Regioselective O-alkylation: synthesis of 1-{2-[(2-chloroquinolin-3-yl)methoxy]-6-chloro-4-phenylquinolin-3-yl}ethanones

Gund, M.,Mohana Roopan, S.,Nawaz Khan, F. R.,Jin, J. S.,Rajesh, K.,Sudheer Kumar, A. VSP 2012 Research on chemical intermediates Vol.38 No.3

Displacements, damage measures and response spectra obtained from a synthetic accelerogram processed by causal and acausal Butterworth filters

Gundes Bakir, Pelin,Richard, J. Vaccaro Techno-Press 2006 Structural Engineering and Mechanics, An Int'l Jou Vol.23 No.4

The aim of this study is to investigate the reliability of strong motion records processed by causal and acausal Butterworth filters in comparison to the results obtained from a synthetic accelerogram. For this purpose, the fault parallel component of the Bolu record of the Duzce earthquake is modeled with a sum of exponentially damped sinusoidal components. Noise-free velocities and displacements are then obtained by analytically integrating the synthetic acceleration model. The analytical velocity and displacement signals are used as a standard with which to judge the validity of the signals obtained by filtering with causal and acausal filters and numerically integrating the acceleration model. The results show that the acausal filters are clearly preferable to the causal filters due to the fact that the response spectra obtained from the acausal filters match the spectra obtained from the simulated accelerogram better than that obtained by causal filters. The response spectra are independent from the order of the filters and from the method of integration (whether analytical integration after a spline fit to the synthetic accelerogram or the trapezoidal rule). The response spectra are sensitive to the chosen corner frequency of both the causal and the acausal filters and also to the inclusion of the pads. Accurate prediction of the static residual displacement (SRD) is very important for structures traversing faults in the near-fault regions. The greatest adverse effect of the high pass filters is their removal of the SRD. However, the noise-free displacements obtained by double integrating the synthetic accelerogram analytically preserve the SRD. It is thus apparent that conventional high pass filters should not be used for processing near-fault strong-motion records although they can be reliably used for far-fault records if applied acausally. The ground motion parameters such as ARIAS intensity, HUSID plots, Housner spectral intensity and the duration of strong-motion are found to be insensitive to the causality of filters.

Controlled synthesis of hierarchical nanoflake structure of NiO thin film for supercapacitor application

Gund, Girish S.,Lokhande, Chandrakant D.,Park, Ho Seok Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.741 No.-

<P><B>Abstract</B></P> <P>The nickel-based oxides or hydroxides are considered a promising electroactive material for supercapacitor application owing to its low cost, well-defined redox activity, and prospect of controllable nanostructures. However, control of nanomorphology and uniform deposition onto a conductive substrate for Ni-based materials remains a critical challenge. Herein, we demonstrate the controlled synthesis of hierarchical nanoflake structure of NiO thin film by a simple and inexpensive successive ionic layer adsorption and reaction (SILAR) method and its consequent effect on supercapacitive performances. The as-prepared NiO thin films confirmed kinetically controlled growth model for the anisotropic nanostructure through a systematic investigation of controlling reaction temperatures and times. The as-optimized binder-free NiO thin film electrodes exhibited a reversible electrochemical feature, providing a high specific capacitance of 674 F g<SUP>−1</SUP> and cycling stability of 72.5% after 2000 cycles. These performances of NiO thin films were attributed to its open mesoporous and large accessible area of hierarchical nanoflakes structure, as well as the fast ion diffusion into the active sites. This work opens new avenues for the design of high capacity metal oxide thin films with hierarchical architecture for electrochemical energy storage applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hierarchical structure of NiO thin film was synthesized by SILAR. </LI> <LI> Synthetic parameters controlled the morphology of NiO thin films. </LI> <LI> Porous nanoflakes of NiO thin films was composed of fine nanoparticles. </LI> <LI> NiO thin films offered easy charge transportation and low ESR. </LI> <LI> NiO thin films showed high specific capacitance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Instrumentation and system identification of a typical school building in Istanbul

Pelin Gundes Bakir 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.43 No.2

This study presents the findings of the structural health monitoring and the real time system identification of one of the first large scale building instrumentations in Turkey for earthquake safety. Within this context, a thorough review of steps in the instrumentation, monitoring is presented and seismic performance evaluation of structures using both nonlinear pushover and nonlinear dynamic time history analysis is carried out. The sensor locations are determined using the optimal sensor placement techniques used in NASA for on orbit modal identification of large space structures. System identification is carried out via the stochastic subspace technique. The results of the study show that under ambient vibrations, stocky buildings can be substantially stiffer than what is predicted by the finite element models due to the presence of a large number of partitioning walls. However, in a severe earthquake, it will not be safe to rely on this resistance due to the fact that once the partitioning walls crack, the bare frame contributes to the lateral stiffness of the building alone. Consequently, the periods obtained from system identification will be closer to those obtained from the FE analysis. A technique to control the validity of the proportional damping assumption is employed that checks the presence of phase difference in displacements of different stories obtained from band pass filtered records and it is confirmed that the ”proportional damping assumption” is valid for this structure. Two different techniques are implemented for identifying the influence of the soil structure interaction. The first technique uses the transfer function between the roof and the basement in both directions. The second technique uses a pre-whitening filter on the data obtained from both the basement and the roof. Subsequently the impulse response function is computed from the scaled cross correlation between the input and the output. The overall results showed that the structure will satisfy the life safety performance level in a future earthquake but some soil structure interaction effects should be expected in the North South direction.

