Fixed-bed column recirculation system for investigation of sorption and biodegradation of organic pollutants in saturated sediment: a detailed design and development

Background: Sorption and biodegradation are the primary processes of organic pollution remediation in aquatic and soil/sediment environments. While researchers have substantially reported their findings regarding these processes, little attention has been given to description of experimental apparatus. This technical paper aims to present the development and detailed design of a fixed-bed column recirculation (FBCR) system which has been widely applied to investigate sorption and biodegradation of organic pollutants in aquatic and/or sediment environments. Findings: The FBCR system was developed and tested by three experiments investigating sorption and biodegradation of two herbicides (isoproturon and mecoprop) in different saturated materials (hydrofilt and river sediment). Efficiency of the FBCR system was assessed according to criteria i.e. reliability, leaking inhibition, reproducibility, practical of use and cost. The results indicated that the latest version (Version 4) of the FBCR system has been significantly improved and ready to extend to similar studies. Conclusions: This system is therefore recommended to researchers who intend to investigate the remediation of organic pollutants in aquatic, soil and sediment environments

An Evaluation of a High Pressure Regulator for NASA's Robotic Lunar Lander Spacecraft

The Robotic Lunar Lander (RLL) development project office at NASA Marshall Space Flight Center is currently studying several lunar surface science mission concepts. The focus is on spacecraft carrying multiple science instruments and power systems that will allow extended operations on the lunar surface or other air-less bodies in the solar system. Initial trade studies of launch vehicle options indicate the spacecraft will be significantly mass and volume constrained. Because of the investment by the DOD in low mass, highly volume efficient components, NASA has investigated the potential integration of some of these technologies in space science applications. A 10,000 psig helium pressure regulator test activity has been conducted as part of the overall risk reduction testing for the RLL spacecraft. The regulator was subjected to typical NASA acceptance testing to assess the regulator response to the expected RLL mission requirements. The test results show the regulator can supply helium at a stable outlet pressure of 740 psig within a +/- 5% tolerance band and maintain a lock-up pressure less than the +5% above nominal outlet pressure for all tests conducted. Numerous leak tests demonstrated leakage less than 10-3 standard cubic centimeters per second (SCCS) for the internal seat leakage at lock-up and less than 10-5 SCCS for external leakage through the regulator body. The successful test has shown the potential for 10,000 psig helium systems in NASA spacecraft and has reduced risk associated with hardware availability and hardware ability to meet RLL mission requirements

An Evaluation of Ultra-High Pressure Regulator for Robotic Lunar Landing Spacecraft

The Robotic Lunar Lander Development (RLLD) Project Office at NASA Marshall Space Flight Center (MSFC) has studied several lunar surface science mission concepts. These missions focus on spacecraft carrying multiple science instruments and power systems that will allow extended operations on the lunar surface. Initial trade studies of launch vehicle options for these mission concepts indicate that the spacecraft design will be significantly mass-constrained. To minimize mass and facilitate efficient packaging, the notional propulsion system for these landers has a baseline of an ultra-high pressure (10,000 psig) helium pressurization system that has been used on Defense missiles. The qualified regulator is capable of short duration use; however, the hardware has not been previously tested at NASA spacecraft requirements with longer duration. Hence, technical risks exist in using this missile-based propulsion component for spacecraft applications. A 10,000-psig helium pressure regulator test activity is being carried out as part of risk reduction testing for MSFC RLLD project. The goal of the test activity is to assess the feasibility of commercial off-the-shelf ultra-high pressure regulator by testing with a representative flight mission profile. Slam-start, gas blowdown, water expulsion, lock-up, and leak tests are also performed on the regulator to assess performance under various operating conditions. The preliminary test results indicated that the regulator can regulate helium to a stable outlet pressure of 740 psig within the +/- 5% tolerance band and maintain a lock-up pressure less than +5% for all tests conducted. Numerous leak tests demonstrated leakage less than 10-3 standard cubic centimeters per second (SCCS) for internal seat leakage at lock-up and less than10-5 SCCS for external leakage through the regulator ambient reference cavity. The successful tests have shown the potential for 10,000 psig helium systems in NASA spacecraft and have reduced risk associated with hardware availability and hardware ability to meet RLL mission requirements

Status of the Combustion Devices Injector Technology Program at the NASA MSFC

To support the NASA Space Exploration Mission, an in-house program called Combustion Devices Injector Technology (CDIT) is being conducted at the NASA Marshall Space Flight Center (MSFC) for the fiscal year 2005. CDIT is focused on developing combustor technology and analysis tools to improve reliability and durability of upper-stage and in-space liquid propellant rocket engines. The three areas of focus include injector/chamber thermal compatibility, ignition, and combustion stability. In the compatibility and ignition areas, small-scale single- and multi-element hardware experiments will be conducted to demonstrate advanced technological concepts as well as to provide experimental data for validation of computational analysis tools. In addition, advanced analysis tools will be developed to eventually include 3-dimensional and multi- element effects and improve capability and validity to analyze heat transfer and ignition in large, multi-element injectors

Elastically Shaped Wing Optimization and Aircraft Concept for Improved Cruise Efficiency

