Electrochemical measurements in a three electrode system under finite conditions, e.g., at an electrode coated with a polymer film incorporating functional molecules have been simulated using a program written in the JAVA language. The simulation with or without a catalytic reaction by the functional molecules has been performed using the program. The shape of a cyclic voltammogram under finite conditions is different from that under infinite conditions applied to ordinary solution electrochemistry. The fraction of the functional molecules that accepted charges (RCT) has been calculated by integrating a concentration distribution. The current under finite conditions in a potential-step measurement deviated from that under infinite conditions above RCT ≈ 0.5. The program was introduced to a document on the electrochemistry written in HTML. It can be used by many students in an electrochemistry class without heavy loads on the server computer.
A self-learning system on the computer network is appropriate for supplementary learning since it is free from restrictions of time and space. Therefore, we have developed a self-learning system complementing regular lectures in order to help the student who wants to catch up with others by self-learning in science. For such a learning system it would be more effective to set up monitoring functions for the student's learning situations. Recently we devised such monitoring tools based on a database management system, “PostgreSQL", and implanted them in our learning system. The monitoring tools are classified into the following categories: A: analysis of access-log to each teaching material, B: individual records of learning progress and frequency of access etc., C: analysis of homepage examination and of questionnaire. These tools are assembled into a homepage for managing purposes. So a teacher is able to know easily the latest information about the student's learning situations by watching the homepage which is visualized graphically as much as possible.
This paper describes an approach to automated identification of three-dimensional common structural features of proteins. The structure of a protein was represented by a set of secondary structure elements (SSEs) in the same manner used in our previous work, where only α-helix and β-strand secondary structure elements were considered. The maximal common subgraph algorithm, based on a graph theoretical clique finding approach, was used to identify the 3D common structural features between a pair of proteins. The program, called AIM (Automated Identification of 3D Motif of proteins), was developed and tested by computational experiments in searching for the secondary structure segments related to the Rossmann-fold motif as a 3D common structural feature between alcohol dehydrogenase and lactate dehydrogenase, which are known to have the 3D motif. The AIM successfully found the peptide segments related to the motif. A 3D substructure searching, in which the common structural feature identified was employed as a query pattern, will be discussed too.
MagSaki software was developed for the magnetic analysis of dinuclear high-spin cobalt(II) complexes. This software performs magnetic analysis to determine magnetic parameters using several types of theoretical calculations, such as the following: (1) a mononuclear complex in an isotropic octahedral field, (2) a mononuclear complex in an axially distorted octahedral field, (3) a dinuclear complex in an isotropic octahedral field, (4) a dinuclear complex in an axially distorted octahedral field and (5) a mono- and dinuclear complex in an isotropic tetrahedral field. The calculation for the axially distorted dinuclear case is based specifically on a new theoretical method that we reported, and the MagSaki software is the first of its kind that evaluates the exchange couping in an axially distorted octahedral field.
In order to estimate mechanical properties of high tension steels for machine tools: Cr-Mo steel, Ni steel, Ni-Cr steel and Ni-Cr-Mo steel, we applied property prediction by a perceptron type neural network. It was found that six mechanical properties: yield point, tensile strength, diaphragm, impulsive force and hardness are predictable within experimental error, almost 20%, using only the amount of C, Mn, Ni, Cr and Mo in the steels.
The dissociation constants and concentration of an acid were determined from a titration curve by Microsoft Excel Solver. It is standard attachment of Microsoft Excel Package and a tool for solving optimization problems. A sample titration curve was obtained by the titration of citric acid solution with sodium hydroxide solution. Despite the fact that a titration curve equation is represented as a complicated non-linear equation, Solver was easily able to find a solution. As a result, the first, second and third step dissociation constants and concentration of citric acid were 1.44×10-3, 5.15×10-5, 2.29×10-6M and 5.14×10-3M, respectively. These values were sufficiently close to those in the literature and to experimental values. Calculation time for solving the problem was 8.60 second by even a personal computer with Pentium 90MHz. Since CPU is rapidly developed, Solver may become a powerful tool for problems with more variables in the near future.