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At least 109 records · Page 6

Hydraulic Testing of the Lost Lake Aquifer Near Recovery Wells RWM 6 and RWM 7

Hydrologic tests were conducted on the Lost Lake Aquifer Zone (LLAZ) at recovery wells RWM 6 and RWM 7 in accordance with the approved test plan (Dixon, 2023). The objective of the testing was to determine well performance parameters of RWM 6 and aquifer hydraulic properties near RWM 6 and RWM 7. Tests at RWM 6 consisted of a step-drawdown test to determine well performance parameters, a constant rate pump test to determine aquifer hydraulic properties, and an aquifer recovery test also used to determine aquifer hydraulic properties. Well performance parameters determined included specific capacity, well efficiency, and head loss coefficients. Prior to testing at RWM 6, a constant rate pump test was conducted at RWM 7. Data from this testing was used to determine aquifer hydraulic properties near RWM 7.

42 ENGINEERING↗

A Novel Model of Thyristor in Reverse Recovery Process for Current Interruption Test of HVDC Circuit Breakers

The high voltage thyristor is widely used in high voltage DC (HVDC) grids due to its large current capability. Recently, the high voltage thyristor is implemented to produce a high current in the HVDC circuit breaker (CB) testing process. Unfortunately, the reverse recovery process (RRP) of a thyristor could induce significant turn-off overvoltage and power losses, jeopardizing the safety of the devices. The existing models of a thyristor cannot describe such hard-switching transient accurately. Therefore, this paper divides this process into four stages based on the physical mechanism and proposes a novel cosine exponential (CE), simulating the voltage and current of the thyristor with analytical equations, which are derived from the equivalent circuit. Moreover, the extraction procedure of the proposed model is illustrated in this paper. Finally, we develop an HVDC CB test platform to validate the proposed model. Experimental results show that the proposed CE model can accurately predict the overvoltage with a relative error of less than 8% at various current varying rates.

Dongye, Zhonghao↗

Hydraulic Testing of the Lost Lake Aquifer Near Recovery Well RWM019

An aquifer pumping test was conducted on the Lost Lake Aquifer Zone (LLAZ) at the recently installed recovery well RWM019 in accordance with the approved test plan (Dixon, 2020). The objective of the testing was to determine baseline well performance parameters and aquifer hydraulic conductivity. This testing consisted of a step-drawdown test to determine well performance properties, a constant pumping rate aquifer test to determine aquifer hydraulic properties, and a post-test aquifer recovery monitoring period also used to estimate aquifer hydraulic properties. Well performance parameters determined included specific capacity, well efficiency, and head loss coefficients. The specific capacity of RWM019 was determined to be approximately 2.6 gpm/ft of drawdown based on the final step of the step-drawdown test. Well efficiency was inversely related to pumping rate and decreased from 87% to 81% over a pumping range of approximately 49 to 79 gpm. The aquifer head loss coefficient was determined to be 2.3 ft/ft 3 /min and the well loss coefficient was determined to be 0.05 min 2 /ft 5 .

42 ENGINEERING↗

Development of a pyrolysis waste recovery model with designs, test plans, and applications for space-based habitats

Extensive literature searches revealed the numerous advantages of using pyrolysis as a means of recovering usable resources from inedible plant biomass, paper, plastics, other polymers, and human waste. A possible design of a pyrolysis reactor with test plans and applications for use on a space-based habitat are proposed. The proposed system will accommodate the wastes generated by a four-person crew while requiring solar energy as the only power source. Waste materials will be collected and stored during the 15-day lunar darkness periods. Resource recovery will occur during the daylight periods. Usable gases such as methane and hydrogen and a solid char will be produced while reducing the mass and volume of the waste to almost infinitely small levels. The system will be operated economically, safely, and in a non-polluting manner.

Roberson, Bobby J.↗

Development and Validation of Sensorimotor Assessment Tasks Using Spaceflight Analogs

