Determination of Support Minimum Rigid Stiffness for Piping Analysis

2015 ◽  
Author(s):  
Jennifer Huang ◽  
Timothy M. Adams
Keyword(s):  
Lower Bound ◽  
Seismic Response ◽  
Natural Frequency ◽  
Iterative Process ◽  
Piping System ◽  
Alternative Approach ◽  
Formal Procedure ◽  
Deflection Criteria ◽  
Spring Constants

Pipe supports are represented as spring constants in piping analysis, and therefore a formal procedure is required to determine the spring constant values. Two current approaches are to enforce deflection criteria to ensure support rigidity or calculate the support stiffness values directly. However, the former approach results in overly conservative support designs and the latter approach becomes an iterative process of designing the supports and observing the response of the piping system. To avoid the issues presented by these methods, an alternative approach is presented which involves increasing values of support stiffness until change in natural frequency of the system diminishes. This method can help establish a lower bound (minimum rigid) stiffness above which there will be no significant change in the seismic response of the piping system. Using this approach only requires the support designs to have stiffness values at or above the minimum value without being concerned with detailed stiffness calculations or using deflection limits. This paper presents the methods and results of an expansive study to establish minimum rigid stiffness values for piping analysis.

Determination of CRLB and Minimum Variance Unbiased Estimator of a DC Signal in AWGN Using Laplace Transform

2021 ◽  
Vol 40 (1) ◽  
pp. 79-86
Author(s):  
Abdi Abdalla
Keyword(s):  
Lower Bound ◽  
Gaussian Noise ◽  
Unbiased Estimator ◽  
Laplace Transformation ◽  
Additive White Gaussian Noise ◽  
Minimum Variance ◽  
Minimum Variance Unbiased Estimator ◽  
Mathematical Background ◽  
Alternative Approach

This paper presents an alternative approach for the determination of Cramer-Rao Lower Bound (CRLB) and Minimum Variance Unbiased Estimator (MVUE) using Laplace transformation. In this work, a DC signal in Additive White Gaussian Noise (AWGN) was considered. During the investigation, a number of experiments were conducted to analyze different possible outputs under different conditions, and then the patterns of the outcomes were studied. Finally closed-form expressions for the CRLB and MVUE were deduced employing the Laplace transformation. The resulting expressions show that the proposed method has almost the same number of steps as the existing method. However, the later requires only the knowledge of algebra to arrive at the CRLB expressions contrary to the existing approach where a strong mathematical background is required and hence making it superior over the existing method, in that sense.

Influence of the distribution of the shear walls on the seismic response of the buildings

2020 ◽  
Vol 15 (1) ◽  
pp. 37-44
Author(s):  
El Mehdi Echebba ◽  
Hasnae Boubel ◽  
Oumnia Elmrabet ◽  
Mohamed Rougui
Keyword(s):  
Structural Analysis ◽  
Seismic Response ◽  
Natural Frequency ◽  
Structural Design ◽  
Structural Response ◽  
Shear Walls ◽  
Structural Elements ◽  
Analysis Software ◽  
Ansys Apdl ◽  
The Impact

Abstract In this paper, an evaluation was tried for the impact of structural design on structural response. Several situations are foreseen as the possibilities of changing the distribution of the structural elements (sails, columns, etc.), the width of the structure and the number of floors indicates the adapted type of bracing for a given structure by referring only to its Geometric dimensions. This was done by studying the effect of the technical design of the building on the natural frequency of the structure with the study of the influence of the distribution of the structural elements on the seismic response of the building, taking into account of the requirements of the Moroccan earthquake regulations 2000/2011 and using the ANSYS APDL and Robot Structural Analysis software.

scholarly journals Immobilization-Free Electrochemical Sensor Coupled with a Graphene-Oxide-Based Aptasensor for Glycated Albumin Detection

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 85
Author(s):  
Wassa Waiwinya ◽  
Thitirat Putnin ◽  
Dechnarong Pimalai ◽  
Wireeya Chawjiraphan ◽  
Nuankanya Sathirapongsasuti ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Detection Method ◽  
Limit Of Detection ◽  
Glycated Albumin ◽  
Cost Effective ◽  
Logarithmic Scale ◽  
Electrochemical Aptasensor ◽  
Alternative Approach

An immobilization-free electrochemical sensor coupled with a graphene oxide (GO)-based aptasensor was developed for glycated human serum albumin (GHSA) detection. The concentration of GHSA was monitored by measuring the electrochemical response of free GO and aptamer-bound GO in the presence of glycated albumin; their currents served as the analytical signals. The electrochemical aptasensor exhibited good performance with a base-10 logarithmic scale. The calibration curve was achieved in the range of 0.01–50 µg/mL. The limit of detection (LOD) was 8.70 ng/mL. The developed method was considered a one-drop measurement process because a fabrication step and the probe-immobilization process were not required. This simple sensor offers a cost-effective, rapid, and sensitive detection method, and could be an alternative approach for determination of GHSA levels.

