647 research outputs found
On Conway-Gordon type theorems for graphs in the Petersen family
For every spatial embedding of each graph in the Petersen family, it is known
that the sum of the linking numbers over all of the constituent 2-component
links is congruent to 1 modulo 2. In this paper, we give an integral lift of
this formula in terms of the square of the linking number and the second
coefficient of the Conway polynomial.Comment: 13 pages, 5 figures. arXiv admin note: text overlap with
arXiv:1104.082
Permeability-control on volcanic hydrothermal system: case study for Mt. Tokachidake, Japan, based on numerical simulation and field observation
We investigate a volcanic hydrothermal system by using numerical simulation with three key observables as reference: the magnetic total field, vent temperature, and heat flux. We model the shallow hydrothermal system of Mt. Tokachidake, central Hokkaido, Japan, as a case study. At this volcano, continuous demagnetization has been observed since at least 2008, suggesting heat accumulation beneath the active crater area. The surficial thermal manifestation has been waning since 2000. We perform numerical simulations of heat and mass flow within a modeled edifice at various conditions and calculate associated magnetic total field changes due to the thermomagnetic effect. We focus on the system’s response for up to a decade after permeability is reduced at a certain depth in the modeled conduit. Our numerical simulations reveal that (1) conduit obstruction (i.e., permeability reduction in the conduit) tends to bring about a decrease in vent temperature and heat flux, as well as heat accumulation below the level of the obstruction, (2) the recorded changes cannot be consistently explained by changing heat supply from depth, and (3) caprock structure plays a key role in controlling the location of heating and pressurization. Although conduit obstruction may be caused by either physical or chemical processes in general, the latter seems more likely in the case of Mt. Tokachidake
Synthesis of a cuprite thin film by oxidation of a Cu metal precursor utilizing ultrasonically generated water vapor
A Cu2O thin film of cuprite crystal structure was fabricated via a decomposition reaction of water vapor generated by ultrasonic vibration. The thin film, which was grown on a soda-lime glass substrate at 530 degrees C, exhibited a prominent (111) preferred orientation with an optical bandgap of about 2.1 eV and resistivity of 2.81 x 10(4) Omega cm. Generation of H-2 gas during the reaction process contributed to suppressing the growth of impurity tenorite phase. In a conventional process of thermal oxidation, the formation of the cuprite phase was always accompanied by that of the tenorite phase due to an excess oxygen exposure near the surface of the films.ArticleTHIN SOLID FILMS. 556:211-215 (2014)journal articl
Propolis Components and Biological Activities from Stingless Bees Collected on South Sulawesi, Indonesia
Three new compounds, namely sulabiroins A (1) and B (2), and 2',3'-dihydro-3'-hydroxypapuanic acid (3), were isolated from the propolis of stingless bees (Tetragonula aff. biroi) collected on South Sulawesi, Indonesia. In addition, ten known compounds, (–)-papuanic acid (4), (–)-isocalolongic acid (5), isopapuanic acid (6), isocalopolyanic acid (7), glyasperin A (8), broussoflavonol F (9), (2S)-5,7-dihydroxy-4'-methoxy-8-prenylflavanone (10), isorhamnetin (11), (1'S)-2-trans,4-trans-abscisic acid (12), and (1'S)-2-cis,4-trans-abscisic acid (13) were identified. The structures of the new and known compounds were determined by spectroscopic analysis. The absolute configurations of sulabiroins A (1) and B (2) were determined by X-ray crystallography analysis and ECD calculation, respectively. The propolis from stingless bee (Tetragonula aff. biroi) collected on South Sulawesi contained compounds not present in propolis from other regions. Sulabiroin A (1) and isorhamnetin (11) were examined for xanthine oxidase (XO) inhibitory activity as one of biological activities; isorhamnetin (11) exhibited potent XO inhibitory activity, with an IC50 value of 3.9 µm
Development of intelligent plastic film winder "Windstar"
Flexible continuous plastic films are used to produce various products, including optical films and packaging materials, because plastic film is suited to use in mass production manufacturing processes. Generally, the web handling process is applied to convey the plastic film, which is ultimately rewound into a roll using a rewinder. In this case, wrinkles, slippage and other defects may occur if the rewinding conditions are inadequate. In this paper, the authors explain the development of a rewinder system that prevents wound roll defects - primarily starring and telescoping. The system is able to prevent such defects by optimizing the rewinding conditions of tension and nip-load. Based on the optimum design technique, the tension and nip-load are calculated using a 32-bit personal computer. Our experiments have also empirically shown that this rewinder system can prevent roll defects when applying optimized tension and nip-load. Additionally, inexperienced operators can control this system easily
Functional network of glycan-related molecules: Glyco-Net in Glycoconjugate Data Bank
<p>Abstract</p> <p>Background</p> <p>Glycans are involved in a wide range of biological process, and they play an essential role in functions such as cell differentiation, cell adhesion, pathogen-host recognition, toxin-receptor interactions, signal transduction, cancer metastasis, and immune responses. Elucidating pathways related to post-translational modifications (PTMs) such as glycosylation are of growing importance in post-genome science and technology. Graphical networks describing the relationships among glycan-related molecules, including genes, proteins, lipids and various biological events are considered extremely valuable and convenient tools for the systematic investigation of PTMs. However, there is no database which dynamically draws functional networks related to glycans.</p> <p>Description</p> <p>We have created a database called Glyco-Net <url>http://www.glycoconjugate.jp/functions/</url>, with many binary relationships among glycan-related molecules. Using search results, we can dynamically draw figures of the functional relationships among these components with nodes and arrows. A certain molecule or event corresponds to a node in the network figures, and the relationship between the molecule and the event are indicated by arrows. Since all components are treated equally, an arrow is also a node.</p> <p>Conclusions</p> <p>In this paper, we describe our new database, Glyco-Net, which is the first database to dynamically show networks of the functional profiles of glycan related molecules. The graphical networks will assist in the understanding of the role of the PTMs. In addition, since various kinds of bio-objects such as genes, proteins, and inhibitors are equally treated in Glyco-Net, we can obtain a large amount of information on the PTMs.</p
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