Journal of Computer Chemistry, Japan
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Volume 11 , Issue 1
Special Issue of the 10th Anniversary 2
Showing 1-9 articles out of 9 articles from the selected issue
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Foreword
Commentary
  • Momoji KUBO
    Volume 11 (2012) Issue 1 Pages A3-A9
    Released: May 10, 2012
    [Advance publication] Released: March 03, 2012
    JOURNALS OPEN ACCESS
    By the recent advancements of nano-technology, “chemical reactions” at nano-scale significantly affect the mechanical property and performance at macro-scale, therefore the electronic-level control of the chemical reaction is essential even in heavy and large mechanical systems. Especially, because the functions of the mechanical systems are generated by “motion”, electronic-level understanding of the multi-physics phenomena including the “chemical reaction” and “friction, impact, stress, fluid, electric field, heat etc.” is very important. Therefore, we thought that the introduction of the quantum chemistry to the mechanical engineering field is a promising approach thus we have developed a multi-physics simulator based on quantum chemical molecular dynamics method. Furthermore, we realized its successful applications to a wide variety of low-carbon mechanical systems.
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Account
  • Hiromi NAKAI
    Volume 11 (2012) Issue 1 Pages 1-16
    Released: May 10, 2012
    JOURNALS OPEN ACCESS
    The article discusses chemical principles such as concept, theorem, rule, and hypothesis, which fulfil the role of so-called milestone in the chemical researches. After overviewing the history of quantum chemistry, the author would like to raise the issue how modern-day theoretical chemists should confront the chemical principles. Next, the symmetry rules for degenerate excitations, which are the chemical principles discovered by the author's group, are described. In particular, this article explains the background of the discovery, the verification by the numerical assessments, and the theoretical interpretation.
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General Papers
  • Kenji MISHIMA, Koichi YAMASHITA
    Volume 11 (2012) Issue 1 Pages 17-23
    Released: May 10, 2012
    [Advance publication] Released: February 20, 2012
    JOURNALS OPEN ACCESS
    In this paper, we extend our theoretical work on the pure state entanglement of bipartite or two-mode physical and chemical systems interacting with general static entangling interactions and external electromagnetic fields to include the mixed state entanglement. It is assumed that the Markov approximation is valid in our model system. Based on the partitioning of the entangling interaction matrix, we investigate the effect of the entangling interaction matrix elements and the relaxation constants on the decoherence of the Bell states. Our calculations indicate that only a few elements of the entangling interaction matrix and relaxation constants are dominant for the decoherence dynamics of the Bell states.
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  • Takeshi OKADA, Hiromasa KANEKO, Kimito FUNATSU
    Volume 11 (2012) Issue 1 Pages 24-30
    Released: May 10, 2012
    [Advance publication] Released: April 12, 2012
    JOURNALS OPEN ACCESS
    Soft sensors are widely used to realize highly efficient operation in chemical processes because not every important variable such as product quality can be measured online. By using soft sensors, one can estimate such a difficult-to-measure variable y from other process variables which are measured online. For estimating y without degradation of a soft sensor model, a time difference (TD) model was developed previously. Though a TD model has high predictive ability, it does not function well when a process is operated under conditions that have never been observed. In order to cope with this problem, a soft sensor model can be updated with newest data. But, updating a model needs time and effort for plant operators. We therefore developed an online monitoring system to judge whether a TD model can predict y accurately or an updating model should be used for both reducing maintenance cost and improving predictive accuracy of soft sensors. The monitoring system is based on a support vector machine or on standard deviations of y-values estimated from various intervals of time difference. We confirmed that the proposed system has functioned successfully in a distillation column with real industrial data.
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  • Hiromasa KANEKO, Kimito FUNATSU
    Volume 11 (2012) Issue 1 Pages 31-42
    Released: May 10, 2012
    [Advance publication] Released: March 03, 2012
    JOURNALS OPEN ACCESS
    Soft sensors have been widely used in industrial plants to estimate process variables that are difficult to measure online (Figure 1). Soft sensor models predicting an objective variable should be constructed with only important explanatory variables in terms of predictive ability, better interpretation of models and lower measurement costs. Besides, some process variables can affect an objective variable with time-delays. We therefore have proposed the methods for selecting important process variables and optimal time-delays of each variable simultaneously, by modifying the wavelength selection methods (Figure 3, 4) in spectrum analysis. The proposed methods can select time-regions of process variables as a unit by using process data that includes process variables that are delayed for a duration ranging from 0 through some decided time. A case study with real industrial data confirmed that predictive, easy-to-interpret, and appropriate models were constructed using the proposed methods (Table 2, 3, Figure 11, 12).
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  • Shigeru SAKURAZAWA, Hana SAKATA, Itsuki KUNITA
    Volume 11 (2012) Issue 1 Pages 43-48
    Released: May 10, 2012
    [Advance publication] Released: March 17, 2012
    JOURNALS OPEN ACCESS
    Observation images of movements of muscle proteins at the molecular level contain detailed information on the chemical reactions involving the proteins. If we can distinguish reaction-related movement from thermal fluctuations, we can visualize genesis locations of chemical reactions. Therefore, we tried to extract coordinated movement distinguished from thermal fluctuation in movement of an actin filament in anin vitromotility assay system to visualize chemical reaction by muscle protein. We extracted the possible skeletal structure of an actin filament by image analysis and visualized local propagation vectors of windings from the propagation direction and propagation velocity of the windings determined by correlation analysis. By using this method, we could find that the propagation distance and velocity of windings from the tail-end to the head-end of the filament showed the tendency to increase as the ATP concentration increased. On the other hand, those from the head-end to the tail-end were independent of ATP concentration. These results mean that these windings have a significant relationship to ATP hydrolysis; especially, the generating points of these windings include significant information.
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Technical Paper
  • Tomoo AOYAMA, Junko KAMBE, Eiko NAKAYAMA, Umpei NAGASHIMA
    Volume 11 (2012) Issue 1 Pages 49-77
    Released: May 10, 2012
    JOURNALS OPEN ACCESS
    We summarize the changes over four months from March 12, 2011, involving the radioactive substances in the south or northwest directions from Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Company. The results obtained are as follows: We extract the ambient dose rate and environmental data from documents published by the Ministry of Education or many local governments; and evaluate the residence half-life of ambient dose rate from May 15 to July 29, for major cities of Kanto and Fukushima prefectures. We show the time-dependent changes for radioactive concentrations of soil, weeds, inland-water in Yagisawa district of Iitate village of Souma county in Fukushima prefecture. And we discuss problems of radioactive intensity of the sewage sludge in Tokyo and Fukushima cities.Knowledge of radioactive Suspended Particulate Matter (SPM) in the atmosphere provides the following: The ambient dose rate is dependent on movements of the SPM. It differs from SPM that is observed by atmospheric environmental regional observation system in Japan; therefore, by using usual SPM detectors, it is difficult to measure the radioactive particles. There is a complex structure in the distribution of radioactive SPM. The structure can be detected by observing the energy of gamma-rays. The movement of radioactive SPM is affected by the atmospheric boundary surfaces. Furthermore, the relationships between rainfall and radioactive substances on the ground are discussed. The periodic structure of ambient dose rate is researched, and a correlation with the temperature is evaluated
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