The Ripple Effect of Graphite Nanofilm on Stretchable Polydimethylsiloxane for Optical Sensing

Graphene-based optical sensing devices have been widely studied for their broad band absorption, high carrier mobility, and mechanical flexibility. Due to graphene’s weak light absorption, studies on graphene-based optical sensing thus far have focused on hybrid heterostructure devices to enhance photo-absorption. Such hybrid devices need a complicated integration process and lead to deteriorating carrier mobility as a result of heterogeneous interfaces. Rippled or wrinkled graphene has been studied in electronic and optoelectronic devices. However, concrete demonstrations of the impact of the morphology of nanofilms (e.g., graphite and graphene) associated with light absorption in optical sensing devices have not been fully examined. This study explored the optical sensing potential of a graphite nanofilm surface with ripples induced by a stretchable polydimethylsiloxane (PDMS) supporting layer under different stretch:release ratios and then transferred onto silicon, both under experimental conditions and via simulation. The optical sensing potential of the rippled graphite nanofilm was significantly enhanced (260 mA/W at the stretch–release state of 30%), as compared to the pristine graphite/PDMS (20 mA/W at the stretch–release state of 0%) under laser illumination at a wavelength of 532 nm. In addition, the results of our simulated computation also confirmed the improved light absorption of rippled graphite nanofilm surface-based optical sensing devices, which was comparable with the results found in the experiment.

Application of Machine Learning Approaches in Intrusion Detection System

The rapid development of technology reveals several safety concerns for making life more straightforward. The advance of the Internet over the years has increased the number of attacks on the Internet. The IDS is one supporting layer for data protection. Intrusion Detection Systems (IDS) offer a healthy market climate and prevent misgivings in the network. Recently, IDS has been used to recognize and distinguish safety risks using Machine Learning (ML). This paper proposed a comparative analysis of the different ML algorithms used in IDS and aimed to identify intrusions with SVM, J48, and Naive Bayes. Intrusion is also classified. Work with the KDD-CUP data set, and their performance has been checked with the WEKA software. A comparison of techniques such as J48, SVM, and Naïve Bayes showed that the accuracy of j48 is the higher one which was (99.96%).

STRUCTURAL INVESTIGATION OF THE INTERMEDIATE LAYER IN A BIMETAL MILL ROLLER PRODUCED BY THE METHOD OF VERTICAL AXIS CENTRIFUGAL CASTING

Subject of the investigation is a bimetallic mill roller with external, working layer from high chromium material and inner, supporting layer from ductile cast iron. The processes, accompanying the formation of a transition layer in bimetallic castings, produced by centrifugal casting have been investigated. Attention has paid to the structural changes in the transition zone, caused by the diffusion processes occurring during the casting and crystallization.

Experimental Research on Foil Vibrations in a Gas Foil Bearing Carried Out Using an Ultra-High-Speed Camera

The foil bearing consists of parts made of very thin, properly shaped foils. Usually, it is very difficult or even impossible to measure the vibrations of these elements during the bearing operation using traditional sensors. Therefore, the authors of this article have proposed an entirely new approach to this issue. This article discusses the analysis of vibrations of the structural supporting layer of a gas foil bearing at high rotational speeds. Instead of using a traditional method to measure the bearing journal movement, the measurement was performed using an ultra-high-speed digital camera. This type of measurement was used for the first time to analyse foil bearing displacement. It turned out that doing so can give a far more vibrant picture of what is happening in gas foil bearings during their operation. The article includes an analysis of foil vibrations. This phenomenon has already been analysed numerically, and this is the first time it has been analysed experimentally. The registered motion of the foils can be compared with the results obtained from numerical models, thus allowing their further development. One such comparison is shown in this article.

Transport Analysis of Anti-Wetting Composite Fibrous Membranes for Membrane Distillation

Composite electrospun fibrous membranes are widely studied for the application of membrane distillation. It is an effective approach to enhance the membrane distillation performance in terms of anti-wetting surface and permeate flux by fabricating composite fibrous membranes (CFMs) with a thin skin layer on a thick supporting layer. In this work, various membranes prepared with different pore sizes and porosities by polyacrylonitrile and polyvinylpyrrolidone were prepared. The membrane characteristics and membrane distillation performance were tested. The mass transfer across the membranes was analyzed experimentally and theoretically in detail. It is shown that the skin layer significantly increases liquid entry pressure of the CFM by 5 times. All the membranes have a similar permeate flux. The permeate flux of membranes is stable at 19.2 ± 1.2 kg/m2/h, and the salt rejection ratios remain above 99.98% at 78 ± 1 °C for 11 h. The pore size and porosity of membranes have an insignificant effect on the temperature distribution of membrane. The porosity and pore size of the skin layer have an insignificant effect on the mass transfer process of the CFM. The mass transfer process of the CFM is governed by the supporting layer.