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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.
51

Racking one’s brain : Vocabulary teaching and the retention of idiomatic expressions

Söderqvist, Niclas January 2016 (has links)
This essay presents a study of retention of idioms delving into a pedagogical approach by presenting them to a group of lower secondary students. The study also explores students’ memory retention whilst concurrently investigating if certain types of idioms are retained to a greater extent than others. For the sake of assessing memory retention in relation to these various types of idiomatic transparency, the selected idioms have been divided into three separate categories; transparent, semi-transparent and opaque depending on their literal and figurative meaning. This essay argues that opaque idioms are retained to a lesser extent in memory due to their non-transparent metaphorical meaning. In fact, the most striking finding is that idioms pertaining to the opaque category are indeed more difficult for students to learn and are also forgotten the fastest. Previous research has put emphasis on the complex structure of idioms and opinions seem divided regarding to what extent the teaching of idioms should be implemented together with other vocabulary items in a classroom setting. On the other hand, the same research emphasizes the great value of idioms; potentially expanding student vocabulary and making the English language more nuanced and native-like.
52

Extended abstract: gender differences in leader's compliant behaviour: selection into leadership and dishonest behaviour of leaders: a gender experiment

Grosch, Kerstin, Müller, Stephan, Rau, Holger A., Zhurakhovska, Lilia 10 November 2021 (has links)
Das erweiterte Abstract beinhaltet die Abschnitte 'Leaders and their incentives to behave non-compliantly', 'the relevance of gender for leader's compliance', die dazu durchgeführte Studie sowie deren Auswertung. / The extended abstract consists of two clauses 'leaders and their incentives to behave non-compliantly', 'the relevance of gender for leader's compliance', as well as the related experimental study and it's conclusion.
53

Behaviour of elliptical tube columns filled with self-compacting concrete

Mahgub, Munir January 2016 (has links)
The present research is conducted to investigate the behaviour of elliptical tube columns filled with self-compacting concrete (SCC). In total, ten specimens, including two empty columns, were tested to failure. The main parameters investigated were the length and the sections of the columns, and the concrete compressive strength. Artificial Neural Network (ANN) model was developed to predict the compressive strength of SCC using a comprehensive database collected from different previous studies. The database was used to train and test the developed ANN. Moreover, parallel to the experimental works, a three dimensional nonlinear finite element (FE) model using ABAQUS software was developed to predict the behaviour of SCC elliptical tube columns. The proposed ABAQUS model was verified against the current experimental results. The experimental results indicated that the failure modes of the SCC filled elliptical steel tube columns having large slenderness ratios were dominated by global buckling. Moreover, the composite columns possessed higher critical axial compressive capacities compared with their hollow section companions due to the composite interaction. However, due to the large slenderness ratio of the test specimens, the change of compressive strength of concrete core did not show significant effect on the critical axial compressive capacity of concrete filled columns although the axial compressive capacity increased with the concrete grade increase. The comparisons between the axial compressive load capacities obtained from experimental study and those predicted using simple methods provided in Eurocode 4 for concrete-filled steel rectangular tube columns showed a reasonable agreement. The proposed three dimensional FE model accurately predicted the failure modes, the load capacity and the load-deflection response of the columns tested. The experimental results, analysis and comparisons presented in this thesis clearly support the application of self-compacting concrete filled elliptical steel tube columns in construction engineering practice.
54

Experimental study of beam to concrete-filled elliptical steel tubular column connections

Yang, Jie, Sheehan, Therese, Dai, Xianghe, Lam, Dennis 25 June 2015 (has links)
Yes / This paper investigated the rotation behaviour of simply bolted I-beam to concrete-filled elliptical steel tubular (CFEST) column connections experimentally. Ten different joint assemblies were tested to failure, with a constant axial compressive load applied to the column and upwards concentrated loads at the beam ends. All of the steel tubes were hot-finished and had a cross-sectional aspect ratio of 2. The orientation of the column and the arrangement of the stiffening plates were taken into consideration. Moment versus rotation relationships and failure modes were compared for each joint, highlighting the benefits of using core concrete and stiffeners in these connections.
55

A data-driven study of operating system energy-performance trade-offs towards system self optimization

