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1

Power saw  

NASA Technical Reports Server (NTRS)

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.

Bradley, Jimmy D. (inventor)

1991-01-01

2

Integrated acoustoelectric SAW source  

NASA Astrophysics Data System (ADS)

The generation of surface acoustic waves (SAWs) and an rf signal has been observed in an integrated acoustoelectronic amplifier with external galvanic feedback in CW operation. The acoustoelectronic amplifier used in the experiment is based on LiNbO3-InSb integrated multilayer structures and has an electronic conductivity of 75 x 10 to the -6th mho, a drift mobility of 1020 sq cm/(V s), active film length 1 cm, and film width 34 microns. Feedback is provided by a length of axial cable. The rf signal results from amplification of noise SAWs by the supersonic electron drift in the InSb film.

Guliaev, Iu. V.; Kotelianskii, I. M.; Krikunov, A. I.; Medved, A. V.; Mishkinis, R. A.

1980-01-01

3

Electric arc saw apparatus  

DOEpatents

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.

Deichelbohrer, Paul R [Richland, WA

1986-01-01

4

Circular Saws. Part I: The Saw Doctor, Saw Shop and Types of Circular Saw Used.  

National Technical Information Service (NTIS)

Few books and articles have been written on the subject of saw doctoring and with modern developments certain aspects quickly become out of date. Books also tend to be written for a country or region which produces sawlogs of a particular size, or species...

D. T. Priest

1980-01-01

5

MATLAB code for SAWS  

Microsoft Academic Search

A planar harmonic Green's matrix function is widely exploited in theory of SAW devices. In many practical cases, the papal approximation to this function is sufficient for analysis. Here, a number of numerical codes are presented in MATLAB for fundamental analysis of surface acoustic waves in piezoelectric crystals, including: derivation of Stroh matrix for given material and Euler angles, visualization

E. Danicki

1999-01-01

6

SAW Chemosensor. Third Progress Report (SAW Chemosensor. De derde Voortgangsrapportage).  

National Technical Information Service (NTIS)

At the Prins Maurits Laboratory TNO, work on surface acoustic wave (SAW) chemical sensors is being performed. Up to now the main subjects have been: implementation of SAW technology on a silicon chip, the development of a SAW sensor for NO2 and the develo...

M. S. Nieuwenhuizen

1992-01-01

7

Rapid SAW Sensor Development Tools  

NASA Technical Reports Server (NTRS)

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.

Wilson, William C.; Atkinson, Gary M.

2007-01-01

8

Electric arc saw apparatus  

DOEpatents

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.

Deichelbohrer, P.R.

1983-08-08

9

Lunar stone saw  

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

10

See-saw and supersymmetry  

SciTech Connect

We review recent results on the connection between the see-saw mechanism and supersymmetry. It is shown that spontaneously broken B-L symmetry, in theories with a renormalizable see-saw, determines completely the low energy structure of the supersymmetric Standard Model: it implies exact R-parity. We then discuss how the violation of the survival principle in supersymmetric SO(10) naturally leads to an intermediate see-saw scale and the lowering of the unification scale. This affects the predictions for proton decay: p{yields}{pi}{sup 0}e{sup +} may be the dominant mode.

Senjanovic, Goran [International Center for Theoretical Physics, 34014 Trieste (Italy)

1999-07-15

11

Programs for Computer Simulation of Hardwood Log Sawing.  

National Technical Information Service (NTIS)

Four computer programs were developed at the University of Kentucky as simulation models for investigating factors affecting sawn log value over four hardwood sawing methods: quadrant sawing, cant sawing, decision sawing, and live sawing with rerip for gr...

D. B. Richards D. W. Lewis E. H. Bulgrin W. K. Adkins

1980-01-01

12

Power Saws: A Review of Injury Data and Power Saw Industry Survey.  

National Technical Information Service (NTIS)

Two activities of an investigation of power saws are described: a review of power saw injury data and two surveys of saw manufacturers' opinions concerning safety aspects of saw use and design. The surveys, dealing with portable circular saws and table an...

V. J. Pezoldt J. J. Persensky

1975-01-01

13

Improved table-saw guard  

NASA Technical Reports Server (NTRS)

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.

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

1980-01-01

14

Reciprocating Saw for Silicon Wafers  

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

15

SAW-Modulated Image Device  

NASA Technical Reports Server (NTRS)

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.

Benz, H. F.

1985-01-01

16

SAW and optical signal processing  

Microsoft Academic Search

Even in this digital age, SAW and Optical devices remain indispensable analogue signal processing technologies whose operation and success derive from common wave propagation phenomena. In this review I hope to explain why this is so, and will remain so for the foreseeable future. Historically, the development and exploitation of these technologies arose during the Cold War primarily from the

Meirion Lewis

2005-01-01

17

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

Code of Federal Regulations, 2013 CFR

...Occupations Particularly Hazardous for the Employment of Minors Between 16 and 18 Years of Age or Detrimental to Their Health or Well-Being § 570.65 Occupations involving the operation of circular saws, band saws, guillotine shears, chain...

2013-07-01

18

SAW and pseudo-SAW properties using matrix methods  

Microsoft Academic Search

Pseudo-surface-waves (PSAW's), or leaky SAW's, were first recognized over 25 years ago and the phase velocity (vp) and attenuation per wavelength (??) of PSAW modes for nonpiezoelectrics were calculated soon after. Since the seventies progress has been made in exploiting the higher velocities and electromechanical coupling constants (K2=2?v\\/v) achievable with PSAW's for piezoelectric device applications; this has stimulated new interest

Eric L. Adler

1994-01-01

19

CDMA for wireless SAW sensor applications  

Microsoft Academic Search

A well known spread spectrum technique is used to get the sensor information from an individually addressed SAW sensor. Coded ID tag type and BPSK type SAW sensors are picked out of a number of sensors by correlating the received signal with the known code of a particular sensor. The ID-tag type and BPSK-coded SAW sensor's function is observed as

G. Ostermayer; A. Pohl; C. Hausleitner; L. Reindl; F. Seifert

1996-01-01

20

Precision surface-acoustic-wave (SAW) oscillators  

Microsoft Academic Search

The evolution of SAW oscillator technology over the past 17 years is described and a review of the current state of the art for high-performance SAW oscillators is presented. This review draws heavily upon the authors' own experience and efforts, which have focused upon the development of a wide variety of SAW oscillators in response to numerous high-performance military system

THOMAS E. PARKER; GARY K. MONTRESS

1988-01-01

21

Remote sensor system using passive SAW sensors  

Microsoft Academic Search

The aim of this paper is to show the possibilities of combining the basic principles of SAW identification (ID) tags with the well known properties of SAW sensors. The concept of SAW ID-sensors created in this way has several advantages over other solutions with the most two important being that the sensors themselves do not require a separate energy source

W. Buff; F. Plath; O. Schmeckebier; M. Rusko; T. Vandahl; H. Luck; F. Moller; D. C. Malocha

1994-01-01

22

SAW devices as wireless passive sensors  

Microsoft Academic Search

Surface acoustic wave (SAW) radio sensors make it possible to read measurement values from a remote location. The decisive advantage of these SAW sensors lies in their passive operation with no need for a separate power supply, and in the possibility of wireless installation at particularly inaccessible locations. The passive SAW sensors are maintenance free. The physical or chemical properties

L. Reindl; G. Scholl; T. Ostertag; C. C. W. Ruppel; W.-E. Bulst; F. Seifert

1996-01-01

23

Reconstructing see-saw models  

SciTech Connect

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.

Ibarra, Alejandro [Instituto de Fisica Teorica, CSIC/UAM, C-XVI, Cantoblanco, 28049 Madrid (Spain)

2007-01-12

24

Frequency Domain Modeling of SAW Devices  

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

25

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

Code of Federal Regulations, 2010 CFR

... Occupations involved in the operations of circular saws, band saws, and guillotine shears (Order 14). 570.65 Section... Occupations involved in the operations of circular saws, band saws, and guillotine shears (Order 14)....

2010-07-01

26

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

Code of Federal Regulations, 2010 CFR

... Occupations involved in the operations of circular saws, band saws, and guillotine shears (Order 14). 570.65 Section... Occupations involved in the operations of circular saws, band saws, and guillotine shears (Order 14)....

2009-07-01

27

Lumber Values from Computerized Simulation of Hardwood Log Sawing.  

National Technical Information Service (NTIS)

Computer simulation sawing programs were used to study the sawing of mathematical models of hardwood logs by the live sawing and three 4-sided sawing methods. One of the 4-sided methods simulated 'grade sawing' by sawing wach successive board from the log...

D. B. Richards E. H. Bulgrin H. Hallock W. K. Adkins

1980-01-01

28

Programmable reflectors for SAW-ID-tags  

Microsoft Academic Search

Surface acoustic wave devices for identification systems (SAW-ID-tags or SAW wireless labels) have a large potential for future applications. We concentrate in this paper on reflective SAW-ID-tags with amplitude modulation. We use splitfinger interdigital transducers as reflecting structures. If the transducers are short circuited or capacitively loaded the reflection disappears almost entirely. On the other hand, if an open circuit

L. Reindl; W. Ruile

1993-01-01

29

Comparison of various silicon sawing methods  

NASA Technical Reports Server (NTRS)

The technology and economics of four methods of wafering silicon boules of large cross section are described. Slurry sawing using either blades or wires, and fixed abrasive sawing using the ID saw or by the FAST method, having the abrasive attached to wires which are arranged in a blade pack, are considered. The technical performance of each method is evaluated and cost/price estimates are summarized.

Wolf, M.

1982-01-01

30

Comparison of various silicon sawing methods  

NASA Astrophysics Data System (ADS)

The technology and economics of four methods of wafering silicon boules of large cross section are described. Slurry sawing using either blades or wires, and fixed abrasive sawing using the ID saw or by the FAST method, having the abrasive attached to wires which are arranged in a blade pack, are considered. The technical performance of each method is evaluated and cost/price estimates are summarized.

Wolf, M.

1982-02-01

31

Saw palmetto ethanol extract inhibits adipocyte differentiation.  

PubMed

The fruits of saw palmetto have been used for the treatment of a variety of urinary and reproductive system problems. In this study we investigated whether the fruit extracts affect in vitro adipogenesis. Saw palmetto ethanol extract inhibited the lipid droplet accumulation by induction media in a dose-dependent manner, and it also attenuated the protein expressions of C-EBP? and PPAR?. Phosphorylation of Erk1/2 and Akt1 were also decreased by saw palmetto ethanol extract. This report suggests that saw palmetto extracts selectively affect the adipocyte differentiation through the modulation of several key factors that play a critical role during adipogenesis. PMID:23179316

Villaverde, Nicole; Galvis, Adriana; Marcano, Adriana; Priestap, Horacio A; Bennett, Bradley C; Barbieri, M Alejandro

2013-07-01

32

Sawing a Local Bedrock Specimen  

NSDL National Science Digital Library

In this activity students bring in samples of local rocks for the teacher to cut in half with a diamond saw. Students then analyze and report on the grain relationships within the rock. As a follow-up activity students can exchange rocks, write an analysis of the sawn sample, and compare notes. In cases where disagreements cannot be resolved, the teacher should offer a third analysis of the sample. Also students can take the rocks home and tell their parents what they learned about the particular sample. Or they can set up before-and-after displays showing cut and uncut samples. Enlarged poster-size diagrams of the more interesting samples can be created. The specific details of texture and composition can be labeled with a string or wire running to the appropriate spot on the specimen.

33

SAW Temperature Sensor and Remote Reading System  

Microsoft Academic Search

A system for remotely reading a SAW temperature sensor has been adapted from an existing, commercially available personnelherchandise detector system. The SAW sensor is a Lithium Niobate wafer with an inter-digital transducer (IDT) which is directly connected to a small transducer which is directly connected to a small microwave antenna and two reflectors. The reading system is a special Fhl

X. Q. Bao; W. Burkhard; V. V. Varadan; V. K. Varadan

1987-01-01

34

Comparison between BAW and SAW sensor principles  

Microsoft Academic Search

A comparison is given between piezoelectrically excited bulk acoustic wave (BAW) and surface acoustic wave (SAW) elements with respect to their primary sensitivity functions and principal capabilities for sensor applications. The importance of mode purity for high dynamic range sensors is emphasized. Characteristic sensor examples are reviewed, and the special demands on the electronics for BAW and SAW elements in

Ewald Benes; M. Groschl; F. Seifert; A. Pohl

1998-01-01

35

Numerical methods for SAW propagation characterization  

Microsoft Academic Search

Due to more and more stringent requirements on SAW filter performance, it is mandatory to precisely characterize the SAW propagation characteristics as a function of manufacturing variations (metal thickness, mark-to-space ratio, etc.). Several authors have already proposed experimental characterizations using sets of test devices. One of the main difficulties of this experimental approach is the accuracy of both the geometrical

P. Ventura; J. M. Hode; M. Solal; J. Desbois; J. Ribbe

1998-01-01

36

Modeling of waveguide-coupled SAW resonators  

Microsoft Academic Search

Coupling of modes in space (COMS) is applied to the analysis of waveguide coupled surface acoustic wave (SAW) resonators. Standard one-dimensional COMS equations are extended to model distributed coupling between adjacent SAW reflector arrays. Computed frequency responses are presented for two-pole and four-pole waveguide coupled resonators

Yufeng Xu; Peter M. Smith

1994-01-01

37

Apparatus for loading a band saw blade  

DOEpatents

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.

Reeves, Steven R. (49 Williams Ave., West Valley, NY 14171)

1990-01-01

38

SAW wireless, passive sensor spread spectrum platforms  

Microsoft Academic Search

SAW technology has been identified as a possible solution for NASA's long term needs for ground, space-flight, and space-exploration sensor requirements. SAW has many unique advantages over possible competing technologies, which include the following properties: passive, radiation hard, operable over wide temperature ranges, small, rugged, inexpensive, and identifiable. The purpose of this paper is a focus on the platform and

J. M. Pavlina; B. Santos; N. Kozlovski; D. C. Malocha

2008-01-01

39

SAW based systems for mobile communications satellites  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

40

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

41

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

42

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

43

Parameterizable Library Components for SAW Devices  

NASA Technical Reports Server (NTRS)

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.

Wilson, William C.; Atkinson, Gary M.

2006-01-01

44

Versatile machine mills, saws light materials  

NASA Technical Reports Server (NTRS)

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.

Rauschl, J. A.

1966-01-01

45

Chemically sensitive interfaces on SAW devices  

SciTech Connect

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.

Ricco, A.J.; Martin, S.J. [Sandia National Labs., Albuquerque, NM (United States); Crooks, R.M.; Xu, Chuanjing [Texas A and M Univ., College Station, TX (United States); Allred, R.E. [Adherent Technologies, Inc., Albuquerque, NM (United States)

1993-11-01

46

SAW Sensor for Fastener Failure Detection  

NASA Technical Reports Server (NTRS)

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.

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

2010-01-01

47

Using SAW Resonators in RF Oscillators  

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

48

FEM simulation of SAW reflection in crystals  

NASA Astrophysics Data System (ADS)

The paper discusses the numerical study of the SAW reflection from single surface imperfections, such as grooves, projections, and steps, on half-infinite piezoelectric substrates. Our analysis is based on FEM computations. A perfectly matched layer (PML) is implemented in order to truncate the computational domain. The amplitude of the reflected SAW is found by applying FFT to the reflected total field on the surface of the substrate.

Darinskii, A. N.; Weihnacht, M.; Schmidt, H.

2012-05-01

49

New architectures for feedthrough SAW recursive devices.  

PubMed

This paper presents an analysis of a new type of feedthrough recursive surface acoustic wave (SAW) device. The device combines a conventional SAW structure with positive feedback in a way that allows use of selective properties of the SAW structure, control of the central frequency and bandwidth, achieving significantly higher quality factors for given dimensions of the structure, and reduction of the sidelobe level. Several possible implementations are discussed from a simple one that uses external circuitry to the most advanced that includes digital supervisory control. Equations are presented that relate the central frequency, bandwidth, and sidelobe level to the parameters of the SAW structure and feedback loop. The simulation results were found to be in good agreement with experimental data. These data show the control of the central frequency within 1%, a 10-fold increase in the quality factor compared to the original SAW structure, and a reduction of the side-lobe level by 20 dB irrespective of the influence of second order effects and random manufacturing fluctuations. PMID:15742568

Kalashnikov, Alexander N; Challis, Richard E

2005-01-01

50

STP Random Walk 2D SAW Program  

NSDL National Science Digital Library

The RandomWalkSAW program simulates a self-avoiding random walk in two dimensions. The walker has an equal probability of going in any direction, but cannot return to a site that has already been visited. The default number of initial walkers is 100 and the total number of steps N = 1024. RandomWalkSAW is part of a suite of Open Source Physics programs that model aspects of Statistical and Thermal Physics (STP). The program is distributed as a ready-to-run (compiled) Java archive. Double clicking the stp RandomWalkSAW.jar file will run the program if Java is installed on your computer. Additional programs can be found by searching ComPADRE for Open Source Physics, STP, or Statistical and Thermal Physics.

Gould, Harvey; Tobochnik, Jan; Christian, Wolfgang; Cox, Anne

2008-10-10

51

Design on semiconductor coupled SAW convolver.  

PubMed

This paper presents results of a design study on a semiconductor coupled surface acoustic wave (SAW) convolver in which bi-directionally propagating SAWs, on a piezoelectric substrate with a high coupling coefficient, couple with bonded semiconductor diodes through multistrips. To obtain convolution signals with a high efficiency, we adopted a diode-balanced bridge structure for the non-linear operation. We also found that the tapping pitches of the multi-strip electrodes have robustness against operation frequency variation and temperature-dependent variation on the delay of the SAW. We verified the effectiveness of the device in a circuit simulation and an experiment on a test circuit, which was fabricated by using an epitaxial lift-off film-bonding process. PMID:11989702

Hohkawa, Kohji; Suda, Takaya; Aoki, Yusuke; Hong, Chulun; Kaneshiro, Chinami; Koh, Keishin

2002-04-01

52

Wideband low loss double mode SAW filters  

Microsoft Academic Search

A method is discussed for achieving a wideband low-loss longitudinally coupled double mode surface acoustic wave (SAW) (DMS) filter using a leaky SAW on a 36° Y-X LiTaO3 and 64° Y-X LiNbO3 substrate with a high electromechanical coupling factor. Its characteristics are analyzed by computer simulation. With the use of the first-mode and third-mode resonance on a 64° Y-X LiNbO3

Takao Morita; Y. Watanabe; M. Tanaka; Y. Nakazawa

1992-01-01

53

Passive Wireless SAW Sensors for IVHM  

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

54

Enhanced Magnetostrictively Transduced SAW Devices - Measurements & Applications  

NASA Astrophysics Data System (ADS)

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.

Woo, Noble C.

2005-03-01

55

Passive wireless SAW sensors for IVHM  

Microsoft Academic Search

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

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

2008-01-01

56

Direct Phase Noise Measurements of SAW Resonators  

Microsoft Academic Search

The most significant contribution of SAW resonators is in the frequency control of low phase noise oscillators at UHF frequencies. Techniques for measuring the phase noise of oscillators are well known, but the contribution to that phase noise of the frequency determining element is usually estimated or found by indirect methods. We present a method for directly measuring the phase

Scott S. Elliott; Robert C. Bray

1984-01-01

57

Surface acoustic waves and SAW materials  

Microsoft Academic Search

Material parameters necessary for optimum design of surface-acoustic-wave (SAW) devices are reviewed. Velocity, coupling coefficient, power flow angle, temperature coefficients, propagation loss (including air loading, diffraction, and beam steering), and equivalent circuit parameters are considered. A brief introduction to the nature of surface waves is followed by sufficient theoretical information to allow full understanding and derivation of the properties and

1976-01-01

58

A review of wireless SAW sensors  

Microsoft Academic Search

Wireless measurement systems with passive surface acoustic wave (SAW) sensors offer new and exciting perspectives for remote monitoring and control of moving parts, even in harsh environments. This review paper gives a comprehensive survey of the present state of the measurement systems and should help a designer to find the parameters required to achieve a specified accuracy or uncertainty of

Alfred Pohl

2000-01-01

59

Mixed orthogonal frequency coded SAW RFID tags.  

PubMed

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

Gallagher, Mark W; Malocha, Donald C

2013-03-01

60

Pure shear horizontal SAW biosensor on langasite  

Microsoft Academic Search

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

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

2004-01-01

61

Surface Acoustic Wave (SAW) Vibration Sensors  

PubMed Central

In the paper a feasibility study on the use of surface acoustic wave (SAW) vibration sensors for electronic warning systems is presented. The system is assembled from concatenated SAW vibration sensors based on a SAW delay line manufactured on a surface of a piezoelectric plate. Vibrations of the plate are transformed into electric signals that allow identification of the sensor and localization of a threat. The theoretical study of sensor vibrations leads us to the simple isotropic model with one degree of freedom. This model allowed an explicit description of the sensor plate movement and identification of the vibrating sensor. Analysis of frequency response of the ST-cut quartz sensor plate and a damping speed of its impulse response has been conducted. The analysis above was the basis to determine the ranges of parameters for vibrating plates to be useful in electronic warning systems. Generally, operation of electronic warning systems with SAW vibration sensors is based on the analysis of signal phase changes at the working frequency of delay line after being transmitted via two circuits of concatenated four-terminal networks. Frequencies of phase changes are equal to resonance frequencies of vibrating plates of sensors. The amplitude of these phase changes is proportional to the amplitude of vibrations of a sensor plate. Both pieces of information may be sent and recorded jointly by a simple electrical unit.

Filipiak, Jerzy; Solarz, Lech; Steczko, Grzegorz

2011-01-01

62

Ultra-Thin Carbon Fiber Wire Saw.  

National Technical Information Service (NTIS)

Researchers focused on the development of an ultra-thin bonded abrasive wire saw which would make it possible to slice large ingots of expensive brittle materials such as Si, GaAs, Ge, SiO2, with minimum kerf losses and would reduce wafering process-induc...

G. L. Thompson P. J. Fordenbacher R. M. Washburn U. Ortabasi

1989-01-01

63

Improved Multiple-DOF SAW Piezoelectric Motors  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

64

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

65

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

66

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

67

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

68

The Role of SAW Oscillators in Military Radar Systems  

Microsoft Academic Search

Surface Acoustic Wave (SAW) oscillators are beginning to find growing applications for military radar systems. This paper deals with the capability of SAW oscillators and the impact on system performance relative to meeting missile and radar requirements.

P. Pedi; J. Loan; E. McManus

1983-01-01

69

Gas sensors based on SAW narrow aperture devices  

Microsoft Academic Search

A new configuration of surface acoustic wave (SAW) gas sensors based on SAW waveguide devices with relatively narrow aperture of several wavelengths is suggested. This suggested configuration permits to impart to SAW sensor a new feature such as a certain electronic tuning of chemical selectivity (without sensitive coating) by applying electric voltage between this waveguide and two planar electrodes closely

Yu. V. Gulyaev; R. G. Kryshtal; A. V. Medved; V. V. Shemet; V. E. Zemlyakov

2000-01-01

70

Theory and application of passive SAW radio transponders as sensors  

Microsoft Academic Search

Surface acoustic wave (SAW) radio transponders make it possible to read identification codes or measurement values from a remote location. The decisive advantage of these SAW transponders lies in their passive operation (i.e., no power-supply), and in the possibility of wireless installation at particularly inaccessible locations. The passive SAW transponders are maintenance free. Identification marks respond to an interrogation signal

Leonhard Reindl; Gerd Scholl; Thomas Ostertag; Holger Scherr; U. Wolff; Frank Schmidt

1998-01-01

71

Vibration control of band saws: Theory and experiment  

Microsoft Academic Search

Active vibration control is a key to the improvement of the cutting performance and productivity of band saws. In this paper a new method is presented for active control of band saw vibration. The transfer function of a closed-loop system consisting of the band saw, a feedback control law and the dynamics of the sensing and force actuation devices is

B. Yang; C. D. Mote

1990-01-01

72

Wireless SAW sensors for surface and subsurface sensing applications  

Microsoft Academic Search

Surface acoustic wave (SAW) devices, used as filters or diplexers, are well established components in communications applications like in mobile handsets or television sets. The characteristics of SAW devices make them also well suitable for the application of wireless sensors or wireless identification tags. A great advantage of SAW sensors is their completely passive operation without the need for additional

Andreas Stelzer; Gernot Schimetta; Leonhard Reindl; Andreas Springer; Robert Weigel

2001-01-01

73

Mathematical modeling of curve sawing techniques for lumber industry  

Microsoft Academic Search

Curve sawing is a technique used more and more widely in lumber mills in order to obtain more commercially valuable pieces from a given log. It is important to understand and know this technique in order for it to be used optimally. This article deals with the mathematical modeling of curve sawing, so that a module pertaining to curve sawing

F. Hébert; F. Grondin; J. Plaice

2000-01-01

74

SAW devices for military communications, radar, and EW systems  

Microsoft Academic Search

A review of the principles and applications of surface acoustic wave (SAW) devices is presented. Most SAW devices have been developed for use in the VHF and UHF bands (30 to 1000 MHz), and are limited at low frequencies by the size and cost of the substrates and at high frequencies by photolithographic resolution. A primary feature of the SAW

C. S. Hartmann; R. J. Kansy; W. D. Daniels; B. R. Potter

1982-01-01

75

Design of miniaturized RF SAW duplexer package.  

PubMed

This paper provides a comprehensive methodology for accurate analysis and design of miniaturized radio frequency (RF) surface acoustic wave (SAW) duplexer package. Full-wave analysis based on the three dimensional (3-D) finite element method (FEM) is applied to get the package model. The die model is obtained by combining the parasitics and acoustics models. The modeling of bonding wire is also discussed. The models of package, die, and bonding wires are assembled together to get the total response. Based on this methodology, several novel ideas are proposed to significantly improve the isolation. Simulation and measurement results are compared, and excellent agreement is found. The technique developed in this paper reduces the design cycle time greatly and can be applied to various RF SAW device packages. PMID:15301004

Dong, Hao; Wu, Thomas X; Cheema, Kamran S; Abbott, Benjamin P; Finch, Craig A; Foo, Hanna

2004-07-01

76

Saw Palmetto for Benign Prostatic Hyperplasia  

Microsoft Academic Search

In this double-blind trial, we randomly assigned 225 men over the age of 49 years who had moderate-to-severe symptoms of benign prostatic hyperplasia to one year of treatment with saw palmetto extract (160 mg twice a day) or placebo. The pri- mary outcome measures were changes in the scores on the American Urological Association Symptom Index (AUASI) and the maximal

Stephen Bent; Christopher Kane; Katsuto Shinohara; John Neuhaus; Esther S. Hudes; Harley Goldberg; Andrew L. Avins

2006-01-01

77

Microsystem packaging of an RF SAW correlator.  

SciTech Connect

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.

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

2005-01-01

78

Design of withdrawal-weighted SAW filters.  

PubMed

This paper presents a new design algorithm for a withdrawal-weighted surface acoustic wave (SAW) transversal filter. The proposed algorithm is based on the effective transmission loss theory and a delta function model of a SAW transversal filter. The design process consists of three steps, which eventually determine eight geometrical design parameters for the filter in order to satisfy given performance specifications. First, the number of fingers in the input and output interdigital transducers (IDTs), plus their geometrical sizes is determined using the insertion loss specification. Second, the number and positions of the polarity reverses in the output IDT are determined using the bandwidth and ripple specifications. Third, the number and position for withdrawing and switching specific fingers in the output IDT and attached electrode area are determined to achieve the desired sidelobe level. The efficiency of the technique is illustrated using a sample design of an IF filter consisting of a uniform input IDT and withdrawal-weighted output IDT. The proposed algorithm is distinct from conventional techniques in that it can optimize the structural geometry of a withdrawal-weighted SAW filter in a direct manner by considering all the performance specifications simultaneously. PMID:12322883

Lee, Youngjin; Lee, Seunghee; Roh, Yongrae

2002-03-01

79

Coagulopathy induced by saw palmetto: a case report.  

PubMed

Saw palmetto is the most popular herbal supplement used to treat symptoms of benign prostatic hyperplasia (BPH). The safety and efficacy of saw palmetto has been established in the literature. While the majority of studies document the efficacy and safety of saw palmetto, some studies document the adverse side effects, including increased risk of bleeding. There are no reports in the literature about increased prothombin time (PT), partial thromboplastin time (PTT) or international normalized ratio (INR) while using saw palmetto. We present a case of hematuria and coagulopathy in a patient who was using saw palmetto. PMID:20120986

Villanueva, Salvador; González, Jenniffer

2009-01-01

80

Sawing performance comparison of brazed and sintered diamond wires  

NASA Astrophysics Data System (ADS)

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.

Huang, Guoqin; Xu, Xipeng

2013-03-01

81

Thermal Imaging of Medical Saw Blades and Guides  

SciTech Connect

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.

Dinwiddie, Ralph Barton [ORNL; Steffner, Thomas E [ORNL

2007-01-01

82

Noise reduction of a table saw  

NASA Astrophysics Data System (ADS)

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).

Carlson, John

2002-05-01

83

Diffraction correction for precision SAW velocity measurements  

NASA Astrophysics Data System (ADS)

Surface acoustic wave (SAW) dispersion measurements can be used to nondestructively characterize shot-peened, laser shock-peened, and other surface-treated specimens. In recent years, there have been numerous efforts to separate the contribution of surface roughness from those of near-surface material variations, such as residual stress, texture, and increased dislocation density. This talk addresses the problem that a perceivable dispersive effect, similar to the one found on rough shot-peened specimens, is exhibited by untreated smooth surfaces as well. The dispersion measurements were performed using laser-ultrasonic scanning combined with special digital signal-processing methods. The observed dispersion effect is on the order of 0.1%, which is comparable to the expected velocity change produced by near-surface compressive residual stresses in metals below their yield strength. The cause of this apparent dispersion is the diffraction of the SAW as it travels over the surface of the specimen. It is demonstrated that a diffraction correction may be introduced to increase the accuracy of surface wave dispersion measurements. A simple diffraction correction model was developed for surface waves; this correction was subsequently validated by laser-interferometric surface wave velocity measurements on 2024-T351 aluminum specimens.

Ruiz M., Alberto; Nagy, Peter B.

2002-05-01

84

Comparative performance of piezoceramic and crystal SAW filters.  

