scholarly journals Optimising water requirement for nursery rearing of rohu Labeo rohita (Hamilton, 1822) in large outdoor concrete tanks: influence of water depth on seed performance

2019 ◽  
Vol 66 (4) ◽  
Author(s):  
Pratap Chandra Das ◽  
Suhas Prakash Kamble
Keyword(s):  
Water Use ◽  
Water Depth ◽  
Labeo Rohita ◽  
Final Body Weight ◽  
Growth And Survival ◽  
Influence Of Water ◽  
Final Length ◽  
Similar Survival ◽  
Consumptive Water ◽  
Water Depths

A study was conducted to find the optimum water depth requirement for nursery rearing of rohu Labeo rohita (Hamilton, 1822). Nine concrete tanks of 50 m2 each (10 x 5 x 1.2 m) were grouped into three treatments T1, T2 and T3 and were filled upto 1.0, 0.75 and 0.5 m water depths, respectively. Each tank was stocked with 0.5 lakh hatchery produced spawn and reared for 20 days. The study revealed significant influence of water depth on growth and survival of fry (p<0.05). Though the final length of fry did not differ among the treatments (p>0.05), T3 with 0.5 m water depth showed significantly lower survival, final body weight and specific growth rate than the other two treatments (p<0.05), whereas tanks with 1.0 and 0.75 m water depths showed almost similar survival, final weight and SGR (p>0.05). Assessment of water use for production of every 1000 fry revealed significant reduction in total water use (TWU) with decreased water depth (p<0.05), while the consumptive water use (CWU) in terms of water exchange and replenishment did not differ between water depth treatments of 1.0 and 0.75 m. The results of the study indicate 0.75 m to be the ideal water depth with better water use efficiency for fry production of the species.

scholarly journals Numerical Analysis of Free-Surface Flows over Rubber Dams

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1271
Author(s):  
Chia-Ren Chu ◽  
Truc Thi Thu Tran ◽  
Tso-Ren Wu
Keyword(s):  
Free Surface ◽  
Water Depth ◽  
Discharge Coefficient ◽  
Free Surface Flows ◽  
Surface Flows ◽  
Eddy Simulation ◽  
Influence Of Water ◽  
Les Model ◽  
Rubber Dams ◽  
Water Depths

This study integrates a large eddy simulation (LES) model and volume of fluid (VOF) method to simulate the free-surface flows over inflexible circular-crested dams of different shapes. The simulated water depths and pressures on the dam surface are validated by the results of laboratory experiments. Then the numerical model examines the effects of the water depths and the Reynolds number on the hydrodynamic force and the discharge coefficient. The simulation results reveal that the time-averaged drag coefficient decreases as the downstream water depth H2 increases, while the influence of water depth H2 on the lift coefficients is less significant. Furthermore, the discharge coefficients of circular and elliptical dams, computed from the simulated velocity profiles over the crest of the dam, agree with the formulae suggested by previous studies when the downstream depth H2/H1 < 0.90. In contrast, the discharge coefficient of a tear-shape dam is slightly larger than those of circular dams.

scholarly journals Exploring Substrate Water Capture in Common Greenhouse Substrates through Preconditioning and Irrigation Pulsing Techniques

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1355
Author(s):  
Brian A. Schulker ◽  
Brian E. Jackson ◽  
William C. Fonteno ◽  
Joshua L. Heitman ◽  
Joseph P. Albano
Keyword(s):  
Water Depth ◽  
Initial Moisture Content ◽  
Irrigation Event ◽  
Pine Bark ◽  
Experimental Unit ◽  
Event Time ◽  
Influence Of Water ◽  
Hydration Characteristics ◽  
The Impact ◽  
Water Depths

Particles in a substrate create a network of pore pathways for water to move through, with size and shape determining the efficacy of these channels. Reduced particle size diversity can lead to increased leachate, poor substrate hydration, and an inefficient irrigation practice. This research examined the hydration characteristics of three greenhouse substrate components at three preconditioned initial moisture contents using subirrigation under five different irrigation durations and three water depths (2 mm, 20 mm, and 35 mm). Sphagnum peatmoss, coconut coir, and aged pine bark were tested at 67%, 50%, and 33% initial moisture (by weight). The objectives were to determine the impact of varying irrigation event durations (5, 10, 20, 30, 60 min) over a 60-min period, and the further influence of water depth and initial moisture, on the water capture abilities of peat, coir, and pine bark. The number of irrigation events depended on the irrigation event time of that experimental unit divided by the total time of 60 min, varying from 12, 6, 3, 2, and 1 event. Hydration efficiency was influenced by initial moisture content (IMC), water depth, pulsing duration, and inherent substrate characteristics (hydrophobicity/hydrophilicity). Initial MC had the largest impact on peat, regardless of water level or irrigation duration. Lower IMCs increased the hydrophobic response of peat, further reducing the amount of water the substrate was able to absorb. Pine bark had a 5–10% decrease in initial hydration between 67%, 50%, and 33% IMC, while coir’s hydrophilic nature reduced any IMC affects. At 50% IMC or less, coir had the highest volumetric water content (VWC) across all substrates, pulsing durations, and water depths. Water depth was found to increase initial hydration and final hydration 6–8% across all substrates. These three materials had altered and varied water capture responses depending on the combination of treatments employed. This work demonstrated the effects of intensity and exposure on substrates and the need for more integrated research for improving water use efficiency on container crops.

