Adhesion and cohesion properties of diamond-like-carbon coatings deposited on biomaterials by saddle field neutral fast atom beam source: measurement and modelling

Diamond-like-carbon (DLC) has been shown to be strategically important in respect to biomedical applications due to its biocompatibility. Despite decades of work on film deposition there is an insufficient understanding in respect of the film’s adhesion characteristics, particularly on biomaterial substrates. The central aim of this study is two pronged. A programme of work has been undertaken to set-up, study, understand and optimise the production technique for DLC deposition, while on the other hand diamond like carbon films have been characterised to investigate the strength of adhesion and cohesive strength with particular reference to biomedical applications. DLC films have been deposited on to substrates of 316L stainless steel, cobalt chrome (CoCr) and Ti6AI4V alloy using a saddle field neutral beam deposition system (Microvac 1200DB, Ion Tech Ltd) with acetylene and acetyleneargon mixture as the process gas. It is noted that numerous parameters influence coating adhesion including the stress in the film, contamination and chemical bonding between the film and the substrate, and the physical properties and roughness of the substrate. Discharge current vs. discharge voltage characteristics were investigated with different pressure and process gas. Uv absorption spectra were used to measure the photon energy and optical band gap of the films. The optical band gap was found in the range of -0.85 and 0.85 -0.97 eV for lower and higher deposition current respectively. The adhesion of the films has been measured as a function of the duration of in-situ etching by a neutral argon beam and also as a function of source current, system pressure and process gas (pure C2H2 and C2H2+Ar gas mixture). The studies were performed on DLC films with thickness -0 .4 |im. The adhesion of the film was measured using pull-off and Rockwell C tests whereas four point bend (FPB) test was used to measure the cohesive strength of the films. Argon pre etching for 15 minutes is recommended to guarantee an optimal adhesion. The etching process also influenced the film structure in terms of the sp3/sp2 ratio and stress. It was also found that this optimisation of the adhesion is correlated with a change in the structure and thickness of the native oxide layer on the steel surface of the substrates. Substrate surface temperature during etching and deposition also influenced film structure and adhesion. Correlation between the residual stress and the adhesion of the films has also been established which helped to identify optimum process parameters for substrate-film adhesion properties. No significant change with deposition pressure has been observed but high anode currents may lead to higher sp3 content. The adhesion strength has been found to be inversely proportional to residual stress and to increase at low deposition pressures. At source anode current of 0.6A, the adhesion is a monotonic function of pressure in the range examined where as with 1.0A source current the behaviour is more complex. The relationship between the stress and the sp3 content of the films measured by analysis of Raman signature has also been investigated. The experimental work of FPB has been used to support and develop a numerical (Finite Element) model for the determination and prediction of the film's cohesive strength. The model takes into account the film hardness, Young’s modulus and thickness and has been shown to be capable of predicting the film’s cohesive strength when combined with a theoretical formulation for brittle fracture. It has been observed that maximum stress developed at the outer surface of film during the bend test, which influenced the initiation of cracks at the outer surface of the film and their propagation through the film-substrate interface. This result has only been valid for films with higher Young's modulus compared with the substrate

A Study on Preparedness of Key Institutions to Advance Inclusive Growth for Small & Medium Producers of The Boutique Fashion Industry in Bangladesh

Boutique Fashion of Bangladesh is an iconic industry with potential to take Bangladeshi cultural heritage to the global domain. It is a fast-growing industry that historically has portrayed the characteristics of a developing country where labour intensity, artisan approach, small and medium entrepreneurship, and local heritage have played a huge role. Despite the industry’s potential to advance inclusive growth, its players, mostly small and medium enterprises (SMEs), are largely neglected. This raise the question of institutional preparedness to support this industry. This study deploys the Triple Triangle Framework (TTF) to first summarize SME competitiveness priorities along nine dimensions of three TTF domains. Later, institutional preparedness has been assessed keeping eight relevant organizations in focus. The study is based on extensive literature review and top-level depth interviews. The finding suggests, despite its potential impact, the industry does not rank high in the list of government’s priority sectors/interventions. While the boutique industry leaders will be able to craft an action-agenda based on the findings of this research, government agencies too will be able to formulate necessary policies and promote institutional arrangements. Keywords: SME, Boutique, Fashion, Inclusive Growth, Facilitating Institutions, Preparednes

