or non-isochronous
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Huang, Yi; Miyauchi, Keisuke; Inoue, Chihiro; Endo, Ginro
2016-01-01
In this study, we found that high-performance hydroponics of arsenic hyperaccumulator fern Pteris vittata is possible without any mechanical aeration system, if rhizomes of the ferns are kept over the water surface level. It was also found that very low-nutrition condition is better for root elongation of P. vittata that is an important factor of the arsenic removal from contaminated water. By the non-aeration and low-nutrition hydroponics for four months, roots of P. vittata were elongated more than 500 mm. The results of arsenate phytofiltration experiments showed that arsenic concentrations in water declined from the initial concentrations (50 μg/L, 500 μg/L, and 1000 μg/L) to lower than the detection limit (0.1 μg/L) and about 80% of arsenic removed was accumulated in the fern fronds. The improved hydroponics method for P. vittata developed in this study enables low-cost phytoremediation of arsenic-contaminated water and high-affinity removal of arsenic from water.
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Julinor, Helmut
1976-01-01
In addition to being an actual source of foodstuffs in inhospitable climates and a potential source of a large portion of the world's food supply, hydroponic gardening is a useful technique in the classroom for illustrating the role of plant life in the world's food chain. (MB)
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Koseki, Shigenobu; Mizuno, Yasuko; Yamamoto, Kazutaka
2011-09-01
The route of pathogen contamination (from roots versus from leaves) of spinach leaves was investigated with a hydroponic cultivation system. Three major bacterial pathogens, Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes, were inoculated into the hydroponic solution, in which the spinach was grown to give concentrations of 10⁶ and 10³ CFU/ml. In parallel, the pathogens were inoculated onto the growing leaf surface by pipetting, to give concentrations of 10⁶ and 10³ CFU per leaf. Although contamination was observed at a high rate through the root system by the higher inoculum (10⁶ CFU) for all the pathogens tested, the contamination was rare when the lower inoculum (10³ CFU) was applied. In contrast, contamination through the leaf occurred at a very low rate, even when the inoculum level was high. For all the pathogens tested in the present study, the probability of contamination was promoted through the roots and with higher inoculum levels. The probability of contamination was analyzed with logistic regression. The logistic regression model showed that the odds ratio of contamination from the roots versus from the leaves was 6.93, which suggested that the risk of contamination from the roots was 6.93 times higher than the risk of contamination from the leaves. In addition, the risk of contamination by L. monocytogenes was about 0.3 times that of Salmonella enterica subsp. enterica serovars Typhimurium and Enteritidis and E. coli O157:H7. The results of the present study indicate that the principal route of pathogen contamination of growing spinach leaves in a hydroponic system is from the plant's roots, rather than from leaf contamination itself.
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Adoption of Recirculating Aquaculture Systems in Large Pangasius Farms: A Choice Experiment
Pham, T.A.N.; Gielen-Meuwissen, M.P.M.; Le, T.C.; Verreth, J.A.J.; Bosma, R.H.; Oude Lansink, A.G.J.M.
2016-01-01
A growing number of European customers’ demands certified pangasius such as ASC in order to ensure sustainable production. Implementing Recirculating Aquaculture Systems (RAS) contributes to an improved water quality, a key issue in achieving ASC certification. This study uses a choice experiment to
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[Plant hydroponics and its application prospect in medicinal plants study].
Zeng, Yan; Guo, Lan-Ping; Huang, Lu-Qi; Sun, Yu-Zhang
2007-03-01
This article introduced the theorem and method of hydroponics. Some examples of studies in agriculture and forestry were presented, the effects of elements, environmental stress and hormones on physiology of medicinal plants by using hydroponics were analyzed. It also introduced the feasibility and advantage of hydroponics in intermediate propagation and allelopathy of medicinal plant. And finally it made the conclusion that the way of hydroponics would be widely used in medicinal plant study.
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Watson, C; Pulford, I D; Riddell-Black, D
2003-01-01
The aim of this study was to ascertain whether metal resistance in willow (Salix) clones grown in a hydroponics screening test correlated with data from the same clones grown independently in a field trial. If so, results from a short-term, glasshouse-based system could be extrapolated to the field, allowing rapid identification of willows suitable for planting in metal-contaminated substrates without necessitating longterm field trials. Principal Components Analysis was used to show groups of clones and to assess the relative importance of the parameters measured in both the hydroponics system and the field; including plant response factors such as increase in stem height, as well as metal concentrations in plant tissues. The clones tested fell into two distinct groups. Salix viminalis clones and the basket willow Black Maul (S. triandra) were less resistant to elevated concentrations of heavy metals than a group of hardier clones, including S. burjatica 'Germany,' S.x dasyclados, S. candida and S. spaethii. The more resistant clones produced more biomass in the glasshouse and field, and had higher metal concentrations in the wood. The less resistant clones had greater concentrations of Cu and Ni in the bark, and produced less biomass in the glasshouse and field. Significant relationships were found between the response of the same clones grown the in short-term glasshouse hydroponics system and in the field.
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Liu, Zhigang; Gao, Kun; Shan, Shengchen; Gu, Riling; Wang, Zhangkui; Craft, Eric J; Mi, Guohua; Yuan, Lixing; Chen, Fanjun
2017-01-01
Root system architecture (RSA) plays an important role in the acquisition of both nitrogen (N) and phosphorus (P) from the environment. Currently RSA is rarely considered as criteria for selection to improve nutrient uptake efficiency in crop breeding. Under field conditions roots can be greatly influenced by uncontrolled environment factors. Therefore, it is necessary to develop fast selection methods for evaluating root traits of young seedlings in the lab which can then be related to high nutrient efficiency of adult plants in the field. Here, a maize recombination inbred line (RILs) population was used to compare the genetic relationship between RSA and nitrogen and phosphorous efficiency traits. The phenotypes of eight RSA-related traits were evaluated in young seedlings using three different growth systems (i.e., paper roll, hydroponics and vermiculite), and then subjected to correlation analysis with N efficiency and P efficiency related traits measured under field conditions. Quantitative trait loci (QTL) of RSA were determined and QTL co-localizations across different growth systems were further analyzed. Phenotypic associations were observed for most of RSA traits among all three culture systems. RSA-related traits in hydroponics and vermiculite weakly correlated with Nitrogen (NupE) uptake efficiency ( r = 0.17-0.31) and Phosphorus (PupE) uptake efficiency ( r = 0.22-0.34). This correlation was not found in the paper roll growth system. A total of 14 QTLs for RSA were identified in paper rolls, 18 in hydroponics, and 14 in vermiculite. Co-localization of QTLs for RSA traits were identified in six chromosome regions of bin 1.04/1.05, 1.06, 2.04/2.05, 3.04, 4.05, and 5.04/5.05. The results suggest the problem of using the phenotype from one growth system to predict those in another growth system. Assessing RSA traits at the seedling stage using either hydroponics or a vermiculite system appears better suited than the paper roll system as an important index
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NGL recovery being hiked by natural-gasoline recirculation
Energy Technology Data Exchange (ETDEWEB)
Rivas M, M.; Bracho, J.L. [Lagoven S.A., Maracaibo (Venezuela); Murray, J.E. [Murray (James E.), Corpus Christi, TX (United States)
1997-07-07
Construction will be completed later this year at two compression plants operated by Lagoven, S.A., to install natural-gasoline recirculation to improve NGL recovery. The project is the result of a study of condensate-stream recirculation and absorber operations at the compression plants Tia Juana 2 (PCTJ-2) and Tia Juana 3 (PCTJ-3), offshore Lake Maracaibo in western Venezuela. The PCTJ-2 and PCTJ-3 gas compression plants have two systems: gas compression and NGL extraction. Previous analysis of the NGL extraction and fractionation processes of Lagoven determined that there are two practical and attractive alternatives for the recirculation of the condensate streams in PCTJ-2 and 3: recirculation of natural gasoline from the Ule LPG plant; recirculation of a conditioned condensate from the de-ethanizer tower of each plant. Both alternatives are discussed. Also described are fractionation capacity, and modifications for adding absorption and fractionation.
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Modeling and simulation of the bioprocess with recirculation
Directory of Open Access Journals (Sweden)
Žerajić Stanko
2007-01-01
Full Text Available The bioprocess models with recirculation present an integration of the model of continuous bioreaction system and the model of separation system. The reaction bioprocess is integrated with separation the biomass, formed product, no consumed substrate or inhibitory substance. In this paper the simulation model of recirculation bioprocess was developed, which may be applied for increasing the biomass productivity and product biosynthesis increasing the conversion of a substrate-to-product, mixing efficiency and secondary C02 separation. The goal of the work is optimal bioprocess configuration, which is determined by simulation optimization. The optimal hemostat state was used as referent. Step-by-step simulation method is necessary because the initial bioprocess state is changing with recirculation in each step. The simulation experiment confirms that at the recirculation ratio a. = 0.275 and the concentration factor C = 4 the maximum glucose conversion to ethanol and at a dilution rate ten times larger.
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Directory of Open Access Journals (Sweden)
G Swarnalatha
2013-01-01
Full Text Available Marijuana is used for psychoactive and recreational purpose. We report a case of fulminant hepatic failure following marijuana drug abuse who recovered following artificial support systems for acute liver failure. There is no published literature of management of marijuana intoxication with molecular adsorbent recirculation system (MARS. MARS is effective and safe in patients with fulminant hepatic failure following marijuana intoxication.
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Paradiso, Roberta; Buonomo, Roberta; Dixon, Mike A.; Barbieri, Giancarlo; De Pascale, Stefania
2014-02-01
Soybean [Glycine max (L.) Merr.] is one of the plant species selected within the European Space Agency (ESA) Micro-Ecological Life Support System Alternative (MELiSSA) project for hydroponic cultivation in Biological Life Support Systems (BLSSs), because of the high nutritional value of seeds. Root symbiosis of soybean with Bradirhizobium japonicum contributes to plant nutrition in soil, providing ammonium through the bacterial fixation of atmospheric nitrogen. The aim of this study was to evaluate the effects of two hydroponic systems, Nutrient Film Technique (NFT) and cultivation on rockwool, and two nitrogen sources in the nutrient solution, nitrate (as Ca(NO3)2 and KNO3) and urea (CO(NH2)2), on root symbiosis, plant growth and seeds production of soybean. Plants of cultivar 'OT8914', inoculated with B. japonicum strain BUS-2, were grown in a growth chamber, under controlled environmental conditions. Cultivation on rockwool positively influenced root nodulation and plant growth and yield, without affecting the proximate composition of seeds, compared to NFT. Urea as the sole source of N drastically reduced the seed production and the harvest index of soybean plants, presumably because of ammonium toxicity, even though it enhanced root nodulation and increased the N content of seeds. In the view of large-scale cultivation for space colony on planetary surfaces, the possibility to use porous media, prepared using in situ resources, should be investigated. Urea can be included in the nutrient formulation for soybean in order to promote bacterial activity, however a proper ammonium/nitrate ratio should be maintained.
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Design validation and performance of closed loop gas recirculation system
International Nuclear Information System (INIS)
Kalmani, S.D.; Majumder, G.; Mondal, N.K.; Shinde, R.R.; Joshi, A.V.
2016-01-01
A pilot experimental set up of the India Based Neutrino Observatory's ICAL detector has been operational for the last 4 years at TIFR, Mumbai. Twelve glass RPC detectors of size 2 × 2 m 2 , with a gas gap of 2 mm are under test in a closed loop gas recirculation system. These RPCs are continuously purged individually, with a gas mixture of R134a (C 2 H 2 F 4 ), isobutane (iC 4 H 10 ) and sulphur hexafluoride (SF 6 ) at a steady rate of 360 ml/h to maintain about one volume change a day. To economize gas mixture consumption and to reduce the effluents from being released into the atmosphere, a closed loop system has been designed, fabricated and installed at TIFR. The pressure and flow rate in the loop is controlled by mass flow controllers and pressure transmitters. The performance and integrity of RPCs in the pilot experimental set up is being monitored to assess the effect of periodic fluctuation and transients in atmospheric pressure and temperature, room pressure variation, flow pulsations, uniformity of gas distribution and power failures. The capability of closed loop gas recirculation system to respond to these changes is also studied. The conclusions from the above experiment are presented. The validations of the first design considerations and subsequent modifications have provided improved guidelines for the future design of the engineering module gas system.
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Rethinking the role of aquatic ecology in hydroponic cultivation
Vermeulen, T.; Streminska, M.; Beerens, N.; Eveleens, B.; Blok, C.
2017-01-01
Hydroponic production systems are challenged by root diseases, but can be made less susceptible to infection. While the systems are mostly unchallenged by nematodes, pathogens that can live and spread though water still cause loss of yield. Common diseases would be Phytophthora, Pythium, Fusarium
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Exergetic performance analysis of a recirculating aquaculture system
International Nuclear Information System (INIS)
Kucuk, Haydar; Midilli, Adnan; Ozdemir, Atilla; Cakmak, Eyuep; Dincer, Ibrahim
2010-01-01
This paper examines exergetic aspects of a Recirculation Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) fingerling rearing at the Trabzon Central Fisheries Research Institute, Turkey. In its thermodynamic analysis, each component of the RAS is treated as a steady-state steady flow system and its exergetic efficiencies are studied. In addition, the following parameters are measured and recorded in experiments: the mass flow rates, inlet and outlet temperatures and of the system components, surrounding temperatures, and electrical work utilized by the components in the RAS. Based on these experimental data, inlet and outlet exergy values, exergy losses, and exergetic efficiencies of each component in the system are determined to assess their performance. Moreover, the overall system exergy efficiency is determined. The results show that exergy efficiencies of the system components are highly affected by varying input exergy flows as a function of the surrounding temperature and chiller's operating period.
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Kals, J.
2004-01-01
Report of a literature study on Recirculating aquaculture production systems executed within the MRG ercirculation program. The report gives an overview of different components, management, economics and technology and is made by the Netherlands Institute for Fisheries Research (RIVO).
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Device for controlling a recirculation flow in a reactor
International Nuclear Information System (INIS)
Shida, Toichi; Tohei, Kazushige; Hirose, Masao; Nakamura, Hideo.
1976-01-01
Object: To provide an emergency cut-off valve in a recirculation system in a reactor to control the recirculation at the time of turbine trip or load cut-off, thereby relieving excessive increase in heat output of fuel. Structure: A recirculation pump is driven through a recirculation pump motor by an AC generator, which is driven by a driving motor through a fluid coupling, so that reactor water passes the emergency cut-off valve and recirculation flow stop valve and then passes a jet pump into the core. At the time of turbine trip or load cut-off, the emergency cut-off valve is closed by a hydraulic circuit, whereby core flow is merely decreased by 20 to 30% in a short period of time to restrain excessive increase in heat output. (Yoshino, Y.)
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Conceptual design of the cryogenic system and estimation of the recirculated power for CFETR
Liu, Xiaogang; Qiu, Lilong; Li, Junjun; Wang, Zhaoliang; Ren, Yong; Wang, Xianwei; Li, Guoqiang; Gao, Xiang; Bi, Yanfang
2017-01-01
The China Fusion Engineering Test Reactor (CFETR) is the next tokamak in China’s roadmap for realizing commercial fusion energy. The CFETR cryogenic system is crucial to creating and maintaining operational conditions for its superconducting magnet system and thermal shields. The preliminary conceptual design of the CFETR cryogenic system has been carried out with reference to that of ITER. It will provide an average capacity of 75 to 80 kW at 4.5 K and a peak capacity of 1300 kW at 80 K. The electric power consumption of the cryogenic system is estimated to be 24 MW, and the gross building area is about 7000 m2. The relationships among the auxiliary power consumed by the cryogenic system, the fusion power gain and the recirculated power of CFETR are discussed, with the suggestion that about 52% of the electric power produced by CFETR in phase II must be recirculated to run the fusion test reactor.
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Systemic granuloma was observed in sampled adult Atlantic salmon Salmo salar raised to harvest size in a freshwater recirculation aquaculture system. The prevalence of this condition was estimated at 10-20% of the population, with affected individuals grossly demonstrating pathology in varying degre...
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Energy Technology Data Exchange (ETDEWEB)
Bruno, Mike S. [Terralog Technologies USA, Inc., Calgary (Canada); Detwiler, Russell L. [Terralog Technologies USA, Inc., Calgary (Canada); Lao, Kang [Terralog Technologies USA, Inc., Calgary (Canada); Serajian, Vahid [Terralog Technologies USA, Inc., Calgary (Canada); Elkhoury, Jean [Terralog Technologies USA, Inc., Calgary (Canada); Diessl, Julia [Terralog Technologies USA, Inc., Calgary (Canada); White, Nicky [Terralog Technologies USA, Inc., Calgary (Canada)
2012-12-13
There is increased recognition that geothermal energy resources are more widespread than previously thought, with potential for providing a significant amount of sustainable clean energy worldwide. Recent advances in drilling, completion, and production technology from the oil and gas industry can now be applied to unlock vast new geothermal resources, with some estimates for potential electricity generation from geothermal energy now on the order of 2 million megawatts. The primary objectives of this DOE research effort are to develop and document optimum design configurations and operating practices to produce geothermal power from hot permeable sedimentary and crystalline formations using advanced horizontal well recirculation systems. During Phase I of this research project Terralog Technologies USA and The University of California, Irvine (UCI), have completed preliminary investigations and documentation of advanced design concepts for paired horizontal well recirculation systems, optimally configured for geothermal energy recovery in permeable sedimentary and crystalline formations of varying structure and material properties. We have also identified significant geologic resources appropriate for application of such technology. The main challenge for such recirculation systems is to optimize both the design configuration and the operating practices for cost-effective geothermal energy recovery. These will be strongly influenced by sedimentary formation properties, including thickness and dip, temperature, thermal conductivity, heat capacity, permeability, and porosity; and by working fluid properties.
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Production of pre-basic potato seed by polyvinyl chloride PVC: articulate gutters hydroponic system
Directory of Open Access Journals (Sweden)
Jonny Everson Scherwinski-Pereira
2009-10-01
Full Text Available The development of more efficient and productive systems for pre-basic seed potato production would improve the quality of the propagative material used by the potato growers, directly affecting the crop yields. A two-year experiment was carried out to evaluate the potato pre-basic seed production by two types of hydroponic systems (fibrocement tiles and articulated PVC gutters, two cultivars (`Baronesa` and `Eliza` and two types of propagative material (plants coming from in vitro culture and minitubers. The PVC gutters system was highly efficient. When using minitubers, this system reached multiplication rates up to 74 tubers per plant. Minitubers were more productive than in vitro plants, independent of cultivar and hydroponic system utilized.Um experimento realizado por dois anos consecutivos avaliou a produção de sementes pré-básicas de batata por meio de sistemas de cultivo hidropônico. O trabalho testou a combinação de dois sistemas de cultivo (telha de fibrocimento e calhas de PVC articuladas, duas cultivares (Baronesa e Eliza e dois tipos de material propagativo (plântulas oriundas do cultivo in vitro e minitubérculos. O sistema de calhas de PVC foi altamente eficiente. Quando foi utilizado minitubérculos, este sistema alcançou taxas de multiplicação de até 74 tubérculos por planta. De modo geral, o uso de minitubérculos como material propagativo apresentou os melhores resultados de produtividade quando comparada ao material in vitro, independentemente da cultivar e sistemas hidropônicos utilizados.
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Hydroponic cultivation improves the nutritional quality of soybean and its products.
Palermo, Mariantonella; Paradiso, Roberta; De Pascale, Stefania; Fogliano, Vincenzo
2012-01-11
Hydroponic cultivation allows the control of environmental conditions, saves irrigation water, increases productivity, and prevents plant infections. The use of this technique for large commodities such as soybean is not a relevant issue on fertile soils, but hydroponic soybean cultivation could provide proteins and oil in adverse environmental conditions. In this paper, the compositions of four cultivars of soybean seeds and their derivates, soy milk and okara, grown hydroponically were compared to that of the same cultivar obtained from soil cultivation in an open field. Besides proximal composition, the concentrations of phytic acid and isoflavones were monitored in the seeds, soy milk, and okara. Results demonstrated that, independent from the cultivar, hydroponic compared to soil cultivation promoted the accumulation of fats (from 17.37 to 21.94 g/100 g dry matter) and total dietary fiber (from 21.67 to 28.46 g/100 g dry matter) and reduced isoflavones concentration (from 17.04 to 7.66 mg/kg dry matter), whereas protein concentration was unaffected. The differences found in seed composition were confirmed in the respective okara products, but the effect of cultivation system was not significant looking at the soy milk composition. Data showed that hydroponic cultivation improved the nutritional quality of soybean seeds with regard to fats and dietary fiber. They also suggest that specific cultivars should be selected to obtain the desired nutritional features of the soybean raw material depending on its final destination.
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Methodology adjustments for organic acid tolerance studies in oat under hydroponic systems
Directory of Open Access Journals (Sweden)
Mauricio Marini Kopp
2009-06-01
Full Text Available The occurrence of anaerobic conditions in hydromorphic soils favors the development of anaerobic microorganisms that produce phytotoxic substances representing primarily by organic acids. The selection of promising oat (Avena sativa L. genotypes for use in those situations requires field evaluations that can be cumbersome, making hydroponics a viable alternative. The objective of this work was to adjust a methodology to use in studies of tolerance to organic acids in oat under hydroponic systems. For such goal, the best germination system was determined in order to reduce the seedling initial establishment effects under hydroponics, the ideal concentration for screening genotypes and the best variable for stress evaluation. It was found that the most efficient germination system was "pleated germination paper" with small and husked seeds. The best concentration for studying organic acid tolerance ranged from 2.3 to 6.2 mM and the most suitable variable for the evaluation was root length.A ocorrência de condições anaeróbias nos solos hidromórficos favorece o desenvolvimento de microrganismos anaeróbios que produzem substâncias fitotóxicas representadas principalmente pelos ácidos orgânicos. A seleção de constituições genéticas de aveia (Avena sativa L. promissoras para utilização nestas situações requer avaliações de difícil execução no campo, tornando a utilização de sistemas hidropônicos mais vantajosa. O objetivo deste trabalho foi ajustar uma metodologia para ser utilizada em estudos de tolerância a ácidos orgânicos em aveia através de sistemas hidropônicos. Para tal fim foi determinada uma forma adequada de promover a germinação das sementes de maneira a reduzir os efeitos do estabelecimento inicial das plântulas na hidroponia, uma faixa de concentração ideal para discriminação dos genótipos e as variáveis de maior interesse para avaliação. O sistema de germinação mais eficiente é através de
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Radionuclide buildup in BWR [boiling water reactor] reactor coolant recirculation piping
International Nuclear Information System (INIS)
Duce, S.W.; Marley, A.W.; Freeman, A.L.
1989-12-01
Since the spring of 1985, thermoluminescent dosimeter, dose rate, and gamma spectral data have been acquired on the contamination of boiling water reactor primary coolant recirculation systems as part of a Nuclear Regulatory Commission funded study. Data have been gathered for twelve facilities by taking direct measurements and/or obtaining plant and vendor data. The project titled, ''Effectiveness and Safety Aspects of Selected Decontamination Processes'' (October 1983) initially reviewed the application of chemical decontamination processes on primary coolant recirculation system piping. Recontamination of the system following pipe replacement or chemical decontamination was studied as a second thrust of this program. During the course of this study, recontamination measurements were made at eight different commercial boiling water reactors. At four of the reactors the primary coolant recirculation system piping was chemically decontaminated. At the other four the piping was replaced. Vendor data were obtained from two boiling water reactors that had replaced the primary coolant recirculation system piping. Contamination measurements were made at two newly operating boiling water reactors. This report discusses the results of these measurements as they apply to contamination and recontamination of boiling water reactor recirculation piping. 16 refs., 29 figs., 9 tabs
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Hydroponic technology for lily flowers and bulbs production using ...
African Journals Online (AJOL)
Aghomotsegin
2015-07-22
Jul 22, 2015 ... the utilization of the hydroponic technology to produce flower and bulb of Asiatic ... when they became 2 cm long and mother bulb scales were removed at ..... cell layer culture system in Lilium:Rgeneration and transformation.
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During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRAS), it was observed that rainbow trout Oncorhynchus mykiss in all WRAS exhibited a higher-than-normal prevalence of side-swimming (i.e. controlled, forward swimming, but with misaligned orientation suc...
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Hybrid preheat/recirculating steam generator
International Nuclear Information System (INIS)
Lilly, G.P.
1985-01-01
The patent describes a hybrid preheat/recirculating steam generator for nuclear power plants. The steam generator utilizes recirculated liquid to preheat incoming liquid. In addition, the steam generator incorporates a divider so as to limit the amount of recirculating water mixed with the feedwater. (U.K.)
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Domestic manufacturing and reliability improvement of reactor water recirculation equipment
International Nuclear Information System (INIS)
Kobayashi, Hidekazu; Oi, Masao; Shida, Toichi; Yokomori, Takashi
1982-01-01
The reactor coolant recirculation system is one of the important systems to control the reactor output in BWR nuclear power plants. Its components require high reliability and maintainability as well as controllability. For many Japanese nuclear power plants, recirculation pumps, fluid couplings and others have been imported so far. Hitachi Ltd. has established a domestic manufacturing organization through the development and test of these equipment. The fundamental design conditions for these equipment are the improvement of the rate of utilization of plant facility, the capability to follow load, and output power stability. In this paper, the specifications, the investigation of moment of inertia and the design features of recirculation pumps, driving motors and variable frequency power supply systems are described. The paper also reports on the combination test implemented to evaluate the recirculation system. The combination test includes the test using water rheostat for the power source facility and the loading test for a recirculation pump. The application of those system equipment to an actual plant was analyzed and evaluated on a basis of the test data obtained. The result showed that the equipment can achieve the rate of change of reactor power of 30%/min. Those equipment have been employed for No. 2 reactor plant of the Fukushima No. 2 Nuclear Power Station, the Tokyo Electric Power Co., Inc. (Wakatsuki, Y.)
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Directory of Open Access Journals (Sweden)
Sebastian Marcus Strauch
2018-05-01
Full Text Available The reuse of effluent waters and sediments from African catfish (Clarias gariepinus recirculation aquaculture systems requires a deeper understanding of the nutrient and energy flows and material pathways. Three semi-commercial systems, differing in stocking density, were sampled for nutritive and pollutant elements of the input- (tap water, feed and output pathways (fillet, carcass, process water, sediments by ICP-OES/MS and calorimetry. Highly water-soluble elements, e.g., potassium, accumulated in the water, whereas iron, copper, chromium and uranium where found in the solids. Feed derived phosphorous was accounted for, 58.3–64.2% inside the fish, 9.7–19.3% in sediments, and small amounts 9.6–15.5% in the process waters. A total of 7.1–9.9% of the feed accumulated as dry matter in the sediments, comprising 5.5–8.7% total organic carbon and 3.7–5.2% nitrogen. A total of 44.5–47.1% of the feed energy was found in the fish and 5.7–7.7% in the sediments. For reuse of water and nutrients in hydroponics, the macro-nutrients potassium, nitrate, phosphorus and the micro-nutrient iron were deficient when compared with generalized recommendations for plant nutrition. Low energy contents and C/N-ratio restrict the solely use of African catfish solids for biogas production or vermiculture. Using the outputs both for biogas supplement and general fertilizer in aquaponics farming (s.l. (combined with additional nutrients appears possible.
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Low Load Model of a Once-through Boiler with Recirculation
DEFF Research Database (Denmark)
Trangbæk, Klaus
2006-01-01
A dynamic simulation model of a once-through boiler in low to medium load is developed. When the system is in low load, water from the evaporator is recirculated through a bottle. This recirculation system is included in the model, which is then shown to fit closed-loop data from a real plant...
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Long term/low dose formalin exposure to small-scale recirculation aquaculture systems
DEFF Research Database (Denmark)
Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg; Nielsen, Jeppe L.
2010-01-01
on a daily basis as compared to untreated systems. In systems intermittently treated with formalin, increased variation and minor reductions of ammonium and nitrite oxidation rates were observed. Nitrifying bacteria were screened by specific gene probes using fluorescence in situ hybridization and quantified...... Nitrobacter sp. was not detected. The relative abundances of AOB and NOB in the untreated system were generally higher compared to the system exposed to formalin. Low dose formalin in recirculated aquaculture systems proved to be a possible treatment strategy, as the effect on nitrification was minimal. Since...
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Negi, Manisha; Sanagala, Raghavendrarao; Rai, Vandna; Jain, Ajay
2016-01-01
Phosphate (Pi), an essential macronutrient for growth and development of plant, is often limiting in soils. Plants have evolved an array of adaptive strategies including modulation of root system architecture (RSA) for optimal acquisition of Pi. In rice, a major staple food, RSA is complex and comprises embryonically developed primary and seminal roots and post-embryonically developed adventitious and lateral roots. Earlier studies have used variant hydroponic systems for documenting the effects of Pi deficiency largely on primary root growth. Here, we report the temporal effects of Pi deficiency in rice genotype MI48 on 15 ontogenetically distinct root traits by using easy-to-assemble and economically viable modified hydroponic system. Effects of Pi deprivation became evident after 4 days- and 7 days-treatments on two and eight different root traits, respectively. The effects of Pi deprivation for 7 days were also evident on different root traits of rice genotype Nagina 22 (N22). There were genotypic differences in the responses of primary root growth along with lateral roots on it and the number and length of seminal and adventitious roots. Notably though, there were attenuating effects of Pi deficiency on the lateral roots on seminal and adventitious roots and total root length in both these genotypes. The study thus revealed both differential and comparable effects of Pi deficiency on different root traits in these genotypes. Pi deficiency also triggered reduction in Pi content and induction of several Pi starvation-responsive (PSR) genes in roots of MI48. Together, the analyses validated the fidelity of this modified hydroponic system for documenting Pi deficiency-mediated effects not only on different traits of RSA but also on physiological and molecular responses. PMID:27200025
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Childhood hypersensitivity pneumonitis associated with fungal contamination of indoor hydroponics.
Engelhart, Steffen; Rietschel, Ernst; Exner, Martin; Lange, Lars
2009-01-01
Childhood hypersensitivity pneumonitis (HP) is often associated with exposure to antigens in the home environment. We describe a case of HP associated with indoor hydroponics in a 14-year-old girl. Water samples from hydroponics revealed Aureobasidium pullulans as the dominant fungal micro-organism (10(4)CFU/ml). The diagnosis is supported by the existence of serum precipitating antibodies against A. pullulans, lymphocytic alveolitis on bronchoalveolar lavage (BAL) fluid, a corresponding reaction on a lung biopsy, and the sustained absence of clinical symptoms following the removal of hydroponics from the home. We conclude that hydroponics should be considered as potential sources of fungal contaminants when checking for indoor health complaints.
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Meriac, A.; Eding, E.H.; Schrama, J.W.; Kamstra, A.; Verreth, J.A.J.
2014-01-01
This study investigated the effect of dietary carbohydrate composition on the production, recovery and degradability of fecal waste from rainbow trout (Oncorhynchus mykiss) in recirculating aquaculture systems (RAS). Dietary carbohydrate composition was altered by substituting starch with non-starch
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Determining stressor-response relationships in reef building corals is a critical need for researchers because of global declines in coral reef ecosystems. A simplified recirculating coral exposure system for laboratory testing of a diversity of species and morphologies of reef b...
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Trough and pot crop systems with leaching recirculation and defoliation levels for mini tomatoes
Directory of Open Access Journals (Sweden)
Lais Perin
2017-11-01
Full Text Available The use of raw rice husk as substrate allows the use of crop systems that promote the recirculation of leachate in long crop cycles. Mini tomatoes present relatively low demand for photoassimilates. Thus, partial defoliation of the sympodium could benefit the crop without damage to the production or quality of the fruits. The objective of this work was to evaluate the plant growth, fruit yield and fruit quality of Cherry Hybrid Wanda and Grape Hybrid Dolcetto mini tomatoes cultivated in two recirculation crop systems (pots and troughs, using raw rice husk as substrate, under three defoliation conditions (without defoliation, removal of one and two leaves of the sympodium. The Cherry cultivar showed higher plant growth, fruit yield and mean fruit size. The Grape cultivar produced fruits with higher sugar concentration. For the Grape cultivar, the removal of one sympodium leaf did not affect the plant responses. However, for the Cherry cultivar, it was necessary to maintain the complete sympodium. The trough cultivation system improved plant growth and yield, whereas the pot system increased fruit sugar concentration.
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Monitoring for shaft cracks on reactor recirculation pumps
International Nuclear Information System (INIS)
Kowal, M.G.; O'Brien, J.T. Jr.
1989-01-01
The article discusses the vibration characteristics associated with a boiling water reactor (BWR) recirculation pump. It also describes the application of diagnostic techniques and shaft crack theory to an on-line diagnostic monitoring system for reactor recirculation pumps employed at Philadelphia Electric Company's Peach Bottom Atomic Power Station. Specific emphasis is placed on the unique monitoring techniques associated with these variable speed vertical pumps
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International Nuclear Information System (INIS)
Oliveira, L.F.S. de; Fleming, P.V.; Frutuoso e Melo, P.F.F.
1983-01-01
A realiability analysis of the air refrigeration and recirculation containment systems (ARRCS) of Angra-1 nuclear power plants, were done, aiming to evaluate the probabilities of occurence of a several accident. The systems were analysed for a 24 hours accident, including time failures and demand failures [pt
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Microscreen effects on water quality in replicated recirculating aquaculture systems
DEFF Research Database (Denmark)
Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg
2015-01-01
This study investigated the effects of three microscreen mesh sizes (100, 60 and 20 μm) on water quality and rainbow trout (Oncorhynchus mykiss) performance compared to a control group without microscreens, in triplicated recirculating aquaculture systems (RAS). Operational conditions were kept....... Fish performed similarly in all treatments. Preliminary screening of trout gills did not reveal any pathological changes related to microscreen filtration and the resulting water quality. Biofilter performance was also unaffected, with 0′-order nitrification rates (k0a) being equivalent for all twelve...
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DEFF Research Database (Denmark)
Andreasen, Morten; Marissal, Matthieu; Sørensen, Kim
2014-01-01
Concerned to push ships to have a lower impact on the environment, the International Maritime Organization are implementing stricter regulation of NOx and SOx emissions, called Tier III, within emission control areas (ECAs). Waste Heat Recovery Systems (WHRS) on container ships consist...... of recovering some of the waste heat from the exhaust gas. This heat is converted into electrical energy used on-board instead of using auxiliary engines. Exhaust Gas Recirculation (EGR) systems, are recirculating a part of the exhaust gas through the engine combustion chamber to reduce emissions. WHRS combined...... with EGR is a potential way to improve system efficiency while reducing emissions. This paper investigates the feasibility of combining the two systems. EGR dilutes the fuel, lowering the combustion temperature and thereby the formation of NOx, to reach Tier III limitation. A double stage WHRS is set up...
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A monitoring system of radioactive tracers in hydroponic solution for research on plant physiology
International Nuclear Information System (INIS)
Suzui, N.; Kawachi, N.; Ishioka, N.; Fujimaki, S.; Yamaguchi, M.
2009-01-01
The mechanism of nutrient uptake in plants has received considerable attention in the field of plant science. Here we describe the development of a new monitoring system of radioactive tracers in hydroponic solution, which enables the noninvasive measurement of radioactive tracer uptake by an intact plant. In addition, we incorporated a weighing instrument into this system in order to simultaneously monitor water uptake by the same plant. For an evaluation of this monitoring system, we conducted a tracer experiment with a rice plant and a positron-emitting radioactive tracer, and successfully obtained continuous data for the amounts of radioactive tracer and water taken up by the intact plant over 36 h. (authors)
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A monitoring system of radioactive tracers in hydroponic solution for research on plant physiology
Energy Technology Data Exchange (ETDEWEB)
Suzui, N.; Kawachi, N.; Ishioka, N.; Fujimaki, S. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Yamaguchi, M. [Takasaki Advanced Radiation Research Institute, Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)
2009-07-01
The mechanism of nutrient uptake in plants has received considerable attention in the field of plant science. Here we describe the development of a new monitoring system of radioactive tracers in hydroponic solution, which enables the noninvasive measurement of radioactive tracer uptake by an intact plant. In addition, we incorporated a weighing instrument into this system in order to simultaneously monitor water uptake by the same plant. For an evaluation of this monitoring system, we conducted a tracer experiment with a rice plant and a positron-emitting radioactive tracer, and successfully obtained continuous data for the amounts of radioactive tracer and water taken up by the intact plant over 36 h. (authors)
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Jung, Heejung S; Grady, Michael L; Victoroff, Tristan; Miller, Arthur L
2017-07-01
Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO 2 ) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO 2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm 3 , although CO 2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO 2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm 3 . We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO 2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO 2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50-75% maintained lower CO 2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants' exposures to particulate matter and CO 2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO 2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO 2 accumulation.
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Hydroponics on a chip: analysis of the Fe deficient Arabidopsis thylakoid membrane proteome.
Laganowsky, Arthur; Gómez, Stephen M; Whitelegge, Julian P; Nishio, John N
2009-04-13
The model plant Arabidopsis thaliana was used to evaluate the thylakoid membrane proteome under Fe-deficient conditions. Plants were cultivated using a novel hydroponic system, called "hydroponics on a chip", which yields highly reproducible plant tissue samples for physiological analyses, and can be easily used for in vivo stable isotope labeling. The thylakoid membrane proteome, from intact chloroplasts isolated from Fe-sufficient and Fe-deficient plants grown with hydroponics on a chip, was analyzed using liquid chromatography coupled to mass spectrometry. Intact masses of thylakoid membrane proteins were measured, many for the first time, and several proteins were identified with post-translational modifications that were altered by Fe deficiency; for example, the doubly phosphorylated form of the photosystem II oxygen evolving complex, PSBH, increased under Fe-deficiency. Increased levels of photosystem II protein subunit PSBS were detected in the Fe-deficient samples. Antioxidant enzymes, including ascorbate peroxidase and peroxiredoxin Q, were only detected in the Fe-deficient samples. We present the first biochemical evidence that the two major LHC IIb proteins (LHCB1 and LHCB2) may have significantly different functions in the thylakoid membrane. The study illustrates the utility of intact mass proteomics as an indispensable tool for functional genomics. "Hydroponics on a chip" provides the ability to grow A. thaliana under defined conditions that will be useful for systems biology.
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Selection and hydroponic growth of bread wheat cultivars for bioregenerative life support systems
Page, V.; Feller, U.
2013-08-01
As part of the ESA-funded MELiSSA program, the suitability, the growth and the development of four bread wheat cultivars were investigated in hydroponic culture with the aim to incorporate such a cultivation system in an Environmental Control and Life Support System (ECLSS). Wheat plants can fulfill three major functions in space: (a) fixation of CO2 and production of O2, (b) production of grains for human nutrition and (c) production of cleaned water after condensation of the water vapor released from the plants by transpiration. Four spring wheat cultivars (Aletsch, Fiorina, Greina and CH Rubli) were grown hydroponically and compared with respect to growth and grain maturation properties. The height of the plants, the culture duration from germination to harvest, the quantity of water used, the number of fertile and non-fertile tillers as well as the quantity and quality of the grains harvested were considered. Mature grains could be harvested after around 160 days depending on the varieties. It became evident that the nutrient supply is crucial in this context and strongly affects leaf senescence and grain maturation. After a first experiment, the culture conditions were improved for the second experiment (stepwise decrease of EC after flowering, pH adjusted twice a week, less plants per m2) leading to a more favorable harvest (higher grain yield and harvest index). Considerably less green tillers without mature grains were present at harvest time in experiment 2 than in experiment 1. The harvest index for dry matter (including roots) ranged from 0.13 to 0.35 in experiment 1 and from 0.23 to 0.41 in experiment 2 with modified culture conditions. The thousand-grain weight for the four varieties ranged from 30.4 to 36.7 g in experiment 1 and from 33.2 to 39.1 g in experiment 2, while market samples were in the range of 39.4-46.9 g. Calcium levels in grains of the hydroponically grown wheat were similar to those from field-grown wheat, while potassium, magnesium
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A hydroponic design for microgravity and gravity installations
Fielder, Judith; Leggett, Nickolaus
1990-01-01
A hydroponic system is presented that is designed for use in microgravity or gravity experiments. The system uses a sponge-like growing medium installed in tubular modules. The modules contain the plant roots and manage the flow of the nutrient solution. The physical design and materials considerations are discussed, as are modifications of the basic design for use in microgravity or gravity experiments. The major external environmental requirements are also presented.
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Manzocco, Lara; Foschia, Martina; Tomasi, Nicola; Maifreni, Michela; Dalla Costa, Luisa; Marino, Marilena; Cortella, Giovanni; Cesco, Stefano
2011-06-01
Nowadays, there is an increasing interest in the hydroponic floating system to cultivate leafy vegetables for ready-to-eat salads. It is reasonable that different growing systems could affect the quality and shelf life of these salads. The quality and shelf life of ready-to-eat lamb's lettuce grown in protected environment in soil plot or in soil-less system over hydroponic solution with or without the addition of 30 µmol L⁻¹ silicon were evaluated. Minimum effects were observed on colour, firmness and microbial counts. Hydroponic cultivation largely affected plant tissue hydration, leading to weight loss and structural modifications during refrigerated storage. The shelf life of lamb's lettuce was limited by the development of visually detectable unpleasant sensory properties. Shelf life, calculated by survival analysis of consumer acceptability data, resulted about 7 days for soil-cultivated salad and 2 days for the hydroponically grown ones. The addition of silicon to the hydroponic solution resulted in an interesting strategy to increase plant tissue yield and reduce nitrate accumulation. Although hydroponic cultivation may have critical consequences on product quality and shelf life, these disadvantages could be largely counterbalance by increased yield and a reduction of nitrate accumulation when cultivation is performed on nutritive solutions with supplemental addition of silicon. Copyright © 2011 Society of Chemical Industry.
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FIST/6IB1, BWR/6 System Responses to Intermediate Break in Recirculation Suction Line LINE
International Nuclear Information System (INIS)
1993-01-01
1 - Description of test facility: BWR/6-218 standard plant. A full size bundle with electrically heated rods is used to simulate the reactor core. A scaling ratio of 1/624 is applied in the design of the system components. Key features of the FIST facility include: (1) Full height test vessel and internals; (2) correctly scaled fluid volume distribution; (3) simulation of ECCS, S/RV, and ADS; (4) level trip capability; (5) heated feedwater supply system, which provides the capability for steady state operation. 2 - Description of test: Test 6IB1 investigates system responses to an intermediate break in the recirculation suction line. BWR system licensing evaluations for various size recirculation break LOCA's indicates that a break size of about 0.2 sq.ft., without LPCS operation, is the highest PCT case for the intermediate break LOCA. Test 6IB1 simulates this event
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Bacterial activity dynamics in the water phase during start-up of recirculating aquaculture systems
DEFF Research Database (Denmark)
Rojas-Tirado, Paula Andrea; Pedersen, Per Bovbjerg; Pedersen, Lars-Flemming
2017-01-01
tMicrobial water quality in recirculating aquaculture systems (RAS) is important for successful RAS opera-tion but difficult to assess and control. There is a need to identify factors affecting changes in the bacterialdynamics – in terms of abundance and activity – to get the information needed...
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Hydroponic Technology for Lily Flowers and Bulbs Production Using ...
African Journals Online (AJOL)
This experiment was carried out to investigate the potential of nutrient film technique (NFT) hydroponic system for flowers and bulbs production of the Asiatic hybrid lily cv. "Blackout" using rainwater and some common nutrient solutions (Hoagland No. 2 Basal Salt Mixture, Murashige and Skoog Basal Salt Mixture and ...
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Automated hydroponics nutrition plants systems using arduino uno microcontroller based on android
Sihombing, P.; Karina, N. A.; Tarigan, J. T.; Syarif, M. I.
