Journal of Kufa - physics

Polyaniline(PAni) was synthesesby oxidation chemical polymerization method.Formic acid with weight ratio (5-50)% used to doped PAni,The optical properties was measured with UV-Spectraphotons. The optical data analyses to found energy gap for all ratio.

Solar energy utilization in fivesymmetricdouble slope single basin solar stills with different insulation under actual field to find out the best insulating material in Basrah.From an economic point of viewit is found that dry hay is the best material to be used for insulating the symmetrical solar stills.

The laser radiation has great important in many applications. In this paper we have studied the influence of laser radiation on solid material. We use a (800 μs) pulsed laser ND: YAGwith (1.06 μ m) wave length,(3 J) energy and power density of (7.6 X 106W/cm2) . We have deduced amathematical function for laser energy with time,then deducing a function for laser power density with time because practically assumed to be constant.A lead material used in this paper for study,we have deduced mathematical functions for thermal properties (conductivity,specific heat,density, diffusivity)with temperature,and solve the partial differential equation(P.D.E)which represent the heat transfer of laser radiation to the material in one dimension,presumes variable and constant laser density ( I=I0andI=I(t)),also thethermal propertiesconductivity , specific heat ,density and diffusivity ( K=K0and K=K(T),C=C0 and C=C(T), )(0Tand,du=du0and du=du(T)) respectively .The results reveal that the time of evaporationincrease when the laser density is taken as variable with time , also it increase when the thermal properties were vary with temperature .We used (Matlab 7.0) to perform all programswhich relatedwith this paper

Equivalent circuitofmatchingnetworkis applied tomeasure the impedances of an RF-excited partial Z-fold waveguide CO2 laser. Inaddition, thedesign criteriaare discussed for the selection of the coil inductances and laser head characteristics for optimum power transfer.

In this work we used the chemicalspray pyrolysis technique to prepare ZnS, PbS, PbZn1-xSx,and PbxZn1-xS, thin films with (x = 0.01, 0.02) at glass substrate at 280 ̊C, 230 ̊C, 270 ̊C and 270 ̊C respectively. And also study the optical and structural properties. The result of X-ray diffraction obtained that the films are polycrystalline and have cubic with hkl (111) and wurtize with hkl (100) phases for ZnS films, the phase for PbS films is cubic with hkl (200) and the phases for PbxZn1-xS and PbZn1-xSx. are cubic with hkl (200) The lattice constants (a) which were calculated 5.939A ̊, for PbS films, 3.36 A ̊ and 5.44 A ̊ for wurtize and cubic of ZnS films respectively, 5.92A ̊for ZnxPb1-xS films with x = 0.02, and 5.921A ̊for PbZnxS1-x films with x = 0.01 Also the absorption spectra used in the range(200 nm –1100 nm) to calculate the optical energy gap which is decrease with increase the film thickness for all the films prepared by this technique.The values of energy gap were determined between (1.58 –1.78 eV) for PbS films, (2.9 –3.1eV) for ZnS films, The energy gap of ZnxPb1-xS films in the range (2.4 –2.9(eV and (2.38–2.75 eV for x= 0.02 and x = 0.01 respectively and The energy gap of PbZnxS1-x (1.57 –1.8(eV and (1.4 –1.6(eV for x = 0.02 and x = 0.01 respectively.The optical constants, such asrefractive index (n) increase with increase the film thickness, while the extinction coefficient (k) decrease with increase the thickness for all the films except ZnS films which are inversely. And the dielectric constants (εr, εi) have the same behavior of refractive index (n) and extinction coefficient (k) respectively.

Thelaser system has been constructed and operated locally to get ultra-violet laser pulse at 337.1 nm. A short laser channel, low pressure system with V-shape electrodes design will be described in detail.We studied several discharge parameters such as gas pressure applied voltage and capacitance of Blumlein capacitors. The best results obtained with applying voltage 10 KV, gas pressure 60 mbar, electrode spacing 1 cm, and repetition rate 1 PPs, no gas flow and E/P ratio 222 V / (cm.torr).IntroductionThe pulsed molecular nitrogen laser is a gas discharge laser that produces ultra violet laser output at 337.1 nm. This laser operateson the (C3u B3g) vibronic system, which involves a change in bothelectronic and vibration energy level [1, 2, 3, and 4]. A pulsed nitrogen laser has been constructed at relatively low cost.This design incorporatesV-shape electrodes to ensure even transverse discharge at low pressure closed system and produces superradiant emission at 337.1nm. Our nitrogen laser was constructed for spectroscopy studies and oil spill detection.

Silicon nano-material have been prepared in this work via electrochemical (EC) and photoelectrochemical (PEC) etching processes of nandp-type silicon wafers in hydrofluoric (HF) acid of 24.5 % concentration. All conditions preparation such as substrate resistivity, etching time, current density and illumination have been changed to study the effect of these parameters on resistivity of these porous siliconlayers.

The accurate simulation of powder compaction involves many different areasin computational mechanics, where appropriate elastoplastic constitutive model, finite deformation framework, enforcement of contact, friction conditions and robust numerical methods are some of the requirements demanded in this simulation.The modified Drucker-Prager Cap (DPC) elasto-plastic constitutive model is used for the calculations that performed using the finite element code ABAQUS 6.4, to simulate densification of alumina powder using cold die pressing. A comparison of the experimental and theoretical density distribution shows that there is a good qualitative agreementin the sense that both produce the important maximum and minimum density regions accurately, despite the overall density distribution of present work is slightly underestimated experimental data.