• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 35
  • 7
  • 6
  • 5
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 73
  • 11
  • 9
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Ethics in Photojournalism: Authenticity and Sensitivity in Coverage of Tragic Events

Shields, Minla Linn 10 May 2014 (has links)
Photojournalism captures moments within an event or space in time that are used to tell a larger story. Photographs are powerful tools for communication because these moments not only represent facts; they also have an ability to speak to viewers on a relatable and emotional level. With this power comes ethical responsibility and natural tension points between photograph, and journalistic practices. Journalism’s ethics codes group points of discussion specific to photographs into categories of manipulation, privacy, or graphic content. This thesis argues that these issues fall into broader overlapping themes of authenticity and sensitivity. Using visual analysis of four photographs from the Boston Marathon bombing and Newtown school shooting, it considers how journalists deal with the relationship between photography and journalistic theory using this ethical framework of authenticity and sensitivity. It concludes with a discussion of best practices for coverage of tragic events from the real-world perspective of the photojournalist.
32

IMPROVED COMPUTATIONAL AND EMPIRICAL MODELS OF HYDROCYCLONES

Narasimha Mangadoddy Unknown Date (has links)
The principal objectives of the work described in this thesis were: 1. To develop an improved multiphase CFD model for classifying cyclones and further improve understanding of the separation mechanism based on fluid flow and turbulence inside the cyclone. 2. To develop an improved Empirical model of classifying cyclones, covering a wide range of design and operating conditions. The multi-phase CFD model developed in this work is based on the approach reported by Brennan et al (2002) and Brennan (2003) using Fluent, and involves individual models for the air-core, turbulence, and particle classification. Two-phase VOF and mixture models for an air/water system were used to predict the air-core and the pressure and flow fields on 3D fitted fine grids. The turbulence was resolved using both DRSM (QPS) and LES turbulence models. The predicted mean and turbulent flow field from the LES and DRSM turbulence models were compared with the LDA measurements of Hsieh (1988). The LES model predicts the experimental data more accurately than the DRSM model. The standard mixture model (Manninnen et al, 1996) and the modified mixture model for a water/air/solids system were used to predict cyclone performance. The standard mixture model was able to predict classification efficiency reasonably at low solids concentrations, but under-predicts the recovery of coarse size fractions to underflow. To improve the predictions at moderate to high feed solids, the author modified the slip velocity with additional Bagnold dispersive forces, Saffman lift forces, and a hindered settling correction for particle drag in the mixture model superimposed on an LES turbulence model. Several cyclone geometries were used for validating the multiphase CFD model. The modified mixture model improves prediction of the separation of coarse size particles, and the predicted closely matches the experimental in various cyclones. The particle classification mechanism has been further elucidated using the simulated particle concentration distributions. At high solids concentrations, the modified CFD model predicts the efficiency curve reasonably well, especially the cut-size of the cyclone, but prediction of fine particle recovery to overflow is poor compared to the experimental data. It appears that the fines are significantly affected by turbulent dispersion and the flow resistance due to the high viscosity of the slurry at the apex is not sufficiently accounted for in the modified Mixture model. The improved multi-phase CFD model was validated against two sets of experimental data available in the literature: particle concentrations measured by gamma ray tomography data in a dense medium cyclone (Subramanian, 2002), and particle size distribution inside a hydrocyclone (Renner, 1976). Large eddy simulation (LES) with the modified Mixture model, including medium with a feed size distribution appears to be promising in predicting medium segregation inside a dense medium cyclone. The CFD predicted sample size distributions at different positions are reasonably comparable with Renner’s (1976) experimental data near the wall and in the bottom cone, but differ considerably near the forced vortex region, and also near the tip of the vortex finder wall. The CFD model shows no air-core formation at the low operating pressure used by Renner, which suggests his experiments involved an unusual/unstable forced vortex based cyclone separation. The effect of turbulence on fluid and solid particle motion was also studied in this thesis. The resolved turbulent fluctuations from LES of the hydrocyclone at steady flow were analysed using ensemble averaging. The ratio of the effective turbulent acceleration of each particle size to the centrifugal acceleration was calculated for various cyclones, which showed that turbulent mixing becomes less important with larger particles. The trends in this ratio correlate with the equilibrium positions of the particles from the multiphase LES. The analysis indicates that the short-circuiting might be aggravated by turbulent mixing across the locus of zero vertical velocity (LZVV) against the classification force, and along the vortex finder wall into the inner upflow region of the cyclone. An experimental study of the “fish-hook” effect was pursued in various industrial scale cyclones to evaluate the effect of various cyclone parameters. The observed diameter at which fine particle recovery starts to increase is mainly affected by feed solids content and spigot diameter, but less influenced by feed pressure. The observed particle recovery to the underflow at the fishhook dip size, the bypass, is always higher than the underflow water split. Any cyclone variable that affects the underflow water split, will also affect the bypass value. CFD studies showing high particle Reynolds numbers for coarse particles were used to provide a qualitative mechanism for fines reporting to the underflow in the wakes behind the larger particles (Tang et all. 1992). The Frachon and Cilliers (1999) model was used to fit and evaluate the fishhook parameters. The variations of these fishhook parameters were quantified for changes in cyclone design and operating conditions. The development of an improved empirical hydrocyclone model was attempted by collecting extensive historical data covering a wide range of cyclones. Additional experiments on 10 and 20 inch Krebs cyclones were performed to fill the gaps in the database, especially at low to moderate feed solids concentration and with different cone sections. Tangential velocity, turbulent diffusion, slurry viscosity and particle hindered settling correlations were identified from CFD as the key inputs to the particle classification mechanism for the empirical model. A new cyclone model structure based on a dimensionless approach has been developed. The model for , , Q gives a very good fit to the data, while the model for separation sharpness gave reasonable correlations with the cyclone design and operating conditions. 208 additional data sets were used to validate the new hydrocyclone model.
33

