Can a Conventional Propulsion System Match the Efficiency of an Underwater Glider Buoyancy Engine?

2019 ◽  
Vol 53 (2) ◽  
pp. 75-82
Author(s):  
Christopher Hockley ◽  
Brian Butka

AbstractAutonomous underwater gliders are a family of autonomous vehicles used for a long-range, long-term observation of oceanic environments. To do this, they leverage changes in net buoyancy and the resulting vertical motion to generate forward locomotion via hydrodynamic surfaces. To function for extended periods, these systems operate in a low-speed, low-drag regime. Conventionally propelled underwater vehicles typically operate at speeds in excess of those achievable by gliders and therefore require more energy in order to compensate for losses due to hydrodynamic drag. An interesting question arises when considering the operational efficiencies of conventionally propelled systems when they operate at speeds typical of underwater gliders. A first-principles energy-based approach to glider operations was derived and verified using real-world data. The energy usage for buoyancy-driven propulsion was compared to conventional propulsion types. The results from these calculations indicate that a conventionally propelled autonomous underwater vehicle can compete with a buoyancy-driven system given the proper propulsive efficiency.

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3497 ◽  
Author(s):  
I. González-Reolid ◽  
J. Molina-Molina ◽  
A. Guerrero-González ◽  
F. Ortiz ◽  
D. Alonso

Apart from their ecological value, the world’s oceans are among the planet’s most valuable resources, a rich source of food and wealth and in urgent need of protection. This article describes BUSCAMOS-RobObs, a robot-based observatory, consisting of an autonomous solar-powered marine robot with specialized sensing systems designed to carry out long-term observation missions in the inland sea of the Mar Menor in southeastern Spain. This highly specialised device is unique because it has the capacity to anchor itself to the seabed and become a “buoy”, either to take measurements at specific points or to recharge its batteries. It thus avoids drifting and possible accidents in the buoy mode, especially near the coast, and resumes monitoring tasks when the required energy levels are reached. The robot is equipped with a broad range of sensors, including side scan sonar, sub-bottom sonar, laser systems, ultrasound sonar, depth meters, a multi-parametric probe and a GPS, which can collect georeferenced oceanic data. Although various types of autonomous vehicles have been described in the literature, they all have limited autonomy (even in the long term) as regards operational time and covering the seabed. The article describes a permanent monitoring mission in the Mar Menor, with a combination of solar energy and a decision-making strategy as regards the optimum route to be followed. The energy and mission simulation results, as well as an account of actual monitoring missions are also included.


Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 878-P
Author(s):  
KATHERINE TWEDEN ◽  
SAMANWOY GHOSH-DASTIDAR ◽  
ANDREW D. DEHENNIS ◽  
FRANCINE KAUFMAN

2001 ◽  
Author(s):  
L Szczepanski ◽  
C Stepniak ◽  
B Targonska-Stepniak

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lisa-Marie Ohle ◽  
David Ellenberger ◽  
Peter Flachenecker ◽  
Tim Friede ◽  
Judith Haas ◽  
...  

AbstractIn 2001, the German Multiple Sclerosis Society, facing lack of data, founded the German MS Registry (GMSR) as a long-term data repository for MS healthcare research. By the establishment of a network of participating neurological centres of different healthcare sectors across Germany, GMSR provides observational real-world data on long-term disease progression, sociodemographic factors, treatment and the healthcare status of people with MS. This paper aims to illustrate the framework of the GMSR. Structure, design and data quality processes as well as collaborations of the GMSR are presented. The registry’s dataset, status and results are discussed. As of 08 January 2021, 187 centres from different healthcare sectors participate in the GMSR. Following its infrastructure and dataset specification upgrades in 2014, more than 196,000 visits have been recorded relating to more than 33,000 persons with MS (PwMS). The GMSR enables monitoring of PwMS in Germany, supports scientific research projects, and collaborates with national and international MS data repositories and initiatives. With its recent pharmacovigilance extension, it aligns with EMA recommendations and helps to ensure early detection of therapy-related safety signals.


2021 ◽  
Vol 8 (3) ◽  
pp. 49
Author(s):  
Min-Soo Seo ◽  
Byeonghyeon Lee ◽  
Kyung-Ku Kang ◽  
Soo-Eun Sung ◽  
Joo-Hee Choi ◽  
...  

DBA/2 mice are a well-known animal model for hearing loss developed due to intrinsic properties of these animals. However, results on the phenotype of hearing loss in DBA/2 mice have been mainly reported at an early stage in mice aged ≤7 weeks. Instead, the present study evaluated the hearing ability at 5, 13, and 34 weeks of age using DBA/2korl mice. Auditory brainstem response test was performed at 8–32 KHz at 5, 13, and 34 weeks of age, and hearing loss was confirmed to be induced in a time-dependent manner. In addition, histopathological evaluation at the same age confirmed the morphological damage of the cochlea. The findings presented herein are the results of the long-term observation of the phenotype of hearing loss in DBA/2 mice and can be useful in studies related to aging-dependent hearing loss.


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