scholarly journals Effect of water flow rate and feed training on "pacamã" (Siluriforme: Pseudopimelodidae) juvenile production

2011 ◽  
Vol 63 (4) ◽  
pp. 973-979 ◽  
Author(s):  
R.K. Luz ◽  
J.C.E. Santos ◽  
M.M. Pedreira ◽  
E.A. Teixeira
Keyword(s):  
Growth Rate ◽  
Water Flow ◽  
Flow Rate ◽  
Specific Growth ◽  
Water Flow Rate ◽  
Flow Rates ◽  
Artemia Nauplii ◽  
Active Feeding ◽  
Dry Diet ◽  
Reduced Water

The effects of different water flow rates and feed training on the production of "pacamã" Lophiosilurus alexandri juveniles were evaluated. In the first experiment, nine day post-hatch larvae (n= 2,400) were stocked at a density of 5 larvae/L. Different water flow (F) rates were tested: F1 = 180; F2 = 600; F3 = 1,300; and F4 = 2,600mL/min. Artemia nauplii were offered as food during the first 15 days of active feeding. In the second experiment for feed training, 720 juveniles (total length of 22.2mm) were stocked at a density of 1.5 juveniles/L. A water flow rate similar to F1 was used. The use of extruded dry diet was tested, and feed training was done with and without other enhanced flavors (Artemia nauplii or Scott emulsion). The water flow rates did not influence the survival or growth of L. alexandri. Cannibalism occurred during feed training. The worst survival, specific growth rate and high mortality were found with the use of extruded dry diet, while similar values were registered with the different feed training diets used. Reduced water flow rate can be used to lower water consumption during larviculture and feed training of L. alexandri.

Effects of Water Flow Rate on Fatigue Life of Carbon Steel in Simulated LWR Environment Under Low Strain Rate Conditions

2003 ◽  
Vol 125 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Akihiko Hirano ◽  
Michiyoshi Yamamoto ◽  
Katsumi Sakaguchi ◽  
Tetsuo Shoji ◽  
Kunihiro Iida
Keyword(s):  
Fatigue Life ◽  
Carbon Steel ◽  
Strain Rate ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Flow Rates ◽  
Life Evaluation ◽  
Significant Difference ◽  
Fatigue Life Evaluation

The flow rate of water flowing on a steel surface is considered to be one of the important factors strongly influencing the fatigue life of the steel, because the water flow produces difference in the local environmental conditions. The effect of the water flow rate on the fatigue life of a carbon steel was thus investigated experimentally. Fatigue testing of the carbon steel was performed at 289°C for various dissolved oxygen contents (DO) of less than 0.01 and 0.05, 0.2, and 1 ppm, and at various water flow rates. Three different strain rates of 0.4, 0.01, and 0.001 %/s were used in the fatigue tests. At the strain rate of 0.4 %/s, no significant difference in fatigue life was observed under the various flow rate conditions. On the other hand, at 0.01 %/s, the fatigue life increased with increasing water flow rate under all DO conditions, such that the fatigue life at a 7 m/s flow rate was about three times longer than that at a 0.3 m/s flow rate. This increase in fatigue life is attributed to increases in the crack initiation life and small-crack propagation life. The major mechanism producing these increases is considered to be the flushing effect on locally corrosive environments at the surface of the metal and in the cracks. At the strain rate of 0.001 %/s, the environmental effect seems to be diminished at flow rates higher than 0.1 m/s. This behavior does not seem to be explained by the flushing effect alone. Based on this experimental evidence, it was concluded that the existing fatigue data obtained for carbon steel under stagnant or relatively low flow rate conditions may provide a conservative basis for fatigue life evaluation. This approach seems useful for characterizing fatigue life evaluation by expressing increasing fatigue life in terms of increasing water flow rate.