AN INSIGHT INTO DIFFERENT MODES OF REMODELER REGULATION: FOCUS ON SACCHAROMYCES CEREVISIAE SWI/SNF

Kundu, Soumyadipta 01 December 2016 (has links)
ATP dependent chromatin remodelers use the energy from ATP hydrolysis to move, disassemble or alter the composition of nucleosomes. Though all remodelers share a conserved ATP hydrolysis and DNA translocase domain, their biochemical actions and in-vivo characteristics differ because of their subunits and accessory domains in the catalytic subunit that regulate its activity. Understanding how these domains contribute to remodeler regulation in terms of substrate interaction and regulation of the catalytic subunit is therefore important to understanding what causes a remodeler to behave differently, and what are the mechanistic underpinnings of such behavior. In this study we have addressed these questions using the SWI/SNF remodeler from budding yeast (Saccharomyces cerevisiae) to explore how different remodelers compare to SWI/SNF in terms of nucleosome interaction. Using a chemical based histone – remodeler photo-crosslinking and labeling approach, we show that different remodelers contact nucleosomes in patterns unique to their functions, and even remodelers that belong to the same family interact with nucleosomes in a unique manner to accomplish their respective remodeling results. In addition we delineate the functions of the AT hook motifs in the catalytic subunit of SWI/SNF using in-vitro and in-vivo techniques. We demonstrate the necessity of the regulatory action of the motif in the context of SWI/SNF remodeling due to its requirement for efficient ATP hydrolysis by the catalytic domain and therefore efficient remodeling. We also demonstrate for the first time that SWI/SNF in yeast is involved in transcriptional repression with evidence that the AT hook alters SWI/SNF activity at particular genomic regions. Regulation of SWI/SNF activity is an increasingly important topic of study, with mutations that cause SWI/SNF dysfunction being implicated in a large number of cancers and neurological diseases. We attempt to find out the biochemical implications of mutations in the catalytic, SnAC and AT hook motifs with respect to SWI/SNF activity. Taken together, this study provides an insight into some of the different mechanisms in which remodelers are regulated using budding yeast as a model system.
34

Armbrytningstekniken top roll var den teknik som var mest vinstgivande vid 2017-2019 års Världsmästerskap i armbrytning