2018-03-01
Technological developments today make the combination of science is very common, including in Computer Science and Agriculture to make both of science need each other. This paper aims to develop a control tool for the flow of nutrients of hydroponic plants automatically using Arduino microcontroller and controlled by smartphone. We use an Arduino Uno microcontroller to automatically control the flow of nutrient solution with logic if else. The microcontroller can also send data of fluid level (solution) and temperature around the plant to smartphone android of the owner of the hydroponics plant. The height of the nutrient solution (water) is detected by the Ultrasonic sensor HC-SR04 and the temperature is detected by the temperature sensor LM35. Data from the sensor will forward into Arduino Uno and displayed in liquid crystal display (LCD) then via wireless fidelity (WIFI) ESP8266 module will transmit the height of the nutrient solution and the temperature around of the plants to Android smartphone.
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International Nuclear Information System (INIS)
Merta, Henryk
2006-01-01
The paper deals with a system of a cascade of two tank reactors, being characterized by the variable stream of recirculating fluid at each stage. The assumed mathematical model enables one to determine the system's dynamics for the case when there is no time delay and for the opposite case. The time series of the conversion degree and of the dimensionless fluid temperature, characteristic for the system considered as well as the operation regions-the latter-basing on Feingenbaum diagrams with respect to the division ratio of the recirculating stream are presented
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Directory of Open Access Journals (Sweden)
Laura Silva
2015-11-01
Full Text Available The experiment evaluates the food production and water treatment of TAN, NO2−–N, NO3−–N, and PO43− in two aquaponics systems using the dynamic root floating technique (DRF. A separate recirculation aquaculture system (RAS was used as a control. The fish cultured was Nile tilapia (Oreochromis niloticus. The hydroponic culture in one treatment (PAK was pak choy (Brassica chinensis, and in the other (COR coriander (Coriandrum sativum. Initial and final weights were determined for the fish culture. Final edible fresh weight was determined for the hydroponic plant culture. TAN, NO2−–N, NO3−–N, and PO43− were measured in fish culture and hydroponic culture once a week at two times, morning (9:00 a.m. and afternoon (3:00 p.m.. The fish biomass production was not different in any treatment (p > 0.05 and the total plant yield was greater (p < 0.05 in PAK than in COR. For the hydroponic culture in the a.m., the PO43− was lower (p < 0.05 in the PAK treatment than in COR, and in the p.m. NO3−–N and PO43− were lower (p < 0.05 in PAK than in COR. The PAK treatment demonstrated higher food production and water treatment efficiency than the other two treatments.
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Root Zone Respiration on Hydroponically Grown Wheat Plant Systems
Soler-Crespo, R. A.; Monje, O. A.
2010-01-01
Root respiration is a biological phenomenon that controls plant growth and physiological development during a plant's lifespan. This process is dependent on the availability of oxygen in the system where the plant is located. In hydroponic systems, where plants are submerged in a solution containing vital nutrients but no type of soil, the availability of oxygen arises from the dissolved oxygen concentration in the solution. This oxygen concentration is dependent on the , gas-liquid interface formed on the upper surface of the liquid, as given by Henry's Law, depending on pressure and temperature conditions. Respiration rates of the plants rise as biomass and root zone increase with age. The respiration rate of Apogee wheat plants (Triticum aestivum) was measured as a function of light intensity (catalytic for photosynthesis) and CO2 concentration to determine their effect on respiration rates. To determine their effects on respiration rate and plant growth microbial communities were introduced into the system, by Innoculum. Surfactants were introduced, simulating gray-water usage in space, as another factor to determine their effect on chemical oxygen demand of microbials and on respiration rates of the plants. It is expected to see small effects from changes in CO2 concentration or light levels, and to see root respiration decrease in an exponential manner with plant age and microbial activity.
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Performance test of nutrient control equipment for hydroponic plants
Rahman, Nurhaidar; Kuala, S. I.; Tribowo, R. I.; Anggara, C. E. W.; Susanti, N. D.
2017-11-01
Automatic control equipment has been made for the nutrient content in irrigation water for hydroponic plants. Automatic control equipment with CCT53200E conductivity controller to nutrient content in irrigation water for hydroponic plants, can be used to control the amount of TDS of nutrient solution in the range of TDS numbers that can be set according to the range of TDS requirements for the growth of hydroponically cultivated crops. This equipment can minimize the work time of hydroponic crop cultivators. The equipment measurement range is set between 1260 ppm up to 1610 ppm for spinach plants. Caisim plants were included in this experiment along with spinach plants with a spinach plants TDS range. The average of TDS device is 1450 ppm, while manual (conventional) is 1610 ppm. Nutrient solution in TDS controller has pH 5,5 and temperature 29,2 °C, while manual is pH 5,6 and temperature 31,3 °C. Manually treatment to hydroponic plant crop, yields in an average of 39.6 grams/plant, greater than the yield of spinach plants with TDS control equipment, which is in an average of 24.6 grams / plant. The yield of caisim plants by manual treatment is in an average of 32.3 grams/crop, less than caisim crop yields with TDS control equipment, which is in an average of 49.4 grams/plant.
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Hydroponics as a valid tool to assess arsenic availability in mine soils.
Moreno-Jiménez, E; Esteban, E; Fresno, T; de Egea, C López; Peñalosa, J M
2010-04-01
The low solubility of As in mine soils limits its phytoavailability. This makes the extrapolation of data obtained under hydroponic conditions unrealistic because the concentration in nutrient solution frequently overexposes plants to this metalloid. This work evaluates whether As supply in hydroponics resembles, to some extent, the As phytoavailable fraction in soils and the implications for phytoremediation. Phytotoxicity of As, in terms of biomass production, chlorophyll levels, and As concentrations in plants, was estimated and compared in both soils and hydroponics. In order for hydroponic conditions to be compared to soil conditions, plant exposure levels were measured in both cultures. Hydroponic As concentration ranging from 2-8microM equated to the same plant organ concentrations from soils with 700-3000mgkg(-1). Total and extractable As fractions exceeded those values, but As concentrations in pore water were bellow them. According to our results (i) hydroponics should include doses in the range 0-10microM As to allow the extrapolation of the results to As-polluted soils, and (ii) phytoextraction of As in mining sites will be limited by low As phytoavailability.
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MINERAL NUTRITION OF CRISPHEAD LETTUCE GROWN IN A HYDROPONIC SYSTEM WITH BRACKISH WATER
Directory of Open Access Journals (Sweden)
HAMMADY RAMALHO E SOARES
2016-01-01
Full Text Available Water availability in the Brazilian semiarid is restricted and often the only water source available has high salt concentrations. Hydroponics allows using these waters for production of various crops, including vegetables, however, the water salinity can cause nutritional disorders. Thus, two experiments were conducted in a greenhouse at the Department of Agricultural Engineering of the Federal Rural University of Pernambuco, to evaluate the effects of salinity on the mineral nutrition of crisphead lettuce, cultivar Taina, in a hydroponic system (Nutrient Film Technique, using brackish water in the nutrient solution, which was prepared by adding NaCl to the local water (0.2 dS m-1. A randomized blocks experimental design was used in both experiments. The treatments consisted of water of different salinity levels (0.2, 1.2, 2.2, 3.2, 4.2 and 5.2 dS m-1 with four replications, totaling 24 plots for each experiment. The water added to compensate for the water-depth loss due to evapotranspiration (WCET was the brackish water of each treatment in Experiment I and the local water without modifications in Experiment II. The increase in the salinity of the water used for the nutrient solution preparation reduced the foliar phosphorus and potassium contents and increased the chloride and sodium contents, regardless of the WCET. Foliar nitrogen, calcium, magnesium and sulfur contents were not affected by increasing the water salinity used for the nutrient solution preparation.
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A portable gas recirculation unit for gaseous detectors
Guida, R.; Mandelli, B.
2017-10-01
The use of greenhouse gases (usually C2H2F4, CF4 and SF6) is sometimes necessary to achieve the required performance for some gaseous detectors. The consumption of these gases in the LHC systems is reduced by recycling the gas mixture thanks to a complex gas recirculation system. Beyond greenhouse gas consumption due to LHC systems, a considerable contribution is generated by setups used for LHC detector upgrade projects, R&D activities, detector quality assurance or longevity tests. In order to minimise this emission, a new flexible and portable gas recirculation unit has been developed. Thanks to its low price, flexibility and user-friendly operation it can be easily adapted for the different types of detector systems and set-ups.
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Delaide, Boris
2017-01-01
Aquaponics is an integrated farming concept that combines fish and hydroponic plant production in a recirculating water system. This innovative technique has the potential to reduce the impact of fish and plant production on the environment by namely closing the nutrient loop. Indeed, the nutrients leaving the fish part are used to grow hydroponic plants. This thesis focused on the mineral elements available in aquaponics to grow plants. The thesis started by deepening the aquaponic conce...
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The effect of feeding three commercially available diets manufactured by three U.S. feed companies on production characteristics and body composition of juvenile cobia Rachycentron canadum reared in recirculating aquaculture systems (RAS) was evaluated in a 57 d growth trial. Juvenile cobia (26.7 +...
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Delaide, Boris; Goddek, Simon; Gott, James; Soyeurt, Hélène; Jijakli, M.H.
2016-01-01
Plant growth performance is optimized under hydroponic conditions. The comparison between aquaponics and hydroponics has attracted considerable attention recently, particularly regarding plant yield. However, previous research has not focused on the potential of using aquaponic solution complemented with mineral elements to commercial hydroponic levels in order to increase yield. For this purpose, lettuce plants were put into AeroFlo installations and exposed to hydroponic (HP), aquaponic (AP...
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Close loop gas recirculation and purification system for INO RPC system
International Nuclear Information System (INIS)
Joshi, A.V.; Kalmani, S.D.; Mondal, N.K.; Satyanarayana, B.; Verma, P.
2013-01-01
Close loop gas recirculation system (CLS) is designed to overcome problems. The present system is a pilot unit catering to about 12 RPC detectors of 2m ÃâĂŤ 2m size. The gas mixture is prepared in required concentration, in-situ, and circulated throughout the loop at controlled flow rates. The pressure band is adjusted to be within 20mm of water column. A Programmable Logic Controller (PLC) keeps track of pressure and flow rates, process sequence and safety conditions. The loss of gas is continuously monitored to assess effectiveness of CLS. The concentration of gas components in the mixtures is monitored by sampling through Residual Gas Analyzer (RGA). The RPC performance parameters, such as leakage current, noise rate, efficiency and cross-talk are monitored vis-a-vis CLS parameters. It has been found that RPC parameters respond in coordination with CLS functioning. Room pressure and temperature also seem to have influence on both of them
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Recirculating induction accelerators for heavy ion fusion
International Nuclear Information System (INIS)
Barnard, J.J.; Deadrick, F.; Bangerter, R.O.
1993-01-01
We have recently completed a two-year study of recirculating induction heavy-ion accelerators (recirculators) as low-cost drivers for inertial-fusion-energy power plants. We present here a summary of that study and other recent work on recirculators
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Evaluation of a Shaker Dust Collector for Use in a Recirculating Ventilation System.
Peters, Thomas M; Sawvel, Russell A; Park, Jae Hong; Anthony, T Renée
2015-01-01
General ventilation with recirculated air may be cost-effective to control the concentration of low-toxicity, contaminants in workplaces with diffuse, dusty operations, such as in agriculture. Such systems are, however, rarely adopted with little evidence showing improved air quality and ability to operate under harsh conditions. The goal of this work was to examine the initial and long-term performance of a fabric-filter shaker dust collector (SDC) in laboratory tests and as deployed within a recirculating ventilation system in an agricultural building. In laboratory tests, collection efficiency and pressure drop were tracked over several filter loading cycles, and the recovery of filter capacity (pressure drop) from filter shaking was examined. Collection efficiencies of particles larger than 5 μm was high (>95%) even when the filter was pristine, showing effective collection of large particles that dominate inhalable concentrations typical of agricultural dusts. For respirable-sized particles, collection efficiencies were low when the filter was pristine (e.g., 27% for 1 μm) but much higher when a dust cake developed on the filter (>99% for all size particles), even after shaking (e.g., 90% for 1 μm). The first shake of a filter was observed to recovery a substantial fraction of filter capacity, with subsequent shakes providing little benefit. In field tests, the SDC performed effectively over a period of three months in winter when incorporated in a recirculating ventilation system of a swine farrowing room. Trends in collection efficiency and pressure drop with loading were similar to those observed in the laboratory with overall collection efficiencies high (>80%) when pressure drop exceeded 230 Pa, or 23% of the maximum loading recommended by the manufacturer. This work shows that the SDC can function effectively over the harsh winter in swine rearing operations. Together with findings of improved air quality in the farrowing room reported in a
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Sulphur recirculation for reduced boiler corrosion; Minskad pannkorrosion med svavelrecirkulation
Energy Technology Data Exchange (ETDEWEB)
Andersson, Sven; Karlsson, Martin (Goetaverken Miljoe AB, Goeteborg (Sweden)); Blomqvist, Evalena; Baefver, Linda; Claesson, Frida; Davidsson, Kent (SP Sveriges Tekniska Forskningsinstitut, Boraas (Sweden)); Froitzheim, Jan; Pettersson, Jesper; Steenari, Britt-Marie (Chalmers Tekniska Hoegskola, Oorganisk miljoekemi, Goeteborg (Sweden))
2010-03-15
Sulphur recirculation is a new technology for reducing boiler corrosion and dioxin formation, which was demonstrated in full-scale tests performed at the Renova Waste to Energy plant at Saevenaes in Goeteborg (Sweden). Sulphur is recirculated from the flue gas cleaning back to the boiler, which reduces the chloride content of the deposits, which in turn reduces boiler corrosion and dioxin formation. Sulphur dioxide was separated from the flue gas in a wet scrubber by adding hydrogen peroxide, producing sulphuric acid. The sulphuric acid was injected into the furnace using nozzles with atomization air, surrounded by recirculated flue gas for improved mixing. By recirculating the sulphur, the sulphur dioxide concentration was increased in the boiler. Each sulphur atom passed the boiler several times and no external sulphur had to be added. Dioxin, ash, deposits and particle samplings together with 1000 h corrosion probe measurements were performed for normal operation (reference) and with sulphur recirculation respectively. During spring 2009, reference measurements were made and the recirculation system was installed and tested. During autumn 2009, a long term test with sulphur recirculation was made. An SO{sub 2} concentration of approximately 800 mg/m3 (n, d.g.) was maintained in the boiler by the system except during a period of extremely low sulphur content in the waste. The sulphur dioxide stack concentrations have been far below the emission limit. Sulphuric acid dew point measurements have shown that the sulphuric acid dosage did not lead to elevated SO{sub 3} concentrations, which may otherwise lead to low temperature corrosion. The chlorine content of both fly ash and boiler ash decreased and the sulphur content increased during the sulphur recirculation tests. The molar chlorine/sulphur ratio (Cl/S) decreased by two thirds in the fly ash as well as in the boiler ash, except for one sample. With sulphur recirculation in operation, the deposit growth was
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Fractal solutions of recirculation tubular chemical reactors
International Nuclear Information System (INIS)
Berezowski, Marek
2003-01-01
Three kinds of fractal solutions of model of recirculation non-adiabatic tubular chemical reactors are presented. The first kind concerns the structure of Feigenbaum's diagram on the limit of chaos. The second kind and the third one concern the effect of initial conditions on the dynamic solutions of models. In the course of computations two types of recirculation were considered, viz. the recirculation of mass (return of a part of products' stream) and recirculation of heat (heat exchange in the external heat exchanger)
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Energy Technology Data Exchange (ETDEWEB)
Okano, T.; Terazoe, H.; Shoji, K. [Central Research Institute of Electric Power Industry, Tokyo (Japan); Yonezawa, K.; Otani, F. [Chugoku Electric Power Co. Inc., Hiroshima (Japan); Sekiyama, T.; Kosakai, K.; Sato, H.
1997-06-01
Equipment which made experiments on air conditioning and hydroponic cultivation possible was set up at the technical research center of the Chugoku Electric Power Co., to study an air conditioning system using night power and energy saving technology for the cultivation. Vegetables suitable to the cultivation were selected. For air conditioning, adopted was a water heat storage air conditioning system using night power. The space between the shade curtain and the greenhouse roof was ventilated to prevent increase in cooling load caused by rise in curtain temperature. Moreover, the cultivation equipment was covered with transparent vinyl film to cool the inside of the equipment. The hydroponic cultivation equipment was trially manufactured which makes the continued production by one worker possible. The cultivation of spinach, leaf lettuce and chingensai throughout the year became possible. The yield of chingensai reached the target, but those of spinach and leaf lettuce were approximately 70% of the targets. Vegetables to be produced in the air-conditioned greenhouse by hydroponic cultivation are thought to be those that can have added values such non-pesticides and ingredients, young plants which were increased by cutting or tissue culturing, etc. 5 refs., 19 figs., 8 tabs.
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Design of a recirculating radon progeny aerosol generation and animal exposure system
International Nuclear Information System (INIS)
Newton, G.J.; Cuddihy, R.G.; Yeh, H.C.; Barr, E.B.; Boecker, B.B.
1988-01-01
Inhalation studies are being conducted at ITRI using laboratory animals exposed to radon-222 progeny attached to vector aerosols that are typical of indoor environments. The purpose of these studies is to identify the cells at risk from inhaled radon progeny and their locations within the respiratory tract. These studies require exposures up to 1000 working level months (WLM) within a few hours. Thus, large amounts of radium-226 are needed to produce the gaseous radon-222. A once-through-exposure-system was considered to be impractical because of statutory discharge limitations and the large amounts of radium that would be required. Therefore, a recirculating exposure system was designed and constructed that removes the aerosol after passing through the exposure chambers and recirculates purified air and radon. The purified radon is mixed with freshly evolving radon from a radon generator and passed Into a reaction-aging chamber where attachment of radon progeny to the vector aerosol occurs. The design includes: (1) 50-200 mg radium-226 in a radon generator, (2) 40 L/min total flow rate, (3) CO 2 removal, (4) reconstitution of oxygen tension and water vapor content to atmospheric levels, and (5) a trap for radon gas. A radon progeny exposure concentration in the range of 4,000 to 50,000 WL is being produced. (author)
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Thermophysical fundamentals of cyclonic recirculating heating devices
Karpov, S. V.; Zagoskin, A. A.
2017-10-01
This report presents the results of experimental and theoretical research of aerodynamics and convective heat transfer in cyclone devices with the new system of external recirculation of heating gas under the influence of radial pressure gradient in a heat carrier’s swirling turbulent flow. The dynamic problem of tangential velocity distribution in a clearance volume is solved at various re-circulation ratio values including limiting quantities (kr = 0; 1) and variations in cyclonic combustion chamber’s design parameters and operating conditions (Rer); the integrated calculation ratios for fundamental aerodynamic characteristics of a recirculation device are derived. The first experimental and numerical studies of convective heat transfer on internal and external surfaces of a hollow shaft in a swirling recirculation flow are derived through the instrumentality of OpenFOAM, these studies are also conducted for a setting of several cylindrical solid inserts. The external surface heat problem of a hollow cylindrical insert is solved with integral and digital methods; generalized similarity equations for the internal and external surfaces extended in range of Reynolds number are derived. The experimental data is in reasonable agreement with the derived curves and the results of mathematic modelling of convective heat transfer. Calculation recommendations for optimal selection of kr values at various ratios of their geometric characteristics and products utilization rate are obtained.
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Failure investigation of stem of valve disc in reactor recirculation system of TAPS Unit-1
International Nuclear Information System (INIS)
Ramadasan, E.; Bahl, J.K.; Sivaramakrishnan, K.S.
1986-01-01
Failure analysis was carried out of failed 17-4 PH stainless steel stem of the valve disc in reactor recirculation system of Unit-1 of Tarapur Atomic Power Station. The examination revealed that the stem failed due to fatigue, accelerated by corrosion. Recommendations have been made to avoid such failures. (author)
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DEFF Research Database (Denmark)
Prehn, Jonas; Waul, Christopher Kevin; Pedersen, Lars-Flemming
2012-01-01
Total ammonia nitrogen (TAN) removal by microbial nitrification is an essential process in recirculating aquaculture systems (RAS). In order to protect the aquatic environment and fish health, it is important to be able to predict the nitrification rates in RAS’s. The aim of this study was to det...... biofilters. The results may thus have practical implications in relation to the design, operational strategy of RAS biofilters and how to optimize TAN removal in fixed film biofilter systems......Total ammonia nitrogen (TAN) removal by microbial nitrification is an essential process in recirculating aquaculture systems (RAS). In order to protect the aquatic environment and fish health, it is important to be able to predict the nitrification rates in RAS’s. The aim of this study...
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How-to-Do-It. Hydroponics and Aquaculture in the High School Classroom.
Nicol, Ernest
1990-01-01
The construction of a hydroponic system for use in the classroom is described. Provided are construction details, a list of materials with approximate cost, a diagram of the setup, and a sample test. Several activities are suggested. (CW)
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Automation of water supply and recirculation-filtration of water at a swimming pool using Zelio PLC
Diniş, C. M.; Popa, G. N.; Iagăr, A.
2018-01-01
The paper proposes the use of the Zelio PLC for the automation of the water supply and recirculation-filtration system of a swimming pool. To do this, the Zelio SR3B261BD - 24V DC with 10 digital inputs (24V DC) and 10 digital outputs (relay contacts) was used. The proposed application makes the control of the water supply pumps and the water recirculation-filtration from a swimming pool. The recirculation-filtration systems for pools and swimming pools are designed to ensure water cleaning and recirculation to achieve optimum quality and lasting service life. The water filtration process is one of the important steps in water treatment in polls and swimming pools. It consists in recirculation of the entire volume of water and begins by absorbing the water in the pool by means of a pump followed by the passing of water through the filter, disinfectant and pH dosing, and reintroducing the water back into the pool or swimming pool through the discharge holes. Filters must to work 24 hours a day to remove pollutants from pools or swimming pools users. Filtration removes suspension particles with different origins. All newly built pools and swimming pools must be fitted with water recirculation systems, and existing ones will be equipped with water recirculation and water treatment systems.
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Corrosion products, activity transport and deposition in boiling water reactor recirculation systems
International Nuclear Information System (INIS)
Alder, H.P.; Buckley, D.; Grauer, R.; Wiedemann, K.H.
1989-09-01
The deposition of activated corrosion products in the recirculation loops of Boiling Water Reactors produces increased radiation levels which lead to a corresponding increase in personnel radiation dose during shut down and maintenance. The major part of this dose rate is due to cobalt-60. The following areas are discussed in detail: - the origins of the corrosion products and of cobalt-59 in the reactor feedwaters, - the consolidation of the cobalt in the fuel pin deposits (activation), - the release and transport of cobalt-60, - the build-up of cobalt-60 in the corrosion products in the recirculation loops. Existing models of the build-up of circuit radioactivity are discussed and the operating experiences from selected reactors are summarised. Corrosion chemistry aspects of the cobalt build-up in the primary circuit have already been studied on a broad basis and are continuing to be researched in a number of centers. The crystal chemistry of chromium-nickel steel corrosion products poses a number of yet unanswered questions. There are major loopholes associated with the understanding of activation processes of cobalt deposited on the fuel pins and in the mass transfer of cobalt-60. For these processes, the most important influence stems from factors associated with colloid chemistry. Accumulation of data from different BWRs contributes little to the understanding of the activity build-up. However, there are examples that the problem of activity build-up can be kept under control. Although many details for a quantitative understanding are still missing, the most important correlations are visible. The activity build-up in the BWR recirculation systems cannot be kept low by a single measure. Rather a whole series of measures is necessary, which influences not only cobalt-60 deposition but also plant and operation costs. (author) 26 figs., 13 tabs., 90 refs
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High-yield production of a human monoclonal IgG by rhizosecretion in hydroponic tobacco cultures.
Madeira, Luisa M; Szeto, Tim H; Henquet, Maurice; Raven, Nicole; Runions, John; Huddleston, Jon; Garrard, Ian; Drake, Pascal M W; Ma, Julian K-C
2016-02-01
Rhizosecretion of recombinant pharmaceuticals from in vitro hydroponic transgenic plant cultures is a simple, low cost, reproducible and controllable production method. Here, we demonstrate the application and adaptation of this manufacturing platform to a human antivitronectin IgG1 monoclonal antibody (mAb) called M12. The rationale for specific growth medium additives was established by phenotypic analysis of root structure and by LC-ESI-MS/MS profiling of the total protein content profile of the hydroponic medium. Through a combination of optimization approaches, mAb yields in hydroponic medium reached 46 μg/mL in 1 week, the highest figure reported for a recombinant mAb in a plant secretion-based system to date. The rhizosecretome was determined to contain 104 proteins, with the mAb heavy and light chains the most abundant. This enabled evaluation of a simple, scalable extraction and purification protocol and demonstration that only minimal processing was necessary prior to protein A affinity chromatography. MALDI-TOF MS revealed that purified mAb contained predominantly complex-type plant N-glycans, in three major glycoforms. The binding of M12 purified from hydroponic medium to vitronectin was comparable to its Chinese hamster ovary (CHO)-derived counterpart. This study demonstrates that in vitro hydroponic cultivation coupled with recombinant protein rhizosecretion can be a practical, low-cost production platform for monoclonal antibodies. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.
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Phytoremediation of arsenic by Trapa natans in a hydroponic system.
Baruah, Sangita; Borgohain, Jayasree; Sarma, K P
2014-05-01
Phytoremediation of arsenic (As) by water chestnut (Trapa natans) in a hydroponic system was studied. Plants were grown at two concentrations of arsenic, 1.28 mg/L and 10.80 mg/L, in a single metal solution. Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX) confirmed highest arsenic concentration in the roots, followed by shoots and leaves. SEM-EDX also confirmed internalization of arsenic in T. natans and the damage caused due to arsenic exposure. Fourier Transform Infra Red Spectroscopy (FT-IRS) indicated that the binding characteristics of the arsenic ions involved the hydroxyl, amide, amino, and thiol groups in the biomass. Chlorophyll concentration decreased with increasing metal concentration and duration of exposure, but proline content increases with increasing concentration in the plant. Morphological changes were studied on the 3rd, 5th and 7th day. Unhealthy growth and chlorosis were found to be related with arsenic toxicity. From the above studies it is clear that T. natans can be used successfully for the removal of arsenic ions by a phytoremediation process.
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An evaluation of debris mobility within a PWR reactor coolant system during the recirculation mode
International Nuclear Information System (INIS)
Andreychek, T.S.
1987-01-01
To provide for the long-term cooling of the nuclear core of a Pressurized Water Rector (PWR) following a hypothetical Loss-of-Coolant Accidnet (LOCA), water is drawn from the containment sump and pumped into the reactor coolant system (RCS). It has been postulated that debris from the containment, such as dirt, sand, and paint from containment walls and in-containment equipment, could be carried into the containment sump due to the action of the RCS coolant that escapes from the breach in the piping and then flows to the sump. Once in the sump, this debris could be pumped into the Safety Injection System (SIS) and ultimately the RCS itself, causing the performance of the SIS to be degraded. Of particular interest is the potential for core blockage that may occur due to debris transport into the core region by the recirculating flow. This paper presents a method of evaluating the potential for debris from the sump to form core blockages under recirculating flow conditions following a hypothetical LOCA for a PWR
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Smart System for Bicarbonate Control in Irrigation for Hydroponic Precision Farming
Directory of Open Access Journals (Sweden)
Carlos Cambra
2018-04-01
Full Text Available Improving the sustainability in agriculture is nowadays an important challenge. The automation of irrigation processes via low-cost sensors can to spread technological advances in a sector very influenced by economical costs. This article presents an auto-calibrated pH sensor able to detect and adjust the imbalances in the pH levels of the nutrient solution used in hydroponic agriculture. The sensor is composed by a pH probe and a set of micropumps that sequentially pour the different liquid solutions to maintain the sensor calibration and the water samples from the channels that contain the nutrient solution. To implement our architecture, we use an auto-calibrated pH sensor connected to a wireless node. Several nodes compose our wireless sensor networks (WSN to control our greenhouse. The sensors periodically measure the pH level of each hydroponic support and send the information to a data base (DB which stores and analyzes the data to warn farmers about the measures. The data can then be accessed through a user-friendly, web-based interface that can be accessed through the Internet by using desktop or mobile devices. This paper also shows the design and test bench for both the auto-calibrated pH sensor and the wireless network to check their correct operation.
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Chinta, Yufita D; Kano, Kazuki; Widiastuti, Ani; Fukahori, Masaru; Kawasaki, Shizuka; Eguchi, Yumi; Misu, Hideyuki; Odani, Hiromitsu; Zhou, Songying; Narisawa, Kazuhiko; Fujiwara, Kazuki; Shinohara, Makoto; Sato, Tatsuo
2014-08-01
Recent reports indicate that organic fertilisers have a suppressive effect on the pathogens of plants grown under hydroponic systems. Furthermore, microorganisms exhibiting antagonistic activity to diseases have been observed in organic hydroponic systems. This study evaluated the effect of corn steep liquor (CSL) on controlling lettuce root rot disease [Fusarium oxysporum f.sp. lactucae (FOL)] in a hydroponic system. The effect of CSL and Otsuka A (a chemical fertiliser) on the inhibition of FOL in terms of mycelial growth inhibition was tested in vivo. Addition of CSL suppressed FOL infection rates. CSL inhibited FOL infection by 26.3-42.5% from 2 days after starting incubation. In comparison, Otsuka A inhibited FOL growth by 5.5-19.4%. In addition, four of 10 bacteria isolated from the nutrient media containing CSL exhibited inhibition zones preventing FOL mycelial growth. We found that CSL suppressed FOL in lettuce via its antifungal and biostimulatory effects. We suggest that activation of beneficial microorganisms present in CSL may be used to decrease lettuce root rot disease and contribute to lettuce root growth. © 2014 Society of Chemical Industry.
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The bio-ethanol production with the thin stillage recirculation
Directory of Open Access Journals (Sweden)
M. Rakin
2009-01-01
Full Text Available In this paper, the bioethanol production with the thin stillage recirculation in mashing was investigated. The mashing was performed with recirculation of: 0, 10, 20 and 30 % of the thin stillage. The thin stillage recirculation was repeated six times. In the experiment without the thin stillage, the recirculation bioethanol yield (compared to the theoretical yield was 97.96 %, which implicates that the experiment conditions were chosen and performed well. With the addition of the thin stillage, the bioethanol yield increased and was above 100 %. Higher bioethanol yield than 100 % can be explained by the fact that the thin stillage contains carbohydrates, amino acids and yeast cells degradation products. The bioethanol yield increased with the increased number of thin stillage recirculation cycles. Dry matter content in fermenting slurry increased with the increased thin stillage quantity and the number of the thin stillage recirculation cycles (8.04 % for the first and 9.40 % for the sixth cycle. Dry matter content in thin stillage increased with the increased thin stillage quantity and the number of thin stillage recirculation cycles. Based on the obtained results it can be concluded that thin stillage recirculation increased the bioethanol yield. The highest bioethanol yields were obtained with recirculation of 10% thin stillage.
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NGL recovery increase through natural gasoline recirculation
Energy Technology Data Exchange (ETDEWEB)
Rivas M., M.; Bracho, J.L.; Murray, J. [Lagoven S.A., Maracaibo (Venezuela). Western Div.
1997-12-31
Given that the gas being processed in the compression plants Tia Juana 2 (PCTJ-2) and Tia Juana 3 (PCTJ-3) of Lagoven, S.A., an operating affiliate of Petroleos de Venezuela, S.A. has become learner through time, current production of natural gas liquids (NGL) and plant efficiency are significantly lower, compared to design and first obtained values. In this sense and aimed at increasing propane production, an optimization study on condensate stream recirculation and absorber installation was carried out to affect the process equilibrium constants thereby obtaining deeper extraction. Recirculation streams options were recirculation of natural gasoline obtained from the downstream fractionation process and recirculation of a conditioned, unfractionated, deethanized condensate stream. From the study, the natural gasoline recirculation scheme was determined to be the most efficient NGL recovery process. Accordingly, Lagoven, S.A. has undertaken a project to carry out this optimization scheme in PCTJ-2 and PCTJ-3. Construction stages are currently underway with completion scheduled at the end of 1997.
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Stabilization of pH in solid-matrix hydroponic systems
Frick, J.; Mitchell, C. A.
1993-01-01
2-[N-morpholino]ethanesulfonic acid (MES) buffer or Amberlite DP-1 (cation-exchange resin beads) were used to stabilize substrate pH of passive-wicking, solid-matrix hydroponic systems in which small canopies of Brassica napus L. (CrGC 5-2, genome : ACaacc) were grown to maturity. Two concentrations of MES (5 or 10 mM) were included in Hoagland 1 nutrient solution. Alternatively, resin beads were incorporated into the 2 vermiculite : 1 perlite (v/v) growth medium at 6% or 12% of total substrate volume. Both strategies stabilized pH without toxic side effects on plants. Average seed yield rates for all four pH stabilization treatments (13.3 to 16.9 g m-2 day-1) were about double that of the control (8.2 g m-2 day-1), for which there was no attempt to buffer substrate pH. Both the highest canopy seed yield rate (16.9 g m-2 day-1) and the highest shoot harvest index (19.5%) occurred with the 6% resin bead treatment, even though the 10 mM MES and 12% bead treatments maintained pH within the narrowest limits. The pH stabilization methods tested did not significantly affect seed oil and protein contents.
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Selection and hydroponic growth of potato cultivars for bioregenerative life support systems
Molders, K.; Quinet, M.; Decat, J.; Secco, B.; Dulière, E.; Pieters, S.; van der Kooij, T.; Lutts, S.; Van Der Straeten, D.
2012-07-01
As part of the ESA-funded MELiSSA program, Ghent University and the Université catholique de Louvain investigated the suitability, growth and development of four potato cultivars in hydroponic culture under controlled conditions with the aim to incorporate such cultivation system in an Environmental Control and Life Support System (ECLSS). Potato plants can fulfill three major functions in an ECLSS in space missions: (a) fixation of CO2 and production of O2, (b) production of tubers for human nutrition and (c) production of clean water after condensation of the water vapor released from the plants by transpiration. Four cultivars (Annabelle, Bintje, Desiree and Innovator) were selected and grown hydroponically in nutrient film technique (NFT) gullies in a growth chamber under controlled conditions. The plant growth parameters, tuber harvest parameters and results of tuber nutritional analysis of the four cultivars were compared. The four potato cultivars grew well and all produced tubers. The growth period lasted 127 days for all cultivars except for Desiree which needed 145 days. Annabelle (1.45 kg/m2) and Bintje (1.355 kg/m2) were the best performing of the four cultivars. They also produced two times more tubers than Desiree and Innovator. Innovator produced the biggest tubers (20.95 g/tuber) and Desiree the smallest (7.67 g/tuber). The size of Annabelle and Bintje potatoes were intermediate. Bintje plants produced the highest total biomass in term of DW. The highest non-edible biomass was produced by Desiree, which showed both the highest shoot and root DW. The manual length and width measurements were also used to predict the total tuber mass. The energy values of the tubers remained in the range of the 2010 USDA and Souci-Fachmann-Kraut food composition databases. The amount of Ca determined was slightly reduced compared to the USDA value, but close to the Souci-Fachmann-Kraut value. The concentration of Cu, Zn and P were high compared to both databases
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Dietary carbohydrates and denitrification in recirculating aquaculture systems
Meriac, A.
2014-01-01
Due to overfishing of global fish stocks and increasing fish meal prices, plant ingredients are being increasingly used as an alternative source of protein in fish feeds. However, the inclusion of unpurified plant ingredients will also increase the content of fibers in feeds. Fibers are nearly indigestible and will therefore increase solid waste production in aquaculture. This solid waste can be used to as a carbon source for denitrification to control nitrate levels in recirculating aquacul...
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Mota, Vasco C.; Martins, Catarina I.M.; Eding, Ep H.; Canário, Adelino V.M.; Verreth, Johan A.J.
2017-01-01
Steroids accumulate in recirculating aquaculture system (RAS), although explanatory factors for such accumulation are still poorly explored. This study investigated the effect of water exchange rate and pH in six replicated RAS on the concentration of the stress hormone cortisol in rainbow trout
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Gu Li; Shi-yang Zhang; Ling Tao; Xiao-li Li; Jing-hua Song; Chun-xue Zhang; Jian-qiang Zhu
2012-01-01
Developing improved aquaculture systems with a more efficient use of water and less environmental impact is becoming a crying need. A re-circulating aquaculture system consisting of paddy field and fish pond is a new culture mode due to aquaculture combing with agriculture. The present study focused on the purification capacity of the paddy field on nitrogen, phosphorus and organic matter, the fluctuation trend of water quality conditions during the whole rearing process and the culture effic...
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A detailed BWR recirculation loop model for RELAP
Energy Technology Data Exchange (ETDEWEB)
Araiza-Martínez, Enrique, E-mail: enrique.araiza@inin.gob.mx; Ortiz-Villafuerte, Javier, E-mail: javier.ortiz@inin.gob.mx; Castillo-Durán, Rogelio, E-mail: rogelio.castillo@inin.gob.mx
2017-01-15
Highlights: • A new detailed BWR recirculation loop model was developed for RELAP. • All jet pumps, risers, manifold, suction and control valves, and recirculation pump are modeled. • Model is tested against data from partial blockage of two jet pumps. • For practical applications, simulation results showed good agreement with available data. - Abstract: A new detailed geometric model of the whole recirculation loop of a BWR has been developed for the code RELAP. This detailed model includes the 10 jet pumps, 5 risers, manifold, suction and control valves, and the recirculation pump, per recirculation loop. The model is tested against data from an event of partial blockage at the entrance nozzle of one jet pump in both recirculation loops. For practical applications, simulation results showed good agreement with data. Then, values of parameters considered as figure of merit (reactor power, dome pressure, core flow, among others) for this event are compared against those from the common 1 jet pump per loop model. The results show that new detailed model led to a closer prediction of the reported power change. The detailed recirculation loop model can provide more reliable boundary condition data to a CFD models for studies of, for example, flow induced vibration, wear, and crack initiation.
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The effect of sludge recirculation rate on a UASB-digester treating domestic sewage at 15 °C.
Zhang, Lei; Hendrickx, Tim L G; Kampman, Christel; Zeeman, Grietje; Temmink, Hardy; Li, Weiguang; Buisman, Cees J N
2012-01-01
The anaerobic treatment of low strength domestic sewage at low temperature is an attractive and important topic at present. The upflow anaerobic sludge bed (UASB)-digester system is one of the anaerobic systems to challenge low temperature and concentrations. The effect of sludge recirculation rate on a UASB-digester system treating domestic sewage at 15 °C was studied in this research. A sludge recirculation rate of 0.9, 2.6 and 12.5% of the influent flow rate was investigated. The results showed that the total chemical oxygen demand (COD) removal efficiency rose with increasing sludge recirculation rate. A sludge recirculation rate of 0.9% of the influent flow rate led to organic solids accumulation in the UASB reactor. After the sludge recirculation rate increased from 0.9 to 2.6%, the stability of the UASB sludge was substantially improved from 0.37 to 0.15 g CH₄-COD/g COD, and the bio-gas production in the digester went up from 2.9 to 7.4 L/d. The stability of the UASB sludge and bio-gas production in the digester were not significantly further improved by increasing sludge recirculation rate to 12.5% of the influent flow rate, but the biogas production in the UASB increased from 0.37 to 1.2 L/d. It is recommended to apply a maximum sludge recirculation rate of 2-2.5% of the influent flow rate in a UASB-digester system, as this still allows energy self-sufficiency of the system.
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The effect of feeding three commercial diets on production characteristics and body composition of juvenile cobia Rachycentron canadum reared using recirculating aquaculture systems (RAS) was evaluated in a 56 d growth trial. Juvenile cobia (29.2 +/= 0.7 g, mean weight +/= SE) were stocked into thr...
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A low-head recirculating aquaculture system (RAS) was evaluated for the production Florida pompano Trachinotus carolinus from juvenile to market size. The RAS consisted of three dual-drain, 3-m diameter culture tanks of 7.8 m3 volume each, two 0.7-m3 moving bed bioreactors filled 67% with K1 kaldnes...
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Perspective for Aquaponic Systems: "Omic" Technologies for Microbial Community Analysis.
Munguia-Fragozo, Perla; Alatorre-Jacome, Oscar; Rico-Garcia, Enrique; Torres-Pacheco, Irineo; Cruz-Hernandez, Andres; Ocampo-Velazquez, Rosalia V; Garcia-Trejo, Juan F; Guevara-Gonzalez, Ramon G
2015-01-01
Aquaponics is the combined production of aquaculture and hydroponics, connected by a water recirculation system. In this productive system, the microbial community is responsible for carrying out the nutrient dynamics between the components. The nutrimental transformations mainly consist in the transformation of chemical species from toxic compounds into available nutrients. In this particular field, the microbial research, the "Omic" technologies will allow a broader scope of studies about a current microbial profile inside aquaponics community, even in those species that currently are unculturable. This approach can also be useful to understand complex interactions of living components in the system. Until now, the analog studies were made to set up the microbial characterization on recirculation aquaculture systems (RAS). However, microbial community composition of aquaponics is still unknown. "Omic" technologies like metagenomic can help to reveal taxonomic diversity. The perspectives are also to begin the first attempts to sketch the functional diversity inside aquaponic systems and its ecological relationships. The knowledge of the emergent properties inside the microbial community, as well as the understanding of the biosynthesis pathways, can derive in future biotechnological applications. Thus, the aim of this review is to show potential applications of current "Omic" tools to characterize the microbial community in aquaponic systems.
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The benefits of flue gas recirculation in waste incineration.
Liuzzo, Giuseppe; Verdone, Nicola; Bravi, Marco
2007-01-01
Flue gas recirculation in the incinerator combustion chamber is an operative technique that offers substantial benefits in managing waste incineration. The advantages that can be obtained are both economic and environmental and are determined by the low flow rate of fumes actually emitted if compared to the flue gas released when recirculation is not conducted. Simulations of two incineration processes, with and without flue gas recirculation, have been carried out by using a commercial flowsheeting simulator. The results of the simulations demonstrate that, from an economic point of view, the proposed technique permits a greater level of energy recovery (up to +3%) and, at the same time, lower investment costs as far as the equipment and machinery constituting the air pollution control section of the plant are concerned. At equal treatment system efficiencies, the environmental benefits stem from the decrease in the emission of atmospheric pollutants. Throughout the paper reference is made to the EC legislation in the field of environmental protection, thus ensuring the general validity in the EU of the foundations laid and conclusions drawn henceforth. A numerical example concerning mercury emission quantifies the reported considerations and illustrates that flue gas recirculation reduces emission of this pollutant by 50%.
