Investigations in geostatistical simulation as an aid to mine planning

Imperial Users onl

Graphical User Interface for Simulink Integrated Performance Analysis Model

The J-2X Engine (built by Pratt & Whitney Rocketdyne,) in the Upper Stage of the Ares I Crew Launch Vehicle, will only start within a certain range of temperature and pressure for Liquid Hydrogen and Liquid Oxygen propellants. The purpose of the Simulink Integrated Performance Analysis Model is to verify that in all reasonable conditions the temperature and pressure of the propellants are within the required J-2X engine start boxes. In order to run the simulation, test variables must be entered at all reasonable values of parameters such as heat leak and mass flow rate. To make this testing process as efficient as possible in order to save the maximum amount of time and money, and to show that the J-2X engine will start when it is required to do so, a graphical user interface (GUI) was created to allow the input of values to be used as parameters in the Simulink Model, without opening or altering the contents of the model. The GUI must allow for test data to come from Microsoft Excel files, allow those values to be edited before testing, place those values into the Simulink Model, and get the output from the Simulink Model. The GUI was built using MATLAB, and will run the Simulink simulation when the Simulate option is activated. After running the simulation, the GUI will construct a new Microsoft Excel file, as well as a MATLAB matrix file, using the output values for each test of the simulation so that they may graphed and compared to other values

"Radioactive tracer methods applied to the study of reaction mechanisms"

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Unscheduled Events, Stock Returns, and Market Efficiency: A COVID-19 Case Study of Industry Leaders

This thesis explores the effects of unscheduled events on stock market returns due to increased uncertainty. A case study is done on the Coronavirus pandemic for the dates of March 9th, 2020, through March 23rd , 2020. The findings allow for short-run and long-run narratives where long-run returns, and short-run volatility explain how the role of psychology and different forecasting strategies are used to differentiate industry outcomes and technology sector returns

A cheeky investigation: Tracking the semantic change of <i>cheeky</i> from monkeys to wines

The present study focuses on the word cheeky which, in the past few decades, has taken on a new meaning (‘mildly illicit’) in addition to, and partly overtaking, its original meaning (‘impudent’). We examine how this semantic change is spreading in different age groups and in different parts of the English-speaking world. As we demonstrate, the newer meaning of cheeky is associated with younger speakers, so we examine whether this correlates with different age groups’ understanding of the new form. Furthermore, in its original sense, cheeky was used more frequently in the United Kingdom than in North America. If the earlier meaning was already marked for North America, how is the newer form understood by speakers there

Weekly Versus Monthly Testosterone Administration On Fast and Slow Skeletal Muscle Fibers in Older Adult Males

Context: In older adults, loss of mobility due to sarcopenia is exacerbated in men with low serum T. T replacement therapy is known to increase muscle mass and strength, but the effect of weekly (WK) vs monthly (MO) administration on specific fiber types is unknown. Objective: To determine the efficacy of WK vs MO T replacement on the size and functional capacity of individual fast and slow skeletal muscle fiber types. Design, Setting, and Patients: Subjects were randomized into a 5-month, double-blind, placebo-controlled trial. All subjects (ages, 61–71 y) were community-dwelling men who had T levels \u3c 500 ng/dL. Intervention: Subjects were dosed weekly for 5 months, receiving continuous T (WK, n = 5; 100 mg T enanthate, im injection), monthly cycled T (MO, n = 7; alternating months of T and placebo), or placebo (n = 7). Muscle biopsies of the vastus lateralis were obtained before and after treatment. Main Outcome Measures: Main outcomes for individual slow and fast fibers included fiber diameter, peak force (P0), rate of tension development, maximal shortening velocity, peak power, and Ca2+ sensitivity. Results: Both treatments increased fiber diameter and peak power, with WK treatment 5-fold more effective than MO in increasing type I fiber P0. WK effects on fiber diameter and force were 1.5-fold higher in slow fibers compared to fast fibers. In fast type II fibers, diameter and P0 increased similarly between treatments. The increased power was entirely due to increased fiber size and force. Conclusions: In conclusion, T replacement effects were fiber-type dependent, restricted to increases in cell size, P0, and peak power, and dependent on the paradigm selected (WK vs MO)

Anomalous relaxation kinetics of biological lattice-ligand binding models

We discuss theoretical models for the cooperative binding dynamics of ligands to substrates, such as dimeric motor proteins to microtubules or more extended macromolecules like tropomyosin to actin filaments. We study the effects of steric constraints, size of ligands, binding rates and interaction between neighboring proteins on the binding dynamics and binding stoichiometry. Starting from an empty lattice the binding dynamics goes, quite generally, through several stages. The first stage represents fast initial binding closely resembling the physics of random sequential adsorption processes. Typically this initial process leaves the system in a metastable locked state with many small gaps between blocks of bound molecules. In a second stage the gaps annihilate slowly as the ligands detach and reattach. This results in an algebraic decay of the gap concentration and interesting scaling behavior. Upon identifying the gaps with particles we show that the dynamics in this regime can be explained by mapping it onto various reaction-diffusion models. The final approach to equilibrium shows some interesting dynamic scaling properties. We also discuss the effect of cooperativity on the equilibrium stoichiometry, and their consequences for the interpretation of biochemical and image reconstruction results.Comment: REVTeX, 20 pages, 17 figures; review, to appear in Chemical Physics; v2: minor correction

Ways that designers and fabricators can help each other

We show that, when designers and fabricators understand each other&apos;s art, there are ways to combine their techniques to achieve the best results with the minimum difficulty. We share some problems that we have encountered, and sometimes caused ourselves, in hopes of helping the reader avoid the same pitfalls.