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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 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Joint optimization of logistics infrastructure investments and subsidies in a regional logistics network with CO 2 emission reduction targets

This study proposes an optimization model that simultaneously incorporates the selection of logistics infrastructure investments and subsidies for green transport modes to achieve specific CO 2 emission targets in a regional logistics network. The proposed model is formulated as a bi-level formulation, in which the upper level determines the optimal selection of logistics infrastructure investments and subsidies for green transport modes such that the benefit-cost ratio of the entire logistics system is maximized. The lower level describes the selected service routes of logistics users. A genetic and Frank-Wolfe hybrid algorithm is introduced to solve the proposed model. The proposed model is applied to the regional logistics network of Changsha City, China. Findings show that using the joint scheme of the selection of logistics infrastructure investments and green subsidies is more effective than using them solely. In conclusion, carbon emission reduction targets can significantly affect logistics infrastructure investments and subsidy levels.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2017

Evaluating penalized logistic regression models to predict Heat-Related Electric grid stress days

Understanding the conditions associated with stress on the electricity grid is important in the development of contingency plans for maintaining reliability during periods when the grid is stressed. In this paper, heat-related grid stress and the relationship with weather conditions is examined using data from the eastern United States. Penalized logistic regression models were developed and applied to predict stress on the electric grid using weather data. The inclusion of other weather variables, such as precipitation, in addition to temperature improved model performance. Several candidate models and datasets were examined. A penalized logistic regression model fit at the operation-zone level was found to provide predictive value and interpretability. Additionally, the importance of different weather variables observed at different time scales were examined. Maximum temperature and precipitation were identified as important across all zones while the importance of other weather variables was zone specific. The methods presented in this work are extensible to other regions and can be used to aid in planning and development of the electrical grid.

Bramer, L. M.↗
DOE OSTI2012

LOGISTIC FUNCTION PROFILE FIT: A least-squares program for fitting interface profiles to an extended logistic function

The extended logistic function provides a physically reasonable description of interfaces such as depth profiles or line scans of surface topological or compositional features. It describes these interfaces with the minimum number of parameters, namely, position, width, and asymmetry. Logistic Function Profile Fit (LFPF) is a robust, least-squares fitting program in which the nonlinear extended logistic function is linearized by a Taylor series expansion (equivalent to a Newton-Raphson approach) with no apparent introduction of bias in the analysis. The program provides reliable confidence limits for the parameters when systematic errors are minimal and provides a display of the residuals from the fit for the detection of systematic errors. The program will aid researchers in applying ASTM E1636-10, 'Standard practice for analytically describing sputter-depth-profile and linescan-profile data by an extended logistic function,' and may also prove useful in applying ISO 18516: 2006, 'Surface chemical analysis-Auger electron spectroscopy and x-ray photoelectron spectroscopy-determination of lateral resolution.' Examples are given of LFPF fits to a secondary ion mass spectrometry depth profile, an Auger surface line scan, and synthetic data generated to exhibit known systematic errors for examining the significance of such errors to the extrapolation of partial profiles.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS2021

Logistics Reduction: RFID Enabled Autonomous Logistics Management (REALM) (LR-REALM)

The Advanced Exploration Systems (AES) Logistics Reduction (LR) project Radio-frequency identification (RFID) Enabled Autonomous Logistics Management (REALM) task focuses on the subset of autonomous logistics management functions pertaining to automated localization and inventory of all physical assets pertaining to, or within, a vehicle utilizing RFID technologies. REALM technology can provide detailed data to enable autonomous operations such as automated crew procedure generation and robotic interaction with logistics and deep space habitats; this is especially of value where communication delays with Earth drive the need for self-reliance. The REALM project will conduct a series of ISS technology demonstrations. The first ISS demonstration, REALM-1, started in February 2017 and was completed at the end of FY19 when it was transitioned to the ISS program for sustaining operations. The second ISS demonstration, REALM-2, started late2019 and will continue for at least one year.

NASA TechPort↗
NASA NTRS1988

Integrated tracking of components by engineering and logistics utilizing logistics asset tracking system

The Logistics Asset Tracking System (LATS) devised by NASA contains data on Space Shuttle LRUs that are daily updated to reflect such LRU status changes as repair due to failure or modification due to changing engineering requirements. The implementation of LATS has substantially increased personnel responsiveness, preventing costly delays in Space Shuttle processing and obviating hardware cannibalization. An evaluation is presented of LATS achievements in the direction of an integrated logistical support posture.

