Vibration Mitigation on Engine Test Stands Using Conventional Analysis Techniques

2014 ◽  
pp. 109-121 ◽  
Author(s):  
B. Swaminathan
Keyword(s):  
Engine Test ◽  
Vibration Mitigation ◽  
Analysis Techniques ◽  
Conventional Analysis

Formation-Rate-Analysis Technique: Combined Drawdown and Buildup Analysis for Wireline Formation Test Data

1999 ◽  
Vol 2 (03) ◽  
pp. 271-280 ◽  
Author(s):  
Ekrem Kasap ◽  
Kun Huang ◽  
Than Shwe ◽  
Dan Georgi
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Field Data ◽  
Formation Rate ◽  
Flow Analysis ◽  
Early Time ◽  
Late Time ◽  
Time Data ◽  
Analysis Techniques ◽  
Conventional Analysis

Summary The formation-rate-analysis (FRASM) technique is introduced. The technique is based on the calculated formation rate by correcting the piston rate with fluid compressibility. A geometric factor is used to account for irregular flow geometry caused by probe drawdown. The technique focuses on the flow from formation, is applicable to both drawdown and buildup data simultaneously, does not require long buildup periods, and can be implemented with a multilinear regression, from which near-wellbore permeability, p * and formation fluid compressibility are readily determined. The field data applications indicate that FRA is much less amenable to data quality because it utilizes the entire data set. Introduction A wireline formation test (WFT) is initiated when a probe from the tool is set against the formation. A measured volume of fluid is then withdrawn from the formation through the probe. The test continues with a buildup period until pressure in the tool reaches formation pressure. WFTs provide formation fluid samples and produce high-precision vertical pressure profiles, which, in turn, can be used to identify formation fluid types and locate fluid contacts. Wireline formation testing is much faster compared with the regular pressure transient testing. Total drawdown time for a formation test is just a few seconds and buildup times vary from less than a second (for permeability of hundreds of millidarcy) to half a minute (for permeability of less than 0.1 md), depending on system volume, drawdown rate, and formation permeability. Because WFT tested volume can be small (a few cubic centimeters), the details of reservoir heterogeneity on a fine scale are given with better spatial resolution than is possible with conventional pressure transient tests. Furthermore, WFTs may be preferable to laboratory core permeability measurements since WFTs are conducted at in-situ reservoir stress and temperature. Various conventional analysis techniques are used in the industry. Spherical-flow analysis utilizes early-time buildup data and usually gives permeability that is within an order of magnitude of the true permeability. For p* determination, cylindrical-flow analysis is preferred because it focuses on late-time buildup data. However, both the cylindrical- and spherical-flow analyses have their drawbacks. Early-time data in spherical-flow analysis results in erroneous p* estimation. Late-time data are obtained after long testing times, especially in low-permeability formations; however, long testing periods are not desirable because of potential tool "sticking" problems. Even after extended testing times, the cylindrical-flow period may not occur or may not be detectable on WFTs. When it does occur, permeability estimates derived from the cylindrical-flow period may be incorrect and their validity is difficult to judge. New concepts and analysis techniques, combined with 3-D numerical studies, have recently been reported in the literature.1–7 Three-dimensional numerical simulation studies1–6 have contributed to the diagnosis of WFT-related problems and the improved analysis of WFT data. The experimental studies7 showed that the geometric factor concept is valid for unsteady state probe pressure tests. This study presents the FRA technique8 that can be applied to the entire WFT where a plot for both drawdown and buildup periods renders straight lines with identical slopes. Numerical simulation studies were used to generate data to test both the conventional and the FRA techniques. The numerical simulation data are ideally suited for such studies because the correct answer is known (e.g., the input data). The new technique and the conventional analysis techniques are also applied to the field data and the results are compared. We first review the theory of conventional analysis techniques, then present the FRA technique for combined drawdown and buildup data. A discussion of the numerical results and the field data applications are followed by the conclusions. Analysis Techniques It has been industry practice to use three conventional techniques, i.e., pseudo-steady-state drawdown (PSSDD), spherical and cylindrical-flow analyses, to calculate permeability and p* Conventional Techniques Pseudo-Steady-State Drawdown (PSSDD). When drawdown data are analyzed, it is assumed that late in the drawdown period the pressure drop stabilizes and the system approaches to a pseudo-steady state when the formation flow rate is equal to the drawdown rate. PSSDD permeability is calculated from Darcy's equation with the stabilized (maximum) pressure drop and the flowrate resulting from the piston withdrawal:9–11 $$k {d}=1754.5\left({q\mu \over r {i}\Delta p {{\rm max}}}\right),\eqno ({\rm 1})$$where kd=PSSDD permeability, md. The other parameters are given in Nomenclature.