1P-496 The thermodynamic and kinetic parameter control in SILAR method for efficient and high capacity metal oxide electrodes

( Girish Gund ),( C. D. Lokhande ),박호석 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.0

The combined deterministic stochastic subspace based system identification in buildings

Pelin Gundes Bakir 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.38 No.3

The Combined Deterministic Stochastic Subspace based System Identification Technique (CDSSSIT) is a powerful input-output system identification technique which is known to be always convergent and numerically stable. The technique determines a Kalman state sequence from the projection of the output-input data. The state space matrices are determied subsequently from this Kalman state sequence using least squares. The objective of this paper is to examine the efficiency of the CDSSSIT in identifying the modal parameters (frequencies and mode shapes) of a stiff structure. The results show that the CDSSSIT predicts the modal parameters of stiff buildings quite accurately but is very sensitive to the location of sensors.

Two dimensional metal chalcogenide-based sub-micron thin antenna for wireless communication

( Girish Gund ),박호석 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

Smart wearable electronic demands thin and flexible radio-frequency (RF) antennas for wireless communication system. Previously, different nanostructured materials and metals have been used for RF antenna depends on their electrical conductivity. Metal-based antennas are thick and bulky due to their theoretical skin depth issue, which restrict miniaturized and portable electronics. Firstly, we report metallic two-dimensional (2D) metal chalcogenide-based monopole patch RF antenna, which is operated even at much lower thickness (sub-micron) than the skin depths of metals and omnidirectional RF propagation with reconfigurable resonance frequency. This work opens new approaches to design RF antennas for body-centric wearable communication systems.

2P-387 The preparative parameters control in chemical method for high capacity metal oxide electrodes

( Girish Gund ),박호석 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

The high potential and capacity of electroactive material is the stateof-the-art of energy storage technology. The scale up of these requirements with the low-cost and ecofriendly approach has become major topic of interest, which limits its commercialization. Accordingly current investigation efforts on the preparation of metal oxide directly on stainless steel substrate using simple Successive Ionic Layer Adsorption and Reaction method to achieve above mentioned demand. Furthermore, the performance enhancement has been achieved through defined nanostructure of electroactive material through controlling the preparative parameters of chemical methods. The performed electrochemical examination disclose the major influences on electrochemical features of metal oxide as consequences of distinct nanostructure growth through controlled parameters. This investigation provide key solutions and fundamental groundwork for energy storage application, which can be expand to other metal oxides.

High Frequency response Flexible Electrochemical Energy Storage Device for Pulse Energy Processing

( Girish Gund ),박호석 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Todays, smart electronics intend towards designing of state-of-the-art of miniaturized, portable and self-powered multifunctional technology. But, desired performance and functionality from electrochemical energy storage devices to support such smart electronics are yet developing and restraining. Mainly, the energy storage and delivery rates are major challenge and appearing ahead of energy storage devices due to limitation of fast charge kinematics within the device. This limitations tend to work devices at only direct current, and quit functioning for pulse energy harvesting and current ripple filtering, which generally do conventional capacitors. In order to resolve this challenge, we fabricated ultrafast frequency response flexible electrochemical capacitors based on new conducting polymer/MXene hybrid electrodes and polymer gel electrolyte. The fabricated devices exhibited good electrochemical performance along with flexible functionality and ripple filtering capability.

Binder-free approach to engineer hybrid supercapacitor

( Girish Gund ),박호석 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Nanostructured hybrid metal oxide@rGO electroactive material was directly coated on nickel-foam (NF) using two step binder-free and additive-less hydrothermal method. The material interface plays a vital role to control the dimensions of grown metal oxide nano-needle structure. The nano-needle dimensions in the case of bare NF are longer and thicker than rGO coated NF due to different surface energy. However, the smaller nano-needles grown on rGO coated NF reveals superior electrochemical performance like specific capacitance, coulombic efficiency, cycling stability, etc. compare to bare NF in alkaline 2 M KOH electrolyte due to improved interface resistances and adhesion. Whereas, rGO coated NF electrode demonstrate good capacitive response in negative potential window in the same alkaline electrolyte. So, the fabricated hybrid supercapacitor (HSC) reveals excellent electrochemical performance.