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Chien, Shih-Hsiang; Chowdhury, Indranil; Hsieh, Ming-Kai; Li, Heng; Dzombak, David A; Vidic, Radisav D
2012-12-01
Secondary-treated municipal wastewater, an abundant and widely distributed impaired water source, is a promising alternative water source for thermoelectric power plant cooling. However, excessive biological growth is a major challenge associated with wastewater reuse in cooling systems as it can interfere with normal system operation as well as enhance corrosion and scaling problems. Furthermore, possible emission of biological aerosols (e.g., Legionella pneumophila) with the cooling tower drift can lead to public health concerns within the zone of aerosol deposition. In this study, the effectiveness of pre-formed and in-situ-formed monochloramine was evaluated for its ability to control biological growth in recirculating cooling systems using secondary-treated municipal wastewater as the only makeup water source. Bench-scale studies were compared with pilot-scale studies for their ability to predict system behavior under realistic process conditions. Effectiveness of the continuous addition of pre-formed monochloramine and monochloramine formed in-situ through the reaction of free chlorine with ammonia in the incoming water was evaluated in terms of biocide residual and its ability to control both planktonic and sessile microbial populations. Results revealed that monochloramine can effectively control biofouling in cooling systems employing secondary-treated municipal wastewater and has advantages relative to use of free chlorine, but that bench-scale studies seriously underestimate biocide dose and residual requirements for proper control of biological growth in full-scale systems. Pre-formed monochloramine offered longer residence time and more reliable performance than in-situ-formed monochloramine due to highly variable ammonia concentration in the recirculating water caused by ammonia stripping in the cooling tower. Pilot-scale tests revealed that much lower dosing rate was required to maintain similar total chlorine residual when pre-formed monochloramine
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STUDY ON BUILDING A SMALL-SCALE AQUAPONIC SYSTEM AND THE OUTSET OF IT
Directory of Open Access Journals (Sweden)
Radu Mihai Filep
2016-07-01
Full Text Available Building a small scale aquaponic system can be considered as a source of profit. On the same floor area two products could be yield: fish and plants (herbs, vegetables, salads, ornamentals. The small scale aquaponic system was built in the laboratory of Fisheries and Aquaculture of the Faculty of Animal Science of the University of Agronomic Sciences and Veterinary Medicine in Bucharest. It has two components, namely component of aquaculture and hydroponics component. The aquaculture component is represented by a tank with a volume of 450 l and the hydroponic component that is composed of a parallelepipedic box lined with PVC foil of 0.5 mm. PVC film’s purpose is to retain water in the hydroponic component. The parallelopipedic box was made of OSB with reinforcements made of pine timber. The substrate chosen for plant growth was river gravel with dimensions between 8 and 16 mm. The surface obtained for the plant growth was 1 m2. Water recirculation was done with a pump with adjustable flow of 300 to 1000 l / h. An aerator with two diffusers was used to assure the fish respiration and the nitrification processes. Construction costs, initialization and use of such a system are small and do not require special knowledge, tools or skills. This system can be built and used in spaces where there is no possibility of using soil for plant growth (balconies, terraces, etc.. This way one can have available herbs, vegetables and fresh fish, even in an apartments building.
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Ultra-violet radiation for the inactivation of microorganisms in hydroponics
International Nuclear Information System (INIS)
Buyanosvsky, G.; Gale, J.; Degani, N.
1981-01-01
The growth of microorganisms in the nutrient solution of a circulating hydroponic system was suppressed by ultra-violet radiation. Applied for three hours daily (572 Jm -2 h -1 ) throughout experiments in which tomato and corn were grown, it was effective in reducing the population of microorganisms from between 500-800 x 10 3 to 10-50 x 10 3 cells per ml. (orig.)
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Ultra-violet radiation for the inactivation of microorganisms in hydroponics
Energy Technology Data Exchange (ETDEWEB)
Buyanosvsky, G; Gale, J [Ben-Gurion Univ. of the Negev, Beersheva (Israel). Jacob Blaustein Inst. for Desert Research; Degani, N [Israel Atomic Energy Commission, Beersheba. Nuclear Research Center-Negev
1981-01-01
The growth of microorganisms in the nutrient solution of a circulating hydroponic system was suppressed by ultra-violet radiation. Applied for three hours daily (572 Jm/sup -2/h/sup -1/) throughout experiments in which tomato and corn were grown, it was effective in reducing the population of microorganisms from between 500-800 x 10/sup 3/ to 10-50 x 10/sup 3/ cells per ml.
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INFLUENCE OF SLUDGE RECIRCULATION ON NUTRIENT REMOVAL IN SUBMERGED MEMBRANE BIOREACTORS
Directory of Open Access Journals (Sweden)
María Casamitjanaa Causa
2015-06-01
Full Text Available Membrane bioreactors (MBR technology is a well-developed wastewater treatment process; however, the integrated operation between biological reactions and physical filtration has been poorly studied. Among other operational parameters, optimal control of sludge recirculation can enhance nitrogen and phosphorous removal processes, but the effects on sludge filterability is not clear. In this paper, different recirculation flow rates were tested to evaluate consequences on sludge filterability and nutrient removal in a MBR-UCT pilot plant treating real municipal wastewater. Three distinct sludge recirculation flows were studied during 10 weeks [external recirculation (from the membrane tank to the anoxic reactor, anoxic recirculation (from the aerobic to the anoxic reactor and anaerobic recirculation (from the anoxic to the anaerobic reactor]. The obtained results have shown that anaerobic recirculation affected nutrient removal in an inversely proportional way, whereas anoxic recirculation had a directly proportional effect. Referring sludge characteristics, filterability and capillarity suction time (CST remained independent of sludge recirculation, whereas CST is proportional to transmembrane pressure (TMP, which seems to depend on external and anoxic sludge recirculation.
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Perspective for Aquaponic Systems: “Omic” Technologies for Microbial Community Analysis
Directory of Open Access Journals (Sweden)
Perla Munguia-Fragozo
2015-01-01
Full Text Available Aquaponics is the combined production of aquaculture and hydroponics, connected by a water recirculation system. In this productive system, the microbial community is responsible for carrying out the nutrient dynamics between the components. The nutrimental transformations mainly consist in the transformation of chemical species from toxic compounds into available nutrients. In this particular field, the microbial research, the “Omic” technologies will allow a broader scope of studies about a current microbial profile inside aquaponics community, even in those species that currently are unculturable. This approach can also be useful to understand complex interactions of living components in the system. Until now, the analog studies were made to set up the microbial characterization on recirculation aquaculture systems (RAS. However, microbial community composition of aquaponics is still unknown. “Omic” technologies like metagenomic can help to reveal taxonomic diversity. The perspectives are also to begin the first attempts to sketch the functional diversity inside aquaponic systems and its ecological relationships. The knowledge of the emergent properties inside the microbial community, as well as the understanding of the biosynthesis pathways, can derive in future biotechnological applications. Thus, the aim of this review is to show potential applications of current “Omic” tools to characterize the microbial community in aquaponic systems.
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Perspective for Aquaponic Systems: “Omic” Technologies for Microbial Community Analysis
Munguia-Fragozo, Perla; Alatorre-Jacome, Oscar; Rico-Garcia, Enrique; Cruz-Hernandez, Andres; Ocampo-Velazquez, Rosalia V.; Garcia-Trejo, Juan F.; Guevara-Gonzalez, Ramon G.
2015-01-01
Aquaponics is the combined production of aquaculture and hydroponics, connected by a water recirculation system. In this productive system, the microbial community is responsible for carrying out the nutrient dynamics between the components. The nutrimental transformations mainly consist in the transformation of chemical species from toxic compounds into available nutrients. In this particular field, the microbial research, the “Omic” technologies will allow a broader scope of studies about a current microbial profile inside aquaponics community, even in those species that currently are unculturable. This approach can also be useful to understand complex interactions of living components in the system. Until now, the analog studies were made to set up the microbial characterization on recirculation aquaculture systems (RAS). However, microbial community composition of aquaponics is still unknown. “Omic” technologies like metagenomic can help to reveal taxonomic diversity. The perspectives are also to begin the first attempts to sketch the functional diversity inside aquaponic systems and its ecological relationships. The knowledge of the emergent properties inside the microbial community, as well as the understanding of the biosynthesis pathways, can derive in future biotechnological applications. Thus, the aim of this review is to show potential applications of current “Omic” tools to characterize the microbial community in aquaponic systems. PMID:26509157
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The bio-ethanol production with the thin stillage recirculation
M. Rakin; J. Pejin; O. Grujić; Lj. Mojović; D. Pejin
2009-01-01
In this paper, the bioethanol production with the thin stillage recirculation in mashing was investigated. The mashing was performed with recirculation of: 0, 10, 20 and 30 % of the thin stillage. The thin stillage recirculation was repeated six times. In the experiment without the thin stillage, the recirculation bioethanol yield (compared to the theoretical yield) was 97.96 %, which implicates that the experiment conditions were chosen and performed well. With the addition of the thin still...
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Touliatos, Dionysios; Dodd, Ian C; McAinsh, Martin
2016-08-01
Vertical farming systems (VFS) have been proposed as an engineering solution to increase productivity per unit area of cultivated land by extending crop production into the vertical dimension. To test whether this approach presents a viable alternative to horizontal crop production systems, a VFS (where plants were grown in upright cylindrical columns) was compared against a conventional horizontal hydroponic system (HHS) using lettuce ( Lactuca sativa L . cv. "Little Gem") as a model crop. Both systems had similar root zone volume and planting density. Half-strength Hoagland's solution was applied to plants grown in perlite in an indoor controlled environment room, with metal halide lamps providing artificial lighting. Light distribution (photosynthetic photon flux density, PPFD) and yield (shoot fresh weight) within each system were assessed. Although PPFD and shoot fresh weight decreased significantly in the VFS from top to base, the VFS produced more crop per unit of growing floor area when compared with the HHS. Our results clearly demonstrate that VFS presents an attractive alternative to horizontal hydroponic growth systems and suggest that further increases in yield could be achieved by incorporating artificial lighting in the VFS.
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Environmental impacts of urban hydroponics in Europe: a case study in Lyon
DEFF Research Database (Denmark)
Romeo, Daina; Vea, Eldbjørg Blikra; Thomsen, Marianne
2018-01-01
to deliver positive environmental and social benefits. However, its efficacy depends on several variables, including the type of UA and the geographical location of the city. This paper analyses ReFarmers’ pilot farm, a vertical high-yield hydroponic croft located in the urban area of Lyon, France, from...... a life cycle perspective. The results show that the hydroponic farm performs better than cultivations in heated greenhouses, and similarly to conventional open field farms. Moreover, the source of the electricity input is a determinant factor that, if carbon neutral (e.g. wind energy) allows vertical...... hydroponic production to outperform the two conventional types of agriculture....
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Exhaust gas recirculation apparatus for internal combustion engine
Energy Technology Data Exchange (ETDEWEB)
Shigemori, M; Eguchi, N
1975-01-07
An exhaust gas recirculation device to reduce nitrogen oxides emission from internal combustion engines is described. The recirculation is achieved by employing a tube connecting between the exhaust pipe and intake tube. A throttle valve is installed within the exhaust pipe between the muffler and recirculation tube, and regulated by exhaust gas temperature. Whenever the gas temperature is high, the valve closes and increases the gas flow to the intake tube. A temperature sensor is installed within the exhaust pipe and controls a solenoid or magnetic air valve linking to the throttle valve through a relay. The recirculation tube can be cooled by a fan to improve the engine power.
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Reliability analysis of air recirculation and-refrigeration systems of Angra-1 reactor containment
International Nuclear Information System (INIS)
Fernandes Filho, T.L.
1982-10-01
A reliability analysis of the air refrigeration and recirculation containment systems (ARRCS) of Angra-1 nuclear power plants, were done. The fault tree analysis was used. The failure primary data were taken out of Wash-1400 and IEEE. These data were processed by these following computer codes : Prep-Kitt, Sample, Trebil, Cressex and Streusl for the two stages of ARRCS operation. The design bases accident studied was a LOCA (loss of coolant). The component that more contribution give to the non-availability of ARRCS is the motor of the ARRCS. (E.G.) [pt
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Llamas, Xavier; Eriksson, Lars
2018-01-01
Large marine two-stroke diesel engines are widely used as propulsion systems for shipping worldwide and are facing stricter NOx emission limits. Exhaust gas recirculation is introduced to these engines to reduce the produced combustion NOx to the allowed levels. Since the current number of engines built with exhaust gas recirculation is low and engine testing is very expensive, a powerful alternative for developing exhaust gas recirculation controllers for such engines is to use control-orien...
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International Nuclear Information System (INIS)
Sanchez S, R.A.
2004-01-01
The present project, is continuation of the project presented in the congress SNM-2003. In this new phase of the project, they were carried out adaptive changes to the modeling and implementation of the module of the full superior of the core of the reactor, they were carried out those modeling of the generation of heat as well as of the energy transfer in the one fuel. These models present the main characteristics of the vessel of the one reactor and of the recirculation system, defined by the main phenomena that they intervene in the physical processes, in the previous version the simulation in real time it required of an extremely quick computer and without executing collateral processes. The tests are presented carried out to the different models belonging to the Simulator of the Reactor Vessel and the Recirculation system for the SUN-RAH (University Simulator of Nucleo electric with Boiling Water Reactor), as well as the results hurtled by this tests. In each section the executions of the tests and the corresponding analyses of results are shown for each pattern. Besides the above mentioned, the advantages presented by the Simulator of the reactor vessel and the recirculation system are pointed. (Author)
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Os, van E.A.
2009-01-01
Closed hydroponic growing systems have a better water use efficiency (WUE) and a lower use of fertilizers, but a larger risk of spreading soil-borne pathogens all over the crop compared to open systems. In climates or regions where availability of water is limited closed systems should be preferred
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Digital feedwater and recirculation flow control for GPUN Oyster Creek
International Nuclear Information System (INIS)
Burjorjee, D.; Gan, B.
1992-01-01
This paper describes the digital system for feedwater and recirculation control that GPU Nuclear will be installing at Oyster Creek during its next outage - expected circa December 1992. The replacement was motivated by considerations of reliability and obsolescence - the analog equipment was aging and reaching the end of its useful life. The new system uses Atomic Energy of Canada Ltd.'s software platform running on dual, redundant, industrial-grade 386 computers with opto-isolated field input/output (I/O) accessed through a parallel bus. The feedwater controller controls three main feed regulating valves, two low flow regulating valves, and two block valves. The recirculation controller drives the five scoop positioners of the hydraulic couplers. The system also drives contacts that lock up the actuators on detecting an open circuit in their current loops
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Energy Technology Data Exchange (ETDEWEB)
Giuliani, G.; Marchesi Donati, F.; Polonara, F. [Ancona Univ. (Italy). Dip. di Energetica; Hewitt, N.J. [University of Ulster at Coleraine, Northern Ireland (United Kingdom). NICERT
1999-09-01
The ability of zeotropic mixtures with a remarkable temperature glide to operate in liquid-recirculation systems is investigated and the results of an experimental comparison between the performances of the pure fluid R134a and the zeotropic mixture R32/134a (25/75% by mass) are presented. R134a performs slightly better in the liquid-recirculation mode than in the traditional dry-expansion mode; on the other hand, liquid-recirculation configuration has a detrimental effect on the zeotropic mixture's performance. The reason for this detrimental effect is the mixture component separation which occurs at the liquid/vapor separator. The effect of this separation is investigated using gas chromatograph analysis.
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International Nuclear Information System (INIS)
Muck, M.T.; Kearl, P.M.; Siegrist, R.L.
1998-01-01
This report presents the results of field testing a horizontal well recirculation system at the Portsmouth Gaseous Diffusion Plant (PORTS). The recirculation system uses a pair of horizontal wells, one for groundwater extraction and treatment and the other for reinjection of treated groundwater, to set up a recirculation flow field. The induced flow field from the injection well to the extraction well establishes a sweeping action for the removal and treatment of groundwater contaminants. The overall purpose of this project is to study treatment of mixed groundwater contaminants that occur in a thin water-bearing zone not easily targeted by traditional vertical wells. The project involves several research elements, including treatment-process evaluation, hydrodynamic flow and transport modeling, pilot testing at an uncontaminated site, and pilot testing at a contaminated site. The results of the pilot test at an uncontaminated site, the Clean Test Site (CTS), are presented in this report
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International Nuclear Information System (INIS)
Newton, M.A.; Reginato, L.L.; Yu, S.S.
1991-06-01
Heavy-ion accelerators are considered to be one of the promising driver alternatives for inertial fusion. In an inertial fusion driver, multiple beams of heavy-ions are accelerated to kinetic energies consistent with the fusion target requirements. During acceleration, the beams of heavy ions are compressed in time from an initial pulse duration that range from 10's to 100's of microseconds to a final pulse duration of approximately 10 nanoseconds. The compressed beam of heavy ions is then focused on the target in a reactor chamber where the energy released from the fusion reaction is converted to thermal energy and eventually to electricity. A recirculator is an induction accelerator which accelerates the particles and bends them in a closed path with pulsed dipole magnets. A single beam traverses the same accelerating cavities many times (50--100) to acquire its final energy. The primary motivation to evaluate recirculators is the potential for low cost that results from re-using many of the most expensive accelerator components, such as the induction cells, pulsers, and focusing magnets, during an acceleration sequence. One of the areas of technology that is critical to the feasibility of a recirculator is the modulator system required to accelerate the ion beams. This system greatly impacts the overall design of the recirculating accelerator. System studies have been conducted to evaluate the cost and efficiency of several recirculator configurations as function of various parameters. These system studies have helped identify desirable induction cell driver characteristics. These characteristics and the trade-offs that were evaluated will be presented and discussed
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Study On The Application Of Nutrient Immobilized Hydrogel As A Substrate For Hydroponics Culture
International Nuclear Information System (INIS)
Vo Thi Thu Ha; Le Quang Luan; Nguyen Thi Nu; Nguyen Thi Vang; Phan Dinh Thai Son; Nguyen Quang Khanh
2007-01-01
The aim of this study is preparation of a nutrient hydrogel from CMC by irradiation for hydroponics culture. The hydrogel with different swelling prepared from CMC combined with PAM, nutrient and alginate by gamma-Co-60 irradiation. The hydrogel prepared by irradiation of the component with 20% CMC, 20% PAM, 1% alginate and nutrients at 15 kGy was suitable for the growth and development of plants. In particularly, the hydrogel showed a positive effect on germination ratio of seeds, the growth of 14 days seedling and the growth of lettuce and Chinese mustard in hydroponics cultivation. The hydrogel was completely collapsed after 5 weeks use in a hydroponics culture. The hydrogel showed a promising for application in hydroponics culture, a new technique for production of high yield and high quality vegetables. (NHA)
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International Nuclear Information System (INIS)
Hameed, M. W.; Udddin, A.
2015-01-01
Hydroponic setups are frequently developed and improved as they are convenient platforms for studying whole plant physiology. Mostly, the available systems produce small amounts of plant material and are therefore, unsuitable for studies requiring large quantities of plant material like isolation of mitochondria. To address this issue, we have modified a hydroponic setup that can sustain hundreds of Arabidopsis and tobacco plants until adult plants are established. The setup is very flexible and easy to construct. It is based on the use of recyclable and sterilizable plastic-net-pots and media containers, which are easily available from the local suppliers. The modified seed-pots and styrofoam sheets facilitate the transfer and harvesting of seedlings. We have used the Percoll based two-step density gradient centrifugation method for the isolation of root mitochondria from the hydroponically grown plants. (author)
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Recirculating induction accelerators for inertial fusion: Prospects and status
International Nuclear Information System (INIS)
Friedman, A.; Barnard, J.J.; Cable, M.D.
1995-01-01
The US is developing the physics and technology of induction accelerators for heavy-ion beam-driven inertial fusion. The recirculating induction accelerator repeatedly passes beams through the same set of accelerating and focusing elements, thereby reducing both the length and gradient of the accelerator structure. This promises an attractive driver cost, if the technical challenges associated with recirculation can be met. Point designs for recirculator drivers were developed in a multi-year study by LLNL, LBNL, and FM Technologies, and that work is briefly reviewed here. To validate major elements of the recirculator concept, we are developing a small (4-5-m diameter) prototype recirculator which will accelerate a space-charge-dominated beam of K + ions through 15 laps, from 80 to 320 keV and from 2 to 8 mA. Transverse beam confinement is effected via permanent-magnet quadrupoles; bending is via electric dipoles. This ''Small Recirculator'' is being developed in a build-and-test sequence of experiments. An injector, matching section, and linear magnetic channel using seven half-lattice periods of permanent-magnet quadrupole lenses are operational. A prototype recirculator half-lattice period is being fabricated. This paper outlines the research program, and presents initial experimental results
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Directory of Open Access Journals (Sweden)
Sudeep Puthravilakom Sadasivan Nair
2010-08-01
Full Text Available In the present study, a goldfish (Carassius auratus Linn. recirculating aquaculture system (GRAS has been developed. The GRAS consisted of a culture tank, a screen filter and a foam fractionator for removal of particulate and dissolved solids and a trickling filter for conversion of ammonium- and nitrite-nitrogen to relatively harmless nitrate-nitrogen. The culture of goldfish at a stocking density of 1.08 kg/m3 was continued for a period of two and half months. Based on mass balance analysis of ammonium- and nitrate-nitrogen and assuming the trickling filter to be a plug flow reactor, a model was formulated to determine the necessary recirculation flow rate at different times of culture for maintaining the major nutrients, viz., ammonium- and nitrate-nitrogen below their permissible limits. The model was calibrated and validated using the real time data obtained from the experimental run. The high values of coefficient of determination and low values of root mean square error show the effectiveness of the model.
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Delaide, Boris; Goddek, Simon; Gott, James; Soyeurt, Hélène; Jijakli, M.H.
2016-01-01
Plant growth performance is optimized under hydroponic conditions. The comparison between aquaponics and hydroponics has attracted considerable attention recently, particularly regarding plant yield. However, previous research has not focused on the potential of using aquaponic solution
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Hydroponic Crop Production using Recycled Nutrients from Inedible Crop Residues
Garland, Jay L.; Mackowiak, Cheryl L.; Sager, John C.
1993-01-01
The coupling of plant growth and waste recycling systems is an important step toward the development of bioregenerative life support systems. This research examined the effectiveness of two alternative methods for recycling nutrients from the inedible fraction (residue) of candidate crops in a bioregenerative system as follows: (1) extraction in water, or leaching, and (2) combustion at 550 C, with subsequent reconstitution of the ash in acid. The effectiveness of the different methods was evaluated by (1) comparing the percent recovery of nutrients, and (2) measuring short- and long-term plant growth in hydroponic solutions, based on recycled nutrients.
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Analysis of heat recovery from a spray dryer by recirculation of exhaust air
International Nuclear Information System (INIS)
Golman, Boris; Julklang, Wittaya
2014-01-01
Highlights: • We study a spray dryer with heat recovery by partial recirculation of exhaust air. • We examine effects of process parameters on energy efficiency and energy savings. • Decreasing drying air temperature and flow rate will increase energy efficiency. • Increasing recirculation ratio and slurry feed rate will increase energy efficiency. - Abstract: Model simulations were employed to investigate the influences of process parameters on the energy recovery in spray drying process that partially recycle the exhaust drying gas. The energy efficiency and energy saving were studied for various values of recirculation ratios with respect to the temperature and flow rate of the drying air, slurry feed rate and concentration of slurry in spray drying of advanced ceramic materials. As a result, significant gains in energy efficiency and energy saving were obtained for a spray drying system with high recirculation ratio of exhaust air. The high slurry feed rate and the low slurry concentration, inlet drying air temperature and drying air flow rate enhanced the energy efficiency of spray drying system. However, the high energy saving was obtained in spray dryers operating at low slurry feed rate and high slurry concentration
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Two studies were conducted to determine if accumulating water quality parameters would negatively impact rainbow trout Oncorhynchus mykiss health and welfare within water recirculation aquaculture systems (WRAS) that were operated at low and near-zero water exchange, with and without ozonation, and ...
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Cui, Li-Hua; Luo, Shi-Ming; Zhu, Xi-Zhen; Liu, Ying-Hu
2003-01-01
Vertical flow constructed wetlands is a typical ecological sanitation system for sewage treatment. The removal rates for COD, BOD5, SS, TN, and TP were 60%, 80%, 74%, 49% and 79%, respectively, when septic tank effluent was treated by vertical flow filter. So the concentration of COD and BOD5 in the treated effluent could meet the quality standard for irrigation water. After that the treated effluent was used for hydroponic cultivation of water spinach and romaine lettuce, the removal efficiencies of the whole system for COD, BOD5, SS, TN and TP were 71.4%, 97.5%, 96.9%, 86.3%, and 87.4%, respectively. And it could meet the integrated wastewater discharge standard for secondary biological treatment plant. It was found that using treated effluent for hydroponic cultivation of vegetables could reduce the nitrate content in vegetables. The removal rates for total bacteria and coliform index by using vertical flow bed system with cinder substrate were 80%-90% and 85%-96%, respectively.
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Influence of leachate recirculation on aerobic and anaerobic decomposition of solid wastes
International Nuclear Information System (INIS)
Bilgili, M. Sinan; Demir, Ahmet; Ozkaya, Bestamin
2007-01-01
In this study, the effect of leachate recirculation on aerobic and anaerobic degradation of municipal solid wastes is determined by four laboratory-scale landfill reactors. The options studied and compared with the traditional anaerobic landfill are: leachate recirculation, landfill aeration, and aeration with leachate recirculation. Leachate quality is regularly monitored by the means of pH, alkalinity, total dissolved solids, conductivity, oxidation-reduction potential, chloride, chemical oxygen demand, ammonia, and total Kjeldahl nitrogen, in addition to generated leachate quantity. Aerobic leachate recirculated landfill appears to be the most effective option in the removal of organic matter and ammonia. The main difference between aerobic recirculated and non-recirculated landfill options is determined at leachate quantity. Recirculation is more effective on anaerobic degradation of solid waste than aerobic degradation. Further studies are going on to determine the optimum operational conditions for aeration and leachate recirculation rates, also with the operational costs of aeration and recirculation
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Development of technique to apply induction heating stress improvement to recirculation inlet nozzle
International Nuclear Information System (INIS)
Chiba, Kunihiko; Nihei, Kenichi; Ootaka, Minoru
2009-01-01
Stress corrosion cracking (SCC) have been found in the primary loop recirculation (PLR) systems of boiling water reactors (BWR). Residual stress in welding heat-affected zone is one of the factors of SCC, and the residual stress improvement is one of the most effective methods to prevent SCC. Induction heating stress improvement (IHSI) is one of the techniques to improve reduce residual stress. However, it is difficult to apply IHSI to the place such as the recirculation inlet nozzle where the flow stagnates. In this present study, the technique to apply IHSI to the recirculation inlet nozzle was developed using water jet which blowed into the crevice between the nozzle safe end and the thermal sleeve. (author)
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Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming
2017-01-01
A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system wa...
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A simple and low-cost recirculating aquaculture system for the production of arapaima juveniles
Burton, Andrew Mark; Moncayo Calderero, Edwin; Burgos Moran, Ricardo Ernesto; Anastacio Sánchez, Rogelio Lumbes; Avendaño Villamar, Ulises Tiberio; Ortega Torres, Nelson Guillermo
2016-01-01
A simple and low-cost recirculating system (RAS) for production of arapaima (Arapaima gigas) juveniles is described. Twenty arapaima fry (mean 13.0 cm, 12.0 g) were housed in three production tanks and fed a high HUFA diet resulting in 90% of fry successfully progressing to juveniles (mean 17.4 cm long; 40.2 g). The fish were then reared for a further 72 days fed on commercial extruded pellet feed achieving a mean length of 42.6 cm and 656.6 g. The simple and low-cost RAS holds good potentia...
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Directory of Open Access Journals (Sweden)
Thiago L Factor
2007-03-01
Full Text Available O presente trabalho teve como objetivo avaliar a produção de minitubérculos básicos de batata em três sistemas hidropônicos de cultivo: aeropônico, DFT (deep flow technique e NFT (nutrient film technique. O experimento foi realizado em ambiente protegido, de maio a setembro de 2005, em Jaboticabal, SP. Adotou-se o delineamento experimental em blocos casualizados com parcelas subdivididas, sendo os três sistemas hidropônicos de cultivo as parcelas principais e, as cultivares Agata e Monalisa, as subparcelas. A massa fresca e o diâmetro longitudinal dos tubérculos não foram influenciados pelos sistemas hidropônicos estudados, com valores médios de 6,2 e 30,2 mm, 6,3 g e 30,0 mm, 6,8 g e 31,0 mm, para os sistemas hidropônicos NFT, DFT e aeroponia, respectivamente. No que se refere às cultivares, Monalisa apresentou maior diâmetro longitudinal e massa fresca (32,2 mm e 7,1 g, valores significativamente superiores aos verificados para a cultivar Agata (28,6 mm e 5,8 g. O número de minitubérculos por planta e por metro quadrado teve valores médios significativamente superiores no sistema aeropônico (49,3 e 874,4 em relação aos sistemas NFT (39,5 e 246,6 e DFT (41,6 e 458,0, respectivamente. A produção de minitubérculos básicos de batata pode ser realizada de maneira eficiente utilizando-se os sistemas hidropônicos estudados, sendo o sistema aeropônico o que apresentou os melhores resultados.The objective of this work was to evaluate the production of potato basic minitubers in three hydroponic systems: aeroponic, DFT (deep flow technique and NFT (nutrient film technique, using cultivars Agata and Monalisa. The experiment was carried out under protected cultivation, from May to September, 2005, in Jaboticabal, São Paulo State, Brazil, in a completely randomized block design, with split-plots. The hydroponic systems were assigned to the experimental plots, whereas cultivars were assigned to sub-plots. Tuber fresh weight and
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A dented LH2 recirculation line is removed from Discovery
1999-01-01
In the Payload Changeout Room, Launch Pad 39B, United Space Alliance and NASA workers look at the replacement main propulsion system liquid hydrogen recirculation line (left) to be installed in Shuttle Discovery's aft compartment. At right is the dented line that has been removed. The 12-inch-long dent was discovered during routine aft compartment inspections Tuesday, Dec. 7. The line recirculates hydrogen from the Shuttle main engines back to the external tank during prelaunch engine conditioning. The line is being replaced and managers expect the replacement work to take about 3 days, followed by system retests and final aft compartment close-outs. Preliminary assessments reflect a launch date of Space Shuttle Discovery on mission STS-103 no earlier than Dec. 16. STS-103 is the third servicing mission for the Hubble Space Telescope.
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Probiotic effects on cobia Rachycentron canadum larvae reared in a recirculating aquaculture system
Directory of Open Access Journals (Sweden)
M. Angélica Garrido-Pereira
2014-11-01
Full Text Available Cobia (Rachycentron canadum is a marine finfish with good potential for mariculture. This study analyzes the effects of probiotic Bacillus spp. on the performance of cobia larvae reared in a recirculating aquaculture system (RAS. Larvae were stocked into two independent RAS for 26 days after hatching. One of the systems (Probiotic treatment received the addition of a commercial probiotic consisting of B. subtilis, B. licheniformis and B. pumilus directly into the water and by live feed. Survival, final weight and water quality were not affected by probiotics. Results showed larvae of the probiotic treatment demonstrated a greater resistance to salinity stress. Immunohistochemical analysis showed a higher expression of CD4 in probiotic treatment. These results suggest that Bacillus spp. probiotics used in RAS have a potential stimulating impact on immune system differentiation and increases salinity stress resistance of cobia larvae.
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Martins, C.I.; Eding, E.H.; Verreth, J.A.J.
2011-01-01
To date, farming fish in recirculating aquaculture systems (RAS) is one of the most environmentally friendly ways of producing fish. However, with the trend towards intensification, and consequently decrease in water exchange rates, these systems may accumulate substances, such as heavy metals, in
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Luo, Jinghuan; Lu, Xueqin; Liu, Jianyong; Qian, Guangren; Lu, Yongsheng
2014-12-01
Biogas, generated from an expanded granular sludge bed (EGSB) reactor treating municipal solid waste (MSW) leachate, was recirculated for calcium removal from the leachate via a carbonation process with simultaneous biogas purification. Batch trials were performed to optimize the solution pH and imported biogas (CO2) for CaCO3 precipitation. With applicable pH of 10-11 obtained, continuous trials achieved final calcium concentrations of 181-375 mg/L (removal efficiencies≈92.8-96.5%) in the leachate and methane contents of 87.1-91.4% (purification efficiencies≈65.4-82.2%) in the biogas. Calcium-balance study indicates that 23-986 mg Ca/d was released from the bio-system under the carbonized condition where CaCO3 precipitating was moved outside the bioreactor, whereas 7918-9517 mg Ca/d was trapped into the system for the controlled one. These findings demonstrate that carbonation removal of calcium by biogas recirculation could be a promising alternative to pretreat calcium-rich MSW leachate and synergistically to improve methane content. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Gang Gao
2017-12-01
Full Text Available Ramie (Boehmeria nivea (L. Gaud. is a traditionally terrestrial fiber crop. However, hydroponic technology can enhance the quantity and quality of disease free Ramie plant seedlings for field cultivation. To date, few studies have attempted to examine the hydroponic induction of ramie roots and the molecular responses of ramie roots to aquatic environment. In this study, ramie tender stems was grown in the soil or in a hydroponic water solution, and cultured in the same environmental conditions. Root samples of terrestrial ramie, and different developmental stages of hydroponic ramie (5 days, 30 days, were firstly pooled for reference transcriptome sequencing by Illumina Hiseq 2000. Gene expression levels of each samples were quantified using the BGISEQ500 platform to help understand the distribution of aquatic root development related genes at the macro level (GSE98903. Our data resources provided an opportunity to elucidate the adaptation mechanisms of ramie seedlings roots in aquatic environment.
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Removal of nitrogen by Algal Turf Scrubber Technology in recirculating aquaculture system
Valeta, J.; Verdegem, M.C.J.
2015-01-01
Ongoing research in recirculation aquaculture focuses on evaluating and improving the purification potential of different types of filters. Algal Turf Scrubber (ATS) are special as they combine sedimentation and biofiltration. An ATS was subjected to high nutrient loads of catfish effluent to
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Corrosion products, activity transport and deposition in boiling water reactor recirculation systems
International Nuclear Information System (INIS)
Alder, H.P.; Buckley, D.; Grauer, R.; Wiedemann, K.H.
1992-01-01
The deposition of activated corrosion products in the recirculation loops of Boiling Water Reactors produces increased radiation levels which lead to a corresponding increase in personnel radiation dose during shut down and maintenance. The major part of this dose rate is due to cobalt-60. Based on a comprehensive literature study concerning this theme, it has been attempted to identify the individual stages of the activity build-up and to classify their importance. The following areas are discussed in detail: The origins of the corrosion products and of cobalt-59 in the reactor feedwaters; the consolidation of the cobalt in the fuel pins deposits (activation); the release and transport of cobalt-60; the build-up of cobalt-60 in the corrosion products in the recirculation loops. Existing models of the build-up of circuit radioactivity are discussed and the operating experiences from selected reactors are summarized. 90 refs, figs and tabs
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Reactor recirculation pump test loop
International Nuclear Information System (INIS)
Taka, Shusei; Kato, Hiroyuki
1979-01-01
A test loop for a reactor primary loop recirculation pumps (PLR pumps) has been constructed at Ebara's Haneda Plant in preparation for production of PLR pumps under license from Byron Jackson Pump Division of Borg-Warner Corporation. This loop can simulate operating conditions for test PLR pumps with 130 per cent of the capacity of pumps for a 1100 MWe BWR plant. A main loop, primary cooling system, water demineralizer, secondary cooling system, instrumentation and control equipment and an electric power supply system make up the test loop. This article describes the test loop itself and test results of two PLR pumps for Fukushima No. 2 N.P.S. Unit 1 and one main circulation pump for HAZ Demonstration Test Facility. (author)
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Beam breakup in a multi-section recirculating linac
International Nuclear Information System (INIS)
Gluckstern, R.L.
1986-01-01
It has long been recognized that recirculating a beam through a linac cavity in order to provide a more efficient acceleration can also lead to an instability in which the transverse displacement on successive recirculations can excite modes which further deflect the initial beam. The effect is of particular concern for superconducting rf cavities where the high Q (or order 10 9 ) implied low starting currents for the instability. Previous work has addressed this effect by calculating the beam trajectory in a single cavity, and its effect on excitation of unwanted modes. The analysis of Gluckstern, Cooper and Channel is extended to the case of recirculation of a CW beam, and the starting current for a multi-cavity structure with several recirculations is computed. Each of the cavities is assumed to provide a simple impulse to the beam proportional to the transverse displacement in that cavity
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Retnaningdyah, Catur
2017-11-01
The objective of this research was to determine the effectiveness of a phytoremediation process using some local hydro macrophytes to reduce fertilizer residue in irrigation water in order to support healthy agriculture and to prevent eutrophication and algae bloom in water. A phytoremediation process was carried out in a hydroponic floating system by using transparent plastic bags of 1 m in diameter and 1 m in height that were placed in collecting ponds before they were used for agricultural activities. Paddy soils were used as substrates in this system. The irrigation water was treated with nutrient enrichment (Urea and SP-36 fertilizers). Then, the system was planted with remediation actors (Azolla sp., Ipomoea aquatica, Limnocharis flava, Marsilea crenata, polyculture of those hydro macrophytes and control). The improvement of the water quality as a result of the phytoremediation process was characterized by a decline in the concentration of some physicochemical parameters, which were measured at 7 days after incubation, as well as an increase in the plankton diversity index value. The results showed that all of the hydro macrophytes used in this research, which was grown in the hydroponic batch culture system for a period of 7 days, were able to significantly improve the irrigation water quality, which was enriched by the synthetic fertilizers Urea and SP36. This was reflected by a significant decrease in the concentration of water TSS, nitrate, BOD, COD and total phosphate and an increase in the value of water DO at 7 days after incubation. Improvement of the water quality is also reflected in the increasing plankton diversity index value as a bioindicator of water pollution indicating a change in the pollution status from moderately polluted to slightly polluted at 7 days after incubation.
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A controlled 3-month study was conducted in 6 replicated water recirculation aquaculture systems (RAS) containing a mixture of sexually mature and immature Atlantic salmon Salmo salar to determine whether water ozonation is associated with a reduction in waterborne hormones. Post-smolt Atlantic salm...
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Nutrients, particularly nitrate (NO3), can accumulate to very high levels within low exchange recirculation aquaculture systems (RAS) and negatively impact a number of cultured species. To prevent the harmful effects of nitrate accumulation and to dispose of concentrated waste biosolids, many RAS ar...
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DEFF Research Database (Denmark)
Mizuno, Takayuki; Shibahara, Kohki; Ye, Feihong
2017-01-01
In this paper, we present long-haul 32-core dense space division multiplexed (DSDM) unidirectional transmission over a single-mode multicore transmission line. We developed a low-crosstalk heterogeneous 32-core fiber with a square lattice arrangement, and a novel partial recirculating loop system...
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Douglas, David R; Tennant, Christopher
2015-11-10
A modulated-bending recirculating system that avoids CSR-driven breakdown in emittance compensation by redistributing the bending along the beamline. The modulated-bending recirculating system includes a) larger angles of bending in initial FODO cells, thereby enhancing the impact of CSR early on in the beam line while the bunch is long, and 2) a decreased bending angle in the final FODO cells, reducing the effect of CSR while the bunch is short. The invention describes a method for controlling the effects of CSR during recirculation and bunch compression including a) correcting chromatic aberrations, b) correcting lattice and CSR-induced curvature in the longitudinal phase space by compensating T.sub.566, and c) using lattice perturbations to compensate obvious linear correlations x-dp/p and x'-dp/p.
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Barbosa, Guilherme Lages; Gadelha, Francisca Daiane Almeida; Kublik, Natalya; Proctor, Alan; Reichelm, Lucas; Weissinger, Emily; Wohlleb, Gregory M; Halden, Rolf U
2015-06-16
The land, water, and energy requirements of hydroponics were compared to those of conventional agriculture by example of lettuce production in Yuma, Arizona, USA. Data were obtained from crop budgets and governmental agricultural statistics, and contrasted with theoretical data for hydroponic lettuce production derived by using engineering equations populated with literature values. Yields of lettuce per greenhouse unit (815 m2) of 41 ± 6.1 kg/m2/y had water and energy demands of 20 ± 3.8 L/kg/y and 90,000 ± 11,000 kJ/kg/y (±standard deviation), respectively. In comparison, conventional production yielded 3.9 ± 0.21 kg/m2/y of produce, with water and energy demands of 250 ± 25 L/kg/y and 1100 ± 75 kJ/kg/y, respectively. Hydroponics offered 11 ± 1.7 times higher yields but required 82 ± 11 times more energy compared to conventionally produced lettuce. To the authors' knowledge, this is the first quantitative comparison of conventional and hydroponic produce production by example of lettuce grown in the southwestern United States. It identified energy availability as a major factor in assessing the sustainability of hydroponics, and it points to water-scarce settings offering an abundance of renewable energy (e.g., from solar, geothermal, or wind power) as particularly attractive regions for hydroponic agriculture.
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Hydroponic vs. Soilless Media: Interaction with Plant Density
Pinnock, Derek R.; Bugbee, Bruce
2000-01-01
Water stress can cause early heading in some plant species. ‘Super Dwarf’ rice was grown in hydroponic culture and soilless media to determine if a slight water stress, caused by the soilless media, would cause earlier heading.
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DEFF Research Database (Denmark)
Spiliotopoulou, Aikaterini; Rojas-Tirado, Paula Andrea; Kaarsholm, Kamilla Marie Speht
2017-01-01
In recirculating aquaculture systems (RAS), the water quality changes continuously. Organic and inorganic compounds accumulates creating toxic conditions for the farmed organisms. Ozone improves water quality diminishing significantly both bacteria load and dissolved organic matter. However......, in a non-meticulously designed system, residual ozone might reach the culture tanks causing significant harm to cultured species or excess costs. The aim of the study was to predict the suitable ozone dosage in pilot RAS, for water treatment purposes, based on laboratory studies. The ozone effect on water...... quality of freshwater RAS and system’s ozone demand was investigated. Bench-scale ozonation experiments revealed the ozone demand of the system to be 180 mg O3/h. Three different ozone dosages were applied to four replicated systems with fixed feed loading (1.56 kg feed/m3 make up water). Results...
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Combined production of fish and plants in recirculating water
Energy Technology Data Exchange (ETDEWEB)
Naegel, L.C.A.
1977-01-01
A pilot plant of ca 2000 l of recirculating fresh water for intensive fish production was constructed in a controlled-environment greenhouse. The feasibility was examined of using nutrients from fish wastewater, mainly oxidized nitrogenous compounds, for plant production, combined with an activated sludge system for water purification. The reduction of nitrates, formed during the extended aeration process by nitrifying bacteria, was not sufficient by higher plants and unicellular algae alone to reduce the nitrate concentration in our system significantly. An additional microbial denitrification step had to be included to effect maximal decrease in nitrogenous compounds. For fish culture in the pilot plant Tilapia mossambica and Cyprinus carpio were chosen as experimental fishes. Both fish species showed significant weight increases during the course of the experiment. Ice-lettuce and tomatoes were tested both in recirculating water and in batch culture. The unicellular algae Scenedesmus spp. were grown in a non-sterile batch culture. All plants grew well in the wastewater without additional nutrients. Determination of the physical and chemical parameters for optimum water purification, the most suitable ratio of denitrification by plants and by microorganisms, and the most favourable fish and plant species for combined culture in recirculating water are important and of current interest in view of the increasing demand for clean, fresh water, and the pressing need to find new ways of producing protein for human nutrition under prevailing conditions of an exponentially expanding world population.
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Recirculating steam generator operation at very low power
International Nuclear Information System (INIS)
Holcblat, A.
2001-01-01
The behaviour of recirculating SG's at very low power has been thoroughly investigated by laboratory and on-site tests as well as numerical simulations. A special experimental program dedicated to recirculation threshold determination has been performed on the Freon SG mock-up CLOTAIRE. These laboratory data are completed with transients of feedwater injections at hot stand-by on two instrumented SG's, one boiler type SG and one economizer type SG. The phenomena are different on both types. In boiler SG's, the SG behaves like a U-tube and recirculation stops around 2% load at stand-by temperature and water level. In economizer SG's, the presence of 2 separate down-comers and a divider plate inside the tube bundle allows a recirculation loop by-passing the separators. The mixing of saturated and cold water induced by this loop limits down-comer cooling and thus alleviates the thermal load on the tube sheet. These tests were used to validate the SG transient analysis 1-D code ANETH. (author)
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Indoor spread of respiratory infection by recirculation of air: a controllable hazard
International Nuclear Information System (INIS)
Riley, R.L.
