Lee model (RADPF5.15 K) algorithm is used to investigate the maximum value of soft X-ray yields from a low energy (2.2 kJ) EAEA plasma focus, as a function of argon gaseous pressures and aspect ratios. Additionally, the maximum soft X-ray yields are computed for various outer electrodes radii ( b ) as well as electrodes radii ratios ( c ). For varied outer electrode radii and electrodes radii ratios, the relationship between the obtained maximal soft X-ray outputs with various plasma focus column parameters and axial phase plasma characteristics as plasma focus column volume, duration pinch time, pinching current, temperature and ion density as well as plasma inductance, speed factor and gas pressure during the discharge axial phase is examined. Furthermore, for the same discharge procedures, the dependency of maximal soft X-ray outputs on magnetic and kinetic pressures of plasma focus column is observed individually. All of the findings of this investigation reveal that the best value of maximal soft X-ray yields = 4.6 × 10 −3 J is found with sizes b = 2.25 cm, c = 1.386, and pinching current = 76.7 kA.

NiCl2-filled polyvinyl alcohol (PVA) films filled prepared by casting process. X-ray diffraction (XRD) revealed that crystalline nature of PVA was reduced with NiCl2 content. The transmittance spectra of NiCl2 filled PVA films were reduced with NiCl2 content, confirming the increase of amorphous phase noticed by XRD for high NiCl2 content samples. In addition, the indirect band gap for PVA film is enhanced by NiCl2 content. However, the direct band gap for PVA film is decreased by NiCl2 content. It is recommended that NiCl2 filled PVA films are useful for packaging community.

We report a simple-to-perform technique to investigate the distribution of the azimuthal magnetic field induction, B θ , and the induced magnetic force acting on the plasma current sheath (PCS) in a plasma focus (PF) discharge. This in situ measurement technique can undoubtedly be beneficial when other fast-imaging techniques are not available. techniques are not available. Experimental work was conducted in the low-energy Mather-type EAEA-PF1 device operated in argon. The axial distribution (B θ ) z along the coaxial electrodes system was measured with a four magnetic-probe set technique at different radial distances (r = 2.625 × 10−2 to 4.125 × 10−2 m) within the annular space between the coaxial electrodes during the 1st and 2nd half cycles of the discharge current waveform, where inner electrode of coaxial electrode system has a +ve polarity and −ve polarity, respectively. Axial, radial and total magnetic force distribution profiles were estimated from B θ data. Investigation of PCS shape in terms of its inclination (curvature) angle, θ, along the axial rundown phase and the correlation between the magnetic forces per unit volume acting on the PCS, the inclination angle θ of the PCS, and the formation of a powerful PF action during the 1st and 2nd half cycles is carried out. Dependence of inclination angle, θ, on total magnetic force per unit volume acting on PCS axial motion was studied, separately, during the 1st and 2nd half cycles.

The present study reports the measurements of plasma current sheath (PCS) dynamics, the energy dissipation processes, and the plasma focus (PF) electrical characteristics, particularly during the axial phase discharge in a Mather-type PF device (EAEA-PF1) energized with a 30 mu F capacitor bank charged with 8, 10 and 12 kV. All these investigations carried out under discharge conditions where the optimal PF action is achieved. At each charging voltage (V-ch), 8 kV, 10 kV and 12 kV, the optimal PF action is studied at different argon gas pressures (P) ranging from 0.4 to 1.2 Torr. The results show that the best PF is formed at V-ch= 8 kV and P = 0.6 Torr, V-ch = 10 kV and P = 0.8 Torr, and V-ch = 12 kV and P = 0.8 Torr. The implosion velocity (V-z) results of PCS show that the maximum value of V-z (4.48 cm/mu s) occurs at the end of the axial phase (i.e., at the coaxial electrode muzzle), which is detected at V-ch = 12 kV and P = 0.8 Torr. Moreover, a less inefficient snowplow action is observed under these discharge conditions. The energy dissipation process data indicate that at V-ch = 12 kV and P = 0.8 Torr, the ratio between the total energy dissipation and the input energy has a maximum value of congruent to 90%, and the minimum residual energy left on the condenser bank (175.39 J) is also achieved under these discharge conditions.

