Matching Items (5)

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Signal Modulation in a High Voltage Plasma

Description

A high voltage plasma arc can be created and sustained in air by subjecting the gases to an electric field with high voltage potential, causing ionization. The internal energy of

A high voltage plasma arc can be created and sustained in air by subjecting the gases to an electric field with high voltage potential, causing ionization. The internal energy of the ionized gases can be transferred to corresponding pressure waves when the matter involved switches between the gaseous and plasma states. By pulse-width modulating a transformer driving signal, the transfer of internal electrical energy to resonating pressure waves may be controlled. Audio wave input to the driver signal can then be modulated into the carrier wave and be used to determine the width of each pulse in the plasma, thus reconstructing the audio signal as pressure, or sound waves, as the plasma arc switches on and off. The result will be the audio waveform resonating out of the plasma arc as audible sound, and thus creating a plasma loudspeaker. Theory of operation was tested through construction of a plasma arc speaker, and resultant audio playback was analyzed. This analysis confirmed accurate reproduction of audio signal in audible sound.

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Date Created
  • 2014-05

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Anomalous Chiral Plasmas in the Hydrodynamic Regime

Description

Chiral symmetry and its anomalous and spontaneous breaking play an important role

in particle physics, where it explains the origin of pion and hadron mass hierarchy

among other things.

Despite its

Chiral symmetry and its anomalous and spontaneous breaking play an important role

in particle physics, where it explains the origin of pion and hadron mass hierarchy

among other things.

Despite its microscopic origin chirality may also lead to observable effects

in macroscopic physical systems -- relativistic plasmas made of chiral

(spin-$\frac{1}{2}$) particles.

Such plasmas are called \textit{chiral}.

The effects include non-dissipative currents in external fields that could be present

even in quasi-equilibrium, such as the chiral magnetic (CME) and separation (CSE)

effects, as well as a number of inherently chiral collective modes

called the chiral magnetic (CMW) and vortical (CVW) waves.

Applications of chiral plasmas are truly interdisciplinary, ranging from

hot plasma filling the early Universe, to dense matter in neutron stars,

to electronic band structures in Dirac and Weyl semimetals, to quark-gluon plasma

produced in heavy-ion collisions.

The main focus of this dissertation is a search for traces of chiral physics

in the spectrum of collective modes in chiral plasmas.

I start from relativistic chiral kinetic theory and derive

first- and second-order chiral hydrodynamics.

Then I establish key features of an equilibrium state that describes many

physical chiral systems and use it to find the full spectrum of collective modes

in high-temperature and high-density cases.

Finally, I consider in detail the fate of the two inherently chiral waves, namely

the CMW and the CVW, and determine their detection prospects.

The main results of this dissertation are the formulation of a fully covariant

dissipative chiral hydrodynamics and the calculation of the spectrum of collective

modes in chiral plasmas.

It is found that the dissipative effects and dynamical electromagnetism play

an important role in most cases.

In particular, it is found that both the CMW and the CVW are heavily damped by the usual

Ohmic dissipation in charged plasmas and the diffusion effects in neutral plasmas.

These findings prompt a search for new physical observables in heavy-ion collisions,

as well as a revision of potential applications of chiral theories in

cosmology and solid-state physics.

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Created

Date Created
  • 2019

Molecular profiling plasma extracellular vesicles from breast cancer patients

Description

Extracellular vesicles (EVs) represent a heterogeneous population of small vesicles, consisting of a phospholipidic bilayer surrounding a soluble interior cargo. These vesicles play an important role in cellular communication by

