Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 29 for “"thermal time"”.
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Environmental drivers of bulb production in brassicas
… the growth and development of bulb turnips. Thermal time requirements for developmental phases of bulb brassicas were quantified and relationships to describe the time to bulb initiation were obtained in field and controlled environments. In the first controlled environment experiment …
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Germination niche of Sardinian endemic species in mountain riparian deciduous forests
… prevents germination in a specified period of time, under any combination of environmental factors that otherwise favour germination and it is mediated, at least in part, by the plant hormones abscisic acid and gibberellins. Dormancy can be broken by some environmental stimuli, such as a cold …
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Effect of planting date on measured growth intervals for a set of genetically diverse maize hybrids
Delayed planting is known to affect the thermal and calendar day requirements of corn hybrids. There are conflicting reports in the literature as to whether the thermal intervals to certain growth stages are increased or decreased by delayed planting. A study of 12 maize hybrids was conducted in …
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Nonlinear electromagnetic-thermal modeling using time domain finite element method in the machinery design
In this thesis, an electromagnetic-thermal co-simulation algorithm is developed for the three-dimensional modeling of electric machines. To couple electromagnetic (EM) and heat transfer processes, the time-domain finite element method is employed for its capability of modeling complex geometries. …
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Germination thresholds of the Mixed-grass Prairie species as affected by global climate change: A FACE study.
… 12.5/2.5, 15/5, 20/10, 25/15, 30/20, 35/25°C). Thermal time requirements (θ50) and base temperatures (Tb) for germination were determined using thermal time models. Elevated CO2 concentrations reduced seed fill and viability, germination and germination rate in Grindelia squarrosa. Heating …
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Substrate dependance, temperature dependance and temperature sensitivity and resolution of doped-silicon microcantilevers
… rst objective seeks to understand the speci c thermal interactions between a heated microcantilever tip and various substrates. The experiments investigate thermal conductance, thermal time constant, and temperature-dependant adhesion force between and cantilever tip and substrates of silicon, …
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A numerical study of equivalence in scanning thermistor bolometer radiometers for earth radiation budget applications
… the ERBE scanning radiometer to characterize its thermal and electrical dynamic behavior. The thermal analysis confirms the thermal time constant of the instrument claimed by the vendor. The electrical model reveals that the instrument can be very sensitive to spatial variations of the incident …
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Visible and Infrared Light Detection Using 2D Materials
… open up the possibility of designing fast (<1 ms thermal time constant) thermal detectors while still maintaining high specific detectivity. This thesis focuses on developing novel light detectors and harvesters based on 2D materials, including multilayer Tungsten Diselenide (WSe₂) solar cells, …
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Respuesta germinativa y tolerancia al estrés salino en comunidades dunares
… base temperature, base osmotic potential, thermal time and hydrotime. A multivariate analysis is performed through Principal Component Analysis and Factor Analysis in order to search for possible groupings between species. As a final result it is shown that the germinative variables related …
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The influence of sowing depth, compaction and fertiliser placement on caucasian, subterranean and white clover grown in pots : A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Agricultural Science with Honours at Lincoln University, New Zealand
… sowing depths. Phyllochron is a measure of the thermal time requirement for the appearance of the number of leaves per plant. White clover phyllochron was calculated to be 91⁰C days and stolon initiation occurred at 374⁰C days. Caucasian clover had a phyllochron of 541⁰ C days and rhizome …
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Thermal detection in the long wave infrared and very long wave infrared regions
Thermal detection has made extensive progress in the last 40 years, however, the speed and detectivity remain insufficient for certain applications. The advancement of microphotonic resonators has brought interest of their use as detection devices due to their small size and high quality factors. …
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Design of a low-mass high-torque brushless motor for application in quadruped robotics
… as peak cogging torque, peak motor torque, and thermal time constant under robot conditions. The motor designed by this thesis was able to produce more torque than the current motor being used by the Biomimetic Robotics Group, by a factor of 1.6, while decreasing the mass by 23%. A lower than …
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A Hydrothermal After-ripening Time Model of Seed Dormancy Loss in Bromus tectorum
… water potential, one of the parameters of hydrothermal time. The rate of change of the mean base water potential is assumed to be a linear function of temperature above a specific base temperature and as a result can be described by a thermal after-ripening (TAR) time model, an extension of …
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Aerodynamic Heating of a Hypersonic Naval Projectile Launched At Sea Level
… flight at sea-level conditions induces severe thermal loads not seen by any other type of current hypersonic system. Appropriate design of the hypersonic round requires a solid understanding of the thermal environment. Numerous codes were obtained and assessed for their applicability to the …
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Vanadium Oxide Microbolometers with Patterned Gold Black or Plasmonic Resonant Absorbers
… IR and 22% for long-wave IR. The increase in the thermal time constant caused by the additional mass of gold black is a modest 15%. However, this film is sensitive to thermal processing; experimental results indicate a decrease in absorptance upon device heating. Sub-wavelength resonant structures …
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Evaluation of a Heat Flux Microsensor in a Transonic Turbine Cascade
… measures heat flux and surface temperature. The thermal time response of both gages was modeled using a 1-D, finite difference technique and a 2-D, finite element solver. The transient response of the directly deposited gage was also tested against insert gages using an unsteady shock wave in a …
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Water use of mature pecan orchards under semi-arid conditions
… managements practices through weather variables, thermal time, fractional canopy cover and crop height (Allen and Pereira, 2009; Miyamoto, 1983; Samani et al., 2011; Sammis et al., 2004; Taylor et al., 2015). These empirical models may not be applicable to South African growing conditions as they …
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CFD Modeling and Simulation of Natural Circulation in Helium- Cooled Very High Temperature Reactors
<p>This thesis investigates the thermal-hydraulic behavior of natural circulation in helium-cooled Very High Temperature Reactor (VHTR) systems, focusing on the performance and validation of passive safety features under Pressurized or Depressurized Loss of Forced Cooling (P-LOFC or D-LOFC) events. …
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From forest to pasture without weeds: A dissertation submitted in partial fulfilment of the requirements for the Degree of Bachelor of Agricultural Science with Honours at Lincoln University
… matter production and growth rates per unit of thermal time. From 17 August to 7 September, nitrogen increased production from 6.5 kg DM/°Cd to 17.5 kg/°Cd. Gorse seedling establishment was 43 seedlings/m² where no nitrogen was used but reduced to 13/ m2 by September with the application of 400 …
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Impacts of Urban Areas on Vegetation Development Along Rural-Urban Gradients in the Upper Midwest: 2003-2012
… from 2003-2012 as a convex quadratic function of thermal time as accumulated growing degree-days (AGDD) calculated from the Moderate-resolution Imaging Spectroradiometer (MODIS) land surface temperature product to model decadal land surface phenology metrics. In general, duration of growing season …
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