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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Highly Efficient Training, Refinement, and Validation of a Knowledge-based Planning Quality-Control System for Radiation Therapy Clinical Trials

Purpose: To demonstrate an efficient method for training and validation of a knowledge-based planning (KBP) system as a radiation therapy clinical trial plan quality-control system. Methods and Materials: We analyzed 86 patients with stage IB through IVA cervical cancer treated with intensity modulated radiation therapy at 2 institutions according to the standards of the INTERTECC (International Evaluation of Radiotherapy Technology Effectiveness in Cervical Cancer, National Clinical Trials Network identifier: 01554397) protocol. The protocol used a planning target volume and 2 primary organs at risk: pelvic bone marrow (PBM) and bowel. Secondary organs at risk were rectum and bladder. Initial unfiltered dose-volume histogram (DVH) estimation models were trained using all 86 plans. Refined training sets were created by removing sub-optimal plans from the unfiltered sample, and DVH estimation models… and DVH estimation models were constructed by identifying 30 of 86 plans emphasizing PBM sparing (comparing protocol-specified dosimetric cutpoints V{sub 10} (percentage volume of PBM receiving at least 10 Gy dose) and V{sub 20} (percentage volume of PBM receiving at least 20 Gy dose) with unfiltered predictions) and another 30 of 86 plans emphasizing bowel sparing (comparing V{sub 40} (absolute volume of bowel receiving at least 40 Gy dose) and V{sub 45} (absolute volume of bowel receiving at least 45 Gy dose), 9 in common with the PBM set). To obtain deliverable KBP plans, refined models must inform patient-specific optimization objectives and/or priorities (an auto-planning “routine”). Four candidate routines emphasizing different tradeoffs were composed, and a script was developed to automatically re-plan multiple patients with each routine. After selection of the routine that best met protocol objectives in the 51-patient training sample (KBP{sub FINAL}), protocol-specific DVH metrics and normal tissue complication probability were compared for original versus KBP{sub FINAL} plans across the 35-patient validation set. Paired t tests were used to test differences between planning sets. Results: KBP{sub FINAL} plans outperformed manual planning across the validation set in all protocol-specific DVH cutpoints. The mean normal tissue complication probability for gastrointestinal toxicity was lower for KBP{sub FINAL} versus validation-set plans (48.7% vs 53.8%, P<.001). Similarly, the estimated mean white blood cell count nadir was higher (2.77 vs 2.49 k/mL, P<.001) with KBP{sub FINAL} plans, indicating lowered probability of hematologic toxicity. Conclusions: This work demonstrates that a KBP system can be efficiently trained and refined for use in radiation therapy clinical trials with minimal effort. This patient-specific plan quality control resulted in improvements on protocol-specific dosimetric endpoints.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2017

Effect of Thermal Storage on the Performance of a Wood Pellet-fired Residential Boiler

Interest in the direct use of biomass for thermal applications as a renewable technology is increasing as is also focus on air pollutant emissions from these sources and methods to minimize the impact. This work has focused on wood pellet-fired residential boilers, which are the cleanest fuel in this category. In the residential application the load varies strongly over the course of a year and a high fraction of the load is typically under 15% of the maximum boiler capacity. Thermal storage can be used even with boilers which have modulation capacity typically to 30% of the boiler maximum. One common pellet boiler was tested at full load and also at the minimum load used in the U.S. certification testing (15%). In these tests the load was steady over the test period. Testing was also done with an emulated load profile for a home in Albany, N.Y. on a typical January, March, and April day. In this case the load imposed on the boiler varied hourly under computer control, based on the modeled load for the example case used. The boiler used has a nominal output of 25 kW and a common mixed hardwood/softwood commercial pellet was used. Moisture content was 3.77%. A dilution tunnel approach was used for the measurement of particulate emissions, in accordance with U.S. certification testing requirements. The test results showed that the use of storage strongly reduces cycling rates under part load conditions. The transients which occur as these boilers cycle contribute to increased particulate emissions and reduced efficiency. The time period of a full cycle at a given load condition can be increased by increasing the storage tank volume and/or increasing the control differential range. It was shown that increasing the period strongly increased the measured efficiency and reduced the particulate emission (relative to the no storage case). The impact was most significant at the low load levels. Storage tank heat loss is shown to be a significant factor in thermal efficiency, particularly at low load. Different methods to measure this heat loss were explored. For one of the tanks evaluated the efficiency loss at the 15% load point was found to be as high as 7.9%. Where storage is used good insulation on the tank, insulation on the piping, and attention to fittings are recommended.