1980-01-01
The overall health benefit to be derived from disinfecting air before recirculation is difficult to predict, but as more and more buildings recirculate air without disinfection, the problem of spreading infection increases. Since the cost of disinfection with uv radiation is small and the cost of morbidity from airborne infections immense, the cost-benefit ratio for disinfecting recirculated air may be attractive, even though the protection of occupants would be limited. Recirculation of air in buildings is a relatively new technology that conserves energy. Like most new technologies, it brings new hazards. Disinfection of recirculated air is an appropriate additional technique with which to counter some of the hazards of air recirculation
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Effects of different hydroponic substrate combinations and watering ...
African Journals Online (AJOL)
Background: Production of medicinal plants in controlled environments, particularly hydroponic technology, provides opportunities for high quality biomass accumulation and optimizes production of secondary metabolites. Applying special watering regimes in combination with efficient soil draining is an encouraging new ...
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Fish mortality in recirculating aquaculture systems (RAS) has been observed by the authors to increase when RAS are managed at low makeup water exchange rates with relatively high feed loading. The precise etiology of this elevated mortality was unknown, all typical water quality parameters were wit...
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Flue gas recirculation to pellets burner
International Nuclear Information System (INIS)
Loefgren, B.E.; Blohm, T.
1999-05-01
The aim of this project has been to study the influence of flue gas recirculation on the combustion results. Primarily regarding the turbulence, stability and air surplus of the flame, but also the influence on environmental factors (CO and unburnt hydrocarbons). Also studied was the possibility of automatic control of the mixing of recirculating flue gases in the combustion process through the use of a λ-sond and O 2 control Project report from the program: Small scale combustion of biofuels. 9 figs, 8 tabs
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Excess nutrients in hydroponic solutions alter nutrient content of rice, wheat, and potato
McKeehen, J. D.; Mitchell, C. A.; Wheeler, R. M.; Bugbee, B.; Nielsen, S. S.
1996-01-01
Environment has significant effects on the nutrient content of field-grown crop plants. Little is known, however, about compositional changes caused by controlled environments in which plants receive only artificial radiation and soilless, hydroponic culture. This knowledge is essential for developing a safe, nutritious diet in a Controlled Ecological Life-Support System (CELSS). Three crops that are candidates for inclusion in a CELSS (rice, wheat, and white potato) were grown both in the field and in controlled environments where the hydroponic nutrient solution, photosynthetic photon flux (PPF), and CO2 level were manipulated to achieve rapid growth rates. Plants were harvested at maturity, separated into discrete parts, and dried prior to analysis. Plant materials were analyzed for proximate composition (protein, fat, ash, and carbohydrate), total nitrogen (N), nitrate, minerals, and amino-acid composition. The effect of environment on nutrient content varied by crop and plant part. Total N and nonprotein N (NPN) contents of plant biomass generally increased under controlled-environment conditions compared to field conditions, especially for leafy plant parts and roots. Nitrate levels were increased in hydroponically-grown vegetative tissues, but nitrate was excluded from grains and tubers. Mineral content changes in plant tissue included increased phosphorus and decreased levels of certain micronutrient elements under controlled-environment conditions. These findings suggest that cultivar selection, genetic manipulation, and environmental control could be important to obtain highly nutritious biomass in a CELSS.
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Rector, Tony; Peyton, Barbara; Steele, John W.; Bue, Grant C.; Campbell, Colin; Makinen, Janice
2014-01-01
Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessonslearned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.
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Rector, Tony; Peyton, Barbara M.; Steele, John W.; Makinen, Janice; Bue, Grant C.; Campbell, Colin
2014-01-01
Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.
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Raised rainbow trout Oncorhynchus mykiss in six replicated water recirculation aquaculture systems (WRAS), and manipulated environmental conditions to promote bacterial gill disease (BGD). For each episode of BGD, gill tissue was sampling from affected fish, unaffected fish within the same WRAS, and...
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Rizal, A.; Dhahiyat, Y.; Zahidah; Andriani, Y.; Handaka, A. A.; Sahidin, A.
2018-04-01
Aquaponics is an evolving closed-system food production technology that integrates recirculating aquaculture with hydroponics. In this paper we give a brief literature overview of the benefit aspects of aquaponics by discussing its social, environmental, and economic impacts in different potential settings. The technology might be applied to commercial or community based urban food production, industrial scale production in rural areas, small scale farming in developing countries or as systems for education and decoration inside buildings. We concluded that due to the different potential applications and settings for installing the technology, benefit impacts need to be considered separately and that due the complexity, communities, urban and rural infrastructure and policy settings, further research and data acquisition is needed to be able to assess all benefit aspects.
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DEFF Research Database (Denmark)
Møller, Martin Sune; Arvin, Erik; Pedersen, Lars-Flemming
2010-01-01
From an environmental point of view, hydrogen peroxide (HP) has beneficial attributes compared with other disinfectants in terms of its ready degradation and neutral by-products. The rapid degradation of HP can, however, cause difficulties with regard to safe and efficient water treatment when...... applied in different systems. In this study, we investigated the degradation kinetics of HP in biofilters from water recirculating aquaculture systems (RAS). The potential effect of HP on the nitrification process in the biofilters was also examined. Biofilter elements from two different pilot-scale RAS......−1 maintained over 3 h had a moderate inhibitory effect on the biofilter elements from one of the RAS with relatively high organic loading, while the nitrification was severely inhibited in the pilot-scale biofilters from the other RAS with a relatively low organic loading. A pilot-scale RAS...
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Yang, Ce; Wang, Yingjun; Lao, Dazhong; Tong, Ding; Wei, Longyu; Liu, Yixiong
2016-08-01
The inlet recirculation characteristics of double suction centrifugal compressor with unsymmetrical inlet structures were studied in numerical method, mainly focused on three issues including the amounts and differences of the inlet recirculation in different working conditions, the circumferential non-uniform distributions of the inlet recirculation, the recirculation velocity distributions of the upstream slot of the rear impeller. The results show that there are some differences between the recirculation of the front impeller and that of the rear impeller in whole working conditions. In design speed, the recirculation flow rate of the rear impeller is larger than that of the front impeller in the large flow range, but in the small flow range, the recirculation flow rate of the rear impeller is smaller than that of the front impeller. In different working conditions, the recirculation velocity distributions of the front and rear impeller are non-uniform along the circumferential direction and their non-uniform extents are quite different. The circumferential non-uniform extent of the recirculation velocity varies with the working conditions change. The circumferential non-uniform extent of the recirculation velocity of front impeller and its distribution are determined by the static pressure distribution of the front impeller, but that of the rear impeller is decided by the coupling effects of the inlet flow distortion of the rear impeller, the circumferential unsymmetrical distribution of the upstream slot and the asymmetric structure of the volute. In the design flow and small flow conditions, the recirculation velocities at different circumferential positions of the mean line of the upstream slot cross-section of the rear impeller are quite different, and the recirculation velocities distribution forms at both sides of the mean line are different. The recirculation velocity distributions in the cross-section of the upstream slot depend on the static pressure
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International Nuclear Information System (INIS)
Colombant, D.; Lau, Y.Y.
1992-01-01
Cavity cross-coupling was recently found to reduce beam breakup (BBU) growth in a recirculating accelerator known as the Spiral Line Induction Accelerator (SLIA). Here, we extend the analysis in two prespects: ong beam pulse lengths and a SLIA upgrade geometry which accelerates a 10 kA, 35 ns beam to 25 MeV via a 70 cavity, 7 turn recirculation. We found that when the beam pulse length τ exceeds the beam's transit time τ' between cross-coupled cavities, BBU growth may be worsened as a result of the cross-coupling among cavities. This situation is not unlike other long pulse recirculating accelerators where beam recirculation leads to beam breakup of a regenerative type. Thus, the advantage of BBU reduction by cavity cross-coupling is restricted primarily to beams with τ<τ', a condition envisioned for all SLIA geometries. For the 70 gap, 7 turn SLIA upgrade, we found that cavity cross-coupling may reduce BBU growth up to factors of a thousand when the quality factor Q of the deflecting modes are relatively high (like 100). In these high Q cases, the amount of growth reduction depends on the arrangement and sequence of beam recirculation. For Q < or approx. 20, BBU growth reduction by factors of hundreds is observed, but this reduction is insensitive to the sequence of beam recirculation. The above conclusions were based on simple models of cavity coupling that have been used in conventional microwave literature. Not addressed is the detail design consideration that leads to the desired degree of cavity coupling. (orig.)
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Dust deposit in recirculation regions
International Nuclear Information System (INIS)
Griemert, R.
1985-03-01
The present report shows investigations, which have been carried out in a closed duct at forward and backward facing steps. Distribution of fluid velocity and fluid fluctuations in and normal to main flow direction as well as the distribution of Reynolds shear stress have been measured. The mass transfer downstream of a backward facing step has been investigated as well. By using graphite-, copper-, tin- and rubber dust, conditions of deposition have been defined experimentally. A serie of photos shows the filling of a recirculation region downstream of a backward facing step with graphite dust. The present investigations allow to avoid deposition of dust in recirculation regions by selecting the fluid numbers in an appropriate way. (orig.) [de
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Exhaust gas recirculation in a homogeneous charge compression ignition engine
Duffy, Kevin P [Metamora, IL; Kieser, Andrew J [Morton, IL; Rodman, Anthony [Chillicothe, IL; Liechty, Michael P [Chillicothe, IL; Hergart, Carl-Anders [Peoria, IL; Hardy, William L [Peoria, IL
2008-05-27
A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.
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[Yeast irrigation enhances the nutritional content in hydroponic green maize fodder].
Bedolla-Torres, Martha H; Palacios Espinosa, Alejandro; Palacios, Oskar A; Choix, Francisco J; Ascencio Valle, Felipe de Jesús; López Aguilar, David R; Espinoza Villavicencio, José Luis; de Luna de la Peña, Rafael; Guillen Trujillo, Ariel; Avila Serrano, Narciso Y; Ortega Pérez, Ricardo
2015-01-01
The objective of this study was to evaluate the effect of irrigation with yeasts (Debaryomyces hansenii var. Fabry, Yarowia lipolytica YIBCS002, Yarowia lipolytica var. BCS and Candida pseudointermedia) on the final nutritional content of hydroponic green maize fodder (Zea Zea mays L.), applied at different fodder growth stages (1. seed-seedling stage, 2. seedling-plant 20cm, 3. during all the culture). Irrespective of the fodder growth stages at which they were applied, all yeasts tested enhanced the content of raw protein, lipids, ash, moisture and energy. The percentage of electrolytes (Na, K, Cl, sulphates, Ca and Mg) showed different responses depending on the kind of yeast applied; D. hansenii exhibited the highest increment in all electrolytes, except for phosphorous. We conclude that the addition of yeasts belonging to the genera Debaryomyces, Candida and Yarowia to the irrigation solution of hydroponic systems enhances the nutrient content of green fodder. This kind of irrigation can be applied to generate high commercial value cultures in limited spaces. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.
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Evaluation of different biomass production systems hydroponic corn
Directory of Open Access Journals (Sweden)
Néstor Vicente Acosta Lozano
2017-02-01
Full Text Available It was assessed the effect of three nutritive solutions (Hoagland, La Molina y FAO and three harvesting time (12, 15 and 18 days on forage yield and nutritive value of green fodder hydroponic from maize (Zea mays, L.. The experiment was developed in “La Sevilla” farm placed in San Marcos town, municipality and province of Santa Elena, Ecuador. The maize seeds 2,5 kg/m2 were washed, disinfected, soaked during 24 hours and placed in germination plates (1 x 1 x 0,04 m in dark condition during three days. It was applied to a fully randomized design with factorial arrangement without interaction 4 x 3 (3 nutritive solutions + 1 control (water x 3 harvesting time and 3 repetitions per treatments. The highest yields in terms of dry matter (137 and 114 kg DM/m2/year and crude protein (21,3 y 15,5 kg CP/m2/year were reached with the Hoagland and FAO solutions at 12 days of age, respectively. It was concluded that the best harvesting time independently of the nutritive solution was at 12 days and in all harvesting time the Hoagland and FAO solutions showed the best agronomic and chemical results.
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Sulfur recirculation for increased electricity production in Waste-to-Energy plants.
Andersson, Sven; Blomqvist, Evalena W; Bäfver, Linda; Jones, Frida; Davidsson, Kent; Froitzheim, Jan; Karlsson, Martin; Larsson, Erik; Liske, Jesper
2014-01-01
Sulfur recirculation is a new technology for reducing boiler corrosion and dioxin formation. It was demonstrated in full-scale tests at a Waste to Energy plant in Göteborg (Sweden) during nearly two months of operation. Sulfur was recirculated as sulfuric acid from the flue gas cleaning back to the boiler, thus creating a sulfur loop. The new technology was evaluated by extensive measurement campaigns during operation under normal conditions (reference case) and operation with sulfur recirculation. The chlorine content of both fly ash and boiler ash decreased and the sulfur content increased during the sulfur recirculation tests. The deposit growth and the particle concentration decreased with sulfur recirculation and the dioxin concentration (I-TEQ) of the flue gas was reduced by approximately 25%. Sulfuric acid dew point measurements showed that the sulfuric acid dosage did not lead to elevated SO3 concentrations, which may otherwise induce low temperature corrosion. In the sulfur recirculation corrosion probe exposures, the corrosion rate decreased for all tested materials (16Mo3, Sanicro 28 and Inconel 625) and material temperatures (450 °C and 525 °C) compared to the reference exposure. The corrosion rates were reduced by 60-90%. Sulfur recirculation prevented the formation of transition metal chlorides at the metal/oxide interface, formation of chromate and reduced the presence of zinc in the corrosion products. Furthermore, measured corrosion rates at 525 °C with sulfur recirculation in operation were similar or lower compared to those measured at 450 °C material temperature in reference conditions, which corresponds to normal operation at normal steam temperatures. This implies that sulfur recirculation allows for higher steam data and electricity production without increasing corrosion. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.
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El-Serehy, Hamed A; Bahgat, Magdy M; Al-Rasheid, Khaled; Al-Misned, Fahad; Mortuza, Golam; Shafik, Hesham
2014-07-01
Interest has increased over the last several years in using different methods for treating sewage. The rapid population growth in developing countries (Egypt, for example, with a population of more than 87 millions) has created significant sewage disposal problems. There is therefore a growing need for sewage treatment solutions with low energy requirements and using indigenous materials and skills. Gravel Bed Hydroponics (GBH) as a constructed wetland system for sewage treatment has been proved effective for sewage treatment in several Egyptian villages. The system provided an excellent environment for a wide range of species of ciliates (23 species) and these organisms were potentially very useful as biological indicators for various saprobic conditions. Moreover, the ciliates provided excellent means for estimating the efficiency of the system for sewage purification. Results affirmed the ability of this system to produce high quality effluent with sufficient microbial reduction to enable the production of irrigation quality water.
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A replacement LH2 recirculation line before installation in Discovery
1999-01-01
A spare four-inch diameter LH2 recirculation line (shown in photo) will be used to replace a damaged LH2 line in the orbiter Discovery. The line recirculates hydrogen from the Shuttle main engines back to the external tank during prelaunch engine conditioning. Workers noted a dent in the line during routine aft compartment inspections Tuesday, Dec. 7. The dent measures 12 inches long and about =-inch deep. Managers expect the replacement work to take about 3 days, followed by system retests and final aft compartment close-outs. Preliminary assessments reflect a launch date of Space Shuttle Discovery on mission STS-103 no earlier than Dec. 16. STS-103 is the third servicing mission for the Hubble Space Telescope.
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I. T. Balashova; S. M. Sirota; E. G. Kozar
2015-01-01
Using the sporophyte selection accelerates in three times the breeding process of new tomato forms with dgenes for the multilevel narrow-shelve hydroponic technology. Analysis two breeding approaches is presented in this paper: the individual selection of recombinant forms from populations and the target hybridization. The target hybridization increases the productivity of the plant and the weight of one fruit in two times.
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Directory of Open Access Journals (Sweden)
Antonia Zarrilli
2010-01-01
Full Text Available Plasma cortisol and milk production responses of 45 lactating Comisana sheeps (4th- 5th parity, divided into three homogeneous groups of 15 subject each, were used to evaluate the effects of two different levels of partial substitution of a complete feed with hydroponically germinating seeds. Germinated oat was employed after 7 days of hydroponic growth. The three groups received the following diets: Control group (T received only complete feed. The other 2 groups were fed on diet containing different levels of hydroponically germinating oat (1,5 kg – group A; 3 kg – group B. All the subjects have shown to accept the diets because the per capita ration was always completely consumed. In the second month, the A and B groups showed lower average values of cortisol (P<0.01 and a statistically significant increase in milk production as compared to T (P<0.05 and P<0.001. The obtained data induced to conclude that integration with hydroponically germinating oat in partial substitution of the complete feed does not modify biochemical and hematological parameters and seems to produce an improvement in animal welfare and production of milk.
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Directory of Open Access Journals (Sweden)
Vahid Azami
2017-06-01
Keywords: Solid oxide fuel cell, Gas turbine, Cathode gas recirculation, Exergy. Article History: Received Feb 23rd 2017; Received in revised form May 26th 2017; Accepted June 1st 2017; Available online How to Cite This Article: Azami, V, and Yari, M. (2017 Comparison between conventional design and cathode gas recirculation design of a direct-syngas solid oxide fuel cell–gas turbine hybrid systems part I: Design performance. International Journal of Renewable Energy Develeopment, 6(2, 127-136. https://doi.org/10.14710/ijred.6.2.127-136
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Paradiso, Roberta; Arena, Carmen; De Micco, Veronica; Giordano, Maria; Aronne, Giovanna; De Pascale, Stefania
2017-01-01
The use of hydroponic systems for cultivation in controlled climatic conditions and the selection of suitable genotypes for the specific environment help improving crop growth and yield. We hypothesized that plant performance in hydroponics could be further maximized by exploiting the action of plant growth-promoting organisms (PGPMs). However, the effects of PGPMs on plant physiology have been scarcely investigated in hydroponics. Within a series of experiments aimed to identify the best protocol for hydroponic cultivation of soybean [ Glycine max (L.) Merr.], we evaluated the effects of a PGPMs mix, containing bacteria, yeasts, mycorrhiza and trichoderma beneficial species on leaf anatomy, photosynthetic activity and plant growth of soybean cv. 'Pr91m10' in closed nutrient film technique (NFT). Plants were grown in a growth chamber under semi-aseptic conditions and inoculated at seed, seedling and plant stages, and compared to non-inoculated (control) plants. Light and epi-fluorescence microscopy analyses showed that leaves of inoculated plants had higher density of smaller stomata (297 vs. 247 n/mm 2 ), thicker palisade parenchyma (95.0 vs. 85.8 μm), and larger intercellular spaces in the mesophyll (57.5% vs. 52.2%), compared to non-inoculated plants. The modifications in leaf functional anatomical traits affected gas exchanges; in fact starting from the reproductive phase, the rate of leaf net photosynthesis (NP) was higher in inoculated compared to control plants (8.69 vs. 6.13 μmol CO 2 m -2 s -1 at the beginning of flowering). These data are consistent with the better maximal PSII photochemical efficiency observed in inoculated plants (0.807 vs. 0.784 in control); conversely no difference in leaf chlorophyll content was found. The PGPM-induced changes in leaf structure and photosynthesis lead to an improvement of plant growth (+29.9% in plant leaf area) and seed yield (+36.9%) compared to control. Our results confirm that PGPMs may confer benefits in
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Directory of Open Access Journals (Sweden)
Roberta Paradiso
2017-05-01
Full Text Available The use of hydroponic systems for cultivation in controlled climatic conditions and the selection of suitable genotypes for the specific environment help improving crop growth and yield. We hypothesized that plant performance in hydroponics could be further maximized by exploiting the action of plant growth-promoting organisms (PGPMs. However, the effects of PGPMs on plant physiology have been scarcely investigated in hydroponics. Within a series of experiments aimed to identify the best protocol for hydroponic cultivation of soybean [Glycine max (L. Merr.], we evaluated the effects of a PGPMs mix, containing bacteria, yeasts, mycorrhiza and trichoderma beneficial species on leaf anatomy, photosynthetic activity and plant growth of soybean cv. ‘Pr91m10’ in closed nutrient film technique (NFT. Plants were grown in a growth chamber under semi-aseptic conditions and inoculated at seed, seedling and plant stages, and compared to non-inoculated (control plants. Light and epi-fluorescence microscopy analyses showed that leaves of inoculated plants had higher density of smaller stomata (297 vs. 247 n/mm2, thicker palisade parenchyma (95.0 vs. 85.8 μm, and larger intercellular spaces in the mesophyll (57.5% vs. 52.2%, compared to non-inoculated plants. The modifications in leaf functional anatomical traits affected gas exchanges; in fact starting from the reproductive phase, the rate of leaf net photosynthesis (NP was higher in inoculated compared to control plants (8.69 vs. 6.13 μmol CO2 m-2 s-1 at the beginning of flowering. These data are consistent with the better maximal PSII photochemical efficiency observed in inoculated plants (0.807 vs. 0.784 in control; conversely no difference in leaf chlorophyll content was found. The PGPM-induced changes in leaf structure and photosynthesis lead to an improvement of plant growth (+29.9% in plant leaf area and seed yield (+36.9% compared to control. Our results confirm that PGPMs may confer benefits in
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Rainbow trout Oncorhynchus mykiss performance and water quality were evaluated and compared within six replicated 9.5 cubic meter water recirculating aquaculture systems (WRAS) operated with and without ozone at various water exchange rates. Three separate studies were conducted: 1) low water exchan...
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Directory of Open Access Journals (Sweden)
G. STEFAN
2008-10-01
Full Text Available The techniques of carp culture are highly diversified, ranging from the extensive production in pond or open water with no fertilization or supplemental feeding to highly intensive systems in concrete tanks or cages. Among the different carp species, common carp is the best species reared in intensive monoculture, the others (Chinese and Indian carps being usually cultivated in polyculture (P. Kestemont, 1995. An experiment was conducted in inside recirculation system conditions to identify the technological performances on carp growth and survival at the Fishing and Aquaculture Department, Galati, during winter period (February, 2007 – March, 2007. The 1-year-old carp (Cyprinus carpio 4792g; 4594 g; 4561 g and 4525 g (total weight grew to 7384g; 7017g; 6924g and 7125 g in 44 days in aquarium 1, 2, 3 and 4, respectively. In all aquariums, the fish appeared healthy and no mortality was observed. Feed conversion efficiencies (FCE had similar values among all aquariums, the highest FCE being found in B4 aquarium with 1, 57 value. Water quality parameters were acceptable range for fish culture. Results show that the carp rearing during winter period in the inside recirculation system is a very good economic solution.
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Energy Technology Data Exchange (ETDEWEB)
Sarker, M. R. I., E-mail: islamrabiul@yahoo.com; Saha, Manabendra, E-mail: manabendra.saha@adelaide.edu.au, E-mail: manab04me@gmail.com; Beg, R. A. [Department of Mechanical Engineering, Rajshahi University of Engineering and Technology, Rajshahi-6204 (Bangladesh)
2016-07-12
A recirculating flow solar particle cavity absorber (receiver) is modeled to investigate the flow behavior and heat transfer characteristics of a novel developing concept. It features a continuous recirculating flow of non-reacting metallic particles (black silicon carbide) with air which are used as a thermal enhancement medium. The aim of the present study is to numerically investigate the thermal behavior and flow characteristics of the proposed concept. The proposed solar particle receiver is modeled using two phase discrete particle model (DPM), RNG k-flow model and discrete ordinate (DO) radiation model. Numerical analysis is carried out considering a solar receiver with only air and the mixture of non-reacting particles and air as a heat transfer as well as heat carrying medium. The parametric investigation is conducted considering the incident solar flux on the receiver aperture and changing air flow rate and recirculation rate inside the receiver. A stand-alone feature of the recirculating flow solar particle receiver concept is that the particles are directly exposed to concentrated solar radiation monotonously through recirculating flow inside the receiver and results in efficient irradiation absorption and convective heat transfer to air that help to achieve high temperature air and consequently increase in thermal efficiency. This paper presents, results from the developed concept and highlights its flow behavior and potential to enhance the heat transfer from metallic particles to air by maximizing heat carrying capacity of the heat transfer medium. The imposed milestones for the present system will be helpful to understand the radiation absorption mechanism of the particles in a recirculating flow based receiver, the thermal transport between the particles, the air and the cavity, and the fluid dynamics of the air and particle in the cavity.
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DEFF Research Database (Denmark)
Pedersen, Lars-Flemming; Suhr, Karin Isabel; Dalsgaard, Anne Johanne Tang
2012-01-01
This study investigated the effects of applying four fixed feed loadings to three replicated recirculating aquaculture systems (RAS) on water quality changes, nitrogenous balances and growth performance of rainbow trout (Oncorhynchus mykiss).Feed loadings ranged from 1.6 to 6.3kgfeed/m3 make-up...... water, with a constant make-up water renewal of 4.7% of total water volume per day in all twelve RAS. Fish densities ranged from 14 to 92kg/m3 during the prolonged trial of 10weeks. Selected water quality parameters were measured during two intensive sampling campaigns, evaluating biofilter...
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Cost Characteristics of the African Catfish Culture in Recirculating ...
African Journals Online (AJOL)
Cost Characteristics of the African Catfish Culture in Recirculating Production Facilities in Ibadan, Oyo State, Nigeria. ... Food Conversion Ratio also ranged from 0.60–0.78 for fingerlings, 1.01-‐ 2.08 for juveniles and 1.15-‐1.68 for grow out system. In all cases, variable cost accounts for more than 75% of total cost.
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Iida, Yuichiro; Fujiwara, Kazuki; Someya, Nobutaka; Shinohara, Makoto
2017-03-16
Rhizobium sp. strain TBD182, isolated from a novel hydroponics system, is an antagonistic bacterium that inhibits the mycelial growth of Fusarium oxysporum but does not eliminate the pathogen. We report the draft genome sequence of TBD182, which may contribute to elucidation of the molecular mechanisms of its fungistatic activity. Copyright © 2017 Iida et al.
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Neuroprotective activity of hydroponic Teucrium polium following bilateral ovariectomy.
Simonyan, K V; Chavushyan, V A
2015-06-01
Ovariectomy is known as "surgical menopause" with decreased levels of estrogen in female rodents. Its reported risks and adverse effects include cognitive impairment. The action of hydroponic Teucrium polium on nucleus basalis of Meynert (bnM) neurons following 6 weeks of ovariectomy was carried out. The analysis of spike activity was observed by on-line selection and the use of a software package. Early and late tetanic, - posttetanic potentiation and depression of neurons to high frequency stimulation of hippocampus were studied. The complex averaged peri-event time and frequency histograms were constructed. The histochemical study of the activity of Са(2+)-dependent acid phosphatase was observed. In conditions of hydroponic Teucrium polium administration, positive changes in neurons and gain of metabolism leading to cellular survival were revealed. The administration of Teucrium polium elicited neurodegenerative changes in bnM.
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Integrated Multi-Trophic Recirculating Aquaculture System for Nile Tilapia (Oreochlomis niloticus
Directory of Open Access Journals (Sweden)
Puchong Sri-uam
2016-06-01
Full Text Available Three densities of the sex-reversed male Nile tilapia, Oreochromis niloticus (20, 25, 50 fish/m3 were cultivated in an integrated multi-trophic recirculating aquaculture system (IMRAS that involves the ecological relationship between several living organisms, i.e., phytoplankton, zooplankton, and aquatic plants. The results indicated that, by providing proper interdependency between various species of living organisms, the concentrations of ammonia, nitrite, nitrate, and phosphate in the system were maintained below dangerous levels for Nile tilapia throughout the cultivation period. The highest wet weight productivity of Nile tilapia of 11 ± 1 kg was achieved at a fish density of 50 fish/m3. The aquatic plants in the treatment tank could effectively uptake the unwanted nitrogen (N and phosphorus (P compounds with the highest removal efficiencies of 9.52% and 11.4%, respectively. The uptake rates of nitrogen and phosphorus by aquatic plants could be ranked from high to low as: Egeria densa > Ceratophyllum demersum > Vallisneria spiralis and Vallisneria americana > Hygrophila difformis. The remaining N was further degraded through nitrification process, whereas the remaining P could well precipitate in the soil sediment in the treatment tank.
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Directory of Open Access Journals (Sweden)
Štěpán Lang
2017-01-01
Full Text Available Aquaculture is currently one of the fastest growing food-producing sectors, accounting for around 50 % of the world’s food fish production. Limited resources, together with climatic change, have stimulated the search for solutions to support and sustain the production of fish as a source of protein for human consumption. The integration of a biological filtration (BF into a semi-recirculating fish rearing system can increase its carrying capacity and increase system efficiency compared to its’ energy consumption with minimum changes of system composition and minimal costs. Question is the capacity of the BF installed to a system and how it affects water quality. Two different amounts of BF media (surface added to semi-recirculating rearing system compared with the same system without BF were tested in case of this study. The results have shown that if the BF capacity is insufficient, BF can have negative effects to the quality of water environment. The insufficient amount of BF media caused 4 times reduction of ammonia nitrogen (N-NH4+ in system with BF compared to non BF system so it increased the system capacity for feed load 4 times. On the other hand it also increased nitrite nitrogen concentrations permanently more than 5.8 times for BF system compared to non BF system and increased rearing costs because the need of adding chlorides to the system to protect fish from nitrites toxicity. When the BF was dimensioned properly (next year there were almost no N-NH4+ in a system (0.10 mg.l−1 and the concentration of N-NO2− was kept at low levels too (0.150 mg .l−1. The nitrates (N‑NO3− concentration reached the level of 5.37 and 8.65 mg.l−1 in 2012 and 2013 respectively.
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Carrot Cultivar Evaluation: Soilless Media vs. Hydroponics
Pinnock, Derek R.; Bugbee, Bruce
2002-01-01
Nine cultivars of carrots were grown in a growth chamber. Each cultivar was grown both in hydroponic and soil-less media root-zone for sixty days. Three 30L tubs were used for each root-zone treatment. Three cultivars were planted in each tub, initially at 180 plants m-2 then thinned to 90 plants m-2 on day 45.
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Char-recirculation biomass gasification system--a site-specific feasibility study
International Nuclear Information System (INIS)
Purdy, K.R.; Kerr, C.P.; Hensley, B.D.
1991-01-01
A site-specific feasibility study was conducted for a char-recirculation biomass gasification plant which would dispose of the chippable solid residues of the area sawmills. The plant would receive green hardwood chips and convert them into active charcoal while producing process steam and electrical power. An economic analysis was performed on the basis of not-for-profit operation, marketing crushed active charcoal to a broker at a discounted price, and displacing purchased electric power. Given a market for the active charcoal, the plant was judged to be economically viable
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Directory of Open Access Journals (Sweden)
Dibo Liu
2016-11-01
Full Text Available Integrated multi-trophic aquaculture (IMTA is a promising direction for the sustainable development of aquaculture. Microalgae have good potential to be integrated with recirculating aquaculture systems because they can use the nitrogen excreted from fish and share the same optimal pH value as in aquaculture. As a byproduct, the microalgae biomass can be used for fish feed or biofuel. However, the recirculating fish-microalgae IMTA system is under constant threat from fish pathogens and phytoplankton-lytic bacteria. Therefore, it is necessary to apply proper disinfectants as prophylaxis or treatment which are effective against these threats, but safe to fish and microalgae. For this purpose, peracetic acid (PAA is a valid option because it is highly effective against fish pathogens and bacteria at low concentrations and degrades spontaneously to harmless residues. In the present study, we exposed the culture of a marine microalgae Tetraselmis chuii once per day for four days to four PAA products with differing hydrogen peroxide (H2O2/PAA proportions at two concentrations (1 and 2 mg L−1 PAA. The H2O2 solutions at equivalent total peroxide (H2O2 + PAA concentrations were tested in parallel. The results show that the growth and photosynthesis of T. chuii were not affected by three of the PAA products (Wofasteril® E400, Wofasteril® E250 and Applichem® 150 and equivalent H2O2 solutions at both concentrations. In contrast, Wofasteril® Lspez and an equivalent H2O2 solution at both concentrations caused irreversible culture collapse, photosynthesis dysfunction and irreversible cell damage. In conclusion, PAA products with low proportions of H2O2 are optimal disinfectants for fish-microalgae IMTA systems.
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Water use efficiency of coriander produced in a low-cost hydroponic system
Directory of Open Access Journals (Sweden)
José A. Santos Júnior
2015-12-01
Full Text Available ABSTRACT The increase of water use efficiency in crop production is a clear need in areas with restricted access to this resource and, in these cases, the adoption of forms of cultivation contextualized to local conditions are essential. Thus, the implications of the variation in the amount of seeds per cell (0.5, 1.0, 1.5 and 2.0 g and spacing between cells (7.0, 10.0 and 15.0 cm on variables related to consumption and water use efficiency for the production of coriander (cv. Tabocas in a low-cost hydroponic system, an alternative for semiarid regions, were evaluated. A completely randomized experimental design, analysed in 4 x 3 factorial scheme with three replicates, was adopted, and the data were subjected to analysis of variance at 0.05 probability level. It was found that the reduction in the spacing between cells has a better cost-benefit ratio with respect to water consumption, biomass produced and cost of seeds. Therefore, it is recommended the adoption of a spacing of 7.0 cm between cells and the use of 1.0 g seeds per cell; this configuration promoted efficiency of 81.59 g L-1 in shoot green mass production and total mass of 62.4 g coriander bunches.
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Hydroponics gel as a new electrolyte gelling agent for alkaline zinc-air cells
Othman, R.; Basirun, W. J.; Yahaya, A. H.; Arof, A. K.
The viability of hydroponics gel as a new alkaline electrolyte gelling agent is investigated. Zinc-air cells are fabricated employing 12 wt.% KOH electrolyte immobilised with hydroponics gel. The cells are discharged at constant currents of 5, 50 and 100 mA. XRD and SEM analysis of the anode plates after discharge show that the failure mode is due to the formation of zinc oxide insulating layers and not due to any side reactions between the gel and the plate or the electrolyte.
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Comparison of recirculation configurations for biological nutrient removal in a membrane bioreactor.
Bekir Ersu, Cagatayhan; Ong, Say Kee; Arslankaya, Ertan; Brown, Patrick
2008-03-01
A 12-L lab-scale membrane bioreactor (MBR), consisting of an anaerobic and anoxic compartment followed by an oxic plate-frame membrane compartment, was evaluated for carbonaceous and nutrient removals by varying the recirculation of mixed liquor and permeate. The hydraulic retention times (HRTs) for the anaerobic, anoxic, and oxic compartments were 2, 2, and 8h, respectively. The solids residence time (SRT) for the oxic compartment was 25 days. Five different recirculation configurations were tested by recirculating mixed liquor and/or permeate recirculation equal to the influent flow rate (identified as 100%) into different locations of the anaerobic and anoxic compartments. Of the five configurations, the configuration with 100% mixed liquor recirculation to the anaerobic compartment and 100% permeate recirculation to the anoxic compartment gave the highest percentage removal with an average 92.3+/-0.5% soluble chemical oxygen demand (sCOD), 75.6+/-0.4% total nitrogen (TN), and 62.4+/-1.3% total phosphorus (TP) removal. When the mixed liquor and permeate recirculation rates were varied for the same configuration, the highest TP removal was obtained for 300% mixed liquor recirculation and 100% permeate recirculation (300%/100%) with a TP removal of 88.1+/-1.3% while the highest TN removal (90.3+/-0.3%) was obtained for 200%/300% recirculation. TN and TP concentrations as low as 4.2+/-0.1 and 1.4+/-0.2mg/L respectively were obtained. Mass loading rates were generally low in the range of 0.11-0.22kgCOD/kgMLSS/d due to high biomass concentrations within the oxic reactor (approx. 8000mg/L). The BioWin model was calibrated against one set of the experimental data and was found to predict the experimental data of effluent TN, TP, and NO(3)(-)-N but over-predicted sCOD and NH(3)-N for various recirculation rates. The anoxic heterotrophic yield for the calibrated model was 0.2kg biomass COD/kg COD utilized while the maximum growth rates were found to be 0.45day(-1) for mu
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Water clarifying and disinfection techniques such as ozonation and ultraviolet irradiation are commonly used in recirculation aquaculture systems (RAS); however, the capital and operating costs of these technologies are expensive. Cost-effective treatment options that maintain fish health and simult...
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The uptake of 131I by some hydroponically grown crops
International Nuclear Information System (INIS)
Asprer, G.A.; Lansangan, L.M.; de la Paz, L.R.
1982-01-01
Biologically labelled vegetables which include kangkong and sweet potato tops were grown hydroponically in a modified Hoagland-Arnon nutrient solution containing radioiodine with 0.5% non-radioactive Nal solution as the medium. The crops considered in this study are commonly eaten by Filipinos. The concentration of the solution as well as the uptake in the plant system were determined at various time intervals. The extent of radioiodine uptake through air-water-plant pathway is one of the parameters needed for calculating the dose that the general populace could be exposed to, due to radioactivity in the environment. (author)
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Reliability analysis of the recirculation phase of the safety injection system of Angra-1
International Nuclear Information System (INIS)
Rivera, R.R.J.M.
1981-09-01
The calculation of several reliability parameters-failure probability, unavailability and unreliability - of the recirculation phase of the safety injection system of Angra-1, was done. This system has two distinct modes of operation (short term and long term) which were fault tree analysed both separately and as a whole. To obtain quantitative results the computer codes SAMPLE and PRET-KITT were utilized. The former was used to consider the uncertainties in the failure data (drawn integrally from WASH-1400) and the latter to obtain time dependent unreliability values. Hardware failures and common-mode failures were considered. Altough the analysis methods employed here differ somewhat from those used in WASH-1400, the results which could be compared were found to have the order of magnitude. A viability study of some suggestions of system's modifications was performed, and it has shown that some significant reliability improvements can be achieved with reasonably simple changes. (Author) [pt
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A hydroponic method for plant growth in microgravity
Wright, B. D.
1985-01-01
A hydroponic apparatus under development for long-term microgravity plant growth is described. The capillary effect root environment system (CERES) is designed to keep separate the nutrient and air flows, although both must be simultaneously available to the roots. Water at a pressure slightly under air pressure is allowed to seep into a plastic depression covered by a plastic screen and a porous membrane. A root in the air on the membrane outer surface draws the moisture through it. The laboratory model has a wire-based 1.241 mm mesh polyethylene screen and a filter membrane with 0.45 micron pores, small enough to prohibit root hair penetration. The design eliminates the need to seal-off the plant environment. Problems still needing attention include scaling up of the CERES size, controlling biofouling of the membrane, and extending the applications to plants without fibrous root systems.
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Lower operating cost due to compressed-air recirculation
Energy Technology Data Exchange (ETDEWEB)
Schauwecker, F
1979-01-01
Compressed air containing dirt and aggressive substances may cause damage in pipelines and pneumatic tools, equipment and systems. In consequence, operating costs can be greatly reduced by cleaning and recirculation of compressed air. Compressed-air driers are among the most common systems used for this purpose. Most of these driers are refrigeration driers; adsorption driers are less common. Refrigeration driers consist of a heat exchanger system, a separation system, and a power-controlled refrigerator. The water vapour concentration is proportional to the air temperature; for this reason, the pressure dew point should be as low as possible, i.e. about 1.5/sup 0/C.
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Effect of adding a swirl on flow pattern and recirculation zone in ADS windowless spallation target
Energy Technology Data Exchange (ETDEWEB)
Liu, Jie, E-mail: nauty@ucas.ac.cn [School of Physics, University of Chinese Academy of Sciences, Beijing (China); Gao, Lei [School of Physics, University of Chinese Academy of Sciences, Beijing (China); Yang, Lei [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Lu, Wen-qiang [School of Physics, University of Chinese Academy of Sciences, Beijing (China)
2014-09-15
Highlights: • The reduction of the recirculation zone and the stability of the free surface are key issues in the target. • A swirl is numerically added in the target to make the recirculation zone small and stable. • Numerical simulation with different boundary conditions is carried out. • Physical analysis is presented to explain the numerical results. - Abstract: Aiming the key issues in the accelerator driven system (ADS), windowless spallation target focus on the minimization of the recirculation zone and on the stability of the free surface, an innovation has been made by numerically adding swirl to the fluid at the inlet. At first, two phase flow pattern in the simulation is compared with the experiments and numerical method is employed correctly. The results reveal that the recirculation zone and the flow pattern are greatly influenced when the swirl strength is changed from 1.0 rad/s to 2.5 rad/s. The height of the recirculation zone decreases with increase in swirl strength and completely disappears when the swirl strength reaches 2.0 rad/s. In addition, larger swirl strength leads to different flow pattern and a new cavitation zone is generated under the recirculation zone. The Bernoulli's equation and angular momentum conservation are applied to make it clear that this phenomena is due to the decrease of the axial pressure caused by the radial velocity. Moreover, the new cavitation zone totally links to the vapor area above the recirculation zone when the swirl strength is 2.5 rad/s. The results are very helpful to the design and optimization of the ADS windowless spallation target.
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Effect of adding a swirl on flow pattern and recirculation zone in ADS windowless spallation target
International Nuclear Information System (INIS)
Liu, Jie; Gao, Lei; Yang, Lei; Lu, Wen-qiang
2014-01-01
Highlights: • The reduction of the recirculation zone and the stability of the free surface are key issues in the target. • A swirl is numerically added in the target to make the recirculation zone small and stable. • Numerical simulation with different boundary conditions is carried out. • Physical analysis is presented to explain the numerical results. - Abstract: Aiming the key issues in the accelerator driven system (ADS), windowless spallation target focus on the minimization of the recirculation zone and on the stability of the free surface, an innovation has been made by numerically adding swirl to the fluid at the inlet. At first, two phase flow pattern in the simulation is compared with the experiments and numerical method is employed correctly. The results reveal that the recirculation zone and the flow pattern are greatly influenced when the swirl strength is changed from 1.0 rad/s to 2.5 rad/s. The height of the recirculation zone decreases with increase in swirl strength and completely disappears when the swirl strength reaches 2.0 rad/s. In addition, larger swirl strength leads to different flow pattern and a new cavitation zone is generated under the recirculation zone. The Bernoulli's equation and angular momentum conservation are applied to make it clear that this phenomena is due to the decrease of the axial pressure caused by the radial velocity. Moreover, the new cavitation zone totally links to the vapor area above the recirculation zone when the swirl strength is 2.5 rad/s. The results are very helpful to the design and optimization of the ADS windowless spallation target
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Ozonation control and effects of ozone on water quality in recirculating aquaculture systems
DEFF Research Database (Denmark)
Spiliotopoulou, Aikaterini; Rojas-Tirado, Paula Andrea; Chetri, Ravi K.
2018-01-01
To address the undesired effect of chemotherapeutants in aquaculture, ozone has been suggested as an alternative to improve water quality. To ensure safe and robust treatment, it is vital to define the ozone demand and ozone kinetics of the specific water matrix to avoid ozone overdose. Different...... ozone dosages were applied to water in freshwater recirculating aquaculture systems (RAS). Experiments were performed to investigate ozone kinetics and demand, and to evaluate the effects on the water quality, particularly in relation to fluorescent organic matter. This study aimed at predicting...... a suitable ozone dosage for water treatment based on daily ozone demand via laboratory studies. These ozone dosages will be eventually applied and maintained at these levels in pilot-scale RAS to verify predictions. Selected water quality parameters were measured, including natural fluorescence and organic...
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Mineral and organic compounds in leachate from landfill with concentrate recirculation.