INTRODUCTION Exploration class missions will require a new level of crew autonomy to self-assess and treat their sensorimotor dysfunction around periods of gravitational transition, where sensorimotor disturbances are at their highest. There is a need to define sensorimotor assessment thresholds that indicate when performance in early extravehicular activities (EVAs) might be impacted or unsafe. The purpose of this study was to develop and validate a set of assessment tasks using sensorimotor spaceflight analogs including the Sensorimotor Disorientation Analog (SDA) and +3G x sustained centrifugation. METHODS For the SDA, forty-one healthy non-astronaut subjects (21 males, 20 females; Mean ± SD, Age: 34.0 ± 7.8 years) volunteered to participate in this study. Subjects attended two testing sessions: 1) familiarization to the tasks and baseline data collection, and 2) tasks completed under two levels of sensorimotor disorientation. Subjects performed a series of seven sensorimotor assessment tasks followed by two operationally relevant EVA analog tasks. The sensorimotor assessments tasks, ordered from least to most provocative of the sensorimotor system, included: postural stability, step test, prone/supine recovery from fall (RFF), four-square-step-test, obstacle negotiation with turns (OTT), kneel-and-reach, and augmented reality full-body coordination. The operational analog tasks included a top-hatch capsule egress and a 5-minute EVA traversal. Disorientation was applied via the SDA which utilized galvanic vestibular stimulation and weighted trunk, wrists, and ankles to target the vestibular and proprioceptive systems such that performance while wearing the SDA mimicked astronaut postflight performance at R+0 and R+1. Sixteen healthy non-astronaut subjects (10 males, 6 females; Age: 35.0 ± 9.5 years) completed +3G x 60-minute sustained centrifugation as an established spaceflight analog replicating the vestibular disruptions seen postflight. Subjects completed a pre-session which included familiarization to the tasks and a 5-minute centrifuge spin. The data collection session included, in order, a baseline data collection, 60-minute centrifuge spin, immediate post-centrifuge data collection, 45-minute seated recovery, and a final data collection. The same assessment and operational analog tasks were conducted as described above. RESULTS Pearsons’ correlation r-values were calculated between assessment and operational analog tasks. The two assessment tasks with the strongest correlations to the operational analog tasks were the RFF (SDA: r≥ 0.57, Centrifuge: r ≥0.55) and OTT (SDA: r≥ 0.66, Centrifuge: r ≥ 0.49). For brevity, repeated measures ANOVA with follow-up paired t-tests are discussed for these two assessment tasks. The SDA found significant differences between all three levels of disorientation for both RFF and OTT (p < 0.001). Significant differences were also found between baseline and immediate post centrifuge testing for both the RFF (p≤ 0.011) and OTT (p = 0.001). Additional results are forthcoming for both disorientation paradigms. DISCUSSION These validation studies provide evidence for down-selection of the assessment tasks that were able to distinguish between levels of sensorimotor disorientation and correlate to performance in operationally relevant tasks for use in upcoming Artemis missions.

S C Moudy↗

Liberty Bell 7 Recovery Evaluation and Nondestructive Testing

An inspection of the Mercury capsule, Liberty Bell 7, and its contents was made on September 1 and 2, 1999. The condition of the capsule and its contents was consistent with long-term exposure to salt water and high pressures at the bottom of the ocean. Many of the metallic materials suffered corrosion, whereas the polymer-based materials seem to have survived remarkably well. No identifiable items or structures were found that appeared to have any scientific value. At this time, no further nondestructive evaluation appears to be justified.

Madaras, Eric I.↗

Free-Spinning-Tunnel Tests of a 0.057-Scale Model of the Chance Vought XF7U-1 Airplane

An investigation of the spin and recovery characteristics of a 0.057-scale model of the Chance Vought XF7U-1 airplane has been conducted in the Langley 20-foot free-spinning tunnel. The effects of control settings and movements on the erect and inverted spin and recovery characteristics were determined, as were also the effects of extending the wing slats, of center-of-gravity movement, and-of variation in the mass distribution. The investigation also included wing-tip spin-recovery-parachute tests, pilot-escape tests, and rudder-control-force tests. The investigation indicated that the spin and recovery characteristics of the airplane will be satisfactory for all conditions. It was found that a single 4.24-foot (full-scale) parachute when opened alone from the outboard wing tip or two 8.77-foot (full-scale) parachutes when opened simultaneously, one from each wing tip, would effect satisfactory emergency recoveries (the drag coefficients of the parachutes, based on the surface area of the parachute, were 0.83 and 0.70 for the 4.24- and 8.77-foot parachutes, respectively). The towline length in both cases was 25 feet (full scale). Tests results showed that, if the pilot should have to leave the airplane during a spin, he should jump from the outboard side (left side in a right spin) of the cockpit. The rudder-control force necessary for recovery from a spin was found to be rather high but appeared to be within the upper limits of a pilot's capabilities.

