Papers by Mufeed A Awawdeh
Canadian Journal of Physics, Jul 1, 2016
Bose-Einstein condensation in a finite one-dimensional atomic Bose gas trapped in an optical latt... more Bose-Einstein condensation in a finite one-dimensional atomic Bose gas trapped in an optical lattice is studied within Bogoliubov's approximation and then beyond this approximation, within the static fluctuation approximation. A Bose-Hubbard model is used to construct the Hamiltonian of the system. The effect of the potential strength on the condensate fraction is explored at different temperatures; so is the effect of temperature on this fraction at different potential strengths. The role of the number of lattice points (the size effect) at constant number density (the filling factor) is examined; so is the effect of the number density on the condensate fraction. The results obtained are compared to other published results wherever possible.
International Journal of Education, 2022
We report on a study of our students’ understanding of gravity using the Newtonian Gravity Concep... more We report on a study of our students’ understanding of gravity using the Newtonian Gravity Concept Inventory (NGCI). This article is supposed to serve two purposes: as a proof of applicability of the test to first year medical students outside the United States and as a general survey of our students’ understanding of gravity. The motivation for this work came initially from students’ misconceptions of gravity and related topics noticed in classrooms. NGCI has 26 multiple-choice questions probing students’ knowledge of gravity in four different domains: Directionality, Gravity as a force, Independence from other forces and threshold. Results confirmed weak overall performance of the 684 students participated in this study (average score of only 38.48%) with misconceptions related to gravity in all four domains. We were able to prove the applicability of the NGCI to our students through calculations of Classical Test Theory statistics and Cronbach’s alpha. We got a Cronbach’s alpha o...
Chinese Physics B, Oct 1, 2018
Journal of Superconductivity and Novel Magnetism, 2017
In this article, Gd3−xErxFe5O12 powders with x= 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 were prepar... more In this article, Gd3−xErxFe5O12 powders with x= 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 were prepared by solid-state reaction method. The properties of the prepared samples were examined by X-ray diffraction, Mössbauer spectroscopy, vibrating sample magnetometry, and differential scanning calorimetry. The XRD patterns of the powders show a single-phase structure and were found to agree with the standard pattern of rare earth iron garnet. Room temperature Mössbauer spectra of the powders indicate that iron is present in three magnetic sites corresponding to two octahedral sites and one tetrahedral site. The saturation magnetization increased with increasing erbium substitution, and the Curie temperature decreased slightly.
Materials Research, 2018
In this paper, Y 3 Al x Fe 5-x O 12 powders with x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0 were prepar... more In this paper, Y 3 Al x Fe 5-x O 12 powders with x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0 were prepared via solid state reaction method. X-ray diffraction, Vibrating Sample Magnetometry, and Mössbauer Spectroscopy were used to study their structural and magnetic properties. The XRD patterns of the samples show single phase structure with decreasing lattice constant when increasing Al concentration. The saturation magnetization decreases from 28.0 to 10.1 emu/g with increasing Al 3+ from 0.0 to 1.0 due to the reduction of the superexchange interactions between iron ions in the a and d sublattices. Room temperature Mössbauer spectra for the samples were collected and analyzed. The hyperfine field values for octahedral and tetrahedral sites of the samples decreased with increasing Al concentration. Moreover, Mössbauer results have shown that Al 3+ ions prefer to replace Fe +3 at the octahedral sites.
Materials Research Bulletin, Feb 1, 2016
Abstract BaFe 12− x Cu x O 19 hexaferrites were prepared using ball milling and sintering at 1100... more Abstract BaFe 12− x Cu x O 19 hexaferrites were prepared using ball milling and sintering at 1100 °C. Refinement of the X-ray diffraction patterns was carried out to determine the structural parameters and the ionic distribution over the crystallographic sites. The preferential site occupation and valence state of Cu was consistent with the results obtained from the analysis of Mossbauer spectra. Further, the magnetic parameters of the samples were discussed in light of the structural and Mossbauer analyses. The magnetic phase transition temperature was found to decrease with the level of Cu substitution, in accordance with the reduction of the superexchange interactions. Further, the magnetic softening of the hexaferrite and the significant reduction in magnetocrystalline anisotropy with Cu substitution was consistent with the ionic distribution in the lattice. This study clearly demonstrated the feasibility of using a simple method to fabricate hexaferrites with a modified coercivity, while maintain the saturation magnetization high enough for practical applications.
