<p>An Eulerian-Eulerian model for dilute gas-particle turbulent flows is</p><p>developed for engineering applications. The aim is to understand the effect of particles on turbulent flows. The model is implemented in a finite element code which is used to perform numerical simulations. The feedback from the particles on the turbulence and the mean flow of the gas in a vertical channel flow is studied. In particular, the influence of the particle response time and particle volume fraction on the preferential concentration of the particles near the walls, caused by the turbophoretic effect is explored. The study shows that the particle feedback decreases the accumulation of particles on the walls. It is also found that even a low particle volume fraction can have a significant impact on the turbulence and the mean flow of the gas. A model for the particle fluctuating velocity in turbulent gas-particle flow is derived using a set of stochastic differential</p><p>equations. Particle-particle collisions were taken into account. The model shows that the particle fluctuating velocity increases with increasing particle-particle collisions and that increasing particle response times decrease the fluctuating velocity.</p>

Thesis (M.A.)--Florida State University, 2003. / Advisor: Dr. Martin Kavka, Florida State University, College of Arts and Sciences, Dept. of Religion. Title and description from dissertation home page (viewed Apr. 7, 2004). Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (p. 161-167).

In any business environment companies experience challenges and competition. In this current worldwide economic crisis, the stakes are now higher. With every crisis comes opportunity. The best companies with the best methods and processes that create highest quality product for less money will have an extraordinary advantage over their less efficient, lower quality competition. The term ‘Lean’ describes how Toyota does business: fewer humans, less effort, less investment, fewer defects, less time to develop, less inventory. For companies that have truly understood and implemented these principles the effects are significant; but many others have failed Lean initiatives. What factors are necessary for a company to successfully adopt the processes proven by over 50 years of success in Toyota? Using both primary and secondary research, I compared attributes of four companies, three of which were successful, and one that did not make the conversion. Three main factors emerged, the Technical Factor -- knowing both your core business and having a deep understanding of Lean principles, the Management Factor -- strong leadership operating within Lean principles and with hands-on approach, and the Human Factor -- approaching the workforce with respect and employee engagement in problem-solving process. The following is a brief review of these factors and the tools and concepts that undergird them. / text

Denna studie är utförd på ett företag i Helsingborg som heter Abdon Finax AB. Företaget startade med mjöltillverkning för att sedan introducera müslin till Sverige. Sedan dess har bolaget fortsatt växa. I dagens samhälle går utvecklingen fort fram. Globaliseringen innebär att konkurrensen ökar och företag tvingas att tävla med varandra om kunderna, vilka ständigt söker bättre kvalitet, lägre kostnader samt kortare ledtider. Detta samtidigt som företagen försöker tjäna mer pengar genom ökad lönsamhet genom bland annat effektivare flöden. På så sätt kan företaget minimera kostnaderna för att kunderna ska kunna tillgodoses samtidigt som företagen tjänar på det. ’’Ibland måste man vara liten för att springa om de stora’’ är ett av Finax valspråk. För att fortsätta ha chansen att springa om de stora krävs flexibilitet i produktionen för att möjliggöra kortare ledtider till kunderna. Syftet med studien har varit att analysera flödet av de glutenfria produkterna på Abdon Finax AB för att finna effektiviseringsområden. För att kunna göra detta har en flödeskartläggning gjorts. Denna gjordes med hjälp av observationer samt intervjuer på företaget. Efter en jämförelse mellan teori och empiri har sedan några kritiska punkter pekats ut för förbättring och effektiviseringsförslag har rekommenderats. Dessa förslag involverar standardisering samt sänkningsförslag på omställningstiderna allt för att företaget ska öka sin flexibilitet och kunna producera i mindre batcher. Vilket ska leda till att ledtiderna minskar och även lagerkostnaderna. I framtiden när ställtiderna har minimerats skulle det vara fullt möjligt att producera efter kundorder vilket minimerar riskerna för att kassera produkter samt minskar lagerkostnaderna ytterligare.