Daughtridge, Lee T., Jr.↗

Optimization of operational strategies for rich gas enhanced oil recovery based on a pilot test in the Bakken tight oil reservoir

Horizontal well drilling and multistage hydraulic fracturing have been demonstrated as effective approaches for stimulating oil production in the Bakken tight oil reservoir. However, after multiple years of production, primary oil recovery in the Bakken is generally less than 10% of the estimated original oil in place. Gas huff ‘n’ puff (HnP) has been tested in the Bakken Formation as an enhanced oil recovery (EOR) method; however, most field pilot test results showed no significant incremental oil production. One of the factors affecting HnP EOR performance is premature gas breakthrough, which is one of the most critical issues observed in the field because of the presence of interwell fractures. Consequently, injected gas rapidly reaches adjacent production wells without contacting reservoir rock and increasing oil recovery. Proper conformance control is therefore needed to avoid early gas breakthrough and improve EOR performance. In this study, a rich gas EOR pilot in the Bakken was carefully analyzed to collect the essential reservoir and operational data. A simulation model with 16 wells was then developed to reproduce the production history and predict the EOR performance with and without conformance control. EOR operational strategies, including single- and multiple-well HnP, with different gas injection constraints were investigated. The simulation results of single-well HnP without conformance control showed that a rich gas injection rate of at least 10 MMscfd was needed to yield meaningful incremental oil production. The strategy of conformance control via water injection could significantly improve oil production in the HnP well, but injecting an excessive amount of water also leads to water breakthrough and loss of oil production in the offset wells. By analyzing the production performance of the wells individually, the arrangement of wells was optimized for multiple-well HnP EOR. The multiwell results showed that rich gas EOR could improve oil production up to 7.4% by employing conformance control strategies. Furthermore, replacing rich gas with propane as the injection gas could result in 14% of incremental oil production.

02 PETROLEUM↗

Re-Configurable Electronics Characterization under Extreme Thermal Environment

The need for reconfigurable electronics is driven by requirements to survive longer missions and harsher environments. It is possible to compensate for degradations in Extreme Environments (EE). EE has effect on electronics: circuits are designed to exploit device characteristics and when a certain temperature or radiation range is exceeded the circuit function gradually degrades. It is possible to employ Hardening by reconfiguration (HBR) to mitigate drifts, degradation, or damage on electronic devices in EE by using reconfigurable devices and an adaptive self-reconfiguration of circuit topology. In this manner degraded components can be salvaged, and completely damaged components can be bypassed. The challenge of conventional design is replaced with that of designing a recover process that automatically performs the (re) design in place of the designer. The objective of testing a Digital Signal Processor (DSP) under the extreme temperatures was to determine the lowest temperature at which the DAP can operate. The objective of testing a Xilinx VirtexII Pro FPGA board was to initially find our whether the evaluation board and the FPGA would survive and continue at temperature ranges from -180 C, and 120 C. The Virtex II functioned correctly at the temperatures tested. The next test was done on the GM-C filter building block using the same temperature range as the Virtex II. The current lower and upper limits were shown to be reduced as the temperature gets lower. The device function can be recovered by increasing the Vb from .08V to .85V. The negative and positive saturation voltages increases as the temperature gets higher. The function of the device can be recovered by decreasing the Vb from .8V to around .75V. The next test was performed to test the recovery of the GmC low pass filter through Vb in a filter circuit. The test indicate that bias voltage control adjustment is an efficient mechanism for circuit recovery at extreme temperatures.

reliability↗

Test bed design for evaluating the Space Station ECLSS Water Recovery System

The design of the Phase III Environmental Control and Life Support System (ECLSS) Water Recovery System (WRS) test bed is in progress at the Marshall Space Flight Center (MSFC), building 4755, in Huntsville, Alabama. The overall design for the ECLSS WRS test bed will be discussed. Described within this paper are the design, fabrication, placement, and testing of the supporting facility which will provide the test bed for the ECLSS subsystems. Topics to be included are sterilization system design, component selection, microbial design considerations, and verification of test bed design prior to initiating WRS testing.

Ezell, Timothy G.↗

Zero-G life support for Space Station Freedom

Optimal design of spacecraft environmental control and life support systems (ECLSS) for long duration missions requires an understanding of microgravity and its long-term influence on ECLSS performance characteristics. This understanding will require examination of the fundamental processes associated with air revitalization and water recovery in a microgravity environment. Short term testing can be performed on NASA's reduced gravity aircraft (a KC-135), but longer tests will need to be conducted on the shuttle or Space Station Freedom. Conceptual designs have been prepared for ECLSS test beds that will allow extended testing of equipment under microgravity conditions. Separate designs have been formulated for air revitalization and water recovery test beds. In order to allow testing of a variety of hardware with minimal alteration of the beds themselves, the designs include storage tanks, plumbing, and limited instrumentation that would be expected to be common to all air (or water) treatment equipment of interest. In the interest of minimizing spacecraft/test bed interface requirements, the beds are designed to recycle process fluids to the greatest extent possible. In most cases, only cooling water and power interfaces are required. A volume equal to that of two SSF lockers was allowed for each design. These bed dimensions would limit testing to equipment with a 0.5- to 1.5-person-equivalent throughput. The mass, volume, and power requirements for the air revitalization test bed are estimated at 125-280 kg, 1.0- 1.4 cubic meters, and 170 min 1070 W. Corresponding ranges for the water recovery test bed are 325-375 kg, 1.0- 1.1 cubic meters, and 350-850 W. These figures include individual test articles and accompanying hardware as well as the tanks, plumbing, and instrumentation included in the bed designs. Process fluid weight (i.e., water weight) is also included.