American Journal of Physics, 1976
ABSTRACT The thermodynamic behavior of the one-dimensional Bose-gas-attractive-delta impurity sys... more ABSTRACT The thermodynamic behavior of the one-dimensional Bose-gas-attractive-delta impurity system is studied in this paper. The system is shown to undergo the Bose-Einstein condensation and the cause of the phase transition is attributed to the bound state introduced by the impurity in the free-particle energy spectrum. The condensed phase is composed of particles captured by the impurity, forming a drop of particles well localized in space. This gives to the Bose-Einstein condensation in this system the appearance of the ordinary vapor-liquid phase transition. The expression for the pressure is obtained and is plotted as a function of the temperature and the system length. The shapes of the isothermal curves reinforce the interpretation of a vapor-liquid transition. The evaluation of the heat capacity at constant length shows the existence of a finite discontinuity at the transition temperature.
This paper reports on the synthesis and characterization of Fe-doped ZnO thin films deposited ont... more This paper reports on the synthesis and characterization of Fe-doped ZnO thin films deposited onto gold coated glass substrates, using electrochemical deposition (ECD) technique at room temperature and different concentrations of Fe. X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and optical transmission measurements were used to characterize the films. The effect of iron doping on the structural, morphological and optical properties of the films was studied. The XRD spectra of the Fe-ZnO films indicate the polycrystalline nature having hexagonal crystal structure. From the XRD pattern, it is observed that peak positions shift toward lower angles with Fe doping. The change in the peak positions with increase in Fe content clearly indicates that Fe ions replace Zn ions in the ZnO films. The SEM images showed different surface morphologies of the grown structures on the gold layer according to the doping concentration. The shape and dimensions of the structures depend on the doping level. The PL spectra illustrate that there is an obvious red-shift for the emission centre from ultraviolet to blue region. The intensities of emissions from defects increase with the increase of Fe doping. The growth and doping mechanism was also briefly discussed.
Solid State Phenomena, 2015
In this article we report on the structural and magnetic properties of BaFe12-4xMoxZn3xO19 hexafe... more In this article we report on the structural and magnetic properties of BaFe12-4xMoxZn3xO19 hexaferrites with Mo-Zn substitution for Fe ions. The starting materials were commensurate with the BaM stoichiometry, and the Mo:Zn ratio was 1:3. The powder precursors were prepared by high energy ball milling, and subsequently sintered at temperatures from 1100 to 1300° C. The structural analyses indicated that all samples sintered at 1100° C were dominated by a major M-type hexaferrite phase. The relative abundance of the BaMoO4 and Zn-spinel secondary phases increased with increasing the concentration of the substituents, resulting in a decrease of the saturation magnetization from about 67 emu/g (for x = 0.0) to 55 emu/g (for x = 0.3). The coercivity also decreased from 3275 Oe (for x = 0.0) to 900 Oe (for x = 0.3), demonstrating the ability to tune the coercivity to the range useful for magnetic recording by the substitution process. The saturation magnetization improved significantly w...
Y-type hexaferrite samples Ba 2 Zn x Co 2-x Fe 12 O 22 with x = 0, 1 and 2 were prepared from pre... more Y-type hexaferrite samples Ba 2 Zn x Co 2-x Fe 12 O 22 with x = 0, 1 and 2 were prepared from precursors synthesized by the citrate sol-gel auto combustion method. The powders were sintered at 1100° C for four hours. X-ray diffraction, scanning electron microscopy and Mössbauer spectroscopy were used to investigate the effect of ball milling on the structure, microstructure and on the hyperfine parameters. X-ray diffraction revealed the presence of a single Y-type hexaferrite in all sintered samples. This phase persisted in samples milled for periods up to four hours. Scanning electron microscopy images indicated that the particles changed shape, and their sizes reduced by a factor of 10 for milling times of four hours. Room temperature Mössbauer spectra of the hexaferrites elucidated the distribution of the various cations at the various sites of the hexaferrite lattice. The hyperfine field (B hf) associated with each component was found to decrease almost exponentially with increasing milling time. The reduction in hyperfine field was associated with the weakening of the superexchange interactions between the spin-up and spin-down sublattices as a consequence of replacing Co 2+ magnetic ions by non-magnetic Zn 2+ ions and with the microstructure in the milled samples.
Y-type hexaferrite samples Ba 2 Zn x Co 2-x Fe 12 O 22 with x = 0, 1 and 2 were prepared from pre... more Y-type hexaferrite samples Ba 2 Zn x Co 2-x Fe 12 O 22 with x = 0, 1 and 2 were prepared from precursors synthesized by the citrate sol-gel auto combustion method. The powders were sintered at 1100° C for four hours. X-ray diffraction, scanning electron microscopy and Mössbauer spectroscopy were used to investigate the effect of ball milling on the structure, microstructure and on the hyperfine parameters. X-ray diffraction revealed the presence of a single Y-type hexaferrite in all sintered samples. This phase persisted in samples milled for periods up to four hours. Scanning electron microscopy images indicated that the particles changed shape, and their sizes reduced by a factor of 10 for milling times of four hours. Room temperature Mössbauer spectra of the hexaferrites elucidated the distribution of the various cations at the various sites of the hexaferrite lattice. The hyperfine field (B hf) associated with each component was found to decrease almost exponentially with increasing milling time. The reduction in hyperfine field was associated with the weakening of the superexchange interactions between the spin-up and spin-down sublattices as a consequence of replacing Co 2+ magnetic ions by non-magnetic Zn 2+ ions and with the microstructure in the milled samples.
