Search results

1 – 10 of 25
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Article
Publication date: 1 February 2002

R. Manickavasagam, K. Jeya Karthik, M. Paramasivam and S. Venkatakrishna Iyer

Poly(styrenesulphonic acid)‐doped polyaniline has been synthesised and the influence of this polymeric compound on the inhibition of corrosion of mild steel in 1M HCl has been…

1054

Abstract

Poly(styrenesulphonic acid)‐doped polyaniline has been synthesised and the influence of this polymeric compound on the inhibition of corrosion of mild steel in 1M HCl has been investigated using weight loss measurements, galvanostatic polarisation studies, electropermeation studies and a.c. impedance measurements. The polymer acts predominantly as an anodic inhibitor. Hydrogen permeation studies and a.c. impedance measurements clearly indicate a very effective performance of the compound as a corrosion inhibitor. The adsorption of the compound on the mild steel surface obeys Temkin's adsorption isotherm.

Details

Anti-Corrosion Methods and Materials, vol. 49 no. 1
Type: Research Article
ISSN: 0003-5599

Access Restricted. View access options
Article
Publication date: 24 May 2011

Mohammad Rashid, Afidah Abdul Rahim and Mohd Jain Noordin

The purpose of this paper is to study the inhibitive effect of p‐toluene sulfonic acid (p‐TSA) doped polyaniline on corrosion of copper in 0.1 M hydrochloric acid (HCl) solution.

773

Abstract

Purpose

The purpose of this paper is to study the inhibitive effect of p‐toluene sulfonic acid (p‐TSA) doped polyaniline on corrosion of copper in 0.1 M hydrochloric acid (HCl) solution.

Design/methodology/approach

The electrochemical deposition of polyaniline doped with p‐TSA on pure copper metal was studied potentiodynamically. The electrochemical study of the working electrode was performed at open‐circuit potential, then using potentiodynamic polarization and also with electrochemical impedance spectroscopy in 0.1 M HCl solution. The p‐TSA doped polymer deposit was characterized using Fourier transform infrared spectroscopy, with the UV‐vis and thermogravimetric analysis/differential scanning calorimetry techniques. The morphology of the deposited polymer was studied by scanning electron microscopy.

Findings

The results revealed that the p‐TSA self‐doped polymer had better corrosion inhibition efficiency than did the un‐doped polyaniline. It exhibited approximately 88.9 percent inhibition efficiency at 2x10−3 M concentration of p‐TSA, according to charge transfer resistance (Rct) values evaluated from Nyquist plots.

Research limitations/implications

The high dissolution tendency of metal surfaces generally occurs before the electropolymerization potential of the monomer is achieved. It was difficult to electrodeposit the conducting organic polymer on the surface of metal.

Practical implications

Some organic conducting polymers are toxic and hazardous from the environmental viewpoint. The electrochemical deposition of p‐TSA doped polyaniline is impractical for larger structures.

Originality/value

The paper demonstrates that p‐TSA doped polyaniline is environmentally benign and can be used for the protection of copper metal as a cathodic inhibitor.

Details

Anti-Corrosion Methods and Materials, vol. 58 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

Access Restricted. View access options
Article
Publication date: 1 September 2006

Maryam Ehteshamzadeh, Taghi Shahrabi and Mirghasem Hosseini

Aims to investigate the inhibitive effect of the new series of Schiff base molecules, namely, N, N′‐ethylen‐bis(salicylidenimine) [S1], N, N′‐isopropylen‐bis(salicylidenimine…

710

Abstract

Purpose

Aims to investigate the inhibitive effect of the new series of Schiff base molecules, namely, N, N′‐ethylen‐bis(salicylidenimine) [S1], N, N′‐isopropylen‐bis(salicylidenimine) [S2] and N, N′‐Ortho‐phenylen acetyl acetone imine, (2‐hydroxy Benzophenone imine) [S3] on corrosion of copper during acid pickling treatment in 1 M HCl solution. Effects of concentration and temperature on the inhibition efficiencies of the selected Schiff bases have been studied systematically.

Design/methodology/approach

All inhibition experiments were conducted on copper sample in 1 M HCl solution. Weight loss measurements were carried out according to the ASTM standard procedure. Polarization curves and impedance spectra were carried out in a three‐electrode cell assembly connected to an EG&G potentiostat M273 and frequency response analyzer M1025.