Dong, Han 01 December 2023 (has links)
This dissertation is motivated by an intersection of changes occurring in modern software and hardware; driven by increasing application performance and energy requirements while Moore's Law and Dennard Scaling are facing challenges of diminishing returns. To address these challenging requirements, new features are increasingly being packed into hardware to support new offloading capabilities, as well as more complex software policies to manage these features. This is leading to an exponential explosion in the number of possible configurations of both software and hardware to meet these requirements. For network-based applications, this thesis demonstrates how these complexities can be tamed by identifying and exploiting the characteristics of the underlying system through a rigorous and novel experimental study. This thesis demonstrates how one can simplify this control strategy problem in practical settings by cutting across the complexity through the use of mechanisms that exploit two fundamental properties of network processing. Using the common request-response network processing model, this thesis finds that controlling 1) the speed of network interrupts and 2) the speed at which the request is then executed, enables the characterization of the software and hardware in a stable and well-structured manner. Specifically, a network device's interrupt delay feature is used to control the rate of incoming and outgoing network requests and a processor's frequency setting was used to control the speed of instruction execution. This experimental study, conducted using 340 unique combinations of the two mechanisms, across 2 OSes and 4 applications, finds that optimizing these settings in an application-specific way can result in characteristic performance improvements over 2X while improving energy efficiency by over 2X.
56

Experimental and Numerical Modeling of the Gated and Ungated Ogee Spillway

Luo, Chuyao 29 March 2023 (has links)
Spillways are hydraulic structures that allow dams to release and convey surplus water or flood from the reservoir to the downstream channel. The spillway is a safety structure that prevents the overtopping of the dam. Many dam failure disasters were due to the inadequate capacity of the spillway, which fully illustrates the prominence of spillway design. According to the control structure, spillways can be divided into gated and ungated type. The gated spillway provides better control of the managed water level and reduces the elevation of the top of the dam. Researchers have mostly used experimental models to investigate these two types of spillways in previous literature. In the past few years, following the rapid development of numerical simulation technology, there have been more studies on the numerical modeling of spillways. However, most of the literature was about ungated spillways and most of it considered the case of low head ratios, while the case with gates, especially the case of vertical plane gates, was less investigated. In this study, the hydraulic characteristics, such as velocity, pressure, and discharge coefficient, of the ungated and gated ogee spillways are investigated by means of physical and numerical models for the case of low and high head ratios. The study covered head ratios varying from 1.4 to 4.6 and the relative gate-openings varying from 0.5 to 2. The second main objective of this study was to evaluate the performance of the numerical model to simulate gated and ungated spillways. It mainly employed 2DV OpenFOAM to simulate three turbulence models (realizable k-ε, RNG k-ε, k-ω SST), and the results were compared and calibrated with the experimental results from the physical model tests performed by the author to verify the performance of the numerical model. This study aims to demonstrate that the numerical model can be used as a complementary tool to the physical model to measure the hydraulic performance of ogee spillways.
57

Experimental Study - High Altitude Forced Convective Cooling of Electromechanical Actuation Systems

Racine, Evan Michael January 2015 (has links)
No description available.
58

Kan tuggning leda till träningsvärk i massetermuskulaturen – en experimentell studie

Domi, Ilir, Neziri, Besart January 2012 (has links)
Syfte: Målsättningen med studien är att hos friska kvinnor utvärdera om intensiv tuggning leder till en proprioceptiv allodyni i massetermuskulaturen. Följande hypoteser testades i studien: 30 minuters intensivt tuggande leder till (1) ökad trötthet och smärta, (2) sänkt smärttröskel, (3) ökad vibrotaktil känslighet (4) samt träningsvärk i massetermuskulaturen bilateralt. Material och Metod: 16 friska kvinnor (medelålder 25.8 ± 5.0 år) deltog i studien som bestod av två 60-minuters sessioner med 24-timmars uppföljning. Vid ena sessionen tuggade försökspersonerna på ett grekiskt tuggummi (Masticha Chios) i 5-minuters intervaller under 30 minuter, och vilade vid den andra sessionen. En vibrameter användes för att mäta vibrationströskel, upplevd vibrationsintensitet och upplevd vibrationsobehag. Upplevd trötthet och upplevd smärtintensitet värderades enligt en visuell analog skala 0-100 mm (VAS skala). Smärttröskeln mättes med en algometer som applicerades på massetermuskelns fäste. Två vägs variansanalys användes för att testa utfallsvariabler för upprepade mätningar och Dunnett’s posthoc-test. Resultat: En signifikant skillnad kunde ses mellan tuggning och icke tuggning för vibrationströskeln (P < 0.001); upplevda tröttheten (P < 0.001); smärttröskeln (P < 0.01); upplevda vibrationsobehaget (P < 0.05). Inga signifikanta skillnader observerades för upplevd smärta och upplevd vibrationsobehag. Däremot kunde en signifikant ökning ses över tid för vibrationströskeln och den upplevda tröttheten. Konklusion: Våra fynd indikerar att det ej finns något samband mellan intensiv tuggning och träningsvärk i massetermuskulaturen. Däremot resulterade tuggningen i ökad muskeltrötthet och vibrationsobehag, samt signifikant högre trösklar för smärta och vibration under försökets gång. Proprioceptiv allodyni kunde ej påvisas. / Aims: To evaluate if intense chewing leads to proprioceptive allodynia in the masseter muscle, and test if (1) pain and fatigue are increased after intense chewing, (2) pressure pain thresholds are decreased after intense chewing, (3) vibration thresholds are increased after intense chewing, (5) intense vibrations exacerbate pain after intense chewing. Materials and Methods: 16 healthy female volunteers (mean age 25.8 ± 5 years) participated in two 60-minute sessions, each with 24-hour follow-ups. In the first session, the subjects were instructed to chew on a viscous chewing gum (Masticha Chios). In the other session the participant were assigned a control task where no chewing was performed. Perceived intensity of vibration and perceived discomfort were assessed with a Vibrameter® on a 0-50-100 visual analog scale (VAS). Two 0-100 mm visual analog scales measured pain intensity and perceived fatigue. The pain threshold was measured with an electronic algometer. These variables were measured to assess delayed onset muscle soreness. All measurements were made on the masseter muscles. Two-way analysis of variance for repeated measures and Dunnett’s post hoc test was used to test for significant alterations in the outcome variables. Results: Significant differences were observed between chewing and no-activity for vibration threshold (P<0.001); perceived fatigue (P<0.001); pain threshold (P<0.01) and vibration discomfort (P<0.05). No significant differences were seen for perceived pain and perceived intensity of vibration. A significant increase over time could only be observed for vibration threshold (P<0.01) and perceived fatigue (P<0.05). Conclusion: Our findings suggest that there is no relation between intense chewing and delayed onset muscle soreness in the masseter muscles. Intense chewing evoked moderate levels of fatigue and discomfort, and a hypoalgesia to mechanical stimulation, and reduced vibrotactile sensitivity.
59

