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Simple volumes : - Spatial complexityLundqvist, Erik January 2019 (has links)
In this thesis project, I have explored ways to reach spatial complexity through the use of a simple system of volumetric building elements. The ambition has been to draw an apartment building with emphasis on a variety in the apartment layouts as well as to let the functions of circulation, which I define as both shared and private functions such as stairs, elevators and passages, become an integrated part of the architectural expression. The volumetric building element, with proportions derived from our infrastructural norms as it requires transformation on a truck, is today an ubiquitous object or even an architectural typology of its own. When they are assembled, it can both become a system of similar parts or one new, larger object. The project has then also been a search for an architectural ambivalence between hiding and exposing the fact that a building is the outcome of a system.
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DEVELOPMENT OF A HIGH-RESOLUTION MECHANICAL SPRAY PATTERNATOR FOR THE CHARACTERIZATION OF FUEL SPRAYSBURROUGHS, ERIC WILLIAM January 2005 (has links)
No description available.
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Tokamak burn phase energy optimization with volumetric and wall interaction effectsWojchouski, Alan Vincent January 1972 (has links)
The energy output during the burn phase will depend upon the ion temperatures and densities. The ion source rates and the plasma current can be varied to control the ion densities. The impurity concentration of the plasma can be controlled by incorporating a charged particle divertor.
A dynamic model of the burn cycle of a Tokamak is used to investigate the ion densities, temperatures and the plasma volume as a function of time. The total energy output per cycle is investigated as a function plasma current, and divertor efficiency. The ion source rates were varied automatically to hold the plasma volume within an operational range.
The point kinetics model of the plasma incorporates ions, energy and volume balance equations and explicitly accounts for the impurity ion buildup through the use of a particle-wall interaction model. The D-D, D-T, D-³He reactions are all considered in this model. The energy carried off by the neutrons in the D-D and D-T reactions is lost from the plasma. Impurities enter the plasma as a result of wall interactions with escaping ions and neutrons.
An equilibrium state vector was obtained using currently projected operating parameters. The total energy density for a burn cycle was found to be a monotonically increasing function of the plasma current. The energy density was found to be the largest for low-atomic-number first wall matteral and no divertor, due to the expansion of the plasma volume. / M.S.
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Excess molar volumes, partial molar volumes and isentropic compressibilities of binary systems (ionic liquid + alkanol)Sibiya, Precious N. January 2009 (has links)
Submitted in fulfillment of the academic requirements for the
Masters Degree in Technology: Chemistry,
Durban University of Technology, 2008. / The thermodynamic properties of binary liquid mixtures involving ionic liquids (ILs) with alcohols were determined. ILs are an important class of solvents since they are being investigated as environmentally benign solvents, because of their negligible vapour pressure, and as potential replacement solvents for volatile organic compounds (VOCs) currently used in industries. Alcohols were chosen for this study because they have hydrogen bonding and their interaction with ILs will help in understanding the intermolecular interactions. Also, their thermodynamic properties are used for the development of specific chemical processes. The excess molar volumes of binary mixtures of {1-ethyl-3-methylimidazolium ethylsulfate + methanol or 1-propanol or 2-propanol}, {trioctylmethylammonium bis (trifluoromethyl-sulfonyl) imide + methanol or ethanol or 1-propanol}, {1-buty-3-methylimidazolium methylsulfate + methanol or ethanol or 1-propanol} were calculated from experimental density values, at T = (298.15, 303.15 and 313.15) K. The Redlich-Kister smoothing polynomial was fitted to the excess molar volume data. The partial molar volumes of the binary mixtures {1-ethyl-3-methylimidazolium ethylsulfate + methanol or 1-propanol or 2-propanol}, {trioctylmethylammonium bis (trifluoromethyl-sulfonyl) imide + methanol or ethanol or 1-propanol}, {1-buty-3-methylimidazolium methylsulfate + methanol or ethanol or 1-propanol} were calculated from the Redlich-Kister coefficients, at T = (298.15, 303.15 and 313.15) K. This information was used to better understand the intermolecular interactions with each solvent at infinite dilution.
iii
The isentropic compressibility of {trioctylmethylammonium bis (trifluoromethyl-sulfonyl) imide + methanol or ethanol or 1-propanol}, were calculated from the speed of sound data at T = 298.15 K. / National Research Fundation ; Durban University of Technology
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Excess molar volume and isentropic compressibility for binary or ternary ionic liquid systemsBahadur, Indra January 2010 (has links)
Submitted in fulfillment of the requirements of the Degree of Doctor of Technology: Chemistry, Durban University of Technology, 2010. / The thermodynamic properties of mixtures involving ionic liquids (ILs) with alcohols or alkyl
acetate or nitromethane at different temperatures were determined. The ILs used were methyl
trioctylammonium bis(trifluoromethylsulfonyl)imide ([MOA]+[Tf2N]-) and 1-butyl-3-
methylimidazolium methyl sulphate [BMIM]+[MeSO4]-.
