the behavior of the first-order black and gray solitons propagtedin optical fiber in the presence of frequency chirp is studied analytically and numerically results show that phase profile of black solitons changes abruptly

The presentwork is a theoretical study in the field of charged particle optics. It concentrates on the design of electrostatic enzil lens for focusing charge particles beams, using inverse method in designingthe electrostatic lens. The paraxial ray equation was solved to obtain the trajectory of the particles, the optical properties such as the focal length and spherical and chromatic aberration coefficients were determined. The shape of the electrode of the electrostatic lens were determined by solving poison equation and the results showed low values of spherical and chromatic aberrations, which are considered as good criteria for good design.

In this article it is proved experimentally that the photon is a particle that has mass and constant wavelength by explaining the effect of refractive index on the wavelength and the natural mass of photon. It is very difficult to measure the mass of photon, a simple and easy process was proposed in this paper to calculate the mass length of photon in vacuum (Y) and in medium (Y*), by measuring the length of laser beam in air (L_air) and in medium (L_med). A new method was postulated to calculate refractive index by using these relations (n = Y*/Y), and (n = L_med / L_air) which supposed a new theory of light.

The dried fruit peel of pomegranate in Punicaceae family was fractionated chromatographically on Sephadex-LH-20 column .Gallic acid (trihydroxybenzoic acid) and its related galloyl esters such as gallotannin(i.e. β-penta-O-galloyl–D-glucose) were obtained homogenously. Different concentrations of gallic acid and gallotannin  were used to determine their inhibitory effect on human serum cholinesterase. The enzyme activity was measured according to the method reported by the WHO .The inhibitory effect of these compounds  on the activity of human serum cholinesterase have been studied in vitro .The inhibitory effect was remarkably clear with increasing concentration of gallic acid .Whereas galloyl ester showed n

The present paper analyzes the signal emitting from the Reticle during changing the spot size of laser falling on the disk and shows the optimum frequency and the amount of energy window in different patterns of modulator (Reticle).  All results are obtained by establishing   a special program named “Disk optical modulator version 3" using the language visual basic 6 ahich contains many parameters. All models of optical modulator consist of twenty sectors, ten sectors are opaque and other ten sectors are transmitted for the laser. The number of sectors depends on several factors as chopping frequency, power transparent and modulation transfer function.   It has been demonstrated by simulations, the optimal

Background: The effect of Helium Neon laser (He-Ne 632.8 nm) was reported to protect cells from damage. We studied lymphocyte cells pre irradiated with (UVC 260 nm) to induce DNA damage. Investigations were carried using gel electrophoresis and test for cell viability. It has also been reported that effect depends on incubation period after damage. The extent of damage to the cells depends on the period of irradiation with UVC also on its intensity.
Objective: In this work we studied the effect of UVC on DNA damage and cell survival
Also study of the effect of He-Ne laser on cell survival after all being pre irradiated with UVC light and its protective effect on DNA post UV damage.
Method: This study was conducted in pathology d

Bagkground:Chlorpromazine is widely used in human medicine in the therapy of schizophrenia, organic psychosis and the manic phase of manic depressive illness. It expressed a selective cytotoxicity and the results of genotoxicity were positive.
Objectives: This study is designed to explore the effect of chlorpromazine on irradiated and non irradiated calf thymus double strands DNA (ctdsDNA) molecule.
Methods: Aliquots of irradiated (subjected to UVB light) and non-radiated ctdsDNA samples were incubatyed with different concentrations of chlorpromazine. Further series of experiments studied the simultaneous effects of chlorpromazine and UVB light on aliquots of ctdsDNA, The changes in optic densities of

Films of silver oxide of different thickness have been prepared by the chemical spray paralysis. Transmission and absorption spectra have recorded in order to study the effect of increasing thickness on some optical parameter such as reflectance, refractive index , and dielectric constant in its two parts . This study reveals that all these paramters affect by increasing the thickness .

Background: Reports denote that changes in day length enhance or suppress components of immune function in several mammalian species. The aim of present experimental study is
directed to test the hypothesis deals with the effect of photoperiods on some immune limbs responsiveness.
Materials and Methods: Twenty six male and female BALB/C mice, 5-7 weeks old, 14- 18gm weight divided into two groups, test groups (n.=8 mice for each sex) and control
groups (n.=5 for each sex). Test groups were kept in a dark room for a month, while control groups were kept in a room where the photoperiod was day light: darkness 12:12hr. All
studied groups immunized with o.2ml (10% sheep red blood cells) on day 4 and 8 of the l