This paper presents the effect of relativistic and ponderomotive nonlinearity on cross-focusing of two intense laser beams in a collisionless and unmagnetized plasma. It should be noted here that while considering the self-focusing due to relativistic electron mass variation, the electron ponderomotive density depression in the channel may also be important. Therefore/these two nonlinearties may simultaneously affect the self-focusing process. These nonlinearities depend not only on the intensity of one laser but also on the second laser. Therefore, one laser beam affects the dynamics of the second beam and hence the process of cross-focusing takes place. The electric field amplitude of the excited electron plasma wave (EPW) has been cal

The military presence in the Gulf region after the British withdrawal from it in 1971 was one of the most important pillars of the American strategy to climb the ladder of global leadership, as the geostrategic features that the region enjoyed provided factors of controlling energy sources and global trade routes. The United States of America guarantees Western Europe and Japan the process of access to energy sources and the exclusion of its opponents from the region, especially the Soviet Union, and the growing American military presence in the Gulf after the invasion of Iraq in 2003. On the other hand, the region experiences many contradictions, some of which threaten its security, such as the exacerbation of disputes between its count

In this paper we generalize Jacobsons results by proving that any integer  in   is a square-free integer), belong to . All units of  are generated by the fundamental unit  having the forms

our generalization build on using the conditions

This leads us to classify the real quadratic fields  into the sets  Jacobsons results shows that  and Sliwa confirm that  and  are the only real quadratic fields in .

The paper include study the effect thickness of the polymeric sample which is manufactured by thermo press way. The sample was used as an active tunable R6G laser media. The remarks show that, when the thickness of the samples is increased, with the same concentration, the spectrum will shift towards the short wavelength, & the quantum fluorescence yield will increased. The best result we obtained for the quantum fluorescence yield is (0.68) at the sample, with thickness (0.304mm) in Ethanol solvent, while when we used the Pure Water as a solvent, we found that the best quantum fluorescence yield is (0.63) at (0.18mm) thickness of the sample.

The paper include studies the effect of solvent of dye doped in polymeric laser sample which manufactured in primo press way, which is used as an active (R6G) tunable dye lasers. The remarks show that, when the viscosity of the solvent (from Pure Water to Ethanol), for the same concentration and thickness of the performance polymeric sample is increased, the absorption spectrum is shifts towards the long wave length (red shift), & towards short wave length (blue shift) for fluorescence spectrum, also increased the quantum fluorescence yield. The best result we obtained for the quantum fluorescence yield is (0.882) with thickness (0.25mm) in Ethanol solvent in concentration (2*10-3mole/liter), while when we used the Pure Water as a solvent,

Multimedia applications impose different QoS requirements (e.g., bounded end-to-end delay and jitter) and need an enhanced transport layer protocol that should handle packet loss, minimize errors, manage network congestion, and transmit efficiently. Across an IP network, the transport layer protocol provides data transmission and affects the QoS provided to the application on hand. The most common transport layer protocols used by Internet applications are TCP and UDP. There are also advanced transport layer protocols such as DCCP and TFRC. The authors evaluated the performance of UDP, DCCP, SCTP, and TFRC over wired networks for three traffic flows: data transmission, video streaming, and voice over IP. The evaluation criteria were thro

 This article briefly analyzing contemporary works appeared in theater writer from Latin America, which comes within the theme of "power." Latin American Literature, such as two-way extremely clear: the vanguard of social and attention, have arrived at certain moments to some extent be regarded as a two-way rival. That desire to participate in the revolution of expression and artistic significance, has appeared evident in the literature of Latin America in the late nineteenth century and ended in the third decade of the twentieth century. The writers that stage would prefer not to serve the objectives of the revolution of Arts own but the objectives of social and political revolution that stimulate the world. These acts were issued

With the increasing rates of cancer worldwide, a great deal of scientific discourse is devoted to arguments and statements about cancer and its causes. Scientists from different fields try to seize any available chance to warn people of the risk of consuming and exposing to carcinogens that have, unfortunately, become essential parts of modern life. The present paper attempts to investigate the proximization strategy through which scientists construct carcinogen risk to enhance people’s preventive actions against these carcinogens. The paper targets the construction which depends on producing the conflict between the values of the people themselves and the contrasting values assigned to carcinogens. To achieve this aim, Cap’s (2

In this work, the relationship between the ionospheric parameters (Maximum Usable Frequency (MUF), Lowest Usable Frequency (LUF) and Optimum working Frequency (OWF)) has been studied for the ionosphere layer over the Iraqi zone. The capital Baghdad (44.42oE, 33.32oN) has been selected to represent the transmitter station and many other cities that spread over Iraqi region have represented as receiver stations. The REC533 communication model considered as one of the modern radio broadcasting version of ITU has been used to calculate the LUF parameter, while the MUF and OWF ionospheric parameters have been generated using ASAPS international communication model which represents one of the most advanced  and accurate HF sky wave prop

One of the most important processes to obtain gasoline with high octane numbers is isomerization. In this paper, Pt/TiO2 was prepared successfully by using the sol–gel method by hydrolysis of titanium tetraisopropoxide as a titania source with ethanol and then platinum was loaded on the synthesized catalyst; the result shows that the sample prepared has a good crystallinity with a surface area of about 85 m2 /g and a pore volume of 0.1938 cm3 /g, while XRD shows that the prepared sample was anatase phase. The efect of both temperature and liquid hourly space velocity of the prepared catalyst was achieved by hydroisomerization of n-hexane in a fxed bed reactor with a temperature of 200–275 °C and LHSV 0.5–2h−1. The results show