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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 54 for “"20 kHz"”.

  1. Beeinflussung metallischer Reibungsvorgänge durch Schall im 20 KHZ-Bereich

    Lehfeldt, Eckart1968

    aachen Repository record

  2. Sonoelectrochemical (20 khz) production of hydrogen from aqueous solutions

    Symes, DanielUniversity of Birmingham2011

    … Hydrogen more efficiently by using ultrasound (20 kHz) combined to electrolysis. Previous studies have shown that ultrasound enhances mass-transfer of electro-active species from the bulk solution to the electrode surface in any electrolytic system and mechanically removes gas bubbles on the …

    birmingham Repository record

  3. Modeling, analysis, and design of a 10 kVA, 20 kHz transformer

    Flory, Isaac LynnwoodVirginia Tech1993

    … a 10 kVA transformer operating at a frequency of 20 kHz using readily available materials. A special winding technique is employed to increase both energy density and transformation efficiency by reducing leakage inductance and eddy current losses in the windings. The procedures for calculating …

    vt Repository record

  4. Effects of different frequencies and other variables on the salicylic acid and terephthalic acid dosimeters applied to the advanced Fenton process and activated carbon cloth

    Milne, LouiseAbertay University2022

    … of six high ultrasound frequencies (378 kHz, 583 kHz, 862 kHz, 995 kHz, 1144 kHz, and 1175 kHz) and one low ultrasound frequency (20 kHz) for the production of hydroxyl radicals was determined by use of the salicylic acid (SA) and terephthalic acid (TA) dosimeters. Using SA, the ability …

    abertay Repository record

  5. Ultrasonic Sealing of Aluminum Foil Based Laminate Food Packaging Materials

    Xu, YifanThe Ohio State University1999

    … frequencies were investigated, with 40-kHz in addition to the industry standard frequency 20-kHz to broaden the scope of research. Although seals meeting set criteria for thepeeling strength were produced in both cases, the 20-kHz stationary sealer provided seals with the highest peeling …

    ohiolink Repository record

  6. Free-field reciprocity calibration of condenser microphones in the low ultrasonic frequency range

    Bouaoua, NourreddineUniversität Oldenburg

    … in the low ultrasonic frequency range from 20 kHz to 160 kHz. A new, fully automated measurement set-up for free-field reciprocity calibration of 1/4-inch condenser microphones has been established, and a procedure for the calculation of the free-field sensitivity of 1/4-inch condenser …

    oldenburg Repository record

  7. Auroral arc detection using a COTS spectral photometer for the Auroral Emission Radio Explorer (AERO) CubeSat Mission

    Payne, Cadence(Cadence Brea)Massachusetts Institute of Technology2020

    … auroral emission in a measurement band from 100 kHz - 15 MHz, which enables the study of interesting emission types such as Auroral Kilometric Radiation (20 kHz -750 kHz), Medium Frequency Bursts (1.6 MHz - 4.4 MHz) and cyclotron emission (2.8 MHz - 3.0 MHz).

    mit Repository record

  8. Pharmacokinetics of Ultrasonically-Released, Micelle-Encapsulated Doxorubicin in the Rat Model and its Effect on Tumor Growth

    Staples, Bryant J.2007

    … tissue. Concurrently, different frequencies (20 kHz, 500 kHz) were tested for the same effects. Treatments consisted of micelle-encapsulated doxorubicin injected intravenously followed by ultrasound application to one of the two bilateral tumors. Also, in different experiments, pharmacokinetic …

    byu Repository record

  9. Evaluation of the sonically induced narrowing of nuclear magnetic resonance spectra of solids

    Howard, Mark J.Aston University1994

    … solids. Successful SINNMR line narrowing using 20 kHz ultrasound is reported for a variety of samples: including trisodium orthophosphate, polytetrafluoroethylene and aluminium alloys. Investigations of SINNMR line narrowing in trisodium phosphate have revealed the relationship between …

    aston Repository record

  10. An integrated circuit for feedback control & compensation of an organic LED display

    Lamba, Kartik SMassachusetts Institute of Technology2006

    … 22.8 Hz, and 64.8 Hz, given a clock frequency of 20 kHz.