PubMed

Bulk elastic, piezoelectric, and dielectric constants of four lead zirconate titanate piezoceramics, Pz24, Pz26, Pz27, Pz28, and a modified lead titanate, PTS, are measured and used to theoretically compute the effective permittivity curve of each material from which the surface acoustic wave (SAW) properties are deduced. In parallel, experimental measurements of the SAW properties are carried out by using a curve fitting algorithm on the real and imaginary parts of the electrical input impedance of an unapodised single electrode SAW transducer. The SAW propagation losses are also measured using a SAW delay line. For these ceramics, the effects of a hot isostatic pressing (HIP) post sintering process on the performances of the device are also studied. All these results are discussed and show that ceramic materials, particularly PTS, have potential for SAW applications. PMID:18244117

Feuillard, G; Lethieccl, M; Janin, Y; Tessier, L; Pourcelot, L

1997-01-01

85

Current developments in SAW oscillator stability  

NASA Technical Reports Server (NTRS)

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.

Parker, T. E.

1977-01-01

86

A monolithic SAW-charge transfer device  

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

87

Discriminating neutrino see-saw models  

NASA Astrophysics Data System (ADS)

We consider how well current theories can predict neutrino mass and mixing parameters, and construct a statistical discriminator which allows us to compare different models to each other. As an example we consider see-saw models based on family symmetry, and single right-handed neutrino dominance, and compare them to each other and to the case of neutrino anarchy with random entries in the neutrino Yukawa and Majorana mass matrices. The predictions depend crucially on the range of the undetermined coefficients over which we scan, and we speculate on how future theories might lead to more precise predictions for the coefficients and hence for neutrino observables. Our results indicate how accurately neutrino masses and mixing angles need to be measured by future experiments in order to discriminate between current models.

Hirsch, M.; King, S. F.

2001-09-01

88

Extremely Low Phase Noise SAW Resonator Oscillator Design and Performance  

Microsoft Academic Search

SAW resonator designs with overnioded cavities. very wide apertures. dual apertures, etc.. as well as modified fabrication techniques. have been used to realize an overall reduction in an oscillator's phase noise spectrum. i.e.. white +M. flicker FM. and random walk FM. The incident RF power handling capability of these SAW resonator designs is in excess of +20 dBm. a key

G. K. Montress; T. E. Parker; M. J. Loboda

1987-01-01

89

PC software for SAW propagation in anisotropic multilayers  

Microsoft Academic Search

A software package that provides an interactive and graphical environment for surface acoustic wave (SAW) and plate-mode propagation studies in arbitrarily oriented anisotropic and piezoelectric multilayers is described. The software, which runs on an IBM PC with math coprocessor, is based on a transfer-matrix formulation for calculating the characteristics of SAW propagation in multilayers that was originally written for a

E. L. Adler; J. K. Slaboszewicz; G. W. Farnell; C. K. Jen

1990-01-01

90

Monitoring the tire pressure at cars using passive SAW sensors  

Microsoft Academic Search

In our paper we present the application of surface acoustic wave (SAW) sensors to the continuous monitoring of the tire pressure in road vehicles. With these, the tire pressure can be read out in every phase of driving. We show the implemented prototype setup for measurement of the tire pressure, the applied SAW sensors, improved versions and the interrogation setup.

Alfred Pohl; G. Ostermayer; L. Reindl; F. Seifert

1997-01-01

91

Inline SAW RFID tag using time position and phase encoding  

Microsoft Academic Search

Surface acoustic wave (SAW) radio-frequency identification (RFID) tags are encoded according to partial reflections of an interrogation signal by short metal reflectors. The standard encryption method involves time position encoding that uses time delays of response signals. However, the data capacity of a SAW RFID tag can be significantly enhanced by extracting additional phase information from the tag responses. In

Sanna Harma; Wesley G. Arthur; Clinton S. Hartmann; Roman G. Maev; Victor P. Plessky

2008-01-01

92

SAW Microsensor Brain Implant for Prediction and Monitoring of Seizures  

Microsoft Academic Search

An implantable surface acoustic wave (SAW) microsensor has been developed for early detection and monitoring of seizures based on local temperature changes in the brain's epileptogenic zones that occur prior to and during an epileptic event. Three SAW sensors were designed and fabricated: a 172 MHz filter, a 434 MHz filter, and a 434 MHz delay line. Their temperature sensitivities

Nachappa Gopalsami; Ivan Osorio; Stanislav Kulikov; Sergey Buyko; Andrey Martynov; Apostolos C. Raptis

2007-01-01

93

Wireless SAW sensors for surface and subsurface sensing applications  

NASA Astrophysics Data System (ADS)

Surface acoustic wave (SAW) devices, used as filters or diplexers, are well established components in communications applications like in mobile handsets or television sets. The characteristics of SAW devices make them also well suitable for the application of wireless sensors or wireless identification tags. A great advantage of SAW sensors is their completely passive operation without the need for additional power supplies. SAW sensors can be designed to sense several physical or chemical quantities like temperature, pressure, stress, or gas concentration. During operation of the wireless sensor the energy delivered from an RF pulse sent by an interrogation unit is picked up by the antenna, stored in the surface acoustic wave, modified by the sensor effect and is finally transmitted back to the interrogation unit. In this paper the basic operating principles of SAW devices are reviewed and two applications, a state-of-the-art tire pressure sensor and a moisture sensor, are presented.

Stelzer, Andreas; Schimetta, Gernot; Reindl, Leonhard; Springer, Andreas; Weigel, Robert

2001-11-01

94

See-saw geometry and leptogenesis  

NASA Astrophysics Data System (ADS)

The representation of the see-saw orthogonal matrix in the complex plane establishes a graphical correspondence between neutrino mass models and geometrical configurations, particularly useful to study relevant aspects of leptogenesis. We first derive the CP asymmetry bound for hierarchical heavy neutrinos and then an expression for the effective leptogenesis phase, determining the conditions for maximal phase and placing a lower bound on the phase suppression for generic models. Reconsidering the lower bounds on the lightest right-handed (RH) neutrino mass M and on the reheating temperature T, we find that models where one of the two heavier neutrino masses is dominated by the lightest right-handed (RH) neutrinos, typically arising from connections with quark masses, undergo both phase suppression and strong wash-out such that M(T)?10 (10) GeV. The window 10 GeV?M,T?10 GeV is accessible only for a class of models where m is dominated by the lightest RH neutrino, with no straightforward connections with quark masses. Within this class we describe a new scenario of thermal leptogenesis where the baryon asymmetry of the Universe is generated by the decays of the second lightest RH neutrino, such that the lower bound on M disappears and is replaced by a lower bound on M. Interestingly, the final asymmetry is independent on the initial conditions. We also discuss the validity of the approximation of hierarchical heavy neutrinos in a simple analytical way.

Di Bari, P.

2005-10-01

95

Acute pancreatitis with saw palmetto use: a case report  

PubMed Central

Introduction Saw palmetto is a phytotherapeutic agent commercially marketed for the treatment of benign prostatic hyperplasia. Evidence suggests that saw palmetto is a safe product, and mild gastrointestinal adverse effects have been reported with its use. We report a case of acute pancreatitis, possibly secondary to the use of saw palmetto. Case presentation A 61-year-old Caucasian man with a history of benign prostatic hyperplasia and gastroesophageal reflux disease developed epigastric pain associated with nausea 36 hours prior to presentation. He denied drinking alcohol prior to the development of his symptoms. His home medications included saw palmetto, lansoprazole and multivitamins. Laboratory results revealed elevated lipase and amylase levels. An abdominal ultrasound demonstrated a nondilated common bile duct, without choledocholithiasis. Computed tomography of his abdomen showed the pancreatic tail with peripancreatic inflammatory changes, consistent with acute pancreatitis. Our patient's condition improved with intravenous fluids and pain management. On the fourth day of hospitalization his pancreatic enzymes were within normal limits: he was discharged home and advised to avoid taking saw palmetto. Conclusion It is our opinion that a relationship between saw palmetto and the onset of acute pancreatitis is plausible, and prescribers and users of saw palmetto should be alert to the possibility of such adverse reactions.

2011-01-01

96

Reduction of sawing noise through constrained layer damping  

SciTech Connect

Understanding the need for noise control in sawing operations is intuitive in people who have heard the characteristic high pitched scream at the lumber yard, in their own workshop, or at a construction site. Saw noise is a distinctive sound that we remember even from long ago boyhood days. So it was no surprise when, in the USA, the Occupational Health and Safety Act included sawing noise among industrial noises that had to be controlled. This paper describes and discusses our experiments and results. Noise emanating from a cut was accumulated then reduced to an average.

Caldwell, D.B.

1982-01-01

97

ISS Asset Tracking Using SAW RFID Technology  

NASA Technical Reports Server (NTRS)

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.

Schellhase, Amy; Powers, Annie

2004-01-01

98

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

PubMed

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

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

2011-02-01

99

Anti-slipping system improves wire saw performance  

NASA Technical Reports Server (NTRS)

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.

Gallo, E. A.

1971-01-01

100

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

101

A Saw-Based Spread Spectrum Wireless Lan System  

Microsoft Academic Search

In Japan, the spread spectrum wireless LAN is prospected to be approved by February 1993. Utilizing a new type SAW device, we succeeded in developing the spread spectrum wireless LAN system. Its data ratio is a 230-kbps.

Kazuyuki TAKEHARA; Toshiyuki TANAKA; K. Okada; T. Tada

1992-01-01

102

Survey of Power Saw Accidents Resulting in Injuries, 1978.  

National Technical Information Service (NTIS)

The report presents results from a survey of power saw accidents in selected States, 1978. The report includes descriptions of the accidents and characteristics of the injured such as occupation, age, and sex.

H. Schaffer

1983-01-01

103

DNA barcode authentication of saw palmetto herbal dietary supplements.  

PubMed

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

Little, Damon P; Jeanson, Marc L

2013-01-01

104

Surface acoustic wave (SAW) acoustophoresis: now and beyond.  

PubMed

On-chip manipulation of micro-objects has long been sought to facilitate fundamental biological studies and point-of-care diagnostic systems. In recent years, research on surface acoustic wave (SAW) based micro-object manipulation (i.e., SAW acoustophoresis) has gained significant momentum due to its many advantages, such as non-invasiveness, versatility, simple fabrication, easy operation, and convenient integration with other on-chip units. SAW acoustophoresis is especially useful for lab-on-a-chip applications where a compact and non-invasive biomanipulation technique is highly desired. In this Focus article, we discuss recent advancements in SAW acoustophoresis and provide some perspectives on the future development of this dynamic field. PMID:22781941

Lin, Sz-Chin Steven; Mao, Xiaole; Huang, Tony Jun

2012-08-21

105

A new generalized modeling of SAW transducers and gratings  

Microsoft Academic Search

A general coupling-of-modes analysis of SAW transducers and gratings is presented. The analysis is applicable to the complete continuum of SAW devices, from transducers with or without internal reflections to grating reflectors comprised of grooves or metallic stripes. The analysis incorporates several important phenomena not previously included in analyses of this type. Both the effects of finite-electrode resistivity and spatially

P. V. Wright

1989-01-01

106

Point-of-care SH-SAW biosensor  

Microsoft Academic Search

This paper describes a two-channel liquid-phase shear horizontal surface acoustic wave (SH-SAW) immunoassay biosensor. The sensor device was designed using a 250MHz SH- SAW delay-line on Quartz substrates, which is composed of a transmitting and receiving transducers and a biochemical reaction area in between them. Those transducers are protected from liquids by a glass lid and epoxy walls which are

Mikihiro Goto; Osamu Iijima; Takashi Kogai; Hiromi Yatsuda

2010-01-01

107

See-saw nystagmus and brainstem infarction: MRI findings  

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

108

``Buzz-saw'' noise: A comparison of measurement with prediction  

Microsoft Academic Search

Accurate prediction of ``buzz-saw'' noise in a turbofan inlet duct necessitates consideration of nonlinear acoustics, modelling a complete fan blade set, modelling an acoustic liner, and calculations at high frequencies. A recent series of papers has described new work concerning the application of one-dimensional propagation models to the prediction of buzz-saw noise. A numerical model, termed the frequency domain numerical

A. McAlpine; M. J. Fisher; B. J. Tester

2006-01-01

109

“Buzz-saw” noise: A comparison of measurement with prediction  

Microsoft Academic Search

Accurate prediction of “buzz-saw” noise in a turbofan inlet duct necessitates consideration of nonlinear acoustics, modelling a complete fan blade set, modelling an acoustic liner, and calculations at high frequencies. A recent series of papers has described new work concerning the application of one-dimensional propagation models to the prediction of buzz-saw noise. A numerical model, termed the frequency domain numerical

A. McAlpine; M. J. Fisher; B. J. Tester

2006-01-01

110

Development of the RF SAW filters based on PCB substrate  

Microsoft Academic Search

Recently produced RF SAW (surface acoustic wave) filters are made using HTCC (high temperature cofired ceramic) with CSP (chip scale package) technology. This paper describes the development of a new 1.4 times 1.1 and 2.0 times 1.4 mm RF SAW filter based on PCB (printed circuit board) substrate instead of HTCC package, which reduces the cost of materials by 40%.

Youngjin Lee; Jongin Im; Seunghee Lee

2006-01-01

111

Magnetic moments in the see-saw model  

Microsoft Academic Search

We study the transition magnetic moments of Majorana neutrinos in the two-generation see-saw model. The stability of the neutrino mass matrix under the radiative corrections induced by the transition couplings gives an important constraint. We show that in the see-saw model there is an unexpected enhancement of the transition magnetic moment of the electron neutrino nue. It is, however, far

K. Enqvist; J. Maalampi; A. Masiero

1989-01-01

112

Oblique ulnar shortening osteotomy by a single saw cut.  

PubMed

Ulnar shortening osteotomy is an effective treatment in patients with ulnar impaction syndrome. Accurate shortening and bony apposition can be obtained for a wide range of shortening lengths with a single-cut osteotomy technique. The saw kef produced by a single saw pass cuts a bony defect with parallel walls. The amount of shortening produced by using standard power bone saws can be increased by stacking as many as three blades together on the saw and by varying the angle at which the cut is made. The amount of shortening is a function of the angle at which the cut is made. The amount of shortening can be increased by a factor of twice the saw kerf if the cut is made at 60 degrees. We tabulated the shortening expected from over 100 combinations of power saw blades and cut angles. Using a series of experimental osteotomies, we demonstrated that the single-cut technique produces a more predictable amount of shortening than the technique of using two parallel cuts to remove a cuff of bone. The single-cut technique is useful for shortening any long bone. PMID:8775195

Labosky, D A; Waggy, C A

1996-01-01

113

“Buzz-saw” noise: A comparison of measurement with prediction  

NASA Astrophysics Data System (ADS)

Accurate prediction of "buzz-saw" noise in a turbofan inlet duct necessitates consideration of nonlinear acoustics, modelling a complete fan blade set, modelling an acoustic liner, and calculations at high frequencies. A recent series of papers has described new work concerning the application of one-dimensional propagation models to the prediction of buzz-saw noise. A numerical model, termed the frequency domain numerical solution or FDNS, has been developed. It can be used to calculate the nonlinear propagation of the rotor-alone pressure field in either a rigid or acoustically-lined inlet duct. From this the in-duct noise level of the buzz-saw tones can be determined. In previous work, validation of this method by comparison with in-duct noise measurements has been limited to rigid inlet ducts, because of the lack of availability of suitable measurements from lined ducts. In this article new measurements of buzz-saw noise in an acoustically-lined inlet duct are utilized. A comparison of measurements of buzz-saw noise in a lined inlet duct, and noise predictions from numerical simulations by the FDNS is presented. The detailed measurements reveal the effect of an acoustic liner on buzz-saw noise. The suitability of the numerical model to be used to provide realistic noise predictions for supersonic ducted fans is also examined.

McAlpine, A.; Fisher, M. J.; Tester, B. J.

2006-03-01

114

Notes on SAW Tag Interrogation Techniques  

NASA Technical Reports Server (NTRS)

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.

Barton, Richard J.

2010-01-01

115

Diamond Wire Saw for Precision Machining of Laser Target Components  

SciTech Connect

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.

Bono, M J; Bennett, D W

2005-08-08

116

Power Consumption and Lumber Yields for Reduced-Kerf Circular Saws Cutting Hardwoods..  

National Technical Information Service (NTIS)

A 9x10 gage, 1/4-inch kerf saw and a 7x8 gage, 9/32-inch kerf saw were used for cutting matched samples of hardwood cants and bolts into pallet parts. The 1/4-inch kerf saw consumed about 15 percent less power than the 1/4-inch kerf saw. Product yield for...

D. G. Cuppett

1982-01-01

117

Theoretical study on SAW characteristics of layered structures including a diamond layer  

Microsoft Academic Search

Diamond has the highest surface acoustic wave (SAW) velocity among all materials and thus can provide much advantage for fabrication of high frequency SAW devices when it is combined with a piezoelectric thin film. Basic SAW properties of layered structures consisting of a piezoelectric material layer, a diamond layer and a substrate were examined by theoretical calculation. Rayleigh mode SAW's

Hideaki Nakahata; Akihiro Hachigo; Kenjiro Higaki; Satoshi Fujii; Shin-ichi Shikata; Naoji Fujimori

1995-01-01

118

A possible case of saw palmetto-induced pancreatitis.  

PubMed

A 65-year-old male with a history of diabetes, hypertension, hyperlipidemia, gout, Barrett esophagitis, and chronic gastritis developed acute pancreatitis after taking one week of the herbal medicine, saw palmetto, for symptoms related to benign prostatic hyperplasia (BPH). Ultrasound and computed tomography ruled out cholelithiasis and obstruction, triglycerides were normal, and he had no recent infection or trauma. He had a history of occasional alcohol consumption, though there was no recent increased intake. The most likely cause of pancreatitis in this case was saw palmetto. Saw palmetto (Serenoa repens) is an herbal medication used primarily in the treatment of symptoms related to BPH. It has a high content of fatty acids and phytosterols which are thought to exert their effects by inhibiting the enzyme 5-alpha-reductase, thereby preventing the conversion of testosterone into dihydrotestosterone (DHT). It has been postulated that saw palmetto directly stimulates estrogenic receptors and inhibits progesterone receptors in the prostate tissue. A previous report implicated the estrogen/antiandrogen properties of saw palmetto as inducing hepatotoxicity in a patient. Additionally, it has also been postulated that stimulation of the estrogenic receptors may lead to increased triglyceride levels or induction of a hypercoagulable state that leads to pancreatic necrosis. Finally, inhibition of cyclooxygenase, a property of saw palmetto, may be linked to acute pancreatitis. Acute pancreatitis, a serious and sometimes fatal disorder may occur secondary to medications. Although the mechanism is not fully known, this is the second case of acute pancreatitis that has been documented secondary to the herbal medication saw palmetto. It is important for clinicians to obtain detailed medication histories, including over-the-counter and herbal medications, in order to prevent further complications from occurring. PMID:20531057

Wargo, Kurt A; Allman, Elena; Ibrahim, Farrah

2010-07-01

119

Tip stabilizer for a chain saw. Final report  

SciTech Connect

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.

Morabit, V.D.

1993-09-10

120

Visualization of laser-generated SAW beams by shake-off of fine particles  

Microsoft Academic Search

Shake-off of micron-sized alumina particles by nanosecond laser-generated SAW pulses is used to visualize SAW propagation on the surfaces of semiconductor crystals. Different phenomena in SAW propagation such as reflection from an edge, deviation of a SAW beam from the phase velocity direction and anisotropic diffraction are demonstrated. SAW focusing on the (001) surface of GaAs is studied

A. A. Kolomenskii; A. A. MaznevZ

1994-01-01

121

Effect of lubricant environment on saw damage in silicon wafers  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

122

A high sensitivity nanomaterial based SAW humidity sensor  

NASA Astrophysics Data System (ADS)

In this paper, a highly sensitive humidity sensor is reported. The humidity sensor is configured by a 128°YX-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.

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

2008-04-01

123

Inline SAW RFID tag using time position and phase encoding.  

PubMed

Surface acoustic wave (SAW) radio-frequency identification (RFID) tags are encoded according to partial reflections of an interrogation signal by short metal reflectors. The standard encryption method involves time position encoding that uses time delays of response signals. However, the data capacity of a SAW RFID tag can be significantly enhanced by extracting additional phase information from the tag responses. In this work, we have designed, using FEM-BEM simulations, and fabricated, on 128 degrees -LiNbO3, inline 2.44-GHz SAW RFID tag samples that combine time position and phase encoding. Each reflective echo has 4 possible time positions and a phase of 0 degrees , -90 degrees , -180 degrees , or -270 degrees. This corresponds to 16 different states, i.e., 4 bits of data, per code reflector. In addition to the enhanced data capacity, our samples also exhibit a low loss level of -38 dB for code reflections. PMID:18986926

Härmä, Sanna; Arthur, Wesley G; Hartmann, Clinton S; Maev, Roman G; Plessky, Victor P

2008-08-01

124

Coupling forces resulting from the type of chain saw used.  

PubMed

Introduction. Woodcutters' working conditions are difficult due to the presence of numerous occupational hazards. Petrol -fuelled chain saws commonly used in forestry produce vibration, which may lead to the development of non-specific disorders in the upper extremities of the chain saw operator, referred to as hand-arm vibration syndrome (HAVS). The magnitude of coupling forces exerted on a vibrating tool handle may affect the severity of HAVS and hand-wrist cumulative trauma disorders. The aim of the presented study was to measure coupling forces exerted by fellers on various chain saws and to find correlation between force magnitude and type of tool used. Material and methods. Coupling forces applied by workers on different types of chain saws were measured by means of a hydro-electronic force meter. All measurements were carried out during the harvesting of wood in real work conditions. Results. Mean force applied by forestry workers on their tools was 44.2 N. Coupling forces registered during cutting wood with small universal chain saws were larger than forces exerted on models characterized by higher power profile. Forces applied on comparable tools produced by various manufacturers also differed. Conclusions. The relationship between coupling forces and power of the chain saw should lead to ergonomic improvements of the tool and vibration-reducing devices. These results can also be used as a recommendation for fellers in a range of using proper machines for different types of cut or types of wood. They may also be applicable to develop more effective methods for assessing vibration exposure risks among woodcutters. PMID:24738519

Malinowska-Borowska, Jolanta

2014-03-31

125

C-SAW: Consortium for Scientific Assistance to Watersheds  

NSDL National Science Digital Library

"The goal for C-SAW is to transfer knowledge and skills to watershed groups or local sponsors thereby helping to build their capacity to plan and conduct watershed assessments, and conduct post-implementation monitoring." Users can learn about the technical assistance provided by C-SAW, including watershed specific assistance, mentoring, and water quality education available to eligible groups in the state of Pennsylvania. Visitors can find the necessary materials to apply for this opportunity. The website also offers links to the program's many partners and other watershed resources and assistance.

126

A surface acoustic wave /SAW/ charge transfer imager  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

127

Modular two-dimensional analysis of SAW filters. I. Theory.  

PubMed

An accurate simulation tool to meet the stringent requirements for broadband surface-acoustic-wave (SAW) filters is described. The primary goal was to develop a modular software tool in which first- and second-order effects can be easily modeled as separate modules providing an overall high-precision model for SAW devices. The model takes into account surface wave diffraction and refraction, quasi-two-dimensional static charge distribution, metal resistance and external load impedances. The angular spectrum of waves formalism is interpreted in such a way as to render possible the simultaneous description of all effects mentioned. A sample of the results is given for the potential distribution. PMID:18263120

Visintini, G; Baghai-Wadji, A R; Manner, O

1992-01-01

128

Magnetic moments in the see-saw model  

NASA Astrophysics Data System (ADS)

We study the transition magnetic moments of Majorana neutrinos in the two-generation see-saw model. The stability of the neutrino mass matrix under the radiative corrections induced by the transition couplings gives an important constraint. We show that in the see-saw model there is an unexpected enhancement of the transition magnetic moment of the electron neutrino ?e. It is, however, far too small to explain the solar neutrino deficiency problem by the helicity flip transition of ?e in the magnetic field of the sun.

Enqvist, K.; Maalampi, J.; Masiero, A.

1989-05-01

129

A Comparison of SAW Wrap-Around Delay Line Geometries.  

National Technical Information Service (NTIS)

In order to realize long UHF/delays in small packages, it is convenient to use wrap-around surface acoustic wave (SAW) devices. The use of slow velocity (typically 1680 m/sec) bismuth germanium oxide (BGO) further reduces size. In the present paper, three...

A. J. Slobodnik W. J. Kearns J. H. Silva T. F. Fenstermacher

1974-01-01

130

Low-cost surface mount packaging for SAWs  

Microsoft Academic Search

The special challenges of surface mount technology as they apply to the surface acoustic wave (SAW) manufacturer are reviewed. Some possible solutions are offered. The effects of each of the problem areas on the choice of package technology are considered. The technology options include ceramic bases (solder, epoxy, resistance welded, or glass frit sealed), plastic (epoxy sealed), and quartz (glass

J. Gore; B. Horine; J. Phillips; R. Hoffman; J. Dodge

1992-01-01

131

Orthogonal Frequency Coded SAW Sensors for Aerospace SHM Applications  

Microsoft Academic Search

National Aeronautics and Space Administration (NASA) aeronautical programs require structural health monitoring (SHM) to ensure the safety of the crew and the vehicles. Future SHM sensors need to be small, lightweight, inexpensive, and wireless. Orthogonal frequency coded (OFC) surface acoustic wave (SAW) reflectors and transducers have been recently introduced for use in communication, as well as in sensor and radio-frequency

W. C. Wilson; D. C. Malocha; N. Kozlovski; D. R. Gallagher; B. Fisher; J. Pavlina; N. Saldanha; D. Puccio; G. M. Atkinson

2009-01-01

132

Innleggingsnoyaktighet i Sagmaskiner (Feeding Accuracy into Sawing Machines).  

National Technical Information Service (NTIS)

The task of this survey was to measure the feeding accuracy into the sawing machines in relation to the geometry of the log. Seven sawmills took part in this survey and the testing was done on 151 logs. The mills' ability to position the log in the canter...

A. Ovrum

2001-01-01

133

Rigorous analysis of finite SAW devices with arbitrary electrode geometries  

Microsoft Academic Search

This paper proposes a rigorous numerical model allowing the analysis of finite SAW filters with only the 2D approximation: all the acoustical and electrical interactions are taken into account as well as mass loading effects. Areas outside the interdigital transducers can be either free surface or fully metallized: in the first case, a charge distribution formulation is used while, in

Pascal Ventura; Jean Michel Hode; Bruno Lopes

1995-01-01

134

A general Green function analysis for SAW devices  

Microsoft Academic Search

Methods for calculating Green functions that can fully characterize the properties of a SAW substrate with respect to both mechanical and electrical excitation are described. The Green function is initially represented as a 4×4 matrix of functions in k (wavenumber) space; it describes the three surface displacement components and the electrical potential in terms of the three surface stress components

R. C. Peach

1995-01-01

135

Suppressing buzz-saw noise in jet engines  

NASA Technical Reports Server (NTRS)

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.

Maestrello, L.

1980-01-01

136

Quartz pressure sensor based on SAW reflective delay line  

Microsoft Academic Search

We have developed a wireless SAW (Surface Acoustic Wave) pressure sensor operating in the pressure range from 0 Pa to 250 kPa. In order to minimize the temperature sensitivity the pressure sensor is based on an all quartz package, which has been designed with the Finite Element Method. The package of the pressure sensor consists of a diaphragm and a

H. Scherr; Gerd Scholl; Franz Seifert; R. Weigel

1996-01-01

137

A global SAW ID tag with large data capacity  

Microsoft Academic Search

The Global SAW Tag uses a recently-invented digital modulation based on simultaneous time position and phase shifting. A unique feature of this tag is that it satisfies global RFID requirements using the international 2.44 GHz ISM band. Precision amplitude and phase weighting of reflectors and accurate control of parasitic effects is critical to implementing this device. This tag has significantly

Clinton S. Hartmann

2002-01-01

138

Overview of design challenges for single phase unidirectional SAW filters  

Microsoft Academic Search

A comprehensive discussion of the design synthesis challenges for single-phase unidirectional transducers (SPUDTs) is presented. The complexity of SPUDT filter design results from the fact that a SPUDT deliberately includes reflections internal to the transducer to cancel the effects of regeneration reflection. This destroys the validity of the impulse-response model which is the basis for all conventional SAW (surface acoustic

C. S. Hartmann; B. P. Abbott

1989-01-01

139

Stellite Tipping of Saws for Cutting Softwood Lumber.  

National Technical Information Service (NTIS)

The report presents the results of two studies. The first study investigated the effectiveness of four wear-resistant alloys - Stellite 12 and 20, Deloro Alloy 50 and 60 - in reducing saw-tooth dulling in cutting unseasoned western red cedar. All four all...

E. Kirbach T. Bonac

1981-01-01

140

Study on Reducing Leachate Production by Saw Powder Adding  

Microsoft Academic Search

In order to study the effect of saw powder on reducing leachate production, accelerating degradation of rubbish, COD and NH3-N concentration of leachate, three cylinder reactors for anaerobic landfill disposal were built to simulate the operation of landfill. In the experiment, leachate quantity, settling height of rubbish layer, COD and NH3-N concentration were monitored. The results come from experiment data

Yin Jun; Jiang Baojun; Wu Xiaoyan; Liang Liang; Liu Xue

2009-01-01

141

Developments in Low Loss, Low Ripple SAW Filters.  

National Technical Information Service (NTIS)

SAW filters are often required by systems to possess low loss, low passband ripple and high out-of-band ejection properties simultaneously. This paper describes two recent developments in the design of such low loss filters. In the first approach, three b...

K. H. Yen K. F. Lau R. B. Stokes A. M. Kong R. S. Kagiwada

1982-01-01

142

SAW (Surface Acoustic Wave) Chemosensor. Second Progress Report,  

National Technical Information Service (NTIS)

The report deals with progress in the development of Surface Acoustic Wave(SAW) gas sensors to be applied both in the civil and military field. Part 2 describes a gas sensor for NO2, covering different metallophthalocyanines as chemical interface, effects...

M. S. Nieuwenhuizen L. P. A. de Jong

1987-01-01

143

Circular and Frame Saw Performance: A Literature Review with Abstracts and Brief Evaluations.  

National Technical Information Service (NTIS)

A survey of literature dealing with the operation and performance of circular and frame saws was carried out. The large number of publications was sorted into subjects such as saw specification, performance, sawn finish, blunting, etc., separately for cir...

D. T. Priest

1983-01-01

144

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

Federal Register 2010, 2011, 2012, 2013

...CPSC-2011-0074] Table Saw Blade Contact Injuries; Notice of Extension of Time...injury associated with table saw blade contact, regulatory alternatives, other possible...including any personal identifiers, contact information, or other personal...

