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  • 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.
411

Cross-Correlation Of Biomedical Images Using Two Dimensional Discrete Hermite Functions

Srinivasan, Nirmala 14 August 2012 (has links)
No description available.
412

Efficacy of Partial ROM Squat in Maximal Strength Training

Bazyler, Caleb 01 August 2013 (has links) (PDF)
Eighteen well trained males (1RM Squat: 150.57 ± 26.79 kg) were assigned to two groups: full ROM training (control) and full ROM with partial ROM training (CP) for the seven-week training intervention. There was a significant time effect (p
413

The Relationship between Isometric Force Characteristics and Vertical Jump Height under Various Loading Conditions.

Kraska, Jenna Marie 12 August 2008 (has links) (PDF)
Purpose: to examine the relationship between isometric force characteristics (IF) and vertical jump height under various loading conditions. Sixty-three collegiate athletes participated in this investigation. Athletes performed static jump (SJ) and countermovement jumps (CMJ) with 0 and 20kg, and isometric mid-thigh pulls on a force plate. Force-time curve analysis was conducted for each isometric pull and jump to determine force related characteristics. Jump height (JH) was derived from flight time. Isometric forces were normalized using allometric scaling: absolute force/ (body mass(kg)0.67)= IPFa. Results: There was a strong positive correlation between isometric peak force and isometric rate of force development (IRFD). Stronger athletes had smaller decrements in jump height with additional loading. Conclusion: The ability to produce higher peak and instantaneous forces and IRFD is related to JH and smaller differences between weighted and unweighted jumps. A weighted jump may be a practical method of assessing relative strength levels.
414

Use and Misuse of X-Ray Photoelectron Spectroscopy (XPS): Reproducibility, Gross Errors, Data Reporting, and Peak Fitting

Major, George Hobbs 18 April 2023 (has links) (PDF)
X-ray photoelectron spectroscopy (XPS) is the most widely used surface analysis technique for chemically probing surfaces. Its popularity stems from the large amount of information that can be gathered about the electronic states of the atoms it probes, including core shell information and valence electron information. Simple qualitative analysis (peak identification) can often be performed, but quantitative analysis is a much more complicated process. Although XPS usage has increased dramatically, so has the amount of erroneous analysis observed in the literature. In my thesis, I first present a perspective on how to improve the quality of surface and material data analysis. This chapter focuses on responsible groups, using population biology models and the Prisoner's Dilemma to describe the situation and the potential changes that must be made to counteract error propagation. I quantify errors in XPS data analysis to provide perspective on the gravity of the situation. Over 400 publications in three journals were analyzed. Additionally, another 900 journals were surveyed to determine the quantity of information in the analysis. The parameters include experimental parameters, e.g., the pass energy, peak fitting parameters, the spot size, X-ray source, and the type of spectrometer. I found that over 40% of the publications had significant errors that could potentially change the conclusions of the publication. About 35% of all papers neglected to note the type of spectrometer used, and 85% did not mention the type of software used for analysis. The latter half of this work focuses on XPS peak fitting. I present a broad overview of peak fitting, including how to determine the appropriate background and peak shapes to use, how to quantify XPS data, and how to account for other phenomena associated with photoemission. The line shape chosen for peak fitting is critical, as it is the synthetic shape that is used to model observed physical phenomena. A detailed review on typical line shapes, including the Voigt and pseudo-Voigt functions is presented, along with how to apply them in peak fitting. How and why asymmetric peak shapes are required is also discussed, including which effects cause asymmetry, and if it is inherent to the material or the method of analysis. Finally, a discussion on using constraints to properly model known effects is presented. These efforts were guided by the findings in the former half of this work. The trends presented here are not unique to XPS. Other fields and techniques have similar reproducibility problems. This work discusses possible solutions and what efforts as a community need to be taken to remedy the reproducibility crisis. Additionally, this work includes guides that have original research to improve approaches to XPS analysis, including peak fitting, constraint parameters, and the appropriate use of line shapes.
415

