324 research outputs found
Analysis of multichannel oceanographic data set from San Francisco Bay by frequency, variance and time-domain techniques
Investigation into high-temperature corrosion in a large-scale municipal waste-to-energy plant
High-temperature corrosion in the superheater of a large-scale waste-to-energy plant was investigated. A comparison of nickel-/iron-based alloys and austenitic stainless steel probes placed in the furnace demonstrated that temperature and particle deposition greatly influence corrosion. Nickel-based alloys performed better than the other metal alloys, though an aluminide coating further increased their corrosion resistance. Sacrificial baffles provided additional room for deposit accumulation, resulting in vigorous deposit-induced corrosion. Computational modelling (FLUENT code) was used to simulate flow characteristics and heat transfer. This study has shown that the use of aluminide coatings is a promising technique for minimising superheater corrosion in such facilities. (C) 2010 Elsevier Ltd. All rights reserved
Relaying inheritance: writing affective and possible working-class presents in the north of England.
This thesis is the story of working with multiple inheritances in the pursuit of a scholarship which might shift association, test out alternative genres and enable a more situated and responsible approach to writing working-class life. The thesis reflects this journey. Part One tells the story of encountering and accepting an inheritance of Billy Casper, Kes and Barry Hines and the active worlds which circulate around the 1968 novel A Kestrel for a Knave. Part Two follows, thinking through obligation and potential using the idea of ‘tekkin’ the jesses off’ (Cocker) where working-class flourishing might spiral out from notions of exceeding rather than escaping (Butler).
The writing spans three distinct but interwoven modalities of affective activity; contact, the processual, and pure potential (Seigworth, Deleuze, Spinoza). I work with them in active composition throughout the thesis, writing actively with Billy, Kes and Barry as well as with all kinds of other varied and constantly emerging attachments. I use a flat citational practice which places academic and ‘non’ academic knowledges on the same footing (Berlant and Stewart).
I work in relay (Haraway) with this central inheritance as well as those who have modelled a ‘capacity to tell big-enough stories’ (Haraway) about working-class life and the propensity for working-class scholars to thrive (Williams). Those who have invited me to be critically rigorous and take attachments seriously (Berlant). Those who have sparked the feeling of resonance, the quality of ‘lovely prizes’ on smooth green baize (Broad Oak Bowling Club members). Those who have allowed me to pay attention to and follow out worldings, tones, and atmospheres which circulate (Stewart). Those who have helped me to imagine an alternative approach to sensing the historical (family cinema trips, Berlant). All have helped me to engage with scholarship as an ongoing relay in which I am a part, inheriting and passing on in continuous and active procession (Stengers)
Terahertz Spectroscopy in Microfluidic Systems
Spectroscopic measurements in the terahertz-frequency-range can offer insight into the picosecond dynamics, molecular conformation, and biological function of chemical systems. Despite the recent emergence of terahertz-frequency time-domain spectroscopy as a tool for the measurement of dry, solid samples, the investigation of liquid analytes is complicated by the strong attenuation of terahertz-frequency signals in aqueous environments. The integration of microfluidic systems with on-chip waveguides offers a potential solution as picosecond pulses confined to a waveguide can interact with nano- or microlitre liquid sample volumes over a distance of several millimetres, with significantly reduced attenuation compared to free-space techniques. Specifically, the single-wire planar Goubau line waveguide has attracted attention in recent years owing to the relatively large extent of the supported evanescent field, enabling sensitive interaction between a propagating electric field and nearby samples. In this work, the first on-chip microfluidic spectrometer, capable of measuring the complex permittivity of liquids in the terahertz-frequency range is introduced.
The fabrication of planar Goubau line devices with integrated photoconductive switches for the generation and detection of terahertz-frequency electric fields is discussed in detail. Given the importance of maximising the signal-to-noise ratio in spectroscopic measurements, an investigation of the signals excited from these switches is conducted, and factors such as the pump-power, generating beam polarisation, and switch geometry are found to have a significant impact on signal generation efficiency and noise. In addition to problematic signal noise, waveguide geometries can introduce artefacts that complicate further analysis. To simplify later modelling of these structures, the sources of unwanted reflections and propagation modes are identified, and prevented by design.