2011-12-02

145

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

Federal Register 2010, 2011, 2012, 2013

...CPSC-2011-0074] Table Saw Blade Contact Injuries; Reopening of the Comment Period...injury associated with table saw blade contact, regulatory alternatives, other possible...including any personal identifiers, contact information, or other personal...

2012-02-15

146

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

NASA Technical Reports Server (NTRS)

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.

Danicki, E.; Hunt, W. D.

1995-01-01

147

3D finite element modeling of real size SAW devices and experimental validation  

Microsoft Academic Search

We report on several successful examples of using finite elements based software package for modeling SAW structures with dimensions above 100 wavelengths in the propagation direction including all the electrodes and spaces. The approach easily incorporates additional layers and elements with arbitrary 3D shapes that are common in SAW devices. Temperature behavior of the frequency response, SAW beam shape, bulk

S. Zhgoon; D. Tsimbal; A. Shvetsov; K. Bhattacharjee

2008-01-01

148

SAW velocity measurement of crystals and thin films by the phase velocity scanning of interference fringes  

Microsoft Academic Search

We present principle and application of a novel noncontact velocity measurement of surface acoustic waves (SAW) on crystals and thin films using laser interference fringes scanned at the phase velocity of SAW. The scanning interference fringes (SIF) are produced by intersecting two laser beams with a frequency difference. The SAW velocity within the laser beam spot is measured as the

Kazushi Yamanaka; Yoshihiko Nagata; Shizuka Nakano; Toshio Koda; Hideo Nishino; Yusuke Tsukahara; Hideo Cho; Masatoshi Inaba; Akinobu Satoh

1995-01-01

149

A novel FEA simulation model for RFID SAW tag.  

PubMed

Based on finite element analysis, we propose a simulation model for radio frequency identification (RFID) SAW tag devices. Electric properties of metal electrode on substrate greatly affect the characteristics of the device and are discussed in the paper. Then the right and left boundary conditions for the device are applied to remove large unwanted waves generated by wave propagation near the boundaries. To save computation time, a 2-D model is proposed, where some mesh skills are applied. The tag device is simulated in 2 steps. First, we use modal analysis to get the device phase velocity and harmonic frequency. Second, a tag with multireflectors is simulated. Based on the simulations, we have designed and fabricated a SAW tag. A comparison is made between simulation and experimental results and shows our simulation model agrees with the experiment very well. PMID:19686991

Peng, Dasong; Yu, Fengqi

2009-08-01

150

Passive hybrid sensing tag with flexible substrate saw device  

DOEpatents

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.

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

2012-12-25

151

Single crystal growth of potassium lithium niobate for SAW applications  

NASA Astrophysics Data System (ADS)

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.

Neurgaonkar, R. R.

1982-10-01

152

A Blocker Filtering Technique for SAW-Less Wireless Receivers  

Microsoft Academic Search

An active filtering technique to remove the out-of-band blockers in wireless receivers is presented. The circuit employs a feed-forward filtering path to produce an arbitrarily narrow frequency response in the low-noise amplifier (LNA), eliminating the need for an external surface acoustic wave (SAW) filter at the receiver front-end. The required notch filtering in the feed-forward path is realized through a

Hooman Darabi

2007-01-01

153

High Performance SAW Resonator Filters for SATELLITE Use  

Microsoft Academic Search

We have developed a surface a coustic wave resonator n oise suppression filter for use in a low-noise earth-satellite frequency source. This narrowband 500 MHz filter was selected for satellite application because a complex phase-locked loop system is the only other way to achieve the required n oise performance. Also, the SAW device is small in size, has low insertion

William J. Tanski; Martin Block; Alfred Vulcan

1980-01-01

154

Characterization and Qualification of a Precision Diamond Saw  

SciTech Connect

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.

Morgenstern, H.A.

1999-03-04

155

Palladium Nanowire Hydrogen Sensor Based on a SAW Transducer  

Microsoft Academic Search

Palladium (Pd) nano-wires were synthesized by electro chemical deposition technique. Pd nano-wires were transferred onto a ZnO\\/36° LiTaO3 Surface Acoustic Wave (SAW) transducer with an approximate operating frequency of 100 MHz. This operational frequency approximately corresponds to the device's highest conductometric sensitivity. These devices were investigated for hydrogen (H2) sensing at the room temperature. It was observed that the device

Massood Z. Atashbar; Kourosh Kalantar-zadeh; Samual J. Ippolitto

2009-01-01

156

BAW and SAW sensors for in-situ analysis  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

157

Modelling Sawing of Metal Tubes Through FEM Simulation  

NASA Astrophysics Data System (ADS)

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.

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

2011-05-01

158

A SAW resonator with two-dimensional reflectors.  

PubMed

It is known that a part of the loss of leaky SAW resonators is due to radiation of acoustic energy in the bus-bars. Many researchers are working on so-called phononic crystals. A 2-D grating of very strong reflectors allows these devices to fully reflect, for a given frequency band, any incoming wave. A new device based on the superposition of a regular SAW resonator and a 2-D periodic grating of reflectors is proposed. Several arrangements and geometries of the reflectors were studied and compared experimentally on 48 degrees rotated Y-cut lithium tantalate. In particular, a very narrow aperture (7.5 lambda) resonator was manufactured in the 900 MHz range. Because of its small size, this resonator has a resonance Q of only 575 when using the standard technology, whereas a resonance Q of 1100 was obtained for the new device without degradation of the other characteristics. Because of the narrow aperture, the admittance of the standard resonator showed a very strong parasitic above the resonance frequency, whereas this effect is drastically reduced for the new device. These results demonstrate the feasibility of the new approach. PMID:20040423

Solal, Marc; Gratier, Julien; Kook, Taeho

2010-01-01

159

Silicon sawing waste treatment by electrophoresis and gravitational settling.  

PubMed

In silicon wafer manufacturing for solar cells, a great amount of hazardous sawing waste with tiny Si particles is produced, resulting in serious environmental problems. Recycling Si and abrasives from the waste is regarded as an effective solution. Based on the view of recycling, Al(2)O(3) might be good abrasives for cutting Si ingot due to its larger density and higher isoelectric point than SiC. This study reports the separation of Si/SiC and Si/Al(2)O(3) mixtures by electrophoresis and gravitational settling. At pH 9, nearly uncharged Al(2)O(3) settled quickly and the negatively charged Si moved toward the anode, leading to an obvious Si distribution on the cell bottom. The experimental results show the separation performance of Si and Al(2)O(3) at pH 9 was better than at pH 2.5, and the performance was higher than that between Si and SiC. The minimum and maximum Al(2)O(3) contents remaining in Si/Al(2)O(3) mixture were 9 wt% and 90 wt% after applying 1 V/cm for 24h at pH 9. The recovered material with high Si content can be considered as a new Si source for solar cell, and the abrasives can be reused in the sawing process. PMID:21402439

Tsai, Tzu-Hsuan

2011-05-15

160

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

PubMed Central

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.

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

2013-01-01

161

Mixed Modeling of a SAW Delay Line Using VHDL-AMS  

NASA Technical Reports Server (NTRS)

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.

Wilson, William C.; Atkinson, Gary M.

2006-01-01

162

The development of a first pass verification module for a SAW filter design automation system  

Microsoft Academic Search

The continuing developments of a non-interactive surface acoustic wave (SAW) filter design automation system, called SAWCOM, are presented. An automation system has been developed by S.M. Richie and D.C. Malocha (1989) for the design and analysis of SAW bidirectional transducers and filters. All dominant SAW acoustic and electrical effects have been modeled for non-reflecting transducers in a modular architecture. Synthesis

M. J. McCollister; S. M. Richie

1991-01-01

163

``Buzz-saw'' noise: A comparison of modal measurements with an improved prediction method  

Microsoft Academic Search

``Buzz-saw'' noise is radiated from a turbofan inlet duct when the fan tip speed is supersonic. In a recent article the effect of an acoustic liner on buzz-saw noise has been examined. Spectral measurements in a rigid and an acoustically lined inlet duct have been compared. Also these measurements have been utilized to assess a buzz-saw noise prediction method. The

A. McAlpine; M. J. Fisher; B. J. Tester

2007-01-01

164

“Buzz-saw” noise: A comparison of modal measurements with an improved prediction method  

Microsoft Academic Search

“Buzz-saw” noise is radiated from a turbofan inlet duct when the fan tip speed is supersonic. In a recent article the effect of an acoustic liner on buzz-saw noise has been examined. Spectral measurements in a rigid and an acoustically lined inlet duct have been compared. Also these measurements have been utilized to assess a buzz-saw noise prediction method. The

A. McAlpine; M. J. Fisher; B. J. Tester

2007-01-01

165

Graphitized Layer Buried in a Diamond: SAW Generation under Picosecond Optical Excitation  

NASA Astrophysics Data System (ADS)

The excitation of SAW was detected on diamond with built-in ion-implanted graphitized layer under its illumination with femtosecond laser pulses. The spectral width of a SAW pulses were in the range of 1.5÷2 GHz. It was found out that the anisotropy of the SAW propagation was practically absent. The increase in the implantation dose from 4·1015 cm?2 to 12·1015 cm?2 was shown to give rise to a dispersion of SAW propagation.

Klokov, A.; Tsvetkov, V.; Sharkov, A.; Aminev, D.; Khmelnitskiy, R.

2014-06-01

166

Effect of anisotropy on characteristics and behavior of shear horizontal SAWs in resonators using langasite.  

PubMed

Orientations of langasite (LGS) with Euler angles (0°, ?, 90°) are potentially useful for applications in wireless SAW sensors because of wide variation of their temperature coefficient of frequency (TCF), between -50 and +50 ppm/°C, combined with high values of electromechanical coupling coefficient, especially if thick electrodes are utilized. The nature and characteristics of shear-horizontally polarized SAWs (SHSAWs) propagating in these orientations are investigated using a combination of numerical techniques: analysis of the BAW slowness surface and its effect on the SH-SAW structure; visualization of displacements that follow wave propagation in the grating; calculation of admittance of infinite periodic gratings; and analysis of SAW dispersion in the gratings, including possible interaction between SH-SAWs and parasitic Rayleigh SAWs. The characteristics of SH-SAWs propagating in symmetric cuts (velocities, localization depth, electromechanical coupling, etc.) are supplemented by analysis of propagation directions deviating from the YZ-plane toward the x-axis of LGS, for the temperature compensated cut with Euler angles (0°, 22°, 90°) and one more orientation for comparison. This extended analysis reveals that in actual devices, the anisotropy may be a reason for strong interaction between SH-SAWs and parasitic Rayleigh SAWs and cause degradation of the device's performance. PMID:23192815

Naumenko, Natalya F

2012-11-01

167

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

PubMed

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

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

2008-03-01

168

[A case of open head injury caused by electric saw].  

PubMed

A rare case of traumatic injury caused by an electric saw is herein described. A 75-year-old male patient was admitted to our hospital as an emergency patient. At the time of the patient's admission, he was fully conscious with no neurological deficits. Computed tomography revealed an intracerebral hematoma in the right frontal lobe, traumatic subarachnoid hemorrhage and pneumocephalus. Emergency surgery was performed at 4 hours 30 minutes after the injury. After a right frontal craniectomy, the intracerebral hematoma was completely evacuated. We applied sufficient debridement. The patient had neither intracranial infection nor vascular injury. We believe that the early operation for the sake of safety was therefore effective for this patient. PMID:21628742

Koizumi, Hiroyuki; Miyasaka, Yoshio; Tanaka, Chihiko; Fujii, Kiyotaka

2011-06-01

169

Investigation of crossed SAW fields by scanning acoustic force microscopy.  

PubMed

We used multimode scanning acoustic force microscopy (SAFM) for studying noncollinearly propagating Rayleigh and Love wave fields. By analyzing torsion and bending movement of SAFM cantilever, normal and in-plane wave oscillation components are accessible. The SAFM principle is the down-conversion of surface oscillations into cantilever vibrations caused by the nonlinearity of the tip-sample interaction. Through mixing of complementary oscillation components, phase velocities of crossed Rayleigh waves on GaAs and crossed Rayleigh and Love waves on the layered system SiO2/ST-cut quartz were obtained simultaneously. Now, it is possible to investigate elastic properties of submicron areas through multimode SAFM measurements. Finally, we present mixing experiments of four SAWs on GaAs and discuss the various influences on the measured SAFM amplitude and phase contrast. PMID:11477772

Behme, G; Hesjedal, T

2001-07-01

170

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

Microsoft Academic Search

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

Alfred Pohl; Gerald Ostermayer; Franz Seifert

1998-01-01

171

SAW1 is required for SDSA double-strand break repair in S. cerevisiae.  

PubMed

SAW1, coding for Saw1, is required for single-strand annealing (SSA) DNA double-strand break (DSB) repair in Saccharomycescerevisiae. Saw1 physically associates with Rad1 and Rad52 and recruits the Rad1-Rad10 endonuclease. Herein we show by fluorescence microscopy that SAW1 is similarly required for recruitment of Rad10 to sites of Synthesis-Dependent Strand Annealing (SDSA) and associates with sites of SDSA repair in a manner temporally overlapped with Rad10. The magnitude of induction of colocalized Saw1-CFP/Rad10-YFP/DSB-RFP foci in SDSA is more dramatic in S and G2 phase cells than in M phase, consistent with the known mechanism of SDSA. We observed a substantial fraction of foci in which Rad10 was localized to the repair site without Saw1, but few DSB sites that contained Saw1 without Rad10. Together these data are consistent with a model in which Saw1 recruits Rad1-Rad10 to SDSA sites, possibly even binding as a protein-protein complex, but departs the repair site in advance of Rad1-Rad10. PMID:24565838

Diamante, Graciel; Phan, Claire; Celis, Angie S; Krueger, Jonas; Kelson, Eric P; Fischhaber, Paula L

2014-03-14

172

Formulation and process modeling of particleboard production using hardwood saw mill wastes using experimental design  

Microsoft Academic Search

Hardwood saw mill residues have traditionally not been favoured by the particleboard industry owing to their high density and extractive contents. The work presented here deals with investigating the use of hardwood saw mill residues, which are currently treated as solid wastes, in producing industry-grade particleboard.The formulation and process modeling of particleboard production using hardwood sawmill wastes has been studied

G. Nirdosha; S. Setunge

2006-01-01

173

Fabrication of polymer SAW sensor array to classify chemical warfare agents  

Microsoft Academic Search

An array with five SAW sensors using different kinds of polymers was fabricated to detect chemical agents and their gas response characteristics were extensively investigated. The SAW devices with different interdigital transducer (IDT) electrode line widths of 3, 4, 6, 8 and 20?m, which corresponded to the central frequencies of 264, 198, 132, 99 and 39.6MHz, respectively, were designed. The

Byung-Su Joo; Jeung-Soo Huh; Duk-Dong Lee

2007-01-01

174

Lumber value differences from reduced CT spatial resolution and simulated log sawing  

Microsoft Academic Search

In the past few years, computed tomography (CT) scanning technology has been applied to the detection of internal defects in hardwood logs for the purpose of obtaining a priori information that can be used to arrive at better log sawing decisions. Because sawyers currently cannot even see the inside of a log until the log faces are revealed by sawing,

Suraphan Thawornwong; Luis G. Occena; Daniel L. Schmoldt

2003-01-01

175

Analysis of Radar Phase-Coded Waveforms using High Intercept Probability SAW Compressive Receiver  

Microsoft Academic Search

The increasing application of coded waveforms to the radar systems requires advanced intelligence and analysis techniques. For this purpose signal processing using SAW devices seems a good approach. Performance of a SAW compressive receiver used as an analyzer of coded RF signals is discussed. Experimental results with particular attention to the Barker code case are presented and compared with results

U. Menegotti; M. Topi

1984-01-01

176

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

NASA Astrophysics Data System (ADS)

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.

Ai, Ye; Marrone, Babetta L.

2014-03-01

177

Usymmetriske Sirkelsagblad: Svingningsmoenstre og Egentrekvenser i Sagblad med Radielle Slisser (Vibration Patterns and Natural Frequencies of Radially Edge Slotted Circular Saws).  

National Technical Information Service (NTIS)

This project is an investigation on saw asymmetry. The research is concentrated on the effect of edge radial saw slots to saw vibration pattern and saw stability properties. Radial saw slots are already much applied in practice in spite of the problems th...

S. Holoeyen

1983-01-01

178

Real-time SAW measurements of NVR in cleanroom and in microenvironment  

SciTech Connect

Using a real-time, Surface Acoustic Wave (SAW) sensing instrument supplied by Femtometrics, we have measured organic contamination, or nonvolatile residues (NVR), in both a cleanroom and a microenvironment. To demonstrate the {open_quotes}real-time{close_quotes} NVR detectability and sensitivity of the SAW instrument, controlled contamination experiments with photoresist material were also conducted. In addition, two cleaning methods for removing contamination from used sensors have been evaluated. One technique uses the on-board temperature varying capability of the SAW instrument, while the other technique utilizes a uv-ozone cleaner for the sensor cleaning. Preliminary results from SAW measurements in the cleanroom and in a microenvironment and tests to evaluate sensor cleaning techniques are presented in this report. A concluding summary with an assessment of the current SAW instrument and potential future applications for this technology is also presented.

Liang, A.Y.; McIntyre, D.C.; Lujan, R.D.; Thornberg, S.M.; Bender, S.F.A.

1994-05-01

179

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

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

180

76 FR 62678 - Table Saw Blade Contact Injuries; Advance Notice of Proposed Rulemaking; Request for Comments and...  

Federal Register 2010, 2011, 2012, 2013

...CPSC-2011-0074] Table Saw Blade Contact Injuries; Advance Notice of Proposed...injury associated with table saw blade contact, the regulatory alternatives discussed...including any personal identifiers, contact information, or other personal...

2011-10-11

181

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

Microsoft Academic Search

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

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

2011-01-01

182

Method and apparatus for improved wire saw slurry  

DOEpatents

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.

Costantini, Michael A. (Hudson, NH); Talbott, Jonathan A. (Amherst, NH); Chandra, Mohan (Merrimack, NH); Prasad, Vishwanath (East Setauket, NY); Caster, Allison (Nashua, NH); Gupta, Kedar P. (Merrimack, NH); Leyvraz, Philippe (Nashua, NH)

2000-09-05

183

Wireless telemetry system for a SAW based microvalve  

NASA Astrophysics Data System (ADS)

Inductively coupled RF telemetry is an optimal method for both power supply and data transmission in long term artificial implants due to small size, high reliability, and extended life span of the device. In this research, we propose the use of the same technique for secure remote interrogation and powering of a human implantable, Surface Acoustic Wave (SAW) correlation based, passive microvalve. This is carried out by interrogating the microvalve with a Barker sequence encoded BPSK signal. In this paper we present the development of a FEM model for the derivation of the induced voltage on a miniature (2.5×2.5×1 mm), inductively coupled, biocompatible spiral antenna/coil, interrogated by a 7.5×7.5×0.2 cm spiral antenna/coil in the near field. The amount of power transferred at a 30-160 MHz range was derived using the S21 coupling response when the two antennas are separated by a human body simulant of 5 cm depth. Furthermore, the effect of varying magnetic coupling on the induced voltage, due to the misorientation of coils/antennas is analysed.

Tikka, Ajay C.; Al-Sarawi, Said F.; Jamali, Behnam; Abbott, Derek

2008-12-01

184

Heat generation by two different saw blades used for tibial plateau leveling osteotomies.  

PubMed

During tibial plateau leveling osteotomy (TPLO) the saw blade produces frictional heat. The purpose of this study was to evaluate and compare heat generated by two TPLO blade designs (Slocum Enterprises [SE] and New Generation Devices [NDG]), with or without irrigation, on cadaveric canine tibias. Thirty-six paired tibias were used to continuously measure bone temperatures during osteotomy through both cortices (i.e., the cis and trans cortices). Each pair was assigned to either an irrigation or nonirrigation group during osteotomy, and each tibia within a pair was osteotomized using a different saw blade design. Saw blade temperatures were recorded and temperatures were compared for all combinations of blade type, cortex, and irrigation. In the cis cortex group, the SE blade generated more bone heat than the NGD blade (P=0.0258). Significant differences in temperature generation between saw blade types were seen only when the osteotomy site was not irrigated (P=0.0156). For all variables measured, bone and saw blade temperature generation was lower with irrigation (P<0.05). None of the osteotomies performed with either saw blade produced a critical duration of damaging temperature ranges in this study. Although saw blade design and irrigation influence heat generation during the TPLO, the potential for bone thermal damage during TPLO is low. The use of the NGD blade with irrigation is recommended. PMID:22267171

Bachelez, Andreas; Martinez, Steven A

2012-01-01

185

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

USGS Publications Warehouse

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.

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

2006-01-01

186

Combined FEM and Green's function analysis of periodic SAW structure, application to the calculation of reflection and scattering parameters  

Microsoft Academic Search

Because of more and more stringent requirements on SAW filter performances, it is important to compute, with very good accuracy, the SAW propagation characteristics, which include the calculation of reflection and scattering parameters. For that reason, the analysis of periodic structures on a semi-infinite piezoelectric substrate is one of the most important problems being investigated by SAW researchers. For infinite

Pascal Ventura; J. M. Hode; J. Desbois; H. Solal

2001-01-01

187

Surface acoustic wave (SAW) gas microsensor for SO sub 2. Final report  

SciTech Connect

Researchers used sulfur dioxide as a model gas for testing the feasibility of developing a multicomponent sensor based on Surface Acoustic Wave (SAW) technology for the rapid identification and detection of ambient environmental gases in the sub-ppm to ppb range. Three different methods were examined in an attempt to impact SO2 specificity to several SAW devices: Chemical Bonded Adsorbents (CBA), Solvent Deposited Films, and Tungsten Trioxide (WO3). Results of the project are given. The major implication of the research will be the resulting merger of two existing technologies: metal oxide gas sensors (MEO) and surface acoustic wave devices (SAW).

McAllister, D.J.

1987-10-01

188

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

NASA Astrophysics Data System (ADS)

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 uses 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.

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

189

Noise source identification and control of a contractor grade table saw  

NASA Astrophysics Data System (ADS)

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.

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

2002-05-01

190

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

SciTech Connect

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.

Kriikku, E.M. [Westinghouse Savannah River Co., Aiken, SC (United States); Reynolds, D.L.; Carroll, J.J.; Dawson, D.M. [Clemson Univ., SC (United States). School of Electrical and Computer Engineering

1993-12-31

191

SAW (Surface Acoustic Wave) and SSBW (Surface Skimming Bulk Waves) Propagation in Indium Phosphide.  

National Technical Information Service (NTIS)

In view of combined use of piezoelectric and semiconductoring properties of Indium Phosphide, new surface (SAW) and surface skimming bulk waves (SSBW) are described. The properties of semi-insulating InP crystals are investigated in terms of piezoelectric...

J. Henaff M. Feldmann

1982-01-01

192

Method for nondestructive testing of the film coating behavior of surface acoustic wave (SAW) sensors  

NASA Astrophysics Data System (ADS)

This paper presents a practical non-destructive method for studying the film coating behavior of SAW devices by using a water soluble dielectric film (manitol) deposited on the SAW device surface by resistive evaporation. After measuring the electrical parameters of the film coated SAW device, the film can easily be removed from its surface by water rinsing without causing any damage to it. The SAW device can then be used over and over again in a large number of film depositions. The method was tested on a 1 GHz surface transverse wave (STW) resonator coated with manitol of varying thickness. After each coating and evaluation, the STW device was successfully recovered without significant performance degradation. Data is presented on the electrical changes of the STW device as a result of depositing manitol coatings of various thicknesses.

Taslakov, M. A.; Avramov, I. D.

2010-04-01

193

Full Dynamic Reactions in the Basic Shaft Bearings of Big Band Saw Machines  

NASA Astrophysics Data System (ADS)

The band saws machines are a certain class woodworking machines for longitudinal or transversal cutting as well as for curvilinear wood cutting. These machines saw the wood through a band-saw blade and two feeding wheels. These wheels usually are very large and they are produced with inaccuracies. The centre of mass of the disc is displaced from the axis of rotation of the distance e (eccentricity) and the axis of the disk makes an angle with the axis of rotation. In this paper, the dy- namic reactions in the bearings of the basic shaft, which drives the band saw machines, are analyzed. These reactions are caused by the external loading and the kinematics and the mass characteristics of the rotating disk. The expressions for the full dynamic reactions are obtained. These expressions allow the parameters of the machines to be chosen in such a way that the loading in the shaft and the bearings to be minimal.

Marinov, Boycho

2013-03-01

194

Modeling electrical response of polymer-coated SAW resonators by equivalent circuit representation.  

PubMed

The paper presents an equivalent circuit model of the polymer coated surface acoustic wave (SAW) resonators by combining coupling-of-mode (COM) description of SAW resonators and perturbation calculation of SAW propagation under polymer loading. An expression for the motional load produced by polymer coating is deduced in terms of COM parameters and polymer characteristics. In addition, expressions for the shifts in resonance frequency and attenuation due to polymer loading are obtained. Simulation results are presented for one-port and two-port resonator devices coated with viscoelastic thin polymer film. The influence of polymer film on resonator response is studied with regard to variations in film thickness and shear modulus. The model simplifies understanding of polymer-coated SAW sensors. PMID:21236460

Kshetrimayum, Roshan; Yadava, R D S; Tandon, R P

2011-07-01

195

The Implications of a 'Sea-Saw' Model of Organizational Effectiveness.  

National Technical Information Service (NTIS)

A 'see-saw' model of organizational effectiveness was designed as a result of a systems analysis of previously collected data describing organizational climates in research and development organizations. The model distinguishes between variables that have...

R. W. Stephenson, H. F. Kaiser, C. E. Erickson

1974-01-01

196

A generalized impulse response model for SAW transducers including effects of electrode reflections  

Microsoft Academic Search

Closed-form expressions are presented which describe the behavior of arbitrarily weighted SAW (surface acoustic wave) transducers that contain uniform internal reflections. These expressions are based on a coupling-of-modes model of a SAW transducer and are expressed in terms of the Fourier transform of the transducer weighting function with respect to a modified frequency variable. This is the same Fourier transform

C. S. Hartmann; B. P. Abbott

1988-01-01

197

SAW characteristics of GaN epitaxial films deposited on different plane sapphire substrates using MOCVD  

Microsoft Academic Search

The GaN\\/sapphire layered structure is a potential candidate for high frequency devices due to high acoustic velocity of sapphire. GaN films were grown on c, a, and r-plane sapphire substrates using an MOCVD system. Surface acoustic wave (SAW) propagation properties of GaN epitaxial layers on the sapphire have been theoretically and experimentally characterized. The experimental characterization of SAW propagation properties

Young-Jin Kim; Gune Hwan Lim; Kook Hyun Choi; Su Jin Chung; Hyeong Joon Kim; Haesung Park; Hyeong Soo Park

2002-01-01

198

Measurement of acoustic properties of liquid using liquid flow SH-SAW sensor system  

Microsoft Academic Search

The SH-SAW resonator having narrow bandwidth and higher Q value has been used for sensing the properties in ionic and viscosity of liquid. The surface acoustic waves with the shear horizontal displacement (SH-SAW) are excited on a piezoelectric substrate; 36 rotated Y cut X prop. LiTaO3 (36 YX LiTaO3) and the liquid flow sensing system was constructed by using two-port

T Nomura; A Saitoh; Y Horikoshi

2001-01-01

199

AFM observation of surface acoustic waves emitted from single symmetric SAW transducers.  

PubMed

We report the first experimental observation of surface acoustic waves (SAWs) launched from a single symmetric SAW transducer, employing scanning acoustic force microscopy (SAFM). SAFM is a simple technique for the imaging of complex interdigital transducer (IDT) radiation patterns with nanometer lateral resolution. We demonstrate submicron lateral resolution and high sensitivity by investigating a single excitation element on a weakly coupling substrate (GaAs), visualizing the launched wave and second-order effects. PMID:11381686

Hesjedal, T; Behme, G

2001-05-01

200

Penile entrapment in a plastic bottle - a case for using an oscillating splint saw.  