Blockchain of Things: Benefits, Challenges and Future Directions

As Internet of Things (IoT) technologies become increasingly integrated into our daily lives through a multitude of Internet-enabled devices, the efficient, secure, and cost-effective management of the vast amount of data generated by these devices poses a significant challenge. Blockchain has recently emerged as a promising technique to address this challenge by providing a means to establish trust without relying on a trusted third party. The convergence of blockchain and IoT presents a transformative opportunity to establish a secure and robust mechanism for managing the data generated by IoT devices. It is recognized as the essential missing link for enabling IoT devices to fully harness their benefits. This Special Issue delves into a diverse range of IoT-enabled blockchain-driven solutions that leverage the integration of IoT and blockchain technologies, aiming to explore and advance the intersection of these two innovative technologies.For this Special Issue, we received 19 papers in total, and 11 of them were accepted and published. The authors presented some novel ideas, frameworks, and smart contract vulnerability detection methods to solve many real-world problems. These advanced models not only offer tailored solutions but also contribute significantly to increased efficiency, heightened security, and improved efficiency, highlighting the transformative potential of the integration of IoT and blockchain technology. We extend our heartfelt gratitude to all authors for their valuable contributions to this field

Mobile Banking: The Bangladesh Experience

This study is about the Mobile Banking in Bangladesh. Major objectives of this study are to give an overview about cost, usage and all other benefits of Mobile Banking as well as to produce a scenario of Mobile Banking in Bangladesh. Both the primary and secondary data have been used for the study purpose.  The major findings of this study are 94% respondents think that it saves time than traditional banking, the highest number of respondents use Mobile Banking for ‘Air-time top-up’ service, out of 50 respondents 92% have replied it is less costlier than traditional banking, 100% respondents have agreed that it is speedy, and 100% respondents have opined any type of set can be used for Mobile Banking. Besides, 64% respondents have mentioned that DBBL plays a significant role in mobile baking sector, whereas 28% respondents have agreed that Bkash performs a vital role. Although this concept is new in Bangladesh but its potentiality is high and already it has started to contribute in the economy significantly. From this research, other researchers and policy makers will get an insight about the Mobile Banking in Bangladesh. Keywords:  M- Banking, Bkash, . ICTD, IBMC, SMS, NFC

Analyzing the intention of the households to drop off mobile phones to the collection boxes: empirical study in Malaysia

Purpose – To achieve proper waste management, the disposal of electronic waste (e-waste) is one suitable method. Most developing countries, including Malaysia, are facing lack of e-waste recycling facilities and low household participation. Using a survey method using a questionnaire, this study aims to examine the intention of Malaysian households to drop-off their mobile phones to the nearest collection boxes (n = 600). Design/methodology/approach – This study expanded the theory of planned behavior by adding environmental awareness and knowledge. In addition, the cost of disposal and the convenience of the available disposal infrastructure weremeasured as two parts of the perceived behavioral control. Findings – The results of this study show that environmental knowledge and awareness have a significant impact on attitudes toward recycling intention of the households. In addition, it was also found that the attitude and cost of disposal infrastructure is positively related to household intention. Originality/value – These results show that if e-waste collection boxes are provided to the nearest community and e-waste management information is distributed, this will increase household participation in e-waste management

A Policy Framework for Subject-Driven Data Sharing

Organizations (e.g., hospitals, university etc.) are custodians of data on their clients and use this information to improve their service. Personal data of an individual therefore ends up hosted under the administration of different data custodians. Individuals (data subjects) may want to share their data with others for various reasons. However, existing data sharing mechanisms provided by the data custodians do not provide individuals enough flexibility to share their data, especially in a cross-domain (data custodian) environment. In this paper, we propose a data sharing policy language and related framework for a data subject to capture their fine-grained data sharing requirements. This proposed language allows the data subject to define data sharing policies that consider context conditions, privacy obligations and re-sharing restrictions. Furthermore, we have implemented a prototype to demonstrate how data subjects can define their data sharing policies and how the policies can be used and enforced at runtime

Effect of the Condensation of Hybrid Organic–Inorganic sol–gel Materials on the Optical Properties of Tripan Blue

The work reported in this paper highlights the effect of sol–gel structures on the optical properties of a typical organic dye (Trypan Blue, TB). Three transition-metal-based hybrid sol–gel materials with different structures and morphologies were developed and characterised by TEM. The optical properties of TB were investigated by incorporating it in the different sol–gel materials and the UV–Visible spectra recorded in both liquid and solid state, in thin-coatings cured at temperatures in the range 100– 150 [1]C. These studies revealed two relevant results. First, the sol–gel morphology plays a critical role in the optical properties of the dye. The effect of the sol–gel host matrix on the optical properties of the dye is attributed to the steric hindrance of the nanostructures, themselves intimately dependant on the reactivity of the transition metal. For instance, the less condensed system showed the highest reactivity with the dye, while the more condensed system exhibited limited interaction with the dye, symbolised by a significant change or quasi-unchanged UV–Visible spectra, respectively. It is also shown that the increase of the condensation degree of the sol–gel coatings by heat-curing can dramatically alter the optical properties of the dye especially for the most condensed sol–gel systems. This has been attributed to proximity effects enabled by the further increase of the materials densities. The results reported here aim to provide a better understanding of how material formulations can influence the optical properties of organic dyes and suggest that the structure of the host matrix along with the applied curing process have to be fully considered and assessed in the choice of organic dyes for a given application

