This paper deals with the experimental results of a xenon flash-lamp pumped passively Q-switched Nd:YAG laser using Cr4+:YAG saturable absorber. The need of a laser cavity to be integrated into a time-of-flight laser range finder is of great interest as an experimental investigation of several laser resonators. Two types of laser resonator, with different lengths, have been studied: the flat-fl...

To my dearest friend Najla Ali We introduce and investigate flat semimodules and k-flat semimodules. We hope these concepts will have the same importance in semimodule theory as in the theory of rings and modules. 1. Introduction. We introduce the notion of flat and k-flat. In Section 2, we study the structure ensuing from these notions. Proposition 2.4 asserts that V is flat if and only if (V ...

There are two intertwined factors that affect performance of concurrent data structures: the ability of processes to access the data in parallel and the cost of synchronization. It has been observed that for a large class of “concurrency-unfriendly” data structures, fine-grained parallelization does not pay off: an implementation based on a single global lock outperforms fine-grained solutions....

Control systems are ubiquitous in modern technology. The use of feedback control can be found in systems ranging from simple thermostats that regulate the temperature of a room, to digital engine controllers that govern the operation of engines in cars, ships, and planes, to ight control systems for high performance aircraft. The rapid advances in sensing, computation, and actuation technologie...

In the present work, a prototype of a new type of solar collectors, which called Direct Absorption Solar Collector, was built and its thermal performance is experimentally compared with conventional flat plate solar collector under transient and steady state conditions. Different volume fractions of multi wall carbon nanotubes in water and ethylene glycol mixture (70%:30% in volume) were used a...