Integrating the real estate development environment--computers and an object oriented approach

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1992.Vita.Includes bibliographical references (leaves 85-88).by Nicholas Tsapatsaris.M.S

High throughput <i>in situ</i> EXAFS instrumentation for the automatic characterization of materials and catalysts

An XAS data acquisition and control system for the in situ analysis of dynamic materials libraries under control of temperature and gaseous environment has been developed. It was integrated at the SRS in Daresbury, UK, beamline 9.3, using a Si (220) monochromator and a 13 element solid state Ge fluorescence detector. The core of the system is an intelligent X, Y, Z, θ positioning system coupled to multi-stream quadrupole mass spectrometry analysis (QMS). The system is modular and can be adapted to other synchrotron radiation beamlines. The entire software control was implemented using Labview and allows the scan of a variety of library sizes, in several positions, angles, gas compositions and temperatures with minimal operator intervention. The system was used for the automated characterization of a library of 91 catalyst precursors containing ternary combinations of Cu, Pt, and Au on γ-Al2O3, and for the evaluation and structural characterization of eight Au catalysts supported on A12O3 and TiO2. Mass spectrometer traces reveal conversion rate oscillations in 6wt % Au/γAl2O3 catalysts. The use of HT experimentation for in situ EXAFS studies demonstrates the feasibility and potential of HT in situ XAFS for synchrotron radiation studies

High-throughput synthesis and characterization of BiMoVOX materials

The high throughput synthesis and characterization of a particular family of ceramic materials, bismuth molybdenum vanadium oxides (BiMoVOX), suitable as inorganic yellow pigments and low temperature oxidation catalysts, is described. Samples, synthesized by calcination and peroxo sol-gel methods, are characterized by X-ray powder diffraction, UV-visible and XAFS spectroscopy. A combined high-throughput XRD/XAFS study of a 54 samples array, with simultaneous refinement of data of both techniques, has been performed. Molybdenum doping of bismuth vanadate results in a phase transition from monoclinic BiV04 to tetragonal Bi(V,Mo)04, both of scheelite type. Both central metals, V5+ and Mo6+, remain in a tetrahedral coordination. UV/visible spectroscopy identifies a linear blue shift as a function of Mo6+ amount

Microreactor cells for high throughput x-ray absorption spectroscopy

High-throughput experimentation has been applied to X-ray Absorption spectroscopy as a novel route for increasing research productivity in the catalysis community. Suitable instrumentation has been developed for the rapid determination of the local structure in the metal component of precursors for supported catalysts. An automated analytical workflow was implemented that is much faster than traditional individual spectrum analysis. It allows the generation of structural data in quasi-real time. We describe initial results obtained from the automated high throughput (HT) data reduction and analysis of a sample library implemented through the 96 well-plate industrial standard. The results show that a fully automated HT-XAS technology based on existing industry standards is feasible and useful for the rapid elucidation of geometric and electronic structure of materials

From BASIS to MIRACLES:Benchmarking and perspectives for high-resolution neutron spectroscopy at the ESS

Results based on virtual instrument models for the first high-flux, high-resolution, spallation based, backscattering spectrometer, BASIS are presented in this paper. These were verified using the Monte Carlo instrument simulation packages McStas and VITESS. Excellent agreement of the neutron count rate at the sample position between the virtual instrument simulation and experiments was found, in both time and energy distributions. This achievement was only possible after a new component for a bent single crystal analyser in McStas, using a Gaussian approximation, was developed. These findings are pivotal to the conceptual design of the next generation backscattering spectrometer, MIRACLES at the European Spallation Source

Evaluation of a method for time-of-flight, wavelength and distance calibration for neutron scattering instruments by means of a mini-chopper and standard neutron monitors

Accurate conversion of neutron time-of-flight (TOF) to wavelength, and its uncertainty, is of fundamental importance to neutron scattering measurements. Especially in cases where instruments are highly configurable, the determination of the absolute wavelength after any change must always be performed. Inspired by the manner with which neutron spectrometers determine the absolute wavelength, we evaluate for the first time, in the author's knowledge, a commonly used method for converting TOF to neutron wavelength, the distance of a monitor from the source of neutrons and we analytically calculate the uncertainty contributions that limit the precision of the conversion. The method was evaluated at the V20 test beamline at the Helmholtz Zentrum Berlin (HZB), emulating the ESS source with a pulse of 2.86 ms length and 14 Hz repetition rate, by using a mini-chopper operated at 140 Hz, beam monitors (BMs) and data acquisition infrastructure. The mini-chopper created well-defined neutron pulses and the BM was placed at two positions, enabling the average wavelength of each of the pulses created to be determined. The used experimental setup resulted in absolute wavelength determination at the monitor positions with a $\delta \lambda_{mean} / \lambda_{mean}$ of $\sim$1.8% for $\lambda >4$ \r{A}. With a modest increase of the distance between the reference monitor positions a $\delta \lambda_{mean} / \lambda_{mean}$ of below 0.5% can be achieved. Further improvements are possible by using a thinner monitor, smaller chopper disc openings and a higher rotational speed chopper. The method requires only two neutron measurements and doesn't necessitate the use of crystals or complex fitting, and could constitute a suitable addition to imaging, diffraction, reflectometers and small angle neutron scattering instruments, at spallation sources, that do not normally utilise fast choppers

High Throughput In Situ XAFS Screening of Catalysts

We outline and demonstrate the feasibility of high-throughput (HT) in situ XAFS for synchrotron radiation studies. An XAS data acquisition and control system for the analysis of dynamic materials libraries under control of temperature and gaseous environments has been developed. The system is compatible with the 96-well industry standard and coupled to multi-stream quadrupole mass spectrometry (QMS) analysis of reactor effluents. An automated analytical workflow generates data quickly compared to traditional individual spectrum acquisition and analyses them in quasi-real time using an HT data analysis tool based on IFFEFIT. The system was used for the automated characterization of a library of 91 catalyst precursors containing ternary combinations of Cu, Pt, and Au on ?-Al2O3, and for the in situ characterization of Au catalysts supported on Al2O3 and TiO2

Beam Longitudinal Dynamics Simulation Suite BLonD

The beam longitudinal dynamics code BLonD has been developed at CERN since 2014 and has become a central tool for longitudinal beam dynamics simulations. In this paper, we present this modular simulation suite and the various physics models that can be included and combined by the user. We detail the reference frame, the equations of motion, the BLonD-specific options for radio-frequency parameters such as phase noise, fixed-field acceleration, and feedback models for the CERN accelerators, as well as the modeling of collective effects and synchrotron radiation. We also present various methods of generating multi-bunch distributions matched to a given impedance model. BLonD is furthermore a well-tested and optimized simulation suite, which is demonstrated through examples, too