1
|
Abou-Hamdan L, Hamyeh S, Iskandar A, Tauk R, Brault J, Tabbal M, Adam PM, Kazan M. Tuning electrical and thermal conductivities of the two-dimensional electron gas in AlN/GaN heterostructures by piezoelectricity. Nanotechnology 2021; 32:115703. [PMID: 33246321 DOI: 10.1088/1361-6528/abce79] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We investigate the electrical and thermal conductivities of the two-dimensional electron gas (2DEG) confined in the quantum well formed at the heterojunction between a thin GaN layer and an AlN layer strained by an Al x Ga1-x N capping layer in the temperature range from 10 to 360 K. The experimental protocol developed to deduce from calorimetric and Hall-effect measurements at a variable temperature the critical characteristics and transport properties of the confined 2DEG is presented. It is found that, in the measured temperature range (10-360 K), the electrical conductivity of the 2DEG is temperature-independent, due to the predominance of scattering processes by interface defects. However, the thermal conductivity shows a linear temperature dependence, mirroring the specific heat of free electrons. The temperature-independent relaxation time associated with the overall electron scattering means that the values obtained for electrical and thermal conductivities are in excellent agreement with those stipulated by the Weidemann-Franz law. It is also found that for weak strain fields in the AlN layer, both the electrical and thermal conductivities of the two-dimensional interfacial electrons increase exponentially with strain. The importance of 2DEG in AlN/GaN quantum wells lies in the fact that the strong piezoelectricity of AlN allows the transport properties of the 2DEG to be tuned or modulated by a weak electric field even with the high density of lattice mismatch induced defects at the AlN-GaN interface .
Collapse
Affiliation(s)
- L Abou-Hamdan
- Department of Physics, American University of Beirut, PO Box 11-0236, Riad El-Solh, Beirut 1107-2020, Lebanon
| | - S Hamyeh
- Department of Physics, American University of Beirut, PO Box 11-0236, Riad El-Solh, Beirut 1107-2020, Lebanon
- Platform for Research in Nanoscience and Nanotechnology, Faculty of Sciences 2, Lebanese University, Fanar Campus, PO Box 90239, Jdeidet, Lebanon
- Light, Nanomaterials and Nanotechnology, Université de Technologie de Troyes, CNRS ERL 7004, F-10004 Troyes, France
| | - A Iskandar
- Department of Physics, American University of Beirut, PO Box 11-0236, Riad El-Solh, Beirut 1107-2020, Lebanon
| | - R Tauk
- Platform for Research in Nanoscience and Nanotechnology, Faculty of Sciences 2, Lebanese University, Fanar Campus, PO Box 90239, Jdeidet, Lebanon
| | - J Brault
- Université Côte d'Azur, CNRS, CRHEA, F-06560 Valbonne, France
| | - M Tabbal
- Department of Physics, American University of Beirut, PO Box 11-0236, Riad El-Solh, Beirut 1107-2020, Lebanon
| | - P-M Adam
- Light, Nanomaterials and Nanotechnology, Université de Technologie de Troyes, CNRS ERL 7004, F-10004 Troyes, France
| | - M Kazan
- Department of Physics, American University of Beirut, PO Box 11-0236, Riad El-Solh, Beirut 1107-2020, Lebanon
| |
Collapse
|
2
|
AlHaddad N, Sidaoui R, Tabbal M, Abbas I, Danjou PE, Cazier-Dennin F, Baydoun R, Samad OE, Rifai A. Application of Doehlert experimental design for the removal of radium from aqueous solution by cross-linked phenoxycalix[4]pyrrole-polymer using Ba(II) as a model. Environ Sci Pollut Res Int 2020; 27:4325-4336. [PMID: 31832953 DOI: 10.1007/s11356-019-07021-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 11/11/2019] [Indexed: 06/10/2023]
Abstract
Ra-226 is a naturally occurring radionuclide that is derived from uranium-238 series, and it is present at low concentrations in rocks, soil, and groundwater. Many efforts have been exerted for the decontamination of radium from aqueous media in order to meet the increasing water demand of the population. To this aim, a new polymer based on cross-linked phenoxycalix[4]pyrrole was designed and employed in solid/liquid extractions in order to remove radium from aqueous solutions. Preliminary experiments have highlighted the capability of this polymer to extract 22% of Ra-226 from aqueous acidic solution. The optimization of the extraction experimental factors in the direction to attend the maximum removal of Ra-226 from water was carried out employing Ba2+ due to its similar chemical behavior as radium, in order to minimize the consumption of Ra-226 solutions and the risk of radioactive contamination. Doehlert experimental plan was then applied to determine the optimal conditions (pH, time, temperature) for the removal of Ba2+ from aqueous solutions.
