Diamond semiconductor technology for RF device applications

This paper presents a comprehensive review of diamond electronics from the RF perspective. Our aim was to find and present the potential, limitations and current status of diamond semiconductor devices as well as to investigate its suitability for RF device applications. While doing this, we briefly analysed the physics and chemistry of CVD diamond process for a better understanding of the reasons for the technological challenges of diamond material. This leads to Figure of Merit definitions which forms the basis for a technology choice in an RF device/system (such as transceiver or receiver) structure. Based on our literature survey, we concluded that, despite the technological challenges and few mentioned examples, diamond can seriously be considered as a base material for RF electronics, especially RF power circuits, where the important parameters are high speed, high power density, efficient thermal management and low signal loss in high power/frequencies. Simulation and experimental results are highly regarded for the surface acoustic wave (SAW) and field emission (FE) devices which already occupies space in the RF market and are likely to replace their conventional counterparts. Field effect transistors (FETs) are the most promising active devices and extremely high power densities are extracted (up to 30 W/mm). By the surface channel FET approach 81 GHz operation is developed. Bipolar devices are also promising if the deep doping problem can be solved for operation at room temperature. Pressure, thermal, chemical and acceleration sensors have already been demonstrated using micromachining/MEMS approach, but need more experimental results to better exploit thermal, physical/chemical and electronic properties of diamond

Selected copper(I) complexes as potential anticancer agent

Choroby nowotworowe są drugą co do częstości występowania przyczyną zgonów na świecie. Jednym z metali przejściowych, którego związki kompleksowe są intensywnie badane pod kątem zastosowania w terapii antynowotworowej jest miedź. W artykule, na wybranych przykładach, omówiono aktywność i mechanizmy cytotoksycznego działania kompleksów miedzi(I).Cancer is the second most frequent cause of death in the world. One of the transition metal, whose complexes are extensively tested for antitumor application is copper. This article presents selected examples of cytotoxic activity and mode of action of copper(I) complexes

Fluorescent Probes and Labels for Cellular Imaging

Metal-responsive fluorescent indicators are powerful tools for visualizing trace metals with subcellular resolution. By taking advantage of the diverse photophysical properties of organic fluorophores, metal ion-selective fluorescent indicators have been rationally designed and tailored towards cellular applications. This review summarizes challenges associated with the probe design and describes recent efforts in our research group in developing selective and sensitive reagents for the detection of zinc and copper in mammalian cells

A Quantitative Study of Cuprous Oxide Photodismutation

A cuprous oxide emulsion was made using noodling and washing emulsion making techniques. An attempt to use phthalated gelatin and coagulation washing resulted in the formation of cuprous hydroxide and destruction of the phthalated gel molecule and lack of coagulation within the emulsion. Cuprous oxide was also slurried with water and coated onto unglazed porcelain plates. The density-log exposure relationship was linear for the cuprous oxide slurry and non-linear for the cuprous oxide emulsion. The cuprous oxide film gave a speed value twenty-five times greater than that obtained with the slurry. The cuprous oxide dismutation system possesses great variability and little repeatability

The Composite Text and Nodule Mining--Over-Regulation as a Threat to the Common Heritage of Mankind

The future of international regulation of the deep seabed has been jeopardized by the Informal Composite Negotiating Text. The author explains why the production restrictions within the text are unduly harsh and overprotective of land-based mineral producers

Copper-Doped Cobalt Spinel Electrocatalysts Supported on Activated Carbon for Hydrogen Evolution Reaction

The development of electrocatalysts based on the doping of copper over cobalt spinel supported on a microporous activated carbon has been studied. Both copper–cobalt and cobalt spinel nanoparticles were synthesized using a silica-template method. Hybrid materials consisting of an activated carbon (AC), cobalt oxide (Co3O4), and copper-doped cobalt oxide (CuCo2O4) nanoparticles, were obtained by dry mixing technique and evaluated as electrocatalysts in alkaline media for hydrogen evolution reaction. Physical mixtures containing 5, 10, and 20 wt.% of Co3O4 or CuCo2O4 with a highly microporous activated carbon were prepared and characterized by XRD, TEM, XPS, physical adsorption of gases, and electrochemical techniques. The electrochemical tests revealed that the electrodes containing copper as the dopant cation result in a lower overpotential and higher current density for the hydrogen evolution reaction.This research was funded by MINECO and FEDER (MAT2016-76595-R)

Bactericidal Surfaces: An Emerging 21st Century Ultra-Precision Manufacturing and Materials Puzzle

Progress made by materials scientists in recent years has greatly helped the field of ultra-precision manufacturing. Ranging from healthcare to electronics components, phenomena such as twinning, dislocation nucleation, and high-pressure phase transformation have helped to exploit plasticity across a wide range of metallic and semiconductor materials. One current problem at the forefront of the healthcare sector that can benefit from these advances is that of bacterial infections in implanted prosthetic devices. The treatment of implant infections is often complicated by the growth of bacterial biofilms on implant surfaces, which form a barrier that effectively protects the infecting organisms from host immune defenses and exogenous antibiotics. Further surgery is usually required to disrupt the biofilm, or to remove the implant altogether to permit antibiotics to clear the infection, incurring considerable cost and healthcare burdens. In this review, we focus on elucidating aspects of bactericidal surfaces inspired by the biological world to inform the design of implant surface treatments that will suppress bacterial colonization. Alongside manufacturing and materials related challenges, the review identifies the most promising natural bactericidal surfaces and provides representative models of their structure, highlighting the importance of the critical slope presented by these surfaces. The scalable production of these complex hierarchical structures on freeform metallic implant surfaces has remained a scientific challenge to date and, as identified by this review, is one of the many 21st-century puzzles to be addressed by the field of applied physics

Grain growth behavior and efficient large scale simulations of recrystallization with the phase-field method

This book summarizes the found insights of grain growth behavior, of multidimensional decomposition for regular grids to efficiently parallelize computing and how to simulate recrystallization by coupling the finite element method with the phase-field method for microstructure texture analysis. The frame of the book is created by the phase-field method, which is the tool used in this work, to investigate microstructure phenomena