Advances of Gyromagnetic Electronics for EMC Problems

A number of EMC problems at microwaves-detection and measurement of power (spectrum) of the signals and suppression of unwanted radiation-can be solved owing to the results obtained in the field of gyromagnetic (spin) electronics. The latter deals with the unique properties of gyromagnetic media (GM) based on microwave ferrites, including high-anisotropy hexagonal ferrites that do not need an intense magnetization field for their operation at ferromagnetic resonance. Approaches to the study of the interaction of GM with an electromagnetic field and ways of modeling frequency-selective measuring devices, absorbing coatings and all-mode filters of harmonics on the basis of GM are discussed. Results of experiments and practical application of the elaborated GM devices for EMC problems are represented. Microwave ferrite resonators are discusse

Surface Plasmon Enhanced Phosphorescent Organic Light Emitting Diodes

The objective of the proposed work was to develop the fundamental understanding and practical techniques for enhancement of Phosphorescent Organic Light Emitting Diodes (PhOLEDs) performance by utilizing radiative decay control technology. Briefly, the main technical goal is the acceleration of radiative recombination rate in organometallic triplet emitters by using the interaction with surface plasmon resonances in noble metal nanostructures. Increased photonic output will enable one to eliminate constraints imposed on PhOLED efficiency by triplet-triplet annihilation, triplet-polaron annihilation, and saturation of chromophores with long radiative decay times. Surface plasmon enhanced (SPE) PhOLEDs will operate more efficiently at high injection current densities and will be less prone to degradation mechanisms. Additionally, introduction of metal nanostructures into PhOLEDs may improve their performance due to the improvement of the charge transport through organic layers via multiple possible mechanisms ('electrical bridging' effects, doping-like phenomena, etc.). SPE PhOLED technology is particularly beneficial for solution-fabricated electrophosphorescent devices. Small transition moment of triplet emitters allows achieving a significant enhancement of the emission rate while keeping undesirable quenching processes introduced by the metal nanostructures at a reasonably low level. Plasmonic structures can be introduced easily into solution-fabricated PhOLEDs by blending and spin coating techniques and can be used for enhancement of performance in existing device architectures. This constitutes a significant benefit for a large scale fabrication of PhOLEDs, e.g. by roll-to-roll fabrication techniques. Besides multieexciton annihilation, the power efficacy of PhOLEDs is often limited by high operational bias voltages required for overcoming built-in potential barriers to injection and transport of electrical charges through a device. This problem is especially pronounced in solution processed OLEDs lacking the accuracy and precision of fabrication found in their small molecule counterparts. From this point of view, it seems beneficial to develop materials allowing reduction of the operation bias voltage via improvement of the charge injection. The materials sought have to be compatible with solution-based fabrication process and allow easy incorporation of metal nanostructures

Near-Infrared and Visible Photoactivation to Uncage Carbon Monoxide from an Aqueous-Soluble PhotoCORM.

Multiphoton excitation allows one to access high energy excited states and perform valuable tasks in biological systems using tissue penetrating near-infrared (NIR) light. Here, we describe new photoactive manganese tricarbonyl complexes incorporating the ligand 4'-p-N,N-bis(2-hydroxyethyl)amino-benzyl-2,2':6',2″-terpyridine (TPYOH), which can serve as an antenna for two photon NIR excitation. Solutions of Mn(CO)3(TPYOH)X (X = Br- or CF3SO3-) complexes are very photoactive toward CO release under visible light excitation (405 nm, 451 nm). The same responses were also triggered by multiphoton excitation at 750 and 800 nm. In this context, we discuss the potential applications of these complexes as visible/NIR light photoactivated carbon monoxide releasing moieties (photoCORMs). We also report the isolation and crystal structures of the TPYOH complexes Mn(TPYOH)Cl2 and [Mn(TPYOH)2](CF3SO3)2, to illustrate a possible photolysis product(s)

High power ultranarrow linewidth picosecond laser system based on tapered fiber amplifier and gain-switched DFB laser diode

We experimentally demonstrate the highest spectral brightness for the pulsed fiber lasers to the best of our knowledge in a compact high power and pulse energy laser system consisting of a DFB laser diode as a master oscillator and a high-power fiber amplifier based on a double-clad active tapered fiber (T-DCF). Due to the unique properties of T-DCF, this system provides more than 1 MW of peak power and pulse energy of more than 60 μJ at a frequency of 500 kHz while maintaining a spectral width of less than 0.1 nm. The spectrum broadening limits the further power scaling of the laser system. The system is capable of delivering up to 150 W average power at 10 MHz pulse repetition rate with 0.14 nm linewidth. We also demonstrate the second harmonic generation of 532 nm with over 30 W at 10 MHz repetition rate and 14.5 W at 500 kHz. The experimental results reveals that the narrow linewidth system based on a DFB laser diode and a T-DCF amplifier is an excellent and robust solution for material processing and Raman spectroscopy.acceptedVersionPeer reviewe