Collapse
Affiliation(s)
- Nancy AlHaddad
- Lebanese Atomic Energy Commission, National Council for Scientific Research, B.P.11-8281, Riad El Solh1107, Beirut, 2260, Lebanon
- Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV), Université du Littoral Côte d'Opale, 145 Avenue Maurice Schumann, MREI 1, 59140, Dunkerque, France
| | - Radwan Sidaoui
- Lebanese Atomic Energy Commission, National Council for Scientific Research, B.P.11-8281, Riad El Solh1107, Beirut, 2260, Lebanon
| | - Malek Tabbal
- Central Research Science Laboratory, Physics Building, American University of Beirut, P.O.Box 11-0236, Physics Dept. Riad El-Solh, Beirut, 1107 2020, Lebanon
| | - Ismail Abbas
- Faculty of Sciences, Lebanese University, Mount of Lebanon, Hadath, Lebanon
| | - Pierre-Edouard Danjou
- Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV), Université du Littoral Côte d'Opale, 145 Avenue Maurice Schumann, MREI 1, 59140, Dunkerque, France
| | - Francine Cazier-Dennin
- Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV), Université du Littoral Côte d'Opale, 145 Avenue Maurice Schumann, MREI 1, 59140, Dunkerque, France
| | - Rana Baydoun
- Lebanese Atomic Energy Commission, National Council for Scientific Research, B.P.11-8281, Riad El Solh1107, Beirut, 2260, Lebanon
| | - Omar El Samad
- Lebanese Atomic Energy Commission, National Council for Scientific Research, B.P.11-8281, Riad El Solh1107, Beirut, 2260, Lebanon
| | - Ahmad Rifai
- Lebanese Atomic Energy Commission, National Council for Scientific Research, B.P.11-8281, Riad El Solh1107, Beirut, 2260, Lebanon.
| |
Collapse
|
3
|
Trad M, Nominé A, Tarasenka N, Ghanbaja J, Noël C, Tabbal M, Belmonte T. Synthesis of Ag and Cd nanoparticles by nanosecond-pulsed discharge in liquid nitrogen. Front Chem Sci Eng 2019. [DOI: 10.1007/s11705-019-1802-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
4
|
Rifai A, AlHaddad N, Noun M, Abbas I, Tabbal M, Shatila R, Cazier-Dennin F, Danjou PE. A click mediated route to a novel fluorescent pyridino-extended calix[4]pyrrole sensor: synthesis and binding studies. Org Biomol Chem 2019; 17:5818-5825. [DOI: 10.1039/c9ob01106d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This new cali[4]pyrrole entity displays molecular fluorescence recognition capabilities towards iron and mercury which are major environmental contaminants.
