Evaporative lifetimes of copper, chromium, beryllium, nickel, iron, and titanium on tungsten and oxygenated tungsten.
Coverage dependent evaporative lifetimes of various metals and oxygenated W ribbon filaments at high temperatures
EVAPORATION RATE↗
SEARCH · Engineering Papers
Results for “EVAPORATION”
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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Evaporation rates of PbTe and Pb sub .5 Sn sub .5 Te pressed and sintered thermoelements.
Evaporation rates of lead telluride and lead tin telluride in pressed and sintered thermoelement form
TIN COMPOUND↗
Assessment of convection, conduction, and evaporation in nucleate boiling
Assessment of convection, conduction, and evaporation in nucleate boiling
NUCLEATE BOILING↗
An improved spatterproof vacuum evaporation source
Improved spatterproof vacuum evaporation source for use in depositing thin solid films on substrate
METAL FILM↗
Study of the process of heat and mass transfer during the evaporation of a liquid with a free surface in a rarefied gas medium
Heat and mass transfer during evaporation of liquid with free surface in rarefied gas medium
EVAPORATION↗
Flash evaporation and thin films of cuprous sulfide, selenide, and telluride.
Thin films of cuprous sulfide, selenide and telluride prepared by flash evaporation, discussing resistivity and absorption coefficient
COPPER COMPOUND↗
Thermal Control of a Venus Lander: Evaporation of Ammonia
Evaporation of ammonia at the temperature and pressure of the surface of Venus will allow electronics' baseplate temperatures to remain at 120 C for limited time determined by the amount of ammonia.
heat transfer↗
Sensitivity of Spacebased Microwave Radiometer Observations to Ocean Surface Evaporation
The methodology of spacebased estimation of evaporation and latent heat flux from the ocean is described.
ocean↗
A Priori Subgrid Analysis of Temporal Mixing Layers with Evaporating Droplets
Subgrid analysis of a transitional temporal mixing layer with evaporating droplets has been performed using three sets of results from a Direct Numerical Simulation (DNS) database, with Reynolds numbers (based on initial vorticity thickness) as large as 600 and with droplet mass loadings as large as 0.5.
subgrid↗
Evaporation Studies of the Metals and Alloys Used in the TEMPUS Flight Experiments
Evaporation rates have been measured for the metals and alloys to be used in the TEMPUS flight experiments in order to facilitate a rational assingnment of a flight sequence that will minimize the effects of particulate and cross contamination.
evaporation↗
Evaluation of Equilibrium and Non-Equilibrium Evaporation Models for Many-Droplet Gas-Liquid Flow Simulations
A variety of liquid droplet evaporation models, including both classical equilibrium and non-equilibrium Langmuir-Knudsen formulations, are evaluated through comparisons with experiments with particular emphasis on computationally efficient procedures for many-droplet gas-liquid flow simulations.
Condensation↗
Dew-Point Evaporative Comfort Cooling (Presentation)
Presentation on innovative indirect evaporative cooling technology developed by Coolerado Corporation given at the Rocky Mountain Chapter ASHRAE conference in April 2012.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
New Insights into Shape Memory Alloy Bimorph Actuators Formed by Electron Beam Evaporation
In order to create shape memory alloy (SMA) bimorph microactuators with high-precision features, a novel fabrication process combined with electron beam (E-beam) evaporation, lift-off resist and isotropic XeF2 dry etching method was developed. To examine the effect of E-beam deposition and annealing process on nitinol (NiTi) characteristics, the NiTi thin film samples with different deposition rate and overflow conditions during annealing process were investigated. With the characterizations using scanning electron microscope and x-ray diffraction, the results indicated that low E-beam deposition rate and argon employed annealing process could benefit the formation of NiTi crystalline structure. In addition, SMA bimorph microactuators with high-precision features as small as 5 microns were successfully fabricated. Furthermore, the thermomechanical performance was experimentally verified and compared with finite element analysis simulation results.