The plasma current sheath (PCS) shape and trapping efficiency η are investigated experimentally. The experiments are carried out at the 2.2-kJ Egyptian Atomic Energy Authority Plasma Focus device, EAEA-PF1, of Mather-type geometry. Three versions of the inner electrode (IE) lengths, z 0 = 9.5, 10.5, and 11.5 cm, are used. The investigations are performed with argon gas at a pressure ranging between P = 0.2 to 1.8 Torr. The PCS shape in term of its inclination angle of curvature θ and thickness λ are detected at an axial distance approaching the coaxial electrode muzzle and at three different radial distances through the annular space within the coaxial electrode assembly. Results on the trapping efficiency η are obtained from the magnetic force and PCS acceleration data under these discharge conditions. Diagnostic tools applied are a Rogowski coil and magnetic probes. Results on the PCS profile show that it has the best profile at an argon gas pressure of 0.8 Torr and IE length of 10.5 cm. The trapping efficiency η has the maximum value at gas pressures within the range of 0.6−1.8 Torr, where the maximum axial force is detected for most experimental data.

In this paper, the results of wettability improvement of Mylar substrate are presented. The experimental work is done with an atmospheric-pressure nonthermal plasma jet, ANPJ device. This device is energized by a low-cost Neon power supply of (10 kV, 30 mA, and 20 kHz). It is operated separately with N2 gas and compressed air at a flow rate of 12 L/min for each of them and input voltage of 6 kV. A Mylar substrate is treated using both carrier gases. The wettability of Mylar substrate is measured using contact angle technique. The contact angle is detected using two techniques: spherical cap approach and Low-bond axisymmetric drop shape analysis. The results show wettability improvement of this substrate surface for both carrier gases but the N2 plasma jet is more effective than Air plasma jet.

This paper presents results of experimental studies carried out with atmospheric pressure non-thermal plasma jet, ANPJ, device energized by a low-cost Neon power supply of (10 kV, 30 mA, and 20 kHz). The discharge takes place by using compressed Air and N2 gas separately with a flow rate from 3 to 25 L/min and charging voltage of 6 kV. All the results are taken during a period time of 100 μs. The excitation electron temperature has been measured using the photomultiplier tube, PMT, with two different wavelength filters of 460 and 500 nm. The plasma jet device operational time effect on the temperature of the device components has been studied by using a thermometer. Scanning electron microscope, SEM, images were taken to visualize the changes in the surface of Polyethylene terephthalate, PET before and after treatment with N2 and Air Plasma Jet separately, and at optimum operation condition of plasma jet device.

The main aim of this work is to study dynamics of plasma current sheath, PCS during the axial acceleration phase in term of its axial velocity, Vz and the induced azimuthal magnetic field induction, Bθ in 2.2 KJ plasma focus, PF device of Mather type. It powered by a capacitor bank of 30 μf capacity with charging voltage of 12 KV. In the present paper all the experimental work are performed for Argon gas pressure in the range of 0.2 – 1.8 Torr. The length of the inner electrode, IE has been changed to 9.5, 10.5 and 11.5 cm respectively. To detect, Bθ and Vz three identical magnetic probes are located at radial distance r1 = 2.75 cm, r2 = 3.5 cm and r3 = 4.25 cm from the IE axis and at axial distance z = 8.15 cm from coaxial electrodes breech. The dependence of Vz and Bθ on gas pressures are measured and the results of them clear that, Vz is decayed with increasing of gas pressures and it has a maximum value for IE length of 10.5 cm, P = 0.2 Torr and at r1, while Bθ has a maximum value for IE length = 11.5 cm, 1.2 Torr at r1 . Also distribution of Vz with p in linear fitting shows that efficient a snow-plough action is obtained approximately for IE length = 10.5 cm. Results of Vz versus radial distance demonstrated that the PCS has a parabolic shape especially at lower Argon gas pressures. Results of modification factor, F as a function of gas pressures show that at IE = 10.5 cm, r1 and for most Argon gas pressures F has a higher values than any others IE lengths and radial distances. Also the decay of dF/dp along radial distances has a smaller values at IE length = 11.5 cm than any other lengths (9.5 and 10.5 cm).