Collapse
Affiliation(s)
- Ahmad Rifai
- Lebanese Atomic Energy Commission
- National Council for Scientific Research
- 2260 Beirut
- Lebanon
| | - Nancy AlHaddad
- Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV)
- Université du Littoral Côte d'Opale
- 59140 Dunkerque
- France
- Lebanese Atomic Energy Commission
| | - Manale Noun
- Lebanese Atomic Energy Commission
- National Council for Scientific Research
- 2260 Beirut
- Lebanon
| | - Ismail Abbas
- Faculty of Sciences 1
- Lebanese University
- Hadath
- Lebanon
| | | | | | - Francine Cazier-Dennin
- Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV)
- Université du Littoral Côte d'Opale
- 59140 Dunkerque
- France
| | - Pierre-Edouard Danjou
- Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV)
- Université du Littoral Côte d'Opale
- 59140 Dunkerque
- France
| |
Collapse
|
5
|
Refaat MM, Ballout JA, Zakka P, Hotait M, Al Feghali KA, Gheida IA, Saade C, Hourani M, Geara F, Tabbal M, Sfeir P, Jalbout W, Al-Jaroudi W, Jurjus A, Youssef B. Swine Atrioventricular Node Ablation Using Stereotactic Radiosurgery: Methods and In Vivo Feasibility Investigation for Catheter-Free Ablation of Cardiac Arrhythmias. J Am Heart Assoc 2017; 6:JAHA.117.007193. [PMID: 29079566 PMCID: PMC5721791 DOI: 10.1161/jaha.117.007193] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Linear accelerator–based stereotactic radiosurgery delivered to cardiac arrhythmogenic foci could be a promising catheter‐free ablation modality. We tested the feasibility of in vivo atrioventricular (AV) node ablation in swine using stereotactic radiosurgery. Methods and Results Five Large White breed swine (weight 40–75 kg; 4 females) were studied. Single‐chamber St Jude pacemakers were implanted in each pig. The pigs were placed under general anesthesia, and coronary/cardiac computed tomography simulation scans were performed to localize the AV node. Cone beam computed tomography was used for target positioning. Stereotactic radiosurgery doses ranging from 35 to 40 Gy were delivered by a linear accelerator to the AV node, and the pigs were followed up with weekly pacemaker interrogations to observe for potential electrocardiographic changes. Once changes were observed, the pigs were euthanized, and pathology specimens of various tissues, including the AV node and tissues surrounding the AV node, were taken to study the effects of radiation. All 5 pigs had disturbances of AV conduction with progressive transition into complete heart block. Macroscopic inspection did not reveal damage to the myocardium, and pigs had preserved systolic function on echocardiography. Immunostaining revealed fibrosis in the target region of the AV node, whereas no fibrosis was detected in the nontargeted regions. Conclusions Catheter‐free radioablation using linear accelerator–based stereotactic radiosurgery is feasible in an intact swine model.
Collapse
Affiliation(s)
- Marwan M Refaat
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Lebanon .,Division of Cardiology, Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Lebanon
| | - Jad A Ballout
- Division of Cardiology, Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Lebanon
| | - Patrick Zakka
- Division of Cardiology, Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Lebanon
| | - Mostafa Hotait
- Division of Cardiology, Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Lebanon
| | - Karine A Al Feghali
- Department of Radiation Oncology, Faculty of Medicine, American University of Beirut, Lebanon
| | - Ibrahim Abu Gheida
- Department of Radiation Oncology, Faculty of Medicine, American University of Beirut, Lebanon
| | - Charbel Saade
- Department of Radiology, Faculty of Medicine, American University of Beirut, Lebanon
| | - Mukbil Hourani
- Department of Radiology, Faculty of Medicine, American University of Beirut, Lebanon
| | - Fady Geara
- Department of Radiation Oncology, Faculty of Medicine, American University of Beirut, Lebanon
| | - Malek Tabbal
- Department of Physics, Faculty of Arts and Sciences, American University of Beirut, Lebanon
| | - Pierre Sfeir
- Division of Cardiothoracic Surgery, Department of Surgery, Faculty of Medicine, American University of Beirut, Lebanon
| | - Wassim Jalbout
- Department of Radiation Oncology, Faculty of Medicine, American University of Beirut, Lebanon
| | - Wael Al-Jaroudi
- Division of Cardiology, Clemenceau Medical Center, Beirut, Lebanon
| | - Abdo Jurjus
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Lebanon
| | - Bassem Youssef
- Department of Radiation Oncology, Faculty of Medicine, American University of Beirut, Lebanon
| |
Collapse
|
6
|
|
7
|
Bao J, Tabbal M, Kim T, Charnvanichborikarn S, Williams JS, Aziz MJ, Capasso F. Point defect engineered Si sub-bandgap light-emitting diode. Opt Express 2007; 15:6727-6733. [PMID: 19546982 DOI: 10.1364/oe.15.006727] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We present a novel approach to enhance light emission in Si and demonstrate a sub-bandgap light emitting diode based on the introduction of point defects that enhance the radiative recombination rate. Ion implantation, pulsed laser melting and rapid thermal annealing were used to create a diode containing a self-interstitial-rich optically active region from which the zero-phonon emission line at 1218 nm originates.
Collapse
|
8
|
Holman KT, Hammud HH, Isber S, Tabbal M. One-dimensional coordination polymer [Co(H2O)4(pyz)](NO3)2·2H2O (pyz=pyrazine) with intra- and inter-chain H-bonds: structure, electronic spectral studies and magnetic properties. Polyhedron 2005. [DOI: 10.1016/j.poly.2004.11.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|