Efficient Real-time Smoke Filtration with 3D LiDAR for Search and Rescue with Autonomous Heterogeneous Robotic Systems

Search and Rescue (SAR) missions in harsh and unstructured Sub-Terranean (Sub-T) environments in the presence of aerosol particles have recently become the main focus in the field of robotics. Aerosol particles such as smoke and dust directly affect the performance of any mobile robotic platform due to their reliance on their onboard perception systems for autonomous navigation and localization in Global Navigation Satellite System (GNSS)-denied environments. Although obstacle avoidance and object detection algorithms are robust to the presence of noise to some degree, their performance directly relies on the quality of captured data by onboard sensors such as Light Detection And Ranging (LiDAR) and camera. Thus, this paper proposes a novel modular agnostic filtration pipeline based on intensity and spatial information such as local point density for removal of detected smoke particles from Point Cloud (PCL) prior to its utilization for collision detection. Furthermore, the efficacy of the proposed framework in the presence of smoke during multiple frontier exploration missions is investigated while the experimental results are presented to facilitate comparison with other methodologies and their computational impact. This provides valuable insight to the research community for better utilization of filtration schemes based on available computation resources while considering the safe autonomous navigation of mobile robots.Comment: Accepted in the 49th Annual Conference of the IEEE Industrial Electronics Society [IECON2023

The Use of Membranes and Membrane Bioreactors for Wastewater Treatment By: Yasmine Healey Submitted: December 4th 2021 Chemical Engineering

In the face of water shortages, population growth, and climate change, improvements in wastewater treatment operations and technology are necessary to reduce the over exploitation of freshwater resources around the world. Conventional wastewater treatment operations have succeeded in the past to treat industrial and municipal wastewater, however with increasing water demands and ever-changing environmental regulations, new and improved technology is necessary for a sustainable future. Membrane filtration and membrane bioreactors have increased in popularity as a new and improved method for wastewater treatment. Membrane bioreactors as well as various membrane filtration systems were studied in this report including their unit operations, applications, and proven removal efficiencies for various wastewater contaminants. Various wastewater treatment studies have proven membranes and membrane bioreactors have superior effluent quality compared to conventional wastewater treatment processes with studies showing ultrafiltration membranes capable of removing 99% and 98% of fats and suspended substances, and over 94% removal of COD and BOD5 in slaughterhouse wastewater.1 A separate study comparing an activated sludge (CAS) system, a membrane bioreactor (MBR), and a moving bed biofilm reactor (MBBR) in the treatment of textile wastewater concluded that the MBR was the most efficient method of wastewater treatment, of which the chemical oxygen demand (COD), total suspended solids (TSS), and color removal efficiency were 91%, 99.4%, and 80% respectively

Online HEPA Filter Replacement

High Efficiency Particulate Arrestance (HEPA) filters serve an important role in safety of nuclear facilities and can be an important tool in safeguards verification of nuclear activities. This paper describes a new design for HEPA filter housing in nuclear facilities to reduce replacement time, improve safety, reduce worker dosage, and facilitate safeguards procedures post replacement. This design must meet the criteria of staying online during filter exchanges, assisting with International Atomic Energy Agency (IAEA) sampling practices, meeting the nuclear air and gas code specifications and relevant subsections, and adhering to the principles of ALARA (as low as reasonably achievable), for maintaining low radiation levels to maximize worker safety. Our new design focuses on improved safety while achieving an online filter exchange. Not only will an online filter exchange reduce facility downtime and save facilities money, it has the potential to offer increased worker safety, and provide easy filter access for IAEA officials who wish to conduct sampling and inspection for safeguards. It would effectively eliminate the need for a facility to shut down for filters to be replaced. In our research, we did not find any current designs on the market that can perform an online HEPA filter exchange. We also conducted research on sealing techniques to support the online system design. We have established a project relationship with Radiation Protection Systems (RPS), Inc.: a contracting company based out of Groton, Connecticut, USA which specializes in mobile HEPA filter and carbon pre-filter housings for nuclear applications. The technical information exchange and partnership with RPS may result in an actual product that could be installed in future nuclear power plants if the design can be proven to work in concept and function. It may also be possible to retrofit existing HEPA installations in some cases. The design includes a double door bag-in, bag-out design and operational procedure to maintain worker safety and allow for zero escape of radioactive volatiles or particulates into the air external to the facility enclosure. A combination of neoprene gasket, silicone gel, and brush sealing techniques are employed in the new design with continuity of airflow during the switch in mind. This innovative design improves safety as well as operational efficiency. The design team is cognizant of safeguards considerations and aimed the design towards facilitating access. In particular, in our new design access to HEPA filter for sampling is much easier which can potentially improve the frequency and quality of sampling during IAEA inspections. Likewise, the lower level of effort (therefore cost) in switching filters will encourage changing filters more frequently. This will lower the risk of filter failures caused by clogged or possibly faulty filters. In fact, the IAEA reported that âAIJInvestigators from other national laboratories have suggested that aging effects could have contributed to over 80 percent of these failures. âAI The prototype design features a HEPA filter train (2 HEPA filters connected by a gel-seal interface) that slide seamlessly through the housing on rollers while the nuclear facility is online, the first (old) filter being dislodged into a sealed bagging unit, and the second (new) filter being clamped into place using a cam shaft clamping mechanism. There are two areas of design innovation here that are particularly exciting. The gel-seal interface that connects the filters will provide an air tight gap between two filters while they are exchanged. The clamping system features a brush seal interface on top and bottom, to maintain airflow and mobility of the filter while facilitating a switch. Because extended radiation exposure may alter the properties of sealants and gaskets we are investigating the use of seals that can be replaced during these quick filter changes. The design prototype is a full-scale model, capable of housing a 12x24x12 inch HEPA filter. Currently, we have completed the design of the new housing unit, created a proof of concept build, as well as conducted the preliminary engineering analysis, cost analysis, and material selection of the final prototype. Manufacturing of the final housing is proceeding and upon completion will be validated with a set of rigorous testing procedures concerning sealing and safety of the system. These tests are standard industry practices and RPS will assist in performing the tests. Namely, ASME test FC-I- 3272, a test in which aerosol particles of 20 m, which are the most penetrating particle sizes (MPPS), are sent through the housing unit and penetration is monitored during an online switch. Further testing will include colored smoke being pumped through the unit to test sealing capabilities and to identify possible particulate buildup. Provided the tests show that the design is successful in maintaining air flow and safety during the filter exchange, methods of improvement for ease of use and the automation of the exchange process, improvements to continuity of knowledge, and radiation monitoring techniques will be investigated for a comprehensive final product design

