In this paper , the CO2 laser receiver system is designed and studied, with wavelength laser 10.6 ?m in room temperature , and to evaluate the performance and discussion it via the package of optical design (ZEMAX), from its output the Spot Diagram is measured through RMS ,and from the Ray fan plot , the aberrations is found which is the normal error for the best focus named (under corrected ) , the other output was the Geometric Encircled Energy in the spot diagram . and found that the radius of spot diagram at 80% (R80%) from the total energy ,and focal shift .The designed system have high efficiency and low cost .

In this work, the design and implementation of a smart energy metering system has been developed. This system consists of two parts: billing center and a set of distributed smart energy meters. The function of smart energy meter is measuring and calculating the cost of consumed energy according to a multi-tariff scheme. This can be effectively solving the problem of stressing the electrical grid and rising consumer awareness. Moreover, smart energy meter decreases technical losses by improving power factor. The function of the billing center is to issue a consumer bill and contributes in locating the irregularities on the electrical grid (non-technical losses). Moreover, it sends the switch off command in case of the consumer bill is not

A computerized investigation has been carried out to design an immersion lens
with low aberration operating under zero magnification condition using inverse problem.
The aberration is highly dependent on the shape of electrodes, for a preassigned electron
beam trajectory the paraxial-ray-equation is solved to determine the electrostatic potential
and field distribution.
From the knowledge of the potential and its first and second derivative the
electron optical properties were computed, the electrode geometry was determined from
the solution of Laplace equation.

In this paper, a single-phase boost type ac-dc converter with power factor correction (PFC) technique is designed and implemented. A current mode control at a constant switching frequency is used as a control strategy for PFC converter. The PFC converter is a single-stage singleswitch boost converter that uses a current shaping technique to reshape the non-sinusoidal input current drawn by the bulky capacitor in the conventional rectifier. This technique should provide an input current with almost free-harmonics, comply with the IEC61000-3-2 limits, and a system operates with near unity power factor. The other function of the boost converter that should be
accomplished is to provide a regulated DC output voltage. The complete designed

At the present time, human lives in a changable world. Complexity of life effects human who became unable to achieve his goals. For him, goals are no longer able to provide him with calm and psychological safty. Anxiety about indefinite future and any changes which transend his ablity to cooperate with affeets his life in general aspeets.

     All these things bring him a very sever tention, then he becomes extremace in his cooperation with these situations. He tends to live a lone in order to be a way from sequenees of changes. Starting from this urgent point, future compnses the core in youth's life, then so many theories and studies affirm this point, and the necessity for mahing sc

تظهر اهمية مفهوم ألذات من حيث انه احد دوافع الفرد الداخلية التي لها تأثير معين على التحصيل الدراسي لدى التلاميذ وعلى تكيفهم مع بيئتهم التربوية أثناء الدراسة، لذلك فان معرفة كيفية قياس مفهوم ألذات وأدراك الفرد لذاته تساعد في عملية تقويم الفرد من حيث قدرته على التكييف وثقته بنفسه كما تفيد في التخطيط عن طريق وضع برامج تساعده في زيادة مفهوم ذاته عن نفسه.

ومما لاشك فيه ان مرحلة الطفولة لها اهمية

Iraq's water crisis represents one of the most pressing environmental and socioeconomic challenges facing the country today. This study examines the evolution of water resource problems in Iraq through a comprehensive historical comparison between the pre-2003 period under Saddam Hussein's regime and the post-2003 era following the U.S.-led invasion and subsequent political transformation. The research employs a mixed-method approach, analyzing quantitative data on water flow rates, infrastructure development, and qualitative assessments of policy impacts across both periods. Key findings reveal that while the pre-2003 period was characterized by deliberate environmental destruction, particularly the draining of the Mesopotamian Marshes, an