scholarly journals Diagnostic Development for Advanced Power Systems

1980 ◽  
Author(s):  
J. C. F. Wang ◽  
W. L. Flower ◽  
D. R. Hardesty
Keyword(s):  
Power Systems ◽  
Small Angle ◽  
Detection System ◽  
Pulsed Laser ◽  
Diagnostic Techniques ◽  
Particle Sizing ◽  
Gas Temperature ◽  
Test Bed ◽  
Optical Diagnostic ◽  
Scattering Measurements

The high temperatures, pressures, and particulate densities present in coal-fired advanced power systems place severe limitations on conventional probe techniques for thermometry, velocimetry, and gas and particulate analysis. Although laser-based techniques for measuring gas temperature, velocity, and composition have been demonstrated in relatively clean flame gases, little is known regarding their applicability to measurements in the product streams from coal-fired combustors. Hence, a program has been established at Sandia to develop and assess advanced physical sampling and laser-based optical diagnostic techniques. This paper describes some of the techniques under development, including a small-angle near-forward scattering optical arrangement for particle sizing and a system for making Raman-scattering measurements of gas temperature using a pulsed laser and a gated detection system. Also described here is the atmospheric combustor exhaust simulator (ACES) facility being constructed as the test bed for the diagnostic techniques.

Laser/Optical Diagnostic Techniques for Plasma Materials Processing

1987 ◽  
Vol 98 ◽  
Author(s):  
Ward C. Roman
Keyword(s):  
Gas Phase ◽  
Synergistic Effects ◽  
Diagnostic Techniques ◽  
Materials Processing ◽  
Gas Temperature ◽  
Optical Diagnostic ◽  
Needed Information ◽  
Starting Point ◽  
Plasma Techniques

ABSTRACTThe application of plasma techniques is emerging as one of the more efficient means of processing materials. Technology transfer of plasma systems, both thermal and nonequilibrium, however, is severely limited by a lack of understanding of the basic mechanisms involved which govern the plasma processes used in many applications including advanced coatings. The aspects of plasma gas temperature, and species concentration and distribution (molecular, atomic, excited) in the gas phase and associated synergistic effects are fragmentary and unclear. Laser/optical diagnostic techniques represent a critical starting point for providing this needed information; they are in-situ, non-intrusive,species and quantum level specific and give excellent spatial and temporal resolution. A survey of Laser/optical diagnostic techniques applicable to plasma materials processing needs is presented. Some examples of the use of different techniques are also given.

Remote sensing of coal-fired MHD by optical diagnostic techniques

1983 ◽  
Author(s):  
D. MURPHREE ◽  
R. COOK ◽  
W. SHEPARD ◽  
L. BAUMAN ◽  
J. GASSAWAY ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Diagnostic Techniques ◽  
Optical Diagnostic

Dimensions de micelles mixtes de p-alkylbenzènesulfonates par diffusion central des rayons X

1977 ◽  
Vol 10 (1) ◽  
pp. 37-44 ◽  
Author(s):  
C. Cabos ◽  
P. Delord ◽  
J. Rouviere
Keyword(s):  
Small Angle ◽  
Small Angle Scattering ◽  
Micellar Solutions ◽  
Probable Structure ◽  
X Ray ◽  
Absolute Scale ◽  
Angle Scattering ◽  
Scattering Measurements ◽  
Two Component ◽  
Most Probable Structure

The structure of micellar solutions is determined from X-ray small-angle scattering measurements on an absolute scale. The most probable structure is chosen by comparison with spherical cylindrical and lamellar models. This method is applied to two-component micelles and it is possible to follow the variation of micellar dimensions when the concentration of each component is varying.

Small angle x-ray scattering measurements of lithographic patterns with sidewall roughness from vertical standing waves

2007 ◽  
Vol 90 (19) ◽  
pp. 193122 ◽  
Author(s):  
Chengqing Wang ◽  
Ronald L. Jones ◽  
Eric K. Lin ◽  
Wen-Li Wu ◽  
Jim Leu
Keyword(s):  
Small Angle ◽  
Standing Waves ◽  
Sidewall Roughness ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Measurements ◽  
Ray Scattering

scholarly journals Hybrid Internal Anomaly Detection System for IoT: Reactive Nodes with Cross-Layer Operation

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Nanda Kumar Thanigaivelan ◽  
Ethiopia Nigussie ◽  
Seppo Virtanen ◽  
Jouni Isoaho
Keyword(s):  
Anomaly Detection ◽  
False Positive ◽  
Detection System ◽  
False Positive Rate ◽  
Security Analysis ◽  
Abnormal Behavior ◽  
Test Bed ◽  
Positive Rate ◽  
Parent Node ◽  
Anomaly Detection System

We present a hybrid internal anomaly detection system that shares detection tasks between router and nodes. It allows nodes to react instinctively against the anomaly node by enforcing temporary communication ban on it. Each node monitors its own neighbors and if abnormal behavior is detected, the node blocks the packets of the anomaly node at link layer and reports the incident to its parent node. A novel RPL control message, Distress Propagation Object (DPO), is formulated and used for reporting the anomaly and network activities to the parent node and subsequently to the router. The system has configurable profile settings and is able to learn and differentiate between the nodes normal and suspicious activities without a need for prior knowledge. It has different subsystems and operation phases that are distributed in both the nodes and router, which act on data link and network layers. The system uses network fingerprinting to be aware of changes in network topology and approximate threat locations without any assistance from a positioning subsystem. The developed system was evaluated using test-bed consisting of Zolertia nodes and in-house developed PandaBoard based gateway as well as emulation environment of Cooja. The evaluation revealed that the system has low energy consumption overhead and fast response. The system occupies 3.3 KB of ROM and 0.86 KB of RAM for its operations. Security analysis confirms nodes reaction against abnormal nodes and successful detection of packet flooding, selective forwarding, and clone attacks. The system’s false positive rate evaluation demonstrates that the proposed system exhibited 5% to 10% lower false positive rate compared to simple detection system.

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