Pre-Eruptive Conditions of the Oligocene Wah Wah Springs Tuff, Southeastern Great Basin Ignimbrite Province

Woolf, Kurtus Steven 06 August 2008 (has links) (PDF)
The Wah Wah Springs Tuff (30.0 Ma) is one of several very large volume ash-flow tuffs (>3200 km³ of erupted magma) that were emplaced near the peak of the flare-up of activity in the Great Basin ignimbrite province of western North America. It can be characterized as a "monotonous intermediate" ignimbrite because of its intermediate concentrations of silica (~63 to ~70 wt. %), apparent uniform chemical and mineralogical characteristics, and crystal-rich nature (32 ± 10 % phenocrysts on a dense rock basis). The major phase assemblage found throughout deposit is similar to other monotonous intermediates with a few exceptions (pl > hnbl > bio, qtz >> cpx, opx > mt, ilm, ap, zcn, and po). Based on experiments on the monotonous intermediate Fish Canyon Tuff (Johnson & Rutherford, 1989a) and this phase assemblage, the Wah Wah Springs magma equilibrated between 775°C – 800°C. One hornblende-plagioclase thermometer with or without quartz (Holland & Blundy, 1994) and one Fe-Ti oxides thermometer (Anderson et al., 1993) most consistently yield temperatures within this range. The Fe-Ti oxides oxy barometer (Anderson et al., 1993) yield fO2 estimates 2 – 3 log units above the quartz-fayalite-magnetite buffer. The Al-in-hornblende geobarometer (Johnson & Rutherford 1989b) indicates pressures between 2.0 and 2.5 kb. Detailed compositional profiles across hornblende and plagioclase grains help constrain how intensive parameters changed during the evolution of the magma shortly before eruption. Plagioclase in the Wah Wah Springs displays oscillatory zonation with overall normal zonation (a maximum change of about An5 from core to rim). Hornblende is also zoned in Al2O3 and TiO2 which typically decrease as much as 2.5 wt. % and 1 wt. % respectively from core to rim. These zoning patterns are consistent with a decrease of temperature from core to rim that accompanied progressive crystallization of a large body of magma that closely approached equilibrium. These conditions in the parent magma for the Wah Wah Springs differ from interpretations of mineral compositions in the Fish Canyon Tuff which led Bachman et al., (2002) to propose that the near solidus magma body was "rejuvenated" or reheated immediately prior to eruption. This model cannot be applied to the Wah Wah Springs. Rather, the Wah Wah Springs magma appears to have been cooling and crystallizing prior to eruption.
416

Life Cycle Assessment (LCA) for a DC-microgrid energy system in Fjärås / Livscykelanalys för ett DC-mikronät energisystem i Fjärås

