A theoretical model is developed to determine time evolution of temperature at the surface of an opaque target placed in air for cases characterized by the formation of laser supported absorption waves (LSAW) plasmas. The model takes into account the power temporal variation throughout an incident laser pulse, (i.e. pulse shape, or simply: pulse profile).
Three proposed profiles are employed and results are compared with the square pulse approximation of a constant power.
We report here the observation of 16 µm superradiance laser action generated from optical pumping of CF4 gas molecules (which is cooled to 140 Kº by a boil-off liquid-N2) by a TEA-CO2 laser 9R12 line. Output laser pulses of 7 mJ and 200 ns have been obtained.
In this work, results of a mathematical analysis of the role of workpiece preheating in laser keyhole welding were presented. This analysis considered the steady-state welding as well as certain range of boundary conditions over which preheating effect would be indicated. This work is an attempt to interpret the role of preheating to increase welding depth and perform keyhole welding with high quality using physical and thermal properties of steel alloys.
An isolate of Leishmania major was grown on the semisolid medium and incubated at 26ºC. The isolate was irradiated by He: Ne laser (632.8 nm, 10 mW) at exposure times (5, 10, 15, 20, 25, 30) minutes in their respective order. The unirradiated groups represent control group. Growth rate and percentage of viability were examined during six days after irradiation. The change in these two parameters reflects the effect of irradiation on the parasite. The results refers that the general growth effected by irradiation in comparison with un irradiation group, The growth rate of parasite decrease with increasing the exposure time in comparison with control group. Parasite viability decrease with irradiation and the percentage of living cell dec
... Show MoreTerrorist crime is considered a serious act that outweighs all other crimes in terms of impact and result, because it has a wide range on societies, and it also contains a great thing of danger represented in its purpose, and here describing terrorism as a crime is a description that does not give the full right to this behavior or that it It abbreviates it and does not show its actual reality, given that terrorism contains several different crimes and the roles of its contributors, and these roles are necessary to reach the result or the end. In which each episode is complementary to the other, it is not a single act, but rather several joint and complex actions that in turn all lead to the result, and the agreement in the terrorist pro
... Show MoreIn The Name of Allah Most Gracious Most Merciful
Cheating is one of the forbidden actions and reprehensible morals that are forbidden by Islamic law, because it involves an assault on rights, whether they are the rights of God Almighty or the rights of God.
people, or self-rights, and because it involves harming others.
Since the Sunnah of the Prophet is the second source of Islamic law, many of the noble hadiths of the Prophet forbid and prohibit cheating.
This study sheds light on it.
The condition of Islam and Muslims and what their political, social, cultural and educational status, and even religious and faith status, has led to whoever feels his belonging to this great religion and that middle nation, to try as much as he can to fix what has been corrupted as much as he can, and perhaps in diagnosing illness and illness as It was said half the way to treatment, and from this standpoint I liked to occupy thought, work consideration and harness part of the youth’s life in order to reach what contributes to reforming the situation and the safety of generations, and this is only in seeking knowledge and learning it by following the guidance of the Messenger (r) and his companions ( y) Therefore, the subject of my re
... Show MoreIn a hybrid cooling solar thermal systems , a solar collector is used to convert solar energy into heat energy in order to super heat the refrigerant leaving the compressor, and this process helps in the transformation of refrigerant state from gaseous state to the liquid state in upper two-thirds of the condenser instead of the lower two-thirds such as in the traditional air-conditioning systems and this will reduce the energy needed to run the process of cooling .In this research two systems with a capacity of 2 tons each were used, a hybrid air-conditioning system with an evacuated tubes solar collector and a traditional air-conditioning system . The refrigerant of each type was R22.The comparison was in the amou
... Show Morethe door of interpretation cannot be closed; Because the Qur’an is a living message, until the Day of Judgment, and Muslims continue to come to it, study it, stir it up, move with it, and live in its shadows until the Day of Judgment.
In anticipation of the blessing of revelation and the lights of revelation, and in pursuit of the service of the Book of God, I decided to choose the subject of my research:
Despondency in the Qur’an an objective study
As the study of one of the topics of the Qur’an on the foundations and steps of objective interpretation makes the reader stand on the Qur’an’s method in dealing with various problems and topics.
Background. Endodontic infections caused by remaining biofilm following disinfection with chemical fluids encourage secondary bacterial infection; hence, employing laser pulses to activate the fluids is advised to improve microbial biofilm clearance. This study investigated the performance of Er,Cr:YSGG laser in photon-induced photoacoustic streaming (PIPS) agitation of 5.25% sodium hypochlorite (NaOCl) to enhance the removal of mature Enterococcus faecalis (E. faecalis) biofilms in complex root canal systems. Methods. The mesial roots of the lower first and second molars were separated and inoculated with E. faecalis bacteria for 30 days. The roots were irrigated with 5.25% NaOCl, some of them were agitated with passive ultrasonic
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