Recent developments in tensile properties of friction welding of carbon fiber-reinforced composite: A review

In this review article, the joining of carbon fiber-reinforced polymer composite with metallic materials by using friction welding techniques was discussed and the effects of process parameters on the weld properties were evaluated. Major parameters involved in this process were plunge depth (PD), dwell time, joining time, and tool rotational speed. A successful friction joint of carbon fiber-reinforced poly composite laminate (CF-PPS)-metal was formed with an interlayer film of additional polyphenylene sulfide. In addition, a detailed overview of the friction techniques was discussed, such as friction stir spot welding (FSSW), friction stir welding (FSW), and refill friction stir spot welding (RFSSW). In this current work, we had focused on the parameters, process, and their development during friction welding of similar and dissimilar metals with CFRP joint. Regarding the FSSW review, the best tensile shear load was 7.1 kN obtained from AA5182 and CFRP at a rotational speed of 3,000 rpm and 5 s welding time. The thickness for AA5182 and CFRP are 1.2 and 3 mm, respectively. The most efficient parameters are rotational speed, PD, dwell time, and shoulder penetration depth. In addition, the heat generated during the process parameters, its influence on mechanical and microstructure properties along with the possible defects and internal cracks of the similar and dissimilar welded joints will be reviewed and discussed

AC-assisted deposition of aggregate free silica films with vertical pore structure

Silica thin films with vertical nanopores are useful to control access to electrode surfaces and may act as templates for growth of nanomaterials. The most effective method to produce these films, electrochemically assisted surfactant assembly, also produces aggregates of silica particles. This paper shows that growth with an AC signal superimposed onto the potential avoids the aggregates and only very small numbers of single particles are found. This finding is linked to better control of the diffusion field of hydroxide ions that are responsible for particle growth. The resultant films are smooth, with very well-ordered hexagonal pore structures

Capteurs électrochimiques de polluants environnementaux à base d'électrodes de carbone modifiées par de la silice mésoporeuse organisée

In this thesis, we present the electrochemical detection of herbicides i.e. paraquat and isoproturon in aqueous samples. These herbicides are used worldwide extensively for weed control in different crops. Their intensive use is a source of environmental contamination and their toxicity is a threat to Human health. Electrochemical sensing is a promising and advantageous technique as compared to conventional detection methods due to its properties such as rapid analysis, ease of operation, cost effectiveness and high sensitivity as a result of working electrode modification. Here, we modified electrodes modified with mesoporous silica thin films to act as herbicide sensors. These electrodes were modified by electrochemically assisted self-assembly process, a well-established process for electrode modification by our group. In the first part adhesion of mesoporous silica film at carbon electrodes was improved with the help of a primary amine which acted as molecular glue for better attachment of these films at electrodes surface. In the next part these modified electrodes were used for electrochemical detection of above stated herbicides. Modified electrodes showed enhanced sensitivity and low limit of detection as compared to unmodified ones. Effect of different solution parameters as well as film thickness and electrode geometry was also studied and found to have critical impact on sensitivity of the systemDans cette thèse, nous présentons la détection électrochimique des herbicides, c'est-à-dire le paraquat et l'isoproturon dans des échantillons aqueux. Leur utilisation intensive est une source de contamination de l'environnement et leur toxicité constitue une menace pour la santé. La détection électrochimique est une technique prometteuse et avantageuse par rapport aux méthodes de détection conventionnelles en raison de ses propriétés telles que l'analyse rapide, la facilité d'utilisation, la rentabilité et la sensibilité élevée résultant de la modification de l'électrode de travail. Ici, nous avons modifié les électrodes modifiées avec des films minces de silice mésoporeuse pour agir comme capteurs d'herbicide. Ces électrodes ont été modifiées par un processus d'auto-assemblage assisté par électrochimie, un processus bien établi pour la modification des électrodes par notre groupe. Dans la première partie, l'adhérence du film de silice mésoporeux aux électrodes de carbone a été améliorée à l'aide d'une amine primaire qui a agi comme colle moléculaire pour une meilleure fixation de ces films à la surface des électrodes. Dans la partie suivante, ces électrodes modifiées ont été utilisées pour la détection électrochimique des herbicides susmentionnés. Les électrodes modifiées ont montré une sensibilité accrue et une limite de détection basse par rapport aux électrodes non modifiées. L'effet des différents paramètres de la solution ainsi que l'épaisseur du film et la géométrie de l'électrode ont également été étudiés et ont un impact critique sur la sensibilité du systèm

Zinc oxide nanostructure deposition into sub-5 nm vertical mesopores in silica hard templates by atomic layer deposition