Findings

Results obtained revealed that the studied Schiff bases act predominantly as cathodic inhibitors. The variations in inhibition efficiencies mainly depend on the type and nature of the inhibitors. Polarization and ac impedance measurements carried out at different concentrations of studied Schiff bases revealed that these compounds are adsorbed on copper surface and the adsorption obeys Langmuir adsorption isotherm. From the adsorption isotherms, the values of equilibrium constant, Kads, and the free energies of adsorption, ΔGads, were calculated. The associated activation energy of corrosion and other thermodynamic parameters such as enthalpies and entropies have also been determined.

Practical implications

The presence of high efficiency and low cost inhibitors is essential in acid pickling treatments for protection of copper and lowering of acid consumption. In comparison with conventional copper corrosion inhibitors such as benzotriazole, this result would be considered as a step forward in determination of new corrosion inhibitor.

Originality/value

This paper reveals that Schiff bases can be successfully used for protection of copper surface in acid pickling solutions.

Details

Anti-Corrosion Methods and Materials, vol. 53 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Access Restricted. View access options
Article
Publication date: 26 August 2014

Mohd Rashid, Suhail Sabir, Umesh Waware and Afidah A. Rahim

– This paper aims to compare the inhibitive effects of polyaniline (PAni), poly(p-toluidine) and poly(aniline-co-p-toluidine) in hydrochloric acid (HCl) solution.

236

Abstract

Purpose

This paper aims to compare the inhibitive effects of polyaniline (PAni), poly(p-toluidine) and poly(aniline-co-p-toluidine) in hydrochloric acid (HCl) solution.

Design/methodology/approach

The electrochemical deposition of PAni, poly(p-toluidine) and poly(aniline-co-p-toluidine) on pure copper metal was studied potentiodynamically. The copolymer deposited was characterized by Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV)-visible spectroscopy and scanning electron microscopy (SEM). The corrosion inhibition studies on copper electrode were performed using electrochemical methods, viz, open circuit potential (OCP) measurements, potentiodynamic polarization scans and electrochemical impedance spectroscopy (EIS) tests, conducted in 0.1 M HCl solution.

Finding

The results of the study reveal that the copolymer of poly(aniline-co-p-toluidine) at the optimum concentration of 1 × 10−3 M has better corrosion inhibition efficiency as compared to PAni and poly(p-toluidine).

Research limitations/implications

The conducting polymers are difficult to deposit on the metal surface because of their high dissolution tendency before the electropolymerization potential of the monomer is achieved.

Practical implications

From an environmental viewpoint, poly(aniline-co-p-toluidine) is a toxic and hazardous conducting polymer.

Originality/value

The paper demonstrates that poly(aniline-co-p-toluidine) showed better dispersion in different organic solvents and had higher corrosion inhibition efficiency than PAni.

Details

Anti-Corrosion Methods and Materials, vol. 61 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Access Restricted. View access options
Article
Publication date: 17 June 2021

Venkatesh Chapala and Polaiah Bojja

Detecting cancer from the computed tomography (CT)images of lung nodules is very challenging for radiologists. Early detection of cancer helps to provide better treatment in…

139

Abstract

Purpose

Detecting cancer from the computed tomography (CT)images of lung nodules is very challenging for radiologists. Early detection of cancer helps to provide better treatment in advance and to enhance the recovery rate. Although a lot of research is being carried out to process clinical images, it still requires improvement to attain high reliability and accuracy. The main purpose of this paper is to achieve high accuracy in detecting and classifying the lung cancer and assisting the radiologists to detect cancer by using CT images. The CT images are collected from health-care centres and remote places through Internet of Things (IoT)-enabled platform and the image processing is carried out in the cloud servers.

Design/methodology/approach

IoT-based lung cancer detection is proposed to access the lung CT images from any remote place and to provide high accuracy in image processing. Here, the exact separation of lung nodule is performed by Otsu thresholding segmentation with the help of optimal characteristics and cuckoo search algorithm. The important features of the lung nodules are extracted by local binary pattern. From the extracted features, support vector machine (SVM) classifier is trained to recognize whether the lung nodule is malicious or non-malicious.

Findings

The proposed framework achieves 99.59% in accuracy, 99.31% in sensitivity and 71% in peak signal to noise ratio. The outcomes show that the proposed method has achieved high accuracy than other conventional methods in early detection of lung cancer.

Practical implications

The proposed algorithm is implemented and tested by using more than 500 images which are collected from public and private databases. The proposed research framework can be used to implement contextual diagnostic analysis.

Originality/value

The cancer nodules in CT images are precisely segmented by integrating the algorithms of cuckoo search and Otsu thresholding in order to classify malicious and non-malicious nodules.

