A novel ultracompact two-mode-interference wavelength division multiplexer for 1.5-/spl mu/m operation

A novel ultracompact 2/spl times/2 wavelength division multiplexer (WDM) for 1.55-/spl mu/m operation based on highly dispersive two-mode interference (TMI) was designed, theoretically modeled, and verified using a finite-difference-time-domain (FDTD) method. A two-moded waveguide assisted with a dispersive tooth-shaped grating provided a mode-dependent reflection band of central wavelength at 1.55 /spl mu/m. The wavelengths of 1538 and 1572 nm that were at the band edges and had the lowest reflection losses and relatively high dispersion were selected for wavelength multiplexing. The result showed that the wavelengths were separated by grating dispersion in a coupler length of 75 /spl mu/m which was much shorter than the required length of 1.1 mm in a regular TMI multiplexer of no grating. Insertion loss of about 1.7 dB and channel contrast of about 12 dB were achieved.     

Effect of Cu concentration on the reactions between Sn-Ag-Cu solders and Ni

The reaction between the Sn-Ag-Cu solders and Ni at 250°C for 10 min and 25 h was studied. Nine different Sn-Ag-Cu solders, with the Ag concentration fixed at 3.9 wt.% and Cu concentrations varied between 0.0–3.0 wt.%, were used. When the reaction time was 10 min, the reactions strongly depended on the Cu concentration. At low-Cu concentrations (≦0.2 wt.%), only a continuous (Ni_1−xCu_x)₃Sn₄ layer formed at the interface. When the Cu concentration increased to 0.4 wt.%, a continuous (Ni_1−xCu_x)₃Sn₄ layer and a small amount of discontinuous (Cu_1−yNi_y)₆Sn₅ particles formed at the interface. When the Cu concentration increased to 0.5 wt.%, the amount of (Cu_1−yNi_y)₆Sn₅ increased and (Cu_1−yNi₆)₆Sn₅ became a continuous layer. Beneath this (Cu_1−yNi_y)₆Sn₅ layer was a very thin but continuous layer of (Ni_1−xCu_x)₃Sn₄. At higher Cu concentrations (0.6–3.0 wt.%), (Ni_1−xCu_x)₃Sn₄ disappeared, and only (Cu_1−yNi_y)₆Sn₅ was present. The reactions at 25 h also depended strongly on the Cu concentration, proving that the strong concentration dependence was not a transient phenomenon limited to a short reaction time. The findings of this study were rationalized using the Cu-Ni-Sn isotherm. This study shows that precise control over the Cu concentration in solders is needed to produce consistent results.     

Time and Temperature Factors in Construction of Rock Strength Criteria

Using the synthesis of the kinetic concept on solid strength and the Coulomb - Mohr strength theory as the base, the failure conditions taking into account the time and temperature factors are obtained.     

Lipase‐catalyzed dynamic kinetic resolution of (R,S)‐fenoprofen thioester in isooctane

A lipase‐catalyzed enantioselective hydrolysis process under in situ racemization of the remaining (R)‐thioetser substrate with trioctylamine as the catalyst was developed for the production of (S)‐fenoprofen from (R,S)‐fenoprofen 2,2,2‐trifluoroethyl thioester in isooctane. Detailed investigations of trioctylamine concentration on the enzyme activation and the kinetic behavior of the thioester in racemization and enzymatic reactions were conducted, in which good agreement between the experimental data and theoretical results was observed. © 2002 Society of Chemical Industry     

Hierarchical production control for a flow shop with dynamic setup changes and random machine breakdowns

In this paper, we study a manufacturing system consisting of two machines separated by two intermediate buffers, and capable of producing two different products. Each product requires a constant processing time on each of the machines. Each machine requires a constant non-negligible setup change time from one product to the other. The demand rate for each product is considered to be piecewise constant. Each machine undergoes failure and repair. The time-to-failure and time-to-repair are exponentially distributed random variables. The setup change and processing operations are resumable. We model our system as a continuous time, continuous flow process. An optimal control problem is formulated for the system to minimize the total expected discounted cost over an infinite horizon. To determine the optimal control policy structure, a discrete version of the problem is solved numerically using a dynamic programming formulation with a piecewise linear penalty function. A real-time control algorithm is then developed with the objective of maintaining low work-in-process inventory and keeping the production close to the demand. The algorithm uses a hierarchical control structure to generate the loading times for each product on each machine in real time and to respond to random disruptions in the system. The system is simulated using this algorithm to study its performance. The performance of the algorithm is also compared to alternative policies.     

