The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform

Murray S Korman - One of the best experts on this subject based on the ideXlab platform.

  • nonlinear tuning curve demonstration comparing a buried mine simulant with a clamped elastic Plate cylindrical soil column oscillator
    Journal of the Acoustical Society of America, 2019
    Co-Authors: Ava B Twitty, Murray S Korman
    Abstract:

    Experiments using soil-Plate-oscillators (SPO) involve a cylindrical column of granular media (masonry sand) supported by a clamped circular elastic Acrylic Plate (12.7 cm diameter, 3.2 mm thick). The Plate is clamped between two 20.3 cm O.D., 12.7 cm I.D., 6.4 cm thick flat toroidal brass “rings.” Two 15 cm diameter subwoofers (10 cm above the soil) are driven by an amplified swept sinusoidal chirp which drives the 2.5-cm soil column. A spectrum analyzer measures the laser Doppler vibrometer particle velocity versus frequency near the center of the column. The resonant frequency decreases with the increasing amplitude—representing softening in the nonlinear system. The back-bone curve (locus of the resonant frequency versus corresponding peak velocity coordinates) has a distinct arching shape where the slope of the velocity increases with the decreasing frequency. Here, the resonant frequency goes from 247 to 203 Hz. A lumped element bilinear hysteresis model describes the shape of the tuning curves and backbone curve. Next, a drum-like simulant (made by replacing the upper toroidal ring by a 0.64-cm thick ring) is buried 2.5-cm deep in an open square concrete tank (57 cm). Nonlinear tuning curve experiments “on” and “off” the mine are compared with the SPO results. Experiments using soil-Plate-oscillators (SPO) involve a cylindrical column of granular media (masonry sand) supported by a clamped circular elastic Acrylic Plate (12.7 cm diameter, 3.2 mm thick). The Plate is clamped between two 20.3 cm O.D., 12.7 cm I.D., 6.4 cm thick flat toroidal brass “rings.” Two 15 cm diameter subwoofers (10 cm above the soil) are driven by an amplified swept sinusoidal chirp which drives the 2.5-cm soil column. A spectrum analyzer measures the laser Doppler vibrometer particle velocity versus frequency near the center of the column. The resonant frequency decreases with the increasing amplitude—representing softening in the nonlinear system. The back-bone curve (locus of the resonant frequency versus corresponding peak velocity coordinates) has a distinct arching shape where the slope of the velocity increases with the decreasing frequency. Here, the resonant frequency goes from 247 to 203 Hz. A lumped element bilinear hysteresis model describes the shape of the tuning curves and ...

  • Nonlinear tuning curve demonstration: Comparing a buried mine simulant with a clamped elastic Plate—Cylindrical soil column oscillator
    The Journal of the Acoustical Society of America, 2019
    Co-Authors: Ava B Twitty, Murray S Korman
    Abstract:

