Science.gov

Sample records for sawing

  1. Saw Palmetto

    MedlinePlus

    ... Foster Common Names: saw palmetto, American dwarf palm tree, cabbage palm Latin Name: Serenoa repens, Sabal serrulata ... more information. Saw palmetto is a small palm tree native to the eastern United States. Its fruit ...

  2. Power saw

    NASA Technical Reports Server (NTRS)

    Bradley, Jimmy D. (Inventor)

    1991-01-01

    A power saw is disclosed for space or robotic operations with jaw members for clamping to a work piece by an operation of a lever arm. The saw assembly is slidably mounted on the jaw assembly and fed into the work piece by a hand operated feed screw. The saw assembly includes a motor and gear belt. A current sensing circuit provides a current signal which actuates colored lights to visually depict the load on the saw blade during the cutting operations.

  3. Gin saw wear test

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most current gin saw manufacturers use a 1074 steel or similar as a basis to manufacture their saw blades. The saw teeth are individually punched on the edges of the blades and then the blade goes through a heat treating process prior to use. There are indications from other industries with similar ...

  4. See-Saw Jeans

    ERIC Educational Resources Information Center

    Sutton, Charlotte D.

    2005-01-01

    This article describes the following case: Pete Wilmington, Vice President of Sales for See-Saw Jeans for Kids, has wrapped up a deal with Wal-Mart to carry See-Saw Jeans for Kids in all Wal-Mart stores on a trial basis for the next year. See-Saw Jeans for Kids is a clothing manufacturer with sales of $41 million, but the Wal-Mart account has the…

  5. Electric arc saw apparatus

    DOEpatents

    Deichelbohrer, Paul R [Richland, WA

    1986-01-01

    A portable, hand held electric arc saw has a small frame for supporting an electrically conducting rotary blade which serves as an electrode for generating an electric arc to erode a workpiece. Electric current is supplied to the blade by biased brushes and a slip ring which are mounted in the frame. A pair of freely movable endless belts in the form of crawler treads stretched between two pulleys are used to facilitate movement of the electric arc saw. The pulleys are formed of dielectric material to electrically insulate the crawler treads from the frame.

  6. Rapid SAW Sensor Development Tools

    NASA Technical Reports Server (NTRS)

    Wilson, William C.; Atkinson, Gary M.

    2007-01-01

    The lack of integrated design tools for Surface Acoustic Wave (SAW) devices has led us to develop tools for the design, modeling, analysis, and automatic layout generation of SAW devices. These tools enable rapid development of wireless SAW sensors. The tools developed have been designed to integrate into existing Electronic Design Automation (EDA) tools to take advantage of existing 3D modeling, and Finite Element Analysis (FEA). This paper presents the SAW design, modeling, analysis, and automated layout generation tools.

  7. Electric arc saw apparatus

    DOEpatents

    Deichelbohrer, P.R.

    1983-08-08

    A portable, hand-held electric arc saw apparatus comprising a small frame for supporting an electrically conducting rotary blade which serves as an electrode for generating an electric arc between the blade and a workpiece of opposite polarity. Electrically conducting means are provided on said frame for transmitting current to said blade. A pair of freely movable endless belts in the form of crawler treads are employed to facilitate movement of the apparatus relative to the workpiece.

  8. Modeling of SAW Delay Lines

    NASA Technical Reports Server (NTRS)

    Wilson, William C.; Atkinson, Gary M.

    2007-01-01

    Integrated Vehicle Health Monitoring (IVHM) of aerospace vehicles requires rugged sensors having reduced volume, mass, and power that can be used to measure a variety of phenomena. Wireless systems are preferred when retro-fitting sensors onto existing vehicles. Surface Acoustic Wave (SAW) devices are capable of sensing: temperature, pressure, strain, chemical species, mass loading, acceleration, and shear stress. SAW technology is low cost, rugged, lightweight, and extremely low power. To aid in the development of SAW sensors for IVHM applications, a first order model of a SAW Delay line has been created.

  9. 29 CFR 570.65 - Occupations involving the operation of circular saws, band saws, guillotine shears, chain saws...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... saws, guillotine shears, chain saws, reciprocating saws, wood chippers, and abrasive cutting discs... shears, chain saws, reciprocating saws, wood chippers, and abrasive cutting discs (Order 14). (a.... (iii) Wood chippers. (iv) Abrasive cutting discs. (3) The occupations of setting-up,...

  10. 29 CFR 570.65 - Occupations involving the operation of circular saws, band saws, guillotine shears, chain saws...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... saws, guillotine shears, chain saws, reciprocating saws, wood chippers, and abrasive cutting discs... shears, chain saws, reciprocating saws, wood chippers, and abrasive cutting discs (Order 14). (a.... (iii) Wood chippers. (iv) Abrasive cutting discs. (3) The occupations of setting-up,...

  11. 29 CFR 570.65 - Occupations involved in the operations of circular saws, band saws, guillotine shears, chain saws...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., band saws, guillotine shears, chain saws, reciprocating saws, wood chippers, and abrasive cutting discs..., guillotine shears, chain saws, reciprocating saws, wood chippers, and abrasive cutting discs (Order 14). (a.... (iii) Wood chippers. (iv) Abrasive cutting discs. (3) The occupations of setting-up,...

  12. 29 CFR 570.65 - Occupations involving the operation of circular saws, band saws, guillotine shears, chain saws...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... saws, guillotine shears, chain saws, reciprocating saws, wood chippers, and abrasive cutting discs... shears, chain saws, reciprocating saws, wood chippers, and abrasive cutting discs (Order 14). (a.... (iii) Wood chippers. (iv) Abrasive cutting discs. (3) The occupations of setting-up,...

  13. SAW correlator spread spectrum receiver

    SciTech Connect

    Brocato, Robert W

    2014-04-01

    A surface acoustic wave (SAW) correlator spread-spectrum (SS) receiver is disclosed which utilizes a first demodulation stage with a chip length n and a second demodulation stage with a chip length m to decode a transmitted SS signal having a code length l=n.times.m which can be very long (e.g. up to 2000 chips or more). The first demodulation stage utilizes a pair of SAW correlators which demodulate the SS signal to generate an appropriate code sequence at an intermediate frequency which can then be fed into the second demodulation stage which can be formed from another SAW correlator, or by a digital correlator. A compound SAW correlator comprising two input transducers and a single output transducer is also disclosed which can be used to form the SAW correlator SS receiver, or for use in processing long code length signals.

  14. Lunar stone saw

    NASA Technical Reports Server (NTRS)

    Clark, Tom; Croker, Todd; Hines, Ken; Knight, Mike; Walton, Todd

    1988-01-01

    This project addresses the problem of cutting lunar stones into blocks to be used to construct shelters to protect personnel and equipment from harmful solar radiation. This plant will manufacture 6 in x 1 ft x 2 ft blocks and will be located near the south pole to allow it to be in the shade at all times. This design uses a computer controlled robot, a boulder handler that uses hydraulics for movement, a computer system that used 3-D vision to determine the size of boulders, a polycrystalline diamond tipped saw blade that utilizes radiation for cooling, and a solar tower to collect solar energy. Only two electric motors are used in this plant because of the heavy weight of electric motors and the problem of cooling them. These two motors will be cooled by thermoelectric cooling. All other motors and actuators are to be hydraulic. The architectural design for the building as well as the conceptual design of the machines for cutting the blocks are described.

  15. 29 CFR 570.65 - Occupations involved in the operations of circular saws, band saws, and guillotine shears (Order...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... saws, band saws, guillotine shears, chain saws, reciprocating saws, wood chippers, and abrasive cutting... fixed or portable machines: (i) Chain saws. (ii) Reciprocating saws. (iii) Wood chippers. (iv) Abrasive..., band saws, guillotine shears, chain saws, reciprocating saws, wood chippers, and abrasive cutting...

  16. Review on SAW RFID tags.

    PubMed

    Plessky, Victor P; Reindl, Leonhard M

    2010-03-01

    SAW tags were invented more than 30 years ago, but only today are the conditions united for mass application of this technology. The devices in the 2.4-GHz ISM band can be routinely produced with optical lithography, high-resolution radar systems can be built up using highly sophisticated, but low-cost RF-chips, and the Internet is available for global access to the tag databases. The "Internet of Things," or I-o-T, will demand trillions of cheap tags and sensors. The SAW tags can overcome semiconductor-based analogs in many aspects: they can be read at a distance of a few meters with readers radiating power levels 2 to 3 orders lower, they are cheap, and they can operate in robust environments. Passive SAW tags are easily combined with sensors. Even the "anti-collision" problem (i.e., the simultaneous reading of many nearby tags) has adequate solutions for many practical applications. In this paper, we discuss the state-of-the-art in the development of SAW tags. The design approaches will be reviewed and optimal tag designs, as well as encoding methods, will be demonstrated. We discuss ways to reduce the size and cost of these devices. A few practical examples of tags using a time-position coding with 10(6) different codes will be demonstrated. Phase-coded devices can additionally increase the number of codes at the expense of a reduction of reading distance. We also discuss new and exciting perspectives of using ultra wide band (UWB) technology for SAW-tag systems. The wide frequency band available for this standard provides a great opportunity for SAW tags to be radically reduced in size to about 1 x 1 mm(2) while keeping a practically infinite number of possible different codes. Finally, the reader technology will be discussed, as well as detailed comparison made between SAW tags and IC-based semiconductor device. PMID:20211785

  17. Improved table-saw guard

    NASA Technical Reports Server (NTRS)

    Dunn, B. R.; Zebus, P. P.

    1980-01-01

    Guard makes lighter contact on materials being sawed. Cuts are better controlled, and damages to fragile foam-type materials are reduced. Overhead support makes it possible to perform slot and step cuts, and thick materials are pushed under guard with less force. Guard is transparent plastic enclosure held by side-attached overhead support arm.

  18. SAW-Modulated Image Device

    NASA Technical Reports Server (NTRS)

    Benz, H. F.

    1985-01-01

    Imaging device uses surface-acoustic-wave (SAW) charge transfer for image readout. Spatial resolution of image changed electronically by changing frequency of applied signal. Surface acoustic waves create traveling longitudinal electric fields. These fields create potential wells that carry along stored charges. Charges injected into wells by photoelectric conversion when light strikes device.

  19. Reciprocating Saw for Silicon Wafers

    NASA Technical Reports Server (NTRS)

    Morrison, A. D.; Collins, E. R., Jr.

    1985-01-01

    Concept increases productivity and wafer quality. Cutting wafers from silicon ingots produces smooth wafers at high rates with reduced blade wear. Involves straight reciprocating saw blade and slight rotation of ingot between cutting strokes. Many parallel blades combined to cut many wafers simultaneously from ingot.

  20. Reconstructing see-saw models

    SciTech Connect

    Ibarra, Alejandro

    2007-01-12

    In this talk we discuss the prospects to reconstruct the high-energy see-saw Lagrangian from low energy experiments in supersymmetric scenarios. We show that the model with three right-handed neutrinos could be reconstructed in theory, but not in practice. Then, we discuss the prospects to reconstruct the model with two right-handed neutrinos, which is the minimal see-saw model able to accommodate neutrino observations. We identify the relevant processes to achieve this goal, and comment on the sensitivity of future experiments to them. We find the prospects much more promising and we emphasize in particular the importance of the observation of rare lnic decays for the reconstruction of the right-handed neutrino masses.

  1. Two Problems with Table Saws

    ERIC Educational Resources Information Center

    Vautaw, William R.

    2008-01-01

    We solve two problems that arise when constructing picture frames using only a table saw. First, to cut a cove running the length of a board (given the width of the cove and the angle the cove makes with the face of the board) we calculate the height of the blade and the angle the board should be turned as it is passed over the blade. Second, to

  2. Two Problems with Table Saws

    ERIC Educational Resources Information Center

    Vautaw, William R.

    2008-01-01

    We solve two problems that arise when constructing picture frames using only a table saw. First, to cut a cove running the length of a board (given the width of the cove and the angle the cove makes with the face of the board) we calculate the height of the blade and the angle the board should be turned as it is passed over the blade. Second, to…

  3. Frequency Domain Modeling of SAW Devices

    NASA Technical Reports Server (NTRS)

    Wilson, W. C.; Atkinson, G. M.

    2007-01-01

    New SAW sensors for integrated vehicle health monitoring of aerospace vehicles are being investigated. SAW technology is low cost, rugged, lightweight, and extremely low power. However, the lack of design tools for MEMS devices in general, and for Surface Acoustic Wave (SAW) devices specifically, has led to the development of tools that will enable integrated design, modeling, simulation, analysis and automatic layout generation of SAW devices. A frequency domain model has been created. The model is mainly first order, but it includes second order effects from triple transit echoes. This paper presents the model and results from the model for a SAW delay line device.

  4. Integration of optoelectronics and SAW technology

    NASA Astrophysics Data System (ADS)

    Schiopu, Paul; Grosu, Neculai; Manea, Adrian; Craciun, Alexandru

    2010-11-01

    The number of radio frequency surface acoustic wave (SAW) filters produced presently exceeds 3 billion per year. The demand for high-frequency SAW filters for telecommunications and remote sensing, has led to extensive research, focusing on new SAW microdevices. SAW devices have shown compact structures, small size, low cost, high sensitivity and fast response. The need of miniaturized systems, with high sensitivity and low energy has motivated the need to integrate on the same substrate all the structure of SAW device and connecting electronic circuits. As a consequence, many types of methods of both constructive and operating characterization of SAW devices have been developed. This paper provides a short introduction regarding the developed level of SAW microdevices and describes the results of literature investigation research of optoelectronic techniques for constructive characterization of SAW microdevices. Further research will be done into the determination of SAW parameters such as the amplitude of surface wave, the velocity of wave propagation on the surface of the piezoelectric substrate. Substrates of quartz, lithium tantalite (LiTaO3) and lithium niobate (LiNbO3), are piezoelectric materials commonly used in manufacturing of SAW devices, but these materials are not compatible with the integrated circuit (IC) technology. Three optoelectronic measurement techniques are known for detection of surface acoustic waves: diffraction grating technique, the knife-edge technique, and the detection of ultrasonic vibrations using optical interferometry. The research work given in this paper concentrates on describing of optoelectronic techniques used for constructive characterization of SAW microdevices. Finally, we try to draw some conclusion where: optoelectronic techniques are predicted to be one of the fundamental measurement methods for measurement of future SAW microdevices.

  5. Innovations in oscillating bone saw blades.

    PubMed

    Ark, T W; Thacker, J G; McGregor, W; Rodeheaver, G T; Edlich, R F

    1997-01-01

    The purpose of this study was to identify some of the determinants of saw-blade design that influence bone-cutting performance. Using a reproducible experimental model, saw-blade performance was judged by measuring the blade temperature and the rate of bone removal. The results of this study demonstrated that the rake angle and blade swing radius had significant influence on saw-blade performance. PMID:10176138

  6. SAW Temperature Sensor on Quartz.

    PubMed

    Zhgoon, Sergei; Shvetsov, Alexander; Ancev, Ivan; Bogoslovsky, Sergei; Sapozhnikov, Gennadiy; Trokhimets, Konstantin; Derkach, Mikhail

    2015-06-01

    For biomedical applications, narrow temperature range and high sensor accuracy requirements define the need for high temperature sensitivity. Wireless SAW sensors connected to antennas need a reference element to account for changes in electromagnetic coupling between the transmitter and receiver antennas. A pair of sensors with different temperature sensitivities may serve as a self-referenced sensor assembly. This justifies the need for materials with useful SAW resonator properties and with the largest difference between temperature coefficients of frequency (TCF) for a resonator pair on a single substrate. We have identified several cuts of quartz having useful properties with a TCF difference up to 140 ppm/C for a pair of resonators on a single substrate. As a rule, placing such resonators on a single substrate requires their rotation by up to 90 relative to each other. The limited range of cuts presents a unique opportunity to place both resonators along the X+90 direction with one resonator using Bleustein-Gulyaev-Shimizu (BGS) waves (with electrodes placed along the x-axis) and the other one (with electrodes inclined by about 10 to the x-axis) using quasi-Rayleigh waves. These cuts are close to the 70Y cut where a high TCF difference is reached together with acceptable characteristics of the resonators. Resonators were designed for all useful cuts (including the 70Y cut) and tested. The use of different periods in reflectors and interdigital transducer (IDT) together with individual choice of gaps between reflectors and IDT meant achieving low spurious content in resonator responses. The quality factors reached values up to 3500 at central frequencies around 915 MHz for both BGS and quasi-Rayleigh types of waves. The measured difference of the TCF is about 138 ppm/C on 70Y cut that is close to the calculated value. PMID:26067041

  7. Continued research on gin saw tooth design

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toothed saws have been used to separate cotton fiber from the seed for over 200 years. There have been many saw tooth designs developed over the years. Most of these designs were developed by trial and error. A complete and scientific analysis of tooth design has never been published. It is not know...

  8. Apparatus for loading a band saw blade

    DOEpatents

    Reeves, Steven R.

    1990-01-01

    A band saw blade is loaded between pairs of guide wheels upon tensioning the blade by guiding the blade between pairs of spaced guide plates which define converging slots that converge toward the guide wheels. The approach is particularly useful in loading blades on underwater band saw machines used to cut radioactive materials.

  9. Apparatus for loading a band saw blade

    DOEpatents

    Reeves, S.R.

    1990-03-20

    A band saw blade is loaded between pairs of guide wheels upon tensioning the blade by guiding the blade between pairs of spaced guide plates which define converging slots that converge toward the guide wheels. The approach is particularly useful in loading blades on underwater band saw machines used to cut radioactive materials. 2 figs.

  10. SAW based systems for mobile communications satellites

    NASA Technical Reports Server (NTRS)

    Peach, R. C.; Miller, N.; Lee, M.

    1993-01-01

    Modern mobile communications satellites, such as INMARSAT 3, EMS, and ARTEMIS, use advanced onboard processing to make efficient use of the available L-band spectrum. In all of these cases, high performance surface acoustic wave (SAW) devices are used. SAW filters can provide high selectivity (100-200 kHz transition widths), combined with flat amplitude and linear phase characteristics; their simple construction and radiation hardness also makes them especially suitable for space applications. An overview of the architectures used in the above systems, describing the technologies employed, and the use of bandwidth switchable SAW filtering (BSSF) is given. The tradeoffs to be considered when specifying a SAW based system are analyzed, using both theoretical and experimental data. Empirical rules for estimating SAW filter performance are given. Achievable performance is illustrated using data from the INMARSAT 3 engineering model (EM) processors.

  11. 27. William E. Barrett, Photographer, August 1975. TRIMMER SAWS LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. William E. Barrett, Photographer, August 1975. TRIMMER SAWS LOOKING BACK FROM SORTING DOCK. SAW BLADES ARE HIDDEN BY HINGED PARTITION. SPIRAL ROLLERS CARRY BOARDS FROM SAWS TO HANDLES. - Meadow River Lumber Company, Highway 60, Rainelle, Greenbrier County, WV

  12. 28. William E. Barrett, Photographer, August 1975. TRIMMER SAWS FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. William E. Barrett, Photographer, August 1975. TRIMMER SAWS FOR CUTTING BOARDS TO LENGTH. SAWS IN FOREGROUND REMOVED. NOTE BELT DRIVE ON REMAINING SAW. - Meadow River Lumber Company, Highway 60, Rainelle, Greenbrier County, WV

  13. 3. AERIAL VIEW OF SAW MILL RIVER CULVERT. NEPPERHAN AVENUE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. AERIAL VIEW OF SAW MILL RIVER CULVERT. NEPPERHAN AVENUE IS AT LEFT, SLIGHTLY FILLED SAW MILL RIVER CULVERT IS ON RIGHT. - Old Croton Aqueduct, Saw Mill River Culvert, Spanning Nepperhan Avenue, Yonkers, Westchester County, NY

  14. Parameterizable Library Components for SAW Devices

    NASA Technical Reports Server (NTRS)

    Wilson, William C.; Atkinson, Gary M.

    2006-01-01

    To facilitate quick fabrication of Surface Acoustic Wave (SAW) sensors we have found it necessary to develop a library of parameterizable components. This library is the first module in our strategy towards a design tool that is integrated into existing Electronic Design Automation (EDA) tools. This library is similar to the standard cell libraries found in digital design packages. The library cells allow the user to input the design parameters which automatically generate a detailed layout of the SAW component. This paper presents the results of our development of parameterizable cells for an InterDigitated Transducer (IDT), reflector, SAW delay line, and both one and two port resonators.

  15. Chemically sensitive interfaces on SAW devices

    SciTech Connect

    Ricco, A.J.; Martin, S.J.; Crooks, R.M.; Xu, Chuanjing; Allred, R.E.

    1993-11-01

    Using surface acoustic wave (SAW) devices, three approaches to the effective use of chemically sensitive interfaces that are not highly chemically selective have been examined: (1) molecular identification from time-resolved permeation transients; (2) using multifrequency SAW devices to determine the frequency dependence of analyte/film interactions; (3) use of an array of SAW devices bearing diverse chemically sensitive interfaces to produce a distinct response pattern for each analyte. In addition to their well-known sensitivity to mass changes (0.0035 monolayer of N{sub 2} can be measured), SAW devices respond to the mechanical and electronic properties of thin films, enhancing response information content but making a thorough understanding of the perturbation critical. Simultaneous measurement of changes in frequency and attenuation, which can provide the information necessary to determine the type of perturbation, are used as part of the above discrimination schemes.

  16. Versatile machine mills, saws light materials

    NASA Technical Reports Server (NTRS)

    Rauschl, J. A.

    1966-01-01

    Versatile milling/sawing machine performs angle cuts, flat and profile milling, machining of grooves and slots, and edge trimming of phenolic panels. The machine is mounted on rails above a table equipped with vacuum capability for holding workpieces.

  17. SAW Sensor for Fastener Failure Detection

    NASA Technical Reports Server (NTRS)

    Wilson, W. C.; Rogge, M. D.; Fisher, B.; Roller, M. J.; Malocha, D. M.

    2010-01-01

    The proof of concept for using surface acoustic wave (SAW) strain sensors in the detection of aircraft fastener failures is demonstrated. SAW sensors were investigated because they have the potential for the development of passive wireless systems. The SAW devices employed four orthogonal frequency coding (OFC) spread spectrum reflectors in two banks on a high temperature piezoelectric substrate. Three SAW devices were attached to a cantilever panel with removable side stiffeners. Damage in the form of fastener failure was simulated by removal of bolts from the side stiffeners. During testing, three different force conditions were used to simulate static aircraft structural response under loads. The design of the sensor, the panel arrangement and the panel testing results are reported. The results show that the sensors successfully detected single fastener failure at distances up to 54.6 cm from the failure site under loaded conditions.

  18. Using SAW Resonators in RF Oscillators

    NASA Technical Reports Server (NTRS)

    Westbrook, R. M.; Deboo, G. J.

    1983-01-01

    Surface-acoustic-wave (SAW) resonators used as frequency-determining elements in radio-frequency oscillators circuits. Oscillators are frequencymodulated, phase-modulated, or pulse-modulated. SAW resonators are especially applicable to low-power subminiature applications, such as biotelemetry and wind-tunnel instrumentation, where they advantageously replace crystals. Resonators are smaller than crystals and very thin--advantage where small package size is important.

  19. Pure shear horizontal SAW biosensor on langasite.

    PubMed

    Berkenpas, Eric; Bitla, Shivashanker; Millard, Paul; da Cunha, Mauricio Pereira

    2004-11-01

    The undetected introduction of pathogens into food or water supplies can produce grave consequences in terms of economic loss and human suffering. Sensitive and selective sensors capable of quickly detecting microbial pathogens are urgently needed to limit the effects of bioterrorist incidents, accidents, or pollution. Shear horizontal surface acoustic wave (SH SAW) devices provide an attractive platform for the design of microbial biosensors that function in liquid media, where Rayleigh-type modes are rapidly attenuated. This paper reports on an exploratory SH SAW delay line designed and fabricated on langasite, La3Ga5SiO14 (LGS), along the novel Euler propagation direction (0 degrees, 22 degrees, 90 degrees). A liquid chamber was fabricated and attached to the top surface, and the device was submitted to liquid and biochemical tests. Moderate (6 dB) additional attenuation of the transmission coefficient, /S21/, was consistently observed when the SH SAW delay line was assembled in the test fixture and submitted to the liquid tests, indicating that LGS is an attractive candidate for liquid sensing. Sensor selectivity can be achieved by integrating the LGS SH SAW delay line with a biochemical recognition layer. A test setup was implemented for the characterization of LGS SH SAW-based biosensors. The delay line response to biomolecule binding was shown by detection of sequential binding of proteins to the SH SAW device delay path. The biotinylated sensor was exposed sequentially to biotin-binding deglycosylated avidin, biotin-modified rabbit IgG, and goat anti-rabbit IgG antibody. As each protein was bound to the sensing surface, marked changes in the delay-line phase were recorded. The reported results demonstrate the capability of these devices to act as biochemical detectors in aqueous solutions, and this work represents the first effort using the novel material LGS in SAW-based biosensor technology. PMID:15600083

  20. Suitability of three saws for minimally invasive bone cutting.

    PubMed

    Kong, Chris; Trejos, Ana Luisa; Naish, Michael D; Patel, Rajni V; Leitch, K Kellie

    2010-03-01

    This study compares 3 different saw types to determine which is best suited for integration into a minimally invasive bone saw. A handheld electric jigsaw, a coping saw, and a Gigli saw were used to cut into porcine ilium. Heat generated was measured using a thermocouple, and forces applied during cutting were recorded using a force/torque sensor. The coping saw generated an average maximum temperature that was 26 degrees C less than that generated using the jigsaw (P < .001) and 14 degrees C less than that for the Gigli saw (P < .001). On average, the maximum force applied through the coping saw was 14 N less than that through the jigsaw (P < .001) and 18 N less than that through the Gigli saw (P < .001). Out of the 3 saws tested, the coping saw is optimal for cutting bone based on heat generation and required force. PMID:20034976

  1. Passive Wireless SAW Sensors for IVHM

    NASA Technical Reports Server (NTRS)

    Wilson, William C.; Perey, Daniel F.; Atkinson, Gary M.; Barclay, Rebecca O.

    2008-01-01

    NASA aeronautical programs require integrated vehicle health monitoring (IVHM) to ensure the safety of the crew and the vehicles. Future IVHM sensors need to be small, light weight, inexpensive, and wireless. Surface acoustic wave (SAW) technology meets all of these constraints. In addition it operates in harsh environments and over wide temperature ranges, and it is inherently radiation hardened. This paper presents a survey of research opportunities for universities and industry to develop new sensors that address anticipated IVHM needs for aerospace vehicles. Potential applications of passive wireless SAW sensors from ground testing to high altitude aircraft operations are presented, along with some of the challenges and issues of the technology.

  2. Measurement and HPT: Sharpening My Old Saw.

    ERIC Educational Resources Information Center

    Binder, Carl

    2003-01-01

    Confirms that intellectual and professional tools be in good working order, avoid superstition, and refrain from faddish/ineffective interventions. HPT (Human Performance Technology) must keep sharpening its saw based on measured results and set clear and measurable goals/expectations; put the means of measuring progress against those goals in the…

  3. High-temperature langasite SAW oxygen sensor.

    PubMed

    Zheng, Peng; Chin, Tao-Lun; Greve, David; Oppenheim, Irving; Malone, Vanessa; Cao, Limin

    2011-08-01

    High-temperature langasite SAW oxygen sensors using sputtered ZnO as a resistive gas-sensing layer were fabricated and tested. Sensitivity to oxygen gas was observed between 500C to 700C, with a sensitivity peak at about 625C, consistent with the theoretical predictions of the acoustoelectric effect. PMID:21859571

  4. Mixed orthogonal frequency coded SAW RFID tags.

    PubMed

    Gallagher, Mark W; Malocha, Donald C

    2013-03-01

    Orthogonal frequency coded (OFC) SAW radio-frequency identification (RFID) tags are currently being explored as a multi-sensor platform because of their passive spread-spectrum operation, low loss, and resilience in harsh environments. Ongoing research continues to search for robust device embodiments that increase the number of identifiable codes, in the presence of intersymbol interference, while maintaining reasonable device lengths. This paper presents a technique that shortens the SAW response length while preserving code diversity and bandwidth by utilizing a multi-track SAW configuration. These new devices allow the time response of multiple OFC chips to overlap and yield a mixed-frequency chip having the sum of the chip bandwidths but shorter overall time response. The theoretical development is presented and examples are discussed for these new mixed orthogonal frequency coded (MOFC) SAW devices. Experimental results for MOFC sensors, fabricated on YZ-LiNbO3, with a 7% fractional bandwidth and five chip frequencies in three cells, provide a good contrast to similar OFC designs. Experimental results are presented for the simultaneous operation of eight wireless temperature sensors--four OFC and four MOFC--in a 915-MHz wireless correlator receiver system, highlighting the ability of these devices to operate in the same system. PMID:23475925

  5. High Temperature Langasite SAW Oxygen Sensor

    SciTech Connect

    Zheng, Peng; Chin, Tao-Lun; Greve, David; Oppenheim, Irving; Malone, Vanessa; Cao, Limin

    2011-08-01

    High-temperature langasite SAW oxygen sensors using sputtered ZnO as a resistive gas-sensing layer were fabricated and tested. Sensitivity to oxygen gas was observed between 500C to 700C, with a sensitivity peak at about 625C, consistent with the theoretical predictions of the acoustoelectric effect.

  6. Enhanced Magnetostrictively Transduced SAW Devices - Measurements & Applications

    NASA Astrophysics Data System (ADS)

    Woo, Noble C.

    2005-03-01

    Surface acoustic wave (SAW) transducers can be made with magnetic materials using magnetostriction as a means of electromechanical coupling. Unlike conventional piezoelectrically transduced SAW devices, the magnetically transduced SAWs do not require an exotic single-crystal substrate or high temperature processing, and therefore may be easily integrated into Si-based integrated circuits. These devices have many potential applications, biosensors being one of the most promising. When the substrate between a transmitter and a detector transducer is functionalized with specific bio-receptors, a binding event will affect propagation of the SAW wave that can be detected with simple electronics. In previous MTSAW devices, the magnetomechanical coupling was found to be poor, resulting in insufficient signal amplitude. To obtain better performance, we are studying the use of alternative magnetostrictive materials including an amorphous CoFeTaZr alloy, CoNbZr, and compositions in the Terfernol family (TbFe2, etc.). We are using combinatorial materials science (continuous composition spread approach) to identify optimum alloy compositions. The devices are also being redesigned to yield better performance.

  7. Improved Multiple-DOF SAW Piezoelectric Motors

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Bao, Xiaoqi; Hull, Anthony; Wright, John

    2003-01-01

    Surface-acoustic-wave (SAW) piezoelectric motors of a proposed type would be capable of operating in multiple degrees of freedom (DOFs) simultaneously and would be amenable to integration into diverse structures and mechanisms. These motors would be compact and structurally simple and would not contain bearings or lead screws. One example of a particularly useful motor of this type would be a two-dimensional- translation stage. Another such example would be a self-actuated spherical joint that could be made to undergo controlled, simultaneous rotations about two orthogonal axes: Such a motor could serve as a mechanism for aiming an "eyeball" camera or as a compact transducer in, and an integral part of, a joint in a robot arm. The multiple-DOF SAW piezoelectric motors as now proposed would be successors to the ones reported in "Multiple-DOF Surface-Acoustic-Wave Piezoelectric Motors" (NPO-20735), NASA Tech Briefs, Vol. 24, No. 12 (December 2000), page 5b. The basic principle of operation of a multiple-DOF SAW piezoelectric motor is a straightforward extension of that of single-DOF SAW piezoelectric motors, which have been reported in several previous NASA Tech Briefs articles: For example, in the case of a linear SAW piezoelectric motor, piezoelectric transducers at opposite ends of a stator excite surface acoustic waves that travel along the surface of the stator. An object (denoted the slider) is pressed against the stator with sufficient pressure (in practice .300 MPa) that it remains in frictional contact with the stator at all times. The slider rides the crests of the waves and is thereby made to move along the surface of the stator. The direction of motion (forward or backward) is controlled by selecting the relative phase of waves generated by the two piezoelectric transducers. The speed increases with the amplitude of the waves and thus with the magnitude of the voltage applied to the transducers.

  8. 8. GENERAL VIEW OF SHINGLE CUTTING SAWS THAT HANDLE BOLTS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. GENERAL VIEW OF SHINGLE CUTTING SAWS THAT HANDLE BOLTS AFTER DEBARKING; AFTER DEBARKING THE BOLTS ARE SENT TO THE SHINGLE WEAVER FOR SAWING - Lester Shingle Mill, 1602 North Eighteenth Street, Sweet Home, Linn County, OR

  9. 15. Basement level of Saw Mill looking northeast into the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Basement level of Saw Mill looking northeast into the turbine pit. Headrace for the Grist Mill is beyond the wall to the right. - Sugar River Grist Mill & Saw Mill, 159 Main Street, Claremont, Sullivan County, NH

  10. 3. ELEVATION OF THE OAK VIADUCT, LOOKING NORTH ON SAW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. ELEVATION OF THE OAK VIADUCT, LOOKING NORTH ON SAW MILL RUN BOULEVARD - Pittsburgh & Castle Shannon Railroad, Oak Viaduct, Overbrook Trolley Line, crossing Saw Mill Run Boulevard & Colerain Street, Pittsburgh, Allegheny County, PA

  11. 32. TRIM SAWS IN BACKGROUND, VIEW FROM SOUTH WEST. NOTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. TRIM SAWS IN BACKGROUND, VIEW FROM SOUTH WEST. NOTE WASTE CONVEYOR IN FOREGROUND, CANT ROLL CASE TO BEAM SAW, THEN ROLL CASE FROM EDGER IN MIDDLE GROUND. - Hull-Oakes Lumber Company, 23837 Dawson Road, Monroe, Benton County, OR

  12. "See-saw" Marcus Gunn syndrome.

    PubMed

    Kumar, Vinod; Goel, Neha; Raina, Usha K; Ghosh, Basudeb

    2011-01-01

    The authors report an unusual case of Marcus Gunn syndrome in an adult patient, characterized by classical Marcus Gunn on one side and inverse Marcus Gunn on the other side. The patient exhibited a "see-saw" kind of eyelid movement on opening and closing the mouth and on moving the jaw from side to side. This clinical entity has been reported very rarely. A similar but etiologically different acquired condition seen commonly in adults, Marin Amat syndrome, is also discussed. PMID:21346672

  13. Microsystem packaging of an RF SAW correlator.

    SciTech Connect

    Palmer, David A.; Brocato, Robert Wesley; Studor, George F.

    2005-01-01

    An electrically programmable surface acoustic wave (SAW) correlator was recently completed from design through small scale production in support of low power space-based communications for NASA. Three different versions of this RF microsystem were built to satisfy design requirements and overcome packaging and system reliability related issues. Flip-chip packaging and conventional thick film hybrid assembly techniques are compared in the fabrication of this microsystem.

  14. Integrated circuit for SAW and MEMS sensors

    NASA Astrophysics Data System (ADS)

    Fischer, Wolf-Joachim; Koenig, Peter; Ploetner, Matthias; Hermann, Rudiger; Stab, Helmut

    2001-11-01

    The sensor processor circuit has been developed for hand-held devices used in industrial and environmental applications, such as on-line process monitoring. Thereby devices with SAW sensors or MEMS resonators will benefit from this processor especially. Up to 8 sensors can be connected to the circuit as multisensors or sensor arrays. Two sensor processors SP1 and SP2 for different applications are presented in this paper. The SP-1 chip has a PCMCIA interface which can be used for the program and data transfer. SAW sensors which are working in the frequency range from 80 MHz to 160 MHz can be connected to the processor directly. It is possible to use the new SP-2 chip fabricated in a 0.5(mu) CMOS process for SAW devices with a maximum frequency of 600 MHz. An on-chip analog-digital-converter (ADC) and 6 PWM modules support the development of high-miniaturized intelligent sensor systems We have developed a multi-SAW sensor system with this ASIC that manages the requirements on control as well as signal generation and storage and provides an interface to the PC and electronic devices on the board. Its low power consumption and its PCMCIA plug fulfil the requirements of small size and mobility. For this application sensors have been developed to detect hazardous gases in ambient air. Sensors with differently modified copper-phthalocyanine films are capable of detecting NO2 and O3, whereas those with a hyperbranched polyester film respond to NH3.

  15. Surface-acoustic-wave (SAW) flow sensor.

    PubMed

    Joshi, S G

    1991-01-01

    The use of a surface-acoustic-wave (SAW) device to measure the rate of gas flow is described. A SAW oscillator heated to a suitable temperature above ambient is placed in the path of a flowing gas. Convective cooling caused by the gas flow results in a change in the oscillator frequency. A 73-MHz oscillator fabricated on 128 degrees rotated Y-cut lithium niobate substrate and heated to 55 degrees C above ambient shows a frequency variation greater than 142 kHz for flow-rate variation from 0 to 1000 cm(3)/min. The output of the sensor can be calibrated to provide a measurement of volume flow rate, pressure differential across channel ports, or mass flow rate. High sensitivity, wide dynamic range, and direct digital output are among the attractive features of this sensor. Theoretical expressions for the sensitivity and response time of the sensor are derived. It is shown that by using ultrasonic Lamb waves, propagating in thin membranes, a flow sensor with faster response than a SAW sensor can be realized. PMID:18267569

  16. Sawing performance comparison of brazed and sintered diamond wires

    NASA Astrophysics Data System (ADS)

    Huang, Guoqin; Xu, Xipeng

    2013-03-01

    Great attention has been paid on fabricating diamond wire by using the brazing diamond because of its strong chemical bonding strength and controllability of grits distribution. Although several serving performances of brazed diamond wire have been reported, seldom do these studies refer to its process characteristics. Sawing performances of a brazed diamond wire are investigated and compared with those of a sintered diamond wire on a wire saw machine. The surface topographies of beads selected from the two wires are micro observed before sawing. The sawing tests are carried out in constant feed rate feeding(CFF) and constant normal force feeding(CNFF). In CFF test, sawing force, power, and the cut depths of positions on contact curve are measured. Then, coupled with the observations of beads topographies, sawing force and its ratio, relations of power against material removal rate, and contact curve linearity are compared and discussed. In CNFF test, the sawing rates of the two wires are investigated. The results indicate that the brazed wire performs with lower sawing force(less 16% of tangential force and 28% of normal force), more energy efficiency(nearly one-fifth of sawing power is saved), at a higher sawing rate (the rate is doubled) and with better contact curve linearity as compared with the sintered wire. This proposed research experimentally evaluates the sawing performances of brazed diamond wire from the aspect of process parameters, which can provide a basis for popularizing the brazed diamond wire.

  17. Controlling dust from concrete saw cutting.

    PubMed

    Shepherd, Susan; Woskie, Susan

    2013-01-01

    Cutting concrete with gas-powered saws is ubiquitous in the construction industry and a source of exposure to respirable crystalline silica. Volunteers from the New England Laborers Training Center were recruited to participate in a field experiment examining dust reductions through the use of water, from a hose and from a sprayer, as a dust control. In four series of tests, reinforced concrete pipe was cut under both "dry" and "wet" control conditions. Overall, the geometric mean respirable dust concentration for "dry" cutting (14.396 mg/m³) exceeded both types of water-based controls by more than tenfold. Wet cutting reduced the respirable dust concentration by 85% compared with dry cutting when comparing tests paired by person and saw blade (n = 79 pairs). Using a respirable cyclone, a total of 178 samples were taken. Due to the high variability in dust exposure found in this and other studies of saw cutting, the data were examined for potential exposure determinants that contribute to that variability. Using mixed models, three fixed effects were statistically significant: control condition, worker experience, and location. A random effect for subject was included in the model to account for repeated measures. When each of the significant fixed effects was included with the random effect, it was apparent that inclusion of worker experience or location reduced the between-worker component of exposure variability, while inclusion of control condition (wet vs. dry) explained a large portion of the within-subject variability. Overall, the fixed effect variable for control condition explained the largest fraction of the total exposure variability. PMID:23252479

  18. Noise reduction of a table saw

    NASA Astrophysics Data System (ADS)

    Carlson, John

    2002-05-01

    The National Institute for Occupational Safety and Health (NIOSH) is sponsoring a design project to address the noise levels that commonly exist at construction worksites. Through engineering control, the problem of noise emission from a table saw will be addressed. The noise emitting sources will be pinpointed using a sound pressure level meter. With this knowledge, the next step will be to reduce the sound pressure levels at the noise sources. This will be done by using noise reduction techniques such as insulation, and vibration dampening. The goal is to reduce the noise emission to a level between 85 and 90 dB(A).

  19. Thermal Imaging of Medical Saw Blades and Guides

    SciTech Connect

    Dinwiddie, Ralph Barton; Steffner, Thomas E

    2007-01-01

    Better Than New, LLC., has developed a surface treatment to reduce the friction and wear of orthopedic saw blades and guides. The medical saw blades were thermally imaged while sawing through fresh animal bone and an IR camera was used to measure the blade temperature as it exited the bone. The thermal performance of as-manufactured saw blades was compared to surface-treated blades, and a freshly used blade was used for temperature calibration purposes in order to account for any emissivity changes due to organic transfer layers. Thermal imaging indicates that the treated saw blades cut faster and cooler than untreated blades. In orthopedic surgery, saw guides are used to perfectly size the bone to accept a prosthesis. However, binding can occur between the blade and guide because of misalignment. This condition increases the saw blade temperature and may result in tissue damage. Both treated ad untreated saw guides were also studied. The treated saw guide operated at a significantly lower temperature than untreated guide. Saw blades and guides that operate at a cooler temperature are expected to reduce the amount of tissue damage (thermal necrosis) and may reduce the number of post-operative complications.

  20. Saw + LMJ: a hybrid semiconductor dicing solution

    NASA Astrophysics Data System (ADS)

    Richerzhagen, Bernold; Plankensteiner, Martin; Kling, Notker U.; Stay, Keith; Brulé, Arnaud

    2008-02-01

    The concept of combining the Laser MicroJet (R) (LMJ) water jet-guided laser with a standard industrial diamond blade saw was first proposed early in 2006. The idea has now been taken a step forward with a joint project between Synova SA and Disco Hi-Tech Europe GmbH. The hybrid machine being developed integrates an LMJ module in place of the second blade saw on a Disco dual-spindle machine. The resulting machine will be fully capable of sequencing the different processes to carry out dicing of complex and layered semiconductors wafer, in any possible combination. It will be possible to program both processes to run independently in parallel or allow sequential operation during the same cutting pass. This extraordinary flexibility, combined with the speed advantages, quality of material cutting and simplification in processing in a fully automatic mode for up to 300 mm wafers, all now available in a single machine, will greatly benefit the manufacturing community. This paper will provide some insight into the design and operation of the hybrid machine and some examples of the improvements gained from its use.

  1. Programmable SAW development :Sandia/NASA project final report.

    SciTech Connect

    Brocato, Robert Wesley

    2004-10-01

    This report describes a project to develop both fixed and programmable surface acoustic wave (SAW) correlators for use in a low power space communication network. This work was funded by NASA at Sandia National Laboratories for fiscal years 2004, 2003, and the final part of 2002. The role of Sandia was to develop the SAW correlator component, although additional work pertaining to use of the component in a system and system optimization was also done at Sandia. The potential of SAW correlator-based communication systems, the design and fabrication of SAW correlators, and general system utilization of those correlators are discussed here.

  2. Building SAWE Capability as an ANSI Accredited Standards Developer

    NASA Technical Reports Server (NTRS)

    Cerro, Jeffrey A.; Davis, Ed; Peterson, Eric; Griffiths, William T.; Brooks, Andy; Stratton, Bonnie; Attar, Jose

    2014-01-01

    This paper presents a 2014 status of the Society of Allied Weight Engineers' process towards becoming an Accredited Standards Developer (ASD) under certification by the United States American National Standards Institute (ANSI). Included is material from the committee's 2013 International presentation, current status, and additional general background material. The document strives to serve as a reference point to assist SAWE Recommended Practice and Standards developers in negotiating United States Standards Strategy, international standards strategy, and the association of SAWE standards and recommended practices to those efforts. Required procedures for SAWE to develop and maintain Recommended Practices and ANSI/SAWE Standards are reviewed.

  3. A monolithic SAW-charge transfer device

    NASA Technical Reports Server (NTRS)

    Papanicolaou, N. A.; Lin, H. C.

    1978-01-01

    Surface acoustic waves excited in a Si-SiO2-ZnO layered structure can produce a traveling electric field in the silicon substrate. Charges stored in the traveling potential wells can be transferred at high speed and density and with less complexity. The monolithic structure under investigation for the SAW-charge transfer device consists of a silicon substrate, a thin silicon dioxide insulating layer on top of which a ZnO piezoelectric film is deposited by sputtering. The surface acoustic waves are excited by interdigital transducers. The signal charge is injected into traveling potential wells that travel with the velocity of sound. Conditions for the transfer of the charges by the traveling wells are analyzed. A surface acoustic wave program was used to determine the optimum structure dimensions and transducer configuration which will produce the highest coupling in the excitation of the piezoelectric waves.

  4. Current developments in SAW oscillator stability

    NASA Technical Reports Server (NTRS)

    Parker, T. E.

    1977-01-01

    The results reported were obtained with two port delay lines and resonators used in a simple feedback oscillator. The feedback oscillator employed inherently operates with the amplifier in a saturated condition and, therefore, the AM noise is suppressed. Consequently the dominant noise is FM. Generally, it can be concluded that for very narrow-band, or fixed-frequency applications, the resonator-type oscillator will give the best noise performance. For applications where tunability and linearity are important, the delay-line-type oscillator may give the best performance. There have been no significant improvements in oscillator temperature stability. The only two demonstrated materials for temperature stable SAW oscillators are ST-cut quartz and the SiO2/LiTaO3 overlay structure. Aging tests have been going on for the past two-and-a-half years and it has become obvious that the observed aging rates are largely related to cleaning and packaging.

  5. Recycling SAW slag proves reliable and repeatable

    SciTech Connect

    Beck, H.P.; Jackson, A.R.

    1996-06-01

    Submerged arc welding (SAW) slag is recycled by taking the fused part of the slag after welding and processing it in a manner that allows it to be reused for the same SAW operation. This slag recycling process has been around the welding industry for many years, and trial-and-error experimentation through the years has made it a reliable and accepted process. Two major reasons why a welding manufacturer would consider the use of recycled submerged arc welding slag are cost savings and the environment. The cost of processing recycled slag is less than the purchase of new flux from the manufacturer. Many times this can amount to savings of 50% or greater. Savings can also be realized by eliminating the need to collect the slag and have it removed to an approved landfill. Environmentally, recycling slag minimizes the use of nonrenewable resources such as minerals, and it reduces the mass of material that must be sent to a landfill. It should be noted, though, that in most recycling processes there is some loss in weight, and not all the slag is processed into reusable flux. Also, there is magnetic separation during processing in which magnetic impurities are removed and disposed of as waste. An average for this loss is 25% of the total weight processed. To realize all of the advantages of recycling, it is essential that the process is performed properly and according to the standards established by industry. Below are steps required for recycling slag as established by two standards setting organizations.

  6. Table saw injuries: epidemiology and a proposal for preventive measures

    PubMed Central

    Chung, Kevin C.; Shauver, Melissa J.

    2014-01-01

    Background Table saws are ubiquitous equipment in professional, home, and school woodshops that have the potential to cause severe injuries. Many of these injuries results in finger and thumb tendon, nerve, and vascular damage or amputation. Long-term outcomes of these injuries can include functional and sensory deficits. Table saw manufacturers are required to equip saws with blade guards to prevent blade contact, but despite these measures, table saw injuries are a common occurrence in US emergency departments. Methods We performed a literature search using PubMed and the Cumulative Index to Nursing and Allied Health Literature to compile epidemiology data relevant to table saw injuries. We also reviewed the US Consumer Product Safety Commission’s briefing package on table saw blade contact injuries. Results Over 30,000 table saw injuries occur annually. Fingers and hands are the most frequently injured body part and lacerations are the most common injury. Individuals suffering from occupational injuries tend to be younger than those injured during amateur woodworking. A small, but important minority of injuries are to students participating in school shop classes. Medical costs for the treatment of table saw injuries are estimated at more than $2 billion every year. Conclusions SawStop technology stops the saw blade when contact with skin is made, resulting in a small cut, rather than a more complicated laceration or amputation. The application of this novel technology in saw designs can prevent serious injuries that deleteriously affect lives at the personal and societal levels. Level of Evidence III PMID:24165629

  7. Impact of gin saw tooth design on textile processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toothed gin saws have been used to separate cotton fiber from the seed for over 200 years. There have been many saw tooth designs developed over the years. Most of these designs were developed by trial and error. A complete and scientific analysis of tooth design has never been done. It is not k...

  8. Spirit at Work (SAW): fostering a healthy RN workplace.

    PubMed

    Wagner, Joan I J; Gregory, David M

    2015-02-01

    A cross-sectional mixed-method survey explored and measured relationships between spirit at work (SAW) concepts, experience, education, practice context, job satisfaction, and organizational commitment using LISREL 8.80 and 2012 survey data from a random sample of 217 surgical and 158 home care registered nurses (RNs) in western Canada. Qualitative data underwent content analysis using a priori coding categories based on established theory. Final model indices fit the observed data. SAW concepts of engaging work and mystical experience accounted for moderate to large amounts of model variance for both home care and surgical nurses, while significant positive relationships between SAW concepts, job satisfaction, and organizational commitment were also reported. Researchers concluded that SAW contributes to improved job satisfaction and organizational commitment while being sensitive to RN experiences across clinical contexts. As an holistic measure of RN workplace perceptions, SAW contributes essential information directed at creating optimal environments for both health care providers and recipients. PMID:24510970

  9. Preliminary experiments on SAW based magnetization switching of nanomagnets

    NASA Astrophysics Data System (ADS)

    Sampath, Vimal; D'Souza, Noel; Bandyopadhyay, Supriyo; Atulasimha, Jayasimha

    2015-03-01

    Magnetization rotation in micron-sized ferromagnetic elements, using Surface Acoustic Waves (SAW), has been demonstrated experimentally while the use of SAW to lower the energy dissipation in switching of nanomagnets with spin transfer torque has been studied theoretically. Furthermore, SAW can be used to ``Bennett clock'' an array of nanomagnets in nanomagnetic logic without requiring lithographic contacts to individual nanomagnets. We report preliminary experiments on use of SAW to switch magnetostrictive Co nanomagnets grown on bulk 128 Y-cut lithium niobate. Switching is studied by imaging the nanomagnets' magnetic states with Magnetic Force Microscopy (MFM) before and after the SAW waves interact with them. Switching of single, isolated nanomagnets of various sizes, and dipole coupled nanomagnets implementing a Boolean NOT gate, is studied. This work is supported by the US National Science Foundation under the SHF-Small Grant CCF-1216614, CAREER Grant CCF-1253370, NEB 2020 Grant ECCS-1124714 and SRC under NRI Task 2203.001.

  10. New developments for SAW channelization for mobile satellite payloads

    NASA Technical Reports Server (NTRS)

    Peach, R. C.; Mabson, P.

    1995-01-01

    The use of SAW technology in mobile communication payloads is becoming widely accepted by the industry since being pioneered by Inmarsat for its third generation of satellites. This paper presents new developments in this area, including broadband processors of the Inmarsat 3 type, and the use of SAW filters at L-band. It is demonstrated that SAW processors have considerable potential for increasing the capacity of future communications payloads, while allowing fully transparent operation without any restriction on traffic type or modulation format. In addition to the evolutionary development of Inmarsat type processors, new SAW applications have also emerged recently. Therefore, despite the rapid changes in the industry, it is predicted that SAW processing has a strong future in satellite communications.

  11. Fatty acid and phytosterol content of commercial saw palmetto supplements.

    PubMed

    Penugonda, Kavitha; Lindshield, Brian L

    2013-09-01

    Saw palmetto supplements are one of the most commonly consumed supplements by men with prostate cancer and/or benign prostatic hyperplasia (BPH). Some studies have found significant improvements in BPH and lower urinary tract symptoms (LUTS) with saw palmetto supplementation, whereas others found no benefits. The variation in the efficacy in these trials may be a result of differences in the putative active components, fatty acids and phytosterols, of the saw palmetto supplements. To this end, we quantified the major fatty acids (laurate, myristate, palmitate, stearate, oleate, linoleate) and phytosterols (campesterol, stigmasterol, β-sitosterol) in 20 commercially available saw palmetto supplements using GC-FID and GC-MS, respectively. Samples were classified into liquids, powders, dried berries, and tinctures. Liquid saw palmetto supplements contained significantly higher (p < 0.05) concentrations of total fatty acids (908.5 mg/g), individual fatty acids, total phytosterols (2.04 mg/g), and individual phytosterols, than the other supplement categories. Powders contained significantly higher (p < 0.05) concentrations of total fatty acids than tinctures, which contain negligible amounts of fatty acids (46.3 mg/g) and phytosterols (0.10 mg/g). Our findings suggest that liquid saw palmetto supplements may be the best choice for individuals who want to take a saw palmetto supplement with the highest concentrations of both fatty acids and phytosterols. PMID:24067389

  12. Analyzing the installation angle error of a SAW torque sensor

    NASA Astrophysics Data System (ADS)

    Fan, Yanping; Ji, Xiaojun; Cai, Ping

    2014-09-01

    When a torque is applied to a shaft, normal strain oriented at 45 direction to the shaft axis is at its maximum, which requires two one-port SAW resonators to be bonded to the shaft at 45 to the shaft axis. In order to make the SAW torque sensitivity high enough, the installation angle error of two SAW resonators must be confined within 5 according to our design requirement. However, there are few studies devoted to the installation angle analysis of a SAW torque sensor presently and the angle error was usually obtained by a manual method. Hence, we propose an approximation method to analyze the angle error. First, according to the sensitive mechanism of the SAW device to torque, the SAW torque sensitivity is deduced based on the linear piezoelectric constitutive equation and the perturbation theory. Then, when a torque is applied to the tested shaft, the stress condition of two SAW resonators mounted with an angle deviating from 45 to the shaft axis, is analyzed. The angle error is obtained by means of the torque sensitivities of two orthogonal SAW resonators. Finally, the torque measurement system is constructed and the loading and unloading experiments are performed twice. The torque sensitivities of two SAW resonators are obtained by applying average and least square method to the experimental results. Based on the derived angle error estimation function, the angle error is estimated about 3.447, which is close to the actual angle error 2.915. The difference between the estimated angle and the actual angle is discussed. The validity of the proposed angle error analysis method is testified to by the experimental results.

  13. Predictive force model for haptic feedback in bone sawing.

    PubMed

    James, Thomas P; Pearlman, John J; Saigal, Anil

    2013-11-01

    Bone sawing simulators with force feedback represent a cost effective means of training orthopedic surgeons in various surgical procedures, such as total knee arthroplasty. To develop a machine with accurate haptic feedback, giving a sensation of both cutting force and rate of material removal, algorithms are required to forecast bone sawing forces based on user input. Presently, studies on forces generated while machining bone are not representative of the high cutting speeds and low depths of cut common to the bone sawing process. The objective of this research was to quantify sawing forces in cortical bone as a function of blade speed and depth of cut. A fixture was developed to simulate linear bone sawing over a range of speeds comparable to surgical reciprocating and oscillating (sagittal) bone saws. A single saw blade tooth was isolated and used to create a slotted cut in bovine cortical bone. Over a range in linear sawing speed from 1700 to 7000 mm/s, a t-test (α=0.05) revealed there was no statistically significant effect of blade speed on either cutting or thrust force. However, an increase in depth of cut from 2 to 10 μm resulted in a 30% increase in thrust force, while cutting force remained constant. The increase in thrust force with depth of cut was relatively linear, R(2)=0.80. Using a two factor, two level design of experiments approach, regression equations were developed to relate sawing forces to changes in blade speed and depth of cut. These equations can be used to predict forces in a haptic feedback model. PMID:23806417

  14. ISS Asset Tracking Using SAW RFID Technology

    NASA Technical Reports Server (NTRS)

    Schellhase, Amy; Powers, Annie

    2004-01-01

    A team at the NASA Johnson Space Center (JSC) is undergoing final preparations to test Surface Acoustic Wave (SAW) Radio Frequency Identification (RFID) technology to track assets aboard the International Space Station (ISS). Currently, almost 10,000 U.S. items onboard the ISS are tracked within a database maintained by both the JSC ground teams and crew onboard the ISS. This barcode-based inventory management system has successfully tracked the location of 97% of the items onboard, but its accuracy is dependant on the crew to report hardware movements, taking valuable time away from science and other activities. With the addition of future modules, the volume of inventory to be tracked is expected to increase significantly. The first test of RFID technology on ISS, which will be conducted by the Expedition 16 crew later this year, will evaluate the ability of RFID technology to track consumable items. These consumables, which include office supplies and clothing, are regularly supplied to ISS and can be tagged on the ground. Automation will eliminate line-of-sight auditing requirements, directly saving crew time. This first step in automating an inventory tracking system will pave the way for future uses of RFID for inventory tracking in space. Not only are there immediate benefits for ISS applications, it is a crucial step to ensure efficient logistics support for future vehicles and exploration missions where resupplies are not readily available. Following a successful initial test, the team plans to execute additional tests for new technology, expanded operations concepts, and increased automation.

  15. Multi-electrodes in SAW with square wave ac power

    SciTech Connect

    Bunker, T.A.

    1982-07-01

    Examines the feasibility of using AC square wave power for multi-electrode submerged arc welding (SAW) by arranging 2 power sources for weld test using two-electrode submerged arc welding. Presents figures showing phase relationship between lead arc current and trail arc current for Scott connected multi-electrode SAW, and arc deflection vs. electrical degrees. Suggests that Scott connection is preferred because it balances the primary line draw. Concludes that the multielectrode submerged arc process with constant potential square wave power increases travel speed and deposition rates which can be added to the economies obtained from a narrow groove joint configuration and the SAW process.

  16. [A reciprocating saw for micro-surgery (author's transl)].

    PubMed

    Feldmann, H

    1977-09-01

    A reciprocating saw for osteoplastic microsurgery of the ear is presented. An electromagnetic oscillator of a common electric razor, used as motor, drives the saw with 100 oscillations per second. The amplitude of the vibrations can be adjusted by a special device within the range of 0.5 to 3 mm. The saw blades are 0.2 mm thick and not set. They perform very smooth straight cuts of 0.2 to 0.3 mm width and can easily be applied in the narrow operative field of the middle ear. PMID:143575

  17. High-reliability SAW bandpass filters for space applications.

    PubMed

    Hickernell, F S

    1988-01-01

    High-reliability surface-acoustic-wave (SAW) bandpass filters have been developed for use in transponders for more than 25 earth-orbital and deep-space satellite programs. SAW filters have been incorporated in several NASA standard TTandC transponders and NASA standard tracking and data relay satellite system (TDRSS) user transponders. The author gives examples of the electrical performance, summarizes the manufacturing processes, and discusses qualification testing for these SAW devices. He identifies reliability problems encountered and their solutions. PMID:18290200

  18. Imprinted laminate wafer-level packaging for SAW ID-tags and SAW delay line sensors.

    PubMed

    Kuypers, Jan H; Tanaka, Shuji; Esashi, Masayoshi

    2011-02-01

    We have developed a wafer-level packaging solution for surface acoustic wave devices using imprinted dry film resist (DFR). The packaging process involves the preparation of an imprinted dry film resist that is aligned and laminated to the device wafer and requires one additional lithography step to define the package outline. Two commercial dry film solutions, SU-8 and TMMF, have been evaluated. Compared with traditional ceramic packages, no detectable RF parasitics are introduced by this packaging process. At the same time, the miniature package dimensions allow for wafer-level probing. The packaging process has the great advantage that the cavity formation does not require any sacrificial layer and no liquids, and therefore prevents contamination or stiction of the packaged device. This non-hermetic packaging process is ideal for passive antenna modules using polymer technology for low-cost SAW identification (ID)-tags or lidding in low-temperature cofired ceramic (LTCC) antenna substrates for high-performance wireless sensors. This technique is also applicable to SAW filters and duplexers for module integration in cellular phones using flip-chip mounting and hermetic overcoating. PMID:21342826

  19. Anti-slipping system improves wire saw performance

    NASA Technical Reports Server (NTRS)

    Gallo, E. A.

    1971-01-01

    System prevents wire saw slippage by providing sufficient friction to turn idler spools even when turns of wire on spools do not provide sufficient friction. Low cost system is easily applied to existing equipment.

  20. Northern view of inside diameter welding station of the saw ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Northern view of inside diameter welding station of the saw line in bay9 of the main pipe mill building. - U.S. Steel National Tube Works, Main Pipe Mill Building, Along Monongahela River, McKeesport, Allegheny County, PA

  1. 12. Interior view showing main section, mezzanine and saw tooth ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Interior view showing main section, mezzanine and saw tooth truss roof with skylight, looking west. - College Heights Lemon Packing House, 519-532 West First Street, Claremont, Los Angeles County, CA

  2. 5. View of north elevation, including saw dust collector and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View of north elevation, including saw dust collector and brick addition, looking south east. - General Dynamics Corporation Shipyard, Joiner & Sheet Metal Shops, 97 East Howard Street, Quincy, Norfolk County, MA

  3. 19. William E. Barrett, Photographer, August 1975. LOWER BAND SAW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. William E. Barrett, Photographer, August 1975. LOWER BAND SAW PULLEYS OF RIGHT-HAND MILL. DRIVE PULLEY IN BELOW TENSION PULLEY. - Meadow River Lumber Company, Highway 60, Rainelle, Greenbrier County, WV

  4. 21. William E. Barrett, Photographer, August 1975. EDGER SAWS FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. William E. Barrett, Photographer, August 1975. EDGER SAWS FOR RIPPING BOARD TO VARIOUS WIDTHS. BLADES VISIBLE BEHIND ROLLERS. - Meadow River Lumber Company, Highway 60, Rainelle, Greenbrier County, WV

  5. See-saw nystagmus and brainstem infarction: MRI findings

    NASA Technical Reports Server (NTRS)

    Kanter, D. S.; Ruff, R. L.; Leigh, R. J.; Modic, M.

    1987-01-01

    A patient with see-saw nystagmus had a lesion localized by Magnetic Resonance Imaging (MRI) to the paramedian ventral midbrain with involvement of the right interstitial nucleus of Cajal. This the first MRI study of see-saw nystagmus associated with a presumed brainstem vascular event. Our findings support animal and human studies suggesting that dysfunction of the interstitial nucleus of Cajal or its connections is central in this disorder.

  6. Effect of critical dimension variation on SAW correlator energy.

    SciTech Connect

    Skinner, Jack L.

    2005-04-01

    The effect of critical dimension (CD) variation and metallization ratio on the efficiency of energy conversion of a surface acoustic wave (SAW) correlator is examined. We find that a 10% variation in the width of finger electrodes predicts only a 1% decrease in the efficiency of energy conversion. Furthermore, our model predicts that a metallization ratio of 0.74 represents an optimum value for energy extraction from the SAW by the interdigitated transducer (IDT).

  7. Effect of critical dimension variation on SAW correlator energy.

    PubMed

    Skinner, J L; Cardinale, G F; Talin, A A; Brocato, R W

    2006-02-01

    The effect of critical dimension (CD) variation and metallization ratio on the efficiency of energy conversion of a surface acoustic wave (SAW) correlator is examined. We find that a 10% variation in the width of finger electrodes predicts only a 1% decrease in the efficiency of energy conversion. Furthermore, our model predicts that a metallization ratio of 0.74 represents an optimum value for energy extraction from the SAW by the interdigitated transducer (IDT). PMID:16529126

  8. Notes on SAW Tag Interrogation Techniques

    NASA Technical Reports Server (NTRS)

    Barton, Richard J.

    2010-01-01

    We consider the problem of interrogating a single SAW RFID tag with a known ID and known range in the presence of multiple interfering tags under the following assumptions: (1) The RF propagation environment is well approximated as a simple delay channel with geometric power-decay constant alpha >/= 2. (2) The interfering tag IDs are unknown but well approximated as independent, identically distributed random samples from a probability distribution of tag ID waveforms with known second-order properties, and the tag of interest is drawn independently from the same distribution. (3) The ranges of the interfering tags are unknown but well approximated as independent, identically distributed realizations of a random variable rho with a known probability distribution f(sub rho) , and the tag ranges are independent of the tag ID waveforms. In particular, we model the tag waveforms as random impulse responses from a wide-sense-stationary, uncorrelated-scattering (WSSUS) fading channel with known bandwidth and scattering function. A brief discussion of the properties of such channels and the notation used to describe them in this document is given in the Appendix. Under these assumptions, we derive the expression for the output signal-to-noise ratio (SNR) for an arbitrary combination of transmitted interrogation signal and linear receiver filter. Based on this expression, we derive the optimal interrogator configuration (i.e., transmitted signal/receiver filter combination) in the two extreme noise/interference regimes, i.e., noise-limited and interference-limited, under the additional assumption that the coherence bandwidth of the tags is much smaller than the total tag bandwidth. Finally, we evaluate the performance of both optimal interrogators over a broad range of operating scenarios using both numerical simulation based on the assumed model and Monte Carlo simulation based on a small sample of measured tag waveforms. The performance evaluation results not only provide guidelines for proper interrogator design, but also provide some insight on the validity of the assumed signal model. It should be noted that the assumption that the impulse response of the tag of interest is known precisely implies that the temperature and range of the tag are also known precisely, which is generally not the case in practice. However, analyzing interrogator performance under this simplifying assumption is much more straightforward and still provides a great deal of insight into the nature of the problem.