09 BIOMASS FUELS↗
DOE OSTI2012

In vivo study of breast carcinoma radiosensitization by targeting eIF4E

Highlights: Black-Right-Pointing-Pointer eIF4E is associated with the formation and progression for breast cancer. Black-Right-Pointing-Pointer pSecX-t4EBP1 can downregulated the expression of eIF4E in direct binding. Black-Right-Pointing-Pointer We transfected pSecX-t4EBP1 into a mouse xenograft model. Black-Right-Pointing-Pointer It can significantly inhibit tumor growth and enhance the radiosensitivity. Black-Right-Pointing-Pointer The possible mechanism is downregulation of HIF-1{alpha} expression. -- Abstract: Background: Eukaryotic initiation factor eIF4E, an important regulator of translation, plays a crucial role in the malignant transformation, progression and radioresistance of many human solid tumors. The overexpression of this gene has been associated with tumor formation in a wide range of human malignancies, including breast cancer. In the present study, we attempted to explore the use of eIF4E as a therapeutic target to enhance radiosensitivity for breast carcinomas in a xenograft BALB/C mice model. Materials and methods: Ninety female BALB/C mice transfected with EMT-6 cells were randomly divided into six groups: control, irradiation (IR), pSecX-t4EBP1, pSecX-t4EBP1 + irradiation, pSecX and pSecX + irradiation. At the end of the experiments, all mice were sacrificed, the xenografts were harvested to measure the tumor volume and mass, and the tumor inhibition rates were calculated. Apoptosis was detected with a flow cytometric assay. Immunohistochemistry was used to detect the expression of HIF-1{alpha}. Results: The xenografts in pSecX-t4EBP1 mice showed a significantly delayed growth and smaller tumor volume, with a higher tumor inhibition rate compared with the control and pSecX groups. A similar result was obtained in the pSecX-t4EBP1 + IR group compared with IR alone and pSecX + irradiation. The expression of HIF-1{alpha} in the tumor cells was significantly decreased, while the apoptosis index was much higher. Conclusions: pSecX-t4EBP1 can significantly inhibit tumor growth and enhance the radiosensitivity of breast carcinoma xenografts in BALB/C mice. This is possibly associated with the downregulation of HIF-1{alpha} expression, which suggests that pSecX-t4EBP1 may serve as an ideal molecular target for the radiosensitization of breast carcinoma.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Long-Term Heating to Improve Receiver Performance

The buildup of hydrogen in the heat transfer fluid (HTF) that circulates through components of parabolic trough power plants decreases receiver thermal efficiency, and ultimately, it decreases plant performance and electricity output. The generation and occurrence of hydrogen in the HTF provides the driving force for hydrogen to permeate from the HTF through the absorber tube wall and into the receiver annulus. Getters adsorb hydrogen from the annulus volume until they saturate and are no longer able to maintain low hydrogen pressure. The increase in hydrogen pressure within the annulus significantly degrades thermal performance of the receiver and decreases overall power-plant efficiency. NREL and Acciona Energy North America (Acciona) are developing a method to control the levels of dissolved hydrogen in the circulating HTF. The basic approach is to remove hydrogen from the expansion tanks of the HTF subsystem at a rate that maintains hydrogen in the circulating HTF to a target level. Full-plant steady-state models developed by the National Renewable Energy Laboratory (NREL) predict that if hydrogen is removed from the HTF within the expansion tanks, the HTF that circulates through the collector field remains essentially free of hydrogen until the HTF returns to the power block in the hot headers. One of the key findings of our modeling is the prediction that hydrogen will reverse-permeate out of the receiver annulus if dissolved hydrogen in the HTF is kept sufficiently low. To test this prediction, we performed extended heating of an in-service receiver that initially had high levels of hydrogen in its annulus. The heating was performed using NREL's receiver test stand. Results of our testing showed that receiver heat loss steadily decreased with daily heating, resulting in a corresponding improvement in receiver thermal efficiency.

