Saad AlJanabi Holland University / DenHaag Research in physics / astronomy. ============================================== measurement of Mass Star To discuss the issue of measurement the mass of star is probably difficult, and the reason is due to the lack of being able to do the work of micro-precision computational results required, in view of the way in which grows by the star and even die. The scientists and researchers think the way that can be calculated mass of the star, which gives results accurate to denounce mass star. We can account by the mass of the sun by which it's effectuation amount of gravity on Earth. We also do not know whether other stars have the planets, as is the case of the sun. Or not? There are a lot of stars groupes are Constellations bilateral, and studies show that more than one third of the stars of this kind in the solar space. Th recipe rotation with orbite of hi e axis of rotation of the stars bilateral one on the other, and naturally, the dark star is rotating about Shining Star, which is a source for him. The star can be monitored in the accompanying with his sun at the same time .

Physics are the most important part of the background information for many of the sciences, and their links with other scientific knowledge, particularly the progress that has happened in this area in the world. Has increased the influence of the physical sciences who are seeking and looking forward to the specialized knowledge. It is clear to all of the students, familiar with the content and building the curriculum, that students of physics are the dilemma, and that the motivation to learn physics will decrease with time, although the level of the results of physical tests increase more Degradation year after year among students in the physical sciences. And because of the shock that they face during the performance of the method of physical science and thier entering first year university, of the gap between that might previously studied in the preliminary stages and Mainasabha in the current phase (the university). In the view of many scientists that it must develop teaching methods and learning and appropriate to these challenges, effective and modern methods.

This paper describes a new method of simulation for inverter circuits by using the interpreted Petri-nets (IPN). This method begins with a formalization stage which culminates in a set of IPN and mathematical equations which translate the requirements of the performance specifications sheet pertinent both to the control strategies to be guaranteed in relation to the status of the process, and to characteristics of these specifications and requirements. The algorithms of the simulation are written directly from these sets of IPN. This method facilitates and organizes writing the simulation algorithms. A single-phase half-bridge inverter circuit is used to validate this method.

The low density, the cohesion-less nature, high percentage of voids, and other undesirable properties of volcanic ash materials in their natural state necessitate their improvement prior to any construction. This study was conducted on natural volcanic ash in order to assess the performance of lime-stabilized mixture (lime-volcanic ash and fine materials). The volcanic ash was mixed with two different types of fine soils individually to improve the grading of the volcanic ash, cohesion properties and to reduce the amount of required lime. Different variables influencing the performances of ash-soil-lime mixture were studied. These variables included water content, lime content, fine soil plasticity, soil content, and curing duration. The laboratory program adopted in this investigation includes material characterization, compaction, deformation properties and strength. Strength characteristics using unconfined compressive strength were studied and recommended values of lime content for specified conditions of road bases and sub-bases are presented in this paper.