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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.
421

FIELD SCALE BROMIDE TRANPORT AS A FUNCTION OF PRECIPITATION AMOUNT, INTENSITY AND APPLICATION TIME DELAY

Vasquez, Vicente 01 January 2010 (has links)
Rapid and deep transport of solutes in soils can potentially pollute groundwater resources. Field estimates of solute leaching depth based on randomized sampling provide extremely variable field average estimates that confound the treatment effects of the leaching study with the high spatial variation of soil hydraulic properties. The purpose of this study was to investigate the spatial scale of variation of solute (Bromide) leaching depth, and apply this scale of variation to study the leaching depth of Bromide as a function of a sinusoidal application of transport causing factors, i.e., rainfall amount, intensity and application time delay. Solute leaching depth varied over different spatial scales. The deepest leaching was observed on plots where the Br center of mass ranged from 19-30 cm depth. Deep leaching occurred with large quantities of low intensity precipitations (5.5 to 6 cm/day) and short time delays (≤ 17 hours), respectively. The hydraulic gradient presented cyclic variation at 8 m wavelength across the 10-30cm depth compartment. Spectral analysis indicated that spatial variation of the leaching depth was mainly affected by precipitation amount and intensity and only a small portion of the leaching depth variation was caused by time delay. Cross-spectral analysis identified common cyclic variation between the Br leaching depth and precipitation amount, intensity and time delay over 32, 32 and 8 m wavelengths, respectively. Simulated Br concentration over depth and horizontal distance and soil water matric potential ψm were in good agreement with experimental observations, the latter revealing a satisfactory Br and water mass balance.
422

THE EFFECT OF CLIENT SELF-DISCLOSURE ON THE PHYSIOLOGICAL AROUSAL OF THE THERAPIST

Blackburn, Kristyn M. 01 January 2011 (has links)
This quantitative study investigated the effect of client self-disclosure on the physiological arousal of the therapist and subsequent ratings of the therapeutic alliance, session smoothness, and session depth. Three therapists and 10 clients participated in a 40-minute videotaped therapy session while being attached to sensors that measured heart rate and skin conductance. The participants completed self-report questionnaires designed to assess the therapeutic alliance and session smoothness and depth immediately following the therapy session. The videotaped therapy sessions were later transcribed and coded by two independent coders for the occurrence of client self-disclosure. Correlation analyses were utilized to determine whether or not a relationship existed between client self-disclosure and the physiological arousal of the therapist. No significant relationships were found to exist between client self-disclosure and the physiological arousal of the therapist. Positive correlations were found to exist between the occurrence of client self-disclosure and the physiological arousal of the therapist as well as between the occurrence of client self-disclosure and the therapeutic alliance. The physiological arousal of the therapist was also found to be positively correlated with the strength of the therapeutic alliance.
423

Crack depth measurement in reinforced concrete using ultrasonic techniques

Arne, Kevin C. 22 May 2014 (has links)
Concrete is the most widely used construction material in the world, so the assessment of damage in concrete is critical from the point of view of both safety and cost. Of particular interest are macro cracks that extend through the concrete cover of the reinforcement, which can potentially expose the reinforcement to corrosive elements. The high density of scatterers such as aggregate and voids in concrete makes quantitative imaging with coherent ultrasound difficult. As an alternative, this research focuses on diffuse energy based ultrasonic methods rather than coherent ultrasonic methods for crack depth assessment. Two types of ultrasonic measurements were made on real cracks formed under four point bending: one that focuses on time of flight measurements from an impactor; while the other uses the arrival time of maximum energy in a diffuse field excited by an impulsive load from a transducer. Each of these ultrasonic techniques is used to interrogate a macro crack in a concrete beam, and the results are compared to determine their accuracy and robustness. The actual crack depth is determined using direct surface measurements and a destructive dye-injected approach with drilled cores. The results suggest that the diffusion method, using a maximum energy approach, more accurately estimates the crack than visual inspection and impact echo methods, which overestimate the depth.
424