Hashemi Farzad, Tabassom January 2019 (has links)
Application of Photovoltaic PV panels for electricity production has rapidly increased in recent years in Sweden after launching a capital subsidy for PV panel installations in 2009. Kungsbacka municipality’s housing company equipped two groups of buildings in Fjärås with PV systems to generate electricity. The newly built residential buildings are connected to a DC-microgrid, whereas the existing buildings have been equipped with a single PV system. This project conducts a cradle to gate life cycle assessment (LCA) for this DC-microgrid energy system. The main purpose of this project is to determine which parts and processes of the DC-microgrid contribute to highest environmental impact throughout their lifespan from cradle to gate stages. Moreover, this study explores the energy payback time (EPBT) and the cumulative energy demand (CED) for the DC-microgrid. Additionally, this study performs two comparative LCA. First the DC-microgrid is being compared with PV system to determine which system has higher environment impacts, and secondly, the DC-microgrid is being compared with the average electricity mix in Sweden in terms of contribution to environmental impacts. The LCA follows the ISO 14040 framework and the baseline method is applied in order to assess 11 environmental impact categories. Two different functional units are adopted in this study. One is based on installed kilowatt peak (kWp) capacity by which environmental impacts of the PV system are compared with the DC-microgrid system. The other functional unit for this study is 1 kWh of delivered electricity to residential buildings produced by the DC-microgrid system. This functional unit is used exclusively for a stand-alone analysis of the DC-microgrid system in order to make it comparable with other microgrid systems or other systems with different energy sources, such as hydro, wind or nuclear. The results of the stand-alone LCA analysis of the DC-microgrid show that the battery has high contribution in human toxicity and terrestrial ecotoxicity whereas the energy hub system (Ehub) is the main contributor to eutrophication, abiotic depletion, fresh water aquatic ecotoxicity and marineaquatic ecotoxicity. The monocrystalline PV panel has the highest impact on global warming and abiotic depletion (fossil fuel). In addition, the EPBT for the DC-microgrid system is approximately 3.7 years. This means that one can get energy free of cost for an estimated time of 26.5 years if the lifetime of the system is assumed to be 30 years. The CED results show that monocrystalline PV production is an intense energy process which requires more non-renewable energy than all remaining parts of the DC-microgrid. The comparison of the DC-microgrid with the PV system reveals that the DC-microgrid has a higher environmental impact almost in all impact categories. This is mainly due to batteries and inverters which have a clear effect on the result. The CED analysis results illustrate that the multicrystalline PV panel production from the PV system is the most energy demanding process in both categories of renewable and non-renewable energy source. Moreover, the analysis illustrates that the DC-microgrid has still higher environmental impacts in all impact categories compared to the average electricity mix in Sweden. This is due to the electricity production in Sweden relies on hydropower and nuclear power with around 83 % of the total electricity production in the year 2017 which causes a lower environmental burden. Although the DC microgrid system shows a higher environmental impact compared to PV system, it is still a proper option to generate electricity since DC-microgrid system allows to achieve some indirect advantages such as energy saving due to an increase in own usage rate and self-sufficiency rate compared to the PV system. It should be noted that the end-of-life procedures becomes very important especially when crediting back for the recycling of materials. The collection and