14 SOLAR ENERGY↗
DOE OSTI2015

SU-E-J-190: Development of Abdominal Compression & Respiratory Guiding System Using Gas Pressure Sensor

Purpose: Abdominal compression is known to be effective but, often makes external-marker-based monitoring of breathing motion not feasible. In this study, we developed and evaluated a system that enables both abdominal compression and monitoring of residual abdominal motion simultaneously. The system can also provide visual-biofeedback capability. Methods: The system developed consists of a compression belt, an abdominal motion monitoring sensor (gas pressure sensor) and a visual biofeedback device. The compression belt was designed to be able to compress the frontal side of the abdomen. The pressure level of the belt is controlled by air volume and monitored in real time using the gas pressure sensor. The system displays not only the real-time monitoring curve but also a guiding respiration model (e.g., a breath hold or shallow breathing curve) simultaneously on the head mounted display to help patients keep their breathing pattern as consistent as possible. Three healthy volunteers were enrolled in this pilot study and respiratory signals (pressure variations) were obtained both with and without effective abdominal compression to investigate the feasibility of the developed system. Two guidance patterns, breath hold and shallow breathing, were tested. Results: All volunteers showed smaller abdominal motion with compression (about 40% amplitude reduction compared to without compression). However, the system was able to monitor residual abdominal motion for all volunteers. Even under abdominal compression, in addition, it was possible to make the subjects successfully follow the guide patterns using the visual biofeedback system. Conclusion: The developed abdominal compression & respiratory guiding system was feasible for residual abdominal motion management. It is considered that the system can be used for a respiratory motion involved radiation therapy while maintaining the merit of abdominal compression. This work was supported by the Radiation Technology R&D program (No. 2013M2A2A7043498) and the Mid-career Researcher Program (2014R1A2A1A10050270) through the National Research Foundation of Korea funded by the Ministry of Science, ICT&Future Planning.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

SU-F-J-130: Margin Determination for Hypofractionated Partial Breast Irradiation

Purpose: To determine the Planning Target Volume (PTV) margin for Hypofractionated Partial Breast Irradiation (HPBI) using the van Herk formalism (M=2.5∑+0.7σ). HPBI is a novel technique intended to provide local control in breast cancer patients not eligible for surgical resection, using 40 Gy in 5 fractions prescribed to the gross disease. Methods: Setup uncertainties were quantified through retrospective analysis of cone-beam computed tomography (CBCT) data sets, collected prior to (prefraction) and after (postfraction) treatment delivery. During simulation and treatment, patients were immobilized using a wing board and an evacuated bag. Prefraction CBCT was rigidly registered to planning 4-dimensional computed tomography (4DCT) using the chest wall and tumor, and translational couch shifts were applied as needed. This clinical workflow was faithfully reproduced in Pinnacle (Philips Medical Systems) to yield residual setup and intrafractional error through translational shifts and rigid registrations (ribs and sternum) of prefraction CBCT to 4DCT and postfraction CBCT to prefraction CBCT, respectively. All ten patients included in this investigation were medically inoperable; the median age was 84 (range, 52–100) years. Results: Systematic (and random) setup uncertainties (in mm) detected for the left-right, craniocaudal and anteroposterior directions were 0.4 (1.5), 0.8 (1.8) and 0.4 (1.0); net uncertainty was determined to be 0.7 (1.5). Rotations >2° in any axis occurred on 8/72 (11.1%) registrations. Conclusion: Preliminary results suggest a non-uniform setup margin (in mm) of 2.2, 3.3 and 1.7 for the left-right, craniocaudal and anteroposterior directions is required for HPBI, given its immobilization techniques and online setup verification protocol. This investigation is ongoing, though published results from similar studies are consistent with the above findings. Determination of margins in breast radiotherapy is a paradigm shift, but a necessary step in moving towards hypofractionated regiments, which may ultimately redefine the standard of care for this select patient population.