Talalaj, Izabela Anna
2015-02-01
The effect of a reverse osmosis concentrate recirculation on the mineral and organic compounds in a landfill leachate was investigated. Investigated was the quality of a leachate from two landfills operated for different periods (a 20-year-old Cell A and a 1-year-old Cell B), where the concentrate was recirculated. Examined were general parameters (conductivity, pH), organic compounds (biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic nitrogen, BOD/COD), and inorganic compounds (nitrogen ammonia, sulfite, sulfate, cyanide, boron, chloride, ferrous, zinc, chrome, copper). The findings from the first year of investigation showed that over the initial period of recirculation, the concentration of organic compounds (BOD, COD) increased, but after 6 months their values stabilized. It indicates that the concentrate recirculation accelerated organic decomposition, especially in the new landfill Cell. The analysis of inorganic parameters showed that recirculation landfills produce a leachate with a higher concentration of N-NH4, and Cl(-). In case of the old landfill Cell, an increase in B and Fe was also noticeable. These compounds are cyclically washed out from a waste dump and require an additional pretreatment in order to exclude them from recirculation cycle. The increased concentration of Cu, Zn, and Fe was noticed during the initial months of recirculation and in the season of intense atmospheric precipitation in the leachate from both Cells. Higher values of electro conductivity, Cl(-), N-NH4 (+), B, and Fe in the leachate from the old field indicate that the attenuation capacity of this landfill is close to exhaustion.
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Volume reduction and material recirculation by freon decontamination
International Nuclear Information System (INIS)
Berners, O.; Buhmann, D.; Yamashita, Y.; Yoshiaki, M.
1989-01-01
This paper discusses the use of freon in a large variety of decontamination in the nuclear and non-nuclear fields. As far as the contamination is loose or smerable, surfaces of nearly all materials can be decontaminated. Freon is electrically non-conductive, chemically neutral and has a low surface tension. So it is capable of creeping under the contaminant and loosening or dissolving it. Used freon can be collected, cleaned and recirculated. Its cleaning can be done easily by evaporation at its lower vapor point of about 48 degrees C (104 degrees F). Good decontamination results could be achieved, expensive materials, tools and equipment could be recirculated. Big volumes of materials could get separated from their contaminants, which is the real radioactive waste. Freon decontamination is an effective, overall economical and approved technology to volume reduction and material recirculation
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Search for a plant for phytoremediation--what can we learn from field and hydroponic studies?
Zabłudowska, E; Kowalska, J; Jedynak, L; Wojas, S; Skłodowska, A; Antosiewicz, D M
2009-10-01
The main aim of the study was to evaluate the strategies for coping with arsenic toxicity developed by the mine species (Calamagrostis arundinacea, Fragaria vesca, Stachys sylvatica, and Epilobium parviflorum), and to compare results obtained from plants exposed to arsenic present in contaminated soil (2000-3500 mg/kg dw) and in hydroponic solution (2 microM and 12 microM arsenate). Here we report basic differences in plant responses to arsenic depending on growth conditions (hydroponic/soil) with respect to uptake, root-to-shoot translocation, distribution, and detoxification/speciation. Calamagrostis has the highest level of As-tolerance among the tested species. When grown in soil, it accumulated the highest amount of As in roots and shoots relative to other species, however, when exposed to arsenic in hydroponics, it had lower As concentrations. The efficiency of arsenic root-to-shoot translocation was also different, being less effective in soil-grown Calamagrostis compared with hydroponics. Furthermore, in Calamagrostis exposed to arsenate in liquid medium, As(III) was the predominant arsenic form, in contrast to plants grown in As-contaminated soil, in which As(V) predominated. In addition, comparison of the level of phytochelatins showed that only PC2 was detected in plants from hydroponics, whereas in those from soil, additionally PC3 and PC4 were found. The results show that the basic components of a plant's response to arsenic, including uptake, accumulation as well as detoxification, change depending on the experimental conditions (arsenic in liquid medium or contaminated soil).
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DOGBONE GEOMETRY FOR RECIRCULATING ACCELERATORS
International Nuclear Information System (INIS)
BERG, J.S.; JOHNSTONE, C.; SUMMERS, D.
2001-01-01
Most scenarios for accelerating muons require recirculating acceleration. A racetrack shape for the accelerator requires particles with lower energy in early passes to traverse almost the same length of arc as particles with the highest energy. This extra arc length may lead to excess decays and excess cost. Changing the geometry to a dogbone shape, where there is a single linac and the beam turns completely around at the end of the linac, returning to the same end of the linac from which it exited, addresses this problem. In this design, the arc lengths can be proportional to the particle's momentum. This paper proposes an approximate cost model for a recirculating accelerator, attempts to make cost-optimized designs for both racetrack and dogbone geometries, and demonstrates that the dogbone geometry does appear to be more cost effective
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Optics of beam recirculation in the CEBAF [Continuous Electron Beam Accelerator Facility] cw linac
International Nuclear Information System (INIS)
Douglas, D.R.
1986-01-01
The use of recirculation in linear accelerator designs requires beam transport systems that will not degrade beam quality. We present a design for the transport lines to be used during recirculation in the CEBAF accelerator. These beam lines are designed to avoid beam degradation through synchrotron radiation excitation or betatron motion mismatch, are insensitive to errors commonly encountered during beam transport, and are optimized for electron beams with energies of 0.5 to 6.0 GeV. Optically, they are linearly isochronous second order achromats based on a ''missing magnet'' FODO structure. We give lattice specifications for, and results of analytic estimates and numerical simulations of the performance of, the beam transport system
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Mechanical design of recirculating accelerator experiments for heavy-ion fusion
International Nuclear Information System (INIS)
Karpenko, V.
1995-01-01
Recirculating induction accelerators have been studied as a potential low cost driver for inertial fusion energy. At LLNL, we are developing a small (4.5-m diameter), scaled, experimental machine which will demonstrate many of the engineering solutions of a full scale driver. The small recirculator will accelerate singly ionized potassium ions from 80 to 320 keV and 2 to 8 mA, using electric dipoles for bending and permanent magnet quadrupoles for focusing in a compact periodic lattice. While very compact, and low cost, this design allows the investigation of most of the critical physics issues associated with space-charge-dominated beams in future IFE power plant drivers. This report describes the recirculator, its mechanical design, its vacuum design, and the process for aligning it. Additionally, a straight magnetic transport experiment is being carried out to test diagnostics and magnetic transport in preparation for the recirculator
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Vortex dynamics in a pipe T-junction: Recirculation and sensitivity
Chen, Kevin K.; Rowley, Clarence W.; Stone, Howard A.
2015-03-01
In the last few years, many researchers have noted that regions of recirculating flow often exhibit particularly high sensitivity to spatially localized feedback. We explore the flow through a T-shaped pipe bifurcation—a simple and ubiquitous, but generally poorly understood flow configuration—and provide a complex example of the relation between recirculation and sensitivity. When Re ≥ 320, a phenomenon resembling vortex breakdown occurs in four locations in the junction, with internal stagnation points appearing on vortex axes and causing flow reversal. The structure of the recirculation is similar to the traditional bubble-type breakdown. These recirculation regions are highly sensitive to spatially localized feedback in the linearized Navier-Stokes operator. The flow separation at the corners of the "T," however, does not exhibit this kind of sensitivity. We focus our analysis on the Reynolds number of 560, near the first Hopf bifurcation of the flow.
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Recirculating electric air filter for use in confined spaces
International Nuclear Information System (INIS)
Bergman, W.; Biermann, A.; Kuhl, W.
1985-01-01
We have developed recirculating electric air filters for use in confined spaces where the existing ventilation system is not adequate for removing suspended particles. Two experimental filters were built and evaluated, both of which consisted of a cylindrical cartridge filter fitted over an air blower. In one design the cylindrical cartridge is a disposable unit with the electrodes and filter medium built as an integrated unit. The second design has a cylindrical cartridge that can be easily disassembled to allow replacement of the filter medium. Both designs were evaluated in a 354-ft 3 test cell using NaCl aerosols. The second design was installed and evaluated in a chamber where highly radioactive 238 PuO 2 powder is formed into pellets. We have derived equations that describe the theory of recirculating air filters. The predicted performance compares well with experimental measurements under controlled conditions. 2 refs., 7 figs., 1 tab. (DT)
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International Nuclear Information System (INIS)
Yu, Byeonghun; Kum, Sung-Min; Lee, Chang-Eon; Lee, Seungro
2013-01-01
In this research, a boiler in a premixed combustion system used to achieve exhaust gas recirculation was investigated as a way to achieve high thermal efficiencies and low pollutant emissions. The effects of various exhaust gas recirculation (EGR) ratios, equivalence ratios and boiler capacities on thermal efficiency, NO x and CO emissions and the flame behavior on the burner surface were examined both experimentally and numerically. The results of the experiments showed that when EGR was used, the NO x and CO concentrations decreased and the thermal efficiency increased. In the case of a 15% EGR ratio at an equivalence ratio of 0.90, NO x concentrations were found to be smaller than for the current operating condition of the boiler, and the thermal efficiency was approximately 4.7% higher. However, unlike NO x concentrations, although the EGR ratio was increased to 20% at an equivalence ratio of 0.90, the CO concentration was higher than in the current operating condition of the boiler. From the viewpoint of burner safety, the red glow on the burner surface was noticeably reduced when EGR was used. These results confirmed that the EGR method is advantageous from the standpoint of reducing emission concentrations and ensuring burner safety. -- Highlights: ► The premixed boiler system applied EGR was investigated to achieve high thermal efficiencies and low pollutant emissions. ► Thermal efficiency and emission characteristics were examined with EGR ratios, equivalence ratios and boiler capacities. ► EGR method is advantageous from the standpoint of reducing emission concentrations and ensuring burner safety.
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International Nuclear Information System (INIS)
Bucur, Ionel; Metes, Mircea
2002-01-01
Between February 18 and March 5, 2002 the Unit 1 of Cernavoda NPP was shutdown in an un-planned outage necessary to repair a crack on the piping of the Recirculated Cooling Water System. The large pipe diameter and the requirement of maintaining the system in operation during the outage, imposed a special technology for fixing the leak (isolation of the line with ice plugs). The paper presents information about the performed repair work. After repair operations the failed duct was checked by non-destructive methods and the results were submitted and approved by regulation authorities. The repair was considered successfully completed and the Unit restarted on March 5, 2002 at 0.57 am when the electric generator was switched on in parallel to the national electric power system. (authors)
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Commercial production of Atlantic salmon smolts, post-smolts, and market-size fish using land-based recirculation aquaculture systems (RAS) is expanding. RAS generally provide a nutrient-rich environment in which nitrate accumulates as an end-product of nitrification. An 8-month study was conducted ...
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De Sanctis, Marco; Beccari, Mario; Di Iaconi, Claudio; Majone, Mauro; Rossetti, Simona; Tandoi, Valter
2013-02-01
The Sequencing Batch Biofilter Granular Reactor (SBBGR) is a promising wastewater treatment technology characterized by high biomass concentration in the system, good depuration performance and low sludge production. Its main drawback is the high energy consumption required for wastewater recirculation through the reactor bed to ensure both shear stress and oxygen supply. Therefore, the effect of low recirculation flow on the long-term (38 months) performance of a laboratory scale SBBGR was studied. Both the microbial components of the granules, and their main metabolic activities were evaluated (heterotrophic oxidation, nitrification, denitrification, fermentation, sulphate reduction and methanogenesis). The results indicate that despite reduced recirculation, the SBBGR system maintained many of its advantageous characteristics. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Uptake of cadmium from hydroponic solutions by willows ( Salix spp ...
African Journals Online (AJOL)
Salix integra 'Weishanhu') and Yizhibi (S. integra 'Yizhibi') were chosen as model plants to evaluate their potential for uptake of cadmium from hydroponic culture and relative uptake mechanism. Cadmium uptake showed a linear increase in the ...
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Impact of capillary rise and recirculation on simulated crop yields
Kroes, J.G.; Supit, I.; Dam, van J.C.; Walsum, van P.E.V.; Mulder, H.M.
2018-01-01
Upward soil water flow is a vital supply of water to crops. The purpose of this study is to determine if upward flow and recirculated percolation water can be quantified separately, and to determine the contribution of capillary rise and recirculated water to crop yield and groundwater recharge.
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Investigation of Microbunching Instabilities in Modern Recirculating Accelerators
Energy Technology Data Exchange (ETDEWEB)
Tsai, Cheng [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
2017-05-21
linear beamline lattice including horizontal and vertical transport bending elements, and beam acceleration or deceleration. These featured generalizations are required for MBI analysis in recirculation accelerators. (2) Construction of CSR impedance models In addition to the steady-state CSR interaction, it has been found that the exit transient effect (or CSR drift) can even result in more serious MBI in high-brightness recirculation arcs. The onedimensional free-space CSR impedances, especially the exit transients, are derived. The steady-state CSR impedance is also extended to non-ultrarelativistic beam energy for MBI analysis of low-energy merger sections in recirculating accelerators. (3) Numerical implementation of the derived semi-analytical formulation This includes the development of a semi-analytical Vlasov solver for MBI analysis, and also benchmarking of the solver against massive particle tracking simulations. (4) Exploration of multistage amplification behavior of CSR microbunching development The CSR-induced MBI acts as an amplifier, which amplifies the sub-bunch modulation of a beam. The amplification is commonly quantified by the amplification gain. A beam transport system can be considered as a cascaded amplifier. Unlike the two-stage amplification of four-dipole bunch compressor chicanes employed in linacs, the recirculation arcs, which are usually constituted by several tens of bending magnets, show a distinguishing feature of up to six-stage microbunching amplification for our example arc lattices. That is, the maximal CSR amplification gain can be proportional to the peak bunch current up to sixth power. A method to compare lattice performance has been developed in terms of gain coefficients, which nearly depend on the lattice properties only. This method has also proven to be an effective way to quantify the current dependence of the maximal (5) Control of CSR MBI in multibend transport or recirculation arcs The existing mitigation schemes of MBI
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Hatayama, Masayoshi; Sato, Takahiko; Shinoda, Kozo; Inoue, Chihiro
2011-03-01
The physiological responses of the arsenic-hyperaccumulator, Pteris vittata, such as arsenic uptake and chemical transformation in the fern, have been investigated. However, a few questions remain regarding arsenic treatment in hydroponics. Incubation conditions such as aeration, arsenic concentration, and incubation period might affect those responses of P. vittata in hydroponics. Arsenite uptake was low under anaerobic conditions, as previously reported. However, in an arsenite uptake experiment, phosphorous (P) starvation-dependent uptake of arsenate was observed under aerobic conditions. Time course-dependent analysis of arsenite oxidation showed that arsenite was gradually oxidized to arsenate during incubation. Arsenite oxidation was not observed in any of the control conditions, such as exposure to a nutrient solution or to culture medium only, or with the use of dried root; arsenite oxidation was only observed when live root was used. This result suggests that sufficient aeration allows the rhizosphere system to oxidize arsenite and enables the fern to efficiently take up arsenite as arsenate. X-ray absorption near edge structure (XANES) analyses showed that long-duration exposure to arsenic using a hydroponic system led to the accumulation of arsenate as the dominant species in the root tips, but not in the whole roots, partly because up-regulation of arsenate uptake by P starvation of the fern was caused and retained by long-time incubation. Analysis of concentration-dependent arsenate uptake by P. vittata showed that the uptake switched from a high-affinity transport system to a low-affinity system at high arsenate concentrations, which partially explains the increased arsenate abundance in the whole root. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
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Hydroponic root mats for wastewater treatment-a review.
Chen, Zhongbing; Cuervo, Diego Paredes; Müller, Jochen A; Wiessner, Arndt; Köser, Heinz; Vymazal, Jan; Kästner, Matthias; Kuschk, Peter
2016-08-01
Hydroponic root mats (HRMs) are ecotechnological wastewater treatment systems where aquatic vegetation forms buoyant filters by their dense interwoven roots and rhizomes, sometimes supported by rafts or other floating materials. A preferential hydraulic flow is created in the water zone between the plant root mat and the bottom of the treatment system. When the mat touches the bottom of the water body, such systems can also function as HRM filter; i.e. the hydraulic flow passes directly through the root zone. HRMs have been used for the treatment of various types of polluted water, including domestic wastewater; agricultural effluents; and polluted river, lake, stormwater and groundwater and even acid mine drainage. This article provides an overview on the concept of applying floating HRM and non-floating HRM filters for wastewater treatment. Exemplary performance data are presented, and the advantages and disadvantages of this technology are discussed in comparison to those of ponds, free-floating plant and soil-based constructed wetlands. Finally, suggestions are provided on the preferred scope of application of HRMs.
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Lee, Ju Yeon; Rahman, Arifur; Azam, Hossain; Kim, Hyung Seok; Kwon, Man Jae
2017-01-01
A balanced nutrient supply is essential for the healthy growth of plants in hydroponic systems. However, the commonly used electrical conductivity (EC)-based nutrient control for plant cultivation can provide amounts of nutrients that are excessive or inadequate for proper plant growth. In this study, we investigated the kinetics of major and minor nutrient uptake in a nutrient solution during the growth of tomato (Solanum lycopersicum var. cerasiforme Alef.) in a closed hydroponic system. The concentrations of major and minor ions in the nutrient solution were determined by various analytical methods including inductively coupled plasma-optical emission spectroscopy (ICP-OES), ion chromatography (IC), ion specific electrodes, and/or colorimetric methods. The concentrations of the individual nutrient ions were compared with changes in the EC. The EC of the nutrient solution varied according to the different growth stages of tomato plants. Variation in the concentrations of NO3-, SO42-, Mg2+, Ca2+, and K+ was similar to the EC variation. However, in the cases of PO43-, Na+, Cl-, dissolved Fe and Mn, Cu2+, and Zn2+, variation did not correspond with that of EC. These ions were generally depleted (to 0 mg L-1) during tomato growth, suggesting that these specific ions should be monitored individually and their supply increased. Nutrient uptake rates of major ions increased gradually at different growth stages until harvest (from 15 mg L-1 d-1). Saturation indices determined by MINEQL+ simulation and a mineral precipitation experiment demonstrated the potential for amorphous calcium phosphate precipitation, which may facilitate the abiotic adsorptive removal of dissolved Fe, dissolved Mn, Cu2+, and Zn2+.
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Treatment of vinasses - recirculation
Directory of Open Access Journals (Sweden)
Germán Andrés Castro Moreno
2009-08-01
Full Text Available The purpose of this minireview is to give an overview of treatments that have been applied on the vinasse, residue from the alcoholic fermentation; appoint some of its advantages and disadvantages, and then submit recirculation, as one of the best options from an economic point of view and easy implementation, for those who are not interested in the ethanol byproducts.
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Uptake and translocation of sulfamethazine by alfalfa grown under hydroponic conditions.
Kurwadkar, Sudarshan; Struckhoff, Garrett; Pugh, Kameron; Singh, Om
2017-03-01
Antibiotics are routinely used in intensive animal agriculture operations collectively known as Concentrated Animal Feed Operations (CAFO) which include dairy, poultry and swine farms. Wastewater generated by CAFOs often contains low levels of antibiotics and is typically managed in an anaerobic lagoon. The objective of this research is to investigate the uptake and fate of aqueous sulfamethazine (SMN) antibiotic by alfalfa (Medicago sativa) grass grown under hydroponic conditions. Uptake studies were conducted using hydroponically grown alfalfa in a commercially available nutrient solution supplemented with 10mg/L of SMN antibiotic. Analysis of alfalfa sap, root zone, middle one-third, and top portion of the foliage showed varying uptake rate and translocation of SMN. The highest average amount of SMN (8.58μg/kg) was detected in the root zone, followed by the top portion (1.89μg/kg), middle one-third (1.30μg/kg), and sap (0.38μg/kg) samples, indicating a clear distribution of SMN within the sampled regions. The ultraviolet (UV) spectra of parent SMN and translocated SMN identified in different parts of the plant present the possibility of metabolization during the uptake process. Uptake of SMN using alfalfa grown under hydroponic conditions has potential as a promising remediation technology for removal of similar antibiotics from wastewater lagoons. Copyright © 2016. Published by Elsevier B.V.
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Safety assessment of greenhouse hydroponic tomatoes irrigated with reclaimed and surface water.
Lopez-Galvez, Francisco; Allende, Ana; Pedrero-Salcedo, Francisco; Alarcon, Juan Jose; Gil, Maria Isabel
2014-11-17
The impact of reclaimed and surface water on the microbiological safety of hydroponic tomatoes was assessed. Greenhouse tomatoes were irrigated with reclaimed and surface water and grown on two hydroponic substrates (coconut fiber and rock wool). Water samples (n=208) were taken from irrigation water, with and without the addition of fertilizers and drainage water, and hydroponic tomatoes (n=72). Samples were analyzed for indicator microorganisms, generic Escherichia coli and Listeria spp., and pathogenic bacteria such as Salmonella spp. and Shiga-toxigenic E. coli (STEC), using multiplex real-time PCR (RT-PCR) after enrichment. The correlation between climatological parameters such as temperature and the levels of microorganisms in water samples was also determined. In irrigation water, generic E. coli counts were higher in reclaimed than in surface water whereas Listeria spp. numbers increased after adding the fertilizers in both water sources. In drainage water, no clear differences in E. coli and Listeria numbers were observed between reclaimed and surface water. No positive samples for STEC were found in irrigation water. Presumptive positives for Salmonella spp. were found in 7.7% of the water samples and 62.5% of these samples were reclaimed water. Salmonella-positive samples by RT-PCR could not be confirmed by conventional methods. Higher concentrations of E. coli were associated with Salmonella-presumptive positive samples. Climatological parameters, such as temperature, were not correlated with the E. coli and Listeria spp. counts. Tomato samples were negative for bacterial pathogens, while generic E. coli and Listeria spp. counts were below the detection limit. The prevalence of presumptive Salmonella spp. found in irrigation water (reclaimed and surface water) was high, which might present a risk of contamination. The absence of pathogens on greenhouse hydroponic tomatoes indicates that good agricultural practices (GAP) were in place, avoiding the
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Automatic aeroponic irrigation system based on Arduino’s platform
Montoya, A. P.; Obando, F. A.; Morales, J. G.; Vargas, G.
2017-06-01
The recirculating hydroponic culture techniques, as aeroponics, has several advantages over traditional agriculture, aimed to improve the efficiently and environmental impact of agriculture. These techniques require continuous monitoring and automation for proper operation. In this work was developed an automatic monitored aeroponic-irrigation system based on the Arduino’s free software platform. Analog and digital sensors for measuring the temperature, flow and level of a nutrient solution in a real greenhouse were implemented. In addition, the pH and electric conductivity of nutritive solutions are monitored using the Arduino’s differential configuration. The sensor network, the acquisition and automation system are managed by two Arduinos modules in master-slave configuration, which communicate one each other wireless by Wi-Fi. Further, data are stored in micro SD memories and the information is loaded on a web page in real time. The developed device brings important agronomic information when is tested with an arugula culture (Eruca sativa Mill). The system also could be employ as an early warning system to prevent irrigation malfunctions.
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Hydroponic cultivation of Physalis angulata L.: growth and production under nitrogen doses
Directory of Open Access Journals (Sweden)
Romeu da Silva Leite
2017-06-01
Full Text Available The Physalis angulata L. species has attracted interest due to the production of compounds with pharmacological activity and its potential for fruiticulture. Given that it is a fast-growing and highly productive species, determining the most adequate nitrogen (N doses could contribute to higher crop yields. This study aimed at assessing the influence of N concentrations, in a hydroponic system, on the growth and production of P. angulata, as well as determining the critical N level in leaves. The experiment was conducted in individual pots with nutrient solutions, applying a completely randomized design and twelve replications, using five N doses (0 mg L-1, 56 mg L-1, 112 mg L-1, 168 mg L-1 and 224 mg L-1. Growth and production indices, amount of total N on leaves and stems and critical N levels were assessed. The increase of N doses in the nutrient solution influenced plant growth and fruit production, as well as the accumulation of total N in the leaves and stems. Based on the maximum economic yield, a dose of 162 mg L-1 of N is recommended for hydroponics, which provided a fruit yield of 7.27 g m-2 and critical total N level in leaves of 51.98 g kg-1.
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Transport and error sensitivity in a heavy-ion recirculator
International Nuclear Information System (INIS)
Sharp, W.M.; Barnard, J.J.; Yu, S.S.
1991-05-01
An envelope code has been developed to facilitate the design of a recirculating accelerator for a heavy-ion fusion reactor. A novel feature of the model is the treatment of the beam charge density as a Lagrangian fluid in the axial direction. Transport results for a preliminary recirculator design are presented, and sensitivity of the transport to errors in the magnet strength is discussed. 4 refs., 4 figs
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Russo, Ana; Gouveia, Célia; Levy, Ilan; Dayan, Uri; Jerez, Sonia; Mendes, Manuel; Trigo, Ricardo
2016-06-01
Coastal zones are under increasing development and experience air pollution episodes regularly. These episodes are often related to peaks in local emissions from industry or transportation, but can also be associated with regional transport from neighbour urban areas influenced by land-sea breeze recirculation. This study intends to analyze the relation between circulation weather patterns, air mass recirculation and pollution levels in three coastal airsheds of Portugal (Lisbon, Porto and Sines) based on the application of an objective quantitative measure of potential recirculation. Although ventilation events have a dominant presence throughout the studied 9-yrs period on all the three airsheds, recirculation and stagnation conditions occur frequently. The association between NO2, SO2 and O3 levels and recirculation potential is evident during summer months. Under high average recirculation potential and high variability, NO2 and SO2 levels are higher for the three airsheds, whilst for O3 each airshed responds differently. This indicates a high heterogeneity among the three airsheds in (1) the type of emission - traffic or industry - prevailing for each contaminant, and (2) the response to the various circulation weather patterns and recirculation situations. Irrespectively of that, the proposed methodology, based on iterative K-means clustering, allows to identify which prevailing patterns are associated with high recirculation potential, having the advantage of being applicable to any geographical location.
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Gancedo, Matthieu
Increase in emission regulations in the transport industry brings the need to have more efficient engines. A path followed by the automobile industry is to downsize the size of the internal combustion engine and increase the air density at the intake to keep the engine power when needed. Typically a centrifugal compressor is used to force the air into the engine, it can be powered from the engine shaft (superchargers) or extracting energy contained into the hot exhaust gases with a turbine (turbochargers). The flow range of the compressor needs to match the one of the engine. However compressors mass flow operating range is limited by choke on the high end and surge on the low end. In order to extend the operation at low mass flow rates, the use of passive devices for turbocharger centrifugal compressors was explored since the late 80's. Hence, casing treatments including flow recirculation from the inducer part of the compressor have been shown to move the surge limit to lower flows. Yet, the working mechanisms are still not well understood and thus, to optimize the design of this by-pass system, it is necessary to determine the nature of the changes induced by the device both on the dynamic stability of the pressure delivery and on the flow at the inlet. The compressor studied here features a self-recirculating casing treatment at the inlet. The recirculation passage could be blocked to carry a direct comparison between the cases with and without the flow feature. To grasp the effect on compressor stability, pressure measurements were taken in the different constituting elements of the compressor. The study of the mean pressure variations across the operating map showed that the tongue region is a limiting element. Dynamic pressure measurements revealed that the instabilities generated near the inducer when the recirculation is blocked increase the overall instability levels at the compressor outlet and propagating pressure waves starting at the tongue occurred
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An implantable centrifugal blood pump with a recirculating purge system (Cool-Seal system).
Yamazaki, K; Litwak, P; Tagusari, O; Mori, T; Kono, K; Kameneva, M; Watach, M; Gordon, L; Miyagishima, M; Tomioka, J; Umezu, M; Outa, E; Antaki, J F; Kormos, R L; Koyanagi, H; Griffith, B P
1998-06-01
A compact centrifugal blood pump has been developed as an implantable left ventricular assist system. The impeller diameter is 40 mm, and pump dimensions are 55 x 64 mm. This first prototype, fabricated from titanium alloy, resulted in a pump weight of 400 g including a brushless DC motor. The weight of a second prototype pump was reduced to 280 g. The entire blood contacting surface is coated with diamond like carbon (DLC) to improve blood compatibility. Flow rates of over 7 L/min against 100 mm Hg pressure at 2,500 rpm with 9 W total power consumption have been measured. A newly designed mechanical seal with a recirculating purge system (Cool-Seal) is used for the shaft seal. In this seal system, the seal temperature is kept under 40 degrees C to prevent heat denaturation of blood proteins. Purge fluid also cools the pump motor coil and journal bearing. Purge fluid is continuously purified and sterilized by an ultrafiltration unit which is incorporated in the paracorporeal drive console. In vitro experiments with bovine blood demonstrated an acceptably low hemolysis rate (normalized index of hemolysis = 0.005 +/- 0.002 g/100 L). In vivo experiments are currently ongoing using calves. Via left thoracotomy, left ventricular (LV) apex descending aorta bypass was performed utilizing an expanded polytetrafluoroethylene (ePTFE) vascular graft with the pump placed in the left thoracic cavity. In 2 in vivo experiments, the pump flow rate was maintained at 5-9 L/min, and pump power consumption remained stable at 9-10 W. All plasma free Hb levels were measured at less than 15 mg/dl. The seal system has demonstrated good seal capability with negligible purge fluid consumption (<0.5 ml/day). In both calves, the pumps demonstrated trouble free continuous function over 6 month (200 days and 222 days).
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Nonlinear Adaptive Control of Exhaust Gas Recirculation for Large Diesel Engines
DEFF Research Database (Denmark)
Nielsen, Kræn Vodder; Blanke, Mogens; Vejlgaard-Laursen, Morten
2015-01-01
recirculation. The paper provides proof of exponential stabilityfor closed loop control of the model given. Difficulties in the system include that certaindisturbance levels will make a desired setpoint in O2 unreachable, for reasons of the physics of thesystem, and it is proven that the proposed control...... will make the system converge exponentiallyto the best achievable state. Simulation examples confirm convergence and good disturbancerejection over relevant operational ranges of the engine....
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Bacterial community analysis of Tatsoi cultivated by hydroponics.
Koo, Ok K; Kim, Hun; Kim, Hyun J; Baker, Christopher A; Ricke, Steven C
2016-07-02
Tatsoi (Brassica narinosa) is a popular Asian salad green that is mostly consumed as a source of fresh produce. The purpose of this study was to assess the microbial diversity of Tatsoi cultivated in a hydroponic system and of its ecosystem. Tatsoi leaves, nutrient solution, and perlite/earth samples from a trickle feed system (TFS) and an ebb-and-flow system (EFS) were collected and their microbial communities were analyzed by pyrosequencing analysis. The results showed that most bacteria in the leaves from the TFS contained genus Sporosarcina (99.6%), while Rhizobium (60.4%) was dominant in the leaves from the EFS. Genus Paucibacter (18.21%) and Pelomonas (12.37%) were the most abundant microbiota in the nutrient solution samples of the TFS. In the EFS, the nutrient solution samples contained mostly genus Rhodococcus and Acinetobacter. Potential microbial transfer between the leaves and the ecosystem was observed in the EFS, while samples in the TFS were found to share only one species between the leaves, nutrient solution, and earth. Together, these results show that the bacterial populations in Tatsoi and in its ecosystem are highly diverse based on the cultivation system.
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Adaptive feedforward control of exhaust recirculation in large diesel engines
DEFF Research Database (Denmark)
Nielsen, Kræn Vodder; Blanke, Mogens; Eriksson, Lars
2017-01-01
is generalized to a class of first order Hammerstein systems with sensor delay and exponentially converging bounds of the control error are proven analytically. It is then shown how to apply the method to the EGR system of a two-stroke crosshead diesel engine. The controller is validated by closed loop......Environmental concern has led the International Maritime Organization to restrict NO푥 emissions from marine diesel engines. Exhaust gas recirculation (EGR) systems have been introduced in order to comply to the new standards. Traditional fixed-gain feedback methods are not able to control the EGR...
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Directory of Open Access Journals (Sweden)
Daniel A. Vandam
2017-05-01
Full Text Available Spinach (Spinacia oleracea cv. Carmel was grown in a conventional glass greenhouse under three different nutrient solution treatments. Lighting and temperature conditions were identical. Six growing systems were used to provide a duplicate trough system for each of these three treatments. Six trials were harvested from each system over a two month time period. Two treatments received hydroponic nutrient inputs, with one treatment at pH 7.0 (referred to as H7 and the other at pH 5.8 (H5, and the third treatment was aquaponic (A7, receiving all of its nutrients from a single fish tank with koi (Cyprinus carpio except for chelated iron. System pH was regulated by adding K2CO3 to aquaponic systems and KOH to hydroponic systems. Comparisons made between treatments were total yield, leaf surface area, tissue elemental content, and dry weight to fresh weight ratio. Dry weight biomass yield values were not different in pairwise comparisons between treatments (A7 vs. H5: p = 0.59 fresh weight, p = 0.42 dry weight. Similarly, surface area results were not different between treatments. The important comparison was that A7 achieved the same growth as H5, the conventional pH with a complete inorganic nutrient solution, despite unbalanced and less than “ideal” nutrient concentrations in the A7 condition.
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Arredondo-Figueroa, J. L.; Ingle de la Mora, G; Guerrero-Legarreta, I; Ponce-Palafox, J. T.; Barriga-Sosa, I. de los A.
2007-01-01
Nitrification and denitrification rates of inorganic nitrogen were studied in a closed recirculating-water system, comparing three load rates of rainbow trout Oncorhynchus mykiss (89, 156 and 194 kg in each tank with two repetitions). Six self-cleaning water circular fish tanks with a volume of 4.3 m³ were used, maintaining a 3.94 m³/day of average flow rate and constant aeration. A total of 371 rainbow trout, 524 ± 8 g initial wet weight were introduced in the system and fed with a commercia...
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Many studies have evaluated the adequacy of alternate ingredient diets for Atlantic salmon, Salmo salar, mainly with focus on fish performance and health; however, comprehensive analysis of fillet quality is lacking, particularly for salmon fed these diets in recirculation aquaculture systems (RAS)....
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Directory of Open Access Journals (Sweden)
Elisabete R. Yonamini Beninni
2002-06-01
Full Text Available O monitoramento do teor de nitrato nos alimentos é importante, uma vez que poderão ser formados compostos prejudiciais à saúde humana e animal após sua ingestão. Com o objetivo de avaliar o teor de nitrato presente em alface, foram coletadas e analisadas as folhas de alface crespa comercializada no Município de Londrina, cultivada em sistemas hidropônico e convencional. Os valores encontrados variaram entre 26 e 2.568 mg.kg-1 de peso fresco, sendo que as plantas cultivadas em sistema hidropônico apresentaram teores superiores em relação às cultivadas em sistema convencional, porém abaixo do limite máximo de nitrato permitido para alface, na Europa.The control of the nitrate level in foods is important because this substance may be harmful to human and animal health. The aim of this work was to evaluate nitrate levels in lettuce produced in hydroponic and conventional systems and commercialized in Londrina, Brazil. The nitrate concentration ranged from 26 to 2,568 mg.kg-1 fresh weight. Hydroponic lettuce showed higher levels of nitrate but in all cases the level of nitrate was lower than the maximum allowed by the Comission of the European Communities.
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International Nuclear Information System (INIS)
De Paepe, Ward; Delattin, Frank; Bram, Svend; De Ruyck, Jacques
2012-01-01
This paper reports on a specific phenomenon, noticed during steam injection experiments on a microturbine. During the considered experiments, measurements indicated an unsteady inlet air temperature of the compressor, resulting in unstable operation of the microturbine. Non-continuous exhaust air recirculation was a possible explanation for the observed behaviour of the microturbine. The aim of this paper is to investigate and demonstrate the effects of exhaust recirculation on a microgasturbine. Depending on wind direction, exhaust air re-entered the engine, resulting in changing inlet conditions which affects the operating regime of the microturbine. For this paper, a series of experiments were performed in the wind tunnel. These series of experiments allowed investigation of the effect of the wind direction on flue gasses flow. Next to the experiments, steady-state simulations of exhaust recirculation were performed in order to study the effect of exhaust recirculation on thermodynamic performance of the microturbine. Dynamic simulations of the non-continuous recirculation revealed the effects of frequency and amplitude on average performance and stability. Results from simulations supported the important impact of exhaust recirculation. Wind tunnel tests demonstrated the influence of the wind direction on recirculation and revealed the necessity to heighten the stack, thus preventing exhaust recirculation. -- Highlights: ► Unstable operation of a T100 microturbine during steam injection tests was noticed, caused by exhaust gas recirculation. ► Wind tunnel tests were performed to study the effect of the wind direction on the recirculation process. ► Steady-state simulations to investigate the effect of exhaust gas recirculation on thermodynamic performance. ► Dynamic simulations to reveal effects of frequency and amplitude on average performance and stability. ► Wind tunnel tests revealed the necessity to heighten the stack to prevent exhaust
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Liquid Hydrogen Recirculation System for Forced Flow Cooling Test of Superconducting Conductors
Shirai, Y.; Kainuma, T.; Shigeta, H.; Shiotsu, M.; Tatsumoto, H.; Naruo, Y.; Kobayashi, H.; Nonaka, S.; Inatani, Y.; Yoshinaga, S.
2017-12-01
The knowledge of forced flow heat transfer characteristics of liquid hydrogen (LH2) is important and necessary for design and cooling analysis of high critical temperature superconducting devices. However, there are few test facilities available for LH2 forced flow cooling for superconductors. A test system to provide a LH2 forced flow (∼10 m/s) of a short period (less than 100 s) has been developed. The test system was composed of two LH2 tanks connected by a transfer line with a controllable valve, in which the forced flow rate and its period were limited by the storage capacity of tanks. In this paper, a liquid hydrogen recirculation system, which was designed and fabricated in order to study characteristics of superconducting cables in a stable forced flow of liquid hydrogen for longer period, was described. This LH2 loop system consists of a centrifugal pump with dynamic gas bearings, a heat exchanger which is immersed in a liquid hydrogen tank, and a buffer tank where a test section (superconducting wires or cables) is set. The buffer tank has LHe cooled superconducting magnet which can produce an external magnetic field (up to 7T) at the test section. A performance test was conducted. The maximum flow rate was 43.7 g/s. The lowest temperature was 22.5 K. It was confirmed that the liquid hydrogen can stably circulate for 7 hours.
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Mummert, A.; Newcomb, T.J.; Neves, R.J.; Parker, B.
2006-01-01
A recirculating double-pond system at White Sulphur Springs National Fish Hatchery in West Virginia, U.S.A., was evaluated for suitability for culturing juvenile freshwater mussels. Newly metamorphosed juveniles of Villosa iris and Lampsilis fasciola were placed in the system, and their growth and survival were evaluated for 94 days. Throughout the study, parameters of water quality remained within ranges suitable for mussel survival. Planktonic algal densities in the pond system ranged from 2850 to 6892 cells/ml. Thirty-seven algal taxa were identified, primarily green algae (Chlorophyta), diatoms (Bacillariophyceae), and blue-green algae (Cyanoprokaryota). Over the culture period, juveniles of L. fasciola experienced significantly lower (p fasciola may indicate a failure of the flow-through pond environment to meet its habitat requirements or that variable microhabitat conditions within culture containers existed. Growth did not differ significantly between the species (p = 0.13). Survival of V. iris and growth of both species were similar to previous trials to culture juvenile mussels. Survival rates as high as 66.4% at 93 days for V. iris suggest that juveniles of some riverine species can be successfully cultured in a recirculating pond environment.
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ANALYSIS OF HYDROPONIC FERTILIZER MATRIXES FOR PERCHLORATE: COMPARISON OF ANALYTICAL TECHNIQUES
Seven retail hydroponic nitrate fertilizer products, two liquid and five solid, were comparatively analyzed for the perchlorate anion (ClO4-) by ion chromatography (IC) with suppressed conductivity detection, complexation electrospray ionization mass spectrometry (cESI-MS), norma...
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International Nuclear Information System (INIS)
Barnard, J.J.; Cable, M.D.; Callahan, D.A.
1996-01-01
Recirculating induction accelerators (recirculators) have been investigated as possible drivers for inertial fusion energy production because of their potential cost advantage over linear induction accelerators. Point designs were obtained and many of the critical physics and technology issues that would need to be addressed were detailed. A collaboration involving Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory researchers is now developing a small prototype recirculator in order to demonstrate an understanding of nearly all of the critical beam dynamics issues that have been raised. We review the design equations for recirculators and demonstrate how, by keeping crucial dimensionless quantities constant, a small prototype recirculator was designed which will simulate the essential beam physics of a driver. We further show how important physical quantities such as the sensitivity to errors of optical elements (in both field strength and placement), insertion/extraction, vacuum requirements, and emittance growth, scale from small-prototype to driver-size accelerator
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DEFF Research Database (Denmark)
Konnerup, Dennis; Trang, Ngo Thuy Diem; Brix, Hans
2011-01-01
quantities of phytoplankton algae were removed in the CWs but abundance of toxic algae such as Microcystis was low. It is concluded that particularly vertical flow CWs have great potential for treatment of fishpond water in recirculating aquaculture systems in the tropics as the discharge of polluted water......Common practice of aquaculture in Vietnam and other countries in South East Asia involves frequent discharge of polluted water into rivers which results in eutrophication and degradation of receiving water bodies. There is therefore a need to develop improved aquaculture systems which have a more...... efficient use of water and less environmental impact. The aim of this study was to assess the suitability of using constructed wetlands (CWs) for the treatment of fishpond water in a recirculating aquaculture system in the Mekong Delta of Vietnam. Water from a fishpond stocked with Nile tilapia (Oreochromis...
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Impact assessment of concentrate recirculation on the landfill gas production
Directory of Open Access Journals (Sweden)
Džolev Nikola M.
2016-01-01
Full Text Available This paper explores the impact of concentrate recirculation, as a product of leachate treated by reverse osmosis plant, on the production of landfill gas at the real-scale landfill for municipal solid waste. In an effort to come up with results experimental measurements were carried out at the landfill in Bijeljina. All measurements performed, were divided into 3 groups. The aims of two groups of measurement were to determine landfill gas and methane yield from concentrate and leachate in laboratory conditions (1st group and to find out concentrations of oxidizing matters (COD and BOD5 present in leachate and concentrate at different points of treatment as well as its variability over the time (2nd group which could be used to calculate the potential of landfill gas and methane generation from concentrate by recirculation, theoretically. 3rd group of measurements, carried out in parallel, have goal to determine the quality and quantity of the collected landfill gas at wells throughout the landfill. The results of analysis carried out in this experimental research show the clear evidence of concentrate recirculation impact on methane production by increasing the landfill gas flow, as well as its concentration within the landfill gas composition, at the nearby well. Although results indicated relatively high impact of concentrate recirculation on landfill gas production, comparing to its theoretical potential, the influence on the landfill at whole, is negligible, due to relatively low volumes in recirculation with respect to its size and objectively low potential given by organic matter present in concentrate.
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Wang, Ruyi; He, Pinjing; Shao, Liming; Zhang, Bin; Li, Guojian
2005-05-01
With pot experiment, this paper studied the membrane lipid peroxidation and the variations of antioxidation system in Cynodon dactylon under recirculated landfill leachate irrigation. The results showed that when irrigated with low dilution ratio ( 25%), there existed an obvious negative fect on Cynodon dactylon, i.e., the chlorophyll a/b ratio decreased, while cell membrane permeability and MDA and H2O2 contents increased, which meant that the membrane lipid peroxidation was accelerated. The contents antioxidants AsA, GSH and Car also showed the similar trend, i.e., they increased with increasing leachate dilution ratio when irrigated with low dilution ratio leachate, but decreased under medium or high dilution ratio leachate irrigation. Among three test anti-oxidative enzymes, SOD and POD activities showed a similar change test antioxidants, and POD activity was more sensitive, while CAT activity was on the contrary. The contents test antioxidants and the activities of SOD and POD were negatively and significantly correlated to MDA content, indicating that they might play an important role in preventing Cynodon dactylon from cell membrane lipid peroxdation.