Y-type hexaferrite samples Ba 2 Zn x Co 2-x Fe 12 O 22 with x = 0, 1 and 2 were prepared from pre... more Y-type hexaferrite samples Ba 2 Zn x Co 2-x Fe 12 O 22 with x = 0, 1 and 2 were prepared from precursors synthesized by the citrate sol-gel auto combustion method. The powders were sintered at 1100° C for four hours. X-ray diffraction, scanning electron microscopy and Mössbauer spectroscopy were used to investigate the effect of ball milling on the structure, microstructure and on the hyperfine parameters. X-ray diffraction revealed the presence of a single Y-type hexaferrite in all sintered samples. This phase persisted in samples milled for periods up to four hours. Scanning electron microscopy images indicated that the particles changed shape, and their sizes reduced by a factor of 10 for milling times of four hours. Room temperature Mössbauer spectra of the hexaferrites elucidated the distribution of the various cations at the various sites of the hexaferrite lattice. The hyperfine field (B hf) associated with each component was found to decrease almost exponentially with increasing milling time. The reduction in hyperfine field was associated with the weakening of the superexchange interactions between the spin-up and spin-down sublattices as a consequence of replacing Co 2+ magnetic ions by non-magnetic Zn 2+ ions and with the microstructure in the milled samples.
Solid State Phenomena
The present study is concerned with the fabrication and characterization of Me 2 Y substituted he... more The present study is concerned with the fabrication and characterization of Me 2 Y substituted hexaferrites, Ba 2 Me 2 Fe 12-x T x O 22 (Me = Co 2+ , Mg 2+ , and Cr 2+ , and T = Fe 3+ , and Ga 3+). The samples were prepared by the conventional ball milling technique and sintering at 1200° C. The effect of the choices of Me and T ions on the structural and magnetic properties of the hexaferrites were investigated. XRD patterns, magnetic parameters, and Mössbauer spectra of the Co 2 Y were consistent with a single phase Y-type hexaferrite. However, the CoCr-Y sample was found to be dominated by the Y-type hexaferrite, and M-type and BaCrO 4 minority phases were observed in the XRD pattern of the sample. The small increase in saturation magnetization from about 34 emu/g up to 37.5 emu/g was therefore attributed to the development of the M-type phase. On the other hand, XRD pattern of the Cr 2 Y sample indicated the dominance of the M-type phase in this sample. The high coercivity (1445...
Biosensors and Bioelectronics, 2005
The spectrophotometric properties of porphyrins are altered upon interaction with chlorophenols a... more The spectrophotometric properties of porphyrins are altered upon interaction with chlorophenols and other organochlorine pollutants. Mesotetra(4-sulfonatophenyl)porphyrin (TPPS), zinc meso-tetra(4-sulfonato phenyl)porphyrin (Zn-TPPS), monosulfonate-tetraphenylporphyrin (TPPS 1 ), meso-tri(4-sulfonatophenyl)mono(4-carboxyphenyl)porphyrin (C 1 TPP), meso-tetra(4-carboxyphenyl)porphyrin (C 4 TPP), and copper meso-tetra(4-carboxyphenyl)porphyrin (Cu-C 4 TPP) in solution exhibit a broad absorbance in the range 400-450 nm Soret region. The interaction of the above mentioned porphyrins in solution with pentachlorophenol (PCP) induces a red shift in the Soret spectrum with absorbance losses at 413, 418, 403, 405, 407, and 404 nm, respectively, and the appearance of new peaks at 421, 427, 431, 416, 417, and 416 nm, respectively. The intensity of the Soret spectral change is proportional to the pentachlorophenol concentration with a detection limit of 1, 0.5, 1.16, 1, 0.5, and 0.5 ppb, respectively. The interaction of (C 4 TPP) and (Cu-C 4 TPP) in solution with PCP shows to concentration dependent for concentrations less than 4 ppb the dependence was log-linear. However, for concentrations greater than 4 ppb the relation was linear.