  9. Diamond Wire Saw for Precision Machining of Laser Target Components

    SciTech Connect

    Bono, M J; Bennett, D W

    2005-08-08

    The fabrication of precision laser targets requires a wide variety of specialized mesoscale manufacturing techniques. The diamond wire saw developed in this study provides the capability to precisely section meso-scale workpieces mounted on the assembly stations used by the Target Fabrication Group. This new capability greatly simplifies the fabrication of many types of targets and reduces the time and cost required to build the targets. A variety of materials are used to fabricate targets, including metals, plastics with custom designed chemical formulas, and aerogels of various densities. The materials are usually provided in the form of small pieces or cast rods that must be machined to the required shape. Many of these materials, such as metals and some plastics, can be trimmed using a parting tool on a diamond turning machine. However, other materials, such as aerogels and brittle materials, cannot be adequately cut with a parting tool. In addition, the geometry of the parts often requires that the workpieces be held in a special assembly station, which excludes the use of a parting tool. In the past, these materials were sectioned using a small, handheld coping saw that used a diamond-impregnated wire as a blade. This miniature coping saw was effective, but it required several hours to cut through certain materials. Furthermore, the saw was guided by hand and often caused significant damage to fragile aerogels. To solve these problems, the diamond wire saw shown in Figure 1 was developed. The diamond wire saw is designed to machine through materials that are mounted in the Target Fabrication Group's benchtop assembly stations. These assembly stations are the primary means of aligning and assembling target components, and there is often a need to machine materials while they are mounted in the assembly stations. Unfortunately, commercially available saws are designed for very different applications and are far too large to be used with the assembly stations. Therefore, a custom diamond wire saw was designed and constructed. The diamond wire saw cuts through workpieces using a continuous loop of diamond-impregnated wire of length 840 mm. The wire loop runs around several idler pulleys and is driven by a simple geared DC motor that rotates at 17 rpm. The linear speed of the wire is 107 inches/minute. The saw is oriented at an angle of 20{sup o} from horizontal, so the operator can view the wire through the cutout at the front end of the saw. When looking through a microscope or camera with a horizontal line of sight, the operator can clearly see the wire as it cuts through the workpiece, as shown in the right side of Figure 1. The saw is mounted on a two-axis stage that allows the operator to align the wire with the workpiece. To cut through the workpiece, the operator drives the wire through the workpiece by turning the feed micrometer. An image of the interior of the diamond wire saw appears in Figure 2. This picture was taken after removing the protective cover plate from the saw.

  10. Tip stabilizer for a chain saw. Final report

    SciTech Connect

    Morabit, V.D.

    1993-09-10

    Prior to receiving the grant, Utilitip was faced with an idea that truly worked, however only a very limited line of component parts would fit various types of chain saws on the market. It also suffered from a severe problem when engaged in the ground of soil penetrating the saw chain area, thus eliminating one of the major benefits of keeping the chain sharp. Consequently, the grant funding was directed towards extending the tooling capabilities to produce parts for a much wider variety of chain saws that are on the market, and further by developing an effective flexible soil shield to prevent abrasive soil entry into the saw chain. Utilitip was able to complete a full set of design for a wide variety of large and small chain saws. This incorporated a design and fabrication of a small Utilitip, as well as a small anti-kickback device. In addition, tooling was also further developed for the large Utilitip and the large anti-kickback device. Accordingly, multiple tools are available for all combinations, as well as back-up provisions. Utilitip, Inc. invented a special, flexible attachment to be glued and/or molded to the tip guard. The soil shield prevents abrasive soil from coming into the chain area. In addition, it allows a flexible arrangement to allow the chain saw to be released from brush without binding. Otherwise, a larger, rigid soil shield would hold or restrict the saw in heavy brush. The rubber shield will flex out of the say and reduce, if not eliminate, this harmful binding.

  11. Effects of layer thickness for SAW, PSAW, and HVPSAW devices.

    PubMed

    da Cunha, M P

    2001-01-01

    Considerable efforts in recent SAW device design and development have been aimed at obtaining high frequency, low loss, and high performance. A large number of applications relate to cellular and mobile telephony, pagers, local area networks, cordless phones, global positioning systems (GPS), and security systems. Pseudo-SAW (PSAW) and high velocity PSAW (HVPSAW) have received great attention because of their high phase velocities and, therefore, the high frequencies of operation that these modes provide. In addition to high phase velocities, the pseudomodes must also present low propagation losses and considerably high electromechanical coupling coefficients to be considered for surface acoustic wave (SAW) devices. This paper verifies that the metallic layer thickness is a relevant SAW device parameter, which must be considered to achieve lower losses for high frequency, low loss SAW devices. Popular PSAW and HVPSAW material orientations, such as 64 degrees YX LiNbO3 (0 degree -26 degrees 0 degree), 36 degrees YX LiTaO3 (0 degree -54 degrees 0 degree), LiNbO3 (90 degrees 90 degrees 36 degrees), LiTaO3 (90 degrees 90 degrees 31 degrees), and Li2B4O7 (0 degree 47.3 degrees 90 degrees), are considered as examples. In addition to the reduced loss analysis and the dispersion analysis for the pseudo modes, the present work discusses the transitions with respect to the layer thickness from the PSAWs and HVPSAWs to the generalized SAWs (GSAWs) and Rayleigh (sagittal particle motion) modes. In addition to contributing to the knowledge of the pseudomodes behavior with layer thickness, this mode transition analysis enlightens the situation in which the losses in the pseudo modes go to zero because of the merging of the pseudo modes into the SAWs (GSAWs and Rayleigh). The fact that the SAWs are a continuation as a function of thickness for the pseudo modes may be conveniently used in the fabrication of low loss devices. In addition, the effects of heavy layer metals, such as gold, in reducing the layer thickness at which the pseudo modes merge to the SAWs are discussed. Numerical results are compared with experimental data available in the literature, and the present analysis elucidates experimentally observed higher order pseudo modes and values of layer thickness for which lower losses are achieved. PMID:11367811

  12. Study of the acoustoelectric effect for SAW sensors.

    PubMed

    Fisher, Brian H; Malocha, Donald C

    2010-03-01

    Research has recently begun on the use of ultrathin films and nanoclusters as mechanisms for sensing of gases, liquids, etc., because the basic material parameters may change because of film morphology. As films of various materials are applied to the surface of SAW devices for sensors, the conductivity of the films may have a strong acoustoelectric effect, whether desired or not. The purpose of this paper is to reexamine the theory and predictions of the acoustoelectric effect for SAW interactions with thin conducting or semi-conducting films. The paper will summarize the theory and predict the effects of thin film conductivity on SAW velocity and propagation loss versus frequency and substrate material. The theory predicts regions of conductivity which result in extremely high propagation loss, and which also correspond to the mid-point between the open and short-circuit velocities. As an example of the verification and possible usefulness of the acoustoelectric effect, recent experimental results of palladium (Pd) thin films on a YZ LiNbO3 SAW delay line have shown large changes in propagation loss, depending on the Pd film thickness, exposure to hydrogen gas, or both. By proper design, a sensitive hydrogen leak detector SAW sensor can be designed. PMID:20211790

  13. High-Temperature SAW Wireless Strain Sensor with Langasite

    PubMed Central

    Shu, Lin; Peng, Bin; Yang, Zhengbing; Wang, Rui; Deng, Senyang; Liu, Xingzhao

    2015-01-01

    Two Surface acoustic wave (SAW) resonators were fabricated on langasite substrates with Euler angle of (0°, 138.5°, 117°) and (0°, 138.5°, 27°). A dipole antenna was bonded to the prepared SAW resonator to form a wireless sensor. The characteristics of the SAW sensors were measured by wireless frequency domain interrogation methods from 20 °C to 600 °C. Different temperature behaviors of the sensors were observed. Strain sensing was achieved using a cantilever configuration. The sensors were measured under applied strain from 20 °C to 500 °C. The shift of the resonance frequency contributed merely by strain is extracted from the combined effects of temperature and strain. Both the strain factors of the two SAW sensors increase with rising ambient temperature, and the SAW sensor deposited on (0°, 138.5°, 117°) cut is more sensitive to applied strain. The measurement errors of the two sensors are also discussed. The relative errors of the two sensors are between 0.63% and 2.09%. Even at 500 °C, the hysteresis errors of the two sensors are less than 5%. PMID:26569255

  14. High-Temperature SAW Wireless Strain Sensor with Langasite.

    PubMed

    Shu, Lin; Peng, Bin; Yang, Zhengbing; Wang, Rui; Deng, Senyang; Liu, Xingzhao

    2015-01-01

    Two Surface acoustic wave (SAW) resonators were fabricated on langasite substrates with Euler angle of (0°, 138.5°, 117°) and (0°, 138.5°, 27°). A dipole antenna was bonded to the prepared SAW resonator to form a wireless sensor. The characteristics of the SAW sensors were measured by wireless frequency domain interrogation methods from 20 °C to 600 °C. Different temperature behaviors of the sensors were observed. Strain sensing was achieved using a cantilever configuration. The sensors were measured under applied strain from 20 °C to 500 °C. The shift of the resonance frequency contributed merely by strain is extracted from the combined effects of temperature and strain. Both the strain factors of the two SAW sensors increase with rising ambient temperature, and the SAW sensor deposited on (0°, 138.5°, 117°) cut is more sensitive to applied strain. The measurement errors of the two sensors are also discussed. The relative errors of the two sensors are between 0.63% and 2.09%. Even at 500 °C, the hysteresis errors of the two sensors are less than 5%. PMID:26569255

  15. A high sensitivity nanomaterial based SAW humidity sensor

    NASA Astrophysics Data System (ADS)

    Wu, Tsung-Tsong; Chen, Yung-Yu; Chou, Tai-Hsu

    2008-04-01

    In this paper, a highly sensitive humidity sensor is reported. The humidity sensor is configured by a 128YX-LiNbO3 based surface acoustic wave (SAW) resonator whose operating frequency is at 145 MHz. A dual delay line configuration is realized to eliminate external temperature fluctuations. Moreover, for nanostructured materials possessing high surface-to-volume ratio, large penetration depth and fast charge diffusion rate, camphor sulfonic acid doped polyaniline (PANI) nanofibres are synthesized by the interfacial polymerization method and further deposited on the SAW resonator as selective coating to enhance sensitivity. The humidity sensor is used to measure various relative humidities in the range 5-90% at room temperature. Results show that the PANI nanofibre based SAW humidity sensor exhibits excellent sensitivity and short-term repeatability.

  16. Effect of lubricant environment on saw damage in silicon wafers

    NASA Technical Reports Server (NTRS)

    Kuan, T. S.; Shih, K. K.; Vanvechten, J. A.; Westdorp, W. A.

    1982-01-01

    The chemomechanical effect of lubricant environments on the inner diameter (ID) sawing induced surface damage in Si wafers was tested for four different lubricants: water, dielectric oil, and two commercial cutting solutions. The effects of applying different potential on Si crystals during the sawing were also tested. It is indicated that the number and depth of surface damage are sensitive to the chemical nature of the saw lubricant. It is determined that the lubricants that are good catalysts for breaking Si bonds can dampen the out of plane blade vibration more effectively and produce less surface damage. Correlations between the applied potential and the depth of damage in the dielectric oil and one of the commercial cutting solutions and possible mechanisms involved are discussed.

  17. SAW convolvers using the transverse-horizontal bilinear field

    NASA Astrophysics Data System (ADS)

    Monks, T.; Paige, E. G. S.; Woods, R. C.

    1983-06-01

    The surface-acoustic-wave (SAW) convolver provides a means of achieving high time-bandwidth, programmable signal processing. The operation of most SAW convolver designs has been based on the detection of an electric-polarization field normal to the crystal surface. The field arises from the mixing of two counter-propagating surface-acoustic waves. The present investigation is concerned with a new type of convolver which is based on the detection of the bilinear electric polarization parallel to the crystal surface and to the input wave-front. The new device is called a transverse-horizontal convolver (THC). A new electrode arrangement is needed to detect the polarization.

  18. A surface acoustic wave /SAW/ charge transfer imager

    NASA Technical Reports Server (NTRS)

    Papanicolauo, N. A.; Lin, H. C.

    1981-01-01

    An 80 MHz, 2-microsecond surface acoustic wave charge transfer device (SAW-CTD) has been fabricated in which surface acoustic waves are used to create traveling longitudinal electric fields in the silicon substrate and to replace the multiphase clocks of charge coupled devices. The traveling electric fields create potential wells which will carry along charges that may be stored in the wells; the charges may be injected into the wells by light. An optical application is proposed where the SAW-CTD structure is used in place of a conventional interline transfer design.

  19. SAW chemical sensor arrays using new thin-film materials

    SciTech Connect

    Ricco, A.J.; Xu, Chuanjing; Crooks, R.M.; Allred, R.E.

    1994-05-01

    We have used two classes of materials, self-assembled monolayers (SAMs) and plasma-grafted films (PGFs), as new chemically sensitive layers for an array of 97-MHz surface acoustic wave (SAW) delay-line-based devices. Responses of these materials to each of 14 different analytes, representing the classes of saturated alkane, aromatic hydrocarbon, chlorinated hydrocarbon, alcohol, ketone, organophosphonate, and water, have been evaluated using our six-SAW device array. Results reveal a qualitative ``chemical orthogonality`` of the films that is very promising for pattern recognition analysis.

  20. Development of SH-SAW sensors for underwater measurement.

    PubMed

    Kwon, Y; Roh, Y

    2004-04-01

    We developed SH (shear horizontal) surface acoustic wave (SAW) sensors to detect protein molecules in liquid solutions applying a particular antibody thin film on the delay line of transverse SAW devices. The antibody investigated was human-immuno-globulin G (HigG) to hold the antigens (anti-HigG) in the protein solution to be measured. The sensor showed stable response to the mass loading effects of the anti-HigG molecules with the sensitivity up to 10.8 ng/ml/Hz. PMID:15047320

  1. Robust Design of SAW Gas Sensors by Taguchi Dynamic Method.

    PubMed

    Tsai, Hsun-Heng; Wu, Der Ho; Chiang, Ting-Lung; Chen, Hsin Hua

    2009-01-01

    This paper adopts Taguchi's signal-to-noise ratio analysis to optimize the dynamic characteristics of a SAW gas sensor system whose output response is linearly related to the input signal. The goal of the present dynamic characteristics study is to increase the sensitivity of the measurement system while simultaneously reducing its variability. A time- and cost-efficient finite element analysis method is utilized to investigate the effects of the deposited mass upon the resonant frequency output of the SAW biosensor. The results show that the proposed methodology not only reduces the design cost but also promotes the performance of the sensors. PMID:22573961

  2. A novel wireless and temperature-compensated SAW vibration sensor.

    PubMed

    Wang, Wen; Xue, Xufeng; Huang, Yangqing; Liu, Xinlu

    2014-01-01

    A novel wireless and passive surface acoustic wave (SAW) based temperature-compensated vibration sensor utilizing a flexible Y-cut quartz cantilever beam with a relatively substantial proof mass and two one-port resonators is developed. One resonator acts as the sensing device adjacent to the clamped end for maximum strain sensitivity, and the other one is used as the reference located on clamped end for temperature compensation for vibration sensor through the differential approach. Vibration directed to the proof mass flex the cantilever, inducing relative changes in the acoustic propagation characteristics of the SAW travelling along the sensing device, and generated output signal varies in frequency as a function of vibration.  A theoretical mode using the Rayleigh method was established to determine the optimal dimensions of the cantilever beam. Coupling of Modes (COM) model was used to extract the optimal design parameters of the SAW devices prior to fabrication. The performance of the developed SAW sensor attached to an antenna towards applied vibration was evaluated wirelessly by using the precise vibration table, programmable incubator chamber, and reader unit.  High vibration sensitivity of ~10.4 kHz/g, good temperature stability, and excellent linearity were observed in the wireless measurements. PMID:25372617

  3. Measurements results of SAW humidity sensor with nafion layer

    NASA Astrophysics Data System (ADS)

    Kawalec, A.; Jasek, K.; Pasternak, M.

    2008-02-01

    The results of measurements of surface acoustic wave (SAW) humidity sensor with nafion layer are described in the paper. The sensitivity, response time as well as hysteresis for different temperatures have been investigated. The sensor sensitivity, linearity and hystersis are discussd. The results show that such sensor may be suitable for accurate humidity measurements in dry or hot enough environment.

  4. Surface Acoustic Wave (SAW) Resonators for Monitoring Conditioning Film Formation.

    PubMed

    Hohmann, Siegfried; Kögel, Svea; Brunner, Yvonne; Schmieg, Barbara; Ewald, Christina; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Länge, Kerstin

    2015-01-01

    We propose surface acoustic wave (SAW) resonators as a complementary tool for conditioning film monitoring. Conditioning films are formed by adsorption of inorganic and organic substances on a substrate the moment this substrate comes into contact with a liquid phase. In the case of implant insertion, for instance, initial protein adsorption is required to start wound healing, but it will also trigger immune reactions leading to inflammatory responses. The control of the initial protein adsorption would allow to promote the healing process and to suppress adverse immune reactions. Methods to investigate these adsorption processes are available, but it remains difficult to translate measurement results into actual protein binding events. Biosensor transducers allow user-friendly investigation of protein adsorption on different surfaces. The combination of several transduction principles leads to complementary results, allowing a more comprehensive characterization of the adsorbing layer. We introduce SAW resonators as a novel complementary tool for time-resolved conditioning film monitoring. SAW resonators were coated with polymers. The adsorption of the plasma proteins human serum albumin (HSA) and fibrinogen onto the polymer-coated surfaces were monitored. Frequency results were compared with quartz crystal microbalance (QCM) sensor measurements, which confirmed the suitability of the SAW resonators for this application. PMID:26007735

  5. Suppressing buzz-saw noise in jet engines

    NASA Technical Reports Server (NTRS)

    Maestrello, L.

    1980-01-01

    Buzz-saw noise, most annoying noise component generated by turbofan engines, can be suppresses by installing porous surface on duct wall directly above engine fan-blade tip. Porous surface and its housing would reduce shock-wave reflection from wall and thus suppress noise.

  6. 28. MODIFIED CHAIN SAW FOR CUTTING ROCK CORES; BRUNTON COMPASS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. MODIFIED CHAIN SAW FOR CUTTING ROCK CORES; BRUNTON COMPASS STAND FOR DETERMINING CORE'S FIELD ORIENTATION; INSECTICIDE DISPENSER MODIFIED TO LUBRICATE CORE DRILLING PROCESS. - U.S. Geological Survey, Rock Magnetics Laboratory, 345 Middlefield Road, Menlo Park, San Mateo County, CA

  7. General view of outside diameter welding stations of the saw ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of outside diameter welding stations of the saw line in bay 8 of the main pipe mill building looking northwest. - U.S. Steel National Tube Works, Main Pipe Mill Building, Along Monongahela River, McKeesport, Allegheny County, PA

  8. Overview of Cannery Building, note the saw tooth monitors with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overview of Cannery Building, note the saw tooth monitors with glazing and with corrugated fiberglass and screens, view facing north - Kahului Cannery, Plant No. 28, Cannery Building and Dryer House/Feed Storage Building, 120 Kane Street, Kahului, Maui County, HI

  9. Brickconstructed saw toothprofile fire wall between the Cannery and original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Brick-constructed saw tooth-profile fire wall between the Cannery and original Warehouse (demolished), note the steel trusses remaining on the wall from the Warehouse roof, view facing north northeast - Kahului Cannery, Plant No. 28, Cannery Building and Dryer House/Feed Storage Building, 120 Kane Street, Kahului, Maui County, HI

  10. A Novel Wireless and Temperature-Compensated SAW Vibration Sensor

    PubMed Central

    Wang, Wen; Xue, Xufeng; Huang, Yangqing; Liu, Xinlu

    2014-01-01

    A novel wireless and passive surface acoustic wave (SAW) based temperature-compensated vibration sensor utilizing a flexible Y-cut quartz cantilever beam with a relatively substantial proof mass and two one-port resonators is developed. One resonator acts as the sensing device adjacent to the clamped end for maximum strain sensitivity, and the other one is used as the reference located on clamped end for temperature compensation for vibration sensor through the differential approach. Vibration directed to the proof mass flex the cantilever, inducing relative changes in the acoustic propagation characteristics of the SAW travelling along the sensing device, and generated output signal varies in frequency as a function of vibration. A theoretical mode using the Rayleigh method was established to determine the optimal dimensions of the cantilever beam. Coupling of Modes (COM) model was used to extract the optimal design parameters of the SAW devices prior to fabrication. The performance of the developed SAW sensor attached to an antenna towards applied vibration was evaluated wirelessly by using the precise vibration table, programmable incubator chamber, and reader unit. High vibration sensitivity of ∼10.4 kHz/g, good temperature stability, and excellent linearity were observed in the wireless measurements. PMID:25372617

  11. Surface Acoustic Wave (SAW) Resonators for Monitoring Conditioning Film Formation

    PubMed Central

    Hohmann, Siegfried; Kögel, Svea; Brunner, Yvonne; Schmieg, Barbara; Ewald, Christina; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Länge, Kerstin

    2015-01-01

    We propose surface acoustic wave (SAW) resonators as a complementary tool for conditioning film monitoring. Conditioning films are formed by adsorption of inorganic and organic substances on a substrate the moment this substrate comes into contact with a liquid phase. In the case of implant insertion, for instance, initial protein adsorption is required to start wound healing, but it will also trigger immune reactions leading to inflammatory responses. The control of the initial protein adsorption would allow to promote the healing process and to suppress adverse immune reactions. Methods to investigate these adsorption processes are available, but it remains difficult to translate measurement results into actual protein binding events. Biosensor transducers allow user-friendly investigation of protein adsorption on different surfaces. The combination of several transduction principles leads to complementary results, allowing a more comprehensive characterization of the adsorbing layer. We introduce SAW resonators as a novel complementary tool for time-resolved conditioning film monitoring. SAW resonators were coated with polymers. The adsorption of the plasma proteins human serum albumin (HSA) and fibrinogen onto the polymer-coated surfaces were monitored. Frequency results were compared with quartz crystal microbalance (QCM) sensor measurements, which confirmed the suitability of the SAW resonators for this application. PMID:26007735

  12. DNA Barcode Authentication of Saw Palmetto Herbal Dietary Supplements

    PubMed Central

    Little, Damon P.; Jeanson, Marc L.

    2013-01-01

    Herbal dietary supplements made from saw palmetto (Serenoa repens; Arecaceae) fruit are commonly consumed to ameliorate benign prostate hyperplasia. A novel DNA mini–barcode assay to accurately identify [specificity = 1.00 (95% confidence interval = 0.74–1.00); sensitivity = 1.00 (95% confidence interval = 0.66–1.00); n = 31] saw palmetto dietary supplements was designed from a DNA barcode reference library created for this purpose. The mini–barcodes were used to estimate the frequency of mislabeled saw palmetto herbal dietary supplements on the market in the United States of America. Of the 37 supplements examined, amplifiable DNA could be extracted from 34 (92%). Mini–barcode analysis of these supplements demonstrated that 29 (85%) contain saw palmetto and that 2 (6%) supplements contain related species that cannot be legally sold as herbal dietary supplements in the United States of America. The identity of 3 (9%) supplements could not be conclusively determined. PMID:24343362

  13. Fiber properties of saw and roller ginned naturally colored cottons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Naturally colored cottons have economic and environmental appeal because they do not require dyeing, but their fibers are not as long as white cottons. To determine the best ginning process two Upland (/G. hirsutim/) colors were roller and saw ginned following a complete block experimental design. ...

  14. Occupational exposure to chain saw exhausts in logging operations

    SciTech Connect

    Nilsson, C.A.; Lindahl, R.; Norstroem, A.

    1987-02-01

    The composition of exhaust emissions from two-stroke chain saw engines was studied. The emissions of exhaust were sampled and analyzed under controlled laboratory experiments. The compounds sampled were those considered primarily responsible for acute health effects - hydrocarbons, aldehydes, nitrogen oxides and carbon monoxide. Exposure to tetramethyllead, dibromoethane and polycyclic aromatic hydrocarbons also was monitored. The results revealed no significant differences in the exhaust emissions from seven different chain saws. Heavily worn-out chain saws do not emit increased amounts of exhaust. A lean fuel-air mixture increases the emission of aldehydes and nitrogen oxides, whereas a rich mixture increases emission of carbon monoxide and hydrocarbons. Based on these new data on the composition of two-stroke chain saw exhaust emissions, operator exposure to chain saw exhaust was evaluated under various logging situations. Exposure measurements revealed no difference in average levels of exposure between logging in the presence or in the absence of snow. The felling operating, however, results in high exposure levels of short duration - especially when the operation is performed while there is deep snow on the ground. This is judged to be the main cause of the discomfort experienced by loggers. Average exposure levels for loggers engaged only in felling are twice those for cutters who also perform limbing, bucking and manual skidding of the timber, since these latter operations involve considerably lower exposure. Typical average levels of exposure are as follows: hydrocarbons, 20 mg/m/sup 3/; formaldehyde, 0.1 mg/m/sup 3/; and carbon monoxide, 20 mg/m/sup 3/.

  15. Quality control of saw blades based on neural networks and laser vibration measurements

    NASA Astrophysics Data System (ADS)

    Brandt, Herbert; Lahmann, Heinz-Wolfgang; Weber, Richard

    1996-08-01

    The performance of a machining process using saw blades depends on the quality of the resulting cross-sectional area. This is determined by parameters like e.g. vibration and axial stiffness of the saw blade. These parameters are itself established by the respective materials, the dimensions of the saw blade and its tension. To evaluate the quality of a saw blade we propose neural networks to analyze vibration measurements.

  16. SAW with multiple electrodes achieves high production rates

    SciTech Connect

    Tusek, J.

    1996-08-01

    Increased demands for higher productivity in the production of welded structures dictate the use of new higher-performance welding procedures. Submerged arc welding (SAW) is already one of the highest performing arc welding processes, but with certain improved variants, its performance can be increased. These variants are multiple-head welding, double electrode welding and submerged arc welding with metal powder addition. These three variations of submerged arc welding have been put into practice and are extensively treated in the welding literature. The application of welding with more than three wires in a joint contact tube is rare, however, and rarely mentioned. The purpose of this article is to show the basic characteristics and eventual applications of SAW using multiple electrodes.

  17. SAW devices based on novel surface wave excitations

    NASA Astrophysics Data System (ADS)

    Therrien, Joel; Dai, Lian

    2015-03-01

    Surface Acoustic Wave (SAW) devices have applications in radio frequency and microwave filtering as well as highly sensitive sensors. Current SAW design employs the use of an array of electrode pairs, referred to as Inter-Digitated Transducers (IDTs) for creating and receiving surface waves on piezoelectric substrates. The pitch of the electrode pairs along with the properties of the substrate determine the operating frequency. The number of electrode pairs determine the bandwidth of the emitted waves. We will present a novel configuration that eliminates the need for the IDTs and replaces with with a single circular electrode located inside a larger ground ring. This configuration induces drumhead modes. We will show that the resonant frequencies follow the zeros of Bessel functions of the first kind. Applications in RF filtering and mass sensing will be presented.

  18. Dual SAW sensor technique for determining mass and modulus changes.

    PubMed

    Hietala, S L; Hietala, V M; Brinker, C J

    2001-01-01

    Surface acoustic wave (SAW) sensors, which are sensitive to a variety of surface changes, have been widely used for chemical and physical sensing. The ability to control or compensate for the many surface forces has been instrumental in collecting valid data. In cases in which it is not possible to neglect certain effects, such as frequency drift with temperature, methods such as the "dual sensor" technique have been utilized. This paper describes a novel use of a dual sensor technique, using two sensor materials (quartz and GaAs) to separate out the contributions of mass and modulus of the frequency change during gas adsorption experiments. The large modulus change in the film calculated using this technique and predicted by the Gassmann equation provide a greater understanding of the challenges of SAW sensing. PMID:11367793

  19. Passive hybrid sensing tag with flexible substrate saw device

    SciTech Connect

    Skinner, Jack L.; Chu, Eric Y.; Ho, Harvey

    2012-12-25

    The integration of surface acoustic wave (SAW) filters, microfabricated transmission lines, and sensors onto polymer substrates in order to enable a passive wireless sensor platform is described herein. Incident microwave pulses on an integrated antenna are converted to an acoustic wave via a SAW filter and transmitted to an impedance based sensor, which for this work is a photodiode. Changes in the sensor state induce a corresponding change in the impedance of the sensor resulting in a reflectance profile. Data collected at a calibrated receiver is used to infer the state of the sensor. Based on this principal, light levels were passively and wirelessly demonstrated to be sensed at distances of up to about 12 feet.

  20. Covalent bound sensing layers on surface acoustic wave (SAW) biosensors.

    PubMed

    Bari, N; Rapp, M

    2001-12-01

    This paper reports on the development of immunosensors based on commercially available surface acoustic wave (SAW) devices working at 380 MHz. Approaches for coating the sensor surface with a sensing layer of receptive biomolecules are presented and discussed. It was found that the sensitivity strongly relates to the immobilization method. Additionally, the sensitivity can be influenced by the density of accessible biomolecules on the active sensing area. Usually, by most of the standard immobilization procedures, two-dimensional layers of receptive biomolecules are obtained. We present a three-dimensional layer, which provides a higher absolute amount of recognition molecules. A dextran layer is photoimmobilized to the sensor surface and the recognition molecules are covalently embedded into the dextran matrix. The feasibility of specific immunosensing is investigated using SAW sensors connected to a fluid handling system. PMID:11679278

  1. Single crystal growth of potassium lithium niobate for SAW applications

    NASA Astrophysics Data System (ADS)

    Neurgaonkar, R. R.

    1982-10-01

    The growth of good quality, crack free medium size KLN single crystals using the Czochralski method, with dielectric and piezoelectric properties comparable or superior to the best known bronze composition SBN was demontrated. However, large ( 1 cm diameter) KLN crystals suitable for SAE Surface Acoustic Waves characterization without considerable cracking were not grown. Therefore, in pursuit of alternative bronze compositions with the potential for large crystal growth, work was initiated or, the growth and characterization of PBN and the stuffed bronze BSKNN. Initial characterization work shows both of these materials to be very promising for future SAW device development, and good quality single crystals of BSKNN with 1 cm square cross-section already were successfully grown. The physical properties of PBN and BSKNN also make them of interest for other piezoelectric, electro-optic, and nonlinear optic applications in addition to SAW devices.

  2. Modeling of saw tooth instability in storage rings

    SciTech Connect

    Dattoli, G.; Mezi, L.; Migliorati, M.; Palumbo, L.

    1999-04-08

    Assuming the validity of the Boussard criterion for the determination of the microwave instability threshold, we derive two coupled non linear differential equations which describe the time evolution of the energy spread and of the instability growth rate under different conditions. The equations reproduce the characteristic features of the saw tooth instability and are in agreement with the results of a time domain simulation code.

  3. Characterization and Qualification of a Precision Diamond Saw

    SciTech Connect

    Morgenstern, H.A.

    1999-03-04

    A precision diamond saw was characterized and qualified for production using the MCCS Encryption Translator (MET) network. This characterization was performed in three steps. First the equipment was evaluated and characterized, and then a process was developed and characterized to saw cofire networks. Finally, the characterized process was qualified for production using the MET network. During the development of the low-temperature cofired ceramic (LTCC) processes needed to build the MCCS Encryption Translator (MET) network, a problem was uncovered. The laser process planned for scribing and separating was found to weaken the LTCC material by about 30%. A replacement process was needed, and precision diamond sawing was chosen. During the equipment evaluation and characterization, several parameters were investigated. These were cut depth, feed rate, spindle speed, and saw blade thickness. Once these were understood the process was then developed. Initially 24 variables were identified for the process, and eventually 12 of these variables were found to be critical. These variables were then adjusted until a process envelope was found that produced acceptable product. Finally parameters were chosen from the middle of the process envelope for production. With the production process set, the next step was to qualify it for production. Two criteria had to be met: visual acceptability and bending strength. The parts were examined under a microscope and found to be visually acceptable. Parts were then put through a four-point bend test, and the strengths recorded were equivalent to those measured in the past. With the completion of this work and the acceptable results, this process was qualified for production use.

  4. BAW and SAW sensors for in-situ analysis

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Y.; Bao, X. Q.; Chang, Z.; Sherrit, S.

    2003-01-01

    In-situ analysis is a major goal in current and future NASA exploration missions. In general in-situ analysis experiments are designed to investigate chmical, biological or geological markers or properties to determine the complex history of the body being studied. In order to expand the number of applicable sensor schemes an investigation into piezoelectric bulk acoustic wave (BAW) and surface acoustic wave (SAW) resonators has been initiated.

  5. On spurious bulk wave excitation in SAW grating reflectors on GaAs(001)(110)

    NASA Technical Reports Server (NTRS)

    Danicki, E.; Hunt, W. D.

    1995-01-01

    Reflection of SAW (surface acoustic waves) from groove gratings on a cubic crystal is analyzed numerically on the basis of perturbation theory. It is shown that for certain angles of incidence, the conversion of SAW into bulk waves vanishes. This reduces the SAW reflection loss from grating.

  6. Hydrogen-Bond Basic Siloxane Phosphonate Polymers for Surface Acoustic Wave (Saw) Sensors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A surface acoustic wave (SAW) sensor coated with a novel hydrogen-bond basic siloxane phosphonate SAW polymer gave excellent initial response and long-term performance when tested against phenol vapor and compared with polyethyleneimine (PEI), a conventional hydrogent-bond basic SAW polymer....

  7. Orthogonal frequency coding for SAW tagging and sensors.

    PubMed

    Puccio, Derek; Malocha, Donald C; Saldanha, Nancy; Gallagher, Daniel R; Hines, Jacqueline H

    2006-02-01

    Surface acoustic wave (SAW)-based sensors can offer wireless, passive operation in numerous environments, and various device embodiments are used for retrieval of the sensed data information. Single sensor systems typically can use a single carrier frequency and a simple device embodiment because tagging is not required. In a multisensor environment, it is necessary to both identify the sensor and retrieve the sensed information. This paper presents the concept of orthogonal frequency coding (OFC) for applications to SAW sensor technology. The OFC offers all advantages inherent to spread spectrum communications, including enhanced processing gain and lower interrogation power spectral density (PSD). It is shown that the time ambiguity in the OFC compressed pulse is significantly reduced as compared with a single frequency tag having the same code length, and additional coding can be added using a pseudo-noise (PN) sequence. The OFC approach is general and should be applicable to many differing SAW sensors for temperature, pressure, liquid, gases, etc. Device embodiments are shown, and a potential transceiver is described. Measured device results are presented and compared with coupling of modes (COM) model predictions to demonstrate performance. Devices then are used in computer simulations of the proposed transceiver design, and the results of an OFC sensor system are discussed. PMID:16529112

  8. Characterization of graphene oxide nanofilms obtained by the SAW atomization

    NASA Astrophysics Data System (ADS)

    Balachova, O. V.; Balashov, S. M.; Kubota, L. T.; Timm, R. A.; Nascimento, P. H.; Pavani Filho, A.; Moshkalev, S.

    2015-03-01

    Due to its ability to absorb water molecules, graphene oxide (GO) is considered a promising material for sensitive coatings in fast surface acoustic wave (SAW) humidity sensors. In this work, we characterize GO films obtained by the SAW atomization technique. It is shown that the atomized submicroliter droplets of aqueous suspension of GO can be deposited onto the surface of Si, LiNbO3 or quartz substrates forming discrete or continuous films of nanometer thickness. The deposited films were examined using AFM and electron microscopy. We discuss the dependence of thickness and structure of the obtained GO films on the parameters of deposition: the number of atomized droplets, a volume of the initial droplet, a distance between the atomizer and the sample, etc. To evaluate the adsorption characteristics of the obtained GO films, we used them as sensitive coatings of the SAW humidity sensors. We found that the adsorption characteristics of the GO films are determined by fast adsorption on the surface of GO sheets and slow adsorption, attributed to limited penetration of water molecules between the sheets, and depend on the number of deposited layers.

  9. Technology towards a SAW based phononic crystal sensor

    NASA Astrophysics Data System (ADS)

    Schmidt, Marc-Peter; Oseev, Aleksandr; Lucklum, Ralf; Hirsch, Soeren

    2015-05-01

    Phononic crystals (PnC) with a specifically designed defect have been recently introduced as novel sensor platform. Those sensors feature a band gap covering the typical input span of the measurand as well as a narrow transmission peak within the band gap where the frequency of maximum transmission is governed by the measurand. This innovative approach has been applied for determination of compounds in liquids [1]. Improvement of sensitivity requires higher probing frequencies around 100 MHz and above. In this range surface acoustic wave devices (SAW) provide a promising basis for PnC based microsensors [2]. The respective feature size of the PnC SAW sensor has dimensions in the range of 100 μm and below. Whereas those dimensions are state of the art for common MEMS materials, etching of holes and cavities in piezoelectric materials having an aspect ratio diameter/depth is challenging. In this contribution we describe an improved technological process to manufacture considerably deep and uniform phononic crystal structures inside of SAW substrates.

  10. 1st Order Modeling of a SAW Delay Line using MathCAD(Registered)

    NASA Technical Reports Server (NTRS)

    Wilson, William C.; Atkinson, Gary M.

    2007-01-01

    To aid in the development of SAW sensors for Integrated Vehicle Health Monitoring applications, a first order model of a SAW Delay line has been created using MathCadA. The model implements the Impulse Response method to calculate the frequency response, impedance, and insertion loss. This paper presents the model and the results from the model for a SAW delay line design. Integrated Vehicle Health Monitoring (IVHM) of aerospace vehicles requires rugged sensors having reduced volume, mass, and power that can be used to measure a variety of phenomena. Wireless systems are preferred when retro-fitting sensors onto existing vehicles [1]. Surface Acoustic Wave (SAW) devices are capable of sensing: temperature, pressure, strain, chemical species, mass loading, acceleration, and shear stress. SAW technology is low cost, rugged, lightweight, and extremely low power. Passive wireless sensors have been developed using SAW technology. For these reasons new SAW sensors are being investigated for aerospace applications.

  11. [The characteristic of the construction features of the power saw blades from the results of experimental studies of power saw injuries to the long tubular bones].

    PubMed

    Nazarov, Yu V

    2016-01-01

    The objective of the present study was to elucidate the characteristic morphological signs of the power saw injuries to human long tubular bones and thereby make possible distinguishing between those inflicted by different types of power jigsaws. The experiments were carried out with the use of the power saws with high-speed reciprocating motion of the blade (power jigsaws and sabre saws). The study was focused on the experimental saw injuries to the human long tubular bones inflicted by the power jigsaws and sabre saws. The mathematical analysis has demonstrated the possibility of determining the properties of the saws and blades employed to inflict the injury based on the morphological and dimensional changes in the long tubular bones. The results of the study indicate that the forensic medical expertise of the injuries inflicted by power saws with high-speed reciprocating motion of the blade based on the morphological and dimensional changes in the long tubular bones makes it possible to identify with a probability of 98.6-99.7% both the construction and the size of the instrument used for sawing. PMID:27030092

  12. Novel SH-SAW gas sensor based on graphene

    NASA Astrophysics Data System (ADS)

    Nikolaou, I.; Hallil, H.; Deligeorgis, G.; Conedera, V.; Garcia, H.; Dejous, C.; Rebire, D.

    2015-05-01

    In this article, a novel gas sensor platform has been studied. Several layers of graphene have been deposited on a SH-SAW, as a sensitive layer. Innovative methods of graphene solutions have been prepared in order to explore gas sensing applications. The real time detection measurement of the coated sensor under ethanol and humidity is presented. The adsorption of vapors leads to a frequency shift of 10.5 kHz and 22.7 kHz, at exposure of 100 ppm of ethanol and 6.22% of Relative Humidity, respectively. The experiments have been realized at room temperature; rapid response and recovery time were observed.

  13. Congenital Achiasma and See-Saw Nystagmus in VACTERL Syndrome

    PubMed Central

    Prakash, Saurabh; Dumoulin, Serge; Fischbein, Nancy; Wandell, Brian A.; Liao, Yaping Joyce

    2013-01-01

    A 29-year-old man with vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal defects, and limb defects (VACTERL) presented with headache, photophobia, and worsening nystagmus. He had near-normal visual acuity and visual fields, absent stereopsis, and see-saw nystagmus. Brain MRI revealed a thin remnant of the optic chiasm but normal-sized optic nerves. Functional MRI during monocular visual stimulation demonstrated non-crossing of the visual evoked responses in the occipital cortex, confirming achiasma. These findings have not previously been reported in VACTERL. PMID:20182207

  14. Modelling Sawing of Metal Tubes Through FEM Simulation

    SciTech Connect

    Bort, C. M. Giorgio; Bosetti, P.; Bruschi, S.

    2011-05-04

    The paper presents the development of a numerical model of the sawing process of AISI 304 thin tubes, which is cut through a circular blade with alternating roughing and finishing teeth. The numerical simulation environment is the three-dimensional FEM software Deform v.10.1. The teeth actual trajectories were determined by a blade kinematics analysis developed in Matlab. Due to the manufacturing rolling steps and subsequent welding stage, the tube material is characterized by a gradient of properties along its thickness. Consequently, a simplified cutting test was set up and carried out in order to identify the values of relevant material parameters to be used in the numerical model. The dedicated test was the Orthogonal Tube Cutting test (OTC), which was performed on an instrumented lathe. The proposed numerical model was validated by comparing numerical results and experimental data obtained from sawing tests carried out on an industrial machine. The following outputs were compared: the cutting force, the chip thickness, and the chip contact area.

  15. Friction drive of an SAW motor. Part V: design criteria.

    PubMed

    Shigematsu, Takashi; Kurosawa, Minoru Kuribayashi

    2008-10-01

    Design criteria for the stable and durable operation of a surface acoustic wave (SAW) motor are discussed. The low electric conductivity and pyroelectricity of the lithium niobate (LN) stator used in the motor hindered the motor's stability. We demonstrated that the use of LN whose conductivity had been enhanced by chemical reduction counteracted the instability caused by contact electrification and meniscus adhesion. The severe failure of the stator surface limits the durability of the SAW motor. Owing to the chemical inertness of LN, the surface failure of the stator was caused by mechanical stresses resulting from the indentation and sliding of the projections placed at the slider surface. The as-fabricated sharp edges of the projections are the obvious cause of failure. Thus, if the projections are necessary, a procedure in which the edges are worn off before operation is the only feasible method to correct this problem. Nevertheless, the optimum geometry to prevent surface failure was deduced as flat plane. The flat plane geometry was useful if the contact pressure is sufficiently large to diminish the effect of the layer of squeezed air between the surfaces. PMID:18986876

  16. Palestine Saw-scaled Vipers hunt disadvantaged avian migrants.

    PubMed

    Yosef, Reuven; Zduniak, Piotr

    2015-11-01

    The selection of an ambush-cum-foraging site and proper prey are indispensable for maintaining an adequate energy intake by sit-and-wait predators to optimize survival and future fitness. This is important for snakes, where an ambush site has suitable ambience. We studied the foraging strategy of the Palestine Saw-scaled Viper (Echis coloratus) at an avian migratory stopover site. Following initial observations, we hypothesized that vipers are able to discern the body mass of a perched bird and hunt accordingly. We implemented an experiment where vipers chose between four groups of migratory Blackcaps with different body mass. Prey choice by vipers of both age classes was not random and adults focused on Blackcaps with the lightest body mass. Juveniles displayed a variability of prey choice but selected mainly birds from the lightest categories. We concluded that Saw-scaled Vipers hunt prey based on thermal cues; juveniles practice on different prey groups prior to perfecting their foraging techniques i.e., hunting is a learned process; and that they prefer birds with the lowest body mass. The last because Blackcaps, when on migration, save energy by entering a state of deep torpor in which they sacrifice their vigilance capabilities. PMID:26319368

  17. Modelling Sawing of Metal Tubes Through FEM Simulation

    NASA Astrophysics Data System (ADS)

    Bort, C. M. Giorgio; Bosetti, P.; Bruschi, S.

    2011-05-01

    The paper presents the development of a numerical model of the sawing process of AISI 304 thin tubes, which is cut through a circular blade with alternating roughing and finishing teeth. The numerical simulation environment is the three-dimensional FEM software Deform™ v.10.1. The teeth actual trajectories were determined by a blade kinematics analysis developed in Matlab™. Due to the manufacturing rolling steps and subsequent welding stage, the tube material is characterized by a gradient of properties along its thickness. Consequently, a simplified cutting test was set up and carried out in order to identify the values of relevant material parameters to be used in the numerical model. The dedicated test was the Orthogonal Tube Cutting test (OTC), which was performed on an instrumented lathe. The proposed numerical model was validated by comparing numerical results and experimental data obtained from sawing tests carried out on an industrial machine. The following outputs were compared: the cutting force, the chip thickness, and the chip contact area.

  18. Silicon saw-tooth refractive lens for high-energy X-rays made using a diamond saw.

    PubMed

    Said, A H; Shastri, S D

    2010-05-01

    Silicon is a material well suited for refractive lenses operating at high X-ray energies (>50 keV), particularly if implemented in a single-crystal form to minimize small-angle scattering. A single-crystal silicon saw-tooth refractive lens, fabricated by a dicing process using a thin diamond wheel, was tested with 115 keV X-rays, giving an ideal 17 microm line focus width in a long focal length, 2:1 ratio demagnification geometry, with a source-to-focus distance of 58.5 m. The fabrication is simple, using resources typically available at any synchrotron facility's optics shop. PMID:20400843

  19. Silicon saw-tooth refractive lens for high-energy x-rays made using a diamond saw.

    SciTech Connect

    Said, A. H.; Shastri, S. D.; X-Ray Science Division

    2010-01-01

    Silicon is a material well suited for refractive lenses operating at high X-ray energies (>50 keV), particularly if implemented in a single-crystal form to minimize small-angle scattering. A single-crystal silicon saw-tooth refractive lens, fabricated by a dicing process using a thin diamond wheel, was tested with 115 keV X-rays, giving an ideal 17 {mu}m line focus width in a long focal length, 2:1 ratio demagnification geometry, with a source-to-focus distance of 58.5 m. The fabrication is simple, using resources typically available at any synchrotron facility's optics shop.

  20. A Passive Wireless Multi-Sensor SAW Technology Device and System Perspectives

    PubMed Central

    Malocha, Donald C.; Gallagher, Mark; Fisher, Brian; Humphries, James; Gallagher, Daniel; Kozlovski, Nikolai

    2013-01-01

    This paper will discuss a SAW passive, wireless multi-sensor system under development by our group for the past several years. The device focus is on orthogonal frequency coded (OFC) SAW sensors, which use both frequency diversity and pulse position reflectors to encode the device ID and will be briefly contrasted to other embodiments. A synchronous correlator transceiver is used for the hardware and post processing and correlation techniques of the received signal to extract the sensor information will be presented. Critical device and system parameters addressed include encoding, operational range, SAW device parameters, post-processing, and antenna-SAW device integration. A fully developed 915 MHz OFC SAW multi-sensor system is used to show experimental results. The system is based on a software radio approach that provides great flexibility for future enhancements and diverse sensor applications. Several different sensor types using the OFC SAW platform are shown. PMID:23666124

  1. A passive wireless multi-sensor SAW technology device and system perspectives.

    PubMed

    Malocha, Donald C; Gallagher, Mark; Fisher, Brian; Humphries, James; Gallagher, Daniel; Kozlovski, Nikolai

    2013-01-01

    This paper will discuss a SAW passive, wireless multi-sensor system under development by our group for the past several years. The device focus is on orthogonal frequency coded (OFC) SAW sensors, which use both frequency diversity and pulse position reflectors to encode the device ID and will be briefly contrasted to other embodiments. A synchronous correlator transceiver is used for the hardware and post processing and correlation techniques of the received signal to extract the sensor information will be presented. Critical device and system parameters addressed include encoding, operational range, SAW device parameters, post-processing, and antenna-SAW device integration. A fully developed 915 MHz OFC SAW multi-sensor system is used to show experimental results. The system is based on a software radio approach that provides great flexibility for future enhancements and diverse sensor applications. Several different sensor types using the OFC SAW platform are shown. PMID:23666124

  2. Impact of micromechanical parameters on wire sawing: a 3D discrete element analysis

    NASA Astrophysics Data System (ADS)

    Nassauer, B.; Kuna, M.

    2015-05-01

    Wire sawing is one of the most prominent technologies for producing solar wafers. In the following paper a numerical model for the simulation of the wire sawing process at microlevel using the discrete element method is presented. The abrasive particles are represented by convex polyhedra. Based on the contact forces on the ingot, local material removal rates are calculated. These local material removal rates are then used to update the shape of the ingot in a stepwise simulation. The model allows for detailed analysis of the influence of different parameters on the micromechanical processes during wire sawing. In particular the influence of wire speed, lapping pressure, particle concentration, particle size, particle shape and debris on the sawing process is investigated. In a post-processing macroscopic process characteristics like kerf width, depth of surface cracks or sawing rate are calculated. Thus, the processes at the microlevel are related to the macroscopic process characteristics, which are of interest when applying wire sawing in practice.

  3. Mixed Modeling of a SAW Delay Line Using VHDL-AMS

    NASA Technical Reports Server (NTRS)

    Wilson, William C.; Atkinson, Gary M.

    2006-01-01

    To aid in the development of SAW sensors for aerospace applications we have created a model of a SAW Delay line using VHDL. The model implements the Impulse Response method to calculate the frequency response, impedance, and insertion loss. The model includes optimization for the number of finger pairs in the IDTs and for the aperture height. This paper presents the model and the results from the model for a SAW delay line design.

  4. An improved performance frequency estimation algorithm for passive wireless SAW resonant sensors.

    PubMed

    Liu, Boquan; Zhang, Chenrui; Ji, Xiaojun; Chen, Jing; Han, Tao

    2014-01-01

    Passive wireless surface acoustic wave (SAW) resonant sensors are suitable for applications in harsh environments. The traditional SAW resonant sensor system requires, however, Fourier transformation (FT) which has a resolution restriction and decreases the accuracy. In order to improve the accuracy and resolution of the measurement, the singular value decomposition (SVD)-based frequency estimation algorithm is applied for wireless SAW resonant sensor responses, which is a combination of a single tone undamped and damped sinusoid signal with the same frequency. Compared with the FT algorithm, the accuracy and the resolution of the method used in the self-developed wireless SAW resonant sensor system are validated. PMID:25429410

  5. 3-D electrostatic hybrid element model for SAW interdigital transducers.

    PubMed

    Jerez-Hanckes, Carlos F; Laude, Vincent; Nédélec, Jean-Claude; Lardat, Raphael

    2008-03-01

    In this work, the singular behavior of charges at corners and edges on the metallized areas in SAW transducers are investigated. In particular, it is demonstrated that a tensor product of the commonly used Tchebychev bases overestimates the singularities at corners, and, hence, it cannot be used in a proper boundary element method formulation. On the other hand, it is shown that a simple finite element method-like approach is impractical due to the enormous number of unknowns required to model the electrode's large length-to-width ratio. These considerations are then used for defining a hybrid element model, which combines Tchebychev and linear polynomials over differently meshed domains. Such an approach is shown to suitably account for charge singularities while greatly reducing the number of unknowns. Results are obtained for isotropic and anisotropic substrates for non-periodic configurations. PMID:18407858

  6. Corrosion inhibitors for water-base slurry in multiblade sawing

    NASA Technical Reports Server (NTRS)

    Chen, C. P.; Odonnell, T. P.

    1982-01-01

    The use of a water-base slurry instead of the standard PC oil vehicle was proposed for multiblade sawing (MBS) silicon wafering technology. Potential cost savings were considerable; however, significant failures of high-carbon steel blades were observed in limited tests using a water-based slurry during silicon wafering. Failures were attributed to stress corrosion. A specially designed fatigue test of 1095 steel blades in distilled water with various corrosion inhibitor solutions was used to determine the feasibility of using corrosion inhibitors in water-base MBS wafering. Fatigue tests indicate that several corrosion inhibitors have significant potential for use in a water-base MBS operation. Blade samples tested in these specific corrosion-inhibitor solutions exhibited considerably greater lifetime than those blades tested in PC oil.

  7. Frequency response of a focused SAW device based on concentric wave surfaces: simulation and experiment

    NASA Astrophysics Data System (ADS)

    Wu, Tsung-Tsong; Tang, He-Tai; Chen, Yung-Yu

    2005-08-01

    Focused interdigital transducers (FIDTs) based on concentric wave surfaces can excite surface acoustic wave (SAW) with high intensity, high beamwidth compression ratio and small localized area. In this paper, we developed a model to analyse the frequency response of a SAW device with FIDTs based on concentric wave surfaces. First, we constructed a focused SAW device by adopting a pair of FIDTs shaped as the concentric wave surface. To calculate its frequency response, a simulation model was established based on the 2D SAW filter model, effective permittivity approach and perturbation theory. Further, the focused SAW devices were designed and fabricated via the microelectromechanical system process technique. A good agreement between the simulated and measured results was found. Finally, the frequency responses of focused SAW devices based on concentric wave surfaces were discussed and some attractive features were found, such as less ripples of pass-band and high stop-band rejection. In addition, in comparison with the conventional SAW devices with uniform interdigital transducers, the focused SAW devices are more sensitive to variations in the focal area, instead of the whole delayline region. Accordingly, they are suitable to be applied to detect or manipulate some localized variations, such as acousto-optic or acousto-electric effects.

  8. Cutting crime: the analysis of the "uniqueness" of saw marks on bone.

    PubMed

    Saville, P A; Hainsworth, S V; Rutty, G N

    2007-09-01

    Witness marks produced on bone by the use of saws have traditionally been examined using stereomicroscopy. The marks are typically found on the kerf wall or floor and give important information about the implement that made them. This paper describes a new approach to the analysis of witness marks left on kerf walls and floors from crimes involving dismemberment. Previously, two types of marks have been identified: deep furrows formed during the pull stroke and fine striations formed on the push stroke. These types of striation allow the class of saw to be identified, but not an individual saw. With the advent of environmental scanning electron microscopy (ESEM), insulating materials can now be examined without the need for conductive coatings to be applied. This allows materials to be examined at higher magnifications than those available with stereomicroscopy. Here we report on a new, third type of striation that is visible at higher magnifications on ESEM images. These striations are formed from the imperfections on the cutting teeth of saws and give real possibilities of uniquely identifying whether or not a particular saw was used to cause the mark. In blind trials conducted on sawing of nylon 6.6, different individual saws could be successfully identified even if different people used the saw. We discuss ways in which these results can be extended to bone and how this may assist in the investigation of the act of dismemberment. PMID:17021897

  9. Differential phase shift keying direct sequence spread spectrum single SAW based correlator receiver.

    PubMed

    Moeller, F; Belkerdid, M A; Malocha, D C; Buff, W

    1998-01-01

    This paper presents the design and measurement of a SAW device to be used in a correlator receiver for a differential phase shift keying direct sequence spread spectrum (DPSK/DSSS) system. The DPSK modulation format allows noncoherent data demodulation while the SAW device correlator acts as the despreading operator. In a conventional DPSK receiver, the received signal is normally split into a lower and upper path. One of the paths contains a correlator, and the other path contains a one data bit delay element and another correlator. The outputs of both paths are then fed to a noncoherent data demodulator. The device presented in this paper combines both the delay element and the two correlators in a single SAW device; therefore, a better temperature tracking mechanism, simplicity, as well as the elimination of the broadband SAW delay line are achieved. The SAW structure contains a broadband SAW transducer, and two serially coded pseudo noise (PN) DPSK filters. The SAW based correlator was built on lithium tantalate. The center frequency was set to 150 MHz, with a 63 chip PN spreading code and a data rate of 300 Kbps. Experimental measurements of the SAW device autocorrelation results are presented. PMID:18244204

  10. 78 FR 31897 - Agency Information Collection Activities; Proposed Collection; Comment Request; CPSC Table Saw...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-28

    ... injuries. 76 FR 62683. Currently, the CPSC does not know how consumers are using the new modular blade... (ANPR) for table saws, under the Consumer Product Safety Act (CPSA), 15 U.S.C. 2051-2084. (76 FR 62678... on a survey of table saw users to determine the effectiveness of modular blade guards. DATES:...

  11. Separation of biological cells in a microfluidic device using surface acoustic waves (SAWs)

    NASA Astrophysics Data System (ADS)

    Ai, Ye; Marrone, Babetta L.

    2014-03-01

    In this study, a surface acoustic wave (SAW)-based microfluidic device has been developed to separate heterogeneous particle or cell mixtures in a continuous flow using acoustophoresis. The microfluidic device is comprised of two components, a SAW transducer and a microfluidic channel made of polydimethylsiloxane (PDMS). The SAW transducer was fabricated by patterning two pairs of interdigital electrodes on a lithium niobate (LiNbO3) piezoelectric substrate. When exciting the SAW transducer by AC signals, a standing SAW is generated along the cross-section of the channel. Solid particles immersed in the standing SAW field are accordingly pushed to the pressure node arising from the acoustic radiation force acting on the particles, referring to the acoustic particle-focusing phenomenon. Acoustic radiation force highly depends on the particle properties, resulting in different acoustic responses for different types of cells. A numerical model, coupling the piezoelectric effect in the solid substrate and acoustic pressure in the fluid, was developed to provide a better understanding of SAW-based particle manipulation. Separation of two types of fluorescent particles has been demonstrated using the developed SAW-based microfluidic device. An efficient separation of E. coli bacteria from peripheral blood mononuclear cell (PBMC) samples has also been successfully achieved. The purity of separated E. coli bacteria and separated PBMCs were over 95% and 91%, respectively, obtained by a flow cytometric analysis. The developed microfluidic device can efficiently separate E. coli bacteria from biological samples, which has potential applications in biomedical analysis and clinical diagnosis.

  12. Finite Element Modelling of the Sawing of DC Cast AA2024 Aluminium Alloy Slabs

    SciTech Connect

    Drezet, J.-M.; Ludwig, O.; Heinrich, B.

    2007-04-07

    In the semi-continuous casting of large cross-section rolling sheet ingots of high-strength aluminum alloys (2xxx and 7xxx series), the control of the residual (internal) stresses generated by the non-uniform cooling becomes a necessity. These stresses must be relieved by a thermal treatment before the head and foot of the ingot can be cut. Otherwise, the saw can be caught owing to compressive stresses or cut parts may be ejected thus injuring people or damaging equipment. These high added-value ingots need to be produced in secure conditions. Moreover, a better control of the sawing procedure could allow the suppression of the thermal treatment and therefore save time and energy. By studying the stress build-up during casting and the stress relief during sawing, key parameters for the control and optimization of the processing steps, can be derived. To do so, the direct chill (DC) casting of the AA2024 alloy is modeled with ABAQUS 6.5 with special attention to the thermo-mechanical properties of the alloy. The sawing operation is then simulated by removing mesh elements so as to reproduce the progression of the saw in the ingot. Preliminary results showing the stress relief during sawing accompanied by the risk of saw blocking due to compression or initiating a crack ahead of the saw, are analyzed with an approach based on the rate of strain energy release.

  13. Machine Shop I. Learning Activity Packets (LAPs). Section D--Power Saws and Drilling Machines.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains two learning activity packets (LAPs) for the "power saws and drilling machines" instructional area of a Machine Shop I course. The two LAPs cover the following topics: power saws and drill press. Each LAP contains a cover sheet that describes its purpose, an introduction, and the tasks included in the LAP; learning steps…

  14. Impact of gin saw tooth design on fiber and textile processing quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toothed gin saws have been used to separate cotton fiber from the seed for over 200 years. There have been many saw tooth designs developed over the years. Most of these designs were developed by trial and error. A complete and scientific analysis of tooth design has never been done. It is not k...

  15. Pure SH-SAW propagation, transduction and measurements on KNbO3.

    PubMed

    Pollard, Thomas B; Kenny, Thomas D; Vetelino, John F; da Cunha, Mauricio Pereira

    2006-01-01

    Potassium niobate (KNbO3) supports the electromechanically active pure shear horizontal surface acoustic wave (SH-SAW) mode along Z-axis cylinder orientations, Euler angles (phi, 90 degrees, 0 degrees), in which two uncoupled wave solutions exist: a purely mechanical sagittal Rayleigh SAW and a piezoelectrically stiffened pure SH-SAW. Within this family of cuts, a maximum electromechanical coupling coefficient for the pure SH-SAW, K2 = 53%, is observed along (0 degrees, 90 degrees, 0 degrees). This pure SH-SAW orientation also has the maximum value of electromechanical coupling observed along rotated Y-cut X propagation directions, Euler angles (0 degrees, theta, 0 degrees). The use of the pure SH-SAW mode is attractive for liquid-sensing applications because the SH-SAW is modestly attenuated by the adjacent liquid, unlike the generalized SAW (GSAW), which has particle displacement normal to the surface. This work investigates propagation and excitation properties of the SH-SAW and the shear horizontal bulk acoustic wave (SH-BAW) on single crystal KNbO3, Euler angles (0 degrees, 90 degrees, 0 degrees). Interdigital transducer (IDT) arrays are analyzed using boundary element method (BEM) techniques, addressing IDT properties such as: power partitioning between the SH-SAW and SH-BAW, SH-BAW radiation as a function of wave vector direction and radiation angle, and overall IDT impedance. The percentage of SH-SAW power to total input power is above 98% for IDTs containing 1.5 to 5.5 wavelengths of active electrodes with surrounding metalized regions. For nonmetalized regions outside the IDT, the ratio drops to between 1 and 2%, showing the importance of an energy trapping structure for efficient SH-SAW excitation and propagation along this orientation. Simulated and experimental IDT admittance results are compared, verifying the validity of the analysis performed. The reported measurements on the frequency variation with temperature indicate that the orientation considered is temperature compensated at about 8 degrees C. The surface of the SH-SAW devices fabricated have been loaded with deionized water and showed additional 1.6 dB transmission loss with respect to the unloaded surface, verifying the suitability of the pure SH-SAW mode on KNbO3 for liquid sensor applications. PMID:16471447

  16. Calibration of the QCM/SAW Cascade Impactor for Measurement of Ozone in the Stratosphere

    NASA Technical Reports Server (NTRS)

    Wright, Cassandra K.; Sims, S. C.; Peterson, C. B.; Morris, V. R.

    1997-01-01

    The Quartz Crystal Microbalance Surface Acoustic Wave (QCM/SAW) cascade impactor collects size-fractionated distributions of aerosols on a series of 10 MHz quartz crystals and employs SAW devices coated with chemical sensors for gas detection. Presently, we are calibrating the ER-2 certified QCM/SAW cascade impactor in the laboratory for the detection of ozone. Experiments have been performed to characterize the QCM and SAW mass loading, saturation limits, mass frequency relationships, and sensitivity. We are also characterizing sampling efficiency by measuring the loss of ozone on different materials. There are parallel experiments underway to measure the variations in the sensitivity and response of the QCM/SAW crystals as a function of temperature and pressure. Results of the work to date will be shown.

  17. Circular saw-related fatalities: A rare case report, review of the literature, and forensic implications.

    PubMed

    Janík, Martin; Straka, Ľubomír; Novomeský, František; Krajčovič, Jozef; Hejna, Petr

    2016-01-01

    Fatalities attributed to powered circular saws appear to be vanishingly rare events with highly wounding and rapidly incapacitating effects. When they do occur, they are mainly self-inflicted in nature. We report the suicide committed by a 79-year-old man using a self-made circular table saw. Autopsy confirmed that the man received multiple heterogeneously distributed saw-type impacts to the head and neck resulting in complete amputation of the upper skull and partial beheading. Homemade or modified commercial sawing instruments and the resultant injuries pose a number of forensic challenges starting from the death scene investigation, continuing with technical examinations, and concluding with determining the manner of death. As with all deaths due to sharp force injuries, fatalities involving power tools such as chainsaws, circular, and band saws warrant a high degree of suspicion of criminal activity and require diligence during all phases of the death investigation. PMID:26832377

  18. Heat generation during ulnar osteotomy with microsagittal saw blades.

    PubMed

    Firoozbakhsh, K; Moneim, M S; Mikola, E; Haltom, S

    2003-01-01

    Ulnar shortening osteotomy is a surgical treatment option for patients with symptomatic ulnar positive variance for a variety of reasons. Delayed healing and nonunion of the osteotomized sites have been reported and present problematic complications of this procedure. Studies have shown nonunion rate with transverse cuts ranging from 8-15%. The goal is to achieve parallel cuts, thus maximizing the contacting bony surface area for a better union rate. The senior surgeon attempted using a custom thick blade to insure parallel cuts. The concern is whether the heat generated during such a cut would contribute to non-union. It is our hypothesis that complications with ulnar shortening osteotomy using a thick blade are secondary to excess heat generation. When generated heat surpasses the threshold temperature of bone tissue, the organic matrix is irreversibly damaged and necrosis of the bony ends may occur. The present study measured the heat generation during ulnar osteotomy using different blade thicknesses. Thirty-five fresh turkey femurs, having similar size and cortical thickness of the human ulna, were used. Loading was done at three different speeds of 0.66, 1.0, and 1.5 mm/second corresponding respectively to 30, 20, and 10 seconds for the complete cut. A general linear statistical model was fitted relating temperature rise to three predictive factors: blade thickness, sensor distance, and initial bone temperature. There was a statistically significant relationship between temperature rise and all three predictor variables at the 99% confidence level. There was no statistically significant relationship between temperature rise and the number of cuts with the same blade up to 10 times. Compared with the single microsagital saw blade, the temperature rise for the double thickness blade was 14% higher and for the triple thickness blade was 23% higher. The temperature rise was inversely related to the speed of the cut. The temperature rise for the bone cut in 30 seconds was 1.5 times higher than the temperature rise when the bone was cut in 10 seconds. Complications with ulnar shortening osteotomy may be secondary to excess heat generation. A new thick saw blade design and the use of proper internal/external irrigation may overcome the problem. PMID:14575249

  19. Laser vibrometer measurements of SAWs for nondestructive testing

    NASA Astrophysics Data System (ADS)

    Longo, Roberto; Vanlanduit, Steve; Guillaume, Patrick

    2006-06-01

    A non-destructive testing (NDT) technique should be able to calculate the position and the size of any defects, in order to measure quality and safety of materials. Complexity is an issue for most NDT tests, requiring specialist knowledge of the technique. This generally means using qualified staff, and omits the possibility of any kind of automation. In this article an experimental methodology for crack detection using Surface Acoustic Waves (SAWs) and optical laser vibrometer measurements will be introduced. The materials under test are a damaged slat track of an Airbus A320 and a steel beam (because in the zone where critical crack propagation occurs the slat track has a beam-like shape) with slots of known depth (0.2, 0.4, 0.6, 0.8 mm). The goal of this article is to compare these ultrasonic-laser measurements in order to understand how much they are suitable to detect damages and imperfections present on the material itself. For future applications, this methodology can be used to monitor the slat track during a fatigue test, to detect damages in an early stage, before a rapid crack growth.