scholarly journals Biosensor Designs for Platelet-derived Microparticles Analysis

2017 ◽  
Vol 53 (04) ◽  
pp. 234-237
Author(s):  
Jyotsna Kailashiya
Keyword(s):  
Myocardial Infarction ◽  
Platelet Activation ◽  
Cost Effective ◽  
Analysis Techniques ◽  
Conventional Analysis ◽  
Analytical Tools ◽  
Effective Analysis ◽  
Potential Biomarkers

ABSTRACTPlatelet-derived microparticles (PMPs) are often used as marker of platelet activation and their count in blood has been found to be significantly associated with many diseases like myocardial infarction, stroke, venous thrombo-embolism etc. PMPs have been proposed as potential biomarkers for these conditions. Biosensors are newer analytical tools, being developed for convenient and cost effective analysis. For PMPs analysis, biosensors offer many advantages over conventional analysis techniques. This mini review compiles designs and techniques of reported biosensors based on antibody capturing for analysis of PMPs.

A Proposal for Integration of Wind Tunnel and Engine Test Programs for the Evaluation of Airframe-Propulsion Compatibility Using Numerical Simulations1

2002 ◽  
Vol 124 (3) ◽  
pp. 447-458 ◽  
Author(s):  
M. Davis ◽  
W. Baker ◽  
G. Power ◽  
D. Beale
Keyword(s):  
High Performance ◽  
Navier Stokes ◽  
Engine Test ◽  
Development Programs ◽  
Analysis Techniques ◽  
Inlet Distortion ◽  
Test And Evaluation ◽  
Current State ◽  
Isolated Systems ◽  
Semi Empirical

The current high-performance aircraft development programs, and the trends in research and development activities suggest a rapidly increasing level of aircraft subsystem integration, particularly between the airframe/inlet and the propulsion system. Traditionally these subsystems have been designed, analyzed, and tested as isolated systems. The interaction between the subsystems is modeled primarily through evaluating inlet distortion in an inlet test and simulating this distortion in engine tests via screens or similar devices. In the current paper, an overview of current techniques for inlet performance and distortion characterization and engine distortion testing is presented. A review of the current state of the art in inlet analysis is also presented along with a discussion of current engine analysis techniques, from a semi-empirical approach to high-fidelity full Navier-Stokes simulations. Finally, a proposal to coordinate the existing test techniques and analysis capabilities to provide a truly integrated inlet-engine test and evaluation capability is outlined.

Leveraging Root Cause Deconvolution Analysis for Logic Yield Ramping

2013 ◽  
Author(s):  
Yan Pan ◽  
Atul Chittora ◽  
Kannan Sekar ◽  
Goh Szu Huat ◽  
You Guo Feng ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Comprehensive Analysis ◽  
Paper Briefly ◽  
Yield Improvement ◽  
Deconvolution Analysis ◽  
Analysis Techniques ◽  
Root Cause ◽  
Conventional Analysis ◽  
Analysis System ◽  
Over Time