The ternary excess molar volumes (
E ) for the mixtures {methyl trioctylammonium bis
(trifluoromethylsulfonyl)imide + methanol or ethanol + methyl acetate or ethyl acetate}and (1-
butyl-3-methylimidazolium methylsulfate + methanol or ethanol or 1-propanol + nitromethane)
were calculated from experimental density values, at T = (298.15, 303.15 and 313.15) K and
T = 298.15, respectively. The Cibulka equation was used to correlate the ternary excess molar
volume data using binary data from literature. The
E values for both IL ternary systems were
negative at each temperature. The negative contribution of
E values are due to the packing
effect and/or strong intermolecular interactions (ion-dipole) between the different molecules.
The density and speed of sound of the binary solutions ([MOA]+[Tf2N]- + methyl acetate or
ethyl acetate or methanol or ethanol), (methanol + methyl acetate or ethyl acetate) and
(ethanol + methyl acetate or ethyl acetate) were also measured at T = ( 298.15, 303.15,
308.15 and 313.15) K and at atmospheric pressure. The apparent molar volume, Vφ , and the
apparent molar isentropic compressibility, κφ , were evaluated from the experimental density
and speed of sound data. A Redlich-Mayer type equation was fitted to the apparent molar
volume and apparent molar isentropic compressibility data. The results are discussed in terms
of solute-solute, solute- solvent and solvent-solvent interactions. The apparent molar volume
and apparent molar isentropic compressibility at infinite dilution, φ
and κφ
, respectively of
the binary solutions have been calculated at each temperature. The φ
values for the binary
v
systems ([MOA]+[Tf2N]- + methyl acetate or ethyl acetate or methanol or ethanol) and
(methanol + methyl acetate or ethyl acetate) and (ethanol + methyl acetate or ethyl acetate)
are positive and increase with an increase in temperature. For the (methanol + methyl acetate
or ethyl acetate) systems φ
values indicate that the (ion-solvent) interactions are weaker.
The κφ
is both positive and negative. Positive κφ
, for ([MOA] + [Tf2N]- + ethyl acetate or
ethanol), (methanol + ethyl acetate) and (ethanol + methyl acetate or ethyl acetate) can be
attributed to the predominance of solvent intrinsic compressibility effect over the effect of
penetration of ions of IL or methanol or ethanol. The positive κφ
values can be interpreted in
terms of increase in the compressibility of the solution compared to the pure solvent methyl
acetate or ethyl acetate or ethanol. The κφ
values increase with an increase in temperature.
Negative κφ
, for ([MOA] + [Tf2N]- + methyl acetate or methanol), and (methanol + methyl
acetate) can be attributed to the predominance of penetration effect of solvent molecules into
the intra-ionic free space of IL or methanol molecules over the effect of their solvent
intrinsic compressibility. Negative κφ
indicate that the solvent surrounding the IL or
methanol would present greater resistance to compression than the bulk solvent. The κφ
values decrease with an increase in the temperature. The infinite dilution apparent molar
expansibility, φ
, values for the binary systems (IL + methyl acetate or ethyl acetate or
methanol or ethanol) and (methanol + methyl acetate or ethyl acetate) and (ethanol + methyl
acetate or ethyl acetate) are positive and decrease with an increase in temperature due to the
solution volume increasing less rapidly than the pure solvent. For (IL + methyl acetate or
ethyl acetate or methanol or ethanol) systems φ
indicates that the interaction between (IL +
methyl acetate) is stronger than that of the (IL + ethanol) or (IL + methanol) or (IL + ethyl
acetate) solution. For the (methanol + methyl acetate or ethyl acetate) systems φ
values
vi
indicate that the interactions are stronger than (ethanol + methyl acetate or ethyl acetate)
systems. / National Research Foundation; Durban University of Technology
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Cibulka correlation for ternary excess molar volumes for [MOA]⁺[Tf₂N]⁻ at different temperaturesTywabi, Zikhona 20 August 2012 (has links)
Dissertation was submitted in fulfilment of the academic requirement for the Masters
Degree in Technology: Chemistry, Durban University of Technology, 2011. / In this work, the binary and ternary excess molar volumes have been calculated from the
density, ρ, measurements using an Anton Paar (DMA 38) vibrating tube digital densimeter.
One component of the ternary systems studied was an ionic liquid. The ionic liquid used is
methyl trioctylammonium bis(trifluoromethylsulfonyl)imide [MOA]+[Tf2N]-. Binary excess
molar volumes were obtained for (1-butanol + ethyl acetate) and (2-butanol + ethyl acetate)
systems at T = (298.15, 303.15, and 313.15) K. Ternary excess molar volumes were obtained
for the mixtures {[MOA]+[Tf2N]- + 2-propanol or 1-butanol or 2-butanol + ethyl acetate} at T
= (298.15, 303.15, and 313.15) K.
The Redlich-Kister equation was fitted to the calculated binary excess molar volume data to
obtain the fitting parameters which were used to calculate the partial molar volumes at
infinite dilution. The calculated partial molar volume was used to better understand the
intermolecular interactions of each component at infinite dilution. The Redlich-Kister
parameters were also used in the Cibulka equation and the Cibulka equation was used to
correlate the ternary excess molar volume data to give the fitting parameters.
