Structural behavior of concrete filled carbon fiber reinforced polymer sheet tube column

In order to examine both static and dynamic behaviors of Concrete Filled Carbon Fiber Reinforced Polymer Sheet Tube (CFCST) columns, experimental tests have been performed. The main variables of this experimental program included the number and wrapping angles of CFRP sheets. Stress versus strain relation of CFCST specimens was investigated by uni-axial tests. And, six full-scaled CFCST columns subjected to quasi-static lateral loading, as well as constant axial compression, were tested. Finally, an analytical procedure to predict the response of CFCST columns subjected to both axial and lateral loadings has been suggested in conjunction with the findings from the experimental tests

Mice as an Animal Model for Japanese Encephalitis Virus Research: Mouse Susceptibility, Infection Route, and Viral Pathogenesis

Japanese encephalitis virus (JEV), a zoonotic flavivirus, is principally transmitted by hematophagous mosquitoes, continually between susceptible animals and incidentally from those animals to humans. For almost a century since its discovery, JEV was geographically confined to the Asia-Pacific region with recurrent sizable outbreaks involving wildlife, livestock, and people. However, over the past decade, it has been detected for the first time in Europe (Italy) and Africa (Angola) but has yet to cause any recognizable outbreaks in humans. JEV infection leads to a broad spectrum of clinical outcomes, ranging from asymptomatic conditions to self-limiting febrile illnesses to life-threatening neurological complications, particularly Japanese encephalitis (JE). No clinically proven antiviral drugs are available to treat the development and progression of JE. There are, however, several live and killed vaccines that have been commercialized to prevent the infection and transmission of JEV, yet this virus remains the main cause of acute encephalitis syndrome with high morbidity and mortality among children in the endemic regions. Therefore, significant research efforts have been directed toward understanding the neuropathogenesis of JE to facilitate the development of effective treatments for the disease. Thus far, multiple laboratory animal models have been established for the study of JEV infection. In this review, we focus on mice, the most extensively used animal model for JEV research, and summarize the major findings on mouse susceptibility, infection route, and viral pathogenesis reported in the past and present, and discuss some unanswered key questions for future studies

Seismic performance of reinforced concrete frames retrofitted with inserted steel frame and adhered waved steel panel

In this paper, two types of seismic retrofitting methods for reinforced concrete frames were suggested and examined through the cyclic loading tests: one is to insert a steel frame to existing partially masonry infilled concrete frame of the building after removing masonry from the concrete frame and the other is to adhere waved steel panels to the existing masonry fully infilled concrete frame. In order to evaluate validity of the suggested methods in seismic performance, five specimens were manufactured and tested: a bare concrete frame, a partially masonry infilled concrete frame, a masonry infilled concrete frame, a steel frame inserted concrete frame, and a waved steel panel adhered concrete frame. Compared were crack pattern, failure mode, load-displacement relation, ductility, stiffness and energy dissipation capacity. The specimens retrofitted with the inserted steel frame showed a maximum load approximately twice that of the partially masonry infilled frame, and the specimen retrofitted with the adhered waved steel panel showed a maximum load approximately twice that of the masonry fully infilled frame

Seismic response of beam-column joints rehabilitated with FRP sheets and buckling restrained braces

An experimental test was performed to evaluate the seismic resistance of reinforced concrete beam-column joints rehabilitated with FRP sheets and Buckling Restrained Braces (BRBs). Six beam-column joints were rehabilitated and tested. The test results were compared in terms of hysteresis loops, stiffness degradation, energy dissipation and ductility. The comparison result showed that wrapping FRP sheets can contribute to increase the effect of confinement and to delay crack development in the joints. Also retrofitting buckling restrained braces (BRBs) can improve the stiffness and energy dissipation capacity. Both FRP sheets and BRBs can effectively improve the strength, stiffness and ductility

Flexural Behavior of Posttensioned Flat Plates Depending on Tendon Layout

This paper discusses the experimental results on the flexural behavior and deflections of posttensioned concrete flat plates depending on tendon layout. One reinforced concrete flat plate and two posttensioned concrete flat plates were manufactured and tested. One-way posttensioning layout and two-way posttensioning layout were considered in this paper. The load-deflection behavior and modes of crack are presented from the test results. Posttension systems effectively controlled crack and deflection. One-way and two-way posttensioning layouts both showed similar maximum load. However, serviceability improved with two-way posttensioning layout compared to one-way posttensioning layout. Also, the yield-line theory was applied to predict the ultimate load for the posttensioned flat plates. The comparison between the test results and estimation by yield-line analysis generally showed good agreement

Ku-band High Efficiency Antenna with Corporate-Series-Fed Microstrip Array

Excellent efficiency of a linearly polarized microstrip array in Ku-band is achieved by having proper impedance matching throughout the array and by properly using the corporate and series fed by microstrip transmission lines. The cavity-backed microstrip patch is used to obtain relatively wide bandwidth. The auto-tracking Ku-band antenna in the azimuth direction has developed with a very low profile for vehicle\u27s rooftop mounting, as well as, a low manufacturing cost. The main beam of array is tilted 15° away from the broadside direction to provide optimum coverage for Korea satellite III