Understanding the complexity of determining the human integration strategy during post-acquisitions

Oxalaryd, Pierre, Sandström, Carolina January 2014 (has links)
Acquisitions have become an increasingly used tool for corporate growth during the lastdecade. Even so, most acquisitions fail, due to a lack of focus on the human elements of the integration process. This research sheds light on the human integration process of acquisitions and more specifically, three of its critical elements; culture, structure and humanresources management. However, when investigating acquisitions at Atlas Copco it becomesapparent that these elements are emphasized and prioritized differently in differentacquisitions. By conducting 22 interviews with managers from both Atlas Copco and managers and employees from three of its acquired organizations, this paper seeks tounderstand how the acquirer should choose an appropriate human integration strategy and what factors that determine that choice. Furthermore, it examines how the acquirer should manage the employees of the acquired firm to facilitate the implementation of changes duringthe integration process. The results shows that the acquirer choose to emphasize and prioritize the aspects that are most important to reform in order to allow the implementationof future changes in the integration process. In these cases, the prioritized aspects are alsoconsidered critical to improve by the employees, therefore the prioritization creates a perception of the acquirer’s good intentions with the integration as a whole. Furthermore, the results reveals that it is important that the acquirer invest in resources for communication,trainings and additional personnel to help the employees understand and support the changesduring the entire process.
425

Surface Winds Affect the Movement of Water Currents and Entrained Zooplankton in a Depth Specific Manner

Barth, Lauren Emily 24 June 2014 (has links)
We deployed depth-specific drifters in the western and eastern parts of the South Arm basin of Lake Opeongo and collected zooplankton samples at west and east fixed stations and at additional up- and downwind locations at three depths of the epilimnion under a range of wind conditions. Water currents had highest association with the immediate wind direction and the direction they travelled was dependent on wind strength. Along the main west-east fetch large zooplankton resided high in the epilimnion and were transported eastwards by strong surface currents where they accumulated. Small zooplankton were more uniformly distributed with depth and their accumulation patterns and transport mechanisms are less clear. Along shorter fetches oriented off-angle with the main one accumulations of zooplankton occurred at all downwind locations under heavy winds although the patterns are more variable and complex. These downwind accumulations likely create high quality habitat for warm water fish.
426

The Role of Telemedicine in the Management of Stroke Patients and Knowledge Sharing among Health Care Providers in Afghanistan

Mayar, Wahidullah 06 August 2013 (has links)
Focusing on the potential use of telemedicine among other efforts for better treatment of stroke patients, this study explored the role of telemedicine in the management of stroke patients and knowledge sharing among health care providers in Afghanistan. To this end, fourteen semi-structured interviews were conducted with physicians, specialists, neurologists, and decision makers from the Afghan Ministry of Public Health (MoPH). Actor-network and diffusion of innovations theories provided a theoretical framework for this exploratory qualitative study. The study was intended: 1) to find out about the major challenges and problems associated with managing stroke patients in Afghanistan; 2) to explore the perceptions of Afghan health professionals about the application of telemedicine as a means of improving the delivery of health services for stroke patients in Afghanistan; and 3) to understand the perceived barriers to knowledge sharing and to ascertain the potential role of telemedicine in knowledge sharing among health care providers in Afghanistan. The findings of this study demonstrated that almost all of the participants were optimistic about the potential positive role telemedicine could play in the management of stroke patients and knowledge sharing among health care providers in Afghanistan. Some important existing organisational, socio-economic, geographical, security, and cultural barriers to the management of stroke patients and knowledge sharing among health care providers in Afghanistan were revealed. To the best knowledge of the researcher, there has been no study of this kind conducted in Afghanistan yet; thus, the findings of this study will likely contribute to the development of health communication in the context of Afghanistan, and could likely be used as a resource for future research about the applications of telemedicine in various medical specialities.
427