Ragnelind, Björn January 2021 (has links)
SyfteUndersöka om fördelningen av antal vinster vid jämförelse av olika armbrytningstekniker skiljer sig från en jämn fördelning under 2017-2019-års VM i armbrytning. Samt hur dessa skiljer sig åt beroende av viktkategori (lättvikt/tungvikt), kön och arm (höger/vänster) samt med eller utan straps.MetodArmbrytningsmatcher hämtade från World Armwrestling Federation’s youtube-kanal analyserades för att registrera vinnande och förlorande teknik utifrån kategorierna viktklass, kön, arm samt straps. För att analysera skillnad i vinstfördelning användes Χ2-test.ResultatResultaten visade att top roll var mer vinstgivande än hook (p < 0,001) och side press (p < 0,001). Däremot var de ingen skillnad i vinstfördelning mellan hook och side press (p = 0,24). Ingen skillnad fanns mellan de olika kategorierna förutom att side press var relativt sett mer framgångsrik mot top roll för lättvikt jämfört med tungvikt (p = 0,035).SlutsatserBaserat på resultaten i denna studie så är rekommendationen att elitaktiva armbrytare använder sig av top roll, då denna teknik har större sannolikhet att vinna över teknikerna side press och hook.
35

Covenant-First Presbyterian Church (Cincinnati) and its Predecessor Congregations: A Case Study in Historical American Organ Building

Heidenreich, Thomas 24 May 2022 (has links)
No description available.
36

Active Lateral Secondary Suspension in a High-Speed Train to Improve Ride Comfort

Orvnäs, Anneli January 2009 (has links)
Active secondary suspension in trains has been studied for a number of years, showing promising improvements in ride comfort. However, due to relatively high implementation and maintenance costs, active technology is not being used in service operation to a large extent. The objective of this study is to develop an active lateral secondary suspension concept that offers good ride comfort improvements and enables centring of the carbody above the bogies when negotiating curves at unbalanced speed. Simultaneously, the active suspension concept should be a cost-effective solution for future series production. The thesis consists of an introductory part and three appended papers. The introductory part describes the concept of active secondary suspension together with different actuator types and control methods. Further, the present simulation model and applied comfort evaluation methods are presented. The introductory part also comprises a summary of the appended papers, an evaluation of track forces and suggestions for further work. Paper A presents the initial development of an active lateral secondary suspension concept based on sky-hook damping in order to improve vehicle dynamic performance, particularly on straight tracks. Furthermore, a Hold-Off-Device (HOD) function has been included in the suspension concept in order to centre the carbody above the bogies in curves and hence avoid bumpstop contact. Preparatory simulations as well as the subsequent on-track tests in the summer of 2007 showed that the active suspension provides improved passenger ride comfort and has significant potential to be a cost-effective solution for future implementation. In Paper B, measurement results from on-track tests performed in 2008 are presented. The active secondary suspension concept was slightly modified compared to the one presented in the first paper. One modification was the implementation of a gyroscope in order to enable detection of transition curves and to switch off the dynamic damping in these sections. Ride comfort in the actively suspended carbody was significantly improved compared to that in the passively suspended car. The satisfactory results led to implementation of the active suspension system in long-term tests in service operation in the beginning of 2009. In Paper C, a quarter-car model in MATLAB has been used to investigate a more advanced control algorithm: H∞ instead of sky-hook. H∞ control provides more flexibility in the design process due to the possibility to control several parameters. In particular, this is done by applying weight functions to selected signals in the system. When comparing the two control strategies through simulations, the results show that H∞ control generates similar carbody accelerations at the same control force as sky-hook; however, the relative displacement displacement is somewhat lower.
37

Physiological Response to Hooking Stress in Largemouth Bass (Micropterus salmoides)