This paper presents the results of the experimental investigations of the axial distribution of magnetic and electric forces profiles. Moreover, is decreases the theoretical estimation of radial and axial plasma current sheath density along the inter electrode discharge region of a 1.5 KJ coaxial Nitrogen plasma discharge device with negative inner electrode polarity. All the data are taken at the average value of inner and outer electrodes radii and along the coaxial electrodes. Maxwell's equations are used in the present work. This device is energized by a condenser bank of 30 mu f capacity with charging voltage of 10 KV and the discharge is operated with Nitrogen gas of a pressure ranging from 1 to 2.2 Torr. This system delivers a peak discharge current of 56 KA with a periodic time of 32 mu s. Dependence of Nitrogen gas pressures on the maximum value of different magnetic and electric forces which affect the Plasma Current Sheath (PCS) motion in different directions of (r, theta, z) and during the axial phase are discussed to get the optimum discharge conditions to operate the coaxial plasma device under consideration. Also the effect of N2 gas pressure on the helical performance of PCS motion is studied at different axial distances along the coaxial electrodes.

This paper presents results of experimental studies carried out with a Mather type plasma focus device of 2.2 kJ energy. A critical effect of plasma focus inner electrode, IE length on the plasma focus action is detected for IE length has been changed to 9.5, 10.5 and 11.5 cm respectively; also for different Argon gas pressure ranging from 0.2 to 1.8 Torr. To verify this effect, it is important to investigate the plasma focus characteristics such as, a focusing time, voltage spike amplitude, focus action intensity, focus duration time, plasma focus inductance, and radius of plasma focus column as well as pinching ratio. The diagnostics used in the experiments include a Rogowski coil and resistive high voltage probe to measure the discharge current and voltage signals respectively. All the results illustrated that, the best focus action has been achieved for IE length of 10.5 cm and at filling Argon gas pressures varied from 0.8 to 1.2 Torr.

The construction and operation of atmospheric nonthermal plasma jet, ANPJ, are presented in this work as well as the experimental investigations of its electrical parameters, the configuration of plasma jet column and its temperature.The device is energized by a low-cost Neon power supply of (10 kV, 30 mA, and 20 kHz) and the discharge takes place by using N2 gas with different flow rates from 3 to 25 L/min and input voltage of 6 kV.Diagnostic techniques such as voltage divider, Lissajous figure, image processing and thermometer are used.The electrical characteristics of discharge at different flow rates of N2 gas such as discharge voltage, current, mean power, power efficiency, and mean energy have been studied.The experimental results show that the maximum plasma jet length of 14 mm is detected at flow rate of 12 L/min.The results of plasma jet (heavy particles) temperature along the jet length show that jet plasma has approximately a room temperature at the jet column end.The results of zero flow rate effect on the ANPJ operation show damage in the Teflon insulator and a corrosion in the Aluminum electrodes.

This paper presents the design and construction of non-thermal plasma jet device which was built in plasma phys. Dept., NRC, AEA, Egypt with a plasma application group. This design will be useful to initiate research in different fields such as low temperature plasma, polymer and biomedical applications. The experimental operation of this device is conducted with power supply of (10 kV, 30 mA, and 20 kHz). The discharge process takes place by using Air as input gas with different flow rates. The experimental results showed that the maximum plasma jet length of 7 mm is detected at air flow rate of 12 L/min. The electrical characteristics of discharge at different flow rates of Air such as discharge voltage, current, mean power, power efficiency, and energy have been studied by using potential dividers and Lissajous figure techniques. The results of plasma jet temperature along the jet length showed that the jet plasma has approximately a room temperature at the end of jet column.