PubMed

Penile entrapment is a rare but serious urological emergency, which can easily lead to stangulation and infarction. We report a case of penile entrapment in a polyethylene terephthalate (PET) bottle in a 49-year-old male. Attempts to cut the bottle with a scalpel or a glass saw were ineffective. Finally, the bottle neck was cut longitudinally with an oscillating saw intended for cutting plaster casts. PMID:16502059

May, Matthias; Gunia, Sven; Helke, Christian; Kheyri, Reza; Hoschke, Bernd

2006-01-01

201

Identification of natural spring water using shear horizontal SAW based sensors  

Microsoft Academic Search

The acoustoelectric interaction between a shear horizontally polarised surface acoustic wave (SH-SAW) sensor and different commercial brands of natural still spring water is investigated. Transient frequency responses for the samples are presented where the sensing mechanism is based upon perturbation of the electrical properties of the adjacent liquid. SH-SAW devices were fabricated on 36° rotated Y-cut, X propagating LiTaO3 and

Andrew P Campitelli; Wojciech Wlodarski; Moussa Hoummady

1998-01-01

202

Predicting the production rate of diamond wire saw using statistical analysis  

Microsoft Academic Search

Performance prediction of diamond wire saws is important in the cost estimation and the planning of the stone quarries. An\\u000a accurate estimation of sawability helps to make the planning of the rock cutting projects more efficient. In this paper, the\\u000a performance prediction of diamond wire saws in cutting carbonate rocks was studied on 14 different carbonate rocks in stone\\u000a quarries

Mohammad Ataei; Reza Mikaiel; Farhang Sereshki; Narges Ghaysari

203

Development of Miniature Quad SAW filter bank based on PCB substrate  

Microsoft Academic Search

A miniaturization and integration are most important design factor in design of mobile handheld phone to enhance multi-function such as Bluetooth, camera and music so on. Especially in RF stage of multi-band GSM mobile phone, dozens of matching L, C passive components and several SAW filters occupy quite a little space, so phone makers partially use 7.0 times 3.5mm SAW

Youngjin Lee; Jonghoo Paik; Seunghee Lee

2007-01-01

204

SH-SAW Sensor Platform for Chemical Detection in Aqueous Solutions  

Microsoft Academic Search

Chemically sensitive polymers coated on delay lines utilizing shear horizontal surface acoustic wave (SH-SAW) sensors are investigated for the detection of organic analytes in liquid environments. The SH-SAW sensor platform was designed and fabricated on 36° rotated Y-cut LiTaOâ. By depositing a SiOâ dielectric layer over the entire device prior to applying the polymer film, partial electrical passivation of the

Steve Casalnuovo; Richard Cernosek; Fabien Josse; Antonio Ricco; Rongnong Zhou

1999-01-01

205

Analysis of acoustomigration and acoustic loss in saw filters employing FEM\\/BEM  

Microsoft Academic Search

FEM\\/BEM analysis has proved to be an excellent method for the accurate ab initio simulation of the acoustically active tracks of SAW components, especially DMS filters. Besides its usefulness for the overall SAW component characterization it permits insight into the underlying physics. Within the FEM\\/BEM approach the stress distribution in the electrodes is, in contrast to the COM and P-matrix

Markus Mayer; Herbert Zidek; Thomas Bauer; Gholamreza Dagdar-Javid; Karl Wagner

2005-01-01

206

Deviations of kerf by handsaws III: the bend of saw blade by unsymmetrical set  

Microsoft Academic Search

To clarify the inducing mechanism of kerf deviation caused by unsymmetrical set of the handsaw, we hypothesized that the moment\\u000a on the bottom edge of the saw blade, which is generated by the unsymmetrical set on handsaw teeth, bends the saw blade and\\u000a this deformation should be one factor of the kerf deviation. To verify this hypothesis, the bend of

Seiji Hirata; Masamitsu Ohta

2006-01-01

207

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

PubMed Central

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)

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

208

Deep-UV LED controlled AlGaN-based SAW oscillator  

NASA Astrophysics Data System (ADS)

We have demonstrated the possibility of controlling the frequency of an AlGaN-based SAW delay-line oscillator by LEDs emitting in deep UV range. The energy bandgap of AlGaN corresponded to the cutoff wavelength of 270 nm. The deep UV LEDs used in these experiments were supplied by Sensor Electronic Technology, Inc. and had the photon energies 265 nm and 305 nm. We also used 375 nm LED from Nichia Corporation. The SAW delay-line oscillator had the SAW delay line between the output and input of an RF wide-band amplifier. Illumination of the SAW propagation path by a UV LED resulted in the downshift of the oscillator frequency. We attribute this shift to the interaction of the SAW with photoexcited carriers in the AlGaN layer. The responsivity of the SAW oscillator significantly varied with the LED wavelength and was slightly dependent on the incident optical power. At optical powers within 15-40 W the responsivities were 0.5 kHz/W at 265 nm, 0.18 kHz/W at 305 nm, and 0.03 kHz/W at 375 nm. No response was observed from the green (560 nm) LED with a similar optical power. The comparatively strong response at 305 nm wavelength (below the energy bandgap of AlGaN) indicated the importance of trapping effects.

Ciplys, D.; Shur, M. S.; Sereika, A.; Rimeika, R.; Gaska, R.; Fareed, Q.; Zhang, J.; Hu, X.; Lunev, A.; Bilenko, Yu.

2006-05-01

209

Considerations for Dynamic Temperature Compensation of Wideband Ladder-type SAW Filter  

NASA Astrophysics Data System (ADS)

Because of there excellent features such as small-size, wide bandwidth, and low insertion loss, the ladder-type filters based on surface acoustic wave (SAW) technology have been widely used as radio-frequency (RF) filters in mobile communications. We can make wide bandwidth, and low insertion loss, the ladder-type SAW filters on a Cu-grating/15°LiNbO3 substrate structure. On the other hand, it is said that wide bandwidth filters is bad temperature characteristic. So this paper discusses dynamic temperature compensation of wideband ladder-type SAW filters. First, we investigate how wide tunability is achievable using variable capacitors parallel- and/or series-connectted to SAW resonators in the filter configuration. Second, we measured the temperature characteristic of resonator. Finally, we simulated temperature compensation of wideband ladder-type SAW filters. As a result, we were able to compensate the change of the characteristic with the ladder-type SAW filter connected variable capacitors.

Nakamura, Nobuyuki; Komatsu, Tomoya; Omori, Tatsuya; Hashimoto, Ken-Ya; Yamaguchi, Masatsune

210

“Buzz-saw” noise: A comparison of modal measurements with an improved prediction method  

NASA Astrophysics Data System (ADS)

"Buzz-saw" noise is radiated from a turbofan inlet duct when the fan tip speed is supersonic. In a recent article the effect of an acoustic liner on buzz-saw noise has been examined. Spectral measurements in a rigid and an acoustically lined inlet duct have been compared. Also these measurements have been utilized to assess a buzz-saw noise prediction method. The prediction method is based on a one-dimensional nonlinear propagation model. Sound absorption by an acoustic lining can be included in the model. In this article, the buzz-saw noise prediction method is improved by the inclusion in the modelling of the effect of a boundary layer on absorption of sound in a lined duct. Also, modal measurements from a circumferential microphone array have been examined. These show that the principal source of buzz-saw noise is not always the rotor-alone pressure field. Non-rotor-alone scattered tones can be a significant source of buzz-saw noise at low supersonic fan speeds. The numerical simulations, which only predict the rotor-alone tones, have been re-evaluated in light of these new modal measurements.

McAlpine, A.; Fisher, M. J.; Tester, B. J.

2007-10-01

211

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

PubMed Central

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.

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

2009-01-01

212

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

PubMed

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

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

2012-07-01

213

Surface Acoustic Wave (SAW) microsensors to monitor multi-component vapor challenges to adsorbents and adsorbent-based air filtration systems  

Microsoft Academic Search

The current effort was done to assess the utility of surface acoustic wave (SAW) detectors for analyzing multicomponent gaseous mixtures in real time. Tasks included surveying currently available SAW detector capability, selecting several candidate SAW coating materials, fabricating vapor monitors, and testing for sensitivity and selectivity. An assessment of possible SAW designs for real-time analysis of multicomponent mixtures is attempted.

N. L. Jarvis

1994-01-01

214

Effect of multiblade slurry saw induced damage on silicon solar cells  

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

215

New thin film fabrication technique using a substrate excited by SAW  

SciTech Connect

The authors introduce a new thin film fabrication technique which uses a surface phonon mode substrate excited by surface acoustic waves (SAW) to control the morphology of very thin films. Permalloy films and Co-Cr-Ta films of 300{Angstrom} thickness were prepared by d.c. magnetron sputtering onto LiNbO{sub 3} single crystal substrate excited by SAW. By scanning electron microscopy (SEM) and scanning tunneling microscopy (STM) observations, the structure of films was found to be drastically changed by SAW excitation as a function of excited amplitude. Especially at the critical excitation voltage, film structure consists of homogeneous grain form and very fine grain size is realized. In the Co-Cr-Ta sputtered films fabricated at this critical SAW excitation voltage of 8V, the value of H{sub c} takes minimum value of about 5 Oe, which is 2 order slower than that of the films fabricated without SAW excitation. In the Mo-permalloy films fabricated at this voltage, stress free films are fabricated and excellent soft magnetic property are realized.

Takahashi, M.; Fujita, A.; Shimatsu, T.; Wakiyama, T. (Tohoku Univ., Sendai (Japan). Faculty of Engineering); Yamada, J.; Shiba, T. (Consumer Products Research Center, Hitachi Ltd., Yokohama 244 (JP))

1990-09-01

216

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

PubMed

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

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

2010-01-01

217

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

NASA Astrophysics Data System (ADS)

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.

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

2011-02-01

218

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

NASA Astrophysics Data System (ADS)

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.

Tsai, Meng-Shiun; Jeng, Jie-Ting

2011-02-01

219

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

NASA Technical Reports Server (NTRS)

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.

Peach, Robert; Malarky, Alastair

1990-01-01

220

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

SciTech Connect

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.

Kim, Hyung Do [School of Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)

2005-12-02

221

Influence of metal thickness on phase velocity and thermal sensitivity of SAW devices.  

PubMed

Most surface acoustic wave (SAW) devices exhibit a very small sensitivity to thermal effects. However, even on intrinsically compensated crystal cuts, the deposition of metal strips at the surface (transducers or reflectors) induces important changes in the thermoelastic properties of the device. A theoretical approach based on the Sinha-Tiersten perturbation method is proposed to model the influence of metallization on SAW properties on (ST, X) quartz, namely the temperature stability of the phase velocity of Rayleigh waves. Because this perturbation method only gives access to the first-order temperature coefficient of frequency (TCF), it is combined with a conventional calculation of the second-order TCF to predict the evolution of the turnover temperature. The proposed calculation also requires temperature derivatives of the elastic constants of the metal, which can be calculated for different materials. Finally, theoretical results are compared with experimental data measured on SAW devices on (ST, X) quartz using aluminum gratings. PMID:11370368

Henry-Briot, E; Ballandras, S; Marianneau, G; Martin, G

2001-03-01

222

Falling beam SoilSaw (trademark), an advanced process for forming underground cutoff walls. Final report  

SciTech Connect

The Falling Beam SoilSaw is a method for forming a continuous barrier wall at depths between 30 and 120 ft deep. The objective of this project was to fully develop and commercialize SoilSaw technology for use in underseepage control (pre- and postconstruction), slope stabilization, and as a method of containing contaminants at hazardous waste sites. Specifically, the objectives were to install a demonstration wall using the SoilSaw technology, determine the physical dimensions (width and depth) of the wall, and determine the in-place properties (permeability and strength). During the time frame of the CPAR study, several walls were constructed by Halliburton NUS for which USACE visually monitored but not strength or permeability data were supplied. Therefore, the results of the objectives will be based on the CPAR data presented in this report.

Leach, R.E.; Saugler, R.K.; Carter, E.E.

1995-08-01

223

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

PubMed Central

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.

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

1995-01-01

224

Formulation and make-up of simulated acidic concentrated water (SAW), high ionic content aqueous solution  

SciTech Connect

This procedure describes the formulation and make-up of Simulated Acidified Water (SAW), a high-ionic-content water to be used for Activity E-20-50 ''Long-Term Corrosion Studies.'' Acidic solutions at the repository may result as a consequence of microbial activity. In formulating the ionic composition of the SAW, it was attempted to simulate the acidification of high ionic content water contacting a waste package. Therefore, the composition of this water is based on the acidification of the Simulated Concentrated Water (SCW), which is described in TIP-CM-07. The pH of the solution will be controlled at a nominal value of 2.

Gdowski, G.

1996-09-30

225

SAW-grade SiO2 for advanced microfluidic devices  

NASA Astrophysics Data System (ADS)

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.

Winkler, Andreas; Menzel, Siegfried; Schmidt, Hagen

2009-05-01

226

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

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

227

Debye-type SAW attenuation in C 60 thin films below the glass-transition temperature  

NASA Astrophysics Data System (ADS)

Ultrasonic attenuation measurements in C 60 thin films were carried out by using the surface acoustic wave (SAW) devices. The measurement temperatures were between 15 and 60 K, and the SAW frequencies were 320, 400 and 480 MHz. The obtained attenuation peaks around 40 K depended on the measurement frequencies. The attenuation can be regarded as a Debye-type mechanism. An activation energy E a=12.4 meV and relaxation time ? 0=9.35×10 -12 s were estimated by Arrhenius plotting. There are previously unreported local barriers (E a=12.4 meV) in the molecular orientational potential.

Takase, Tsuyoshi; Moriyama, Fuminori; Sun, Yong; Miyasato, Tatsuro

2002-05-01

228

What Jamie Saw. Trade Book Teaching Ideas from the OLRC Reading Group. Teacher to Teacher Series.  

ERIC Educational Resources Information Center

Intended for teachers of adult literacy, these teaching ideas for the book, "What Jamie Saw," begin with a summary and introductory notes for this book on abuse and its effects on children. Teaching ideas include such suggestions as asking students to write down powerful sentences, to jot notes in their journals about specified units, and to place…

Padak, Nancy; Carolyn Coman

229

Anxiety reaction in children during removal of their plaster cast with a saw  

Microsoft Academic Search

e have had experience of an 18-month-old boy with a cardiomyopathy who died a few minutes after removal of his cast with a saw, apparently from a malignant cardiac arrhythmia triggered by anxiety. We therefore examined the anxiety reaction to this method of removal of a plaster cast in 20 healthy children; ten were provided with hearing protectors and ten

K. Katz; R. Fogelman; J. Attias; E. Baron; M. Soudry

2001-01-01

230

Rapid Acquisition for Direct Sequence Spread-Spectrum Communications Using Parallel SAW Convolvers  

Microsoft Academic Search

In this paper, a technique is described which uses multiple surface acoustic wave (SAW) devices in parallel to reduce the acquisition time of a direct sequence spread-spectrum communication system. Analysis of system performance in both the search and lock modes is presented, and key quantities such as probability of false alarm, probability of correct detection, mean dwell time, and mean

L. B. Milstein; J. Gevargiz; P. K. Das

1985-01-01

231

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

SciTech Connect

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.

Stephenson, G. J. Jr. [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States); Goldman, T. [Theoretical Division, MS-B283, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); McKellar, B. H. J. [University of Melbourne Parkville, Victoria 3052 (Australia)

2006-07-11

232

Development of low-loss band-pass filters using SAW resonators for portable telephones  

Microsoft Academic Search

A bandpass filter using surface acoustic wave (SAW) resonators in a ladder circuit structure for portable telephone systems is reported. For filter design, a simulation tool is used to consider the effects of electrodes (their apertures, the number of paired elements, thickness, and bulk wave radiation). Filter input and output impedance conditions are designed by the resonator capacitance to match

O. Ikata; T. Miyashita; T. Matsuda; T. Nishihara; Y. Satoh

1992-01-01

233

The detection properties of ammonia SAW gas sensors based on L-glutamic acid hydrochloride  

Microsoft Academic Search

This study has investigated an improved surface acoustic wave (SAW) ammonia gas sensor based on L-glutamic acid hydrochloride. It presents an excellent reversibility, sensitivity, and repeatability to ammonia. The frequency shift versus ammonia concentration above 40°C was a monotonic function, and the limit of detection of the sensor at 50°C was 80 ppb.

Chi-Yen Shen; Chun-Pu Huang; Wang-Tsung Huang

2005-01-01

234

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

Microsoft Academic Search

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

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

1997-01-01

235

Temperature Compensated SAW Devices Using Bonded LiTaO3\\/Sapphire  

Microsoft Academic Search

A novel temperature compensated SAW substrate was developed by using direct bonding techniques. This method has merits to keep the same coupling factor and propagation loss as the original piezoelectric substrate and need not strict control of substrate thickness. Temperature compensating method using direct bonding techniques requires support substrate with small thermal expansion coefficient and large elastic coefficients. Sapphire is

Michio Miura; Shogo Inoue; Jun Tsutsumi; Takashi Matsuda; Masanori Ueda; Yoshio Satoh; Osamu Ikata; Yasuo Ebata

2007-01-01

236

Temperature Compensated SAW Devices Using Bonded LiTaO3/Sapphire  

NASA Astrophysics Data System (ADS)

A novel temperature compensated SAW substrate was developed by using direct bonding techniques. This method has merits to keep the same coupling factor and propagation loss as the original piezoelectric substrate and need not strict control of substrate thickness. Temperature compensating method using direct bonding techniques requires support substrate with small thermal expansion coefficient and large elastic coefficients. Sapphire is one of the ideal materials for the support substrate. Thickness of the piezoelectric substrate has large influence on the temperature characteristics and spurious responses caused by reflection of bulk acoustic wave at the bonding interface. We found appropriate thickness of LiTaO3 with good temperature characteristics and no spurious responses. Using bonded LiTaO3/sapphire SAW substrate, US-PCS SAW duplexer with small temperature coefficient of frequency and good frequency characteristics was developed. Power durability of the duplexer using bonded LiTaO3/sapphire SAW substrate was excellent because of high thermal conductivity of sapphire.

Miura, Michio; Inoue, Shogo; Tsutsumi, Jun; Matsuda, Takashi; Ueda, Masanori; Satoh, Yoshio; Ikata, Osamu; Ebata, Yasuo

237

The learning curve in solving a jig-saw puzzle: a teaching device  

Microsoft Academic Search

The time needed for completion of a 100-piece jig-saw puzzle was recorded through 70 trials, with an interval of 2 weeks between the first and last 35 trials. A negatively accelerated learning curve was obtained. The phenomena of fluctuations in efficiency, the physiological limit, and the plateau may also be demonstrated with this device.

L. E. Alteneder

1935-01-01

238

Pharmacological effects of saw palmetto extract in the lower urinary tract  

Microsoft Academic Search

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 5?-reductase. Today, ?1-adrenoceptor antagonists and muscarinic cholinoceptor antagonists are commonly used in the

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

2009-01-01

239

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

PubMed

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?saw palmetto to show improvement in BPH symptoms and SDys as well. [Corrections made here after initial online publication.] PMID:22522969

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

2013-02-01

240

Chemical warfare agents simulants detection with an optimized SAW sensor array  

Microsoft Academic Search

An E-nose based on surface acoustic wave (SAW) sensors has been developed, and sensitive polymer coatings have been optimized to detect simulants of chemical warfare agents (CWAs). The polymers selected have allowed to discriminate among simulants and classify them at low concentrations in air through Pattern Recognition Methods. Good detection responses have been achieved for very low concentrations, such as

D. Matatagui; J. Martí; M. J. Fernández; J. L. Fontecha; J. Gutiérrez; I. Gràcia; C. Cané; M. C. Horrillo

2011-01-01

241

Optimized design of a SAW sensor array for chemical warfare agents simulants detection  

Microsoft Academic Search

Chemical warfare agent simulants detection is of great interest for security reasons. An electronic nose based on Surface Acoustic Wave (SAW) sensors has been developed and sensor polymer coatings have been optimized. These allowed us to detect very low concentrations of certain simulants. A good classification was achieved.

D. Matatagui; J. Martí; M. J. Fernández; J. L. Fontecha; J. Gutiérrez; I. Gràcia; C. Cané; M. C. Horrillo

2009-01-01

242

Effect of saw palmetto extract on PI3K cell signaling transduction in human glioma  

PubMed Central

Saw palmetto extract can induce the apoptosis of prostate cancer cells. The aim of the present study was to investigate the effect of saw palmetto extract on the phosphatidylinositol 3-kinase (PI3K)/Akt signaling transduction pathway in human glioma U87 and U251 cell lines. Suspensions of U87 and U251 cells in a logarithmic growth phase were seeded into six-well plates at a density of 104 cells/well. In the experimental group, 1 ?l/ml saw palmetto extract was added, while the control group was cultured without a drug for 24 h. The expression levels of PI3K, B-cell lymphoma-extra large (Bcl-xL) and p53 were evaluated through western blot analysis. In the experimental group, the U87 and U251 cells exhibited a lower expression level of PI3K protein as compared with the control group (t=6.849; P<0.001). In addition, the two cell lines had a higher expression level of p53 protein in the experimental group as compared with the control group (t=40.810; P<0.001). Protein expression levels of Bcl-xL decreased significantly in the experimental group as compared with the control group (t=19.640; P=0.000). Therefore, saw palmetto extract induces glioma cell growth arrest and apoptosis via decreasing PI3K/Akt signal transduction.

YANG, YANG; HUI, LV; YUQIN, CHE; JIE, LI; SHUAI, HOU; TIEZHU, ZHOU; WEI, WANG

2014-01-01

243

Effect of Saw Palmetto on the Development and Progression of Prostate Carcinoma in TRAMP Mice.  

National Technical Information Service (NTIS)

We established a breeding colony for TRAMP (transgenic adenocarcinoma of the mouse prostate) mice in order to study the effects of saw palmetto berry extract (SPE) on the spontaneous development of prostate cancer. Four week old mice have been assigned to...

C. E. Roselli

2006-01-01

244

Packageless SAW Devices with Isolated Layer Acoustic Waves (ILAW) and Waveguiding Layer Acoustic Waves (WLAW)  

Microsoft Academic Search

We report on two novel layered structure concepts and their acoustic wave properties for efficient, mechanically isolated, temperature compensated, and technologically attractive packageless SAW device applications as RF filters and duplexers. The piezoelectric substrate is covered with a layer of SiO2 or Pyrex that is in turn covered by a material of higher acoustical impedance creating an isolated layer acoustic

K. Bhattacharjee; A. Shvetsov; S. Zhgoon

2007-01-01

245

3D Modeling and Simulation of SH-SAW Devices Using the Finite Element Method  

Microsoft Academic Search

Shear horizontal surface acoustic wave (SH-SAW) devices have been extensively used in chemical and biosensing applications mainly because these waves are not attenuated in liquid media like Rayleigh waves. It is extremely important to model and simulate the device prior to its actual fabrication in order to gain a better understanding of the device performance and optimizing its design parameters.

Sridevi Krishnamurthy; Massood Z. Atashbar; S. Kalantar-zadeh

2007-01-01

246

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

ERIC Educational Resources Information Center

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…

Bishart, Gus; Werner, Claire

247

Temperature Compensated Cuts of Berlinite and Beta-Eucryptite for SAW Devices.  

National Technical Information Service (NTIS)

Calculations of the surface acoustic wave (SAW) properties of berlinite (AlPO4) and beta-eucryptite (beta-LiAlSiO4) show that both materials are temperature compensated along both singly rotated and doubly rotated orientations. For berlinite, several orie...

R. M. O'Connell P. H. Carr

1977-01-01

248

Advances in SAW gas sensors based on the condensate-adsorption effect.  

PubMed

A surface-acoustic-wave (SAW) gas sensor with a low detection limit and fast response for volatile organic compounds (VOCs) based on the condensate-adsorption effect detection is developed. In this sensor a gas chromatography (GC) column acts as the separator element and a dual-resonator oscillator acts as the detector element. Regarding the surface effective permittivity method, the response mechanism analysis, which relates the condensate-adsorption effect, is performed, leading to the sensor performance prediction prior to fabrication. New designs of SAW resonators, which act as feedback of the oscillator, are devised in order to decrease the insertion loss and to achieve single-mode control, resulting in superior frequency stability of the oscillator. Based on the new phase modulation approach, excellent short-term frequency stability (±3 Hz/s) is achieved with the SAW oscillator by using the 500 MHz dual-port resonator as feedback element. In a sensor experiment investigating formaldehyde detection, the implemented SAW gas sensor exhibits an excellent threshold detection limit as low as 0.38 pg. PMID:22247697

Liu, Jiuling; Wang, Wen; Li, Shunzhou; Liu, Minghua; He, Shitang

2011-01-01

249

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

Microsoft Academic Search

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

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

2002-01-01

250

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

Microsoft Academic Search

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

Manfred Hofer; Norman Finger; G. Kovacs; J. Schoberl; S. Zaglmayr; U. Langer; R. Lerch

2006-01-01

251

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

Microsoft Academic Search

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

Effie Howe; Geoffrey Harding

2000-01-01

252

“Buzz-saw” noise: Prediction of the rotor-alone pressure field  

NASA Astrophysics Data System (ADS)

Public expectations of lower environmental noise levels, and increasingly stringent legislative limits on aircraft noise, result in noise being a critical technical issue in the development of jet engines. Noise at take-off, when the engines are at high-power operating conditions, is a key reference level for engine noise certification. "Buzz-saw" noise is the dominant fan tone noise from modern high-bypass-ratio turbofan aircraft engines during take-off. Rotor-alone tones are the key component of buzz-saw noise. The rotor-alone pressure field is cut-off at subsonic fan tip speeds; buzz-saw noise is associated with supersonic fan tip speeds, or equivalently, high power engine operating conditions. A recent series of papers has described new work concerning the prediction of buzz-saw noise. The prediction method is based on modelling the nonlinear propagation of one-dimensional sawtooth waveforms. A sawtooth waveform is a simplified representation of the rotor-alone pressure field. Previous validation of the prediction method focussed entirely on reproducing the spectral characteristics of buzz-saw noise; this was dictated at that time by the availability of spectral data only for comparison between measurement and prediction. In this paper, full validation of the method by comparing measurement and prediction of the rotor-alone pressure field is published for the first time. It is shown that results from the modelling based on a one-dimensional sawtooth waveform capture the essential features of the rotor-alone pressure field as it propagates upstream inside a hard-walled inlet duct. This verifies that predictions of the buzz-saw noise spectrum, which are in good agreement with the measured data, are based on a model which reproduces the key physics of the noise generation process. Validation results for the rotor-alone pressure field in an acoustically lined inlet duct are also shown. Comparisons of the measured and predicted rotor-alone pressure field are more difficult to interpret because the acoustic lining significantly modifies the sawtooth waveform, but there remains good agreement with the measured spectral data. The buzz-saw noise prediction code used to generate the simulations in this paper has been used by the Rolls-Royce Noise Department since 2004.

McAlpine, A.; Schwaller, P. J. G.; Fisher, M. J.; Tester, B. J.

2012-10-01

253

Assessment of langatate material constants and temperature coefficients using SAW delay line measurements.  

PubMed

This paper reports on the assessment of langatate (LGT) acoustic material constants and temperature coefficients by surface acoustic wave (SAW) delay line measurements up to 130 degrees C. Based upon a full set of material constants recently reported by the authors, 7 orientations in the LGT plane with Euler angles (90 degrees, 23 degrees, Psi) were identified for testing. Each of the 7 selected orientations exhibited calculated coupling coefficients (K(2)) between 0.2% and 0.75% and also showed a large range of predicted temperature coefficient of delay (TCD) values around room temperature. Additionally, methods for estimating the uncertainty in predicted SAW propagation properties were developed and applied to SAW phase velocity and temperature coefficient of delay calculations. Starting from a purchased LGT boule, the SAW wafers used in this work were aligned, cut, ground, and polished at University of Maine facilities, followed by device fabrication and testing. Using repeated measurements of 2 devices on separate wafers for each of the 7 orientations, the room temperature SAW phase velocities were extracted with a precision of 0.1% and found to be in agreement with the predicted values. The normalized frequency change and the temperature coefficient of delay for all 7 orientations agreed with predictions within the uncertainty of the measurement and the predictions over the entire 120 degrees C temperature range measured. Two orientations, with Euler angles (90 degrees, 23 degrees, 123 degrees) and (90 degrees, 23 degrees, 119 degrees), were found to have high predicted coupling for LGT (K(2) > 0.5%) and were shown experimentally to exhibit temperature compensation in the vicinity of room temperature, with turnover temperatures at 50 and 60 degrees C, respectively. PMID:20211767

Sturtevant, Blake T; Pereira da Cunha, Mauricio

2010-03-01

254

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

PubMed

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 400°C to 900°C 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 400°C to 900°C. Multiple SAW orientations were identified with zero-TCD between 400°C and 500°C. Although no orientations that have turn-over temperatures above 500°C were identified, several have low frequency variation with temperature, of the order of -0.8% over the range 400°C to 800°C. Temperature-sensitive orientations with TCD up to 75 ppm/°C at 900°C 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 25°C to -205 ppm/°C at 900°C. PMID:24626037

Davulis, Peter; Pereira da Cunha, Mauricio

2012-02-01

255

SH-SAW Sensor Platform for Chemical Detection in Aqueous Solutions  

SciTech Connect

Chemically sensitive polymers coated on delay lines utilizing shear horizontal surface acoustic wave (SH-SAW) sensors are investigated for the detection of organic analytes in liquid environments. The SH-SAW sensor platform was designed and fabricated on 36{degree} rotated Y-cut LiTaO{sub 3}. By depositing a SiO{sub 2} dielectric layer over the entire device prior to applying the polymer film, partial electrical passivation of the interdigital transducers (IDT) is obtained while increasing the mass sensitivity of the device. Changes in the mechanical properties of the chemically sensitive polymer materials were clearly detectable through a frequency shift at least one order of magnitude larger than that of a coated-quartz crystal resonator (QCR) in a similar experiment.

Casalnuovo, Steve; Cernosek, Richard; Josse, Fabien; Ricco, Antonio; Zhou, Rongnong

1999-07-20

256

NDE of zinc layer on steel substrate using laser-ultrasonic SAW  

NASA Astrophysics Data System (ADS)

Laser-ultrasound spectroscopy, a non-contact ultrasonic technique was used to characterize the Lame coefficients ((lambda) ,(mu) ) and thickness (h) of a zinc layer on a steel substrate. This characterization is based on fitting the measured velocity dispersion curve of surface acoustic waves (SAW) to the dispersion calculated one using the conjugates gradients algorithm (C.G). A short laser pulse was used to generate a wideband pulse of ultrasound and a laser interferometer was used for its detection. From a large number of echoes we identified the one corresponding to the SAW. Furthermore other useful information were obtained from these data like attenuation and surface skimming longitudinal wave. Measurements of the velocity dispersion of the Rayleigh wave were achieved up to 50 MHz. The evaluation of layer's parameters performed for similar cases, on a pseudo-experimental model, were obtained with accuracy better then 1% for (h, (mu) ) and about 4% to 6% for (lambda) .

Chenni, Bouzid; Moreau, Andre; Pouliquen, J.

2002-06-01

257

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

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

258

Effect of texturing process involving saw-damage etching on crystalline silicon solar cells  

NASA Astrophysics Data System (ADS)

For high efficiency silicon solar cells, surface texturing is used to increase the short circuit current by reducing the surface reflection loss. Surface texturing is an anisotropic wet chemical etching process commonly used to form random pyramids. We investigated how the process is affected by surface conditions. We also compared the texturing behavior and cell performances of as-cut, polished and saw-damage etched wafers. Textured samples with different processing times were analyzed to detect pyramids and determine weighted reflectances. After the texturing process, conventional screen-printed solar cells were fabricated to observe the cell performance. The pseudo I-V curves and quantum efficiency for the samples were analyzed. Performance of samples with different surface conditions makes no difference. Thus, the processing-cost of solar cells can be reduced by omitting the saw-damage etching process.

Kim, Hyunho; Park, Sungeun; Kang, Byungjun; Kim, Seongtak; Tark, Sung Ju; Kim, Donghwan; Dahiwale, S. S.