Nanostructures synthesised by hard-templating assisted methods are advantageous as they retain the size and morphology of the host templates which are vital characteristics for their intended applications. A number of techniques have been employed to deposit materials inside porous templates, such as electrodeposition, vapour deposition, lithography, melt and solution filling, but most of these efforts have been applied with pore sizes higher in the mesoporous regime or even larger. Here, we explore atomic layer deposition (ALD) as a method for nanostructure deposition into mesoporous hard templates consisting of mesoporous silica films with sub-5 nm pore diameters. The zinc oxide deposited into the films was characterised by small-angle X-ray scattering, X-ray diffraction and energy-dispersive X-ray analysis

Electrografting of 3-Aminopropyltriethoxysilane on a Glassy Carbon Electrode for the Improved Adhesion of Vertically Oriented Mesoporous Silica Thin Films

International audienceVertically oriented mesoporous silica has proven to be of interest for applications in a variety of fields (e.g., electroanalysis, energy, and nanotechnology). Although glassy carbon is widely used as an electrode material, the adherence of silica deposits is rather poor, causing mechanical instability. A solution to improve the adhesion of mesoporous silica films onto glassy carbon electrodes without compromising the vertical orientation and the order of the mesopores will greatly contribute to the use of this kind of modified carbon electrode. We propose here the electrografting of 3-amino-propyltriethoxysilane on glassy carbon as a molecular glue to improve the mechanical stability of the silica film on the electrode surface without disturbing the vertical orientation and the order of the mesoporous silica obtained by electrochemically assisted self-assembly. These findings are supported by a series of surface chemistry techniques such as X-ray photoelectron spectroscopy, scanning and transmission electron microscopy, and cyclic voltammetry. Finally, methylviologen was used as a model redox probe to investigate the cathodic potential region of both glassy carbon and indium tin oxide electrodes modified with mesoporous silica in order to demonstrate further the interest in the approach developed here

Comparative growth response related to hair mineral analysis in dromedary camel calves

Background: The dromedary camel plays significant role in supporting livelihood of pastoral and agro-pastoral systems as well as a source of income generation and national economy in arid regions. Aim: Current study was executed to check the comparative growth response relative to hair mineral status in Marecha camel calves reared under intensive (IMS) and extensive (EMS) management system at Thal desert Punjab, Pakistan. Methods: Twelve male and female Camelus dromedarius calves of almost same weight and age were divided into two groups of 6 (3 male and 3 female). The calves of first group were maintained at Camel Breeding and Research Station Rakh Mahni in semi-open housing system while the second group in available housing under field conditions. The first group calves were fed concentrate at 1 kg/head/day along with gram straw (Cicer arientinum) ad libitum while in second group calves were allowed grazing/browsing for 10 hours daily along with household refusals including kitchen wastes. Watering was done twice a day. Impressum digital weighing scale was used for fortnightly weighing. Data collected on different parameters was subjected to statistical analysis with 2×2 factorial arrangements of treatments under completely randomized design. Results: After 120 days’ trial period the mean body weight and average daily gain (ADG) of male and female calves was significantly increased (P<0.05) in IMS as 80.8±2.7, 77.8±2.7 kg and 0.67±0.02, 0.65±0.02 kg/d than EMS as 64.5±2.6, 52.9±2.6 kg and 0.54±0.02, 0.44±0.02 kg/d of male and female calves. Intake of crop residues (P<0.05) was found to be 6.9±0.45 and 6.4±0.45 kg/d in male and female calves, respectively in IMS and 3.5±0.23 for male and female calves both in EMS. The conversion index g/kg ADI was 97.1, 101.5 and 154.3, 125.7 for male and female calves, respectively in IMS and EMS. Regarding hair mineral status Ca, Mg, Cu, Zn, Fe and Mn concentrations were found to be significantly different (P<0.05) among calf groups in IMS and EMS. Conclusion: This study indicates that wool analysis and management of weight gain in camel calves may be further explored to support increased meat supply in arid regions

Dataset supporting an article &#39;Mesoporous silica films as hard templates for electrodeposition of nanostructured gold&#39;

Raw data used in preparation of figures in the manuscript and supplementary information of the linked manuscript at https://doi.org/10.1039/d2na00512c. Micrographs are provided in the manuscript and supplementary information. Original data used to produce other figures is provided in the provided text format files. These contain small angle X-ray scattering, electrochemical and X-ray diffraction results. </span

Mesoporous silica films as hard templates for electrodeposition of nanostructured gold

Metallic nanostructures have widespread applications in fields including materials science, electronics and catalysis. Mesoporous silica films synthesised by evaporation induced self-assembly and electrochemically assisted self-assembly with pores below 10 nm were used as hard templates for the electrodeposition of Au nanostructures. Electrodeposition conditions were optimised based on pore orientation and size. The growth of nanostructures was initiated at the electrode surface as confirmed by microscopy. The hard templates and Au electrodeposits were characterised electrochemically as well as with X-ray diffraction, small angle scattering and transmission electron microscopy. Finally, mesoporous silica hard templates were removed by hydrofluoric acid etching and stable Au nanoparticles on different electrode surfaces were achieved