    Experiments using soil-Plate-oscillators (SPO) involve a cylindrical column of granular media (masonry sand) supported by a clamped circular elastic Acrylic Plate (12.7 cm diameter, 3.2 mm thick). The Plate is clamped between two 20.3 cm O.D., 12.7 cm I.D., 6.4 cm thick flat toroidal brass “rings.” Two 15 cm diameter subwoofers (10 cm above the soil) are driven by an amplified swept sinusoidal chirp which drives the 2.5-cm soil column. A spectrum analyzer measures the laser Doppler vibrometer particle velocity versus frequency near the center of the column. The resonant frequency decreases with the increasing amplitude—representing softening in the nonlinear system. The back-bone curve (locus of the resonant frequency versus corresponding peak velocity coordinates) has a distinct arching shape where the slope of the velocity increases with the decreasing frequency. Here, the resonant frequency goes from 247 to 203 Hz. A lumped element bilinear hysteresis model describes the shape of the tuning curves and backbone curve. Next, a drum-like simulant (made by replacing the upper toroidal ring by a 0.64-cm thick ring) is buried 2.5-cm deep in an open square concrete tank (57 cm). Nonlinear tuning curve experiments “on” and “off” the mine are compared with the SPO results. Experiments using soil-Plate-oscillators (SPO) involve a cylindrical column of granular media (masonry sand) supported by a clamped circular elastic Acrylic Plate (12.7 cm diameter, 3.2 mm thick). The Plate is clamped between two 20.3 cm O.D., 12.7 cm I.D., 6.4 cm thick flat toroidal brass “rings.” Two 15 cm diameter subwoofers (10 cm above the soil) are driven by an amplified swept sinusoidal chirp which drives the 2.5-cm soil column. A spectrum analyzer measures the laser Doppler vibrometer particle velocity versus frequency near the center of the column. The resonant frequency decreases with the increasing amplitude—representing softening in the nonlinear system. The back-bone curve (locus of the resonant frequency versus corresponding peak velocity coordinates) has a distinct arching shape where the slope of the velocity increases with the decreasing frequency. Here, the resonant frequency goes from 247 to 203 Hz. A lumped element bilinear hysteresis model describes the shape of the tuning curves and ...

  • nonlinear tuning curve and two tone tests using glass beads vibrating over clamped elastic Plate
    Proceedings of Meetings on Acoustics, 2018
    Co-Authors: Emily V Santos, Murray S Korman
    Abstract:

    A soil Plate oscillator (SPO) apparatus consists of two circular flanges sandwiching and clamping a thin circular elastic Plate. The apparatus can model the acoustic landmine detection problem. Uniform spherical glass beads – representing a nonlinear mesoscopic elastic material – are supported at the bottom by the Acrylic Plate (4.5 inch diam, 1/8 inch thick) and stiff cylindrical sidewalls of the upper flange. A magnetic disk centered and fastened below the Plate is driven by an AC coil placed below the magnet. Nonlinear tuning curves of the magnet’s acceleration are measured by driving the coil with a swept sinusoidal signal applied to a constant current amplifier. In two-tone tests, air-borne sound from 3 inch diameter speakers drive the bead column surface at closely spaced frequencies near the fundamental resonance. Nonlinearly generated combination frequency tones are compared for each of the bead diameter experiments.

  • demonstration of acoustic landmine detection using a clamped soil Plate oscillator with airborne sound excitation
    Journal of the Acoustical Society of America, 2018
    Co-Authors: Jenna M Cartron, Murray S Korman
    Abstract:

    Landmine detection in gravel road beds, soil, or sand for some mines (constructed out of plastic) are difficult to detect using ground penetrating radar. In acoustic landmine detection, one would like to remotely detect a vibration profile across the surface of the soil (sand or gravel) due to the interaction between a large soil column and the localized elastic top Plate. In an idealized laboratory experiment, the soil Plate oscillator (SPO) apparatus models an idealization of an acoustic landmine detection experiment. The clamped circular Acrylic Plate (1/8 in. thick) models the top Plate of a plastic buried mine while the soil column (350 g dry sifted masonry sand) supported by the Plate models the burial depth. A constant current amplified sinusoidal chirp from a sweep spectrum analyzer drives two three inch diam speakers (placed above the column) generating airborne excitation. A laser Doppler vibrometer (LDV) measured the rms particle velocity at 15 scan locations across the 4.5 inch diameter soil surface in sweeps between 50 Hz and 1250 Hz. The LDV-microphone frequency response vs. scan position is used to extract a response profile at any individual frequency. These mixed mode shapes are compared for both in-phase and out-of-phase excitation.Landmine detection in gravel road beds, soil, or sand for some mines (constructed out of plastic) are difficult to detect using ground penetrating radar. In acoustic landmine detection, one would like to remotely detect a vibration profile across the surface of the soil (sand or gravel) due to the interaction between a large soil column and the localized elastic top Plate. In an idealized laboratory experiment, the soil Plate oscillator (SPO) apparatus models an idealization of an acoustic landmine detection experiment. The clamped circular Acrylic Plate (1/8 in. thick) models the top Plate of a plastic buried mine while the soil column (350 g dry sifted masonry sand) supported by the Plate models the burial depth. A constant current amplified sinusoidal chirp from a sweep spectrum analyzer drives two three inch diam speakers (placed above the column) generating airborne excitation. A laser Doppler vibrometer (LDV) measured the rms particle velocity at 15 scan locations across the 4.5 inch diameter soil s...