Permafrost in Canada's Subarctic Region of Northern Ontario

Tam, Andrew 16 February 2010 (has links)
An investigation of permafrost (permanently frozen soil) was conducted in Canada’s subarctic region of Northern Ontario. Environmental baseline conditions and permafrost states were estimated using seasonal freezing and thawing energies based on observed climate data and the Stefan equation. Field studies provided measurements of the active layer depths and validated the permafrost states; laboratory studies of the soil samples provided characterization for organic materials that have high affinity for soil moisture. Palsas (unique dome-like formations) were observed to have enhanced permafrost cores beneath a thermal insulating organic layer. With climate change, results suggest the possibility of shifts from the classification of continuous to discontinuous permafrost states in areas lacking the presence of organic materials that can have environmental and ecological impacts. Northern infrastructures may become destabilized with the degradation of permafrost while palsas may become lone permafrost refuges for biodiversity that depend on cooler ecosystems, such as polar bears.
428

Optimization of Span-to-depth Ratios in High-strength Concrete Girder Bridges

Poon, Sandy Shuk-Yan 16 February 2010 (has links)
Span-to-depth ratio is an important bridge design parameter that affects structural behaviour, construction costs and aesthetics. A study of 86 constant-depth girders indicates that conventional ratios have not changed significantly since 1958. These conventional ratios are now questionable, because recently developed high-strength concrete has enhanced mechanical properties that allow for slenderer sections. Based on material consumption, cost, and aesthetics comparisons, the thesis determines optimal ratios of an 8-span highway viaduct constructed with high-strength concrete. Three bridge types are investigated: cast-in-place on falsework box-girder and solid slabs, and precast segmental span-by-span box-girder. Results demonstrate that total construction cost is relatively insensitive to span-to-depth ratio over the following ranges of ratios: 10-35, 30-45, and 15-25 for the three bridge types respectively. This finding leads to greater freedom for aesthetic expressions because, compared to conventional values (i.e. 18-23, 22-39, and 16-19), higher ranges of ratios can now be selected without significant cost premiums.
429

Developing and Evaluating Rapid Test Methods for Measuring the Sulphate Penetration Resistance of Concrete in Relation to Chloride Penetration Resistance

Karkar, Ester 12 December 2011 (has links)
External sulphate attack on concrete can lead to cracking, expansion and sometimes loss of cohesiveness of hardened cement paste. Therefore, aside from using sulphate resistant cementitious binders, it is important to design concrete which can resist sulphate penetration. In this research, both ASTM C1202 and NT Build 492 electrical migration tests were modified such that sulphate rather than chloride penetration resistances were measured. Modifications included exposing concrete specimens to Na2SO4 rather than NaCl solutions and measuring the depth of sulphate penetration visually using BaCl2+KMnO4 rather than AgNO3 solution. Nine concrete mixtures of varying w/cm, slag replacement and cement types were tested in both original standard tests and modified tests to evaluate the influence of these material variables on test results and compare chloride to sulphate results. It was found that while migration coefficients and total charge passing were lower for sulphate, the influence of material variables were relatively similar.
430

Permafrost in Canada's Subarctic Region of Northern Ontario

Tam, Andrew 16 February 2010 (has links)
An investigation of permafrost (permanently frozen soil) was conducted in Canada’s subarctic region of Northern Ontario. Environmental baseline conditions and permafrost states were estimated using seasonal freezing and thawing energies based on observed climate data and the Stefan equation. Field studies provided measurements of the active layer depths and validated the permafrost states; laboratory studies of the soil samples provided characterization for organic materials that have high affinity for soil moisture. Palsas (unique dome-like formations) were observed to have enhanced permafrost cores beneath a thermal insulating organic layer. With climate change, results suggest the possibility of shifts from the classification of continuous to discontinuous permafrost states in areas lacking the presence of organic materials that can have environmental and ecological impacts. Northern infrastructures may become destabilized with the degradation of permafrost while palsas may become lone permafrost refuges for biodiversity that depend on cooler ecosystems, such as polar bears.

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