36 MATERIALS SCIENCE↗
Removal of Bond Sodium from Full-Length Unirradiated Fermi-1 Blanket Elements and Assembly via Melt-Drain-Evaporate Process
Equipment was designed, fabricated, tested, and operated in an inert atmosphere radiological glovebox at Idaho National Laboratory to demonstrate the removal of bond sodium from full-length unirradiated Fermi-1 radial blanket elements and an entire radial blanket assembly using a Melt-Drain-Evaporate process. A series of three runs was performed with individual and multiple radial Fermi-1 blanket elements, and a fourth run was conducted with an entire Fermi-1 radial blanket assembly. After each run, the depleted uranium alloy slugs in every element slid out of its cladding, mechanically exhibiting the effectual absence of bond sodium. Quantitative and further qualitative analyses of the treated Fermi-1 material revealed the substantive, if not complete, absence of sodium metal in blanket element components. Indeed, entire columns of depleted uranium alloy slugs and associated cladding from select treated elements were separately contacted with water to react with residual sodium metal on the element surfaces, forming hydrogen gas. Samples of the resultant gas were analyzed to quantify the hydrogen concentration, which correlated to a residual sodium metal content for the treated element. Accordingly, no detectable sodium metal (<7 µg) was found on the surfaces of multiple depleted uranium alloy slugs after removal from its cladding. Detectable sodium metal, ranging from 14 to 30 µg, was found on the surfaces of one separated column of slugs and two separated full-length cladding segments. Each element originally contained ~25 g of bond sodium, resulting in quantitative sodium metal removal efficiencies of =99.9998%. The remaining separated uranium alloy slugs and cladding segments from the four runs were piece-wise immersed in alcohol while videorecording possible gas bubble formation as an additional qualitative analysis for residual sodium metal on treated surfaces, which identified the predominant absence of sodium reactivity on the balance of treated Fermi-1 blanket material. The results of this demonstration substantiate a path forward for treatment and disposal of 34 metric tons heavy metal of irradiated sodium-bonded Fermi-1 blanket material currently stored at Idaho National Laboratory.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Sharing Lessons Learned 'Across the Pond' on Two Major Construction Projects: Evaporator D and SWPF - 16050
This paper compares and contrasts two projects, the Salt Waste Processing Facility at Savannah River in the US and Evaporator D at Sellafield in the UK, to highlight the similar challenges that each project has experienced since contract award and how these challenges have been addressed. The paper compares the life-cycles of the projects, project strategy, design, construction, and regulatory issues, along with cost and schedule performance. There is also some discussion about the anticipated challenges in the future as the projects move into the startup and commissioning phase. Overall, the paper identifies some of the common areas that have affected these projects and how these similarities have been the subject of sharing and collaborating lessons learned on a broader scale, even though the delivery organizations operate in different countries under different regulatory and Government frameworks. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
On the Robustness of a Cement-Based Matrix for the Conditioning of Evaporator Concentrates - 16417
The presented work is research in progress on the robustness of a cement-based matrix designed for the conditioning of evaporator concentrates with highly variable chemical composition. A change in the waste composition can induce significant alteration of the cement-waste form. However, all criteria imposed by the authorities on the immobilized waste need to be met and the processability of all these possible waste compositions has to be guaranteed. Defining a domain of acceptable waste compositions usually requires to investigating many parameters, which results, with classical approaches, in a high number of trials. Design of experiments (DOE) is shown to be a fruitful alternative which enables to keep the total number of runs within reason without compromising the quality of the achieved results. An example is given, showing how a Plackett-Burman design can be used to determine, among all the waste components, those which significantly influence the properties of the cement-waste forms when they vary within the experimental domain of interest. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Use of Robotics in Liquid Waste System - {sup 3}H Evaporator, Tank Closure and Defense Waste Processing Facility - 18525
The Savannah River Site (SRS) Liquid Waste System (LWS) safely stores and treats high-level radioactive waste. The LWS consists of 51 waste storage tanks (eight of which are operationally closed and filled with grout), waste evaporators, treatment facilities, and solidification facilities such as the Defense Waste Processing Facility (DWPF) and Salt-stone Production Facility (SPF). At Savannah River Remediation (SRR), the liquid waste contractor, robotic technologies are needed to enter areas and spaces that are otherwise inaccessible or prohibit direct access by workers due to unsafe, unstable, or unknown physical or structural conditions; or configurations that are hard to reach or beyond reach without taking extraordinary mechanical measures. As discussed below, SRR uses robotic technologies at various LWS facilities to reduce dose to the workers as well as provide access to unreachable locations due to the presence of radiological or chemical hazards. (author)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Effect of Evaporation on Vapor Space Flammability in DWPF Process Vessels - 20278
The Savannah River Site (SRS) Defense Waste Processing Facility (DWPF) processes liquid high-level waste (HLW) and encapsulates it in glass within stainless-steel containers suitable for safe, long-term storage and disposal. Radiolytic and chemical decomposition of the liquid waste generates hydrogen and other flammable gases creating a hazard. The rate of flammable gas generation increases by an order of magnitude as temperature increases from sub-boiling to boiling. DWPF controls this hazard in process tanks by ensuring a minimum purge flow through each tank's head space. The minimum purge flow rate is established assuming dry air and neglecting evaporation. However, this study determined that steam from boiling in a representative process tank is sufficient to dilute flammable gases and, thereby, preclude flammability. For sub-boiling, water vapor is an insufficient diluent considering hydrogen's lower flammable limit (LFL) in air. However, the upper and lower flammable limits approach each other in a hydrogen-air-water-vapor environment as the water vapor concentration increases. This effect may preclude flammable conditions if water vapor concentration is about 60 volume percent or higher. A saturated, constant-pressure air-water system would achieve 60 volume percent water vapor at 86 deg. C. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