Abstract The root cause deconvolution (RCD) provides an easy-to-understand defect Pareto, together with targeted physical failure analysis candidates. Unfortunately, even the RCD analysis also has some assumptions and limitations, and its result cannot always be interpreted literally. This calls for a variety of conventional yield analysis techniques to be adopted in parallel to improve the confidence in the RCD results. This paper briefly introduces the RCD analysis and explains how it distinguishes itself from other conventional volume diagnosis analysis techniques. Its typical inputs and outputs are discussed as well. Next, the paper focuses on two case studies where the authors leverage RCD for logic yield improvement together with other conventional analysis techniques. It then proposes a comprehensive analysis system that is backed up by accumulating RCD results over time and across different design IPs.

scholarly journals Visualization of vermilion degradation using pump-probe microscopy

2019 ◽  
Vol 5 (6) ◽  
pp. eaaw3136 ◽  
Author(s):  
Jin Yu ◽  
Warren S. Warren ◽  
Martin C. Fischer
Keyword(s):  
Elevated Temperatures ◽  
High Spatial Resolution ◽  
Degradation Products ◽  
Metallic Mercury ◽  
Pump Probe ◽  
Probe Microscopy ◽  
Analysis Techniques ◽  
Ultraviolet Exposure ◽  
Conventional Analysis ◽  
Pulsed Laser Irradiation

Here, we demonstrate the use of pump-probe microscopy for high-resolution studies of vermilion degradation. Vermilion (mostly α-HgS), an important red pigment used in historical paintings, blackens over time, and metallic Hg and β-HgS have been implicated as possible degradation products. Conventional analysis techniques have trouble differentiating α- and β-HgS with sufficiently high spatial resolution. However, pump-probe microscopy can differentiate metallic mercury, α- and β-HgS, and map each distribution on the microscopic scale. We studied artificial degradation of α-HgS; femtosecond-pulsed laser irradiation induces an irreversible phase shift of α- to β-HgS, in which the initial presence of β-HgS grains can increase the rate of conversion in their vicinity. Continuous ultraviolet exposure instead generates both liquid Hg and β-HgS, with a conversion rate that increases with elevated temperatures. Last, we reveal the presence of β-HgS as a natural degradation product in discolored vermilion layers in a 14th century Italian painting.

A Proposal for Integration of Wind Tunnel and Engine Test Programs for the Evaluation of Airframe-Propulsion Compatibility Using Numerical Simulations

1999 ◽  
Author(s):  
Milt Davis ◽  
William Baker ◽  
Greg Power ◽  
Dave Beale
Keyword(s):  
High Performance ◽  
Navier Stokes ◽  
Engine Test ◽  
Development Programs ◽  
Analysis Techniques ◽  
Inlet Distortion ◽  
Test And Evaluation ◽  
Current State ◽  
Isolated Systems ◽  
Semi Empirical

The current high-performance aircraft development programs, and the trends in research and development activities suggest a rapidly increasing level of aircraft subsystem integration, particularly between the airframe/inlet and the propulsion system. Traditionally these subsystems have been designed, analyzed, and tested as isolated systems. The interaction between the subsystems is modeled primarily through evaluating inlet distortion in an inlet test and simulating this distortion in engine tests via screens or similar devices. In the current paper, an overview of current techniques for inlet performance and distortion characterization and engine distortion testing is presented. A review of the current state-of-the-art in inlet analysis is also presented along with a discussion of current engine analysis techniques, from a semi-empirical approach to high-fidelity full Navier-Stokes simulations. Finally, a proposal to coordinate the existing test techniques and analysis capabilities to provide a truly integrated inlet-engine test and evaluation capability is outlined.

An example of spectrum imaging used for comparison of EELS quantitative analysis techniques on Al-Li

1991 ◽  
Vol 49 ◽  
pp. 726-727
Author(s):  
John A. Hunt
Keyword(s):  
Quantitative Analysis ◽  
Large Data ◽  
Difference Spectrum ◽  
Large Data Sets ◽  
Foil Thickness ◽  
Data Sets ◽  
Analysis Techniques ◽  
Spectrum Imaging ◽  
Normal Spectrum ◽  
Electron Energy Loss

