Gas levitator having fixed levitation node for containerless processing

A method and apparatus is disclosed for levitating a specimen of material in a containerless environment at a stable nodal position independent of gravity. An elongated levitation tube has a contoured interior in the form of convergent section, constriction, and a divergent section in which the levitation node is created. A gas flow control means prevents separation of flow from the interior walls in the region of a specimen. The apparatus provides for levitating and heating the specimen simultaneously by combustion of a suitable gas mixture combined with an inert gas

Numerical Simulation for Droplet Combustion Using Lagrangian Hydrodynamics

A predictive model of spray combustion must incorporate models for the wide variety of physical environments in a practical combustor. In regions where droplets are closely spaced, combustion resembles a diffusion flame; where they are well separated, an envelope or wake flame results. The relative velocity field between the fuel droplets and oxidizer in influences boundary layer development about the droplet, recirculating flow patterns, and droplet shape and stability. A model must encompass these interacting temporal and spatial effects as well as complicated combustor boundaries. The objective of the current work is to develop the triangular gridding method for describing the individual and collective properties of vaporizing and burning fuel droplets

An Analysis of the School Buildings of McMinn County in Terms of the Requirements for New Buildings set forth in the Rules and Regulations, 1950, of the Tennessee State Board of Education

In the summer of 1949 the McMinn County School Superintendents and representatives of the College of Education of the University of Tennessee held a conference for the purpose of organizing a program of study and improvement of the McMinn County Schools. This conference resulted in the formation of a group of representative McMinn County school people which included the county and city school superintendents, supervisor, attendance teacher, and interested principles and teachers of McMinn County

The Rational Design and Lithographic Fabrication of Surface Enhanced Raman Spectroscopy Substrates

The analytical capabilities of surface-enhanced Raman spectroscopy (SERS) reside in the performance characteristics of the SERS-active substrate. Signal enhancement observed in SERS is attributable to the presence of noble metal nanostructures on substrate surfaces. The rational design and control of variables such as shape and size, and distribution, density, and spacing of these nanostructures can lead to substrates that have greater analytical sensitivity and yield more reproducible enhancement. Through systematic control of the morphology of our SERS substrates, we have created ordered periodic arrays as well as random aggregates of nanoscale particles using electron beam lithography (EBL). A unique aspect of these EBL-created substrates is that the morphology is known with great precision. Once fabricated, the arrays and/or aggregates are coated with a SERS-active noble metal through physical vapor deposition (PVD). Both the uniform and random lithographically produced nanopatterns are studied by surface enhanced Raman spectroscopy to examine the Stokes responses of various analytes, while scanning electron microscopy (SEM) is used to examine pattern surfaces post lithographic development and post noble metal deposition. In the case of the ordered structures, raw and normalized SERS data is seen to correlate with data from simple electrostatic calculations as well as the broad background continuum underlying each spectrum collected. Borrowing from the biological concepts of cloning and combinatorial chemistry, random morphology patterns are designed and spectrally mapped to locate “hot spots” within aggregates. Regardless of the type of substrate, ordered or random, by using EBL, the substrates can be reproducibly fabricated, yielding consistent analyte environments each time the substrate is created

Numerical simulations of fuel droplet flows using a Lagrangian triangular mesh

The incompressible, Lagrangian, triangular grid code, SPLISH, was converted for the study of flows in and around fuel droplets. This involved developing, testing and incorporating algorithms for surface tension and viscosity. The major features of the Lagrangian method and the algorithms are described. Benchmarks of the algorithms are given. Several calculations are presented for kerosene droplets in air. Finally, extensions which make the code compressible and three dimensional are discussed

Decentralized Data Fusion and Active Sensing with Mobile Sensors for Modeling and Predicting Spatiotemporal Traffic Phenomena

The problem of modeling and predicting spatiotemporal traffic phenomena over an urban road network is important to many traffic applications such as detecting and forecasting congestion hotspots. This paper presents a decentralized data fusion and active sensing (D2FAS) algorithm for mobile sensors to actively explore the road network to gather and assimilate the most informative data for predicting the traffic phenomenon. We analyze the time and communication complexity of D2FAS and demonstrate that it can scale well with a large number of observations and sensors. We provide a theoretical guarantee on its predictive performance to be equivalent to that of a sophisticated centralized sparse approximation for the Gaussian process (GP) model: The computation of such a sparse approximate GP model can thus be parallelized and distributed among the mobile sensors (in a Google-like MapReduce paradigm), thereby achieving efficient and scalable prediction. We also theoretically guarantee its active sensing performance that improves under various practical environmental conditions. Empirical evaluation on real-world urban road network data shows that our D2FAS algorithm is significantly more time-efficient and scalable than state-of-the-art centralized algorithms while achieving comparable predictive performance.Comment: 28th Conference on Uncertainty in Artificial Intelligence (UAI 2012), Extended version with proofs, 13 page

Small-angle neutron scattering of (Er₀.₈Ho₀.₂)Rh₄B₄

The (Er1-xHox)Rh4B4 pseudoternary alloy system has a minimum in the phase boundary between the superconducting and ferromagnetic phases near x=0.3. This minimum has been identified as due to the competing magnetic anisotropies of Er and Ho. It has also been suggested that there could be a Lifschitz point near the minimum. Using the 30-m SANS camera at the National Center for Small-Angle Scattering Research at ORNL, we have observed a peak in the SANS pattern for (Er 0.8Ho0.2)Rh4B4 at Q=0.065 Å-1. This peak appears for temperatures between Tc2, measured upon cooling, and Tm, and corresponds to a modulation of the magnetic moment with a wavelength of about 100 Å, demonstrating that the modulated moment phase exists away from the ErRh 4B4 end of the phase diagram. The wavelength of the modulation is the same as was previously observed in ErRh4B 4. The fact that the wavelength of the modulation remains finite near x=0.3 appears to rule out the possibility of Lifschitz behavior near this point

Modeling solar wind mass‐loading in the vicinity of the Sun using 3‐D MHD simulations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106053/1/jgra50759.pd