Effects of Metal Hydride Coatings at the Electrodes on Neutron Production Rate in a Discharge-Type Fusion Neutron Source

A glow discharge (GD) fusion neutron source that utilizes nuclear fusion reactions of deuterium has been upgraded. The fusion reactions in this device mainly occur by collisions between the charged or neutral particles and the hydrogen isotopes trapped at the surface of electrodes. In addition, it is known that the metal hydride coating on the electrode enhances the neutron production rate (NPR). Therefore, the elemental distribution, including deuterium, in the depth direction on the electrode is an essential factor in neutron production. However, the distribution on the electrode has not been experimentally investigated. This study aims to analyze the distribution experimentally and indicate the effect of the metal hydride coatings. To achieve this purpose, we prepared the titanium (Ti)-coated cathode and the uncoated cathode, of which the base material was stainless steel. After that, the neutron production test was performed in the range of from 5-to 40-mA currents and from 20-to 60-kV applied voltage. This test indicated that the NPR was improved by coating the cathode with Ti than the uncoated cathode. In addition, depth profiling on the cathodes by glow discharge optical emission spectroscopy (GD-OES) was performed. While the analysis indicated that the concentration of deuterium on both cathodes was increased after the test, there was no significant difference in the concentration of deuterium between both cathodes. Furthermore, the concentration of Ti on the Ti-coated cathode was vastly decreased. The cause of these changes needs to be investigated

Micro-fading spectrometry: investigating the wavelength specificity of fading

A modified microfading spectrometer incorporating a linear variable filter is used to investigate the wavelength dependence of fading of traditional watercolour pigments, dosimeters and fading standards at a higher spectral resolution and/or sampling than had previously been attempted. While the wavelength dependence of photochemical damage was largely found to correlate well with the absorption spectra of each material, exceptions were found in the case of Prussian blue and Prussian green pigments (the latter includes Prussian blue), for which an anti-correlation between the spectral colour change and the absorption spectrum was found

Urochordate Histoincompatible Interactions Activate Vertebrate-Like Coagulation System Components

The colonial ascidian Botryllus schlosseri expresses a unique allorecognition system. When two histoincompatible Botryllus colonies come into direct contact, they develop an inflammatory-like rejection response. A surprising high number of vertebrates' coagulation genes and coagulation-related domains were disclosed in a cDNA library of differentially expressed sequence tags (ESTs), prepared for this allorejection process. Serine proteases, especially from the trypsin family, were highly represented among Botryllus library ortholgues and its “molecular function” gene ontology analysis. These, together with the built-up clot-like lesions in the interaction area, led us to further test whether a vertebrate-like clotting system participates in Botryllus innate immunity. Three morphologically distinct clot types (points of rejection; POR) were followed. We demonstrated the specific expression of nine coagulation orthologue transcripts in Botryllus rejection processes and effects of the anti-coagulant heparin on POR formation and heartbeats. In situ hybridization of fibrinogen and von Willebrand factor orthologues elucidated enhanced expression patterns specific to histoincompatible reactions as well as common expressions not augmented by innate immunity. Immunohistochemistry for fibrinogen revealed, in naïve and immune challenged colonies alike, specific antibody binding to a small population of Botryllus compartment cells. Altogether, molecular, physiological and morphological outcomes suggest the involvement of vertebrates-like coagulation elements in urochordate immunity, not assigned with vasculature injury

Genomic view of the evolution of the complement system

The recent accumulation of genomic information of many representative animals has made it possible to trace the evolution of the complement system based on the presence or absence of each complement gene in the analyzed genomes. Genome information from a few mammals, chicken, clawed frog, a few bony fish, sea squirt, fruit fly, nematoda and sea anemone indicate that bony fish and higher vertebrates share practically the same set of complement genes. This suggests that most of the gene duplications that played an essential role in establishing the mammalian complement system had occurred by the time of the teleost/mammalian divergence around 500 million years ago (MYA). Members of most complement gene families are also present in ascidians, although they do not show a one-to-one correspondence to their counterparts in higher vertebrates, indicating that the gene duplications of each gene family occurred independently in vertebrates and ascidians. The C3 and factor B genes, but probably not the other complement genes, are present in the genome of the cnidaria and some protostomes, indicating that the origin of the central part of the complement system was established more than 1,000 MYA

A dynamic model and performance analysis of a stepped rotary flow control valve

The hydraulic independent metering (IM) is an advanced actuator driving technique that allows the implementation of advanced control algorithms or methods. The main concept of IM is to control hydraulic actuators ports, which are the meterin and meter-out, separately. In this paper, a novel stepped rotary type valve has been developed for embedding in hydraulic independent metering systems, instead of conventional types such as poppet and spool. The insertion leads to developing different and novel control techniques, which require a software in loop and hardware in loop simulation of the proposed system. The paper explores the dynamic representation of this valve and defines its own performance limitations. This includes the development of a linear model comprising its two main sub-parts which are the stepper motor and the rotary orifice. Consequently, the linear timeinvariant methods are used to explore the performance of the valve by considering the effect of different parameters namely the pressure drop, friction coefficient, damping coefficient and bristle coefficient