The integration of microfluidic systems with on-chip waveguides presents several interesting challenges. Intimate contact between the waveguide and analyte allows for sensitive measurement of the sample properties, yet the electronic circuitry required to generate and detect a probing terahertz field must be isolated from the risk of a short-circuit presented by the potentially conductive liquid. A device structure is proposed that simultaneously overcomes these design limitations, and comprises a geometry that can be accurately modelled. Given the lack of analytical models with which the planar Goubau line can be described, numerical modelling techniques are used to create an accurate simulation of the device structure. A method is then introduced that allows interpretation of experimental data, such that the complex permittivity of unknown liquid samples can be calculated.
This new technique is used to measure the complex permittivity of a selection of well-studied polar alcohols, and the results are found to compare well to those available in literature. A free-space terahertz spectroscopy system is then used to measure liquid samples that have not been published in order to verify the results of the on-chip spectrometer when used to measure a wider range of liquid samples
P2_2 Understanding Goku's Spirit Bomb
 Goku's iconic "Spirit Bomb" has aided the hero in difficult situations in the world of Dragon Ball. With the aid of a photon sphere model, we obtain a glimpse into the necessary requisites. By creating a hypothetical sun-sized SB, we find that a photon sphere would require 5x1042 humans and would span 1x108 episodes.
Experiments and modeling of fixed-bed debarking residue pyrolysis: The effect of fuel bed properties on product yields
This paper presents a study on the fixed-bed pyrolysis of debarking residue obtained from Norway spruce. Analysis is based on the dynamic model of packed bed pyrolysis which was calibrated by determining appropriate reaction rates and enthalpies to match the model predictions with the experimental data. The model comprises mass, energy and momentum equations coupled with a rate equation that describes both the primary and secondary pyrolysis reactions. The experiments used for the model calibration determined the yields of solid, liquid and gaseous pyrolysis products as well as their compositions at three distinct holding temperatures. Subsequently, the dynamic model was used to predict the product yields and to analyze the underlying phenomena controlling the overall pyrolysis reaction in a fixed-bed reactor.Peer reviewe
Dynamics of long flexible cylinders at high-mode number in uniform and sheared flows
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections."February 2007."Includes bibliographical references (leaves 81-82).The primary objective of this thesis is to characterize the response of risers at high-mode numbers in sheared and uniform ocean currents. As part of this thesis work, three separate experiments have been planned and executed. The objective of these tests was to create a set of model tests at high-mode numbers, the first test was in uniform currents and the other tests in sheared currents. In the experiments, Vortex-Induced Vibrations (VIV) happened at one frequency at one time, rather than at many frequencies simultaneously. The single VIV frequency varied with time, but the VIV frequencies did not co-exist. The major impact of time-sharing frequencies is that it increases the damage rate and fatigue of the pipe. The high density of the sensors on the pipe allowed for analysis that had not previously been done. Two methodologies are presented to locate the area of the power-in region. Once the region where the vibration originated has been found, the different phenomena that effect the location of the power-in region that were discovered are shown. Four different factors are presented that effect the locations of the power-in region: the incidence angle of the current, the gradient of the current direction, the current profile, and the end effects at high mode number.(cont.) Two dimensionless parameters are presented which help in the prediction of VIV given a current profile. The first is the power-in determination factor which predicts the region where the power-in occurs using a combination of the current velocity and the power-in length. The second parameter, the time sharing parameter, helps to determine whether the riser will respond with a single frequency, or switch between frequencies in time.by Susan B. Swithenbank.Ph.D
Temporin A and Bombinin H2 Antimicrobial Peptides Exhibit Selective Cytotoxicity to Lung Cancer Cells
On-chip Terahertz Spectroscopy of Liquid Mixtures
We demonstrate 'through-substrate' sensing of fluids for application in the terahertz spectroscopy of biological materials. This technique employs planar Goubau lines with integrated photoconductive material, formed on a flexible, thin polyimide substrate, and bonded to a microfluidic channel. Few-picosecond pulses are used to probe liquid samples confined within the channel, over a total interaction length of 4 mm, overcoming water-absorption limitations of free-space terahertz transmission measurements
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