    mit Repository record

  11. Nuclear magnetic resonance spectroscopy and ultrasound

    Patel, Sunil U.Aston University1989

    … arrangements. A commercial instrument of 20 kilo-hertz has also been employed to test the above hypothesis and also to demonstrate the usefulness of ultrasound in sonochemistry. The latter objective being, detection of radical formation in monomer and polymer ultrasonic degradation. The …

    aston Repository record

  12. The parallel connection of single phase DC to AC power converters

    Woods, Joseph1999

    … (IGBTs), a high switching frequency (10 kHz to 20 kHz), and a frequency modulated (FM) communication scheme. Thus, the modularity is enhanced by using an FM signal in order to eliminate the wiring normally required to share the converter output current control parameters.

    concordia Repository record

  13. Low resonant frequency beam design for a piezoelectric energy harvesting device

    Brewer, John A. (John Adam)Massachusetts Institute of Technology2005

    The TREAD Act of 2000 proposed rules that will soon make tire pressure sensors standard on all automobiles. The trend seems to be for small chips that can be imbedded in tires and perform sensing, signal processing, and RF transmission in one package. But powering these devices will be another …

    mit Repository record

  14. Characterization of redundant UHF communication systems for CubeSats

    Shea, Stephen J., JrMassachusetts Institute of Technology2016

    … and 3 MHz bandwidth for downlink and 450 MHz and 20 kHz for uplink. The Micron Radio is 401 MHz downlink, 450 MHz uplink and both signals have a bandwidth of 20 kHz. The primary and backup radios are both UHF-band, which means there is a risk of the radios damaging each other on orbit that we must …

    mit Repository record

  15. Development of Multi-perspective Diagnostics and Analysis Algorithms with Applications to Subsonic and Supersonic Combustors

    Wickersham, Andrew JosephVirginia Tech2014

    … chemiluminescence imaging up to 20 kHz. Non-intrusive and full-field imaging measurements provide a wealth of information for model validation and design optimization of propulsion systems. However, it is challenging to obtain such measurements due to various implementation …

    vt Repository record

  16. Continuous biodiesel process using ultrasonic in-line reactor for Jatropha Curcas Oil (JCO)

    Mohd Yusoff, Nurrul RahmahUniversiti Tun Hussein Onn Malaysia2017

    … methanol to oil 12:1, frequency ultrasonic of 20 KHz and ultrasonic output 600 Watt at temperature 65°C. The biodiesel produced by this method has been referred according to ASTM D6751. From the result, the biodiesel produced from this method has satisfied the requirement biodiesel standard. …

    uthm Repository record

  17. A Fully-Implantable Low-Noise Emi-Resistant Piezoelectric-Polymer Microphone and Amplifier for the Middle Ear

    Yeiser, AaronMassachusetts Institute of Technology2022

    … e− (0.062 fC) over its bandwidth of 100 Hz to 20 kHz, equivalent to 0.015 nm of displacement. When implanted, we achieve a pressure sensitivity of 80–100 fC/Pa referenced to ear canal pressure below 2 kHz and 8–10 fC/Pa above 4 kHz. We expect this sensitivity at high frequency to substantially …

    mit Repository record

  18. Modeling and Implementation of Controller for Switched Reluctance Motor With Ac Small Signal Model

    Wang, XiaoyanVirginia Tech2001

    … nature of the PWM controller when running at 20 kHz switching frequency. The experimental results also indicate a stable current loop operation.

    vt Repository record

  19. Aplicação de diferentes processos físicos no creme de leite de cabra: efeito na estrutura e na lipólise convencional ou assistida por ultrassom

    Capela, Arthur Pomplio daUniversidade Federal de Viçosa2022

    … otimizadas. Para isso, primeiramente CLC (20% de gordura) foi processado a 50°C por US (15 e 30 min, 20 kHz e 38,4W/L), DAC (5 e 10 min, 12.500 e 25.000 rpm), AGT (4 e 8 min, 550 W), HC (15 MPa) e HAP (40 MPa). Após os processos, a estrutura do CLC foi avaliada pela cremeação em …

    brazil-ufv Repository record

  20. A Power Conditioning System for Superconductive Magnetic Energy Storage based on Multi-Level Voltage Source Converter

    Lee, Dong-HoVirginia Tech1999

    … handle up to 250-kVA with a 1800-V DC link, a 200-A maximum load current , and a switching frequency reaching 20-kHz with the help of zero-current-transition (ZCT) soft-switching. This PCS has a great number of advantages over conventional ones in terms of size, speed, and cost. Conventional …

    vt Repository record

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