Spectrum-imaging is a useful technique for comparing different processing methods on very large data sets which are identical for each method. This paper is concerned with comparing methods of electron energy-loss spectroscopy (EELS) quantitative analysis on the Al-Li system. The spectrum-image analyzed here was obtained from an Al-10at%Li foil aged to produce δ' precipitates that can span the foil thickness. Two 1024 channel EELS spectra offset in energy by 1 eV were recorded and stored at each pixel in the 80x80 spectrum-image (25 Mbytes). An energy range of 39-89eV (20 channels/eV) are represented. During processing the spectra are either subtracted to create an artifact corrected difference spectrum, or the energy offset is numerically removed and the spectra are added to create a normal spectrum. The spectrum-images are processed into 2D floating-point images using methods and software described in [1].

Dissociated Σ=27 boundaries in silicon

1988 ◽  
Vol 46 ◽  
pp. 624-625
Author(s):  
A. Garg ◽  
W.A.T. Clark ◽  
J.P. Hirth
Keyword(s):  
Electron Diffraction ◽  
Local Minimum ◽  
Boundary Energy ◽  
Coincidence Site Lattice ◽  
Boundary Plane ◽  
Low Energy ◽  
Theoretical Understanding ◽  
Site Lattice ◽  
Kikuchi Pattern ◽  
Analysis Techniques

In the last twenty years, a significant amount of work has been done in the theoretical understanding of grain boundaries. The various proposed grain boundary models suggest the existence of coincidence site lattice (CSL) boundaries at specific misorientations where a periodic structure representing a local minimum of energy exists between the two crystals. In general, the boundary energy depends not only upon the density of CSL sites but also upon the boundary plane, so that different facets of the same boundary have different energy. Here we describe TEM observations of the dissociation of a Σ=27 boundary in silicon in order to reduce its surface energy and attain a low energy configuration.The boundary was identified as near CSL Σ=27 {255} having a misorientation of (38.7±0.2)°/[011] by standard Kikuchi pattern, electron diffraction and trace analysis techniques. Although the boundary appeared planar, in the TEM it was found to be dissociated in some regions into a Σ=3 {111} and a Σ=9 {122} boundary, as shown in Fig. 1.

Material analysis techniques using the ion mill

1996 ◽  
Vol 54 ◽  
pp. 1034-1035
Author(s):  
J. P. Benedict ◽  
R. M. Anderson ◽  
S. J. Klepeis
Keyword(s):  
Polished Surface ◽  
Surface Material ◽  
Analysis Techniques ◽  
Material Analysis ◽  
Optical Inspection ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Argon Ions ◽  
The Impact ◽  
Scanning Electron

Ion mills equipped with flood guns can perform two important functions in material analysis; they can either remove material or deposit material. The ion mill holder shown in Fig. 1 is used to remove material from the polished surface of a sample for further optical inspection or SEM ( Scanning Electron Microscopy ) analysis. The sample is attached to a pohshing stud type SEM mount and placed in the ion mill holder with the polished surface of the sample pointing straight up, as shown in Fig 2. As the holder is rotating in the ion mill, Argon ions from the flood gun are directed down at the top of the sample. The impact of Argon ions against the surface of the sample causes some of the surface material to leave the sample at a material dependent, nonuniform rate. As a result, the polished surface will begin to develop topography during milling as fast sputtering materials leave behind depressions in the polished surface.

Developmental Sentence Scoring

1984 ◽  
Vol 15 (3) ◽  
pp. 154-168 ◽  
Author(s):  
Mary Ann Lively
Keyword(s):  
Expressive Language ◽  
Analysis Techniques ◽  
Language Analysis ◽  
Scoring Errors

Developmental Sentence Scoring (DSS) is a useful procedure for quantifying thegrammatic structure of children's expressive language. Like most language analysis techniques, however, DSS requires considerable study and practice to use it correctly and efficiently. Clinicians learning DSS tend to make many scoring errors at first and they display similar confusions and mistakes. This article identifies some of these common "problem" areas and provides scoring examples to assist clinicians in learning the DSS procedure.

Sign in / Sign up

Export Citation Format

Share Document