Numerical and Experimental Study of the Deformation of Gray Cast Iron Plates

Iqbal, Khurram 02 1900 (has links)
Helical heating coils are widely used in most conventional electric stoves for many years, these heating coils can reach 600-700°C, which is higher than the ignition point of oil and grease (about 400°C), leading to many fires. Pioneering Technology Inc. has developed a Safe-T Element plate to address such problem. The Safe-T Element plate is manufactured from Gray Cast Iron. However, these plates deform during its use. This study was carried out to investigate the current Safe-T Element design, both experimentally and numerically, in order to determine the root causes behind the deformation problem of the plate, and to suggest changes to the existing design in order to limit its distortion to acceptable targets. A chemical analysis was carried out to establish the type of material of the Safe-T Element plate. Chemical analysis showed that the material of the plate is cast iron. The microstructure of the plate was tested in order to examine its type and homogeneity. Tensile testing was carried to establish the grade of the material, and to calculate the value of its young's modulus and yield strength. Tensile testing indicated that the material of the Safe-T Element plate is close to Gray Cast Iron Class 40. Differential scanning calorimetry testing was carried out to investigate thermal stability of the plate material. This test indicated that material is thermally stable. Thermal cycling testing indicated that the root cause of the deformation problem is elastic thermal buckling. Temperature uniformity tests were carried out. More than 100°C temperature variation in the radial direction was observed. To address the distortion of the plate, an optimum geometry has been suggested based on the findings of the numerical investigation by removing the outer ring from the original design of the plate. / Thesis / Master of Applied Science (MASc)
60

An Experimental Study on the Local Void Fraction Measurements in Large-Diameter Vertical Pipes using Optical Fiber Probes

Stankovic, Branko 08 1900 (has links)
This thesis contains the details of an experimental study on the local void fraction measurements in large-diameter vertical pipes using optical fiber probes. The experiments were conducted in vertical transparent acrylic pipe of a 20-cm diameter. An experimental test facility used for performing of experiments, was designed as a low-pressure air-water loop, which can operate in either a natural circulation mode or a forced circulation mode. Radial void fraction profiles were measured using an optical fiber probe. An average cross-sectional void fraction was calculated by integration of the data obtained by the optical fiber probe. The average void fraction was also calculated using two-phase pressure-drop measurements . The results were compared and the resulting good accuracy of the optical fiber probe was determined. The flow regime results were plotted in terms of superficial gas and liquid velocities using flow regime maps of several researchers. Absence of the slug flow regime in large-diameter pipes was observed during the experiments. The data were correlated using the drift-flux model. A near unity distribution parameter showed that nearly uniform radial distribution of the void fraction dominates in two-phase flow through large-diameter vertical pipes. / Thesis / Master of Engineering (ME)

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