Effects of water flow rate on growth rate, mortality and biomass return of abalone in slab tanks

2009 ◽  
Vol 41 (6) ◽  
pp. 839-846 ◽  
Author(s):  
Matthew Wassnig ◽  
Rodney D Roberts ◽  
Anton Krsinich ◽  
Robert W Day
Keyword(s):  
Growth Rate ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate

201 Impact of Water Flow Rate on Finishing Pig Performance

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 68-69
Author(s):  
Hannah E Miller ◽  
Jorge Y Perez-Palencia ◽  
Crystal L Levesque ◽  
Robert C Thaler
Keyword(s):  
Body Weight ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Low Flow ◽  
Flow Rates ◽  
Finishing Pig ◽  
Daily Water ◽  
Pig Performance ◽  
High Treatment

Abstract A survey of South Dakota pork producers in 2019 demonstrated that water flow rate for nipple drinkers was highly variable among barns. Sixty-eight percent had water flow rates above the recommended rate of 500–1,000 mL/min (NSNG, 2010). The objective of this study was to determine the impact of water flow rate on finishing pig performance during the summer months. A total of 396 mixed-sex pigs, in two groups, were utilized in a 77-day trial (34.55 to103.8 kg BW) with 6 pigs/pen. Pens were assigned to one of three water flow rates (high, medium, low) based on the 3-hole diameters of the commercial water nipples used in the facility (2.0, 1.0, 0.80 mm; n = 22 pens/treatment). Daily water usage was recorded for each treatment along with room temperature, outside temperature, and relative humidity. Individual pen water flow rate was recorded every two weeks. At every diet phase change (26± 2.6 days), feed disappearance and individual pig body weight were recorded. Water flow rates averaged 1846±188, 906±214, 508±100 mL/min for high, medium, and low flow rates, respectively. Daily water disappearance for high, medium, and low treatments were 6.8, 2.3, 1.7±3.2 liters/pig, respectively. Final body weight (BW; 103.8±7.4 kg) did not differ. Daily gain (ADG) from 34.5±4.5 to 55.5±4.6 kg BW was greatest (P < 0.05) for high treatment. Daily intake (ADFI) and gain:feed (G:F) from 55.5±4.6 to 79.1±5.3 kg BW were greatest (P < 0.05) for high treatment. Cumulative ADFI was 2.27, 2.18, 2.16±0.16 kg (P < 0.05) in high, medium, and low flow ranges, respectively. There was no differences in cumulative ADG or G:F. Water flow rate had a significant impact on ADFI although there was minimal impact on gain and G:F. Water nipples should be regularly checked as part of normal barn maintenance to ensure adequate, but not excessive, water is available.

scholarly journals Performance of Solar Absorption-Subcooled Compression Hybrid Cooling System for Different Flow Rates of Hot Water

2020 ◽  
Vol 10 (3) ◽  
pp. 810 ◽  
Author(s):  
Jinfang Zhang ◽  
Zeyu Li ◽  
Yue Jing ◽  
Yongrui Xu
Keyword(s):  
Energy Saving ◽  
Water Flow ◽  
Flow Rate ◽  
Cooling System ◽  
Water Flow Rate ◽  
Hot Water ◽  
Solar Absorption ◽  
Flow Rates ◽  
High Rise ◽  
Daily Energy

The solar absorption-subcooled compression hybrid cooling system (SASCHCS) is tech-economically feasible for high-rise buildings. Since such a system operates with no auxiliary heat source, the performance coupling of its absorption subsystem and solar collectors is sensitive to the variation of hot water flow rate. In this regard, the relationship of system performance and hot water flow rate is required to be clarified exactly. Therefore, this paper aims to illustrate the effect mechanism of hot water flow rate and to propose the corresponding decision criterion. The case study is based on a typical high-rise office building in subtropical Guangzhou. The daily working process of this system with different hot water flow rates is simulated and analyzed. Subsequently, the useful heat of collectors and cooling capacity of the absorption subsystem with the hot water flow rate is discussed in detail. The results show that the SASCHCS operates with hot water temperatures ranging from 60 °C to 90 °C. The energy saving increases with the rise of hot water flow rate, but such variation tends to be flat for the excessively high flow rate. As the collector flow rate increases from 1 m3/h to 10 m3/h, the daily energy saving improves by 21% in August. Similarly, the daily energy saving increases by 37.5% as generator hot water flow rate increases from 1 m3/h to 10 m3/h. In addition, the collector flow rate of 3.6 m3/h (13.33 (kg/m2 h)) and the generator flow rate of 5.2 m3/h (19.26 (kg/m2 h)) are optimal for the annual operation, with considering power consumption of water pumps. This paper is helpful for the improvement of SASCHCS operating performance.

scholarly journals Experimental Study on Thermal Radiation Attenuation Using Water Mist of Twin-fluid Atomizer