2013-11-01

259

SAW propagation characteristics and fabrication technology of piezoelectric thin film\\/diamond structure  

Microsoft Academic Search

The authors report a theoretical analysis of the surface-acoustic wave (SAW) propagation characteristics of ZnO\\/diamond and AlN\\/diamond structures. The analysis shows about 12000 m\\/s and a large electromechanical coupling coefficient K2 of 0.03 for AlN thin film. The numerical analysis for the ZnO\\/diamond structure shows that there exists a coupling between the Rayleigh wave and the Sezawa wave at H\\/?=0.2

K. Yamanouchi; N. Sakurai; T. Satoh

1989-01-01

260

The Natural Single-Phase Unidirectional Transducer: A New Low-Loss SAW Transducer  

Microsoft Academic Search

This paper describes a completely new design approach for low-loss SAW transducers and components. This new approach utilizes special unconventional asymmetric crystal orientations. On these new orientations, which exist on conventional piezoelectric cryslals, simple single-level uniform twoelectrodes-per-wavelength transducers can exhibit a unidirectional response. In contrast to low-loss three-phase transducers, air-gap crossovers are not required and all electrode and gap widths

P. V. Wright

1985-01-01

261

SAW chemical sensing using poly-ynes and organometallic polymer films  

Microsoft Academic Search

We have investigated chemical sensing properties of three polymeric films (organic and organometallic poly-ynes) by a surface acoustic wave (SAW) and surface transverse wave (STW) sensor, at room temperature. The sensor system, consisting of an acoustic two-port resonator operating at 433.92 and 380.8MHz, respectively, has been configured as a frequency oscillator, including an integrated electronic module. The polymeric membranes have

M Penza; G Cassano; A Sergi; C Lo Sterzo; M. V Russo

2001-01-01

262

Granular dampers for the reduction of vibrations of an oscillatory saw  

NASA Astrophysics Data System (ADS)

Instruments for surgical and dental application based on oscillatory mechanics submit unwanted vibrations to the operator’s hand. Frequently the weight of the instrument’s body is increased to dampen its vibration. Based on recent research regarding the optimization of granular damping we developed a prototype granular damper that attenuates the vibrations of an oscillatory saw twice as efficiently as a comparable solid mass.

Heckel, Michael; Sack, Achim; Kollmer, Jonathan E.; Pöschel, Thorsten

2012-10-01

263

Temperature compensated LiTaO3\\/sapphire saw substrate for high power applications  

Microsoft Academic Search

A new temperature-compensated SAW substrate for high power applications was developed based on bonded LiTaO3\\/sapphire. Because of its small thermal expansion coefficient, large Young's modulus, and large electric resistivity, sapphire is an ideal material for a support substrate. In addition, the large thermal conductivity of sapphire brings efficient heat dissipation. Surface activated bonding was used and optimized to strongly bond

M. Miura; T. Matsuda; M. Ueda; Y. Satoh; O. Ikata; Y. Ebata; H. Takagi

2005-01-01

264

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

NASA Technical Reports Server (NTRS)

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

Barton, Richard J.

2013-01-01

265

Rapid detection of organophosphate pesticides in aqueous environment using a polysiloxane coated SH-SAW device  

Microsoft Academic Search

The choice of the chemically sensing layer for gas and liquid-phase microsensors greatly influences their sensitivity, selectivity, reversibility, and response time. It has been shown in previous work that poly(epichlorohydrin) (PECH) and polyurethane (PU) coated SH-SAW sensors on 36deg rotated Y-cut LiTaO3 can be used to reversibly detect organophosphate (OP) pesticides (phosmet and parathion) directly in the liquid phase with

A. Mensah-Brown; F. Josse; M. J. Wenzel; E. Yaz; S. Schneider

2008-01-01

266

Cutting crime: the analysis of the “uniqueness” of saw marks on bone  

Microsoft Academic Search

Witness marks produced on bone by the use of saws have traditionally been examined using stereomicroscopy. The marks are typically\\u000a found on the kerf wall or floor and give important information about the implement that made them. This paper describes a\\u000a new approach to the analysis of witness marks left on kerf walls and floors from crimes involving dismemberment. Previously,

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

2007-01-01

267

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

PubMed Central

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.

2010-01-01

268

S.A.W. 350 microsec binary phase-shift-keyed matched filter  

Microsoft Academic Search

The design, fabrication, and performance of a 3570 chip, 350 microsec binary phase-shift keyed SAW matched filter with a signal\\/noise gain of 34 dB are described. This filter is realized by cascading seven 50 microsec sections, each with an additional transducer, appropriately positioned on the surface-wave substrate, with wideband amplifiers to equalize interstage losses. The effects of device imperfections and

K. V. Lever; E. Patterson; P. C. Stevens; I. M. Wilson

1976-01-01

269

NDE of zinc layer on steel substrate using laser-ultrasonic SAW  

Microsoft Academic Search

Laser-ultrasound spectroscopy, a non-contact ultrasonic technique was used to characterize the Lame coefficients ((lambda) ,(mu) ) and thickness (h) of a zinc layer on a steel substrate. This characterization is based on fitting the measured velocity dispersion curve of surface acoustic waves (SAW) to the dispersion calculated one using the conjugates gradients algorithm (C.G). A short laser pulse was used

Bouzid Chenni; Andre Moreau; J. Pouliquen

2002-01-01

270

SAW ID tag for industrial application with large data capacity and anticollision capability  

Microsoft Academic Search

Surface acoustic wave (SAW) RFID tags are promising devices for the identification of work pieces in an industrial environment. Their practicality was tested using different types of ID tags operating in the 2.45 GHz ISM band with a code volume of 220- 236. The tags were produced to withstand temperatures up to 350degC. The performance was assessed by measuring the

Gudrun Bruckner; Rene Fachberger

2008-01-01

271

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

PubMed

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

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

2006-06-01

272

Combination of a SAW-biosensor with MALDI mass spectrometric analysis  

Microsoft Academic Search

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 ?-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

G. Treitz; T. M. A. Gronewold; E. Quandt; M. Zabe-Kühn

2008-01-01

273

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

274

Measurement and FEM/BEM simulation of transverse effects in SAW resonators on lithium tantalate.  

PubMed

It is well known that transverse effects contribute significantly to the loss of SAW resonators on lithium tantalate. In particular, for frequencies above resonance, the surface wave is not guided inside the transducer and radiates into the busbars. In addition, because bulk modes can also be excited, scalar models are not sufficient to accurately predict transverse effects. It is also known that the layout of a SAW resonator (electrode gaps and dummy electrodes) has a strong impact on the transverse effects. In this paper, a periodic FEM/BEM model is presented and is used to simulate the transverse effects for various SAW resonator layouts. Test devices matching those simulated are fabricated and measured; the measured results are compared with the simulated results and show good agreement. By analyzing the dispersion curves produced from the FEM/BEM model in the different regions of the device, several frequency bands corresponding to different transverse behaviors are identified. These results are consistent with the elastic displacements, also computed by the FEM/BEM model. It is further shown that guided conditions in the gap between the transducer and the busbar occur for a frequency range above resonance. This result is in agreement with measurements showing that resonators with smaller gaps exhibit smaller spurious responses in their admittance. PMID:24158295

Solal, Marc; Chen, Li; Gratier, Julien

2013-11-01

275

Code optimization for direct sequence spread spectrum and SAW-matched filter implementation.  

PubMed

This paper introduces a new optimization algorithm for the minimization of the time sidelobes of the correlation function of a pseudonoise (PN) sequence by applying dynamic weighting to the sequence. The resulting optimized time sidelobe level sequences are to be used in direct sequence spread spectrum (DS-SS) systems with digital modulations such as BPSK, DPSK, QPSK, etc. The new optimization algorithm starts with a PN sequence. It first optimizes the correlation time sidelobes for the case where the consecutive data bits are identical (11 or 00). It then optimizes the correlation time sidelobes for the case of alternating consecutive data bits (10 or 01). The suppressed time sidelobe level sequences are derived by iterating these algorithms alternately starting from the initial PN sequence. The derived suppressed time sidelobe sequences show excellent correlation characteristics when compared to conventional PN sequences such as maximal length sequences, Gold sequences and Barker codes. Surface acoustic wave (SAW) devices were used to implement the optimized time sidelobe level sequences in a matched filter pair. The design of the apodized SAW-matched filters and their predicted second order effects are presented. The experimental results for the SAW-matched filters for the optimized time sidelobe level sequences derived from a Barker code were found to be in good agreement with the theoretical predictions from this new algorithm. PMID:18238632

Hikino, O; Belkerdid, M A; Malocha, D C

2000-01-01

276

Homologous recombination induced by doxazosin mesylate and saw palmetto in the Drosophila wing-spot test.  

PubMed

Benign prostatic hyperplasia (BPH) is the most common tumor in men over 40 years of age. Acute urinary retention (AUR) is regarded as the most serious hazard of untreated BPH. ?-Blockers, such as doxazosin mesylate, and 5-? reductase inhibitors, such as finasteride, are frequently used because they decrease both AUR and the need for BPH-related surgery. An extract of the fruit from American saw palmetto plant has also been used as an alternative treatment for BPH. The paucity of information available concerning the genotoxic action of these compounds led us to assess their activity as inducers of different types of DNA lesions using the somatic mutation and recombination test in Drosophila melanogaster. Finasteride did not induce gene mutation, chromosomal mutation or mitotic recombination, which means it was nongenotoxic in our experimental conditions. On the other hand, doxazosin mesylate and saw palmetto induced significant increases in spot frequencies in trans-heterozygous flies. In order to establish the actual role played by mitotic recombination and by mutation in the genotoxicity observed, the balancer-heterozygous flies were also analyzed, showing no increment in the total spot frequencies in relation to the negative control, for both drugs. Doxazosin mesylate and saw palmetto were classified as specific inducers of homologous recombination in Drosophila proliferative cells, an event linked to the loss of heterozygosity. PMID:22015851

Gabriel, Katiane Cella; Dihl, Rafael Rodrigues; Lehmann, Mauricio; Reguly, Maria Luiza; Richter, Marc François; Andrade, Heloisa Helena Rodrigues de

2013-03-01

277

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

PubMed Central

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).

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

2011-01-01

278

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

PubMed

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

Shigematsu, Takashi; Kurosawa, Minoru Kuribayashi

2008-10-01

279

The Power Durability Dependence on Temperature, Input Power and Structure of Electrodes in SAW Filter  

NASA Astrophysics Data System (ADS)

The dependence of power durability on temperature and input power has been studied in detail by using SAW filter with AlMgCu/Ti/AlMgCu/Ti 4-layered electrodes. In case of SAW filters, acceleration factors of degradation are temperature and input power. These 2 factors are not independent in actual SAW filters, but it is necessary to control the condition to keep the independency of these 2 factors in accelerated deterioration test. As the results of power durability estimation of 4-layered electrodes which had done in consideration of the point above, the activation energy of diffusion showed value of bulk diffusion level in the test using 800MHz band filters, and the dependence of input power was increase in proportion to the frequency of input power. Additionally, we successfully improved power durability of 4-layered electrodes by modifying the layered structure and increasing Mg content in AlMgCu alloy layers. In the former case, the dependency of input power didn't change but the absolute level against input power was improved. On the other hand, the dependency of input power and the absolute level against input power didn't change but the dependence of temperature is increase in the latter case.

Takayama, Ryoichi; Nakanishi, Hidekazu

280

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

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

281

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

SciTech Connect

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.

Emanuel Sachs Tonio Buonassisi

2013-01-16

282

Saw Palmetto  

MedlinePLUS

... Is CAM? Safety Information For Health Care Professionals Clinical Practice Guidelines Literature Reviews More » Research NCCAM Research ... at NCCAM Division of Intramural Research Policies & Guidelines Clinical Trials Labs at NCCAM More » Grants & Funding Funding ...

283

A Microcomputer-Controlled Pseudo Noise Modulated CW-Radar With SAW-Convolver For Signal Processing  

Microsoft Academic Search

In the past there was a rapid development of new components for matched filtering of signals with large time-bandwidth-product on the basis of surface acoustic waves (SAW). Such components, as there is the SAW-Convolver \\/1\\/, allow the realization of very fast and precise operating distance measurement systems with a minimum of components in the signal processing circuitry. In addition continous

B. Wigger; W. Knapp; E. Besenfelder

1988-01-01

284

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

Microsoft Academic Search

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

Mitsutaka Hikita; Toyoji Tabuchi; Nobuhiko Shibagaki

1993-01-01

285

Characterization of ZnO\\/diamond SAW devices elaborated on the smooth nucleation side of MPACVD diamond  

Microsoft Academic Search

We designed a SAW filter in this work by combining the piezoelectric ZnO film with a freestanding double layer diamond film deposited using CH4-H2 pulsed MPACVD process through two growth stages. The AFM measurements on the nucleation side of the diamond film has shown that this side is smooth enough to perform photolithography process in the SAW device elaboration, while

L. Le Brizoual; T. Lamara; F. Sarry; M. Belmahi; O. Elmazria; J. Bougdira; M. Remy; P. Alnot

2005-01-01

286

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

SciTech Connect

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.

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

287

Numerical study of the spectral 3-D green's function singularities for piezoelectric SAW components.  

PubMed

This article deals with the numerical study of the singularities appearing in the spectral 3-D Green's function associated with the piezoelectric surface acoustic wave components (so-called SAW components). These electrical units are currently used today in several devices produced by the telecommunications industry (radio, TV, radar, and digital telecommunication systems). The need to improve their performance has motivated engineers and researchers to use mathematical modeling intensively, in particular the integral equations technique here used, which requires the computing of the associated Green's function and the study of its properties. PMID:16463506

Durán, Mario; Nédélec, Jean-Claude; Ossandón, Sebastián

2005-12-01

288

Achievable Performance and Effective Interrogator Design for SAW RFID Sensor Tags  

NASA Technical Reports Server (NTRS)

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.

Barton, Richard J.

2011-01-01

289

Spectrum shaping SAW filters for high-bit-rate digital radio.  

PubMed

The structure of a QAM radio system is explained. Some novel designs that demonstrate the current status of spectral shaping SAW (surface acoustic wave) filters are presented. Compensation of second-order effects is discussed. Experimental results for a filter for a 140-Mb/s 16 QAM cochannel system with a roll-off factor of 0.19 are shown. Two other examples of filters for a 140-Mb/s, 64 QAM system with a 35% relative bandwidth are also presented. PMID:18290203

Ganss-Puchstein, R; Ruppel, C W; Stocker, H R

1988-01-01

290

Surface acoustic waves (SAW) interaction with 2DES at spin-splitted Landau levels  

NASA Astrophysics Data System (ADS)

Peculiarities associated with spin splitting of the Landau levels were observed during the study of the absorption coefficient and the velocity shift of SAW ( f=30 MHz), interacting with two-dimensional electron system (2DES) in the GaAs/AlGaAs heterostructures ( n=1.3·10 11- 2.8·10 11 cm-2) at T=1.5-4.2 K in magnetic fields up to 7 T. An enhanced Landé factor has been determined: g ??5 . The spin-splitted Landau band width has been assessed.

Drichko, Irina L.; Diakonov, Andrey M.; Preobrazenskii, Valery V.; Smirnov, Ivan Yu; Toropov, Alexandr I.

2000-07-01

291

Evaluation of elastic properties of plasma-sprayed materials by laser-SAW technique  

Microsoft Academic Search

The present work has evaluated the elastic properties of low-pressure plasma-sprayed NiCrAlY and atmospheric plasma-sprayed ZrO2-8%Y2O3 materials at ambient and elevated temperatures up to 900 °C by using a laser surface acoustic wave (SAW) technique. Lamb (Rayleigh) waves were excited in free-standing films (sprayed coatings) by a pulsed-YAG-laser irradiation. The dispersive group velocities of A0-mode Lamb waves were utilized in

X. Q. Ma; Y. Mizutani; M. Takemoto; K. Ono

1999-01-01

292

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

PubMed Central

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.

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

2014-01-01

293

Effects of viscous liquid on SH-SAW in layered magnetoelectric structures.  

PubMed

We investigate analytically shear horizontal surface acoustic wave (SH-SAW) propagation in layered magnetoelectric structures loaded with viscous liquid, which involves a thin piezomagnetic layer bonded perfectly to an unbounded piezoelectric substrate. The dispersive relations are obtained and the effects of liquid viscosity on the phase velocity and attenuation of the waves are analyzed and discussed. From the results we can find that the effects of the liquid viscosity on the properties of SH-SAW are remarkable. The phase velocity decreases with increase of the viscous coefficient, or with increase of the frequency, and the attenuation increases with the frequency of the waves and the liquid viscosity, respectively. The relationship between attenuation and frequency or viscosity is nonlinear, but the former is a concave curve, whereas the latter is a convex curve. The attenuation decreases with the piezomagnetic coefficient, and increases obviously with the thickness of the layer. The analytical method and the results are useful for the design of acoustic wave devices based on magnetoelectric materials for liquid phase application, which could be resonated by either magnetic or electric fields. PMID:23259978

Yuan, Lili; Du, Jianke; Ma, Tingfeng; Wang, Ji

2013-03-01

294

Determination of Physical Response in (Mo/AlN) SAW Devices  

NASA Astrophysics Data System (ADS)

This paper describes the experimental conditions in surface acoustic wave (SAW) designed on aluminum nitride (AlN) films grown on Si3N4 substrates by using pulsed laser deposition. Moreover it was studied the dependency of optical properties with temperature of deposition. The thickness, measured by profilometry technology, was 150 nm for all films. Moreover, SAW devices with a Mo/AlN/Si3N4 configuration were fabricated employing AlN buffer and Mo Channel. The morphology and composition of the films were studied using atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy analysis (XPS), respectively. The optical reflectance spectra and color coordinates of the films were obtained by optical spectral reflectometry technique in the range of 400-900 cm-1. In this work, a clear dependence in morphological properties, optical properties, frequency response and acoustic wave velocity as function of applied deposition temperature was found. It was also observed a reduction in reflectance of about 10% and an increase of acoustic wave velocity of about 1.2% when the temperature was increased from 200°C to 630°C.

Caicedo, J. C.; Pérez, J. A.; Caicedo, H. H.; Riascos, H.

2013-04-01

295

Thin-film induced effects on the stability of SAW devices.  

PubMed

Measurements show an upward shift on the order of 50 ppm in the resonant frequency of a surface acoustic wave (SAW) resonator, as taken before and after the device is hermetically sealed in vacuum following a certain glass-frit sealing process. The authors analyze some of the thin-film phenomena that are potential sources of the observed frequency shift and that may affect the long-term stability of such devices. Various factors contributing to the shifts include: 1) intrinsic or structural stresses in the bonding layers as well as in the interdigital transducer (IDT) fingers; 2) thermal stresses due to the differences in thermal expansion coefficients of the metallic IDT fingers and the bonding agent (glass frits) from those of quartz; 3) partial oxidation of the IDT fingers and transmission lines during the frit glazing process; and 4) possible metal diffusion into quartz. Quantitative estimates of the contribution of two factors to the total observed frequency shift after a certain glass-frit sealing process are provided. Rough estimates of the frequency shifts due to the oxidized film are made from the dispersion curves for a uniform thin aluminum film and for its oxide film as fully plated on a quartz substrate. It is concluded that the results may provide a way of estimating the magnitude of the intrinsic stress for a given long-term stability of the SAW device. PMID:18284973

Sinha, B K; Locke, S

1989-01-01

296

Single circuit board implementation of a Digitally Compensated SAW Oscillator (DCSO)  

NASA Astrophysics Data System (ADS)

A circuit, using standard off-the-shelf components, for digital temperature compensation of a SAW oscillator was designed. This circuit was implemented on a single circuit board. A crucial component of the circuit, the AFIT IC, designed by four previous AFIT students and fabricated by NCR, failed to operate at a required frequency of 37 MHz. This caused an early halt to the project; however, several parts of the design were tested individually with good results. The portion of the circuit consisting of the D/A converter, op amp, and phase shifter was tested. For various addresses programmed on the D/A converter inputs, which simulated the output from the two EPROMs, a total phase shift of 107 degrees was obtained from the phase shift circuit. The thermometer and clock paths of the SAW device were made to oscillate at their respective resonant frequencies by introducing the proper amounts of phase shift and attenuation into the feedback loops. The thermometer and clock resonant frequencies were 309 MHz and 298 MHz respectively.

McGuire, J. W.

1983-12-01

297

Preparation of novel saw-toothed and riblike alpha-Si3N4 whiskers.  

PubMed

alpha-Si(3)N(4) whiskers with novel saw-toothed and riblike structures have been synthesized in a high yield by a carbothermal reduction and nitridation route. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and selected-area electron diffraction (SAED). The results show that the saw-toothed whiskers with one smooth surface and another toothlike surface have lengths about several tens of microns and widths in the range of 600-1200 nm. The riblike whiskers are composed of Si(3)N(4) rod-arrays, which grow closely packed perpendicular to the central axial whiskers with uniform diameter and length. The growth mechanism of the products can be considered as a combination of VS mechanism and secondary epitaxial nucleation process. The photoluminescence (PL) spectrum of the whiskers shows a strong blue light emission peak at 406 nm and a weak peak at 485 nm, suggesting their potential applications in light and electron emission devices. PMID:16494313

Xu, Yajie; Cao, Chuanbao; Chen, Zhuo; Li, Jie; Wang, Fuchi; Cai, Hongnian

2006-02-23

298

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

SciTech Connect

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.

Saugier, K.; Isaac, R.E.

1996-02-01

299

Achievable Performance and Effective Interrogator Design for SAW RFID Sensor Tags  

NASA Technical Reports Server (NTRS)

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.

Barton Richard J.

2012-01-01

300

Applications of piezoelectric ZnO film deposited on diamond-like carbon coated onto Si substrate under fabricated diamond SAW filter  

Microsoft Academic Search

The applications of surface acoustic wave (SAW) devices aim directly at piezoelectric thin films deposited onto amorphous diamond-like carbon (DLC) coated on silicon substrates from target ZnO in this study. Our high-velocity SAW filters are characterized using multi-layer structures of thin films by DLC depositing. However, if propagating velocity of diamond is much higher, then the SAW phase velocity of

I-Tseng Tang; Han-Jan Chen; W. C Hwang; Y. C Wang; Mau-Phon Houng; Yeong-Her Wang

2004-01-01

301

A SF6 gas sensor using a dual track SAW device based on multi-wall carbon nanotubes  

NASA Astrophysics Data System (ADS)

In this paper, we propose a sulfur hexafluoride (SF6) gas sensor using a dual track surface acoustic wave (SAW) device based on multi-wall carbon nanotubes (MWCNTs). The sensor consists of a dual track SAW device and MWCNT film sensitive to SF6 gas. The measurement acoustic track of the sensor is coated with an MWCNT film treated by an acid process which selectively absorbs SF6 gas, while the reference acoustic track is uncoated. Experimental results confirm that the SF6 gas sensor using a dual track SAW device based on multi-wall CNTs has good response characteristics to different concentrations of SF6 gas from 0.5 to 20 ppm. The sensor has good linearity and reproducibility, and its sensitivity is approximately 7.4 kHz ppm-1. Furthermore, the sensor has a smaller cross-sensitivity for SO2 and HF.

Wen, Changbao; Zhu, Changchun; Ju, Yongfeng; Liu, Li; Li, Wanlin; Yan, Dong; Xu, Hongke; Qiu, Yanzhang

2011-03-01

302

A numerical method to derive accurate temperature coefficients of material constants from high-temperature SAW measurements: application to langasite.  

PubMed

The design of wireless SAW sensors for high-temperature applications requires accurate knowledge of the constitutive materials' physical properties in the desired temperature range. In particular, it is crucial to use reliable temperature coefficients of the stiffness, piezoelectric, dielectric, and expansion constants of the propagation medium to achieve correct simulations of the considered devices. Currently, the best-suited piezoelectric material for high-temperature SAW applications is langasite (LGS). Unfortunately, the available coefficients do not allow for precise prediction of the temperature dependence of LGS-based SAW devices above 300°C. A novel method, based on a simulated annealing algorithm coupled with a Rayleigh wave simulation program, was developed to find optimal LGS temperature coefficients. This approach has proven to yield accurate results up to at least 800°C. PMID:24081262

Nicolay, Pascal; Aubert, Thierry

2013-10-01

303

Effect of applied force and blade speed on histopathology of bone during resection by sagittal saw.  

PubMed

A sagittal saw is commonly used for resection of bone during joint replacement surgery. During sawing, heat is generated that can lead to an increase in temperature at the resected surface. The aim of this study was to determine the effect of applied thrust force and blade speed on generating heat. The effect of these factors and their interactions on cutting temperature and bone health were investigated with a full factorial Design of Experiments approach for two levels of thrust force, 15 N and 30 N, and for two levels of blade oscillation rate, 12,000 and 18,000 cycles per minute (cpm). In addition, a preliminary study was conducted to eliminate blade wear as a confounding factor. A custom sawing fixture was used to crosscut samples of fresh bovine cortical bone while temperature in the bone was measured by thermocouple (n=40), followed by measurements of the depth of thermal necrosis by histopathological analysis (n=200). An analysis of variance was used to determine the significance of the factor effects on necrotic depth as evidenced by empty lacunae. Both thrust force and blade speed demonstrated a statistically significant effect on the depth of osteonecrosis (p<0.05), while the interaction of thrust force with blade speed was not significant (p=0.22). The minimum necrotic depth observed was 0.50mm, corresponding to a higher level of force and blade speed (30 N, 18,000 cpm). Under these conditions, a maximum temperature of 93°C was measured at 0.3mm from the kerf. With a decrease in both thrust force and blade speed (15N, 12,000 cpm), the temperature in the bone increased to 109°C, corresponding to a nearly 50% increase in depth of the necrotic zone to 0.74 mm. A predictive equation for necrotic depth in terms of thrust force and blade speed was determined through regression analysis and validated by experiment. The histology results imply that an increase in applied thrust force is more effective in reducing the depth of thermal damage to surrounding bone than an increase in blade speed. PMID:24405736

James, Thomas P; Chang, Gerard; Micucci, Steven; Sagar, Amrit; Smith, Eric L; Cassidy, Charles

2014-03-01

304

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

Microsoft Academic Search

DNA immobilization enhancement is demonstrated in a structure consisting of ZnO nanotips on 128° Y-cut LiNbO3.The ZnO nanotips are grown by metal-organic 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

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

2006-01-01

305

[Dispersion of the nematodes belonging to the Bursaphelenchus xylophilus species group with saw timber in Russian Federation].  

PubMed

Four new records of Bursaphelenchus mucronatus in saw-timbers from the Asian part of Russia (Irkutsk Oblast and Krasnoyarsk Krai, larch, pine and spruce wood) intercepted in St. Petersburg, are described, measured and illustrated. The diagnosis of B. mucronatus is amended and its relationships within species group xylophilus, and especially its differences from a quarantine pests B. xylophilus, are given. The record of the B. mucronatus transition from Asiatic into European part of Russia suggests possible transcontinental way of the xylophilus group penetration with saw-timber. Pest risk analysis of B. xylophilus for the European part of Russia is discussed in scope of the global warming. PMID:20198962

Akhmatovich, N A; Ryss, A Iu

2009-01-01

306

Saw-tooth substorms: Inconsistency of repetitive bay-like magnetic disturbances with behavior of aurora  

NASA Astrophysics Data System (ADS)

The relationships between the magnetic disturbance onsets, aurora dynamics and particles injections at the geostationary orbit have been analyzed in detail for 25 sawtooth substorms. It is shown that inconsistency between the above signatures of the substorms onset is typical of the powerful sawtooth substorms, unlike the isolated (“classical”) magnetospheric substorms. The distinguishing feature of the aurora in case of saw-tooth substorms is permanently high level of auroral activity irrespective of the magnetic disturbance onsets and the double oval structure of the aurora display. The close relationship between the aurora behavior and the particle injections at geostationary orbit is also broken. The conclusion is made, that the classical concept of the substorm development, put forward by Akasofu (1964) for isolated substorms, is not workable in cases of the sawtooth disturbances, when the powerful solar wind energy pumping into the magnetosphere provides a permanent powerful aurora particle precipitation into the auroral zone.

Troshichev, O.; Stauning, P.; Liou, K.; Reeves, G.

2011-02-01

307

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

SciTech Connect

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.

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

1999-09-23

308

Stability of the offset V-osteotomy. Test jig development and saw bone model assessment.  

PubMed

In the offset V-bunionectomy used for hallux valgus repair, both the Kalish and the Vogler variations have a long dorsal arm, but the apex is more distal in the Kalish procedure. This study investigated the effect that pin orientation and location of the osteotomy apex have on weightbearing stability. The authors studied saw bone models that were loaded to failure in an Instron 4201 materials testing machine and, in addition, designed, fabricated, and used a unique jig assembly to help minimize data variability. Statistically significant differences were found between the surgical techniques and pin orientations: the Kalish osteotomy was stronger than the Vogler procedure, and in both osteotomies, the plantarly directed Kirschner wire orientation was stronger than the dorsally directed orientation. PMID:11847259

Gonda, Elizabeth; Bauer, Gary R; Hillstrom, Howard J; Song, Jinsup; Cho, Helen H; Lundberg, Lori A

2002-02-01

309

Evaluation of elastic properties of plasma-sprayed materials by laser-SAW technique  

NASA Astrophysics Data System (ADS)

The present work has evaluated the elastic properties of low-pressure plasma-sprayed NiCrAlY and atmospheric plasma-sprayed ZrO2-8%Y2O3 materials at ambient and elevated temperatures up to 900 °C by using a laser surface acoustic wave (SAW) technique. Lamb (Rayleigh) waves were excited in free-standing films (sprayed coatings) by a pulsed-YAG-laser irradiation. The dispersive group velocities of A0-mode Lamb waves were utilized in evaluating the elastic properties of the films. The results indicated that the Young's moduli (E) and densities (?) of the sprayed materials, especially sprayed ZrO2, were lower than those of dense materials and decreased with increasing temperature. Deviation in the Rayleigh wave dispersion curves suggests a means of determining the integrity of interfaces.

Ma, X. Q.; Mizutani, Y.; Takemoto, M.; Ono, K.

1999-12-01

310

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

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

311

Micro-machining of the ceramics: Can lasers match the performance of diamond saws?  

NASA Astrophysics Data System (ADS)

The advent of commercial grade picosecond and femtosecond lasers has opened the way for laser micromachining of metals. There has however been no or little work reported on the ceramics. Use of diamond saws is still the preferred way of cutting the ceramics such as an Al2O3-TiC composite (referred to as N58 hereafter) that is widely used in the manufacture of read/write heads for magnetic recording hard disk drives. These read/write heads are commonly referred to as "sliders". We report here attempts to cut rows of sliders using various lasers. The cut length was 0.85 mm and the thickness was 0.23 mm. We found that all the nanosecond pulse range lasers, left slag at the laser input edge of the cut and on the cut wall. In many cases the slag deposit doesn't allow one to cut through the entire thickness as the slag interferes with successive laser pulses. Our best results were obtained with picosecond and femtosecond lasers. We were able to cut through entire thickness of the strip with these lasers. The slag was much less than that from the nanosecond lasers, but not low enough for our application. There were slag deposits or loose-appearing material on the cut walls also. The roughness was at best in the micron range. In all the cases studied the cut quality as measured by cut surface roughness and slag formation as well as the cutting speed was worst than that obtained from the diamond saws currently used in the industry.

