114 untethered UUV dives: lessons learned
The Ocean Engineering Division at the Naval Command Control and Ocean Surveillance Center RDT&E Division (NRaD) has developed and field tested two successive untethered, supervisory controlled UUV systems: a prototype, and an improved model. These robotic vehicle systems were part of the Advanced Unmanned Search System (AUSS) programme. It was only after the prototype was fielded, many lessons were learned. As a consequence of the prototype experience, the improved model was developed. The second system was a complete redesign, using state-of-the-art subsystems and technologies. The resulting product was both capable and reliable, yet flexible, creating a plethora of system evolutionary possibilities. Sea tests, improved tactics, and systems engineering became synergistic and interactive. AUSS involved pioneering research in underwater search and in UUV systems. Important knowledge was also gained in systems analysis, system engineering, and program evolution. Invaluable experience was gained from 114 successful untethered dives. The purpose of this paper is to share many of the lessons learned during the AUSS program.
Evolution of a Search System: Lessons Learned with the Advanced Unmanned Search System.
Abstract : This document follows the evolution of the Advanced Unmanned Search System (AUSS) and the lessons learned. The events leading up to the development of the AUSS, the subsystem focus, systems engineering, and the interactive development and field testing are all included.
Parboiled rice effluent: A wastewater niche for microalgae and cyanobacteria with growth coupled to comprehensive remediation and phosphorus biofertilization
Abstract The potential of microalgae and cyanobacteria for bioremediation of wastewater by nutrient uptake combined with simultaneous biomass production is a well recognized perception of today's world. The present study illustrates the treatment of a highly polluted wastewater generated during parboiling of paddy in rice mill industries, widely operational in developing countries where rice is the staple food crop, with the help of microalgal and cyanobacterial isolates capable of growing at high rates in parboiled rice mill effluent (RME). This endeavor leads to comprehensive bioremediation of the said effluent and subsequent use of the harvested biomass as slow release phosphorus biofertilizers and the treated effluent for crop irrigation. The RME-acclimatized algal consortium demonstrated highest growth in terms of fresh weight and greatest remediation efficiency at the end of 36 days' treatment of RME, with 93.9% phosphorus and 100% ammonia-nitrogen removal, 98.7%, 91.6% and 93.5% reduction in biological oxygen demand, chemical oxygen demand and total dissolved solid, respectively, and an increment of 186 ± 0.3 mg L − 1 dissolved oxygen, bringing down the pollutants level well below the discharge limits suggested by Central Pollution Control Board, India. Additionally, microalgae in the consortium aggregated in clumps spontaneously in presence of the filaments of Phormidium sp. facilitating easy harvest. The RME-acclimatized algal consortium demonstrated highest accumulation of polyphosphate (poly-P) (0.76 ± 0.01% of dry weight) as well as highest release of phosphorus in non-sterile soil emphasizing the essential role of soil phosphorus solubilizing organisms to leach soluble phosphorus from the insoluble poly-P present in the biomass. The rice seedlings watered with treated RME also showed improved growth effect on shoot height and leaf width. The study results establish the suitability of RME as an excellent growth media for microalgae and cyanobacteria.