This paper presents the findings of a study conducted tn 2010 by the NASA Innovation Fund Award project entitled "Elastically Shaped Future Air Vehicle Concept". The study presents three themes in support of meeting national and global aviation challenges of reducing fuel burn for present and future aviation systems. The first theme addresses the drag reduction goal through innovative vehicle configurations via non-planar wing optimization. Two wing candidate concepts have been identified from the wing optimization: a drooped wing shape and an inflected wing shape. The drooped wing shape is a truly biologically inspired wing concept that mimics a seagull wing and could achieve about 5% to 6% drag reduction, which is aerodynamically significant. From a practical perspective, this concept would require new radical changes to the current aircraft development capabilities for new vehicles with futuristic-looking wings such as this concept. The inflected wing concepts could achieve between 3% to 4% drag reduction. While the drag reduction benefit may be less, the inflected-wing concept could have a near-term impact since this concept could be developed within the current aircraft development capabilities. The second theme addresses the drag reduction goal through a new concept of elastic wing shaping control. By aeroelastically tailoring the wing shape with active control to maintain optimal aerodynamics, a significant drag reduction benefit could be realized. A significant reduction in fuel burn for long-range cruise from elastic wing shaping control could be realized. To realize the potential of the elastic wing shaping control concept, the third theme emerges that addresses the drag reduction goal through a new aerodynamic control effector called a variable camber continuous trailing edge flap. Conventional aerodynamic control surfaces are discrete independent surfaces that cause geometric discontinuities at the trailing edge region. These discontinuities promote vorticities which result in drag rises as well as noise sources. The variable camber trailing edge flap concept could provide a substantial drag reduction benefit over a conventional discrete flap system. Aerodynamic simulations show a drag reduction of over 50% could be achieved with the flap concept over a conventional discrete flap system

Formula SAE Final Project Report

The Formula SAE team at Trinity University has been working on a race car project since 2015 and has made significant progress in constructing a nearly complete car. This year, the team focused on continuing that progress by working towards implementing a new design, an airfoil, and redesigning suspension components, while also ensuring compliance with various regulations and standards. This year’s team has faced several constraints along the way, including time and budget limitations, complying with safety, technical, and environmental regulations, and following specific design constraints for the airfoil. To achieve set goals and eventually participate in FSAE competitions, the team must also follow applicable codes and standards, including the General Regulations and Rules of Conduct in the 2023 Formula SAE rules and specific standards related to the subsystems of the car, such as bodywork and aerodynamic devices. The team identified incomplete subsystems that needed to be addressed, one of which was the engine\u27s ability to idle. The team tested the spark and injector timing relative to the crank position using a 120 frame per second high-speed camera. Then using TunerStudio, a software for tuning an aftermarket MegaSquirt ECU, the team came up with four separate tunes that had varying spark and injector timings to get the car to start and idle. Despite getting combustion to occur and for the car to run for a few power strokes, the team was unsuccessful in achieving a consistent and steady idle. The team had ambitious goals for the project, but unforeseen difficulties prevented many of the design requirements from being met. Requirements such as maximum speed, user control, safety belts and seat, steering system, and airfoil mounting system were not fully tested or implemented. The team identified components that need to be fabricated by future teams, including a brake failure emergency shut off switch and a brake light. The team developed a CFD wind tunnel model to test the proposed airfoil design and conducted a validation test for the CFD model using literature results as the subsonic wind tunnel facility on campus was not available. The FSAE team planned to compare the downforce generated by a 3D printed model of an airfoil to the Ansys CFD model by testing the 3D printed model in a subsonic wind tunnel, but access to the wind tunnel was not available. Instead, the team compared the Ansys coefficients to those obtained from an experiment, and the results show promising accuracy of the Ansys model. However, the team suggests focusing on the performance and accuracy at higher angles of attack to improve the model. Furthermore, the team created a hypothetical racetrack to analyze the performance benefit of the airfoil and made several assumptions to simplify the process. The team calculated the lap times by dividing the distance traveled by the velocity of the car at different points of the racetrack, accounting for the aerodynamic effects of the airfoil, and the effect of downforce on the car. Overall, the 2022-23 Formula SAE team at Trinity University has faced numerous challenges in their race car project, including adhering to regulations, addressing incomplete subsystems, and conducting validation tests without proper facilities. However, the team made significant progress and will continue to work towards implementing a new design and analyzing the performance benefits of an airfoil

Resource Prospector Propulsion Cold Flow Test

For the past year, NASA Marshall Space Flight Center and Johnson Space Center have been working on a government version of a lunar lander design for the Resource Prospector Mission. A propulsion cold flow test system, representing an early flight design of the propulsion system, has been fabricated. The primary objective of the cold flow test is to simulate the Resource Prospector propulsion system operation through water flow testing and obtain data for anchoring analytical models. This effort will also provide an opportunity to develop a propulsion system mockup to examine hardware integration to a flight structure. This paper will report the work progress of the propulsion cold flow test system development and test preparation. At the time this paper is written, the initial waterhammer testing is underway. The initial assessment of the test data suggests that the results are as expected and have a similar trend with the pretest prediction. The test results will be reported in a future conference

Opinion Dynamics With Cross-Coupling Topics: Modeling and Analysis

To model the cross couplings of multiple topics, we develop a set of rules for opinion updates of a group of agents. The rules are used to design or assign values to the elements of weighting matrices. The cooperative and anticooperative couplings are modeled in both the inverse-proportional and proportional structures. The behaviors of opinion dynamics are analyzed using a nullspace property of the state-dependent matrix-weighted Laplacian matrices and a Lyapunov candidate. Various consensus properties of the state-dependent matrix-weighted Laplacian matrices are predicted according to the interagent network topology and interdependent topical coupling topologies