  20. Method and apparatus for improved wire saw slurry

    DOEpatents

    Costantini, Michael A.; Talbott, Jonathan A.; Chandra, Mohan; Prasad, Vishwanath; Caster, Allison; Gupta, Kedar P.; Leyvraz, Philippe

    2000-09-05

    A slurry recycle process for use in free-abrasive machining operations such as for wire saws used in wafer slicing of ingots, where the used slurry is separated into kerf-rich and abrasive-rich components, and the abrasive-rich component is reconstituted into a makeup slurry. During the process, the average particle size of the makeup slurry is controlled by monitoring the condition of the kerf and abrasive components and making necessary adjustments to the separating force and dwell time of the separator apparatus. Related pre-separator and post separator treatments, and feedback of one or the other separator slurry output components for mixing with incoming used slurry and recirculation through the separator, provide further effectiveness and additional control points in the process. The kerf-rich component is eventually or continually removed; the abrasive-rich component is reconstituted into a makeup slurry with a controlled, average particle size such that the products of the free-abrasive machining method using the recycled slurry process of the invention are of consistent high quality with less TTV deviation from cycle to cycle for a prolonged period or series of machining operations.

  1. A radiation detector design mitigating problems related to sawed edges

    NASA Astrophysics Data System (ADS)

    Aurola, A.; Marochkin, V.; Tuuva, T.

    2014-12-01

    In pixelated silicon radiation detectors that are utilized for the detection of UV, visible, and in particular Near Infra-Red (NIR) light it is desirable to utilize a relatively thick fully depleted Back-Side Illuminated (BSI) detector design providing 100% Fill Factor (FF), low Cross-Talk (CT), and high Quantum Efficiency (QE). The optimal thickness of such detectors is typically less than 300μm and above 40μm and thus it is more or less mandatory to thin the detector wafer from the backside after the front side of the detector has been processed and before a conductive layer is formed on the backside. A TAIKO thinning process is optimal for such a thickness range since neither a support substrate on the front side nor lithographic steps on the backside are required. The conductive backside layer should, however, be homogenous throughout the wafer and it should be biased from the front side of the detector. In order to provide good QE for blue and UV light the conductive backside layer should be of opposite doping type than the substrate. The problem with a homogeneous backside layer being of opposite doping type than the substrate is that a lot of leakage current is typically generated at the sawed chip edges, which may increase the dark noise and the power consumption. These problems are substantially mitigated with a proposed detector edge arrangement which 2D simulation results are presented in this paper.

  2. SAW ethanol gas sensors based on cryptophane-A sensitive film

    NASA Astrophysics Data System (ADS)

    Sun, Ping; Jiang, Yadong; Xie, Guangzhong; Du, Xiaosong

    2010-10-01

    Surface acoustic wave (SAW) devices have been widely used for various chemical sensing applications because the sensor signal can be detected by simple and inexpensive electronics. The interactions between target analyte and the sensor surface cause changes in the mechanical, electrical, dielectric properties of the sensing coating deposited onto acoustic transducer. The changes in these properties will lead to changes in the velocity and amplitude of wave modes, which can be measured by frequency and insertion loss (IL) changes when the acoustic element is realized as a delay line or resonator. Among the different sensing coatings, the supermolecules are of considerable interest because the host molecules can be thought as original receptors allowing a specific recognition of guest molecules based on "key-lock" system. In this paper, SAW ethanol gas sensors that utilize the supermolecule of cryptophane-A as sensitive layer have been studied. We synthesized cryptophane-A from vanillyl alcohol using a double trimerisation method and deposited it on the SAW devices to fabricate cryptophane-A based SAW gas sensors. The SAW frequency and insertion loss (IL) were measured using a network analyzer. The frequency shift as the response of the cryptophane-A based SAW sensors to different concentration ethanol was measured at room temperature. It is found that the cryptophane-A based SAW sensor has high sensitivity and good reproductivity to ethanol. The frequency response increased linearly with the concentration of the ethanol.

  3. Development of a Wireless and Passive SAW-Based Chemical Sensor for Organophosphorous Compound Detection.

    PubMed

    Xu, Fang-Qian; Wang, Wen; Xue, Xu-Feng; Hu, Hao-Liang; Liu, Xin-Lu; Pan, Yong

    2015-01-01

    A new wireless and passive surface acoustic wave (SAW)-based chemical sensor for organophosphorous compound (OC) detection is presented. A 434 MHz reflective delay line configuration composed by single phase unidirectional transducers (SPUDTs) and three shorted reflectors was fabricated on YZ LiNbO₃ piezoelectric substrate as the sensor element. A thin fluoroalcoholpolysiloxane (SXFA) film acted as the sensitive interface deposited onto the SAW propagation path between the second and last reflectors of the SAW device. The first reflector was used for the temperature compensation utilizing the difference method. The adsorption between the SXFA and OC molecules modulates the SAW propagation, especially for the time delay of the SAW, hence, the phase shifts of the reflection peaks from the corresponding reflectors can be used to characterize the target OC. Prior to the sensor fabrication, the coupling of modes (COM) and perturbation theory were utilized to predict the SAW device performance and the gas adsorption. Referring to a frequency-modulated continuous wave (FMCW)-based reader unit, the developed SAW chemical sensor was wirelessly characterized in gas exposure experiments for dimethylmethylphosphonate (DMMP) detection. Sensor performance parameters such as phase sensitivity, repeatability, linearity, and temperature compensation were evaluated experimentally. PMID:26633419

  4. Comparative ecology of the Flammulated Owl and Northern Saw-whet Owl during fall migration

    USGS Publications Warehouse

    Stock, S.L.; Heglund, P.J.; Kaltenecker, G.S.; Carlisle, J.D.; Leppert, L.

    2006-01-01

    We compared the migration ecology of two owl species that exhibit different migration strategies: the Flammulated Owl (Otus flammeolus) and the Northern Saw-whet Owl (Aegolius acadicus). During fall 1999-2004, we captured 117 Flammulated Owls and 1433 Northern Saw-whet Owls in the southern Boise Mountains of southwestern Idaho. These owl species exhibited contrasting seasonal timing and body condition. Flammulated Owl captures peaked in mid-September and Northern Saw-whet Owl captures peaked in early to mid-October. Flammulated Owls displayed greater body condition than Northern Saw-whet Owls and increasing condition scores during the season, whereas Northern Saw-whet Owls had no apparent seasonal condition patterns. Based on seasonal timing of captures, both species showed unimodal movement patterns characteristic of fall migrants. However, in 1999 both species' capture rates were at least double those in other years of this study. Flammulated Owls' earlier arrival and departure, coupled with superior body condition, were consistent among years and typical of a long-distance migration strategy. In contrast, the Northern Saw-whet Owls' later arrival, more lengthy passage, and variable body condition were more characteristic of a short-distance migrant strategy. Furthermore, Northern Saw-whet Owls' body condition was significantly lower during the irruptive year than during nonirruptive years, supporting the notion that population density affects their migratory condition. ?? 2006 The Raptor Research Foundation, Inc.

  5. Development of a Wireless and Passive SAW-Based Chemical Sensor for Organophosphorous Compound Detection

    PubMed Central

    Xu, Fang-Qian; Wang, Wen; Xue, Xu-Feng; Hu, Hao-Liang; Liu, Xin-Lu; Pan, Yong

    2015-01-01

    A new wireless and passive surface acoustic wave (SAW)-based chemical sensor for organophosphorous compound (OC) detection is presented. A 434 MHz reflective delay line configuration composed by single phase unidirectional transducers (SPUDTs) and three shorted reflectors was fabricated on YZ LiNbO3 piezoelectric substrate as the sensor element. A thin fluoroalcoholpolysiloxane (SXFA) film acted as the sensitive interface deposited onto the SAW propagation path between the second and last reflectors of the SAW device. The first reflector was used for the temperature compensation utilizing the difference method. The adsorption between the SXFA and OC molecules modulates the SAW propagation, especially for the time delay of the SAW, hence, the phase shifts of the reflection peaks from the corresponding reflectors can be used to characterize the target OC. Prior to the sensor fabrication, the coupling of modes (COM) and perturbation theory were utilized to predict the SAW device performance and the gas adsorption. Referring to a frequency-modulated continuous wave (FMCW)-based reader unit, the developed SAW chemical sensor was wirelessly characterized in gas exposure experiments for dimethylmethylphosphonate (DMMP) detection. Sensor performance parameters such as phase sensitivity, repeatability, linearity, and temperature compensation were evaluated experimentally. PMID:26633419

  6. Hybrid Surface Acoustic Wave- Electrohydrodynamic Atomization (SAW-EHDA) For the Development of Functional Thin Films

    NASA Astrophysics Data System (ADS)

    Choi, Kyung Hyun; Kim, Hyun Bum; Ali, Kamran; Sajid, Memoon; Uddin Siddiqui, Ghayas; Chang, Dong Eui; Kim, Hyung Chan; Ko, Jeong Beom; Dang, Hyun Woo; Doh, Yang Hoi

    2015-10-01

    Conventional surface acoustic wave - electrostatic deposition (SAW-ED) technology is struggling to compete with other thin film fabrication technologies because of its limitation in atomizing high density solutions or solutions with strong inter-particle bonding that requires very high frequency (100 MHz) and power. In this study, a hybrid surface acoustic wave - electrohydrodynamic atomization (SAW-EHDA) system has been introduced to overcome this problem by integrating EHDA with SAW to achieve the deposition of different types of conductive inks at lower frequency (19.8 MHZ) and power. Three materials, Poly [2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV), Zinc Oxide (ZnO), and Poly(3, 4-ethylenedioxythiophene):Polystyrene Sulfonate (PEDOT:PSS) have been successfully deposited as thin films through the hybrid SAW-EHDA. The films showed good morphological, chemical, electrical, and optical characteristics. To further evaluate the characteristics of deposited films, a humidity sensor was fabricated with active layer of PEDOT:PSS deposited using the SAW-EHDA system. The response of sensor was outstanding and much better when compared to similar sensors fabricated using other manufacturing techniques. The results of the device and the films’ characteristics suggest that the hybrid SAW-EHDA technology has high potential to efficiently produce wide variety of thin films and thus predict its promising future in certain areas of printed electronics.

  7. Hybrid Surface Acoustic Wave- Electrohydrodynamic Atomization (SAW-EHDA) For the Development of Functional Thin Films

    PubMed Central

    Choi, Kyung Hyun; Kim, Hyun Bum; Ali, Kamran; Sajid, Memoon; Uddin Siddiqui, Ghayas; Chang, Dong Eui; Kim, Hyung Chan; Ko, Jeong Beom; Dang, Hyun Woo; Doh, Yang Hoi

    2015-01-01

    Conventional surface acoustic wave - electrostatic deposition (SAW-ED) technology is struggling to compete with other thin film fabrication technologies because of its limitation in atomizing high density solutions or solutions with strong inter-particle bonding that requires very high frequency (100 MHz) and power. In this study, a hybrid surface acoustic wave - electrohydrodynamic atomization (SAW-EHDA) system has been introduced to overcome this problem by integrating EHDA with SAW to achieve the deposition of different types of conductive inks at lower frequency (19.8 MHZ) and power. Three materials, Poly [2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV), Zinc Oxide (ZnO), and Poly(3, 4-ethylenedioxythiophene):Polystyrene Sulfonate (PEDOT:PSS) have been successfully deposited as thin films through the hybrid SAW-EHDA. The films showed good morphological, chemical, electrical, and optical characteristics. To further evaluate the characteristics of deposited films, a humidity sensor was fabricated with active layer of PEDOT:PSS deposited using the SAW-EHDA system. The response of sensor was outstanding and much better when compared to similar sensors fabricated using other manufacturing techniques. The results of the device and the films’ characteristics suggest that the hybrid SAW-EHDA technology has high potential to efficiently produce wide variety of thin films and thus predict its promising future in certain areas of printed electronics. PMID:26478189

  8. 75 FR 13543 - Decision To Evaluate a Petition To Designate a Class of Employees for the Simonds Saw and Steel...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-22

    ... HUMAN SERVICES Decision To Evaluate a Petition To Designate a Class of Employees for the Simonds Saw and... designate a class of employees for Simonds Saw and Steel Co., Lockport, New York, to be included in the... evaluation, is as follows: Facility: Simonds Saw and Steel Co. Location: Lockport, New York. Job Titles...

  9. Assessment of Present State-of-the-art Sawing Technology of Large Diameter Ingots for Solar Sheet Material

    NASA Technical Reports Server (NTRS)

    Yoo, H. I.

    1978-01-01

    Work is reported on: (1) slicing of the ingots with the multiblade slurry saw, the multiwire slurry saw and the I.D. saw, (2) characterization of the sliced wafers, and (3) analysis of add-on slicing cost based on Solar Array Manufacturing Industry Costing Standard.

  10. [Determination of the power jigsaw sawing velocity from the morphological properties of the affected human skin].

    PubMed

    Nazarov, Iu V; Tolmachev, I A

    2014-01-01

    The objective of the present work was to elucidate the characteristic morphological features of the injuries inflicted to the human skin by a power jigsaw depending on the sawing velocity. The study has demonstrated the possibility of mathematical analysis of the sawing velocity based on the morphological peculiarities of the injury to the skin. The data obtained indicate that forensic medical expertise of the injuries inflicted by a power jigsaw can be based on the study of the width of the abraded edges of the wound in order to determine the sawing velocity. PMID:25796928

  11. Calibration of the QCM/SAW Cascade Impactor for Measurement of Ozone

    NASA Technical Reports Server (NTRS)

    Williams, Cassandra K.; Peterson, C. B.; Morris, V. R.

    1997-01-01

    The Quartz Crystal Microbalance Surface Acoustic Wave (QCM/SAW) cascade impactor is an instrument designed to collect size-fractionated distributions of aerosols on a series of quartz crystals and employ SAW devices coated with chemical sensors for gas detection. We are calibrating the cascade impactor in our laboratory for future deployment for in-situ experiments to measure ozone. Experiments have been performed to characterize the QCM and SAW mass loading, saturation limits, mass frequency relationships, and sensitivity. The characteristics of mass loading, saturation limits, mass-frequency relationships, sensitivity, and the loss of ozone on different materials have been quantified.

  12. Temperature and stiffness correction of SAW devices for wireless strain sensing

    NASA Astrophysics Data System (ADS)

    Oppenheim, Irving J.; Carey, Nicola S.; Chin, T.-L.; Zheng, Peng; Greve, David W.

    2011-04-01

    Surface acoustic wave (SAW) devices are solid-state components in which a wave propagates along the surface of a piezoelectric material. Changes in strain or temperature cause shifts in the acoustic wave speed and/or the path length, enabling SAW devices to act as sensors. We present experimental studies on lithium niobate SAW devices acting as passively-powered devices. Sensitivity, reproducibility, and linearity are excellent when measuring strain at constant temperature, but the devices are also sensitive to temperature changes. We show experimental results of strain measurement incorporating temperature compensation.

  13. Reducing kickback of portable combustion chain saws and related injury risks: laboratory tests and deductions.

    PubMed

    Dąbrowski, Andrzej

    2012-01-01

    Portable chain saws are still very dangerous machines. Reduced prices of these machines mean they are widely available to people who like DIY (do it yourself) and professionals. Kickback of chain saws is extremely dangerous for the operator. This paper discusses the results of laboratory investigations of combustion chain saws. The tests were conducted on a standardized kickback test stand and covered the course of kickback, its energy, angle and duration. The results showed that during the contact of a saw chain with wood, the first to appear was the process of wood cutting, which absorbed 90-95% of the reduced energy of the cutting system. The greater the absorbed energy, the smaller the kickback angle. Wood cutting work is particularly influenced by proper chain tension, the use of chains with anti-kickback links, guide bars with sliding endings and a quickly activated chain brake. PMID:22995138

  14. Study of a high-precision SAW-MOEMS strain sensor with laser optics

    NASA Astrophysics Data System (ADS)

    Liu, Xinwei; Chen, Shufen; Li, Honglang; Zou, Zhengfeng; Fu, Lei; Meng, Yanbin

    2015-02-01

    A novel structure design of a surface acoustic wave (SAW) micro-optic-electro-mechanical-system (MOEMS) strain sensor with a light readout unit is presented in this paper. By measuring the polarization intensity ratio of the TE/TM mode outputted from the waveguide, the strain produced from an object can be measured precisely. The basic working principle of the SAW MOEMS strain sensor is introduced and the mathematical model of the strain sensor system is established. The SAW characteristics effected by the strain sensor are mathematically deduced. The coupling coefficient between the SAW modes and light modes can be calculated based on the theory of coupling modes. The conversion coefficient of polarized light modes is obtained. Due to the restrictions of the specific parameters of the device, the level of technology and the material characteristics, the sensitivity of the strain sensor system is calculated through simulation as 0.1???, with a dynamic range of 0 ~ 50???.

  15. Wireless SAW sensor for high temperature applications: material point of view

    NASA Astrophysics Data System (ADS)

    Elmazria, Omar; Aubert, Thierry

    2011-06-01

    In addition to being small, simple and robust, surface acoustic wave (SAW) devices have the advantage of being passive (batteryless), remotely requestable (wireless) and inexpensive if fabricated on a large scale. The use of SAW devices as passive and wireless sensors allows them to operate in extreme conditions such as those with high levels of radiation, high temperatures up to 1000C, or electromagnetic interference, in which no other wireless sensor can operate. This is obviously conditioned by the fact that the materials constituting the device can withstand these harsh conditions. General principle of the SAW sensor in wireless configuration is developed and a review of recent works concerning the field of high temperature applications is presented with a specific attention given to the characterization of materials constituting the SAW device: piezoelectric substrate and metallic electrodes.

  16. Development of a Hydrogen Gas Sensor Using a Double Saw Resonator System at Room Temperature

    PubMed Central

    Yunusa, Zainab; Hamidon, Mohd Nizar; Ismail, Alyani; Isa, Maryam Mohd; Yaacob, Mohd Hanif; Rahmanian, Saeed; Ibrahim, Siti Azlida; Shabaneh, Arafat A.A

    2015-01-01

    A double SAW resonator system was developed as a novel method for gas sensing applications. The proposed system was investigated for hydrogen sensing. Commercial Surface Acoustic Wave (SAW) resonators with resonance frequencies of 433.92 MHz and 433.42 MHz were employed in the double SAW resonator system configuration. The advantages of using this configuration include its ability for remote measurements, and insensitivity to vibrations and other external disturbances. The sensitive layer is composed of functionalized multiwalled carbon nanotubes and polyaniline nanofibers which were deposited on pre-patterned platinum metal electrodes fabricated on a piezoelectric substrate. This was mounted into the DSAWR circuit and connected in parallel. The sensor response was measured as the difference between the resonance frequencies of the SAW resonators, which is a measure of the gas concentration. The sensor showed good response towards hydrogen with a minimum detection limit of 1%. PMID:25730480

  17. Modified impedance control for robotic saw cutting: Simulation and implementation in three degrees of freedom

    SciTech Connect

    Kriikku, E.M. ); Reynolds, D.L.; Carroll, J.J.; Dawson, D.M. . School of Electrical and Computer Engineering)

    1993-01-01

    The Savannah River Site (SRS) production and decommissioning operations produce solid radioactive transuranic (TRU) waste. This waste must be repackaged and sent to the Waste Isolation Pilot Plant (WIPP) for permanent disposal. The Savannah River Technology Center (SRTC) built a test facility to demonstrate simulated waste processing. The test facility use's a CIMCORP multi-axis robot system, a CIMROC[trademark] II robot controller, and an electric circular saw to remotely open and size reduce plywood crates. The robot can either be teleoperated using joysticks or autonomously controlled via the, CIMROC[trademark] II. Both methods are inadequate for circular saw cutting of plywood crates due to frequent saw blade binding. Blade binding results from the current commercial robot controller limitations. The limitations are overcome by incorporating additional sensor information into the existing controller structure. In this paper we utilize a force sensor and a frequency counter to implement a modified impedance controller which prevents saw blade binding.

  18. Modified impedance control for robotic saw cutting: Simulation and implementation in three degrees of freedom

    SciTech Connect

    Kriikku, E.M.; Reynolds, D.L.; Carroll, J.J.; Dawson, D.M.

    1993-12-31

    The Savannah River Site (SRS) production and decommissioning operations produce solid radioactive transuranic (TRU) waste. This waste must be repackaged and sent to the Waste Isolation Pilot Plant (WIPP) for permanent disposal. The Savannah River Technology Center (SRTC) built a test facility to demonstrate simulated waste processing. The test facility use`s a CIMCORP multi-axis robot system, a CIMROC{trademark} II robot controller, and an electric circular saw to remotely open and size reduce plywood crates. The robot can either be teleoperated using joysticks or autonomously controlled via the, CIMROC{trademark} II. Both methods are inadequate for circular saw cutting of plywood crates due to frequent saw blade binding. Blade binding results from the current commercial robot controller limitations. The limitations are overcome by incorporating additional sensor information into the existing controller structure. In this paper we utilize a force sensor and a frequency counter to implement a modified impedance controller which prevents saw blade binding.

  19. Slicing of single crystal and polycrystalline silicon ingots using multi-blade saws

    NASA Technical Reports Server (NTRS)

    Ross, J. B.

    1980-01-01

    Optimization of the Multi-Blade Slurry wafering technique was evaluated. Several wafering runs were made. Sufficient data necessary for a complete cost analysis of each of the three types of saw utilized are provided.

  20. A new triply rotated quartz cut for the fabrication of low loss IF SAW filters.

    PubMed

    Ballandras, Sylvain; Steichen, William; Briot, Emmanuelle; Solal, Marc; Doisy, Martine; Hodé, Jean-Michel

    2004-01-01

    Analysis of the quartz properties shows the existence of unexplored angular domains for which Rayleigh waves can be efficiently excited, exhibiting physical characteristics better than the ones of the (ST,X) cut. This paper presents a family of quartz cuts allowing significant improvements of surface acoustic wave (SAW) devices on quartz. A first set of experiments has been performed, confirming the theoretical predictions of the basic properties of SAW on these cuts. A second set of measurements then was achieved to refine the identification of coefficients needed to perform industrial SAW design. A demonstration of the improvements accessible using this new cut is presented. A low loss SAW filter working at 71 MHz has been fabricated using smaller aluminum thickness than that for standard quartz cuts, and exhibiting all the properties required for its industrial implementation. PMID:14995023

  1. Development of a hydrogen gas sensor using a double SAW resonator system at room temperature.

    PubMed

    Yunusa, Zainab; Hamidon, Mohd Nizar; Ismail, Alyani; Mohd Isa, Maryam; Yaacob, Mohd Hanif; Rahmanian, Saeed; Ibrahim, Siti Azlida; Shabaneh, Arafat A A

    2015-01-01

    A double SAW resonator system was developed as a novel method for gas sensing applications. The proposed system was investigated for hydrogen sensing. Commercial Surface Acoustic Wave (SAW) resonators with resonance frequencies of 433.92 MHz and 433.42 MHz were employed in the double SAW resonator system configuration. The advantages of using this configuration include its ability for remote measurements, and insensitivity to vibrations and other external disturbances. The sensitive layer is composed of functionalized multiwalled carbon nanotubes and polyaniline nanofibers which were deposited on pre-patterned platinum metal electrodes fabricated on a piezoelectric substrate. This was mounted into the DSAWR circuit and connected in parallel. The sensor response was measured as the difference between the resonance frequencies of the SAW resonators, which is a measure of the gas concentration. The sensor showed good response towards hydrogen with a minimum detection limit of 1%. PMID:25730480

  2. Noise source identification and control of a contractor grade table saw

    NASA Astrophysics Data System (ADS)

    Bleedorn, Kristin; McKee, Matthew; Yarbough, Dale; Yu, Chen; Zechmann, Edward L.; Mann, J. Adin

    2002-05-01

    Sponsored by the National Institute for Occupational Safety and Health (NIOSH) as part of their initiative to explore noise reduction strategies for construction equipment, a team of engineering students at Iowa State University studied a contractor grade table saw. Based on standards, published work, and preliminary tests, a repeatable noise measurement procedure was developed for the table saw operation. The wood-feed rate and force were measured. With the saw operating in a standard and consistent manner, noise sources on the saw were identified using sound intensity measurement techniques and through the application of noise control strategies to individual sources. At this stage, noise control strategies, such as enclosing the motor, are effective for noise source identification but not practical. The effectiveness of both approaches to identifying the noise sources will be discussed. Based on rank ordering the contribution of each noise source to the overall sound levels, permanent noise control strategies are suggested.

  3. Effect of Increasing Doses of Saw Palmetto on Lower Urinary Tract Symptoms: A Randomized Trial

    PubMed Central

    Barry, Michael J.; Meleth, Sreelatha; Lee, Jeannette Y.; Kreder, Karl J.; Avins, Andrew L.; Nickel, J. Curtis; Roehrborn, Claus G.; Crawford, E. David; Foster, Harris E.; Kaplan, Steven A.; McCullough, Andrew; Andriole, Gerald L.; Naslund, Michael J.; Williams, O. Dale; Kusek, John W.; Meyers, Catherine M.; Betz, Joseph M.; Cantor, Alan; McVary, Kevin T.

    2012-01-01

    Context Saw palmetto fruit extracts are widely used for treating lower urinary tract symptoms attributed to benign prostatic hyperplasia. However, recent clinical trials have questioned their efficacy, at least at standard doses (320 mg daily). Objective To determine the effect of a saw palmetto extract at up to three times the standard dose on lower urinary tract symptoms attributed to benign prostatic hyperplasia. Design Multicenter placebo-controlled randomized trial conducted from June, 2008 through October, 2010. Setting Eleven North American clinical sites. Participants Were men at least 45 years old, with a peak urinary flow rate ≥ 4 ml/sec, an AUA Symptom Index (AUASI) score ≥ 8 and ≤ 24, and no exclusions. Interventions One, two, and then three 320 mg daily doses of saw palmetto extract or placebo, with dose increases at 24 and 48 weeks. Main Outcome Measures Primary outcome was the difference in AUASI score from baseline to 72 weeks. Secondary outcomes were measures of urinary bother; nocturia; uroflow; postvoid residual; prostate-specific antigen; participants’ global assessments; and indices of sexual function, continence, sleep quality, and prostatitis symptoms. Results From baseline to 72 weeks, mean AUASI scores decreased from 14.4 to 12.2 points with saw palmetto and from 14.7 to 11.7 points with placebo. The group mean difference in AUASI score change from baseline to 72 weeks between the saw palmetto and placebo groups was 0.79 points favoring placebo (bound of the 95% confidence interval most favorable to saw palmetto was 1.77 points, one-sided P=0.91). Saw palmetto was no more effective than placebo for any secondary outcome. No attributable side effects were identified. Conclusions Increasing doses of a saw palmetto fruit extract did not reduce lower urinary tract symptoms more than placebo. (CAMUS study number NCT00603304 http://www.ClinicalTrials.gov) PMID:21954478

  4. Ultra-wideband communication system prototype using orthogonal frequency coded SAW correlators.

    PubMed

    Gallagher, Daniel R; Kozlovski, Nikolai Y; Malocha, Donald C

    2013-03-01

    This paper presents preliminary ultra-wideband (UWB) communication system results utilizing orthogonal frequency coded SAW correlators. Orthogonal frequency coding (OFC) and pseudo-noise (PN) coding provides a means for spread-spectrum UWB. The use of OFC spectrally spreads a PN sequence beyond that of CDMA; allowing for improved correlation gain. The transceiver approach is still very similar to that of the CDMA approach, but provides greater code diversity. Use of SAW correlators eliminates many of the costly components that are typically needed in the intermediate frequency (IF) section in the transmitter and receiver, and greatly reduces the signal processing requirements. Development and results of an experimental prototype system with center frequency of 250 MHz are presented. The prototype system is configured using modular RF components and benchtop pulse generator and frequency source. The SAW correlation filters used in the test setup were designed using 7 chip frequencies within the transducer. The fractional bandwidth of approximately 29% was implemented to exceed the defined UWB specification. Discussion of the filter design and results are presented and are compared with packaged device measurements. A prototype UWB system using OFC SAW correlators is demonstrated in wired and wireless configurations. OFC-coded SAW filters are used for generation of a transmitted spread-spectrum UWB and matched filter correlated reception. Autocorrelation and cross-correlation system outputs are compared. The results demonstrate the feasibility of UWB SAW correlators for use in UWB communication transceivers. PMID:23475929

  5. An interrogation unit for passive wireless SAW sensors based on fourier transform.

    PubMed

    Hamsch, Matthias; Hoffmann, Rene; Buff, Werner; Binhack, Michael; Klett, Stefan

    2004-11-01

    The application of surface acoustic wave (SAW) resonators as sensor elements for different physical parameters such as temperature, pressure, and force has been well-known for several years. The energy storage in the SAW and the direct conversion from physical parameter to a parameter of the wave, such as frequency or phase, enables the construction of a passive sensor that can be interrogated wireless. This paper presents a temperature-measurement system based on passive wireless SAW sensors. The principle of SAW sensors and SAW sensor interrogation is discussed briefly. A new measurement device developed for analyzing the sensor signals is introduced. Compared to former interrogation units that detect resonance frequency of the SAW resonator by comparing amplitudes of sensor response signals related to different stimulating frequencies, the new equipment is able to measure the resonance frequency directly by calculating a Fourier transformation of the resonator response signal. Measurement results of an experimental setup and field tests are presented and discussed. PMID:15600089

  6. A Reduced Three Dimensional Model for SAW Sensors Using Finite Element Analysis

    PubMed Central

    El Gowini, Mohamed M.; Moussa, Walied A.

    2009-01-01

    A major problem that often arises in modeling Micro Electro Mechanical Systems (MEMS) such as Surface Acoustic Wave (SAW) sensors using Finite Element Analysis (FEA) is the extensive computational capacity required. In this study a new approach is adopted to significantly reduce the computational capacity needed for analyzing the response of a SAW sensor using the finite element (FE) method. The approach is based on the plane wave solution where the properties of the wave vary in two dimensions and are uniform along the thickness of the device. The plane wave solution therefore allows the thickness of the SAW device model to be minimized; the model is referred to as a Reduced 3D Model (R3D). Various configurations of this novel R3D model are developed and compared with theoretical and experimental frequency data and the results show very good agreement. In addition, two-dimensional (2D) models with similar configurations to the R3D are developed for comparison since the 2D approach is widely adopted in the literature as a computationally inexpensive approach to model SAW sensors using the FE method. Results illustrate that the R3D model is capable of capturing the SAW response more accurately than the 2D model; this is demonstrated by comparison of centre frequency and insertion loss values. These results are very encouraging and indicate that the R3D model is capable of capturing the MEMS-based SAW sensor response without being computationally expensive. PMID:22303156

  7. Mass sensitivity calculation of the protein layer using love wave SAW biosensor.

    PubMed

    Lee, Sangdae; Kim, Ki Bok; Il Kim, Yong

    2012-07-01

    Love waves, a variety of surface acoustic waves (SAWs), can be used to detect very small biological surface interactions and so have a wide range of potential applications. To demonstrate the practicality of a Love wave SAW biosensor, we fabricated a 155-MHz Love wave SAW biosensor and compared it with a commercial surface Plasmon resonance (SPR) using glycerol-water solution with known densities and viscosities to calibrate the response signals of the biosensors. And the mass per unit area of anti-mouse IgG bound with protein G onto the sensitive layer of the biosensor was calculated on the basis of the calibration result. The sensitivity of the Love wave SAW biosensor was the same as or greater than that of the SPR biosensor. Furthermore, the Love wave SAW biosensor was capable of measuring a much wider range of viscosities than the SPR biosensor. Although the operating principle of the Love wave SAW biosensor is completely different from that of the SPR biosensor, the subtle changes in the viscoelastic properties of the biological layer that accompany biological binding reactions on the sensitive layer can be monitored and measured in the same ways as with the SPR biosensor. PMID:22966717

  8. Evolutionary origins and development of saw-teeth on the sawfish and sawshark rostrum (Elasmobranchii; Chondrichthyes).

    PubMed

    Welten, Monique; Smith, Moya Meredith; Underwood, Charlie; Johanson, Zerina

    2015-09-01

    A well-known characteristic of chondrichthyans (e.g. sharks, rays) is their covering of external skin denticles (placoid scales), but less well understood is the wide morphological diversity that these skin denticles can show. Some of the more unusual of these are the tooth-like structures associated with the elongate cartilaginous rostrum 'saw' in three chondrichthyan groups: Pristiophoridae (sawsharks; Selachii), Pristidae (sawfish; Batoidea) and the fossil Sclerorhynchoidea (Batoidea). Comparative topographic and developmental studies of the 'saw-teeth' were undertaken in adults and embryos of these groups, by means of three-dimensional-rendered volumes from X-ray computed tomography. This provided data on development and relative arrangement in embryos, with regenerative replacement in adults. Saw-teeth are morphologically similar on the rostra of the Pristiophoridae and the Sclerorhynchoidea, with the same replacement modes, despite the lack of a close phylogenetic relationship. In both, tooth-like structures develop under the skin of the embryos, aligned with the rostrum surface, before rotating into lateral position and then attaching through a pedicel to the rostrum cartilage. As well, saw-teeth are replaced and added to as space becomes available. By contrast, saw-teeth in Pristidae insert into sockets in the rostrum cartilage, growing continuously and are not replaced. Despite superficial similarity to oral tooth developmental organization, saw-tooth spatial initiation arrangement is associated with rostrum growth. Replacement is space-dependent and more comparable to that of dermal skin denticles. We suggest these saw-teeth represent modified dermal denticles and lack the 'many-for-one' replacement characteristic of elasmobranch oral dentitions. PMID:26473044

  9. Theoretical and Experimental Investigations to Improve the Performance of Surface Acoustic Wave (SAW) Biosensors

    NASA Astrophysics Data System (ADS)

    Richardson, Mandek

    The objective of this dissertation is to improve the performance of surface acoustic wave (SAW) biosensors for use in point-of-care-testing (POCT) applications. SAW biosensors have the ability to perform fast, accurate detection of an analyte in real time without the use of labels. However, the technology suffers from the inability to differentiate between specific and non-specific binding. Due to this limitation, direct testing of bodily fluids using SAW sensors to accurately determine an analyte's concentration is difficult. In addition, these sensors are challenged by the need to detect small concentrations of a biomarker that are typically required to give a clinical diagnosis. Sensitivity, selectivity and reliability are three critical aspects for any sensing platform. To improve sensitivity the delay path of a SAW sensor has been modified with microcavities filled with various materials. These filled cavities increased sensitivity by confining wave energy to the surface by way of constructive interference and waveguiding. Thus, the improved sensitivity will result in a lower limit of detection. In addition, insertion loss is decreased as a consequence of increased wave confinement to the surface. Sensor selectivity and reliability are adversely affected by non-specific binding of unwanted species present in a sample. To address this issue a multifunctional SAW sensor is presented. The sensor consists of two SAW delay lines oriented orthogonal to each on ST-quartz in order to generate two distinct wave modes. One wave mode is used for sensing while the other is used to remove loosely bound material. By using the same transduction mechanism for both removal and sensing, the sensor chip is simplified and complex electronics are avoided. The findings of this research involve the technological advances for SAW biosensors that make their use in POCT possible.

  10. In situ observation and measurement of the SAW thin-film acoustoelectric effect.

    PubMed

    Fisher, Brian; Malocha, Donald

    2012-03-01

    The thin-film acoustoelectric effect in SAW devices describes the interaction of electrical energy between a SAW in a piezoelectric medium and a thin film in the wave's propagation path. The real-time observation of the thin-film acoustoelectric interaction is useful in the design and characterization of SAW sensors (i.e., temperature, humidity, viscosity, voltage, current, Hall effects, etc.). An in situ test fixture was designed to be mechanically, thermally, and electrically stable. Data acquisition software and an electron beam evaporation system were configured for real-time thin-film characterization during film growth. Data have been observed for more than 20 SAW devices and over a wide range of frequencies (i.e., 62 MHz to 1 GHz). The results suggest that the use of the in situ procedure yielded good agreement between theoretical predictions and the measured data, which demonstrates a method for the characterization of a SAW H(2)-gas sensor in real-time. PMID:22481781

  11. Effect of multiblade slurry saw induced damage on silicon solar cells

    NASA Technical Reports Server (NTRS)

    Daud, T.; Liu, J. K.; Pollock, G. A.; Koliwad, K. M.

    1978-01-01

    A correlation between the optimum etch loss and the depth of damage is established using wafers produced by the Multiblade Slurry (MBS) and the Internal Diameter (ID) saws. The observations are based on the measurement of the performance of solar cells fabricated on these wafers. Sample preparation and test results are described and the following conclusions are made: (1) the amount of silicon removal necessary for optimum solar cell performance coincides with the depth of saw-induced damage; (2) optimization of cell performance is not affected by the method of silicon removal; (3) sawing conditions should be optimized to minimize the extent of saw-induced damage; (4) the MBS saw is found to induce damage to a lesser extent; (5) since the extent of damage in MBS-sawn wafers is in the limit of etch loss required in texture etching, it is possible to achieve optimum improvement in cell performance by merely texture etching the surface of as-sawn wafers.

  12. Integrated active mixing and biosensing using surface acoustic waves (SAW) and surface plasmon resonance (SPR) on a common substrate.

    PubMed

    Renaudin, Alan; Chabot, Vincent; Grondin, Etienne; Aimez, Vincent; Charette, Paul G

    2010-01-01

    This article presents a device incorporating surface plasmon resonance (SPR) sensing and surface acoustic wave (SAW) actuation integrated onto a common LiNbO(3) piezoelectric substrate. The device uses Rayleigh-type SAW to provide active microfluidic mixing in the fluid above the SPR sensor. Validation experiments show that SAW-induced microfluidic mixing results in accelerated binding kinetics of an avidin-biotin assay. Results also show that, though SAW action causes a parasitic SPR response due to heat injection into the fluid, a relatively brief relaxation time following the SAW pulses allows the effect to dissipate, without affecting the overall assay response. Since both SPR sensors and SAW transducers can be fabricated simultaneously using low-cost microfabrication methods on a single substrate, the proposed design is well-suited to lab-on-chip applications. PMID:20024058

  13. Comparison of saw ginning and high-speed roller ginning with different lint cleaners of mid-south grown cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four cotton cultivars were ginned with a saw-gin equipment line and also with a high-speed roller-gin line. The saw-gin line using an air-jet and controlled-batt saw-type lint cleaner was compared to the high-speed roller-gin line using two versions of an experimental lint cleaner, of a basic design...

  14. [The current state of the expertise of the injuries inflicted by the power-driven sawing tools].

    PubMed

    Nazarov, Yu V; Tolmachev, I A; Bozhchenko, A P

    2016-01-01

    This review of the literature covers the major articles published during the past 40 years that treat the problem of forensic medical expertise of the injuries to human organs inflicted by the power saws with high-speed reciprocating motion of the blade (power jigsaws and sabre saws.) The authors analyze the current state-of-the-art in this field and the available possibilities for the forensic medical expertise to evaluate the injuries inflicted by the sawing devices. PMID:27144264

  15. Sniffing lung cancer related biomarkers using an oxidized graphene SAW sensor

    NASA Astrophysics Data System (ADS)

    Zhang, Xin-Fang; Zhang, Zheng-Wei; He, Yan-Lan; Liu, Yi-Xing; Li, Shuang; Fang, Jing-Yue; Zhang, Xue-Ao; Peng, Gang

    2016-04-01

    Decane is one of the volatile organic compounds (VOCs) in human breath. Successful detection of decane in human breath has vast prospects for early lung cancer diagnosis. In this paper, a novel detecting device based on a filter surface acoustic wave (SAW) gas sensor is presented. SAW sensors coated with a thin oxidized graphene film were used to detect decane in parts per million (ppm) concentrations. Control and signal detection circuits were designed using a vector network analyzer with a detection resolution of insertion loss down to 0.0001 dB. The results showed that the SAW sensor could respond quickly with great sensitivity when exposed to 0.2 ppm decane. This device shows tremendous potential in medical diagnosis and environmental assessment.

  16. Investigations of bilayer sensor structure with copper phthalocyanine and palladium for hydrogen detection in SAW system

    NASA Astrophysics Data System (ADS)

    Jakubik, W. P.

    2006-11-01

    Bilayer structure with copper phthalocyanine (CuPc 100 nm) and palladium ( 18 nm), has been studied for hydrogen gas-sensing application at 30circC and 50circC temperatures. The structure was fabricated in a two different vacuum deposition processes (first the CuPc film and than the Pd) onto a LiNbO{3} Y- cut Z-propagating substrate for a SAW method and additionally (in this same technological processes) onto a glass substrate with a planar microelectrode array for simultaneously monitoring of the structure planar resistance. A good correlation has been observed between this two methods - frequency changes for SAW method coincide with decreasing of the bilayer structure resistance. Although the simultaneously measurements not always were possible (too big resistance of the sample) they can give informations about the acoustoelectric interactions between SAW and charge carriers in the bi-layer structure.

  17. Development of a generalized model to analyze time and frequency responses for SAW sensors

    NASA Astrophysics Data System (ADS)

    Tsai, Meng-Shiun; Jeng, Jie-Ting

    2011-02-01

    Most of the research on applications of wireless surface acoustic wave (SAW) sensors has focused on the fabrication process. No detailed theoretical models have been developed to illustrate the time and frequency domain characteristics of SAW devices. In this paper, the generalized model of the wireless SAW sensor is established by using the coupling-of-modes (COM) model together with the wave equations. The generalized model is developed to analyze four main applications, which include tag-ID design, the bio-reaction process, tension measurement and temperature sensing. Both the time response and frequency response are investigated to determine the appropriate signal processing for different applications. It is found that for the time response using the inverse fast Fourier transform (IFFT) is more suitable for tag-ID and the phase shift is better for bio-sensing, tension and temperature sensing. Furthermore, the developed model can be utilized to expedite the design process for wireless sensing devices.

  18. Bosonic See-Saw Mechanism and Its Application to Supersymmetry and Technicolor

    SciTech Connect

    Kim, Hyung Do

    2005-12-02

    We introduce the idea of bosonic see-saw mechanism in analogy with the see-saw mechanism. Bosonic see-saw is a new symmetry breaking mechanism and we apply it to explain electroweak symmetry breaking as an inevitable consequence of supersymmetry breaking. The breaking of electroweak symmetry occurs at tree level once supersymmetry is broken. Absence of color/charge breaking in this model is related to doublet-triplet splitting in grand unified theory. An extension of MSSM with a weak triplet shows very interesting results especially when {mu} = 0. It provides the most natural understanding of why we have only electroweak symmetry breaking rather than having color/charge breaking. In the limit {mu} = 0, the model predicts very light chargino mass, 104 GeV while Higgs is heavy, 130 GeV. Finally we mention the possibility of applying the same idea to technicolor idea.

  19. Development of Raman acousto-optic frequency shifter based on SAW

    NASA Astrophysics Data System (ADS)

    Chunmei, Wang; Zhiyu, Wen; Zuwei, Zhang; Yingyi, Zhang

    2014-08-01

    A Raman acousto-optic frequency shifter (AOFS) based on surface acoustic wave (SAW) is presented. It consists of a double-ended SAW resonator and optical waveguide system. The structure parameters of the SAW resonator are optimized using COM software and the optical waveguide system is designed using an effective index method. The AOFS prototype fabricated using MEMS technology is detected. The optical beat signals superimposed by ±1st-order and ±2nd-order diffracted beams are detected. The frequency shift of 78.2201 MHz related to the 1st-order diffracted beams and 156.2306 MHz related to the 2nd-order diffracted beams are obtained respectively.

  20. Enhanced spectral efficiency using bandwidth switchable SAW filtering for mobile satellite communications systems

    NASA Technical Reports Server (NTRS)

    Peach, Robert; Malarky, Alastair

    1990-01-01

    Currently proposed mobile satellite communications systems require a high degree of flexibility in assignment of spectral capacity to different geographic locations. Conventionally this results in poor spectral efficiency which may be overcome by the use of bandwidth switchable filtering. Surface acoustic wave (SAW) technology makes it possible to provide banks of filters whose responses may be contiguously combined to form variable bandwidth filters with constant amplitude and phase responses across the entire band. The high selectivity possible with SAW filters, combined with the variable bandwidth capability, makes it possible to achieve spectral efficiencies over the allocated bandwidths of greater than 90 percent, while retaining full system flexibility. Bandwidth switchable SAW filtering (BSSF) achieves these gains with a negligible increase in hardware complexity.

  1. Objective classification of performance in the use of a piercing saw in jewellery making.

    PubMed

    Baber, Chris; Cengiz, Tulin Gunduz; Starke, Sandra; Parekh, Manish

    2015-11-01

    Data from 15 jewellery students, in their 1st and 3rd years of training, were analysed to show how data collected from work settings can be used to objectively evaluate performance in the use of tools. Participants were asked to use a piercing saw to cut 5 lines in a piece of metal. Performance was categorised in terms of functional dynamics. Data from strain gauges and a tri-axial accelerometer (built into the handle of the saw) were recorded and thirteen metrics derived from these data. The key question for this paper is which metrics could be used to distinguish levels of ability. Principal Components Analysis identified five components: sawing action; grasp of handle; task completion time; lateral deviation of strokes; and quality of lines cut. Using representative metrics for these components, participants could be ranked in terms of performance (low, medium, high) and statistical analysis showed significant differences between participants on key metrics. PMID:26154220

  2. Development of a high-sensitivity strain measurement system based on a SH SAW sensor

    NASA Astrophysics Data System (ADS)

    Oh, Haekwan; Lee, Keekeun; Eun, Kyoungtae; Choa, Sung-Hoon; Yang, Sang Sik

    2012-02-01

    A strain measurement system based on a shear horizontal surface acoustic wave (SH SAW) was developed. The developed system is composed of a SAW microsensor, a printed circuit board (PCB), an adhesive and a strain gauge. When a compression force is applied to the PCB by the strain gauge, the PCB is bent so that external strain energy can be evenly delivered to the microsensor without any detachment of the sensor from the board. When a stretching force is applied to the PCB under the condition that one side of the PCB is fixed and the other side is modulated, the actual length of the SAW delay line between the two interdigital transducers (IDTs) is increased. The increase in the delay line length causes a change in the time for the propagating SAW to reach the output IDT. If strain energy is applied to the piezoelectric substrate, the substrate density is changed, which then changes the propagation velocity of the SAW. Coupling-of-modes modeling was conducted prior to fabrication to determine the optimal device parameters. Depending on the strain, the frequency difference was linearly modulated. The obtained sensitivity for stretching was 17.3 kHz/% for the SH wave mode and split electrode. And the obtained sensitivity for bending was 46.1 kHz/% for the SH wave mode and split electrode. The SH wave showed about 15% higher sensitivity than the Rayleigh wave, and the dog-bone PCB showed about 8% higher sensitivity than the rectangular PCB. The obtained sensitivity was about five times higher than that of existing SAW-based strain sensors.

  3. Evolutionary origins and development of saw-teeth on the sawfish and sawshark rostrum (Elasmobranchii; Chondrichthyes)

    PubMed Central

    Welten, Monique; Smith, Moya Meredith; Underwood, Charlie; Johanson, Zerina

    2015-01-01

    A well-known characteristic of chondrichthyans (e.g. sharks, rays) is their covering of external skin denticles (placoid scales), but less well understood is the wide morphological diversity that these skin denticles can show. Some of the more unusual of these are the tooth-like structures associated with the elongate cartilaginous rostrum ‘saw’ in three chondrichthyan groups: Pristiophoridae (sawsharks; Selachii), Pristidae (sawfish; Batoidea) and the fossil Sclerorhynchoidea (Batoidea). Comparative topographic and developmental studies of the ‘saw-teeth’ were undertaken in adults and embryos of these groups, by means of three-dimensional-rendered volumes from X-ray computed tomography. This provided data on development and relative arrangement in embryos, with regenerative replacement in adults. Saw-teeth are morphologically similar on the rostra of the Pristiophoridae and the Sclerorhynchoidea, with the same replacement modes, despite the lack of a close phylogenetic relationship. In both, tooth-like structures develop under the skin of the embryos, aligned with the rostrum surface, before rotating into lateral position and then attaching through a pedicel to the rostrum cartilage. As well, saw-teeth are replaced and added to as space becomes available. By contrast, saw-teeth in Pristidae insert into sockets in the rostrum cartilage, growing continuously and are not replaced. Despite superficial similarity to oral tooth developmental organization, saw-tooth spatial initiation arrangement is associated with rostrum growth. Replacement is space-dependent and more comparable to that of dermal skin denticles. We suggest these saw-teeth represent modified dermal denticles and lack the ‘many-for-one’ replacement characteristic of elasmobranch oral dentitions. PMID:26473044

  4. Maintenance of stellite and tungsten carbide saw tips: respiratory health and exposure-response evaluations.

    PubMed Central

    Kennedy, S M; Chan-Yeung, M; Marion, S; Lea, J; Teschke, K

    1995-01-01

    OBJECTIVE--To study exposure to cobalt and chromium in saw maintenance rooms and test respiratory health among saw filers at lumber mills. Hard-metal lung disease is associated with cobalt in the manufacture of tungsten carbide tools; recently it has also been reported among tool maintenance workers. Lumber mills often use saws tipped with tungsten carbide or with a newer alloy, stellite (containing more cobalt, as well as chromium). METHODS--A cross sectional study of 118 saw filers at eight lumber mills was carried out that included a standardised questionnaire, spirometry, personal air sampling, and examination of tasks every 10 minutes (by observation). Comparison data were from a study of bus mechanics tested with similar methods. RESULTS AND CONCLUSION--Cobalt exposure was associated with tungsten carbide grinding but not with stellite grinding. Chromium exposure was associated mainly with stellite welding. Saw filers had a twofold increase in phlegm and wheeze (P < 0.01) and a threefold increase in cough, phlegm, and wheeze related to work (P < 0.001), but no increase in breathlessness. Stellite welding was associated with a significant increase in nasal symptoms and cough related to work and a small decrease in airflow (forced expiratory volume in one second/forced vital capacity (FEV1/FVC%), P < 0.05). Saw filers wet grinding with tungsten carbide had significant reductions in forced expiratory lung volumes (FEV1 and FVC, P < 0.05) and were significantly more likely to have FEV1 and FVC values in the abnormal range. Cobalt exposure (in wet grinding) and duration of work that involved tungsten carbide grinding were both associated with significant reductions in FEV1 and FVC. Average cobalt exposures in this study were about 5 micrograms/m3, well below the currently accepted permissible concentration, which suggests that the current workplace limit for cobalt may be too high. PMID:7735392

  5. Accelerated binding kinetics by surface acoustic waves (SAW) micromixing in surface plasmon resonance (SPR) system for biodetection

    NASA Astrophysics Data System (ADS)

    Renaudin, Alan; Chabot, Vincent; Grondin, Etienne; Aimez, Vincent; Charette, Paul G.

    2011-02-01

    A design incorporating surface plasmon resonance (SPR) biosensing and surface acoustic wave (SAW) active microfluidic mixing, integrated on a single LiNbO3 piezoelectric substrate, is presented. Validation experiments show that SAW-mixing (microstreaming) results in accelerated binding kinetics (time-to-saturation) for a standard assay with appropriate SAW excitation parameters. Since both SPR sensors and SAW transducers can be fabricated simultaneously using low-cost microfabrication methods, the proposed design should contribute to improved lab-on-chip devices for detecting and identifying biomolecules of interest with greater accuracy and speed across multiple applications.

  6. SAW filter manufacture and piezoelectric materials evaluation based on printed electronics technology

    NASA Astrophysics Data System (ADS)

    Liu, Xiao-chen; Li, Kun; Xuan, Xiu-wei; Cao, Yang; Teng, Jian-fu

    2014-09-01

    In this paper, the silver nanoparticle ink and ink-jet printing technology are used to manufacture the surface acoustic wave (SAW) filters. The characteristics of three common substrate piezoelectric materials of ST-quartz, Y36°-LiTaO3 and Y128°-LiNbO3 are evaluated. The experimental results show that Y128°-LiNbO3 matches the ink much better than others. The printed SAW filter with Y128°-LiNbO3 as piezoelectric substrate is realized, and its center frequency and bandwidth are 18.4 MHz and 500 kHz, respectively.

  7. SAW-grade SiO2 for advanced microfluidic devices

    NASA Astrophysics Data System (ADS)

    Winkler, Andreas; Menzel, Siegfried; Schmidt, Hagen

    2009-05-01

    Acoustoelectronic devices based on surface acoustic wave (SAW) technology are primarily used in radio frequency filters, delay lines, duplexers, amplifiers and RFID tags. Thereby, SAW's are excited at the surface of piezoelectric materials (e.g. Quartz, LiTaO3, LiNbO3) by an RF signal applied via interdigital transducers (IDTs)1. Novel SAW applications that emerged recently in the field of microfluidics such as the handling of minimum quantities of fluids or gases2,3 require a fluid compatible design approach, high power durability and long lifetime of the devices. However, conventional SAW devices with finger electrodes arranged on top of the chip surface experience acoustomigration damage4,5 at high power input and/or higher operating temperature leading to failure of the device. Additionally, inappropriate material systems or chip surface topography can limit their performance in microfluidic application. To overcome these limitations the electrodes can be buried in an acoustically suited ("SAW-grade") functional layer which moreover should be adjustable to the specific biotechnological task. Depending on the properties of this layer, it can suppress the acoustomigration impact6 and improve the power durability of the device. Also, a reduction of the thermally-induced frequency shift is possible7. The present paper describes a novel SAW based chip technology approach using a modular concept. Here, the electrodes are buried in surface polished SAW-grade SiO2 fabricated by means of reactive RF magnetron sputtering from a SiO2- target. This approach will be demonstrated for two different metallization systems based on Al or Cu thin films on 128° YX-LiNbO3 substrates. We also show the application of the SiO2-layer with respect to compensation of thermallyinduced frequency shift and bio /chemical surface modification. Investigations were carried out using atomic force microscopy, laser-pulse acoustic measurement, glow-discharge optical emission spectroscopy, spectral reflectometry, variable angle ellipsometry and x-ray photoelectron spectroscopy. The electrode edge covering of sputter deposited SiO2 layers and the reactive ion etching of the SiO2 layers are also discussed. This modular technology gives the possibility to improve the compatibility of surface acoustic wave devices to microfluidics and generally allows the integration of SAW driven actuators (pumps and mixing devices) and sensors (sensitive to surface mass change or complex viscosity change) together with other microfluidic elements (e.g. electrophoresis, heating elements) on one chip.

  8. Aberrations in saw-tooth refractive lenses in short focal length x-ray focusing

    NASA Astrophysics Data System (ADS)

    Antimonov, Mikhail A.; Khounsary, Ali M.; Shastri, Sarvjit D.

    2013-10-01

    Saw-tooth refractive lenses (SRL) provide a comparatively attractive option for X-ray focusing for various reasons, including their simple, continuous tunability in energy and focal length. Optimal focusing of a conventional SRL at short focal lengths is limited by the SRL's length in relation to the focal length. Three approaches to overcome this limitation are described. Analytical solutions verified with ray-tracing are presented. These are bending, variation of the saw-tooth tip angles, and variation of the period.

  9. Optimization of frequency characteristics for SAW device using apodization weighting method

    NASA Astrophysics Data System (ADS)

    Zhou, Lei; Zhang, Kai-liang; Wang, Fang; Han, Ye-mei; Miao, Yin-ping; Li, Dong-mei; Liang, Sheng-fa

    2015-03-01

    In this paper, the positive influence of apodization weighting method on frequency characteristics of surface acoustic wave (SAW) temperature sensor is investigated. Simulation and experiment results show that side lobe suppression abilities of the sensor can be improved by using apodization weighting which is based on Chebyshev window. Meanwhile, we find that the side lobe of the sensor can be further restrained, when the dummy electrodes are removed. Frequency-temperature characteristics of the devices are independent of the inclusion of dummy electrodes. The apodization weighted SAW temperature sensor shows great application potential in occasions with strong electromagnetic interference.

  10. New immobilization method for SAW-biosensors: covalent attachment of antibodies via CNBr.

    PubMed

    Wessa, T; Rapp, M; Ache, H J

    1999-01-01

    Surface acoustic wave devices (SAWs) based on horizontally polarized shear waves can be used as mass-sensitive immunosensors. If the standard material, aluminium, is used for the interdigital transducers (IDTs) of these devices a pretreatment with a shielding layer of polyimide is necessary to prevent corrosion processes. However, this layer also prevents an easy covalent attachment of the necessary receptive molecules. Therefore, we developed a new activation method of this inert polyimide surface by treating with cyanogenbromide using the established cyano-transfer-technique. With a subsequent covalent attachment of anti-glucose oxidase (anti-GOD) a very sensitive SAW-immunosensor for glucose oxidase (GOD) can be obtained. PMID:10028654

  11. Early development of rostrum saw-teeth in a fossil ray tests classical theories of the evolution of vertebrate dentitions.

    PubMed

    Smith, Moya Meredith; Riley, Alex; Fraser, Gareth J; Underwood, Charlie; Welten, Monique; Kriwet, Jürgen; Pfaff, Cathrin; Johanson, Zerina

    2015-10-01

    In classical theory, teeth of vertebrate dentitions evolved from co-option of external skin denticles into the oral cavity. This hypothesis predicts that ordered tooth arrangement and regulated replacement in the oral dentition were also derived from skin denticles. The fossil batoid ray Schizorhiza stromeri (Chondrichthyes; Cretaceous) provides a test of this theory. Schizorhiza preserves an extended cartilaginous rostrum with closely spaced, alternating saw-teeth, different from sawfish and sawsharks today. Multiple replacement teeth reveal unique new data from micro-CT scanning, showing how the 'cone-in-cone' series of ordered saw-teeth sets arrange themselves developmentally, to become enclosed by the roots of pre-existing saw-teeth. At the rostrum tip, newly developing saw-teeth are present, as mineralized crown tips within a vascular, cartilaginous furrow; these reorient via two 90° rotations then relocate laterally between previously formed roots. Saw-tooth replacement slows mid-rostrum where fewer saw-teeth are regenerated. These exceptional developmental data reveal regulated order for serial self-renewal, maintaining the saw edge with ever-increasing saw-tooth size. This mimics tooth replacement in chondrichthyans, but differs in the crown reorientation and their enclosure directly between roots of predecessor saw-teeth. Schizorhiza saw-tooth development is decoupled from the jaw teeth and their replacement, dependent on a dental lamina. This highly specialized rostral saw, derived from diversification of skin denticles, is distinct from the dentition and demonstrates the potential developmental plasticity of skin denticles. PMID:26423843

  12. Early development of rostrum saw-teeth in a fossil ray tests classical theories of the evolution of vertebrate dentitions

    PubMed Central

    Smith, Moya Meredith; Riley, Alex; Fraser, Gareth J.; Underwood, Charlie; Welten, Monique; Kriwet, Jürgen; Pfaff, Cathrin; Johanson, Zerina

    2015-01-01

    In classical theory, teeth of vertebrate dentitions evolved from co-option of external skin denticles into the oral cavity. This hypothesis predicts that ordered tooth arrangement and regulated replacement in the oral dentition were also derived from skin denticles. The fossil batoid ray Schizorhiza stromeri (Chondrichthyes; Cretaceous) provides a test of this theory. Schizorhiza preserves an extended cartilaginous rostrum with closely spaced, alternating saw-teeth, different from sawfish and sawsharks today. Multiple replacement teeth reveal unique new data from micro-CT scanning, showing how the ‘cone-in-cone’ series of ordered saw-teeth sets arrange themselves developmentally, to become enclosed by the roots of pre-existing saw-teeth. At the rostrum tip, newly developing saw-teeth are present, as mineralized crown tips within a vascular, cartilaginous furrow; these reorient via two 90° rotations then relocate laterally between previously formed roots. Saw-tooth replacement slows mid-rostrum where fewer saw-teeth are regenerated. These exceptional developmental data reveal regulated order for serial self-renewal, maintaining the saw edge with ever-increasing saw-tooth size. This mimics tooth replacement in chondrichthyans, but differs in the crown reorientation and their enclosure directly between roots of predecessor saw-teeth. Schizorhiza saw-tooth development is decoupled from the jaw teeth and their replacement, dependent on a dental lamina. This highly specialized rostral saw, derived from diversification of skin denticles, is distinct from the dentition and demonstrates the potential developmental plasticity of skin denticles. PMID:26423843

  13. Investigation of fiber maturity effect on saw-type lint cleaner fiber damage and yarn properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One-half of plots of two cotton cultivars with similar mature fiber length were harvested after two defoliation treatments (early/late) to get less and more mature cottons. These seed cotton lots were ginned with the same seed cotton cleaning but with 0, 1, or 3 saw-type lint cleaners with low dryi...

  14. 76 FR 75504 - Table Saw Blade Contact Injuries; Notice of Extension of Time for Comments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-02

    ... protect the user from accidental contact with the blade. In the Federal Register of July 9, 2003 (68 FR... rule requiring specified warnings and instructions to address table saw blade contact injuries (76 FR... Act (``CPSA''), 15 U.S.C. 2051-2084. In the Federal Register of October 11, 2011 (76 FR 62678),...

  15. 77 FR 8751 - Table Saw Blade Contact Injuries; Reopening of the Comment Period

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-15

    ... accidental contact with the blade. In the Federal Register of July 9, 2003 (68 FR 40912) and September 5... blade contact injuries in the Federal Register of October 11, 2011 (76 FR 62678). CPSC staff also... warnings and instructions to address table saw blade contact injuries (76 FR at 62683). The ANPR...

  16. Observing the motion of seed coat fragments on a saw-type lint cleaner

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to observe how seed coat fragments (in ginned lint) reacted after colliding with grid bars mounted on a full-size saw-type lint cleaner. A high-speed video camera recorded the collision. A 45° and 105° grid bar were used in the study. The grid bars were labeled to describe t...

  17. Development of fuzzy logic system to predict the SAW weldment shape profiles

    NASA Astrophysics Data System (ADS)

    Narang, H. K.; Mahapatra, M. M.; Jha, P. K.; Biswas, P.

    2012-09-01

    A fuzzy model was presented to predict the weldment shape profile of submerged arc welds (SAW) including the shape of heat affected zone (HAZ). The SAW bead-on-plates were welded by following a full factorial design matrix. The design matrix consisted of three levels of input welding process parameters. The welds were cross-sectioned and etched, and the zones were measured. A mapping technique was used to measure the various segments of the weld zones. These mapped zones were used to build a fuzzy logic model. The membership functions of the fuzzy model were chosen for the accurate prediction of the weld zone. The fuzzy model was further tested for a set of test case data. The weld zone predicted by the fuzzy logic model was compared with the experimentally obtained shape profiles and close agreement between the two was noted. The mapping technique developed for the weld zones and the fuzzy logic model can be used for on-line control of the SAW process. From the SAW fuzzy logic model an estimation of the fusion and HAZ can also be developed.

  18. Production Machine Shop Employment Competencies. Part Two: Saws, Drills, and Grinders.

    ERIC Educational Resources Information Center

    Bishart, Gus; Werner, Claire

    Competencies for production machine shop are provided for the second of four topic areas: saws, drills, and grinders. Each competency appears in a one-page format. It is presented as a goal statement followed by one or more "indicator" statements, which are performance objectives describing an ability that, upon attainment, will establish…

  19. Surface Acoustic Wave (SAW) biosensors: coupling of sensing layers and measurement.

    PubMed

    Lnge, Kerstin; Gruhl, Friederike J; Rapp, Michael

    2013-01-01

    Surface acoustic wave (SAW) devices based on horizontally polarized surface shear waves enable direct and label-free detection of proteins in real time. Signal response changes result mainly from mass increase and viscoelasticity changes on the device surface. With an appropriate sensor configuration all types of binding reactions can be detected by determining resonant frequency changes of an oscillator. To create a biosensor, SAW devices have to be coated with a sensing layer binding specifically to the analyte. Intermediate hydrogel layers used within the coating have been proven to be very suitable to easily immobilize capture molecules or ligands corresponding to the analyte. However, aside from mass increase due to analyte binding, the SAW signal response in a subsequent binding experiment strongly depends on the morphology of the sensing layer, as this may lead to different relative changes of viscoelasticity. Bearing these points in mind, we present two basic biosensor coating procedures, one with immobilized capture molecule and a second with immobilized ligand, allowing reliable SAW biosensor signal responses in subsequent binding assays. PMID:23329462

  20. Simultaneous and wireless measurement of CO2 and humidity using a SAW reflective delay line

    NASA Astrophysics Data System (ADS)

    Lim, Chunbae; Wang, Wen; Lee, Keekeun; Oh, Hae-Kwan; Yang, Sangsik

    2009-02-01

    A 440MHz wireless and passive surface acoustic wave (SAW) based chemical sensor was developed for simultaneous measurement of CO2 gas and relative humidity (RH) using a reflective delay line pattern as the sensor element. The reflective delay line was structured by an inter-digital transducer (IDT) and several shorted grating reflectors positioned both sites of the IDTs along the SAW propagation direction. A Teflon AF 2400 film with large solubility, permeability, and selectivity towards to CO2 and a hydrophilic SiO2 layer for water vapor sensing are used as the sensitive film and deposited onto the piezoelectric substrate. A simulation on the SAW device was performed using the coupling of modes (COM). The measured reflection coefficient S11 in time domain of the fabricated SAW device shows sharp reflection peaks with high signal-to-noise (S/N) ratio, small signal attenuation, and few spurious peaks. During the CO2 and humidity testing, high sensitivity (~2o ppm-1 for CO2 detection and 7.45o/%RH for humidity sensing), good linearity and repeatability were observed in the CO2 concentration of 50~400ppm and humidity of 20~80%RH. Temperature and humidity compensations were also investigated during the sensitivity evaluation process.

  1. On the Modeling of Electrical Response of SAW Resonator-based Sensors Versus Temperature

    NASA Astrophysics Data System (ADS)

    Ballandras, S.; Laroche, T.; Courjon, E.; Daniau, W.; Baron, T.; Garcia, J.; Alzuaga, S.

    Surface acoustic wave (SAW) resonators built on Langasite (LGS) are capable to withstand temperature in excess of 900∘ C and demonstration of wireless interrogation of packaged sensors up to 700∘ C has been achieved for several tens of hours. These promising results emphasize the need for an accurate characterization of the raw material in order to design SAW resonators with a high level of confidence in the prediction, particularly concerning the temperature coefficient of frequency (TCF). Several data set have been published for LGS, offering prediction capabilities but also a significant level of data dispersion. Therefore, the evaluation of the effective thermal properties of SAW under periodic gratings turns out less robust than expected. Based also on published data and on measurements achieved within the SAWHOT project, harmonic admittance calculations have been achieved for deriving the evolution of mixed matrix parameters allowing for accurate SAW device simulation at any temperature. Adjusting the temperature coefficients then yield improved sets of material coefficients for design purpose. Using these data, we have demonstrated the possibility to develop a differential temperature sensor operating at temperature up to 600°C.

