Sarbjit Kaur, Niraj Bala and Charu Khosla
The biomaterials are natural or synthetic materials used to improve quality of life either by replacing tissue/organ or assisting their function in medical field. The purpose of…
Abstract
Purpose
The biomaterials are natural or synthetic materials used to improve quality of life either by replacing tissue/organ or assisting their function in medical field. The purpose of the study is to analyze the hydroxyapatite (HAP), HAP-TiO2 (25 percent) composite coatings deposited on 316 LSS by High Velocity Flame Spray (HVFS) technique.
Design/methodology/approach
The coatings exhibit almost uniform and dense microstructure with porosity (HAP = 0.153 and HAP-TiO2 composite = 0.138). Electrochemical corrosion testing was done on the uncoated and coated specimens in Ringer solution (SBF). As-sprayed coatings were characterized by XRD, SEM/EDS and cross-sectional X-ray mapping techniques before and after dipping in Ringer solution. Microhardness of composite coating (568.8 MPa) was found to be higher than HAP coating (353 MPa).
Findings
During investigations, it was observed that the corrosion resistance of steel was found to have increased after the deposition of HAP and HAP-TiO2 composite coatings. Thus, coatings serve as an effective diffusion barrier to prohibit the diffusion of ions from the SBF into the substrate. Composite coatings have been found to be more corrosion resistant as compared to HAP coating in the simulated body fluid.
Research limitations/implications
It has been concluded that corrosion resistance of HAP as well as composite coating is because of the desirable microstructural changes such as low porosity high microhardness and flat splat structures in coatings as compared to bare specimen.
Practical implications
This study is useful in the selection of biomedical implants.
Social implications
This study is useful in the field of biomaterials.
Originality/value
No reported literature on corrosion behavior of HAP+ 25%- TiO2 has been noted till now using flame spray technique. The main focus of the study is to investigate the HAP as well as composite coatings for biomedical applications.
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Amita Rani, Niraj Bala and C.M. Gupta
Hot corrosion is the major degradation mechanism of failure of boiler and gas turbine components. The present work aims to investigate the hot corrosion resistance of detonation…
Abstract
Purpose
Hot corrosion is the major degradation mechanism of failure of boiler and gas turbine components. The present work aims to investigate the hot corrosion resistance of detonation gun sprayed (D-gun) Cr2O3-75 per cent Al2O3 ceramic coating on ASTM-SA210-A1 boiler steel.
Design/methodology/approach
The coating exhibits nearly uniform, adherent and dense microstructure with porosity less than 0.8 per cent. Thermogravimetry technique is used to study the high temperature hot corrosion behavior of bare and coated boiler steel in molten salt environment (Na2SO4-60 per cent V2O5) at high temperature 900°C for 50 cycles. The corrosion products are analyzed by using X-ray diffraction, scanning electron microscopy (SEM) and field emission scanning electron microscope/energy-dispersive analysis (EDAX) to reveal their microstructural and compositional features for elucidating the corrosion mechanisms.
Findings
During investigations, it was found that the Cr2O3-75 per cent Al2O3 coating on Grade A-1 boiler steel is found to be very effective in decreasing the corrosion rate in the molten salt environment at 900°C. The coating has shown lesser weight gains along with better adhesiveness of the oxide scales with the substrate till the end of the experiment. Thus, coatings serve as an effective diffusion barrier to preclude the diffusion of oxygen from the environment into the substrate boiler steel.
Research limitations/implications
Therefore, it is concluded that the better hot corrosion resistance of the coating is due to the formation of desirable microstructural features such as very low porosity, uniform fine grains and the flat splat structures in the coating; as compared to the bare substrate under cyclic conditions.
Practical implications
This research is useful for coal-fired boilers and other power plant boilers.
Social implications
This research is useful for power generation plants.
Originality/value
There is no reported literature on hot corrosion behavior of Cr2O3-75 per cent Al2O3 coating deposited on the selected substrates by D-gun spray technique. The present work has been focused to study the influence of the Cr2O3-75 per cent Al2O3 coating developed with D-gun spraying technique on high temperature corrosion behavior of ASTM-SA210-A-1 boiler steel in an aggressive environment of Na2SO4-60 per cent V2O5 molten salt at 900°C under cyclic conditions.
