Current Search: Plasma (x)
-
-
Title
-
Measurement of Electron Temperature and Density in a Reflex Discharge.
-
Creator
-
Scalise, Stanley J., Stetson, Robert F., Florida Atlantic University
-
Abstract/Description
-
An experimental investigation of a reflex discharge in Argon is carried out. Definition is made of a region of acceptable operating parameters consistent with continuous, stable operation of the plasma. Electron temperature is measured through the use of spectroscopy, electrostatic wave propagation, and Langmuir Probes. An electron temperature in the 1 eV to 5 eV range is indicated. Electron density is measured through the observation of the upperhybrid frequency. This observation yields an...
Show moreAn experimental investigation of a reflex discharge in Argon is carried out. Definition is made of a region of acceptable operating parameters consistent with continuous, stable operation of the plasma. Electron temperature is measured through the use of spectroscopy, electrostatic wave propagation, and Langmuir Probes. An electron temperature in the 1 eV to 5 eV range is indicated. Electron density is measured through the observation of the upperhybrid frequency. This observation yields an electron density in the region from .27 x 10^8/cm^3 to 2.38 x 10^8/cm^3. The microwave apparatus used in the density measurement is described in detail.
Show less
-
Date Issued
-
1967
-
PURL
-
http://purl.flvc.org/fau/fd/FA00000825
-
Subject Headings
-
Plasma (Ionized gases), Low temperature plasmas, Plasma density, Microwave measurements, Plasma diagnostics
-
Format
-
Document (PDF)
-
-
Title
-
MODE-MODE COUPLING OF PLASMA WAVES IN SYSTEMS WITH STRONG NON-LINEARITIES.
-
Creator
-
LODDEN, JAMES ALAN, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
-
Abstract/Description
-
The coupled equations of motion describing electrostatic plasma oscillations are derived using a collective coordinate approach. The boundary between the physical and nonphysical regions of phase space is discussed. The two mode case is studied in detail for both small and large initial disturbances. For small initial disturbances the motion was found to be periodic. For large initial disturbances, non-periodic growing solutions were found that approached one of two asymptotic limits. For...
Show moreThe coupled equations of motion describing electrostatic plasma oscillations are derived using a collective coordinate approach. The boundary between the physical and nonphysical regions of phase space is discussed. The two mode case is studied in detail for both small and large initial disturbances. For small initial disturbances the motion was found to be periodic. For large initial disturbances, non-periodic growing solutions were found that approached one of two asymptotic limits. For these solutions, the variables became infinitely large in a finite time.
Show less
-
Date Issued
-
1976
-
PURL
-
http://purl.flvc.org/fcla/dt/13828
-
Subject Headings
-
Coupled mode theory, Plasma waves
-
Format
-
Document (PDF)
-
-
Title
-
Experimental Investigation of Cyclotron Harmonic Emission by a Reflex Discharge Plasma.
-
Creator
-
Hanisch, John L., Stetson, Robert F., Florida Atlantic University
-
Abstract/Description
-
Emission of radiation from an argon and helium plasma perpendicular to the applied magnetic field in the x-band is discussed. Microwave emission was observed when the cyclotron frequency at the center of the plasma was above the mixer frequency of the radiometer, and at what appears to be multiples of the cyclotron frequency. An explanation of the microwave emission based on the solution of the Boltzmann equation assuming electron-neutral collisions is discussed. The temperature and density...
Show moreEmission of radiation from an argon and helium plasma perpendicular to the applied magnetic field in the x-band is discussed. Microwave emission was observed when the cyclotron frequency at the center of the plasma was above the mixer frequency of the radiometer, and at what appears to be multiples of the cyclotron frequency. An explanation of the microwave emission based on the solution of the Boltzmann equation assuming electron-neutral collisions is discussed. The temperature and density of the plasma were determined from probe and spectroscopic experiments. Temperatures in the range of 4 to 16 eV were measured and probe data indicated a plasma density from (0.5 - 3) x 10^9 cm^-3.
Show less
-
Date Issued
-
1968
-
PURL
-
http://purl.flvc.org/fau/fd/FA00000755
-
Subject Headings
-
Plasma (Ionized gases), Physics--Experiments
-
Format
-
Document (PDF)
-
-
Title
-
PROBE MEASUREMENTS IN A LISITANO COIL CREATED, MAGNETICALLY CONFINED HYDROGEN PLASMA.
-
Creator
-
SAEKS, JEFFREY IAN., Florida Atlantic University
-
Abstract/Description
-
Hydrogen plasmas were produced in an axially symmetric magnetic field which was nearly uniform in the Lisitano coil region. The field could be converted from a shallow mirror to a deep mirror (R = 44), to a cusp geometry by varying the current ratio in two sets of magnet coils. Unguarded Langmuir probes and a periodic potential probe proved unsatisfactory due to sheath growth. A gridded Langmuir probe measured ion temperature of 26 eV and electron temperature of 9 eV, with ion density 7 to...