  • classroom demonstration of nonlinear tuning curve vibration and two tone tests using a column of glass beads vibrating over a clamped elastic Plate
    Journal of the Acoustical Society of America, 2018
    Co-Authors: Emily V Santos, Murray S Korman
    Abstract:

    A soil Plate oscillator (SPO) apparatus consists of two circular flanges sandwiching and clamping a thin circular elastic Plate. The apparatus can model the acoustic landmine detection problem. Here, uniform spherical glass beads—representing a nonlinear mesoscopic elastic material—are supported at the bottom by the Acrylic Plate (4.5 inch diam, 1/8 inch thick) and stiff cylindrical sidewalls of the upper flange. A magnetic disk centered and fastened below the Plate is driven by an AC coil placed below the magnet. Nonlinear tuning curves of the magnet’s acceleration are measured by driving the coil with a swept sinusoidal signal applied to a constant current amplifier. Ten (separate) tuning curve experiments are performed using a fixed column of 350 grams of beads using 1,2,3,…,10 mm diameter beads. The backbone curves (peak acceleration vs. corresponding resonant frequency) exhibit a linear region with comparable slopes, while the detailed curvature vs. bead diameter reveals more structure. A bilinear hy...

Sherman Salim - One of the best experts on this subject based on the ideXlab platform.

  • Efektivitas minyak kayu manis dalam menghambat pertumbuhan koloni candida albicans pada resin akrilik
    2016
    Co-Authors: Rostiny Rostiny, Erna Fakhriyana, Sherman Salim
    Abstract:

    Background: Acrylic is usually used as material of dentures, especially base of dentures which can become entrapment of plaque and microorganism, includes Candida albicans. This is due to micro porosity of Acrylic surface which is difficult to clean with only brushing. Thus, prevalence of candidal infection is higher at patient with poor oral hygiene. Denture immersion in a chemical solution is capable of rapid inactivation of pathogenic microorganisms. But the cost of chemical solution is relatively expensive. Thus, herbal medicines as chemical cleansing agent can be alternative to solve this problem. Cinnamon cassia is among the earliest known spices used by humankind. Essential oil of Cinnamon cassia has antifungal, antibacterial, anti cancer, anti spasmodic effects and decrease blood pressure. Purpose: The aim of this research was to evaluate the effect of essential oil of Cinnamon cassia on colony growth of Candida albicans on heat cured Acrylic Plate. Method: Samples of Acrylic Plate were contaminated by Candida albicans and were immersed in essential oil of Cinnamon cassia with different concentration: 0,01%, 0,03%, 0,05% and water as control. Then samples of Acrylic were vibrated to fall off Candida albicans and the colonies of candida were counted by Quebec Colony Counter. Results: There were significant difference between of each groups except group of essential oils 0,03% and 0,05%. Conclusion: Essential oil of Cinnamon cassia with concentration 0,03% can inhibit colony growth of Candida albicans on heat cured Acrylic.