Details

International Journal of Pervasive Computing and Communications, vol. 17 no. 5
Type: Research Article
ISSN: 1742-7371

Keywords

Access Restricted. View access options
Article
Publication date: 4 September 2007

Ravindra K. Pande and A. Uniyal

The study aims to highlight fundamental causes and effects of disasters in the northern district of Uttarkashi, which lies in the fragile mountains of Himalaya. Disasters such as…

761

Abstract

Purpose

The study aims to highlight fundamental causes and effects of disasters in the northern district of Uttarkashi, which lies in the fragile mountains of Himalaya. Disasters such as the 1991 Uttarkashi Earthquake, the flash floods of the Bhagirathi river and the devastation caused by the Gyansu landslide are discussed.

Design/methodology/approach

The following approach was used for this study: precise geographical location of the various landslides was marked through Global Positioning System Receiver (GPS); landslide types were identified based on activity (active or old) and debris flow slide and rock fall were marked based on the sliding material and slope condition; the land use/land cover pattern of Varunawat Parvat was also assessed; the vulnerability of population, houses and infrastructure etc. was listed; the condition of existing stability measures, e.g. check dams and drains, was assessed; and slide‐specific mitigation measures were suggested.

Findings

The Himalayan state of Uttaranchal has been witnessing the fury of nature for a long time. In recent years there has been an increase in the frequency of natural disasters. Earthquakes, landslides, cloudbursts and flash floods have caused great damage to life and property in various parts of the state. The Himalayan orogenic belt is tectonically active and subject to modifications by natural processes. Adding further to the fragility of this belt are the anthropogenic activities like the unplanned cutting of slope for construction activity, blasting of highly jointed rock mass for road construction and unplanned disposal of the slope cut debris material.

Research limitations/implications

The study is based on the data/information collected during the monsoon season from 15 June to 15 September 2003. The period is short for developing any hypothesis but sufficient care has been taken to consider vital factors.

Practical implications

A calamity of rare severity requires a high level of recovery and management. Sound mitigation mechanism helps the Government and the community to tackle the problem immediately and efficiently.

Originality/value

The study highlights fundamental causes and effects of the landslide and suggests steps to overcome them.

Details

Disaster Prevention and Management: An International Journal, vol. 16 no. 4
Type: Research Article
ISSN: 0965-3562

Keywords

Access Restricted. View access options
Article
Publication date: 28 February 2020

Hamidreza Shojaie Chahregh and Saeed Dinarvand

As transferring biological fluid through an artery is nowadays a pivotal subject, the purpose of this paper is to study the mathematical model of hybrid nanofluid flow comprising…

476

Abstract

Purpose

As transferring biological fluid through an artery is nowadays a pivotal subject, the purpose of this paper is to study the mathematical model of hybrid nanofluid flow comprising pure blood as base fluid and TiO2 and Ag as nanoparticles through the porous channel, which can be an applicable model for drug delivery.

Design/methodology/approach

Both walls of the channel have different permeability, which enables the fluid to enter and exit, and variable height, which dilates and squeezes at the uniform rate. By taking advantage of the similarity transformation technique, governing equations have been converted into a system of the non-linear ordinary differential equation. This problem is solved numerically by utilizing BVP4C built-in function in MATLAB software to explore the impacts of pertinent parameters.

Findings

The plots of velocity and temperature profile, normal pressure distribution and wall shear stress, as well as Nusselt number for involved parameters, are presented and the logic and physical reasons beyond them are highlighted. It has been observed that the asymmetry of the channel, caused by different permeability at walls, affects the nature of flow significantly.

Originality/value

To the best of the authors’ knowledge, no one has ever attempted to study the flow through a deformable porous channel with blood as a base fluid and as hybrid nanoparticles to describe medical phenomena and treatment applications. Indeed, the achievements of this paper are purely original and the numerical results were never published by any researcher.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 11
Type: Research Article
ISSN: 0961-5539

Keywords

Access Restricted. View access options
Article
Publication date: 5 February 2021

Navin Kumar, Ravinderjit Singh Walia and Surjit Angra

The purpose of this study is to develop jute-glass hybrid fibre reinforced polyester-based bio-composites using an indigenously developed pultrusion set-up and to present a…

158

Abstract

Purpose

The purpose of this study is to develop jute-glass hybrid fibre reinforced polyester-based bio-composites using an indigenously developed pultrusion set-up and to present a detailed discussion on their mechanical characterization.