This paper reports on the synthesis and characterization of Fe-doped ZnO thin films deposited ont... more This paper reports on the synthesis and characterization of Fe-doped ZnO thin films deposited onto gold coated glass substrates, using electrochemical deposition (ECD) technique at room temperature and different concentrations of Fe. X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and optical transmission measurements were used to characterize the films. The effect of iron doping on the structural, morphological and optical properties of the films was studied. The XRD spectra of the Fe-ZnO films indicate the polycrystalline nature having hexagonal crystal structure. From the XRD pattern, it is observed that peak positions shift toward lower angles with Fe doping. The change in the peak positions with increase in Fe content clearly indicates that Fe ions replace Zn ions in the ZnO films. The SEM images showed different surface morphologies of the grown structures on the gold layer according to the doping concentration. The shape and dimensions of the structures depend on the doping level. The PL spectra illustrate that there is an obvious red-shift for the emission centre from ultraviolet to blue region. The intensities of emissions from defects increase with the increase of Fe doping. The growth and doping mechanism was also briefly discussed.
In this article we report on the structural and magnetic properties of BaFe 12-4x Mo x Zn 3x O 19... more In this article we report on the structural and magnetic properties of BaFe 12-4x Mo x Zn 3x O 19 hexaferrites with Mo-Zn substitution for Fe ions. The starting materials were commensurate with the BaM stoichiometry, and the Mo:Zn ratio was 1:3. The powder precursors were prepared by high energy ball milling, and subsequently sintered at temperatures from 1100 to 1300° C. The structural analyses indicated that all samples sintered at 1100° C were dominated by a major M-type hexaferrite phase. The relative abundance of the BaMoO 4 and Zn-spinel secondary phases increased with increasing the concentration of the substituents, resulting in a decrease of the saturation magnetization from about 67 emu/g (for x = 0.0) to 55 emu/g (for x = 0.3). The coercivity also decreased from 3275 Oe (for x = 0.0) to 900 Oe (for x = 0.3), demonstrating the ability to tune the coercivity to the range useful for magnetic recording by the substitution process. The saturation magnetization improved significantly with sintering at T > 1100° C, and the coercivity decreased significantly, signaling the transformation of the samples to soft magnetic materials. These magnetic changes were due to the high-temperature reaction of the spinel phase with the BaM phase to produce the W-type hexaferrite phase on the one hand, and to the growth of the particles on the other hand. The magnetic phases were further investigated using Mössbauer spectroscopy and thermomagnetic measurements. Our study indicated that the sample with x = 0.2 has the highest saturation magnetization (74 emu/g at sintering temperature of 1300° C) and a tunable coercivity between 2100 Oe and 450 Oe.
Sensors and Actuators B: …, 2003
The spectrophotometric properties of porphyrins are altered upon interaction with nucleic acids, ... more The spectrophotometric properties of porphyrins are altered upon interaction with nucleic acids, proteins, and amino acids. Meso-tetra (4sulphonatophenyl) porphyrin (TPPS) immobilized as a monolayer onto a cellulose film exhibits an absorbance peak in the Soret region at 421 nm. The interaction of the porphyrin with arginine, glycine, histidine and serine induces blue shifts in the Soret spectrum with absorbance losses at 422, 427, 427, and 421/427 nm, respectively, and the appearance of new peaks at 410/415, 412, 414, and 412 nm, respectively. The intensity of the Soret spectral change is proportional to the log of amino acid concentration. The detection limit with immobilized porphyrin for the above amino acids is 30, 20, 30 and 60 nM, respectively. These results suggest the possibility to develop a solid-state optically based selective and sensitive sensor of different L-amino acids. #
Radiation Protection …, 2009
The Jordan Rift Valley (JRV) is considered Jordan food bowl, especially during the winter season.... more The Jordan Rift Valley (JRV) is considered Jordan food bowl, especially during the winter season. Here, soil and vegetable samples collected from greenhouses in the northern JRV were analyzed for their radioactive content. The activity concentrations of 238 U, 235 U, 232 Th, 226 Ra, 137 Cs and 40 K in soil were found to be (± SD) 33 ±12, 2.2 ±0.7, 11.2 ±3.3, 40.5±15.5, 3.5 ±1.3, and 156.0±46.6 (Bq/kg), respectively. In vegetables, the activity concentration of 40 K was found in the range of 698-1439 Bq/kg, while those of 226 Ra and 228 Ra were found to be in the range of BDL-2.56 and BDL-3.35 Bq/kg, respectively. Transfer factors for 40 K were found to be high and ranged from 5 to 8, while those for 226 Ra and 228 Ra were found to be from < 0.01 to 0.07 and from <0.09 to 0.42, respectively. The calculated external annual effective dose is found to be within the worldwide range.
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Papers by Mufeed A Awawdeh