2021 ◽  
Vol 35 (4) ◽  
pp. 24-32
Author(s):  
Jae Geun Jo ◽  
Chi Young Lee
Keyword(s):  
Thermal Radiation ◽  
Water Flow ◽  
Flow Rate ◽  
Air Flow ◽  
Water Flow Rate ◽  
Water Mist ◽  
Air Flow Rate ◽  
Radiation Attenuation ◽  
Rate Condition ◽  
Flow Rates

In this study, the thermal radiation attenuation performance of water mist was investigated using twin-fluid atomizers. The water and air flow rates of Small atomizer were 36~105 g/min and 10~30 L/min, whereas those of Large atomizer were 37~300 g/min and 20~60 L/min, respectively. In the present experimental range, the thermal radiation attenuation of Small atomizer and Large atomizer were 6.1~11.9% and 5.2~14.6%, respectively. With the increase in water and air flow rates, the thermal radiation attenuation increased, and under similar water and air flow rate conditions, Small atomizer showed higher thermal radiation attenuation than Large atomizer. Based on the present experimental data, it was found that the air (gas) discharge area is a potentially important factor in determining the thermal radiation attenuation performance. Additionally, through the analysis of thermal radiation attenuation per unit water flow rate, it was confirmed that the twin-fluid atomizer can result in higher thermal radiation attenuation than the single-fluid atomizer under the same water flow rate condition.

Displacement of Fluometuron and Diuron through Saturated Glass Beads and Soil

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 544-548 ◽  
Author(s):  
J. M. Davidson ◽  
P. W. Santelmann
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Glass Bead ◽  
Water Flow Rate ◽  
Soil Surface ◽  
Chloride Ion ◽  
Glass Beads ◽  
Low Flow ◽  
Flow Rates ◽  
Loam Soil

Solutions containing 3-(m-trifluromethylphenyl)-l,l-di-methylurea (fluometuron) or 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) were displaced through saturated 250-μ glass beads or through Norge loam soil at two water flow rates. The procedure used allowed uniform application of herbicide solutions to the soil surface and subsequent displacement of the herbicide through soil or glass bead columns at a constant water flow rate. Fluometuron was as mobile as the chloride ion at both high and low flow rates. The shape of the fluometuron distribution curves obtained at the two flow rates were distinctly different. The volume of water required to displace fluometuron through a material that adsorbed the herbicide was greater than that necessary to displace the fluometuron through materials giving a smaller amount of adsorption. More diuron was adsorbed by the glass bead system than fluometuron.

scholarly journals Effect of prey concentrations and feed training on production of Hoplias lacerdae juvenile

2015 ◽  
Vol 87 (2) ◽  
pp. 1125-1132 ◽  
Author(s):  
RONALD K. LUZ ◽  
MARIA CÉLIA PORTELLA
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Second Phase ◽  
Prey Concentration ◽  
Total Length ◽  
Formulated Diet ◽  
Artemia Nauplii ◽  
Active Feeding

The aim of this work was to investigate the effects of daily prey concentration during the first 15 days of active feeding of Hoplias lacerdae larvae, and the juvenile size on the feed training. In the first phase, the larvae received five Artemia nauplii concentrations (P). In the second phase, the juveniles from each treatment were trained to accept formulated diet. Superior growth was related to higher initial daily prey concentrations (900 and 1100 nauplii larvae-1). During feed training, the growth tendency was similar to that verified in the first phase. The lowest values of specific growth rate (SGR) were registered after the introduction of the semi-moist diet used in the feed training. However, the values of SGR recovered along the experiment and similar rates were found among the treatments. Survival, mortality and cannibalism were similar in the different treatments at the end of both phases. It can be concluded that: the prey concentration affects growth of H. lacerdae during the first 15 days of active feeding, and feed training can be initialized with juveniles of about 16 mm of total length.

scholarly journals Effect of pad water flow rate on evaporative cooling system efficiency in laying hen housing

2020 ◽  
Vol 51 (4) ◽  
pp. 209-219
Author(s):  
Mohamed Saied Ghoname
Keyword(s):  
Water Flow ◽  
Air Temperature ◽  
Flow Rate ◽  
Indoor Air ◽  
Cooling System ◽  
Water Flow Rate ◽  
Comfort Zone ◽  
Flow Rates ◽  
Saturation Efficiency ◽  
The Mean