Renfroe, Michael B.↗
NASA NTRS2008

The Pressurized Logistics Module: Providing Consumables and Resupply Logistics to the Lunar Surface for a Long-duration Manned Mission

In response to President Bush s 2004 Vision for Space Exploration initiative, NASA established an agency-wide Lunar Architecture Team (LAT) to develop the high-level requirements, assumptions, ground-rules and objectives for a manned mission to the moon. During Phase II of the evaluation, the Habitation Focus Element Group was directed to conceptually develop and design a Pressurized Logistics Module (PLM). The PLM task was delivered with one major requirement: to derive a system with minimal mass and cost, and a maximum, functional, internal volumetric area in order to provide the maximum amount of consumables, supportability and logistic re-supply for a crew of four to the Lunar surface with an overall integrated maximum weight of 5200kg. The PLM was derived from the Habitation Group s "mini-Hab" option. This concept required that the PLM have an aluminum-clad graphite epoxy external truss, utilized for increased mobility and stability, which would encompass a 2.7 meter diameter pressurized aluminum-lithium cylinder. Several trade studies and analyses were performed to determine the final length and orientation of the module, the number of systems required to maintain the PLM, and the number of hatches/mating mechanisms which would successfully and efficiently meet the requirements. Of the five specific configurations assessed, the PLM was determined to have a 3 meter by 3 meter by 5 meter external truss with a 2.7 meter diameter and 5 meter long horizontal, pressurized cylinder with one hatch/mating mechanism on one end cone. Two major assumptions aided in the formulation of the technical baseline: 1) the PLM should be sustainable for up to 18 months on the Lunar Lander without connection to its final destination, the Lunar Outpost, and 2) it must be self-sufficient to withstand a maximum eight hour transit from the Lander to the Outpost. Per these assumptions, eight major systems constitute the PLM: structures, passive mating, protection, power, thermal, avionics, life support and outfitting. Including a conservative 20% growth, the overall estimated tare weight for the PLM was determined to be 2181kg. The tare weight of the design allowed the available internal volume of the cylinder with a 0.20 meter high floor to transport the maximum of either 176 single Crew Transfer Bags (CTBs) or 3019kg.

Carpenter, Amanda↗
NASA NTRS1995

A Probabilistic Tool that Aids Logistics Engineers in the Establishment of High Confidence Repair Need-Dates at the NASA Shuttle Logistics Depot

The NASA Shuttle Logistics Depot (NSLD) is tasked with the responsibility for repair and manufacture of Line Replaceable Unit (LRU) hardware and components to support the Space Shuttle Orbiter. Due to shrinking budgets, cost effective repair of LRU's becomes a primary objective. To achieve this objective, is imperative that resources be assigned to those LRU's which have the greatest expectation of being needed as a spare. Forecasting the times at which spares are needed requires consideration of many significant factors including: failure rate, flight rate, spares availability, and desired level of support, among others. This paper summarizes the results of the research and development work that has been accomplished in producing an automated tool that assists in the assignment of effective repair start-times for LRU's at the NSLD. This system, called the Repair Start-time Assessment System (RSAS), uses probabilistic modeling technology to calculate a need date for a repair that considers the current repair pipeline status, as well as, serviceable spares and projections of future demands. The output from the system is a date for beginning the repair that has significantly greater confidence (in the sense that a desired probability of support is ensured) than times produced using other techniques. Since an important output of RSAS is the longest repair turn-around time that will ensure a desired probability of support, RSAS has the potential for being applied to operations at any repair depot where spares are on-hand and repair start-times are of interest. In addition, RSAS incorporates tenants of Just-in-Time (JIT) techniques in that the latest repair start-time (i.e., the latest time at which repair resources must be committed) may be calculated for every failed unit This could reduce the spares inventory for certain items, without significantly increasing the risk of unsatisfied demand.