Decadal gross level assessment of green and blue consumptive water use over Indian agro-ecosystems

2021 ◽  
Vol 42 (17) ◽  
pp. 6628-6669
Author(s):  
Indrani Choudhury ◽  
B.K. Bhattacharya ◽  
R. Eswar ◽  
M. Sekhar
Keyword(s):  
Water Use ◽  
Consumptive Water Use ◽  
Consumptive Water

scholarly journals Microplastic contamination of the drilling bivalve Hiatella arctica in Arctic rhodolith beds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sebastian Teichert ◽  
Martin G. J. Löder ◽  
Ines Pyko ◽  
Marlene Mordek ◽  
Christian Schulbert ◽  
...  
Keyword(s):  
Polyethylene Terephthalate ◽  
Water Depth ◽  
The Arctic ◽  
Polymer Composition ◽  
Bivalve Species ◽  
Filter Feeder ◽  
Hiatella Arctica ◽  
Long Term Consequences ◽  
Water Depths

AbstractThere is an increasing number of studies reporting microplastic (MP) contamination in the Arctic environment. We analysed MP abundance in samples from a marine Arctic ecosystem that has not been investigated in this context and that features a high biodiversity: hollow rhodoliths gouged by the bivalve Hiatella arctica. This bivalve is a filter feeder that potentially accumulates MPs and may therefore reflect MP contamination of the rhodolith ecosystem at northern Svalbard. Our analyses revealed that 100% of the examined specimens were contaminated with MP, ranging between one and 184 MP particles per bivalve in samples from two water depths. Polymer composition and abundance differed strongly between both water depths: samples from 40 m water depth showed a generally higher concentration of MPs and were clearly dominated by polystyrene, samples from 27 m water depth were more balanced in composition, mainly consisting of polyethylene, polyethylene terephthalate, and polypropylene. Long-term consequences of MP contamination in the investigated bivalve species and for the rhodolith bed ecosystem are yet unclear. However, the uptake of MPs may potentially impact H. arctica and consequently its functioning as ecosystem engineers in Arctic rhodolith beds.

scholarly journals Production and water yield of cauliflower under irrigation depths and nitrogen doses

2019 ◽  
Vol 23 (8) ◽  
pp. 561-565
Author(s):  
Reginaldo M. de Oliveira ◽  
Rubens A. de Oliveira ◽  
Sanzio M. Vidigal ◽  
Ednaldo M. de Oliveira ◽  
Lorença B. Guimarães ◽  
...  
Keyword(s):  
Water Depth ◽  
Irrigation Water ◽  
Water Yield ◽  
Crop Evapotranspiration ◽  
Fresh Weight ◽  
Randomized Design ◽  
Mean Diameter ◽  
Irrigation Depth ◽  
Completely Randomized Design ◽  
Water Depths

ABSTRACT Cauliflower is a brassica produced and consumed in Brazil, whose cultivation depends on the adequate supply of water and nutrients. The objective of this study was to evaluate the effect of irrigation depths and nitrogen doses on the production components and water yield of cauliflower hybrid Barcelona CMS. The treatments consisted of five irrigation water depths (0, 75, 100, 125 and 150% of the crop evapotranspiration) combined with five nitrogen doses (0, 75, 150, 300 and 450 kg ha-1). The experiment was conducted in a completely randomized design with a split-plot arrangement. The effects of these factors were evaluated using the response surface methodology. The water yield of the crop decreases with increasing irrigation water depth; therefore, the yield is higher when water replenishment is lower than the recommended. The highest estimated total inflorescence yield is 24,547.80 kg ha-1, with a inflorescence mean diameter of 19.60 cm, a inflorescence mean height of 12.25 cm, and an inflorescence fresh weight of 858.90 g plant-1, obtained with an irrigation water depth equivalent to 132.09% of the crop evapotranspiration (ETc) and a nitrogen dose of 450 kg ha-1. The highest inflorescence diameter and height are obtained with an irrigation depth equivalent to 128.70 and 108.20% of ETc, respectively, and a nitrogen dose of 450 kg ha-1. Therefore, the best productivity response of the Barcelona CMS cauliflower hybrid can be obtained using an irrigation depth greater than the crop evapotranspiration, regardless of the nitrogen doses.

