Nagia Dawood - Academia.edu (original) (raw)

Papers by Nagia Dawood

Journal of Analytical Atomic Spectrometry, 2017

Herein, tandem inductively coupled plasma mass spectrometry with a collision/reaction cell (ICP-C... more Herein, tandem inductively coupled plasma mass spectrometry with a collision/reaction cell (ICP-CRC-MS/MS) was used to accurately characterize the rare earth element (REE) pattern and the radiogenic isotope ratios of 143Nd/144Nd.

Polymers

Plasma gasification is considered an environmentally friendly process to convert plastic waste in... more Plasma gasification is considered an environmentally friendly process to convert plastic waste into fuel oil; a prototype system is described to test and validate the plasma treatment of plastic waste as a strategic vision. The proposed plasma treatment project will deal with a plasma reactor with a waste capacity of 200 t/day. The annual plastic waste production in tons in all regions of Makkah city during 27 years for all months in the years 1994 to 2022 is evaluated. A statistics survey of plastic waste displays the average rate generation ranging from 224 thousand tons in the year 1994 to 400 thousand tons in the year 2022, with an amount of recovered pyrolysis oil; 3.17 × 105 t with the equivalent energy; 12.55 × 109 MJ, and an amount of recovered diesel oil; 2.7 × 105 t with an amount of electricity for sale 2.96 × 106 MW.h. The economic vision will be estimated, using the results of energy generated from diesel oil as an industrial fuel extracted from plastic waste equivalent...

Journal of Applied Physics, 1974

A new approach to the problem of electromagnetic wave propagation through a vacuum‐plasma interfa... more A new approach to the problem of electromagnetic wave propagation through a vacuum‐plasma interface is formulated and used to solve two simple antenna problems. First, the impedance of a spherical body covered by a vacuum sheath and immersed in a plasma is calculated. The result is found to coincide with the empirical formula commonly used so far. Second, a cylindrical antenna also isolated from the plasma by a sheath is studied. The antenna can support guided modes whose dispersion relation is derived. An experiment has been performed in order to verify this dispersion relation. Experimental results are found to be in favor of the present approach.

Journal of King Saud University - Science, 2021

The surface properties of bio-fibres change by surface plasma treatment without changing their in... more The surface properties of bio-fibres change by surface plasma treatment without changing their internal properties. In this study, radio-frequency plasma was used to treat the surface of date palm leaves. Plasma treatment was conducted for different times (1, 5, and 8 min) and at different powers (80, 100, and 120 W), keeping the gas pressure fixed at 0.95 torr. Water-drop contact angles, scanning electronmicroscope images, surface free-energy measurements, and X-ray diffraction spectra were recorded for the surfaces of the leaves after plasma treatment. Contact-angle values were found to decrease and the surface energy in decrease. The observed changes in surface properties are attributable to a combination of the increase in polar chemical functional groups. Electron micrographs show improvement in the sample surface morphology after plasma treatment. The study showed that the surface modification of fibres by plasma could improve interfacial adhesion between the DPF and an epoxy matrix.

Nanomaterials, 2022

All Muslim pilgrims must wear Ihram clothes during the Hajj and Umrah seasons, which presents a g... more All Muslim pilgrims must wear Ihram clothes during the Hajj and Umrah seasons, which presents a great challenge regarding how to eliminate the spread of microbes attached to the cotton fabric of Ihram from the surrounding environment. Targeted fashion research of the recent past presents a new industrial treatment, which has led us to study the impact of heat directed from an atmospheric pressure plasma jet (APPJ), coupled with photocatalytic nanomaterials, for the antibacterial treatment of Escherichia coli (E. coli) attached to cotton fabric samples, to improve pollutant remediation. The average rates of heat transfer to the bacterial colonies attached to cotton fabric samples, as a function of the laminar mode, were 230 and 77 mW for dry and wet argon discharges, respectively. The jet temperatures (TJ) and heat transfer (QH) decreased more for wet argon discharge than for dry argon discharge. This is because, due to the wettability by TiO2 photocatalyst concentration dosage incre...

