• Archives of Pharmacal Research
• /
• v.24 no.6
• /
• pp.499-502
• /
• 2001

To evaluate the role of imidazolidinone moiety of potential anticancer 4-phenyl-1-arylsulfonylimidazolidinones 1 for their cytotoxicity conformationally similar 4-phenyl-2-arylsulfonylaminooxazolines 2 were synthesized and compared their cytotoxicities with those of the corresponding 1. Compounds 2 showed much reduced activity compared to N-arylsulfonylimidazolidinones 1. This result might indicate that the imidazolidinone ring of 1 have the other roles for the activity as an essential structural motif in addition to conformational contribution .

• Advances in concrete construction
• /
• v.5 no.1
• /
• pp.1-15
• /
• 2017

This research project aimed at evaluating experimentally the effect of natural perlite powder as an alternative supplementary cementing material (SCM) on the performance of fiber reinforced self-consolidating repair mortars (FR-SCRMs). For this purpose, four FR-SCRMs mixes incorporating 0%, 10%, 20%, and 30% of natural perlite powder as cement replacements were prepared. The evaluation was based on fresh (slump flow, flow time, and unit weight), hardened (air-dry unit weight, compressive and flexural strengths, dynamic modulus of elasticity), and durability (water absorption test) performances. The results reveal that structural repair mortars confronting the performance requirements of class R4 materials (European Standard EN 1504-3) could be designed using 10%, 20%, and 30% of perlite powder as cement substitutions. Bonding results between repair mortars containing perlite powder and old concrete substrate investigated by the slant shear test showed good interlocking justifying the effectiveness of these produced mortars.

• Structural Engineering and Mechanics
• /
• v.78 no.3
• /
• pp.297-303
• /
• 2021

In this paper, a mathematical model is used to the evaluation of thermoelastic interactions in fiber-reinforced material with a spherical cavity. With the goal of establishing the generalized thermoelastic model with thermal relaxation time are exploited. inner surface of the spherical cavity is tractions free and loaded by the uniform step in temperature. The finite element scheme is used to get the problem numerical solutions. The numerical results have been discussed graphically to show the impacts of the presence and the absence of reinforcement.

• Journal of the Korea Society of Computer and Information
• /
• v.24 no.9
• /
• pp.69-75
• /
• 2019

We propose a method to analyze user requirements to design a virtual reality-based risk management system. This paper presents surveys, interviews, prototype evaluation methods, and implementation process. Architectural heritage is easily exposed to natural and artificial dangers caused by various material combinations and structural features. So, risk management of cultural heritage plays a key role in preserving and managing cultural heritage. However, risk management has been carried out through empirical methods using distributed data. This study analyzes user requirements for designing functions and interfaces of VR-based risk management system and evaluates prototypes to overcome the above problems. As a result, most heritage managers wanted a system function to support risk analysis and response. They also found that they prefer 2D information such as existing drawings and photos rather than 3D information. The results of the user requirements analysis derived from this study will be used to create risk management applications.

• Earthquakes and Structures
• /
• v.16 no.2
• /
• pp.141-148
• /
• 2019

In this study, a well-established model and a new simplified version of it, that help avoid collapses in reinforced concrete structures during strong earthquakes, are presented and discussed. Using this model, the initial formation of plastic hinges and the final concentration of the damages only in beams are accurately assured. The model also assures that the columns and the beam-column joints can remain intact. This model can be applied for the design of modern R/C structures, as well as for the design of strengthening schemes of old R/C structures by the use of reinforced concrete jackets. The model can also predict the form of earthquake damages in old structures but also earthquake damages in the modern structures.

• Structural Engineering and Mechanics
• /
• v.69 no.6
• /
• pp.591-605
• /
• 2019

Investigations on seismic performance of eccentrically braced frames equipped with dual vertical links have received little attention. Therefore, the main goal of this paper is to describe design steps for such frames and evaluate nonlinear performance of this system according to the reliability analysis. In this study, four and eight story frame structures are analyzed and the response modification factors for different intensity and damage levels are derived in a matrix form based on a new approach. According to the obtained results, the system has high ductility and acceptable seismic performance. Moreover, it is concluded that using response modification factor equal to 8 in the design of system provides desirable seismic reliability under the design and maximum probable hazard levels. Due to desirable performance and significant advantages of the dual vertical links, this system can be used as a main lateral load bearing system, in addition to its application for rehabilitation of damaged structures.

• Computers and Concrete
• /
• v.24 no.3
• /
• pp.259-269
• /
• 2019

The work aims at the comparison among commonly used research programs concerning moment-curvature ($M-{\chi}$) diagrams of confined R.C. members. The software considered in this work are Sap2000, SeismoStruct and Opensees. The curves provided by these software, given the same modelling, have been compared to those provided by a theoretical fiber model. A parametric analysis has been led on rectangular column sections with different level of axial load and different stirrups spacing. The accuracy of the modelling of the considered structural programs has been investigated by comparing their results with those obtained by applying the theoretical fiber model.

• Journal of the Korean Society of Safety
• /
• v.34 no.2
• /
• pp.7-14
• /
• 2019

A palladium can adsorb hydrogen and detect leaking hydrogen through changes in color and electrical resistance. This study is to evaluate the structural behavior of carbon fiber adding palladium composite materials used in the hydrogen storage vessel. A multi-scale analysis technique was used to analyze accurately the behavior of each material in relation to the microscopic composition. The multi-scale analysis is more proper and precise for composite materials because of considering the individual microscopic structure and properties of each material for composite materials. Also the crack evaluation was performed by XFEM analysis to confirm the reinforcement performance of aluminum as a liner of the hydrogen vessel. The results show that the addition of the palladium material increased the macroscopic stress, but microscopically the carbon fiber stress was reduced. It means the performance improvement of the palladium added carbon fiber/Al composite.

• Structural Engineering and Mechanics
• /
• v.70 no.2
• /
• pp.133-141
• /
• 2019

The aim of the present paper is to present the cyclic behavior of strengthened reinforced concrete shear wall test specimen, which was reinforced with cold drawn welded wire mesh fabric. Two reinforced concrete shear wall specimens have been tested in the present study. The walls were tested under reversed cyclic loading with loading applied near the tip of the walls. The control wall is tested in its original state to serve as a baseline for the evaluation of the repair and strengthening techniques. The two test specimens include a control wall and a repaired wall. The control wall test specimen was designed and detailed to simulate non-ductile reinforced concrete shear walls that do not meet the modern seismic provisions. The response of the original wall was associated with the brittle failure. The control shear wall was repaired by addition of the reinforcements and the concrete and then it was reloaded. The effectiveness of the repair technique was investigated. Test results indicate that there can be a near full restoration of the walls' strength. The data from this test, augmenting other data available in the literature, will be useful in calibrating improved analytical methods as they are developed.

• Journal of Trauma and Injury
• /
• v.34 no.2
• /
• pp.136-140
• /
• 2021

We present a case of delayed diagnosis of traumatic tricuspid valve rupture in a patient who was emergently brought to the operating room for repair of lacerations to the heart and liver without intraoperative transesophageal echocardiography (TEE). Initial postoperative transthoracic echocardiography (TTE) did not show structural pathology. One week later, TTE with better image quality showed severe tricuspid regurgitation. Subsequently, TEE clearly demonstrated rupture of the anterior papillary muscle and flail anterior tricuspid leaflet. The case description is followed by a brief discussion of the utility of TEE in the setting of blunt thoracic trauma.