Show moreHydrogen plasmas were produced in an axially symmetric magnetic field which was nearly uniform in the Lisitano coil region. The field could be converted from a shallow mirror to a deep mirror (R = 44), to a cusp geometry by varying the current ratio in two sets of magnet coils. Unguarded Langmuir probes and a periodic potential probe proved unsatisfactory due to sheath growth. A gridded Langmuir probe measured ion temperature of 26 eV and electron temperature of 9 eV, with ion density 7 to 10x10^8 cm^-3. The magnetic boundary value problem was solved analytically and comparison with previous experiments at Florida Atlantic University showed the electron temperature to depend on the magnetic field gradient in the Lisitano coil. It was also seen that high voltage (250 V) on the periodic probe was not ionizing neutrals.
Show less
-
Date Issued
-
1978
-
PURL
-
http://purl.flvc.org/fcla/dt/13905
-
Subject Headings
-
Hydrodynamics, Plasma probes, Magnetism--Experiments
-
Format
-
Document (PDF)
-
-
Title
-
TIME EVOLUTION OF TRUNCATED SOLITONS ACCORDING TO THE KORTEWEG-DE VRIES EQUATION.
-
Creator
-
ERICKSON, GARY MICHAEL., Florida Atlantic University
-
Abstract/Description
-
The long-time behavior of the solution for x >> t^1/3 of the Korteweg-de Vries equation is found when the initial data consists of a right or left-truncated soliton. The initial data in either case is found to evolve into a complete soliton of smaller amplitude. The amplitude, velocity, and phase shift of the resultant soliton is explicitly given, and the emergence of this soliton from the initial disturbance is described in both cases.
-
Date Issued
-
1978
-
PURL
-
http://purl.flvc.org/fcla/dt/13950
-
Subject Headings
-
Solitons, Plasma dynamics, Nonlinear waves, Wave equation
-
Format
-
Document (PDF)
-
-
Title
-
Hippocampal neurogenesis in the SERT ALA56 mouse model to autism.
-
Creator
-
Di Mase, Julieta Maria, Guthrie, Kathleen, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
-
Abstract/Description
-
The causes of autism spectrum disorder (ASD) are not all known, but it is suspected that the serotonin transporter (SERT) plays an important role for some subjects with ASD. Mutations in the SLC6A4 gene, that encodes SERT, including the Ala56 mutation (Gly56Ala), have been found in some autism patients. This mutation makes the transporter more active and reduces the probability of serotonergic neurotransmission in the brain, which is linked to behavioral changes that are associated with core...
Show moreThe causes of autism spectrum disorder (ASD) are not all known, but it is suspected that the serotonin transporter (SERT) plays an important role for some subjects with ASD. Mutations in the SLC6A4 gene, that encodes SERT, including the Ala56 mutation (Gly56Ala), have been found in some autism patients. This mutation makes the transporter more active and reduces the probability of serotonergic neurotransmission in the brain, which is linked to behavioral changes that are associated with core domain deficits of ASD 1. Depression also has been linked to decreases in the availability of serotonin (5-hydroxytryptamine; 5-HT) in the central nervous system (CNS), and is associated with reduced hippocampal neurogenesis. Selective serotonin reuptake inhibitors (SSRIs), drugs used to block SERTs, are used to treat depression and/or anxiety by inhibiting SERT to increase synaptic 5-HT levels.
Show less
-
Date Issued
-
2019
-
PURL
-
http://purl.flvc.org/fau/fd/FA00013297
-
Subject Headings
-
Autism Spectrum Disorder, Hippocampus, Neurogenesis, Serotonin Plasma Membrane Transport Proteins
-
Format
-
Document (PDF)
-
-
Title
-
Computer Simulation of Charged Particle Trajectories.
-
Creator
-
Hogan, William A., Lamborn, Bjorn, Florida Atlantic University
-
Abstract/Description
-
A computer analysis is made of the trajectories of charged particles injected tangentially into the mid-plane of a static mirror field. Conditions necessary for the non-adiabatic transfer of particle energy from the plane perpendicular to the field to the direction parallel to the field are discussed. Two distinct mechanisms are observed: (1) When the requirements for parametric resonance are satisfied, energy is absorbed into longitudinal motion; and (2) When the particle exhibits the...
Show moreA computer analysis is made of the trajectories of charged particles injected tangentially into the mid-plane of a static mirror field. Conditions necessary for the non-adiabatic transfer of particle energy from the plane perpendicular to the field to the direction parallel to the field are discussed. Two distinct mechanisms are observed: (1) When the requirements for parametric resonance are satisfied, energy is absorbed into longitudinal motion; and (2) When the particle exhibits the characteristic looping behavior, energy may be transferred between the longitudinal and transverse degrees of freedom. Various numerical methods are employed to integrate the equations of motion. The fourthorder Runge-Kutta Method is found to be the most accurate.