  2. Numerics of surface acoustic wave (SAW) driven acoustic streaming and radiation force

    NASA Astrophysics Data System (ADS)

    Nama, Nitesh; Barnkob, Rune; Kahler, Christian; Costanzo, Francesco; Jun Huang, Tony

    2015-11-01

    Recently, surface acoustic wave (SAW) based systems have shown great potential for various lab-on-a-chip applications. However, the physical understanding of the precise acoustic fields and associated acoustophoresis is rather limited. In this work, we present a numerical study of the acoustophoretic particle motion inside a SAW-actuated, liquid-filled polydimethylsiloxane (PDMS) microchannel. We utilize a perturbation approach to divide the flow variables into first- and second-order components. The first-order fields result in a time-averaged acoustic radiation force on suspended particles, as well as the time-averaged body force terms that drive the second-order fields. We model the SAW actuation by a displacement function while we utilize impedance boundary conditions to model the PDMS walls. We identify the precise acoustic fields generated inside the microchannel and investigate a range of particle sizes to characterize the transition from streaming-dominated acoustophoresis to radiation-force-dominated acoustophoresis. Lastly, we demonstrate the ability of SAW devices to tune the position of vertical pressure node inside the microchannel by tuning the phase difference between the two incoming surface acoustic waves.

  3. Instructional Media Production for Early Childhood Education: A. B. C. Jig-Saw Puzzle, a Model

    ERIC Educational Resources Information Center

    Yusuf, Mudashiru Olalere; Olanrewaju, Olatayo Solomon; Soetan, Aderonke K.

    2015-01-01

    In this paper, a. b. c. jig-saw puzzle was produced for early childhood education using local materials. This study was a production based type of research, to serve as a supplemental or total learning resource. Its production followed four phases of development referred to as information, design, production and evaluation. The storyboard cards,…

  4. The Income Volatility See-Saw: Implications for School Lunch. ERS Report Summary

    ERIC Educational Resources Information Center

    Newman, Constance

    2006-01-01

    Income volatility challenges the functioning of the safety net provided by U.S. Department of Agriculture (USDA) food assistance programs for low-income families in time of need. Low-income families may be on a see-saw of income changes that make it difficult for program administrators to accurately target benefits and to define sensible…

  5. Neutrino Oscillation Parameters in a Six-channel Reduced Rank See-Saw

    SciTech Connect

    Stephenson, G. J. Jr.; Goldman, T.; McKellar, B. H. J.

    2006-07-11

    We demonstrate that it is possible to find parameters in a rank one see-saw model which give a reasonable representation of atmospheric neutrino data and of the LSND result. Solar neutrino data will require a complete description of the matter effect in the six channel space.

  6. Machine Shop. Module 4: Power Saw and Drill Press Operation. Instructor's Guide.

    ERIC Educational Resources Information Center

    Walden, Charles H.; Daniel, Bill

    This document consists of materials for a six-unit course on the following topics: (1) power saw safety and maintenance; (2) cutting stock to length; (3) band machining and contouring; (4) drill press types and safety; (5) drill press work-holding devices; and (6) tools and tool holders. The instructor's guide begins with a list of competencies

  7. Detection/classification/quantification of chemical agents using an array of surface acoustic wave (SAW) devices

    NASA Astrophysics Data System (ADS)

    Milner, G. Martin

    2005-05-01

    ChemSentry is a portable system used to detect, identify, and quantify chemical warfare (CW) agents. Electro chemical (EC) cell sensor technology is used for blood agents and an array of surface acoustic wave (SAW) sensors is used for nerve and blister agents. The combination of the EC cell and the SAW array provides sufficient sensor information to detect, classify and quantify all CW agents of concern using smaller, lighter, lower cost units. Initial development of the SAW array and processing was a key challenge for ChemSentry requiring several years of fundamental testing of polymers and coating methods to finalize the sensor array design in 2001. Following the finalization of the SAW array, nearly three (3) years of intensive testing in both laboratory and field environments were required in order to gather sufficient data to fully understand the response characteristics. Virtually unbounded permutations of agent characteristics and environmental characteristics must be considered in order to operate against all agents and all environments of interest to the U.S. military and other potential users of ChemSentry. The resulting signal processing design matched to this extensive body of measured data (over 8,000 agent challenges and 10,000 hours of ambient data) is considered to be a significant advance in state-of-the-art for CW agent detection.

  8. Seed Germination Methods and Establishment of Saw-Palmetto, Serenoa Repens, in South Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Saw-pametto, Serenoa repens, a native of Florida rangelands, and used medicinally in prostate formulations, was evaluated as an alternative crop for South Texas (USA). Fresh seeds, obtained from the USDA Plant Introduction Station, Miami, Florida on Oct.28, 1999, were sown directly into artificial ...

  9. An experimental study of the physiological effects of chain saw operation.

    PubMed Central

    Miyakita, T; Miura, H; Futatsuka, M

    1987-01-01

    This experimental study was designed to determine whether a combination of noise and vibration produced more pronounced changes in temporary shifts of finger skin temperature and temporary threshold shift (TTS) of hearing than those resulting from exposure to either stress alone. Nineteen healthy subjects were exposed to six different combinations of vibration, noise, and handle holding by using a chain saw for a pre-determined time. The mean value of normalised finger skin temperature decreased much more when the subjects operated a chain saw at high speed (exposure 1) than when they operated the chain saw with the noise isolated by double hearing protection (exposure 2). In five of the 14 subjects significantly larger TTS values at 4 kHz were observed in the former condition (exposure 1) compared with the values obtained when they stood beside someone else operating a chain saw (exposure 3). The results of this study suggest that noise may play a part in inducing the constriction of the peripheral vessels seen with local exposure to vibration, and that hand-arm vibration may produce an additive effect on the noise induced TTS. PMID:3814533

  10. Effects of Friction Reduction on Fiber Damage in a Saw-Type Lint Cleaner

    Technology Transfer Automated Retrieval System (TEKTRAN)

    U.S. cotton is at a competitive disadvantage from a fiber-quality standpoint, because lint cleaning is required for mechanically harvested cotton, and lint cleaning causes fiber damage. Lint-cleaning research has focused mainly on modifying saw-type lint cleaners, but the work reported here focuses...

  11. Machine Shop. Module 4: Power Saw and Drill Press Operation. Instructor's Guide.

    ERIC Educational Resources Information Center

    Walden, Charles H.; Daniel, Bill

    This document consists of materials for a six-unit course on the following topics: (1) power saw safety and maintenance; (2) cutting stock to length; (3) band machining and contouring; (4) drill press types and safety; (5) drill press work-holding devices; and (6) tools and tool holders. The instructor's guide begins with a list of competencies…

  12. Capped guanidino-?-cyclodextrin first synthesis based on intramolecular Staudinger-Aza-Wittig (SAW) reaction.

    PubMed

    Couturier, C; Dumarcay-Charbonnier, F; Lambert, A; Barth, D; Marsura, A

    2014-11-01

    An intramolecularly promoted SAW reaction between a phosphinimide and an isocyanate intermediate led to an original bridged trisubstituted ((A,C),E)-?-cyclodextrin. The latter was in a second step converted into a new capped (ACE)-(guanidino)-?-cyclodextrin. PMID:25438653

  13. SAW/GC detection of taggants and other volatile compounds associated with contraband materials

    NASA Astrophysics Data System (ADS)

    Staples, Edward J.; Watson, Gary W.; McGuirre, David S.; Williams, Dudley

    1997-02-01

    Research on a Surface Acoustic Wave (SAW) Gas Chromatography (GC) non-intrusive inspection system has demonstrated the ability to identify and quantify the presence of non- volatile contraband vapors in less than 10 seconds. The technique can be used to detect volatile compounds associated with the contraband compound as well. This is important because volatile taggants in explosives make them easy to detect and volatile organic compounds are routinely used in the manufacturing of illicit drugs. The results of tests with volatile organic compounds associated with drugs of abuse, and volatile taggants for explosives are presented. The latter materials are particularly useful in detecting plastic explosives and results for Semtex and C-4 spiked with a taggant show that detectability is improved. Similar testing protocols and methods for drugs, currency, organo-phosphate agents, and taggant compounds have also been demonstrated. The SAW/GC method needs no high voltages, utilizes essentially all solid state devices, and involves no radioactive or hazardous materials SAW detection systems have demonstrated dynamic ranges greater than 1,000,000 and the ability to selectively screen for vapors from explosive and drugs of abuse at the part per billion level with little or no interference. Most important for law-enforcement, SAW/GC devices can be produced in small packages at low cost.

  14. Determination and experimental verification of high-temperature SAW orientations on langatate.

    PubMed

    Davulis, Peter M; da Cunha, Mauricio Pereira

    2012-02-01

    Langatate (LGT) is a member of the langasite family of crystals appropriate for high-temperature frequency control and sensing applications. This paper identifies multiple LGT SAW orientations for use at high temperature, specifically in the 400C to 900C range. Orientations with low sensitivity to temperature are desired for frequency control devices and many sensors, conversely large temperature sensitivity is a benefit for temperature sensors. The LGT SAW temperature behavior has been calculated for orientations sweeping the Euler angles (0, ?, ?), (90, ?, ?), and (?, 90, ?), based on newly identified high-temperature elastic constants and temperature coefficients for this material. The temperature coefficient of delay (TCD) and total frequency change over the temperature range were analyzed from 400C to 900C. Multiple SAW orientations were identified with zero-TCD between 400C and 500C. Although no orientations that have turn-over temperatures above 500C were identified, several have low frequency variation with temperature, of the order of -0.8% over the range 400C to 800C. Temperature-sensitive orientations with TCD up to 75 ppm/C at 900C were identified, with potential for high-temperature sensor applications. The reported predictions are shown to agree with measured behavior of LGT SAW delay lines fabricated along 6 orientations in the (90, 23, ?) plane. In addition, this work demonstrates that concurrently operated LGT SAW devices fabricated on the same wafer provide means of temperature sensing. In particular, the measured frequency difference between delay lines oriented along (90, 23, 0) and (90, 23, 48) has fractional temperature sensitivity that ranges from -172 ppm/C at 25C to -205 ppm/C at 900C. PMID:24626037

  15. Finite element calculation of the dispersion relations of infinitely extended SAW structures including bulk wave radiation

    NASA Astrophysics Data System (ADS)

    Hofer, Manfred; Finger, Norman; Zaglmayr, Sabine; Schoeberl, Joachim; Kovacs, Guenter; Langer, Ulrich; Lerch, Reinhard

    2002-07-01

    In the design procedure of surface acoustic wave (SAW) devices simple models like equivalent circuit models or the Coupling of Modes (COM) model are used to achieve short calculation times. Therefore, these models can be used for iterative component optimization. However, they are subject to many simplifications and restrictions. In order to improve the parameters required for the simpler models and to achieve better insight ot the physics of SAW devices analysis tools solving the constitutional partial differential equations are needed. We have developed an efficient calculation scheme based on the finite element method. It makes use of newly established periodic boundary conditions (PBCs) allowing the simulation of an infinitely extended SAW device. This is a good approximation of many SAW devices which show a large number of periodically arranged electrodes. We have developed two different formulations for the PBCs: One leads to a small quadratic eigenvalue problem operating on a larger matrix. These formulations allow the calculation of the complete dispersion relation. Bulk acoustic waves (BAWs) which are generated due to mode conversion at electrode edges are allowed to leave the calculation area nearly without reflection. Therefore, the calculation scheme also considers damping coefficients caused by the conversion of surface waves into bulk waves. This behavior coincides well with real SAW devices in which the substrate thickness is large compared to the used wavelengths and, additionally, the bulk waves are scattered in all directions at the rough substrate bottom. In the paper, a short introduction to the basic theory of the numerical calculation scheme will be given first. The applicability of the calculation scheme will be demonstrated by comparing analytical, measured and simulated results.

  16. Radiative Efficiency Enhancement in Blue Saw-Like InGaN/GaN Light-Emitting Diodes

    NASA Astrophysics Data System (ADS)

    Park, Seoung-Hwan

    2013-05-01

    Light emission characteristics of saw-like blue InGaN/GaN quantum well (QW) light-emitting diodes (LEDs) are theoretically investigated using the multiband effective mass theory. The saw-like QW structure has several advantages such as the enhancement in light emission, the reduction in the quantum Stark effect, and the increase in the internal efficiency, compared with a conventional InGaN/GaN QW structure. The increase in the spontaneous emission peak of the saw-like QW structure is mainly attributed to the fact that the electron wavefunction is shifted toward the left side with the inclusion of the saw-like layer while the hole wavefunction is nearly invariant. The internal efficiency of the saw-like QW structure is shown to be much larger than that of a conventional QW structure. Hence, we expect that this structure can be used as high-efficiency blue InGaN/GaN LEDs.

  17. Design and use of multiple blade slurry sawing in a production atmosphere

    NASA Technical Reports Server (NTRS)

    Lynah, F. P., Jr.; Ross, J. B.

    1982-01-01

    The technique and uses of the multiple blade slurry (MBS) saw are considered. Multiple bands of steel are arranged in a frame and the frame is reciprocated with the steel bands to a workpiece, while simultaneously applying abrasive at the point of contact. The blades wear slots in the workpiece and progress through the piece resulting in several parts of wafers. The transition to MBA from diamond slicing is justified by savings resulting from minimized kerf losses, minimized subsurface damage, and improved surface quality off the saw. This allows wafering much closer to finished thickness specifications. The current state of the art MBS technology must be significantly improved if the low cost solar array (LSA) goals are to be attained. It is concluded that although MBS will never be the answer to every wafering requirement, the economical production of wafers to LSA project specifications will be achieved.

  18. Developments towards a surface acoustic wave (SAW) sensor for detecting volatiles and its evaluation system

    NASA Astrophysics Data System (ADS)

    Ali, Azam; Mohamed, K.; Ranford, S. L.; Zhang, H.

    2009-07-01

    This work presents developments towards sensors with a flexible information management system. Substrates used for engineering passive and wireless surface acoustic wave (SAW) devices with interactive materials were tested for detection of temperature, humidity, carbon dioxide and other volatiles associated with food exports. Testing of new interactive materials was carried out using quartz crystal microbalance (QCM) methods. In preparation for testing new interactive materials, SAW devices with dimensions of 44 mm2 were fabricated on quartz and lithium niobate (LiNbO3) substrates. To evaluate the devices, a system was developed using a data acquisition tool and human-machine interface developed with LABVIEW software to achieve inter-operability between sensing devices and controlled micro-environments.

  19. Wireless sensing using oscillator circuits locked to remote high-Q SAW resonators.

    PubMed

    Pohl, A; Ostermayer, G; Seifert, F

    1998-01-01

    This paper introduces a method of wireless read out of high Q surface acoustic wave (SAW) resonator sensors. The resonator is excited by a short RF pulse and decays after switching off the interrogating signal. In the measurement system, a gated phase locked loop (GPLL) locks to the resonance frequency of the SAW resonator within a few bursts. Then the frequency of the GPLL oscillator is synchronized to the resonance of the sensor and can be measured easily. The concept is intended to yield an alternative to interrogators with expensive signal processing. Considering the inherent limitations, the proposed system presents a low cost solution for temperature, force, torque, etc. measurements. We describe the sensors, the signals, and the implemented system. Results of temperature measurements using quartz resonators are presented, and merits and disadvantages are discussed. PMID:18244275

  20. Precision SAW filters for a large phased-array radar system

    NASA Astrophysics Data System (ADS)

    Haydl, W. H.; Sander, W.; Wirth, W.-D.

    1981-05-01

    The electronically steerable radar (ELRA) at the Forschungsinstitut fuer Funk und Mathematik is an experimental S-band phased-array radar system consisting of separate transmitting and receiving arrays employing several coherent and incoherent signal-processing and data-handling techniques, incorporating multiple beam and multifunction operation for target search and tracking, adaptive interference suppression, and target resolution. This paper deals with the development and application of two types of SAW filters for the IF amplifier channel of the receiving array. Compared to conventional filters with lumped elements, these filters have some important merits. By making use of a special tuning technique, the center frequencies of all filters were adjusted, resulting in an rms deviation of less than 1 kHz. One type of the SAW filters represents an almost ideal approach of realizing a matched filter for rectangular shaped pulses. The conformity of the frequency responses of several hundred filters improved the noise suppression capability of the system.

  1. New materials and multidimensional cluster analysis for SAW chemical sensor arrays

    SciTech Connect

    Ricco, A.J.; Osbourn, G.C.; Bartholomew, J.W.; Crooks, R.M.; Chuanjing, Xu; Allred, R.E.

    1994-05-01

    We use six-element arrays of 97-MHz ST-quartz surface acoustic wave (SAW) devices to detect changes in thin-film mass and mechanical properties resulting from sorption of analytes by films representing two new classes of chemical sensor interface: self-assembled monolayers (SAMs) and plasma-grafted films (PGFs). While these materials do not display exceptional chemical selectivity, various combinations of the 7 different SAMs and 8 PGFs examined to produce distinct response patterns for each of 13 analytes. The analytes include aliphatic, aromatic, and chlorinated hydrocarbons; alcohols; ketones; organophosphonates; and water. Evaluation of the SAW array data using multidimensional cluster analysis techniques show that each chemical species can be correctly identified 100% of the time over the 9%- to 49%-of-saturation range using data from many combinations of four or more films.

  2. Properties of SAW synchronous two-port resonators on GdCa₄O(BO₃)₃ crystal.

    PubMed

    Soluch, Waldemar

    2011-02-01

    Surface acoustic wave (SAW) synchronous two-port resonators were fabricated and measured on several orientations of the GdCa₄O(BO₃)₃ crystal. Resonance frequencies, insertion losses, and unloaded quality factors of the resonators, measured at room temperature, were in the ranges of about 432.3 to 437.5 MHz, 3.8 to 6.3 dB, and 6500 to 7500, respectively. The properties of this crystal, such as its lack of a phase transition up to its melting temperature of about 1500 °C, a SAW temperature coefficient of frequency of about -80 ppm/ °C, and good parameters of the resonators make the crystal attractive for high-temperature sensor applications. PMID:21342834

  3. Simulation research on cutting brittle optical material with diamond wire saw based on LS-DYNA

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Liu, Jianbo; Xiao, Yonghao; Zhao, Shicao

    2014-08-01

    The quality of optical material cutting affects the efficiency and quality of follow-up polishing processing directly. Among various ways of cutting, the diamond wire saw cutting of fixed abrasive has advantages of narrow cutting seam, efficient cutting, high chip quality, little pollution to environment, ability to process bigger diameter workpiece, etc. So it has been used widely in optical material processing. In this paper, the coupled algorithm of FEM/SPH has been used to simulate deformation, fracture of brittle optical material in diamond grain cutting. The influence of workpiece feeding rate, cutting speed and cutting depth on the surface roughness are then analyzed in detail. Numerical simulation results show that the coupled algorithm efficiently explains the mechanism of material removal. From these results, we can not only determine optimum technology parameters for the manufacture of diamond wire saw, but also provide basis for improving the wire cutting efficiency and finished-product rate of optical material.

  4. Improving BPH symptoms and sexual dysfunctions with a saw palmetto preparation? Results from a pilot trial.

    PubMed

    Suter, Andreas; Saller, Reinhard; Riedi, Eugen; Heinrich, Michael

    2013-02-01

    In elderly men, benign prostatic hyperplasia (BPH) is a major risk factor for sexual dysfunctions (SDys). Additionally, the standard treatments for BPH symptoms, alpha blockers and 5-alpha-reductase inhibitors, cause SDys themselves. Preparations from saw palmetto berries are an efficacious and well-tolerated symptomatic treatment for mild to moderate BPH and have traditionally been used to treat SDys. We conducted an open multicentric clinical pilot trial to investigate whether the saw palmetto berry preparation Prostasan® influenced BPH symptoms and SDys. Eighty-two patients participated in the 8-week trial, taking one capsule of 320 mg saw palmetto extract daily. At the end of the treatment, the International Prostate Symptom Score was reduced from 14.4 ± 4.7 to 6.9 ± 5.2 (p < 0.0001); SDys measured with the brief Sexual Function Inventory improved from 22.4 ± 7.2 to 31.4 ± 9.2 (p < 0.0001), and the Urolife BPH QoL-9 sex total improved from 137.3 ± 47.9 to 195.0 ± 56.3 (p < 0.0001). Investigators' and patients' assessments confirmed the good efficacy, and treatment was very well tolerated and accepted by the patients. Correlation analyses confirmed the relationship between improved BPH symptoms and reduced SDys. This was the first trial with saw palmetto to show improvement in BPH symptoms and SDys as well. [Corrections made here after initial online publication.] PMID:22522969

  5. Kinetic assay of antitrypsin in human serum by a surface acoustic wave(SAW)-impedance sensor.

    PubMed

    Cai, Q; Wei, W; Wang, R; Nie, L; Yao, S

    1996-08-01

    Antitrypsin in human serum was determined by using both the SAW-impedance sensor system and spectrophotometry, indicating that the mean value for women was significantly higher than the mean value for men; the value for acute pancreasis patients is about 2-folds of the normal values, and there is no significant difference between the acute pancreasis patients and the pancreatic cancer patients. PMID:15045267

  6. Some Fundamental Limits on SAW RFID Tag Information Capacity and Collision Resolution

    NASA Technical Reports Server (NTRS)

    Barton, Richard J.

    2013-01-01

    In this paper, we apply results from multi-user information theory to study the limits of information capacity and collision resolution for SAW RFID tags. In particular, we derive bounds on the achievable data rate per tag as a function of fundamental parameters such as tag time-bandwidth product, tag signal-to-noise ratio (SNR), and number of tags in the environment. We also discuss the implications of these bounds for tag waveform design and tag interrogation efficiency

  7. Selective detection of elemental mercury vapor using a surface acoustic wave (SAW) sensor.

    PubMed

    Kabir, K M Mohibul; Sabri, Ylias M; Matthews, Glenn I; Jones, Lathe A; Ippolito, Samuel J; Bhargava, Suresh K

    2015-08-21

    The detection of elemental mercury (Hg(0)) within industrial processes is extremely important as it is the first major step in ensuring the efficient operation of implemented mercury removal technologies. In this study, a 131 MHz surface acoustic wave (SAW) delay line sensor with gold electrodes was tested towards Hg(0) vapor (24 to 365 ppbv) with/without the presence of ammonia (NH3) and humidity (H2O), as well as volatile organic compounds (VOCs) such as acetaldehyde (MeCHO), ethylmercaptan (EM), dimethyl disulfide (DMDS) and methyl ethyl ketone (MEK), which are all common interfering gas species that co-exist in many industrial applications requiring mercury monitoring. The developed sensor exhibited a detection limit of 0.7 ppbv and 4.85 ppbv at 35 and 55 C, respectively. Furthermore, a repeatability of 97% and selectivity of 92% in the presence of contaminant gases was exhibited by the sensor at the chosen operating temperature of 55 C. The response magnitude of the developed SAW sensor towards different concentrations of Hg(0) vapor fitted well with the Langmuir extension isotherm (otherwise known as loading ratio correlation (LRC)) which is in agreement with our basic finite element method (FEM) work where an LRC isotherm was observed for a simplified model of the SAW sensor responding to different Hg contents deposited on the Au based electrodes. Overall, the results indicate that the developed SAW sensor can be a potential solution for online selective detection of low concentrations of Hg(0) vapor found in industrial stack effluents. PMID:26065560

  8. Pseudo-orthogonal frequency coded wireless SAW RFID temperature sensor tags.

    PubMed

    Saldanha, Nancy; Malocha, Donald C

    2012-08-01

    SAW sensors are ideal for various wireless, passive multi-sensor applications because they are small, rugged, radiation hard, and offer a wide range of material choices for operation over broad temperature ranges. The readable distance of a tag in a multi-sensor environment is dependent on the insertion loss of the device and the processing gain of the system. Single-frequency code division multiple access (CDMA) tags that are used in high-volume commercial applications must have universal coding schemes and large numbers of codes. The use of a large number of bits at the common center frequency to achieve sufficient code diversity in CDMA tags necessitates reflector banks with >30 dB loss. Orthogonal frequency coding is a spread-spectrum approach that employs frequency and time diversity to achieve enhanced tag properties. The use of orthogonal frequency coded (OFC) SAW tags reduces adjacent reflector interactions for low insertion loss, increased range, complex coding, and system processing gain. This work describes a SAW tag-sensor platform that reduces device loss by implementing long reflector banks with optimized spectral coding. This new pseudo-OFC (POFC) coding is defined and contrasted with the previously defined OFC coding scheme. Auto- and cross-correlation properties of the chips and their relation to reflectivity per strip and reflector length are discussed. Results at 250 MHz of 8-chip OFC and POFC SAW tags will be compared. The key parameters of insertion loss, cross-correlation, and autocorrelation of the two types of frequency-coded tags will be analyzed, contrasted, and discussed. It is shown that coded reflector banks can be achieved with near-zero loss and still maintain good coding properties. Experimental results and results predicted by the coupling of modes model are presented for varying reflector designs and codes. A prototype 915-MHz POFC sensor tag is used as a wireless temperature sensor and the results are shown. PMID:22899121

  9. Finite-element simulation of wave propagation in periodic piezoelectric SAW structures.

    PubMed

    Hofer, Manfred; Finger, Norman; Kovacs, Günter; Schöberl, Joachim; Zaglmayr, Sabine; Langer, Ulrich; Lerch, Reinhard

    2006-06-01

    Many surface acoustic wave (SAW) devices consist of quasiperiodic structures that are designed by successive repetition of a base cell. The precise numerical simulation of such devices, including all physical effects, is currently beyond the capacity of high-end computation. Therefore, we have to restrict the numerical analysis to the periodic substructure. By using the finite-element method (FEM), this can be done by introducing periodic boundary conditions (PBCs) at special artificial boundaries. To be able to describe the complete dispersion behavior of waves, including damping effects, the PBC has to be able to model each mode that can be excited within the periodic structure. Therefore, the condition used for the PBCs must hold for each phase and amplitude difference existing at periodic boundaries. Based on the Floquet theorem, our two newly developed PBC algorithms allow the calculation of both, the phase and the amplitude coefficients of the wave. In the first part of this paper we describe the basic theory of the PBCs. Based on the FEM, we develop two different methods that deliver the same results but have totally different numerical properties and, therefore, allow the use of problem-adapted solvers. Further on, we show how to compute the charge distribution of periodic SAW structures with the aid of the new PBCs. In the second part, we compare the measured and simulated dispersion behavior of waves propagating on periodic SAW structures for two different piezoelectric substrates. Then we compare measured and simulated input admittances of structures similar to SAW resonators. PMID:16846152

  10. Laboratory and field evaluation of a SAW microsensor array for measuring perchloroethylene in breath.

    PubMed

    Groves, William A; Achutan, Chandran

    2004-12-01

    This article describes the laboratory and field performance evaluation of a small prototype instrument employing an array of six polymer-coated surface acoustic wave (SAW) sensors and a thermal desorption preconcentration unit for rapid analysis of perchloroethylene in breath. Laboratory calibrations were performed using breath samples spiked with perchloroethylene to prepare calibration standards spanning a concentration range of 0.1-10 ppm. A sample volume of 250 mL was preconcentrated on 40 mg of Tenax GR at a flow rate of 100 mL/min, followed by a dry air purge and thermal desorption at a temperature of 200 degrees C. The resulting pulse of vapor was passed over the sensor array at a flow rate of 20 mL/min and sensor responses were recorded and displayed using a laptop computer. The total time per analysis was 4.5 min. SAW sensor responses were linear, and the instrument's limit of detection was estimated to be 50 ppb based on the criterion that four of the six sensors show a detectable response. Field performance was evaluated at a commercial dry-cleaning operation by comparing prototype instrument results for breath samples with those of a portable gas chromatograph (NIOSH 3704). Four breath samples were collected from a single subject over the course of the workday and analyzed using the portable gas chromatograph (GC) and SAW instruments. An additional seven spiked breath samples were prepared and analyzed so that a broader range of perchloroethylene concentrations could be examined. Linear regression analysis showed excellent agreement between prototype instrument and portable GC breath sample results with a correlation coefficient of 0.99 and a slope of 1.04. The average error for the prototype instrument over a perchloroethylene breath concentration range of 0.9-7.2 ppm was 2.6% relative to the portable GC. These results demonstrate the field capabilities of SAW microsensor arrays for rapid analysis of organic vapors in breath. PMID:15742707

  11. Development of diamond-tipped chain saws for slot cutting in welded tuff

    SciTech Connect

    Zimmerman, R.M.; Finley, R.E.; Schuch, R.L.; Dodds, D.J.

    1987-12-31

    This paper describes the development and performance evaluations of two chain saws, one with a 1.1-m bar and the other with a 2.1-m bar, that were used to cut thin (less than 15 mm) planar slots in a jointed, welded tuff in G-tunnel on the Nevada Test Site as part of the Nevada Nuclear Waste Storage Investigations Project.

  12. Development of diamond-tipped chain saws for slot cutting in welded tuff

    SciTech Connect

    Zimmerman, R.M.; Finley, R.E.; Schuch, R.L.; Dodds, D.J.

    1987-12-31

    This paper describes the development and performance evaluations of two chain saws, one with a 1.1-m bar and the other with a 2.1-m bar, that were used to cut thin (less than 15 mm) planar slots in a jointed, welded tuff in G-Tunnel on the Nevada Test Site as part of the Nevada Nuclear Waste Storage Investigations Project. 6 refs., 3 figs., 2 tabs.

  13. Mind your hand during the energy crunch: Functional Outcome of Circular Saw Hand Injuries

    PubMed Central

    2010-01-01

    Background Although injuries due to circular saws are very common all over the world, there is surprisingly little information available about their functional outcomes. As the socioeconomic impact of these injuries is immense and determined by the casualties' disability and impairment, it is the objective of this study to present data on the functional outcome, disability, and impairment of hand injuries due to electric circular saws. Methods Patients treated from 1999 through 2007 for circular saw-related hand injuries were contacted and asked for clinical follow-up assessment. The clinical follow-up protocol consisted of a physical examination and an assessment of static muscle power (grip and pinch strength). For assessment of the subjective experience of the patients regarding their injury-related disability and impairment, the DASH follow-up questionnaire was used. The occupational impact of these injuries was measured by number of lost working days. Finally, safety-related behaviour of the patients was investigated. Results 114 Patients were followed-up on average 52 months after the injury. Average in-house treatment was 8.8 days. Average time lost from work was 14.8 weeks. A significant reduction of static muscle testing parameters compared with the uninjured hand was revealed for grip strength, tip pinch, key pinch, and palmar pinch. Average DASH score was 17.4 (DASH work 15.8, DASH sports/music 17.7). Most patients had more than ten years experience in using these power tools. Conclusion The everyday occurrence of circular saw-related hand injuries followed by relatively short periods of in-house treatment might distort the real dimension of the patients' remaining disability and impairment. While the trauma surgeon's view is generally confined to the patients' clinical course, the outcome parameters in this follow-up investigation, with loss of working time as the key factor, confirm that the whole socioeconomic burden is much greater than the direct cost of treatment. PMID:20819215

  14. Cell detachment and label-free cell sorting using modulated surface acoustic waves (SAWs) in droplet-based microfluidics.

    PubMed

    Bussonnière, Adrien; Miron, Yannick; Baudoin, Michaël; Bou Matar, Olivier; Grandbois, Michel; Charette, Paul; Renaudin, Alan

    2014-09-21

    We present a droplet-based surface acoustic wave (SAW) system designed to viably detach biological cells from a surface and sort cell types based on differences in adhesion strength (adhesion contrast) without the need to label cells with molecular markers. The system uses modulated SAW to generate pulsatile flows in the droplets and efficiently detach the cells, thereby minimizing the SAW excitation power and exposure time. As a proof of principle, the system shows efficient sorting of HEK 293 from A7r5 cells based on adhesion contrast. Results are obtained in minutes with sorting purity and efficiency reaching 97% and 95%, respectively. PMID:25029952

  15. Development of a Room Temperature SAW Methane Gas Sensor Incorporating a Supramolecular Cryptophane A Coating

    PubMed Central

    Wang, Wen; Hu, Haoliang; Liu, Xinlu; He, Shitang; Pan, Yong; Zhang, Caihong; Dong, Chuan

    2016-01-01

    A new room temperature supra-molecular cryptophane A (CrypA)-coated surface acoustic wave (SAW) sensor for sensing methane gas is presented. The sensor is composed of differential resonator-oscillators, a supra-molecular CrypA coated along the acoustic propagation path, and a frequency signal acquisition module (FSAM). A two-port SAW resonator configuration with low insertion loss, single resonation mode, and high quality factor was designed on a temperature-compensated ST-X quartz substrate, and as the feedback of the differntial oscillators. Prior to development, the coupling of modes (COM) simulation was conducted to predict the device performance. The supramolecular CrypA was synthesized from vanillyl alcohol using a double trimerisation method and deposited onto the SAW propagation path of the sensing resonators via different film deposition methods. Experiential results indicate the CrypA-coated sensor made using a dropping method exhibits higher sensor response compared to the unit prepared by the spinning approach because of the obviously larger surface roughness. Fast response and excellent repeatability were observed in gas sensing experiments, and the estimated detection limit and measured sensitivity are ~0.05% and ~204 Hz/%, respectively. PMID:26751450

  16. Surface morphology of ultrathin graphene oxide films obtained by the SAW atomization

    NASA Astrophysics Data System (ADS)

    Balachova, Olga V.; Balashov, Sergey M.; Costa, Carlos A. R.; Pavani Filho, A.

    2015-08-01

    Lately, graphene oxide (GO) thin films have attracted much attention: they can be used as humidity-sensitive coatings in the surface acoustic wave (SAW) sensors; being functionalized, they can be used in optoelectronic or biodevices, etc. In this research we study surface morphology of small-area thin GO films obtained on Si and quartz substrates by deposition of very small amounts of H2O-GO aerosols produced by the SAW atomizer. An important feature of this method is the ability to work with submicrovolumes of liquids during deposition that provides relatively good control over the film thickness and quality, in particular, minimization of the coffee ring effect. The obtained films were examined using AFM and electron microscopy. Image analysis showed that the films consist of GO sheets of different geometry and sizes and may form discrete or continuous coatings at the surface of the substrates with the minimum thickness of 1.0-1.8 nm which corresponds to one or two monolayers of GO. The thickness and quality of the deposited films depend on the parameters of the SAW atomization (number of atomized droplets, a volume of the initial droplet, etc.) and on sample surface preparation (activation in oxygen plasma). We discuss the structure of the obtained films, uniformity and the surface coverage as a function of parameters of the film deposition process and sample preparation. Qualitative analysis of adhesion of GO films is made by rinsing the samples in DI water and subsequent evaluation of morphology of the remained films.

  17. An in-flight study of cabin buzz-saw noise

    NASA Astrophysics Data System (ADS)

    Reed, David; Uellenberg, Stefan; Davis, Evan

    2002-11-01

    This paper examines the characteristics of multiple-pure-tone noise generated by high-speed turbofans under conditions of supersonic fan tip speeds, especially as it is observed in an aircraft passenger cabin. This phenomenon, also known as buzz-saw noise, is an important noise source in commercial airplane passenger cabins and has proved to be difficult to treat with sound-absorbing materials. Recent flight test experiments by The Boeing Company have demonstrated extraordinary success in suppressing cabin buzz-saw noise by strategic placement of engine inlet acoustic linings. The observed behavior is explained by a propagation and radiation model, which is validated by in-flight measurements made with a phased microphone array mounted on the fuselage skin of a Boeing 777. A structural acoustic model is also offered to explain the different transmission characteristics of buzz-saw noise and turbulent boundary layer excitation. Correlation length scales measured on the fuselage surface for these two noise sources are key inputs to the structural model.

  18. Friction drive of an SAW motor. Part IV: physics of contact.

    PubMed

    Shigematsu, Takashi; Kurosawa, Minoru Kuribayashi

    2008-10-01

    A procedure for modeling the frictional heating and electricity of a surface acoustic wave (SAW) motor is proposed. The frictional heat is developed during friction drive when sliding occurs at the frictional interface; the heat is conducted into the solids, resulting in an increase in temperature. The spatial distribution of the heat source was associated with the contact pressure distribution, and the heat conduction from the heat source was formulated. Owing to the piezoelectricity and pyroelectricity of the stator used in the present study, the elastic deformation and temperature increase produce the electric fields. The electric fields in the stator were determined with respect to each cause. Electric discontinuity at the boundary between the stator and the slider, moreover, produces electrostatic force, which was calculated using a Maxwell stress tensor. All the analyses revealed the underlying physical fields in addition to the mechanical fields of the SAW motor. By the use of those analytical methods, the frictional properties of the SAW motor were discussed. We pointed out that another physical phenomenoniquestcontact electrificationiquestcould arise at the contact interface. The electrostatic force due to contact electrification had sufficient strength to change the friction property, which corresponded to the variation of the friction coefficient from 0.1 to 1. PMID:18986875

  19. Development of a Room Temperature SAW Methane Gas Sensor Incorporating a Supramolecular Cryptophane A Coating.

    PubMed

    Wang, Wen; Hu, Haoliang; Liu, Xinlu; He, Shitang; Pan, Yong; Zhang, Caihong; Dong, Chuan

    2016-01-01

    A new room temperature supra-molecular cryptophane A (CrypA)-coated surface acoustic wave (SAW) sensor for sensing methane gas is presented. The sensor is composed of differential resonator-oscillators, a supra-molecular CrypA coated along the acoustic propagation path, and a frequency signal acquisition module (FSAM). A two-port SAW resonator configuration with low insertion loss, single resonation mode, and high quality factor was designed on a temperature-compensated ST-X quartz substrate, and as the feedback of the differntial oscillators. Prior to development, the coupling of modes (COM) simulation was conducted to predict the device performance. The supramolecular CrypA was synthesized from vanillyl alcohol using a double trimerisation method and deposited onto the SAW propagation path of the sensing resonators via different film deposition methods. Experiential results indicate the CrypA-coated sensor made using a dropping method exhibits higher sensor response compared to the unit prepared by the spinning approach because of the obviously larger surface roughness. Fast response and excellent repeatability were observed in gas sensing experiments, and the estimated detection limit and measured sensitivity are ~0.05% and ~204 Hz/%, respectively. PMID:26751450

  20. Advances in SXFA-Coated SAW Chemical Sensors for Organophosphorous Compound Detection

    PubMed Central

    Wang, Wen; He, Shitang; Li, Shunzhou; Liu, Minghua; Pan, Yong

    2011-01-01

    A polymer-coated surface acoustic wave (SAW)-based chemical sensor for organophosphorous compound sensing at extremely low concentrations was developed, in which a dual-delay-line oscillator coated with fluoroalcoholpolysiloxane (SXFA) acted as the sensor element. Response mechanism analysis was performed on the SXFA-coated chemical sensor, resulting in the optimal design parameters. The shear modulus of the SXFA, which is the key parameter for theoretical simulation, was extracted experimentally. New designs were done on the SAW devices to decrease the insertion loss. Referring to the new phase modulation approach, superior short-term frequency stability (±2 Hz in seconds) was achieved from the SAW oscillator using the fabricated 300 MHz delay line as the feedback element. In the sensor experiment on dimethylmethylphosphonate (DMMP) detection, the fabricated SXFA-coated chemical sensor exhibited an excellent threshold detection limit up to 0.004 mg/m3 (0.7 ppb) and good sensitivity (∼485 Hz/mg/m3 for a DMMP concentration of 2∼14 mg/m3). PMID:22319366

  1. Maximum measurement range and accuracy of SAW reflective delay line sensors.

    PubMed

    Zheng, Zehua; Han, Tao; Qin, Peng

    2015-01-01

    In a surface acoustic wave (SAW) wireless sensor with a reflective delay line structure, three reflectors are often used to eliminate 2? ambiguity of phase measurement. The maximum range of the measured parameter and the maximum accuracy have recently been attracting much research attention. In this paper, an analytical formula for all the factors influencing the measurement range and accuracy of the delay line SAW sensor are deduced for the first time. The factors include: the sensor sensitivity, the topology of the delay line, the available wireless bandwidth and the allowed maximum phase measuring error of the reading system, which is easier to retrieve and more fully describes the possible noises than SNR. Additionally, many designers believe that increasing the reflector could improve accuracy continuously or realize multi-resolution measurement. However, they ignore some certain criteria that the reflector location must satisfy. The reachable maximum accuracy by every increase of a reflector is also presented. A SAW temperature sensor system using 128 YX-LiNbO3 is designed to verify the above theoretical analysis. PMID:26492251

  2. Maximum Measurement Range and Accuracy of SAW Reflective Delay Line Sensors

    PubMed Central

    Zheng, Zehua; Han, Tao; Qin, Peng

    2015-01-01

    In a surface acoustic wave (SAW) wireless sensor with a reflective delay line structure, three reflectors are often used to eliminate 2? ambiguity of phase measurement. The maximum range of the measured parameter and the maximum accuracy have recently been attracting much research attention. In this paper, an analytical formula for all the factors influencing the measurement range and accuracy of the delay line SAW sensor are deduced for the first time. The factors include: the sensor sensitivity, the topology of the delay line, the available wireless bandwidth and the allowed maximum phase measuring error of the reading system, which is easier to retrieve and more fully describes the possible noises than SNR. Additionally, many designers believe that increasing the reflector could improve accuracy continuously or realize multi-resolution measurement. However, they ignore some certain criteria that the reflector location must satisfy. The reachable maximum accuracy by every increase of a reflector is also presented. A SAW temperature sensor system using 128 YX-LiNbO3 is designed to verify the above theoretical analysis. PMID:26492251

  3. Advances in SXFA-coated SAW chemical sensors for organophosphorous compound detection.

    PubMed

    Wang, Wen; He, Shitang; Li, Shunzhou; Liu, Minghua; Pan, Yong

    2011-01-01

    A polymer-coated surface acoustic wave (SAW)-based chemical sensor for organophosphorous compound sensing at extremely low concentrations was developed, in which a dual-delay-line oscillator coated with fluoroalcoholpolysiloxane (SXFA) acted as the sensor element. Response mechanism analysis was performed on the SXFA-coated chemical sensor, resulting in the optimal design parameters. The shear modulus of the SXFA, which is the key parameter for theoretical simulation, was extracted experimentally. New designs were done on the SAW devices to decrease the insertion loss. Referring to the new phase modulation approach, superior short-term frequency stability (2 Hz in seconds) was achieved from the SAW oscillator using the fabricated 300 MHz delay line as the feedback element. In the sensor experiment on dimethylmethylphosphonate (DMMP) detection, the fabricated SXFA-coated chemical sensor exhibited an excellent threshold detection limit up to 0.004 mg/m(3) (0.7 ppb) and good sensitivity (?485 Hz/mg/m(3) for a DMMP concentration of 2?14 mg/m(3)). PMID:22319366

  4. Recent developments on surface acoustic wave (SAW) sensors for harsh conditions

    NASA Astrophysics Data System (ADS)

    Schiopu, Paul; Chilibon, Irinela; Grosu, Neculai; Craciun, Alexandru

    2015-02-01

    The results of research into Surface Acoustic Waves (SAW) devices have been recognized for their efficiency and versatility in the electrical signals processing. Actual progress in the industrial application of piezoelectric materials such as Lithium Niobate (LiNbO3), Langasite (LGS), Lanthanum-Gallium Silicate La3Ga5SiO14 and Gallium Orthophosphate (GaPO4), allows the manufacturing of devices with piezoelectric performances, which overcome the limits obtained with quartz crystals. The single crystal materials have a long term high stability - near to infinite - and moreover, some of these have an excellent behavior with temperature variation. Today, GaPO4 with its properties is by far the best suited piezoelectric material to be used in sensor applications for machine monitoring and pressure measurements, at high temperatures. SAW micro devices based on GaPO4 operate at temperatures of up to 8000C. For a particular case, of harsh-environment applications, additional challenges need to be overcome, relating to substrate integrity and operation, thin film electrode fabrication, device packaging, and sensor interrogation. This paper reviews the novel progres in the area of (SAW) sensors for harsh conditions.

  5. Evaluation of Relative Sensitivity of SAW and Flexural Plate Wave Devices for Atmospheric Sensing

    NASA Technical Reports Server (NTRS)

    White, Richard M.; Black, Justin; Chen, Bryan

    1998-01-01

    The objective of this project is to evaluate the suitability of the ultrasonic flexural plate wave (FPW) device as the detector in a gas chromatograph (GC). Of particular interest is the detection of nitrous oxide (N2O). From experimental results we conclude analyte detection is achieved through two mechanisms: changes in gas density, and mass loading of the device membrane due to the sorption of gas molecules. Reducing the dead volume of the FPW chamber increased the FPW response. A comparison of the FPW response to that of the surface acoustic wave (SAW) detector provided with the GC (made by MSI, Microsensor Technologies, Inc.), shows that for unseparated N2O in N2, the FPW exhibits a sensitivity that is at least 550 times greater than that of the SAW device. A Porapak Q column was found to separate N2O from its carrier gas, N2 or He. With the Porapak Q column, a coated FPW detected 1 ppm N2O in N2 or He, with a response magnitude of 7 Hz. A coated SAW exhibited a response of 25 Hz to pure N2O. The minimal detectable N2O concentrations of the sensors were not evaluated.

  6. Detection, Identification, Location, and Remote Sensing Using SAW RFID Sensor Tags

    NASA Technical Reports Server (NTRS)

    Barton, Richard J.; Kennedy, Timothy F.; Williams, Robert M.; Fink, Patrick W.; Ngo, Phong H.

    2009-01-01

    The Electromagnetic Systems Branch (EV4) of the Avionic Systems Division at NASA Johnson Space Center in Houston, TX is studying the utility of surface acoustic wave (SAW) radiofrequency identification (RFID) tags for multiple wireless applications including detection, identification, tracking, and remote sensing of objects on the lunar surface, monitoring of environmental test facilities, structural shape and health monitoring, and nondestructive test and evaluation of assets. For all of these applications, it is anticipated that the system utilized to interrogate the SAW RFID tags may need to operate at fairly long range and in the presence of considerable multipath and multiple-access interference. Towards that end, EV4 is developing a prototype SAW RFID wireless interrogation system for use in such environments called the Passive Adaptive RFID Sensor Equipment (PARSED) system. The system utilizes a digitally beam-formed planar receiving antenna array to extend range and provide direction-of-arrival information coupled with an approximate maximum-likelihood signal processing algorithm to provide near-optimal estimation of both range and temperature. The system is capable of forming a large number of beams within the field of view and resolving the information from several tags within each beam. The combination of both spatial and waveform discrimination provides the capability to track and monitor telemetry from a large number of objects appearing simultaneously within the field of view of the receiving array. In this paper, we will consider the application of the PARSEQ system to the problem of simultaneous detection, identification, localization, and temperature estimation for multiple objects. We will summarize the overall design of the PARSEQ system and present a detailed description of the design and performance of the signal detection and estimation algorithms incorporated in the system. The system is currently configured only to measure temperature (jointly with range and tag ID), but future versions will be revised to measure parameters other than temperature as SAW tags capable of interfacing with external sensors become available. It is anticipated that the estimation of arbitrary parameters measured using SAW-based sensors will be based on techniques very similar to the joint range and temperature estimation techniques described in this paper.

  7. Thin, High Lifetime Silicon Wafers with No Sawing; Re-crystallization in a Thin Film Capsule

    SciTech Connect

    Emanuel Sachs Tonio Buonassisi

    2013-01-16

    The project fits within the area of renewable energy called photovoltaics (PV), or the generation of electricity directly from sunlight using semiconductor devices. PV has the greatest potential of any renewable energy technology. The vast majority of photovoltaic modules are made on crystalline silicon wafers and these wafers accounts for the largest fraction of the cost of a photovoltaic module. Thus, a method of making high quality, low cost wafers would be extremely beneficial to the PV industry The industry standard technology creates wafers by casting an ingot and then sawing wafers from the ingot. Sawing rendered half of the highly refined silicon feedstock as un-reclaimable dust. Being a brittle material, the sawing is actually a type of grinding operation which is costly both in terms of capital equipment and in terms of consumables costs. The consumables costs associated with the wire sawing technology are particularly burdensome and include the cost of the wire itself (continuously fed, one time use), the abrasive particles, and, waste disposal. The goal of this project was to make wafers directly from molten silicon with no sawing required. The fundamental concept was to create a very low cost (but low quality) wafer of the desired shape and size and then to improve the quality of the wafer by a specialized thermal treatment (called re-crystallization). Others have attempted to create silicon sheet by recrystallization with varying degrees of success. Key among the difficulties encountered by others were: a) difficulty in maintaining the physical shape of the sheet during the recrystallization process and b) difficulty in maintaining the cleanliness of the sheet during recrystallization. Our method solved both of these challenges by encapsulating the preform wafer in a protective capsule prior to recrystallization (see below). The recrystallization method developed in this work was extremely effective at maintaining the shape and the cleanliness of the wafer. In addition, it was found to be suitable for growing very large crystals. The equipment used was simple and inexpensive to operate. Reasonable solar cells were fabricated on re-crystallized material.

  8. INTERNATIONAL UNION OF OPERATING ENGINEERS NATIONAL HAZMAT PROGRAM - ADAMANT CIRCULAR SAW OENHP{number_sign}: 2001-05, VERSION A

    SciTech Connect

    Unknown

    2002-01-01

    Florida International University's (FIU) Hemispheric Center for Environmental Technology (HCET) evaluated five saws for their effectiveness in cutting up specially prepared fiberglass-reinforced plywood crates. These crates were built as surrogates for crates that presently hold radioactive contaminated glove boxes at the Department of Energy's (DOE) Los Alamos facility. The Adamant circular saw was assessed on August 14, 2001. During the FIU test of efficacy, a team from the Operating Engineers National Hazmat Program (OENHP) evaluated the occupational safety and health issues associated with this technology. The Adamant was only used during a limited ''test'' on a regular plywood crate due to safety considerations of the tool for this application. The Adamant circular saw, a counter-rotating twin-cutter, constructed with blades that work differently than conventional cutting wheels with twin blades, each rotating in opposite directions. It is used to cut wood and metals. Each blade is approximately 8 3/4 inches in diameter with a maximum cutting depth of 2 1/2 inches. The machine has two rotation speeds: 1,900 and 2,900 rotations per minute (rpm). The saw is operated with an interlocked, guarded trigger switch located at the end of the saw opposite the cutting blades. To operate the saw, the safety interlock must be depressed prior to powering the saw with the trigger control. The saw is supported by a handle at the front of the saw near the cutting blades. The top part of the blades is guarded near the handle, with approximately three-fourths of the face of the blades exposed. The Adamant circular saw is an innovative technology used to cut metals and wood. Its safety features include: interlocking switch for powering the saw, overload indicator and shutoff, and an electronic brake that stops the engine immediately when the start button is released. The top part of the blades is guarded near the motor. With approximately three-fourths of the face of the blades open, the operator is exposed to the potential risk of serious and minor cuts and abrasions when using and handling the saw. There is also potential for damage to the blades if the saw is not stored properly. Without guarding on the lower part of the blades, these can be damaged if the saw is dropped or rested on the cutting blades. Based upon the industrial hygiene sampling conducted for the other four saws demonstrated at FIU, noise levels, nuisance dust, and airborne fiberglass may be a problem when using this technology for the cutting of fiberglass-reinforced plywood crates. No industrial hygiene sampling was conducted while the Adamant saw was in use. Engineering controls should be used to eliminate these problems whenever possible. Where this is not possible, administrative controls, training, and proper personal protective equipment (PPE) should be used. Respirators should be used if engineering controls do not sufficiently control the dust or fiberglass generated. Respirators should be equipped with an organic vapor and acid gas cartridge with High Efficiency Particulate Air (HEPA) filter, since during the demonstration, the workers complained of an odd smell, which may have been the breakdown of the fiberglass.

  9. Electron confinement in multi-anode saw tooth silicon drift detectors with an anode pitch of 250 {micro}m

    SciTech Connect

    Sonsky, J.; Valk, H.; Huizenga, J.; Hollander, R.W.; Eijk, C.W.E. van; Sarro, P.M.

    1999-06-01

    Recently it has been experimentally shown that saw tooth shaped p{sup +} strips allows confinement of drifting electrons in the lateral direction. This is achieved by means of potential gutters induced by an appropriate saw tooth design p{sup +} cathodes. The saw tooth period p{sub x} = 500 {micro}m. The final detector is intended to have an anode pitch of 250 {micro}m. The simulation of a saw tooth configuration with p{sub x} = 250 {micro}m, p{sub y} = 200 {micro}m, and {alpha} = 60{degree} showed that potential gutters with a depth of 80 mV will be produced assuming a drift field of 250 V/cm. The authors will give experimental evidence of these shallow charge confining potential gutters.

  10. A surface acoustic wave (SAW)-enhanced grating-coupling phase-interrogation surface plasmon resonance (SPR) microfluidic biosensor.

    PubMed

    Sonato, A; Agostini, M; Ruffato, G; Gazzola, E; Liuni, D; Greco, G; Travagliati, M; Cecchini, M; Romanato, F

    2016-03-23

    A surface acoustic wave (SAW)-enhanced, surface plasmon resonance (SPR) microfluidic biosensor in which SAW-induced mixing and phase-interrogation grating-coupling SPR are combined in a single lithium niobate lab-on-a-chip is demonstrated. Thiol-polyethylene glycol adsorption and avidin/biotin binding kinetics were monitored by exploiting the high sensitivity of grating-coupling SPR under azimuthal control. A time saturation binding kinetics reduction of 82% and 24% for polyethylene and avidin adsorption was obtained, respectively, due to the fluid mixing enhancement by means of the SAW-generated chaotic advection. These results represent the first implementation of a nanostructured SAW-SPR microfluidic biochip capable of significantly improving the molecule binding kinetics on a single, portable device. In addition, the biochip here proposed is suitable for a great variety of biosensing applications. PMID:26932784

  11. Piezoelectric shunt damping of a circular saw blade with autonomous power supply for noise and vibration reduction

    NASA Astrophysics Data System (ADS)

    Pohl, Martin; Rose, Michael

    2016-01-01

    Circular saws are widespread tools for machining metal, wood or even ceramics. Due to the thin blade and excitation by the workpiece contact of the cutting edges, circular saws are prone to vibration and intense noise emission. Damping the blade will lower the hearing protection requirements of the users and possibly increase precision. Therefore a new damping concept for circular saw blades is presented in this paper. It is based on negative capacitance shunted piezoelectric transducers which are applied to the saw blade core. The required energy for the electronics is harvested from the rotation by a generator, so that no change of the machine tool is required. All components are integrated into an autonomous saw tool. Finally, the system is experimentally investigated without rotation, in idling and in cutting condition in a circular saw test stand in the Institute for Machine Tools and Production Engineering (IWF) at TU Braunschweig. The experimental investigation shows a good reduction of the vibration amplitude over a wide frequency range in the non-rotating condition. When rotating, the damping effect is lower and limited to some narrow frequency bands. The proposed reason for the reduced damping effect in rotating condition consists in the saturation of the electronic circuits due to the limited supply voltage capabilities.

  12. iSAW: Integrating Structure, Actors, and Water to study socio-hydro-ecological systems

    NASA Astrophysics Data System (ADS)

    Hale, Rebecca L.; Armstrong, Andrea; Baker, Michelle A.; Bedingfield, Sean; Betts, David; Buahin, Caleb; Buchert, Martin; Crowl, Todd; Dupont, R. Ryan; Ehleringer, James R.; Endter-Wada, Joanna; Flint, Courtney; Grant, Jacqualine; Hinners, Sarah; Horsburgh, Jeffery S.; Jackson-Smith, Douglas; Jones, Amber S.; Licon, Carlos; Null, Sarah E.; Odame, Augustina; Pataki, Diane E.; Rosenberg, David; Runburg, Madlyn; Stoker, Philip; Strong, Courtenay

    2015-03-01

    Urbanization, climate, and ecosystem change represent major challenges for managing water resources. Although water systems are complex, a need exists for a generalized representation of these systems to identify important components and linkages to guide scientific inquiry and aid water management. We developed an integrated Structure-Actor-Water framework (iSAW) to facilitate the understanding of and transitions to sustainable water systems. Our goal was to produce an interdisciplinary framework for water resources research that could address management challenges across scales (e.g., plot to region) and domains (e.g., water supply and quality, transitioning, and urban landscapes). The framework was designed to be generalizable across all human-environment systems, yet with sufficient detail and flexibility to be customized to specific cases. iSAW includes three major components: structure (natural, built, and social), actors (individual and organizational), and water (quality and quantity). Key linkages among these components include: (1) ecological/hydrologic processes, (2) ecosystem/geomorphic feedbacks, (3) planning, design, and policy, (4) perceptions, information, and experience, (5) resource access and risk, and (6) operational water use and management. We illustrate the flexibility and utility of the iSAW framework by applying it to two research and management problems: understanding urban water supply and demand in a changing climate and expanding use of green storm water infrastructure in a semi-arid environment. The applications demonstrate that a generalized conceptual model can identify important components and linkages in complex and diverse water systems and facilitate communication about those systems among researchers from diverse disciplines.

  13. High-energy x-ray optics with silicon saw-tooth refractive lenses.

    SciTech Connect

    Shastri, S. D.; Almer, J. A.; Ribbing, C. R.; Cederstrom, B. C.; X-Ray Science Division; Uppsala Univ.; Royal Inst. of Tech.

    2007-01-01

    Silicon saw-tooth refractive lenses have been in successful use for vertical focusing and collimation of high-energy X-rays (50-100 keV) at the 1-ID undulator beamline of the Advanced Photon Source. In addition to presenting an effectively parabolic thickness profile, as required for aberration-free refractive optics, these devices allow high transmission and continuous tunability in photon energy and focal length. Furthermore, the use of a single-crystal material (i.e. Si) minimizes small-angle scattering background. The focusing performance of such saw-tooth lenses, used in conjunction with the 1-ID beamline's bent double-Laue monochromator, is presented for both short ({approx}1:0.02) and long ({approx}1:0.6) focal-length geometries, giving line-foci in the 2 {micro}m-25 {micro}m width range with 81 keV X-rays. In addition, a compound focusing scheme was tested whereby the radiation intercepted by a distant short-focal-length lens is increased by having it receive a collimated beam from a nearer (upstream) lens. The collimation capabilities of Si saw-tooth lenses are also exploited to deliver enhanced throughput of a subsequently placed small-angular-acceptance high-energy-resolution post-monochromator in the 50-80 keV range. The successful use of such lenses in all these configurations establishes an important detail, that the pre-monochromator, despite being comprised of vertically reflecting bent Laue geometry crystals, can be brilliance-preserving to a very high degree.

  14. Effect of operating parameters on the removal of bone cement by a sawing process.

    PubMed

    James, Thomas P; Sheehan, Brian; Sagar, Amrit

    2014-03-01

    The number of total knee arthroplasty revision surgeries is increasing each year, driven by the wide availability and general acceptance of the procedure accompanied by an aging population of implants. Metal implants are often secured to the tibial plateau by a mantle of poly(methyl methacrylate) bone cement. During revision surgery, a power oscillating saw is used to remove bone cement while preparing the boney bed. Presently, there are no published studies on the mechanics of bone cement removal by a sawing process. The aim of this research was to quantify the effect of blade speed and applied thrust force on the volumetric cutting rate of bone cement. A custom reciprocating saw with variable stroke length was used to conduct a three-factor design of experiments. Two levels, without center-points, were sufficient to model the effect of stroke length (6.75, 10.13 mm), thrust force (11, 19 N), and reciprocating speed in strokes per minute (6000, 8000 SPM) on cutting rate. The results indicate that each of the three parameters had a significant impact on cutting rate (p < 0.001), with a linear relationship between both force and cutting rate (r = 0.98) and blade speed and cutting rate (r = 0.98). For the parameters considered, increasing the reciprocating speed had the most significant effect on cutting rate. For example, while holding force and stroke length constant (11 N, 10.13 mm), an increase in speed from 6000 to 8000 SPM nearly doubled the cutting rate of bone cement. A cutting rate model was developed by regression analysis of the experimental data and validated through additional experiments. The model has applications in haptic feedback for surgical simulators to differentiate between the cutting rates of bone and bone cement during virtual training of resident surgeons. PMID:24562099

  15. Achievable Performance and Effective Interrogator Design for SAW RFID Sensor Tags

    NASA Technical Reports Server (NTRS)

    Barton, Richard J.

    2011-01-01

    For many NASA missions, remote sensing is a critical application that supports activities such as environmental monitoring, planetary science, structural shape and health monitoring, non-destructive evaluation, etc. The utility of the remote sensing devices themselves is greatly increased if they are passive that is, they do not require any on-board power supply such as batteries and if they can be identified uniquely during the sensor interrogation process. Additional passive sensor characteristics that enable greater utilization in space applications are small size and weight, long read ranges with low interrogator power, ruggedness, and operability in extreme environments (vacuum, extreme high/low temperature, high radiation, etc.) In this paper, we consider one very promising passive sensor technology, called surface acoustic wave (SAW) radio-frequency identification (RFID), that satisfies all of these criteria. Although SAW RFID tags have great potential for use in numerous space-based remote sensing applications, the limited collision resolution capability of current generation tags limits the performance in a cluttered sensing environment. That is, as more SAW-based sensors are added to the environment, numerous tag responses are superimposed at the receiver and decoding all or even a subset of the telemetry becomes increasingly difficult. Background clutter generated by reflectors other than the sensors themselves is also a problem, as is multipath interference and signal distortion, but the limiting factor in many remote sensing applications can be expected to be tag mutual interference. This problem may be greatly mitigated by proper design of the SAW tag waveform, but that remains an open research problem, and in the meantime, several other related questions remain to be answered including: What are the fundamental relationships between tag parameters such as bit-rate, time-bandwidth-product, SNR, and achievable collision resolution? What are the differences in optimal or near-optimal interrogator designs between noise-limited environments and interference-limited environments? What are the performance characteristics of different interrogator designs in term of parameters such as transmitter power level, range, and number of interfering tags? In this paper, we present the results of a research effort aimed at providing at least partial answers to all of these questions.

  16. Proposal for generalised supersymmetry Les Houches Accord for see-saw models and PDG numbering scheme

    NASA Astrophysics Data System (ADS)

    Basso, L.; Belyaev, A.; Chowdhury, D.; Hirsch, M.; Khalil, S.; Moretti, S.; O'Leary, B.; Porod, W.; Staub, F.

    2013-03-01

    The SUSY Les Houches Accord (SLHA) 2 extended the first SLHA to include various generalisations of the Minimal Supersymmetric Standard Model (MSSM) as well as its simplest next-to-minimal version. Here, we propose further extensions to it, to include the most general and well-established see-saw descriptions (types I/II/III, inverse, and linear) in both an effective and a simple gauged extension of the MSSM framework. In addition, we generalise the PDG numbering scheme to reflect the properties of the particles.

  17. The Effect of Increasing Doses of Saw Palmetto Fruit Extract on Serum PSA Levels: Analysis of the CAMUS Randomized Trial

    PubMed Central

    Andriole, Gerald L.; McCullum-Hill, Christie; Sandhu, Gurdarshan S.; Crawford, E. David; Barry, Michael J.; Cantor, Alan

    2014-01-01

    Purpose Saw palmetto extracts are used for treating lower urinary tract symptoms in men despite level I evidence concluding that saw palmetto was ineffective in reducing lower urinary symptoms. We sought to determine whether higher doses of saw palmetto as studied in CAMUS affect serum PSA levels. Materials and Methods The CAMUS trial was a randomized, placebo-controlled double blind multi-centered North American trial conducted between June 5, 2008 and October 10, 2012 in which 369 men >45 years of age with AUA symptom score ≥ 8 and ≤ 24 were randomly assigned to placebo or dose escalation saw palmetto, which consisted of 320mg for first 24 weeks to 640mg for next 24 weeks to 960mg for last 24 weeks of this 72 week trial. Serum PSA levels (Beckman-Coulter) were obtained at baseline and at weeks 24, 48 and 72 and were compared between treatment groups using the pooled t and Fisher's exact tests. Results Serum PSA levels were similar at baseline for the placebo (1.93 ± 1.59 ng/ml) and saw palmetto groups (2.20 ± 1.95, p = 0.16). Changes in PSA levels over the course of the study were similar: placebo group mean change 0.16 ± 1.08 ng/ml and saw palmetto group mean change 0.23 ± 0.83 ng/ml (p value 0.50). Additionally, no differential effect on serum PSA levels was observed between treatment arms when groups were stratified by baseline PSA values. Conclusions Saw palmetto extract does not affect serum PSA levels more than placebo even at relatively high doses. PMID:23253958

  18. Accuracy of experimental mandibular osteotomy using the image-guided sagittal saw.

    PubMed

    Pietruski, P; Majak, M; Swiatek-Najwer, E; Popek, M; Szram, D; Zuk, M; Jaworowski, J

    2016-06-01

    The aim of this study was to perform an objective assessment of the accuracy of mandibular osteotomy simulations performed using an image-guided sagittal saw. A total of 16 image-guided mandibular osteotomies were performed on four prefabricated anatomical models according to the virtual plan. Postoperative computed tomography (CT) image data were fused with the preoperative CT scan allowing an objective comparison of the results of the osteotomy executed with the virtual plan. For each operation, the following parameters were analyzed and compared independently twice by two observers: resected bone volume, osteotomy trajectory angle, and marginal point positions. The mean target registration error was 0.95±0.19mm. For all osteotomies performed, the mean difference between the planned and actual bone resection volumes was 8.55±5.51%, the mean angular deviation between planned and actual osteotomy trajectory was 8.08±5.50°, and the mean difference between the preoperative and the postoperative marginal point positions was 2.63±1.27mm. In conclusion, despite the initial stages of the research, encouraging results were obtained. The current limitations of the navigated saw are discussed, as well as the improvements in technology that should increase its predictability and efficiency, making it a reliable method for improving the surgical outcomes of maxillofacial operations. PMID:26780924

  19. SoilSaw{trademark} demonstration. Final report, September 1992--January 1995

    SciTech Connect

    Saugier, K.; Isaac, R.E.

    1996-02-01

    The US Department of Energy (DOE) has identified leaking underground storage tanks and buried mixed waste at numerous sites within the DOE complex. Preventing these wastes from entering the environment is a challenging task. One method of preventing waste migration is to isolate the contaminants using subsurface containment barriers. Isolation and containment can be accomplished by both in situ and ex situ methods. This report describes a novel in situ construction method of forming vertical containment barriers (slurry walls) using the SoilSaw{trademark} Barrier System. The SoilSaw{trademark} Barrier System is shown to be a feasible process for constructing subsurface vertical containment barriers to depths of fifty feet. The process is most efficient in sandy soil (including free flowing sand) with barrier construction rates of over 130 square feet per minute. Productivity diminishes to approximately 30 square feet per minute as soils become harder and more cohesive. The present hardware is designed to form a barrier of approximately 12 inch in width. Additional barrier widths can be constructed with this technology by application of wider jet heads. The requirement for a varied arrangement of barrier widths is an increase in hydraulic horse power and additional jet heads.