60 APPLIED LIFE SCIENCES↗
NASA NTRS1982

A dynamic measure of controllability and observability for the placement of actuators and sensors on large space structures

The degree of controllability of a large space structure is found by a four step procedure: (1) finding the minimum control energy for driving the system from a given initial state to the origin in the prescribed time; (2) finding the region of initial state which can be driven to the origin with constrained control energy and time using optimal control strategy; (3) scaling the axes so that a unit displacement in every direction is equally important to control; and (4) finding the linear measurement of the weighted "volume" of the ellipsoid in the equicontrol space. For observability, the error covariance must be reduced toward zero using measurements optimally, and the criterion must be standardized by the magnitude of tolerable errors. The results obtained using these methods are applied to the vibration modes of a free-free beam.

Vandervelde, W. E.↗
NASA NTRS2014

NASA Wearable Technology CLUSTER 2013-2014 Report

Wearable technology has the potential to revolutionize the way humans interact with one another, with information, and with the electronic systems that surround them. This change can already be seen in the dramatic increase in the availability and use of wearable health and activity monitors. These devices continuously monitor the wearer using on-­‐body sensors and wireless communication. They provide feedback that can be used to improve physical health and performance. Smart watches and head mounted displays are also receiving a great deal of commercial attention, providing immediate access to information via graphical displays, as well as additional sensing features. For the purposes of the Wearable Technology CLUSTER, wearable technology is broadly defined as any electronic sensing, human interfaces, computing, or communication that is mounted on the body. Current commercially available wearable devices primarily house electronics in rigid packaging to provide protection from flexing, moisture, and other contaminants. NASA mentors are interested in this approach, but are also interested in direct integration of electronics into clothing to enable more comfortable systems. For human spaceflight, wearable technology holds a great deal of promise for significantly improving safety, efficiency, autonomy, and research capacity for the crew in space and support personnel on the ground. Specific capabilities of interest include: Continuous biomedical monitoring for research and detection of health problems. Environmental monitoring for individual exposure assessments and alarms. Activity monitoring for responsive robotics and environments. Multi-modal caution and warning using tactile, auditory, and visual alarms. Wireless, hands-free, on-demand voice communication. Mobile, on-demand access to space vehicle and robotic displays and controls. Many technical challenges must be overcome to realize these wearable technology applications. For example, to make a wearable device that is both functional and comfortable for long duration wear, developers must strive to reduce electronic mass and volume while also addressing constraints imposed by the body attachment method. Depending on the application, the device must be placed in a location that the user can see and reach, and that provides the appropriate access to air and the wearer's skin. Limited power is available from body-­‐worn batteries and heat must be managed to prevent discomfort. If the clothing is to be washed, there are additional durability and washability hurdles that traditional electronics are not designed to address. Finally, each specific capability has unique technical challenges that will likely require unique solutions. In addition to the technical challenges, development of wearable devices is made more difficult by the diversity of skills required and the historic lack of collaboration across domains. Wearable technology development requires expertise in textiles engineering, apparel design, software and computer engineering, electronic design and manufacturing, human factors engineering, and application-­‐specific fields such as acoustics, medical devices, and sensing. Knowledge from each of these domains must be integrated to create functional and comfortable devices. For this reason, the diversity of knowledge and experience represented in the Wearable Technology is critical to overcoming the fundamental challenges in the field.

