From the organic thin film transistor to the 3-D textile organic cylindrical transistors - perspectives, expectations and predictions

In this paper we examine the possibility to simulate and study the behaviour of a fiber-based Textile Transistor in a commercial TCAD system. We also examine the capability of such transistors to operate in sufficiently low voltages, aiming to the potential realization of low-voltage wearable textiles in the future. We have seen that it is potentially feasible to build transistors which can operate in low voltages by using typical materials. Even if some of the selected typical materials have to be replaced by others more suitable for practical use in the textile industry, the simulation is a good starting point for estimating the device typical operation and parameters

Optimization of cylindrical textile organic field effect transistors using TCAD simulation tool

We used a commercial TCAD tool in order to simulate a cylindrical Textile Organic Field Effect Transistor (TOFET) and study the impact of different critical region sizes in its electrical characteristics. The simulation was based on models and parameters similar to those of previous simulations in Organic Thin Film Transistors. We have seen that it is potentially feasible to build transistors which can operate in low voltages by using typical materials. Even if some of the selected typical materials have to be replaced by others more suitable for practical use in the textile industry, the simulation is a good starting point for estimating the device typical operation and parameters. By optimizing critical region sizes of the device we conclude that the device should have an active layer thickness below 100 nm, channel length around 10 mu m and gate oxide thickness as small as possible (300 nm or less), in order to have optimum transistor performance

Monte carlo computational software and methods in radiation dosimetry

The fast developments and ongoing demands in radiation dosimetry have piqued the attention of many software developers and physicists to create powerful tools to make their experiments more exact, less expensive, more focused, and with a wider range of possibilities. Many software toolkits, packages, and programs have been produced in recent years, with the majority of them available as open source, open access, or closed source. This study is mostly focused to present what are the Monte Carlo software developed over the years, their implementation in radiation treatment, radiation dosimetry, nuclear detector design for diagnostic imaging, radiation shielding design and radiation protection. Ten software toolkits are introduced, a table with main characteristics and information is presented in order to make someone entering the field of computational Physics with Monte Carlo, make a decision of which software to use for their experimental needs. The possibilities that this software can provide us with allow us to design anything from an X-Ray Tube to whole LINAC costly systems with readily changeable features. From basic x-ray and pair detectors to whole PET, SPECT, CT systems which can be evaluated, validated and configured in order to test new ideas. Calculating doses in patients allows us to quickly acquire, from dosimetry estimates with various sources and isotopes, in various materials, to actual radiation therapies such as Brachytherapy and Proton therapy. We can also manage and simulate Treatment Planning Systems with a variety of characteristics and develop a highly exact approach that actual patients will find useful and enlightening. Shielding is an important feature not only to protect people from radiation in places like nuclear power plants, nuclear medical imaging, and CT and X-Ray examination rooms, but also to prepare and safeguard humanity for interstellar travel and space station missions. This research looks at the computational software that has been available in many applications up to now, with an emphasis on Radiation Dosimetry and its relevance in today's environment. © 2021 by the author(s)

Antimicrobial properties of gold and copper-coated textile electrodes produced though electro-less deposition

Abstract: Gold-coated and copper-coated para-aramide textile fabrics, produced through electro-less deposition method have been studied concerning their antimicrobial properties. It is studied the behaviour of the specific textiles to develop micro-organisms in contact to the human body and also their capability to inhibit the development of various micro-organisms. This work deals with the antimicrobial behaviour of fabrics that contain metallic copper as well as metallic gold in their composition. Copper has antimicrobial activity. However, the copper plating and gold plating of yarns, threads or fabrics is a process that has been recently and gradually improving. Additionally, the surface of the fabric has unevenness and allows the creation of pockets of development and incubation of microorganisms. The fabrics have been subjected into contamination with some microbes and bacteria so as to be tested concerning their antimicrobial properties. The strains used were: 2 Gram positive bacteria: Staphylococcus aureus (ATCC 25923) and Staphylococcus epidermidis (ATCC 12228) and 4 Gram negative bacteria: Escherichia coli (ATCC 25922), Enterobacter cloacae (ATCC 13047), Klebsiella pneumoniae (ATCC 13883) and Pseudomonas aeruginosa (ATCC 227853). It is attempted to demonstrate that the use of fabric containing copper or gold in its composition (e.g sheet/blanket), significantly reduces the presence of microbes in the region with which it comes into contact. In such a way, there may be feasible to avoid Healthcare Associated Infections or spreading germs through the hospital staff or even to reduce the severity of existing infections by reducing the concentration of the causative factor through the known antimicrobial activity of copper

Evaluating the ultraviolet protection factor (UPF) of various knit fabric structures

Public awareness regarding the risks of prolonged skin exposure to the sun light and more specifically to the UV spectrum part is increased during the last decades. Clothing is the most natural and suitable way of protecting the human body, thus the market interest in clothes that can offer adequate UV protection is growing continuously. Previous research works have revealed the main factors that influence the ability of fabrics to block harmful UV radiation. However, the variability of these factors and the versatility of their combined effect make UV protection factor prediction difficult and hence the design of fabrics with high performance against UV radiation becomes a complicated task. Hopefully, the most critical and predictable among all factors is the fabric structure itself. Expectedly, closer and tighter structures offer higher UV protection. Due to this fact, the majority of previous research concern woven structures which generally are less porous and offer a higher UV protection. However, the possibility to obtain knitted fabrics with adequate UV protection factor is of great interest, since knitted fabrics are more appropriate for sports as well as for casual summer fashion garments. Current literature regarding the UV protection factor of knitted fabrics is very limited and concerns mostly fabrics produced in machines of relative large gauges. In the present work the UV protection factor of various typical weft-knitted structures, produced in a flat knitting machine with 7 gauge and by using grey 100% Organic Cotton yarns, Ne 30/2, 330 TPM (twists per meter) is studied. The yarn has been selected due to the increasing market interest for Organic Cotton products