scholarly journals Rules are Rules: Reconceiving Monetary Gold as a Rule of Procedure

AJIL Unbound ◽  
2021 ◽  
Vol 115 ◽  
pp. 144-148
Author(s):  
Juliette McIntyre
Keyword(s):  
Iterative Process ◽  
Third Parties ◽  
Judicial Decision ◽  
Procedural Rule ◽  
Legal Principle ◽  
The Icj ◽  
Rule Making ◽  
Intervention Procedure ◽  
Formal Rules

The Case of the Monetary Gold Removed from Rome in 1943 is familiar to all international lawyers. Like a catechism, we are taught that the ICJ will not proceed with a case where the legal interests of a State not before the Court “would not only be affected by a decision, but would form the very subject-matter of the decision.” Mollengarden and Zamir's proposal that the Court should dispense with the Monetary Gold principle feels almost heretical. The authors contend that the ICJ Statute sets out a framework for balancing the interests of third parties through the use of the intervention procedure, and that Monetary Gold “disrupts that balance.” Monetary Gold is, they submit, to be treated as only a judicial decision, entitled under Article 36(1)(d) of the Statute to little deference as a source of legal principle. I suggest taking an altogether different approach. The best way to understand the place of the Monetary Gold principle is in the context of the ICJ's rule making powers pursuant to Article 30(1) of the Court's Statute. These rule making powers are not limited to the promulgation of formal Rules of Court but extend to the determination of appropriate procedures during the hearing of a case. These procedural rules (small r), articulated in the context of particular cases, may in time evolve into formal Rules of Court through an iterative process. Monetary Gold is an instance of the Court defining a small r procedural rule in a manner that is consistent with the Court's Statute.

The Influence of Support Hardware and Piping System Seismic Response on Snubber Support Damping

1997 ◽  
Vol 119 (4) ◽  
pp. 451-456 ◽  
Author(s):  
C. Lay ◽  
O. A. Abu-Yasein ◽  
M. A. Pickett ◽  
J. Madia ◽  
S. K. Sinha
Keyword(s):  
Seismic Response ◽  
Fundamental Frequency ◽  
Damping Ratio ◽  
Damping Coefficient ◽  
Piping System ◽  
Nodal Displacement ◽  
Damping Coefficients ◽  
Fundamental Frequencies ◽  
Piping Systems

The damping coefficients and ratios of piping system snubber supports were found to vary logarithmically with pipe support nodal displacement. For piping systems with fundamental frequencies in the range of 0.6 to 6.6 Hz, the support damping ratio for snubber supports was found to increase with increasing fundamental frequency. For 3-kip snubbers, damping coefficient and damping ratio decreased logarithmically with nodal displacement, indicating that the 3-kip snubbers studied behaved essentially as coulomb dampers; while for the 10-kip snubbers studied, damping coefficient and damping ratio increased logarithmically with nodal displacement.

Detection of peroxyacetyl nitrate in air using chemiluminescence aerosol detector

2014 ◽  
Vol 68 (11) ◽  
Author(s):  
Pavel Mikuška ◽  
Lukáš Bružeňák ◽  
Zbyněk Večeřa
Keyword(s):  
Alkaline Solution ◽  
Limit Of Detection ◽  
Packed Column ◽  
Direct Reaction ◽  
Peroxyacetyl Nitrate ◽  
Brij 35 ◽  
Alternative Approach ◽  
Sensitive Determination ◽  
Triton X

AbstractA method for the rapid and sensitive determination of peroxyacetyl nitrate (PAN) in air based on a chemiluminescence reaction with an alkaline solution of luminol in the chemiluminescence aerosol detector is described. The PAN is chromatographically separated from nitrogen dioxide and ozone in a packed column filled with 5 % OV-1 on Chromosorb 30/60 and the eluted PAN is detected via the direct reaction with the luminol solution consisting of 0.002 mol L−1 luminol, 1 vol. % Brij-35 and 0.1 mol L−1 KOH. The limit of detection is 14.9 ng m−3 (3 ppt) of PAN. Alternatively, the PAN after separation is thermally converted to NO2 which is detected by the chemiluminescence reaction with a solution consisting of 0.002 mol L−1 luminol, 0.5 mol L−1 KOH, 0.2 mol L−1 Na2SO3, 0.1 mol L−1 KI, 0.05 mol L−1 EDTA and 0.5 vol. % triton X-100. The alternative approach affords the simultaneous determination of PAN and NO2. The limit of detection is 50 ppt of PAN and 50 ppt of NO2. The time resolution is 3 min. The method was applied to the measurement of ambient peroxyacetyl nitrate in air.

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