The binary excess molar volumes,VmE , for the (1-butanol + ethyl acetate) and (2-butanol +
ethyl acetate) are positive at each temperature over the entire composition range. At high
mole fractions of the alcohol for the binary systems (2-propanol or 1-butanol or 2-butanol +
ethyl acetate), VmE is positive again, similar to the Cibulka ternary correlation. The positive
V E m values are due to the breaking of intermolecular interactions in the pure components
during the mixing process. The ternary excess molar volume,V E
123 , values are negative for all mole fractions. The
negative values are due to a more efficient packing and/ or attractive intermolecular
interactions in the mixtures than in the pure liquid. There is also a contraction in volume
which can be attributed to electron-donor-acceptor type interactions between the ionic liquid
and 2-propanol or 1-butanol or 2-butanol as well as ethyl acetate. / National Research Foundation.
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Camera Node for Conical Volumetric Surveillancezhang, zhennan January 2014 (has links)
Generally cameras are used for area based surveillance, but with advancement in technology, cameras can be employed for wide area space surveillance (volumetric space surveillance). The volumetric systems require a number of cameras in order to cover a large area. Single panoramic cameras do not provide required functionality for wide area space surveillance and Pan-Tile-Zoom (PTZ) cameras do not either cover wide areas. To meet this challenge, we propose a cost effective smart volumetric surveillance system which utilizes smaller number of cameras in order to provide a coverage of 360 degree. A test case used for this system includes detection of birds in the wind farms. The proposed approach provides a solution for recording/preventing collision of birds with wind turbine. To realize the system, a model is developed with two camera nodes. This model provides a 360 degree conical volumetric space coverage. The system is utilizing a servo motor with capability of changing speed and arduino embedded platform for controlling different functionality. After triggering the camera nodes from arduino, software perform the image analysis. This cost effective and wide area surveillance system consumes at least half lower power as compared to traditional linear systems with eight cameras. It is worth noting that the system provides conical shaped area coverage of 200 square meters with height ranging from approximately 40 to 100 meters. The system would capture images in raw format in local storage and the test results show that saving images with PNG format requires a small memory size as compared to BMP and TIFF. Experiment results indicate that surveillance system can be effectively employed for detecting birds in opening places.
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Evaluation of Volumetric Change of Periapical Lesions After Apicoectomy as a Measure of Postsurgical Healing Utilizing Cone Beam Computed TomographyArasu, Eshwar 01 January 2017 (has links)
The aim of this study was to evaluate whether volumetric changes in persistent periapical lesions can be detected in follow-ups six months to five years after apicoectomy using cone-beam computed tomography. Patients with a previous treatment history of apicoectomy and for whom a pre-surgical CBCT scan was taken between November 2010 and December 2015 were invited to participate in the study. A post-surgical CBCT image of the treated tooth was obtained at the recall visit. Volumetric and linear measurements of periapical lesions on initial and postoperative CBCT images were performed using DiThreshGUI software and two calibrated examiners—a board-certified endodontist and a board-certified oral radiologist. Repeated-measures ANOVA were used to estimate the magnitude of reduction and to test for differences (at alpha=0.05). A total of 20 patients with 27 surgically treated teeth were recalled at an average interval of 37 months. Reduction in the size of lesions was observed in 24 teeth (88%); overall, the volumes significantly decreased as detected by software-assisted measurement of volume (P = .0002) and by calculation from linear measurements (P < .0001). Volumetric analysis detected a reduction of 86% in lesions while the linear-derived volume measurements yielded an average reduction of 96%. These two methods of lesion assessment were strongly correlated with one another in pre-surgical scans (r>0.88) when apical lesions are measurable.
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Vícedimensionální přechodové funkce pro vizualizaci skalárních objemových dat / Multidimensional transfer functions for scalar volumetric data visualizationMach, Pavel January 2015 (has links)
Direct volume rendering is an algorithm used for displaying three-dimensional scalar data, like image from Computed Tomography. This algorithm makes use of a concept of Transfer functions for assigning optical properties to the data values. We studied two dimensional transfer functions, that besides primary values have additional dataset as an input. In particular, we studied computation of this secondary dataset with respect to the primary image function shape. This was done by analysing eigenvalues of the Hessian matrix in each image point. We proposed one formula and implemented several others for computing the probability that image point belongs to the blood vessel. Powered by TCPDF (www.tcpdf.org)
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Novel Design of a Wideband Ribcage-Dipole Array and its Feeding NetworkHarty, Daniel D. 14 January 2011 (has links)
In this thesis the focus was on the design, fabrication, and tests of the feeding networks individually and within an array system. The array feeding network is a corporate-fed type utilizing equal-split, stepped-multiple sections of the conventional Wilkinson power divider in microstrip form with a unique topology. The feeding network was specifically designed for a broadside relatively small linearly-polarized wideband UHF non-scanning array for directed power applications that uses an array radiator with a new volumetric ribcage dipole configuration. The array has a large impedance bandwidth and consistent front lobe gain over the wide frequency band. Theoretical and experimental results describing the performance of the array feeding network and the array are presented and discussed.
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