  • Pengaruh sinamat aldehid minyak kayu manis terhadap kekuatan impak resin akrilik
    2012
    Co-Authors: Rostiny Rostiny, Sherman Salim, Lie Ingrid Felicia Widyanto
    Abstract:

    Background: Acrylic denture can give a new problem to the patients if their oral hygiene and denture hygiene didn’t get a good care. The most common problem is the increasing number of Candida albicans which can cause denture stomatitis. To prevent that problem, the Acrylic denture must be cleaned by denture cleanser. The denture cleanser is quite expensive and not everyone can afford to buy it, so traditional substance can be an alternative cleanser. Cinnamaldehyde in cinnamon oil 0,05% is used in this research due to its effectiveness inhibit the growth of C. albicans and its low toxicity to the oral mucosa tissue. Purpose: The study aims is to find how long the Acrylic Plate can be soaked in the cinnamaldehyde in cinnamon oil 0,05% which have no effect on decreasing the impact strength of Acrylic Plate. Method: This research was done in experimental laboratory method with after only control group design and using Acrylic Plates. The sample is divided to six group. Group 1, 2, and 3 Acrylic Plates was soaked in the aquadest for 4 , 12, and 19 days. Group 4, 5, and 6 Acrylic Plates was soaked in the cinnamaldehyde cinnamon oil 0,05% for 4, 12, and 19 days. Then impact strength of the samples was tested. Result: There were no significant differences of the impact strength between the Acrylic Plates soaked in the aquadest for 4,12, and 19 days and in the cinnamaldehyde cinnamon oil 0,05% for 4, 12, and 19 days. Conclusion: Cinnamaldehyde cinnamon oil 0,05% didn’t reduce the impact strength of the Acrylic Plates.

  • Perendaman resin akrilik heat cured dalam larutan Tea Tree Oil 0,25% terhadap pertumbuhan Candida Albicans (Immersion heat cured Acrylic resin in 0,25% tea tree oil solution to inhibit the growth of candida albicans)
    2011
    Co-Authors: Tri Setya Lestariningrum, Sherman Salim, Harry Prajitno
    Abstract:

    Background.Especially base of denture which can become entrapment of plaque and microorganism, includes Candida albicans. This is due to micro porosity of Acrylic surface which is difficult to clean with only brushing. Most effective way to clean denture by immerse to denture cleaner. Recently, new essential oils from Melaleuca alternifolia leaves, which also known as tea tree oils which have antifungal activities. Purpose. To analyze the effectivity of tea tree oil 0,25% solution to the growth of Candida albicans in heat cured Acrylic Plate. Method. Samples of Acrylic Plate were contamined by Candida albicans and were immersed in sterile aquadest and tea tree oil 0,25% solution each for 30 minutes and 2 hours. Sample were vibrated the colonies of Candida albicans were counted by Quebec Colony Counter. Results. There’s a significant different of Candida albicans in sterile aquadest group and tea tree oil 0,25% solution. Conclusion. Tea tree oil 0,25% solution is effective to inhibit the growth of Candida albicans.

  • Efektivitas minyak kayu manis dalam menghambat pertumbuhan koloni candida albicans pada resin akrilik(Effectivity of cinnamon oil to inhibit colony growth of candida albicans on Acrylic resin)
    2010
    Co-Authors: Erna Fakhriyana, Rostiny, Sherman Salim
    Abstract:

    Background: Acrylic is usually used as material of dentures, espe cially base of dentures which can become entrapment of plaque and microorganism, includes Candida albicans. This is due to micro porosity of Acrylic surface which is difficult to clean with only brushing. Thus, prevalence of candidal infection is higher at patient with poor oral hygiene. Denture immersion in a chemical solution is capable of rapid inactivation of pathogenic microorganisms. But the cost of chemical solution is relatively expensive. Thus, herbal medicines as chemical cleansing agent can be alternative to solve this problem. Cinnamon cassia is among the earliest known spices used by humankind. Essential oil of Cinnamon cassia has antifungal, antibacterial, anti cancer, anti spasmodic effects and decrease blood pressure. Purpose: The aim of this research was to evaluate the effect of essential oil of Cinnamon cassia on colony growth of Candida albicans on heat cured Acrylic Plate. Method: Samples of Acrylic Plate were contaminated by Candida albicans and were immersed in essential oil of Cinnamon cassia with different concentration: 0,01%, 0,03%, 0,05% and water as control. Then samples of Acrylic were vibrated to fall off Candida albicans and the colonies of candida were counted by Quebec Colony Counter. Results: There were significant difference between of each groups except group of essential oils 0,03% and 0,05%. Conclusion: Essential oil of Cinnamon cassia with concentration 0,03% can inhibit colony growth of Candida albicans on heat cured Acrylic

Harry Prajitno - One of the best experts on this subject based on the ideXlab platform.