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Exhaust Gas Recirculation Control for Large Diesel Engines - Achievable Performance with SISO Design
DEFF Research Database (Denmark)
Hansen, Jakob Mahler; Blanke, Mogens; Niemann, Hans Henrik
2013-01-01
This paper investigates control possibilities for Exhaust Gas Recirculation (EGR) on large diesel engines. The goal is to reduce the amount of NOx in the exhaust gas by reducing the oxygen concentration available for combustion. Control limitations imposed by the system are assessed using linear...
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Bindschedler, Laurence V; Mills, Davinia J S; Cramer, Rainer
2012-01-01
Hydroponic isotope labeling of entire plants (HILEP) combines hydroponic plant cultivation and metabolic labeling with stable isotopes using (15)N-containing inorganic salts to label whole and mature plants. Employing (15)N salts as the sole nitrogen source for HILEP leads to the production of healthy-looking plants which contain (15)N proteins labeled to nearly 100%. Therefore, HILEP is suitable for quantitative plant proteomic analysis, where plants are grown in either (14)N- or (15)N-hydroponic media and pooled when the biological samples are collected for relative proteome quantitation. The pooled (14)N-/(15)N-protein extracts can be fractionated in any suitable way and digested with a protease for shotgun proteomics, using typically reverse phase liquid chromatography nanoelectrospray ionization tandem mass spectrometry (RPLC-nESI-MS/MS). Best results were obtained with a hybrid ion trap/FT-MS mass spectrometer, combining high mass accuracy and sensitivity for the MS data acquisition with speed and high-throughput MS/MS data acquisition, increasing the number of proteins identified and quantified and improving protein quantitation. Peak processing and picking from raw MS data files, protein identification, and quantitation were performed in a highly automated way using integrated MS data analysis software with minimum manual intervention, thus easing the analytical workflow. In this methodology paper, we describe how to grow Arabidopsis plants hydroponically for isotope labeling using (15)N salts and how to quantitate the resulting proteomes using a convenient workflow that does not require extensive bioinformatics skills.
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DEFF Research Database (Denmark)
Pedersen, Lars-Flemming
of these agents on biofilter nitrification performance. All experiments were conducted through addition of chemical additives to closed pilot scale recirculating aquaculture systems (RAS) with fixed media submerged biofilters under controlled operating conditions with rainbow trout (Oncorhynchus mykiss...... to positively correlate to temperature, available biofilter surface-area, and the frequency of FA-exposure. Prolonged biofilter exposure to FA did not negatively affect nitrification, and could therefore be a method to optimize FA treatment in RAS and reduce FA discharge. HP degradation was rapid and could...... prolonged multiple HP dosages at 10 mg/L were found to inhibit nitrite oxidation in systems with low organic loading. PAA decay was found to be concentration-dependent. It had a considerable negative effect on nitrite oxidation over a prolonged period of time when applied at a dosage ≥2 mg/L. PAA and HP...
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Morris, Carlton E.; Martinez, Edwin; Bonsi, C. K.; Mortley, Desmond G.; Hill, Walter A.; Ogbuehi, Cyriacus R.; Loretan, Phil A.
1989-01-01
The potential of the sweet potato as a food source for future long term manned space missions is being evaluated for NASA's Controlled Ecological Life Support Systems (CELSS) program. Sweet potatoes have been successfully grown in a specially designed Tuskegee University nutrient film technique (TU NFT) system. This hydroponic system yielded storage roots as high as 1790 g/plant fresh weight. In order to determine the effect of channel size on the yield of sweet potatoes, the width and depth of the growing channels were varied in two separate experiments. Widths were studied using the rectangular TU NFT channels with widths of 15 cm (6 in), 30 cm (12 in) and 45 cm (18 in). Channel depths of 5 cm (2 in), 10 cm (4 in), and 15 cm (6 in) were studied using a standard NASA fan shaped Biomass Production Chamber (BPC) channel. A comparison of preliminary results indicated that, except for storage root number, the growth and yield of sweet potatoes were not affected by channel width. Storage root yield was affected by channel depth although storage root number and foliage growth were not. Both experiments are being repeated.
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Daniel A. Vandam; Tyler S. Anderson; David de Villiers; Michael B. Timmons
2017-01-01
Spinach (Spinacia oleracea cv. Carmel) was grown in a conventional glass greenhouse under three different nutrient solution treatments. Lighting and temperature conditions were identical. Six growing systems were used to provide a duplicate trough system for each of these three treatments. Six trials were harvested from each system over a two month time period. Two treatments received hydroponic nutrient inputs, with one treatment at pH 7.0 (referred to as H7) and the other at pH 5.8 (H5), an...
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Identification of suitable media based on hydroponic culture for production Zucchini squash
Directory of Open Access Journals (Sweden)
TP Suvo
2016-12-01
Full Text Available An experiment was conducted to identify the hydroponic culture based suitable media for the production of Zucchini Squash in the Biochemistry Laboratory, Patuakhali Science and Technology University, Dumki, Patuakhali, Bangladesh during 2014. Zucchini plant (Cucurbita pepo L. were grown in closed soilless systems to determine the effect of four different hydroponics media on plant growth, yield and nutrient contents (fruit moisture content, ascorbic acid content on fruit, fruit protein content, protein content in leaves. Three types of substrates (coconut husk, jute, cotton along with Hoagland solution were used in this experiment. Result revealed that media using Jute fiber showed significant effect on plant growth and nutritional values than the other media (media of cotton with Hoagland solution, coconut husk with Hoagland solution and only Hoagland solution. The plant grown using jute media showed the highest plant height (60.33 cm, number of leaves (17.33, yield (1.5 kg plant-1, fruit moisture content (97.33%, Ascorbic acid content in fruit (28.73 mg 100g-1, protein percentage in fruit (1.406% and percentage (1.326% in leaves than the other media. Therefore, with the controlled nutrient supply, less expense, less labor, no use of pesticides or fertilizer with controlled environment the use of jute fiber as a substrate with Hoagland solution can be an effective one.
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Accumulation of 90Sr, Ca, Mg, K and Na in crane's-bill plants cultavated on soil and hydroponics
International Nuclear Information System (INIS)
Analyan, V.L.; Sarkisyan, G.A.
1981-01-01
Accumulation of 90 Sr in plants under the conditions of soil and hydroponic cultures from the viewpoint of the possibility of obtaining ''pure'' vegetable production has been studied. Predominant absorption of 90 Sr by soil plants as compared with calcium is shown. In the course of using the hydroponic cultivation method redominant radiostrontium absorption has been manifested to all investigated nuclides including potassium. The accumulation coefficients analysis has shown that among soil plants the fisarst place is occupied by potassium, while the 90 Sr coefficients are greater than Ca on hydroponics, where the true, not distorted by soil sorption processes absorptive plant capacity has been manifested, the first places in the series are occupied by 90 Sr and K, then come Ca and Mg
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Recirculating cooling water solute depletion models
International Nuclear Information System (INIS)
Price, W.T.
1990-01-01
Chromates have been used for years to inhibit copper corrosion in the plant Recirculating Cooling Water (RCW) system. However, chromates have become an environmental problem in recent years both in the chromate removal plant (X-616) operation and from cooling tower drift. In response to this concern, PORTS is replacing chromates with Betz Dianodic II, a combination of phosphates, BZT, and a dispersant. This changeover started with the X-326 system in 1989. In order to control chemical concentrations in X-326 and in systems linked to it, we needed to be able to predict solute concentrations in advance of the changeover. Failure to predict and control these concentrations can result in wasted chemicals, equipment fouling, or increased corrosion. Consequently, Systems Analysis developed two solute concentration models. The first simulation represents the X-326 RCW system by itself; and models the depletion of a solute once the feed has stopped. The second simulation represents the X-326, X-330, and the X-333 systems linked together by blowdown. This second simulation represents the concentration of a solute in all three systems simultaneously. 4 figs
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Chekli, Laura
2017-03-10
This study investigated the sustainable reuse of wastewater using fertilizer drawn forward osmosis (FDFO) process through osmotic dilution of commercial nutrient solution for hydroponics, a widely used technique for growing plants without soil. Results from the bench-scale experiments showed that the commercial hydroponic nutrient solution (i.e. solution containing water and essential nutrients) exhibited similar performance (i.e., water flux and reverse salt flux) to other inorganic draw solutions when treating synthetic wastewater. The use of hydroponic solution is highly advantageous since it provides all the required macro- (i.e., N, P and K) and micronutrients (i.e., Ca, Mg, S, Mn, B, Zn and Mo) in a single balanced solution and can therefore be used directly after dilution without the need to add any elements. After long-term operation (i.e. up to 75% water recovery), different physical cleaning methods were tested and results showed that hydraulic flushing can effectively restore up to 75% of the initial water flux while osmotic backwashing was able to restore the initial water flux by more than 95%; illustrating the low-fouling potential of the FDFO process. Pilot-scale studies demonstrated that the FDFO process is able to produce the required nutrient concentration and final water quality (i.e., pH and conductivity) suitable for hydroponic applications. Coupling FDFO with pressure assisted osmosis (PAO) in the later stages could help in saving operational costs (i.e., energy and membrane replacement costs). Finally, the test application of nutrient solution produced by the pilot FDFO process to hydroponic lettuce showed similar growth pattern as the control without any signs of nutrient deficiency.
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Recirculation of Chilean copper smelting dust with high impurities contents to the smelting process
Energy Technology Data Exchange (ETDEWEB)
Sano, H.; Fujisawa, T. [Nagoya Univ., Nagoya (Japan). EcoTopia Science Inst.; Montenegro, V. [Nagoya Univ., Nagoya (Japan). Dept. of Materials Science and Engineering
2007-07-01
Dust generated during the copper smelting process is generally stabilized using hydrometallurgical methods as it contains high concentrations of arsenic. In this laboratory study, dust was recirculated during the smelting process in order to recover more copper and decrease dust emissions while recovering more copper. The behaviour of impurities and their influence on matte quality was also investigated. Industrial matte, flue dust, slag, and copper concentrates from a Chilean smelter were used as test materials. Dust recirculation tests were conducted in a simulated electric furnace. Off-gases were collected in a reaction tube, and the condensed volatile matter, slag, and matte phases were analyzed for their elemental content by inductively coupled plasma atomic emission spectrometry. The distribution of arsenic (As); antimony (Sb), bismuth (Bi), lead (Pb), and zinc (Zn) were investigated by varying the amounts of dust recirculating to the smelting stage with 21 per cent of the oxygen. Results showed that distributions of all analyzed elements increased with recirculation. It was concluded that copper can be recovered using the dust recirculation technique. However, impurities may limit the efficacy of the dust recirculation process. 6 refs., 3 tabs., 4 figs.
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Previous research indicates that rainbow trout (Oncorhynchus mykiss) begin to exhibit health and welfare problems when cultured within water recirculating aquaculture systems (WRAS) operated at low exchange (6.7 days hydraulic retention time) and a mean feed loading rate of 4.1 kg feed/m3 daily make...
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Macarisin, Dumitru; Patel, Jitendra; Sharma, Vijay K
2014-03-03
Contamination of fresh produce could represent a public health concern because no terminal kill step is applied during harvest or at the processing facility to kill pathogens. In addition, once contaminated, pathogens may internalize into produce and be protected from disinfectants during the postharvest processing step. The objective of the current study was to determine the potential internalization of Escherichia coli O157:H7 into spinach roots and subsequent transfer to the edible parts. Because curli are involved in biofilm formation, we investigated whether their presence influence the internalization of E. coli O157:H7 into spinach. Further, the effect of the spinach cultivar on E. coli O157:H7 internalization was evaluated. Spinach plants were grown in contaminated soil as well as hydroponically to prevent mechanical wounding of the roots and inadvertent transfer of pathogens from the contamination source to the non-exposed plant surfaces. Results showed that E. coli O157:H7 could internalize into hydroponically grown intact spinach plants through the root system and move to the stem and leaf level. The incidence of internalization was significantly higher in hydroponically grown plants when roots were exposed to 7 log CFU/mL compared to those exposed to 5 log CFU/mL. The effect of cultivar on E. coli O157:H7 internalization was not significant (P>0.05) for the analyzed spinach varieties, internalization incidences showing almost equal distribution between Space and Waitiki, 49.06% and 50.94% respectively. Wounding of the root system in hydroponically grown spinach increased the incidence of E. coli O157:H7 internalization and translocation to the edible portions of the plant. Experimental contamination of the plants grown in soil resulted in a greater number of internalization events then in those grown hydroponically, suggesting that E. coli O157:H7 internalization is dependent on root damage, which is more likely to occur when plants are grown in soil
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Surrogate Model for Recirculation Phase LBLOCA and DET Application
International Nuclear Information System (INIS)
Fynan, Douglas A; Ahn, Kwang-Il; Lee, John C.
2014-01-01
In the nuclear safety field, response surfaces were used in the first demonstration of the code scaling, applicability, and uncertainty (CSAU) methodology to quantify the uncertainty of the peak clad temperature (PCT) during a large-break loss-of-coolant accident (LBLOCA). Surrogates could have applications in other nuclear safety areas such as dynamic probabilistic safety assessment (PSA). Dynamic PSA attempts to couple the probabilistic nature of failure events, component transitions, and human reliability to deterministic calculations of time-dependent nuclear power plant (NPP) responses usually through the use of thermal-hydraulic (TH) system codes. The overall mathematical complexity of the dynamic PSA architectures with many embedded computational expensive TH code calculations with large input/output data streams have limited realistic studies of NPPs. This paper presents a time-dependent surrogate model for the recirculation phase of a hot leg LBLOCA in the OPR-1000. The surrogate model is developed through the ACE algorithm, a powerful nonparametric regression technique, trained on RELAP5 simulations of the LBLOCA. Benchmarking of the surrogate is presented and an application to a simplified dynamic event tree (DET). A time-dependent surrogate model to predict core subcooling during the recirculation phase of a hot leg LBLOCA in the OPR-1000 has been developed. The surrogate assumed the structure of a general discrete time dynamic model and learned the nonlinear functional form by performing nonparametric regression on RELAP5 simulations with the ACE algorithm. The surrogate model input parameters represent mass and energy flux terms to the RCS that appeared as user supplied or code calculated boundary conditions in the RELAP5 model. The surrogate accurately predicted the TH behavior of the core for a variety of HPSI system performance and containment conditions when compared with RELAP5 simulations. The surrogate was applied in a DET application replacing
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International Nuclear Information System (INIS)
Charles L Kling; Stephen S Barshay; Mathew C Jacob; Michael J Friedman
2005-01-01
Full text of publication follows: On June 9, 2003 the US NRC issued Bulletin No. 2003-01 that deals with the potential impact of debris blockage on containment sump recirculation at PWRs during a Loss-of-Coolant Accident (LOCA). In response to the bulletin, the Omaha Public Power District (OPPD) is in the process of developing procedural and operational strategies for their Fort Calhoun Station (FCS) to address the issues raised. Westinghouse provided engineering support to OPPD in identifying and resolving issues related to alternative means of supplying safety injection water to the reactor coolant system (RCS) in the absence of containment sump recirculation. Nuclear power plants are designed to protect the core following a LOCA by providing a continuous supply of cooling water to the core. In the long term, the Refueling Water Storage Tank (RWST) inventory will be depleted and core heat removal accomplished via recirculation of water previously injected into the Reactor Coolant System (RCS) and collected in the containment sump. Debris generated within the containment as a result of the impingement of fluid jets in the Zone of Influence (ZOI) of the RCS break and containment wash down may find its way into the containment sump. As the safety injection pumps take suction from the sump, in the recirculation mode of operation, the debris suspended in the sump water could begin to accumulate in the sump screen that is located in the recirculation path. Should sufficient debris accumulate on the sump screen, a flow blockage could potentially develop. This would result in insufficient safety injection pump NPSH, thereby impairing the recirculation mode of injection into RCS. Potential debris blockage and prevention of sump recirculation may be addressed by refilling the RWST with water and injecting this water directly into the core. This paper identifies and attempts to resolve several issues related to this alternative mode of RCS injection. In particular, the
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Rector, Tony; Steele, John W.; Bue, Grant C.; Campbell, Colin; Makinen, Janice
2012-01-01
A water loop maintenance device and process to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop has been undergoing a performance evaluation. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the water recirculation maintenance device and process is to further enhance this advantage through the leveraging of fluid loop management lessons-learned from the International Space Station (ISS). A bed design that was developed for a Hamilton Sundstrand military application, and considered for a potential ISS application with the Urine Processor Assembly, provides a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance process further leverages a sorbent developed for ISS that introduces a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware. This
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Steele, John W.; Rector, Tony; Bue, Grant C.; Campbell, Colin; Makinen, Janice
2012-01-01
A dual-bed device to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop has been designed and is undergoing testing. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing sublimator technology. The driver for the development of a water recirculation maintenance device is to further enhance this advantage through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A bed design that was developed for a Hamilton Sundstrand military application, and considered for a potential ISS application with the Urine Processor Assembly, provides a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high-capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit Transport Water Loop. The bed design further leverages a sorbent developed for the ISS that introduces a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System. The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of crewed spaceflight Environmental Control and Life Support System hardware.
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Steele, John W.; Rector, Tony; Bue, Grant C.; Campbell, Colin; Makinen, Janice
2013-01-01
A dual-bed device to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop has been designed and is undergoing testing. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the development of a water recirculation maintenance device is to further enhance this advantage through the leveraging of fluid loop management lessons-learned from the International Space Station (ISS). A bed design that was developed for a Hamilton Sundstrand military application, and considered for a potential ISS application with the Urine Processor Assembly, provides a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The bed design further leverages a sorbent developed for ISS that introduces a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.
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Steele, John W.; Rector, Tony; Bue, Grant C.; Campbell, Colin; Makinen, Janice
2011-01-01
A dual-bed device to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop has been designed and is undergoing testing. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the development of a water recirculation maintenance device is to further enhance this advantage through the leveraging of fluid loop management lessons-learned from the International Space Station (ISS). A bed design that was developed for a Hamilton Sundstrand military application, and considered for a potential ISS application with the Urine Processor Assembly, provides a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The bed design further leverages a sorbent developed for ISS that introduces a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a clear demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.
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Directory of Open Access Journals (Sweden)
Crepeau Gérald
2012-04-01
Full Text Available The European emission standards EURO 5 and EURO 6 define more stringent acceptable limits for exhaust emissions of new vehicles. The Exhaust Gas Recirculation (EGR system is a partial but essential solution for lowering the emission of nitrogen oxides and soot particulates. Yet, due to a more intensive use than in the past, the fouling of the EGR system is increased. Ensuring the reliability of the EGR system becomes a main challenge. In partnership with PSA Peugeot Citroën, we designed an experimental setup that mimics an operating EGR system. Its distinctive features are (1 its ability to reproduce precisely the operating conditions and (2 its ability to measure the temperature field on the heat exchanger surface with an Infra Red camera for detecting in real time the evolution of the fooling deposit based on its thermal resistance. Numerical codes are used in conjunction with this experimental setup to determine the evolution of the fouling thickness from its thermal resistance.
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Low-dose hydrogen peroxide application in closed recirculating aquaculture systems
DEFF Research Database (Denmark)
Pedersen, Lars-Flemming; Good, C.; Pedersen, Per Bovbjerg
2012-01-01
biofilter nitrite oxidation in low-intensity RAS but not in high-intensity RAS. The impact of HP exposure time on biofilter nitrification capacity was then assessed in biofilter bench-scale experiments with nitrite spiking. Exposure time was found to significantly affect nitrite oxidation. Compared...... with unexposed biofilter elements, nitrite oxidation was reduced more than 90% following 3 h of exposure to 15 mg HP/L, whereas 30 min of exposure had only minor negative effects on nitrite oxidation. The findings of this study demonstrate the potential for developing HP water treatment practices for RAS...... and contradict prevailing notions that HP cannot be used safely in RAS that employ biofiltration. The development of effective new HP treatment protocols for recirculating aquaculture could reduce the current dependence on formalin to improve water quality and control parasitic loads...
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Performance Study of Ceramic Filter Module in Recirculated Aquaculture System (RAS)
Ng, L. Y.; Ng, C. Y.
2017-06-01
The growth of world population has led to significant increase in seafood demand over the world. Aquaculture has been widely accepted by many countries to increase the seafood production owing to the decline of natural seafood resources. The aquaculture productivity, however, is directly linked to the pond water quality. In this study, attempts were made to employ ceramic micro-filter to improve the pond water quality through filtration processes. There were two batches of filtration processes, short term (1 hour) and long term (48 hours). Significant improvements on real pond water quality were recorded through the short term microfiltration process, which reduced turbidity (96%), total suspended solids (TSS) (80%), biochemical oxygen demand (BOD) (72%), chemical oxygen demand (COD) (55%), ammonia (60%), nitrate (96%) and phosphorus (83%). The long term filtration process also showed high efficiency in the removal of solid particle and organic matters. The results showed that all of the parameters were successfully reduced to acceptable ranges (turbidityfiltered pond water. Current study showed that the microfiltration using ceramic micro-filter has high potential to be used in recirculating aquaculture system throughout the aquaculture activities in order to maintain the pond water quality, thus, increase the survival rate of cultured species.
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Theoretical analysis of recirculation zone and buffer zone in the ADS windowless spallation target
International Nuclear Information System (INIS)
Liu, Jie; Pan, Chang-zhao; Tong, Jian-fei; Lu, Wen-qiang
2015-01-01
Highlights: • Height of recirculation zone is very important in windowless target design. • A theoretical formula for the height is derived based on the Bernoulli equation. • Numerical simulation for the LBE is performed and the height of recirculation zone is also obtained. • The theoretically-derived simulation-predicted recirculation zone heights agree with each other very well and the theoretical derivation is proved to be correct. - Abstract: The thermo-hydraulic analysis including reduction of the height of recirculation zone and stability of the free surface is very important in the design and optimization of ADS windowless spallation targets. In the present study, the Bernoulli equation is used to analyze the entire flow process in the target. Formulae for the height of the recirculation zone and the buffer zone are both obtained explicitly. Furthermore, numerical simulation for the heavy metal lead–bismuth eutectic liquid and vapor with cavitation phase change is also performed, and a novel method to calculate the height of the recirculation zone is put forward. By comparison of the theoretical formulae and numerical results, it is clearly shown that they agree with each other very well, and the heights predicted by the two methods are both determined by their own upstream flow parameters
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Maintenance experience on reactor recirculation pumps at Tarapur Atomic Power Station
International Nuclear Information System (INIS)
Singh, A.K.
1995-01-01
Reactor recirculation pumps at Tarapur Atomic Power Station (TAPS) are vertical, single stage centrifugal pumps having mechanical shaft seals and are driven by vertical mounted 3.3 kV, 3 phase, 1500 h.p. electric motors. During these years of operation TAPS has gained enough experience and expertise on the maintenance of reactor recirculation pumps which are dealt in this article. Failure of mechanical shaft seals, damage on pump carbon bearings, motor winding insulation failures and motor shaft damage have been the main areas of concern on recirculation pump. A detailed procedure step by step with component sketches has helped in eliminating errors during shaft seal assembly and installation. Pressure breakdown devices in seal assembly were rebuilt. Additional coolant water injection for shaft seal cooling was provided. These measures have helped in extending the reactor recirculation pump seal life. Pump bearing problems were mainly due to failure of anti-rotation pins and dowel pins of bearing assembly. These pins were redesigned and strengthened. Motor stator winding insulation failures were detected. Stator winding replacement program has been taken up on regular basis to avoid winding insulation failure due to aging. 3 refs., 2 tabs., 7 figs
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Zhang, Qing; Guan, Yanxing; Xiang, Tianxin; Liu, Shaozheng; Chen, Qingjie; Zhang, Qing
2017-02-01
The treatment of hyperthyroidism associated with severe liver dysfunction (LD) is a clinical challenge, and there has been no unified examination of this problem. The objective of this study was to assess the efficacy and safety of radioiodine ( 131 I) in combination with a molecular adsorbent recirculating system (MARS) for the treatment of hyperthyroidism complicated by severe liver LD. A total of 116 hyperthyroidism patients with concomitant LD who received MARS treatment were studied retrospectively. The patients were grouped according to whether or not they also received 131 I treatment: Group 1 (59 patients) received 131 I following MARS treatment, while Group 2 (57 cases) received only MARS. Clinical outcomes, including thyroid hormone levels, liver function parameters, and therapeutic efficacy were calculated. The overall response rate was significantly greater in Group 1 than in Group 2 (Ptreatment compared with before treatment (Ptreatments (Ptreatment of hyperthyroidism complicated by severe LD was effective and safe. The use of this system could rapidly improve liver function and metabolism, allowing 131 I therapy to be applied as early as possible with a shortened recovery time of liver function. ALSS = artificial liver support system ALT = alanine transaminase AST = aspartate transaminase ATD = antithyroid drugs DBil = direct bilirubin FT3 = free tri-iodothyronine FT4 = free thyroxine 131 I = radioiodine INR = international normalized ratio LD = liver dysfunction MARS = molecular adsorbent recirculating system MELD = model for end-stage liver disease PT = prothrombin time TBil = total bilirubin TSH = thyroid-stimulating hormone.
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The sensitivity of an hydroponic lettuce root elongation bioassay to metals, phenol and wastewaters.
Park, Jihae; Yoon, Jeong-Hyun; Depuydt, Stephen; Oh, Jung-Woo; Jo, Youn-Min; Kim, Kyungtae; Brown, Murray T; Han, Taejun
2016-04-01
The root elongation bioassay is one of the most straightforward test methods used for environmental monitoring in terms of simplicity, rapidity and economy since it merely requires filter paper, distilled water and Petri dishes. However, filter paper as a support material is known to be problematic as it can reduce the sensitivity of the test. The newly developed hydroponic method reported here differs from the conventional root elongation method (US EPA filter paper method) in that no support material is used and the exposure time is shorter (48 h in this test versus 120 h in the US EPA test). For metals, the hydroponic test method was 3.3 (for Hg) to 57 (for Cu) times more sensitive than the US EPA method with the rank orders of sensitivity, estimated from EC50 values, being Cu≥Cd>Ni≥Zn≥Hg for the former and Hg≥Cu≥Ni≥Cd≥Zn for the latter methods. For phenol, the results did not differ significantly; EC50 values were 124 mg L(-1) and 108-180 mg L(-1) for the hydroponic and filter paper methods, respectively. Lettuce was less sensitive than daphnids to wastewaters, but the root elongation response appears to be wastewater-specific and is especially sensitive for detecting the presence of fluorine. The new hydroponic test thus provides many practical advantages, especially in terms of cost and time-effectiveness requiring only a well plate, a small volume of distilled water and short exposure period; furthermore, no specialist expertise is required. The method is simpler than the conventional EPA technique in not using filter paper which can influence the sensitivity of the test. Additionally, plant seeds have a long shelf-life and require little or no maintenance. Copyright © 2015 Elsevier Inc. All rights reserved.
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Nutrient supply of plants in aquaponic systems
Bittsánszky, András; Uzinger, Nikolett; Gyulai, Gábor; Mathis, Alex; Junge, Ranka; Villarroel, Morris; Kotzen, Benzion; Komives, Tamas
2016-01-01
In this preliminary article we present data on plant nutrient concentrations in aquaponic systems, and compare them to nutrient concentrations in “standard” hydroponic solutions. Our data shows that the nutrient concentrations supplied by the fish in aquaponic system are significantly lower for most nutrients, compared to hydroponic systems. Nevertheless, plants do thrive in solutions that have lower nutrient levels than “standard” hydroponic solutions. This is especially true for green leafy...
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Martins, C.I.; Eding, E.H.; Verreth, J.A.J.
2011-01-01
As a consequence of water re-use and high stocking densities, Recirculating Aquaculture Systems (RAS) may lead to an accumulation of substances released by the fish into the water, e.g. cortisol and alarm pheromones. This study investigated the effect of stressing fish on the feeding motivation of
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Common “off-flavors” in fish cultured in water recirculation aquaculture systems (WRAS) are “earthy” and “musty” due to the presence of the off-flavor metabolites geosmin and 2-methylisoborneol (MIB), respectively. Previously, ozone addition has been applied to WRAS at relatively low doses to break...
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A recirculating stream aquarium for ecological studies.
Gordon H. Reeves; Fred H. Everest; Carl E. McLemore
1983-01-01
Investigations of the ecological behavior of fishes often require studies in both natural and artificial stream environments. We describe a large, recirculating stream aquarium and its controls, constructed for ecological studies at the Forestry Sciences Laboratory in Corvallis.
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International Nuclear Information System (INIS)
Suzuki, Mitsuhiro; Tasaka, Kanji; Yonomoto, Taisuke; Anoda, Yoshinari; Kumamaru, Hiroshige; Nakamura, Hideo; Murata, Hideo; Shiba, Masayoshi; Iriko, Masanori.
1985-03-01
This report presents the experimental results of RUN 962 and RUN 963 in ROSA-III program, which are 50 and 100 % break LOCA tests at the BWR recirculation pump discharge line, respectively. The ROSA-III test facility simulates a volumetrically scaled (1/424) BWR system and has four half-length electrically heated fuel bundles, two active recirculation loops, three types of ECCSs and steam and feedwater systems. The experimental data of RUN 962 and RUN 963 were compared with those of RUN 961, a 200 % discharge line break test to study the break area effects on the transient thermal hydraulic phenomena. The least flow areas at the jet pump drive nozzles and recirculation pump discharge nozzle in the broken recirculation loop limitted the discharge flows from the pressure vessel and the depressurization rate in the 100 and 200 % break tests, whereas the least flow area at break nozzle limitted the depressurization rate in the 50 % break test. The highest PCT was observed in the 50 % break test among the three tests. (author)
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Directory of Open Access Journals (Sweden)
Luiz V. E. Villela Junior
2003-04-01
Full Text Available Objetivando-se o aproveitamento do efluente de biodigestor no cultivo hidropônico do meloeiro, desenvolveu-se a presente pesquisa. O experimento foi conduzido no Departamento de Engenharia Rural da Faculdade de Ciências Agrárias e Veterinárias da UNESP, campus de Jaboticabal, cultivando-se o meloeiro (Cucumis melo L. cv. Bonus nº 2. O delineamento experimental utilizado foi em blocos casualisados, com 6 repetições, cujos tratamentos foram: 1 cultivo hidropônico em sistema fechado tipo NFT ("nutrient film technique" com uso de solução nutritiva organo-mineral (biofertilizante com complementação mineral; 2 cultivo hidropônico em sistema fechado tipo NFT, com uso de solução nutritiva 100% mineral; 3 cultivo hidropônico em sistema aberto, com substrato e solução nutritiva organo-mineral e 4 cultivo hidropônico em sistema aberto, com substrato e solução nutritiva 100% mineral. O biofertilizante e o substrato foram obtidos a partir do efluente de biodigestor, produzido com estrume bovino. As plantas cultivadas no tratamento 1 tiveram desenvolvimento prejudicado, devido ao acúmulo de partículas sólidas junto ao sistema radicular. O tratamento 2 proporcionou às plantas desenvolvimento vegetativo mais rápido e maior produtividade. Os frutos produzidos no tratamento 2 apresentaram maior peso, formato mais alongado e maior teor de sólidos solúveis totais. A substituição parcial de adubos minerais por biofertilizante mostrou-se possível em sistema hidropônico aberto com substrato.With the objective to use effluent of biodigestor in the hydroponic cultivation, an experiment was conducted in the Department of Rural Engineering Faculty of Agricultural and Veterenary Sciences of UNESP, campus of Jaboticabal where a melon crop (Cucumis melo L. cv. Bonus nº 2 was cultivated. The experimental design used was a randomized blocks, with 6 repetitions and the treatments studied were: 1 hydroponic cultivation in closed system type NFT
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International Nuclear Information System (INIS)
Park, Jong Woon; Kim, Chang Hyun
2006-01-01
A primary safety issue regarding long-term recirculation core cooling following a LOCA (Loss of Coolant Accident) is that LOCA-generated debris may be transported to the recirculation sump screen, resulting in adverse blockage on the sump screen and deterioration of available NPSH (Net Positive Suction Head) of ECCS (Emergency Core Cooling System). USNRC identified this as Generic Safety Issue (GSI) 191 and issued the Generic Letter 04-02 to resolve the issue. The GL required that all PWR owners perform an engineering assessment of their containment recirculation sumps to ensure they will not suffer from excessive blockage. The guidance report (GR) for PWR sump performance evaluation has been developed by NEI (Nuclear Energy Institute) and approved by the USNRC. In Korea, Korea Hydro and Nuclear Power Company (KHNP) is performing the assessment of Kori unit 1 and planning for remaining plants in the near future. The objective of the assessment is to derive required plant modifications including insulation, sump screen, etc. To derive the cost-effective modification items, we have to get insight on the parametric effects of plant conditions and design. Therefore, the general effects of debris source, containment environments and debris interceptor on the performance of ECCS recirculation sump with respect to head loss are parametrically investigated
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International Nuclear Information System (INIS)
Khan, E.U.; Rector, D.R.
1982-01-01
Reactor fuel and blanket assemblies within a Liquid Metal Fast Breeder Reactor (LMFBR) can be subjected to severe radial heat flux gradients. At low-flow conditions, with power-to-flow ratios of nearly the same magnitude as design conditions, buoyancy forces cause flow redistribution to the side of a bundle with the higher heat generation rate. Recirculation of fluid within a rod bundle can occur during a natural convection transient because of the combined effect of flow coastdown and buoyancy-induced redistribution. An important concern is whether recirculation leads to high coolant temperatures. For this reason, the COBRA-WC code was developed with the capability of modeling recirculating flows. Experiments have been conducted in a 2 x 6 rod bundle for flow and power transients to study recirculation in the mixed-convection (forced cooled) and natural-convection regimes. The data base developed was used to validate the recirculation module in the COBRA-WC code. COBRA-WC code calculations were made to predict flow and temperature distributions in a typical LMFBR blanket assembly for the worst-case, natural-circulation transient
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Rossinskyi, Volodymyr
2018-02-01
The biological wastewater treatment technologies in anoxic and aerobic bioreactors with recycle of sludge mixture are used for the effective removal of organic compounds from wastewater. The change rate of sludge mixture recirculation between bioreactors leads to a change and redistribution of concentrations of organic compounds in sludge mixture in bioreactors and change hydrodynamic regimes in bioreactors. Determination of the coefficient of internal recirculation of sludge mixture between bioreactors is important for the choice of technological parameters of biological treatment (wastewater treatment duration in anoxic and aerobic bioreactors, flow capacity of recirculation pumps). Determination of the coefficient of internal recirculation of sludge mixture requires integrated consideration of hydrodynamic parameter (flow rate), kinetic parameter (rate of oxidation of organic compounds) and physical-chemical parameter of wastewater (concentration of organic compounds). The conducted numerical experiment from the proposed mathematical equations allowed to obtain analytical dependences of the coefficient of internal recirculation sludge mixture between bioreactors on the concentration of organic compounds in wastewater, the duration of wastewater treatment in bioreactors.
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Preliminary investigations of the rhizosphere nature of hydroponically grown lettuces
Antunes, Inês; Paille, Christel; Lasseur, Christophe
Due to capabilities of current launchers, future manned exploration beyond the Earth orbit will imply long journeys and extended stays on planet surfaces. For this reason, it is of a great importance to develop a Regenerative Life Support System that enables the crew to be, to a very large extent, metabolic consumables self-sufficient. In this context, the European Space Agency, associated with a scientific and engineering con-sortium, initiated in 1989 the Micro-Ecological Life Support System Alternative (MELiSSA) project. This concept, inspired on a terrestrial ecosystem (i.e. a lake), comprises five intercon-nected compartments inhabited by micro-organisms and higher-plants aiming to produce food, fresh water, and oxygen from organic waste, carbon dioxide, and minerals. Given the important role of the higher-plant compartment for the consumption of carbon dioxide and the production of oxygen, potable water, and food, it was decided to study the microbial communities present in the root zone of the plants (i.e. the rhizosphere), and their synergistic and antagonistic influences in the plant growth. This understanding is important for later investigations concerning the technology involved in the higher plant compartment, since the final goal is to integrate this compartment inside the MELiSSA loop and to guarantee a healthy and controlled environment for the plants to grow under reduced-gravity conditions. To perform a preliminary assessment of the microbial populations of the root zone, lettuces were grown in a hydroponic system and their growth was characterized in terms of nutrient uptake, plant diameter, and plant wet and dry weights. In parallel, the microbial population, bacteria and fungi, present in the hydroponic medium and also inside and outside the roots were analyzed in terms of quantity and nature. The goal of this presentation is to give a preliminary review in the plant root zone of the micro-organisms communities and as well their proportions
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Directory of Open Access Journals (Sweden)
Velasco José
2016-11-01
Full Text Available In an initial phase, a trial with growing hydroponic lettuce was installed, considering all the macro and micronutrients necessary and sufficient for growth, where treatments were applied with and without liquid humus, combining separately with inoculation of mycorrhiza and bacteria Bacillus type, observing that the significant effect by the individual use of the liquid humus is up to 50%. Subsequently, in a Phase II, different doses of only liquid humus with only mycorrhizae were evaluated, where applying of 8 L of pure liquid humus per 36 L of stock solution of hydroponics crop, the plants had the highest weight (40.7%, the highest altitude (39% and the longest (42% compared to the witness. Instead, the combination of liquid humus plus mycorrhizal is 6 L per 36 L of stock solution, which stimulated a further growth and weight of growing lettuce in hydroponics conditions. In general, the use of liquid humus decreased the production time from 60 to 52 days.
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Two-phase flow phenomena in broken recirculation line of BWR
International Nuclear Information System (INIS)
Kato, Masami; Arai, Kenji; Narabayashi, Tadashi; Amano, Osamu.
1986-01-01
When a primary recirculation line of BWR is ruptured, a primary recirculation pump may be subjected to very high velocity two-phase flow and its speed may be accelerated by this flow. It is important for safety evaluation to estimate the pump behavior during blowdown. There are two problems involved in analyzing this behavior. One problem concerns the pump characteristics under two-phase flow. The other involves the two-phase conditions at the pump inlet. If the rupture occurs at a suction side of the pump, choking is considered to occur at a broken jet pump nozzle. Then, a void fraction becomes larger downstream from the jet pump nozzle and volumetric flow through the pump will be very high. However, there is little experimental data available on two-phase flow downstream from a choking plane. Blowdown tests were performed using a simulated broken recirculation line and measured data were analyzed by TRAC-PlA. Analytical results agreed with measured data. (author)
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Multi-point optimization of recirculation flow type casing treatment in centrifugal compressors
Tun, Min Thaw; Sakaguchi, Daisaku
2016-06-01
High-pressure ratio and wide operating range are highly required for a turbocharger in diesel engines. A recirculation flow type casing treatment is effective for flow range enhancement of centrifugal compressors. Two ring grooves on a suction pipe and a shroud casing wall are connected by means of an annular passage and stable recirculation flow is formed at small flow rates from the downstream groove toward the upstream groove through the annular bypass. The shape of baseline recirculation flow type casing is modified and optimized by using a multi-point optimization code with a metamodel assisted evolutionary algorithm embedding a commercial CFD code CFX from ANSYS. The numerical optimization results give the optimized design of casing with improving adiabatic efficiency in wide operating flow rate range. Sensitivity analysis of design parameters as a function of efficiency has been performed. It is found that the optimized casing design provides optimized recirculation flow rate, in which an increment of entropy rise is minimized at grooves and passages of the rotating impeller.
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International Nuclear Information System (INIS)
Rivera Mendez, Yurany Dayanna; Moreno Chacon, Andres Leonardo; Romero, Hernan Mauricio
2013-01-01
The interspecific hybrid, Elaeis oleifera x Elaeis guineensis (OxG) is an alternative for improving the competitiveness and sustainability of the Latin American oil palm agro-industry, because of its partial resistance to some lethal diseases and also because of the high quality of its oil. A comparative characterization was conducted of the physiological and biochemical performance of seedlings of six OxG hybrids grown in hydroponics. Gas exchange, vegetative growth, protein, sugar and photosynthetic pigment content, and antioxidant system activity were determined. With the exception of gas exchange, the other variables showed significant differences between materials. The U1273 and U1737 materials showed greater vegetative growth with no expression of biochemical traits, while the U1914 and U1990 materials showed high levels of reducing and total sugars, photosynthetic pigments, and antioxidant system activities, characteristics that could confer them adaptation to stress conditions. With the standardized hydroponics technique, the optimal conditions for the growth of seedlings were ensured, the differences between materials were established, and so those with promising features from the physiological and biochemical standpoint were identified. Finally, it could be used to study in a simple, fast, clean and inexpensive way, the effect of levels and sources of mineral nutrients on the growth and development of oil palm.
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Energy Technology Data Exchange (ETDEWEB)
Analyan, V L; Sarkisyan, G A [AN Armyanskoj SSR, Erevan. Inst. Agrokhimicheskikh Problem i Gidroponiki
1981-01-01
Accumulation of /sup 90/Sr in plants under the conditions of soil and hydroponic cultures from the viewpoint of the possibility of obtaining ''pure'' vegetable production has been studied. Predominant absorption of /sup 90/Sr by soil plants as compared with calcium is shown. In the course of using the hydroponic cultivation method predominant radiostrontium absorption has been manifested to all investigated nuclides including potassium. The accumulation coefficients analysis has shown that among soil plants the first place is occupied by potassium, while the /sup 90/Sr coefficients are greater than Ca on hydroponics, where the true, not distorted by soil sorption processes absorptive plant capacity has been manifested, the first places in the series are occupied by /sup 90/Sr and K, then come Ca and Mg.
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International Nuclear Information System (INIS)
Ghalachyan, L.M.; Kocharyan, K.A.; Aristakesyan, A.A.; Asatryan, A.Z.
2015-01-01
Peculiarities of some heavy metals (HM), (Mn, Ni, Ti, V, Co, Cu, Pb, Mo, Cr, Zr) accumulation have been studied in spice herbs (basil, dill, coriander, savory) grown in open-air hydroponics and soil cultures of the Ararat Valley. It turned out that the amount of HM content in spice herbs grown in open-air hydroponic conditions was less than in the ones grown in soil conditions. The content of Pb and Ni in spice herbs exceeded the allowed concentration limits (ACL), especially in soil plants. Practical recommendations on obtaining ecologically safe agricultural products have been prepared. The biotechnological hydroponics method of producing spice herbs in the Ararat Valley is ecologically more beneficial than the soil method. Practical proposals of obtaining ecologically safe agricultural products have been developed
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Optical dating of the hydroponic farm at Korea
International Nuclear Information System (INIS)
Hong, D.G.; Galloway, R.B.; Kim, M.J.; Park, S.B.
2003-01-01
For age determination, the single aliquot regenerative-dose (SAR) method was applied to quartz from archaeological materials, using luminescence stimulated by blue light. The quartz samples were extracted from sediment from the hydroponic farm related to rice cultivation in an area of archaeological interest in Buyeo, south of Seoul. The optically stimulated luminescence (OSL) dates obtained offered good agreement with the ages derived by typological assessment and 14 C ages. These ages should contribute significantly to interpretation of the history of rice cultivation in Korea. (author)
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Previous research and experience has linked elevated dissolved carbon dioxide (CO2) to reduced growth performance, poor feed conversion, and a variety of health issues in farm-raised fish, including Atlantic salmon Salmo salar. Supplemental control measures in water recirculation aquaculture systems...