recycling of the PV panels at their end-of-life should be considered for future work as soon as reliable data are available. / Användningen av solpaneler har de senaste åren kommit att öka markant i Sverige. Ökningen beror på det statliga bidraget för installation av solceller som lanserades 2009. Kungsbacka kommun installerade solcellssystem i två olika typer av byggnader, ny och äldre befintlig byggnad. Den nya byggnaden anslöts till direkt mikronät (DC-mikcrogrid) och den äldre byggnaden utrustades med solcellssystem. Detta projekt utför en ’från vaggan till porten’ livscykelanalys (LCA) för energisystemet direkt mikronät. Syftet är i huvudsak att fastställa vilka delar och processer av det direkta mikronätet som bidrar till störst miljöpåverkan genom dess livslängd, det vill säga från vaggan till porten. Vidare undersöker studien återbetalningstiden (Energy PayBack Time, EPBT) och den ackumulerade energianvändningen (Cumulative Energy Demand, CED) för det direkta mikronätet. Studien utför två komparativa LCA varpå det direkta mikronätet först jämförs med solcellssystemet i syfte att fastställa vilket av systemen har större miljöpåverkan. Studien ämnar också jämföra det direkta mikronätet med den genomsnittliga energimixen i Sverige, också avseende miljöpåverkan. LCA metoden följer ISO 14040-ramverket. Studien är baserad på två funktionella enheter vilka består av installerad kilowatt peak (kWp) kapacitet vilken används för att jämföra solcellssystemet och det direkta mikromåttet. Den andra funktionella enheten är 1 kWh levererad elektricitet till bostäder som producerats genom det direkta mikronätet. Denna funktionella enhet används för en ’stand-alone’ analys av det direkta mikronätet i syfte att göra det jämförbart med andra mikrosystem eller system med olika energikällor så som vatten-, vind- och kärnkraft. Resultaten från ‘stand-alone’ livscykelanalysen av det direkta mikronätet visar på att batteriet har en större effekt på mänsklig toxicitet terrestrisk ekotoxicitet, varpå systemet för energihubb bidrar främst till övergödning, abiotisk utarmning, vattenlevande ekotoxicitet och havslevande ekotoxicitet. Monokristallin solpanel har större påverkan på global uppvärmning och övergödning (fossilabränslen). I övrigt är EPBT för det direkta mikronätet cirka 3,7 år vilket innebär att energin beräknas kostnadsfri i cirka 26,5 år, givet att det kan antas att systemets livslängd är 30 år. CED-resultat visar på att microkristallin solpanel är en intensiv energiprocess som kräver mer icke-förnybar energi jämfört med resterande delar av det direkta mikronätet. Jämförelsen mellan det direkta mikronätet och solcellssystemet visar på att det direkta mikronätet har större miljöpåverkan i de flesta kategorier. Detta beror i huvudsak på batterier och växelriktare som har tydlig effekt på resultatet. Av resultatet från CED-analysen framgår att produktion av multikristallin solpanel av solcellssystemet är det mest energikrävande processen i båda kategorierna för förnybar och icke-förnybar energikälla. Vidare framgår av analysen att det direkta mikronätet har en större miljöpåverkan i alla kategorier, jämfört med påverkan från genomsnittet av energimixen i Sverige. Detta beror på att elproduktionen i Sverige mestadels består av vatten- och kärnkraft som tillsammans 2017 utgjorde 83 procent av den totala energiproduktionen. Denna produktion orsakaren mindre miljöbelastning. Trots att det direkta mikronätet påvisar en högre miljöpåverkan än solcellssystemet, är det fortfarande ett alternativ till att generera elektricitet eftersom det direkta mikronätet bidrar till indirekta fördelar såsom energibesparing. Energibesparingen i det direkta mikronnätet sker således genom ökad användning av den egenproducerade energin samt självförsörjning. Det ska vidare tilläggas att ’end-of-life’ procedurerna blir viktiga i synnerhet när de återvunna materialet återanvänds. Vidare bör solpaneler återanvändas vid ’end-of-life’ vilket bör finnas i åtanke för vidarestudier och i samband med att data tillgängliggörs.
417