  20. A novel 440 MHz wireless SAW microsensor integrated with pressure temperature sensors and ID tag

    NASA Astrophysics Data System (ADS)

    Lee, Keekeun; Wang, Wen; Kim, Taehyun; Yang, Sangsik

    2007-03-01

    This paper presents the development of a 440 MHz range surface acoustic wave (SAW)-based microsensor integrated with pressure-temperature sensors and ID tag. Two piezoelectric substrates were bonded, in which a ~150 m air gap was structured by metal poles. The pressure sensor was placed on the top substrate, whereas the ID tag and temperature sensor were located on the bottom substrate. Coupling of modes (COM) modeling was used to find optimal design parameters. Using the extracted optimal design parameters, the SAW device was fabricated. In wireless device testing using a network analyzer, sharp reflection peaks with high S/N ratio, small signal attenuation and small spurious peaks were observed in the time domain. All the reflection peaks were well matched with the predicted values from the simulation. With 10 mW RF power from the network analyzer, a ~1 m readout distance was observed. Depending on applied external pressure, the phase shifts of the reflection peaks were linearly varied. The evaluated sensitivity was about ~2.9 kPa-1. Eight sharp ON reflection peaks were observed for the ID tag. The temperature sensor was characterized from 20 C to 200 C. A large phase shift per unit temperature change was observed.

  1. Research on the h-BN films for high frequency SAW devices

    NASA Astrophysics Data System (ADS)

    Sun, Lian-jie; Chen, Xi-ming

    2011-11-01

    Hexagonal Boron Nitride (h-BN) films For high-frequency SAW devices were deposited on Ti/Al/Si(111) wafers by RF magnetron sputtering. The structure of h-BN films was investigated by fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) spectra. And the surface morphology and piezoelectric properties of h-BN film was characterized by atomic force microscopy (AFM). And the characterization results show that when the RF power is 300w and other experimental parameters were fixed, h-BN films was in high purity and the c-axis oriented, h-BN films was in high purity and the c-axis oriented, and the particles of which are uniform and compact, roughness is 2.63nm with piezoelectric and piezoelectric response even, meet the requirements of high sound propagation speed and excellent piezoelectric for high frequency SAW devices. The studies of piezoelectric test of thin films have shown that PFM test method of atomic force microscopy was suitable for characterization of piezoelectric and properties of the piezoelectric response distribution of nano-structure semiconductor thin film.

  2. Development of flexible SAW sensors for non-destructive testing of structure

    NASA Astrophysics Data System (ADS)

    Takpara, R.; Duquennoy, M.; Courtois, C.; Gonon, M.; Ouaftouh, M.; Martic, G.; Rguiti, M.; Jenot, F.; Seronveaux, L.; Pelegris, C.

    2016-02-01

    In order to accurately examine structures surfaces, it is interesting to use surface SAW (Surface Acoustic Wave). Such waves are well suited for example to detect early emerging cracks or to test the quality of a coating. In addition, when coatings are thin or when emergent cracks are precocious, it is necessary to excite surface waves beyond 10MHz. Finally, when structures are not flat, it makes sense to have flexible or conformable sensors for their characterization. To address this problem, we propose to develop SAW type of interdigital sensors (or IDT for InterDigital Transducer), based on flexible piezoelectric plates. Initially, in order to optimize these sensors, we modeled the behavior of these sensors and identified the optimum characteristic sizes. In particular, the thickness of the piezoelectric plate and the width of the interdigital electrodes have been studied. Secondly, we made composites based on barium titanate foams in order to have flexible piezoelectric plates and to carry out thereafter sensors. Then, we studied several techniques in order to optimize the interdigitated electrodes deposition on this type of material. One of the difficulties concerns the fineness of these electrodes because the ratio between the length (typically several millimeters) and the width (a few tens of micrometers) of electrodes is very high. Finally, mechanical, electrical and acoustical characterizations of the sensors deposited on aluminum substrates were able to show the quality of our achievement.

  3. Exotic see-saw mechanism for neutrinos and leptogenesis in a Pati-Salam model

    NASA Astrophysics Data System (ADS)

    Addazi, Andrea; Bianchi, Massimo; Ricciardi, Giulia

    2016-02-01

    We discuss non-perturbative corrections to the neutrino sector, in the context of a D-brane Pati-Salam-like model, that can be obtained as a simple alternative to SO(10) GUT's in theories with open and unoriented strings. In such D-brane models, exotic stringy instantons can correct the right-handed neutrino mass matrix in a calculable way, thus affecting mass hierarchies and modifying the see-saw mechanism to what we name exotic see-saw. For a wide range of parameters, a compact spectrum of right-handed neutrino masses can occur that gives rise to a predictive scenario for low energy observables. This model also provides a viable mechanism for Baryon Asymmetry in the Universe (BAU) through leptogenesis. Finally, a Majorana mass for the neutron is naturally predicted in the model, leading to potentially testable neutron-antineutron oscillations. Combined measurements in neutrino and neutron-antineutron sectors could provide precious informations on physics at the quantum gravity scale.

  4. Polymer coating behavior of Rayleigh-SAW resonators with gold electrode structure for gas sensor applications.

    PubMed

    Avramov, Ivan D; Lnge, Kerstin; Rupp, Swen; Rapp, Bastian; Rapp, Michael

    2007-01-01

    Results from systematic polymer coating experiments on surface acoustic wave (SAW) resonators and coupled resonator filters (CRF) on ST-cut quartz with a corrosion-proof electrode structure entirely made of gold (Au) are presented and compared with data from similar SAW devices using aluminium (Al) electrodes. The recently developed Au devices are intended to replace their earlier Al counterparts in sensor systems operating in highly reactive chemical gas environments. Solid parylene C and soft poly[chlorotrifluoroethylene-co-vinylidene fluoride] (PCFV) polymer films are deposited under identical conditions onto the surface of Al and Au devices. The electrical performance of the Parylene C coated devices is monitored online during film deposition. The PCVF coated devices are evaluated after film deposition. The experimental data show that the Au devices can stand up to 40% thicker solid films for the same amount of loss increase than the Al devices and retain better resonance and phase characteristics. The frequency sensitivities of Au and Al devices to parylene C deposition are nearly identical. After coating with soft PCFV sensing film, the Au devices provide up to two times higher gas sensitivity when probed with cooling agent, octane, or tetrachloroethylene. PMID:17225810

  5. Detection and high-precision positioning of liquid droplets using SAW systems.

    PubMed

    Bennès, Jonathan; Alzuaga, Sébastien; Chérioux, Frédŕic; Ballandras, Sylvain; Vairac, Pascal; Manceau, Jean-Francois; Bastien, Francois

    2007-10-01

    The capability to accurately handle liquids in small volumes is a key point for the development of lab-on-chip devices. In this paper, we investigate an application of surface acoustic waves (SAW) for positioning micro-droplets. A SAW device based on a 2 x 2 matrix of inter-digital transducers (IDTs) has been fabricated on a (YXI)/128 degrees LiNbO3 substrate, which implies displacement and detection in two dimensions of droplets atop a flat surface. Each IDT operates at a given frequency, allowing for an easy addressing of the active channel. Furthermore, very low cross-talk effects were observed as no frequency mixing arose in our device. Continuous as well as pulsed excitations of the IDTs have been studied, yielding, respectively, continuous and step-by-step droplet displacement modes. In addition, we also have used these two excitation types to control the velocity and the position of the droplets. We also have developed a theoretical analysis of the detection mode, which has been validated by experimental assessment. PMID:18019253

  6. Highly focused high-frequency travelling surface acoustic waves (SAW) for rapid single-particle sorting.

    PubMed

    Collins, David J; Neild, Adrian; Ai, Ye

    2016-02-01

    High-speed sorting is an essential process in a number of clinical and research applications, where single cells, droplets and particles are segregated based on their properties in a continuous flow. With recent developments in the field of microscale actuation, there is increasing interest in replicating the functions available to conventional fluorescence activated cell sorting (FACS) flow cytometry in integrated on-chip systems, which have substantial advantages in cost and portability. Surface acoustic wave (SAW) devices are ideal for many acoustofluidic applications, and have been used to perform such sorting at rates on the order of kHz. Essential to the accuracy of this sorting, however, is the dimensions of the region over which sorting occurs, where a smaller sorting region can largely avoid inaccurate sorting across a range of sample concentrations. Here we demonstrate the use of flow focusing and a highly focused SAW generated by a high-frequency (386 MHz), 10 μm wavelength set of focused interdigital transducers (FIDTs) on a piezoelectric lithium niobate substrate, yielding an effective sorting region only ~25 μm wide, with sub-millisecond pulses generated at up to kHz rates. Furthermore, because of the use of high frequencies, actuation of particles as small as 2 μm can be realized. Such devices represent a substantial step forward in the evolution of highly localized forces for lab-on-a-chip microfluidic applications. PMID:26646200

  7. Achievable Performance and Effective Interrogator Design for SAW RFID Sensor Tags

    NASA Technical Reports Server (NTRS)

    Barton Richard J.

    2012-01-01

    For many NASA missions, remote sensing is a critical application that supports activities such as environmental monitoring, planetary science, structural shape and health monitoring, non-destructive evaluation, etc. The utility of the remote sensing devices themselves is greatly increased if they are passive V that is, they do not require any on-board power supply such as batteries V and if they can be identified uniquely during the sensor interrogation process. Additional passive sensor characteristics that enable greater utilization in space applications are small size and weight, long read ranges with low interrogator power, ruggedness, and operability in extreme environments (vacuum, extreme high/low temperature, high radiation, etc.) In this paper, we consider one very promising passive sensor technology, called surface acoustic wave (SAW) radio-frequency identification (RFID), that satisfies all of these criteria. In general, RFID is a method of identifying items using radio waves to interrogate tags encoded with a unique identifier that are affixed to the items of interest. In the case of passive tags, only the interrogator, which transmits power to the tags in the form of radio-frequency electromagnetic radiation, requires access to a power supply. Passive RFID technologies are used today in many applications, including asset tracking and management, security and access control, and remote sensing. To date, most of the development and application in RFID technology has focused on either asset/inventory tracking and control or security and access control because these are the largest commercial application areas. Recently however, there has been growing interest in using passive RFID technology for remote sensing applications, and SAW devices are at the forefront of RFID sensing technology development. Although SAW RFID tags have great potential for use in numerous space-based remote sensing applications, the limited collision resolution capability of current generation tags limits the performance in a cluttered sensing environment. That is, as more SAW-based sensors are added to the environment, numerous tag responses are superimposed at the receiver and decoding all or even a subset of the telemetry becomes increasingly difficult. Background clutter generated by reflectors other than the sensors themselves is also a problem, as is multipath interference and signal distortion, but the limiting factor in many remote sensing applications can be expected to be tag mutual interference. This problem may be greatly mitigated by proper design of the SAW tag waveform, but that remains an open research problem, and in the meantime, several other related questions remain to be answered including: (1) What are the fundamental relationships between tag parameters such as bit-rate, time-bandwidth-product, SNR, and achievable collision resolution? (2) What are the differences in optimal or near-optimal interrogator designs between noise-limited environments and interference-limited environments? (3) What are the performance characteristics of different interrogator designs in term of parameters such as transmitter power level, range, and number of interfering tags? In this paper, we will present the results of a research effort aimed at providing at least partial answers to all of these questions.

  8. Occupational Injuries in Ohio Wood Product Manufacturing: A Descriptive Analysis With Emphasis on Saw-Related Injuries and Associated Causes

    PubMed Central

    Beery, Lindsay; Harris, James R.; Collins, James W.; Current, Richard S.; Amendola, Alfred A.; Meyers, Alysha R.; Wurzelbacher, Steven J.; Lampl, Mike; Bertke, Stephen J.

    2015-01-01

    Background Stationary sawing machinery is often a basic tool in the wood product manufacturing industry and was the source for over 2,500 injury/illness events that resulted in days away from work in 2010. Methods We examined 9 years of workers’ compensation claims for the state of Ohio in wood product manufacturing with specific attention to saw-related claims. For the study period, 8,547 claims were evaluated; from this group, 716 saw-related cases were examined. Results The sawmills and wood preservation sub-sector experienced a 71% reduction in average incidence rate and an 87% reduction in average lost-time incidence rate from 2001 to 2009. The top three injury category descriptions for lost-time incidents within saw-related claims were fracture (35.8%), open wounds (29.6%), and amputation (14.8%). Conclusions For saw-related injuries, preventing blade contact remains important but securing the work piece to prevent kickback is also important. PMID:25123487

  9. Efficient light deflection of a narrow guided beam in LiNbO3 using two SAW pulses

    NASA Astrophysics Data System (ADS)

    Yamashita, T.; Matano, M.; Inoue, N.; Katoh, M.

    1985-01-01

    Consideration is given to a new narrow guided beam design with enhanced optical deflection efficiency due to dual surface acoustic wave (SAW) pulses. The main idea behind the design is the use of multiple SAW transducers aligned along the axes of an LiNbO3 waveguide so that: (1) all the excited SAW pulses are deflected simultaneously; and (2) each light beam deflected by a corresponding SAW pulse is not interfered with by an adjacent SAW pulse. The performance characteristics of the device were investigated experimentally using a He-Ne laser and a photomultiplier connected to a pair of wide-channel waveguides and a slab waveguide. Waveforms of the Bragg deflection in the single-transducer and dual-transducer configurations were obtained, and deflection efficiencies were derived as a function of the electrical input power of 350 MHz. It is shown that the deflection efficiency of the waveguide was increased by 20 percent in the dual-transducer configuration. Some applications of acoustooptic narrow guided beams in signal processing devices are discussed.

  10. [The peculiarities of deposition of foreign particles in the skin region experimentally damaged by the electrical saw cutting element].

    PubMed

    Nazarov, Yu V

    2015-01-01

    The objective of the present study was to detect the deposition of foreign particles and other introduced objects in the human skin region damaged by the electrical saw cutting elements and to use the data thus obtained for the estimation of the speed and the type of the instrument, the main characteristics of the cutter covering and/or composition of its surface. The experiments included the sawing of the skin fragments using the small steel saws differing in the type of the surface cover, such as the uncoated (steel), stained, nickel- or chromium-plated, blue-finished saws with the movement speed of the cutting element 500, 1000, 2500, 2,000, and 3,000 revolutions per minute. The study provided information about the peculiarities of deposition of foreign particles and other introduced objects in the damaged regions of the human skin that allow not only to establish the fact of using the electrical saw with a high-speed back-and-forth movements of the cutting element but also the type of the instrument and the main characteristics of its cover and/or the composition of its surface. PMID:26856056

  11. Comparison of the sensitive property between soman and its simulant DMMP by hydrogen-bond acidic polymer coated SAW sensor

    NASA Astrophysics Data System (ADS)

    Wang, Yang; Du, Xiaosong; Long, Yin; Jiang, Yadong

    2014-08-01

    Hydrogen-bond acidic (HBA) polymers are widely used for the detection of dimethyl methyl phosphonate (DMMP, a simulant of real nerve agents) based on surface acoustic wave (SAW) sensors. This paper presented an HBA polymer PLF, and subsequently the polymer was dissolved into chloroform and spray-coated on a SAW device to fabricate a gas sensor. Then the sensor was equipped into a SAW test platform to investigate its sensitive property to soman vapor and its simulant DMMP at the concentrations below 20 mg/m3. Results revealed that the sensor showed high sensitivity to the analyte vapors, furthermore, the response of the sensor to soman vapor was relatively smaller and slower than that to DMMP. Tests to some common interference vapors were studied at the concentration of 10 mg/m3, and the results indicated that the sensor showed a good selective property.

  12. Investigation of new low-loss and high-power SAW filters for reverse-frequency-allocated cellular radios.

    PubMed

    Hikita, M; Tabuchi, T; Shibagaki, N

    1993-01-01

    Japanese cellular radios employ reverse frequency-allocations of the transmitter and receiver frequency bands. A rather narrowband surface acoustic wave (SAW) transmitter prefilter and a new type of SAW low-loss and high-power transmitter final stage filter-dual configurations to previously developed US cellular radio system filter-have been developed. The dual configurations provide the stopbands for the filter at the lower side of the pass bands, which is a requirement for reverse frequency-allocation systems. Design procedures, including those for the piezoelectric substrates and the experimental results obtained for the filters of 1.5 dB low insertion-loss and over 30 dB stop band rejection at 920 MHz, are also presented. In addition, the frequency characteristics of the SAW antenna duplexer module used in Japanese new common carrier (NCC) systems are discussed. PMID:18263176

  13. Life threatening intracerebral haemorrhage following saw- scaled viper (Echis carinatus) envenoming-authenticated case report from Sri Lanka

    PubMed Central

    2013-01-01

    Background Echis carinatus (Saw scaled viper {SSV}) is a venomous snake found in the parts of Middle East and Central Asia. SSV envenoming is characterized by local swelling and coagulopathy. Various bleeding manifestations are commonly seen with SSV envenoming. In contrast to other part of Asia, saw scale viper envenoming has not been reported to cause life threatening haemorrhagic manifestations in Sri Lanka. Case presentation We report a 19 years old healthy boy who developed massive left temporo-parietal intra cerebral haemorrhage following Echis carinatus (Saw scaled viper) bite in Sri Lanka. Conclusion Although subspecies of SSV in Sri Lanka is regarded as a ‘non lethal venomous snake’, the occurrence of rare potentially fatal complications such as intracerebral haemorrhage should be considered in their management. This case report is intended to bring the awareness of this fatal complication of SSV envenoming in Sri Lanka. PMID:23565979

  14. SAW RFID-Tags for Mass-Sensitive Detection of Humidity and Vapors

    PubMed Central

    Lieberzeit, Peter A.; Palfinger, Christian; Dickert, Franz L.; Fischerauer, Gerhard

    2009-01-01

    One-port surface acoustic wave (SAW) devices with defined reflector patterns give characteristic signal patterns in the time domain making them identifiable and leading to so-called RFID-Tags. Each sensor responds with a burst of signals, their timed positions giving the identification code, while the amplitudes can be related to the analyte concentration. This paper presents the first combination of such a transducer with chemically sensitive layer materials. These include crosslinked polyvinyl alcohol for determining relative humidity and tert-butylcalix[4]arene for detecting solvent vapors coated on the free space between the reflectors. In going from the time domain to the frequency domain by Fourier transformation, changes in frequency and phase lead to sensor responses. Hence, it is possible to measure the concentration of tetrachloroethene in air down to 50 ppm, as well as 1% changes in relative humidity. PMID:22303149

  15. Economics of ingot slicing with an internal diameter saw for low-cost solar cells

    NASA Technical Reports Server (NTRS)

    Daud, T.; Liu, J. K.; Fiegl, G.

    1981-01-01

    Slicing of silicon ingots using diamond impregnated internal diameter blade saws has been a standard technology of the semiconductor industry. This paper describes work on improvements to this technology for 10 cm diameter ingot slicing. Ingot rotation, dynamic blade edge control with feedback, mechanized blade dressing and development of thinner blades are the approaches tried. A comparison of the results for wafering with and without ingot rotation is also made. A sensitivity analysis of the major cost elements in wafering is performed for 10 cm diameter ingot and extended to the 15 cm diameter ingot case. Various parameter values such as machine cost, feed rate and consumable materials cost are identified both for single and multiple ingot slicing.

  16. Ultra low-power hybrid spintronics-straintronics clocked with Surface Acoustic Waves (SAW)

    NASA Astrophysics Data System (ADS)

    Salehi Fashami, Mohammad; Bandyopadhyay, Supriyo; Atulasimha, Jayasimha

    2014-03-01

    The study of magnetization dynamics in magnetostrictive materials triggered with surface acoustic waves (SAWs) is of great interest not only from a fundamental point of view, but also for potential applications in energy efficient nanomagnetic computing. In this presentation, we model magnetization dynamics in dipole coupled arrays of nanomagnets clocked by acoustic waves. Specifically, this theoretical work demonstrates the feasibility of sequential logic devices such as flip-flops by showing that NAND gates and information propagation with cross-over of nanomagnet ``wires'' can be implemented and synchronously clocked with surface acoustic waves. We acknowledge support of the National Science Foundation (NSF) under NSF CAREER grant CCF-1253370, the NEB2020 Grant ECCS-1124714 and SHF grant CCF-1216614 as well as the Semiconductor Research Company (SRC) under NRI task 2203.001.

  17. Shape-Selectivity with Liquid Crystal and Side-Chain Liquid Crystalline Polymer SAW Sensor Interfaces

    SciTech Connect

    FRYE-MASON,GREGORY CHARLES; OBORNY,MICHAEL C.; PUGH,COLEEN; RICCO,ANTONIO; THOMAS,ROSS C.; ZELLERS,EDWARD T.; ZHANG,GUO-ZHENG

    1999-09-23

    A liquid crystal (LC) and a side-chain liquid crystalline polymer (SCLCP) were tested as surface acoustic wave (SAW) vapor sensor coatings for discriminating between pairs of isomeric organic vapors. Both exhibit room temperature smectic mesophases. Temperature, electric-field, and pretreatment with self-assembled monolayers comprising either a methyl-terminated or carboxylic acid-terminated alkane thiol anchored to a gold layer in the delay path of the sensor were explored as means of affecting the alignment and selectivity of the LC and SCLCP films. Results for the LC were mixed, while those for the SCLCP showed a consistent preference for the more rod-like isomer of each isomer pair examined.

  18. Evaluation of Residual Stresses Using Laser-Generated SAWs on Surface of Laser-Welding Plates

    NASA Astrophysics Data System (ADS)

    Dong, Li-ming; Li, Jia; Ni, Chen-yin; Shen, Zhong-hua; Ni, Xiao-wu

    2013-06-01

    In this paper, residual stresses in laser-welding plates are studied by both numerical simulation and experiment based on laser ultrasonics. First, a three-dimensional finite-element model is developed to predict temperature distributions and thermo-structure response during the laser-welding process of an aluminum alloy plate, and the residual stresses around the joint are described from structure analysis. After that, experiments based on surface acoustic waves generated by a pulsed laser are carried out to determine the velocity distribution of SAWs around the joint, from which the distribution of main residual stresses are calculated according to acoustoelastic theory. By comparing the thermal-structure model results with the measurements, it is found that the numerical simulation results are in good agreement with the experimental data.

  19. Los Alamos National Laboratory corregated metal pipe saw facility preliminary safety analysis report. Volume I

    SciTech Connect

    1990-09-19

    This Preliminary Safety Analysis Report addresses site assessment, facility design and construction, and design operation of the processing systems in the Corrugated Metal Pipe Saw Facility with respect to normal and abnormal conditions. Potential hazards are identified, credible accidents relative to the operation of the facility and the process systems are analyzed, and the consequences of postulated accidents are presented. The risk associated with normal operations, abnormal operations, and natural phenomena are analyzed. The accident analysis presented shows that the impact of the facility will be acceptable for all foreseeable normal and abnormal conditions of operation. Specifically, under normal conditions the facility will have impacts within the limits posted by applicable DOE guidelines, and in accident conditions the facility will similarly meet or exceed the requirements of all applicable standards. 16 figs., 6 tabs.

  20. New Mass Properties Engineers Aerospace Ballasting Challenge Facilitated by the SAWE Community

    NASA Technical Reports Server (NTRS)

    Cutright, Amanda; Shaughnessy, Brendan

    2010-01-01

    The discipline of Mass Properties Engineering tends to find the engineers; not typically vice versa. In this case, two engineers quickly found their new responsibilities deep in many aspects of mass properties engineering and required to meet technical challenges in a fast paced environment. As part of NASA's Constellation Program, a series of flight tests will be conducted to evaluate components of the new spacecraft launch vehicles. One of these tests is the Pad Abort 1 (PA-1) flight test which will test the Launch Abort System (LAS), a system designed to provide escape for astronauts in the event of an emergency. The Flight Test Articles (FTA) used in this flight test are required to match mass properties corresponding to the operational vehicle, which has a continually evolving design. Additionally, since the structure and subsystems for the Orion Crew Module (CM) FTA are simplified versions of the final product, thousands of pounds of ballast are necessary to achieve the desired mass properties. These new mass properties engineers are responsible for many mass properties aspects in support of the flight test, including meeting the ballasting challenge for the CM Boilerplate FTA. SAWE expert and experienced mass properties engineers, both those that are directly on the team and many that supported via a variety of Society venues, significantly contributed to facilitating the success of addressing this particular mass properties ballasting challenge, in addition to many other challenges along the way. This paper discusses the details regarding the technical aspects of this particular mass properties challenge, as well as identifies recommendations for new mass properties engineers that were learned from the SAWE community along the way.

  1. Distraction osteogenesis for complex foot deformities: Gigli saw midfoot osteotomy with external fixation.

    PubMed

    Lamm, Bradley M; Gourdine-Shaw, Monique C; Thabet, Ahmed M; Jindal, Gaurav; Herzenberg, John E; Burghardt, Rolf D

    2014-01-01

    Open midfoot wedge osteotomy correction can cause neurovascular compromise, requires extensive exposure, sacrifices normal joints, and shortens the foot. We used a minimally invasive technique to treat complex foot deformities by combining percutaneous Gigli saw midfoot osteotomy, circular external fixation, and acute, gradual, or gradual with acute manipulation correction. The medical records of 23 patients (26 feet) with complex foot deformities (congenital, 18 feet; neuromuscular, 4 feet; post-traumatic, 3 feet; malunion, 1 foot) who had undergone treatment within an 18-year period (1990 through 2007) were retrospectively reviewed. We also performed the procedure on 10 cadaveric limbs to determine whether anatomic structures were at risk. Correction was achieved in all feet. The mean duration of external fixation treatment was 4.2 (range 3 to 7) months. The mean follow-up duration was 4.7 (range 2 to 18) years. A significant difference was observed in the pre- and postoperative, lateral view, talar-first metatarsal angle (p = .001). Minor complications (4 feet) consisted of bony exostoses. Major complications included recurrent deformity in 3 feet and sural nerve entrapment in 1 foot. Two patients had mild and one moderate foot pain. Three patients had impaired gait function; the remaining patients had functional gait. The mean interval until wearing regular shoes after external fixation removal was 2.3 (range 1 to 4) months. All but 1 of the patients were satisfied with the final results. We observed no cadaveric neurovascular injury. Our results have shown that percutaneous Gigli saw midfoot osteotomy can be performed without neurovascular injury and is capable of successfully correcting complex foot deformities. PMID:24891089

  2. Saw-tooth instability studies at the Stanford Linear Collider damping rings

    SciTech Connect

    Podobedov, B.

    1999-12-14

    Saw-tooth instability occurs during high current operation in the Stanford Linear Collider (SLC) damping rings. This instability is single bunch, and it can be cast as a longitudinal microwave instability. It is caused by the beam interaction with short range wakefields in the ring vacuum chamber. The saw-tooth instability manifests itself in the periodic blow-up in quadruple or higher moments in the longitudinal beam distribution. Most of the instability studies have been experimental. Since the measurements of coherent particle motion within a short ultrarelativistic beam are largely unconventional the authors had to develop some original diagnostics. These includes, for example, the down-conversion of the high frequency ({approximately}10 GHz) broad-band beam position monitor (BPM) signals. The authors have also employed a state-of-the-art Hamamatsu streak camera that is capable of resolving the longitudinal beam distribution with sub-picosecond accuracy. As a result of the streak camera experiments the authors have quantitatively described the phase space of unstable bunches. The authors have found the radial structure of the instability mode and established that it only displaces a few percent of the beam particles. In another series of experiments the authors have correlated the instability signals from the beams before the extraction from the damping rings with their trajectories in the linac downstream. This showed that the instability results in a significant transverse beam jitter in the linac which compromises the damping ring performance as an injector. In addition, the authors have studied the instability behavior under the broad range of stored beam parameters using both passive observation and driven excitation. These measurements revealed unexpected beam behavior significantly above the instability threshold. Finally, the authors performed several low current experiments to estimate the damping ring vacuum chamber impedance.

  3. Transverse waveguide mode suppression for Pt-electrode SAW resonators on quartz and LGS.

    PubMed

    Meulendyk, Bennett J; Pereira da Cunha, Mauricio

    2011-12-01

    SAW resonators on ST-X quartz and langasite (LGS) [0°, 144°, 24°] are currently being used for hydrogen fluoride (HF) vapor sensing and high-temperature sensing, respectively. For these applications, the use of Pt-based electrodes allows the resonators to withstand the targeted harsh environments. This work reveals that for Pt-electrode resonators with conventional short-circuit gratings on the aforementioned quartz and LGS orientations, acoustic energy leaks from the grating region to the bus bars, thus degrading the resonator response. To resolve this problem, this paper proposes and implements open-circuit gratings for resonators fabricated with these substrate/metal combinations. The open-circuit gratings guide the acoustic energy within the grating region, resulting in greater quality factors and reduced losses in the resonator response. In addition, scalar potential theory is utilized in this work to identify transverse waveguide modes in the responses of open-circuit grating resonators on quartz and LGS. A transverse waveguide mode dispersion relation was derived to extend the scalar potential theory to account for asymmetry in the slowness curve around the propagation direction. This is the case for several commonly used LGS orientations, in particular LGS [0°, 144°, 24°]. Finally, this work addresses spurious transverse mode mitigation by scaling both the transducer's grating aperture and electrode overlap width. Open circuit grating resonators with appropriately scaled transducer designs were fabricated and tested, resulting in a 71% increase in quality factor and a spurious mode rejection of over 26 dBc for Pt-electrode devices on ST-X quartz. This progress directly translates into better frequency resolution and increased dynamic range for HF vapor sensors and high-temperature SAW devices. PMID:23443708

  4. Combination of a SAW-biosensor with MALDI mass spectrometric analysis.

    PubMed

    Treitz, G; Gronewold, T M A; Quandt, E; Zabe-Khn, M

    2008-05-15

    A S-sens K5 surface acoustic wave biosensor was coupled with mass spectrometry (SAW-MS) for the analysis of a protein complex consisting of human blood clotting cascade factor alpha-thrombin and human antithrombin III, a specific blood plasma inhibitor of thrombin. Specific binding of antithrombin III to thrombin was recorded as a function of time with a S-sens K5 biosensor. Two out of five elements of the sensor chip were used as references. To the remaining three elements coated with RNA anti-thrombin aptamers, thrombin and antithrombin III were bound consecutively. The biosensor measures mass changes on the chip surface showing that 20% of about 400fmol/cm2 thrombin formed a complex with the 1.7-times larger antithrombin III. Mass spectrometry (MS) was applied to identify the bound proteins. Sensor chips with aptamer-captured (1) thrombin and (2) thrombin-antithrombin III complex (TAT-complex) were digested with proteases on the sensor element and subsequently identified by peptide mass fingerprint (PMF) with matrix assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry. A significant identification of thrombin was achieved by measuring the entire digest with MALDI-ToF MS directly from the sensor chip surface. For the significant identification of both proteins in the TAT-complex, the proteolytic peptides had to be separated by nano-capillary-HPLC prior to MALDI-ToF MS. SAW-MS is applicable to protein interaction analysis as in functional proteomics and to miniaturized diagnostics. PMID:18316185

  5. On the Old Saw That Dialogue Is a Socratic but Not an Aristotelian Method of Moral Education

    ERIC Educational Resources Information Center

    Kristjánsson, Kristján

    2014-01-01

    Kristján Kristjánsson's aim in this article is to bury the old saw that dialogue is exclusively a Socratic but not an Aristotelian method of education for moral character. Although the truncated discussion in Aristotle's "Nicomachean Ethics" of the character development of the young may indicate that it is merely the result of…

  6. Roughening and smoothing behavior of Al/Zr multilayers grown on flat and saw-tooth substrates

    NASA Astrophysics Data System (ADS)

    Voronov, D. L.; Anderson, E. H.; Cambie, R.; Gullikson, E. M.; Salmassi, F.; Warwick, T.; Yashchuk, V. V.; Padmore, H. A.

    2011-09-01

    Diffraction gratings with high efficiency and high groove density are required for EUV and soft x-ray spectroscopy techniques (such as Resonant Inelastic X-ray Scattering, RIXS) designed for state-of-the-art spectral resolution and throughput. A multilayer coated blazed grating (MBG) fabricated by deposition of a multilayer on a saw-tooth substrate could address these challenges. In order to obtain high diffraction efficiency one should provide perfect triangular grooves on a substrate and perfect replication of the groove profile during the multilayer deposition. However, multilayers trend to smooth out the corrugated surface of the substrates, resulting in the main limiting factor for efficiency of ultra-dense MBGs. Understanding of the growth of multilayers on saw-tooth substrates is a key for further grating improvement. In this work we investigate growth behavior of Al/Zr multilayers on saw-tooth substrates with a groove density of 10,000 lines/mm. We apply existing growth models to describe an evolution of Power Spectral Density functions of a grating surface during the multilayer deposition, and identify a main smoothing mechanism. We found that growth of flat multilayers is well modeled with surface diffusion caused by surface curvature as a main relaxation mechanism, while growth of the multilayer on saw-tooth substrates obeys different kinetics. Limitations of the linear approach and possible model improvements by accounting for an additional component of the surface diffusion flux, caused by a gradient of adatom concentration on a corrugated surface are discussed.

  7. On the Old Saw That Dialogue Is a Socratic but Not an Aristotelian Method of Moral Education

    ERIC Educational Resources Information Center

    Kristjnsson, Kristjn

    2014-01-01

    Kristjn Kristjnsson's aim in this article is to bury the old saw that dialogue is exclusively a Socratic but not an Aristotelian method of education for moral character. Although the truncated discussion in Aristotle's "Nicomachean Ethics" of the character development of the young may indicate that it is merely the result of

  8. DNA immobilization and SAW response in ZnO nanotips grown on LiNbO3 substrates.

    PubMed

    Zhang, Zheng; Emanetoglu, Nuri William; Saraf, Gaurav; Chen, Yimin; Wu, Pan; Zhong, Jian; Lu, Yicheng; Chen, Jingqiu; Mirochnitchenko, Oleg; Inouye, Masayori

    2006-04-01

    DNA immobilization enhancement is demonstrated in a structure consisting of ZnO nanotips on 128 degrees Y-cut LiNbO3. The ZnO nanotips are grown by metalorganic chemical vapor deposition (MOCVD) on the top of a SiO2 layer that is deposited and patterned on the LiNbO3 SAW delay path. The effects of ZnO nanotips on the SAW response are investigated. X-ray diffraction and scanning electron microscopy are used to analyze the ZnO nanotips, which are of single crystalline quality, and they are uniformly aligned with their c-axis perpendicular to the substrate surface. The photoluminescence (PL) spectrum of the ZnO nanotips shows strong near bandedge transition with insignificant deep level emission, confirming their good optical property. DNA immobilization enhancement is experimentally validated by radioactive labeling tests and SAW response changes. The ZnO nanotips enhance the DNA immobilization by a factor of 200 compared to ZnO film with flat surface. DNA hybridization with complementary and noncomplementary second strand DNA oligonucleotides is used to study the selective binding of the structure. This device structure possesses the advantages of both traditional SAW sensors and ZnO nanostructures. PMID:16615583

  9. Reducing the risk of injury from table saw use: the potential benefits and costs of automatic protection.

    PubMed

    Graham, John D; Chang, Joice

    2015-02-01

    The use of table saws in the United States is associated with approximately 28,000 emergency department (ED) visits and 2,000 cases of finger amputation per year. This article provides a quantitative estimate of the economic benefits of automatic protection systems that could be designed into new table saw products. Benefits are defined as reduced health-care costs, enhanced production at work, and diminished pain and suffering. The present value of the benefits of automatic protection over the life of the table saw are interpreted as the switch-point cost value, the maximum investment in automatic protection that can be justified by benefit-cost comparison. Using two alternative methods for monetizing pain and suffering, the study finds switch-point cost values of $753 and $561 per saw. These point estimates are sensitive to the values of inputs, especially the average cost of injury. The various switch-point cost values are substantially higher than rough estimates of the incremental cost of automatic protection systems. Uncertainties and future research needs are discussed. PMID:25082447

  10. AlN films deposited by dc magnetron sputtering and high power impulse magnetron sputtering for SAW applications

    NASA Astrophysics Data System (ADS)

    Ait Aissa, K.; Achour, A.; Elmazria, O.; Simon, Q.; Elhosni, M.; Boulet, P.; Robert, S.; Djouadi, M. A.

    2015-04-01

    In this work, aluminium nitride (AlN) films were deposited on silicon substrates buffered by an epitaxial AlN thin film for surface acoustic wave (SAW) applications. The films were deposited by dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) deposition techniques. The structural properties of AlN films were investigated using x-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy and atomic force microscopy. In both cases of films deposited by dcMS and HiPIMS, the XRD results showed that the obtained films are oriented, with full width at half maximum rocking curves of around 1°. Raman spectroscopy revealed higher residual stress relaxation in the AlN epilayers grown by HiPIMS compared to AlN grown by dcMS, highlighted by a blue shift in the E2(high) Raman mode. The SAW measurements indicated an insertion loss of AlN-SAW devices of about 53 and 35 dB for the AlN films deposited by dcMS and HiPIMS respectively. The relation between the structural properties of AlN and the characteristics of AlN-SAW devices were correlated and discussed.

  11. Surface Acoustic Waves (SAW)-Based Biosensing for Quantification of Cell Growth in 2D and 3D Cultures

    PubMed Central

    Wang, Tao; Green, Ryan; Nair, Rajesh Ramakrishnan; Howell, Mark; Mohapatra, Subhra; Guldiken, Rasim; Mohapatra, Shyam Sundar

    2015-01-01

    Detection and quantification of cell viability and growth in two-dimensional (2D) and three-dimensional (3D) cell cultures commonly involve harvesting of cells and therefore requires a parallel set-up of several replicates for time-lapse or dose–response studies. Thus, developing a non-invasive and touch-free detection of cell growth in longitudinal studies of 3D tumor spheroid cultures or of stem cell regeneration remains a major unmet need. Since surface acoustic waves (SAWs) permit mass loading-based biosensing and have been touted due to their many advantages including low cost, small size and ease of assembly, we examined the potential of SAW-biosensing to detect and quantify cell growth. Herein, we demonstrate that a shear horizontal-surface acoustic waves (SH-SAW) device comprising two pairs of resonators consisting of interdigital transducers and reflecting fingers can be used to quantify mass loading by the cells in suspension as well as within a 3D cell culture platform. A 3D COMSOL model was built to simulate the mass loading response of increasing concentrations of cells in suspension in the polydimethylsiloxane (PDMS) well in order to predict the characteristics and optimize the design of the SH-SAW biosensor. The simulated relative frequency shift from the two oscillatory circuit systems (one of which functions as control) were found to be concordant to experimental data generated with RAW264.7 macrophage and A549 cancer cells. In addition, results showed that SAW measurements per se did not affect viability of cells. Further, SH-SAW biosensing was applied to A549 cells cultured on a 3D electrospun nanofiber scaffold that generate tumor spheroids (tumoroids) and the results showed the device's ability to detect changes in tumor spheroid growth over the course of eight days. Taken together, these results demonstrate the use of SH-SAW device for detection and quantification of cell growth changes over time in 2D suspension cultures and in 3D cell culture models, which may have potential applications in both longitudinal 3D cell cultures in cancer biology and in regenerative medicine. PMID:26703604

  12. Surface Acoustic Waves (SAW)-Based Biosensing for Quantification of Cell Growth in 2D and 3D Cultures.

    PubMed

    Wang, Tao; Green, Ryan; Nair, Rajesh Ramakrishnan; Howell, Mark; Mohapatra, Subhra; Guldiken, Rasim; Mohapatra, Shyam Sundar

    2015-01-01

    Detection and quantification of cell viability and growth in two-dimensional (2D) and three-dimensional (3D) cell cultures commonly involve harvesting of cells and therefore requires a parallel set-up of several replicates for time-lapse or dose-response studies. Thus, developing a non-invasive and touch-free detection of cell growth in longitudinal studies of 3D tumor spheroid cultures or of stem cell regeneration remains a major unmet need. Since surface acoustic waves (SAWs) permit mass loading-based biosensing and have been touted due to their many advantages including low cost, small size and ease of assembly, we examined the potential of SAW-biosensing to detect and quantify cell growth. Herein, we demonstrate that a shear horizontal-surface acoustic waves (SH-SAW) device comprising two pairs of resonators consisting of interdigital transducers and reflecting fingers can be used to quantify mass loading by the cells in suspension as well as within a 3D cell culture platform. A 3D COMSOL model was built to simulate the mass loading response of increasing concentrations of cells in suspension in the polydimethylsiloxane (PDMS) well in order to predict the characteristics and optimize the design of the SH-SAW biosensor. The simulated relative frequency shift from the two oscillatory circuit systems (one of which functions as control) were found to be concordant to experimental data generated with RAW264.7 macrophage and A549 cancer cells. In addition, results showed that SAW measurements per se did not affect viability of cells. Further, SH-SAW biosensing was applied to A549 cells cultured on a 3D electrospun nanofiber scaffold that generate tumor spheroids (tumoroids) and the results showed the device's ability to detect changes in tumor spheroid growth over the course of eight days. Taken together, these results demonstrate the use of SH-SAW device for detection and quantification of cell growth changes over time in 2D suspension cultures and in 3D cell culture models, which may have potential applications in both longitudinal 3D cell cultures in cancer biology and in regenerative medicine. PMID:26703604

  13. Development and comparative investigation of Ag-sensitive layer based SAW and QCM sensors for mercury sensing applications.

    PubMed

    Kabir, K M Mohibul; Sabri, Ylias M; Kandjani, Ahmad Esmaielzadeh; Ippolito, Samuel J; Bhargava, Suresh K

    2016-04-21

    Piezoelectric acoustic wave devices integrated with noble metal surfaces provide exciting prospects for the direct measurement of toxic gas species such as mercury (Hg) in the atmosphere. Even though gold (Au) based acoustic wave sensors have been utilized extensively for detecting Hg, the potential of using other metal surfaces such as silver (Ag) is yet to be thoroughly studied. Here, we developed Ag sensitive layer-based surface acoustic wave (SAW) and quartz crystal microbalance (QCM) sensors and focused on their comparative analysis for Hg sensing applications with parameters such as the sensor sensitivity, selectivity, adsorption/desorption isotherm and Hg diffusion into the surface thoroughly studied. The SAW sensor was fabricated with nickel (Ni) interdigitated transducer (IDT) electrodes and a Ag thin film on the delay line of the device. In the case of the QCM sensor, the electrodes were constructed of Ag thin film and simultaneously employed as a sensitive layer. Mercury sensing experiments were conducted for a range of concentrations between 24-365 ppbv without/with the presence of some common industrial interfering gas species (i.e. ammonia, acetaldehyde, ethyl mercaptan, dimethyl disulphide, methyl ethyl ketone and humidity) at various operating temperatures in the range of 35-95 °C. The SAW sensor was found to possess up to 70 times higher response magnitudes than its QCM counterpart at 35 °C while up to 30 and 23 times higher response magnitudes were observed for the SAW sensor at elevated temperatures of 75 and 95 °C, respectively. Furthermore, the SAW sensor showed good selectivity (>89%) toward Hg(0) vapor in the presence of all the interferents tested at an operating temperature of 75 °C while the QCM sensor exhibited significant cross-sensitivity when ethyl mercaptan was introduced along with Hg(0) vapor. Overall, it is indicative that Ag-based acoustic wave sensors do have great potential for Hg sensing applications, given that right operating conditions are applied. PMID:26981609

  14. Chemical quality of the Saw Mill River, Westchester County, New York, 1981-83

    USGS Publications Warehouse

    Rogers, R.J.

    1984-01-01

    Surface waters, bottom sediments and coatings formed on artificial substrates (ceramic tiles) were analyzed to evaluate the chemical quality of the Saw Mill River, New York. Heavy metals, nutrients, and organic contaminants were studied. Dissolved orthophosphate concentrations were highest in the lower third of the river. Dissolved manganese was the only metal to exceed U.S. Environmental Protection Agency water-quality criteria. Arsenic, cadmium, copper, lead, and zinc concentrations were highest in waters from the lowest 4 river miles. Concentrations of copper, lead, and zinc in bottom sediments from the lowest 3 river miles were greater than in upstream sediments. Concentrations of nine heavy metals were higher on tiles emplaced below river mile 3 than on tiles upstream. Few organic compounds were detected in the water column; none persisted at all sites. Chlordane, DDD, DDE, DDT, dieldrin, and polychlorinated biphenyls (PCB's) were found in bottom sediments throughout the basin. PCB concentrations were highest in the lowest 6 river miles; the other organic compounds exhibited no spatial patterns. Polynuclear aromatic hydrocarbons were most abundant in bottom sediments from the lowest 2 river miles. Collectively the distribution of contaminants indicates that river quality deteriorates in the lower, more heavily urbanized reach. (USGS)

  15. Pharmacological effects of saw palmetto extract in the lower urinary tract

    PubMed Central

    Suzuki, Mayumi; Ito, Yoshihiko; Fujino, Tomomi; Abe, Masayuki; Umegaki, Keizo; Onoue, Satomi; Noguchi, Hiroshi; Yamada, Shizuo

    2009-01-01

    Saw palmetto extract (SPE), an extract from the ripe berries of the American dwarf palm, has been widely used as a therapeutic remedy for urinary dysfunction due to benign prostatic hyperplasia (BPH) in Europe. Numerous mechanisms of action have been proposed for SPE, including the inhibition of 5α-reductase. Today, α1-adrenoceptor antagonists and muscarinic cholinoceptor antagonists are commonly used in the treatment of men with voiding symptoms secondary to BPH. The improvement of voiding symptoms in patients taking SPE may arise from its binding to pharmacologically relevant receptors in the lower urinary tract, such as α1-adrenoceptors, muscarinic cholinoceptors, 1,4-dihyropyridine receptors and vanilloid receptors. Furthermore, oral administration of SPE has been shown to attenuate the up-regulation of α1-adrenoceptors in the rat prostate induced by testosterone. Thus, SPE at clinically relevant doses may exert a direct effect on the pharmacological receptors in the lower urinary tract, thereby improving urinary dysfunction in patients with BPH and an overactive bladder. SPE does not have interactions with co-administered drugs or serious adverse events in blood biochemical parameters, suggestive of its relative safety, even with long-term intake. Clinical trials (placebo-controlled and active-controlled trials) of SPE conducted in men with BPH were also reviewed. This review should contribute to the understanding of the pharmacological effects of SPE in the treatment of patients with BPH and associated lower urinary tract symptoms (LUTS). PMID:19262550

  16. Flux composition, microstructure and mechanical properties of HY-100 SAW weldments

    SciTech Connect

    Brothers, D.G.; Kettell, K.W.; Fox, A.G.

    1994-12-31

    The mechanical properties of submerged arc welds (SAW) on high strength steels are sensitive to weld-metal chemistry and thus the chemical composition of the welding consumables. Consumable chemistry determines the size, distribution, and composition of the nonmetallic inclusions present in the weld metal which together with cooling rate determines weld-metal microstructure and thus mechanical properties. Multirun submerged arc welds were made on HY-100 steel and all-weld variables were kept constant except the flux composition for which five different commercial fluxes were investigated. The basicity of each flux was calculated and correlated with weld-metal chemistry and it was found that lower basicity fluxes appeared to generate a higher oxygen activity in the weld-metal leading to more pronounced oxidation of carbon, manganese, and silicon and thus loss of weld-metal yield strength. Inclusion analyses showed the inclusion in the weld-metals to contain MnO, Al{sub 2}O{sub 3}, SiO{sub 2}, and TiO{sub 2}. These results suggest that the optimum flux for welding high-strength steels should have a high enough basicity and MnO content to avoid the loss of alloying elements from the weld metal due to high oxygen activity and to generate sufficient numbers of non-metallic inclusions to keep the DBTT low by forming significant amounts of acicular ferrite.

  17. Saw-tooth refractive lens for high energy x-ray focusing

    NASA Astrophysics Data System (ADS)

    Antimonov, Mikhail A.; Khounsary, Ali M.

    2014-09-01

    Saw-tooth refractive lens (SRL) provides a comparatively attractive option for X-ray focusing. An SRL assembly consists of two parts, each with an array of triangular structures (prisms), set tilted symmetrically with respect to the incoming beam. Its main advantage is a simple, continuous tunability in energy and focal length. SRLs can be used for both long and short focal length focusing. Long focal distance focusing of an SRL can accurately be predicted using simple analytical relations. However, the focus size at short focal distances focusing may deviate appreciably from the expected demagnified source size when: (1) the length of the SRL is comparable with the focusing distance, (2) the incident beam is not monochromatic, and (3) and the distance between adjacent prism tips, the tip step, is large . The first factor was considered in a previous work while the other two are addressed is this paper. This preliminary work is aimed at a better understanding of the SRL lenses for focusing an undulator beamline at the Advanced Photon Source (APS).

  18. Continuous in vivo blood pressure measurements using a fully implantable wireless SAW sensor.

    PubMed

    Murphy, Olive H; Bahmanyar, Mohammad Reza; Borghi, Alessandro; McLeod, Christopher N; Navaratnarajah, Manoraj; Yacoub, Magdi H; Toumazou, Christofer

    2013-10-01

    In this paper, the development of a fully implantable wireless sensor able to provide continuous real-time accurate pressure measurements is presented. Surface Acoustic Wave (SAW) technology was used to deposit resonators on crystalline quartz wafers; the wafers were then assembled to produce a pressure sensitive device. Excitation and reading via a miniature antenna attached to the pressure sensor enables continuous external interrogation. The main advantages of such a configuration are the long term stability of quartz and the low power necessary for the interrogation, which allows 24/7 interrogation by means of a hand-held, battery powered device. Such data are of vital importance to clinicians monitoring and treating the effects of hypertension and heart failure. A prototype was designed and tested using both a bio-phantom test rig and an animal model. The pressure traces for both compare very well with a commercially available catheter tip pressure transducer. The work presented in this paper is the first known wireless pressure data from the left ventricle of the heart of a living swine. PMID:23559403

  19. Design of SAW filters in SS-FDMA routers for mobile satellite systems

    NASA Astrophysics Data System (ADS)

    Ananasso, Fulvio; Deacon, John M.

    1989-11-01

    The present paper reports the design of a SAW filter bank consisting of 26 linear phase filters with bandwidths ranging from 60 to 2180 kHz, 0.5/40 dB transition width narrower than 30 kHz, and stopband rejection as high as possible. Passbank amplitude and phase ripple limits are 1 dB and 4 deg peak-to-peak respectively. Three candidate filters of bandwidth 60 kHz, 400 kHz and 2.180 MHz were selected for detailed design, taking into account spurious effects such as acoustic regeneration and diffraction as well as technology limits. The electrical specifications are met by all but the 2180 kHz filter, whose shape factor, for a 30 kHz transition band, would be 1.027 : 1, beyond the state of the art. The filter bank has about 27 dB insertion loss per filter, plus roughly 14 dB (1 : 26) power split loss.

  20. Snakebite Envenoming by Sochurek's Saw-scaled Viper Echis Carinatus Sochureki.

    PubMed

    Valenta, Jiří; Stach, Zdeněk; Michálek, Pavel

    2016-01-01

    A snake breeder, 47-years-old man, was bitten by the saw-scaled viper (Echis carinatus sochureki). After admission to Toxinology Centre, within 1.5 h, laboratory evaluation showed clotting times prolonged to non-measurable values, afibrinogenaemia, significantly elevated D-dimers, haemolysis and myoglobin elevation. Currently unavailable antivenom was urgently imported and administered within 10 hours. In 24 hours, oligoanuric acute kidney injury (AKI) and mild acute respiratory distress syndrome (ARDS) developed. Despite administration of 10 vials of urgently imported Polyvalent Snake Antivenom Saudi Arabia, the venom-induced consumption coagulopathy (VICC) and AKI persisted. Another ten vials of antivenom were imported from abroad. VICC slowly subsided during the antivenom treatment and disappeared after administration of total 20 vials during 5 day period. No signs of haemorrhage were present during treatment. After resolving VICC, patient was transferred to Department of Nephrology for persisting AKI and requirement for haemodialysis. AKI completely resolved after 20 days. Despite rather timed administration of appropriate antivenom, VICC and AKI developed and the quantity of 20 vials was needed to cease acute symptoms of systemic envenoming. The course illustrates low immunogenicity of the venom haemocoagulation components and thus higher requirements of the antivenom in similar cases. PMID:26995204

  1. Application of convolve-multiply-convolve SAW processor for satellite communications

    NASA Technical Reports Server (NTRS)

    Lie, Y. S.; Ching, M.

    1991-01-01

    There is a need for a satellite communications receiver than can perform simultaneous multi-channel processing of single channel per carrier (SCPC) signals originating from various small (mobile or fixed) earth stations. The number of ground users can be as many as 1000. Conventional techniques of simultaneously processing these signals is by employing as many RF-bandpass filters as the number of channels. Consequently, such an approach would result in a bulky receiver, which becomes impractical for satellite applications. A unique approach utilizing a realtime surface acoustic wave (SAW) chirp transform processor is presented. The application of a Convolve-Multiply-Convolve (CMC) chirp transform processor is described. The CMC processor transforms each input channel into a unique timeslot, while preserving its modulation content (in this case QPSK). Subsequently, each channel is individually demodulated without the need of input channel filters. Circuit complexity is significantly reduced, because the output frequency of the CMC processor is common for all input channel frequencies. The results of theoretical analysis and experimental results are in good agreement.

  2. Characterizing components of the Saw Palmetto Berry Extract (SPBE) on prostate cancer cell growth and traction.

    PubMed

    Scholtysek, Carina; Krukiewicz, Aleksandra A; Alonso, José-Luis; Sharma, Karan P; Sharma, Pal C; Goldmann, Wolfgang H

    2009-02-13

    Saw Palmetto Berry Extract (SPBE) is applied for prostate health and treatment of urinary tract infections, nonbacterial prostitis and Benign Prostatic Hyperplasia (BPH) in man. An assumption is that SPBE affects tumor cell progression and migration in breast and prostate tissue. In this work, DU-145 cells were used to demonstrate that SPBE and its sterol components, beta-sitosterol and stigmasterol, inhibit prostate cancer growth by increasing p53 protein expression and also inhibit carcinoma development by decreasing p21 and p27 protein expression. In the presence of cholesterol, these features are not only reversed but increased significantly. The results show for the first time the potential of SPBE, beta-sitosterol and stigmasterol as potential anti-tumor agents. Since the protein p53 is also regarded as nuclear matrix protein facilitating actin cytoskeletal binding, 2D tractions were measured. The cell adhesion strength in the presence of SPBE, beta-sitosterol and cholesterol and the observation was that the increase in p53 expression triggered an increase in the intracellular force generation. The results suggest a dual function of p53 in cells. PMID:19059205

  3. The 2.2 GHz Surface Acoustic Wave (SAW) oscillator development Ku-band frequency source development

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Two 2.2 GHz SAW oscillators using aluminum nitride on sapphire (AlN/Al2O3) delay lines were fabricated. The oscillators were electronically temperature compensated and characterized. One of the oscillators was used as the frequency reference for the Ku band source; the second oscillator is available for continued evaluation. A 15 GHz frequency source was designed and fabricated. The 15 GHz source consists of a Ku band FET oscillator which is phase locked to the frequency multiplied (X7) output of the 2.2 GHz SAW reference source. The Ku band source was built using microstrip circuit designs, which are hybrid compatible. Two wafer runs of 2.2 GHz TED devices were fabricated and evaluated. The devices were mounted on microstrip test substrates and evaluated as 15 GHz divide by 7 circuits. The device evaluation indicated that in their present form the TED is not a practical circuit element.

  4. Control of surface mobility for conformal deposition of Mo-Si multilayers on saw-tooth substrates

    NASA Astrophysics Data System (ADS)

    Voronov, D. L.; Anderson, E. H.; Gullikson, E. M.; Salmassi, F.; Warwick, T.; Yashchuk, V. V.; Padmore, H. A.

    2013-11-01

    Multilayer-coated blazed gratings (MBG) are the most promising solution for ultra-high resolution soft X-ray spectroscopy, since they can have very high groove density and provide high-order operation and very high diffraction efficiency. The performance of MBGs however depends critically on the conformal deposition of the multilayer (ML) stack on a saw-tooth substrate and the minimization of roughness. We present an analysis of the roughening and smoothing processes during growth of Mo/Si multilayers deposited over a range of pressures of Ar sputtering gas on flat and saw-tooth substrates. A Linear Continuum Model (LCM) of the film growth was used to understand the interplay between smoothing and roughening of the ML films and to predict the optimum conditions for deposition. The MBG coated under the optimal deposition conditions demonstrated high diffraction efficiency in the EUV and soft X-ray wavelength ranges

  5. INTERNATIONAL UNION OF OPERATING ENGINEERS NATIONAL HAZMAT PROGRAM - EVOLUTION 180 CIRCULAR SAW OENHP: 2001-03, VERSION A

    SciTech Connect

    Unknown

    2002-01-25

    Florida International University's (FIU) Hemispheric Center for Environmental Technology (HCET) evaluated five saws for their effectiveness in cutting specially prepared fiberglass-reinforced plywood crates. These crates were built as surrogates for crates that presently hold radioactively contaminated gloveboxes at the Department of Energy's (DOE) Los Alamos facility. The Evolution 180 circular saw was assessed on August 14, 2001. During the FIU test of efficacy, a team from the Operating Engineers National Hazmat Program (OENHP) evaluated the occupational safety and health issues associated with this technology. The Evolution 180 is a portable, metal cutting circular saw with a 7-inch diameter blade. The blade is contained within the main housing and has a retractable lower blade guard to prevent operator access to the blade during operation and shutdown. The saw is equipped with a chip collector. The maximum cutting thickness for metal is one-quarter inch and can cut steel tubing and pipe 2 inches in diameter. The unit is operated with an on/off guarded trigger switch and is supported with the hand guide mounted to the side of the saw. An adjustable lever sets the depth of the cut. The machine's circuitry will automatically shut the saw motor off if excessive overload is detected during operation. The one-half hour demonstration involved vertical and horizontal cuts and blade changes. During this process, operators experienced binding of the saw. This caused the blade to become hot, causing the sawdust collected in the chip collector to smoke. Care should be exercised to use the appropriate blade for the application, operator training, and personal protective equipment (PPE). Personal noise sampling indicated that neither worker was over the Occupational Safety and Health Administration's (OSHA) Action Level of 85 decibels (dBA) with time-weighted averages (TWA's) of 69.1 and 68.8 dBA. The personal noise sample taken during the special demonstration with the stainless steel plate had a TWA of 69.8 dBA. These data are not entirely representative as they were gathered during a simulation and not at the actual worksite. Additional sampling should be conducted on-site, but the workers should wear hearing protection until it is determined that it is no longer necessary. The total nuisance dust sample for the Evolution 180 circular saw was 3.5 milligrams per cubic meter (mg/m{sup 3}), which is lower than the OSHA Permissible Exposure Limit (PEL) of 15 mg/m{sup 3} and the American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold Limit Value (TLV) of 10 mg/m{sup 3}. The fiber analysis yielded 1.74 fibers per cubic centimeter (f/cc), which is above the PEL of 1 f/cc. Although the nuisance dust levels were low, fiberglass dust levels were higher than the PEL. Since fiberglass dust is known to be a strong skin irritant and a possible human carcinogen, the workers should continue to wear appropriate suits and gloves, as well as a full-face air-purifying respirator. The respirator should be equipped with a combination organic vapor and acid gas cartridge in combination with a High Particulate Air (HEPA) filter, since particulate filter, since during the demonstration, the workers complained of an odd smell, which may have been from the breakdown of the fiberglass.

  6. Detection of coffee flavour ageing by solid-phase microextraction/surface acoustic wave sensor array technique (SPME/SAW).

    PubMed

    Barié, Nicole; Bücking, Mark; Stahl, Ullrich; Rapp, Michael

    2015-06-01

    The use of polymer coated surface acoustic wave (SAW) sensor arrays is a very promising technique for highly sensitive and selective detection of volatile organic compounds (VOCs). We present new developments to achieve a low cost sensor setup with a sampling method enabling the highly reproducible detection of volatiles even in the ppb range. Since the VOCs of coffee are well known by gas chromatography (GC) research studies, the new sensor array was tested for an easy assessable objective: coffee ageing during storage. As reference method these changes were traced with a standard GC/FID set-up, accompanied by sensory panellists. The evaluation of GC data showed a non-linear characteristic for single compound concentrations as well as for total peak area values, disabling prediction of the coffee age. In contrast, the new SAW sensor array demonstrates a linear dependency, i.e. being capable to show a dependency between volatile concentration and storage time. PMID:25624226

  7. INTERNATIONAL UNION OF OPERATING ENGINEERS NATIONAL HAZMAT PROGRAM - PORTER-CABLE CIRCULAR SAW OENHP: 2001-04, VERSION A

    SciTech Connect

    Unknown

    2002-01-15

    Florida International University's (FIU) Hemispheric Center for Environmental Technology (HCET) evaluated five saws for their effectiveness in cutting specially prepared fiberglass-reinforced plywood crates. These crates were built as surrogates for crates that presently hold radioactively contaminated glove boxes at the Department of Energy's (DOE) Los Alamos facility. The Porter-Cable circular saw was assessed on August 15-16, 2001 (Porter-Cable No.1 and Porter-Cable No.2, respectively). During the FIU test of efficacy, a team from the Operating Engineers National Hazmat Program (OENHP) evaluated the occupational safety and health issues associated with this technology. The Porter-Cable saw is a straightforward machine for cutting wood of varying thickness. The blade is fully guarded with a fixed upper and a lower retractable guard. The lower guard retracts as the blade engages the work piece. The unit is operated with an on/off guarded trigger switch and is supported with a handgrip mounted near the front of the saw. The saw is equipped with a directional nozzle, which aims sawdust away from the operator and the line of cut. An optional vacuum system, attached to the directional nozzle, is used to remove and collect dust. During the demonstration of Porter-Cable No.1, personal noise sampling indicated that one worker was under and one was at the Occupational Safety and Health Administration's (OSHA) Action Level of 85 decibels (dBA) with time-weighted averages (TWA's) of 82.7 and 84.6 dBA, respectively. During the demonstration of Porter-Cable No.2, however, both workers did exceed the Action Level with TWA's of 89.7 and 90.0 dBA. These data are not entirely representative as they were gathered during a simulation and not at the actual worksite. Additional sampling should be conducted on-site, but the workers should wear hearing protection until it is determined that it is no longer necessary. The total nuisance dust sample for Porter-Cable No.1 was 3.53 milligrams per cubic meter (mg/m{sup 3}), which is lower than the OSHA Permissible Exposure Limit (PEL) of 15 mg/m{sup 3} and the American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold Limit Value (TLV) of 10 mg/m{sup 3}. Porter-Cable No.2's nuisance dust results yielded a value of 22.05 mg/m{sup 3}, which is over the PEL and TLV. The fiber analysis for the first demonstration yielded 12.9 fibers per cubic centimeter (f/cc), which is much higher than the PEL of 1 f/cc. Galson Laboratories considered the fiber analysis for the second demonstration void due to the overloading of dust on the filter. Kickback, the sudden reaction to a pinched blade, is possible with this saw and could cause the saw to lift up and out of the work piece and toward the operator. Proper work position and firm control of the saw minimizes the potential for a sprain or strain. Care needs to be exercised to support the work piece properly and to not force the tool.

  8. Material property evaluations of bimetallic welds, stainless steel saw fusion lines, and materials affected by dynamic strain aging

    SciTech Connect

    Rudland, D.; Scott, P.; Marschall, C.; Wilkowski, G.

    1997-04-01

    Pipe fracture analyses can often reasonably predict the behavior of flawed piping. However, there are material applications with uncertainties in fracture behavior. This paper summarizes work on three such cases. First, the fracture behavior of bimetallic welds are discussed. The purpose of the study was to determine if current fracture analyses can predict the response of pipe with flaws in bimetallic welds. The weld joined sections of A516 Grade 70 carbon steel to F316 stainless steel. The crack was along the carbon steel base metal to Inconel 182 weld metal fusion line. Material properties from tensile and C(T) specimens were used to predict large pipe response. The major conclusion from the work is that fracture behavior of the weld could be evaluated with reasonable accuracy using properties of the carbon steel pipe and conventional J-estimation analyses. However, results may not be generally true for all bimetallic welds. Second, the toughness of austenitic steel submerged-arc weld (SAW) fusion lines is discussed. During large-scale pipe tests with flaws in the center of the SAW, the crack tended to grow into the fusion line. The fracture toughness of the base metal, the SAW, and the fusion line were determined and compared. The major conclusion reached is that although the fusion line had a higher initiation toughness than the weld metal, the fusion-line J-R curve reached a steady-state value while the SAW J-R curve increased. Last, carbon steel fracture experiments containing circumferential flaws with periods of unstable crack jumps during steady ductile tearing are discussed. These instabilities are believed to be due to dynamic strain aging (DSA). The paper discusses DSA, a screening criteria developed to predict DSA, and the ability of the current J-based methodologies to assess the effect of these crack instabilities. The effect of loading rate on the strength and toughness of several different carbon steel pipes at LWR temperatures is also discussed.

  9. A New Hyphenated ? TrapGCSurface Acoustic Wave (SAW) Based Electronic Nose For Monitoring Of Coffee Quality

    NASA Astrophysics Data System (ADS)

    Carvalho, Mauro; Voigt, Achim; Rapp, Michael

    2009-05-01

    An easy-to-use and versatile analytical method for complex matrix analisis like coffee was developed. The system consists of a microtrap sample preparation, a home made simplified gaschomatographic separation unit and an 8-fold surface acoustic wave based sensors (SAW) array detector. For the coffee quality analysis a successful discrimination of three coffee samples could be achieved. The system would be further developed into a fully automated, low cost version that can be broadly used by the coffee producers.