Correlation between the structure and the anticorrosion barrier properties of hybrid sol–gel coatings: application to the protection of AA2024-T3 alloys

Hybrid sol–gel materials have been extensively studied as viable alternatives to toxic chromate (VI)-based coatings for the corrosion protection of AA2024-T3 in the aerospace industry, due to the wide range of available chemistries they offer and the tremendous development potential of innovative functional coatings. However, so far, little work has been performed in identifying the effect of the employed chemistries on the structure and anticorrosion properties of the coatings. This work proposes to contribute to a better understanding of the relationship existing between the structure, morphology and anticorrosion properties of hybrid sol–gel coatings deposited on AA2024- T3 aluminium surfaces, the most widely used alloy in the aerospace industry. The sol–gels are prepared employing two hybrid precursors; an organosilane, 3-trimethoxysilylpropylmethacrylate, and a zirconium complex prepared from the chelation of zirconium n-propoxide, and methacrylic acid. The structure of the hybrid sol–gel formulation is modified by altering the concentration of the transition metal complex. The structure and morphology of the coatings are characterised by dynamic light scattering, fourier transform infrared spectroscopy, silicon nuclear magnetic resonance spectroscopy, differential scanning calorimetry, scanning electron microscopy, atomic-force microscopy and the anticorrosion barrier properties characterised by electrochemical impedance spectroscopy and neutral salt-spray. It is found that the transition metal concentration affected the morphology and structure, as well as the anticorrosion performances of the hybrid sol–gel coatings. A direct correlation between the morphology of the coatings and their final anticorrosion barrier properties is demonstrated, and the optimum material amongst this series is determined to be comprised of a concentration of between 20 and 30% of transition metal

Fruit Quality Assessment with Densely Connected Convolutional Neural Network

Accurate recognition of food items along with quality assessment is of paramount importance in the agricultural industry. Such automated systems can speed up the wheel of the food processing sector and save tons of manual labor. In this connection, the recent advancement of Deep learning-based architectures has introduced a wide variety of solutions offering remarkable performance in several classification tasks. In this work, we have exploited the concept of Densely Connected Convolutional Neural Networks (DenseNets) for fruit quality assessment. The feature propagation towards the deeper layers has enabled the network to tackle the vanishing gradient problems and ensured the reuse of features to learn meaningful insights. Evaluating on a dataset of 19,526 images containing six fruits having three quality grades for each, the proposed pipeline achieved a remarkable accuracy of 99.67%. The robustness of the model was further tested for fruit classification and quality assessment tasks where the model produced a similar performance, which makes it suitable for real-life applications.Comment: Accepted in 12th ICECE (4 pages, 3 Figures, 3 Tables

Enhanced corrosion protection and biocompatibility of a PLGA-silane coating on AZ31 Mg alloy for orthopaedic applications

This paper reports a multi-step procedure to fabricate a novel corrosion resistant and biocompatible PLGA-silane coating on the magnesium (Mg) alloy AZ31. The first step involves alkaline passivation followed by dip coating in a methyltriethoxysilane (MTES) and tetraethoxysilane (TEOS) mixture to produce a cross-linked siloxane coating. The second step is to impart an amine functionalization to the silane modified surface by using 3-aminopropyl-triethoxy silane (APTES) for promoting adhesion of the acid terminated poly-(lactic-co-glycolic) acid (PLGA) as a final coating step. Static contact angle measurements, Fourier transform infrared spectroscopy and scanning electron microscopy analysis confirmed the successful assembly of coatings on the AZ31 Mg alloy. Potentiodynamic polarization and impedance spectroscopy studies showed the improved initial corrosion resistance of the coated AZ31 substrate. Measurements of magnesium ion release, pH changes and hydrogen evolution showed enhanced corrosion protection of coated substrate over uncoated AZ31 alloy for 21 and 14 days respectively. The MTT assay, live-dead cells staining, DNA quantification and alkaline phosphatase activity assay were used to measure the biocompatibility, proliferation and differentiation of MC3T3-E1 osteoblast cells. Scanning electron microscopy was used to observe cell morphology and integration with the coated surface. The coated substrate showed improved cytocompatibility as compared to the uncoated AZ31 alloy surface. The application of such coatings on biodegradable Mg alloys enhanced their corrosion resistance and biocompatibility. An additional advantage is that the coating also served as a potential delivery vehicle for specific drugs and bio-active molecules releasing from an implant surface as the coatings, such as PLGA, adapt during the corrosion process, thereby enhancing bone regeneration