Geant4 Simulations of Hadron Therapy and Refinement of User Interface / Geant4 simuleringar av partikelterapi och förfinande av användargränssnitt

Ekelund, Emil, Fogelberg Skoglösa, David January 2019 (has links)
Radiotherapy is one of the most used methods for treating cancer and the most common way to execute such treatments is to irradiate tumors with high energy photons. This can damage healthy tissue along the irradiation line. By using hadron therapy and instead irradiate the tumor with charged particles (protons or Carbon 12 ions), the energy can be concentrated to a more specific place in the body. However, the method is not well studied and the tools available for simulating hadron therapy can be hard to use. When simulating hadron therapy and other nuclear interactions a large amount of calculations need to be executed. Monte Carlo methods is a numerical method to solve equations based on repeated number sampling and is used in the simulation program Geant4. Hadron therapy was simulated with Geant4 and the data was analyzed with the data analysis framework ROOT. New macros and analysis scripts were created with the intention to help new Geant4 users. The aim to make Geant4 easier to use was partially met. The implementation of code for the low energy region of Carbon 12 projectiles was unsuccessful.
418

Control And Topology Improvements In Half-bridge Dc-dc Converters

Deng, Songquan 01 January 2005 (has links)
Efficiency and transient response are two key requirements for DC-DC converters. Topology and control are two key topics in this dissertation. A variety of techniques for DC-DC converter performance improvement are presented in this work. Focusing on the efficiency issue, a variety of clamping techniques including both active and passive methods are presented after the ringing issues in DC-DC converters are investigated. By presenting the clamping techniques, a big variety of energy management concepts are introduced. The active bridge-capacitor tank clamping and FET-diode-capacitor tank clamping are close ideas, which transfer the leakage inductor energy to clamping capacitor to prevent oscillation between leakage inductor and junction capacitor of MOSFETs. The two-FET-clamping tank employs two MOSFETs to freewheeling the leakage current when the main MOSFETs of the half-bridge are both off. Driving voltage variation on the secondary side Synchronous Rectifier (SR) MOSFETs in self-driven circuit due to input voltage variation in bus converter applications is also investigated. One solution with a variety of derivations is proposed using zerner-capacitor combination to clamping the voltage while maintaining reasonable power losses. Another efficiency improvement idea comes from phase-shift concept in DC-DC converters. By employing phase-shift scheme, the primary side and the secondary side two MOSFETs have complementary driving signals respectively, which allow the MOSFET to be turned on with Zero Voltage Switching (ZVS). Simulation verified the feasibility of the proposed phase-shifted DC-DC converter. From the control scheme point of view, a novel peak current mode control concept for half-bridge topologies is presented. Aiming at compensating the imbalanced voltage due to peak current mode control in symmetric half-bridge topologies, an additional voltage compensation loop is used to bring the half-bridge capacitor voltage back to balance. In the proposed solutions, one scheme is applied on symmetric half-bridge topology and the other one is applied on Duty-cycle-shifted (DCS) half-bridge topology. Both schemes employ simple circuitry and are suitable for integration. Loop stability issues are also investigated in this work. Modeling work shows the uncompensated half-bridge topology cannot be stabilized under all conditions and the additional compensation loop helps to prevent the voltage imbalance effectively.
419

Return-To-The-Platform: The Case of a Collegiate Level Weightlifter Recovering from a Meniscus Injury

Harden, Nicholas 01 December 2022 (has links)
The purpose of this study was to observe physiological metrics relative to training-induced adaptations in conjunction with laboratory- and competition-based performances in a super-heavyweight weightlifter recovering from a meniscus injury. A retrospective analysis was conducted on a collegiate level male weightlifter (23.2 yrs; 131.9 kg; 187.3 cm) over the course of 21-weeks post-meniscus surgery. Body mass, body fat percentage, hydration status, vastus lateralis muscle cross-sectional area, jump performance, and isometric midthigh pull were regularly assessed as part of an ongoing athlete monitoring program. Pre-injury baseline (T0) measurements were collected relative to a major national competition (COMP1). Post-injury measurements took place at the end of sequential training blocks: strength-endurance training block 1 (T1), basic strength block 2 (T2), and transmutation block 3 (T3). The final measurement session (T4) was conducted three-days post-local competition (COMP2). Only statistically significant increases were observed from T0-T4 for muscle CSA (p=0.0367), isometric peak force (pp=0.0367), and rate of force development at 250ms (p=.0367). While non-significant changes were observed for jumping performance, jump height and net impulse did, however, return to baseline. Competition based performances also showed marked improvements from pre-to-post injury via an increase in weightlifting total (3.2%∆, +9kg) and Sinclair score (1.8%∆, +5.3au). Thus, based on these findings, implementing an evidence-based training program along with a sound athlete monitoring protocol can aid with reducing an athlete’s return-to-train timeline while improving physiological, laboratory- and competition-based performance outcomes.
420

Streamflow Responses To Rainfall Events In Wetland, Urban And Agricultural Environments

Cox, Susan 04 1900 (has links)
<p> Through the use of unit hydrographs this paper demonstrates the effect of land uses on the stream discharge of three watersheds located in Southern Ontario. The watersheds represent urban, agricultural and wetland environments. The three different environments each demonstrate different responses to a unit magnitude of uniformly distributed precipitation. </p> <p> The rainfall events occurred during September and October 1981 and 1986. Three durations of events, six, twelve and twenty-four hours, are studied. </p> <p> The paper demonstrates that an urban watershed experiences a greater magnitude of peak discharge and faster response time than either of the other two studied watersheds. The unit hydrograph resulting from a wetland showed that the wetland watershed was an important regulator of streamflow. </p> <p> Special emphasis were placed on the urbanization of agricultural lands as this is the most applicable land use change currently occurring in Southern Ontario.The results from this study will be useful when assessing the magnitude of the potential runoff problem when these agricultural watersheds are urbanized. </p> / Thesis / Bachelor of Arts (BA)

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