scholarly journals Effect of Water Flow on Underwater Wet Welded A36 Steel

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 682
Author(s):  
Eko Surojo ◽  
Aziz Harya Gumilang ◽  
Triyono Triyono ◽  
Aditya Rio Prabowo ◽  
Eko Prasetya Budiana ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Physical And Mechanical Properties ◽  
Shielded Metal Arc Welding ◽  
Effect Of Water ◽  
Bending Effect ◽  
Metal Arc Welding ◽  
A36 Steel

Underwater wet welding (UWW) combined with the shielded metal arc welding (SMAW) method has proven to be an effective way of permanently joining metals that can be performed in water. This research was conducted to determine the effect of water flow rate on the physical and mechanical properties (tensile, hardness, toughness, and bending effect) of underwater welded bead on A36 steel plate. The control variables used were a welding speed of 4 mm/s, a current of 120 A, electrode E7018 with a diameter of 4 mm, and freshwater. The results show that variations in water flow affected defects, microstructure, and mechanical properties of underwater welds. These defects include spatter, porosity, and undercut, which occur in all underwater welding results. The presence of flow and an increased flow rate causes differences in the microstructure, increased porosity on the weld metal, and undercut on the UWW specimen. An increase in water flow rate causes the acicular ferrite microstructure to appear greater, and the heat-affected zone (HAZ) will form finer grains. The best mechanical properties are achieved by welding with the highest flow rate, with a tensile strength of 534.1 MPa, 3.6% elongation, a Vickers microhardness in the HAZ area of 424 HV, and an impact strength of 1.47 J/mm2.

scholarly journals Effects of water flow rate and surface cover plant density on the growth of duckweed (Lemna minor L.)

2020 ◽  
Vol 5 (2) ◽  
pp. 98
Author(s):  
Renata Caprina Samantha Mahadewi Hutabarat ◽  
Didik Indradewa
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Plant Density ◽  
Lemna Minor ◽  
Water Flow Rate ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Surface Cover ◽  
Agriculture Sector ◽  
Effect Of Water

Globally, agriculture sector is facing unprecedented challenges in producing fertilizers and increasing the amount of fertilizer production without having negative impact on the environment. Thus, the organic fertilizers are needed to be produced as they do not give any damages to the environment. Duckweed plant has a lot of potentials that can be used in the agriculture sector. This plant can breed in approximately 16-48 hours by splitting. The water needs and its breeding speed ability are the basis for conducting this research. The research objective was to determine the effect of water flow rate and surface cover plant density on the growth and yield of duckweed plants. This research was conducted in November–December 2018 in Cangkringan District, Sleman, Special Region of Yogyakarta, Indonesia. The experiment was arranged in a split plot design. The main plot was irrigation water flow rate, consisting of two levels, namely large water flow rate (0.336 L.second-1) and small water flow rate (0.085 L.second-1). The subplot was the density of the duckweed plant surface cover, consisting of 10%, 20%, 40% and 60%. The results of this study indicated there was no effect of water flow rate on the plant growth, yield, and yield quality of duckweed plants. The C/N ratio of the duckweed plants fulfilled the requirement to be used as green manure.

The Effect of Water Flow Rate on Zooplankton and Its Role in Phosphorus Cycling in Small Impoundments

1993 ◽  
Vol 28 (6) ◽  
pp. 35-43 ◽  
Author(s):  
J. Ejsmont-Karabin ◽  
T. Weglenska ◽  
R. J. Wisniewski
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Exchange ◽  
Water Flow Rate ◽  
Turnover Time ◽  
Running Waters ◽  
Effect Of Water ◽  
Phosphorus Regeneration ◽  
Long Time ◽  
Zooplankton Communities

The attempt was made to determine the effect of water flow rate on Zooplankton density, trophic structure and the role of phosphorus regeneration by Zooplankton in phosphorus sedimentation in four impoundments with a water exchange from less than 10 hours to 8-12 days. Formation of stagnant environments together with the increasing time of water exchange in impoundments created good conditions for development of Zooplankton communities. As a result, the rate of phosphorus regeneration was higher and the turnover time of the total and seston phosphorus was shorter in impoundments than in streams above impoundments. A hypothesis that the stations with a long time of water exchange could be a kind of a trap for nutrients excluded from cycling in running waters is validated.

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