الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
According to the limited and scarcity water resources in Egypt, it has become necessary work to rationalize the water use with choose irrigation methods.
Localized irrigation methods are suitable for horticultural crops (Fruit- Vegetable), localized irrigation are achieved far-reaching interest in the economy in the scarce resources of water. It is a localized irrigation systems is surface drip irrigation system. Surface trickle irrigation cares with water distribution uniformity. The uniformity of water is related to the pressure variation along the lateral line. The main problem faced irrigation efficiency distribution under trickle irrigation systems was low pressure and flow rates along trickle line.
The Objectives of this investigation were:
Study the effect of by-pass technique on the hydraulic performance of different trickle irrigation systems equipment.
Evaluate the soil moisture distribution pattern under the modifying technique to improve trickle line efficiency and water distribution uniformity.
Laboratory experiments were carried out during 2012 to 2014 at the National Irrigation Laboratory of Agricultural Engineering Research Institute (AEnRI), Dokki, Giza.
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SUMMARY AND CONCLUSION
Wafaa M. Abd El-Bary, M.Sc., 2015
Materials and methods used: -
Used in this research tube, “low-density polyethylene hoses LDPE diameter of 16 mm with a thickness of 1.3 mm”. And use many factors:
1. Different flow rates and installation emitters:
- On-line emitter (14 Lph);
- Built-in emitter (8 Lhm).
2. Different microtube “spaghetti” diameter (by-pass technique):
- A diameter of 4 mm;
- A diameter of 8 mm.
Methodology in this study:-
Installation four microtubes in the last third on the trickle line.
- Evaluate performance emitters before installation by-pass technique.
- Evaluate performance emitters after installation by-pass technique. Installation microtube reverses emitters and the distance between the emitters and microtube 5 cm.
Repeat the previous two in the case of two steps: Installation of two microtubes in the last third on the trickle line.
The laboratory experiments were conducted under different pressures (0.50- 0.75- 1.00- 1.25 bar) were measured by:
- Emitter flow rates and it’s calibrated.
- Emitter variation manufacturer’s coefficient.
- Emission Uniformity.
Measuring moisture distribution under trickle irrigation systems in sandy soil.
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SUMMARY AND CONCLUSION
Wafaa M. Abd El-Bary, M.Sc., 2015
The main results in this study could be summarized in the following:
1- The emitters performance was determined by using performance equation which was been in power relation in between average of flow rates (Lph) and pressure (bar) according ASAE (1996).
a. On-line emitter with nominal flow rates of about 14 Lph and operating pressure (bar), data indicate that the emission uniformity ( ) was 96.28 % (Excellent), and of 3.91% (Excellent) and actual flow rate 13.68 Lph.
b. Built-in emitter; distance between emitters= 0.5m with nominal flow rates of about 8 Lhm, the emission uniformity ( ) was 98.84 % (Excellent), and of 1.16 % (Excellent) and actual flow 8 Lhm.
2- Using on-line emitter with nominal flow rates of about 14 Lph, trickle line length 30 meter, distance between emitters=0.5, 1.5 and 3 meters and microtube diameter (mid) 4mm, present the following results respectively, emitters performance equation which was been in power relation in between average of flow rates (by-pass) and pressure (bar).
a. Installing four microtubes, where emission uniformity equal to 90.9%, 96.28% and 96.03% (Excellent), Variation percentage of flow rates 2.56%, 1.53% and 2.26% respectively.
b. At installing two microtubes, present the following results respectively, where emission uniformity equal to 92.22%, 96.28% and 96.03% (Excellent), Variation percentage of flow rates 1.63%, 1.53% and 4.63% respectively.
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SUMMARY AND CONCLUSION
Wafaa M. Abd El-Bary, M.Sc., 2015
3- Using built-in emitter with nominal flow rates of about 8 Lhm, trickle line length 60 meter and at installing microtube diameter (mid) 4 and 8 mm present the following results respectively, emitters performance equation which was been in power relation in between average of flow rates (Lph) and pressure (bar).
a. At installing four microtubes, where emission uniformity ( ) equal to 95.64%, 94.67% (Excellent), Variation percentage of flow rates 3.89% and 3.28% respectively.
b. At installing two microtubes, present the following results respectively, where emission uniformity equal to 94.25% (Excellent) and Variation percentage of flow rates 6.59 % at mid 4mm. But at installing mid 8mm lead to no significant different in emitters performance through and emitters performance equation which was been in power relation in between average of flow rates (Lph) and pressure (bar).
4- The moisture distribution under trickle system in sandy soil increasing in depth; decrease between point source equilibrium in between two axis, at installing two microtube diameters (mid) 4 and 8 mm present the following results respectively, the system achieves 78% and 40% from the field capacity.
Recommendation from this study:
Firstly: When using on-line emitter with nominal flow rates of about 14 Lph: distance between emitters=3.0 m and microtube diameter 4mm.
Installing no. of microtubes= two at last third trickle line.
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SUMMARY AND CONCLUSION
Wafaa M. Abd El-Bary, M.Sc., 2015
Secondly: When using built-in emitter with nominal flow rates of about 8 Lhm: distance between emitters=0.5 m and microtube diameter 4mm.
Installing no. of microtubes= two at last third trickle line.
from the previous recommendation, can definition by-pass in Agriculture Engineering: A new technique consist of microtube using as a parallel line in last third of trickle line to improve trickle irrigation systems efficiency and water distribution uniformity.