Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Drying”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,279 records · Page 71
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Biomass Size Reduction, Drying, and Densification

The overall objective is to solve the particle attrition issue during biomass grinding and pelleting and to enable pelleting as a viable option for production of on-spec material or conversion-ready cellulosic feedstocks.

09 BIOMASS FUELS↗
DOE OSTI2015

Used nuclear fuel dry storage cask materials monitoring system: a proof of concept to deploy retrieve monitoring equipment - 15504

The cask materials monitoring system is a proof-of-concept to deploy and retrieve monitoring equipment. The system is an airlock-type system that is bolted to the cask fill/drain port. It consists of the following major components: (1) a monitoring module that contains the equipment for monitoring the cask environment, (2) a sliding shield plug that provides radiation shielding throughout the deployment and retrieval of the monitoring equipment module, (3) a primary seal flange that is permanently installed on the cask that provides cask boundary confinement, and (4) a containment tube that provides the airlock function providing cask confinement when the primary seal is broken. In this proof-of-concept development, corrosion coupons were selected as the monitoring equipment for deployment into a spent nuclear fuel cask. However, the system has the potential for a variety of uses. The integration of a camera deployment system into the cask materials monitoring system will permit inspection of used nuclear fuel while maintaining cask atmosphere. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

An assessment of total depletion uncertainties for a GBC-32 dry storage cask with PLUS7 fuels using Monte Carlo sampling and two-way ANOVA F-test

It is important to accurately evaluate depletion uncertainties that exist due to the limitations of a computer code on accuracy in a nuclear depletion calculation for criticality safety analysis. In this work, the bias and bias uncertainty in the effective neutron multiplication factor (k{sub eff}) for the generic 32 PWR-assembly burnup credit (GBC-32) cask system were assessed using the Monte Carlo uncertainty sampling method for three different burnups and the isotopic biases and uncertainties obtained with the calculated and measured isotopic concentrations. The PLUS7 used nuclear fuel assemblies discharged from the Hanbit Nuclear Power Plant Unit 3 were assumed to be loaded into the GBC-32 cask. In addition, the statistical F-test in the two-way analysis of variance (ANOVA) was suggested to efficiently estimate the statistically converged total depletion uncertainty in k{sub eff}, with a significant reduction of computing efforts in the Monte Carlo criticality calculations, and it was applied to the GBC-32 cask system after a sensitivity analysis was performed to select the important nuclides having significant contributions to the total depletion uncertainty. With the statistical F-tests in the two-way ANOVA, 100 criticality calculations were needed to get a statistically converged total depletion uncertainty for 10 and 30 GWD/MTU, while 120 criticality calculations were needed for 50 GWD/MTU. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2018

A New Safeguards Technique for Spent Fuel Verification in Dry Storage by Using He-4 Detectors - 18262

It is demanded to find key issues and critical paths for verifying and monitoring a spent nuclear fuel cask or storage with a purpose of non-proliferation of nuclear weapon. However, unfortunately there are no reliable methods to verify the containment in a spent nuclear fuel cask or storage. Therefore, research and development (R and D) has been continuously required to develop new and alternative technologies for searching and verifying undeclared nuclear materials, activities, and facilities. Therefore, the present authors have developed a new safeguards technique of passively scanning a spent fuel cask or storage using pressurized He-4 scintillation neutron detectors. A new approach is to quickly verify content in a spent nuclear fuel cask or presence of all special nuclear materials in unknown packages by comparing experimental and computational results. For that, the present authors have developed a new algorithm and user-interface coupled ORIGEN-ARP and MCNP codes, and the prototype safeguards apparatus employing the array of He-4 fast neutron detectors has been designed, built, and tested. The feasibility test of this new apparatus has been performed with Cf-252 neutron sources and the laboratory scale model cask, minimized by a factor of ten compared to the actual dimension of a KN-21 cask. This technique has several advantages over current methods based on neutron and gamma detection; (1) incident neutron energy information is preserved, (2) disturbance of gamma-ray is excellently rejected (discriminated), and (3) much higher neutron counts and operational cost and space-effectiveness are expected since no moderator is required for fast neutrons. The final goal of this study will (1) conduct a prototype instrument and employ it to monitor a nuclear spent fuel cask or storage at a commercial nuclear power reactor facilities, (2) use spectral-specific measurement data to show proof of concept for measurable data successfully converted to quantifiable signatures, such as diversion/removal of fuel, and maintenance of fuel and cask integrity of fuel, and (3) develop a cask imaging capability. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

High atmospheric demand for water can limit forest carbon uptake and transpiration as severely as dry soil

Abstract When stressed by low soil water content (SWC) or high vapor pressure deficit (VPD), plants close stomata, reducing transpiration and photosynthesis. However, it has historically been difficult to disentangle the magnitudes of VPD compared to SWC limitations on ecosystem‐scale fluxes. We used a 13 year record of eddy covariance measurements from a forest in south central Indiana, USA, to quantify how transpiration and photosynthesis respond to fluctuations in VPD versus SWC. High VPD and low SWC both explained reductions in photosynthesis relative to its long‐term mean, as well as reductions in transpiration relative to potential transpiration estimated with the Penman‐Monteith equation. Flux responses to typical fluctuations in SWC and VPD had similar magnitudes. Integrated over the year, VPD fluctuations accounted for significant reductions of GPP in both nondrought and drought years. Our results suggest that increasing VPD under climatic warming could reduce forest CO 2 uptake regardless of changes in SWC.

Sulman, Benjamin N.↗
DOE OSTI2024

How dry is dead? Evaluating the impact of desiccation on the viability of the invasive species Cissus quadrangularis

Abstract Cissus quadrangularis is a succulent vine that degrades forests where it is not native by growing over trees and causing them to break or by impeding regeneration. Methods for its control have been tried but no satisfactory approach has been found yet. We carried out an experiment to analyze how much desiccation Cissus can endure before losing its ability to grow when rehydrated, using fragments of 0.5, 1, 2, and 3 internodes to test if desiccation tolerance was affected by fragment length. We found that Cissus remains viable after losing up to 80% of its weight, with shorter fragments losing viability (capacity to grow) at 70% weight loss. No fragments sustained viability at 90% water loss, establishing a critical threshold for Cissus desiccation tolerance. Our study also showed that shorter fragments (0.5 internodes) were less viable compared to longer ones (1, 2 or 3 internodes). Cissus has a remarkable tolerance to desiccation. Therefore, management strategies should ensure complete dehydration of Cissus fragments to prevent its regrowth. Reducing fragments to smaller sizes could amplify the effectiveness of control measures by reducing their viability, but risks of increasing propagule numbers should be considered.

Mondragón‐Botero, Ariadna↗
DOE OSTI2022

Squeeze Film Damper Experimental and Numerical Correlation: Test Setup Description and Parameter Identification of Dry System

The process of characterizing a damper involves both experimental techniques and model simulation. Experiments characterize dynamic behavior of a system through empirical modal analysis using impact and shaker testing. The layout of the test setup is crucial for a low-mass, nonlinear system. Physical arrangement, orientation of the system, and instrumentation affect the results that are discussed in this paper. These results can be used to validate a numerical simulation of the same system. With a validated model, important physical input parameters and modeling techniques can be determined and implemented in future designs. In other words, this modeling can be used with confidence to design alternative dampers that may be difficult, costly, and time-consuming to characterize experimentally.

Cook, Jason↗