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John Devapriam, Lammata Raju, Niraj Singh, Richard Collacott and Sabyasachi Bhaumik
The prevalence rate of arson in offenders with intellectual disabilities (ID) has been reported to be higher than that in the general population. This retrospective study focuses…
Abstract
The prevalence rate of arson in offenders with intellectual disabilities (ID) has been reported to be higher than that in the general population. This retrospective study focuses on examining the characteristics of offenders with ID and the range of identified reasons for the index offence. The findings indicate a higher prevalence of arson in this population, along with the fact that the majority of people with ID who have committed arson tend to bypass the Criminal Justice System. A significant number are likely to repeat the behaviour and will also commit other offences. The most common reason for arson appears to be revenge, closely followed by suggestibility. The majority had an associated diagnosis of personality disorders along with an Axis 1 psychiatric diagnosis. Other factors include large family size, history of childhood psychiatric disorders, abuse, homelessness, unemployment and relationship difficulties.
Bijith Marakarkandy, Nilay Yajnik and Chandan Dasgupta
The integration of relevant antecedents into TAM would lead to better understanding of the decision factors which act as enablers for the adoption of internet banking. The purpose…
Abstract
Purpose
The integration of relevant antecedents into TAM would lead to better understanding of the decision factors which act as enablers for the adoption of internet banking. The purpose of the paper is to determine the influence of the antecedents subjective norm, image, banks initiative, internet banking self-efficacy, internet usage efficacy, trust, perceived risk, trialability and government support on the existing constructs of the technology acceptance model (TAM) and to test measurement invariance and the moderating effect of the demographic variables on the relationship between the latent constructs used in this augmented TAM.
Design/methodology/approach
A survey questionnaire was administered on internet banking users and a total of 300 responses were collected. A two-step approach suggested by Hair et al. (2006) and Schumacker and Lomax (2004) was used in this study. The proposed model was assessed using the confirmatory factor analysis approach. The structural model was then tested in order to establish nomological validity. The data based on four demographic dimensions gender, age, income, education were divided into two groups for each of these demographic dimensions. The invariance test was first performed on the measurement model and then on the structural model. The measurement model and structural model were subjected to tests of equivalence of parameters across groups.
Findings
To a large extent the results of the study supports the proposed model and thereby contributes to understand the influence of subjective norm, image, banks initiative, internet banking self-efficacy, internet usage efficacy, trust, perceived risk and government support on internet banking adoption. The predictor variables in the augmented TAM were able to explain 29.9 per cent of the variance in the actual usage of internet banking as compared to the TAM which was able to explain only 26.5 per cent variance in the actual usage of internet banking. A significant difference in the relationship between the different constructs of the model was observed when the model was subjected to multi-group invariance testing.
Research limitations/implications
The study suffers from the same limitations as most other studies involving TAM. In this study self-reported measures about the usage were taken as the actual usage. The findings of the study can be of use to marketers for target-specific marketing by customizing the marketing campaign focussing on the factors that were found to be strong influencers leading to the usage of internet banking for each target audience.
Originality/value
The main challenge in this study was to develop the conceptual model for the internet banking adoption by extending the TAM and to get a robust theoretical support from the extant literature for the relevant factors along with their relationship to uncover new insights about factors responsible for the internet banking adoption. The augmented model had an improved predictive capability and explanatory utility.
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Elijah Oluwatosin Oyewole and Joshua Oluwasuji Dada
The opportunities that the building information modeling (BIM) mode of project delivery presents warrant the need for the construction professionals to be adequately trained on…
Abstract
Purpose
The opportunities that the building information modeling (BIM) mode of project delivery presents warrant the need for the construction professionals to be adequately trained on BIM technology and processes. The purpose of this paper is to assess the training gaps that exist between the perceived and expected knowledge of BIM practice among construction professionals in Nigeria.
Design/methodology/approach
The study was carried out through a structured questionnaire survey administered on identifying training gaps among registered Nigerian construction professionals toward BIM adoption. Relevant information on the perceived and expected BIM mode of practices was systematically collected from 212 participants who are familiar with BIM concepts. The data generated were analyzed using descriptive statistics and gap analysis.
Findings
Gap analysis was employed in determining the significance of BIM training gap for various practices among the construction professionals. The most significant gaps in BIM practice with gap analysis value>1 are the project review technique and clash detection for architectural practice. Among quantity surveyors, cost estimating, preparation of bills of quantities and project budgeting are the practice areas where there are significant training gaps in adopting BIM. For engineering practices, the gap analysis reveals a significant training gap in design creation and coordination, as-built-modeling, clash detection and space management.
Research limitations/implications
The research is limited to the perception of the respondents on actual and ideal BIM practices, not considering the process workflow, facility requirements and other issues that revolve round BIM adoption and implementation. It is also limited to professionals in the industry, and further studies will be appropriate to address these limitations.
Practical implications
The study reveals that there is a great need to meet the training gaps for BIM adoption in ensuring efficiency of construction project delivery.
Originality/value
The gaps that exist between the actual and expected BIM training were statistically established.