Innovative Stormwater Treatment Technologies: Best Management Practices Manual

Urban stormwater carries a number of pathogens, nutrients, heavy metals, sediment, and other contaminants as surface runoff flows over land. The increase in impervious or paved surfaces associated with development in urban areas reduces the natural infiltration of precipitation into the ground. With impervious cover, precipitation collects and carries contaminants before draining into nearby surface waters. Stormwater runoff from paved surfaces in developed areas can degrade downstream waters with both contaminants and increased volumes of water. This publication aims to make information on innovative stormwater treatment technologies more available to New Hampshire’s urban planners, developers, and communities. Traditional runoff management techniques such as detention basins and infiltration swales may be preferable, but are not always practical for treating urban stormwater. Lack of space for natural solutions is often a problem in existing developed areas, making innovative treatment technologies an attractive alternative. Mostly designed for subsurface installation, urban “retrofits” use less space than conventional methods to treat stormwater. This manual provides information on the innovative stormwater “retrofit” technologies currently available for use in developed areas in New Hampshire

High speed commercial transport fuels considerations and research needs

NASA is currently evaluating the potential of incorporating High Speed Civil Transport (HSCT) aircraft in the commercial fleet in the beginning of the 21st century. NASA sponsored HSCT enabling studies currently underway with airframers and engine manufacturers, are addressing a broad range of technical, environmental, economic, and related issues. Supersonic cruise speeds for these aircraft were originally focused in the Mach 2 to 5 range. At these flight speeds, both jet fuels and liquid methane were considered potential fuel candidates. For the year 2000 to 2010, cruise Mach numbers of 2 to 3+ are projected for aircraft fuel with thermally stable liquid jet fuels. For 2015 and beyond, liquid methane fueled aircraft cruising at Mach numbers of 4+ may be viable candidates. Operation at supersonic speeds will be much more severe than those encountered at subsonic flight. One of the most critical problems is the potential deterioration of the fuel due to the high temperature environment. HSCT fuels will not only be required to provide the energy necessary for flight, but will also be subject to aerodynamic heating and, will be required to serve as the primary heat sink for cooling the engine and airframe. To define fuel problems for high speed flight, a fuels workshop was conducted at NASA Lewis Research Center. The purpose of the workshop was to gather experts on aviation fuels, airframe fuel systems, airport infrastructure, and combustion systems to discuss high speed fuel alternatives, fuel supply scenarios, increased thermal stability approaches and measurements, safety considerations, and to provide directional guidance for future R and D efforts. Subsequent follow-up studies defined airport infrastructure impacts of high speed fuel candidates. The results of these activities are summarized. In addition, an initial case study using modified in-house refinery simulation model Gordian code (1) is briefly discussed. This code can be used to simulate different types of refineries, emphasizing jet fuel production and relative cost factors