Removal of heavy metals from aqueous waste solution using poly acrylic acid / 2-hydroxyethyle methacrylate (p-AAc/HEMA) was investigated. Experiments were carried out as function of contact time, initial concentration, pH, partipcle size and temperature. Adsorption data were modeled using the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetics equations. It was shown that pseudo-second-order kinetic equation could best describe the adsorption kinetics. The results indicated that poly acrylic acid / 2-hydroxyethyle methacrylate (p-AAc/HEMA) is suitable as adsorbent material for adsorption of Sr2+, Co2+, Cd2+, Zn2+, Nd3+ and Eu (3+) radio active nuclei from aqueous solutions.

In the context of cognitive radio or military applications, it is a crucial task to distinguish various OFDM based systems such as fixed WiMAX and Wi-Fi from each others. This paper presents a novel technique that deals with the classification of OFDM signals using higher order moments and cumulants with different types of classifiers and clustering techniques is proposed. Four classification techniques were considered, namely, Support Vector Machines, K-nearest neighbors, Maximum Likelihood and neural network (NN) classifiers. Two clustering techniques were utilized, namely, Fuzzy K-Means and Fuzzy C-means. Simulation results show that the proposed technique is able to classify different types of OFDM signals in Rayleigh fading and additive white Gaussian noise (AWGN) channels with high accuracy. It is also shown that the NN classifier outperforms the other three considered classifiers.

Digital signal classification using clustering has many applications in the civilian and military domains. Most of the proposed classifiers can only recognize a few types of digital signals. This paper presents a novel technique that deals with the classification of multi-user chirp modulation signals using clustering techniques. In this technique, a combination of higher order moments and cumulants are proposed as the effective features. Simulation results show that the proposed technique is able to classify the different types of chirp signals in additive white Gaussian noise (AWGN) channels and fuzzy c-means clustering (FCM) outperform fuzzy k-means clustering (FKM).

Automatic Digital signal type classification (ADSTC) has many important applications in both of the civilian and military domains. Most of the proposed classifiers can only recognize a few types of digital signals. This paper presents a novel technique that deals with the classification of multi-user chirp modulation signals. In this technique, a combination of higher order moments and higher order cumulants (up to eighth) are proposed as the effective features and different types of classifiers are used. Simulation results show that the proposed technique is able to classify the different types of chirp signals in additive white Gaussian noise (AWGN) channels with high accuracy and the neural network classifier (NN) outperforms other classifiers, namely, maximum likelihood classifier (ML), k nearest neighbor classifier (KNN), support vector machine classifier (SVM).

Polyaniline (PANI-EB) containing MFe2O4 (M is an element in a divalent state; M2+ = Fe2+, Co2+, Ni2+, Mn2+, and Zn2+) were prepared by chemical method. The results of this investigation indicate that; i) the size of MFe2O4 in PANI is in the range 10 to 20 nm. ii) the MFe2O4 nanoparticles have the characteristic reflections of the Fd-3m spinel cubic structure. iii) the presence of ferromagnetic phase in PANI/Fe3O4 and PANI/CoFe2O4 samples, while samples containing Ni2+, Mn2+, and Zn2+ showed a superparamagnetic behavior. The results of Thermogravimetric analysis indicated that the addition of MFe2O4 nanoparticles to PANI improved the nanocomposites thermal stability. The interaction between MFe2O4 nanoparticles and PANI matrix may be occurred by the formation of the hydrogen bonding between the amine group of PANI and Oxygen of MFe2O4.

Abstracts are not published in this journal

Electron spin resonance (ESR) and d.c. conductivity measurements have been made on a prepared binary tellurite glass in the temperature range 200–400 K. The d.c. conductivity was found to be temperature dependent and had two regimes. The data were consistent with the small polaron transport mechanism and the polaron activation energy was 0.22 eV. The ESR spectra at high temperatures were characterized by two overlapping lines, a broad line with g = 2.00 and a narrow line with g = 1.967. At temperatures lower than 258 K, the narrow line disappeared and the broad line remained. This suggests that carriers become localized at T < 258 K. At T > 273 K, the conductivity arises from hopping of carriers between cerium sites. It was also found that the reduced valency ratio C (i.e., the ratio of the concentration of Ce4+ ions to the total Ce ion concentration in the glass) increases with temperature.