Combination cytotoxic effects of cis-diamminedichloroplatinum(II) and 5-fluorouracil with and without leucovorin against human non-small cell lung cancer cell lines

Both cisplatin (CDDP) and leucovorin (LV) have been shown to enhance cytotoxicity of 5-fluorouracil (FUra) against murine and human neoplasms by increasing intracellular reduced folate concentrations. We were interested in their use in a combination to inhibit non-small cell lung cancer (NSCLC) cell growth and therefore conducted an in vitro study to investigate the cytotoxic activities of combinations of CDDP plus FUra, with and without LV (20 microM), against seven NSCLC cell lines. A tetrazolium assay with application of the classical isobole method was used to test drug combinations. We found that LV enhanced FUra but not CDDP cytotoxicity and that the degree of enhancement was negatively correlated with the effect of FUra. There was an overall additive combination effect of CDDP plus FUra, although there may be synergy at higher effect levels. There was synergy to a combination of CDDP, FUra, and LV, presumably primarily related to the synergistic effects of adding LV to FUra. In summary, LV and CDDP enhanced FUra cytotoxicity in a complementary fashion and there was clear synergy of a combination of CDDP, FUra, and LV against a panel of NSCLC cell lines. Our in vitro results provide a rationale for controlled clinical studies of this three-drug regimen in patients with NSCLC.     

Colour image detection and matching using modified generalisedHough transform

A new approach to 2-dimensional (2D) colour-image detection and matching using a modified version of the generalised Hough transform (GHT) is proposed. In the conventional GHT, the useful colour information existing in the input image and the relationship between each pixel and its neighbourhood are not used. Furthermore, lighting changes in the image are not usually considered. Therefore, the conventional GHT is seldom applied to colour images. In the proposed approach, lighting are removed using normalised colour values. Next, certain critical pixels of an input colour image whose neighbourhoods have larger variances of normalised colour values are extracted. For each critical pixel, a feature vector, which includes the normalised colour values of the pixel as well as those of the pixel's neighbours, is then constructed. A modified voting rule for the GHT is therefore proposed which is based on a similarity-measure function of the feature vectors. High maximum peaks in the cell array are searched finally as the result. The proposed method is robust for colour-image detection and matching in noisy, occlusive, and lighting-change environments, as demonstrated by experimental results     

A newly robust controller design for the position control ofpermanent-magnet synchronous motor

A robust controller which is designed by employing variable-structure control and linear-quadratic method is presented for a permanent-magnet synchronous motor (PMSM) position control system. It is to achieve accurate control performance in the presence of plant parameter variation and load disturbance. In addition, it possesses the design flexibility of the conventional state feedback control. It is applied to the position control of a PMSM. Simulation and experimental results show that the proposed approach gives a better position response and is robust to parameter variations and load disturbance     

Playing with pets and longevity among older people.

Models of the relations between contact with pets and better health are examined in an archival prospective study using data derived from the longitudinal study initiated by Terman in 1921 (current N?=?343 men, 300 women) . In survival analyses of documented longevity, playing with pets in 1977 (M age?=?67 years) was not associated with mortality risk through 1991 for the total sample nor for those who were unmarried or those who were less satisfied with their human relationships. Playing with pets was not associated with health-prone attributes or healthy behaviors such as personality, social ties, education, and smoking. (PsycINFO Database Record (c) 2011 APA, all rights reserved)