CONSUMPTIVE WATER USE OF RAINFED MAIZE IN NIGERIA

1986 ◽  
Vol 7 (2) ◽  
pp. 128-144 ◽  
Author(s):  
S.O. Ojo ◽  
M. Ijioma ◽  
A.O. Ojo
Keyword(s):  
Water Use ◽  
Consumptive Water Use ◽  
Consumptive Water

Mechanical Qualification of Dynamic Deep Water Power Cable

2011 ◽  
Author(s):  
Roger Slora ◽  
Stian Karlsen ◽  
Per Arne Osborg
Keyword(s):  
Water Depth ◽  
Deep Water ◽  
Failure Modes ◽  
Electrical Power ◽  
Oil And Gas Industry ◽  
Electrical Heating ◽  
Power Cable ◽  
Water Power ◽  
System Integrity ◽  
Water Depths

There is an increasing demand for subsea electrical power transmission in the oil- and gas industry. Electrical power is mainly required for subsea pumps, compressors and for direct electrical heating of pipelines. The majority of subsea processing equipment is installed at water depths less than 1000 meters. However, projects located offshore Africa, Brazil and in the Gulf of Mexico are reported to be in water depths down to 3000 meters. Hence, Nexans initiated a development programme to qualify a dynamic deep water power cable. The qualification programme was based on DNV-RP-A203. An overall project plan, consisting of feasibility study, concept selection and pre-engineering was outlined as defined in DNV-OSS-401. An armoured three-phase power cable concept assumed suspended from a semi-submersible vessel at 3000 m water depth was selected as qualification basis. As proven cable technology was selected, the overall qualification scope is classified as class 2 according to DNV-RP-A203. Presumed high conductor stress at 3000 m water depth made basis for the identified failure modes. An optimised prototype cable, with the aim of reducing the failure mode risks, was designed based on extensive testing and analyses of various test cables. Analyses confirmed that the prototype cable will withstand the extreme loads and fatigue damage during a service life of 30 years with good margins. The system integrity, consisting of prototype cable and end terminations, was verified by means of tension tests. The electrical integrity was intact after tensioning to 2040 kN, which corresponds to 13 000 m static water depth. A full scale flex test of the prototype cable verified the extreme and fatigue analyses. Hence, the prototype cable is qualified for 3000 m water depth.

An Experimental Study of Shallow Water Wave Statistics on Mild Bed Slopes

2011 ◽  
Author(s):  
Vasiliki Katsardi ◽  
Chris Swan
Keyword(s):  
Water Depth ◽  
Measured Data ◽  
Intermediate Water ◽  
Statistical Distributions ◽  
Spectral Bandwidth ◽  
Peak Period ◽  
Wave Statistics ◽  
Wave Heights ◽  
Bed Slope ◽  
Water Depths

This paper describes a new series of laboratory observations, undertaken in a purpose built wave flume, in which a number of scaled simulations of realistic ocean spectra were allowed to evolve over a range of mild bed slopes. The purpose of the study was to examine the distribution of wave heights and its dependence on the local water depth, d, the local bed slope, m, and the nature of the input spectrum; the latter considering variations in the spectral peak period, Tp, the spectral bandwidth and the wave steepness. The results of the study show that for mild bed slopes the statistical distributions of wave heights are effectively independent of both the bed slope and the spectral bandwidth. However, the peak period plays a very significant role in the sense that it alters the effective water depth. Following detailed comparisons with the measured data, the statistical distributions for wave heights in relatively deep water are found to be in reasonable agreement with the Forristall [1] and Glukhovskii [2] distributions. For intermediate water depths, the Battjes & Groenendijk [3] distribution works very well. However, for the shallowest water depths none of the existing distributions provides good agreement with the measured data; all leading to an over-estimate of the largest wave heights.

scholarly journals Effect of dietary incorporation of fish/prawn meal on performance of Catla catla (Hamilton) during nursery phase

2017 ◽  
Vol 64 (1) ◽  
pp. 44
Author(s):  
Pratap Chandra Das ◽  
Suhas Prakash Kamble ◽  
Kartik Chandra Parida ◽  
Kedar Nath Mohanta
Keyword(s):  
Fish Meal ◽  
Protein Efficiency Ratio ◽  
Specific Growth ◽  
Catla Catla ◽  
Efficiency Ratio ◽  
Groundnut Oil ◽  
Growth And Survival ◽  
Cooking Process ◽  
Final Weight ◽  
Final Length

Nursery evaluation of catla spawn was carried out by feeding three iso-nitrogenous diets (35% protein in raw and cooked form) for a period of 30 days. The three test diets (treatments) in raw form were: T1 - groundnut oil cake (GOC) + rice bran (RB) + vitamin-mineral (V-M) premix; T2 - GOC+RB+fish meal (FM) + V-M premix, T3 - GOC+RB+prawn meal (PM)+V-M premix. The diet groups GT1, GT2 and GT3 respectively were same feed combinations in cooked form. Incorporation of prawn meal as animal protein source led to significantly higher final weight, final length, % weight gain, specific growth rate (SGR) and protein efficiency ratio (PER) compared to diet with and without fish meal incorporation. Whereas, diet containing fish meal improved the fry growth and survival rate only when it was cooked. Cooked diet either with fish or prawn meal incorporation led to better fry growth over the respective non-cooked diets, revealing the advantage of cooking process for better nourishment in catla fry during nursery phase.

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