scholarly journals Performance of Control System Using Microcontroller for Sea Water Circulation

2018 ◽  
Vol 307 ◽  
pp. 012022 ◽  
Author(s):  
A. Indriani ◽  
Y. Witanto ◽  
A.S. Pratama ◽  
Supriyadi ◽  
Hendra ◽  
...  
Keyword(s):  
Control System ◽  
Sea Water ◽  
Water Circulation

Northern Light Offshore Pipeline – Negative Transport Temperature Inside the HDD

2021 ◽  
Author(s):  
Giuseppe Blasioli ◽  
Furio Marchesani ◽  
Maurizio Badalini ◽  
Vincenzo Luci ◽  
Tove Bekkeheien ◽  
...  
Keyword(s):  
Sea Water ◽  
Element Model ◽  
Water Circulation ◽  
Operating Conditions ◽  
Ice Formation ◽  
Circulation System ◽  
Directional Drilling ◽  
Radial Temperature ◽  
Pressure Losses ◽  
Offshore Pipeline

Abstract The transport of CO2 through offshore pipelines is one of the last business that the Operators are beginning to face, in line with the coming needs for climate change mitigations. The scenario for CO2 Capture, Transport and Storage anticipates capture and treatment at local plants, the transportation by ships in a liquid phase at low temperatures (close to −30 °C) to a terminal for the following offshore submarine transportation in a pipeline up to an injection well, for the final (and permanent) storage underground. In order to optimize the operating costs for CO2 transport via pipeline, and to reduce energy consumptions, no heating is applied from ship to pipeline inlet. In such case, the pipeline will reach approximately a temperature of −30 °C in the initial landfall section. The design of the offshore pipeline subject to this operating conditions, very cold fluid inside and a sea water temperature slightly over 0°C outside (North Sea), must face the possibility of ice formation around the pipe. For the Northern Lights project, this possibility has been analyzed and the HDD (Horizontal Directional Drilling) at landfall resulted the only section where the ice formation could jeopardize the pipeline integrity. Detailed assessment for both normal operating conditions and contingency cases has been performed. In the former case, a steady state thermal analysis with analytical method (thermal resistances) has been applied to calculate both the longitudinal, along the pipeline axis, and radial temperature profile: all the water inside the HDD freezes. Therefore, a water circulation system has been studied to prevent the ice formation. The pumping system required to ensure enough water flow has been dimensioned considering pressure losses inside the HDD. Power consumption in the order of 3 kW is expected. The breakdown of the pumps has been analyzed in order to determine the available time before the sea water freeze inside the HDD obstructing any circulation. A transient analysis has been carried out simulating the temperature after water circulation arrest. Both analytical and Finite Element Model have been used to calculate the transient process causing water freezing.

scholarly journals The aquarium and sea-water circulation system at the Plymouth Laboratory

1952 ◽  
Vol 31 (1) ◽  
pp. 193-211 ◽  
Author(s):  
Douglas P. Wilson
Keyword(s):  
Natural History ◽  
School Children ◽  
Life Histories ◽  
Sea Water ◽  
Water Circulation ◽  
Circulation System ◽  
Marine Animals ◽  
Public Display ◽  
Water Circulation System ◽  
Small Charge

The aquarium or tank room, to which visitors are admitted on payment of a small charge, was not designed primarily for public display, but was intended principally to facilitate scientific observations on the habits and life histories of marine animals. This original purpose it has never lost, but of recent years it has increasingly catered also for the steadily growing number of people interested in natural history, and for numerous classes of school-children brought by their teachers. Since the aquarium was re-opened in November 1946 attendances have shown a big increase over comparable pre-war figures.

A middle Cenomanian euselachian assemblage from the Dunvegan Formation of northwestern Alberta

2008 ◽  
Vol 45 (10) ◽  
pp. 1185-1197 ◽  
Author(s):  
Todd D. Cook ◽  
Mark V.H. Wilson ◽  
Alison M. Murray
Keyword(s):  
Sea Water ◽  
Water Circulation ◽  
Geographical Range ◽  
Western Interior Seaway ◽  
Salinity Variation ◽  
The Core ◽  
Core Composition ◽  
Circulation Patterns ◽  
Faunal Diversity ◽  
Insight Into

A euselachian assemblage was recovered from the middle Cenomanian Dunvegan Formation situated in northwestern Alberta. This assemblage is the most northern described within the Western Interior Seaway and provides an important insight into the euselachian faunal diversity of this little-known region of the seaway. Despite its high paleolatitude, the assemblage contains a number of elasmobranch taxa, including Hybodus , Squalicorax , Archaeolamna , Cretodus , Dallasiella , and Cretoxyrhina . The Dunvegan assemblage also contains the first known reports from Canada of the odontaspid shark Johnlongia parvidens , the cretoxyrhinid shark Protolamna carteri , and the ray Pseudohypolophus mcnultyi . This assemblage extends the northern geographical range of all taxa. Preliminary comparisons with other middle Cenomanian Western Interior Seaway assemblages show that the core composition of the Dunvegan assemblage is remarkably similar to that of other time-equivalent assemblages; however, conspicuously absent are species that are exceedingly common in other localities situated farther south. We suggest that absence of these taxa from the Dunvegan localities may be caused by a temperature intolerance associated with latitude and sea-water circulation patterns, or by an inability to inhabit environments that exhibit salinity variation.