  10. Quasi-static field analysis of SAW devices with arbitrary geometries of electrodes and of metallic enclosures.

    PubMed

    Reichinger, H; Baghai-Wadji, A R

    1994-01-01

    An easy-to-implement, accurate, and fast method to calculate 2-D quasi-static capacitance and inductance of electrodes in SAW devices is presented. The method is outlined by considering electrodes with any cross-section geometries in dielectric environment, consisting of two anisotropic materials with a plane interface. The analysis allows the inclusion of arbitrarily shaped metallic packages. A significant shift of charges on enclosures, due to the substrate anisotropy, is observed. PMID:18263267

  11. Achieving optimal flatness and surface roughness properties for novel x-ray optic structures formed by dicing saws

    NASA Astrophysics Data System (ADS)

    Wieczorek, Michael; Khachatryan, Ruben; Shvyd'ko, Yuri; Smith, Robert H.; Iwasaki, Kenichi; Miller, Suzanne; Qian, Jun; Huang, Xianrong; Assoufid, Lahsen

    2012-10-01

    Crystal-based x-ray optics are widely used in the synchrotron radiation field. Such optics include monochromators, channel-cut crystals, spectral analyzers, and phase plates that are generally made with standard fabrication tools such as grinders, ultrasonic mills, blade saws, and wire saws. However, modern synchrotron radiation instruments require more complicated and high-precision crystal structures that cannot be fabricated by these conventional tools. Examples include narrow channels and crystal cavities that require smooth and strain-free sidewalls or inner surfaces. Since it is extremely difficult to polish such surfaces by conventional means, specialized cutting tools are required to make the as-cut surfaces as smooth as possible. A possible way to obtain such smooth surfaces is to use a dicing saw as a fabrication tool - a tool typically used in the microelectronics industry to cut or dice semiconductor and other materials. Here we present our studies on the use of dicing saws for cutting innovative, monolithic, x-ray optic devices comprised of tall, narrow-standing, thin crystal-plate arrays. We report cutting parameters that include the rotational speed of the cutting blade (a.k.a. spindle speed), cutting speed (a.k.a. feed rate), number of passes for each cut depth (if required), and diamond grit size for producing the flattest and most smooth side walls. Blade type and construction (sintered, Ni, and resin) also play critical roles in achieving optimum results. The best experimental data obtained produced an average surface roughness of 49 nm and a peak-to-valley flatness of 3625 nm. By achieving these results, we have been able to assist experimenters in the synchrotron radiation field in their efforts to create functional and novel optical devices.

  12. Predicting the Relationship Between System Vibration with Rock Brittleness Indexes in Rock Sawing Process

    NASA Astrophysics Data System (ADS)

    Mikaeil, Reza; Ataei, Mohammad; Ghadernejad, Saleh; Sadegheslam, Golsa

    2014-03-01

    The system vibration is a very significant measure of the sawing performance, because it indicates the amount of energy required to saw the rock. The maintenance cost of system is also dependant on system vibration. A few increases in system vibration cause a huge increase in the maintenance cost of the system. In this paper, the vibration of system in terms of RMSa was investigated and models for estimation of vibration by means of rock brittleness indexes and operational specifications were designed via statistical models and multiple curvilinear regression analysis. In this study, the relationships between rock brittleness indexes and operational specifications were investigated by regression analysis in statistical package for social science (SPSS) and the results of determination coefficients have been presented. In the second part, the diagrams show that a point lying on the line indicates an exact estimation. In the plot for model, the points are scattered uniformly about the diagonal line, suggesting that the models are good. It is very useful to evaluate the vibration of system and select the suitable operational characteristics by only some mechanical properties of rock. Drgania układu uważane są za miernik wydajności procesu urabiania, ponieważ pokazują ilość energii niezbędnej do urabiania skały. Od poziomu drgań zależą także koszty eksploatacji systemu. Nieznaczny nawet wzrost poziomu drgań prowadzi do znacznego zwiększenia kosztów eksploatacyjnych urządzenia. W pracy tej przeprowadzono analizę drgań (ich wartości skutecznych) i opracowano model estymacji poziomu drgań w oparciu o współczynnik kruchości skał i parametry eksploatacyjne urządzenia. W pracy wykorzystano modele statystyczne i wielokrotną analizę metodą regresji krzywoliniowej. W pracy obecnej związek pomiędzy współczynnikiem kruchości skał a parametrami eksploatacyjnymi urządzenia badano z wykorzystaniem analizy metodą regresji dostępnej w statystycznym pakiecie oprogramowania dla nauk społecznych (SPSS) a wyniki podano w postaci wyznaczonych współczynników. W drugiej części pracy przedstawiono wykres pokazujący, ze punkt leżący na linii oznacza dokładne oszacowanie. W wykresie wykonanym dla modelu punkty rozrzucone są równomiernie wokół linii przekątnej, co sugeruje że modele są właściwe. Określenie poziomu drgań urządzenia jest niezwykle korzystnym zabiegiem pozwalającym na dobór parametrów pracy urządzenia jedynie w oparciu o mechaniczne właściwości skał.

  13. Detection, Identification, Location, and Remote Sensing using SAW RFID Sensor Tags

    NASA Technical Reports Server (NTRS)

    Barton, Richard J.

    2009-01-01

    In this presentation, we will consider the problem of simultaneous detection, identification, location estimation, and remote sensing for multiple objects. In particular, we will describe the design and testing of a wireless system capable of simultaneously detecting the presence of multiple objects, identifying each object, and acquiring both a low-resolution estimate of location and a high-resolution estimate of temperature for each object based on wireless interrogation of passive surface acoustic wave (SAW) radiofrequency identification (RFID) sensor tags affixed to each object. The system is being studied for application on the lunar surface as well as for terrestrial remote sensing applications such as pre-launch monitoring and testing of spacecraft on the launch pad and monitoring of test facilities. The system utilizes a digitally beam-formed planar receiving antenna array to extend range and provide direction-of-arrival information coupled with an approximate maximum-likelihood signal processing algorithm to provide near-optimal estimation of both range and temperature. The system is capable of forming a large number of beams within the field of view and resolving the information from several tags within each beam. The combination of both spatial and waveform discrimination provides the capability to track and monitor telemetry from a large number of objects appearing simultaneously within the field of view of the receiving array. In the presentation, we will summarize the system design and illustrate several aspects of the operational characteristics and signal structure. We will examine the theoretical performance characteristics of the system and compare the theoretical results with results obtained from experiments in both controlled laboratory environments and in the field.

  14. Structural Loading on the QCM/SAW Instrument Aboard the ER-2 Used for Atmospheric Testing

    NASA Technical Reports Server (NTRS)

    Bainum, Peter M.; Jones, Phyllis D.; Irish, Sandra M.; Xing, Guang-Qian

    1998-01-01

    Several experiments have been proposed to capture and evaluate samples of the atmosphere where SST's travel. One means to achieve this is to utilize the quartz crystal microbalance (QCM) / surface acoustical wave (SAW) instrument installed aboard the ER-2, formerly the U-2 reconnaissance aircraft. The QCM is a cascade impactor designed to perform in-situ, real-time measurements of aerosols and chemical vapors at an altitude of 60,000-70,000 feet. The primary use of the ER-2 is by NASA for Earth resources to test new sensor systems before being placed aboard satellites. One of the main reasons the ER-2 is used for this flight experiment is its capability to fly approximately twelve miles above the sea level (can reach an altitude of 78,000 feet). Because the ER-2 operates at such a high altitude, it is of special interest to scientists interested in space exploration or supersonic aircraft. The purpose of some of the experiments is to extinct data from the atmosphere around the ER-2. For the current CSTEA flight experiment, the housing of the QCM is in a frame that connects to an outer pod that attaches to the fuselage of the ER-2. Due to the location of the QCM within the housing frame and the location of the pod on the ER-2, the pod and its contents are subject to structural loads. In addition to structural loads, structural vibrations are also of importance because the QCM output data is based on the determination of beat frequencies between a pair of oscillators (one coated, the second uncoated, according to the chemical reaction being monitored). A structural analysis of this system can indicate whether potential resonances may exist between the (higher) structural modal frequencies and the beat frequencies. In addition undesirable deformations may result due to maximum expected static or dynamic loads during typical flight conditions. If the deformations are excessive they may adversely affect the accuracy the instrumentation output.

  15. Development of saw palmetto (Serenoa repens) fruit and extract standard reference materials.

    PubMed

    Schantz, Michele M; Bedner, Mary; Long, Stephen E; Molloy, John L; Murphy, Karen E; Porter, Barbara J; Putzbach, Karsten; Rimmer, Catherine A; Sander, Lane C; Sharpless, Katherine E; Thomas, Jeanice B; Wise, Stephen A; Wood, Laura J; Yen, James H; Yarita, Takashi; NguyenPho, Agnes; Sorenson, Wendy R; Betz, Joseph M

    2008-10-01

    As part of a collaboration with the National Institutes of Health's Office of Dietary Supplements and the Food and Drug Administration's Center for Drug Evaluation and Research, the National Institute of Standards and Technology has developed two standard reference materials (SRMs) representing different forms of saw palmetto (Serenoa repens), SRM 3250 Serenoa repens fruit and SRM 3251 Serenoa repens extract. Both of these SRMs have been characterized for their fatty acid and phytosterol content. The fatty acid concentration values are based on results from gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC/MS) analysis while the sterol concentration values are based on results from GC-FID and liquid chromatography with mass spectrometry analysis. In addition, SRM 3250 has been characterized for lead content, and SRM 3251 has been characterized for the content of beta-carotene and tocopherols. SRM 3250 (fruit) has certified concentration values for three phytosterols, 14 fatty acids as triglycerides, and lead along with reference concentration values for four fatty acids as triglycerides and 16 free fatty acids. SRM 3251 (extract) has certified concentration values for three phytosterols, 17 fatty acids as triglycerides, beta-carotene, and gamma-tocopherol along with reference concentration values for three fatty acids as triglycerides, 17 fatty acids as free fatty acids, beta-carotene isomers, and delta-tocopherol and information values for two phytosterols. These SRMs will complement other reference materials currently available with concentrations for similar analytes and are part of a series of SRMs being developed for dietary supplements. PMID:18677464

  16. See-saw rocking: an in vitro model for mechanotransduction research

    PubMed Central

    Tucker, R. P.; Henningsson, P.; Franklin, S. L.; Chen, D.; Ventikos, Y.; Bomphrey, R. J.; Thompson, M. S.

    2014-01-01

    In vitro mechanotransduction studies, uncovering the basic science of the response of cells to mechanical forces, are essential for progress in tissue engineering and its clinical application. Many varying investigations have described a multitude of cell responses; however, as the precise nature and magnitude of the stresses applied are infrequently reported and rarely validated, the experiments are often not comparable, limiting research progress. This paper provides physical and biological validation of a widely available fluid stimulation device, a see-saw rocker, as an in vitro model for cyclic fluid shear stress mechanotransduction. This allows linkage between precisely characterized stimuli and cell monolayer response in a convenient six-well plate format. Models of one well were discretized and analysed extensively using computational fluid dynamics to generate convergent, stable and consistent predictions of the cyclic fluid velocity vectors at a rocking frequency of 0.5 Hz, accounting for the free surface. Validation was provided by comparison with flow velocities measured experimentally using particle image velocimetry. Qualitative flow behaviour was matched and quantitative analysis showed agreement at representative locations and time points. Maximum shear stress of 0.22 Pa was estimated near the well edge, and time-average shear stress ranged between 0.029 and 0.068 Pa. Human tenocytes stimulated using the system showed significant increases in collagen and GAG secretion at 2 and 7 day time points. This in vitro model for mechanotransduction provides a versatile, flexible and inexpensive method for the fluid shear stress impact on biological cells to be studied. PMID:24898022

  17. Mechanical comparison of fixation techniques for the offset V osteotomy: a saw bone study.

    PubMed

    Jacobson, Keith; Gough, Adam; Mendicino, Samuel S; Rockett, Matthew S

    2003-01-01

    Four different techniques for the fixation of an offset V bunionectomy were tested on solid-foam saw-bone models for the purpose of determining the strongest form of fixation for the osteotomy. Twenty identical models were placed into 4 different groups. Groups varied as to the placement and caliber of fixation. Models were loaded with a servo-hydraulic testing machine until failure of fixation occurred. Video analysis was used to record the pattern of failure of the fixation. Failure occurred either distal to the first screw, through the first screw hole, between the 2 screws, through the second screw hole, or proximal to the second screw. The mean force to failure of the groups was group 1, 58.1 N; group 2, 59.3 N; group 3, 64.0 N; and group 4, 105.66 N. There was a statistical significant difference between group 4 and the other 3 groups (F(1) = 55.45, P < 0.05). There was no statistical difference between groups 1 to 3. In groups 1 to 3, 87% of the failures were through the distal screw hole, whereas the remaining 13% were through the proximal screw hole. In group 4, 60% of the failures were through the proximal screw hole and 40% were through the distal screw hole. It was concluded that, in this model, the strongest form of fixation for an offset V osteotomy was the 2.7-mm cortical screw placed distally with the proximal point of fixation being a threaded 0.062-inch Kirschner wire. PMID:14688775

  18. Safe fronto-orbito-zygomatic osteotomy using a diamond-coated threadwire saw in orbito-zygomatic craniotomy

    PubMed Central

    Wada, Kojiro; Mori, Kentaro; Toyooka, Terushige; Otani, Naoki; Fujii, Kazuya; Ueno, Hideaki; Tomura, Satoshi; Tomiyama, Arata

    2015-01-01

    Orbito-zygomatic craniotomy is a widely accepted skull-based technique, but osteotomy at the malar eminence (ME) is complicated. We have developed a safe fronto-orbito-zygomatic (FOZ) osteotomy by creating small guide burr holes in the superior and lateral parts of the orbital wall and cutting the bone using a diamond-coated threadwire saw. This method involves standard two-piece osteotomy by creating small superior and lateral guide orbital burr holes instead of sectioning into the superior and inferior orbital fissures. The guide burr holes are connected using a diamond-coated threadwire saw to create the FOZ bar. This method was applied to the treatment of four patients with skull-based tumors or internal carotid and basilar artery aneurysms. Postoperative three-dimensional bone density computed tomography showed minimum bone gap in the ME. No craniotomy-related complication has occurred. FOZ osteotomy by creating guide burr holes in the orbital wall and cutting the bone using a diamond-coated threadwire saw is safe and results in minimum bone gap in the ME. PMID:26396621

  19. Modelling based on Spatial Impulse Response Model for Optimization of Inter Digital Transducers (SAW Sensors) for Non Destructive Testing

    NASA Astrophysics Data System (ADS)

    Fall, D.; Duquennoy, M.; Ouaftouh, M.; Piwakowski, B.; Jenot, F.

    This study deals with modelling SAW-IDT transducers for their optimization. These sensors are specifically developed to characterize properties of thin layers, coatings and functional surfaces. Among the methods of characterization, the ultrasonic methods using Rayleigh surface waves are particularly interesting because the propagation of these waves is close to the surface of material and the energy is concentrated within a layer under the surface of about one wavelength thick. In order to characterize these coatings and structures, it is necessary to work in high frequencies, this is why in this study, SAW-IDT sensors are realized for surface acoustic wave generation. For optimization of these SAW-IDT sensors, particularly their band-width, it is necessary to study various IDT configurations by varying the number of electrodes, dimensions of the electrodes, their shapes and spacings. Thus it is necessary to implement effective and rapid technique for modelling. The originality of this study is to develop simulation tools based on Spatial Impulse Response model. Therefore it will be possible to reduce considerably computing time and results are obtained in a few seconds, instead of several hours (or days) by using finite element method. In order to validate this method, theoretical and experimental results are compared with finite element method and Interferometric measurements. The results obtained show a good overall concordance and confirm effectiveness of suggested method.

  20. A comparison of protocols for the optimisation of detection of bacteria using a surface acoustic wave (SAW) biosensor.

    PubMed

    Howe, E; Harding, G

    2000-01-01

    A dual channel surface acoustic wave (SAW) device has been used as a biosensor to detect two different microorganisms, Legionella and Escherichia coli, simultaneously. A series of experiments was conducted to optimise the use of the SAW for bacterial detection using a novel protocol of coating bacteria on the sensor surface prior to addition of the antibody. Results were compared with an experiment in which a conventional protocol was utilised, where antibody was coated on the sensor surface prior to exposure to bacteria. The concentration of bacteria that attached to the surface of the SAW device was related to the antibody that specifically bound to it and therefore to frequency in a dose dependent fashion. Unlike conventional microbiological techniques quantitative results can be obtained for Legionella and E. coli down to 10(6) cells per ml within 3 h. In addition E. coli was detected down to 10(5) cells per ml in a modified protocol using sheep IgG as a blocking agent. PMID:11213225

  1. INTERNATIONAL UNION OF OPERATING ENGINEERS NATIONAL HAZMAT PROGRAM - DEWALT RECIPROCATING SAW OENHP{number_sign}: 2001-01, VERSION A

    SciTech Connect

    Unknown

    2002-01-31

    Florida International University's (FIU) Hemispheric Center for Environmental Technology (HCET) evaluated five saws for their effectiveness in cutting specially prepared fiberglass-reinforced plywood crates. These crates were built as surrogates for crates that presently hold radioactively contaminated glove boxes at the Department of Energy's (DOE) Los Alamos facility. The DeWalt reciprocating saw was assessed on August 13, 2001. During the FIU test of efficacy, a team from the Operating Engineers National Hazmat Program (OENHP) evaluated the occupational safety and health issues associated with this technology. The DeWalt reciprocating saw is a hand-held industrial tool used for cutting numerous materials, including wood and various types of metals depending upon the chosen blade. Its design allows for cutting close to floors, corners, and other difficult areas. An adjustable shoe sets the cut at three separate depths. During the demonstration for the dismantling of the fiberglass-reinforced plywood crate, the saw was used for extended continuous cutting, over a period of approximately two hours. The dismantling operation involved vertical and horizontal cuts, saw blade changes, and material handling. During this process, operators experienced vibration to the hand and arm in addition to a temperature rise on the handgrip. The blade of the saw is partially exposed during handling and fully exposed during blade changes. Administrative controls, such as duty time of the operators and the machine, operator training, and personal protective equipment (PPE), such as gloves, should be considered when using the saw in this application. Personal noise sampling indicated that both workers were exposed to noise levels exceeding the Occupational Safety and Health Administration's (OSHA) Action Level of 85 decibels (dBA) with time-weighted averages (TWA's) of 88.3 and 90.6 dBA. Normally, a worker would be placed in a hearing conservation program if his TWA was greater than the Action Level. In this case, however, monitoring was conducted during a simulation, not during the actual work conducted at the worksite. Additional sampling should be conducted at the worksite to determine the actual noise levels for the workers. Until it is determined that the actual TWA's are less than the Action Level, the workers should use PPE. A training program on the proper use and wearing of the selected PPE should be provided to each worker. Nuisance dust monitoring yielded a concentration of 10.69 milligrams per cubic meter (mg/m{sup 3}). Although this is less than the OSHA Permissible Exposure Limit (PEL) of 15 mg/m{sup 3}, it is above the American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold Limit Value (TLV) of 10 mg/m{sup 3}. Fiberglass dust monitoring yielded a fiber count of 1.7 fibers per cubic centimeter (f/cc). This is above the PEL and the TLV of 1.0 f/cc. Therefore, controls should be implemented (engineering or PPE) to reduce the workers' exposure to the dust. Respirators should be used if engineering controls do not sufficiently control the dust or fiberglass generated. Respirators should be equipped with an organic vapor and acid gas cartridge with a High Efficiency Particulate Air (HEPA) filter, since during the demonstration, the workers complained of an odd smell, which may have been from the breakdown of the fiberglass.

  2. [The establishment of the fact of the application of an electric circular saw with the high-speed reciprocating motion of the blade].

    PubMed

    Nazarov, Iu V; Tolmachev, I A; Bozhchenko, A P

    2014-01-01

    This paper reports a case of forensic medical expertise of an unintentional (accidental) injury inflicted by an electric circular saw with the high-speed reciprocating motion of the blade (jigsaw) under conditions of human operational activities. PMID:25764881

  3. Deep Sub-micro mol{\\cdot }mol^{-1} Water-Vapor Measurement by Dual-Ball SAW Sensors for Temperature Compensation

    NASA Astrophysics Data System (ADS)

    Takeda, N.; Oizumi, T.; Tsuji, T.; Akao, S.; Takayanagi, K.; Nakaso, N.; Yamanaka, K.

    2015-12-01

    A collimated surface acoustic wave (SAW) circles around the equator of a sphere hundreds of times. Because of the long distance travel of the collimated SAW, a small change in the SAW propagation caused by the environment of the sphere can be accumulated as a measurable range in amplitude and/or in delay time. So, a spherical SAW device enables highly sensitive water-vapor measurements. In this paper, deep sub \\upmu mol{\\cdot }mol^{-1} water-vapor detection by 1 mm diameter quartz crystal ball SAW sensors is described. To measure such a low water-vapor concentration in real time, it is necessary to compensate the temperature dependence of the ball SAW sensor, which is about 20 ppm{\\cdot }°C^{-1} in delay time change. A dual-frequency burst analog detector was developed for the temperature compensation in real time. By using a harmonic SAW sensor, which was excited by 80 MHz and 240 MHz at the same time, it was confirmed that the delay time drift for a temperature range of 21.0°C ± 1.0°C became less than 0.05 ppm in delay time change. By using dual-ball SAW sensors (which included a 150 MHz sensor with a water-vapor sensitive layer and a 240 MHz sensor as a reference), water-vapor concentrations from 0.1 \\upmu mol{\\cdot }mol^{-1} to 5 \\upmu mol{\\cdot }mol^{-1} were successfully measured. It appears that the delay time change is proportional to the square root of the water-vapor concentration. The detection limit determined by the electrical noise of the system was estimated at 0.01 \\upmu mol{\\cdot }mol^{-1}.

  4. A SAW-based chemical sensor for detecting sulfur-containing organophosphorus compounds using a two-step self-assembly and molecular imprinting technology.

    PubMed

    Pan, Yong; Yang, Liu; Mu, Ning; Shao, Shengyu; Wang, Wen; Xie, Xiao; He, Shitang

    2014-01-01

    This paper presents a new effective approach for the sensitive film deposition of surface acoustic wave (SAW) chemical sensors for detecting organophosphorus compounds such as O-ethyl-S-2-diisopropylaminoethyl methylphosphonothiolate (VX) containing sulfur at extremely low concentrations. To improve the adsorptive efficiency, a two-step technology is proposed for the sensitive film preparation on the SAW delay line utilizing gold electrodes. First, mono[6-deoxy-6-[(mercaptodecamethylene)thio

  5. A SAW-Based Chemical Sensor for Detecting Sulfur-Containing Organophosphorus Compounds Using a Two-Step Self-Assembly and Molecular Imprinting Technology

    PubMed Central

    Pan, Yong; Yang, Liu; Mu, Ning; Shao, Shengyu; Wang, Wen; Xie, Xiao; He, Shitang

    2014-01-01

    This paper presents a new effective approach for the sensitive film deposition of surface acoustic wave (SAW) chemical sensors for detecting organophosphorus compounds such as O-ethyl-S-2-diisopropylaminoethyl methylphosphonothiolate (VX) containing sulfur at extremely low concentrations. To improve the adsorptive efficiency, a two-step technology is proposed for the sensitive film preparation on the SAW delay line utilizing gold electrodes. First, mono[6-deoxy-6-[(mercaptodecamethylene)thio

  6. A solution to reducing insertion loss and achieving high sidelobe rejection for wavelet transform and reconstruction processor using SAW devices

    NASA Astrophysics Data System (ADS)

    Jiang, Hua; Lu, Wenke; Zhang, Guoan; Xie, Zhengguang

    2013-02-01

    An arbitrary wavelet transform and reconstruction processor is composed of multiple single-scale wavelet transform devices (SSWTDs) with different scales. For improving the performance of the processor using surface acoustic wave (SAW) devices, this research investigates how to reduce the insertion loss (IL) and achieve a high sidelobe rejection. To reduce the triple transit echo (TTE) and to achieve a high signal-noise ratio (SNR), the structure of the SSWTD consists of two electrode-widths-controlled (EWC) single phase unidirectional transducers (SPUDTs). In the propagation process of the SAW, the unidirectional characteristic of the new structure reduces the bidirectional loss of the entire device. In addition, to enlarge the fractional bandwidth and the sidelobe rejection, the internal structure of the SSWTD uses an input apodized transducer according to the envelope of the Morlet wavelet function as well as an output withdrawal weighting transducer. In this paper, we present a SSWTD for scale 2-2 as an example to illustrate the design method and experimental results. The new device is fabricated on 128 rotated YX-cut lithium niobate (Y128X-LiNbO3) with the electromechanical coupling coefficient k2 = 5.5% and the SAW velocity 3992 m/s. We get the experimental frequency response with the center frequency 68.14 MHz, the minimum IL -9.96 dB, the fractional bandwidth 3.3%, the maximum passband ripples 0.4 dB and the sidelobe rejection greater than 40 dB. The proposed method and structure can be extended to an arbitrary SSWTD. The experimental results confirm that the performance of the wavelet transform and reconstruction processor can be improved by the proposed solution.

  7. Dynamics of vegetation and soils of oak/saw palmetto scrub after fire: Observations from permanent transects

    NASA Technical Reports Server (NTRS)

    Schmalzer, Paul A.; Hinkle, G. Ross

    1991-01-01

    Ten permanent 15 m transects previously established in two oak/saw palmetto scrub stands burned in December 1986, while two transects remained unburned. Vegetation in the greater than 0.5 m and the less than 0.5 m layers on these transects was sampled at 6, 12, 18, 24, and 36 months postburn and determined structural features of the vegetation (height, percent bare ground, total cover). The vegetation data were analyzed from each sampling by height layer using detrended correspondence analysis ordination. Vegetation data for the greater than 0.5 m layer for the entire time sequence were combined and analyzed using detrended correspondence analysis ordination. Soils were sampled at 6, 12, 18, and 24 months postburn and analyzed for pH, conductivity, organic matter, exchangeable cations (Ca, Mg, K, Na), NO3-N, NH4-N, Al, available metals (Cu, Fe, Mn, Zn), and PO4-P. Shrub species recovered at different rates postfire with saw palmetto reestablishing cover greater than 0.5 m within one year, but the scrub oaks had not returned to preburn cover greater than 0.5 m in 3 years after the fire. These differences in growth rates resulted in dominance shifts after the fire with saw palmetto increasing relative to the scrub oaks. Overall changes in species richness were minor, although changes occurred in species richness by height layers due to different growth rates. Soils of well drained and poorly drained sites differed markedly. Soil responses to the fire appeared minor. Soil pH increased at 6 and 12 months postfire; calcium increased at 6 months postburn. Nitrate-nitrogen increased at 12 months postburn. Low values of conductivity, PO4-P, Mg, K, Na, and Fe at 12 months postburn may be related to heavy rainfall the preceding month. Seasonal variability in some soil parameters appeared to occur.

  8. Local heat transfer distribution in a square channel with 90 continuous, 90 saw tooth profiled and 60 broken ribs

    SciTech Connect

    Gupta, Abhishek; SriHarsha, V.; Prabhu, S.V.; Vedula, R.P.

    2008-02-15

    Internal channel cooling is employed in advanced gas turbines blade to allow high inlet temperatures so as to achieve high thrust/weight ratios and low specific fuel consumption. The objective of the present study is to measure the local heat transfer distributions in a double wall ribbed square channel with 90 continuous, 90 saw tooth profiled and 60 V-broken ribs. Comparison is made between the 90 continuous ribs (P/e = 7 and 10 for a e/D = 0.15) and 90 saw tooth profiled rib configurations (P/e = 7 for an e/D = 0.15) for the same rib height to the hydraulic diameter ratio (e/D). The effect of pitch to rib height ratio (P/e = 7.5,10 and 12) of 60 V-broken ribbed channel with a constant rib height to hydraulic diameter ratio (e/D) of 0.0625 on the local heat transfer distribution is studied. The Reynolds number based on duct hydraulic diameter is ranging from 10,000 to 30,000. A thin stainless steel foil of 0.05 mm thickness is used as heater and infrared thermography technique is used to obtain the local temperature distribution on the surface. The images are captured in the periodically fully developed region of the channel. It is observed that the heat transfer augmentations in the channel with 90 saw tooth profiled ribs are comparable with those of 90 continuous ribs. The enhancements caused by 60 V-broken ribs are higher than those of 90 continuous ribs. The effect of pitch to the rib height ratio (P/e) is not significant for channel with 60 V-broken ribs for a given rib height to hydraulic diameter ratio (e/D = 0.0625). (author)

  9. Observed Polarization Dependence Of The Surface Acoustic Wave(Saw) Acousto-Optic (A-0) Interaction In Lithium Niobate

    NASA Astrophysics Data System (ADS)

    Shockley, D. K.; Garvin, C.

    1987-11-01

    A polarization sensitivity was observed in the bandwidth and interaction efficiency during the investigation of the SAW acousto-optic (AO) interaction in lithium niobate. It was observed that input light linearly polarized along the propagation direction of the acoustic beam allowed an increased interaction bandwidth when compared with input illumination polarized orthogonal to the acoustic propagation direction. The polarization of the optical beam remained unchanged to within one part in 10,000. Experimental findings show that this polarization sensitivity was parameterized by acoustic wavelength. Results of the wavelength parameterization are reported and comparisons drawn to theoretical work performed in the Johns Hopkins University study funded by Harry Diamond Laboratories.

  10. Laboratory evaluation to reduce respirable crystalline silica dust when cutting concrete roofing tiles using a masonry saw.

    PubMed

    Carlo, Rebecca V; Sheehy, John; Feng, H Amy; Sieber, William K

    2010-04-01

    Respirable crystalline silica dust exposure in residential roofers is a recognized hazard resulting from cutting concrete roofing tiles. Roofers cutting tiles using masonry saws can be exposed to high concentrations of respirable dust. Silica exposures remain a serious threat for nearly two million U.S. construction workers. Although it is well established that respiratory diseases associated with exposure to silica dust are preventable, they continue to occur and cause disability or death. The effectiveness of both a commercially available local exhaust ventilation (LEV) system and a water suppression system in reducing silica dust was evaluated separately. The LEV system exhausted 0.24, 0.13, or 0.12 m(3)/sec of dust laden air, while the water suppression system supplied 0.13, 0.06, 0.03, or 0.02 L/sec of water to the saw blade. Using a randomized block design, implemented under laboratory conditions, the aforementioned conditions were evaluated independently on two types of concrete roofing tiles (s-shape and flat) using the same saw and blade. Each engineering control (LEV or water suppression) was replicated eight times, or four times for each type of tile. Analysis of variance was performed by comparing the mean airborne respirable dust concentrations generated during each run and engineering control treatment. The use of water controls and ventilation controls compared with the "no control" treatment resulted in a statistically significant (p < 0.05) reduction of mean respirable dust concentrations generated per tile cut. The percent reduction for respirable dust concentrations was 99% for the water control and 91% for the LEV. Results suggest that water is an effective method for reducing crystalline silica exposures. However, water damage potential, surface discolorations, cleanup, slip hazards, and other requirements may make the use of water problematic in many situations. Concerns with implementing an LEV system to control silica dust exposures include sufficient capture velocity, additional weight of the saw with the LEV system, electricity connections, and cost of air handling unit. PMID:20169490

  11. Optimization of discharge types and electrode structure in a cylinder discharge reactor with saw-wheel array electrodes

    NASA Astrophysics Data System (ADS)

    Zhang, Chunyang; Shang, Kefeng; Lu, Na; Li, Jie; Wu, Yan

    2013-03-01

    The application of corona discharge technology in gas purification and wastewater treatment has been received great attention in recent years. The configuration of discharge electrode and the discharge types directly affect the discharge power and the power density, and then affect the generation of active species as well as the removal efficiency of pollutants. A novel cylinder-type discharge reactor with saw-wheel-array electrodes was developed for removal of SO2/NOx from flue gas, and influence factors such as electrode structure (ratio of spacing of saw-wheel slices and discharge distance, herein defined as R) and power supply types (positive DC, negative DC, and pulse power) on discharge characteristics and the output power was discussed. The experimental results show that the current and output power of three types of discharges firstly increased with R increasing from 0.3-1.7, and then tended to a stability from 1.7-2.5 while the power density reached a maximum at the ratio of 1.7.

  12. Pulse mode shear horizontal-surface acoustic wave (SH-SAW) system for liquid based sensing applications.

    PubMed

    Martin, Fabrice; Newton, Michael I; McHale, Glen; Melzak, Kathryn A; Gizeli, Electra

    2004-01-15

    In this work, we describe a novel pulse mode shear horizontal-surface acoustic wave (SH-SAW) polymer coated biosensor that monitors rapid changes in both amplitude and phase. The SH-SAW sensors were fabricated on 36 degrees rotated Y-cut X propagating lithium tantalate (36 YX.LT). The sensitivity of the device to both mass loading and visco-elastic effects may be increased by using a thin guiding layer of cross-linked polymer. Two acoustic modes are excited by the electrodes in this crystalline direction. Metallisation of the propagation path of the 36 YX.LT devices allows the two modes to be discriminated. Successive polymer coatings resulted in the observation of resonant conditions in both modes as the layer thickness was increased. Using the 36 YX.LT devices, we have investigated the application of a novel pulse mode system by sensing a sequence of deposition and removal of a biological layer consisting of vesicles of the phospholipid POPC. A continuous wave system was used to verify the accuracy of the pulse mode system by sensing a series of poly(ethylene glycol) (PEG) solutions. The data clearly demonstrates the ability of the 36 YX.LT pulse mode system to provide rapid measurements of both amplitude and phase for biosensing applications. PMID:14683647

  13. Specific targeting of ultrasound contrast agent (USCA) for diagnostic application: an in vitro feasibility study based on SAW biosensor.

    PubMed

    Joseph, Shiba; Gronewold, Thomas Marten Arnold; Schlensog, Marc Dominic; Olbrich, Carsten; Quandt, Eckhard; Famulok, Michael; Schirner, Michael

    2005-03-15

    The present study described a new strategy to examine the interaction between the targeted ultrasound contrast agent (USCA) and its target under flow conditions with a surface acoustic wave (SAW) transducer. The sensing principle is based on the measurement of the phase change on the sensing element upon the binding of specific biomolecules. Love-wave biosensor array was consisting of sensor elements and reference elements. The sensor elements have been prepared by coating the sensor surface with tumor marker EDB-fibronectin by means of SAM technique and carbodiimide chemistry. Reference elements were left blank or coated with fibronectin and used to eliminate thermal drift, unspecific binding, and turbulence from injection of liquids by calculating the differential phase shift with respect to the sensor elements. The binding of targeted USCA to the sensor surface was constantly recorded by monitoring the phase shift on the sensor element. The binding of targeted USCA generated a high phase shift on the sensor elements, but almost no change on the reference elements. Control experiments using non-targeted and isotype-targeted USCA confirmed the specificity of binding due to anti-EDB-fibronectin scFv-antibody-fragment-EDB-fibronectin antigen interaction. The suitability of the SAW technique to monitor the specific binding behavior of targeted micron-sized USCA in real time has been well established. PMID:15681200

  14. Highly sensitive room-temperature surface acoustic wave (SAW) ammonia sensors based on Co₃O₄/SiO₂ composite films.

    PubMed

    Tang, Yong-Liang; Li, Zhi-Jie; Ma, Jin-Yi; Su, Hai-Qiao; Guo, Yuan-Jun; Wang, Lu; Du, Bo; Chen, Jia-Jun; Zhou, Weilie; Yu, Qing-Kai; Zu, Xiao-Tao

    2014-09-15

    Surface acoustic wave (SAW) sensors based on Co3O4/SiO2 composite sensing films for ammonia detection were investigated at room temperature. The Co3O4/SiO2 composite films were deposited onto ST-cut quartz SAW resonators by a sol-gel method. SEM and AFM characterizations showed that the films had porous structures. The existence of SiO2 was found to enhance the ammonia sensing property of the sensor significantly. The sensor based on a Co3O4/SiO2 composite film, with 50% Co3O4 loading, which had the highest RMS value (3.72), showed the best sensing property. It exhibited a positive frequency shift of 3500 Hz to 1 ppm ammonia as well as excellent selectivity, stability and reproducibility at room temperature. Moreover, a 37% decrease in the conductance of the composite film as well as a positive frequency shift of 12,500 Hz were observed when the sensor was exposed to 20 ppm ammonia, indicating the positive frequency shift was derived from the decrease in film conductance. PMID:25151235

  15. INTERNATIONAL UNION OF OPERATING ENGINEERS NATIONAL HAZMAT PROGRAM - MILWAUKEE WORM DRIVE CIRCULAR SAW OENHP{number_sign}: 2001-02, VERSION A

    SciTech Connect

    Unknown

    2002-01-05

    Florida International University's (FIU) Hemispheric Center for Environmental Technology (HCET) evaluated five saws for their effectiveness in cutting specially prepared fiberglass-reinforced plywood crates. These crates were built as surrogates for crates that presently hold radioactively contaminated glove boxes at the Department of Energy's (DOE) Los Alamos facility. The Milwaukee worm drive circular saw was assessed on August 14, 2001. During the FIU test of efficacy, a team from the Operating Engineers National Hazmat Program (OENHP) evaluated the occupational safety and health issues associated with this technology. The Milwaukee worm drive circular saw is a hand-held tool with a 7 1/4-inch diameter circular blade for cutting wood. The saw contains a fixed upper and a retractable lower blade guard to prevent access to the blade during use. The unit is operated with an on/off guarded trigger switch; and is supported with a handgrip mounted on top of the saw. An adjustable lever sets the depth of cut. The retractable blade guard permits blind or plunge cuts and protects from blade access during shutdown and blade coast. Kickback, the sudden reaction to a pinched blade, is possible when using this saw and could cause the saw to lift up and out of the work piece toward the operator. Proper work position and firm control of the saw minimizes the potential for a sprain or strain. Care needs to be exercised to support the work piece properly and to not force the tool. Personal noise sampling indicated that one worker was near the Occupational Safety and Health Administration's (OSHA) Action Level of 85 decibels (dBA) while the other was at the Action Level with time-weighted averages (TWA's) of 82.7 and 84.6 dBA, respectively. These data are not entirely representative as they were gathered during a simulation and not at the actual worksite. Additional sampling should be conducted on-site, but the workers should wear hearing protection until it is determined that it is no longer necessary. Air sampling was performed while the workers dismantled the fiberglass-reinforced crates. The total nuisance dust sample for the Milwaukee circular saw was 36.07 milligrams per cubic meter (mg/m{sup 3}), which is much higher than the OSHA Permissible Exposure Limit (PEL) of 15 mg/m{sup 3} and the American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold Limit Value (TLV) of 10 mg/m{sup 3}. Galson Laboratories considered the fiber analysis void due to the overloading of the filter. The PEL for fiberglass is 1 fiber per cubic centimeter (f/cc).

  16. Performance, kinetics, and equilibrium of methylene blue adsorption on biochar derived from eucalyptus saw dust modified with citric, tartaric, and acetic acids.

    PubMed

    Sun, Lei; Chen, Dongmei; Wan, Shungang; Yu, Zebin

    2015-12-01

    Biochar derived from eucalyptus saw dust modified with citric, tartaric, and acetic acids at low temperatures was utilized as adsorbent to remove methylene blue (MB) from aqueous solutions. Fourier transform infrared spectroscopy analysis showed that the carboxyl group was introduced on the biochar surface. Adsorption experiment data indicated that eucalyptus saw dust modified with citric acid showed higher MB adsorption efficiency than that modified with tartaric and acetic acids. Pseudo-second-order kinetics was the most suitable model for describing MB adsorption on biochar compared with pseudo-first-order, Elovich, and intraparticle diffusion models. The calculated values of ?G(0) and ?H(0) indicated the spontaneous and endothermic nature of the adsorption process. MB adsorption on biochar followed the Langmuir isotherm. The maximum adsorption capacities for eucalyptus saw dust modified with citric, tartaric, and acetic acids were 178.57, 99.01, and 29.94 mg g(-1), respectively, at 35C. PMID:26402873

  17. Development of Methods of Producing Large Areas of Silicon Sheet by the Slicing of Silicon Ingots Using Inside Diameter (I.D.) Saws

    NASA Technical Reports Server (NTRS)

    Aharonyan, P.

    1979-01-01

    Methods of producing large areas of silicon sheets were developed by using inside diameter (I.D.) saws to slice silicon ingots. A 16 inch automated I.D. slicing machine was modified to accept programmable electric feed system, a crystal rotating system and a dyna-track blade monitoring and control system. The saw and accessories were used to slice 75 mm diameter single crystal silicon ingots while rotating them. The automated saw automatically recovered the wafers and loaded them into a cassette. The amount of material lost during slicing was reduced by using smaller blades than ones normally used to slice the wafers. Slicing runs on 100 mm diameter silicon is the next goal.

  18. Enhancing chemical identification efficiency by SAW sensor transients through a data enrichment and information fusion strategy—a simulation study

    NASA Astrophysics Data System (ADS)

    Singh, Prashant; Yadava, R. D. S.

    2013-05-01

    The paper proposes a new approach for improving the odor recognition efficiency of a surface acoustic wave (SAW) transient sensor system based on a single polymer coating. The vapor identity information is hidden in transient response shapes through dependences on specific vapor solvation and diffusion parameters in the polymer coating. The variations in the vapor exposure and purge durations and the sensor operating frequency have been used to create diversity in transient shapes via termination of the vapor-polymer equilibration process up to different stages. The transient signals were analyzed by the discrete wavelet transform using Daubechies-4 mother wavelet basis. The wavelet approximation coefficients were then processed by principal component analysis for creating feature space. The set of principal components define the vapor identity information. In an attempt to enhance vapor class separability we analyze two types of information fusion methods. In one, the sensor operation frequency is fixed and the sensing and purge durations are varied, and in the second, the sensing and purge durations are fixed and the sensor operating frequency is varied. The fusion is achieved by concatenation of discrete wavelet coefficients corresponding to various transients prior to the principal component analysis. The simulation experiments with polyisobutylene SAW sensor coating for operation frequencies over [55-160] MHz and sensing durations over [5-60] s were analyzed. The target vapors are seven volatile organics: chloroform, chlorobenzene, o-dichlorobenzene, n-heptane, toluene, n-hexane and n-octane whose concentrations were varied over [10-100] ppm. The simulation data were generated using a SAW sensor transient response model that incorporates the viscoelastic effects due to polymer coating and an additive noise source in the output. The analysis reveals that: (i) in single transient analysis the class separability increases with sensing duration for a given frequency of operation, and also with frequency for a given sensing duration, and (ii) the information fusion based on both the multiple sensing cycles and the multiple sensing frequencies enhances the class separability by nearly an order of magnitude.

  19. Chemical class specificity using self-assembled monolayers on SAW devices: Effects of adsorption time and substrate grain size

    SciTech Connect

    Thomas, R.C.; Ricco, A.J.; DiRubio, C.R.; Yang, H.C.; Crooks, R.M.

    1997-07-01

    The authors report selectivity and sensitivity for 97-MHz SAW (surface acoustic wave) sensors functionalized with (COO{sup {minus}}){sub 2}/Cu{sup 2+}-terminated, organomercaptan-based, self-assembled monolayers (SAMs). Responses were obtained as a function of SAM formation time on thin Au films of controlled grain size. The authors find that the SAM films (1) preferentially adsorb classes of organic analytes according to simple chemical interaction concepts, (2) reversibly adsorb multilayers of some analytes well below their saturation vapor pressure, (3) adsorb more diisopropylmethylphosphonate (DIMP) at a given partial pressure as SAM solution-phase adsorption time increases, and (4) adsorb more DIMP at a given partial pressure as the grain size of the supporting Au film decreases.

  20. Staircase and saw-tooth field emission steps from nanopatterned n-type GaSb surfaces

    SciTech Connect

    Kildemo, M.; Levinsen, Y. Inntjore; Le Roy, S.; Soenderga ring rd, E.

    2009-09-15

    High resolution field emission experiments from nanopatterned GaSb surfaces consisting of densely packed nanocones prepared by low ion-beam-energy sputtering are presented. Both uncovered and metal-covered nanopatterned surfaces were studied. Surprisingly, the field emission takes place by regular steps in the field emitted current. Depending on the field, the steps are either regular, flat, plateaus, or saw-tooth shaped. To the author's knowledge, this is the first time that such results have been reported. Each discrete jump in the field emission may be understood in terms of resonant tunneling through an extended surface space charge region in an n-type, high aspect ratio, single GaSb nanocone. The staircase shape may be understood from the spatial distribution of the aspect ratio of the cones.

  1. Saw-Scaled Viper Bites in Sri Lanka: Is It a Different Subspecies? Clinical Evidence from an Authenticated Case Series

    PubMed Central

    Gnanathasan, Ariaranee; Rodrigo, Chaturaka; Peranantharajah, Thambipillai; Coonghe, Anthonia

    2012-01-01

    The saw-scaled viper (SSV) (Echis carinatus) is considered to be a highly venomous snake in Sri Lanka despite any published clinical justification. Being a rarity, the clinical profile of SSV bites is not well established in Sri Lanka. We report a series of 48 (n-48) SSV bites from the Northern Province of Sri Lanka. The majority (65%) of victims had evidence of local envenoming at the site of the bite; however, 29% showed spontaneous bleeding and 71% had coagulopathy. There were no deaths in the series. The envenoming was mild in contrast to the mortality and significant morbidity associated with SSV bites in West Africa and some parts of India. These observations need to be further explored with laboratory studies to identify the venom components, study of morphological characteristics, and genetic profiling of the Sri Lankan SSV to see if it is different from the subspecies found elsewhere. PMID:22302858

  2. Measurements of the effectiveness of dust control on cut-off saws used in the construction industry.

    PubMed

    Thorpe, A; Ritchie, A S; Gibson, M J; Brown, R C

    1999-10-01

    Materials used in the construction industry frequently contain large quantities of silica. When they are cut or shaped with power tools considerable respirable dust can be produced. Three dust control systems for use with cut-off saws have been evaluated on site: wet dust suppression using mains water, the same system using water from a portable water tank, and local exhaust ventilation. The efficiency of water suppression on cut-off saws has been precisely quantified in controlled laboratory conditions by means of measurements with and without dust control. When dust control was used on-site, the mean concentrations of airborne silica were reduced by a factor of between three and seven, the accuracy being limited by the relatively high limit of detection for silica. All controls systems generally reduced respirable dust levels by at least 90%. Although the effectiveness of dust suppression did not depend on blade type, a diamond blade was more effective than a resin-bonded blade with the pressurised water system; cutting a slab with this type of blade could be completed before the water tank required repressurization. In laboratory tests, the application of water reduced the dust concentration to < 4% of its value without control. The method for monitoring the dust concentration was sufficiently sensitive to measure a difference in concentration produced during cutting in different directions. It is important, however, that the pressure in supply reservoirs is properly maintained, that the water is correctly applied and that it is used at the correct rate. If this is done effective dust control can be achieved. PMID:10582028

  3. Single-monolayer in situ modulus measurements using a SAW device: Photocrosslinking of a diacetylenic thiol-based monolayer

    SciTech Connect

    Ricco, A.J.; Staton, A.W.; Crooks, R.M.; Kim, Taisun

    1997-10-01

    We report direct measurement of the modulus change that accompanies the crosslinking of a single molecular monolayer. We measured a change in elastic modulus of 5 x 10{sup 10} dyn/cm{sup 2} as a result of ultraviolet-induced photocrosslinking of a single surface-confined monolayer of the conjugated diacetylenic thiol HS(CH{sub 2}){sub 10}C{triple_bond}CC{triple_bond}C(CH{sub 2}){sub 10}COOH, designated {open_quotes}DAT{close_quotes} hereafter. The modulus measurement was made on a monolayer of DAT chemisorbed upon a gold film on the surface of a 97-MHz ST-quartz surface acoustic wave delay line. The ratio of the changes recorded in SAW velocity and attenuation, approximately 4:1, suggests that the measured effect is mainly a change in the elastic (real) component of the complex shear modulus, viscous changes playing a lesser role. In relation to typical polymer modulus values, the change of 5 x 10{sup 10} dyn/cm{sup 2} is consistent with a change from a rubbery material (G{prime} {approximately} 10{sup 7} - 10{sup 8} dyn/cm{sup 2}) to a fairly rigid, glassy material (G{prime} {approximately} 10{sup 10} dyn/cm{sup 2}), reasonable for comparison of the monolayer in its as-adsorbed and crosslinked forms. This report of the direct SAW-based measurement of the modulus change associated with the crosslinking of a single molecular monolayer is complementary to and consistent with previous in-situ measurements of this process using thickness-shear mode resonators.

  4. Evaluation of surgically assisted rapid maxillary expansion with piezosurgery versus oscillating saw and chisel osteotomy - a randomized prospective trial

    PubMed Central

    2013-01-01

    Background Ultrasonic bone-cutting surgery has been introduced as a feasible alternative to the conventional sharp instruments used in craniomaxillofacial surgery because of its precision and safety. The piezosurgery medical device allows the efficient cutting of mineralized tissues with minimal trauma to soft tissues. Piezoelectric osteotome has found its role in surgically assisted rapid maxillary expansion (SARME), a procedure well established to correct transverse maxillary discrepancies. The advantages include minimal risk to critical anatomic structures. The purpose of this clinical comparative study (CIS 2007-237-M) was to present the advantages of the piezoelectric cut as a minimally invasive device in surgically assisted, rapid maxillary expansion by protecting the maxillary sinus mucosal lining. Methods Thirty patients (18 females and 12 males) at the age of 18 to 54 underwent a surgically assisted palatal expansion of the maxilla with a combined orthodontic and surgical approach. The patients were randomly divided into two separate treatment groups. While Group 1 received conventional surgery using an oscillating saw, Group 2 was treated with piezosurgery. The following parameters were examined: blood pressure, blood values, required medication, bleeding level in the maxillary sinus, duration of inpatient stay, duration of surgery and height of body temperature. Results The results displayed no statistically significant differences between the two groups regarding laboratory blood values and inpatient stay. The duration of surgery revealed a significant discrepancy. Deploying piezosurgery took the surgeon an average of 10 minutes longer than working with a conventional-saw technique. However, the observation of the bleeding level in the paranasal sinus presented a major and statistically significant advantage of piezosurgery: on average the bleeding level was one category above the one of the remaining patients. Conclusion This method of piezoelectric surgery with all its advantages is going to replace many conventional operating procedures in oral and maxillofacial surgery. Trial registration CIS 2007-237-M PMID:23414112

  5. Evaluation of cut-off saw exposure control methods for respirable dust and crystalline silica in roadway construction.

    PubMed

    Middaugh, Beauregard; Hubbard, Bryan; Zimmerman, Neil; McGlothlin, James

    2012-01-01

    Dust reduction equipment adapted for single-person operation was evaluated for gas-powered, commercially available cut-off saws during concrete curb cutting. Cutting was performed without dust control and with two individual exposure control methods: wet suppression and local exhaust ventilation (LEV). The wet suppression system comprised a two-nozzle spray system and a 13.3-L hand-pressurized water supply system with an optimum mean flow rate of 0.83 L/min for 16 min of cutting. The LEV system consisted of a spring-loaded guard, an 18.9-L collection bag, and a centrifugal fan with an estimated exhaust rate of 91 ft(3)/min. Task-based, personal filter samples were obtained for four saw operators during cutting durations of 4 to 16 min on five job sites. Seventeen filter samples were collected without dust control, 14 with wet suppression, and 12 with LEV, yielding a geometric mean respirable dust concentration of 16.4 mg/m(3), 3.60 mg/m(3), and 4.40 mg/m(3), respectively. A dust reduction of 78.0% for wet suppression and 73.2% for LEV was observed vs. no dust control. A statistically significant difference (p < 0.001) was also revealed for wet suppression and LEV when compared with no dust control; however, a significant difference (p = 0.09) was not observed between wet suppression and LEV. Despite these significant dust reductions, workers are still projected to exceed the ACGIH 8-hr time-weighted average threshold limit value for quartz (0.025 mg/m(3)) in less than 1 hr of cutting for both dust control methods. Further research is still needed to improve dust reduction and portability of both control methods, but the current LEV system offers important advantages, including a drier, less slippery work area and year-round functionality in cold weather. PMID:22394370

  6. The effect of purification of single-walled carbon nanotube bundles on the alcohol sensitivity of nanocomposite Langmuir Blodgett films for SAW sensing applications

    NASA Astrophysics Data System (ADS)

    Penza, M.; Tagliente, M. A.; Aversa, P.; Re, M.; Cassano, G.

    2007-05-01

    HiPco (high-pressure CO dissociation process) single-walled carbon nanotube (SWCNT) bundles containing Fe particles were purified in a two-step purification process by thermal annealing in oxygen and post-treatment in HCl. Nanocomposite films of pristine and purified SWCNTs embedded in an organic matrix of cadmium arachidate (CdA) were prepared by a Langmuir-Blodgett (LB) molecular engineering technique with a fixed weight filler content of 75 wt% onto a surface acoustic wave (SAW) transducer operating as an oscillator at a frequency of 433 MHz. The raw and purified samples were characterized at various stages of the purification process using thermogravimetric analysis (TGA), high-resolution transmission electron microscopy (HR-TEM), along with energy-dispersive x-ray spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM) and x-ray diffraction (XRD). Functional characterizations of the SWCNT-nanocomposite-based SAW sensors were investigated towards methanol, isopropanol and ethanol, and demonstrated high sensitivity, reversibility, fast response and ppm level detection at room temperature. Results indicate that the sensitivity of the SAW sensors based on a nanocomposite film of oxygen-annealed SWCNTs is enhanced to the alcohols tested at room temperature. Purification of the SWCNTs in the nanocomposite film affects the SAW sensitivity to alcohol by modulating the sensing properties. The sensing mechanisms are analysed and discussed.

  7. Fatty acid analysis of saw palmetto (Serenoa repens) and pygeum (Prunus africanum) in dietary supplements by mass spectrometry in the selected ion monitoring mode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Saw palmetto and pygeum are natural products commonly used in dietary supplements for the treatment of enlarged prostate glands. These plant materials are rich in fatty acids, and the fatty acid compositions of both plants are similar. The goal of this study was to develop a gas chromatography-mass ...

  8. Muscle activity and spine load during anterior chain whole body linkage exercises: the body saw, hanging leg raise and walkout from a push-up.

    PubMed

    McGill, Stuart; Andersen, Jordan; Cannon, Jordan

    2015-01-01

    This study examined anterior chain whole body linkage exercises, namely the body saw, hanging leg raise and walkout from a push-up. Investigation of these exercises focused on which particular muscles were challenged and the magnitude of the resulting spine load. Fourteen males performed the exercises while muscle activity, external force and 3D body segment motion were recorded. A sophisticated and anatomically detailed 3D model used muscle activity and body segment kinematics to estimate muscle force, and thus sensitivity to each individual's choice of motor control for each task. Gradations of muscle activity and spine load characteristics were observed across tasks. On average, the hanging straight leg raise created approximately 3000 N of spine compression while the body saw created less than 2500 N. The hanging straight leg raise created the highest challenge to the abdominal wall (>130% MVC in rectus abdominis, 88% MVC in external oblique). The body saw resulted in almost 140% MVC activation of the serratus anterior. All other exercises produced substantial abdominal challenge, although the body saw did so in the most spine conserving way. These findings, along with consideration of an individual's injury history, training goals and current fitness level, should assist in exercise choice and programme design. PMID:25111163

  9. Approaching sub-50 nanoradian measurements by reducing the saw-tooth deviation of the autocollimator in the Nano-Optic-Measuring Machine

    NASA Astrophysics Data System (ADS)

    Qian, Shinan; Geckeler, Ralf D.; Just, Andreas; Idir, Mourad; Wu, Xuehui

    2015-06-01

    Since the development of the Nano-Optic-Measuring Machine (NOM), the accuracy of measuring the profile of an optical surface has been enhanced to the 100-nrad rms level or better. However, to update the accuracy of the NOM system to sub-50 nrad rms, the large saw-tooth deviation (269 nrad rms) of an existing electronic autocollimator, the Elcomat 3000/8, must be resolved. We carried out simulations to assess the saw-tooth-like deviation. We developed a method for setting readings to reduce the deviation to sub-50 nrad rms, suitable for testing plane mirrors. With this method, we found that all the tests conducted in a slowly rising section of the saw-tooth show a small deviation of 28.8 to <40 nrad rms. We also developed a dense-measurement method and an integer-period method to lower the saw-tooth deviation during tests of sphere mirrors. Further research is necessary for formulating a precise test for a spherical mirror. We present a series of test results from our experiments that verify the value of the improvements we made.

  10. Facile synthesis of silver nano/micro-ribbons or saws assisted by polyoxomolybdate as mediator agent and vanadium(IV) as reducing agent.

    PubMed

    Marchal-Roch, Catherine; Mayer, Cédric R; Michel, Aude; Dumas, Eddy; Liu, Feng-Xian; Sécheresse, Francis

    2007-09-28

    Original and effective syntheses of crystalline silver wires and saw bundles, using reduced Keggin polyoxomolybdovanadate (POM) as mediator and reducing agent, were performed in acetonitrile at room temperature; several parameters influencing the final silver 1D-structures, with micrometric length and nanometric thickness, were varied: the nature of the POM, silver salts, vanadium(iv) source and the mild conditions. PMID:17851616

  11. Detection of cellular damage by hydrogen peroxide using SV40-T2 cells on shear horizontal surface acoustic wave (SH-SAW) sensor.

    PubMed

    Higashiyama, Takumi; Katsuyama, Akihiro; Otori, Hideki; Kamimura, Toru; Uehara, Atsushi; Kainuma, Miho; Takumi, Ryo; Kudo, Yukako; Ebina, Masayuki; Mochitate, Katsumi; Kon, Tasuku; Furuya, Yasubumi; Kikuchi, Hideaki

    2014-08-01

    The rat lung epithelial cell line SV40-T2 was used to develop a cellular biosensing system to assay for environmental toxicants. The novel approach on which this system is based involves direct attachment of cultured rat or human cells onto a cell-adhesive matrix on the device through which shear horizontal surface acoustic waves (SH-SAW) are transmitted using 50 MHz SAW resonator. This novel design enables sensitive monitoring of changes of the electrophysical characteristics of cells, such as their conductivity and relative permittivity. A time-dependent change of phase of SAW and change of insertion loss (change of amplitude) were observed when the cells were treated with 0.5 or 1.0 mM H2O2. The change of insertion loss was biphasic, with an early phase (1-3 h) and a late phase (3-6 h). The late phase coincided with the destruction of cell-cell tight junctions detected by measurement of the transepithelial electrical resistance and paracellular permeability; in contrast, the early phase coincided with the destruction of intracellular actin filaments by H2O2. The early-phase effect of H2O2 on phase shift may be attributable to the change of intracellular permittivity by a change of cellular polarity. Immunofluorescence microscopy showed the disappearance of zonula occludens protein 1 from the region of cell-cell contact. These results suggest the correlation between the change of insertion loss as an SAW parameter and the destruction of tight junctions of the cells on the SH-SAW device in the late phase. PMID:24835005

  12. Identification and Affinity-Quantification of ß-Amyloid and α-Synuclein Polypeptides Using On-Line SAW-Biosensor-Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Slamnoiu, Stefan; Vlad, Camelia; Stumbaum, Mihaela; Moise, Adrian; Lindner, Kathrin; Engel, Nicole; Vilanova, Mar; Diaz, Mireia; Karreman, Christiaan; Leist, Marcel; Ciossek, Thomas; Hengerer, Bastian; Vilaseca, Marta; Przybylski, Michael

    2014-08-01

    Bioaffinity analysis using a variety of biosensors has become an established tool for detection and quantification of biomolecular interactions. Biosensors, however, are generally limited by the lack of chemical structure information of affinity-bound ligands. On-line bioaffinity-mass spectrometry using a surface-acoustic wave biosensor (SAW-MS) is a new combination providing the simultaneous affinity detection, quantification, and mass spectrometric structural characterization of ligands. We describe here an on-line SAW-MS combination for direct identification and affinity determination, using a new interface for MS of the affinity-isolated ligand eluate. Key element of the SAW-MS combination is a microfluidic interface that integrates affinity-isolation on a gold chip, in-situ sample concentration, and desalting with a microcolumn for MS of the ligand eluate from the biosensor. Suitable MS- acquisition software has been developed that provides coupling of the SAW-MS interface to a Bruker Daltonics ion trap-MS, FTICR-MS, and Waters Synapt-QTOF- MS systems. Applications are presented for mass spectrometric identifications and affinity (KD) determinations of the neurodegenerative polypeptides, ß-amyloid (Aß), and pathophysiological and physiological synucleins (α- and ß-synucleins), two key polypeptide systems for Alzheimer's disease and Parkinson's disease, respectively. Moreover, first in vivo applications of αSyn polypeptides from brain homogenate show the feasibility of on-line affinity-MS to the direct analysis of biological material. These results demonstrate on-line SAW-bioaffinity-MS as a powerful tool for structural and quantitative analysis of biopolymer interactions.

  13. Identification and affinity-quantification of -amyloid and ?-synuclein polypeptides using on-line SAW-biosensor-mass spectrometry.

    PubMed

    Slamnoiu, Stefan; Vlad, Camelia; Stumbaum, Mihaela; Moise, Adrian; Lindner, Kathrin; Engel, Nicole; Vilanova, Mar; Diaz, Mireia; Karreman, Christiaan; Leist, Marcel; Ciossek, Thomas; Hengerer, Bastian; Vilaseca, Marta; Przybylski, Michael

    2014-08-01

    Bioaffinity analysis using a variety of biosensors has become an established tool for detection and quantification of biomolecular interactions. Biosensors, however, are generally limited by the lack of chemical structure information of affinity-bound ligands. On-line bioaffinity-mass spectrometry using a surface-acoustic wave biosensor (SAW-MS) is a new combination providing the simultaneous affinity detection, quantification, and mass spectrometric structural characterization of ligands. We describe here an on-line SAW-MS combination for direct identification and affinity determination, using a new interface for MS of the affinity-isolated ligand eluate. Key element of the SAW-MS combination is a microfluidic interface that integrates affinity-isolation on a gold chip, in-situ sample concentration, and desalting with a microcolumn for MS of the ligand eluate from the biosensor. Suitable MS-acquisition software has been developed that provides coupling of the SAW-MS interface to a Bruker Daltonics ion trap-MS, FTICR-MS, and Waters Synapt-QTOF- MS systems. Applications are presented for mass spectrometric identifications and affinity (K(D)) determinations of the neurodegenerative polypeptides, -amyloid (A), and pathophysiological and physiological synucleins (?- and -synucleins), two key polypeptide systems for Alzheimer's disease and Parkinson's disease, respectively. Moreover, first in vivo applications of ?Syn polypeptides from brain homogenate show the feasibility of on-line affinity-MS to the direct analysis of biological material. These results demonstrate on-line SAW-bioaffinity-MS as a powerful tool for structural and quantitative analysis of biopolymer interactions. PMID:24845351

  14. Fabrication of 0.25-um electrode width SAW filters using x-ray lithography with a laser plasma source

    NASA Astrophysics Data System (ADS)

    Bobkowski, Romuald; Li, Yunlei; Fedosejevs, Robert; Broughton, James N.

    1996-05-01

    A process for the fabrication of surface acoustic wave (SAW) devices with line widths of 250 nm and less, based on x-ray lithography using a laser-plasma source has been developed. The x-ray lithography process is based on keV x-ray emission from Cu plasma produced by 15 Hz, 50 ps, 248 nm KrF excimer laser pulses. The full structure of a 2 GHz surface acoustic wave filter with interdigital transducers in a split-electrode geometry has been manufactured. The devices require patterning a 150 nm thick aluminum layer on a LiNbO3 substrate with electrodes 250 nm wide. The manufacturing process has two main steps: x-ray mask fabrication employing e-beam lithography and x-ray lithography to obtain the final device. The x-ray masks are fabricated on 1 micrometers thick membranes of Si2N4. The line patterns on the masks are written into PMMA resist using a scanning electron microscope which has been interfaced to a personal computer equipped to control the x and y scan voltages. The opaque regions of the x-ray mask are then formed by electroplating fine grain gold into the open spaces in the etched PMMA. The mask and sample are mounted in an exposure cassette with a fixed spacer of 10 micrometers separating them. The sample consists of a LiNbO3 substrate coated with Shipley XP90104C x-ray resist which has been previously characterized. The x-ray patterning is carried out in an exposure chamber with flowing helium background gas in order to minimize debris deposition on the filters. After etching the x-ray resist, the final patterns are produced using metallization and a standard lift-off technique. The SAW filters are then bonded and packaged onto impedance matching striplines. The resultant devices are tested using Scalar Network Analyzers. The final devices produced had a center frequency of 1.93 GHz with a bandwidth of 98 MHz, close to the expected performance of our simple design.

  15. Saw1 localizes to repair sites but is not required for recruitment of Rad10 to repair intermediates bearing short non-homologous 3' flaps during single-strand annealing in S. cerevisiae.

    PubMed

    Mardirosian, Melina; Nalbandyan, Linette; Miller, Aaron D; Phan, Claire; Kelson, Eric P; Fischhaber, Paula L

    2016-01-01

    SAW1 is required for efficient removal by the Rad1-Rad10 nuclease of 3' non-homologous DNA ends (flaps) formed as intermediates during two modes of double-strand break (DSB) repair in S. cerevisiae, single-strand annealing (SSA) and synthesis-dependent strand annealing. Saw1 was shown in vitro to bind flaps with high affinity, but displayed diminished affinity when flaps were short (<30 deoxynucleotides [nt]), consistent with it not being required for short flap cleavage. Accordingly, this study, using in vivo fluorescence microscopy showed that SAW1 was not required for recruitment of Rad10-YFP to DNA DSBs during their repair by SSA when the flaps were ~10 nt. In contrast, recruitment of Rad10-YFP to DSBs when flaps were ~500 nt did require SAW1 in G1 phase of cell cycle. Interestingly, we observed a substantial increase in colocalization of Saw1-CFP and Rad10-YFP at DSBs when short flaps were formed during repair, especially in G1, indicating significant recruitment of Saw1 despite there being no requirement for Saw1 to recruit Rad10. Saw1-CFP was seldom observed at DSBs without Rad10-YFP. Together, these results support a model in which Saw1 and Rad1-Rad10 are recruited as a complex to short and long flaps in all phases of cell cycle, but that Saw1 is only required for recruitment of Rad1-Rad10 to DSBs when long flaps are formed in G1. PMID:26699908

  16. Production of Xylanase from Arthrobacter sp. MTCC 6915 Using Saw Dust As Substrate under Solid State Fermentation

    PubMed Central

    Murugan, Sevanan; Arnold, Donna; Pongiya, Uma Devi; Narayanan, P. M.