Nitric Oxide Releasing Materials Triggered by Near-Infrared Excitation Through Tissue Filters

Novel materials for the phototherapeutic release of the bioregulator nitric oxide (nitrogen monoxide) are described. Also reported is a method for scanning these materials with a focused NIR beam to induce photouncaging while minimizing damage from local heating. The new materials consist of poly(dimethylsiloxane) composites with near-infrared-to-visible upconverting nanoparticles (UCNPs) that are cast into a biocompatible polymer disk (PD). These PDs are then impregnated with the photochemical nitric oxide precursor Roussin's black salt (RBS) to give UCNP_RBS_PD devices that generate NO when irradiated with 980 nm light. When the UCNP_RBS_PD composites were irradiated with NIR light through filters composed of porcine tissue, physiologically relevant NO concentrations were released, thus demonstrating the potential of such devices for minimally invasive phototherapeutic applications

Problems and technologies of remote access to unified information space of urban pipeline systems

The paper presents the experience of applying modern information technologies while operating the urban pipeline systems. Consideration is given to the main problems interfering with ensuring the efficient modes of pipeline systems operation that are caused by uncertainty and inconsistency of information on the actual condition of the system that, in turn, are originated by different technological factors. The paper also pays attention to the lack of continuity, inconsistency and duplication of data in different software packages (accounting, billing, resources planning and management, geo-information systems, SAPR, SCADA, digital models of pipeline systems, etc.) used by companies, which complicates operation of pipeline systems. The paper discusses advantages of development and introduction of unified information space in a company, related problems of its updating, and methods of remote access to it. Causes originating this problem are analyzed and ways for its solution are searched for from the standpoint of the latest information technologies. For solving this problem the authors propose specialized software that implies active use of wireless communication channels, mobile devices, etc. This mobile information package is briefly described as a prototype intended for remote access to unified information space of a company and to a digital model of the pipeline system in particular using mobile communication devices. Considered are the advantages of this development and scenarios of its application

Surface Plasmon Enhanced Phosphorescent Organic Light Emitting Diodes

The objective of the proposed work was to develop the fundamental understanding and practical techniques for enhancement of Phosphorescent Organic Light Emitting Diodes (PhOLEDs) performance by utilizing radiative decay control technology. Briefly, the main technical goal is the acceleration of radiative recombination rate in organometallic triplet emitters by using the interaction with surface plasmon resonances in noble metal nanostructures. Increased photonic output will enable one to eliminate constraints imposed on PhOLED efficiency by triplet-triplet annihilation, triplet-polaron annihilation, and saturation of chromophores with long radiative decay times. Surface plasmon enhanced (SPE) PhOLEDs will operate more efficiently at high injection current densities and will be less prone to degradation mechanisms. Additionally, introduction of metal nanostructures into PhOLEDs may improve their performance due to the improvement of the charge transport through organic layers via multiple possible mechanisms ('electrical bridging' effects, doping-like phenomena, etc.). SPE PhOLED technology is particularly beneficial for solution-fabricated electrophosphorescent devices. Small transition moment of triplet emitters allows achieving a significant enhancement of the emission rate while keeping undesirable quenching processes introduced by the metal nanostructures at a reasonably low level. Plasmonic structures can be introduced easily into solution-fabricated PhOLEDs by blending and spin coating techniques and can be used for enhancement of performance in existing device architectures. This constitutes a significant benefit for a large scale fabrication of PhOLEDs, e.g. by roll-to-roll fabrication techniques. Besides multieexciton annihilation, the power efficacy of PhOLEDs is often limited by high operational bias voltages required for overcoming built-in potential barriers to injection and transport of electrical charges through a device. This problem is especially pronounced in solution processed OLEDs lacking the accuracy and precision of fabrication found in their small molecule counterparts. From this point of view, it seems beneficial to develop materials allowing reduction of the operation bias voltage via improvement of the charge injection. The materials sought have to be compatible with solution-based fabrication process and allow easy incorporation of metal nanostructures

Entropy, Information and Complexity or Which Aims the Arrow of Time?

In this article, we analyze the interrelationships among such notions as entropy, information, complexity, order and chaos and show using the theory of categories how to generalize the second law of thermodynamics as a law of increasing generalized entropy or a general law of complification. This law could be applied to any system with morphisms, including all of our universe and its subsystems. We discuss how such a general law and other laws of nature drive the evolution of the universe, including physicochemical and biological evolutions. In addition, we determine eliminating selection in physicochemical evolution as an extremely simplified prototype of natural selection. Laws of nature do not allow complexity and entropy to reach maximal values by generating structures. One could consider them as a kind of “breeder” of such selection