Based on data from the Fermi Gamma-ray Space Telescope, we have discovered two gigantic gamma-ray emitting bubble structures in our Milky Way (known as the Fermi bubbles), extending \(\sim 50\) degrees above and below the Galactic center with a width of \(\sim 40\) degrees in longitude. The gamma-ray emission associated with these bubbles has a significantly harder spectrum \((dN/dE \sim E^{-2})\) than the inverse Compton emission from known cosmic ray electrons in the Galactic disk, or the gamma-rays produced by decay of pions from proton-ISM collisions. There is no significant difference in the spectrum or gamma-ray luminosity between the north and south bubbles. The bubbles are spatially correlated with the hard-spectrum microwave excess known as the WMAP haze; we also found features in the ROSAT soft X-ray maps at \(1.5 - 2 keV\) which line up with the edges of the bubbles. The Fermi bubbles are most likely created by some large episode of energy injection in the Galactic center, such as past accretion events onto the central massive black hole, or a nuclear starburst in the last \(\sim 10 Myr\). Study of the origin and evolution of the bubbles also has the potential to improve our understanding of recent energetic events in the inner Galaxy and the high-latitude cosmic ray population. Furthermore, we have recently identified a gamma-ray cocoon feature within the southern bubble, with a jet-like feature along the cocoon's axis of symmetry, and another directly opposite the Galactic center in the north. If confirmed, these jets are the first resolved gamma-ray jets ever seen. / Astronomy

The implementation of high-speed passenger trains (HST) within existing highway right-of-way (ROW) offers a solution for regions with a demand for the capacity and service offered by HST but lacking the support for sharing freight rail ROW or acquiring new ROW corridors. The states of Florida, Colorado, California and Nevada propose to use highway ROW for their HST projects to increase the capacity of the corridor, prevent or minimize impacts and prevent disruption of freight rail operations. Despite the constraints of using existing highway ROW, such as speed-limiting degrees of curvature and safety concerns, solutions and mitigation measures exist. The purpose of this thesis is to present the HST projects in the United States proposing use of highway ROW, the potential benefits and engineering issues to consider and the feasibility of using the existing I-35 ROW in Texas for HST. / text

Modern wireless communication systems strive to enable communications at high data rates, over wide geographical areas, and to multiple users. Unfortunately, this can be a daunting task in practice, as natural laws governing the wireless medium may hinder point-to-point transmissions. Communications over large distances (path loss), and physical obstructions in line-of-sight signals (shadowing) are prime examples of such impediments. One promising solution is to deploy intermediary terminals to help reestablish such broken point-to-point communication links. Such terminals are called relay nodes, and the corresponding systems are referred to as being relay-aided. As in the case of point-to-point communication, design of efficient transmission and reception techniques in relay-aided systems depends on the availability of propagational channel state information. In practice, such information is only accurate to a certain degree which is governed by overhead constraints, feedback delay, and channel fluctuations due to mobility. Understanding the impacts of such partial channel state information, and devising transmission and reception methods based on such understandings, is the main topic of this dissertation. The transmission protocol classifies relays as either one-way, where the relay receives signals from one terminal, or two-way, where the relay receives signals from more than one terminal. Designs and solutions for both one- and two-way relaying systems are presented in this dissertation. Emphasis is placed on two-way relaying systems given their superior efficiency in utilizing channel resources. For one-way relaying this dissertation presents power loading strategies for multiuser-multicast systems derived based on the availability of full or partial channel state information at the terminals. In the case of two-way relaying, both single and multi-user systems are analyzed. For single-user two-way relaying, this dissertation presents optimal methods of acquiring partial channel state information via pilot-aided channel estimation methods. This includes an analysis of the effects of channel estimation upon the system sum-rate. Also, the design of channel equalizers exhibiting robustness to partial channel state information is proposed. For multi-user two-way relaying, this dissertation presents several precoding strategies at the relay terminal(s) to combat the effects co-channel interference in light of the existence of self-interference inherent to two-way relaying operations. / text

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