    2011-01-01

    Saw dust was used as substrate for xylanase production from Arthrobacter sp. MTCC 6915. The study of period of incubation, temperature, pH, carbon, and nitrogen sources for xylanase production was optimized. Xylanase production was found to be optimum at an incubation period of 96 hrs (117.0 U/mL), temperature 30°C (105.0 U/mL), and pH 9.0 (102.9 U/mL). The results showed that the xylanase production was found to be higher in the presence of carboxymethylcellulose (176.4 U/mL) and dextrose (126.0 U/mL). It was also observed that peptone (170.1 U/mL) and beef extract (161.7 U/mL) supported maximum xylanase production.The enzyme was characterized and found to be fairly active at pH 9 (764.4 U/mL) and temperature 60°C (819 U/mL). Even in the present study, a major difference in the production temperature (30°C) and optimal temperature (60°C) of the enzyme activity was observed. However, the pH of the production media and the enzyme activity were found to be the same (pH 9). PMID:22013512

  17. A comparative study of the SSC resistance of a novel welding process IEA with SAW and MIG

    SciTech Connect

    Natividad, C. . E-mail: consnatividad@yahoo.com.mx; Salazar, M. . E-mail: salazarm@imp.mx; Espinosa-Medina, M.A.; Perez, R.

    2007-08-15

    The Stress Sulphide Cracking resistance of X65 weldments produced by Indirect Electric Arc, Submerged Arc Welding (SAW) and Metal Inert Gas (MIG) processes were evaluated in a NACE solution saturated with H{sub 2}S at 25 deg. C, 37 deg. C and 50 deg. C using Slow Strain Rate Tests (SSRT) and electrochemical measurements. Weldments produced by the Indirect Electric Arc presented the best Stress Sulphide Cracking resistance at 25 deg. C. This behavior is attributed to the microstructural modification of the weld bead from ferrite in a needlelike form to a fine grain microstructure, which was not observed at 37 deg. C and 50 deg. C. In addition, the hydrogen permeation flux increased with the temperature, this result is associated with the ferrite phase. The electrochemical results show a decrease of the trapping sites for the atomic hydrogen on this weldment. This behavior has not been observed for the other welding processes due to their microstructure (a typical columnar growth of coarse grain)

  18. Numerical simulation of operation modes in atmospheric pressure uniform barrier discharge excited by a saw-tooth voltage

    SciTech Connect

    Li Xuechen; Niu Dongying; Yin Zengqian; Fang Tongzhen; Wang Long

    2012-08-15

    The characteristics of dielectric barrier discharge excited by a saw-tooth voltage are simulated in atmospheric pressure helium based on a one-dimensional fluid model. A stepped discharge is obtained per half voltage cycle with gas gap width less than 2 mm by the simulation, which is different to the pulsed discharge excited by a sinusoidal voltage. For the stepped discharge, the plateau duration increases with increasing the voltage amplitude and decreasing the gas gap. Therefore, uniform discharge with high temporal duty ratio can be realized with small gap through increasing the voltage amplitude. The maximal densities of both electron and ion appear near the anode and the electric field is almost uniformly distributed along the gap, which indicates that the stepped discharge belongs to a Townsend mode. In contrast to the stepped discharge with small gas gap, a pulsed discharge can be obtained with large gas gap. Through analyzing the spatial density distributions of electron and ion and the electric field, the pulsed discharge is in a glow mode. The voltage-current (V-I) characteristics are analyzed for the above mentioned discharges under different gas gaps, from which the different discharge modes are verified.

  19. Field portable detection of VOCs using a SAW/GC system. Final report, June 21, 1994--September 21, 1996

    SciTech Connect

    Chang, F.; Staples, E.J.

    1998-06-01

    This report describes research on a fast GC vapor analysis system which uses a new type of Surface Acoustic Wave detector technology to characterize organic contamination in soil and groundwater. The project was sponsored by the Department of Energy, Morgantown Energy Technology Center, whose mission, in addition to other goals, is the development of tools and methods for characterization, remediation, and monitoring of underground environmental conditions. The research tasks were to demonstrate detectability and specificity of a Surface Acoustic Wave Gas Chromatograph (SAW/GC) to a representative number of VOC materials followed by field demonstrations of the new technology at a DOE site. All tasks of the project were successfully carried out and a fast vapor analysis system based upon a new type of Surface Acoustic Wave detector technology was developed. The prototype analyzer has the ability to characterize organic contamination in soil and groundwater at the part per billion level in less than 10 seconds. The detector is unique because it utilized an uncoated quartz crystal, contrary to current developments of using coated crystals.

  20. Co-pyrolysis behaviors of saw dust and Shenfu coal in drop tube furnace and fixed bed reactor.

    PubMed

    Li, Shuaidan; Chen, Xueli; Wang, Li; Liu, Aibin; Yu, Guangsuo

    2013-11-01

    Co-pyrolysis behaviors of saw dust (SD) and Shenfu bituminous coal (SF) were studied in a drop tube furnace and a fixed bed reactor at different temperatures respectively. Six different biomass/coal ratios (B:C) were used. Compared the results with the calculated value obtained by the additional behavior, CO volume yields were lower while H2, CH4, CO2, volume yields were higher. Blend char yields had a good agreement with the calculated values, and their structures remained similar with SD and SF char's. Synergy effect occurred in gaseous phase, which was mainly caused by the secondary reactions. Compared the blend char yields in the drop tube furnace with those in the fixed bed reactor, the results showed the contacting way of biomass and coal particles had little influence on char yield in co-pyrolysis process. The reactivity index of blend char achieved the minimum at B:C=40:60 and the maximum at B:C=80:20. PMID:24041762

  1. Noise-induced generation of saw-tooth type transitions between climate attractors and stochastic excitability of paleoclimate

    NASA Astrophysics Data System (ADS)

    Alexandrov, Dmitri V.; Bashkirtseva, Irina A.; Ryashko, Lev B.

    2015-11-01

    Motivated by important paleoclimate applications we study a three dimensional model of the Quaternary climatic variations in the presence of stochastic forcing. It is shown that the deterministic system exhibits a limit cycle and two stable system equilibria. We demonstrate that the closer paleoclimate system to its bifurcation points (lying either in its monostable or bistable zone) the smaller noise generates small or large amplitude stochastic oscillations, respectively. In the bistable zone with two stable equilibria, noise induces a complex multimodal stochastic regime with intermittency of small and large amplitude stochastic fluctuations. In the monostable zone, the small amplitude stochastic oscillations localized in the vicinity of unstable equilibrium appear along with the large amplitude oscillations near the stable limit cycle. For the analysis of these noise-induced effects, we develop the stochastic sensitivity technique and use the Mahalanobis metric in the three-dimensional case. To approximate the distribution of random trajectories in Poincare sections, we use a method of confidence ellipses. A spatial configuration of these ellipses is defined by the stochastic sensitivity and noise intensity. The glaciation/deglaciation transitions going between two polar Earth's states with the warm and cold climate become easier and quicker with increasing the noise intensity. Our stochastic analysis demonstrates a near 100 ky saw-tooth type climate self fluctuations known from paleoclimate records. In addition, the enhancement of noise intensity blurs the sharp climate cycles and reduces the glaciation-deglaciation periods of the Earth's paleoclimate.

  2. Composite desiccant material "CaCl2/Vermiculite/Saw wood": a new material for fresh water production from atmospheric air

    NASA Astrophysics Data System (ADS)

    Kumar, Manoj; Yadav, Avadhesh

    2016-04-01

    In this study a novel composite desiccant material "CaCl2/Vermiculite/Saw wood" have been synthesized and tested for the water generation from atmospheric air. The vermiculite- saw wood used as a host matrix and CaCl2 as a hygroscopic salt. A solar glass desiccant box type system with a collector area of 0.36 m2 has been used. Design parameters for water generation are height of glass from the desiccant material bed as 0.22 m, inclination in angle as 30º, the effective thickness of glass as 3 mm and number of glazing as single. It has been found that the concentration of calcium chloride is the most influencing factor for fresh water generation from atmospheric air. The maximum amount of water produced by using novel composite desiccant material is 195 ml/kg/day.

  3. Antigen-antibody selective recognition using LiTaO3 SH-SAW sensors: investigations on macromolecules effects on binding kinetic constants

    NASA Astrophysics Data System (ADS)

    Bergaoui, Y.; Zerrouki, C.; Fourati, N.; Fougnion, J. M.; Abdelghani, A.

    2011-10-01

    A gravimetric surface acoustic wave (SAW) biosensor, based on the biotin-streptavidin and antistreptavidin-streptavidin recognitions, has been carried out. A network analyser and a pulse excitation technique were used to monitor both amplitude and phase changes. The SAW biosensor presented a total selective recognition of streptavidin-antistreptavidin and HRPstreptavidin-antistreptavidin. The presence of HRP (Horseradish peroxidase) affects neither the selectivity nor the sensitivity (of order of 0.25/nM) of the biosensor, nevertheless, it causes a reduction of binding kinetics by a factor ranging between 2 to 5, as well as a diminution of antistreptavidin saturation concentration (of 40%). Results showed that equilibrium constants can be different, depending on evaluation method (from saturation values or from linear part of the output signal variation according to solution concentration).

  4. Camphor sulfonic acid-doped polyaniline nanofiber-based 64o YX LiNbO3 SAW hydrogen gas sensor

    NASA Astrophysics Data System (ADS)

    Wlodarski, W.; Sadek, Abu Z.; Baker, C.; Kalantar-zadeh, K.; Kaner, R. B.; Mulcahy, Dennis

    2007-01-01

    A template-free, rapidly-mixed reaction was employed to synthesize polyaniline nanofibers using chemical oxidative polymerization of aniline. Camphor sulfonic acid (CSA) was used in the synthesis to obtain 50 nm average diameter polyaniline nanofibers. The nanofibers were deposited onto a 64 YX LiNbO 3 SAW transducer. The sensor was tested towards hydrogen (H II) gas while operating at room temperature. A fast response and recovery with high sensitivity and good repeatability were observed.

  5. Reduction in airborne contamination levels at the 9201-5 Arc Melt sawing operation. A Y-12 Plant 1982 ALARA goal

    SciTech Connect

    Beck, D.E.; West, C.M.

    1983-02-01

    Lowering the uranium airborne contamination level at the two saws in the 9201-5 Arc Melt Area was chosen as a Y-12 Plant As-Low-As-Reasonably-Achievable (ALARA) goal for 1982. This priority was convincingly communicated to those involving by giving specific instructions to suspend saw operations any time there was evidence of a problem until that problem could be corrected. Using control charts on air flow rates into the saw enclosures and pressure drops across filters in the saw ventilation (Delta Phase I) exhaust system, it was possible to decide when filter changes or other adjustments were necessary to maintain the exhaust flow rates needed for improved airborne contamination control. The keeping of these charts, along with the actions taken on the basis of the data gathered, made it possible to meet the goal of reducing airborne contamination levels in 1982, as compared with 1981, although production in the Arc Melt Area increased significantly. These data also showed that use of one brand of filter in the prefilter system resulted in the need to change filters more frequently than when another brand was used. This fact triggered an investigation which revealed the cause for the shorter useful life of that filter and a request that only specifically approved filters be purchased for use in this system. Use of these control data also made it possible to establish that the exhaust system operated more effectively without the Roto-clone hydrostatic pecipitators because exhaust air flow was increased without reduction in filter life.

  6. Eating with a saw for a jaw: functional morphology of the jaws and tooth-whorl in Helicoprion davisii.

    PubMed

    Ramsay, Jason B; Wilga, Cheryl D; Tapanila, Leif; Pruitt, Jesse; Pradel, Alan; Schlader, Robert; Didier, Dominique A

    2015-01-01

    The recent reexamination of a tooth-whorl fossil of Helicoprion containing intact jaws shows that the symphyseal tooth-whorl occupies the entire length of Meckel's cartilage. Here, we use the morphology of the jaws and tooth-whorl to reconstruct the jaw musculature and develop a biomechanical model of the feeding mechanism in these early Permian predators. The jaw muscles may have generated large bite-forces; however, the mechanics of the jaws and whorl suggest that Helicoprion was better equipped for feeding on soft-bodied prey. Hard shelled prey would tend to slip anteriorly from the closing jaws due to the curvature of the tooth-whorl, lack of cuspate teeth on the palatoquadrate (PQ), and resistance of the prey. When feeding on soft-bodied prey, deformation of the prey traps prey tissue between the two halves of the PQ and the whorl. The curvature of the tooth-whorl and position of the exposed teeth relative to the jaw joint results in multiple tooth functions from anterior to posterior tooth that aid in feeding on soft-bodied prey. Posterior teeth cut and push prey deeper into the oral cavity, while middle teeth pierce and cut, and anterior teeth hook and drag more of the prey into the mouth. Furthermore, the anterior-posterior edges of the teeth facilitate prey cutting with jaw closure and jaw depression. The paths traveled by each tooth during jaw depression are reminiscent of curved pathways used with slashing weaponry such as swords and knifes. Thus, the jaws and tooth-whorl may have formed a multifunctional tool for capturing, processing, and transporting prey by cyclic opening and closing of the lower jaw in a sawing fashion. PMID:25181366

  7. Electric field enhancement due to a saw-tooth asperity in a channel and implications on microscale gas breakdown

    NASA Astrophysics Data System (ADS)

    Venkattraman, Ayyaswamy

    2014-10-01

    The electric field enhancement due to an isolated saw-tooth asperity in an infinite channel is considered with the goal of providing some inputs to the choice of field enhancement factors used to describe microscale gas breakdown. The Schwarz-Christoffel transformation is used to map the interior of the channel to the upper half of the transformed plane. The expression for the electric field in the transformed plane is then used to determine the electric field distribution in the channel as well as field enhancement near the asperity. The effective field enhancement factor is determined and its dependence on operating and geometrical parameters is studied. While the effective field enhancement factor depends only weakly on the height of the asperity in comparison to the channel, it is influenced significantly by the base angles of the asperity. Due to the strong dependence of field emission current density on electric field, the effective field enhancement factor (βeff) is shown to vary rapidly with the applied electric field irrespective of the geometrical parameters. This variation is included in the analysis of microscale gas breakdown and compared with results obtained using a constant βeff as is done traditionally. Even though results for a varying βeff may be approximately reproduced using an equivalent constant βeff independent of E-field, it might be important for a range of operating conditions. This is confirmed by extracting βeff from experimental data for breakdown in argon microgaps with plane-parallel cathodes and comparing its dependence on the E-field. While the use of two-dimensional asperities is shown to be a minor disadvantage of the proposed approach in its current form, it can potentially help in developing predictive capabilities as opposed to treating βeff as a curve-fitting parameter.

  8. Crystal structure of the disintegrin heterodimer from saw-scaled viper (Echis carinatus) at 1.9 A resolution.

    PubMed

    Bilgrami, Sameeta; Yadav, Savita; Kaur, Punit; Sharma, Sujata; Perbandt, Markus; Betzel, Christian; Singh, Tej P

    2005-08-23

    Disintegrins constitute a family of potent polypeptide inhibitors of integrins. Integrins are transmembrane heterodimeric molecules involved in cell-cell and cell-extracellular matrix interactions. They are involved in many diseases such as cancer and thrombosis. Thus, disintegrins have a great potential as anticancer and antithrombotic agents. A novel heterodimeric disintegrin was isolated from the venom of saw-scaled viper (Echis carinatus) and was crystallized. The crystals diffracted to 1.9 A resolution and belonged to space group P4(3)2(1)2. The data indicated the presence of a pseudosymmetry. The structure was solved by applying origin shifts to the disintegrin homodimer schistatin solved in space group I4(1)22 with similar cell dimensions. The structure refined to the final R(cryst)/R(free) factors of 0.213/0.253. The notable differences are observed between the loops, (Gln39-Asp48) containing the important Arg42-Gly43-Asp44, of the present heterodimer and schistatin. These differences are presumably due to the presence of two glycines at positions 43 and 46 that allow the molecule to adopt variable conformations. A comparative analysis of the surface-charge distributions of various disintegrins showed that the charge distribution on monomeric disintegrins occurred uniformly over the whole surface of the molecule, while in the dimeric disintegrins, the charge is distributed only on one face. Such a feature may be important in the binding of two integrins to a single dimeric disintegrin. The phylogenetic analysis developed on the basis of amino acid sequence and three-dimensional structures indicates that the protein diversification and evolution presumably took place from the medium disintegrins and both the dimeric and short disintegrins evolved from them. PMID:16101289

  9. An Acoustic Charge Transport Imager for High Definition Television Applications: Low-Voltage SAW Amplifiers on Multilayer GaAs/ZnO Substrates

    NASA Technical Reports Server (NTRS)

    Hunt, W. D.; Brennan, K. F.; Summers, C. J.; Cameron, Thomas P.

    1996-01-01

    This thesis addresses the acoustoelectric issues concerning the amplification of surface acoustic waves (SAWs) and the reflection of SAWs from slanted reflector gratings on GaAs, with application to a novel acoustic charge transport (ACT) device architecture. First a simple model of the SAWAMP was developed, which was subsequently used to define the epitaxially grown material structure necessary to provide simultaneously high resistance and high electron mobility. In addition, a segmented SAWAMP structure was explored with line widths on the order of an acoustic wavelength. This resulted in the demonstration of SAWAMPS with an order of magnitude less voltage and power requirements than previously reported devices. A two-dimensional model was developed to explain the performance of devices with charge confinement layers less then 0.5 mm, which was experimentally verified. This model was extended to predict a greatly increased gain from the addition of a ZnO overlay. These overlays were experimentally attempted, but no working devices were reported due to process incompatibilities. In addition to the SAWAMP research, the reflection of SAWs from slanted gratings on GaAs was also studied and experimentally determined reflection coefficients for both 45 deg grooves and Al stripes on GaAs have been reported for the first time. The SAWAMp and reflector gratings were combined to investigate the integrated ring oscillator for application to the proposed ACT device and design parameters for this device have been provided.

  10. Mechanism and modeling of saw-tooth structure formation in the L1{sub 2}-L1{sub 0} two-phase system

    SciTech Connect

    Le Bouar, Y.; Khachaturyan, A.G.

    2000-05-11

    The strain-accommodating mechanism of formation of the saw-tooth microstructure in the LI{sub 2} + LI{sub 0} two-phase ordered system is proposed. To describe the atomic scale kinetics of ordering and decomposition in this system, the master equation, which explicitly incorporates the effect of the transformation strain, is formulated. It is used to simulate the precipitation of the LI{sub 0} phase from the LI{sub 2} parent phase in the Co-Pt alloy. The computer simulation shows that the decomposition occurs heterogeneously on antiphase boundaries of the LI{sub 2} structure if the composition is near the solubility limit of the LI{sub 2} phase. It eventually produces the saw-tooth microstructure. The decomposition transforms the (010) anti-phase boundary into a layer of the single-variant tetragonal LI{sub 0} phase separating the LI{sub 2} antiphase domains. Later, the strain accommodation transforms this single-variant LI{sub 0} phase layer into the saw-tooth pattern. The simulation results are in excellent qualitative and quantitative agreement with out TEM images of Co{sub 38.5}Pt{sub 61.5}.

  11. Prediction of Performance of Diamond Wire Saw with Respect to Texture Characteristics of Rock / Prognozowanie Wydajności Pracy Strunowej Piły Diamentowej W Odniesieniu Do Charakterystyki Tekstury Skał

    NASA Astrophysics Data System (ADS)

    Ghaysari, N.; Ataei, M.; Sereshki, F.; Mikaiel, R.

    2012-12-01

    In this study, prediction of production rate in diamond wire saw has been investigated. Performance measurements of diamond wire saw carried out in 7 different quarries of carbonate rocks in Iran. For determination textural properties, rock samples were collected from these quarries. At first, a thin section was prepared for each rock and then 5 digital photographs were taken from each section. After this, all images were digitized using AutoCAD software. Then, area, perimeter, longest diameter and shortest diameter were assigned. According to these parameters, all of the other textural characteristics and texture coefficient were determined too. The correlation between sawing rate and textural characteristics were evaluated using multiple and simple regression analyses. Then developed model was validated by P-value test. It was concluded that area, perimeter, diameter equivalent and index of grain size homogeneity are very effective on production rate. Production rate using diamond wire saw can reliably be predicted using developed model.

  12. Temporal Dynamics of Vegetation Phenological in Mongolia Using NOAA-AVHRR Data -- the Saw-tooth Pattern

    NASA Astrophysics Data System (ADS)

    Karnieli, A.; Bayasgalan, M.; Khudulmur, S.; Bayarjargal, Y.; Tucker, C. J.

    2004-12-01

    The objective of this study was to examine the temporal trend of the Mongolian natural vegetation phenology during 18 years between 1981 and 1999, in various ecosystems, by using two Pathfinder NOAA-AVHRR Land (PAL) products -- the Normalized Different Vegetation Index (NDVI) and Land Surface Temperature (LST). Mongolia was selected as a study area for implementing the above objectives since it enables a regional research (rather than continental or global scale). The north-south cross section is relatively short (ca. 500 km) between latitude 42o to 52o N, and covers 6 different ecosystems -- Tundra, Mountain, Forest Steppe, Steppe, Desert Steppe, and Desert. Along this cross section, precipitation ranges from more than 350 (in the north) to less than 75 mm. The entire territory consists only on natural vegetation without anthropogenic influences such as urban heat island, industry, agricultural crops etc. For estimating the growing season dynamics, an accurate determination of the beginning (greenup onset) and ending (senescence, or decline) dates of the vegetation phenology were computed. For achieving these dates four combined criteria were calculated based on the NDVI and LST datasets. Main finding of the project shows that no significant results are achieved when analyzing the entire study period over 18 years. However, when breaking the period into two sub-periods, from 1982 to 1991 and from 1992 to 1999, phenology parameters can be easily detected and results are more significant. It is shown that on the average of the entire territory, the onset starts 10 and 16 days earlier, and the decline occurs 6 and 3 days later, during the first and second sub-periods, respectively. Consequently, on the average the phenology cycle of the growing season lasts 17--19 days longer. The above-mentioned sub-periods can be visualized as a saw-tooth pattern. It is due to the eruption of Mount Pinatubo in the Philippines in June 1991, led to a global cooling of 0.5oC due to aerosols injected into the stratosphere. The three phenological parameters were interrupted by the event for 1--2 years, but both continued afterwards.

  13. A saw is first identified as an object used on wood: ERP evidence for temporal differences between Thematic and Functional similarity relations.

    PubMed

    Wamain, Yannick; Pluciennicka, Ewa; Kalénine, Solène

    2015-05-01

    The role of functional and motor information in manipulable artifact object semantic organization is still poorly understood. In particular, several types of semantic relations involving object functional knowledge may be distinguished. Functional similarity relations group objects with similar functions at relatively specific (e.g. saw-axe, both used to cut wood) or general (saw-knife, both used to cut) levels. Thematic relations group objects based on their complementarity in events (saw used upon/with wood). Recent eye-tracking data showed distinct temporal time courses for the different semantic relations, with fastest processing of thematic relations and slowest processing of general function similarity relations. Behavioral data suggest the involvement of distinct cognitive mechanisms in manipulable artifact object semantic processing. The aim of the present study was to assess the neural correlates of thematic, and specific and general function similarity relation processing. Specifically, we investigated whether time course differences between semantic relations could be highlighted at the neurophysiological level. We used a protocol combining semantic priming with electroencephalography, and manipulated the type of semantic relation and the duration of the interval between prime and target objects. Two consistent and complementary results were shown. On N1 and P3 components, semantic priming was observed for thematic relations only. On N400 component, the type of semantic relation interacted with interval duration, and semantic priming was visible for all 3 relations after the longest interval only. Results revealed graded processing time courses for thematic, specific function similarity, and general function similarity relations at the neural level, and further indicate that thematic relations impact object processing during the early stages of object recognition. Findings suggest a hierarchical organization of three types of semantic relations based on functional knowledge. The parallel between semantic relations involving manipulable artifact objects and levels of action representations is discussed. PMID:25725356

  14. The Effect of Intraoperative Sounds of Saw and Hammer on Psychological Condition in Patients with Total Knee Arthroplasty: Prospective Randomized Study

    PubMed Central

    Kömürcü, Erkam; Kaymaz, Burak; Gölge, Umut Hatay; Nusran, Gürdal; Göksel, Ferdi; Şahin, Hasan; Ömür, Dilek; Hancı, Volkan

    2015-01-01

    Purpose. Surgical procedures are likely to be stressful for patients and their families. Total knee arthroplasty (TKA) is a major surgical procedure used in the treatment of osteoarthritis. During this procedure the sounds of the saw and hammer may irritate the patient and adversely affect mood. The present study examines the effect of these intraoperative sounds during TKA on postoperative mood and anxiety, by comparing two different anesthetic procedures. Methods. A total of 40 patients who underwent TKA for grade IV gonarthrosis participated in the study. Patients were randomly divided into two groups: 20 patients in the general anesthesia group and 20 patients in the spinal anesthesia group. Mood and anxiety changes were evaluated using the Profile of Mood States (POMS) and State-Trait Anxiety Inventory (STAI) instruments, respectively. Results. The postoperative POMS value in the spinal anesthesia group was definitively higher than the general anesthesia group, though the difference in preoperative and postoperative POMS and STAI scores between the two groups was not significant. Conclusion. It would seem that sounds of hammer and saw have no evident negative effect on patient's mood. Regional anesthesia is advisable for TKA patients and appropriate sedation can be administered during the operation if needed. PMID:25793222

  15. An evaluation of an aftermarket local exhaust ventilation device for suppressing respirable dust and respirable crystalline silica dust from powered saws.

    PubMed

    Garcia, Alberto; Jones, Erica; Echt, Alan S; Hall, Ronald M

    2014-01-01

    The objective of this study was to quantify the respirable dust and respirable silica exposures of roofing workers using an electric-powered circular saw with an aftermarket local exhaust ventilation attachment to cut concrete roofing tiles. The study was conducted to determine whether the local exhaust ventilation attachment was able to control respirable dust and respirable silica exposure below occupational exposure limits (OELs). Time-integrated filter samples and direct reading respirable dust concentrations were evaluated. The local exhaust ventilation consisted of a shroud attached to the cutting plane of the saw; the shroud was then connected to a small electric axial fan, which is intended to collect dust at the point of generation. All sampling was conducted with the control in use. Roofers are defined as those individuals who only lay tiles. Cutters/roofers are defined as those workers who operate the powered saw to cut tiles and also lay tiles. Respirable dust from this evaluation ranged from 0.13 to 6.59 milligrams per cubic meter (mg/m(3)) with a geometric mean of 0.38 mg/m(3) for roofers and from 0.45 to 3.82 mg/m(3) with a geometric mean of 1.84 mg/m(3) for cutters/roofers. Cutters/roofers usually handle areas close to crevices, edges, or tips of the roof whereas roofers handle areas where complete tiles can be placed. The respirable dust exposures for all cutters/roofers indicated concentrations exceeding the Occupational Safety and Health Administration's (OSHA) permissible exposure limit (PEL) for respirable dust containing silica; it was also exceeded for some of the roofers. The respirable silica concentrations ranged from 0.04 to 0.15 mg/m(3) with a geometric mean of 0.09 mg/m(3) for roofers, and from 0.13 to 1.21 mg/m(3) with a geometric mean of 0.48 mg/m(3) for cutters/roofers. As with respirable dust, the respirable silica exposures for cutters/roofers were higher than the exposures for roofers. PMID:25148513

  16. An Evaluation of an Aftermarket Local Exhaust Ventilation Device for Suppressing Respirable Dust and Respirable Crystalline Silica Dust from Powered Saws

    PubMed Central

    Garcia, Alberto; Jones, Erica; Echt, Alan S.; Hall, Ronald M.

    2015-01-01

    The objective of this study was to quantify the respirable dust and respirable silica exposures of roofing workers using an electric powered circular saw with an aftermarket local exhaust ventilation attachment to cut concrete roofing tiles. The study was conducted to determine whether the local exhaust ventilation attachment was able to control respirable dust and respirable silica exposure below occupational exposure limits. Time-integrated filter samples and direct reading respirable dust concentrations were evaluated. The local exhaust ventilation consisted of a shroud attached to the cutting plane of the saw; the shroud was then connected to a small electric axial fan, which is intended to collect dust at the point of generation. All sampling was conducted with the control in use. Roofers are defined as those individuals who solely lay tiles. Cutters/roofers are defined as those workers who operate the powered saw to cut tiles and also lay tiles. Respirable dust from this evaluation ranged from 0.13 to 6.59 milligrams per cubic meter (mg/m3) with a geometric mean of 0.38 mg/m3 for roofers and from 0.45 to 3.82 mg/m3 with a geometric mean of 1.84 mg/m3 for cutters/roofers. Cutters/roofers usually handle areas close to crevices, edges, or tips of the roof whereas roofers handle areas where complete tiles can be placed. The respirable dust exposures for all cutters/roofers indicated concentrations exceeding the Occupational Safety and Health Administration’s (OSHA) permissible exposure limit (PEL) for respirable dust containing silica; it was also exceeded for some of the roofers. The respirable silica concentrations ranged from 0.04 to 0.15 mg/m3 with an average of 0.09 mg/m3 for roofers, and from 0.13 to 1.21 mg/m3 with an average of 0.48 mg/m3 for cutters/roofers. As with respirable dust, the respirable silica exposures to cutters/roofers were higher than the exposures for roofers. PMID:25148513

  17. Development of methods of producing large areas of silicon sheet by the slicing of silicon ingots using Inside Diameter (I.D.) saws

    NASA Technical Reports Server (NTRS)

    Aharonyan, P.

    1980-01-01

    Modifications to a 16 inch STC automated saw included: a programmable feed system; a crystal rotating system; and a STC dynatrack blade boring and control system. By controlling the plating operation and by grinding the cutting edge, 16 inch I.D. blades were produced with a cutting edge thickness of .22 mm. Crystal rotation mechanism was used to slice 100 mm diameter crystals with a 16 inch blade down to a thickness of .20 mm. Cutting rates with crystal rotation were generally slower than with standard plunge I.D. slicing techniques. Using programmed feeds and programmed rotation, maximum cutting rates were from 0.3 to 1.0 inches per minute.

  18. Development of methods of producing large areas of silicon sheet by the slicing of silicon ingots using Inside-Diameter (I.D.) saws

    NASA Technical Reports Server (NTRS)

    Aharonyan, P.

    1980-01-01

    Inside diametar wafering equipment, blades and processes were used to develop methods to produce large areas of silicon sheet. Modifications to a 16 inch STC automated saw included: programmable feed system, crystal rotating system, and STC dynatrack blade monitoring and control system. By controlling the plating operation and by grinding of the cutting edge, 16 inch ID blades with a cutting edge thickness of .22 mm can be produced. Crystal rotation mechanism was used to slice 100 mm diameter crystals with a 16 inch blade down to a thickness of .20 mm. Cutting rates with crystal rotation were generally slower than with standard plunge ID slicing techniques. Using programmed feeds and programmed rotation, maximum cutting rates were from 0.3 to 1.0 inches per minute.

  19. Using Nano-mechanics and Surface Acoustic Wave (SAW) for Disease Monitoring and Diagnostics at a Cellular Level in Red Blood Cells

    NASA Astrophysics Data System (ADS)

    Sivanantha, Ninnuja; Ma, Charles; Collins, David J.; Sesen, Muhsincan; Brenker, Jason; Coppel, Ross L.; Neild, Adrian; Alan, Tuncay

    A popular approach to monitoring diseases and their diagnosis is through biological, pathological or immunological characterization. However, at a cellular level progression of certain diseases manifests itself through mechanical effects as well. Here, we present a method which exploits localised flow; surface acoustic wave (SAW) induced acoustic streaming in a 9 μL droplet to characterize the adhesive properties of red blood cells (healthy, gluteraldehyde treated and malaria infected) in approximately 50 seconds. Our results show a 79% difference in cell mobilization between healthy malaria infected RBCs (and a 39% difference between healthy and treated ones), indicating that the method can serve as a platform for rapid clinical diagnosis; where separation of two or more different cell populations in a mixed solution is desirable. It can also act as a key biomarker for monitoring some diseases offering quantitative measures of disease progression and response to therapy.

  20. Investigations of AlN thin film crystalline properties in a wide temperature range by in situ X-ray diffraction measurements: Correlation with AlN/sapphire-based SAW structure performance.

    PubMed

    At Assa, Keltouma; Elmazria, Omar; Boulet, Pascal; Aubert, Thierry; Legrani, Ouadra; Mangin, Denis

    2015-07-01

    Aluminum nitride on sapphire is a promising substrate for SAW sensors operating at high temperatures and high frequencies. To get a measure of the suitability and temperature stability of such devices, an experimental relationship between the SAW performance and the structural properties of the AlN thin films was investigated in the temperature range between the ambient temperature and 1000C. The crystalline structure of the AlN films was examined in situ versus temperature by X-ray diffraction. The results reveal that the AlN films remain (002) oriented even at high temperatures. A gradual increase of the tensile stress in the film due to the thermal expansion mismatch with the substrate has been observed. This increase accelerates around 600C as the AlN film crystalline quality improves. This phenomenon could explain the amelioration in the SAW performance of AlN/sapphire devices observed previously between 600C and 850C. At higher temperatures, surface oxidation of the AlN films reduces the SAW performance. The potential of ZnO thin films as protective layers was finally examined. PMID:26168184

  1. [Multivariate analysis on the relationship between subjective symptoms and risk factors for the development of symptoms including working conditions, life habits and physical status in forestry workers using chain saw].

    PubMed

    Nagase, H; Nakamura, H; Nakamura, H; Nohara, S; Miura, K; Ohnishi, T

    1992-11-01

    To determine the risk factors of the subjective symptoms experienced by chain saw workers, we surveyed 206 forestry workers using this device in their work. The strength of the relationship between their symptoms and such potential risk factors as occupational, behavioral, and physical factors was evaluated by a multiple logistic regression model. It was found that many years of chain saw operation, and numerous hours of chain saw operation per day, increased the risk of white finger, numbness of hands and arms, chillness of hands and arms and difficulty in joint movement, indicating that these symptoms were closely related to vibration exposure. Many years of forestry work before chain saw work also increased the risk of joint pain, suggesting that bone and joint disorders are related to heavy manual work not using a chain saw. A second job involving manual labor increased the risk of weakness in the arms, stiffness of the shoulders, and lumbago. Infrequent bathing was associated with increased risk of pain in hands and arms and lumbago. Older workers had a higher prevalence of stomach discomfort. No risk factor was found to significantly increase the risk of easy fatigability, forgetfulness and sleep disorder. It was found that not only exposure to vibration but also other factors contributed to the prevalence of pain in hands and arms, joint pain, weakness in arms, stiffness of shoulder, and lumbago. Second job and infrequent bathing appeared to be related to the occurrence of certain subjective symptoms. These contributory factors should be taken into account when evaluating subjective symptoms encountered in field studies of forestry workers. PMID:1334168

  2. Effects of different levels of wheat bran, rice bran and maize powder supplementation with saw dust on the production of shiitake mushroom (Lentinus edodes (Berk.) Singer).

    PubMed

    Moonmoon, Mahbuba; Shelly, Nasrat Jahan; Khan, Md Asaduzzaman; Uddin, Md Nazim; Hossain, Kamal; Tania, Mousumi; Ahmed, Saleh

    2011-10-01

    The cultivation of shiitake mushroom (Lentinus edodes) is increasing rapidly in Bangladesh due to its nutritional and medicinal importance with excellent flavor and longer shelf life. With the aim of increased production, we have cultivated L. edodes on saw dust (SD) supplemented with different levels (10%, 15%, 20%, 25%, 30%, 35% and 40%) of wheat bran (WB), rice bran (RB), maize powder (MP) and their combination (WB+RB+MP = 1:1:1) to investigate the growth, yield and quality of this mushroom. Most of the growth, yield and quality parameters varied significantly when mushrooms were cultivated with different levels of supplementation. The yield of mushroom was increased with the level of each supplementation upto a certain level, and then decreased. SD supplemented with 25% WB produced the highest number of fruiting bodies (34.8/500 g packet), highest biological yield (153.3/500 g packet), and biological efficiency (76.6%) of L. edodes. But the yield of the best quality mushroom was observed on SD with 40% WB supplementation; however, the qualities were not always supplementation dose dependent. In this study, we report that 25% WB supplementation with SD may be very effective for higher yield and 40% WB supplementation for better quality of L. edodes. PMID:23961143

  3. Determination of Campesterol, Stigmasterol, and Beta-Sitosterol in Saw Palmetto Raw Materials and Dietary Supplements by Gas Chromatography: Collaborative Study

    PubMed Central

    Sorenson, Wendy R.; Sullivan, Darryl

    2008-01-01

    An interlaboratory study was conducted to evaluate a method for the determination of campesterol, stigmasterol, and beta-sitosterol in saw palmetto raw materials and dietary supplements at levels >1.00 mg/100 g based on a 2−3 g sample. Test samples were saponified at high temperature with ethanolic KOH solution. The unsaponifiable fraction containing phytosterols (campesterol, stigmasterol, and beta-sitosterol) was extracted with toluene. Phytosterols were derivatized to trimethylsilyl ethers and then quantified by gas chromatography with hydrogen flame ionization detection. Twelve blind duplicates, one of which was fortified, were successfully analyzed by 10 collaborators. Recoveries were obtained for the sample that was fortified. The results were 99.8, 111, and 111% for campesterol, stigmasterol, and beta-sitosterol, respectively. For repeatability, the relative standard deviation (RSDr) ranged from 3.93 to 17.3% for campesterol, 3.56 to 22.7% for stigmasterol, and 3.70 to 43.9% for beta-sitosterol. For reproducibility, the RSDR ranged from 7.97 to 22.6%, 0 to 26.7%, and 5.27 to 43.9% for campesterol, stigmasterol, and beta-sitosterol, respectively. Overall, the Study Director approved 5 materials with acceptable HorRat values for campesterol, stigmasterol, and beta-sitosterol ranging from 1.02 to 2.16. PMID:17580618

  4. A saw-less direct conversion long term evolution receiver with 25% duty-cycle LO in 130 nm CMOS technology

    NASA Astrophysics Data System (ADS)

    Siyuan, He; Changhong, Zhang; Liang, Tao; Weifeng, Zhang; Longyue, Zeng; Wei, Lü; Haijun, Wu

    2013-03-01

    A CMOS long-term evolution (LTE) direct convert receiver that eliminates the interstage SAW filter is presented. The receiver consists of a low noise variable gain transconductance amplifier (TCA), a quadrature passive current commutating mixer with a 25% duty-cycle LO, a trans-impedance amplifier (TIA), a 7th-order Chebyshev filter and programmable gain amplifiers (PGAs). A wide dynamic gain range is allocated in the RF and analog parts. A current commutating passive mixer with a 25% duty-cycle LO improves gain, noise, and linearity. An LPF based on a Tow-Thomas biquad suppresses out-of-band interference. Fabricated in a 0.13 μm CMOS process, the receiver chain achieves a 107 dB maximum voltage gain, 2.7 dB DSB NF (from PAD port), -11 dBm IIP3, and > +65 dBm IIP2 after calibration, 96 dB dynamic control range with 1 dB steps, less than 2% error vector magnitude (EVM) from 2.3 to 2.7 GHz. The total receiver (total I Q path) draws 89 mA from a 1.2-V LDO on chip supply.

  5. Enumeration of four-connected three-dimensional nets. III. Conversion of edges of three-connected two-dimensional nets into saw chains.

    PubMed

    Han; Smith

    1999-03-01

    A three-repeat saw (s) chain has each vertical edge separated by a tooth composed of two tilted edges zig and zag. Some horizontal (h) edges from a parallel stack of three-connected two-dimensional (2D) nets can be converted into an s chain. Each resulting four-connected vertex in the three-dimensional (3D) net may be part of either one, two or three s chains. The first type of (h,s)* 3D net is related by a sigma-type mirror plane to a (h,z)* net listed in paper II [Han & Smith (1998). Acta Cryst. A55, 342-359]. The second type does not have an (h,z)* relative. Using the same three-connected 2D nets as in paper II, 174 four-connected 3D nets were selected from the first two types, including six in known structures: 'nepheline hydrate' (International Zeolite Association Structure Commission code JBW), AlPO(4)-12-TAMU (ATT), offretite (OFF), Linde Type L (LTL), SUZ-4 (SZF) and ZSM-10 (ZST). The third type with three back-to-back s chains is represented by edingtonite (EDI), and systematic enumeration is in progress. The geometrical and topological properties of the 3D nets are given. Idealized unit-cell data and atomic coordinates for tetrahedral bonding were obtained for 40 selected 3D nets by distance-least-squares (DLS) refinement. PMID:10927266

  6. Effects of different levels of wheat bran, rice bran and maize powder supplementation with saw dust on the production of shiitake mushroom (Lentinus edodes (Berk.) Singer)

    PubMed Central

    Moonmoon, Mahbuba; Shelly, Nasrat Jahan; Khan, Md. Asaduzzaman; Uddin, Md. Nazim; Hossain, Kamal; Tania, Mousumi; Ahmed, Saleh

    2010-01-01

    The cultivation of shiitake mushroom (Lentinus edodes) is increasing rapidly in Bangladesh due to its nutritional and medicinal importance with excellent flavor and longer shelf life. With the aim of increased production, we have cultivated L. edodes on saw dust (SD) supplemented with different levels (10%, 15%, 20%, 25%, 30%, 35% and 40%) of wheat bran (WB), rice bran (RB), maize powder (MP) and their combination (WB+RB+MP = 1:1:1) to investigate the growth, yield and quality of this mushroom. Most of the growth, yield and quality parameters varied significantly when mushrooms were cultivated with different levels of supplementation. The yield of mushroom was increased with the level of each supplementation upto a certain level, and then decreased. SD supplemented with 25% WB produced the highest number of fruiting bodies (34.8/500 g packet), highest biological yield (153.3/500 g packet), and biological efficiency (76.6%) of L. edodes. But the yield of the best quality mushroom was observed on SD with 40% WB supplementation; however, the qualities were not always supplementation dose dependent. In this study, we report that 25% WB supplementation with SD may be very effective for higher yield and 40% WB supplementation for better quality of L. edodes. PMID:23961143

  7. The Different Sensitive Behaviors of a Hydrogen-Bond Acidic Polymer-Coated SAW Sensor for Chemical Warfare Agents and Their Simulants

    PubMed Central

    Long, Yin; Wang, Yang; Du, Xiaosong; Cheng, Luhua; Wu, Penglin; Jiang, Yadong

    2015-01-01

    A linear hydrogen-bond acidic (HBA) linear functionalized polymer (PLF), was deposited onto a bare surface acoustic wave (SAW) device to fabricate a chemical sensor. Real-time responses of the sensor to a series of compounds including sarin (GB), dimethyl methylphosphonate (DMMP), mustard gas (HD), chloroethyl ethyl sulphide (2-CEES), 1,5-dichloropentane (DCP) and some organic solvents were studied. The results show that the sensor is highly sensitive to GB and DMMP, and has low sensitivity to HD and DCP, as expected. However, the sensor possesses an unexpected high sensitivity toward 2-CEES. This good sensing performance can’t be solely or mainly attributed to the dipole-dipole interaction since the sensor is not sensitive to some high polarity solvents. We believe the lone pair electrons around the sulphur atom of 2-CEES provide an electron-rich site, which facilitates the formation of hydrogen bonding between PLF and 2-CEES. On the contrary, the electron cloud on the sulphur atom of the HD molecule is offset or depleted by its two neighbouring strong electron-withdrawing groups, hence, hydrogen bonding can hardly be formed. PMID:26225975

  8. The Different Sensitive Behaviors of a Hydrogen-Bond Acidic Polymer-Coated SAW Sensor for Chemical Warfare Agents and Their Simulants.

    PubMed

    Long, Yin; Wang, Yang; Du, Xiaosong; Cheng, Luhua; Wu, Penglin; Jiang, Yadong

    2015-01-01

    A linear hydrogen-bond acidic (HBA) linear functionalized polymer (PLF), was deposited onto a bare surface acoustic wave (SAW) device to fabricate a chemical sensor. Real-time responses of the sensor to a series of compounds including sarin (GB), dimethyl methylphosphonate (DMMP), mustard gas (HD), chloroethyl ethyl sulphide (2-CEES), 1,5-dichloropentane (DCP) and some organic solvents were studied. The results show that the sensor is highly sensitive to GB and DMMP, and has low sensitivity to HD and DCP, as expected. However, the sensor possesses an unexpected high sensitivity toward 2-CEES. This good sensing performance can't be solely or mainly attributed to the dipole-dipole interaction since the sensor is not sensitive to some high polarity solvents. We believe the lone pair electrons around the sulphur atom of 2-CEES provide an electron-rich site, which facilitates the formation of hydrogen bonding between PLF and 2-CEES. On the contrary, the electron cloud on the sulphur atom of the HD molecule is offset or depleted by its two neighbouring strong electron-withdrawing groups, hence, hydrogen bonding can hardly be formed. PMID:26225975

  9. Cytotoxic activities of [Ser⁴⁹]phospholipase A₂ from the venom of the saw-scaled vipers Echis ocellatus, Echis pyramidum leakeyi, Echis carinatus sochureki, and Echis coloratus.

    PubMed

    Conlon, J Michael; Attoub, Samir; Arafat, Hama; Mechkarska, Milena; Casewell, Nicholas R; Harrison, Robert A; Calvete, Juan J

    2013-09-01

    Fractionation by reversed-phase HPLC of venom from four species of saw-scaled viper: Echis ocellatus, Echis pyramidum leakeyi, Echis carinatus sochureki, and Echis coloratus led to identification in each sample of an abundant protein with cytotoxic activity against human non-small cell lung adenocarcinoma A549 cells. The active component in each case was identified by MALDI-TOF mass fingerprinting of tryptic digests as [Ser⁴⁹]phospholipase A₂ ([Ser⁴⁹]PLA₂). An isoform of [Ser⁴⁹]PLA₂ containing the single Ala¹⁸→ Val substitution and a partially characterized [Asp⁴⁹]PLA₂ were also present in the E. coloratus venom. LC₅₀ values against A549 cells for the purified [Ser⁴⁹]PLA₂ proteins from the four species are in the range 2.9-8.5 μM. This range is not significantly different from the range of LC₅₀ values against human umbilical vein endothelial HUVEC cells (2.5-12.2 μM) indicating that the [Ser⁴⁹]PLA₂ proteins show no differential anti-tumor activity. The LC₅₀ value for [Ser⁴⁹]PLA₂ from E. ocellatus against human erythrocytes is >100 μM and the MIC values against Escherichia coli and Staphylococcus aureus are >100 μM. It is suggested that the [Ser⁴⁹]PLA₂ proteins play a major role in producing local tissue necrosis and hemorrhage at the site of envenomation. PMID:23747272

  10. Boreal Soil and Air Warming (BoSAW): a Manipulative Experiment on the Effects of Warming on Boreal Forest C budgets

    NASA Astrophysics Data System (ADS)

    Bronson, D.; Gower, S.; Tanner, M.; van Herk, I.; Linder, S.

    2006-12-01

    Boreal forests are predicted to experience the greatest warming of any forest biome in the world, 4.0 to 6.0° C in the next 50 to 100 years, but a process-based understanding of how warming will affect the structure and function of this economically and ecologically important region is lacking. Due to the large quantities of carbon stored in the boreal forest, a great potential exists for further temperature increases through a positive feedback. BoSAW is a large-scale manipulative experiment warming both soil and air in a Canadian boreal forest that was created to address many of these questions. The study site is located in Thompson, Manitoba, Canada (55° 53'N, 98° 20'W) in a black spruce plantation. Using large greenhouse chambers on plots with soil heating cables we have been able to effectively hold air and soil temperature 5° C above ambient temperature for three growing seasons (2004-2006). We examine the effects of increased soil and air temperature on several aspects of black spruce ecophysiology including: (1) the phenology of understory and overstory, (2) above and belowground net primary production and root dynamics, (3) microbial populations, and (4) soil surface carbon dioxide flux. The results of this study will help scientists elucidate the effects of climate warming and policy makers understand the potentially significant role the boreal forest may play in carbon sequestration or emissions.

  11. A strong control of the South American SeeSaw on the intra-seasonal variability of the isotopic composition of precipitation in the Bolivian Andes

    NASA Astrophysics Data System (ADS)

    Vimeux, Françoise; Tremoy, Guillaume; Risi, Camille; Gallaire, Robert

    2011-07-01

    Water stable isotopes (δ) in tropical regions are a valuable tool to study both convective processes and climate variability provided that local and remote controls on δ are well known. Here, we examine the intra-seasonal variability of the event-based isotopic composition of precipitation (δD Zongo) in the Bolivian Andes (Zongo valley, 16°20'S-67°47'W) from September 1st, 1999 to August 31st, 2000. We show that the local amount effect is a very poor parameter to explain δD Zongo. We thus explore the property of water isotopes to integrate both temporal and spatial convective activities. We first show that the local convective activity averaged over the 7-8 days preceding the rainy event is an important control on δD Zongo during the rainy season (~ 40% of the δD Zongo variability is captured). This could be explained by the progressive depletion of local water vapor by unsaturated downdrafts of convective systems. The exploration of remote convective controls on δD Zongo shows a strong influence of the South American SeeSaw (SASS) which is the first climate mode controlling the precipitation variability in tropical South America during austral summer. Our study clearly evidences that temporal and spatial controls are not fully independent as the 7-day averaged convection in the Zongo valley responds to the SASS. Our results are finally used to evaluate a water isotope enabled atmospheric general circulation model (LMDZ-iso), using the stretched grid functionality to run zoomed simulations over the entire South American continent (15°N-55°S; 30°-85°W). We find that zoomed simulations capture the intra-seasonal isotopic variation and its controls, though with an overestimated local sensitivity, and confirm the role of a remote control on δ according to a SASS-like dipolar structure.

  12. Thermal development of Cephalonomia tarsalis (Hymenoptera: Bethylidae) parasitoid of the saw-toothed stored product beetles of the genus Oryzaephilus sp. (Coleoptera: Sylvanidae).

    PubMed

    Eliopoulos, Panagiotis A; Kontodimas, Dimitrios C

    2016-02-01

    The effect of temperature on the development and survival of Cephalonomia tarsalis (Ashmead) (Hymenoptera: Bethylidae), larval ectoparasitoid of beetles of Oryzaephilus sp. (Coleoptera: Silvanidae) was studied in the laboratory. Durations of the development of the egg, larva and pupa were measured in eight constant temperatures (15, 17.5, 20, 25, 30, 32.5, 35 and 37.5°C) parasitizing larvae of the saw-toothed beetle Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). The duration of development was decreased with temperature increase within the range 17.5-32.5°C. Survival was higher when immatures were exposed to medium temperatures (20-30°C) compared with those lived in a more extreme temperature regime (<20 and >30°C). Wasps failed to complete their development at 15 and 37.5°C. Thermal parameters (upper, lower and optimum developmental threshold, thermal constant) were estimated by fitting the linear and a non-linear (Logan I) model to our data. Upper and lower developmental thresholds ranged between 35.1-37.0°C and 13.2-13.8°C, respectively. The optimum temperature for development was estimated between 33.6°C and 34.6°C. Tests for developmental rate isomorphy (DRI) showed that change in the average proportion of time spent in each developmental stage was marginally significant, proving that development of C. tarsalis is probably incompatible with DRI. However, this conclusion is questionable given that lower developmental thresholds did not differ significantly among various developmental stages (bootstrap test). Thermal constant for total development was calculated 212.4 degree-days. Our results are discussed not only on the basis of thermal biology, but also of improving the efficiency of C. tarsalis as biocontrol agent. PMID:26857981

  13. The effect of a SiO2 layer on the performance of a ZnO-based SAW device for high sensitivity biosensor applications

    NASA Astrophysics Data System (ADS)

    Chen, Xi; Liu, Dali; Chen, Jiansheng; Wang, Guolei

    2009-11-01

    The properties of ZnO/SiO2/Si surface acoustic wave (SAW) love mode biosensors are studied in this paper. This specific structure is very suitable for biosensors since the reactive ZnO surface offers the opportunity for effective bio-ZnO interfaces, and the development of sensors directly on Si substrates provides the chance for full integration with read-out and signal processing circuitry in the mature Si technology. However, investigations of the dependence of buffer layer SiO2 on the performance of biosensors are very few. Therefore, the main interest of this paper is to find the relation between the properties of biosensors and the SiO2 layer. Some important results are obtained by solving the coupled electromechanical field equations. It is found that the mass loading sensitivity can be further improved by adding the SiO2 layer; furthermore, the maximal sensitivity of the biosensors can be obtained by adjusting the thicknesses of the two layers. Accordingly, consideration of the buffer layer is very important in the optimization of devices. On the other hand, it is found that the thickness of the piezoelectric guiding layer has an evident effect on the electromechanical coupling coefficient, while that of the SiO2 layer has a tiny effect on it. Moreover, we find that the effect of initial stresses on the properties of biosensors depends on the distribution of acoustic flow power in the two layers. This analysis is meaningful for the manufacture and applications of the ZnO/SiO2/Si structure love wave biosensor.

  14. Understanding processing-microstructure-properties relationships in Bi2Sr2CaCu2Ox/Ag round wires and enhanced transport through saw-tooth processing

    NASA Astrophysics Data System (ADS)

    Naderi, Golsa; Liu, Xiaotao; Nachtrab, William; Schwartz, Justin

    2013-10-01

    Superconducting magnets generating magnetic fields above 25 T are needed for many scientific applications. Due to fundamental limitations in NbTi and Nb3Sn, such high-field superconducting magnets require alternative high-field conductors. One candidate conductor is round wire composites of Bi2Sr2CaCu2Ox sheathed in a Ag-alloy matrix (Bi2212/Ag). The performance of such wires is sensitive to the heat treatment, so improvements in the critical current density (Jc) require a thorough understanding of the processing-structure-properties relationships. Here we present a two-part study. In part I, a new heat treatment approach, saw-tooth processing (STP), is introduced based upon previous results showing that Bi2212 nucleation is site-saturation limited. The microstructural evolution of Bi2212 filaments during processing is discussed and results from STP are compared with those from other processes. STP is shown to increase Jc by 120% and 70% relative to partial-melt processing at 5 T and self-field respectively, and by 65% and 34% relative to split-melt processing. Yet STP also complicates the heat treatment by introducing a number of new heat treatment variables that affect the grain morphology, phase assemblage and oxygen content of the Bi2212 filaments and thus the transport properties. In part II, the effects of STP heat treatment parameters on the microstructure and transport properties are discussed. It is shown that wires with the highest transport critical current densities primarily have filaments with two types of microstructures, one comprised primarily of highly textured Bi2212 grains, and another with a noticeable amount of Bi2Sr2CuOx with the Bi2212.

  15. Gilgamesh: He Who Saw All.

    ERIC Educational Resources Information Center

    California Univ., Berkeley. Office of Resources for International and Area Studies.

    The historical Gilgamesh was a Sumarian king of Uruk around 2700 B.C. Sumarian fragments of the legend that grew up around him have been found dating back to about 2000 B.C. These lesson plans on Gilgamesh were developed during the Office of Resources for International and Area Studies (ORIAS) summer institute on history through literature, in…

  16. Germany as We Saw It.

    ERIC Educational Resources Information Center

    Stanford Univ., CA.

    Close-up studies of German life in the Stuttgart area are reported by participants of Stanford University's 1961 National Defense Education Act second-level institute for secondary school teachers of German, held at Bad Boll, Germany. Topics covered include: (1) religious life, (2) political life, (3) problems of settlement, (4) occupational…

  17. Randomised Controlled Double-Blind Non-Inferiority Trial of Two Antivenoms for Saw-Scaled or Carpet Viper (Echis ocellatus) Envenoming in Nigeria

    PubMed Central

    Abubakar, Isa S.; Abubakar, Saidu B.; Habib, Abdulrazaq G.; Nasidi, Abdulsalam; Durfa, Nandul; Yusuf, Peter O.; Garnvwa, John; Sokomba, Elijah; Salako, Lateef; Theakston, R. David G; Juszczak, Ed; Alder, Nicola; Warrell, David A.

    2010-01-01

    Background In West Africa, envenoming by saw-scaled or carpet vipers (Echis ocellatus) causes great morbidity and mortality, but there is a crisis in supply of effective and affordable antivenom (ISRCTN01257358). Methods In a randomised, double-blind, controlled, non-inferiority trial, “EchiTAb Plus-ICP” (ET-Plus) equine antivenom made by Instituto Clodomiro Picado was compared to “EchiTAb G” (ET-G) ovine antivenom made by MicroPharm, which is the standard of care in Nigeria and was developed from the original EchiTAb-Fab introduced in 1998. Both are caprylic acid purified whole IgG antivenoms. ET-G is monospecific for Echis ocellatus antivenom (initial dose 1 vial) and ET-Plus is polyspecific for E. ocellatus, Naja nigricollis and Bitis arietans (initial dose 3 vials). Both had been screened by pre-clinical and preliminary clinical dose-finding and safety studies. Patients who presented with incoagulable blood, indicative of systemic envenoming by E. ocellatus, were recruited in Kaltungo, north-eastern Nigeria. Those eligible and consenting were randomly allocated with equal probability to receive ET-Plus or ET-G. The primary outcome was permanent restoration of blood coagulability 6 hours after the start of treatment, assessed by a simple whole blood clotting test repeated 6, 12, 18, 24 and 48 hr after treatment. Secondary (safety) outcomes were the incidences of anaphylactic, pyrogenic and late serum sickness-type antivenom reactions. Findings Initial doses permanently restored blood coagulability at 6 hours in 161/194 (83.0%) of ET-Plus and 156/206 (75.7%) of ET-G treated patients (Relative Risk [RR] 1.10 one-sided 95% CI lower limit 1.01; P = 0.05). ET-Plus caused early reactions on more occasions than did ET-G [50/194 (25.8%) and 39/206 (18.9%) respectively RR (1.36 one-sided 95% CI 1.86 upper limit; P = 0.06). These reactions were classified as severe in 21 (10.8%) and 11 (5.3%) of patients, respectively. Conclusion At these doses, ET-Plus was slightly more effective but ET-G was slightly safer. Both are recommended for treating E. ocellatus envenoming in Nigeria. Trial Registration Current Controlled Trials ISRCTN01257358 PMID:20668549

  18. Clay Swelling and Particle Redistribution in a Saw-Cut Fracture in the Paintbrush Nonwelded Unit of the Topopah Spring Tuff

    NASA Astrophysics Data System (ADS)

    Kneafsey, T. J.; Oldenburg, C. M.; Salve, R.

    2001-12-01

    Flow through the altered nonwelded tuffs of the Paintbrush unit (PTn) at Yucca Mountain, Nevada, is thought to be primarily through the highly porous rock matrix. Due to matrix flow and the sloping structure of the unit, the PTn is thought to divert downward-flowing water laterally. However, large fractures and faults in the PTn may also provide pathways for flow through the unit and these may prevent or interrupt lateral flow through the unit. In field tests where water was released directly into a fault in the altered PTn, flow rates declined over time. To evaluate processes such as matrix swelling and particle redistribution that might explain this decline, we performed a laboratory experiment using a 12 cm diameter x 21.6 cm long core with an axial saw-cut fracture. The core was extracted from the argillic Tpbt2C layer. We monitored permeability, inlet and outlet flow rate, and the volume change of the rock core (contained in a pressure vessel) while flow occurred through the fracture and matrix. Water containing various sodium chloride concentrations (1 M, 0.5 M, 0 M, and 1M) was flowed through the fracture to observe the effect of salt concentration on fracture permeability in the smectite-rich rock core. The sample swelled initially, despite the high salt concentration (1 M) of the inlet water. The permeability of the fracture decreased with declining salt concentration and increased with increasing salt concentration indicating that clay swelling decreased fracture aperture and reduced the flow rate. Particle redistribution (dispersion and flocculation) was indicated by particles in the effluent. Particles from lower salinity flows remained suspended in the effluent container, while those from higher salinity flows settled more easily, were larger, and more compact. If particle redistribution were controlling the flow, the permeability should have increased during low salinity water flow because of particle erosion. This work was supported by the Director, Office of Civilian Radioactive Waste Management, U.S. Department of Energy, through Memorandum Purchase Order EA9013MC5X between Bechtel SAIC Company, LLC and the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab). The support is provided to Berkeley Lab through the U.S. Department of Energy Contract No. DE-AC03-76SF00098.

  19. Wireless SAW Sensors Having Integrated Antennas

    NASA Technical Reports Server (NTRS)

    Gallagher, Mark (Inventor); Malocha, Donald C. (Inventor)

    2015-01-01

    A wireless surface acoustic wave sensor includes a piezoelectric substrate, a surface acoustic wave device formed on the substrate, and an antenna formed on the substrate. In some embodiments, the antenna is formed on the surface of the substrate using one or more of photolithography, thin film processing, thick film processing, plating, and printing.

  20. Analysis of aging data on SAW oscillators

    NASA Technical Reports Server (NTRS)

    Parker, T. E.

    1980-01-01

    Test oscillators including delay lines and resonators in the 300-400 MHz range have been investigated with reference to the long-term stability (aging) characteristics. All devices were fabricated on rotated Y-cut quartz plates (40 deg), and either gold or platinum metallization was used; all packages were high-quality hermetic enclosures, and the mounting was strictly mechanical, with no organics or silicone rubbers used. It is shown that drift of less than 2 ppm in the first year can be obtained on a significant fraction of the devices when reasonably clean packages are used. The data also suggest that the transducer metallization (at least for aluminum) is very likely the source of the relaxation mechanism that causes the frequency drift.

  1. What Brown saw and you can too

    NASA Astrophysics Data System (ADS)

    Pearle, Philip; Collett, Brian; Bart, Kenneth; Bilderback, David; Newman, Dara; Samuels, Scott

    2010-12-01

    A discussion of Robert Brown's original observations of particles ejected by pollen of the plant Clarkia pulchella undergoing what is now called Brownian motion is given. We consider the nature of those particles and how he misinterpreted the Airy disk of the smallest particles to be universal organic building blocks. Relevant qualitative and quantitative investigations with a modern microscope and with a "homemade" single lens microscope similar to Brown's are presented.

  2. Determination of the potency of a novel saw palmetto supercritical CO2 extract (SPSE) for 5α-reductase isoform II inhibition using a cell-free in vitro test system

    PubMed Central

    Pais, Pilar; Villar, Agustí; Rull, Santiago

    2016-01-01

    Background The nicotinamide adenine dinucleotide phosphate-dependent membrane protein 5α-reductase catalyses the conversion of testosterone to the most potent androgen – 5α-dihydrotestosterone. Two 5α-reductase isoenzymes are expressed in humans: type I and type II. The latter is found primarily in prostate tissue. Saw palmetto extract (SPE) has been used extensively in the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH). The pharmacological effects of SPE include the inhibition of 5α-reductase, as well as anti-inflammatory and antiproliferative effects. Clinical studies of SPE have been inconclusive – some have shown significant results, and others have not – possibly the result of varying bioactivities of the SPEs used in the studies. Purpose To determine the in vitro potency in a cell-free test system of a novel SP supercritical CO2 extract (SPSE), an inhibitor of the 5α-reductase isoenzyme type II. Materials and methods The inhibitory potency of SPSE was compared to that of finasteride, an approved 5α-reductase inhibitor, on the basis of the enzymatic conversion of the substrate androstenedione to the 5α-reduced product 5α-androstanedione. Results By concentration-dependent inhibition of 5α-reductase type II in vitro (half-maximal inhibitory concentration 3.58±0.05 μg/mL), SPSE demonstrated competitive binding toward the active site of the enzyme. Finasteride, the approved 5α-reductase inhibitor tested as positive control, led to 63%–75% inhibition of 5α-reductase type II. Conclusion SPSE effectively inhibits the enzyme that has been linked to BPH, and the amount of extract required for activity is comparatively low. It can be confirmed from the results of this study that SPSE has bioactivity that promotes prostate health at a level that is superior to that of many other phytotherapeutic extracts. The bioactivity of SPSE corresponds favorably to that reported for the hexane extract used in a large number of positive BPH clinical trials, as well as to finasteride, the established standard of therapy among prescription drugs. Future in vitro and clinical trials involving SPEs would be useful for elucidating their comparative differences, as well as appropriate patient selection for their use. PMID:27186566

  3. Weighted SAW reflector gratings for orthogonal frequency coded SAW tags and sensors

    NASA Technical Reports Server (NTRS)

    Puccio, Derek (Inventor); Malocha, Donald (Inventor)

    2011-01-01

    Weighted surface acoustic wave reflector gratings for coding identification tags and sensors to enable unique sensor operation and identification for a multi-sensor environment. In an embodiment, the weighted reflectors are variable while in another embodiment the reflector gratings are apodized. The weighting technique allows the designer to decrease reflectively and allows for more chips to be implemented in a device and, consequently, more coding diversity. As a result, more tags and sensors can be implemented using a given bandwidth when compared with uniform reflectors. Use of weighted reflector gratings with OFC makes various phase shifting schemes possible, such as in-phase and quadrature implementations of coded waveforms resulting in reduced device size and increased coding.