Patterson, Daniel; Singh, Gurinder P.

2007-03-01

312

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

NASA Technical Reports Server (NTRS)

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.

Cutright, Amanda; Shaughnessy, Brendan

2010-01-01

313

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

PubMed

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

Meulendyk, Bennett J; Pereira da Cunha, Mauricio

2011-12-01

314

Evanescent CHOTs for the optical generation and detection of ultrahigh frequency SAWs  

NASA Astrophysics Data System (ADS)

The use of optical gratings for the generation and detection of ultrahigh frequency narrowband surface acoustic waves is well known. Detection of surface acoustic waves (SAWs) using an optical grating, (without an interferometric set-up) relies on diffraction of light from the grating. Cheap Optical Transducers (CHOTs) for SAWs are optical ultrasonic transducers which are designed to optimise the diffraction from such gratings to yield a local interferometer. They have been demonstrated for typical NonDestructive evaluation (NDE) frequencies (0.5 and 100 MHz). In this paper, we discuss how the CHOTs operate and how their detection mechanism breaks down, when the optical diffraction orders from the grating become evanescent upon moving to multi GHz frequency range. We show that it is possible to design devices with enhanced sensitivity, in this range. This is done by adding a thin "background film" underneath grating fingers, in order to optimise and exploit the interaction between the deformation of the grating and the evanescent fields/ resonances involved in such gratings. The result is a novel operating mechanism, based on an energy balance between the 0-order reflection and resistive heating. These novel transducers are called evanescent wave CHOT (eCHOT). We have used Finite Element Method (FEM) modelling to link the physical displacements caused by the elastic waves with the optical behaviour. We demonstrated that the devices show enhanced sensitivity over a wider range of parameters, than possible with a device designed with conventional CHOT specifications, making the eCHOT an ideal candidate for GHz / nano scale ultrasonics. The eCHOT involves highly resistive thin films and yields thin structures advantageous for ultrahigh frequency ultrasonics. The operating mechanism of the eCHOT suggests that more exotic structures could be built to enhance the sensitivity of these devices.

Arca, A.; Stratoudaki, T.; Smith, R.; Clark, M.; Somekh, M. G.

2011-01-01

315

Stabilization of Fundamental-Frequency Microwave Oscillators for Radio-Relay Systems -- Microwave BAW and SAW Oscillators (Panel)  

Microsoft Academic Search

High frequency fundamental operation up to 2-3 GHz is possible with both surface acoustic wave (SAW) and bulk acoustic wave (BAW) oscillators. The present characteristics and the estimated future capabilities are described in view of radio-relay communication requirements.

J. Henaff

1978-01-01

316

Role of Saw1 in Rad1/Rad10 complex assembly at recombination intermediates in budding yeast  

PubMed Central

The Saccharomyces cerevisiae Rad1/Rad10 complex is a multifunctional, structure-specific endonuclease that processes UV-induced DNA lesions, recombination intermediates, and inter-strand DNA crosslinks. However, we do not know how Rad1/Rad10 recognizes these structurally distinct target molecules or how it is incorporated into the protein complexes capable of incising divergent substrates. Here, we have determined the order and hierarchy of assembly of the Rad1/Rad10 complex, Saw1, Slx4, and Msh2/Msh3 complex at a 3? tailed recombination intermediate. We found that Saw1 is a structure-specific DNA binding protein with high affinity for splayed arm and 3?-flap DNAs. By physical interaction, Saw1 facilitates targeting of Rad1 at 3? tailed substrates in vivo and in vitro, and enhances 3? tail cleavage by Rad1/Rad10 in a purified system in vitro. Our results allow us to formulate a model of Rad1/Rad10/Saw1 nuclease complex assembly and 3? tail removal in recombination.

Li, Fuyang; Dong, Junachao; Eichmiller, Robin; Holland, Cory; Minca, Eugen; Prakash, Rohit; Sung, Patrick; Yong Shim, Eun; Surtees, Jennifer A; Eun Lee, Sang

2013-01-01

317

A new efficient combined FEM and periodic Green's function formalism for the analysis of periodic SAW structures  

Microsoft Academic Search

Analyzing periodic structures on a semi-infinite piezoelectric substrate is one of the most important problems being investigated by SAW researchers. Recently, numerical mixed FEM\\/BEM models have been presented to analyze periodic transducers including mass loading effects and the effectiveness of these methods have been demonstrated. However, the numerical interpolation used (“pulse function” or FEM basis function) is not well suited

P. Ventura; J. M. Hode; M. Solal

1995-01-01

318

Analysis and design of low-loss SAW devices with internal reflections using coupling-of-modes theory  

Microsoft Academic Search

The analysis and design of a new family of SAW (surface acoustic wave) devices which take advantage of distributed internal reflections are discussed. It is noted that the deliberate inclusion of reflections makes many new devices possible. Among these are new low-loss filter structures, resonators and notch elements. However, the inclusion of internal reflections significantly complicates the analysis of these

P. V. Wright

1989-01-01

319

A saw-tooth genetic algorithm combining the effects of variable population size and reinitialization to enhance performance  

Microsoft Academic Search

A genetic algorithm (GA) is proposed that uses a variable population size and periodic partial reinitialization of the population in the form of a saw-tooth function. The aim is to enhance the overall performance of the algorithm relying on the dynamics of evolution of the GA and the synergy of the combined effects of population size variation and reinitialization. Preliminary

Vlasis K. Koumousis; Christos P. Katsaras

2006-01-01

320

Evaluation of Love waves chemical sensors to detect organophosphorus compounds: Comparison to SAW and SH-APM devices  

Microsoft Academic Search

We report on the application of Love-wave devices for organophosphorus detection. First, we propose a theoretical modelling of Love devices. Experimental results on organophosphorus detection are then exposed. Finally, we compare theses results to theoretical results and to SAW and SH-APM experimental results, and we present some conclusions

CCline Zimmermann; D. Rebiere; C. Dejous; J. Pistre; E. Chastaing

2000-01-01

321

Developments of blade dressing technique using SiC board for C90 low-k wafer sawing  

Microsoft Academic Search

Blade preparation or conditioning is one of the critical factors (aside from dicing blades, process parameters, and dicing tapes) one needs to consider, in order to establish optimum sawing parameters for good dicing quality. Blade dressing is important, to dispose off the excess bonding material and to expose the diamond particles for cutting. The conventional medium use to condition\\/season the

Koh Wen Shi; K. Y. Yow; Rachel Khoo

2011-01-01

322

A New Hyphenated mu Trap-GC-Surface Acoustic Wave (SAW) Based Electronic Nose For Monitoring Of Coffee Quality  

Microsoft Academic Search

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

Mauro Carvalho; Achim Voigt; Michael Rapp

2009-01-01

323

Derivation of coupling-of-modes parameters for SAW device analysis by means of boundary element method  

Microsoft Academic Search

A method for derivation of coupling-of-modes (COM) parameters for surface acoustic wave (SAW) device analysis is proposed. Emphasis is laid upon the COM parameter derivation by means of the boundary element method (BEM) analysis, and the COM analysis of a floating electrode unidirectional transducer. Results have shown that the transducer characterization using the COM parameters derived from the BEM analysis

Ken-ya HASHIMOTO; Masatsune YAMAGUCHI

1991-01-01

324

The study of space communications spread spectrum systems. Part 1: Saw-based joint group demodulation of frequency shift keyed and differential phase shift keyed signals  

Microsoft Academic Search

A surface acoustic wave (SAW) device based processor, capable of the joint group demodulation of frequency shift keying (FSK) and differential phase shift keying (DPSK) signals, and intended for use in the Canadian extremely high frequency (EHF) Satcom system is proposed. The processor is based on the ability of SAW filters to implement wideband, real time, Fourier transforms with an

Peter T. Traynor; Peter J. McLane

1990-01-01

325

Skur Med Stukede Tenner PA Sirkelsagblad Med Hoey Matning PR. Tann (Sawing with Swage Set Circular Sawblades with High Bites Per Tooth).  

National Technical Information Service (NTIS)

Experimental sawing of spruce with swage set circular sawblades using higher bites per tooth than normal in Norwegian sawmills. It was expected that the longer sawdust chips would be more suitable for the production of pulp. The effect of sawing with high...

M. Breznjak K. Moen

1969-01-01

326

TALSPEAK CURVE: AN ILLUSTRATION OF A SEE-SAW EFFECT IN SEPARATIONS  

SciTech Connect

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.

Peter Zalupski; Leigh Martin

2010-11-01

327

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

USGS Publications Warehouse

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)

Rogers, R. J.

1984-01-01

328

Successful emergency department thoracotomy for traumatic cardiac rupture: effective utilization of a fret sternum saw.  

PubMed

Mortality following blunt chest injury and cardiac rupture remains high despite advances in the care of traumatic injuries. Indeed, most patients succumb to these injuries even prior to reaching a hospital. However, timely recognition and surgical intervention can save lives. We present the case of a 40-year-old woman who presented to our emergency department in cardiac arrest due to rupture of her left atrium following a major motor vehicle collision. The patient underwent emergency department thoracotomy with successful repair of the cardiac rupture. Emergency department thoracotomy, when indicated and performed by trained surgeons, can be the only life-saving procedure available. Rapid median sternotomy using a cost-effective fret sternum saw does not require significantly more time than a left lateral thoracotomy or clamshell incision in an emergency situation. It can be an effective and alternative method of thoracic entry in the emergency department. Prognosis of cardiac rupture depends largely on the mechanism of injury, location of injury, signs of life: vital signs, and availability of timely intervention. When indicated, hesitation should be avoided. Expedient cardiac exposure is essential and leads to better results with improved survival rates in patients with blunt cardiac rupture. PMID:24936846

Nakamura, Tsukasa; Masuda, Koji; Hitomi, Eiji; Osaka, Yoshio; Nakao, Toshimasa; Yoshimura, Norio

2014-05-01

329

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

NASA Technical Reports Server (NTRS)

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.

Lie, Y. S.; Ching, M.

1991-01-01

330

Study of flow induced by sine wave and saw tooth plasma actuators  

NASA Astrophysics Data System (ADS)

The effect of plasma actuator that uses saw-tooth or sine-wave shape electrodes on boundary layer flows is experimentally investigated. The measurement results are compared with a corresponding standard configuration (conventional design using two rectangular strip electrodes)—the actuator that produces a nearly two-dimensional horizontal wall jet upon actuation. PIV measurements are used to characterize the actuators in a quiescent chamber. Operating in a steady manner, the new actuators result in the formation of streamwise and spanwise vortices. That is to say, the new actuators render the plasma actuators inducing three-dimensional variations in the shear layer, offering significant flexibility in flow control. The affected flowfield with the new actuators is significantly larger than that with the conventional linear actuators. While the conventional linear actuators affect primarily the boundary layer flow on a scale of about 1 cm above the wall, the new actuators affect the near wall region at a significantly larger scale. This new design broadens the applicability and enhances the flow control effects and it is potentially a more efficient flow control device.

Liu, Zhifeng; Wang, Lianze; Fu, Song

2011-11-01

331

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

SciTech Connect

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.

Scholtysek, Carina; Krukiewicz, Aleksandra A. [Center for Medical Physics and Technology, Biophysics Group, Friedrich-Alexander-University of Erlangen-Nuremberg, Henke Str. 91, Erlangen 91052 (Germany); Alonso, Jose-Luis [Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129 (United States); Sharma, Karan P.; Sharma, Pal C. [Boston BioProducts, Inc., Worcester, MA 01604 (United States); Goldmann, Wolfgang H. [Center for Medical Physics and Technology, Biophysics Group, Friedrich-Alexander-University of Erlangen-Nuremberg, Henke Str. 91, Erlangen 91052 (Germany)], E-mail: wgoldmann@biomed.uni-erlangen.de

2009-02-13

332

Small and low-loss IF SAW filters using zinc oxide film on quartz substrate.  

PubMed

It was previously reported that a Rayleigh wave propagating on a zinc oxide film (ZnO)/ST-cut 35 degrees X propagation quartz substrate structure has the characteristics of an excellent temperature coefficient of frequency (TCF) and a large electromechanical coupling factor k(s). This substrate was applied to various intermediate-frequency (IF) stage filters. During the filter development, it was clarified that a spurious response due to the Love wave was generated. In this study, a new quartz substrate has been developed with a specific cut and propagation angle, that has the same values of the TCF and the coupling factor as the above-mentioned ones. In addition, it does not have the spurious response due to the Love wave. The combination of this specific-cut-angle quartz and ZnO film has been applied to IF filters for wideband code division multiple access (W-CDMA) and narrow-band CDMA (N-CDMA) systems. The insertion losses of their IF filters were 3-5 dB better and their TCF was superior (deltaf/f = 0.37 ppm/degrees C: one-third) compared with the conventional surface acoustic wave (SAW) filters. PMID:15139548

Kadota, Michio; Kando, Hajime

2004-04-01

333

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

PubMed

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

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

2013-10-01

334

Dual SAW sensor technique for determining mass and modulus changes in thin silicate films during gas adsorption  

SciTech Connect

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 where 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.

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

2000-01-10

335

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

NASA Technical Reports Server (NTRS)

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.

1979-01-01

336

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

SciTech Connect

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.

Unknown

2002-01-25

337

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

SciTech Connect

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.

Unknown

2002-01-15

338

Development of liquid chromatographic methods for the determination of phytosterols in Standard Reference Materials containing saw palmetto.  

PubMed

Liquid chromatographic (LC) methods using atmospheric pressure chemical ionization/mass spectrometric (APCI-MS) detection were developed for the separation and analysis of the phytosterols campesterol, cycloartenol, lupenone, lupeol, beta-sitosterol, and stigmasterol. Brassicasterol and cholesterol were also included for investigation as internal standards. The methods were used to identify and quantify the phytosterols in each of two Serenoa repens (saw palmetto) Standard Reference Materials (SRMs) developed by the National Institute of Standards and Technology (NIST). Values obtained by LC-MS were compared to those obtained using the more traditional approach of gas chromatography with flame ionization detection. This is the first reported use of LC-MS to determine phytosterols in saw palmetto dietary supplement materials. PMID:18374927

Bedner, Mary; Schantz, Michele M; Sander, Lane C; Sharpless, Katherine E

2008-05-23

339

Influence of non-newtonian fluid dynamics on SAW induced acoustic streaming in view of biological applications  

Microsoft Academic Search

Surface acoustic wave (SAW) devices are finding increasing use in medical diagnostic applications, such as detection of specific proteins in bodily fluids for detection of pathologies. These devices can also be used in Lab-On-a-Chip devices for biological applications that utilize micro-fluidics for detection, transport, mixing, and biological assays. In applications aimed at biological sensing, the sensing medium such as blood

Subramanian KRS Sankaranarayanan; Reetu Singh; Venkat R Bhethanabotla

2011-01-01

340

Effects of pumpkin seed oil and saw palmetto oil in Korean men with symptomatic benign prostatic hyperplasia  

PubMed Central

This study was to investigate the role of complementary and alternative medicine in the prevention and treatment of benign prostatic hyperplasia. For this purpose, a randomized, double-blind, placebo-controlled trial was performed over 12 months on 47 benign prostatic hyperplasia patients with average age of 53.3 years and international prostate symptom score over 8. Subjects received either sweet potato starch (group A, placebo, 320 mg/day), pumpkin seed oil (group B, 320 mg/day), saw palmetto oil (group C, 320 mg/day) or pumpkin seed oil plus saw palmetto oil (group D, each 320 mg/day). International prostate symptom score, quality of life, serum prostate specific antigen, prostate volume and maximal urinary flow rate were measured. In groups B, C and D, the international prostate symptom score were reduced by 3 months. Quality of life score was improved after 6 months in group D, while those of groups B and C were improved after 3 months, compared to the baseline value. Serum prostate specific antigen was reduced only in group D after 3 months, but no difference was observed in prostate volume in all treatment groups. Maximal urinary flow rate were gradually improved in groups B and C, with statistical significance after 6 months in group B and after 12 months in group C. None of the parameters were significantly improved by combined treatment with pumpkin seed oil and saw palmetto oil. From these results, it is suggested that administrations of pumpkin seed oil and saw palmetto oil are clinically safe and may be effective as complementary and alternative medicine treatments for benign prostatic hyperplasia.

Hong, Heeok; Kim, Chun-Soo

2009-01-01

341

Performance Prediction of Large-Diameter Circular Saws Based on Surface Hardness Tests for Mugla (Turkey) Marbles  

Microsoft Academic Search

Surface hardness tests such as Shore hardness (SH) and Schmidt hammer rebound hardness (SR) may provide a quick and inexpensive\\u000a measure of rock hardness, which may be widely used for estimating the mechanical properties of rock material such as strength,\\u000a sawability, drillability and cuttability. In the marble industry, circular sawing with diamond sawblades constitutes a major\\u000a cost in the processing.

Avni Güney

2011-01-01

342

Gas sensitivity comparison of polymer-coated SAW and stw resonators operating at the same acoustic wave length  

Microsoft Academic Search

Results from systematic gas sensing experiments on polymer coated surface-transverse-wave- (STW) and surface-acoustic-wave- (SAW) based two-port resonators on rotated Y-cut quartz, operating at the same acoustic wave length of 7.22 ?m, are presented. The acoustic devices are coated with chemosensitive films of different viscoelastic properties and thicknesses, as solid hexamethyldisiloxane (HMDSO), semisolid styrene (ST) and soft allyl alcohol (AA). The

I. D. Avramov; M. Rapp; S. Kurosawa; P. Krawczak; E. Radeva

2001-01-01

343

Cultivation of different strains of king oyster mushroom (Pleurotus eryngii) on saw dust and rice straw in Bangladesh  

PubMed Central

Pleurotus eryngii is a popular mushroom due to its excellent consistency of cap and stem, culinary qualities and longer shelf life. In Bangladesh, where Pleurotus mushrooms are very popular, P. eryngii may take position among the consumers, but currently this mushroom is not cultivated in large scale there. In this study, 3 strains of P. eryngii such as Pe-1 (native to Bangladesh), Pe-2 (germplasm collected from China) and Pe-3 (germplasm collected from Japan) were cultivated on saw dust and rice straw and their growth and yield parameters were investigated. Pe-1 on saw dust showed the highest biological yield and efficiency (73.5%) than other strains. Also, the mycelium run rate and number of fruiting bodies were higher in Pe-1 than other two strains. The quality of mushroom strains was near about similar. On saw dust, the yield and efficiency were better than those cultivated on rice straw, however, on straw; the mushroom fruiting bodies were larger in size. This study shows the prospects of P. eryngii cultivation in Bangladesh and suggests further study in controlled environment for higher yield and production.

Moonmoon, Mahbuba; Uddin, Md. Nazim; Ahmed, Saleh; Shelly, Nasrat Jahan; Khan, Md. Asaduzzaman

2010-01-01

344

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

PubMed

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

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

2003-01-01

345

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

NASA Technical Reports Server (NTRS)

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.

Barton, Richard J.

2009-01-01

346

Extensive clonal spread and extreme longevity in saw palmetto, a foundation clonal plant.  

PubMed

The lack of effective tools has hampered out ability to assess the size, growth and ages of clonal plants. With Serenoa repens (saw palmetto) as a model, we introduce a novel analytical framework that integrates DNA fingerprinting and mathematical modelling to simulate growth and estimate ages of clonal plants. We also demonstrate the application of such life-history information of clonal plants to provide insight into management plans. Serenoa is an ecologically important foundation species in many Southeastern United States ecosystems; yet, many land managers consider Serenoa a troublesome invasive plant. Accordingly, management plans have been developed to reduce or eliminate Serenoa with little understanding of its life history. Using Amplified Fragment Length Polymorphisms, we genotyped 263 Serenoa and 134 Sabal etonia (a sympatric non-clonal palmetto) samples collected from a 20 × 20 m study plot in Florida scrub. Sabal samples were used to assign small field-unidentifiable palmettos to Serenoa or Sabal and also as a negative control for clone detection. We then mathematically modelled clonal networks to estimate genet ages. Our results suggest that Serenoa predominantly propagate via vegetative sprouts and 10,000-year-old genets may be common, while showing no evidence of clone formation by Sabal. The results of this and our previous studies suggest that: (i) Serenoa has been part of scrub associations for thousands of years, (ii) Serenoa invasion are unlikely and (ii) once Serenoa is eliminated from local communities, its restoration will be difficult. Reevaluation of the current management tools and plans is an urgent task. PMID:21848843

Takahashi, Mizuki K; Horner, Liana M; Kubota, Toshiro; Keller, Nathan A; Abrahamson, Warren G

2011-09-01

347

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

PubMed

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

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

348

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

PubMed

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

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

2014-08-01

349

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

350

A SAW-Based Chemical Sensor for Detecting Sulfur-Containing Organophosphorus Compounds Using a Two-Step Self-Assembly and Molecular Imprinting Technology.  

PubMed

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

Pan, Yong; Yang, Liu; Mu, Ning; Shao, Shengyu; Wang, Wen; Xie, Xiao; He, Shitang

2014-01-01

351

Application of principal component analysis and artificial neural networks to recognize the individual VOCs of methanol\\/2-propanol in a binary mixture by SAW multi-sensor array  

Microsoft Academic Search

This work reports on the performance of a volatile organic compounds (VOCs) identification system based on a surface acoustic wave (SAW) multi-sensor array with four acoustic sensing elements, developed in dual configuration as multiplexed two-port resonator 433.92MHz oscillators and a reference SAW element, in order to recognize the different individual components in a binary mixture of VOCs such as methanol

M Penza; G Cassano

2003-01-01

352

Temperature compensated LiTaO3\\/sapphire bonded SAW substrate with low loss and high coupling factor suitable for US-PCS application  

Microsoft Academic Search

A novel temperature-compensated SAW substrate was developed based on bonded LiTaO3\\/sapphire. Because of its small TEC (thermal expansion coefficient) and large Young's modulus, sapphire is an ideal material for a support substrate. The frequency and temperature characteristics of the bonded LiTaO3\\/sapphire SAW substrate and its application to a US-PCS duplexer are described.

M. Miura; T. Matsuda; Y. Satoh; M. Ueda; O. Ikata; Y. Ebata; H. Takagi

2004-01-01

353

Fabrication and characterization of high frequency SAW device with IDT\\/ZnO\\/AlN\\/Si configuration: role of AlN buffer  

Microsoft Academic Search

Surface acoustic wave (SAW) devices with a ZnO\\/buffer\\/Si configuration have been fabricated, employing poly-AlN (deposited by RF magnetron sputtering) and epi-AlN (deposited by plasma-assisted MBE) as the buffer layer. In particular, the effects of the AlN buffers on the orientation of ZnO films as well as the performance of SAW devices are studied. Piezoelectric ZnO films are deposited using RF

Jun-Phil Jung; Jin-Bock Lee; Jung-Sun Kim; Jin-Seok Park

2004-01-01

354

A SAW-Based Chemical Sensor for Detecting Sulfur-Containing Organophosphorus Compounds Using a Two-Step Self-Assembly and Molecular Imprinting Technology  

PubMed Central

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

Pan, Yong; Yang, Liu; Mu, Ning; Shao, Shengyu; Wang, Wen; Xie, Xiao; He, Shitang

2014-01-01

355

Local heat transfer distribution in a square channel with 90 continuous, 90 saw tooth profiled and 60 broken ribs  

SciTech Connect

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)

Gupta, Abhishek; SriHarsha, V.; Prabhu, S.V.; Vedula, R.P. [Department of Mechanical Engineering, IIT Bombay, Powai, Mumbai 400 076 (India)

2008-02-15

356

Atlantic ocean heat piracy and the bipolar climate see-saw during Heinrich and Dansgaard-Oeschger events  

NASA Astrophysics Data System (ADS)

The millennial-scale asynchrony of Antarctic and Greenland climate records during the last glacial period implies that the global climate system acts as a bipolar see-saw driven by either high-latitudinal and/or near-equatorial sea-surface perturbations. Based on the results of recent modelling of generic Heinrich and Dansgaard-Oeschger scenarios, we discuss the possibility that oscillations of the deep-ocean conveyor may have been sufficient to cause this bipolar see-saw. The bipolar climate asynchrony in our scenarios is caused by the toggle between North Atlantic heat piracy and South Atlantic counter heat piracy. Ocean circulation has an enhanced sensitivity to the northern deep-water source as the North Atlantic Deep Water (NADW) cannot enter the Southern Ocean at depths shallower than the bottom of the Drake Passage. Any shoaling of the NADW can, therefore, increase the northward incursion of Antarctic Bottom Water (AABW), and trigger an interhemispheric climate oscillation. As hundreds of years are required to warm the respective high latitudes, the observed climate lead and lags between the two hemispheres can be explained entirely by the variability of the meridional overturning and by the corresponding change in the oceanic heat transport. Accordingly, it is entirely feasible for the global climate to work like a pendulum, which theoretically could be controlled by pushing at either of the deep-water sources. Our model scenarios suggest that it is entirely feasible for the bipolar climate see-saw to be controlled solely by variations in NADW formation.

Seidov, Dan; Maslin, Mark

2001-05-01

357

Dynamics of vegetation and soils of oak/saw palmetto scrub after fire: Observations from permanent transects  

NASA Technical Reports Server (NTRS)

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.

Schmalzer, Paul A.; Hinkle, G. Ross

1991-01-01

358

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)

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 (Y128°X-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.

Jiang, Hua; Lu, Wenke; Zhang, Guoan; Xie, Zhengguang

2013-02-01

359

INTERNATIONAL UNION OF OPERATING ENGINEERS NATIONAL HAZMAT PROGRAM - MILWAUKEE WORM DRIVE CIRCULAR SAW OENHP{number_sign}: 2001-02, VERSION A  

SciTech Connect

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).

Unknown

2002-01-05

360

Economic consequences of accidents to hands and forearms by log splitters and circular saws: cost of illness study.  

PubMed

We estimated costs associated with injuries to hands from log splitters and circular saws used to cut up firewood and assessed the value of prevention. The study was carried out as a cost of illness study with an incidence approach based on 57 consecutive patients (median age 51; range 8-81) with injuries to the hand or forearm. Twenty-six of the 57 had an amputation which required microsurgery and 31/57 had various injuries. Median Hand Injury Severity Score (HISS) reflecting the severity of all injuries was 67 (range 6-332). Median DASH score after 2-7 years was 12.5 (0-73.3). Total cost (direct costs, costs of lost productivity, and lost quality of life) was estimated to roughly EUR 14 million (EUR 2.8 million/year), where the cost of lost quality of life is 82% of the total cost and loss of productivity and direct costs are 9% each. Injuries sustained from log splitters and circular saws account for considerable costs, but first and foremost human suffering. PMID:21446797

Eriksson, Martin; Karlsson, Johan; Carlsson, Katarina Steen; Dahlin, Lars B; Rosberg, Hans-Eric

2011-02-01

361

A Study on the Motion of Micro-Parts on a Saw-Tooth Surface by the PTV Method  

NASA Astrophysics Data System (ADS)

This study investigates the motion of micro-parts of different sizes on a symmetrically vibratory feeder system that consists of a saw-tooth surface made of carbide, brass, and zirconia. The velocity and position of micro-parts are time-dependently measured by the particle tracking velocimetry method. We investigate the micro-parts motion for a range of frequencies applied to the surface. The obtained results show that unidirectional motion can be attained by the present feeder system regardless of the surface material and the micro-part size. The motion behavior of micro-parts varies for different experiments and surfaces in spite of the same driving voltage and frequency. This implies that the motion of micro-parts is affected by uncertainties in the system. The micro-part motion consists of numerous frequencies, and the first frequency coincided with the exciting frequency. The results also show that the carbide saw-tooth surface produces the largest micro-part velocity among the three surface materials. Comparing relationship between feeding velocity and velocity spectrum clarifies that the micro-part moves faster when spectrum was clear. The experiments on the carbide surface indicate that the micro-part moves smoothly and a large velocity is observed within 50-70 Hz of driven frequency.

Le, Phuong Hoai; Dinh, Thien Xuan; Mitani, Atsushi; Hirai, Shinichi

362

Optimization of discharge types and electrode structure in a cylinder discharge reactor with saw-wheel array electrodes  

NASA Astrophysics Data System (ADS)

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.

Zhang, Chunyang; Shang, Kefeng; Lu, Na; Li, Jie; Wu, Yan

2013-03-01

363

Rectified cell migration on saw-like micro-elastically patterned hydrogels with asymmetric gradient ratchet teeth.  

PubMed

To control cell motility is one of the essential technologies for biomedical engineering. To establish a methodology of the surface design of elastic substrate to control the long-range cell movements, here we report a sophisticated cell culture hydrogel with a micro-elastically patterned surface that allows long-range durotaxis. This hydrogel has a saw-like pattern with asymmetric gradient ratchet teeth, and rectifies random cell movements. Durotaxis only occurs at boundaries in which the gradient strength of elasticity is above a threshold level. Consequently, in gels with unit teeth patterns, durotaxis should only occur at the sides of the teeth in which the gradient strength of elasticity is above this threshold level. Therefore, such gels are expected to support the long-range biased movement of cells via a mechanism similar to the Feynman-Smoluchowski ratchet, i.e., rectified cell migration. The present study verifies this working hypothesis by using photolithographic microelasticity patterning of photocurable gelatin gels. Gels in which each teeth unit was 100-120 µm wide with a ratio of ascending:descending elasticity gradient of 1:2 and a peak elasticity of ca. 100 kPa supported the efficient rectified migration of 3T3 fibroblast cells. In addition, long-range cell migration was most efficient when soft lanes were introduced perpendicular to the saw-like patterns. This study demonstrates that asymmetric elasticity gradient patterning of cell culture gels is a versatile means of manipulating cell motility. PMID:24147112

Kidoaki, Satoru; Sakashita, Hiroyuki

2013-01-01

364

Specific targeting of ultrasound contrast agent (USCA) for diagnostic application: an in vitro feasibility study based on SAW biosensor.  