Show less
-
Date Issued
-
1970
-
PURL
-
http://purl.flvc.org/fau/fd/FA00000753
-
Subject Headings
-
Magnetic fields--Computer programs, Plasma confinement, Equations of motion
-
Format
-
Document (PDF)
-
-
Title
-
DEVELOPING PLASMA-BASED DIAGNOSTICS: FROM PANCREATIC DUCTAL ADENOCARCINOMA TO HIV.
-
Creator
-
Makler, Amy, Asghar, Waseem, Florida Atlantic University, Department of Biological Sciences
-
Abstract/Description
-
Plasma-based diagnostics are ideal for detecting a variety of diseases because they offer a method of detection that is minimally invasive, readily available, and easy to use for monitoring patients as they progress through a disease or respond to treatment. The only serum marker for PDAC is CA19-9 which lacks specificity, has limited sensitivity, and is unreliable for early detection. It is therefore of great importance to develop a diagnostic that is viable for screening and early detection...
Show morePlasma-based diagnostics are ideal for detecting a variety of diseases because they offer a method of detection that is minimally invasive, readily available, and easy to use for monitoring patients as they progress through a disease or respond to treatment. The only serum marker for PDAC is CA19-9 which lacks specificity, has limited sensitivity, and is unreliable for early detection. It is therefore of great importance to develop a diagnostic that is viable for screening and early detection. Exosomal miRNA were determined via bioinformatics analyses and then examined in PDAC cell lines to identify markers with greatest potential. These markers were then examined in plasma from PDAC patients and control groups. Four markers, miR-93-5p, miR-339-3p, miR-425-5p, and miR-425-3p, emerged as the most viable biomarker panel with the ability to detect PDAC in 100% of the early stages (N=5) compared to CA19-9 which showed increased levels in only one patient with early stage PDAC. Additionally, the diagnostic has a specificity of 80% and a sensitivity of 94.7%, making it comparable to CA19-9, and may even be beneficial for use in conjunction with CA19-9. A plasma-based diagnostic was also developed for multi-strain HIV-1 detection utilizing the loop-mediated isothermal amplification (LAMP) method. LAMP primers were developed against the integrase and vpr regions of the HIV-1 genome. They were tested first in cultured HIV samples and then examined for their ability to amplify HIV-1 subtypes A-G. The integrase primer set provided a reliable means of diagnosing all 55 strains and isolates in under 30 minutes, whereas vpr was inconsistent and exhibited high variability in detecting the HIV subtypes. Our limit of detection for B-subtype with integrase was 30 viral copies/reaction. This could provide the basis for a novel, point-of-care diagnostic for use in underdeveloped regions.
Show less
-
Date Issued
-
2023
-
PURL
-
http://purl.flvc.org/fau/fd/FA00014141
-
Subject Headings
-
Plasma, Biomarkers, Carcinoma, Pancreatic Ductal, HIV-1, Diagnosis
-
Format
-
Document (PDF)
-
-
Title
-
The Effect of Maximal Aerobic Exercise on Plasma BDNF and BDNF Expression in PBMCs in Obese and Non-Obese Individuals.
-
Creator
-
Maharaj, Arun, Whitehurst, Michael, Florida Atlantic University, College of Education, Department of Exercise Science and Health Promotion
-
Abstract/Description
-
The purpose of this study was to determine if maximal aerobic exercise promotes BDNF expression in obese individuals. Plasma levels and the expression of BDNF in PBMCs were examined. 22 participants (10 obese, 12 non-obese) completed a V02max treadmill test and blood was obtained pre, post, and 1 and 2 hours into exercise recovery. Plasma and PBMCs were isolated and analyzed for BDNF via ELISA and Western blot techniques. A significant effect for time was observed for plasma BDNF (P=
Show moreThe purpose of this study was to determine if maximal aerobic exercise promotes BDNF expression in obese individuals. Plasma levels and the expression of BDNF in PBMCs were examined. 22 participants (10 obese, 12 non-obese) completed a V02max treadmill test and blood was obtained pre, post, and 1 and 2 hours into exercise recovery. Plasma and PBMCs were isolated and analyzed for BDNF via ELISA and Western blot techniques. A significant effect for time was observed for plasma BDNF (P= <0.00 1 ). Additionally, A significant group-by-time interaction was found from pre-to-RIH for BDNF expression in PBMCs (P= 0.046). Further, significant correlations were found between BMI and waist circumference (r= .91, P< 0.001), WHR (r= .51, P= 0.002) and Pre-to-RlH ratio (r=0.58, P=0.008). Young obese subject's BDNF response to maximal exercise was consistent with previous studies. Post-exercise BDNF expressed in PBMCs were significantly higher than rest suggesting immunological-neuroprotective interactions in the CNS.
Show less
-
Date Issued
-
2016
-
PURL
-
http://purl.flvc.org/fau/fd/FA00004664, http://purl.flvc.org/fau/fd/FA00004664
-
Subject Headings
-
Biochemical markers, Blood lipoproteins, Blood plasma -- Physiology, Exercise -- Physiological aspects, Obesity -- Exercise therapy
-
Format
-
Document (PDF)