Kolodney, Matthew↗

Ares I-X: Lessons for a New Era of Spaceflight

Since 2005, the Ares Projects at Marshall Space Flight Center (MSFC) have been developing the Ares I crew launch vehicle and Ares V cargo launch vehicle. On October 28, 2009, the first development flight test of the Ares I crew launch vehicle, Ares I-X, lifted off from a launch pad at Kennedy Space Center (KSC) on successful suborbital flight. Despite the President s intention to cancel the Constellation Program of which Ares is a part, this historic flight has produced a great amount of data and numerous lessons learned for any future launch vehicles. This paper will describe the accomplishments of Ares I-X and the lessons that other programs can glean from this successful mission. Ares I was designed to carry up to four astronauts to the International Space Station (ISS). It also was designed to be used with the Ares V cargo launch vehicle for a variety of missions beyond low-Earth orbit (LEO). The Ares I-X development flight test was conceived in 2006 to acquire early engineering and environment data during liftoff, ascent, and first stage recovery. The test achieved the following primary objectives: Demonstrated control of a dynamically similar, integrated Ares I/Orion, using Ares I relevant ascent control algorithms. Performed an in-flight separation/staging event between a Ares I-similar First Stage and a representative Upper Stage. Demonstrated assembly and recovery of a new Ares I-like First Stage element at KSC. Demonstrated First Stage separation sequencing, and quantify First Stage atmospheric entry dynamics, and parachute performance. Characterized the magnitude of integrated vehicle roll torque throughout First Stage flight.

Davis, Stephan R.↗

Systems approach to software fault tolerance

Computing systems are employed for aerospace applications with high reliability requirements. In order to provide the needed reliability, it was necessary to make use of computing systems with fault-tolerance characteristics. Traditionally, fault tolerance is achieved through the use of hardware redundance. However, fault-tolerant techniques based on suitable software design considerations have also been developed. The present paper is concerned with the major issues arising in the context of an application of fault-tolerant software techniques to dynamic systems. Attention is given to fault-tolerant flight software, software component stability, system stability with fault-tolerant software, the preservation of functional performance, N-version vs. recovery blocks in flight software, systems-based software, static and dynamic models, static and dynamic consistency tests, and recovery block initialization.

Caglayan, A. K.↗

Spaceflight-Induced Cardiovascular Changes and Recovery During NASA's Functional Task Test

Microgravity-induced physiological changes could impair a crewmember s performance upon return to a gravity environment. The Functional Task Test (FTT) is designed to correlate these physiological changes to performance in mission-critical tasks. The Recovery from Fall/Stand Test (RFST) simulates one such task, measuring the ability to recover from a prone position and the cardiovascular response to orthostasis. The purpose of this study was to evaluate spaceflight-induced cardiovascular changes during the FTT. METHODS: Five astronauts participated in the FTT before 10-15 day missions, on landing day (R+0), and one (R+1), six (R+6) and thirty (R+30) days after landing. The RFST consisted of a 2-minute prone rest followed by a 3-minute stand during which heart rate (HR, Holter) and continuous blood pressure (BP, Finometer) were measured. Spectral heart rate variability (HRV) was calculated during the RFST to approximate autonomic function. Statistical analysis was performed with two-factor repeated measures ANOVA. RESULTS: During RFST, HR was higher on R+0 than preflight (p<0.004). This increase in HR persisted on R+1 and R+6 during the stand portion of RFST (p<0.026). BP was well-regulated on all test days. Parasympathetic activity was diminished on R+0 (p=0.035). Sympathovagal balance tended to be affected by spaceflight (main effect, p=0.072), appearing to be slightly elevated during postflight RFST except on R+30. Additionally, analysis of HR during the functional tasks yielded a higher HR on R+0 than preflight during 8 of 11 tasks analyzed, where all tasks had HR return to preflight values by R+30 (p<0.05). CONCLUSION: Spaceflight causes an increase in HR, decrease in parasympathetic activity, and increase in sympathovagal balance, which we confirmed during RFST. These spaceflight-induced changes seen in the RFST, along with the increased postflight HR in most functional tasks, can be used to assess functional performance after short-duration spaceflight.

Arzeno, N. M.↗