PubMed

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

Joseph, Shiba; Gronewold, Thomas Marten Arnold; Schlensog, Marc Dominic; Olbrich, Carsten; Quandt, Eckhard; Famulok, Michael; Schirner, Michael

2005-03-15

365

Rectified Cell Migration on Saw-Like Micro-Elastically Patterned Hydrogels with Asymmetric Gradient Ratchet Teeth  

PubMed Central

To control cell motility is one of the essential technologies for biomedical engineering. To establish a methodology of the surface design of elastic substrate to control the long-range cell movements, here we report a sophisticated cell culture hydrogel with a micro-elastically patterned surface that allows long-range durotaxis. This hydrogel has a saw-like pattern with asymmetric gradient ratchet teeth, and rectifies random cell movements. Durotaxis only occurs at boundaries in which the gradient strength of elasticity is above a threshold level. Consequently, in gels with unit teeth patterns, durotaxis should only occur at the sides of the teeth in which the gradient strength of elasticity is above this threshold level. Therefore, such gels are expected to support the long-range biased movement of cells via a mechanism similar to the Feynman-Smoluchowski ratchet, i.e., rectified cell migration. The present study verifies this working hypothesis by using photolithographic microelasticity patterning of photocurable gelatin gels. Gels in which each teeth unit was 100–120 µm wide with a ratio of ascending:descending elasticity gradient of 1:2 and a peak elasticity of ca. 100 kPa supported the efficient rectified migration of 3T3 fibroblast cells. In addition, long-range cell migration was most efficient when soft lanes were introduced perpendicular to the saw-like patterns. This study demonstrates that asymmetric elasticity gradient patterning of cell culture gels is a versatile means of manipulating cell motility.

Kidoaki, Satoru; Sakashita, Hiroyuki

2013-01-01

366

Premonitory Acoustic Emissions and Slip Nucleation during Stick Slip Experiments in Naturally and Smooth (Saw-cut) Faulted Westerly Granite  

NASA Astrophysics Data System (ADS)

We compare premonitory microcracking and stick slip events for two Westerly granite samples containing a natural and a saw-cut (smooth) fault. The samples were 190.5 mm in length, and 76.2 mm in diameter. Stick slip events were induced by triaxial loading at 150 MPa confining stress, at a constant strain rate of 5 x10-6 s-1. One sample contained a polished saw-cut fracture (roughened using 220 grit), at 30 degrees to the sample axis. The second contained a natural fracture that had been previously (quasi-statically) induced by triaxial loading. The experiments were monitored using a novel continuous Acoustic Emission (AE) recorder. Three stick slip events were induced on the saw-cut sample, accompanied by fewer than 100 located AEs. Frictional coefficients were 0.48, 0.51, and 0.59 respectively. The first motion of each stick slip was recorded as a large-amplitude AE signal. These located on the saw-cut fault plane, and represent nucleation sites of the stick-slip events. Nucleation location varied between events, probably being controlled by stress heterogeneities or surface conditions on the fault. Prior to the first slip, AE located at the fault tips, with a small amount of premonitory creep. (Approximately 1 cm of each fault tip was removed when the fault was cut and these areas were packed with sand.) AE Source mechanisms were calculated using Moment Tensor inversion, and correspond to compressive sources, consistent with crushing of infill material about the fault tips. Prior to the second and third slips, no premonitory creep was observed. AE locations concentrate on a small patch within the fault plane. Source mechanisms are consistent with double couple events, orientated in agreement with the macro-scale fault plane geometry. For the natural fault, one stick slip event was induced, with a frictional coefficient of 0.72. Over 3000 AE were located. Again, the stick slip event can be located on the fault plane, in an area that had previously been acoustically quiet, presumably locked due to fault topography. Premonitory AE located mainly on the lower portion of the fault plane, and we did not observe an increase in AE rate immediately prior to rupture. Significant post-slip activity was located. b-values are constant at approximately 1.2 in the 100 seconds before slip. For the post-slip sequence there is an instant decrease (0.6) and subsequent recovery (1.0) in b-value. The surface topography generated considerable differences in premonitory, and post slip AE activity. However the ultrasonic signature of the slip events appears similar for both the saw-cut and natural fault. From an analysis of AE location error residuals, the initial nucleation size is estimated to be less than 3 mm in both experiments. However it is unclear whether we are resolving the size of the AE, or just its first particle motion; this depends on whether these AE can be modeled as dynamic or kinematic cracks (the latter refers to instantaneous motion of the whole source).

Young, R. P.; Thompson, B. D.; Lockner, D. A.

2005-12-01

367

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)

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.

Aharonyan, P.

1979-01-01

368

Implementation of wireless battery-free microgyrosensor by utilizing one-port SAW delay line and an antenna with double resonant frequencies  

NASA Astrophysics Data System (ADS)

A wireless, battery-free gyroscope was developed by employing a one-port surface acoustic wave (SAW) reflective delay line, a SAW resonator, and an antenna. Two SAW devices with different center frequencies were simultaneously activated by one antenna with double resonant frequencies. During wireless testing, the developed gyroscope showed clear reflection peaks with high S/N ratios in both the time and frequency domains. Upon rotation of the device, large shifts of the reflection peaks were observed owing to a secondary wave interference effect caused by the Coriolis force that depends on the spinning rate. The measured sensitivity and linearity of the developed gyroscope were, respectively, 1.35 deg/(deg/s) and 0.91, which are promising values for our targeted applications. The temperature and vibration/shock effects were also characterized

Fu, C.; Elmarzia, O.; Lee, K.

2014-03-01

369

Enhancing chemical identification efficiency by SAW sensor transients through a data enrichment and information fusion strategy—a simulation study  

NASA Astrophysics Data System (ADS)

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.

Singh, Prashant; Yadava, R. D. S.

2013-05-01

370

Staircase and saw-tooth field emission steps from nanopatterned n-type GaSb surfaces  

SciTech Connect

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.

Kildemo, M.; Levinsen, Y. Inntjore; Le Roy, S.; Soenderga ring rd, E. [Department of Physics, Norwegian University of Science and Technology (NTNU), NO-7491 Trondlieim (Norway); Department of Physics, Norwegian University of Science and Technology (NTNU), NO-7491 Trondlieim, Norway and AB CERN, CH- 1211 Geneva 23 (Switzerland); Laboratoire Surface du Verre et Interfaces, UMR 125 Unite Mixte de Recherche CNRS/Saint-Gobain Laboratoire, 39 Quai Lucien Lefranc, F-93303 Aubervilliers Cedex (France)

2009-09-15

371

Saw-Scaled Viper Bites in Sri Lanka: Is It a Different Subspecies? Clinical Evidence from an Authenticated Case Series  

PubMed Central

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.

Gnanathasan, Ariaranee; Rodrigo, Chaturaka; Peranantharajah, Thambipillai; Coonghe, Anthonia

2012-01-01

372

Saw-scaled viper bites in Sri Lanka: is it a different subspecies? Clinical evidence from an authenticated case series.  

PubMed

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

Gnanathasan, Ariaranee; Rodrigo, Chaturaka; Peranantharajah, Thambipillai; Coonghe, Anthonia

2012-02-01

373

Evaluation of cut-off saw exposure control methods for respirable dust and crystalline silica in roadway construction.  

PubMed

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

Middaugh, Beauregard; Hubbard, Bryan; Zimmerman, Neil; McGlothlin, James

2012-01-01

374

Single-monolayer in situ modulus measurements using a SAW device: Photocrosslinking of a diacetylenic thiol-based monolayer  

SciTech Connect

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.

Ricco, A.J.; Staton, A.W. [Sandia National Labs., Albuquerque, NM (United States); Crooks, R.M. [Texas A& M Univ., College Station, TX (United States). Dept. of Chemistry; Kim, Taisun [Hallym Univ., Kang-Won Do (Korea, Republic of). Dept. of Chemistry

1997-10-01

375

Evaluation of surgically assisted rapid maxillary expansion with piezosurgery versus oscillating saw and chisel osteotomy - a randomized prospective trial  

PubMed Central

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

2013-01-01

376

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)

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.

Penza, M.; Tagliente, M. A.; Aversa, P.; Re, M.; Cassano, G.

2007-05-01

377

4E-2 Theoretical and Experimental Study of the Differential Thermal Expansion Effect on the TCD of Layered SAW Temperature Sensors Application to Aluminum Nitride Based Layered Structures  

Microsoft Academic Search

In this paper, we show that the stress and strain fields induced in a layered SAW structure by the thermal expansion of the different layers must be taken into account to compute the global structure temperature coefficient of delay (TCD). Experimental and numerical results are provided. The numerical model is described. It is based at the same time on the

P. Nicolay; O. Elmazria; B. Assouar; F. Sarry; L. Lebrizoual

2007-01-01

378

Stump Heights and Sprouting of European Aspen, Pubescent and Silver Birches, and Damage to Norway Spruce and Scots Pine Following Mechanical and Brush Saw Cleaning.  

National Technical Information Service (NTIS)

Results of precommercial thinning (cleaning) by brush saw and by a machine-mounted device, consisting of a hydraulically-driven heavy disc with two short steel flails mounted in a journal bearing, are presented. Plots cleaned by machine had a larger numbe...

T. Johansson

1992-01-01

379

Low propagation loss in a one-port SAW resonator fabricated on single-crystal diamond for super-high-frequency applications.  

PubMed

Diamond has the highest known SAW phase velocity, sufficient for applications in the gigahertz range. However, although numerous studies have demonstrated SAW devices on polycrystalline diamond thin films, all have had much larger propagation loss than single-crystal materials such as LiNbO3. Hence, in this study, we fabricated and characterized one-port SAW resonators on single-crystal diamond substrates synthesized using a high-pressure and high-temperature method to identify and minimize sources of propagation loss. A series of one-port resonators were fabricated with the interdigital transducer/ AlN/diamond structure and their characteristics were measured. The device with the best performance exhibited a resonance frequency f of 5.3 GHz, and the equivalent circuit model gave a quality factor Q of 5509. Thus, a large fQ product of approximately 2.9 × 10(13) was obtained, and the propagation loss was found to be only 0.006 dB/wavelength. These excellent properties are attributed mainly to the reduction of scattering loss in a substrate using a single-crystal diamond, which originated from the grain boundary of diamond and the surface roughness of the AlN thin film and the diamond substrate. These results show that single-crystal diamond SAW resonators have great potential for use in low-noise super-high-frequency oscillators. PMID:23661133

Fujii, Satoshi; Odawara, Tatsuya; Yamada, Haruya; Omori, Tatsuya; Hashimoto, Ken-Ya; Torii, Hironori; Umezawa, Hitoshi; Shikata, Shinichi

2013-05-01

380

Detection of cellular damage by hydrogen peroxide using SV40-T2 cells on shear horizontal surface acoustic wave (SH-SAW) sensor.  

PubMed

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

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

381

Identification and Affinity-Quantification of ß-Amyloid and ?-Synuclein Polypeptides Using On-Line SAW-Biosensor-Mass Spectrometry  

NASA Astrophysics Data System (ADS)

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 (?- and ß-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.

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

2014-05-01

382

Identification and Affinity-Quantification of ß-Amyloid and ?-Synuclein Polypeptides Using On-Line SAW-Biosensor-Mass Spectrometry.  

PubMed

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 (?- and ß-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

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

383

Analysis of SAW properties in ZnO/AlxGa1-xN/c-Al2O3 structures.  

PubMed

Piezoelectric thin films on high acoustic velocity nonpiezoelectric substrates, such as ZnO, AlN, or GaN deposited on diamond or sapphire substrates, are attractive for high frequency and low-loss surface acoustic wave devices. In this work, ZnO films are deposited on AlxGa1-xN/c-Al2O3 (0 < or = chi < or = 1) substrates using the radio frequency (RF) sputtering technique. In comparison with a single AlxGa1-xN layer deposited on c-Al2O3 with the same total film thickness, a ZnO/AlxGa1-xN/c-Al2O3 multilayer structure provides several advantages, including higher order wave modes with higher velocity and larger electromechanical coupling coefficient (K2). The surface acoustic wave (SAW) velocities and coupling coefficients of the ZnO/AlxGa1-xN/c-Al2O3 structure are tailored as a function of the Al mole percentage in AlxGa1-xN films, and as a function of the ZnO (h1) to AlxGa1-xN (h2) thickness ratio. It is found that a wide thickness-frequency product (hf) region in which coupling is close to its maximum value, K(2)max, can be obtained. The K(2)max of the second order wave mode (h1 = h2) is estimated to be 4.3% for ZnO/GaN/c-Al2O3, and 3.8% for ZnO/AlN/c-Al2O3. The bandwidth of second and third order wave modes, in which the coupling coefficient is within +/- 0.3% of K(2)max, is calculated to be 820 hf for ZnO/GaN/c-Al2O3, and 3620 hf for ZnO/AlN/c-Al2O3. Thus, the hf region in which the coupling coefficient is close to the maximum value broadens with increasing Al content, while K(2)max decreases slightly. When the thickness ratio of AlN to ZnO increases, the K(2)max and hf bandwidth of the second and third higher wave modes increases. The SAW test devices are fabricated and tested. The theoretical and experimental results of velocity dispersion in the ZnO/AlxGa1-xN/c-Al2O3 structures are found to be well matched. PMID:16212255

Chen, Ying; Emanetoglu, Nuri William; Saraf, Gaurav; Wu, Pan; Lu, Yicheng; Parekh, Aniruddh; Merai, Vinod; Udovich, Eric; Lu, Dong; Lee, Dong S; Armour, Eric A; Pophristic, Milan

2005-07-01

384

Co-pyrolysis behaviors of saw dust and Shenfu coal in drop tube furnace and fixed bed reactor.  

PubMed

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

Li, Shuaidan; Chen, Xueli; Wang, Li; Liu, Aibin; Yu, Guangsuo

2013-11-01

385

A comparative study of the SSC resistance of a novel welding process IEA with SAW and MIG  

SciTech Connect

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)

Natividad, C. [Facultad de Quimica, UNAM Circuito interior, C.U., Edificio BC.P. 04510, Mexico, D.F (Mexico)]. E-mail: consnatividad@yahoo.com.mx; Salazar, M. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, San Bartolo Atepehuacan, 07730, Mexico, D.F (Mexico)]. E-mail: salazarm@imp.mx; Espinosa-Medina, M.A. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, San Bartolo Atepehuacan, 07730, Mexico, D.F (Mexico); Perez, R. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, San Bartolo Atepehuacan, 07730, Mexico, D.F (Mexico)

2007-08-15

386

Field portable detection of VOCs using a SAW/GC system. Final report, June 21, 1994--September 21, 1996  

SciTech Connect

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.

Chang, F.; Staples, E.J.

1998-06-01

387

Numerical simulation of evaluation of surface breaking cracks by array-lasers generated narrow-band SAW  

NASA Astrophysics Data System (ADS)

Most of the factors limiting the extensive application of laser-based ultrasonic for nondestructive evaluation of surface breaking crack are its poor sensitivity, low efficiency relative to conventional contact ultrasonic methods and limit on the dimension of the cracks. For this reason, a new technique that multiplepulse narrow-band ultrasound generated by laser arrays has been proposed. It is found that crack detection dependent on spectrum of narrow-band ultrasound generated by laser arrays can be operated with low amplitude requirements. In this paper, the narrow-band ultrasound generated by pulse laser arrays interacting with surface breaking cracks has been simulated in detail by the finite element method (FEM) according to the thermoelastic theory. The pulsed array lasers were assumed to be transient heat source, and the surface acoustic wave (SAW) which propagating on the top of the plate was computed based on thermoelastic theory. Then the frequency spectrums of both reflected waves by crack and transmission ones through crack were compared with the direct waves. Results demonstrate that multiple-frequency components of the narrow-band ultrasound were varied with change of the depth of surface breaking cracks significantly, which provides the possibility for precise evaluation of surface breaking cracks.

Dong, Li-Ming; Ni, Chen-Yin; Shen, Zhong-Hua; Ni, Xiao-Wu

2011-09-01

388

Production of Xylanase from Arthrobacter sp. MTCC 6915 Using Saw Dust As Substrate under Solid State Fermentation  

PubMed Central

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).

Murugan, Sevanan; Arnold, Donna; Pongiya, Uma Devi; Narayanan, P. M.

2011-01-01

389

Air cavity-based Fabry-Perot interferometer sensor fabricated using a sawing technique for refractive index measurement  

NASA Astrophysics Data System (ADS)

We have demonstrated a refractive index sensor based on a fiber optic Fabry-Perot (FP) interferometer with an open air cavity fabricated using a one-step mechanical sawing technique. The sensor head consists of a short FP cavity near the fiber patch cord tip, which was assembled by joining a ceramic ferrule and a single-mode fiber together. Owing to the open air cavity in the sensor head, various liquid samples with different refractive index can fill in-line air cavity, which makes the device usable as a refractometer. Moreover, due to the sensor head encircled with the robust ceramic ferrule, the device is attractive for sensing measurement in harsh environments. The sensor was tested in different refractive index solutions. The experimental result shows that the attenuation peak wavelength of the sensor is shifted toward a shorter wavelength with increasing refractive index, and the refractive index sensitivity is ˜92.5 nm/refractive index unit (RIU) and 73.75 dB/RIU. The proposed sensor can be used as an in-line refractometer for many potential applications in the sensing field.

Jung, Eun Joo; Lee, Woo-Jin; Kim, Myoung Jin; Hwang, Sung Hwan; Rho, Byung Sup

2014-01-01

390

Assessing the quality of x-ray optic surfaces of Si crystals cut by diamond-wire and rotating-blade sawing techniques.  

SciTech Connect

The next generation of X-ray diffraction optics will benefit from crystal surfaces with very high quality (extremely flat and strain-free), but knowledge on how to achieve such surfaces and how surface imperfections affect the diffraction properties is sparse in the literature. As a first step to initialize a systematic study on this topic, we evaluate in this paper the surface quality of two Si (111) wafers cut by a diamond-wire saw and a rotating blade saw, respectively. We concentrate on revealing lattice strains induced by the two cutting methods and on strain evolution during three rounds of chemical etching (without polishing). The measurements also provide some important clues as to how surface roughness affects rocking curve widths and other diffraction properties.

Wieczorek, M.; Huang, X.; Maj, J.; Conley, R.; Qian, J.; Macrander, A.; Christensen, C.; Hodsden, J.; Khachatryan, R. (X-Ray Science Division); (Diamondwire Technology)

2008-01-01

391

An Analysis of SAW Interdigital Transducers with Internal Reflections and the Application to the Design of Single-Phase Unidirectional Transducers  

Microsoft Academic Search

A new coupling-of-modes (COM) analysis of SAW interdigital transducers (IDTs) is presented. The analysis includes the effects of multiple reflections within a transducer. The fundamental equations are derived and some simple closed-form results a re given. In addition, some general properties having regard to the relative phase of transduction and reflection c oefficients within a transducer are derived. A new

C. S. Hartmann; P. V. Wricjht; R. J. Kansy; E. M. Garber

1982-01-01

392

A Study of Unknown Resonance near Upper Stop Band for 43°In-Plane Rotated ST-Cut Quartz SAW Resonator  

NASA Astrophysics Data System (ADS)

An unknown resonance is studied, which exists near upper stop band of IDT reflection characteristics, for the 43° in-plane rotated ST-cut of quartz SAW resonator. In this study, we analyze the displacement loci of surface wave at first, and find that slight skew angles exist in them. Simple simulation model is introduced to analyze the phenomenon and anti-symmetric model of T matrix explains that phenomenon adequately.

Takagi, Michiaki; Kanna, Shigeo; Iizawa, Keigo; Yamazaki, Takashi

393

Randomized trial of a combination of natural products (cernitin, saw palmetto, B-sitosterol, vitamin E) on symptoms of benign prostatic hyperplasia (BPH)  

Microsoft Academic Search

Because benign prostatic hyperplasia (BPH) is relatively common, it is important to discover safe and effective means to treat this often debilitating perturbation. Accordingly, we examined the effectiveness of a combination of natural products (cernitin, saw palmetto, B-sitosterol, vitamin E) in treating symptoms of BPH. We undertook a randomized, placebo-controlled, double-blind study. Patients were enrolled from 3 urological practices in

Harry G. Preuss; Charlyn Marcusen; James Regan; Ira W. Klimberg; Timothy A. Welebir; William A. Jones

2001-01-01

394

The Visual Response Properties of Neurons in the Nucleus of the Basal Optic Root of the Northern Saw-Whet Owl (Aegolius acadicus)  

Microsoft Academic Search

The nucleus of the basal optic root (nBOR) in birds is a component of the accessory optic system (AOS) which is involved in the analysis of visual flowfields normally resulting from self-motion. Using standard extracellular techniques, we recorded from 81 single-unit and multi-unit clusters in the nBOR of the northern saw-whet owl, Aegolius acadicus, an avian species that has a

Douglas R. Wylie; Steven W. Shaver; Barrie J. Frost

1994-01-01

395

In vivo assessment of botanical supplementation on human cytochrome P450 phenotypes: Citrus aurantium, Echinacea purpurea, milk thistle, and saw palmetto  

Microsoft Academic Search

Objectives: Phytochemical-mediated modulation of cytochrome P450 (CYP) activity may underlie many herb-drug interactions. Single–time point phenotypic metabolic ratios were used to determine whether long-term supplementation of Citrus aurantium, Echinacea purpurea, milk thistle (Silybum marianum), or saw palmetto (Serenoa repens) extracts affected CYP1A2, CYP2D6, CYP2E1, or CYP3A4 activity.Methods: Twelve healthy volunteers (6 women, 6 men) were randomly assigned to receive C

Bill J. Gurley; Stephanie F. Gardner; Martha A. Hubbard; D. Keith Williams; W. Brooks Gentry; Julie Carrier; Ikhlas A. Khan; David J. Edwards; Amit Shah

2004-01-01

396

Investigation of ash deposit formation during co-firing of coal with sewage sludge, saw-dust and refuse derived fuel  

Microsoft Academic Search

Blends of a South African bituminous “Middleburg” coal and alternative fuels (sewage sludge, saw-dust and refuse derived fuel) have been fired in the slagging reactor to examine the effect of the added fuel on slagging propensity of the mixtures. Two ceramic deposition probes have been used to investigate the initial stages of slagging at 1300°C and 1200°C, at 0.5s and

Tomasz Kupka; Marco Mancini; Michael Irmer; Roman Weber

2008-01-01

397

Draft (1/5/01) The 32nd Northeast Regional Stock Assessment Workshop (32nd SAW): Advisory Report on Stock Status  

NSDL National Science Digital Library

The Northeast Fisheries Science Center (NEFSC-NOAA) has posted the 32nd Northeast Regional Stock Assessment Workshop (SAW) advisory report. The draft report targets fishery managers and provides scientific advice on the status of the resource (e.g., various fish stocks) via technical summaries. The report (.pdf format) includes stock assessments for Gulf of Maine-Georges Bank American Plaice, Sea Scallop, Silver Hake, and Gulf of Maine Haddock.

2001-01-01

398

An Acoustic Charge Transport Imager for High Definition Television Applications: Low-Voltage SAW Amplifiers on Multilayer GaAs/ZnO Substrates  

NASA Technical Reports Server (NTRS)

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.

Hunt, W. D.; Brennan, K. F.; Summers, C. J.; Cameron, Thomas P.

1996-01-01

399

Influence of spinel substrate and over-layer for enhanced SAW and AO properties with KNbO3 thin film.  

PubMed

Surface acoustic wave (SAW) propagation characteristics have been studied using modeling calculations for a potassium niobate (KNbO3) thin film-layered structure with (001) and (110) orientation on a single crystal spinel (MgAl2O4) substrate, and a spinel buffer layer on silicon. Variation in the electromechanical coupling and acoustic attenuation has been compared. A significantly high value of coupling factor (k2max = 23%) is obtained for the (001)KNbO3/spinel structure by introducing an optimum thickness of spinel over-layer for potential wide bandwidth SAW device applications. The dispersion characteristics with the (110) KNbO3 orientation indicate an initial peak in the coupling coefficient value (k2max = 8.8%) at a relatively low KNbO3 film thickness that appears attractive for fabricating devices with thinner films. The KNbO3 film with (001) orientation is found attractive for efficient acousto-optic (AO) device application with the formation of a symmetric waveguide structure (spinel(0.5 microm)/KNbO3(1.0 microm)/spinel). A high value of k2 = 23.5% with 50% diffraction efficiency has been obtained for the spinel(0.5 microm)/KNbO3(1.0 microm)/spinel structure at 1 GHz SAW frequency and 633 nm optical wavelength at a very low input drive power of 15.4 mW. PMID:12839169

Nayak, Ranu; Gupta, Vinay; Sreenivas, Kondepudy

2003-06-01

400

Lunar Stone Saw.  

National Technical Information Service (NTIS)

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 sou...

T. Clark T. Croker K. Hines M. Knight T. Walton

1988-01-01

401

Effects of three novel metalloproteinases from the venom of the West African saw-scaled viper, Echis ocellatus on blood coagulation and platelets  

Microsoft Academic Search

Two metalloproteinases, a 24-kDa P-I EoVMP1 and a 56-kDa P-III EoVMP2, have recently been isolated from the venom of the West African saw-scaled viper Echis ocellatus. We now reveal a new 65-kDa haemorrhagic group P-III metalloproteinase which we have designated EoVMP3. The aim of this study was to determine whether these three snake venom metalloproteinases (SVMPs) affect platelets and blood

J.-M. Howes; A. S. Kamiguti; R. D. G. Theakston; M. C. Wilkinson; G. D. Laing

2005-01-01

402

Binary Channel SAW Mustard Gas Sensor Based on PdPc0.3PANI0.7 hybrid Sensitive Film  

NASA Astrophysics Data System (ADS)

This paper discussed the working principle of binary channel surface acoustic wave (SAW) lithium niobate piezoelectric chip detecting mustard, established the mathematic model of beat frequency output ?f and the mustard gas density ?. The MEMS craft solved the parameters of the binary channel SAW chip such as its interdigital electrode number was 15~25 couple, width and spacing were both 25µm, degree of overlapping was 2mm, fundamental frequency was 10~35MHz, frequency-domain width was 5~20Hz, and its back pt hot film's. According to TG-DSC thermal analysis, vacuum coating craft was adopted to solve the hybrid sensitive film forming craft parameter of PdPc0.3PANI0.7(phthalocyanine palladium0.3Poiyaniline0.7). The micro-appearance of sensitive film was analyzed through SEM. The sensor's sensitivity and response characteristic were tested and analyzed: appear linear change, its response time is less than 5min while its recovery time is less than 8min.

Shi, Y. B.; Xiang, J. J.; Feng, Q. H.; Hu, Z. P.; Zhang, H. Q.; Guo, J. Y.

2006-10-01

403

Combination of e-beam lithography and of high velocity AIN/diamond-layered structure for SAW filters in X band.  

PubMed

In this work, we report on the fabrication results of surface acoustic wave (SAW) devices operating at frequencies up to 8 GHz. In previous work, we have shown that high acoustic velocities (9 to 12 km/s) are obtained from the layered AIN/diamond structure. The interdigital transducers (IDTs) made of aluminium with resolutions up to 250 nm were successfully patterned on AIN/diamond-layered structures with an adapted technological process. The uniformity and periodicity of IDTs were confirmed by field emission scanning electron microscopy and atomic force microscopy analyses. A highly oriented (002) piezoelectric aluminum nitride thin film was deposited on the nucleation side of the CVD diamond by magnetron sputtering technique. The X-ray diffraction effectuated on the AIN/diamond-layered structure exhibits high intensity peaks related to the (002) AIN and (111) diamond orientations. According to the calculated dispersion curves of velocity and the electromechanical coupling coefficient (K2), the AIN layer thickness was chosen in order to combine high velocity and high K2. Experimental data extracted from the fabricated SAW devices match with theoretical values quite well. PMID:17718340

Kirsch, Philippe; Assouar, Mohamed B; Elmazria, Omar; Hakiki, M El; Mortet, Vincent; Alnot, Patrick

2007-07-01

404

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)

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.

Aharonyan, P.

1980-01-01

405

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)

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.

Aharonyan, P.

1980-01-01

406

Use of Classical Least Squares/Partial Least Squares (CLS/PLS) hybrid algorithm for calibration and calibration maintenance of Surface Acoustic Wave (SAW) devices.  

SciTech Connect

Many data analysis algorithms that are currently employed in SAW sensors lack the ability to easily maintain calibration models in the presence of unmodeled interferents or sensor drift. The classical least squares/partial least squares (CLS/PLS) hybrid algorithm is tested in this study for its ability to update calibration models for unmodeled interferents and sensor drift with information from only a single recalibration standard. Use of the CLS/PLS hybrid algorithm for calibration and calibration maintenance of surface acoustic wave (SAW) devices was investigated for synthetic mixtures of iso-octane-methanol-water and with synthetic mixtures of nerve agent analogs, di-iso-propyl methyl phosphonate (DIMP)-kerosene-water along with a true ternary mixture of dimethyl methyl phosphonate (DMMP)-kerosene-water. Calibration statistics using the hybrid algorithm were found to be as good as those obtained from a standard partial least squares (PLS) analysis. In prediction, the hybrid algorithm models were found to perform equivalently to PLS models in the absence of unmodeled interferents or sensor drift, with an accuracy of 5-10% of the reference values and a high degree of precision. In the case of prediction in the presence of unmodeled interferents and/or sensor drift, PLS models and prediction augmented CLS/PLS (PACLS/PLS) hybrid models were compared using a single standard sample to update each model for prediction. For the cases studied, PACLS/PLS hybrid models were comparable to or outperformed updated PLS models that used subset recalibration or piece-wise direct standardization.

Simonson, Robert Joseph; Rivera, Dion Arledge; Staton, Alan W.; Alam, Mary Kathleen; Yelton, William Graham

2003-06-01

407

Harmonic frequency analysis of SAW resonator chemical sensors: application to the detection of carbon dioxide and humidity 1 Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by Lockheed Martin Energy Research Corporation for the US Department of Energy under Contract No. DE-AC05-96OR22464. 1  

Microsoft Academic Search

We have investigated the possibility of increasing surface acoustic wave (SAW) gas sensor sensitivity and detection limit by operating a SAW device at its fundamental frequency (250 MHz for the devices used in this paper), while monitoring frequency changes at a higher harmonic. In particular we have compared frequency changes at the third harmonic with that of the fundamental mode,

Kofi Korsah; C. L. Ma; Bill Dress

1998-01-01

408

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

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.

Moonmoon, Mahbuba; Shelly, Nasrat Jahan; Khan, Md. Asaduzzaman; Uddin, Md. Nazim; Hossain, Kamal; Tania, Mousumi; Ahmed, Saleh

2010-01-01

409

A saw-less direct conversion long term evolution receiver with 25% duty-cycle LO in 130 nm CMOS technology  

NASA Astrophysics Data System (ADS)

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 ?m 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.

Siyuan, He; Changhong, Zhang; Liang, Tao; Weifeng, Zhang; Longyue, Zeng; Wei, Lü; Haijun, Wu

2013-03-01

410

Boreal Soil and Air Warming (BoSAW): a Manipulative Experiment on the Effects of Warming on Boreal Forest C budgets  

NASA Astrophysics Data System (ADS)

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.