scholarly journals Simulation of the Azov Sea Water Circulation Subject to the River Discharge

2015 ◽  
Author(s):  
V.V. Fomin ◽  
A.A. Polozok ◽  
I.N. Fomina ◽  
◽  
◽  
...  
Keyword(s):  
River Discharge ◽  
Sea Water ◽  
Water Circulation ◽  
Azov Sea

Hovering Control Based on Buoyancy Control Approach for Under-Actuated AUVs

2014 ◽  
Vol 687-691 ◽  
pp. 402-406
Author(s):  
Bao Gen Liu ◽  
Yu Ling Ye
Keyword(s):  
Control System ◽  
Sea Water ◽  
Control Law ◽  
Control Approach ◽  
Depth Data ◽  
Pressure Water ◽  
Water Tanks ◽  
Hovering Control ◽  
Buoyancy Control

A buoyancy control system was presented to realize the powerless descent/ascent motion for an under-actuated AUV like REMUS. The sea water was injected into or drained out of the pressure water tanks to tunes the residual buoyancy of the vehicle, and the buoyancy control was realized. An engineering hovering control law based on buoyancy control approach was proposed to keep the vehicle hovering at the programmed depth. The injection and drainage instructs were worked out only based on depth data and its difference, so the hovering control system need not additional sensors. The simple and reliable hovering control system was applied to a type of huge under-actuated AUV, and the experiment results show that it is feasible.

Characteristics of Temperature and Salinity Distribution in the Wonorejo Estuary, Surabaya, Based on Field Measurement

2017 ◽  
Vol 862 ◽  
pp. 102-106
Author(s):  
Anita Diah Pahlewi ◽  
Suntoyo ◽  
Wahyudi ◽  
Muhammad Taufik
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Vertical Mixing ◽  
Pollutant Dispersion ◽  
Bottom Layer ◽  
Water Area ◽  
Water Circulation ◽  
Salinity Distribution ◽  
Salinity Increase ◽  
Longitudinal Position

Wonorejo waters have a significant value, both economically and socially. One of ecosystem that have close relationships with Wonorejo waters is Estuary. Temperature and salinity have role in water circulation, where the water circulation have impact to some organism distribution and pollutant dispersion. The purpose of this study is to investigate the characteristic of temperature and salinity distribution in Wonorejo Estuary body’s water. Furthermore, it can be used for determining the type of Wonorejo Estuary. The observation has been done at Wonorejo Estuary in August 2015 to measure the vertical and horizontal temperature and salinity distribution. The measurement of temperature and salinity used Conductivity, Salinity, Temperature tool by YSI. The result show that commonly the temperature and salinity vertical profile are almost similar from surface layer until the bottom layer. But they have trend where the salinity increase, while the temperature decrease to the water depth. There is no thermocline layer due to the shallow water area, it is so from the upper layer until the bottom layer still influenced by dragforce and the vertical mixing between fresh water and sea water occurs. The horizontal temperature distribution in the open sea surface tend to zonation, which is not depend to longitudinal position. The salinity value in each depth are not change obviously indicate that there is a vertical well mixed between fresh water and sea water.

scholarly journals Deep water circulation in the Hunter Channel (Southwest Atlantic) in a late Pleistocene and Holocene by benthonic foraminifera

2019 ◽  
Vol 59 (1) ◽  
pp. 133-142
Author(s):  
N. P. Lukashina
Keyword(s):  
Late Pleistocene ◽  
Deep Water ◽  
Sea Water ◽  
Bottom Layer ◽  
Water Circulation ◽  
Southwest Atlantic ◽  
East Part ◽  
The North ◽  
Lower Circumpolar Deep Water ◽  
Argentine Basin

Was reconstructed deep-sea water circulation near the Hunter Channel (Rio Grande Rise – South-West Atlantic) in a late Pleistocene and Holocene (MIS 4-MIS 1) by benthonic foraminifera. Was studied three cores of bottom sediment. Now moves the upper North Atlantic deep water (NADW) through the Hunter Channel from the North to the South. The lower NADW in the same direction came in MIS 2 and in MIS 4. There was the lower Circumpolar deep water (CPDW), NADW and Antarctic bottom water (AnBW) in MIS 3 periodically. CPDW prevail in a near bottom layer and in Holocene and in the late Pleistocene before the Hunter Channel sidewise the Argentine Basin. So in the Hunter Channel and on the way to it from south side for all studied period AnBW was almost not. Dissolution of carbonates during the Holocene happens in the deepest east part of the Hunter Channel. In Ice Ages processes of dissolution amplified and affected east part of the channel. Dissolution happen and happened not at the expense of AnBW, and at the expense of NADW which becomes there aggressive in relation to a calcium carbonate.

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