Kohji Toda - One of the best experts on this subject based on the ideXlab platform.

  • Propagation characteristics of leaky Lamb waves in layered substrate and operation performance of interdigital transducer
    Electrical Engineering in Japan, 2006
    Co-Authors: Takeshi Fujita, Kohji Toda
    Abstract:

    Propagation characteristics of seven lowest modes of leaky Lamb waves in a layered substrate composed of a piezoelectric ceramic Plate and an Acrylic Plate, under the condition of a liquid–solid boundary at the Acrylic Plate side, are described relative to operation performances of an interdigital transducer (IDT) for underwater ultrasound. The IDT operates effectively for radiating or detecting via a mode conversion from the leaky Lamb wave to a longitudinal wave in a liquid. The incorporation of a layered substrate is useful for multiple-mode operations with higher transducer efficiencies, while retaining sufficient mechanical strength. It is noticeable that the cross points of the velocity curves of the leaky Lamb wave modes and the longitudinal wave modes in two kinds of thin Plates for the layered substrate are unique for the transducer operations. The transducer operations are examined in the construction of a liquid delay line. The transducers designed for operating on the cross points of three modes are well explained in comparison between the calculated and experimental results. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 154(2): 1–9, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20177

  • Propagation Characteristics of Leaky Lamb Waves in Layered Substrate and Operation Performances of Interdigital Transducer
    IEEJ Transactions on Fundamentals and Materials, 2004
    Co-Authors: Takeshi Fujita, Kohji Toda
    Abstract:

    Propagation characteristics of seven lowest modes of leaky Lamb waves in a layered substrate composedof a piezoelectric ceramic Plate and an Acrylic Plate, under the condition of a liquid-solid boundaryat the Acrylic Plate side, are described in the relationshipwith operation performances of an interdigital transducer (IDT) for underwater ultrasound. The IDT operates effectively for radiating or detecting via a mode conversionfrom the leaky Lamb wave to a longitudinal wave in a liquid. The incorporation of a layered substrate is useful for multiple-modes operations with higher transducer efficiencies, while retaining sufficient mechanical strength. It is noticeable that the cross points of the velocity curves of the leaky Lamb wave modes and the longitudinal wave modes in two kinds of thin Plates for the layered substrate are unique for the transducer operations. The transducer operations are examined in the construction of a liquid delay line. The transducers designed for operating on the cross points of three modes are well explained in comparisonbetween the calculated and experimental results.

  • Velocity Curve Change of Leaky Lamb Waves in a Layered Substrate Induced by Liquid-Loading
    Japanese Journal of Applied Physics, 1999
    Co-Authors: Kenji Motegi, Kohji Toda
    Abstract:

    A liquid-loading effect on the propagation characteristics of leaky Lamb waves (LLWs) is studied, based on numerical calculations and experiments. A layered substrate consisting of a thin piezoelectric ceramic Plate and a thin Acrylic Plate is used as a propagation guide of the LLW. Interdigital transducers are mounted on the free surface of the ceramic Plate and a liquid is in contact with one of the two surfaces of the Acrylic Plate. Under the condition that the density ratio of water and the Acrylic Plate is high (0.85), anomalous behaviors of the velocity dispersion curves appear, which do not occur for water-loading on substrates with much higher densities such as ceramic and glass Plates. Two typical features of the LLW propagating in the layered substrate are jump of the propagation mode under the influence of the liquid-loading and the modal change of the interaction between two propagation modes. The state change of mode coupling induced by liquid loading is promising for constructing sensing devices.

Tri Setya Lestariningrum - One of the best experts on this subject based on the ideXlab platform.