Bronson, D.; Gower, S.; Tanner, M.; van Herk, I.; Linder, S.

2006-12-01

411

Mechanical comparison of fixation techniques for the offset V osteotomy: a saw bone study 1 1 No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject article  

Microsoft Academic Search

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

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

2003-01-01

412

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)

Water stable isotopes (?) in tropical regions are a valuable tool to study both convective processes and climate variability provided that local and remote controls on ? are well known. Here, we examine the intra-seasonal variability of the event-based isotopic composition of precipitation (?D 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 ?D 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 ?D Zongo during the rainy season (~ 40% of the ?D 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 ?D 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 ? according to a SASS-like dipolar structure.

Vimeux, Françoise; Tremoy, Guillaume; Risi, Camille; Gallaire, Robert

2011-07-01

413

Understanding processing-microstructure-properties relationships in Bi2Sr2CaCu2Ox/Ag round wires and enhanced transport through saw-tooth processing  

NASA Astrophysics Data System (ADS)

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.

Naderi, Golsa; Liu, Xiaotao; Nachtrab, William; Schwartz, Justin

2013-10-01

414

Venom lethality and diet: differential responses of natural prey and model organisms to the venom of the saw-scaled vipers (Echis).  

PubMed

The composition of snake venoms shows a high degree of variation at all taxonomic levels, and natural selection for diet has been implicated as a potential cause. Saw-scaled vipers (Echis) provide a good model for studying this phenomenon. The venoms of arthropod feeding species of Echis are significantly more toxic to natural scorpion prey than those of species which feed predominantly upon vertebrate prey. Although testing venom activity on natural prey is important for our understanding of the evolution of venom, natural prey species are often difficult to obtain in sufficient numbers for toxinological work. In order to test the viability of using cheaper and more easily available model organisms for toxicity assessments in evolutionary research, and the extent to which toxicity of arthropod-eating Echis venoms is increased to arthropods in general or targeted to certain groups, we conducted median lethal dosage (LD(50)) and time to death trials using the desert locust (Schistocerca gregaria) as a model arthropod, rarely consumed by wild Echis. The venoms of arthropod specialist Echis were found to be significantly more toxic to locusts than the venom of a vertebrate feeding outgroup (Bitis arietans), and one arthropod specialist venom was found to be more toxic than those species which feed upon arthropods infrequently or not at all. The venoms of arthropod specialists were also found to cause death and incapacitation faster than the vertebrate feeding outgroup. Despite some similarity of trends, there are considerable differences between the response of natural prey (scorpions) and a model arthropod (locust) to the venoms of Echis species. This suggests that when possible, natural prey rather than convenient model organisms should be used to gain an understanding of the functional significance of variation in venom composition in snakes. PMID:22079297

Richards, D P; Barlow, A; Wüster, W

2012-01-01

415

SAWFAST - a SAW diffraction channelizer  

SciTech Connect

One important aspect of modern electronic warfare systems is the ability to sort signals according to their frequency. This paper describes a novel surface acoustic wave channelizer to perform this sorting at IF frequencies. The operating principles are analogous to an optical diffraction grating. Prototype devices that cover a 260 MHz bandwidth with a sidelobe rejection to about 40 dB are described.

Elliott, J.H.; Stokes, R.B.; Yen, K.H.

1986-09-01

416

Inner magnetosphere responses to the solar wind-magnetosphere energy transfers: Storms, saw-tooth oscillations and steady magnetospheric convection events.  

NASA Astrophysics Data System (ADS)

We present a quantitative investigation of the processes controlling the inner magnetospheric magnetic field topology during several dynamical states of the Earth's magnetosphere, namely, geomagnetic storms, sawtooth oscillations and steady magnetospheric convection (SMC) events. For this analysis we use our event-oriented model, a unique tool to provide a realistic representation of the magnetospheric magnetic field during disturbed times for specific events. The model is specified using solar wind and IMF data, all available in-situ and ground magnetic field measurements, and in addition, the magnetic field direction information derived from plasma electron distribution functions from the LANL MPA instrument. The output from this model is an input to the Inner Magnetosphere Particle Transport and Acceleration model (IMPTAM). This model traces ions and electrons with arbitrary pitch angles in the drift approximation in time-dependent magnetic and electric fields taking into account the loss processes. The initial particle distribution and boundary conditions are set and varied during the modeling based on observations during specific events. We model two storm events, one moderate with Dst drop of - 150 nT on November 6-7, 1997 and one intense with Dst drop of - 250 nT on October 21-23, 1999, two saw-tooth events, on October 22, 2001 and April 18, 2002, and two SMC events on February 3-4, 1998 and May 5, 1998. With this modeling we quantify which of the major current systems cause what aspects of the magnetic field distortion during magnetospheric dynamical states. With our physics-based numerical models we will determine the flow of plasma leading to the current systems that dominate the magnetic field distortion of the magnetosphere. In addition, the contribution of temporal variations of plasma dynamics (e.g., dispersed and dispersionless injections) to magnetic field distortions will be investigated. Furthermore, the detailed comparison between sawtooth oscillations and steady magnetosphric convection (SMC) events in terms of their observational features and model outputs will be conducted. By the analysis of sawtooth oscillations and steady magnetospheric convection (SMC) events a fundamental question whether the sawtooth events form a new class of magnetospheric events or whether they are simply quasi-periodic storm-time substorms will be addressed.

Ganushkina, N.; Kubyshkina, M.; Liemohn, M.; Pulkkinen, T.

2009-04-01

417

Pharmacologically relevant receptor binding characteristics and 5alpha-reductase inhibitory activity of free Fatty acids contained in saw palmetto extract.  

PubMed

Saw palmetto extract (SPE), used widely for the treatment of benign prostatic hyperplasia (BPH) has been shown to bind alpha(1)-adrenergic, muscarinic and 1,4-dihydropyridine (1,4-DHP) calcium channel antagonist receptors. Major constituents of SPE are lauric acid, oleic acid, myristic acid, palmitic acid and linoleic acid. The aim of this study was to investigate binding affinities of these fatty acids for pharmacologically relevant (alpha(1)-adrenergic, muscarinic and 1,4-DHP) receptors. The fatty acids inhibited specific [(3)H]prazosin binding in rat brain in a concentration-dependent manner with IC(50) values of 23.8 to 136 microg/ml, and specific (+)-[(3)H]PN 200-110 binding with IC(50) values of 24.5 to 79.5 microg/ml. Also, lauric acid, oleic acid, myristic acid and linoleic acid inhibited specific [(3)H]N-methylscopolamine ([(3)H]NMS) binding in rat brain with IC(50) values of 56.4 to 169 microg/ml. Palmitic acid had no effect on specific [(3)H]NMS binding. The affinity of oleic acid, myristic acid and linoleic acid for each receptor was greater than the affinity of SPE. Scatchard analysis revealed that oleic acid and lauric acid caused a significant decrease in the maximal number of binding sites (B(max)) for [(3)H]prazosin, [(3)H]NMS and (+)-[(3)H]PN 200-110. The results suggest that lauric acid and oleic acid bind noncompetitively to alpha(1)-adrenergic, muscarinic and 1,4-DHP calcium channel antagonist receptors. We developed a novel and convenient method of determining 5alpha-reductase activity using LC/MS. With this method, SPE was shown to inhibit 5alpha-reductase activity in rat liver with an IC(50) of 101 microg/ml. Similarly, all the fatty acids except palmitic acid inhibited 5alpha-reductase activity, with IC(50) values of 42.1 to 67.6 microg/ml. In conclusion, lauric acid, oleic acid, myristic acid, and linoleic acid, major constituents of SPE, exerted binding activities of alpha(1)-adrenergic, muscarinic and 1,4-DHP receptors and inhibited 5alpha-reductase activity. PMID:19336899

Abe, Masayuki; Ito, Yoshihiko; Oyunzul, Luvsandorj; Oki-Fujino, Tomomi; Yamada, Shizuo

2009-04-01

418

An east-west climate see-saw in the Mediterranean during the last 2.6 ka: evidence and mechanisms  

NASA Astrophysics Data System (ADS)

Global precipitation anomalies during the Common Era show a spatial coherency that appears to be about an order of magnitude lower (i.e. smaller) than for temperature changes, as some areas became wetter while others experienced drought (Seager et al., 2007, Quat. Sci. Rev. 26, 2322-36). The Mediterranean basin (10°W-40°E; 30°-45°N) is influenced by some of the main mechanisms acting upon the global climate system and its regional water resources are sensitive to hydro-climatic variations. Reconstructing the timing, intensity, and patterns of hydrological variability in the Mediterranean is important for testing spatial-temporal coherency in palaeo-precipitation, and for understanding underlying climate forcing mechanisms. The region offers a broad spectrum of documentary information and natural archives which allow high-resolution climate reconstructions (Luterbacher et al., 2012, In: Lionello et al. (eds) The Mediterranean Climate: from past to future. Elsevier, pp. 87-185). During the period of instrumental records, the NAO has strongly influenced inter-annual precipitation variations in the western Mediterranean, while parts of the eastern basin have shown an anti-phase relationship in precipitation and atmospheric pressure. A wide array of proxy-climate data from Iberia and Morocco indicate overall drier conditions during the Medieval Climate Anomaly (MCA) and a generally wetter climate in the Little Ice Age (LIA)(Moreno et al., 2012, Quat. Sci. Rev. 43, 16-32). This pattern is consistent with strong NAO forcing of western Mediterranean climate over the last 1.1 ka (Trouet et al., 2009; Science 324, 78-80). High-resolution palaeolimnological evidence from central Anatolia exhibit an opposite pattern, implying that an east-west climate see-saw operated in the Mediterranean basin during the LIA and MCA (Roberts et al., 2012; Glob. Planet. Change 84-85, 23-34). However, the strongest evidence for higher (lower) winter season precipitation during the MCA (LIA) does not come from the southeast sector of the Mediterranean basin, as would be expected from the pattern of NAO forcing seen during the instrumental period. Prior to the MCA, many proxy-climate records show changes of significantly larger amplitude than during the last millennium, notably during and after the Roman period. However, absolute chronologies become less precise with dating errors of ±>50 yr (Dermody et al., 2012; Clim. Past 8, 637-651), making correlations less robust. Before 2.6 ka BP, i.e. coincident with the northern European grenzhorizont, proxy-climate records from the Mediterranean show changes which imply a significant shift in atmospheric boundary conditions (e.g. radiative forcing). It is clear that hydro-climatic trends have been non-uniform across the Mediterranean in recent millennia. The contrasting spatio-temporal patterns across the basin appear to have been determined by a combination of different climate modes along with major physical geographical controls, not by NAO forcing alone, and/or the character of the NAO and its teleconnections have been non-stationary.

Roberts, C.; Moreno-Caballud, A.; Valero-Garces, B. L.; Luterbacher, J.; Xoplaki, E.; Allcock, S. L.

2012-12-01

419

Evaluation of residual stress using saw  

NASA Astrophysics Data System (ADS)

The characteristics of the Rayleigh surface wave are investigated indirectly by measuring the angular dependency of the backward radiation of the incident ultrasonic wave in the scuffing specimens, and then compared to the residual stress distribution. The peak intensity of the backward radiation profile decreases and the right half width of the profile increases as the increase in the variation of residual stress distribution for the scuffing specimen. The peak intensity and angle depend on the amount of residual stress as well as the inhomogeneity in microstructure that causes scattering during the propagation of the surface waves. The result observed in this study demonstrates high potential of the backward radiated ultrasound as a tool for nondestructive evaluation of the subsurface gradients of materials. .

Kwon, Sung D.; Song, Sung J.; Lee, Young Z.

2002-05-01

420

Stringy unification helps see-saw mechanism.  

National Technical Information Service (NTIS)

In this paper we explore the possibility of intermediate scale physics in the context of superstring models with higher Kac-Moody levels, by focusing on left-right and Pati-Salam symmetries. We find that the left-right scale may lie in the range 10(sup 10...

K. Benakli G. Senjanovic

1995-01-01

421

They saw a game; a case study  

Microsoft Academic Search

When the Dartmouth football team played Princeton in 1951, much controversy was generated over what actually took place during the game. Basically, there was disagreement between the two schools as to what had happened during the game. A questionnaire designed to get reactions to the game and to learn something of the climate of opinion was administered at each school

Albert H. Hastorf; Hadley Cantril

1954-01-01

422

Analysis of aging data on SAW oscillators  

NASA Technical Reports Server (NTRS)

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.

Parker, T. E.

1980-01-01

423

What Brown saw and you can too  

NASA Astrophysics Data System (ADS)

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.

Pearle, Philip; Collett, Brian; Bart, Kenneth; Bilderback, David; Newman, Dara; Samuels, Scott

2010-12-01

424

Effects of D-004, a lipid extract of the fruit of the Cuban royal palm (Roystonea regia) or the lipidosterolic extract of saw palmetto (Serenoa repens) on the sexual activity in male rats: A controlled, experimental study.  

PubMed

Background: The etiology of benign prostatic hyperplasia (BPH) is not completely understood, but hormonal changes in aging men seem to be pivotal. Dihydrotestosterone, a potent, active metabolite of testosterone, is formed by the enzymatic action of prostate 5?-reductase and causes cell growth and hyperplasia. Consistent with this action, male sexual dysfunction has been clinically documented to be among the drug-related adverse events associated with 5?-reductase inhibitors. The lipidosterolic extract of saw palmetto (LESP) fruit (Serenoa repens) has been used to treat BPH. D-004, a lipid extract of Roystonea regia Royal palm fruit, has been found to prevent prostatic hyperplasia induced by testoste-rone in rodents and to competitively inhibit prostate 5?-reductase activity in vitro. Objective: The purpose of this study was to assess the effects of D-004 and LESP, administered as single or repeated doses, on the sexual activity in male rats. Methods: This controlled, experimental study was conducted at the Pharmacology Department, Centre of Natural Products, National Centre for Scientific Research, Havana City, Cuba. Adult male Wistar rats weighing 250 to 300 g were randomized into 5 groups: 2 groups treated orally with D-004 (400 and 800 mg/kg); 2 groups treated orally with LESP (400 and 800 mg/kg); and 1 control group orally administered a water vehicle. Sexual activity behavior (the number of mounts and intromissions, mount latency, and intromission latency) was assessed during 2 observation periods: 90 minutes after the initial dose and at the end of the 30-day treatment. Latency was defined as time elapsed between the first mount and intromission. Results: A total of 50 rats (mean [SD] age, 10 [3] weeks; mean [SD] weight, 295 [10] g) were included in the experiment. There were no significant difterences in the mean number of mounts, intromissions, mount latency, or intromission latency in the groups treated with single or repeated doses of D-004 or LESP (400 and 800 mg/kg) compared with the controls. There was also no between-group difterence in mating behavior among the active treatment groups. All rats survived up to study completion, with normal behavior (weight gain, food intake, daily observations, without any sign of toxicity). There were no observable adverse events during the study. Conclusions: D-004 and LESP administered as a single dose or repeated doses for 30 days did not significantly affect male rat sexual activity behavior compared with a vehicle control group. PMID:24692784

Fernández, Lilia C; Mas, Rosa; Fernández, Julio; Mendoza, Sarahí; Gámez, Rafael; Pardo, Balia

2008-02-01

425

Weighted SAW reflector gratings for orthogonal frequency coded SAW tags and sensors  

NASA Technical Reports Server (NTRS)

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.

Puccio, Derek (Inventor); Malocha, Donald (Inventor)

2011-01-01

426

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

Microsoft Academic Search

We have developed a wafer-level packaging solu- tion 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 solu- tions, SU-8 and TMMF,

Jan H. Kuypers; Shuji Tanaka; Masayoshi Esashi

2011-01-01

427

Performance evaluation of algorithms for SAW-based temperature measurement.  

PubMed

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

Schuster, Stefan; Scheiblhofer, Stefan; Reindl, Leonhard; Stelzer, Andreas

2006-06-01

428

Would You Recognize Fahr's Disease if You Saw It?  

PubMed

Idiopathic basal ganglia calcification or Fahr's disease is a neurological condition with a prominent movement disorder. Diagnostically, brain imaging with computerized tomographic scanning reveals bilateral brain calcifications, usually of the basal ganglia. A positive family history is very common, along with a generational anticipatory effect, thus familial basal ganglia calcification is an alternative name. Cognitive deficits and psychiatric symptoms are often present. This progressive disease has no cure, but symptomatic treatment may be beneficial. PMID:24653939

Goyal, Dharmendra; Khan, Mashal; Qureshi, Bushra; Mier, Catherine; Lippmann, Steven

2014-01-01

429

Photolithographic Techniques for Surface Acoustic Wave (SAW) Devices.  

National Technical Information Service (NTIS)

The object of the program is the establishment of a production capability for surface acoustic wave devices of varied design and material for the purpose of meeting estimated military needs for a period of two years after the completion of the contract an...

A. R. Janus W. R. Smith

1975-01-01

430

Hammers and Saws for the Improvement of Educational Research  

ERIC Educational Resources Information Center

This article examines different conceptions of causation and their implications for understanding educational phenomena and conducting educational research. Specifically, I discuss four research designs for pursuing questions about causation in education. Two of these research designs take a variance approach to causation (that is, they attempt to…

Eisenhart, Margaret

2005-01-01

431

Hole saw drill attachment has zero force reaction  

NASA Technical Reports Server (NTRS)

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.

Holmes, A. E.; Riley, R. H., Jr.

1966-01-01

432

Analysis of the natural single phase unidirectional SAW transducer  

Microsoft Academic Search

The calculation of fundamental parameters needed for the analysis of a natural single-phase unidirectional transducer (NSPUDT) is reported. Analytical forms for the NSPUDT parameters on arbitrary crystal cuts are given in terms of material constants and electrode geometry. The acoustic-wave velocity, electromechanical-coupling parameter, power-flow angle, static capacitance, transduction coefficient, and reflection from a single strip due to both electrical and

Thor Thorvaldsson

1989-01-01

433

Fractional moment methods for Anderson localization with SAW representation  

NASA Astrophysics Data System (ADS)

The Green function contains much information about physical systems. Mathematically, the fractional moment method (FMM) developed by Aizenman and Molchanov connects the Green function and the transport of electrons in the Anderson model. Recently, it has been discovered that the Green function on a graph can be represented using self-avoiding walks on a graph, which allows us to connect localization properties in the system and graph properties. We discuss FMM in terms of the self-avoiding walks on a general graph, the only general condition being that the graph has a uniform bound on the vertex degree.

Suzuki, Fumika

2013-03-01

434

Chop Saw SUCCESS!: "Crash Proofing" a Metalworking Lab  

ERIC Educational Resources Information Center

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…

Domermuth, David

2004-01-01

435

The Income Volatility See-Saw: Implications for School Lunch  

Microsoft Academic Search

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 successively lower income groups and that the major determinants of changes

Constance Newman

2006-01-01

436

Efficient analysis tool for coupled-SAW-resonator filters.  

PubMed

The advantages of the coupled-mode (COM) formalism and the transmission-matrix approach are combined in order to create exact and computationally efficient analysis and synthesis tools for the design of coupled surface acoustic wave resonator filters. The models for the filter components, in particular gratings, interdigital transducers (IDTs) and multistrip couplers (MSCs), are based on the COM approach that delivers closed-form expressions. To determine the pertinent COM parameters, the COM differential equations are solved and the solution is compared with analytically derived expressions from the transmission-matrix approach and the Green's function method. The most important second-order effects, such as energy storage, propagation loss, and mechanical and electrical loading, are fully taken into account. As an example, a two-pole, acoustically coupled resonator filter at 914.5 MHz on AT quartz is investigated. Excellent agreement between theory and measurement is found. PMID:18267581

Scholl, G; Christ, A; Ruile, W; Russer, P H; Weigel, R

1991-01-01

437

Saw Sensor Array for Chemical Warfare Agent Simulants  

Microsoft Academic Search

A surface acoustic wave array of sensors was developed for the detection of chemical warfare agent simulants. Sensors were coated with different polymers for a higher accuracy. Data acquired were processed; principal components analysis (PCA) and probabilistic neural network (PNN) were used for the discrimination and classification of the chemical agents.

J. Marti; D. Matatagui; M. J. Fernaindez; J. L. Fontecha; M. Aleixandre; F. J. Gutierrez; M. C. Horrillo; I. Gracia; C. Cane

2009-01-01

438

Single Crystal Growth of Potassium Lithium Niobate for SAW Applications.  

National Technical Information Service (NTIS)

We have successfully demonstrated 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. However, w...

R. R. Neurgaonkar

1983-01-01

439

Would We Recognize Progress if We Saw It? A Commentary  

ERIC Educational Resources Information Center

Comments on the nature of special education as an enterprise and judgment of its progress are offered. Five independent but necessary and sufficient criteria for judgment of progress in special education for students with emotional or behavioral disorders are suggested. Comments are made on each of the articles in the series, and concluding…

Kauffman, James M.

2008-01-01

440

I Can't Believe I Saw the Whole Thing!  

ERIC Educational Resources Information Center

The author explains some of the principles underlying holography, a process by which literally hundreds of images can be stored on a single piece of film and then reproduced, one by one, in three dimension.'' (Editor/AK)

Asimov, Isaac

1972-01-01

441

"I Saw the Universe and I Saw the World": Exploring Spiritual Literacy with Young Children in a Primary Classroom  

ERIC Educational Resources Information Center

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…

Binder, Marni J.

2011-01-01

442

Information SeeSaw: Availability vs. Security Management in the UbiComp World  

Microsoft Academic Search

\\u000a The ubiquitous computing vision brings about a number of information security and privacy challenges, some of which we already\\u000a face in the mobile computing arena. This work focuses on a context-specific class of information leakage threats not involving\\u000a a malicious custodian. Information exposure threats arise as a side effect of a particular choice of data management procedures employed during legitimate

Boris Dragovic; Calicrates Policroniades

2005-01-01

443

Design, fabrication, and application of precise SAW delay lines used in an FMCW radar system  

Microsoft Academic Search

An inexpensive frequency-modulated continuous-wave (FMCW) radar system is presented in this paper, which, nevertheless, meets all industrial requirements. The FMCW radar uses a low-cost nonlinear voltage-controlled oscillator (VCO), operating at an IF of 2.45 GHz to generate the frequency modulation of the radar system. This VCO signal is applied twice, first to generate the radar transmitter signal at 24 GHz,

Leonhard Reindl; Clemens C. W. Ruppel; Stefan Berek; Ulrich Knauer; Martin Vossiek; Patric Heide; Lutz Oréans

2001-01-01

444

Signal model and linearization for nonlinear chirps in FMCW Radar SAW-ID tag request  

Microsoft Academic Search

In this paper, we present a frequency-modulated continuous-wave radar interrogation concept, based on direct digital synthesis (DDS), that operates without the commonly necessary high-frequency DDS reference oscillator. As the generated frequency sweeps are nonlinear, standard Fourier transform methods for baseband signal evaluation cannot be applied directly. We show the corresponding signal model, derive a linearization concept on the basis of

Stefan Scheiblhofer; Stefan Schuster; Andreas Stelzer

2006-01-01

445

Properdin and Factor H: Opposing Players on the Alternative Complement Pathway "See-Saw"  

PubMed Central

Properdin and factor H are two key regulatory proteins having opposite functions in the alternative complement pathway. Properdin up-regulates the alternative pathway by stabilizing the C3bBb complex, whereas factor H downregulates the pathway by promoting proteolytic degradation of C3b. While factor H is mainly produced in the liver, there are several extrahepatic sources. In addition to the liver, factor H is also synthesized in fetal tubuli, keratinocytes, skin fibroblasts, ocular tissue, adipose tissue, brain, lungs, heart, spleen, pancreas, kidney, muscle, and placenta. Neutrophils are the major source of properdin, and it is also produced by monocytes, T cells and bone marrow progenitor cell line. Properdin is released by neutrophils from intracellular stores following stimulation by N-formyl-methionine-leucine-phenylalanine (fMLP) and tumor necrosis factor alpha (TNF-?). The HEP G2 cells derived from human liver has been found to produce functional properdin. Endothelial cells also produce properdin when induced by shear stress, thus is a physiological source for plasma properdin. The diverse range of extrahepatic sites for synthesis of these two complement regulators suggests the importance and need for local availability of the proteins. Here, we discuss the significance of the local synthesis of properdin and factor H. This assumes greater importance in view of recently identified unexpected and novel roles of properdin and factor H that are potentially independent of their involvement in complement regulation.

Kouser, Lubna; Abdul-Aziz, Munirah; Nayak, Annapurna; Stover, Cordula M.; Sim, Robert B.; Kishore, Uday

2013-01-01

446

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

Federal Register 2010, 2011, 2012, 2013

...new modular blade guard. Because the usage patterns are directly linked to the safety...participate in the follow-up, full-scale Computer Assisted Telephone Interviewing (CATI) survey about their usage of, and opinions about, the...

2013-05-28

447

NASA Lewis Helps Develop Advanced Saw Blades for the Lumber Industry  

NASA Technical Reports Server (NTRS)

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.

1998-01-01

448

PSAW/MicroSWIS [Microminiature Surface Acoustic Wave (SAW) based Wirelesss Instrumentation System  

NASA Technical Reports Server (NTRS)

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.

Heermann, Doug; Krug, Eric

2004-01-01

449

Interesting differences between CH4 and d18Oatm records of bipolar see-saw activity  

NASA Astrophysics Data System (ADS)

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.

Severinghaus, Jeffrey; Baggenstos, Daniel; Rhodes, Rachael; Brook, Edward

2014-05-01

450

Utility Theory for Evaluation of Optimal Process Condition of SAW: A Multi-Response Optimization Approach  

SciTech Connect

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.

Datta, Saurav [Department of Mechanical Engineering, National Institute of Technology, Rourkela, Orissa-769008 (India); Biswas, Ajay; Bhaumik, Swapan [Department of Mechanical Engineering, National Institute of Technology, Agartala, Barjala, Tripura (W), Pin-799055 (India); Majumdar, Gautam [Department of Mechanical Engineering, Jadavpur University, Raja S. C. Mallik Road, Kolkata-700032 (India)

2011-01-17

451

Design of Low-Loss SAW Filters Employing Distributed Acoustic Reflection Transducers  

Microsoft Academic Search

A new structure for an internal reflection type interdigi tal transducer is presented , which enables broadband rejection of unwanted spurious reflection signals. The proposed structure might be called a distributed acoustic reflection transducer (DART) , since it consists of many acoustic reflection dot elements distributed over the entire region of the transducer. Several basic properties of the new transducer

T. Kodama; H. Kawabata; Y. Yasuhara; H. Sato

1986-01-01

452

I saw this and thought of you: some social uses of camera phones  

Microsoft Academic Search

This paper presents aspects of a study into how and why people use camera phones. The study examined people's intentions at the time of image capture and subsequent patterns of use. Motivated by current interest in \\

Tim Kindberg; Mirjana Spasojevic; Rowanne Fleck; Abigail Sellen

2005-01-01

453

I Saw It on TV. More Vocational Educators Use PSAs and Videos to Reach Potential Students.  

ERIC Educational Resources Information Center

Discusses how a growing number of states and school districts are using public service announcements (PSAs) to recruit students. Describes how a world-class decathlete appeared for free in a PSA for the Idaho Division of Vocational Education. (JOW)

Maxwell, Bruce

1994-01-01

454

SAW and BAW response of c-axis AlN thin films sputtered on platinum  

Microsoft Academic Search

We evaluate the longitudinal and transverse piezoelectric response of highly (00·2)-oriented AlN films sputtered on platinum layers. We have observed that the existence of some defects in the films, associated with the appearance of weak diffraction peaks other than the 00·2 reflection in the XRD patterns, annihilates the piezoelectric response, even in films with very large grain size. In the

M. Clement; L. Vergara; J. Olivares; E. Iborra; J. Sangrador; A. Sanz-Hervas; C. Zinck

2004-01-01

455

Defect detection in partially completed SAW and TIG welds using online radioscopy and image processing  

Microsoft Academic Search

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

Gary R. Bonser; Shaun W. Lawson

1998-01-01

456

One GHz leaky SAW velocity of metal layers and bilayers evaporated onto fused quartz  

NASA Technical Reports Server (NTRS)

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.

Walikainen, Dale

1992-01-01

457

Are Outer Hair Cells Pressure Sensors? Basis of a SAW Model of the Cochlear Amplifier  

NASA Astrophysics Data System (ADS)

Because outer hair cells bear stereocilia it is natural to assume that, like inner hair cells, the unique stimulus to which they react is stereociliar deflection. But is this long-standing assumption necessarily true? This work considers a number of recurring anomalies which have appeared in the literature over the years and concludes that their common underlying feature is an OHC response to pressure. At low SPLs, intracochlear fluid pressure could provide an additional, and perhaps dominant, stimulus for driving the cochlear amplifier.

Bell, A.

2003-02-01

458

Application of Saw Delay Line Attenuation and Transverse Acoustoelectric Voltage for Determination of Semiconductor Surface Properties.  

National Technical Information Service (NTIS)

The study of the semiconductor surfaces, using acoustoelectric voltage and delay line attenuation as a tool has been recently reported. Acoustoelectric voltage is the result of non-linear interaction between semiconductor space charge carriers and surface...

M. E. Motamedi R. T. Webster P. Das

1975-01-01

459

Design of Rayleigh SAW Resonators for Applications as Gas Sensors in Highly Reactive Chemical Environments  

Microsoft Academic Search

This work presents the performance and important design considerations of the first successful highly efficient Rayleigh surface acoustic wave (RSAW) resonator filters using gold (Au) electrode structure. Au metallisation provides corrosion immunity when the devices are operated as polymer coated gas sensors in chemically reactive environments. It is shown that Au, due to its 7 times higher density than Al,

Ivan D. Avramov

2006-01-01

460

The Performance and Relative Costs of Frame Saw Spacer Blocks Made from Various Materials.  

National Technical Information Service (NTIS)

The purpose of the report is to assess the suitability of various materials used for the manufacture of spacer blocks; to determine the relative performance and useful life of the various materials; to determine the cost of using spacer blocks made from t...

D. T. Priest

1980-01-01

461

ENSO-driven carbon see saw in the Indo-Pacific  

NASA Astrophysics Data System (ADS)

The sediment trap experiments have been carried out during the 2001/2002 El Niño/La Niña 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 Niña conditions. A reduced capping-effect during dryer El Niño 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 Niño weakens upwelling and reduces the CO2 emission in the equatorial Pacific Ocean.

Rixen, Tim; Ittekkot, Venugopalan; Herunadi, Bambang; Wetzel, Patrick; Maier-Reimer, E.; Gaye-Haake, Birgit

2006-04-01

462