Bullington, J. V.↗
NASA NTRS2012

NASA Advanced Explorations Systems: Concepts for Logistics to Living

The NASA Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) project strives to enable a largely mission-independent cradle-to-grave-to-cradle approach to minimize logistics contributions to total mission architecture mass. The goals are to engineer logistics materials, common crew consumables, and container configurations to meet the following five basic goals: 1. Minimize intrinsic logistics mass and improve ground logistics flexibility. 2. Allow logistics components to be directly repurposed for on-orbit non-logistics functions (e.g., crew cabin outfitting) thereby indirectly reducing mass/volume. 3. Compact and process logistics that have not been directly repurposed to generate useful on-orbit components and/or compounds (e.g., radiation shielding, propellant, other usable chemical constituents). 4. Enable long-term stable storage and disposal of logistics end products that cannot be reused or repurposed (e.g., compaction for volume reduction, odor control, and maintenance of crew cabin hygienic conditions). 5. Allow vehicles in different mission phases to share logistics resources. This paper addresses the work being done to meet the second goal, the direct repurposing of logistics components to meet other on-orbit needs, through a strategy termed Logistics to Living (L2L). L2L has several areas but can be defined as repurposing or converting logistical items (bags, containers, foam, components, etc.) into useful crew items or life support augmentation on-orbit after they have provided their primary logistics function. The intent is that by repurposing items, dedicated crew items do not have to be launched and overall launch mass is decreased. For non-LEO missions, the vehicle interior volume will be relatively fixed so L2L will enable this volume to be used more effectively through reuse and rearrangement of logistical components. Past work in the area of L2L has already conceptually developed several potential technologies [Howe, Howard 2010]. Several of the L2L concepts that have shown the most potential in the past are based on NASA cargo transfer bags (CTBs) or their equivalents which are currently used to transfer cargo to and from the ISS. A high percentage of all logistics supplies are packaging mass and for a 6-month mission a crew of four might need over 100 CTBs. These CTBs are used for on-orbit transfer and storage but eventually becomes waste after use since down mass is very limited. The work being done in L2L also considering innovative interior habitat construction that integrate the CTBs into the walls of future habitats. The direct integration could provide multiple functions: launch packaging, stowage, radiation protection, water processing, life support augmentation, as well as structure. Reuse of these CTBs would reduce the amount of waste generated and also significantly reduce future up mass requirements for exploration missions. Also discussed here is the L2L water wall , an innovative reuse of an unfolded CTB as a passive water treatment system utilizing forward osmosis. The bags have been modified to have an inner membrane liner that allows them to purify wastewater. They may also provide a structural water-wall element that can be used to provide radiation protection and as a structural divider. Integration of the components into vehicle/habitat architecture and consideration of operations concepts and human factors will be discussed. In the future these bags could be designed to treat wastewater, concentrated brines, and solid wastes, and to dewater solid wastes and produce a bio-stabilized construction element. This paper will describe the follow-on work done in design, fabrication and demonstrations of various L2L concepts, including advanced CTBs for reuse/repurposing, internal outfitting studies and the CTB-based forward osmosis water wall.

Shull, Sarah A.↗
NASA NTRSDate not supplied

Regenerative ECLSS and Logistics Analysis for Sustained Lunar Surface Missions

As NASA begins to develop concepts for sustained crew missions to the lunar surface, it will be essential to evaluate the logistics requirements needed to enable such missions. Lunar surface missions will involve crews of four astronauts living on the surface for periods of 30 days or longer. Astronauts will either live in a surface habitat or transfer between a habitat and a pressurized rover. The amount of logistics that must be delivered to the surface to support the crew, support the surface systems, and conduct science could be substantial. Because NASA plans to conduct these missions on an annual basis, the complexity and cost of logistics delivery will likely drive campaign sustainability. The amount of required logistics is partially a function of the ECLSS system in the habitable elements on the surface. The higher the capability of regenerative ECLSS that can be accommodated, the lower the logistics requirements. However, the increased regenerative ECLSS capabilities will also increase the initial delivery mass of elements and require additional maintenance and spares to maintain the systems. This paper describes an effort to evaluate lunar sustained logistics requirements, including sensitivity analysis for ECLSS architecture options and their impact on requirements. The authors determine logistics requirements using an integrated surface ECLSS model. The model considers different configurations of rover and habitat setups with multiple ECLSS options on both. The tool can also model gas and liquid transfer options between the habitat and the rover. The authors use the model to evaluate several different ECLSS configurations and their logistics requirements. The authors then complete a sensitivity analysis that compares logistic requirements and the initial delivery mass over increasing ECLSS capabilities. Finally, the authors make recommendations for an ECLSS architecture option that balances the tradeoffs between logistics requirements and ECLSS mass.

Environmental Control and Life Support↗
DOE OSTI2017

Impact of the biorefinery size on the logistics of corn stover supply – A scenario analysis

In this study, three scenarios are considered to quantify the impact of the biorefinery size on the required biomass logistical resources. The biorefinery scenarios include small scale (175 dt/day)-SS, medium scale (520 dt/day)-MS and large scale (860 dt/day)-LS. These scenarios are compared against the following logistical resources (1) harvest area and contracted fields, (2) logistics equipment fleet and the workforce to run this fleet and (3) intermediate storage sites and their biomass inventory levels. To this end, the IBSAL-MC simulation model is applied to a corn stover logistics system in Southwestern Ontario. The obtained results show (1) the harvest area and the number of contracted fields increase by 65% and 78% from the SS scenario to the MS and LS scenarios, respectively, (2) the average biomass delivered costs are estimated to be $82.09, $87.49 and $93.75/dry tonne in the SS, MS and LS scenarios. The increase in the capital costs to develop a dedicated logistics equipment fleet are estimated to be far greater than the increase in the delivered costs as the size of the biorefinery increases. The upfront capital costs are estimated to be 6.72 dollars, 21.83 and 35.51 million in these scenarios. To run the logistics equipment fleet efficiently, 37, 136 and 235 well-trained operators are required in the SS, MS ad LS scenarios, respectively, and (3) the inventory level and the land requirement for storage in the MS and LS scenarios are estimated to be 225% and 425% greater than those of the SS scenario. The sensitivity analysis indicates that the logistical resources are highly sensitive to corn yield and farm participation rate. Overall, this study shows the importance of considering the size of the required logistical resources and the associated level of logistical complexity in evaluating the economic viability of a biorefinery project.

09 BIOMASS FUELS↗