Journal of Modern Physics, 2017

Surfaces of optical elements are deposited by antireflection coatings (ARCs) to decrease the refl... more Surfaces of optical elements are deposited by antireflection coatings (ARCs) to decrease the reflection of light. Surface needs treatment before depositing the ARC one of treatment processes by plasma for adhesion improvement and surface hardening. A comparison of RF and DC glow discharges treated CR-39 polymer films gives insight into the mechanism of these surface processes. The surface properties of the plasma-treated samples are examined by microscopy techniques include contact angle measurements, scanning electron microscopy (SEM), atomic force microscopy (AFM), infrared (IR) spectroscopy and refractive index measurements. Results show that the plasma treatment modifies the polymer surface in both composition and morphology. It is found that the surface wettability is enhanced after plasma treatment. It is found that, RF plasma is more effective than DC plasma in CR-39 surface modification, as it implants more oxygen atoms into the surface and makes the contact angle declining to a lower level.

Journal of Taibah University for Science

Journal of Taibah University for Science, 2020

The paper presents the effect of cold plasma (RF-Ar low-pressure plasma) on Moringa oleifera seed... more The paper presents the effect of cold plasma (RF-Ar low-pressure plasma) on Moringa oleifera seeds. Five groups of seeds characterized by the different exposure times (1, 5, 10 and 15 mints) as well as untreated seeds. The highest germination parameters were obtained for seeds treated for the exposure times of 1 min. Analysis of the data showed a statistically significant impact of RF plasma on the seeds germination parameters. The surface properties of the plasma-treated samples are examined using scanning electron microscopy (SEM). Improvements appeared in the germination percentage and germination potential of the treated seeds and increase in the length of the plant for seeds exposed to the RF plasma at treatment time 1 and 5 min. from 4,32% to 26.40% for roots and from 15.91 % to 18.62 % for shoots, respectively. Also, it is observed that the weight of seeds increased for the samples treated at 1 and 5 min from 4.89% to 6.22%, and the weight of the shoots is increased from 6.19...

Effects of admixing argon to air DB discharge, at atmospheric pressure, on the electrical and opt... more Effects of admixing argon to air DB discharge, at atmospheric pressure, on the electrical and optical emission characteristics have been carried out. Optical emission spectroscopy is used to investigate the effect of argon admixing on the emission intensity of the nitrogen second positive systems (300-450 nm) and its relative population of) , (3 2 ν ′ Π u C N state. Also the vibrational temperature of the nitrogen second positive systems has been calculated for the sequence ∆v=-2, that follows the Boltzman's distribution. It was found that the vibrational temperature of second positive system can be raised significantly from 0.31 to 0.35 eV in air DBD plasma at discharge current 0.5 mA with admixing of Ar gas at flow rate of 3 L/min. Admixing of argon to air DB discharge, enhances also the discharge current, the electron density and the consumed power. Mechanisms of excitation and ionization processes of nitrogen molecules in this mixture have been studied. Processes which are responsible for the enhancement of the population density of) , (3 2 ν ′ Π u C N and its vibrational temperature have been reported.

Radiation Effects and Defects in Solids

... Walley El-Dine, N., Sroor, A., El-Shershaby, A., El-Bahi, SM and Ahmed, FJ 2004. Appl. Radiat... more ... Walley El-Dine, N., Sroor, A., El-Shershaby, A., El-Bahi, SM and Ahmed, FJ 2004. Appl. Radiat. Isot. ... Sci. Tech., 17: 123128. 13. Walley El-Dine, N., Sroor, A., El-Shershaby, A., El-Bahi, SM andAhmed, FJ 2004. Appl. Radiat. Isot., 60: 105109. 14. White, GJ and Rood, AS 2001. ...

