Receipt for Cash, 6-16-1934

Receipt: Payment documentation on Burbridge & Higbee paper: To R.H. Walker cash $125.00 - Paid Mrs. R.H. Walker by M Styles

Spherical solid-propellant rocket motor Patent

Spherical solid propellant rocket engine desig

High-throughput in-situ characterization and modelling of precipitation kinetics in compositionally graded alloys

The development of new engineering alloy chemistries is a time consuming and iterative process. A necessary step is characterization of the nano/microstructure to provide a link between the processing and properties of each alloy chemistry considered. One approach to accelerate the identification of optimal chemistries is to use samples containing a gradient in composition, ie. combinatorial samples, and to investigate many different chemistries at the same time. However, for engineering alloys, the final properties depend not only on chemistry but also on the path of microstructure development which necessitates characterization of microstructure evolution for each chemistry. In this contribution we demonstrate an approach that allows for the in-situ, nanoscale characterization of the precipitate structures in alloys, as a function of aging time, in combinatorial samples containing a composition gradient. The approach uses small angle x-ray scattering (SAXS) at a synchrotron beamline. The Cu-Co system is used for the proof-of-concept and the combinatorial samples prepared contain a gradient in Co from 0% to 2%. These samples are aged at temperatures between 450{\textdegree}C and 550{\textdegree}C and the precipitate structures (precipitate size, volume fraction and number density) all along the composition gradient are simultaneously monitored as a function of time. This large dataset is used to test the applicability and robustness of a conventional class model for precipitation that considers concurrent nucleation, growth and coarsening and the ability of the model to describe such a large dataset.Comment: Published in Acta Materiali

Relating phase field and sharp interface approaches to structural topology optimization

A phase field approach for structural topology optimization which allows for topology changes and multiple materials is analyzed. First order optimality conditions are rigorously derived and it is shown via formally matched asymptotic expansions that these conditions converge to classical first order conditions obtained in the context of shape calculus. We also discuss how to deal with triple junctions where e.g. two materials and the void meet. Finally, we present several numerical results for mean compliance problems and a cost involving the least square error to a target displacement

Cruise Tourism in St.Lucia; Promoting Locally Owned and Operated Tourism Businesses

Small Island Developing States (SIDS) face a unique set of challenges when it comes to the field of Planning. In 1992, the United Nations Earth Summit brought international attention to SIDS; the combination of geographic isolation, small size, and limited resources were listed as a few of the unique environmental and economic disadvantages facing these islands. The island of St.Lucia, located in the Lesser Antilles of the Caribbean, is classified by the United Nations as one of the vulnerable SIDS in the Caribbean region. Since the 1992 Earth Summit, the literature on planning strategies for SIDS has shifted away from an economic based mass tourism strategies toward a culturally and environmentally focused sustainable tourism strategies; such as eco-tourism and community-based tourism. Mass tourism, through the form of cruise ship tourism, is currently the largest sector of the Caribbean tourism market. Based on the cruise tourism trends over the past 30 years, the Caribbean cruise tourism industry is expected to continue to grow at a rapid pace. The continual growth in this form of mass tourism contradicts the current planning policy trends toward sustainable tourism strategies. In order to better understand ways of connecting cruise tourism to small island sustainable tourism, this thesis examines aspects of the mass cruise tourism-sustainable tourism contradiction. This thesis evaluates the various types of tourism development strategies for SIDS, as well as, examines St.Lucia’s current tourism development policies. Interviews with local onshore business owners were then conducted in order to understand the relationship between local cruise-dependant businesses and the cruise ship industry. Finally, recommendations are given on ways to incorporate cruise tourism into St.Lucia’s existing community-based tourism goals

Optimal control of the propagation of a graph in inhomogeneous media

We study an optimal control problem for viscosity solutions of a Hamilton–Jacobi equation describing the propagation of a one-dimensional graph with the control being the speed function. The existence of an optimal control is proved together with an approximate controllability result in the $H^{-1}$-norm. We prove convergence of a discrete optimal control problem based on a monotone finite difference scheme and describe some numerical results

Long term time-lapse microgravity and geotechnical monitoring of relict salt-mines, Marston, Cheshire, UK.

The area around the town of Northwich in Cheshire, U. K., has a long history of catastrophic ground subsidence caused by a combination of natural dissolution and collapsing abandoned mine workings within the underlying Triassic halite bedrock geology. In the village of Marston, the Trent and Mersey Canal crosses several abandoned salt mine workings and previously subsiding areas, the canal being breached by a catastrophic subsidence event in 1953. This canal section is the focus of a long-term monitoring study by conventional geotechnical topographic and microgravity surveys. Results of 20 years of topographic time-lapse surveys indicate specific areas of local subsidence that could not be predicted by available site and mine abandonment plan and shaft data. Subsidence has subsequently necessitated four phases of temporary canal bank remediation. Ten years of microgravity time-lapse data have recorded major deepening negative anomalies in specific sections that correlate with topographic data. Gravity 2D modeling using available site data found upwardly propagating voids, and associated collapse material produced a good match with observed microgravity data. Intrusive investigations have confirmed a void at the major anomaly. The advantages of undertaking such long-term studies for near-surface geophysicists, geotechnical engineers, and researchers working in other application areas are discussed

Hand Held Data Recorder (HHDR)

A HHDR is used to collect data from the field and to download that data to a database to generate reports for meters in the districts. The data can be collected intermittently or on a daily basis since these are not route based data collectors. The data is collected by means of a hand held portable unit that scans a bar code identification label that is permanently affixed to the meter. Data is then entered by means of a keypad or a scan sheet and the operator goes to the next meter. At the end of the day the unit is brought back to the office and the information is downloaded into the database. This provides a quick and error-free way to enter data better than manually entering the information into a logbook

Canal Flow Rate Measurement Guidelines – ITRC 2005: Hydroacoustic Meters

A Hydroacoustic flow meter provides remote velocity sampling and integrated flow measurement based on the physical principle called the Doppler shift. The sensors can either project a continuous or pulsed beam of acoustic signals at angles above the horizontal position of the sensor. Flow velocity is calculated by averaging the measured variations in sound frequency reflected back from particles in the water. Depth is measured with a ceramic-based pressure transducer integrally mounted in a surface mount velocity sensor and the device calculates the flow rate

District Application of Hand Held Data Recorder Technology

A hand held data recorder (HHDR) enables a district to collect field data in a quick and virtually error-free manner. These units can be used to scan bar code location/equipment identifiers or the operator can manually key in this information followed by the current data. Some HHDRs can be programmed with error checking routines that prompt the operator when an entry is inconsistent with regards to the previous reading from that location. Each entry includes a time and date stamp. When the operator has collected all of the data for the day or for a route, the data is downloaded to a district computer and the previous reading log in the HHDR memory is updated via the computer. This method of data entry reduces the time associated with entering data into multiple ledger books and minimizes the chance of entry errors that occur with manual data handling