A versatile electrolyte system for electrodeposition of p-block elements from single ohase supercritical CH2F2

For the first time, a versatile electrolyte bath is described that can be used to electrodeposit a wide range of p-block elements from supercritical difluoromethane (scCH2F2). The bath comprises the tetrabutylammonium chlorometallate complex of the element in an electrolyte of 50×10−3 mol dm−3 tetrabutylammonium chloride at 17.2 MPa and 358 K. Through the use of anionic ([GaCl4]−, [InCl4]−, [GeCl3]−, [SnCl3]−, [SbCl4]−, and [BiCl4]−) and dianionic ([SeCl6]2− and [TeCl6]2−) chlorometallate salts, the deposition of elemental Ga, In, Ge, Sn, Sb, Bi, Se, and Te is demonstrated. In all cases, with the exception of gallium, which is a liquid under the deposition conditions, the resulting deposits are characterised by SEM, energy-dispersive X-ray analysis, XRD and Raman spectroscopy. An advantage of this electrolyte system is that the reagents are all crystalline solids, reasonably easy to handle and not highly water or oxygen sensitive. The results presented herein significantly broaden the range of materials accessible by electrodeposition from supercritical fluid and open up the future possibility of utilising the full scope of these unique fluids to electrodeposit functional binary or ternary alloys and compounds of these elements

The Influence of Digital Modulations on 320 Gbit/s Optical Time Division Multiplexing

In this article the optical time division multiplexingtechnique for high speed point-to-point optical networksis discussed. We performed test of influence of selected types modulation formats in the optical time division multiplexing simulation model with a distance of 30 km. Additionally, this paper focuses on maximum bandwidth usage, improvement of bit error rate and the another goal is to achieve the maximal transmission distance by using of special compensation optical fiber. Optimal length of compensation optical fiber was found and used during simulations. We demonstrated positive influence compensation optical fiber on bit error rate. For comparisonof modulation formats such as return-to-zero, non-return-to-zero, chirped-return-to-zero, carrier-suppressed-return-to-zero, and m-ary quadrature amplitude modulation were tested. Our results confirm that it is possible to achieve better bit error rate for selected modulation formats

Synergic effect of Bi, Sb and Te for the increased stability of bulk alloying anodes for sodium-ion batteries

Effective use of materials that undergo alloying reactions with sodium is hampered by the substantial volume changes that occur during cycling. One of the most common approaches to improve cycling stability is nanostructuring. However, the processes required for material’s particle downsizing are hardly transferable to large scale production. To alleviate such problems, the ternary alloy Bi0.25Sb1.75Te3 has been designed and its electrochemical performance investigated. The choice of system was driven by the large reversible capacities displayed by both Sb and Te coupled with the highly desirable fracture resistance of Bi. Indeed, micron-sized bulk powder of Bi0.25Sb1.75Te3 showed high capacity retention (retaining 91% of the initial capacity after 100 cycles at 200 mA g-1) and an excellent average coulombic efficiency (99.9% for 100 cycles), both of which are superior to those observed for the bi-component counterpart Sb2Te3 as bulk and nanosized forms. This behaviour indicates that a small substitution of Sb with Bi does have profound effects on the electrochemical performance. Even more compelling is the observation that enhanced performance and stability are observed when the active material is in the form of micron-sized powder and not when nanosized in a carbon composite. This behaviour is ascribed to the influence of particle size on the (de)sodiation reaction pathways and on the thickness and composition of the SEI passivation layer. The improved stability of the ternary alloy shows that careful optimization of multicomponent systems could lead to remarkable performance enhancement without the necessity of size confinement, opening the way to facile and low-cost electrode manufacturin

Simulation And Measurement Of Mach-Zehnder Interferometer

The paper focuses on simulation and measurement of Mach-Zehnder interferometer. This type of sensor is used as a distributed fiber optic sensor for sensing vibration, mechanical tension and temperature. Fiber optic sensors based on optical interferometry are now widely used, e.g. Sagnac interferometer in optic gyroscopes. Mach-Zehnder interferometer is used for measurement of transformers temperature. The article includes a simulation of interferometric systems in VPIphotonics simulation software and it also includes scientific notation of a signal and a short description of the used simulation systems