Efficient Dye Contaminant Elimination and Simultaneously Electricity Production via a Bi-Doped TiO2 Photocatalytic Fuel Cell

TiO2 develops a higher efficiency when doping Bi into it by increasing the visible light absorption and inhibiting the recombination of photogenerated charges. Herein, a highly efficient Bi doped TiO2 photoanode was fabricated via a one-step modified sol-gel method and a screen-printing technique for the anode of photocatalytic fuel cell (PFC). A maximum degradation rate of 91.2% of Rhodamine B (RhB) and of 89% after being repeated 5 times with only 2% lost reflected an enhanced PFC performance and demonstrated an excellent stability under visible-light irradiation. The excellent degradation performance was attributed to the enhanced visible-light response and decreased electron-hole recombination rate. Meanwhile, an excellent linear correlation was observed between the efficient photocurrent of PFC and the chemical oxygen demand of solution when RhB is sufficient.

Investigation of ZnO doping on LaFeO3/Fe2O3 prepared from yarosite mineral extraction for ethanol gas sensor applications

<abstract> <p>In this study, we used a natural resource, yarosite minerals, as a Fe₂O₃ precursor. Yarosite minerals were used for the synthesis of LaFeO₃/Fe₂O₃ doped with ZnO via a co-precipitation method using ammonium hydroxide, which produced a light brown powder. Then, an ethanol gas sensor was prepared using a screen-printing technique and characterized using gas chamber tools at 100,200, and 300 ppm of ethanol gas to investigate the sensor's performance. Several factors that substantiate electrical properties such as crystal and morphological structures were also studied using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), respectively. The crystallite size decreased from about 61.4 nm to 28.8 nm after 0.5 mol% ZnO was added. The SEM characterization images informed that the modified LaFeO₃ was relatively the same but not uniform. Lastly, the sensor's electrical properties exhibited a high response of about 257% to 309% at an operating temperature that decreased from 205 ℃ to 180 ℃. This finding showed that these natural resources have the potential to be applied in the development of ethanol gas sensors in the future. Hence, yarosite minerals can be considered a good natural resource that can be further explored to produce an ethanol gas sensor with more sensitive response. In addition, this method reduces the cost of material purchase.</p> </abstract>

Sustainable functional finishing for cotton fabrics using screen-printing process and gallotannin

To seek a more environmentally friendly textile finishing technique, the screen-printing method was adopted to apply functional material to cotton fabrics. In addition, gallotannin was used as a functional material because it is naturally abundant in many plant-derived substances and shows various health-promoting features such as antimicrobial, antioxidant, and other attractive properties. Therefore, a gallotannin/thickener paste was applied to the surface of cotton fabrics through the screen-printing technique, and the gallotannin-printed cotton fabrics were thoroughly investigated using scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), and other methods. The gallotannin printed area was substantially brown in appearance, and gallotannin moiety appeared to combine with cotton cellulose through heat treatment. Furthermore, functional properties of the gallotannin-printed cotton fabrics were examined in terms of antibacterial activity, deodorizing property, and ultraviolet-blocking property, of which it demonstrated excellent abilities. However, the antibacterial ability toward Gram-negative bacteria (K. pneumoniae) decreased as the laundry cycle increased.

A carbon dioxide detector fabrication with screen printing technique for use in airplanes

Purpose From the beginning of aviation history, fire has been a serious problem for aircrafts. The purpose of this study is to provide a reference document on current risks and proposed reductions for smoke and fire incidents in commercial transport aircrafts. For this purpose, metal oxide carbon dioxide (CO2) detector was produced with the screen printing technique to detect CO2 and carbon monoxide gases from the sensors required to observe the occurrence of fire that may occur in the aircraft and to take the necessary steps to control it. Design/methodology/approach The screen printing technique was used as the gas sensor production technique for the produced sensor and tin oxide was used as the metal oxide in the produced samples. The samples produced were examined under the gases with specified gas detecting properties, and it was concluded that they can be used simultaneously with smoke detectors to increase the detection reliability and decrease the alarm time with the smoke detectors currently used in today's passenger aircrafts. Findings When the electrical characteristics of the sensor made were examined, it was observed that it meets the requirements of the Federal Aviation Administration and European Aviation Safety Agency standards (the fire should be detected within 1 min), and the false alarm situation experienced in the smoke sensors used today can be eliminated. Originality/value There is no other sensor than the smoke detectors that are used for fire detection in cargo section, lavatories and avionic compartment on aircrafts. With this study, the gas detecting feature of the produced samples was examined under the specified gases, and it was concluded that they can be used simultaneously with smoke detectors to increase detection reliability and decrease alarm time as compared to with the smoke detectors currently used in today's passenger aircrafts.

Highly Stretchable and Durable Nanocomposite Bow-Tie Antenna for Wearable Application

We present a highly stretchable and compact bow-tie antenna which operates at 5 GHz for wearable applications. The dimensions of the bow-tie antenna were 7.9 mm×17.8 mm. The stretchable antenna was fabricated with a composite mixture of silver flake and polymer binder. The composite paste was printed on polyurethane and textile using the screen printing technique. The RF performances, stretchability, bendability, and durability of the antennas were evaluated, which are critical requirements in wearable electronics. The stretchable bow-tie antennas showed excellent RF performances and stretchability up to a stretching strain of 40%. The antennas could be bent up to a bending radius of 20 mm without degrading RF performance. The stretchable antennas also exhibited outstanding mechanical endurance after 10,000 cyclic stretching tests. The antennas were not affected by the presence of the body and showed very stable RF performances, exhibiting promising results for mobile and wearable applications.

Annealing Effect on Structural, Morphological and Electrical Properties by Screen Printed Bunsenite NiO Thick Films.

Thick films of NiO deposited on glass substrate by screen printing technique. The nano powder of AR grade NiO was used for the preparation of thick films. The X-ray diffraction (XRD), Scanning Electron Microscopy and Electrical Characterization was carried out for unannealed and annealed films. The annealed films were at 250 0 C-400 0 C in a muffle furnace. Using characterisation techniques, the success of the synthesised nanoparticles was confirmed. The x-ray diffraction was used for structural characterization which confirms the polycrystalline nature of the films with cubic structure. From the SEM analysis the films show uniformity, roughness, large crystals and agglomeration of particles. The SEM-EDS analysed morphology and chemical compositions. The correlations between structural and morphological properties are reported. The D.C. resistance of the films was measured by half bridge method in air atmosphere at 30OC to 350OC. From the electrical parameters the NiO films shows semiconducting nature. The TCR, activation energy and sheet resistivity, specific surface area were calculated at different annealing temperatures. The electrical conductivity at room temperature was calculated as 4.56 × 𝟏𝟎 −𝟒 (𝜴 ∙ 𝒎) −𝟏

Fabrication and Characterization of Highly Deformable Artificial Muscle Fibers Based on Liquid Crystal Elastomers

Artificial muscles have important applications in areas ranging from robotics to prosthetics and medical devices. In this study, highly deformable artificial muscle fibers that utilize superior actuating properties of liquid crystal elastomers and liquid-like deformability of liquid metal are reported. An effective and low-cost fabrication approach using screen printing technique is developed. The actuating properties of the artificial muscle fibers, including the dependence of temperature, contraction strain, and pulling force of the artificial muscle fiber on electric heating current and heating time, are characterized. The results could provide important guidance to design and for development of soft systems that utilize the actuating mechanisms of liquid crystal elastomers.