Simon, Cory↗
DOE OSTI2014

Hitting the target: fragment screening with acoustic in situ co-crystallization of proteins plus fragment libraries on pin-mounted data-collection micromeshes

A method is presented for screening fragment libraries using acoustic droplet ejection to co-crystallize proteins and chemicals directly on micromeshes with as little as 2.5 nl of each component. This method was used to identify previously unreported fragments that bind to lysozyme, thermolysin, and trypsin. Acoustic droplet ejection (ADE) is a powerful technology that supports crystallographic applications such as growing, improving and manipulating protein crystals. A fragment-screening strategy is described that uses ADE to co-crystallize proteins with fragment libraries directly on MiTeGen MicroMeshes. Co-crystallization trials can be prepared rapidly and economically. The high speed of specimen preparation and the low consumption of fragment and protein allow the use of individual rather than pooled fragments. The Echo 550 liquid-handling instrument (Labcyte Inc., Sunnyvale, California, USA) generates droplets with accurate trajectories, which allows multiple co-crystallization experiments to be discretely positioned on a single data-collection micromesh. This accuracy also allows all components to be transferred through small apertures. Consequently, the crystallization tray is in equilibrium with the reservoir before, during and after the transfer of protein, precipitant and fragment to the micromesh on which crystallization will occur. This strict control of the specimen environment means that the crystallography experiments remain identical as the working volumes are decreased from the few microlitres level to the few nanolitres level. Using this system, lysozyme, thermolysin, trypsin and stachydrine demethylase crystals were co-crystallized with a small 33-compound mini-library to search for fragment hits. This technology pushes towards a much faster, more automated and more flexible strategy for structure-based drug discovery using as little as 2.5 nl of each major component.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2014

Decline of Cosmetic Outcomes Following Accelerated Partial Breast Irradiation Using Intensity Modulated Radiation Therapy: Results of a Single-Institution Prospective Clinical Trial

Purpose: To report the final cosmetic results from a single-arm prospective clinical trial evaluating accelerated partial breast irradiation (APBI) using intensity modulated radiation therapy (IMRT) with active-breathing control (ABC). Methods and Materials: Women older than 40 with breast cancer stages 0-I who received breast-conserving surgery were enrolled in an institutional review board-approved prospective study evaluating APBI using IMRT administered with deep inspiration breath-hold. Patients received 38.5 Gy in 3.85-Gy fractions given twice daily over 5 consecutive days. The planning target volume was defined as the lumpectomy cavity with a 1.5-cm margin. Cosmesis was scored on a 4-category scale by the treating physician. Toxicity was scored according to National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE version 3.0). We report the cosmetic and toxicity results at a median follow-up of 5 years. Results: A total of 34 patients were enrolled. Two patients were excluded because of fair baseline cosmesis. The trial was terminated early because fair/poor cosmesis developed in 7 of 32 women at a median follow-up of 2.5 years. At a median follow-up of 5 years, further decline in the cosmetic outcome was observed in 5 women. Cosmesis at the time of last assessment was 43.3% excellent, 30% good, 20% fair, and 6.7% poor. Fibrosis according to CTCAE at last assessment was 3.3% grade 2 toxicity and 0% grade 3 toxicity. There was no correlation of CTCAE grade 2 or greater fibrosis with cosmesis. The 5-year rate of local control was 97% for all 34 patients initially enrolled. Conclusions: In this prospective trial with 5-year median follow-up, we observed an excellent rate of tumor control using IMRT-planned APBI. Cosmetic outcomes, however, continued to decline, with 26.7% of women having a fair to poor cosmetic result. These results underscore the need for continued cosmetic assessment for patients treated with APBI by technique.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

High-Dose-Rate Monotherapy: Safe and Effective Brachytherapy for Patients With Localized Prostate Cancer

