Seismic testing of a static power static transfer switch

2021 ◽  
Author(s):  
James Wilcoski

This test report documents seismic qualification testing of a Static Power Static Transfer Switch (STS). The STS is a mission-critical unit that will be installed at Eareckson Air Station (EAS), on the island of Shemya, Alaska. Two units were built, one of which was tested on the ERDC-CERL shake table on 10 November 2020, and the other delivered to EAS for installation. This report presents details on the STS configuration, seismic tests conducted, and the performance of the unit. The unit passed the final seismic test and can now confidently be installed at the EAS.

Network ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 28-49
Author(s):  
Ehsan Ahvar ◽  
Shohreh Ahvar ◽  
Syed Mohsan Raza ◽  
Jose Manuel Sanchez Vilchez ◽  
Gyu Myoung Lee

In recent years, the number of objects connected to the internet have significantly increased. Increasing the number of connected devices to the internet is transforming today’s Internet of Things (IoT) into massive IoT of the future. It is predicted that, in a few years, a high communication and computation capacity will be required to meet the demands of massive IoT devices and applications requiring data sharing and processing. 5G and beyond mobile networks are expected to fulfill a part of these requirements by providing a data rate of up to terabits per second. It will be a key enabler to support massive IoT and emerging mission critical applications with strict delay constraints. On the other hand, the next generation of software-defined networking (SDN) with emerging cloudrelated technologies (e.g., fog and edge computing) can play an important role in supporting and implementing the above-mentioned applications. This paper sets out the potential opportunities and important challenges that must be addressed in considering options for using SDN in hybrid cloud-fog systems to support 5G and beyond-enabled applications.


Author(s):  
S. Khatiwada ◽  
N. Chouw ◽  
J.W. Butterworth

Pounding damage in major earthquakes has been observed frequently in the form of aesthetic, minor or major structural cracks and collapse of buildings. These observations have attracted many numerical and experimental studies that led to analytical models for simulating seismic pounding. This study considers pounding between two steel portal frames without a seismic gap. The first frame has a constant natural period while the second frame has variable stiffness and mass values. Five different ground motions are applied to eight combinations of adjacent frames using a shake table. Numerical simulations for the same configurations are carried out with five pounding force models, viz. linear viscoelastic model, modified linear viscoelastic model, nonlinear viscoelastic model, Hertzdamp model and modified Hertzdamp model. The contact element stiffness and coefficient of restitution for numerical models are determined experimentally. The amplification of maximum displacement of the first frame predicted by the numerical simulations is compared with the shake table results. It was found that the Hertzdamp model always overestimated the responses while the other four models also frequently overestimated the amplifications. The predictions from the four models were not significantly different. Since the linear viscoelastic model requires substantially less computation, compared with the other models this model is more suitable for numerical modelling of pounding responses. However, more study is required to refine the numerical models before building pounding can be modelled with enough confidence.


1997 ◽  
Vol 2 (1) ◽  
pp. 41-72
Author(s):  
Ingrid Ljungberg van Beinum

Discussions between women and men about men and women form the focus of this article, These discussions took place in the context of an inter-organizational action research project. The position of women in organizations and the subordination of women in general is seen as a relational phenomenon. The relationship between women and men is considered paradigmatic and therefore constitutes the critical unit of analysis as well as the strategic unit of action in this study. The participating organizations had no difficulty in initiating collaboration between women and men and to get them to engage in a joint action to develop a program aimed at improving gender relationships. However, ambiguity emerges as the basic characteristic of gender relationships in view of the fundamental otherness of the other. Dialogue between men and women is not only shaped by the relationship between women and men, but is also forming and transforming it. Dialogue is both means and end, it is the subject as well as the context. Therefore, the criteria for an ethics of mediation, necessary for managing the inevitable ambiguity in the relationship between women and men through mutual respect for their differences, have to come from within the dialogue.


2018 ◽  
Vol 13 (5) ◽  
pp. 897-916 ◽  
Author(s):  
Hiroshi Nakazawa ◽  
Tadashi Hara ◽  
Daisuke Suetsugu ◽  
Tsuyoshi Nishi ◽  
Kentaro Kuribayashi ◽  
...  

In the 2015 earthquake in Gorkha, Nepal, damaged different kinds of structures around the Kathmandu Basin. On the other hand, in mountainous areas, it was confirmed that gabion structures such as retaining walls along roads showed their high flexibility by performing their functions. In this paper, based on the results of the damage field survey on gabion retaining walls, a full-scale shake table test is conducted to evaluate the earthquake resistance of gabion retaining walls on roads, which are a common site in Nepal. The soil container used for the full-scale shake table test has the following internal dimensions: 4.0 m height, 3.1 m width, and 11.5 m depth. Earthen bank retaining walls with height of 3 m were arranged in three rows in a perpendicular direction to the cross-section, and the ground behind the retaining wall was prepared. The sinusoidal waves of 3 Hz were applied, consisting of 2 s of gradual increase, 4 s of steady part, and 2 s of gradual decrease; the input waves were provided in four stages of acceleration amplitude. Three types of gabion retaining walls were considered, i.e., vertical-type, stepwise-type and gravity-type, and 3D terrestrial laser measurement was conducted before and after shake table test of each case. Comparison of the residual deformations of the gabion retaining walls measured by 3D terrestrial laser showed that the vertical-type wall did not collapse but tilted forward after the shake teble test. A similar damage situation was confirmed by the field survey in Nepal. The other two cases suffered only slight deformation and are considered to be effective structures for application on sites. Finally, the trial wedge method was applied to the experimental results of the vertical-type of gabion retaining and useful suggestions for future earthquake-resistant design were made by comparing the active collapse angle with the positions of deformation, such as cracking which occurred in the ground behind the retaining wall after shaking. Then, the applicability of trial wedge method and its problem in the design of gabion retaining wall were shown.


Static power dissipation is a major problem in CMOS circuits and this is due to the increase in sub threshold leakage current which is the effect of voltage scaling and also leading to reducing the threshold voltage. Here we propose Lector technique to reduce the leakage current and at the same time it will not increase the dynamic power dissipation. Two leakage control transistors of which one is p-type and the other one is n-type were introduced into the logic gate. The source of one transistor controls the gate terminal of the other transistor. For any combination of input one of the two leakage control transistors will be near to its cutoff voltage by this the leakage currents can be minimized as the path resistance to ground will increase. For both idle and active states of circuit the proposed Lector technique is applicable which will result in more leakage reduction when compared to remaining techniques used for leakage reduction and it will also out pass the limitations Occurred due to the implementation of other power and delay reduction techniques. Experimental results indicate a delay is reduced by 50.3% and power is reduced by 94.4% for proposed level shifter circuits.


1988 ◽  
Vol 62 (03) ◽  
pp. 411-419 ◽  
Author(s):  
Colin W. Stearn

Stromatoporoids are the principal framebuilding organisms in the patch reef that is part of the reservoir of the Normandville field. The reef is 10 m thick and 1.5 km2in area and demonstrates that stromatoporoids retained their ability to build reefal edifices into Famennian time despite the biotic crisis at the close of Frasnian time. The fauna is dominated by labechiids but includes three non-labechiid species. The most abundant species isStylostroma sinense(Dong) butLabechia palliseriStearn is also common. Both these species are highly variable and are described in terms of multiple phases that occur in a single skeleton. The other species described areClathrostromacf.C. jukkenseYavorsky,Gerronostromasp. (a columnar species), andStromatoporasp. The fauna belongs in Famennian/Strunian assemblage 2 as defined by Stearn et al. (1988).


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