An experiment was conducted in three commercial laying hen houses with 32-week-old hens in the summer of 2017 in a commercial farm in Gharbia Province, Egypt (31.06ºN, 31.16ºE) using an evaporative pad cooling system to determine the most suitable water flow rate for maintaining indoor air temperature within the thermal comfort zone. The experiment was conducted using three different water flow rates, i.e. 4.76, 5.65, and 6.35 L min–1.m–2, to assess the effect of different water flow rates on evaporative pad cooling system performance and determine the most suitable water flow rate for maintaining the thermal comfort zone of laying hens. The evaporative pad cooling system maintained the mean indoor air temperature below 28°C. The mean indoor air relative humidity during the experimental period ranged from 72.6 to 73.8%. The 4.76 L min–1.m–2 water flow rate resulted in the highest saturation efficiency (ca. 73.75%). In contrast, the 6.35 L min–1 m–2 water flow rate resulted in the lowest saturation efficiency (70.63%). The mean cooling energy values were 69.11, 66.0, and 66.65 kwh for water flow rates of 4.76, 5.56, and 6.35 Lmin–1m–2, respectively. The highest temperature-humidity index was 27.78°C, which indicated that birds were not stressed in all treatments.

scholarly journals Water Flow Affects Zooplankton Feeding by the Scleractinian CoralGalaxea fascicularison a Polyp and Colony Level

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Tim Wijgerde ◽  
Pascal Spijkers ◽  
Eric Karruppannan ◽  
Johan A. J. Verreth ◽  
Ronald Osinga
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Marine Invertebrates ◽  
Abiotic Factors ◽  
Water Flow Rate ◽  
Interactive Effects ◽  
Feeding Rates ◽  
Flow Rates ◽  
Coral Heterotrophy ◽  
Colony Level

Several factors may affect heterotrophic feeding of benthic marine invertebrates, including water flow rate and polyp context (i.e., the presence of neighbouring polyps). We tested the interactive effects of water flow rate and polyp context on zooplankton feeding by the scleractinian coralGalaxea fascicularis. Single polyps and colonies were incubated in a flow cell for 30 minutes with an ambientArtemianauplii concentration of 10,000 L−1and water flow rates ranging from 1.25 to 40 cm s−1. Water flow rate and polyp context showed significant main and interactive effects on feeding rates ofG. fascicularispolyps. More specifically, feeding rates were optimal at flow rates of 1.25 cm s−1for single polyps and 5 to 10 cm s−1for polyps inhabiting colonies. The presence of epizoic acoelomorph flatworms may have negatively affected the observed feeding rates, especially at high flow. Our results demonstrate that water flow affects coral feeding and thus heterotrophic nutrient input at both a polyp and colony level. These findings are of relevance to our understanding of how biotic and abiotic factors interact on coral heterotrophy and may serve to optimise coral aquaculture.

scholarly journals Experimental Evaluation of Optimum Water to Air Flow Ratio in an Induced Draft Wet Cooling Tower

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Talib O Ahmadu ◽  
Hamisu A Dandajeh
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cooling Tower ◽  
Air Flow ◽  
Water Flow Rate ◽  
Cooling Power ◽  
Cooling Efficiency ◽  
Flow Ratio ◽  
Flow Rates ◽  
Optimum Water

Cooling towers are devices used to dissipate waste thermal heat to the ambient environment. Appropriate cooling water and air flow rates are necessary to ensure optimum cooling power and cooling efficiency. Also, a simple design is required for cost effectiveness and minimal maintenance issues. This paper experimentally evaluates the cooling power, cooling efficiency, as well as the optimum water to air flow ratio in a spray type induced draft wet cooling tower. The cooling tower, 6 kW cooling capacity, was developed to operate without packings. The experiments were conducted for three different air flow rates and six different water flow rates. Four different inlet water temperatures of 35, 40, 45 and 50 oC were used. The temperature range is a typical range for inlet water temperature to the cooling tower for an absorption cooling system. For each of the inlet water temperatures, air and water flow rates were varied. The effects of this variation on cooling power and cooling efficiency were studied. Effect of varying water to air flow ratio on cooling power and cooling efficiency were studied. Results showed that the cooling power increased with increasing water flow rate, while the cooling efficiency decreased with increasing water flow rate. Decreasing the air flow rate was seen to cause a decrease in both cooling power and cooling efficiency. Maximum cooling power and cooling efficiency of 5.33 kW and 63% respectively were obtained. An optimum water to air flow ratio of 1.6 was obtained. The cooling tower was seen to have operated satisfactorily without packings. Keywords— cooling tower, cooling power, cooling efficiency, flow ratio, thermal energy

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