Purpose: High-dose-rate (HDR) brachytherapy used as the only treatment (monotherapy) for early prostate cancer is consistent with current concepts in prostate radiobiology, and the dose is reliably delivered in a prospectively defined anatomic distribution that meets all the requirements for safe and effective therapy. We report the disease control and toxicity of HDR monotherapy from California Endocurietherapy (CET) and William Beaumont Hospital (WBH) in low- and intermediate-risk prostate cancer patients. Methods and Materials: There were 298 patients with localized prostate cancer treated with HDR monotherapy between 1996 and 2005. Two biologically equivalent hypofractionation protocols were used. At CET the dose was 42 Gy in six fractions (two implantations 1 week apart) delivered to a computed tomography-defined planning treatment volume. At WBH the dose was 38 Gy in four fractions (one implantation) based on intraoperative transrectal ultrasound real-time treatment planning. The bladder, urethral, and rectal dose constraints were similar. Toxicity was scored with the National Cancer Institute Common Toxicity Criteria for Adverse Events version 3. Results: The median follow-up time was 5.2 years. The median age of the patients was 63 years, and the median value of the pretreatment prostate-specific antigen was 6.0 ng/mL. The 8-year results were 99% local control, 97% biochemical control (nadir +2), 99% distant metastasis-free survival, 99% cause-specific survival, and 95% overall survival. Toxicity was scored per event, meaning that an individual patient with more than one symptom was represented repeatedly in the morbidity data table. Genitourinary toxicity consisted of 10% transient Grade 2 urinary frequency or urgency and 3% Grade 3 episode of urinary retention. Gastrointestinal toxicity was <1%. Conclusions: High disease control rates and low morbidity demonstrate that HDR monotherapy is safe and effective for patients with localized prostate cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
NASA NTRS2004

Adjoint Algorithm for CAD-Based Shape Optimization Using a Cartesian Method

Adjoint solutions of the governing flow equations are becoming increasingly important for the development of efficient analysis and optimization algorithms. A well-known use of the adjoint method is gradient-based shape optimization. Given an objective function that defines some measure of performance, such as the lift and drag functionals, its gradient is computed at a cost that is essentially independent of the number of design variables (geometric parameters that control the shape). More recently, emerging adjoint applications focus on the analysis problem, where the adjoint solution is used to drive mesh adaptation, as well as to provide estimates of functional error bounds and corrections. The attractive feature of this approach is that the mesh-adaptation procedure targets a specific functional, thereby localizing the mesh refinement and reducing computational cost. Our focus is on the development of adjoint-based optimization techniques for a Cartesian method with embedded boundaries.12 In contrast t o implementations on structured and unstructured grids, Cartesian methods decouple the surface discretization from the volume mesh. This feature makes Cartesian methods well suited for the automated analysis of complex geometry problems, and consequently a promising approach to aerodynamic optimization. Melvin et developed an adjoint formulation for the TRANAIR code, which is based on the full-potential equation with viscous corrections. More recently, Dadone and Grossman presented an adjoint formulation for the Euler equations. In both approaches, a boundary condition is introduced to approximate the effects of the evolving surface shape that results in accurate gradient computation. Central to automated shape optimization algorithms is the issue of geometry modeling and control. The need to optimize complex, "real-life" geometry provides a strong incentive for the use of parametric-CAD systems within the optimization procedure. In previous work, we presented an effective optimization framework that incorporates a direct-CAD interface. In this work, we enhance the capabilities of this framework with efficient gradient computations using the discrete adjoint method. We present details of the adjoint numerical implementation, which reuses the domain decomposition, multigrid, and time-marching schemes of the flow solver. Furthermore, we explain and demonstrate the use of CAD in conjunction with the Cartesian adjoint approach. The final paper will contain a number of complex geometry, industrially relevant examples with many design variables to demonstrate the effectiveness of the adjoint method on Cartesian meshes.

Nemec, Marian↗
DOE OSTI2014

Simplified continuum solvent model with a smooth cavity based on volumetric data

We present a continuum solvent model (CSM) with a smooth cavity for the application in grid-based electronic structure methods. The cavity is identified with the inherently smooth distribution function of a binary mixture at infinite dilution. We obtain a cavity model based on atomic van der Waals radii and one free parameter controlling the overall size. This single parameter is sufficient to adequately reproduce experimental partial molar volumes. The CSM based on this cavity is of similar accuracy in the prediction of aqueous solvation Gibbs energies of small neutral molecules and ions as other CSMs with a smooth cavity. We apply the model to systems in non-aqueous solution, i.e., spiropyran/merocyanin energetics, a proton transfer reaction in dimethyl sulfoxide, and the electrostatic screening of charged gold clusters in an ionic liquid.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