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Pelletron-based MeV-range electron beam recirculation
Crawford, A C; Sharapa, A N; Shemyakin, A
1999-01-01
In this paper we describe the successful recirculation of a DC electron beam at energies 1-1.5 MeV and currents up to 0.7 A with typical relative losses of 5-20x10 sup - sup 6. Currents of 200 mA were maintained for periods of up to five hours without a single breakdown. We found that the aperture-limiting diaphragm in the gun anode significantly increased the stability of the recirculation. We also found that the stability depended strongly on vacuum pressure in the beamline. The performance of the collector with transverse magnetic fields was found to be adequate for beam currents up to 0.6 A, which is in agreement with our low-energy bench test results. (author)
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Nakano, Jinichiro; Bennett, James P.; Nakano, Anna
2017-12-12
Embodiments relate to systems and methods for regenerating and recirculating a CO, H.sub.2 or combinations thereof utilized for metal oxide reduction in a reduction furnace. The reduction furnace receives the reducing agent, reduces the metal oxide, and generates an exhaust of the oxidized product. The oxidized product is transferred to a mixing vessel, where the oxidized product, a calcium oxide, and a vanadium oxide interact to regenerate the reducing agent from the oxidized product. The regenerated reducing agent is transferred back to the reduction furnace for continued metal oxide reductions.
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The effect of sludge recirculation rate on a UASB-digester treating domestic sewage at 15 °C
Zhang, L.; Hendrickx, T.L.G.; Kampman, C.; Zeeman, G.; Temmink, B.G.; Weiguang Li,; Buisman, C.J.N.
2012-01-01
The anaerobic treatment of low strength domestic sewage at low temperature is an attractive and important topic at present. The upflow anaerobic sludge bed (UASB)-digester system is one of the anaerobic systems to challenge low temperature and concentrations. The effect of sludge recirculation rate
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CFD modeling of hydro-biochemical behavior of MSW subjected to leachate recirculation.
Feng, Shi-Jin; Cao, Ben-Yi; Li, An-Zheng; Chen, Hong-Xin; Zheng, Qi-Teng
2018-02-01
The most commonly used method of operating landfills more sustainably is to promote rapid biodegradation and stabilization of municipal solid waste (MSW) by leachate recirculation. The present study is an application of computational fluid dynamics (CFD) to the 3D modeling of leachate recirculation in bioreactor landfills using vertical wells. The objective is to model and investigate the hydrodynamic and biochemical behavior of MSW subject to leachate recirculation. The results indicate that the maximum recirculated leachate volume can be reached when vertical wells are set at the upper middle part of a landfill (H W /H T = 0.4), and increasing the screen length can be more helpful in enlarging the influence radius than increasing the well length (an increase in H S /H W from 0.4 to 0.6 results in an increase in influence radius from 6.5 to 7.7 m). The time to reach steady state of leachate recirculation decreases with the increase in pressure head; however, the time for leachate to drain away increases with the increase in pressure head. It also showed that methanogenic biomass inoculum of 1.0 kg/m 3 can accelerate the volatile fatty acid depletion and increase the peak depletion rate to 2.7 × 10 -6 kg/m 3 /s. The degradation-induced void change parameter exerts an influence on the processes of MSW biodegradation because a smaller parameter value results in a greater increase in void space.
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Further development of the V-code for recirculating linear accelerator simulations
Energy Technology Data Exchange (ETDEWEB)
Franke, Sylvain; Ackermann, Wolfgang; Weiland, Thomas [Institut fuer Theorie Elektromagnetischer Felder, Technische Universitaet Darmstadt (Germany); Eichhorn, Ralf; Hug, Florian; Kleinmann, Michaela; Platz, Markus [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany)
2011-07-01
The Superconducting Darmstaedter LINear Accelerator (S-DALINAC) installed at the institute of nuclear physics (IKP) at TU Darmstadt is designed as a recirculating linear accelerator. The beam is first accelerated up to 10 MeV in the injector beam line. Then it is deflected by 180 degrees into the main linac. The linac section with eight superconducting cavities is passed up to three times, providing a maximal energy gain of 40 MeV on each passage. Due to this recirculating layout it is complicated to find an accurate setup for the various beam line elements. Fast online beam dynamics simulations can advantageously assist the operators because they provide a more detailed insight into the actual machine status. In this contribution further developments of the moment based simulation tool V-code which enables to simulate recirculating machines are presented together with simulation results.
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Directory of Open Access Journals (Sweden)
John Clifford Sutton
2006-09-01
Full Text Available The etiology and epidemiology of Pythium root rot in hydroponically-grown crops are reviewed with emphasis on knowledge and concepts considered important for managing the disease in commercial greenhouses. Pythium root rot continually threatens the productivity of numerous kinds of crops in hydroponic systems around the world including cucumber, tomato, sweet pepper, spinach, lettuce, nasturtium, arugula, rose, and chrysanthemum. Principal causal agents include Pythium aphanidermatum, Pythium dissotocum, members of Pythium group F, and Pythium ultimum var. ultimum. Perspectives are given of sources of initial inoculum of Pythium spp. in hydroponic systems, of infection and colonization of roots by the pathogens, symptom development and inoculum production in host roots, and inoculum dispersal in nutrient solutions. Recent findings that a specific elicitor produced by P. aphanidermatum may trigger necrosis (browning of the roots and the transition from biotrophic to necrotrophic infection are considered. Effects on root rot epidemics of host factors (disease susceptibility, phenological growth stage, root exudates and phenolic substances, the root environment (rooting media, concentrations of dissolved oxygen and phenolic substances in the nutrient solution, microbial communities and temperature and human interferences (cropping practices and control measures are reviewed. Recent findings on predisposition of roots to Pythium attack by environmental stress factors are highlighted. The commonly minor impact on epidemics of measures to disinfest nutrient solution as it recirculates outside the crop is contrasted with the impact of treatments that suppress Pythium in the roots and root zone of the crop. New discoveries that infection of roots by P. aphanidermatum markedly slows the increase in leaf area and whole-plant carbon gain without significant effect on the efficiency of photosynthesis per unit area of leaf are noted. The platform of
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Impact of capillary rise and recirculation on simulated crop yields
Kroes, Joop; Supit, Iwan; van Dam, Jos; van Walsum, Paul; Mulder, Martin
2018-05-01
Upward soil water flow is a vital supply of water to crops. The purpose of this study is to determine if upward flow and recirculated percolation water can be quantified separately, and to determine the contribution of capillary rise and recirculated water to crop yield and groundwater recharge. Therefore, we performed impact analyses of various soil water flow regimes on grass, maize and potato yields in the Dutch delta. Flow regimes are characterized by soil composition and groundwater depth and derived from a national soil database. The intermittent occurrence of upward flow and its influence on crop growth are simulated with the combined SWAP-WOFOST model using various boundary conditions. Case studies and model experiments are used to illustrate the impact of upward flow on yield and crop growth. This impact is clearly present in situations with relatively shallow groundwater levels (85 % of the Netherlands), where capillary rise is a well-known source of upward flow; but also in free-draining situations the impact of upward flow is considerable. In the latter case recirculated percolation water is the flow source. To make this impact explicit we implemented a synthetic modelling option that stops upward flow from reaching the root zone, without inhibiting percolation. Such a hypothetically moisture-stressed situation compared to a natural one in the presence of shallow groundwater shows mean yield reductions for grassland, maize and potatoes of respectively 26, 3 and 14 % or respectively about 3.7, 0.3 and 1.5 t dry matter per hectare. About half of the withheld water behind these yield effects comes from recirculated percolation water as occurs in free-drainage conditions and the other half comes from increased upward capillary rise. Soil water and crop growth modelling should consider both capillary rise from groundwater and recirculation of percolation water as this improves the accuracy of yield simulations. This also improves the accuracy of the
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Environmental impacts of urban hydroponics in Europe: a case study in Lyon
DEFF Research Database (Denmark)
Romeo, Daina; Vea, Eldbjørg Blikra; Thomsen, Marianne
2018-01-01
a life cycle perspective. The results show that the hydroponic farm performs better than cultivations in heated greenhouses, and similarly to conventional open field farms. Moreover, the source of the electricity input is a determinant factor that, if carbon neutral (e.g. wind energy) allows vertical...
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Directory of Open Access Journals (Sweden)
Dalva Paulus
2008-03-01
,50 x 0,25 m pode ser recomendada para o cultivo hidropônico de Mentha arvensis.The mint (Mentha arvensis L. is an aromatic plant that produces essential oil with high menthol concentration. For the hydroponic cultivation of vegetables and fruits, a great number of recommended formulas exist; however, little information exists about hydroponic solutions for mint. The goal of this work was to evaluate a nutrient solution for the mint cultivation in hydroponic system. Two experiments were carried out from October to December, 2004. For the field experiment, transplants were obtained from cuttings and produced in organic mineral substrates (plantmax®. Later they were transplanted in seed beds of 5.00 m length and 1.00 m width, spacings of 0.60 x 0.30 m. For the hydroponic system NFT, seedlings were obtained from cuttings and planted in phenolic foam where they stayed during 18 days. After that, they were transplanted to a production canal. The experimental design was a 2x2 factorial (nutrient solution concentrations x spacings. The hydroponic solution with 100% concentration in transplant and 50% replacement when the electric condutivity decreased 50% of the initial value and 0.5 x 0.25 m spacings resulted in the highest concentration of essential oil (0.60 mL 100 g-1 fresh leaves, menthol (82,4% and total dry matter (45 g plant-1. In hydroponic system the yield of dry matter and content of essential oil was higher than under soil conditions 27 g planta-1 of dry matter, concentration oil 0.53 mL 100 g-1 and 64,43% of menthol. The hydroponic solution with 100% concentration in transplant and 50% replacement when the electric condutivity decreased 50% of the initial value and 0.5 x 0.25 m spacing can be recommended for the cultivation of mint in hydroponic solution.
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Development of FET-switched induction accelerator cells for heavy-ion fusion recirculators
International Nuclear Information System (INIS)
Newton, M.A.; Cravey, W.R.; Hawkins, S.A.; Kirbie, H.C.; Ollis, C.W.
1993-01-01
The ''recirculator,'' a recirculating heavy-ion induction accelerator, has been identified as a promising approach for an inertial fusion driver. One of the technical challenges to building a recirculator is the requirement for a modulator that can drive the induction accelerator cells at repetition rates ≥ 100 kHz with variable pulse width and pulse repetition rate capability. A high repetition rate modulator and cell is presently being developed for use on a proposed heavy-ion recirculator. The goal is to develop an array of field-effect transistors to switch 5 kV, 1 μs pulses onto a Metglas induction core at pulse rates exceeding 100 kHz. Each transistor in the array is driven by a fiber-optic isolated gate signal that is powered by a dc/dc converter. The circuit architecture provides for core reset between pulses and produces bursts of pulses that are variable in pulse width and prf. The transistor switching array, energy storage capacitors, reset circuit and cell core are all combined into a single compact, low-impedance package. Progress of this development work will be presented with supporting data
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Effect of gas recirculation in a pilot-scale cow-dung digester
Energy Technology Data Exchange (ETDEWEB)
Pathak, B N; Kulkarni, D N; Dave, J M; Mohanrao, G J
1965-01-01
Laboratory experiments showed that if, during anaerobic digestion of cow manure, the contents of the digestion vessel are mixed by recirculating gas, nearly twice as much gas is produced, and there is less variation in the temperature of the digesting liquor, the pH value, the carbon-dioxide content of the gas, and the reduction in volatile matter. Results of experiments during which gas was recirculated for periods ranging from 0 to 4 hours are tabulated.
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Qu, Youpeng
2012-02-01
A recirculation microbial desalination cell (rMDC) was designed and operated to allow recirculation of solutions between the anode and cathode chambers. This recirculation avoided pH imbalances that could inhibit bacterial metabolism. The maximum power density was 931±29mW/m 2 with a 50mM phosphate buffer solution (PBS) and 776±30mW/m 2 with 25mM PBS. These power densities were higher than those obtained without recirculation of 698±10mW/m 2 (50mM PBS) and 508±11mW/m 2 (25mM PBS). The salt solution (20g/L NaCl) was reduced in salinity by 34±1% (50mM) and 37±2% (25mM) with recirculation (rMDC), and by 39±1% (50mM) and 25±3% (25mM) without recirculation (MDC). These results show that electrolyte recirculation using an rMDC is an effective method to increase power and achieve efficient desalination by eliminating pH imbalances. © 2011 Elsevier Ltd.
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Decoupled systems on trial: Eliminating bottlenecks to improve aquaponic processes.
Directory of Open Access Journals (Sweden)
Hendrik Monsees
Full Text Available In classical aquaponics (coupled aquaponic systems, 1-loop systems the production of fish in recirculating aquaculture systems (RAS and plants in hydroponics are combined in a single loop, entailing systemic compromises on the optimal production parameters (e.g. pH. Recently presented decoupled aquaponics (2-loop systems have been awarded for eliminating major bottlenecks. In a pilot study, production in an innovative decoupled aquaponic system was compared with a coupled system and, as a control, a conventional RAS, assessing growth parameters of fish (FCR, SGR and plants over an experimental period of 5 months. Soluble nutrients (NO3--N, NO2--N, NH4+-N, PO43-, K+, Ca2+, Mg2+, SO42-, Cl2- and Fe2+, elemental composition of plants, fish and sludge (N, P, K, Ca, Mg, Na, C, abiotic factors (temperature, pH, oxygen, and conductivity, fertilizer and water consumption were determined. Fruit yield was 36% higher in decoupled aquaponics and pH and fertilizer management was more effective, whereas fish production was comparable in both systems. The results of this pilot study clearly illustrate the main advantages of decoupled, two-loop aquaponics and demonstrate how bottlenecks commonly encountered in coupled aquaponics can be managed to promote application in aquaculture.
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Decoupled systems on trial: Eliminating bottlenecks to improve aquaponic processes.
Monsees, Hendrik; Kloas, Werner; Wuertz, Sven
2017-01-01
In classical aquaponics (coupled aquaponic systems, 1-loop systems) the production of fish in recirculating aquaculture systems (RAS) and plants in hydroponics are combined in a single loop, entailing systemic compromises on the optimal production parameters (e.g. pH). Recently presented decoupled aquaponics (2-loop systems) have been awarded for eliminating major bottlenecks. In a pilot study, production in an innovative decoupled aquaponic system was compared with a coupled system and, as a control, a conventional RAS, assessing growth parameters of fish (FCR, SGR) and plants over an experimental period of 5 months. Soluble nutrients (NO3--N, NO2--N, NH4+-N, PO43-, K+, Ca2+, Mg2+, SO42-, Cl2- and Fe2+), elemental composition of plants, fish and sludge (N, P, K, Ca, Mg, Na, C), abiotic factors (temperature, pH, oxygen, and conductivity), fertilizer and water consumption were determined. Fruit yield was 36% higher in decoupled aquaponics and pH and fertilizer management was more effective, whereas fish production was comparable in both systems. The results of this pilot study clearly illustrate the main advantages of decoupled, two-loop aquaponics and demonstrate how bottlenecks commonly encountered in coupled aquaponics can be managed to promote application in aquaculture.
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International Nuclear Information System (INIS)
Shirong Tang; Xiaochang Wang
2002-01-01
Both Indian mustard and sunflower were grown in a hydroponic solution treated with different concentration activities of 134 Cs or with different amounts of copper or with both in order to investigate the interaction between copper and radiocesium. It was found that 134 Cs activity concentration applied in the nutrient solution exerted more influence on the uptake and translocation of copper by Indian mustard than by sunflower. Indian mustard grown in hydroponic solution containing certain levels of copper and being treated with higher 134 Cs activity concentration showed higher uptake of copper than sunflower. However, in the case of root copper concentrations, sunflower showed significantly higher copper immobilization by roots than Indian mustard. It was also found that the presence of copper the the hydroponic solution did modify radiocesium uptake by both species. The application of 1 mg/l in the growth medium could greatly increase the uptake of 134 Cs by both species. With 3 mg/l concentration of copper amended to the solution, the accumulation of 134 Cs by both species was decreased compared to the 1 mg/l copper treatment. These lines of evidence show that there is stronger interaction between copper and radiocesium in Indian mustard than in sunflower during the root uptake through nutrient solution. (author)
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Directory of Open Access Journals (Sweden)
M Gullian-Klanian
2013-03-01
Full Text Available The aim of this paper was evaluate the performance of Nile tilapia fingerlings (Oreochromis niloticus raised at hyper intensive stocking density in a recirculating aquaculture system (RAS with minimum water replacing. The experimental system was performed in a single-batch nursery system to obtain 50 g fish size in 60 days. Fish (2.07 ± 0.04 g were stocked in triplicate at 400 (T1, 500 (T2 and 600 (T3 fish m-3 (0.84, 1.05, 1.22 kg m-3. RAS functioned with 12,000 L of recirculating water and 252 L day-1of water replacing (2.1% daily. The efficiency of the biofilter for removing the total ammonia nitrogen (TAN was 48 ± 12.5 mg L-1. Stocking density did not affect significantly the survival (89.5 to 93.6%. The growth rate of T1 (0.96 g day-1; 5.01% day-1 and T2 (0.92 g day-1; 4.95 % day-1 was significantly higher than T3 (0.83 g day-1; 4.80% day-1. The specific growth rate (SGR of T1 was 41% influenced by temperature. For T2 and T3 the SGR were influenced by the variation of dissolved oxygen (DO that explained 47 and 44% of the fish weight variation, respectively. The SGR from T3 was also affected by the concentration of ammonia nitrogen (31%. The high stocking density affected the overall size of fish and the size homogeneity, but had no negative effect on the length-weight relationship (L-W. Data support the conclusion that fingerling stocked at 400 and 500 fish m-3 shows high performance during 9-weeks when the biomass not exceed 37 kg m-3. At this time fish have reached the desired final nursery weight (50 g for transfer to grow-out facilities.
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International Nuclear Information System (INIS)
Lefter, J.
1992-01-01
James A. FitzPatrick recirculation pumps are vertical units consisting of General Electric 5,300 hp variable speed motors driving Byron Jackson Pumps. Speed range is from 400 rpm at 20% reactor power to 1,480 rpm at 100% power. Full speed pump output is 42,500 gpm at 530 ft. head. This paper describes the vibration monitoring system. The design of this vibration monitoring system took about five months and was installed during plant refueling outage between February and May 1990. The objectives of this project were as follows: (1) document and assess the mechanical condition of each RRP during plant startup normal operation and shutdown; (2) identify any areas of operation that might be harmful to the unit; (3) perform impact testing of the proximity probe brackets to determine if any bracket resonances existed in the 0 to 20 times operating speed region (0 to 20X); (4) define and recommend Acceptance Regions in the TDM system
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Investigation of flashing de-aeration with and without recirculation
International Nuclear Information System (INIS)
Kjellstroem, B.; Toecksberg, B.
1977-06-01
A series of experiments with flashing de-areation has been carried out at the institute of Thermal Energytechnology of the Royal Institute of Technology in Stockholm. The results of the experiments with flashing de-areation without recirculation of the condensate show very low contents of dissolved oxygen in the de-aerated water. The results indicate that the de-aeration process is independent of the pressure. De-aeration efficiencies over 99 percent were measured. The continued experiments with recirculation of the condensate show a considerably deteriorated de-aeration performance together with a marked pressure dependency. A simple theoretical model has been formulated which explains these results. Comparisons between the experimental data and calculations with this model indicate that a conservative estimation of the oxygen content of the outgoing water can be obtained if the oxygen content of the recirculated condensate is calculated for the partial pressure of noncondensible gases equal to the total pressure in the condensor. It seems also possible to estimate a lower limit for the oxygen content of the outgoing water. The range of oxygen content between those limits is about a factor of 10 for the conditions investigated. Further studies of the uptake of oxygen during condensation seem necessary if a more accurate prediction is desired
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Root uptake and translocation of perfluorinated alkyl acids by three hydroponically grown crops
Felizeter, S.; McLachlan, M.S.; de Voogt, P.
2014-01-01
Tomato, cabbage, and zucchini plants were grown hydroponically in a greenhouse. They were exposed to 14 perfluorinated alkyl acids (PFAAs) at four different concentrations via the nutrient solution. At maturity the plants were harvested, and the roots, stems, leaves, twigs (where applicable), and
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Hartig' net formation of Tricholoma vaccinum-spruce ectomycorrhiza in hydroponic cultures.
Henke, Catarina; Jung, Elke-Martina; Kothe, Erika
2015-12-01
For re-forestation of metal-contaminated land, ectomycorrhizal trees may provide a solution. Hence, the study of the interaction is necessary to allow for comprehensive understanding of the mutually symbiotic features. On a structural level, hyphal mantle and the Hartig' net formed in the root apoplast are essential for plant protection and mycorrhizal functioning. As a model, we used the basidiomycete Tricholoma vaccinum and its host spruce (Picea abies). Using an optimized hydroponic cultivation system, both features could be visualized and lower stress response of the tree was obtained in non-challenged cultivation. Larger spaces in the apoplasts could be shown with high statistical significance. The easy accessibility will allow to address metal stress or molecular responses in both partners. Additionally, the proposed cultivation system will enable for other experimental applications like addressing flooding, biological interactions with helper bacteria, chemical signaling, or other biotic or abiotic challenges relevant in the natural habitat.
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Thermodynamic Model for Updraft Gasifier with External Recirculation of Pyrolysis Gas
Directory of Open Access Journals (Sweden)
Fajri Vidian
2016-01-01
Full Text Available Most of the thermodynamic modeling of gasification for updraft gasifier uses one process of decomposition (decomposition of fuel. In the present study, a thermodynamic model which uses two processes of decomposition (decomposition of fuel and char is used. The model is implemented in modification of updraft gasifier with external recirculation of pyrolysis gas to the combustion zone and the gas flowing out from the side stream (reduction zone in the updraft gasifier. The goal of the model obtains the influences of amount of recirculation pyrolysis gas fraction to combustion zone on combustible gas and tar. The significant results of modification updraft are that the increases amount of recirculation of pyrolysis gas will increase the composition of H2 and reduce the composition of tar; then the composition of CO and CH4 is dependent on equivalence ratio. The results of the model for combustible gas composition are compared with previous study.
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Bachli, Esther B; Schuepbach, Reto A; Maggiorini, Marco; Stocker, Reto; Müllhaupt, Beat; Renner, Eberhard L
2007-05-01
Numerous, mostly uncontrolled, observations suggest that artificial liver support with the Molecular Adsorbent Recirculating System (MARS) improves pathophysiologic sequelae and outcome of acute and acute-on-chronic liver failure. MARS is felt to be safe, but extracorporeal circuits may activate coagulation. To assess the frequency of and risk factors for activation of coagulation during MARS treatment. Retrospective analysis of coagulopathy/bleeding complications observed during 83 consecutive MARS sessions in 21 patients (11 men; median age 46 years; median three sessions per patient; median duration of session 8 h). Nine clinically relevant episodes of coagulopathy/bleeding were observed in eight patients, forced to premature cessation of MARS in seven and ended lethal in four. Four complications occurred during the first, five during later (third to seventh) MARS sessions and two bleeders tolerated further sessions without complications. Coagulation parameters worsened significantly also during MARS sessions not associated with bleeding (PMARS therapy, potentially leading to bleeding complications and mortality.
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Energy Technology Data Exchange (ETDEWEB)
Sagawe, G.; Bahnemann, D. [Hannover Univ. (Germany). Inst. fuer Technische Chemie; Brandi, R.J.; Cassano, A.E. [Universidad Nacional de Litoral, Santa Fe (Argentina). Inst. de Desarrollo Tecnologico para la Imdustria Quimica
2004-11-01
A solar photoreactor operated in the batch, recirculating mode is analyzed in terms of very simple observable variables such as the impinging photon flux, the incident area, the initial concentration, the flow rate, the reactor volume and a property defined as the Observed Photonic Efficiency. The proposed equipment is made of a tubular reactor, a tank, a pump and the connecting pipes. The analysis is formulated in terms of the photon input corresponding to an equivalent batch system that is derived as a new reaction coordinate for photoreactions. Employing several plausible approximations, the pollutant concentration evolution in the tank is cast in terms of very simple analytical solutions. Process photonic efficiencies are defined for the system operation and calculated with respect to the maximum achievable yield corresponding to the differential operation of the solar recirculating reactor. (Author)
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Couras, C S; Louros, V L; Gameiro, T; Alves, N; Silva, A; Capela, M I; Arroja, L M; Nadais, H
2015-01-01
This work studied the influence of effluent recirculation upon the kinetics of anaerobic degradation of dairy wastewater in the feedless phase of intermittent upflow anaerobic sludge bed (UASB) reactors. Several laboratory-scale tests were performed with different organic loads in closed circuit UASB reactors inoculated with adapted flocculent sludge. The data obtained were used for determination of specific substrate removal rates and specific methane production rates, and adjusted to kinetic models. A high initial substrate removal was observed in all tests due to adsorption of organic matter onto the anaerobic biomass which was not accompanied by biological substrate degradation as measured by methane production. Initial methane production rate was about 45% of initial soluble and colloidal substrate removal rate. This discrepancy between methane production rate and substrate removal rate was observed mainly on the first day of all experiments and was attenuated on the second day, suggesting that the feedless period of intermittent UASB reactors treating dairy wastewater should be longer than one day. Effluent recirculation expressively raised the rate of removal of soluble and colloidal substrate and methane productivity, as compared with results for similar assays in batch reactors without recirculation. The observed bed expansion was due to the biogas production and the application of effluent recirculation led to a sludge bed contraction after all the substrates were degraded. The settleability of the anaerobic sludge improved by the introduction of effluent recirculation this effect being more pronounced for the higher loads.
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Paul S Wills, PhD; Pfeiffer, Timothy; Baptiste, Richard; Watten, Barnaby J.
2016-01-01
Control of alkalinity, dissolved carbon dioxide (dCO2), and pH are critical in marine recirculating aquaculture systems (RAS) in order to maintain health and maximize growth. A small-scale prototype aragonite sand filled fluidized bed reactor was tested under varying conditions of alkalinity and dCO2 to develop and model the response of dCO2 across the reactor. A large-scale reactor was then incorporated into an operating marine recirculating aquaculture system to observe the reactor as the system moved toward equilibrium. The relationship between alkalinity dCO2, and pH across the reactor are described by multiple regression equations. The change in dCO2 across the small-scale reactor indicated a strong likelihood that an equilibrium alkalinity would be maintained by using a fluidized bed aragonite reactor. The large-scale reactor verified this observation and established equilibrium at an alkalinity of approximately 135 mg/L as CaCO3, dCO2 of 9 mg/L, and a pH of 7.0 within 4 days that was stable during a 14 day test period. The fluidized bed aragonite reactor has the potential to simplify alkalinity and pH control, and aid in dCO2 control in RAS design and operation. Aragonite sand, purchased in bulk, is less expensive than sodium bicarbonate and could reduce overall operating production costs.
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Bubenheim, David L.; Harper, Lynn D.; Wignarajah, Kanapathipillai; Greene, Catherine
1994-01-01
The water present in waste streams from a human habitat must be recycled in Controlled Ecological Life Support Systems (CELSS) to limit resupply needs and attain self-sufficiency. Plants play an important role in providing food, regenerating air, and producing purified water via transpiration. However, we have shown that the surfactants present in hygiene waste water have acute toxic effects on plant growth (Bubenheim et al. 1994; Greene et al., 1994). These phytotoxic affects can be mitigated by allowing the microbial population on the root surface to degrade the surfactant, however, a significant suppression (several days) in crop performance is experienced prior to reaching sub-toxic surfactant levels and plant recovery. An effective alternative is to stabilize the microbial population responsible for degradation of the surfactant on an aerobic bioreactor and process the waste water prior to utilization in the hydroponic solution (Wisniewski and Bubenheim, 1993). A sensitive bioassay indicates that the surfactant phytotoxicity is suppressed by more than 90% within 5 hours of introduction of the gray water to the bioreactor; processing for more than 12 hours degrades more than 99% of the phytotoxin. Vapor Compression Distillation (VCD) is a physical / chemical method for water purification which employees sequential distillation steps to separate water from solids and to volatilize contaminants. The solids from the waste water are concentrated in a brine and the pure product water (70 - 90% of the total waste water volume depending on operating conditions) retains non of the phytotoxic effects. Results of the bioassay were used to guide evaluations of the suitability of recovered gray water following biological and VCD processing for hydroponic lettuce production in controlled environments. Lettuce crops were grown for 28 days with 100% of the input water supplied with recovered water from the biological processor or VCD. When compared with the growth of plants
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International Nuclear Information System (INIS)
Hellborg, R.; Hakansson, K.; Faarinen, M.; Kiisk, M.; Persson, P.; Skog, G.; Stenstroem, K.
2002-01-01
A recirculating terminal pumping system has been installed in the 3 MV Pelletron tandem accelerator in Lund. An extremely limited space in the high voltage terminal and the absence of electrical power in the terminal, forced us to provide a unique design for the installation and powering of the new pumps. Details of the technical design, as well as experience of the use of the new system for accelerator mass spectrometry, will be given. (author)
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Impact of capillary rise and recirculation on simulated crop yields
Directory of Open Access Journals (Sweden)
J. Kroes
2018-05-01
Full Text Available Upward soil water flow is a vital supply of water to crops. The purpose of this study is to determine if upward flow and recirculated percolation water can be quantified separately, and to determine the contribution of capillary rise and recirculated water to crop yield and groundwater recharge. Therefore, we performed impact analyses of various soil water flow regimes on grass, maize and potato yields in the Dutch delta. Flow regimes are characterized by soil composition and groundwater depth and derived from a national soil database. The intermittent occurrence of upward flow and its influence on crop growth are simulated with the combined SWAP-WOFOST model using various boundary conditions. Case studies and model experiments are used to illustrate the impact of upward flow on yield and crop growth. This impact is clearly present in situations with relatively shallow groundwater levels (85 % of the Netherlands, where capillary rise is a well-known source of upward flow; but also in free-draining situations the impact of upward flow is considerable. In the latter case recirculated percolation water is the flow source. To make this impact explicit we implemented a synthetic modelling option that stops upward flow from reaching the root zone, without inhibiting percolation. Such a hypothetically moisture-stressed situation compared to a natural one in the presence of shallow groundwater shows mean yield reductions for grassland, maize and potatoes of respectively 26, 3 and 14 % or respectively about 3.7, 0.3 and 1.5 t dry matter per hectare. About half of the withheld water behind these yield effects comes from recirculated percolation water as occurs in free-drainage conditions and the other half comes from increased upward capillary rise. Soil water and crop growth modelling should consider both capillary rise from groundwater and recirculation of percolation water as this improves the accuracy of yield simulations. This also improves the
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Energy Technology Data Exchange (ETDEWEB)
Analyan, V.L.; Sarkisyan, G.A. (AN Armyanskoj SSR, Erevan. Inst. Agrokhimicheskikh Problem i Gidroponiki)
1981-01-01
Accumulation of /sup 90/Sr in plants under the conditions of soil and hydroponic cultures from the viewpoint of the possibility of obtaining ''pure'' vegetable production has been studied. Predominant absorption of /sup 90/Sr by soil plants as compared with calcium is shown. In the course of using the hydroponic cultivation method predominant radiostrontium absorption has been manifested to all investigated nuclides including potassium. The accumulation coefficients analysis has shown that among soil plants the first place is occupied by potassium, while the /sup 90/Sr coefficients are greater than Ca on hydroponics, where the true, not distorted by soil sorption processes absorptive plant capacity has been manifested, the first places in the series are occupied by /sup 90/Sr and K, then come Ca and Mg.
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Fate of pharmaceutical compounds in hydroponic mesocosms planted with Scirpus validus.
Zhang, Dong Qing; Gersberg, Richard M; Hua, Tao; Zhu, Junfei; Goyal, Manish Kumar; Ng, Wun Jern; Tan, Soon Keat
2013-10-01
A systematic approach to assess the fate of selected pharmaceuticals (carbamazepine, naproxen, diclofenac, clofibric acid and caffeine) in hydroponic mesocosms is described. The overall objective was to determine the kinetics of depletion (from solution) and plant uptake for these compounds in mesocosms planted with S. validus growing hydroponically. The potential for translocation of these pharmaceuticals from the roots to the shoots was also assessed. After 21 days of incubation, nearly all of the caffeine, naproxen and diclofenac were eliminated from solution, whereas carbamazepine and clofibric acid were recalcitrant to both photodegradation and biodegradation. The fact that the BAFs for roots for carbamazepine and clofibric acid were greater than 5, while the BAFs for naproxen, diclofenac and caffeine were less than 5, implied that the latter two compounds although recalcitrant to biodegradation, still had relatively high potential for plant uptake. Naproxen was sensitive to both photodegradation (30-42%) and biodegradation (>50%), while diclofenac was particularly sensitive (>70%) to photodegradation alone. No significant correlations (p > 0.05) were found between the rate constants of depletion or plant tissue levels of the pharmaceuticals and either log Kow or log Dow. Copyright © 2013 Elsevier Ltd. All rights reserved.
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BWR 2 % main recirculation line break LOCA tests RUNs 915 and 920 without HPCS in ROSA-III program
International Nuclear Information System (INIS)
Suzuki, Mitsuhiro; Nakamura, Hideo; Anoda, Yoshinari; Kumamaru, Hiroshige; Yonomoto, Taisuke; Koizumi, Yasuo; Tasaka, Kanji
1987-03-01
This report presents the experimental results of BWR LOCA integral tests, RUNs 915 and 920, which are performed in the ROSA-III program simulating 2 % main recirculation line break LOCA tests with and without pressure control system operation. The ROSA-III test facility simulates a BWR system with volume scale of 1/424 and has four half-length electrically heated fuel bundles, two active recirculation loops, four types of ECCS's, and steam and feedwater systems. The report presents (1) the experimental results of 2 % small break LOCA phanomena in the ROSA-III system and (2) the effects of the pressure control system on the LOCA phenomena. The pressure control system contributed to (A) prevent bulk flashing in the early blowdown phase, (B) early closure of MSIV by L2 level trip, (C) early actuation of ADS by L1 level trip. However, the core thermal responses of the two tests were similar because of the similar mass inventory in PV after the ADS actuation in both tests. (author)
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Navigating towards Decoupled Aquaponic Systems: A System Dynamics Design Approach
Directory of Open Access Journals (Sweden)
Simon Goddek
2016-07-01
Full Text Available The classical working principle of aquaponics is to provide nutrient-rich aquacultural water to a hydroponic plant culture unit, which in turn depurates the water that is returned to the aquaculture tanks. A known drawback is that a compromise away from optimal growing conditions for plants and fish must be achieved to produce both crops and fish in the same environmental conditions. The objective of this study was to develop a theoretical concept of a decoupled aquaponic system (DAPS, and predict water, nutrient (N and P, fish, sludge, and plant levels. This has been approached by developing a dynamic aquaponic system model, using inputs from data found in literature covering the fields of aquaculture, hydroponics, and sludge treatment. The outputs from the model showed the dependency of aquacultural water quality on the hydroponic evapotranspiration rate. This result can be explained by the fact that DAPS is based on one-way flows. These one-way flows results in accumulations of remineralized nutrients in the hydroponic component ensuring optimal conditions for the plants. The study also suggests to size the cultivation area based on P availability in the hydroponic component as P is an exhaustible resource and has been identified one of the main limiting factors for plant growth.
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International Nuclear Information System (INIS)
Lambert, Philippa; Lepine, Gaelle; Rapenne, Sophie; Demay, Eric; Jardin, Audrey; Shakourzadeh, Khalil; Alos-Ramos, Olga
2012-09-01
The main issue of condenser open recirculating cooling systems remains scaling. This can have high economic consequences due to a loss of thermal exchange, an increase of maintenance costs and potentially plant shutdown. To tackle this problem, EDF is currently designing new chemicals' dosing equipment for anti-scalants or acid. To optimise treatment cost and limit the chemicals' environmental impact, dosing and control systems should be efficient enough to add only the required quantity to prevent scaling without overdosing. CooliSS C , a model developed for simulating the water chemistry of open recirculating cooling systems, can be used to adjust acid dosage and to pre-evaluate selected acid control systems. In circuits with no current treatment, where the scaling situation is being monitored, CooliSS C is a useful tool in predicting scaling potential and could even be used to predict the expected quantity of deposits. In the first case study, CooliSS ST, the static version of the model, was used to evaluate the sulfuric acid injection needs for Golfech nuclear power plant following a modification to the condenser cooling water circuit operating conditions. The results obtained via simulation were compared with manual calculations in order to demonstrate the accuracy of the software. In the second case study, CooliSS DX, the dynamic version of the CooliSS C model, was used to evaluate new acid control systems planned for Cruas nuclear power plant before the systems' commissioning. CooliSS DX predicts the scaling rate in the different parts of the cooling water system as a function of time. In fact, this version is able to calculate the variations of chemical composition along the circuit when operating conditions change (make-up quality, flow rates, evaporation rate, temperature...). A module was combined to CooliSS DX to evaluate acid control equipment. This module allows the initial calculation of the acid flow rate as a function of operating
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Quality and Quantity of Sorghum Hydroponic Fodder from Different Varieties and Harvest Time
Chrisdiana, R.
2018-02-01
This experiment was designed to compare different varieties and harvest time of sorghum hydroponic fodder based on nutrient content and biomass production. Experimental design for fodder productivity was completely randomized design with 2 x 3 factorial, i.e., sorghum varieties (KD 4 and Super-1) and time of harvesting the sorghum hydroponic fodder (8,12 and 16 d). Total biomass and DM production, were affected significantly (p<0.05) on harvest time. Total biomass and nutrient content were increased in longer harvest time. The nutrient content were increased with decreasing total value of DM. Super-1 varieties produce larger biomass and nutrient content higher than KD4 (p<0.05). Based on sorghum hidroponic fodder quality and quantity, sorghum hidroponic fodder with Super-1 varieties harvested at 12 d had a good quality of fodder and it can be alternative of technology providing quality forage and land saving with a short time planting period and continous production.
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Coal ash as a substrate in hydroponics: chemical and agronomical aspects
Energy Technology Data Exchange (ETDEWEB)
Giusquiani, P L; Gigliotti, G; Businelli, D; Varallo, G [University of Perugia, Perugia (Italy)
1995-05-01
Tomato plants were grown in hydroponics using pelleted fly and heavy ash as substrates. The water stability of the substrates and their ability in a nutrient solution to sorb or desorb ions have been studied. Both substrates showed a satisfactory stability to water treatments. Interactions between the nutrient solution and the substrates did not influence the ion uptake by tomato plants nor plant growth and productivity.
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Watanabe, Rei; Gehad, Ahmed; Yang, Chao; Campbell, Laura; Teague, Jessica E.; Schlapbach, Christoph; Elco, Christopher; Huang, Victor; Matos, Tiago R.; Kupper, Thomas S.; Clark, Rachael A.
2015-01-01
The skin of an adult human contains approximately 20 billion memory T cells. Epithelial barrier tissues are infiltrated by a combination of resident and recirculating T cells in mice but the relative proportions and functional activities of resident versus recirculating T cells have not been evaluated in human skin. We discriminated resident from recirculating T cells in human engrafted mice and lymphoma patients using alemtuzumab, a medication that depletes recirculating T cells from skin, and then analyzed these T cell populations in healthy human skin. All non-recirculating resident memory T cells (TRM) expressed CD69, but the majority were CD4+, CD103− and located in the dermis, in contrast to studies in mice. Both CD4+ and CD8+ CD103+ TRM were enriched in the epidermis, had potent effector functions and had a limited proliferative capacity compared to CD103− TRM. TRM of both types had more potent effector functions than recirculating T cells. Induction of CD103 on human T cells was enhanced by keratinocyte contact, depended on TGFβ and was independent of T cell keratinocyte adhesive interactions. We observed two distinct populations of recirculating T cells, CCR7+/L-selectin+ central memory T cells (TCM) and CCR7+/L-selectin− T cells, which we term migratory memory T cells (TMM). Circulating skin-tropic TMM were intermediate in cytokine production between TCM and effector memory T cells. In patients with cutaneous T cell lymphoma, malignant TCM and TMM induced distinct inflammatory skin lesions and TMM were depleted more slowly from skin after alemtuzumab, suggesting TMM may recirculate more slowly. In summary, human skin is protected by four functionally distinct populations of T cells, two resident and two recirculating, with differing territories of migration and distinct functional activities. PMID:25787765
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Directory of Open Access Journals (Sweden)
Aline Mabel Rosa
2014-08-01
Full Text Available Lettuce (Lactuca sativa L. is the most commonly consumed leaf vegetable in the Brazilian diet, and it is a good source of vitamins and minerals. It is widely grown in the conventional farming system. However, the hydroponic farming system has been gaining importance in the market, wining confidence from consumers, who are becoming increasingly more demanding on food quality. The objective of this study was to evaluate the performance of two lettuce cultivars on hydroponic and conventional farming systems for the production of fresh mass (FM and dry mass (DM, photosynthesis, contents of chlorophyll and anthocyanin. The following two experiments were carried out: hydroponics farming (HF and conventional farming (CF, performed in protect and unprotect environments, respectively, in Florianópolis, SC. Mimosa Verde cultivar (MV showed greater fresh mass than Mimosa Roxa (MR, in both farming systems and the two cultivars presented better performance in the hydroponic system (287.7 g MV and 139.1 g MR than the conventional system (129.7 g MV and 111.8 g MR. Mimosa Verde cultivar presented lower average contents of total chlorophyll (7.7 mg g-¹ FM than Mimosa Roxa (11.8 mg g-¹FM, and both cultivars displayed higher means for this variable in the hydroponic farming system. Mimosa Roxa presented higher contents of anthocyanin in the conventional system (88.24 mg g-¹ FM than the ones in the hydroponic system (36.89 mg g-¹ FM. The best results for CO2 net assimilation rate regarded to photosyntheticaly active photon flux density were found in the hydroponic system, for both lettuce cultivars. Variation in the contents of chlorophyll were also found. Those variations were higher in the protected system than in the hydroponic system and contents of anthocyanin were higher in the conventional system.
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International Nuclear Information System (INIS)
Fu, Jianqin; Zhu, Guohui; Zhou, Feng; Liu, Jingping; Xia, Yan; Wang, Shuqian
2016-01-01
Highlights: • In-cylinder residual gas fraction almost increases linearly with exhaust gas recirculation rate. • Heat transfer loss and exhaust gas energy loss decrease with exhaust gas recirculation rate. • Engine indicated thermal efficiency can be increased by 4.29% at 1600 r/min and 2.94 bar. • The effective range of exhaust gas recirculation rate can be extended by intake tumble. - Abstract: To improve the economy and emission performance of gasoline engine under part load, the approach of exhaust gas recirculation coupling with intake tumble was investigated by bench testing. Based on a naturally aspirated gasoline engine, the sweeping test of exhaust gas recirculation rate was conducted in two intake modes (with/without intake tumble), and the parameters related to engine heat-work conversion process and emission performance were measured. Through comparing and analyzing the measured data, the effects of exhaust gas recirculation coupling with intake tumble on gasoline engine economy and emission performance were revealed. The results show that pumping loss decreases gradually while in-cylinder residual gas fraction increases linearly with the exhaust gas recirculation rate increasing; the high-pressure cycle efficiency ascends with exhaust gas recirculation rate increasing due to the decrease of heat transfer loss and exhaust gas energy loss. Thus, the improvement of indicated thermal efficiency is the superposition of double benefits of low-pressure cycle and high-pressure cycle. At 1600 r/min and 2.94 bar, the indicated thermal efficiency can be increased by 4.29%. With the increase of exhaust gas recirculation rate, nitrogen oxide emissions almost fall linearly, but hydrocarbon and carbonic oxide emissions have no obvious change in the effective range of exhaust gas recirculation rate. The biggest advantage of intake tumble is that it can extend the effective range of exhaust gas recirculation rate. As a result, the potential of energy
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Lv, Tao; Zhang, Yang; Casas, Mònica E; Carvalho, Pedro N; Arias, Carlos A; Bester, Kai; Brix, Hans
2016-04-01
Pollution from pesticide residues in aquatic environments is of increasing concern. Imazalil and tebuconazole, two commonly used systemic pesticides, are water contaminants that can be removed by constructed wetlands. However, the phytoremediation capability of emergent wetland plants for imazalil and tebuconazole, especially the removal mechanisms involved, is poorly understood. This study compared the removal of both pesticides by four commonly used wetland plants, Typha latifolia, Phragmites australis, Iris pseudacorus and Juncus effusus, and aimed to understand the removal mechanisms involved. The plants were individually exposed to an initial concentration of 10 mg/L in hydroponic solution. At the end of the 24-day study period, the tebuconazole removal efficiencies were relatively lower (25%-41%) than those for imazalil (46%-96%) for all plant species studied. The removal of imazalil and tebuconazole fit a first-order kinetics model, with the exception of tebuconazole removal in solutions with I. pseudacorus. Changes in the enantiomeric fraction for imazalil and tebuconazole were detected in plant tissue but not in the hydroponic solutions; thus, the translocation and degradation processes were enantioselective in the plants. At the end of the study period, the accumulation of imazalil and tebuconazole in plant tissue was relatively low and constituted 2.8-14.4% of the total spiked pesticide in each vessel. Therefore, the studied plants were able to not only take up the pesticides but also metabolise them. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Morales, Anabelle; Garland, Jay L.; Lim, Daniel V.