Extracellular vesicles (EVs) represent a heterogeneous population of small vesicles, consisting of a phospholipidic bilayer surrounding a soluble interior cargo. These vesicles play an important role in cellular communication by virtue of their protein, RNA, and lipid content, which can be transferred among cells. Peripheral blood is a rich source of circulating EVs. An analysis of EVs in peripheral blood could provide access to unparalleled amounts of biomarkers of great diagnostic, prognostic as well as therapeutic value. In the current study, a plasma EV enrichment method based on pluronic co-polymer was first established and characterized. Plasma EVs from breast cancer patients were then enriched, profiled and compared to non-cancer controls. Proteins signatures that contributed to the prediction of cancer samples from non-cancer controls were created by a random-forest based cross-validation approach. We found that a large portion of these signatures were related to breast cancer aggression. To verify such findings, KIAA0100, one of the features identified, was chosen for in vitro molecular and cellular studies in the breast cancer cell line MDA-MB-231. We found that KIAA0100 regulates cancer cell aggression in MDA-MB-231 in an anchorage-independent manner and is particularly associated with anoikis resistance through its interaction with HSPA1A. Lastly, plasma EVs contain not only individual proteins, but also numerous molecular complexes. In order to measure millions of proteins, isoforms, and complexes simultaneously, Adaptive Dynamic Artificial Poly-ligand Targeting (ADAPT) platform was applied. ADAPT employs an enriched library of single-stranded oligodeoxynucleotides to profile complex biological samples, thus achieving a deep coverage of system-wide, native biomolecules. Profiling of EVs from breast cancer patients was able to obtain a prediction AUC performance of 0.73 when compared biopsy-positive cancer patient to healthy controls and 0.64 compared to biopsy-negative controls and such performance was not associated with the physical breast condition indicated by BIRAD scores. Taken together, current research demonstrated the potential of profiling plasma EVs in searching for therapeutic targets as well as diagnostic signatures.

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Created

Date Created
  • 2018

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Detailed Design of a Pulsed Plasma Thrust Stand

Description

This thesis gives a detailed design process for a pulsed type thruster. The thrust stand designed in this paper is for a Pulsed Plasma Thruster built by Sun Devil Satellite

This thesis gives a detailed design process for a pulsed type thruster. The thrust stand designed in this paper is for a Pulsed Plasma Thruster built by Sun Devil Satellite Laboratory, a student organization at Arizona State University. The thrust stand uses a torsional beam rotating to record displacement. This information, along with impulse-momentum theorem is applied to find the impulse bit of the thruster, which varies largely from other designs which focus on using the natural dynamics their fixtures. The target impulse to record on this fixture was estimated to be 275 μN-s of impulse. Through calibration and experimentation, the fixture is capable of recording an impulse of 332 μN-s ± 14.81 μN-s, close to the target impulse. The error due to noise was characterized and evaluated to be under 5% which is deemed to be acceptable.

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Created

Date Created
  • 2017

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Ex Vivo Protein Post Translational Modifications in Poorly Stored Blood Plasma and Serum and their use as Markers of Biospecimen Integrity

Description

Exposure of blood plasma/serum (P/S) to thawed conditions, greater than -30°C, can produce biomolecular changes that misleadingly impact measurements of clinical markers within archived samples. Reported here is a low

Exposure of blood plasma/serum (P/S) to thawed conditions, greater than -30°C, can produce biomolecular changes that misleadingly impact measurements of clinical markers within archived samples. Reported here is a low sample-volume, dilute-and-shoot, intact protein mass spectrometric assay of albumin proteoforms called “ΔS-Cys-Albumin” that quantifies cumulative exposure of archived P/S samples to thawed conditions. The assay uses the fact that S-cysteinylation (oxidation) of albumin in P/S increases to a maximum value when exposed to temperatures greater than -30°C. The multi-reaction rate law that governs this albumin S-cysteinylation formation in P/S was determined and was shown to predict the rate of formation of S-cysteinylated albumin in P/S samples—a step that enables back-calculation of the time at which unknown P/S specimens have been exposed to room temperature. To emphasize the capability of this assay, a blind challenge demonstrated the ability of ΔS-Cys-Albumin to detect exposure of individual and grouped P/S samples to unfavorable storage conditions. The assay was also capable of detecting an anomaly in a case study of nominally pristine serum samples collected under NIH-sponsorship, demonstrating that empirical evidence is required to guarantee accurate knowledge of archived P/S biospecimen storage history.

The ex vivo glycation of human serum albumin was also investigated showing that P/S samples stored above their freezing point leads to significant increases in glycated albumin. These increases were found to occur within hours at room temperature, and within days at -20 °C. These increases continued over a period of 1-2 weeks at room temperature and over 200 days at -20 °C, ultimately resulting in a doubling of glycated albumin in both healthy and diabetic patients. It was also shown that samples stored at lower surface area-to-volume ratios or incubated under a nitrogen atmosphere experienced less rapid glucose adduction of albumin—suggesting a role for oxidative glycation in the ex vivo glycation of albumin.

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Created

Date Created
  • 2018