Design/methodology/approach

The work was carried out to observe the hybridization effect of natural and synthetic fibres in combination with hybrid fillers loading mainly on strength and other properties. The used hybrid fillers were a combination of 9 Wt.% of carbon black%, 6 Wt.% of eggshell ash powder and 6 Wt.% of coconut coir ash powder. A lab-based developed pultrusion set-up was used to develop these hybrid GJFRP composites of 1,500 mm length. The developed composites were tested for tensile strength, compressive strength and impact strength.

Findings

The maximum tensile, compressive and impact strength obtained are 88.37 MPa, 56.13 MPa and 731.91 J/m from 9 Wt.%, 9 Wt.% and 0 Wt.% of hybrid fillers loading, respectively. Breaking energy was found maximum as 7.31 J in hybrid glass-jute hybrid fibre reinforced plastic composites with no filler loading and it was observed that filler loading was decreasing the impact strength of developed hybrid composites. Shrinkage and its variations in the diameter of the finally developed cylindrical shape composites were observed after cooling and solidification. Scanning electron microscopy was used to observe the internal cracks, bonding of fibres and resin, voids, etc.

Originality/value

Development of hybrid filler based novel eco-friendly bio-composites and its experimental investigation on the impact strength, tensile strength and compressive strength has not been attempted yet.

Details

World Journal of Engineering, vol. 18 no. 5
Type: Research Article
ISSN: 1708-5284

Keywords

Access Restricted. View access options
Article
Publication date: 4 October 2019

Jeevananthan Manickavasagam and Visalakshmi S.

The algorithmic trading has advanced exponentially and necessitates the evaluation of intraday stock market forecasting on the grounds that any stock market series are foreseen to…

253

Abstract

Purpose

The algorithmic trading has advanced exponentially and necessitates the evaluation of intraday stock market forecasting on the grounds that any stock market series are foreseen to follow the random walk hypothesis. The purpose of this paper is to forecast the intraday values of stock indices using data mining techniques and compare the techniques’ performance in different markets to accomplish the best results.

Design/methodology/approach

This study investigates the intraday values (every 60th-minute closing value) of four different markets (namely, UK, Australia, India and China) spanning from April 1, 2017 to March 31, 2018. The forecasting performance of multivariate adaptive regression spline (MARSplines), support vector regression (SVR), backpropagation neural network (BPNN) and autoregression (1) are compared using statistical measures. Robustness evaluation is done to check the performance of the models on the relative ratios of the data.

Findings

MARSplines produces better results than the compared models in forecasting every 60th minute of selected stocks and stock indices. Next to MARSplines, SVR outperforms neural network and autoregression (1) models. The MARSplines proved to be more robust than the other models.

Practical implications

Forecasting provides a substantial benchmark for companies, which entails long-run operations. Significant profit can be earned by successfully predicting the stock’s future price. The traders have to outperform the market using techniques. Policy makers need to estimate the future prices/trends in the stock market to identify the link between the financial instruments and monetary policy which gives higher insights about the mechanism of existing policy and to know the role of financial assets in many channels. Thus, this study expects that the proposed model can create significant profits for traders by more precisely forecasting the stock market.

Originality/value

This study contributes to the high-frequency forecasting literature using MARSplines, SVR and BPNN. Finding the most effective way of forecasting the stock market is imperative for traders and portfolio managers for investment decisions. This study reveals the changing levels of trends in investing and expectation of significant gains in a short time through intraday trading.

Details

Benchmarking: An International Journal, vol. 27 no. 2
Type: Research Article
ISSN: 1463-5771

Keywords

Access Restricted. View access options
Article
Publication date: 1 October 2007

B.W. Steyn‐Bruwer and W.D. Hamman

This study investigates overtrading, which is the result of an expansion rate that is too high in relation to a particular business’s structure. It often results in cash flow…

270

Abstract

This study investigates overtrading, which is the result of an expansion rate that is too high in relation to a particular business’s structure. It often results in cash flow problems. The phenomenon of overtrading is described in a case study on Profurn. In this study, a ratio was developed that can be used to identify companies in an overtrading position. Selected variables were tested by means of the Kruskal Wallis test in order to pinpoint variables that can discriminate successfully between companies that are overtrading and ones that are not. Overtrading occurred in 15.5% of the company years of listed South African companies between September 1989 and December 2005. Of the 35 variables tested, 31 were found to be able to discriminate statistically between company years in which overtrading occurred as opposed to ones in which it did not occur. These variables can therefore be used to profile companies that overtrade.

Details

Meditari Accountancy Research, vol. 15 no. 2
Type: Research Article
ISSN: 1022-2529

Keywords

1 – 10 of 25
Per page
102050