A review of materials used in tomographic volumetric additive manufacturing

Abstract Volumetric additive manufacturing is a novel fabrication method allowing rapid, freeform, layer-less 3D printing. Analogous to computer tomography (CT), the method projects dynamic light patterns into a rotating vat of photosensitive resin. These light patterns build up a three-dimensional energy dose within the photosensitive resin, solidifying the volume of the desired object within seconds. Departing from established sequential fabrication methods like stereolithography or digital light printing, volumetric additive manufacturing offers new opportunities for the materials that can be used for printing. These include viscous acrylates and elastomers, epoxies (and orthogonal epoxy-acrylate formulations with spatially controlled stiffness) formulations, tunable stiffness thiol-enes and shape memory foams, polymer derived ceramics, silica-nanocomposite based glass, and gelatin-based hydrogels for cell-laden biofabrication. Here we review these materials, highlight the challenges to adapt them to volumetric additive manufacturing, and discuss the perspectives they present. Graphical abstract

36 MATERIALS SCIENCE↗
NASA NTRS1975

Space tug/shuttle interface compatibility study. Volume 1: Executive summary

Shuttle interfaces required for space tug accommodation are primarily involved with supporting and servicing the tug during launch countdown, flight, and postlanding; deploying and retrieving the tug on orbit; and maintaining control over the tug when it is in or near the orbiter. Each of these interface areas was investigated to determine the best physical and operational method of accomplishing the required functions, with an overriding goal of establishing simple and flexible orbiter interface requirements suitable for tug, tug payloads, IUS and other cargo. It is concluded the orbiter payload accommodations and the MSFC baseline tug are generally interface compatible. Specific minor changes to tug and orbiter interfaces were identified to provide full compatibility. A system concept for supporting and deploying tug from orbiter is described.

Source record↗
NASA NTRS1986

Integrated air revitalization system for Space Station

Fifty-one distinct functions are encompassed by the Space Station's Environmental Control and Life Support System; one exception to this noninteractivity of functions is the regenerative air revitalization system that removes and reduces CO2 and generates O2. The integration of these interdependent functions, and of humidity control, into a single system furnishes opportunities for process simplification as well as for power, weight and volume requirement reductions by comparison with discrete subsystems. Attention is presently given to a system which quantifies these integration-related savings and identifies additional advantages that accrue to this integrating design method.

Boyda, R. B.↗
NASA NTRS2018

Water Walls Architecture: Massively Redundant And Highly Reliable Life Support For Long Duration Exploration Missions

The Water Wall concept proposes a system for structural elements that provide,thermal, radiation, water, solids and air treatment functions which are placed at the periphery of inflatable or rigid habitats. It also provides novel and potentially game changing mass reduction and reuse options for radiation protection. The approach would allow water recycling, air treatment, thermal control, and solids residuals treatment and recycling to be removed from the usable habitat volume, and placed in the walls by way of a radiation shielding water wall. It would also provide a mechanism to recover and reuse water treatment (solids) residuals to strengthen the habitat shell and a method of deriving radiation shielding from wastes generated on orbit. Water wall treatment elements would be a much-enlarged version of the commercially available hydration bags. Some water bags may have pervaporation membranes facing outward, which would provide the ability to remove H20, C02 and trace organics from the atmosphere and some would have hydrophobic internal membranes which would provide water, and waste recycling and some power generation.

Water Recycling↗
DOE OSTI2015

Detection of gas leakage

A method of detecting leaks and measuring volumes as well as a device, the Power-free Pump Module (PPM), provides a self-contained leak test and volume measurement apparatus that requires no external sources of electrical power during leak testing or volume measurement. The PPM is a portable, pneumatically-controlled instrument capable of generating a vacuum, calibrating volumes, and performing quantitative leak tests on a closed test system or device, all without the use of alternating current (AC) power. Capabilities include the ability is to provide a modest vacuum (less than 10 Torr) using a venturi pump, perform a pressure rise leak test, measure the gas's absolute pressure, and perform volume measurements. All operations are performed through a simple rotary control valve which controls pneumatically-operated manifold valves.

47 OTHER INSTRUMENTATION↗