  4. The Sun as you never saw it before

    NASA Astrophysics Data System (ADS)

    1997-02-01

    The remarkable images come from SOHO's visible-light coronagraph LASCO. It masks the intense rays from the Sun's surface in order to reveal the much fainter glow of the solar atmosphere, or corona. Operated with its widest field of view, in its C3 instrument, LASCO's unprecedented sensitivity enables it to see the thin ionized gas of the solar wind out to the edges of the picture, 22 million kilometres from the Sun's surface. Many stars are brighter than the gas, and they create the background scene. The results alter human perceptions of the Sun. Nearly 30 years ago, Apollo photographs of the Earth persuaded everyone of what until then they knew only in theory, that we live on a small planet. Similarly the new imagery shows our motion in orbit around the Sun, and depicts it as one star among - yet close enough to fill the sky emanations that engulf us. For many centuries even astrologers knew that the Sun was in Sagittarius in December and drifting towards the next zodiacal constellation, Capricornus. This was a matter of calculation only, because the Sun's own brightness prevented a direct view of the starfield. The SOHO-LASCO movie makes this elementary point of astronomy a matter of direct observation for the first time. The images are achievable only from a vantage point in space, because the blue glow of the Earth's atmosphere hides the stars during the day. A spacial allocation of observing time, and of data tranmission from the SOHO spacecraft, enabled the LASCO team to obtain large numbers of images over the period 22-28 December 1996. Since then, a sustained effort in image processing, frame by frame, has achieved a result of high technical and aesthetic quality. Only now is the leader of the LASCO team, Guenter Brueckner of the US Naval Research Laboratory, satisfied with the product and ready to authorize its release. "I spend my life examining the Sun," Brueckner says, "but this movie is a special thrill. For a moment I forget the years of effort that went into creating LASCO and SOHO, and leave aside the many points of scientific importance in the images, I am happy to marvel at a new impression of the busy star that gives us life, and which affects our environment in many ways that we are only now beginning to understand." Transatlantic cooperation The Solar and Heliospheric Observatory SOHO is a project of international cooperation between ESA and NASA. ESA and the European aerospace industry built the spacecraft, and NASA launched it on 2 December 1995. Operating 1,500,000 kilometres out on the sunward side of the Earth, near the position called Lagrangian point L1, SOHO has an uninterrupted view of the Sun from an undisturbed vantage point, and a precision of pointing which makes delicate observations possible. SOHO carries 12 sets of instruments provided by scientific teams, each led by a European or an American principal investigator. They study the solar interior by helioseismology, the solar atmosphere seen by ultraviolet and visible light, and the solar wind and energetic particles. There is much transatlantic collaboration within the various teams. Besides the Naval Research Laboratory in Washington, LASCO involves the Max-Planck-Institüt für Aeronomie at Lindau (Germany), the Unversity of Birmingham (England) and Laboratoire d'Astronomie Spatiale at Marseille (France). Sharing LASCO's electronic systems, and many operations and analyses, is SOHO's extreme ultraviolet imager EIT. This is the responsibility of a team led from Orsay (France) and it observes activity in the Sun's hot atmosphere related to the wider events seen by LASCO. Roger Bonnet, who presides over the multinational effort as ESA's Director of Science, shares the enthusiasm for the Christmas movie. "For the first time we see the Sun clearly among the stars, thanks to SOHO and LASCO," Bonnet comments. "Now when we say that the Sun is a typical star, and a key to understanding the whole Universe, that is no longer a theoretical statement but something everyone can see. The quality of the images confirms that SOHO is the finest and most stable spacecraft ever devoted to the study of the Sun." Features of the motion picture North is at the top of the scene, which corresponds with the orientation of the Sun as seen at midday in the northern hemisphere of the Earth. SOHO's progress in orbit around the Sun remains in step with the Earth's motion. It travels towards the right (west) in relation to the stars, during the period of observation. As a result, the Sun's position appears to shift to the left (eastwards) in front of the stars. LASCO C3 observes an area of the sky 32 times wider than the visible Sun itself. If you spread the fingers of one hand and hold them at arm's length towards the sky, they will span the 17-degree width of LASCO's field of view. For comparison, the Sun is less than half the width of your little finger. At the time of the observations, SOHO is looking towards the heart of the Milky Way Galaxy, which lies in the constellation of Sagittarius. The Milky Way, made by the light of billions of distant stars, forms a luminous band slanting down and to the right. Dark lanes seen in the Milky Way are real features familiar to astronomers. They are created by dust clouds in the disk of the Galaxy which obscure the distant stars. A doomed comet, previously unknown, enters on the left of the image on 22 December. Its path curves towards the Sun and on 23 December. Its path curves towards the Sun and on 23 December it disappears behind the occulting mask of the coronagraph. It fails to reappear on the far side of the Sun. Whether or not its trajectory took it directly towards the visible surface, the comet must have evaporated in Sun's atmosphere. It was one of a family of comets known as sungrazers, believed to be remnants of a large comet that that broke up perhaps 900 years ago. Other fragments were responsible for spectacular comet apparitions in 1843, 1882 and 1965. The object in the movie is called Comet SOHO 6. It is one of seven sungrazers discovered so far by LASCO, with its unparalleled view of the solar vicinity. Analyses of the comets'orbits, now in progress, are a prerequisite for their inclusion in the official record of comet discoveries. LASCO also provided unique pictures of Comet Hyakutake passing behind the Sun at the beginning of May 1996. Debris strewn from the tails of many comets makes a disk of dust around the Sun, in the ecliptic plane where the planets orbit. It scatters sunlight and is sometimes visible at twilight on the Earth, as the Zodiacal Light. In the raw images obtained by LASCO, the Zodiacal Light is brighter than the solar corona. Image processing has to subtract its effects precisely, to bring the solar wind and the Milky Way into plain view. Random flashes of light in the images are due to cosmic rays striking the detector. These should be regarded, not as blemishes, but as part of the scenery. Cosmic rays are energetic particles coming from exploded stars in the Milky Way, and variations in the solar wind influence their intensity in the vicinity of SOHO and the Earth. Operating beyond the Earth's magnetic field, which repels many particles, SOHO is more exposed to the cosmic rays. In the largest outburst from the Sun seen in the Christmas movie, a mass ejection causes billions of tonnes of gas to race out into space on the right-hand (western) side of the Sun. The origin of this event much lower in the Sun's atmosphere was evident in an expanding bubble seen in processed images from the extreme ultraviolet imager EIT. Coronagraph views obtained during the same Christmas period in the narrower fields of LASCO's C1 and C2 instruments also helped to reveal the Sun's complex behaviour. Coronal mass ejections are the hurricanes of space weather. SOHO is ideally placed and instrumented to report and even anticipate their origins in the Sun's atmosphere. Although the Sun is supposedly very quiet at present, being close to the minimum count of sunspots, LASCO observes so many outbursts large and small - roughly one a day - that scientists are having to think again about how to define a coronal mass ejection. SOHO's continuing success Later LASCO images, on 6 January 1997, revealed a large mass ejection directed towards the Earth. As it swelled it appeared as a halo around the Sun. The mass ejection reached SOHO itself less than four days later, and the solar-wind analyser CELIAS detected an acceleration in the solar wind, from 350 to more than 500 kilometres per second. Soon afterwards, American, Russian and Japanese satellites operating closer to the Earth registered the event, which caused a magnetic storm and bright auroras. The failure of an American TV satellite on 11 January may have been directly related to this event. Mass ejections and other upheavals on the Sun will become even commoner during the coming years, as the count of sunspots increases towards the expected maximum of solar activity in 2000-01. Meanwhile, SOHO is seeking the fundamental reason for the cycle of sunspot activity, which is essentially a magnetic phenomenon. One of the helioseismic instruments probing the solar interior, SOI/MDI, has detected a likely source for the Sun's puzzling magnetism. There may be a natural dynamo operating at the base of the turbulent outer region of the Sun, called the convective zone. This rotates about 7 per cent faster than the underlying and more cohesive region of dense gas, the radiative zone. With the spacecraft in excellent condition and their instruments performing beyond expectations, SOHO's scientists are urging ESA and NASA to allow them to continue their work beyond April 1998, when the initial year of their scientific operations will have been completed.

  5. Friction drive of an SAW motor. Part III: modeling.

    PubMed

    Shigematsu, Takashi; Kurosawa, Minoru Kuribayashi

    2008-10-01

    A 2-layer modeling method of friction drive of a surface acoustic wave motor is proposed. The surface layer accounts for the previously proposed point-contact friction drive model, which was generalized to correspond spatially to the underlying layer that is comprised of a 3-D elasticity field. A method to determine stiffness through the use of analytical solutions of 3-D contact problems bridges the 2 layers. Because the determined stiffness expresses the accuracy of the results regarding either layer, the validity of the results concerning the stiffness and the resulting stress field was evaluated by comparison with the results of finite element analysis. Furthermore, we executed numerical simulations by using the friction drive model, which were compared with the measured displacements of the frictional surface of the slider. The simulation accurately represented the normal displacement of the frictional surface; the modeling procedure in the normal direction was found to be reliable. However, because the friction coefficient drastically changes the tangential displacement, we could not discuss the reliability of the modeling procedure in the tangential direction. A thorough discussion of the friction drive would thus require further investigation of the friction phenomena. PMID:18986874

  6. Friction drive of an SAW motor. Part II: analyses.

    PubMed

    Shigematsu, Takashi; Kurosawa, Minoru Kuribayashi

    2008-09-01

    The mechanics of the friction drive of a surface acoustic wave motor were investigated by means of contact mechanics theory. As a means to control the contact condition, the motor's slider had projections on its frictional surface. Assuming the projection was a rigid circular punch and the slider body was an elastic half-space allowed application of contact mechanics formulae to the analyses of the friction drive. Because the projection contacted the Rayleigh wave vibration, the projection's responses were considered dynamic; thus, the dynamics were also analyzed in the same framework of contact mechanics formulae. Moreover, the analyses were applied to measurements of the projection's displacement to examine the detailed mechanics during the friction drive. We calculated the contact/frictional forces based on the measurement and indicated the necessity of further investigation of the surface acoustic wave motor's friction drive, because the usual friction law was unable to explain the measurement. PMID:18986897

  7. Surface photovoltage measurements and finite element modeling of SAW devices.

    SciTech Connect

    Donnelly, Christine

    2012-03-01

    Over the course of a Summer 2011 internship with the MEMS department of Sandia National Laboratories, work was completed on two major projects. The first and main project of the summer involved taking surface photovoltage measurements for silicon samples, and using these measurements to determine surface recombination velocities and minority carrier diffusion lengths of the materials. The SPV method was used to fill gaps in the knowledge of material parameters that had not been determined successfully by other characterization methods. The second project involved creating a 2D finite element model of a surface acoustic wave device. A basic form of the model with the expected impedance response curve was completed, and the model is ready to be further developed for analysis of MEMS photonic resonator devices.

  8. Germany As We Saw It. Third Edition, 1963.

    ERIC Educational Resources Information Center

    Stanford Univ., CA.

    Closeup studies of German life in the Stuttgart area are reported here by 79 participants of Stanford University's 1963 National Defense Education Act Second-Level Institute for Elementary and Secondary School Teachers held at Bad Boll, Germany. Elementary and secondary education, work and family life, and housing and housing developments are…

  9. Temperature and Strain Coefficient of Velocity for Langasite SAW Devices

    NASA Technical Reports Server (NTRS)

    Wilson, W. C.; Atkinson, G. M.

    2013-01-01

    Surface Acoustic Wave sensors on Langasite substrates are being investigated for aerospace applications. Characterization of the Langasite material properties must be performed before sensors can be installed in research vehicles. The coefficients of velocity for both strain and temperature have been determined. These values have also been used to perform temperature compensation of the strain measurements.

  10. Hole saw drill attachment has zero force reaction

    NASA Technical Reports Server (NTRS)

    Holmes, A. E.; Riley, R. H., Jr.

    1966-01-01

    Zero reaction tools require no force application by workers in space. The tool accomplishes hole cutting by holding the workpiece and feeding the cutting blade into and through it by forces entirely absorbed within the tool.

  11. Fiber properties of saw and roller ginned naturally colored cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Naturally colored cottons have economic and environmental appeal because they do not require dyeing. Naturally colored cottons do not have the same fiber length and strength as white cotton cultivars. To determine the optimal ginning process for colored fiber two Upland (G. hirsutim) colors were r...

  12. Performance evaluation of algorithms for SAW-based temperature measurement.

    PubMed

    Schuster, Stefan; Scheiblhofer, Stefan; Reindl, Leonhard; Stelzer, Andreas

    2006-06-01

    Whenever harsh environmental conditions such as high temperatures, accelerations, radiation, etc., prohibit usage of standard temperature sensors, surface acoustic wave-based temperature sensors are the first choice for highly reliable wireless temperature measurement. Interrogation of these sensors is often based on frequency modulated or frequency stepped continuous wave-based radars (FMCW/FSCW). We investigate known algorithms regarding their achievable temperature accuracy and their applicability in practice. Furthermore, some general rules of thumb for FMCW/FSCW radar-based range estimation by means of the Cramer-Rao lower bound (CRLB) for frequency and phase estimation are provided. The theoretical results are verified on both simulated and measured data. PMID:16846150

  13. Chop Saw SUCCESS!: "Crash Proofing" a Metalworking Lab

    ERIC Educational Resources Information Center

    Domermuth, David

    2004-01-01

    The Technology Department at Appalachian State University runs a metals lab to introduce students to basic metalworking processes. Many of the students have never worked with metal before. The class objectives call for teaching students metal properties, processing, and design problem solving. The average student is a 20-year-old junior whom…

  14. Did You See Any More Than What You Saw?

    ERIC Educational Resources Information Center

    Hall, H. L.

    1997-01-01

    Suggests ways for journalists to better their writing skills, for example, being aware of unnecessary words and redundancies and the fact that the simplest word is usually the best word. Tells reporters which words to avoid, such as "many,""some," and "a lot." Gives examples of some mistakes that journalists have made. (PA)

  15. "I Saw All That": A Lakota Girl's Puberty Ceremony.

    ERIC Educational Resources Information Center

    Bol, Marsha C.; Menard, Nellie Z. Star Boy

    2000-01-01

    Draws on the memoirs of Nellie Menard, Lakota archives, and other published materials to describe the traditional puberty ceremonies held for Lakota girls. Discusses the practice of seclusion, during which an elderly woman instructed the girl in appropriate behavior and women's crafts; the initiate's new social status; the ball-throwing ceremony;…

  16. "I Saw the Universe and I Saw the World": Exploring Spiritual Literacy with Young Children in a Primary Classroom

    ERIC Educational Resources Information Center

    Binder, Marni J.

    2011-01-01

    This paper explores the concept of promoting spiritual literacy as viewed through the eyes of a holistic educator of young children in an inner-city primary classroom. Similar to discussions of spirituality in education, the idea of spiritual literacy is often elusive and can create discomfort and tensions. Drawing on stories of experience, the…

  17. Asp-49 is not an absolute prerequisite for the enzymic activity of low-M(r) phospholipases A2: purification, characterization and computer modelling of an enzymically active Ser-49 phospholipase A2, ecarpholin S, from the venom of Echis carinatus sochureki (saw-scaled viper).

    PubMed Central

    Polgár, J; Magnenat, E M; Peitsch, M C; Wells, T N; Clemetson, K J

    1996-01-01

    Several studies have shown that Asp-49 is the residue that controls calcium binding in, and so plays a critical role in the calcium-mediated activation of, low-M(r) group I-III phospholipases A2 (PLA2s). The present paper provides experimental evidence that Asp-49 is not an absolute prerequisite for the enzymic activity of PLA2s, and that proteins with amino acid(s) other than Asp at position 49 can exhibit significant phospholipase activity. The purification, complete amino acid sequence and characterization of ecarpholin S, a PLA2 from Echis carinatus sochureki (saw-scaled viper) venom, is described. This single-chain, 122-amino-acid, basic (pI 7.9) protein is a group II PLA2. Although Asp-49 is replaced by Ser and Tyr-28 by Phe (both of these positions being involved in the Ca(2+)-binding site of PLA2s), the lipolysis of soybean phosphatidylcholine and egg yolk in the presence of 10 mM CaCl2 was 1.5 times and 2.9 times greater respectively with ecarpholin S than with recombinant human group II PLA2. The Ca(2+)-dependencies of the enzymic activities of ecarpholin S and rPLA2 were found to be similar. Ecarpholin S added to washed platelets induced aggregation; the presence of Ca2+ was a prerequisite for this platelet-aggregating effect. Computer modelling of the Ca(2+)-binding site of Ser-49 PLA2 compared with the Asp-49 and Lys-49 forms, for which crystallographic data exist, shows that the Ca(2+)-binding site is sterically blocked by Lys-49 but not by Ser-49; in the latter, the Ser hydroxy group may replace the Asp carboxylate in stabilization of Ca2+ binding. Sequence comparisons of ecarpholin S and other low-M(r) PLA2s predicts the presence of a Ser-49 group in the protein family of low-M(r) PLA2s that is distinct from the Asp-49 and Lys-49 groups. PMID:8921006

  18. Asp-49 is not an absolute prerequisite for the enzymic activity of low-M(r) phospholipases A2: purification, characterization and computer modelling of an enzymically active Ser-49 phospholipase A2, ecarpholin S, from the venom of Echis carinatus sochureki (saw-scaled viper).

    PubMed

    Polgár, J; Magnenat, E M; Peitsch, M C; Wells, T N; Clemetson, K J

    1996-11-01

    Several studies have shown that Asp-49 is the residue that controls calcium binding in, and so plays a critical role in the calcium-mediated activation of, low-M(r) group I-III phospholipases A2 (PLA2s). The present paper provides experimental evidence that Asp-49 is not an absolute prerequisite for the enzymic activity of PLA2s, and that proteins with amino acid(s) other than Asp at position 49 can exhibit significant phospholipase activity. The purification, complete amino acid sequence and characterization of ecarpholin S, a PLA2 from Echis carinatus sochureki (saw-scaled viper) venom, is described. This single-chain, 122-amino-acid, basic (pI 7.9) protein is a group II PLA2. Although Asp-49 is replaced by Ser and Tyr-28 by Phe (both of these positions being involved in the Ca(2+)-binding site of PLA2s), the lipolysis of soybean phosphatidylcholine and egg yolk in the presence of 10 mM CaCl2 was 1.5 times and 2.9 times greater respectively with ecarpholin S than with recombinant human group II PLA2. The Ca(2+)-dependencies of the enzymic activities of ecarpholin S and rPLA2 were found to be similar. Ecarpholin S added to washed platelets induced aggregation; the presence of Ca2+ was a prerequisite for this platelet-aggregating effect. Computer modelling of the Ca(2+)-binding site of Ser-49 PLA2 compared with the Asp-49 and Lys-49 forms, for which crystallographic data exist, shows that the Ca(2+)-binding site is sterically blocked by Lys-49 but not by Ser-49; in the latter, the Ser hydroxy group may replace the Asp carboxylate in stabilization of Ca2+ binding. Sequence comparisons of ecarpholin S and other low-M(r) PLA2s predicts the presence of a Ser-49 group in the protein family of low-M(r) PLA2s that is distinct from the Asp-49 and Lys-49 groups. PMID:8921006

  19. What you see depends on what you saw, and what else you saw: the interactions between motion priming and object priming.

    PubMed

    Jiang, Xiong; Jiang, Yang; Parasuraman, Raja

    2014-12-01

    Both visual object priming and motion priming have been reported independently, but the interactions between the two are still largely unexplored. Here we investigated this question using a novel type of SFM stimuli, 3-D helixes, and found that the motion direction perception of an ambiguous helix can be biased by the motion direction of a preceding SFM stimulus - a classic motion priming effect. However, the effectiveness of motion priming depends on object priming: a neutral object priming produced a weak motion priming, a congruent object priming led to a strong motion priming, and critically, an incongruent object priming abolished and overpowered the motion priming. In contrast, object priming alone (in the absence of motion overlap) had little effects biasing motion perception. Taken together, these results suggest that there exists an integrated neural representation of motion and structure of 3-D SFM stimuli, and motion priming of 3-D SFM stimuli might happen at an intermediate stage between MT/V5 (which is not shape selective) and LO (lateral occipital, which is not motion selective). This novel type of stimuli, 3-D helixes, along with the prime-target paradigm, thus might offer a unique tool to examine neural bases underlying the perception of 3-D SFM stimuli and perceptual priming. PMID:25281908

  20. The "Saw-It-All-Along" Effect: Demonstrations of Visual Hindsight Bias

    ERIC Educational Resources Information Center

    Harley, Erin M.; Carlsen, Keri A.; Loftus, Geoffrey R.

    2004-01-01

    The authors address whether a hindsight bias exists for visual perception tasks. In 3 experiments, participants identified degraded celebrity faces as they resolved to full clarity (Phase 1). Following Phase 1, participants either recalled the level of blur present at the time of Phase 1 identification or predicted the level of blur at which a…

  1. "Hey, I Saw Your Grandparents at Walmart": Teacher Education for Rural Schools and Communities

    ERIC Educational Resources Information Center

    Eppley, Karen

    2015-01-01

    This is a case study about how teacher education might better prepare rural teacher candidates for rural schools. Parents, teachers, community members, and students associated with a rural school described what is important in the preparation of teachers for today's rural schools. Their goals and wishes for their children's school and…

  2. TALSPEAK CURVE: AN ILLUSTRATION OF A SEE-SAW EFFECT IN SEPARATIONS

    SciTech Connect

    Peter Zalupski; Leigh Martin

    2010-11-01

    A superbly balanced thermodynamic struggle for metal ion coordination by aqueous aminopolycarboxylate reagent, DTPA, and non-aqueous organophosphorous phase transfer reagent, HDEHP, affords the separation of trivalent actinides from trivalent lanthanides under the umbrella of the Talspeak liquid-liquid distribution process. This thermodynamic relationship has been linked to an analogous “see-saw” behavior, where the balance is distorted when either of the key complexing players is subject to adverse conditions that interfere with their optimal operation. The thermodynamic balance is tipped in favour of HDEHP whenever increased acidity of the aqueous solution out-competes the metal ion complexation by aqueous complexing agent. Also enhanced steric crowding may switch-off efficient coordination of the metal ion. When HDEHP is depolymerised due to the presence of aliphatic alcohol in the organic phase its phase transferring power is diminished. Such complication paves way for DTPA to establish its dominance on the distribution of trivalent metal ions in the 2-phase system. The illustrated sensitivity of the thermodynamic balance between DTPA and HDEHP in Talspeak-type systems may serve as informative tool when studying less-predictable realms of Talspeak chemistry.

  3. "Remember where you last saw that card": children's production of external symbols as a memory aid.

    PubMed

    Eskritt, Michelle; Lee, Kang

    2002-03-01

    Four experiments examined the age at which children start to use external symbols to aid their memory and how external symbol use affects both their memory performance and information allocation strategies. In Experiment 1, children in Grades 1, 3, 5, and 7 played a memory card game (Concentration) twice, once with the opportunity to make notes to aid performance and once without the opportunity. Grades I and 3 students tended to produce nonmnemonic notations, whereas Grades 5 and 7 students were more likely to produce functional, adultlike notations that aided performance in the task. In Experiments 2a and 2b, unexpected removal of children's notations led to a decrease in performance. suggesting that the spontaneously produced notations were being used as an external store rather than as an aid to encoding information. Experiment 3 examined whether all information was placed in external storage or if some types of information remained in memory. Grade 7 students who had their notations unexpectedly taken away were able to recognize the identity of the cards they had previously seen but had more difficulty remembering their locations. They appeared to place the location information mainly in external storage while retaining the identity information in memory. These results suggest that in mid-childhood, children begin to distribute information actively between internal and external memory storage. PMID:11881760

  4. Do medical conferences have a role to play? Sharpen the saw.

    PubMed

    Mishra, Sundeep

    2016-01-01

    Medical conferences are supposed to fulfill a critically important role in the ongoing education of physicians, technicians, nurses, and other health care providers. There are many functions which these conferences meet apart from merely imparting education: sharpening the skills, ability to interact with peers and KOLs, trying new equipment, evolving novel and locally relevant ideas, developing consensus in contentious areas all leading to improvement in health-care delivery, and patient outcomes. However, at the moment, the conferences are too many and not very effective in delivering the purported benefit. Further, there is need to reconcile the entanglement of interests between the organizers (usually physicians) and the fund donors (industry). PMID:27133315

  5. Nasal osteotomy--utilizing dual plane reciprocating nasal saw blades: a 6-year follow-up.

    PubMed

    Giampapa, V C; DiBernardo, B E

    1993-06-01

    Observation of the nasal bone anatomy has demonstrated a double S-curve configuration from the base of the pyriform aperture to the medial canthus. The most common method of osteotomy uses a curved osteotome or a chisel. The movement of either is facilitated by tapping with a mallet. With this method, frequent green-stick fractures, fragmentation, and other complications have been encountered. For the last 6 years, a dual plane, curved stainless steel blade has been used to accomplish low to high osteotomies. This gives a precise lateral transverse osteotomy without medial osteotomy being required. This technique allows the operator to produce a well-defined and precise lateral osteotomy with fewer potential complications and less postoperative swelling as well as improved patient comfort. In cases of secondary rhinoplasty or old nasal trauma, sites of previous fibrous union are able to be osteotomized with precisely controlled cuts, avoiding unpredictable fragmentation or fracture lines. PMID:8368774

  6. One GHz leaky SAW velocity of metal layers and bilayers evaporated onto fused quartz

    NASA Astrophysics Data System (ADS)

    Walikainen, Dale

    1992-04-01

    An acoustic microscope operating at 1 GHz was used to determine the surface acoustic wave velocities v of thin film metal layers and metal bilayers deposited onto fused quartz. V(0)'s influence was reduced by gating. This produced a calibrated accuracy of 3 percent. A program was constructed from the explicitly solved 6 x 6 theoretical determinant. Single film thicknesses were decided upon by using this theory to produce a v equal to a standard. Since the single film v's were linear with respect to their thickness, half the single film thicknesses were used for the bilayered films. The velocities for these bilayered films agreed with theory. This experimentally confirms the theoretical technique used here to examine bilayered systems, or a prototype composite interphase. No discrepancy was seen for gold films as others have reported. V(z) seemed insensitive to the formation of intermetallics or CuO. Some annealed and unannealed platinum films did not change the v from that of fused quartz. Two platinum films whose v's were in agreement with theory peeled off with the tape test.

  7. The "saw-it-all-along" effect: demonstrations of visual hindsight bias.

    PubMed

    Harley, Erin M; Carlsen, Keri A; Loftus, Geoffrey R

    2004-09-01

    The authors address whether a hindsight bias exists for visual perception tasks. In 3 experiments, participants identified degraded celebrity faces as they resolved to full clarity (Phase 1). Following Phase 1, participants either recalled the level of blur present at the time of Phase 1 identification or predicted the level of blur at which a peer would make an accurate identification. In all experiments, participants overestimated identification performance of naive observers. Visual hindsight bias was greater for more familiar faces--those shown in both phases of the experiment--and was not reduced following instructions to participants to avoid the bias. The authors propose a fluency-misattribution theory to account for the bias and discuss implications for medical malpractice litigation and eyewitness testimony. PMID:15355129

  8. Interesting differences between CH4 and d18Oatm records of bipolar see-saw activity

    NASA Astrophysics Data System (ADS)

    Severinghaus, Jeffrey; Baggenstos, Daniel; Rhodes, Rachael; Brook, Edward

    2014-05-01

    Abrupt changes in atmospheric methane concentration have long been used to infer changes in low-latitude hydrology. A lesser-used tracer is the oxygen-18 content of atmospheric dioxygen (d18Oatm), which is produced by photosynthesis and records the O-18 content of chloroplast water among other variables. Observations from ice core trapped air records suggest that strong Asian monsoons produce dioxygen with a relatively negative d18Oatm, whereas periods of weak Asian monsoon rainfall and strong southern hemisphere monsoons are characterized by relatively positive d18Oatm (Severinghaus et al., 2009, Science). Generally, CH4 and d18Oatm are anticorrelated, with high CH4 and negative d18Oatm during times of northern hemisphere warmth, strong Asian monsoons, and the bipolar seesaw in its "warm north" mode. However, interesting exceptions to this pattern occur during Heinrich Stadials and during the initial phases of the last deglaciation. Here, ice core data suggest episodes in which CH4 rise is not associated with negative d18Oatm, but instead positive d18Oatm. It is suggested that these intervals can be explained as being times of strong southern hemisphere low-latitude rainfall, which creates the positive values in d18Oatm. We hypothesize that dioxygen produced in southern hemisphere locales generally has higher O-18 content, due to the higher O-18 content of chloroplast water and the prevailing precipitation O-18 in those regions. In summary, we hypothesize that d18O of photosynthetic O2 is a more monotonic function of latitude, compared with methane production, which can be bimodally produced in the low latitudes of both hemispheres.

  9. Utility Theory for Evaluation of Optimal Process Condition of SAW: A Multi-Response Optimization Approach

    SciTech Connect

    Datta, Saurav; Biswas, Ajay; Bhaumik, Swapan; Majumdar, Gautam

    2011-01-17

    Multi-objective optimization problem has been solved in order to estimate an optimal process environment consisting of optimal parametric combination to achieve desired quality indicators (related to bead geometry) of submerged arc weld of mild steel. The quality indicators selected in the study were bead height, penetration depth, bead width and percentage dilution. Taguchi method followed by utility concept has been adopted to evaluate the optimal process condition achieving multiple objective requirements of the desired quality weld.

  10. Utility Theory for Evaluation of Optimal Process Condition of SAW: A Multi-Response Optimization Approach

    NASA Astrophysics Data System (ADS)

    Datta, Saurav; Biswas, Ajay; Bhaumik, Swapan; Majumdar, Gautam

    2011-01-01

    Multi-objective optimization problem has been solved in order to estimate an optimal process environment consisting of optimal parametric combination to achieve desired quality indicators (related to bead geometry) of submerged arc weld of mild steel. The quality indicators selected in the study were bead height, penetration depth, bead width and percentage dilution. Taguchi method followed by utility concept has been adopted to evaluate the optimal process condition achieving multiple objective requirements of the desired quality weld.

  11. Defect detection in partially completed SAW and TIG welds using online radioscopy and image processing

    NASA Astrophysics Data System (ADS)

    Bonser, Gary R.; Lawson, Shaun W.

    1998-03-01

    An application of machine vision applied to the analysis of radioscopic images of incomplete weld geometries is described. The rationale of the work is to identify weld defects as soon as they are produced, thereby reducing the costs of any subsequent repairs. Existing methods of weld and defect identification are compared, leading to the development of filtering and 'window' based variance operator for segmentation of suspect defect areas inside the weld region is described. The software and radioscopic imaging system have been benchmarked through a series of demonstration trials on both 80 mm thick carbon steel submerged arc welded testpieces, and 25mm thick carbon steel tungsten inert gas welded testpieces. The range of intentionally implanted defects, from root cracks to lack of side wall fusion, were detected with an overall accuracy of 87 percent, and classified in terms of defect size, shape, and position within the weld region.

  12. Influence of macrostructure on tensile properties of multipass SAW C-Mn steel deposits

    NASA Astrophysics Data System (ADS)

    Yongyuth, P.; Ghosh, P. K.; Gupta, P. C.; Patwardhan, A. K.; Prakash, Satya

    1993-06-01

    Blocks of 'all weld' metal were prepared by a multipass submerged arc process, using a C-Mn filler wire, at different welding currents and speeds by keeping the arc voltage constant. The variation in welding parameters was found to alter the macrostructure primarily by influencing its co-axial dendrite content. The chemical composition and hardness of the dendritic and the heat affected regions were affected little by the welding parameters. A dendrite content up to 37%, had no significant effect on the tensile properties. However an increase in it beyond 37% was found to enhance the UTS and YS and reduce percent elongation. The tensile strength was found to be a maximum in the L orientation and a minimum in the S direction. The use of post-weld heat treatment (PWHT) at 873 K caused spheroidization of cementite there by somewhat reducing the hardness and strength. The treatment while not affecting the basic dendritic morphology reduced the observed difference in tensile properties along the L, T and S directions. Implications of the data vis-a-vis industrial applications have been discussed.

  13. '"We Saw Inhumanity Close up." What Is Gained by School Students from Scotland Visiting Auschwitz?

    ERIC Educational Resources Information Center

    Cowan, Paula; Maitles, Henry

    2011-01-01

    As the education for citizenship agenda continues to impact on schools in the UK and with the Holocaust Educational Trust (HET) in conjunction with the Scottish Government introducing its Lessons From Auschwitz (LFA) project for students and teachers in Scotland, this article focuses on the Scottish context and investigates the school processes by…

  14. HIGH SURFACE AREA POLYMER COATINGS FOR SAW-BASED CHEMICAL SENSOR APPLICATIONS. (R826648)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  15. The see-saw a vertical-lift incubator designed for channel catfish egg masses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish egg masses are typically incubated in baskets that are suspended in water that is agitated with rotating or oscillating paddles. We designed and tested a new vertical-lift incubator (the “See-Saw”) to incubate channel catfish egg masses. Preliminary research in commercial hatcheries...

  16. '"We Saw Inhumanity Close up." What Is Gained by School Students from Scotland Visiting Auschwitz?

    ERIC Educational Resources Information Center

    Cowan, Paula; Maitles, Henry

    2011-01-01

    As the education for citizenship agenda continues to impact on schools in the UK and with the Holocaust Educational Trust (HET) in conjunction with the Scottish Government introducing its Lessons From Auschwitz (LFA) project for students and teachers in Scotland, this article focuses on the Scottish context and investigates the school processes by

  17. "I Saw it in a Different Light": International Learning Experiences in Baccalaureate Nursing Education.

    ERIC Educational Resources Information Center

    Walsh, Linda V.; DeJoseph, Jeanne

    2003-01-01

    Ten nursing students and two faculty mentors participated in an immersion experience in Guatemala. Themes from interviews included the experience of being "other," growth as a professional nurse, and expansion of world views. (Contains 16 references.) (SK)

  18. "Hey, I Saw Your Grandparents at Walmart": Teacher Education for Rural Schools and Communities

    ERIC Educational Resources Information Center

    Eppley, Karen

    2015-01-01

    This is a case study about how teacher education might better prepare rural teacher candidates for rural schools. Parents, teachers, community members, and students associated with a rural school described what is important in the preparation of teachers for today's rural schools. Their goals and wishes for their children's school and

  19. Quality Comparison of Saw and Roller Ginning Three Mid-South Cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three cultivars; Fibermax 960 BR, Deltapine 147 RF, and Deltapine 164 B2RF; were grown normally at Stoneville, MS and spindle harvested during the 2008 crop year. The cottons were processed with the same precleaning: dryer at 250F, cylinder cleaner, stick machine, dryer at 240F, and cylinder clea...

  20. NASA Lewis Helps Develop Advanced Saw Blades for the Lumber Industry

    NASA Technical Reports Server (NTRS)

    1998-01-01

    NASA Lewis Research Center's Structures and Material Divisions are centers of excellence in high-temperature alloys for aerospace applications such as advanced aircraft and rocket engines. Lewis' expertise in these fields was enlisted in the development of a new generation of circular sawblades for the lumber industry to use in cutting logs into boards. The U.S. Department of Agriculture's (USDA) Forest Products Laboratory and their supplier had succeeded in developing a thinner sawblade by using a nickel-based alloy, but they needed to reduce excessive warping due to residual stresses. They requested assistance from Lewis' experts, who successfully eliminated the residual stress problem and increased blade strength by over 12 percent. They achieved this by developing an innovative heat treatment based on their knowledge of nickel-based superalloys used in aeropropulsion applications.

  1. They Saw a Movie: Long-Term Memory for an Extended Audiovisual Narrative

    ERIC Educational Resources Information Center

    Furman, Orit; Dorfman, Nimrod; Hasson, Uri; Davachi, Lila; Dudai, Yadin

    2007-01-01

    We measured long-term memory for a narrative film. During the study session, participants watched a 27-min movie episode, without instructions to remember it. During the test session, administered at a delay ranging from 3 h to 9 mo after the study session, long-term memory for the movie was probed using a computerized questionnaire that assessed…

  2. What the Butler Saw: Lee Daniels's Studies in Biography and History

    ERIC Educational Resources Information Center

    Beck, Bernard

    2014-01-01

    The movie "Lee Daniels' The Butler" is an example of a work that is meant not only to entertain but to convey an important attitude and offer important viewpoints. The movie deals with a deep issue in the history of movies and the history of the country: racial inequality. Three issues are discussed in this article: (a) African…

  3. As the Europeans Saw Them: The Aleuts of the Eighteenth Century, Social Studies Unit, Book II.

    ERIC Educational Resources Information Center

    Partnow, Patricia H., Comp.

    This booklet is intended for use as reading material for the social studies unit, The Aleuts of the Eighteenth Century. Excerpts from journals of seven 18th-century explorers or travelers describe the inhabitants of the Aleutian Islands. The accounts have been translated from original notes kept by members of the Russian navy, ship commanders, a

  4. Surface acoustic wave (SAW) microsensor array for measuring VOCs in drinking water.

    PubMed

    Groves, W A; Grey, A B; O'Shaughnessy, P T

    2006-09-01

    Exposure to volatile organic chemicals (VOCs) in drinking water has been linked to a number of adverse health effects including cancer, liver, and kidney damage. However, the large number of potential contaminants and the cost and complexity of existing analytical methods limits the extent to which water quality is routinely characterized. This project focused on the laboratory development and evaluation of an instrument for field analysis of VOCs in drinking water. The instrument is based on an array of six polymer-coated surface-acoustic-wave microsensors. A test-set consisting of dichloromethane, chloroform, 1,1,1-trichloroethane, perchloroethylene, and m-xylene was used in a series of experiments designed to optimize the purge-trap preconcentration system, calibrate the instrument over the concentration range of 0.2-2 times the USEPA maximum contaminant levels (MCLs), and compare results to those of a reference laboratory. The primary goal was to develop a cost-effective alternative for on-site evaluation of VOCs in water. Calibration and evaluation test results for spiked water samples demonstrate adequate sensitivity for 19 of the 21 regulated VOCs considered using a ten minute sampling and analysis cycle. Monte Carlo simulations characterized the performance of trained artificial neural networks (ANNs) which had correct classification rates of 99%, 90%, and 80% for the five individual test-set vapors and their binary and ternary mixtures, respectively. These results demonstrate the excellent potential of this technology for addressing the need for improved VOC field-screening methods for water supplies. PMID:16951753

  5. Monitoring complex formation in the blood-coagulation cascade using aptamer-coated SAW sensors.

    PubMed

    Gronewold, T M A; Glass, S; Quandt, E; Famulok, M

    2005-04-15

    Specific binding of the anticoagulants heparin and antithrombin III to the blood clotting cascade factor human thrombin was recorded as a function of time with a Love-wave biosensor array consisting of five sensor elements. Two of the sensor elements were used as references. Three sensor elements were coated with RNA or DNA aptamers for specific binding of human thrombin. The affinity between the aptamers and thrombin, measured using the biosensor, was within the same range as the value of K(D) measured by filter binding experiments. Consecutive binding of the thrombin inhibitors heparin, antithrombin III or the heparin-antithrombin III complex to the immobilized thrombin molecules, and binding of a ternary complex of heparin, anithrombin III, and thrombin to aptamers was evaluated. The experiments showed attenuation of binding to thrombin due to heparin-antithrombin III complex formation. Binding of heparin activated the formation of the inhibitory complex of antithrombin III with thrombin about 2.7-fold. Binding of the DNA aptamer to exosite II appeared to inhibit heparin binding to exosite I. PMID:15741074

  6. What the Butler Saw: Lee Daniels's Studies in Biography and History

    ERIC Educational Resources Information Center

    Beck, Bernard

    2014-01-01

    The movie "Lee Daniels' The Butler" is an example of a work that is meant not only to entertain but to convey an important attitude and offer important viewpoints. The movie deals with a deep issue in the history of movies and the history of the country: racial inequality. Three issues are discussed in this article: (a) African

  7. Fast FEM/BEM simulation of SAW devices via asymptotic waveform evaluation.

    PubMed

    Laude, Vincent; Reinhardt, Alexandre; Wilm, Mikaël; Khelif, Abdelkrim; Ballandras, Sylvain

    2004-03-01

    The finite element method/boundary element method (FEM/BEM) computation model applied to surface acoustic wave devices requires the solution of a large linear system for each frequency point. An asymptotic waveform evaluation technique is used to obtain an approximate solution of the linear system that is valid over a large frequency bandwidth. The approximate solution was shown to be very accurate and vastly reduces the computation time. PMID:15128223

  8. They Saw a Movie: Long-Term Memory for an Extended Audiovisual Narrative

    ERIC Educational Resources Information Center

    Furman, Orit; Dorfman, Nimrod; Hasson, Uri; Davachi, Lila; Dudai, Yadin

    2007-01-01

    We measured long-term memory for a narrative film. During the study session, participants watched a 27-min movie episode, without instructions to remember it. During the test session, administered at a delay ranging from 3 h to 9 mo after the study session, long-term memory for the movie was probed using a computerized questionnaire that assessed

  9. ENSO-driven carbon see saw in the Indo-Pacific

    NASA Astrophysics Data System (ADS)

    Rixen, Tim; Ittekkot, Venugopalan; Herunadi, Bambang; Wetzel, Patrick; Maier-Reimer, E.; Gaye-Haake, Birgit

    2006-04-01

    The sediment trap experiments have been carried out during the 2001/2002 El Nio/La Nia transition in the monsoon-driven and freshwater influenced upwelling system off South Java. The results indicate that enhanced precipitation rates and associated river discharges increase the CO2-uptake of the biological pump by increasing the organic carbon export and reducing the carbonate precipitation. The freshwater, furthermore, forms a buoyant low salinity surface layer that caps off the nutrient and CO2-rich subsurface waters which shortens the upwelling season during wet La Nia conditions. A reduced capping-effect during dryer El Nio conditions strengthens the upwelling and as shown by our model results increase CO2 emission into the atmosphere along the freshwater influenced continental margins in SE Asia. By contrast El Nio weakens upwelling and reduces the CO2 emission in the equatorial Pacific Ocean.

  10. The first time ever I saw your feet: inversion effect in newborns' sensitivity to biological motion.

    PubMed

    Bardi, Lara; Regolin, Lucia; Simion, Francesca

    2014-04-01

    Inversion effect in biological motion perception has been recently attributed to an innate sensitivity of the visual system to the gravity-dependent dynamic of the motion. However, the specific cues that determine the inversion effect in naïve subjects were never investigated. In the present study, we have assessed the contribution of the local gravity-dependent motion (i.e., the orientation of individual dot trajectories) and the global configuration (i.e., the vertical location of the dots representing the feet within the display) in determining the inversion effect for biological motion in humans at birth. Results showed that 2-day-old newborns, at their 1st exposure to point-light displays, preferred a biological motion stimulus representing the legs of a walking animal compared with an identical display in which individual dot trajectories were locally inverted so that the motion violates the gravity force (Experiment 1). Interestingly, the global configuration affected the analysis of the gravity-dependent profile of dots motion. Indeed, the spontaneous preference disappeared when the local dots representing feet were embedded in a more complex global display and all the dots representing feet were located on the ground below the rest of the body (Experiment 2). Finally, results revealed that the orientation of the global configuration per se is not a crucial factor in determining newborns' preference (Experiment 3). These results suggest that humans possess an inborn predisposition about the direction of the gravity force that imprints biological motion and supports the hypothesis that a mechanism for the detection of biological motion is already at work before visual experience. PMID:24099548

  11. Using Minority Carrier Lifetime Measurement to Determine Saw Damage Characteristics on Si Wafer Surfaces

    SciTech Connect

    Sopori, Bhushan; Devayajanam, Srinivas; Basnyat, Prakash

    2015-06-14

    The damage on the Si wafer surfaces, caused by ingot cutting, is determined from measurement of minority carrier lifetime (..tau..eff). Samples are sequentially etched to remove thin layers from each surface and lifetime is measured after each etch step. The thickness-removed at which the lifetime reaches a peak value corresponds to the damage depth. This technique also allows the depth distribution of the damage to be quantified in terms of surface recombination velocity (SRV). An accurate measurement of ..tau..eff requires corrections to optical reflection, and transmission to account for changes in the surface morphology and in the wafer thickness.

  12. The Income Volatility See-Saw: Implications for School Lunch. Economic Research Report Number 23

    ERIC Educational Resources Information Center

    Newman, Constance

    2006-01-01

    Income volatility challenges the effectiveness of the safety net that USDA food assistance programs provide low-income families. This study examines income volatility among households with children and the implications of volatility for eligibility in the National School Lunch Program (NSLP). The results show that income volatility was higher for…

  13. PSAW/MicroSWIS [Microminiature Surface Acoustic Wave (SAW) based Wirelesss Instrumentation System

    NASA Technical Reports Server (NTRS)

    Heermann, Doug; Krug, Eric

    2004-01-01

    This Final Report for the PSAW/MicroSWIS Program is provided in compliance with contract number NAS3-01118. This report documents the overall progress of the program and presents project objectives, work carried out, and results obtained. Program Conceptual Design Package stated the following objectives: To develop a sensor/transceiver network that can support networking operations within spacecraft with sufficient bandwidth so that (1) flight control data, (2) avionics data, (3) payload/experiment data, and (4) prognostic health monitoring sensory information can flow to appropriate locations at frequencies that contain the maximum amount of information content but require minimum interconnect and power: a very high speed, low power, programmable modulation, spread-spectrum radio sensor/transceiver.

  14. I Came, I Saw, I Put It on My Resume for Medical School

    ERIC Educational Resources Information Center

    Weldy Boyd, Amanda C.

    2011-01-01

    The author argues for the myriad benefits of extracurricular involvement to students' psychosocial development and calls upon administrators and professors to encourage students to participate in carefully selected activities with earnest commitment of their time and efforts. The author contends that colleges demonstrate that they encourage…

  15. They Went, They Saw, They Learned: Medical Students' Reflections on Community Clinic Visits

    ERIC Educational Resources Information Center

    Beylefeld, Adriana A.

    2014-01-01

    Medicine has become a profession with increasing accountability to the needs of society. To meet this need, real-world, community-located experiences and reflection are frequently used to promote students' learning and personal growth. This article reports first-year medical students' reflective writing after visiting a primary…

  16. One GHz leaky SAW velocity of metal layers and bilayers evaporated onto fused quartz

    NASA Technical Reports Server (NTRS)

    Walikainen, Dale

    1992-01-01

    An acoustic microscope operating at 1 GHz was used to determine the surface acoustic wave velocities v of thin film metal layers and metal bilayers deposited onto fused quartz. V(0)'s influence was reduced by gating. This produced a calibrated accuracy of 3 percent. A program was constructed from the explicitly solved 6 x 6 theoretical determinant. Single film thicknesses were decided upon by using this theory to produce a v equal to a standard. Since the single film v's were linear with respect to their thickness, half the single film thicknesses were used for the bilayered films. The velocities for these bilayered films agreed with theory. This experimentally confirms the theoretical technique used here to examine bilayered systems, or a prototype composite interphase. No discrepancy was seen for gold films as others have reported. V(z) seemed insensitive to the formation of intermetallics or CuO. Some annealed and unannealed platinum films did not change the v from that of fused quartz. Two platinum films whose v's were in agreement with theory peeled off with the tape test.

  17. Old Saws and New Materials: A Consideration of Some Ethical Problems.

    ERIC Educational Resources Information Center

    Morse, John F.

    1968-01-01

    Reports of job-hopping, opportunism, grantsmanship, and wheeling-dealing, based on the availability of federal research funds, by university faculty has created much concern in governmental and educational circles about the ethical problems these activities pose for the academic profession. In 1963, the Office of Science and Technology(OST) and…

  18. Control Methods for Wire Arrangement Unit of New Multi-Wire Saw

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Qian, Juying; Cai, Ji-Fei; Wang, Yan

    To solve such problems as unstable wire transmission caused by overly dense or overlaid local wire arrangement, an electronic cam wire arrangement method is put forward in this paper, adopting servo motor to drive the cam, making the wire arrangement motor follow the speed change of taking-up motor, outputing the wire arrangement motor speed with the deduced functional operation relation, and controlling the wire arrangement pulley to evenly distribute the steel wire on the taking-up roller.

  19. Versatile materials for use as chemically sensitive interfaces in SAW-based sensor arrays

    SciTech Connect

    Crooks, R.M.; Bergbrieter, D.E.; Bruening, M.L.; Wells, M.; Zhou, Yuefen; Ricco, A.J.; Osbourn, G.C.

    1996-07-01

    The primary research objective of the work described here is to design, synthesize, and characterize new materials for use as chemical sensor interfaces, integrate these materials, using appropriate transducers, into sensor arrays, and then develop appropriate mathematical algorithms for interpreting the array response. In this paper, we will discuss two new types of materials we have developed that are ideally suited for use as chemically sensitive interfaces for array-based chemical sensing applications, since they: (1) provide general specificity towards classes of functional groups rather than individual compounds; (2) are intermediate in structure between monolayers and polymers; (3) exhibit both endo- and exo-recognition. The first class of materials is surface-confined dendrimers and the second is hyperbranched polymers.

  20. Comparison of high-speed roller and saw ginning on Texas high plains cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New high-quality cotton cultivars have been adopted in the Southern High Plains recently and, as a result, interest has grown in finding harvest and ginning practices that better preserve fiber quality. Advancements in roller ginning technology have increased the ginning rate of some roller gins to ...

  1. Dansgaard-Oeschger Oscillations and the Bi-Polar SeeSaw in a Comprehensive Model of Glacial Climate

    NASA Astrophysics Data System (ADS)

    Peltier, W. R.; Vettoretti, G.

    2013-12-01

    The millennial timescale variability characteristic of Marine Oxygen Isotopic Stage 3 that is observed most clearly in Summit, Greenland ice-cores has never been adequately explained. The mechanism responsible for the bi-polar seesaw relationship between the Polar Regions that accompanies these events has remained similarly enigmatic. This situation has continued to exist in large part as a consequence of the fact that the D-O oscillation has never been shown to arise in a comprehensive coupled model of glacial climate. We will describe a series of very long timescale high resolution integrations of the NCAR CESM1 model under glacial boundary conditions in which the continental ice cover is assumed to be fixed to that of the new ICE-6G (VM5a) model. Greenhouse gases are also fixed to those inferred in the basis of Antarctic ice-core measurements. In order that the equilibrium dynamical state of the ocean not be prejudiced by the initial conditions, the ocean is initialized from a state of rest with modern ocean heat content. The spin-up of the model to statistical equilibrium is characterized by the existence of a series of cooling thresholds which, once crossed, lead the climate system into full glacial cold conditions in which sea ice cover has significantly expanded. In the high spatial resolution version of CESM1, the same resolution employed in CMIP5 experiments, we find that the glacial state is unsteady and characterized by millennium timescale oscillations, each of which has the form of a relaxation oscillation with the fast timescale warming phase of the oscillation caused by a rapid onset of deep water production in the North Atlantic due to convective instability of the water column. The subsequent slow timescale phase of each oscillation is associated with a slow expansion of sea ice cover which leads the system back into stadial conditions. These characteristics accurately mimic the GRIP and NGRIP records of individual D-O oscillations, not only in terms of the period of the individual oscillations but also concerning their amplitude. We compare the model predicted temperature variations for the Summit, Greenland and Dronning Maud Land, Antarctica sites and thereby show that the model replicates the bi-polar seesaw behavior inferred on the basis of the δ18O records from the collocated ice cores. The 'bare' D-O oscillation is thereby shown not to require co-variation of land ice volume for its existence, although negative feedback associated with freshwater forcing during the fast transitions into the interstadial state is expected to be important in sculpting the detailed form of individual Bond cycles.

  2. Optimization of the Depth of Penetration by Welding Input Parameters in SAW Process Using Response Surface Methodology

    NASA Astrophysics Data System (ADS)

    Kazemi, Mohsen; Aghakhani, Masood; Haghshenas-Jazi, Ehsan; Behmaneshfar, Ali

    2016-02-01

    The aim of this paper is to optimize the depth of penetration with regard to the effect of MgO nanoparticles and welding input parameters. For this purpose, response surface methodology (RSM) with central composite rotatable design (CCRD) was used. The welding current, arc voltage, nozzle-to-plate distance, welding speed, and thickness of MgO nanoparticles were determined as the factors, and depth of penetration was considered as the response. Quadratic polynomial model was used for determining the relationship between the response and factors. A reduced model was obtained from the data which the values of R 2, R 2 (pred), and R 2 (adj) of this model were 92.05, 69.05, and 86.31 pct, respectively. Thus, this model was suitable, and it was used to determine the optimum levels of factors. The results show that the welding current, arc voltage, and nozzle-to-plate distance factors should be adjusted in high level, and welding speed and thickness of MgO nanoparticles factors should be adjusted in low level.

  3. Defect detection of partially complete SAW and TIG welds using the ultrasonic time-of-flight diffraction method

    NASA Astrophysics Data System (ADS)

    Lawson, Shaun W.; Bonser, Gary R.

    1998-03-01

    An application of machine vision applied to the analysis of ultrasonic images formed using the time-of-flight diffraction (TOFD) method on incomplete weld geometries is described. The rationale of the work being to identify weld defects as soon as they are produced, thereby reducing the costs of any subsequent repairs. The analysis uses TOFD scans as input to a filtering and 'window' based variance operator for the segmentation of suspect defect areas inside the weld region. A suite of pc based software and a high temperature TOFD data acquisition system have been benchmarked through a series of demonstration trials on both 80mm thick carbon steel submerged arc welded testpieces, and 25mm thick carbon steel tungsten inert gas welded testpieces. The range of intentionally implanted defects, from root cracks to lack of side wall fusion, were detected with an overall accuracy of 79 percent on a data set of 174 defects on scans performed at 10-90 percent weld completion.

  4. 'See-saw' expression of microRNA-198 and FSTL1 from a single transcript in wound healing.

    PubMed

    Sundaram, Gopinath M; Common, John E A; Gopal, Felicia E; Srikanta, Satyanarayana; Lakshman, Krishnaswamy; Lunny, Declan P; Lim, Thiam C; Tanavde, Vivek; Lane, E Birgitte; Sampath, Prabha

    2013-03-01

    Post-transcriptional switches are flexible effectors of dynamic changes in gene expression. Here we report a new post-transcriptional switch that dictates the spatiotemporal and mutually exclusive expression of two alternative gene products from a single transcript. Expression of primate-specific exonic microRNA-198 (miR-198), located in the 3'-untranslated region of follistatin-like 1 (FSTL1) messenger RNA, switches to expression of the linked open reading frame of FSTL1 upon wounding in a human ex vivo organ culture system. We show that binding of a KH-type splicing regulatory protein (KSRP, also known as KHSRP) to the primary transcript determines the fate of the transcript and is essential for the processing of miR-198: transforming growth factor-? signalling switches off miR-198 expression by downregulating KSRP, and promotes FSTL1 protein expression. We also show that FSTL1 expression promotes keratinocyte migration, whereas miR-198 expression has the opposite effect by targeting and inhibiting DIAPH1, PLAU and LAMC2. A clear inverse correlation between the expression pattern of FSTL1 (pro-migratory) and miR-198 (anti-migratory) highlights the importance of this regulatory switch in controlling context-specific gene expression to orchestrate wound re-epithelialization. The deleterious effect of failure of this switch is apparent in non-healing chronic diabetic ulcers, in which expression of miR-198 persists, FSTL1 is absent, and keratinocyte migration, re-epithelialization and wound healing all fail to occur. PMID:23395958

  5. 'Dear diary I saw an angel, she looked like heaven on earth': Sex talk and sex education.

    PubMed

    Pattman, Rob; Chege, Fatuma

    2003-01-01

    In this paper we highlight and address some of the problems involved in teaching HIV/AIDS education in southern and eastern Africa, and especially in generating open discussion among pupils about sex and sexuality. The paper draws on the findings of a UNICEF-funded study, in which we were involved, as research consultants (2001). The study focused on 'young people, gender, sexuality and HIV/AIDS education' and was conducted in Botswana, Kenya, Rwanda, South Africa, Tanzania, Zambia and Zimbabwe. In Botswana, Rwanda and Kenya, teachers and young people were interviewed about their attitudes towards and experiences of teaching/learning HIV/AIDS education. Young people were also interviewed more generally, in all the countries, about what it was like being a boy or girl of their age. We argue that HIV/AIDS education, as it is commonly taught, as a series of moral injunctions (against pre marital sex) effectively silences young people, and means that sex 'becomes' naughty when they do talk about it. We propose HIV/AIDS pedagogies, which emulate the practices our researchers adopted when researching the identities and views of boys and girls, especially concerning gender and sexuality. By addressing young people as experts about themselves and in a holistic and non-judgemental way, our interviewees were able to speak about anxieties and pleasures, many of which related to sexuality. This, they had not been able to do with other adults, and even with other children. We focus on the regulation and production of gender identities through the ways boys and girls talked about sex in our interviews and also in their participation in HIV/AIDS classes. In particular we look at how boys and girls 'performed' gender when discussing sexuality with boys often very loud and girls quiet, with boys presenting themselves as sexual and girls presenting themselves as asexual. We argue for approaches to HIV/AIDS education which challenge gender power relations without alienating boys by problematising them, and without reproducing stereotypes of boys as subjects and girls as objects of sexual desire. We examine the implications of this for single sex and mixed group work and for addressing 'sexual harassment'. Importantly, we found that both girls and boys described people of the opposite sex and heterosexual desire very differently in mixed-sex group interviews and in the diaries they kept. Rather than addressing girls and boys as unitary gendered subjects, we argue for approaches in HIV/AIDS education, which are responsive to the different and contradictory ways boys and girls present themselves and talk about sexual desire and the opposite sex in different contexts. PMID:25872106

  6. The mechanical properties of 2. 25Cr-1Mo weld metals deposited by the SAW-NG process

    SciTech Connect

    Chandel, R.; Gianetto, R.F.; Knight, R.F.; McGrath, J.A.; Orr, R.F.

    1985-09-01

    A series of narrow gap welds were prepared in 2.25Cr-1Mo steel plate using the submerged arc, narrow gap process with a Miller square wave ac 1000 power source. The notch toughness properties were assessed in the PWHT condition and after a temperembrittlement step-cooling treatment. Optimum notch toughness properties (>54 J at -40C) were achieved in the PWHT condition in welds with a low oxygen and sulfur content (total <0.035 pct), a fine bainitic microstructure, and a high (approx. =80 pct) proportion of recrystallized structure. For welds subject to the temper-embrittlement step-cooling treatment, the upward shift in Charpy transition temperature was of the order of 20 to 25C, irrespective of the levels of impurity elements, P, Sn, Sb, and As.

  7. Diffraction of a surface optical wave in an optical slab waveguide by a surface acoustic wave /SAW/

    NASA Astrophysics Data System (ADS)

    Parygin, V. N.; Tankovskii, N. S.

    1982-12-01

    A general equation is formulated for the interaction of a light wave and a surface acoustic wave in an optical slab waveguide, and a solution is obtained which determines the light intensity in all the possible modes and diffraction orders. It is shown that there is an analogy between light diffraction in a multimode optical waveguide and light diffraction in an anisotropic medium.

  8. The First Time Ever I Saw Your Feet: Inversion Effect in Newborns' Sensitivity to Biological Motion

    ERIC Educational Resources Information Center

    Bardi, Lara; Regolin, Lucia; Simion, Francesca

    2014-01-01

    Inversion effect in biological motion perception has been recently attributed to an innate sensitivity of the visual system to the gravity-dependent dynamic of the motion. However, the specific cues that determine the inversion effect in naïve subjects were never investigated. In the present study, we have assessed the contribution of the local…

  9. 76 FR 62678 - Table Saw Blade Contact Injuries; Advance Notice of Proposed Rulemaking; Request for Comments and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ... accidental contact with the blade. In the Federal Register of July 9, 2003 (68 FR 40912) and September 5, 2003 (68 FR 52753), we invited comments on the issues raised by the petition (Petition No. CP03-2)....

  10. Real-time monitoring of calcium carbonate and cationic peptide deposition on carboxylate-SAM using a microfluidic SAW biosensor.

    PubMed

    Pohl, Anna; Weiss, Ingrid M

    2014-01-01

    A microfluidic biosensor with surface acoustic wave technology was used in this study to monitor the interaction of calcium carbonate with standard carboxylate self-assembled monolayer sensor chips. Different fluids, with and without biomolecular components, were investigated. The pH-dependent surface interactions of two bio-inspired cationic peptides, AS8 and ES9, which are similar to an extracellular domain of the chitin synthase involved in mollusc shell formation, were also investigated in a biological buffer system. A range of experimental conditions are described that are suitable to study non-covalent molecular interactions in the presence of ionic substances, such as, mineral precursors below the solubility equilibrium. The peptide ES9, equal to the mollusc chitin synthase epitope, is less sensitive to changes in pH than its counterpart AS8 with a penta-lysine core, which lacks the flanking acidic residues. This study demonstrates the extraordinary potential of microfluidic surface acoustic wave biosensors to significantly expand our experimental capabilities for studying the principles underlying biomineralization in vitro. PMID:25383294

  11. "Such a smoking nation as this I never saw...": smoking, nationalism, and manliness in nineteenth-century Hungary.

    PubMed

    Maxwell, Alexander

    2006-01-01

    Tobacco smoking became an important marker of Hungarian national identity during the nineteenth century. this national symbol ultimately had an economic origin: Hungarian tobacco producers resisted the tobacco monopoly of the Habsburg central government, and led an ultimately successful consumer boycott of Austrian products. Tobacco nationalism, however, became a common theme in Hungarian popular culture in its own right, as tobacco use came to symbolize community and fraternity. The use of tobacco was also highly gendered; smoking as a metaphor for membership shows that the Hungarian nation was a gender-exclusive "national brotherhood." PMID:20058399

  12. Channel catfish hatchery production efficiency using a vertical-lift incubator the see-saw at various egg loading densities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish spawns are typically incubated in ¼-in mesh baskets suspended in water that is agitated with paddles positioned between baskets. We tested a new vertical-lift incubator (the “See-Saw”) to incubate channel catfish spawns. Previous research demonstrated that when loaded with spawns at...

  13. TGfU--Would You Know It if You Saw It? Benchmarks from the Tacit Knowledge of the Founders

    ERIC Educational Resources Information Center

    Butler, Joy

    2014-01-01

    This paper explores the tacit expert knowledge and understanding about games curriculum and pedagogy of three men, Len Almond, David Bunker, and Rod Thorpe, credited as the founders of the Teaching Games for Understanding (TGfU) model. The model emerged from teacher practice in the late 1970s and was little theorized at the time, apart from a…

  14. The "See-saw" - A High-intensity Catfish Egg Incubator Designed to Save Space and Conserve Water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Catfish spawns (egg masses) have been incubated and hatched in much the same way for nearly a century. Spawns are placed in ¼”-mesh hardware cloth baskets suspended in metal troughs and water is circulated with paddles placed between the baskets. While this practical system has apparently worked wel...

  15. I know your face but not where I saw you: context memory is impaired for other-race faces.

    PubMed

    Horry, Ruth; Wright, Daniel B

    2008-06-01

    People are more likely to falsely identify a face of another race than a face of their own race. When witnesses make identifications, they often need to remember where they have previously encountered a face. Failure to remember the context of an encounter can result in unconscious transference and lead to misidentifications. Forty-five White participants were shown White and Black faces, each presented on one of five backgrounds. The participants had to identify these faces in an old/new recognition test. If participants stated that they had seen a face, they had to identify the context in which the face had originally appeared. Participants made more context errors with Black faces than with White faces. This shows that the own-race bias extends to context memory. PMID:18567263

  16. The First Time Ever I Saw Your Feet: Inversion Effect in Newborns' Sensitivity to Biological Motion

    ERIC Educational Resources Information Center

    Bardi, Lara; Regolin, Lucia; Simion, Francesca

    2014-01-01

    Inversion effect in biological motion perception has been recently attributed to an innate sensitivity of the visual system to the gravity-dependent dynamic of the motion. However, the specific cues that determine the inversion effect in nave subjects were never investigated. In the present study, we have assessed the contribution of the local

  17. "I saw it with my own ears": The Effects of Peer Conversations on Preschoolers' Reports of Nonexperienced Events.

    ERIC Educational Resources Information Center

    Principe, Gabrielle F.; Ceci, Stephen J.

    2002-01-01

    Explored effects of naturally-occurring peer interactions and repeated suggestive interviews on preschoolers' event memories. Found that suggestive interviews, combined with peer exposure, led to children's claims of witnessing target activities comparable to those of children who actually witnessed these activities. Assent rates for misleading…

  18. Interfacing low-energy SAW nebulization with Liquid Chromatography-Mass Spectrometry for the analysis of biological samples

    PubMed Central

    Tveen-Jensen, Karina; Gesellchen, Frank; Wilson, Rab; Spickett, Corinne M.; Cooper, Jonathan M.; Pitt, Andrew R.

    2015-01-01

    Soft ionization methods for the introduction of labile biomolecules into a mass spectrometer are of fundamental importance to biomolecular analysis. Previously, electrospray ionization (ESI) and matrix assisted laser desorption-ionization (MALDI) have been the main ionization methods used. Surface acoustic wave nebulization (SAWN) is a new technique that has been demonstrated to deposit less energy into ions upon ion formation and transfer for detection than other methods for sample introduction into a mass spectrometer (MS). Here we report the optimization and use of SAWN as a nebulization technique for the introduction of samples from a low flow of liquid, and the interfacing of SAWN with liquid chromatographic separation (LC) for the analysis of a protein digest. This demonstrates that SAWN can be a viable, low-energy alternative to ESI for the LC-MS analysis of proteomic samples. PMID:25978651

  19. Non-Destructive Detection of Rebar Buried in a Reinforced Concrete Wall with Wireless Passive SAW Sensor

    NASA Astrophysics Data System (ADS)

    Fan, Yanping; Ji, Xiaojun; Cai, Ping; Lu, Qianhui

    2013-01-01

    In order to reduce the damage to the old reinforced concrete walls and work out the best construction scheme during the renovation of old buildings, it is often required to detect the position of rebar buried in concrete walls. In this paper, we propose a non-destructive method to detect the buried rebar by self-inductive sensor combined with surface acoustic wave resonator (SAWR). The proposed method has the advantages of wireless, passive and convenient operations. In our new design, the sensing element of self-inductance coil was made as a component of SAWR matching network. The distribution of rebar could be measured according to the system resonant frequency, using a signal demodulation device set. The depth of buried rebar and the deviation of output resonant frequency from inherent frequency of SAWR have an inverse relation. Finally, the validity of the method was verified in theoretical calculation and simulation.

  20. Real-time monitoring of calcium carbonate and cationic peptide deposition on carboxylate-SAM using a microfluidic SAW biosensor

    PubMed Central

    Pohl, Anna

    2014-01-01

    Summary A microfluidic biosensor with surface acoustic wave technology was used in this study to monitor the interaction of calcium carbonate with standard carboxylate self-assembled monolayer sensor chips. Different fluids, with and without biomolecular components, were investigated. The pH-dependent surface interactions of two bio-inspired cationic peptides, AS8 and ES9, which are similar to an extracellular domain of the chitin synthase involved in mollusc shell formation, were also investigated in a biological buffer system. A range of experimental conditions are described that are suitable to study non-covalent molecular interactions in the presence of ionic substances, such as, mineral precursors below the solubility equilibrium. The peptide ES9, equal to the mollusc chitin synthase epitope, is less sensitive to changes in pH than its counterpart AS8 with a penta-lysine core, which lacks the flanking acidic residues. This study demonstrates the extraordinary potential of microfluidic surface acoustic wave biosensors to significantly expand our experimental capabilities for studying the principles underlying biomineralization in vitro. PMID:25383294