Wideband, high efficiency optical modulator requires less than 10 watts drive power

Wideband optical modulation system operates with less than 10-watts drive power. It consists of an optical modulator and transistorized driver that combines small cross-section potassium dideuterium phosphate crystals with laser beam-condensing optics. Optical modulation systems may serve importantly in future space wideband communication systems

Wideband high efficiency optical modulator Final report, 15 Feb. 1966 - 15 Mar. 1967

Design of wideband high efficiency optical modulation system tested over 100-MHz ban

Comparison Between Genetic Algorithm and Electromagnetism-Like Algorithm for Solving Inverse Kinematics

A comparison study between Electromagnetism-Like Algorithm (EM) and Genetic Algorithm (GA)has been presented in this work to solve the Inverse Kinematics (IK) of a four-link planar robot manipulator. The comparison is focused on some points for both algorithms like the accuracy of the results and the speed of convergence. Different target points have been taken to check the performance of each algorithm to solve the IK problem. The results showed that EM algorithm needs less population size and number of generations to get the true solution. There are multiple robot configurations at the goal points and both algorithms are able to find these solutions at each point. Self developed software simulator is used to display some of these solutions at each goal position

A Comparative Analysis of Various Chaotic Genetic Algorithms for Multimodal Function Optimization

This study proposes a novel method of introducing chaotic induced genes into Genetic Algorithms (GA) in order to solve unimodal and multimodal mathematical test functions. The integration of chaotic elements based on logistic map into GA has significantly improved the accuracy in the aspect of the best fitness value. Simulation results show that the influence of Chaos theory does improve the optimization accuracy of the mathematical functions used

An Adaptive Immune Algorithm based Gravimetric Fluid Dispensing Machine

A dispensing system is used in a materials-mixing plant to provide accurate blend ratios in producing the desired end-use product. The AIS-based (Artificial Immune Systems) fine tuning of dispensing parameters is proposed by optimizing the components of dispensing time and stopping time delay to obtain constant and accurate reading from the precision balance scale. Based on the new dispensing sequence, experimental tests had been carried out using different materials with varying viscosities. The results indicate that the combination of both PWM and AIS techniques would minimize overshoot while exhibiting lower steady-state error and faster response time. These are important in order to overcome the limitations of the conventional volumetric dispensing and manual parameter tuning presently applied in the dispensing system used in the coatings industry

Use of different tissues of horseshoe crabs Tachypleus gigas for biomonitoring heavy metal bioavailability and contamination in intertidal area of Peninsular Malaysia

In this study, female horseshoe crabs Tachypleus gigas were collected from three sampling sites in the west intertidal waters of Peninsular Malaysia. The horseshoe crabs species were analyzed for Cu, Cu, Ni and Zn in the different dissected ten parts namely prosomatic carapace, opisthosomatic carapace, telson, operculum, remaining shells, muscles in the opisthosoma, eggs, gills, digestive tract, and remaining soft tissue. Cu and Zn levels in all the edibles were lower than the max permissible limits of food safety guidelines but Cd concentration of the horseshoe crabs eggs were found to have slightly exceeded the permissibly limits for food safety. Higher bioavailabilities of metals to biomonitor T. gigas were found at populations collected from high anthropogenic site at Kg. Pasir Puteh. This verified the higher metal levels in the tissues of T. gigas were related to the anthropogenic sources of the sampling site

Mass production of Penaeus monodon Fabricius juveniles in earthen nursery ponds

Different culture techniques were tried for rearing larvae of Penaeus monodon, in order to obtain preliminary data on stocking density, water management, fertilization versus feeding and effect of different types of vertical substrate. The results of the experiments showed that: (1) older fry have greater chances of survival; (2) the traditional nursery pond designs and practices used for milkfish in the Philippines are applicable to prawn only at very low densities and give acceptable high survival rates only when used with the older postlarval stage

Negative stiffness and enhanced damping of individual multiwalled carbon nanotubes

The mechanical instabilities and viscoelastic response of individual multiwalled carbon nanotubes and nanofibers (MWCNTs/Fs) under uniaxial compression are studied with atomic force microscopy. Specific buckling events are evident by regimes of negative stiffness, i.e., marked drops in force with increasing compression. Uniaxial cyclic loading can be repeatedly executed even in initially postbuckled regimes, where the CNTs/Fs display incremental negative stiffness. Increases in mechanical damping of 145–600 % in these initially postbuckled regimes, as compared to the linear prebuckled regimes, are observed. Increased damping is attributed to frictional energy dissipation of walls in buckled configurations of the MWCNTs/Fs. This represents the extension of the concept of negative stiffness to the scale of nanostructures and opens up possibilities for designing nanocomposites with high stiffness and high damping simultaneously