Low-density plasma is generated in a cylindrical DC magnetron discharge tube. The radial and axia... more Low-density plasma is generated in a cylindrical DC magnetron discharge tube. The radial and axial distributions of the magnetic field strengths are drawn. The discharge current and voltage (I a-V a) characteristic curves of the glow discharge have been measured for Ar and He gases pressures. The effect of the applied magnetic field on the (I a-V a) characteristic curves and on the cathode fall thickness is discussed. The breakdown potentials (V B) of the discharge are lower when the magnetic field is applied.

The European Physical Journal D, 2014

We report a theoretical analysis of the measurements that carried out to study the breakdown of x... more We report a theoretical analysis of the measurements that carried out to study the breakdown of xenon gas over a wide pressure range induced by laser source operating at different wavelengths. The study provided an investigation of the effect of laser wavelength as well as gas pressure on the physical processes associated with this phenomenon. To this aim a modified electron cascade model is applied. The model based on the numerical solution of the time dependent Boltzmann equation for the electron energy distribution function (EEDF) simultaneously with a set of rate equations which describe the rate of change of the formed excited states population. Comparison between the calculated and measured threshold intensities for the experimentally tested laser wavelengths and gas pressure range is obtained. Furthermore computations of the EEDF and its parameters showed the actual correlation between the gain and loss processes which determine the threshold breakdown intensity of xenon and the two experimentally tested parameters; laser wavelength and gas pressure.

Article history: Received 19 September 2016 Accepted 10 December 2016 Published 31 December 2016

Radiation Protection Dosimetry, 2014

Indoor radon concentration levels in a large number of dwellings in Al-Madinah Al-Munawarah Provi... more Indoor radon concentration levels in a large number of dwellings in Al-Madinah Al-Munawarah Province have been measured. Al-Madinah Al-Munawarah is in the western region of Saudi Arabia. It is the second holiest city in Islam after Mecca, because it is the burial place of the Islamic Prophet Muhammad. The city was divided into four regions: western (contains nine sites), eastern (contains six sites), northern (contains nine sites) and southern (contains five sites). Radon gas concentration was measured using the closed chamber technique employing 232 cm 2 sheets of CR-39 solid-state nuclear track detectors. The detectors were kept for a period of 5 to 6 months from September 2010 to February 2011 in order to expose to radon gas. The results of the survey in the western and eastern sites showed that the overall minimum, maximum and average radon concentration levels were 20+ + + + +1.6, 27+ + + + +3.2 and 21+ + + + +2.5 Bq m-3 , respectively. The lowest average radon concentration (20+ + + + +1.6 Bq m 23) was found in Al Anabes and Al Suqya in the western region and Bani Dhafar in the eastern region, while the highest average concentration (27+ + + + +3.2 Bq m 23) was found in Teeyba in the western region and Al 'Aridh in the eastern region, with an average of 21+ + + + +2.5 Bq m 23 in the western and eastern sites of Al-Madinah Al-Munawarah. Also in the northern region, the minimum radon concentration was 20+ + + + +1.6 Bq m 23 in Oyun, while the maximum was 42+ + + + +1.6 Bq m 23 in Sayyed al Shuhadd and Hai Nasr. In the southern region, the minimum radon concentration was 25+ + + + +2.6 Bq m 23 at Hai Al Hejrah, while the maximum value was 37+ + + + +2.6 Bq m 23 at Al Awali and Dawadia. The average radon concentration was 26+ + + + +2.5 Bq m 23 for Al-Madinah Al-Munawarah (western, eastern, northern and southern regions). The corresponding annual effective dose E (mSv y 21) to public from 222 Rn and its progeny was estimated to be 0.66 mSv y 21 as an average value for Al-Madinah Al-Munawarah. The authors concluded that all the dwellings monitored for indoor radon concentration and annual effective dose show values within the permissible level and this is a blessing from God that this area, which many visitors come from all over the world (to visit the burial place of the Prophet Muhammad), is safe. Consequently, the health hazards related to radiation are expected to be negligible. Occupants of these dwellings are relatively safe.