1996-01-01
Plants may serve as reservoirs for human-associated bacteria (H-AB) in long-term space missions containing bioregenerative life support systems. The current study examined the abilities of five human-associated potential pathogens, Pseudomonas aeruginosa, Pseudomonas cepacia, Staphylococcus aureus, Streptococcus pyogenes, and Escherichia coli, to colonize and grow in the rhizosphere of hydroponically grown wheat, a candidate crop for life support. All of these bacteria have been recovered from past NASA missions and present potential problems for future missions. The abilities of these organisms to adhere to the roots of axenic five-day-old wheat (Triticum aestivum L. cv. Yecora rojo) were evaluated by enumeration of the attached organisms after a one hour incubation of roots in a suspension (approximately 10(exp 8 cu/ml)) of the H-AB. Results showed that a greater percentage of P. aeruginosa cells adhered to the wheat roots than the other four H-AB. Similarly incubated seedlings were also grown under attempted axenic conditions for seven days to examine the potential of each organism to proliferate in the rhizosphere (root colonization capacity). P. cepacia and P. aeruginosa showed considerable growth. E. coli and S. aureus showed no significant growth, and S. pyogenes died off in the wheat rhizosphere. Studies examining the effects of competition on the survival of these microorganisms indicated that P. aeruginosa was the only organism that survived in the rhizosphere of hydroponically grown wheat in the presence of different levels of microbial competition.
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Modeling Tar Recirculation in Biomass Fluidized Bed Gasification
Heineken, Wolfram; De la Cuesta de Cal, Daniel; Zobel, Nico
2016-01-01
A biomass gasification model is proposed and applied to investigate the benefits of tar recirculation within a gasification plant. In the model, tar is represented by the four species phenol, toluene, naphthalene, and benzene. The model is spatially one-dimensional, assuming plug flow for the
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Monitoring of Leachate Recirculation in a Bioreactor Using Electrical Resistivity
Grellier, S.; Bureau, N.; Robain, H.; Tabbagh, A.; Camerlynck, C.; Guerin, R.
2004-05-01
increasing moisture content). The positive anomaly could be explained by an increasing of biogas proportion in waste porosity. For this experiment, leachate temperature is relatively cold (between 5 and 10° C, as the injection trials take place at the end of October), leachate conductivity is about 9200 μ S cm-1 (i.e. a resistivity of 1.1 Ω m) and waste resistivity in the borehole region is about 80 Ω m. This is a situation where the temperature difference between waste and leachate is large and the resistivity difference between waste and leachate is high. The resistivity variation is essentially due to waste moisture increase. ERT method allows leachate diffusion to be seen through the waste mass and the influence zone of the leachate recirculation system to be determined.
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International Nuclear Information System (INIS)
Herholz, K.
1985-01-01
Based on data from routine intravenous Xe133-rCBF studies in 50 patients, using Obrist's algorithm the effect of counting rate statistics and amount of recirculating activity on reproducibility of results was investigated at five simulated counting rate levels. Dependence of the standard deviation of compartmental and noncompartmental flow parameters on recirculation and counting rate was determined by multiple linear regression analysis. Those regression equations permit determination of the optimum accuracy that may be expected from individual flow measurements. Mainly due to a delay of the start-of-fit time an exponential increase in standard deviation of flow measurements was observed as recirculation increased. At constant start-of-fit, however, a linear increase in standard deviation of compartmental flow parameters only was found, while noncompartmental results remained constant. Therefore, and in regard to other studies of potential sources of error, an upper limit of 2.5 min for the start-of-fit time and usage of noncompartmental flow parameters for measurements affected by high recirculation are suggested
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Feeding a fish meal-free grain-based diet (GB) was compared to feeding a fish meal-based diet (FM) relative to water quality criteria, waste production, water treatment process performance, and rainbow trout Oncorhynchus mykiss performance within six replicated water recirculating aquaculture system...
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Aquaponic System: A sustainable production form in Family Farming and periurban area
Directory of Open Access Journals (Sweden)
Renan Borro Celestrino
2018-05-01
Full Text Available Aquaponics is a food culture system that involves the integration of hydroponics and aquaculture with recirculation of water and nutrients. Due to its sustainable characteristics, it presents alternatives for the production of animal protein and olerícolas in an integrated way, less impacting the ecosystem. For the development of this essay, a methodological structure of an applied nature and of a scientific character with a qualitative-quantitative approach was adopted, it is a descriptive and experimental research. The data were collected through field research in triangulation with the bibliographic reference. Taking into account the sustainability and practicality of the aquaponic system, the purpose of this work was to survey the cost for the small-scale implementation of the system for family agriculture and peri-urban areas, as well as to present the step-by-step driving the system. The practical experiment consisted of 27 kilos of fish fed with ration referring to 2% of its live weight, the residues nourished 144 seedlings of the Crespa Lettuce. The aquaponic system for family and peri-urban agriculture tends to be a sustainable alternative, presenting low implantation costs, the practicality of management and healthier production due to the organic nutrition of the plants and the non-use of chemicals in the system.
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Estevez, Maria M; Sapci, Zehra; Linjordet, Roar; Schnürer, Anna; Morken, John
2014-04-01
The effects of recirculating the liquid fraction of the digestate during mesophilic anaerobic co-digestion of steam-exploded Salix and cow manure were investigated in laboratory-scale continuously stirred tank reactors. An average organic loading rate of 2.6 g VS L(-1) d(-1) and a hydraulic retention time (HRT) of 30 days were employed. Co-digestion of Salix and manure gave better methane yields than digestion of manure alone. Also, a 16% increase in the methane yield was achieved when digestate was recirculated and used instead of water to dilute the feedstock (1:1 dilution ratio). The reactor in which the larger fraction of digestate was recirculated (1:3 dilution ratio) gave the highest methane yields. Ammonia and volatile fatty acids did not reach inhibitory levels, and some potentially inhibitory compounds released during steam explosion (i.e., furfural and 5-hydroxy methyl furfural) were only detected at trace levels throughout the entire study period. However, accumulation of solids, which was more pronounced in the recycling reactors, led to decreased methane yields in those systems after three HRTs. Refraining from the use of fresh water to dilute biomass with a high-solids content and obtaining a final digestate with increased dry matter content might offer important economic benefits in full-scale processes. To ensure long-term stability in such an approach, it would be necessary to optimize separation of the fraction of digestate to be recirculated and also perform proper monitoring to avoid accumulation of solids. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Sethi, Sapna; Kothiyal, N C; Nema, Arvind K
2012-07-01
Leachate recirculation at neutral PH accompanied with buffer/nutrients addition has been used successfully in earlier stabilization of municipal solid waste in bioreactor landfills. In the present study, efforts were made to enhance the stabilization rate of municipal solid waste (MSW) and organic solid waste (OSW) in simulated landfill bioreactors by controlling the pH of recirculated leachate towards slightly alkaline side in absence of additional buffer and nutrients addition. Enhanced stabilization in waste samples was monitored with the help of analytical tools like Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD). Predominance of bands assigned to inorganic compounds and comparatively lower intensities of bands for organic compounds in the FTIR spectra of waste samples degraded with leachate recirculation under controlled pH confirmed higher rate of biodegradation and mineralization of waste than the samples degraded without controlled leachate recirculation. XRD spectra also confirmed to a greater extent of mineralization in the waste samples degraded under leachate recirculation with controlled pH. Comparison of XRD spectra of two types of wastes pointed out higher degree of mineralization in organic solid waste as compared to municipal solid waste.
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Directory of Open Access Journals (Sweden)
Anantha Raman Lakshmipathi
2017-01-01
Full Text Available Exhaust gas re-circulation is a method used in compression ignition engines to control and reduce NOx emission. These emissions are controlled by reducing the oxygen concentration inside the cylinder and thereby reducing the flame temperature of the charge mixture inside the combustion chamber. In the present investigation, experiments were performed to study the effect of exhaust gas re-circulation on performance and emission characteristics in a four stroke single cylinder, water cooled and constant speed diesel engine. The experiments were performed to study the performance and emissions for different exhaust gas re-circulation ratios of the engine. Performance parameters such as brake thermal efficiency, indicated thermal efficiency, specific fuel consumption, total fuel consumption and emission parameters such as oxides of nitrogen, unburned hydrocarbons, carbon monoxide, carbon dioxide and smoke opacity were measured. Reductions in NOx and CO2 were observed but other emissions like HC, CO, and smoke opacity were found to have increased with the usage of exhaust gas re-circulation. The 15% exhaust gas re-circulation was found optimum for the engine in the aspects of performance and emission.
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Activity buildup in the recirculation system of boiling water reactors
International Nuclear Information System (INIS)
Grauer, R.
1987-05-01
The deposition of activated corrosion products in the recirculation system of boiling water reactors produces increased radiation levels which lead to a corresponding increase in personnel irradiation dose rates during shut down and maintenance. The major part of this dose rate is due to Co-60. Based on a comprehensive literature study concerning this theme, the author has attempted to identify the individual stages of the activity build up and to classify their importance. The following areas are discussed in detail: - the origins of the corrosion products and of Co-59 in the reactor feedwater; - the consolidation of the cobalt in the fuel element crud deposits (activation); - the release and transport of the Co-60; - the build up of Co-60 in the corrosion products of the primary circuit. Existing models for the build up of cirquit radioactivity are discussed and the operating experience from selected reactors are summarized. Finally the state of the art of knowledge concerning the individual stages in the development of the activation build up is depicted. This highlights the existing gaps and thus identifies areas for possible R+D activities. Corrosion chemistry aspects of the cobald build up in the primary cirquit have already been studied on a broad basis and are continuing to be researched in a number of centers. The crystal chemistry of austenitic steel corrosion products poses a number of yet unanswered questions. There are major loopholes associated with an understanding of the activation processes of the cobalt deposited on the fuel elements and in the mass transfer of Co-60. For these processes, the most important influence stems from factors associated with colloid chemistry. In this respect there is ample room for new and original research contributions. It is recommended that sections 8 and 9 of this report should be read as an 'Executive Summary'. (author)
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The Effect of Anaerobic and Aerobic Fish Sludge Supernatant on Hydroponic Lettuce
Directory of Open Access Journals (Sweden)
Simon Goddek
2016-06-01
Full Text Available The mobilization of nutrients from fish sludge (i.e., feces and uneaten feed plays a key role in optimizing the resource utilization and thus in improving the sustainability of aquaponic systems. While several studies have documented the aerobic and anaerobic digestion performance of aquaculture sludge, the impact of the digestate on plant growth has yet to be understood. The present study examines the impact of either an aerobic or an anaerobic digestion effluent on lettuce plant growth, by enriching a mixture of aquaculture and tap water with supernatants from both aerobic and anaerobic batch reactors. The lettuce plants grown in the hydroponic system supplied with supernatant from an anaerobic reactor had significantly better performance with respect to weight gain than both, those in the system where supernatant from the aerobic reactor was added, as well as the control system. It can be hypothesized that this effect was caused by the presence of NH4+ as well as dissolved organic matter, plant growth promoting rhizobacteria and fungi, and humic acid, which are predominantly present in anaerobic effluents. This study should therefore be of value to researchers and practitioners wishing to further develop sludge remineralization in aquaponic systems.
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MacIntyre, Olathe; Stasiak, Michael; Cottenie, Karl; Trevors, Jack; Dixon, Mike
An assembled microbial community in the hydroponics solution of an advanced life support system may improve plant performance and productivity in three ways: (1) exclusion of plant pathogens from the initial community, (2) resistance to infection, and (3) plant-growth promotion. However, the plant production area is likely to have a hypobaric (low pressure) and hypoxic (low oxygen) atmosphere to reduce structural mass and atmosphere leakage, and these conditions may alter plant-microbe interactions. Plant performance and productivity of radish (Raphanus sativus L. cv. Cherry Bomb II) grown under hypobaric and hypoxic conditions were investigated at the University of Guelph's Controlled Environment Systems Research Facility. Changes in the microbial communities that routinely colonized the re-circulated nutrient solution, roots, and leaves of radishes in these experiments were quantified in terms of similarity in community composition, abundance of bacteria, and community diversity before and after exposure to hypobaric and hypoxic conditions relative to communities maintained at ambient growth conditions. The microbial succession was affected by extreme hypoxia (2 kPa oxygen partial pressure) while hypobaria as low as 10 kPa total pressure had little effect on microbial ecology. There were no correlations found between the physiological profile of these unintentional microbial communities and radish growth. The effects of hypobaric and hypoxic conditions on specific plant-microbe interactions need to be determined before beneficial gnotobiotic communities can be developed for use in space. The bacterial strains Tal 629 of Bradyrhizobium japonicum and WCS417 of Pseudomonas fluorescens, and the plant pathogen Fusarium oxysporum f. sp. raphani will be used in future experiments. B. japonicum Tal 629 promotes radish growth in hydroponics systems and P. fluorescens WCS417 induces systemic resistance to fusarium wilt (F. oxysporum f. sp. raphani) in radish under ambient
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A study on the optimal hydraulic loading rate and plant ratios in recirculation aquaponic system.
Endut, Azizah; Jusoh, A; Ali, N; Wan Nik, W B; Hassan, A
2010-03-01
The growths of the African catfish (Clarias gariepinus) and water spinach (Ipomoea aquatica) were evaluated in recirculation aquaponic system (RAS). Fish production performance, plant growth and nutrient removal were measured and their dependence on hydraulic loading rate (HLR) was assessed. Fish production did not differ significantly between hydraulic loading rates. In contrast to the fish production, the water spinach yield was significantly higher in the lower hydraulic loading rate. Fish production, plant growth and percentage nutrient removal were highest at hydraulic loading rate of 1.28 m/day. The ratio of fish to plant production has been calculated to balance nutrient generation from fish with nutrient removal by plants and the optimum ratio was 15-42 gram of fish feed/m(2) of plant growing area. Each unit in RAS was evaluated in terms of oxygen demand. Using specified feeding regime, mass balance equations were applied to quantify the waste discharges from rearing tanks and treatment units. The waste discharged was found to be strongly dependent on hydraulic loading rate. 2009 Elsevier Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Sjerić, Momir; Taritaš, Ivan; Tomić, Rudolf; Blažić, Mislav; Kozarac, Darko; Lulić, Zoran
2016-01-01
Highlights: • A cylinder model was calibrated according to experimental results. • A full cycle simulation model of turbocharged spark-ignition engine was made. • Engine performance with high pressure exhaust gas recirculation was studied. • Cooled exhaust gas recirculation lowers exhaust temperature and knock occurrence. • Leaner mixtures enable fuel consumption improvement of up to 11.2%. - Abstract: The numerical analysis of performance of a four cylinder highly boosted spark-ignition engine at full load is described in this paper, with the research focused on introducing high pressure exhaust gas recirculation for control of engine limiting factors such as knock, turbine inlet temperature and cyclic variability. For this analysis the cycle-simulation model which includes modeling of the entire engine flow path, early flame kernel growth, mixture stratification, turbulent combustion, in-cylinder turbulence, knock and cyclic variability was applied. The cylinder sub-models such as ignition, turbulence and combustion were validated by using the experimental results of a naturally aspirated multi cylinder spark-ignition engine. The high load operation, which served as a benchmark value, was obtained by a standard procedure used in calibration of engines, i.e. operation with fuel enrichment and without exhaust gas recirculation. By introducing exhaust gas recirculation and by optimizing other engine operating parameters, the influence of exhaust gas recirculation on engine performance is obtained. The optimum operating parameters, such as spark advance, intake pressure, air to fuel ratio, were found to meet the imposed requirements in terms of fuel consumption, knock occurrence, exhaust gas temperature and variation of indicated mean effective pressure. By comparing the results of the base point with the results that used exhaust gas recirculation the improvement in fuel consumption of 8.7%, 11.2% and 1.5% at engine speeds of 2000 rpm, 3500 rpm and 5000
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Integrating biological treatment of crop residue into a hydroponic sweetpotato culture
Trotman, A. A.; David, P. P.; Bonsi, C. K.; Hill, W. A.; Mortley, D. G.; Loretan, P. A.
1997-01-01
Residual biomass from hydroponic culture of sweetpotato [Ipomoea batatas (L.) Lam.] was degraded using natural bacterial soil isolates. Sweetpotato was grown for 120 days in hydroponic culture with a nutrient solution comprised of a ratio of 80% modified half Hoagland solution to 20% filtered effluent from an aerobic starch hydrolysis bioreactor. The phytotoxicity of the effluent was assayed with `Waldmann's Green' lettuce (Lactuca sativa L.) and the ratio selected after a 60-day bioassay using sweetpotato plants propagated vegetatively from cuttings. Controlled environment chamber experiments were conducted to investigate the impact of filtrate from biological treatment of crop residue on growth and storage root production with plants grown in a modified half Hoagland solution. Incorporation of bioreactor effluent, reduced storage root yield of `Georgia Jet' sweetpotato but the decrease was not statistically significant when compared with yield for plants cultured in a modified half Hoagland solution without filtrate. However, yield of `TU-82-155' sweetpotato was significantly reduced when grown in a modified half Hoagland solution into which filtered effluent had been incorporated. Total biomass was significantly reduced for both sweetpotato cultivars when grown in bioreactor effluent. The leaf area and dry matter accumulation were significantly (P < 0.05) reduced for both cultivars when grown in solution culture containing 20% filtered effluent.
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Chronic exposure to elevated levels of dissolved carbon dioxide (CO2) has been linked to reduced growth, physiological disturbances and negative health outcomes in intensively reared fish. Although pumping to a degassing tower can lower concentrations of dissolved CO2 in water recirculation aquacult...
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Directory of Open Access Journals (Sweden)
Arif Hasan Khan Robin
2015-10-01
Full Text Available Wheat is an important cereal crop worldwide that often suffers from moisture deficits at the reproductive stage. Polyethylene glycol (PEG-treated hydroponic conditions create negative osmotic potential which is compared with moisture deficit stress. An experiment was conducted in a growth chamber to study the effects of PEG on root hair morphology and associated traits of wheat varieties. Plants of 13 wheat varieties were grown hydroponically and three different doses of PEG 6000 (w/v: 0% (control, 0.3% and 0.6% (less than −1 bar were imposed on 60 days after sowing for 20 days’ duration. A low PEG concentration was imposed to observe how initial low moisture stress might affect root hair development. PEG-treated hydroponic culture significantly decreased root hair diameter and length. Estimated surface area reduction of root hairs at the main axes of wheat plants was around nine times at the 0.6% PEG level compared to the control plants. Decrease in root hair diameter and length under PEG-induced culture decreased “potential” root surface area per unit length of main root axis. A negative association between panicle traits, length and dry weight and the main axis length of young roots indicated competition for carbon during their development. Data provides insight into how a low PEG level might alter root hair development.
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Energy Technology Data Exchange (ETDEWEB)
Yonezawa, K [Chugoku Electric Power Co. Inc., Hiroshima (Japan)
1996-03-25
A demonstrative test was conducted to verify economical efficiency of practical scale hydroponic horticulture under structure making use of a part of the Osaki thermal power plant to be constructed. In the test, the hydroponic culture of leek and tomatoes was carried out for six years starting 1989 to study its economical efficiency. Using the M-type hydroponic culture facilities, the structures are 1200m wide, 29m long, and 21 tons in the culture liquid level in case of leek, and 350m wide, 29m long, and 10 tons in the culture liquid level in case of tomatoes. The evaluation was made estimating the crop amount of leek as about 35 tons and that of tomatoes as about 60 tons and regarding that the sales amount is equal to the crop amount. The sales amount of leek is 28 million yen, and when seeking income/expenditure from expenses, deficit of 1 million yen per 30 a cannot be avoided excluding the equipment depreciation cost. As to tomatoes, the shipment cost is approximately 14 million yen without the equipment depreciation cost, but the sales amount is approximately 13-19 million yen largely affected by the unit price. A study on the sale method is needed. 7 figs., 11 tabs.
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Possible Internalization of an Enterovirus in Hydroponically Grown Lettuce
Directory of Open Access Journals (Sweden)
Annalaura Carducci
2015-07-01
Full Text Available Several studies have shown that enteric viruses can be transferred onto the surface of vegetables and fruits through spray irrigation, but, recently, reports have suggested viral contamination of vegetables sub-irrigated with reused wastewater. Hydroponic cultures, used to grow ready to eat fresh lettuce, have also been used to study the possibility of viral absorption through roots. This study was conducted to assess a possible risk of viral contamination in lettuce from contaminated water. The leaves of lettuce plants grown in hydroponic cultures where the roots were exposed to water containing Coxsakievirus B2, were analysed for evidence of the virus. The plants and water were sampled at different times and virus was measured using quantitative RT-PCR and infectivity assay. In leaf samples, the lowest observed infective data were lower than the qRT-PCR detection limits, suggesting that free viral RNA or damaged viruses are eliminated rapidly while infectious particles remain stable for a longer time. The obtained data revealed that the leaves were contaminated at a water concentration of 4.11 ± 1 Log Most Probable Number/L (8.03 ± 1 Log GC/L a concentration observed in contaminated untreated water of wastewater treatment plants. However, the absorption dynamics and whether the virus is inactive in the leaves still remains to be clarified. Nevertheless, this work has practical implications for risk management in using reclaimed water for agricultural use; when irrigated vegetables are destined for raw consumption, virological contamination in water sources should be evaluated.
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Possible Internalization of an Enterovirus in Hydroponically Grown Lettuce.
Carducci, Annalaura; Caponi, Elisa; Ciurli, Adriana; Verani, Marco
2015-07-17
Several studies have shown that enteric viruses can be transferred onto the surface of vegetables and fruits through spray irrigation, but, recently, reports have suggested viral contamination of vegetables sub-irrigated with reused wastewater. Hydroponic cultures, used to grow ready to eat fresh lettuce, have also been used to study the possibility of viral absorption through roots. This study was conducted to assess a possible risk of viral contamination in lettuce from contaminated water. The leaves of lettuce plants grown in hydroponic cultures where the roots were exposed to water containing Coxsakievirus B2, were analysed for evidence of the virus. The plants and water were sampled at different times and virus was measured using quantitative RT-PCR and infectivity assay. In leaf samples, the lowest observed infective data were lower than the qRT-PCR detection limits, suggesting that free viral RNA or damaged viruses are eliminated rapidly while infectious particles remain stable for a longer time. The obtained data revealed that the leaves were contaminated at a water concentration of 4.11 ± 1 Log Most Probable Number/L (8.03 ± 1 Log GC/L) a concentration observed in contaminated untreated water of wastewater treatment plants. However, the absorption dynamics and whether the virus is inactive in the leaves still remains to be clarified. Nevertheless, this work has practical implications for risk management in using reclaimed water for agricultural use; when irrigated vegetables are destined for raw consumption, virological contamination in water sources should be evaluated.
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Directory of Open Access Journals (Sweden)
L.A. Favero-Filho
2008-11-01
Full Text Available Chronic neurodegenerative processes have been identified in the rat forebrain after prolonged survival following hyperthermia (HT initiated a few hours after transient global ischemia. Since transient global ischemia and ischemic penumbra share pathophysiological similarities, this study addressed the effects of HT induced after recirculation of focal brain ischemia on infarct size during long survival times. Adult male Wistar rats underwent intra-luminal occlusion of the left middle cerebral artery for 60 min followed by HT (39.0-39.5°C or normothermia. Control procedures included none and sham surgery with and without HT, and middle cerebral artery occlusion alone. Part I: 6-h HT induced at recirculation. Part II: 2-h HT induced at 2-, 6-, or 24-h recirculation. Part III: 2-h HT initiated at recirculation or 6-h HT initiated at 2-, 6- or 24-h recirculation. Survival periods were 7 days, 2 or 6 months. The effects of post-ischemic HT on cortex and striatum were evaluated histopathologically by measuring the area of remaining tissue in the infarcted hemisphere at -0.30 mm from bregma. Six-hour HT initiated from 6-h recirculation caused a significant decrease in the remaining cortical tissue between 7-day (N = 8 and 2-month (N = 8 survivals (98.46 ± 1.14 to 73.62 ± 8.99%, respectively. When induced from 24-h recirculation, 6-h HT caused a significant reduction of the remaining cortical tissue between 2- (N = 8 and 6-month (N = 9 survivals (94.97 ± 5.02 vs 63.26 ± 11.97%, respectively. These data indicate that post-ischemic HT triggers chronic neurodegenerative processes in ischemic penumbra, suggesting that similar fever-triggered effects may annul the benefit of early recirculation in stroke patients over the long-term.
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Galagarza, Oscar A; Kuhn, David D; Smith, Stephen A; Hrubec, Terry C
2017-09-01
Striped catfish (Pangasius hypophthalmus) is a valuable aquaculture fish species produced primarily in Southeast Asia. In the United States, it is bred as an ornamental species. Striped catfish has high productivity and great demand in numerous countries around the world, yet little is known about its normal physiology. The objective of this study was to establish hematologic and blood chemistry RIs for healthy juvenile Striped catfish. Blood samples were collected from 70 Striped catfish raised in recirculating aquaculture systems. Whole blood and plasma samples were analyzed for multiple hematologic and chemistry variables using standard techniques. The RIs for hematology were as follows: PCV 23.5-35.9%, MCV 106.3-156.6 fL, RBC count 1.79-2.75 × 10 6 cells/μL, thrombocytes 26,318-73,333 cells/μL, total WBC count 36,294-94,286 cells/μL, total lymphocytes 18,997-59,998 cells/μL, small lymphocytes 13,763-51,490 cells/μL, large lymphocytes 715-21,200 cells/μL, granulocytes 4504-18,291 cells/μL, and monocytes 0-7549 cells/μL. Plasma chemistry RIs were the following: ALP 32.7-74.6 U/L, AST 20.3-1235.8 U/L, sodium 135.2-147.7 mmol/L, potassium 3.3-5.0 mmol/L, chloride 120.1-133.6 mmol/L, calcium 2.7-3.6 mmol/L, magnesium 0.9-1.3 mmol/L, phosphorous 1.4-2.7 mmol/L, glucose 4.6-7.6 mmol/L, cholesterol 2.8-5.3 mmol/L, total protein 30-42 g/L, albumin 7-11 g/L, globulin 22-32 g/L, albumin:globulin ratio 0.27-0.37, creatinine 0-8 μmol/L, and osmolality 251.8-327.9 mOsm/kg. Reference intervals reported here can help veterinarians and fish health specialists monitor the health status of Striped catfish under recirculating aquaculture conditions for research, exhibition, and production purposes. © 2017 American Society for Veterinary Clinical Pathology.
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Energy Technology Data Exchange (ETDEWEB)
Chung, Jinwook [R& D Center, Samsung Engineering Co., Ltd., 415-10 Woncheon-dong, Youngtong-gu, Suwon, Gyeonggi-do 443-823 (Korea, Republic of); Kim, Seungjin; Baek, Seungcheon [Department of Civil and Environmental Engineering, Hanyang University, Sa 3-dong, Sangnok-gu, Ansan, Gyeonggi-do 426-791 (Korea, Republic of); Lee, Nam-Hoon [Department of Environmental & Energy Engineering, Anyang University, 22 Samdeok-ro, 37 Beon-gil, Manan-gu, Anyang, Gyeonggi-do 430-714 (Korea, Republic of); Park, Seongjun; Lee, Junghun; Lee, Heechang [Department of Civil and Environmental Engineering, Hanyang University, Sa 3-dong, Sangnok-gu, Ansan, Gyeonggi-do 426-791 (Korea, Republic of); Bae, Wookeun, E-mail: wkbae@hanyang.ac.kr [Department of Civil and Environmental Engineering, Hanyang University, Sa 3-dong, Sangnok-gu, Ansan, Gyeonggi-do 426-791 (Korea, Republic of)
2015-03-21
Highlights: • To solve the drawbacks (NH{sub 4}{sup +} accumulation) of leachate recirculation, ex-situ SBR was applied. • Produced NO{sub 2}{sup −} was recirculated and denitrified to N{sub 2} in landfill with insufficient carbon source. • Despite the inhibition of methanogenesis by DO and nitrate, CH{sub 4} fraction eventually increased. - Abstract: Leachate recirculation for rapid landfill stabilization can result in the accumulation of high-strength ammonium. An on-site sequencing batch reactor (SBR) was therefore, applied to oxidize the ammonium to nitrite, which was then recirculated to the landfill for denitrification to nitrogen gas. At relatively higher ammonium levels, nitrite accumulated well in the SBR; the nitrite was denitrified stably in the landfill, despite an insufficient biodegradable carbon source in the leachate. As the leachate was recirculated, the methane and carbon dioxide contents produced from the landfill fluctuated, implying that the organic acids and hydrogen produced in the acid production phase acted as the carbon source for denitrification in the landfill. Leachate recirculation combined with ex-situ partial nitrification of the leachate may enhance the biodegradation process by: (a) removing the nitrogen that is contained with the leachate, and (b) accelerating landfill stabilization, because the biodegradation efficiency of landfill waste is increased by supplying sufficient moisture and its byproducts are used as the carbon source for denitrification. In addition, partial nitrification using an SBR has advantages for complete denitrification in the landfill, since the available carbon source is in short supply in aged landfills.
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International Nuclear Information System (INIS)
Mattias, H.B.
1976-01-01
Boiler recirculation pumps are important components of modern power stations. The development of large recirculation pumps up to a driving power of 1,500 kW was faced with some problems in meeting the plant requirements. In this paper, the present state of development is dealt with. The development problems in the fields of hydrodynamics, cavitation, corrosion and erosion are dealt with as well as the problems of the design of the casing with regard to thermodynamics and strength. Finally, operational experience with the boiler recirculation pump for 600 MW power stations will be reported on. (orig./AK) [de
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Gjesteland, Ingrid
2013-01-01
This thesis describes an extensive study on how water quality changes over time in a small scale recirculating system where waste water from smolt production was used to grow lettuce for commercial use. The treatment effect of lettuce on different solutions was tested and corresponding lettuce yield was evaluated. In order to enhance the treatment effect a rock wool filter was used on certain solutions. Important water quality parameters were measured every day, and the element concentration ...
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DEFF Research Database (Denmark)
Lieke, Kirsten Inga; Rosenørn, Thomas; Pedersen, Jannik
2013-01-01
microscopy (TEM) grids on two stages. Micro- and nanostructural characteristics of sin-gle particles were studied by TEM. Image analysis was carried out on overview and high-resolution images, revealing influence of the exhaust gas treatment (scrubber) on the particle morphology and mixing state. Soot......This work provides insight into the morphology and mixing state of submicron particles in diesel exhaust from a ship engine with an exhaust gas recirculation scrubber. Particles from this low-speed ship engine on test bed were collected using a microiner-tial impactor with transmission electron...
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Estrada, Nubia Luz; Böhlke, J K; Sturchio, Neil C; Gu, Baohua; Harvey, Greg; Burkey, Kent O; Grantz, David A; McGrath, Margaret T; Anderson, Todd A; Rao, Balaji; Sevanthi, Ritesh; Hatzinger, Paul B; Jackson, W Andrew
2017-10-01
Natural perchlorate (ClO 4 - ) in soil and groundwater exhibits a wide range in stable isotopic compositions (δ 37 Cl, δ 18 O, and Δ 17 O), indicating that ClO 4 - may be formed through more than one pathway and/or undergoes post-depositional isotopic alteration. Plants are known to accumulate ClO 4 - , but little is known about their ability to alter its isotopic composition. We examined the potential for plants to alter the isotopic composition of ClO 4 - in hydroponic and field experiments conducted with snap beans (Phaseolus vulgaris L.). In hydroponic studies, anion ratios indicated that ClO 4 - was transported from solutions into plants similarly to NO 3 - but preferentially to Cl - (4-fold). The ClO 4 - isotopic compositions of initial ClO 4 - reagents, final growth solutions, and aqueous extracts from plant tissues were essentially indistinguishable, indicating no significant isotope effects during ClO 4 - uptake or accumulation. The ClO 4 - isotopic composition of field-grown snap beans was also consistent with that of ClO 4 - in varying proportions from irrigation water and precipitation. NO 3 - uptake had little or no effect on NO 3 - isotopic compositions in hydroponic solutions. However, a large fractionation effect with an apparent ε ( 15 N/ 18 O) ratio of 1.05 was observed between NO 3 - in hydroponic solutions and leaf extracts, consistent with partial NO 3 - reduction during assimilation within plant tissue. We also explored the feasibility of evaluating sources of ClO 4 - in commercial produce, as illustrated by spinach, for which the ClO 4 - isotopic composition was similar to that of indigenous natural ClO 4 - . Our results indicate that some types of plants can accumulate and (presumably) release ClO 4 - to soil and groundwater without altering its isotopic characteristics. Concentrations and isotopic compositions of ClO 4 - and NO 3 - in plants may be useful for determining sources of fertilizers and sources of ClO 4 - in their growth
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High-yield production of a human monoclonal IgG by rhizosecretion in hydroponic tobacco cultures
Madeira, L.M.; Szeto, T.H.; Henquet, Maurice; Raven, Nicole; Runions, John; Huddleston, Jon; Garrard, Ian; Drake, P.M.W.; Ma, Julian K.C.
2016-01-01
Rhizosecretion of recombinant pharmaceuticals from in vitro hydroponic transgenic plant cultures is a simple, low cost, reproducible and controllable production method. Here, we demonstrate the application and adaptation of this manufacturing platform to a human antivitronectin IgG1
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Ardiansyah, A; Fotedar, R
2016-07-01
Duckweed (Lemna minor L.) is a potential biofilter for nutrient removal and acts as a substrate for heterotrophic bacteria in recirculating aquaculture systems (RAS). Here, we determined the effects of harvesting frequency of duckweed on heterotrophic bacteria in RAS. Twelve independent RAS consisting of fish-rearing tank, biofilter tank and waste-collection tank were used to study the interactions between duckweed harvest frequencies up to 6 days and the composition, abundance and diversity of heterotrophic bacteria. After 36 days, heterotrophic bacteria in the biofilter tank were primarily Gram-negative cocci or ovoid, coccobacilli, Gram-negative bacilli and Gram-positive bacilli. Most bacterial genera were Bacillus and Pseudomonas while the least common was Acinetobacter. Duckweed harvested after every 2 days produced the highest specific growth rates (SGR) and total harvested biomass of duckweed, but harboured less abundant bacteria, whereas 6-day harvests had a higher growth index (GI) of duckweed than 2-day harvests, but caused a poor relationship between SGR and biomass harvest with the abundance and diversity of heterotrophic bacteria. Stronger correlations (R(2) > 0·65) between duckweed SGR and biomass harvest with the heterotrophic bacteria diversity were observed at 4-day harvest frequency and the control. This study provides significant information on the interaction between the harvest frequency of duckweed and the composition, abundance and diversity of heterotrophic bacteria in recirculating aquaculture systems (RAS). Different harvest frequencies significantly influence the abundance and diversity of heterotrophic bacteria, which in turn may influence the nitrogen uptake efficiency of the system. The research is useful in improving the efficiency of removing nitrogenous metabolites in RAS directly by the duckweed and associated heterotrophic bacteria. © 2016 The Society for Applied Microbiology.
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Bubenheim, David L.; Wignarajah, Kanapathipillai; Kliss, Mark H. (Technical Monitor)
1996-01-01
Recovery of resources from waste streams is essential for future implementation and reliance on a regenerative life support system. The major waste streams of concern are from human activities and plant wastes. Carbon, water and inorganics are the primary desired raw materials of interest. The goal of resource recovery is maintenance of product quality to insure support of reliable and predictable levels of life support function performance by the crop plant component. Further, these systems must be maintained over extended periods of time, requiring maintenance of nutrient solutions to avoid toxicity and deficiencies. Today, reagent grade nutrients are used to make nutrient solutions for hydroponic culture and these solutions are frequently changed during the life cycle or sometimes managed for only one crop life cycle. The focus of this study was to determine the suitability of the ash product following incineration of inedible biomass as a source of inorganic nutrients for hydroponic crop production. Inedible wheat biomass was incinerated and ash quality characterized. The incinerator ash was dissolved in adequate nitric acid to establish a consistent nitrogen concentration in all nutrient solution treatments. Four experimental nutrient treatments were included: control, ash only, ash supplemented to match control, and ash only quality formulated with reagent grade chemicals. When nutrient solutions are formulated using only ash following-incineration of inedible biomass, a balance in solution is established representing elemental retention following incineration and nutrient proportions present in the original biomass. The resulting solution is not identical to the control. This imbalance resulted in suppression of crop growth. When the ash is supplemented with nutrients to establish the same balance as in the control, growth is identical to the control. The ash appears to carry no phytotoxic materials. Growth in solution formulated with reagent grade chemicals
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Removal of 4-chlorobenzoic acid from spiked hydroponic solution by willow trees (Salix viminalis)
DEFF Research Database (Denmark)
Deavers, K.; Macek, T.; Karlson, U.
2010-01-01
. Methods The removal of 4-CBA by willow trees was investigated with intact, septic willow trees growing in hydroponic solution and with sterile cell suspensions at concentrations of 5 mg/L and 50 mg/L 4-CBA. Nutrient solutions with different levels of ammonium and nitrate were prepared to achieve different...
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Directory of Open Access Journals (Sweden)
Björn Baßmann
2017-07-01
Full Text Available African catfish (Clarias gariepinus were investigated for physiological stress parameters to assess the influence of different cultivation techniques on fish welfare. The fish were reared in two conceptually identical recirculating aquaculture systems (RAS constructed in a greenhouse. One system was combined with a floating raft hydroponic unit to culture cucumbers (Cucumis sativus only using the process water. The second system remained without the plant cultivation unit and functioned as the control. Water quality was monitored regularly by measuring dissolved nutrients and physical water parameters. During 87 days, a total of 71 fish from each system (n = 142 were studied, with a final sampling of all fish (n = 107 at the end of the experiment. Blood from the caudal vein was analyzed for the stress hormone cortisol and the glucose concentration. In addition, fish were investigated for external injuries on their skin, fins and barbels. The results demonstrate that the system design had no influence on fish mortalities and growth rates. Furthermore, cortisol and blood glucose levels did not differ significantly between the two systems. However, the number of external injuries was significantly lower in the aquaponics, providing evidence that co-cultivation of fish and plants might offer benefits to the welfare of the fish.
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Production density in excess of a critical threshold can result in a negative relationship between stocking density and fish production. This study was conducted to evaluate production characteristics of juvenile cobia Rachycentron canadum, reared to market size in production-scale recirculating aq...
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Directory of Open Access Journals (Sweden)
Saleem Mustafa
2015-11-01
Full Text Available Closing the cycle of commercial species of fish in a recirculating aquaculture system is gaining importance for a number of practical advantages. Founder broodstock originating from the wild population is conditioned to live in hatchery tanks under suitable environmental and feeding conditions and is induced to breed. The juveniles are grown to maturity and facilitated to spawn in captivity to close the life cycle in the hatchery. This experiment was carried out on tiger grouper (Epinephelus fuscoguttatus. After preliminary observations, it was possible to identify appropriate environmental conditions in terms of water quality parameters, volume of broodstock tanks and ration. Growth was nearly isometric (growth exponent = 2.9185 and the condition factor = 1.86. This reflected good management conditions. Cues that trigger sex reversal in this protogynous fish in the hatchery were different from those that operate in nature. It appears that the differentiation of some individuals of a cohort into male sex is linked to socio-demographic cues as well as internal condition of the fish because it related to age and physiological condition. This view was reinforced by a lack of response in young fish to similar cues. The information generated through this study defines what is required for optimum conditioning of tiger grouper broodstock and explains the cues involved in sex differentiation.
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Directory of Open Access Journals (Sweden)
Gong Jing
2014-01-01
Full Text Available Experiments were carried out in a spark-ignition engine fueled with iso-propanol/gasoline blends. Emission characteristics of this engine were investigated experimentally, including gaseous emissions (HC, CO, NOx and particulate matter emission in term of number and size distributions. The effects of different iso-propanol percentages, loads and exhaust gas recirculation rates on emissions were analyzed. Results show that the introduction of exhaust gas recirculation reduces the NOx emission and NOx emission gives the highest value at full load condition. HC and CO emissions present inconspicuous variations at all the loads except the load of 10%. Additionally, HC emission shows a sharp increase for pure propanol when the exhaust gas recirculation rate is up to 5%, while little variation is observed at lager exhaust gas recirculation rates. Moreover, the particulate matter number concentration increases monotonically with the increase of load and the decrease of exhaust gas recirculation rate. There exists a critical spark timing that produces the highest particulate matter number concentration at all the blending ratios.
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International Nuclear Information System (INIS)
Guo, Su; Liu, Deyou; Chen, Xingying; Chu, Yinghao; Xu, Chang; Liu, Qunming; Zhou, Ling
2017-01-01
Highlights: •A nonlinear dynamic model of recirculation DSG parabolic trough is developed. •Collector row, water separator and spray attemperator are modeled, respectively. •The dynamic behaviors of the collector field are simulated and analyzed. •Transfer functions of water level and outlet fluid temperature are derived. •Multi-model switching generalized predictive control strategy is developed. -- Abstract: This work describes and evaluates a new nonlinear dynamic model, and a new generalized predictive control scheme for a collector field of direct steam generation parabolic troughs in recirculation mode. Modeling the dynamic behaviors of collector fields is essential to design, testing and validation of automatic control systems for direct steam generation parabolic troughs. However, the behaviors of two-phase heat transfer fluids impose challenges to simulating and developing process control schemes. In this work, a new nonlinear dynamic model is proposed, based on the nonlinear distributed parameter and the nonlinear lumped parameter methods. The proposed model is used to simulate and analyze the dynamic behaviors of the entire collector field for recirculation mode direct steam generation parabolic troughs under different weather conditions, without excessive computational costs. Based on the proposed model, transfer functions for both the water level of the separator and outlet steam temperatures are derived, and a new multi-model switching generalized predictive control scheme is developed for simulated control of the plant behaviors for a wide region of operational conditions. The proposed control scheme achieves excellent control performance and robustness for systems with long delay, large inertia and time-varying parameters, and efficiently solves the model mismatching problem in direct steam generation parabolic troughs. The performances of the model and control scheme are validated with design data from the project of Integration of Direct