A strain sensor using twisted optical fibers

A sensor using twisted optical fibers to detect the strain distribution along the length of an object is discussed. This sensor is based on the optical loss due to fiber curvature. The distributed strain along the sensor axis is converted into distributed optical loss. The relation between the strain and optical loss is theoretically derived and experimentally confirmed for uniform tensile strain. The dependence of the sensor characteristics on sensor structure and fiber parameter are also shown. Measurement of the strain applied to fibers in an optical cable is also discussed     

Radio wave propagation loss in the VHF to microwave region due tovehicles in tunnels

An experiment was undertaken to determine how obstacles in tunnels affect microwave propagation loss. The major emphasis of the study was on determining the propagation loss due to the following parameters: number, location, and size of vehicles, and cross-sectional shapes of tunnels. The laboratory experiments was performed using tunnel models with arched and rectangular cross sections. The dominant mode was transmitted into these tunnels from entrances. Different readings of field strength were taken along the length of the tunnels to determine the effect that vehicles can have on the propagation characteristics. The scale ratio of the tunnel dimensions to the wavelength is about 2-3. It is shown that the basic propagation loss due to vehicles in tunnels is determined mainly by the number and the size of the vehicles. Vehicle location and tunnel cross-sectional shape do not affect the propagation loss significantly     

A structure-biological activity study based on cluster analysis and the nonlinear mapping method of pattern recognition

Cluster analysis is used in a study of structure—activity relationships of biologically active compounds. A hierarchal clustering technique was applied to 29 typical antibiotics using 27 antibacterial activities. These antibiotics were of various types; penicillins, cephalosporins, aminoglycosides, macrolides, tetracyclines, and peptides. The result was obtained as a branching tree diagram. The technique allowed the antibiotics to be distributed into 6 clusters, each cluster mostly consisting of compounds with a similar structure. Nonlinear mapping was used to display the 27-dimensional data structure of the antibiotics. The nonlinear map was compared with the clusters obtained by cluster analysis.     

Structure-activity relationship study of leucinostatin A,a modulator of tumor−stroma interaction

Structure-activity relationship study of leucinostatin A, a natural nonapeptide, was performed to gain insight into the structural requirements for leucinostatin A to exhibit antiproliferative activity against DU-145 prostate cancer cells under cocultured conditions with the corresponding stromal cells. Twenty truncated peptide analogs of leucinostatin A revealed that the nonapeptide structure as a whole is essential for the biological activity. Alanine scanning demonstrated the importance of some of the amino acid components, including hydroxyleucine and the second leucine from the N-terminus. Two of the three aminoisobutyric acids could be substituted with one of the enantiomers of alanine, clearly demonstrating that each methyl group in these portions has a distinct influence on the growth-inhibitory activity.     

Indirect Synthesis System for Ammonia from Nitrogen and Water Using Nonthermal Plasma Under Ambient Conditions

The indirect synthesis of NH₃ from N₂ and H₂O through plasma processing is proposed and demonstrated. NH₃ is a promising hydrogen storage material because of its high hydrogen storage density. Mg₃N₂ is a key material for indirect NH₃ synthesis, because the reaction of Mg₃N₂ with water easily generates NH₃ at room temperature. In this paper, therefore, we focus on generating Mg₃N₂ by nitridation of MgO with nonthermal atmospheric-pressure dielectric barrier discharge (DBD) plasma in a N₂ atmosphere. By intermittent DBD nitridation treatment while the reaction device was cooled in a water bath, a maximum Mg₃N₂ generation efficiency of 93 mg/kWh was estimated. Because NH₃ is generated through a simple chemical reaction, our scheme does not cause NH₃ decomposition by plasma, which is one of the greatest concerns associated with plasma synthesis. Contrary to the conventional NH₃ generation process, which emits CO₂ and requires high temperature and pressure, our scheme enables NH₃ synthesis from N₂ and H₂O without CO₂ emissions. This allows for an onsite small-scale NH₃ synthesis system to be realized under mild conditions, which is necessary for a future low-carbon society.     

Output feedback stabilizability and stabilization algorithms for 2D systems

Alternative methods are proposed for test of output feedback stabilizability and construction of a stable closed-loop polynomial for 2D systems. By the proposed methods, the problems can be generally reduced to the 1D case and solved by using 1D algorithms or Gröbner basis approaches. Another feature of the methods is that their extension to certain specialnD (n>2) cases can be easily obtained.Moreover, the Rabinowitsch trick, a technique ever used in showing the well-known Hilbert's Nullstellensatz, is generalized in some sense to the case of modules over polynomial ring. These results eventually lead to a new solution algorithm for the 2D polynomial matrix equationD(z, w)X(z, w)+N(z, w)Y(z, w)=V(z, w) withV(z, w) stable, which arises in the 2D feedback design problem. This algorithm shows that the equation can be effectively solved by transforming it to an equivalent Bezout equation so that the Gröbner basis approach for polynomial modules can be directly applied.Notation R the field of real numbers - C the field of complex numbers - R[z, w] commutative ring of 2D polynomials inz andw with coefficients inR - M(R[z, w]) set of matrices with appropriate dimensions with entries inR[z, w] - R[z, w] ⁿ module of orderedn-tuples inR[z, w] - R[z, w] ^{n ×m} set ofn ×m matrices with entries inR[z, w] - closed unit disc inC, i.e., {z C| |z| 1} - ² closed unit bidisc, i.e., {(z, w) C ²| |z| 1, |w| 1} - A ^T transpose of matrixA