Gustaveson, A. Wayne 01 May 1978 (has links)
Recent concern about large initial and delayed mortalities resulting from tournament angling for largemouth bass has indicated that it would be desirable to further evaluate the fate of fish that are released after being captured by angling. This study was designed to evaluate sublethal physiological disruptions caused by hooking stress after largemouth bass were played under standardized conditions (0-5 minutes) and to estimate the time needed for recovery of the homeostatic mechanisms (to 72 hours). Blood lactate was used as a measure of metabolic fatigue; plasma osmolality and chloride measurements were used to evaluate osmoregulatory disturbances and gill ion-exchange; and plasma glucose was used as an index of response to generalized non-specific physiological stress. Fatigue of largemouth bass, as indicated by blood lactate values, increased with playing time (0-5 minutes) and was accentuated by an increase in water temperature. Blood lactate levels continued to increase during recovery up to 8 hours but returned to approximate initial values by 24 hours. Plasma chloride values did not change with playing time (0-5 minutes) at water temperatures of 11-13 C and 28-30 C but increased significantly after 1 minute of playing time at 16-20 C indicating an osmoregulatory disturbance. However, at 11-13 C, the plasma chloride values decreased to below values for controls (0 minute) by 72 hours. At 16-20 C, the plasma chloride levels were nearly normal by 24 hours and were at normal levels by 72 hours. Plasma osmolality increased with playing time at all temperatures indicating an immediate osmoregulatory disturbance. The osmolality values returned to initial levels by 72 hours at the cooler water temperature of 11-13 C. However, at the warmer water temperature of 16-20 C, the osmolality values had not returned to the initial values by 72 hours. Plasma glucose did not change at the cooler water temperatures of 11-13 C and 16-20 C but increased significantly at 5 minutes of playing time at 28-30 C reflecting the metabolic response of this species to warmer water temperature. The glucose values remained high throughout the entire 72-hour recovery period. Smaller bass fatigued faster than larger bass at the higher water temperatures (21-26 C and 28-30 C) as indicated by increased blood lactate values. Smaller bass also demonstrated a faster response in plasma glucose levels, probably as a function of fish size and metabolism. Plasma chloride and osmolality in smaller bass showed a response similar to larger bass with an immediate disturbance in osmoregulatory process of fish as playing time increased. Stress imposed on largemouth bass that were caught by angling was demonstrated by changes in the blood chemistry which indicated that sublethal disruption had occurred in the metabolism and osmoregulation of the fish. Handling or holding fish after capture, as in fishing tournaments, probably produces more stress on the fish than the act of being caught and played by anglers. Angling stress is additive to other stresses already imposed on the fish and could result in increased mortality of released fish if the fish cannot adapt readily. Furthermore, released fish may also be more susceptible to diseases or fungal infections and more vulnerable to predation.
38

A Comparison of Mobile Radar-Inferred Rain-Drop Size Estimates between Tornadic and Non-Tornadic Supercell Hook Echoes

Foster, James A. 01 June 2020 (has links)
No description available.
39

Friends With Benefits: A New Sexual Phenomenon

Albers, John 01 January 2006 (has links)
With the ever increasing rates of sexual violence and sexually transmitted diseases, many people wishing to continue an active and healthy sexual lifestyle are forced to avoid bars, clubs, and other places that "pick-ups" or casual sex might occur. It has been noted that an alternative to this has arisen among college age students in Orlando, Florida. As yet with no official term it is colloquially know as "Friends With Benefits." Research through professional and scholarly journals makes no mention of this phenomenon. The bulk of this study attempts to document the prevalence of this phenomenon in college age student in Orlando, Florida. Through the development of surveys accurate statistics can be obtained and possible contributing factors regarding its instigation can be found. Further discussion should predict what overall and long-term affects "Friends With Benefits'' will have on society and its views on acceptable dating practices.
40

Optimizing 3D Printed Prosthetic Hand and Simulator

Estelle, Stephen 09 January 2019 (has links) (PDF)
The purpose of this study is to examine the position and use of an upper extremity prosthetic simulator on non-amputees. To see how a 3D printed prosthetic simulator can be optimized to serve the user correctly and accurately. In addition, this study examines the improvement of the Hosmer 5X Prosthetic Hook with the addition of newly designed trusses on to the prosthetic, as well as utilizing a new manufacturing method known as 3D printing. These topics are important because there is no standardized prosthetic simulator for schools and research facilities to use. Off the shelf prosthetic simulator cost upwards of $2000, often too expensive for early stage research. By optimizing the Hosmer 5X Prosthetic Hook with 3D printing, this new opportunity could allow amputees, from a range of income classes, to have access to a wide variety of prosthetics that are strong enough to support everyday living activities. A low-cost prosthetic that is easily distributable and accessible can give people a chance to regain their independence by giving them different options of efficient prosthetic devices, without having to spend so much. The devices in this project were design and analyzed on SOLIDWORKS, 3D scanned on the Artec Space Spider, and surfaced on Geomagic Wrap. Key results include developing a low-cost, robust prosthetic simulator capable of operating a Hosmer 5X Prosthetic hook, as well as developing a lighter version of the Hosmer 5X Prosthetic Hook that is more cost efficient and easily obtainable to the population around the world.

Page generated in 0.0937 seconds